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Sample records for disease longitudinal analysis

  1. Applied longitudinal analysis

    CERN Document Server

    Fitzmaurice, Garrett M; Ware, James H

    2012-01-01

    Praise for the First Edition "". . . [this book] should be on the shelf of everyone interested in . . . longitudinal data analysis.""-Journal of the American Statistical Association   Features newly developed topics and applications of the analysis of longitudinal data Applied Longitudinal Analysis, Second Edition presents modern methods for analyzing data from longitudinal studies and now features the latest state-of-the-art techniques. The book emphasizes practical, rather than theoretical, aspects of methods for the analysis of diverse types of lo

  2. Characterization of changes in serum anti-glycan antibodies in Crohn's disease--a longitudinal analysis.

    Directory of Open Access Journals (Sweden)

    Florian Rieder

    Full Text Available INTRODUCTION: Anti-glycan antibodies are a promising tool for differential diagnosis and disease stratification of patients with Crohn's disease (CD. We longitudinally assessed level and status changes of anti-glycan antibodies over time in individual CD patients as well as determinants of this phenomenon. METHODS: 859 serum samples derived from a cohort of 253 inflammatory bowel disease (IBD patients (207 CD, 46 ulcerative colitis (UC were tested for the presence of anti-laminarin (Anti-L, anti-chitin (Anti-C, anti-chitobioside (ACCA, anti-laminaribioside (ALCA, anti-mannobioside (AMCA and anti-Saccharomyces cerevisiae (gASCA antibodies by ELISA. All patients had at least two and up to eleven serum samples taken during the disease course. RESULTS: Median follow-up time for CD was 17.4 months (Interquartile range (IQR 8.0, 31.6 months and for UC 10.9 months (IQR 4.9, 21.0 months. In a subgroup of CD subjects marked changes in the overall immune response (quartile sum score and levels of individual markers were observed over time. The marker status (positive versus negative remained widely stable. Neither clinical phenotype nor NOD2 genotype was associated with the observed fluctuations. In a longitudinal analysis neither changes in disease activity nor CD behavior led to alterations in the levels of the glycan markers. The ability of the panel to discriminate CD from UC or its association with CD phenotypes remained stable during follow-up. In the serum of UC patients neither significant level nor status changes were observed. CONCLUSIONS: While the levels of anti-glycan antibodies fluctuate in a subgroup of CD patients the antibody status is widely stable over time.

  3. Bayesian analysis of longitudinal Johne's disease diagnostic data without a gold standard test

    DEFF Research Database (Denmark)

    Wang, C.; Turnbull, B.W.; Nielsen, Søren Saxmose

    2011-01-01

    the posterior estimates of the model parameters that provide the basis for inference concerning the accuracy of the diagnostic procedure. Based on the Bayesian approach, the posterior probability distribution of the change-point onset time can be obtained and used as a criterion for infection diagnosis......-point process with a Weibull survival hazard function was used to model the progression of the hidden disease status. The model adjusted for the fixed effects of covariate variables and random effects of subject on the diagnostic testing procedure. Markov chain Monte Carlo methods were used to compute....... An application is presented to an analysis of ELISA and fecal culture test outcomes in the diagnostic testing of paratuberculosis (Johne's disease) for a Danish longitudinal study from January 2000 to March 2003. The posterior probability criterion based on the Bayesian model with 4 repeated observations has...

  4. Longitudinal categorical data analysis

    CERN Document Server

    Sutradhar, Brajendra C

    2014-01-01

    This is the first book in longitudinal categorical data analysis with parametric correlation models developed based on dynamic relationships among repeated categorical responses. This book is a natural generalization of the longitudinal binary data analysis to the multinomial data setup with more than two categories. Thus, unlike the existing books on cross-sectional categorical data analysis using log linear models, this book uses multinomial probability models both in cross-sectional and longitudinal setups. A theoretical foundation is provided for the analysis of univariate multinomial responses, by developing models systematically for the cases with no covariates as well as categorical covariates, both in cross-sectional and longitudinal setups. In the longitudinal setup, both stationary and non-stationary covariates are considered. These models have also been extended to the bivariate multinomial setup along with suitable covariates. For the inferences, the book uses the generalized quasi-likelihood as w...

  5. Big data in Parkinson's disease: using smartphones to remotely detect longitudinal disease phenotypes.

    Science.gov (United States)

    Prince, John; Arora, Siddharth; de Vos, Maarten

    2018-04-26

    To better understand the longitudinal characteristics of Parkinson's disease (PD) through the analysis of finger tapping and memory tests collected remotely using smartphones. Using a large cohort (312 PD subjects and 236 controls) of participants in the mPower study, we extract clinically validated features from a finger tapping and memory test to monitor the longitudinal behaviour of study participants. We investigate any discrepancy in learning rates associated with motor and non-motor tasks between PD subjects and healthy controls. The ability of these features to predict self-assigned severity measures is assessed whilst simultaneously inspecting the severity scoring system for floor-ceiling effects. Finally, we study the relationship between motor and non-motor longitudinal behaviour to determine if separate aspects of the disease are dependent on one another. We find that the test performances of the most severe subjects show significant correlations with self-assigned severity measures. Interestingly, less severe subjects do not show significant correlations, which is shown to be a consequence of floor-ceiling effects within the mPower self-reporting severity system. We find that motor performance after practise is a better predictor of severity than baseline performance suggesting that starting performance at a new motor task is less representative of disease severity than the performance after the test has been learnt. We find PD subjects show significant impairments in motor ability as assessed through the alternating finger tapping (AFT) test in both the short- and long-term analyses. In the AFT and memory tests we demonstrate that PD subjects show a larger degree of longitudinal performance variability in addition to requiring more instances of a test to reach a steady state performance than healthy subjects. Our findings pave the way forward for objective assessment and quantification of longitudinal learning rates in PD. This can be particularly

  6. Substantia Nigra Free Water Increases Longitudinally in Parkinson Disease.

    Science.gov (United States)

    Guttuso, T; Bergsland, N; Hagemeier, J; Lichter, D G; Pasternak, O; Zivadinov, R

    2018-02-01

    Free water in the posterior substantia nigra obtained from a bi-tensor diffusion MR imaging model has been shown to significantly increase over 1- and 4-year periods in patients with early-stage idiopathic Parkinson disease compared with healthy controls, which suggests that posterior substantia nigra free water may be an idiopathic Parkinson disease progression biomarker. Due to the known temporal posterior-to-anterior substantia nigra degeneration in idiopathic Parkinson disease, we assessed longitudinal changes in free water in both the posterior and anterior substantia nigra in patients with later-stage idiopathic Parkinson disease and age-matched healthy controls for comparison. Nineteen subjects with idiopathic Parkinson disease and 19 age-matched healthy control subjects were assessed on the same 3T MR imaging scanner at baseline and after approximately 3 years. Baseline mean idiopathic Parkinson disease duration was 7.1 years. Both anterior and posterior substantia nigra free water showed significant intergroup differences at baseline ( P Parkinson disease versus healthy controls); however, only anterior substantia nigra free water showed significant longitudinal group × time interaction increases ( P = .021, idiopathic Parkinson disease versus healthy controls). There were no significant longitudinal group × time interaction differences found for conventional diffusion tensor imaging or free water-corrected DTI assessments in either the anterior or posterior substantia nigra. Results from this study provide further evidence supporting substantia nigra free water as a promising disease-progression biomarker in idiopathic Parkinson disease that may help to identify disease-modifying therapies if used in future clinical trials. Our novel finding of longitudinal increases in anterior but not posterior substantia nigra free water is potentially a result of the much longer disease duration of our cohort compared with previously studied cohorts and the known

  7. Within-subject template estimation for unbiased longitudinal image analysis.

    Science.gov (United States)

    Reuter, Martin; Schmansky, Nicholas J; Rosas, H Diana; Fischl, Bruce

    2012-07-16

    Longitudinal image analysis has become increasingly important in clinical studies of normal aging and neurodegenerative disorders. Furthermore, there is a growing appreciation of the potential utility of longitudinally acquired structural images and reliable image processing to evaluate disease modifying therapies. Challenges have been related to the variability that is inherent in the available cross-sectional processing tools, to the introduction of bias in longitudinal processing and to potential over-regularization. In this paper we introduce a novel longitudinal image processing framework, based on unbiased, robust, within-subject template creation, for automatic surface reconstruction and segmentation of brain MRI of arbitrarily many time points. We demonstrate that it is essential to treat all input images exactly the same as removing only interpolation asymmetries is not sufficient to remove processing bias. We successfully reduce variability and avoid over-regularization by initializing the processing in each time point with common information from the subject template. The presented results show a significant increase in precision and discrimination power while preserving the ability to detect large anatomical deviations; as such they hold great potential in clinical applications, e.g. allowing for smaller sample sizes or shorter trials to establish disease specific biomarkers or to quantify drug effects. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Dynamics of the connectome in Huntington's disease: A longitudinal diffusion MRI study

    OpenAIRE

    Odish, Omar F.F.; Caeyenberghs, Karen; Hosseini, Hadi; van den Bogaard, Simon J.A.; Roos, Raymund A.C.; Leemans, Alexander

    2015-01-01

    Abstract Objectives To longitudinally investigate the connectome in different stages of Huntington's disease (HD) by applying graph theoretical analysis to diffusion MRI data. Experimental design We constructed weighted structural networks and calculated their topological properties. Twenty-two premanifest (preHD), 10 early manifest HD and 24 healthy controls completed baseline and 2 year follow-up scans. We stratified the preHD group based on their predicted years to disease onset into a far...

  9. Longitudinal morphometric MRI study of Alzheimer's disease

    International Nuclear Information System (INIS)

    Ogomori, Koji; Takano, Koichi; Kuwabara, Yasuo; Nakano, Seigo; Nawata, Hideyuki; Yano, Rika; Nishimura, Ryoji; Takita, Masashi

    2009-01-01

    A longitudinal morphometric MRI study of Alzheimer's disease (AD) was conducted to determine the relationship between the progression of the symptoms and the progression of the brain atrophy. The Voxel-based Specific Regional Analysis System for Alzheimer's Disease (VSRAD), developed by Matsuda et al. was used as a method of morphometry to perform the statistical MR image analysis. Thirty-eight patients of AD patients were investigated with VSRAD. These patients were divided into two groups according to the progression of symptoms based on a clinical evaluation. One group was the progress group (20 patients), while the other group was the stable group (18 patients) for comparison. The relationship was investigated between the speed of the symptomatic progression and the change in each VSRAD indicator. Consequently, the entorhinal Z-score and the entorhinal atrophy rate showed a correlation with the speed of the symptomatic progression. The increase of the entorhinal Z-score in the follow-up was larger in the progress group than that in the stable group (0.65/1.28 years in the progress group and 0.05/1.26 years in the stable group.). These results suggest that a rapid symptomatic progression in an AD patient accompanies the rapid progression of atrophy in the entorhinal cortex. (author)

  10. Birth order and paediatric allergic disease: A nationwide longitudinal survey.

    Science.gov (United States)

    Kikkawa, T; Yorifuji, T; Fujii, Y; Yashiro, M; Okada, A; Ikeda, M; Doi, H; Tsukahara, H

    2018-05-01

    Environmental factors seem to be related to the incidence of allergic disease. Children with a later birth order are often exposed to environments, where pathogens and endotoxins can be found, and thus have a higher risk of developing infectious diseases. Therefore, birth order is regarded as an indicator that reflects post-natal environment. However, longitudinal studies are limited on this subject. This study sought to elucidate the relationships between birth order and allergic disease. From a nationwide longitudinal study that followed children born in 2001 (n = 47 015), we selected doctors' visits for 3 types of allergic disease-bronchial asthma, food allergy and atopic dermatitis-from infancy to 12 years of age and conducted binomial log-linear regression analysis to evaluate the associations between birth order and these diseases. We adjusted for the child and parental factors and estimated risk ratio (RR) and 95% confidence interval (CI) for each outcome. The associations between birth order and bronchial asthma were diverse; later birth order increased the risk in early childhood, but decreased the risks during school age. For example, the adjusted RR comparing third-born or higher and first-born children was 1.19 (95% CI, 1.05-1.35) between 30 and 42 months of age, but was 0.76 (95% CI, 0.65-0.89) between 10 and 11 years. Later birth order was generally protective for food allergy but increased the risk of atopic dermatitis. The influence of birth order depended on the type of allergic disease and the childhood period. Childhood is unique in terms of physical and immunological development, and the immune response to the post-natal environment in childhood appears to be heterogeneous. © 2018 John Wiley & Sons Ltd.

  11. Test-retest reliability and longitudinal analysis of automated hippocampal subregion volumes in healthy ageing and Alzheimer's disease populations.

    Science.gov (United States)

    Worker, Amanda; Dima, Danai; Combes, Anna; Crum, William R; Streffer, Johannes; Einstein, Steven; Mehta, Mitul A; Barker, Gareth J; C R Williams, Steve; O'daly, Owen

    2018-04-01

    The hippocampal formation is a complex brain structure that is important in cognitive processes such as memory, mood, reward processing and other executive functions. Histological and neuroimaging studies have implicated the hippocampal region in neuropsychiatric disorders as well as in neurodegenerative diseases. This highly plastic limbic region is made up of several subregions that are believed to have different functional roles. Therefore, there is a growing interest in imaging the subregions of the hippocampal formation rather than modelling the hippocampus as a homogenous structure, driving the development of new automated analysis tools. Consequently, there is a pressing need to understand the stability of the measures derived from these new techniques. In this study, an automated hippocampal subregion segmentation pipeline, released as a developmental version of Freesurfer (v6.0), was applied to T1-weighted magnetic resonance imaging (MRI) scans of 22 healthy older participants, scanned on 3 separate occasions and a separate longitudinal dataset of 40 Alzheimer's disease (AD) patients. Test-retest reliability of hippocampal subregion volumes was assessed using the intra-class correlation coefficient (ICC), percentage volume difference and percentage volume overlap (Dice). Sensitivity of the regional estimates to longitudinal change was estimated using linear mixed effects (LME) modelling. The results show that out of the 24 hippocampal subregions, 20 had ICC scores of 0.9 or higher in both samples; these regions include the molecular layer, granule cell layer of the dentate gyrus, CA1, CA3 and the subiculum (ICC > 0.9), whilst the hippocampal fissure and fimbria had lower ICC scores (0.73-0.88). Furthermore, LME analysis of the independent AD dataset demonstrated sensitivity to group and individual differences in the rate of volume change over time in several hippocampal subregions (CA1, molecular layer, CA3, hippocampal tail, fissure and presubiculum

  12. Analysis of longitudinal data from animals with missing values using SPSS.

    Science.gov (United States)

    Duricki, Denise A; Soleman, Sara; Moon, Lawrence D F

    2016-06-01

    Testing of therapies for disease or injury often involves the analysis of longitudinal data from animals. Modern analytical methods have advantages over conventional methods (particularly when some data are missing), yet they are not used widely by preclinical researchers. Here we provide an easy-to-use protocol for the analysis of longitudinal data from animals, and we present a click-by-click guide for performing suitable analyses using the statistical package IBM SPSS Statistics software (SPSS). We guide readers through the analysis of a real-life data set obtained when testing a therapy for brain injury (stroke) in elderly rats. If a few data points are missing, as in this example data set (for example, because of animal dropout), repeated-measures analysis of covariance may fail to detect a treatment effect. An alternative analysis method, such as the use of linear models (with various covariance structures), and analysis using restricted maximum likelihood estimation (to include all available data) can be used to better detect treatment effects. This protocol takes 2 h to carry out.

  13. Correspondence analysis of longitudinal data

    NARCIS (Netherlands)

    Van der Heijden, P.G.M.|info:eu-repo/dai/nl/073087998

    2005-01-01

    Correspondence analysis is an exploratory tool for the analysis of associations between categorical variables, the results of which may be displayed graphically. For longitudinal data with two time points, an analysis of the transition matrix (showing the relative frequencies for pairs of

  14. Longitudinal Study of Gray Matter Changes in Parkinson Disease.

    Science.gov (United States)

    Jia, X; Liang, P; Li, Y; Shi, L; Wang, D; Li, K

    2015-12-01

    The pathology of Parkinson disease leads to morphological brain volume changes. So far, the progressive gray matter volume change across time specific to patients with Parkinson disease compared controls remains unclear. Our aim was to investigate the pattern of gray matter changes in patients with Parkinson disease and to explore the progressive gray matter volume change specific to patients with Parkinson disease with disease progression by using voxel-based morphometry analysis. Longitudinal cognitive assessment and structural MR imaging of 89 patients with Parkinson disease (62 men) and 55 healthy controls (33 men) were from the Parkinson's Progression Markers Initiative data base, including the initial baseline and 12-month follow-up data. Two-way analysis of covariance was performed with covariates of age, sex, years of education, imaging data from multiple centers, and total intracranial volume by using Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra tool from SPM8 software. Gray matter volume changes for patients with Parkinson disease were detected with decreased gray matter volume in the frontotemporoparietal areas and the bilateral caudate, with increased gray matter volume in the bilateral limbic/paralimbic areas, medial globus pallidus/putamen, and the right occipital cortex compared with healthy controls. Progressive gray matter volume decrease in the bilateral caudate was found for both patients with Parkinson disease and healthy controls, and this caudate volume was positively associated with cognitive ability for both groups. The progressive gray matter volume increase specific to the patients with Parkinson disease was identified close to the left ventral lateral nucleus of thalamus, and a positive relationship was found between the thalamic volume and the tremor scores in a subgroup with tremor-dominant patients with Parkinson disease. The observed progressive changes in gray matter volume in Parkinson disease may provide

  15. Transverse versus Longitudinal Incisions for Femoral Artery Exposure in Treating Patients with Peripheral Vascular Disease.

    Science.gov (United States)

    Parikh, Punam P; Rubio, Gustavo A; Patel, Kunal; Gupta, Kapil; Jones, Keith; Rey, Jorge; Robinson, Handel

    2018-02-01

    This study evaluates differences in wound complication rate when transverse versus longitudinal incision is utilized to expose femoral vessels in managing patients with peripheral vascular disease. A retrospective review from 2013 to 2015 was conducted of 150 patients undergoing 156 lower extremity revascularizations with femoral artery exposure through a groin incision. Patients were stratified into 2 groups, transverse versus longitudinal groin incision. Data were reviewed for 3 surgeons that utilize either transverse or longitudinal groin incision in patients undergoing common or iliofemoral endarterectomies, or where femoral artery was used as inflow and/or outflow vessel for limb revascularization. Each group had a comparative outcomes analysis based on incision type. The primary outcome was wound complication, defined as any wound infection, lymphocele, hematoma, dehiscence, pseudoaneurysm, or necrosis. Other outcomes studied included unplanned return to operating room for wound complication, wound vacuum therapy, and soft-tissue flap closure. Data were analyzed using 2-tailed chi-squared test and Student's t-test. Patients in the transverse (n = 85 cases) versus longitudinal (n = 71 cases) cohorts were similar in relation to demographics and comorbidities. Overall mean follow-up was 220 days. Patients with a transverse as compared to longitudinal incision had a significantly lower overall wound complication rate, 7% vs. 42%, respectively (P transverse incisions were associated with lower incidence of unplanned return to the operating room to manage wound complications than patients with a longitudinal incision (5% vs. 23%, respectively; P Transverse versus longitudinal incisions were also associated with significantly lower need for wound vacuum therapy (6% vs. 15%, respectively; P Transverse groin incisions for femoral artery exposure may offer a lower risk of wound complications for open procedures as compared to a longitudinal incision

  16. Reliability of the Alzheimer's disease assessment scale (ADAS-Cog) in longitudinal studies.

    Science.gov (United States)

    Khan, Anzalee; Yavorsky, Christian; DiClemente, Guillermo; Opler, Mark; Liechti, Stacy; Rothman, Brian; Jovic, Sofija

    2013-11-01

    Considering the scarcity of longitudinal assessments of reliability, there is need for a more precise understanding of cognitive decline in Alzheimer's Disease (AD). The primary goal was to assess longitudinal changes in inter-rater reliability, test retest reliability and internal consistency of scores of the ADAS-Cog. 2,618 AD subjects were enrolled in seven randomized, double-blind, placebo-controlled, multicenter-trials from 1986 to 2009. Reliability, internal-consistency and cross-sectional analysis of ADAS-Cog and MMSE across seven visits were examined. Intra-class correlation (ICC) for ADAS-Cog was moderate to high supporting their reliability. Absolute Agreement ICCs 0.392 (Visit-7) to 0.806 (Visit-2) showed a progressive decrease in correlations across time. Item analysis revealed a decrease in item correlations, with the lowest correlations for Visit 7 for Commands (ICC=0.148), Comprehension (ICC=0.092), Spoken Language (ICC=0.044). Suitable assessment of AD treatments is maintained through accurate measurement of clinically significant outcomes. Targeted rater education ADAS-Cog items over-time can improve ability to administer and score the scale.

  17. Longitudinal Andhra Pradesh Eye Disease Study: rationale, study design and research methodology.

    Science.gov (United States)

    Khanna, Rohit C; Murthy, Gudlavalleti Vs; Marmamula, Srinivas; Mettla, Asha Latha; Giridhar, Pyda; Banerjee, Seema; Shekhar, Konegari; Chakrabarti, Subhabrata; Gilbert, Clare; Rao, Gullapalli N

    2016-03-01

    The rationale, objectives, study design and procedures for the longitudinal Andhra Pradesh Eye Disease Study are described. A longitudinal cohort study was carried out. Participants include surviving cohort from the rural component of Andhra Pradesh Eye Disease Study. During 1996-2000, Andhra Pradesh Eye Disease Survey was conducted in three rural (n = 7771) and one urban (n = 2522) areas (now called Andhra Pradesh Eye Disease Study 1). In 2009-2010, a feasibility exercise (Andhra Pradesh Eye Disease Study 2) for a longitudinal study (Andhra Pradesh Eye Disease Study 3) was undertaken in the rural clusters only, as urban clusters no longer existed. In Andhra Pradesh Eye Disease Study 3, a detailed interview will be carried out to collect data on sociodemographic factors, ocular and systemic history, risk factors, visual function, knowledge of eye diseases and barriers to accessing services. All participants will also undergo a comprehensive eye examination including photography of lens, optic disc and retina, Optic Coherence Tomography of the posterior segment, anthropometry, blood pressure and frailty measures. Measures include estimates of the incidence of visual impairment and age-related eye disease (lens opacities, glaucoma and age-related macular degeneration) and the progression of eye disease (lens opacities and myopia) and associated risk factors. Of the 7771 respondents examined in rural areas in Andhra Pradesh Eye Disease Study 1, 5447 (70.1%) participants were traced in Andhra Pradesh Eye Disease Study 2. These participants will be re-examined. Andhra Pradesh Eye Disease Study 3 will provide data on the incidence and progression of visual impairment and major eye diseases and their associated risk factors in India. The study will provide further evidence to aid planning eye care services. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

  18. A Systematic Review of Longitudinal Studies Which Measure Alzheimer's Disease Biomarkers.

    Science.gov (United States)

    Lawrence, Emma; Vegvari, Carolin; Ower, Alison; Hadjichrysanthou, Christoforos; De Wolf, Frank; Anderson, Roy M

    2017-01-01

    Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disease, with no effective treatment or cure. A gold standard therapy would be treatment to slow or halt disease progression; however, knowledge of causation in the early stages of AD is very limited. In order to determine effective endpoints for possible therapies, a number of quantitative surrogate markers of disease progression have been suggested, including biochemical and imaging biomarkers. The dynamics of these various surrogate markers over time, particularly in relation to disease development, are, however, not well characterized. We reviewed the literature for studies that measured cerebrospinal fluid or plasma amyloid-β and tau, or took magnetic resonance image or fluorodeoxyglucose/Pittsburgh compound B-positron electron tomography scans, in longitudinal cohort studies. We summarized the properties of the major cohort studies in various countries, commonly used diagnosis methods and study designs. We have concluded that additional studies with repeat measures over time in a representative population cohort are needed to address the gap in knowledge of AD progression. Based on our analysis, we suggest directions in which research could move in order to advance our understanding of this complex disease, including repeat biomarker measurements, standardization and increased sample sizes.

  19. The Role of Microsimulation in Longitudinal Data Analysis

    Directory of Open Access Journals (Sweden)

    Douglas A. Wolf

    2001-12-01

    microsimulation also has the potential to contribute to longitudinal data analysis in several ways, including extending the range of outputs generated by a model, addressing several defective-data problems, and serving as a vehicle for missing-data imputation. This paper discusses microsimulation procedures suitable for several commonly-used statistical models applied to longitudinal data. It also addresses the unique role that can be played by microsimulation in longitudinal data analysis, and the problem of accounting for the several sources of variability associated with microsimulation procedures.

  20. Coronary heart disease index based on longitudinal electrocardiography

    Science.gov (United States)

    Townsend, J. C.; Cronin, J. P.

    1977-01-01

    A coronary heart disease index was developed from longitudinal ECG (LCG) tracings to serve as a cardiac health measure in studies of working and, essentially, asymptomatic populations, such as pilots and executives. For a given subject, the index consisted of a composite score based on the presence of LCG aberrations and weighted values previously assigned to them. The index was validated by correlating it with the known presence or absence of CHD as determined by a complete physical examination, including treadmill, resting ECG, and risk factor information. The validating sample consisted of 111 subjects drawn by a stratified-random procedure from 5000 available case histories. The CHD index was found to be significantly more valid as a sole indicator of CHD than the LCG without the use of the index. The index consistently produced higher validity coefficients in identifying CHD than did treadmill testing, resting ECG, or risk factor analysis.

  1. Analysis of longitudinal data from animals where some data are missing in SPSS

    Science.gov (United States)

    Duricki, DA; Soleman, S; Moon, LDF

    2017-01-01

    Testing of therapies for disease or injury often involves analysis of longitudinal data from animals. Modern analytical methods have advantages over conventional methods (particularly where some data are missing) yet are not used widely by pre-clinical researchers. We provide here an easy to use protocol for analysing longitudinal data from animals and present a click-by-click guide for performing suitable analyses using the statistical package SPSS. We guide readers through analysis of a real-life data set obtained when testing a therapy for brain injury (stroke) in elderly rats. We show that repeated measures analysis of covariance failed to detect a treatment effect when a few data points were missing (due to animal drop-out) whereas analysis using an alternative method detected a beneficial effect of treatment; specifically, we demonstrate the superiority of linear models (with various covariance structures) analysed using Restricted Maximum Likelihood estimation (to include all available data). This protocol takes two hours to follow. PMID:27196723

  2. Longitudinal analysis of mouse SDOCT volumes

    Science.gov (United States)

    Antony, Bhavna J.; Carass, Aaron; Lang, Andrew; Kim, Byung-Jin; Zack, Donald J.; Prince, Jerry L.

    2017-03-01

    Spectral-domain optical coherence tomography (SDOCT), in addition to its routine clinical use in the diagnosis of ocular diseases, has begun to fund increasing use in animal studies. Animal models are frequently used to study disease mechanisms as well as to test drug efficacy. In particular, SDOCT provides the ability to study animals longitudinally and non-invasively over long periods of time. However, the lack of anatomical landmarks makes the longitudinal scan acquisition prone to inconsistencies in orientation. Here, we propose a method for the automated registration of mouse SDOCT volumes. The method begins by accurately segmenting the blood vessels and the optic nerve head region in the scans using a pixel classification approach. The segmented vessel maps from follow-up scans were registered using an iterative closest point (ICP) algorithm to the baseline scan to allow for the accurate longitudinal tracking of thickness changes. Eighteen SDOCT volumes from a light damage model study were used to train a random forest utilized in the pixel classification step. The area under the curve (AUC) in a leave-one-out study for the retinal blood vessels and the optic nerve head (ONH) was found to be 0.93 and 0.98, respectively. The complete proposed framework, the retinal vasculature segmentation and the ICP registration, was applied to a secondary set of scans obtained from a light damage model. A qualitative assessment of the registration showed no registration failures.

  3. Cross-Sectional Analysis of Longitudinal Mediation Processes.

    Science.gov (United States)

    O'Laughlin, Kristine D; Martin, Monica J; Ferrer, Emilio

    2018-01-01

    Statistical mediation analysis can help to identify and explain the mechanisms behind psychological processes. Examining a set of variables for mediation effects is a ubiquitous process in the social sciences literature; however, despite evidence suggesting that cross-sectional data can misrepresent the mediation of longitudinal processes, cross-sectional analyses continue to be used in this manner. Alternative longitudinal mediation models, including those rooted in a structural equation modeling framework (cross-lagged panel, latent growth curve, and latent difference score models) are currently available and may provide a better representation of mediation processes for longitudinal data. The purpose of this paper is twofold: first, we provide a comparison of cross-sectional and longitudinal mediation models; second, we advocate using models to evaluate mediation effects that capture the temporal sequence of the process under study. Two separate empirical examples are presented to illustrate differences in the conclusions drawn from cross-sectional and longitudinal mediation analyses. Findings from these examples yielded substantial differences in interpretations between the cross-sectional and longitudinal mediation models considered here. Based on these observations, researchers should use caution when attempting to use cross-sectional data in place of longitudinal data for mediation analyses.

  4. Macular function and morphologic features in juvenile stargardt disease: longitudinal study.

    Science.gov (United States)

    Testa, Francesco; Melillo, Paolo; Di Iorio, Valentina; Orrico, Ada; Attanasio, Marcella; Rossi, Settimio; Simonelli, Francesca

    2014-12-01

    To evaluate disease progression in a cohort of patients with a clinical and genetic diagnosis of Stargardt disease. Longitudinal cohort study. A total of 56 selected patients with a clinical and molecular diagnosis of Stargardt disease, an early age of onset, and a median follow-up length of 2 years. Patients underwent routine examination, including full-field electroretinography, microperimetry, and optical coherence tomography. Best-corrected visual acuity (BCVA), mean retinal sensitivity, fixation stability, preferred retinal locus, inner segment/outer segment (IS/OS) junction loss, and atrophic lesion area. A total of 56 patients with a mean age at disease onset of 15.3 years (range, 3-28 years), a mean disease duration of 12.1 years, and a mean age at baseline of 27.4 years were analyzed. The median BCVA was 20/200 in both eyes. Optical coherence tomography parameters (IS/OS alteration and retinal pigment epithelium lesion area) were obtained in only 49 patients because the signal quality was poor in the remaining 7 patients. Optical coherence tomography revealed a mean retinal pigment epithelium lesion area of 2.6 mm(2), preserved foveal IS/OS in 4.1% of patients, loss of foveal IS/OS in 59.2% of patients, and extensive loss of macular IS/OS in 36.7% of patients. Microperimetric findings showed a reduced macular sensitivity (mean, 10 decibels [dB]) and an unstable fixation in half of the patient cohort. The longitudinal analysis showed a significant progressive reduction of BCVA and macular sensitivity (at an estimated rate of 0.04 decimals and 1.19 dB/year, respectively) associated with a significant enlargement of retinal pigment epithelium lesion area (0.282 mm(2)/year). No significant changes in ophthalmoscopic findings and electroretinographic responses were detected. This study highlights the importance of microperimetry and optical coherence tomography in monitoring patients with Stargardt disease. Quantifying the decline of visual functionality and

  5. Longitudinal Transcriptome Analysis Reveals a Sustained Differential Gene Expression Signature in Patients Treated for Acute Lyme Disease.

    Science.gov (United States)

    Bouquet, Jerome; Soloski, Mark J; Swei, Andrea; Cheadle, Chris; Federman, Scot; Billaud, Jean-Noel; Rebman, Alison W; Kabre, Beniwende; Halpert, Richard; Boorgula, Meher; Aucott, John N; Chiu, Charles Y

    2016-02-12

    Lyme disease is a tick-borne illness caused by the bacterium Borrelia burgdorferi, and approximately 10 to 20% of patients report persistent symptoms lasting months to years despite appropriate treatment with antibiotics. To gain insights into the molecular basis of acute Lyme disease and the ensuing development of post-treatment symptoms, we conducted a longitudinal transcriptome study of 29 Lyme disease patients (and 13 matched controls) enrolled at the time of diagnosis and followed for up to 6 months. The differential gene expression signature of Lyme disease following the acute phase of infection persisted for at least 3 weeks and had fewer than 44% differentially expressed genes (DEGs) in common with other infectious or noninfectious syndromes. Early Lyme disease prior to antibiotic therapy was characterized by marked upregulation of Toll-like receptor signaling but lack of activation of the inflammatory T-cell apoptotic and B-cell developmental pathways seen in other acute infectious syndromes. Six months after completion of therapy, Lyme disease patients were found to have 31 to 60% of their pathways in common with three different immune-mediated chronic diseases. No differential gene expression signature was observed between Lyme disease patients with resolved illness to those with persistent symptoms at 6 months post-treatment. The identification of a sustained differential gene expression signature in Lyme disease suggests that a panel of selected human host-based biomarkers may address the need for sensitive clinical diagnostics during the "window period" of infection prior to the appearance of a detectable antibody response and may also inform the development of new therapeutic targets. Lyme disease is the most common tick-borne infection in the United States, and some patients report lingering symptoms lasting months to years despite antibiotic treatment. To better understand the role of the human host response in acute Lyme disease and the

  6. Mendelian randomization analysis of a time-varying exposure for binary disease outcomes using functional data analysis methods.

    Science.gov (United States)

    Cao, Ying; Rajan, Suja S; Wei, Peng

    2016-12-01

    A Mendelian randomization (MR) analysis is performed to analyze the causal effect of an exposure variable on a disease outcome in observational studies, by using genetic variants that affect the disease outcome only through the exposure variable. This method has recently gained popularity among epidemiologists given the success of genetic association studies. Many exposure variables of interest in epidemiological studies are time varying, for example, body mass index (BMI). Although longitudinal data have been collected in many cohort studies, current MR studies only use one measurement of a time-varying exposure variable, which cannot adequately capture the long-term time-varying information. We propose using the functional principal component analysis method to recover the underlying individual trajectory of the time-varying exposure from the sparsely and irregularly observed longitudinal data, and then conduct MR analysis using the recovered curves. We further propose two MR analysis methods. The first assumes a cumulative effect of the time-varying exposure variable on the disease risk, while the second assumes a time-varying genetic effect and employs functional regression models. We focus on statistical testing for a causal effect. Our simulation studies mimicking the real data show that the proposed functional data analysis based methods incorporating longitudinal data have substantial power gains compared to standard MR analysis using only one measurement. We used the Framingham Heart Study data to demonstrate the promising performance of the new methods as well as inconsistent results produced by the standard MR analysis that relies on a single measurement of the exposure at some arbitrary time point. © 2016 WILEY PERIODICALS, INC.

  7. Macular function and morphological features in juvenile Stargardt disease: Longitudinal study

    Science.gov (United States)

    Testa, Francesco; Melillo, Paolo; Iorio, Valentina Di; Orrico, Ada; Attanasio, Marcella; Rossi, Settimio; Simonelli, Francesca

    2014-01-01

    Purpose to evaluate disease progression in a cohort of patients with clinical and genetic diagnosis of Stargardt disease. Design longitudinal cohort study. Subjects 56 selected patients with a clinical and molecular diagnosis of Stargardt disease, an early age of onset and a median follow-up length of two years. Methods patients underwent routine examination including full-field electroretinography, microperimetry and optical coherence tomography. Main Outcome Measures best corrected visual acuity, mean retinal sensitivity, fixation stability, preferred retinal locus, inner-outer segment (IS/OS) junction loss, atrophic lesion area. Results 56 patients with a mean age of disease onset of 15.3 years (range: 3 - 28 years), a mean disease length of 12.1 years and a mean age at baseline of 27.4 years were analyzed. The median best corrected visual acuity was 20/200 in both eyes. Optical coherence tomography parameters (IS/OS alteration and retinal pigment epithelium lesion area) were obtained in 49 patients because signal quality was poor in the remaining 7 patients. Optical coherence tomography revealed a mean retinal pigment epithelium lesion area of 2.6 mm2, preserved foveal IS/OS in 4.1% of patients, loss of foveal IS/OS in 59.2%, and extensive loss of macular IS/OS in 36.7%. Microperimetric findings showed a reduced macular sensitivity (mean 10 dB) and an unstable fixation in half of the patient cohort. The longitudinal analysis showed a significant progressive reduction of best corrected visual acuity and macular sensitivity (at an estimated rate of 0.04 decimals and 1.19 dB per year, respectively) associated with a significant enlargement of retinal pigment epithelium lesion area (0.282 mm2 per year). No significant changes in ophthalmoscopic findings and electroretinographic responses were detected. Conclusions this study highlights the importance of microperimetry and optical coherence tomography in monitoring Stargardt patients. In fact, quantifying the

  8. Longitudinal muscle of the esophagus: its role in esophageal health and disease.

    Science.gov (United States)

    Mittal, Ravinder K

    2013-07-01

    The muscularis propria of the esophagus is organized into circular and longitudinal muscle layers. The function of the longitudinal muscle and its role in bolus propulsion are not clear. The goal of this review is to summarize what is known of the role of the longitudinal muscle in health, as well as in sensory and motor disorders of the esophagus. Simultaneous manometry and ultrasound imaging reveal that, during peristalsis, the two muscle layers of the esophagus contract in perfect synchrony. On the contrary, during transient lower esophageal sphincter (LES) relaxation, longitudinal muscle contracts independent of the circular muscle. Recent studies have provided novel insights into the role of the longitudinal muscle in LES relaxation and descending relaxation of the esophagus. In certain diseases (e.g. some motility disorders of the esophagus), there is discoordination between the two muscle layers, which likely plays an important role in the genesis of dysphagia and delayed esophageal emptying. There is close temporal correlation between prolonged contractions of the longitudinal muscles of the esophagus and esophageal 'angina-like' pain. Novel techniques to record longitudinal muscle contraction are reviewed. Longitudinal muscles of the esophagus play a key role in the physiology and pathophysiology of esophageal sensory and motor function. Neuro-pharmacologic controls of circular and longitudinal muscle are different, which provides an opportunity for the development of novel pharmacological therapies in the treatment of esophageal sensory and motor disorders.

  9. A longitudinal analysis of the effect of nonmedical exemption law and vaccine uptake on vaccine-targeted disease rates.

    Science.gov (United States)

    Yang, Y Tony; Debold, Vicky

    2014-02-01

    We assessed how nonmedical exemption (NME) laws and annual uptake of vaccines required for school or daycare entry affect annual incidence rates for 5 vaccine-targeted diseases: pertussis, measles, mumps, Haemophilus influenzae type B, and hepatitis B. We employed longitudinal mixed-effects models to examine 2001-2008 vaccine-targeted disease data obtained from the National Notifiable Disease Surveillance System. Key explanatory variables were state-level vaccine-specific uptake rates from the National Immunization Survey and a state NME law restrictiveness level. NME law restrictiveness and vaccine uptake were not associated with disease incidence rate for hepatitis B, Haemophilus influenzae type B, measles, or mumps. Pertussis incidence rate, however, was negatively associated with NME law restrictiveness (b = -0.20; P = .03) and diphtheria-pertussis-tetanus vaccine uptake (b = -0.01; P = .05). State NME laws and vaccine uptake rates did not appear to influence lower-incidence diseases but may influence reported disease rates for higher-incidence diseases. If all states increased their NME law restrictiveness by 1 level and diphtheria-pertussis-tetanus uptake by 1%, national annual pertussis cases could decrease by 1.14% (171 cases) and 0.04% (5 cases), respectively.

  10. A Longitudinal Study on Resting State Functional Connectivity in Behavioral Variant Frontotemporal Dementia and Alzheimer's Disease.

    Science.gov (United States)

    Hafkemeijer, Anne; Möller, Christiane; Dopper, Elise G P; Jiskoot, Lize C; van den Berg-Huysmans, Annette A; van Swieten, John C; van der Flier, Wiesje M; Vrenken, Hugo; Pijnenburg, Yolande A L; Barkhof, Frederik; Scheltens, Philip; van der Grond, Jeroen; Rombouts, Serge A R B

    2017-01-01

    Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) are the most common types of early-onset dementia. We applied longitudinal resting state functional magnetic resonance imaging (fMRI) to delineate functional brain connections relevant for disease progression and diagnostic accuracy. We used two-center resting state fMRI data of 20 AD patients (65.1±8.0 years), 12 bvFTD patients (64.7±5.4 years), and 22 control subjects (63.8±5.0 years) at baseline and 1.8-year follow-up. We used whole-network and voxel-based network-to-region analyses to study group differences in functional connectivity at baseline and follow-up, and longitudinal changes in connectivity within and between groups. At baseline, connectivity between paracingulate gyrus and executive control network, between cuneal cortex and medial visual network, and between paracingulate gyrus and salience network was higher in AD compared with controls. These differences were also present after 1.8 years. At follow-up, connectivity between angular gyrus and right frontoparietal network, and between paracingulate gyrus and default mode network was lower in bvFTD compared with controls, and lower compared with AD between anterior cingulate gyrus and executive control network, and between lateral occipital cortex and medial visual network. Over time, connectivity decreased in AD between precuneus and right frontoparietal network and in bvFTD between inferior frontal gyrus and left frontoparietal network. Longitudinal changes in connectivity between supramarginal gyrus and right frontoparietal network differ between both patient groups and controls. We found disease-specific brain regions with longitudinal connectivity changes. This suggests the potential of longitudinal resting state fMRI to delineate regions relevant for disease progression and for diagnostic accuracy, although no group differences in longitudinal changes in the direct comparison of AD and bvFTD were found.

  11. Longitudinal data analysis a handbook of modern statistical methods

    CERN Document Server

    Fitzmaurice, Garrett; Verbeke, Geert; Molenberghs, Geert

    2008-01-01

    Although many books currently available describe statistical models and methods for analyzing longitudinal data, they do not highlight connections between various research threads in the statistical literature. Responding to this void, Longitudinal Data Analysis provides a clear, comprehensive, and unified overview of state-of-the-art theory and applications. It also focuses on the assorted challenges that arise in analyzing longitudinal data. After discussing historical aspects, leading researchers explore four broad themes: parametric modeling, nonparametric and semiparametric methods, joint

  12. Longitudinal changes in task-evoked brain responses in Parkinson’s disease patients with and without mild cognitive impairment

    Directory of Open Access Journals (Sweden)

    Urban eEkman

    2014-07-01

    Full Text Available Cognitive deficits are common in Parkinson’s disease. Previous cross-sectional research has demonstrated a link between cognitive impairments and fronto-striatal dopaminergic dysmodulation. However, longitudinal studies that link disease progression with altered task-evoked brain activity are lacking. Therefore, our objective was to longitudinally evaluate working-memory related brain activity changes in Parkinson’s disease patients with and without mild cognitive impairment.Patients were recruited within a longitudinal cohort study of incident patients with idiopathic parkinsonism. We longitudinally (at baseline examination and at 12-months follow-up compared 28 patients with Parkinson’s disease without mild cognitive impairment with 11 patients with Parkinson’s disease and mild cognitive impairment. Functional MRI blood oxygen level dependent signal was measured during a verbal two-back working-memory task. Patients with mild cognitive impairment under-recruited bilateral medial prefrontal cortex, right putamen, and lateral parietal cortex at both time-points (main effect of group: p<0.001, uncorrected. Critically, a significant group-by-time interaction effect (p<0.001, uncorrected was found in the right fusiform gyrus, indicating that working-memory related activity decreased for patients with Parkinson’s disease and mild cognitive impairment between baseline and follow-up, while patients without mild cognitive impairment were stable across time-points. The functional connectivity between right fusiform gyrus and bilateral caudate nucleus was stronger for patients without MCI relative to patients with MCI.Our findings support the view that deficits in working-memory updating are related to persistent fronto-striatal under-recruitments in patients with early phase Parkinson’s disease and mild cognitive impairment. The longitudinal evolution of mild cognitive impairment in Parkinson’s disease translates into additional task

  13. The traditional Japanese dietary pattern and longitudinal changes in cardiovascular disease risk factors in apparently healthy Japanese adults.

    Science.gov (United States)

    Niu, Kaijun; Momma, Haruki; Kobayashi, Yoritoshi; Guan, Lei; Chujo, Masahiko; Otomo, Atsushi; Ouchi, Eriko; Nagatomi, Ryoichi

    2016-02-01

    Few epidemiological studies have assessed the relationship between the traditional Japanese dietary pattern and longitudinal changes in cardiovascular disease risk factors among Japanese people. We designed a 3-year longitudinal study of 980 subjects living in Japan to evaluate how the Japanese dietary pattern is related to longitudinal changes in well-recognized risk factors for cardiovascular disease among apparently healthy Japanese adults. Dietary consumption was assessed via a validated food frequency questionnaire. Principal component analysis was used to derive three major dietary patterns-"Japanese," "sweets-fruits-cooked wheaten food," and "Izakaya (Japanese Pub)" from 39 food groups. After adjustment for potential confounders, the mean (95% confidence interval) for the change per year in diastolic blood pressure for men, systolic blood pressure, and diastolic blood pressure for women related to the "Japanese" dietary pattern factor score tertiles were 0.89 (0.10, 1.68), 2.25 (0.19, 4.31), and 0.75 (-1.00, 2.50) for the lowest tertile, 0.77 (-0.02, 1.56), 1.01 (-1.13, 3.15), and 0.44 (-1.38, 2.26) for the middle tertile and - 0.04 (-0.81, 0.72), -0.48 (-2.52, 1.56), and -0.77 (-2.51, 0.96) for the highest tertile (trend P value = 0.03, pattern factor score tertiles and the longitudinal change in serum triglyceride concentration only in men (trend P value = 0.02). Greater adherence to a traditional Japanese diet was independently related to a decreased change every year in diastolic blood pressure in men and women and in systolic blood pressure in women over a 3-year follow-up period. The findings suggest that the "Japanese" dietary pattern appeared to be related to a fall in blood pressure, which might have a beneficial effect on cardiovascular disease. A randomized trial is required to clarify the underlying mechanism.

  14. Multivariate longitudinal data analysis with mixed effects hidden Markov models.

    Science.gov (United States)

    Raffa, Jesse D; Dubin, Joel A

    2015-09-01

    Multiple longitudinal responses are often collected as a means to capture relevant features of the true outcome of interest, which is often hidden and not directly measurable. We outline an approach which models these multivariate longitudinal responses as generated from a hidden disease process. We propose a class of models which uses a hidden Markov model with separate but correlated random effects between multiple longitudinal responses. This approach was motivated by a smoking cessation clinical trial, where a bivariate longitudinal response involving both a continuous and a binomial response was collected for each participant to monitor smoking behavior. A Bayesian method using Markov chain Monte Carlo is used. Comparison of separate univariate response models to the bivariate response models was undertaken. Our methods are demonstrated on the smoking cessation clinical trial dataset, and properties of our approach are examined through extensive simulation studies. © 2015, The International Biometric Society.

  15. Longitudinal Study of the Transition From Healthy Aging to Alzheimer Disease

    Science.gov (United States)

    Johnson, David K.; Storandt, Martha; Morris, John C.; Galvin, James E.

    2009-01-01

    Background Detection of the earliest cognitive changes signifying Alzheimer disease is difficult. Objective To model the cognitive decline in preclinical Alzheimer disease. Design Longitudinal archival study comparing individuals who became demented during follow-up and people who remained nondemented on each of 4 cognitive factors: global, verbal memory, visuospatial, and working memory. Setting Alzheimer Disease Research Center, Washington University School of Medicine, St Louis, Missouri. Participants One hundred thirty-four individuals who became demented during follow-up and 310 who remained nondemented. Main Outcome Measures Inflection point in longitudinal cognitive performance. Results The best-fitting model for each of the 4 factors in the stable group was linear, with a very slight downward trend on all but the Visuospatial factor. In contrast, a piecewise model with accelerated slope after a sharp inflection point provided the best fit for the group that progressed. The optimal inflection point for all 4 factors was prior to diagnosis of dementia: Global, 2 years; Verbal and Working Memory, 1 year; and Visuospatial, 3 years. These results were also obtained when data were limited to the subset (n=44) with autopsy-confirmed Alzheimer disease. Conclusions There is a sharp inflection point followed by accelerating decline in multiple domains of cognition, not just memory, in the preclinical period in Alzheimer disease when there is insufficient cognitive decline to warrant clinical diagnosis using conventional criteria. Early change was seen in tests of visuospatial ability, most of which were speeded. Research into early detection of cognitive disorders using only episodic memory tasks may not be sensitive to all of the early manifestations of disease. PMID:19822781

  16. Sensitivity analysis of longitudinal cracking on asphalt pavement using MEPDG in permafrost region

    Directory of Open Access Journals (Sweden)

    Chen Zhang

    2015-02-01

    Full Text Available Longitudinal cracking is one of the most important distresses of asphalt pavement in permafrost regions. The sensitivity analysis of design parameters for asphalt pavement can be used to study the influence of every parameter on longitudinal cracking, which can help optimizing the design of the pavement structure. In this study, 20 test sections of Qinghai–Tibet Highway were selected to conduct the sensitivity analysis of longitudinal cracking on material parameter based on Mechanistic-Empirical Pavement Design Guide (MEPDG and single factorial sensitivity analysis method. Some computer aided engineering (CAE simulation techniques, such as the Latin hypercube sampling (LHS technique and the multiple regression analysis are used as auxiliary means. Finally, the sensitivity spectrum of material parameter on longitudinal cracking was established. The result shows the multiple regression analysis can be used to determine the remarkable influence factor more efficiently and to process the qualitative analysis when applying the MEPDG software in sensitivity analysis of longitudinal cracking in permafrost regions. The effect weights of the three parameters on longitudinal cracking in descending order are air void, effective binder content and PG grade. The influence of air void on top layer is bigger than that on middle layer and bottom layer. The influence of effective asphalt content on top layer is bigger than that on middle layer and bottom layer, and the influence of bottom layer is slightly bigger than middle layer. The accumulated value of longitudinal cracking on middle layer and bottom layer in the design life would begin to increase when the design temperature of PG grade increased.

  17. A Primer on Longitudinal Data Analysis in Education. Technical Report #1320

    Science.gov (United States)

    Nese, Joseph F. T.; Lai, Cheng-Fei; Anderson, Daniel

    2013-01-01

    Longitudinal data analysis in education is the study growth over time. A longitudinal study is one in which repeated observations of the same variables are recorded for the same individuals over a period of time. This type of research is known by many names (e.g., time series analysis or repeated measures design), each of which can imply subtle…

  18. Longitudinal Transcriptome Analysis Reveals a Sustained Differential Gene Expression Signature in Patients Treated for Acute Lyme Disease

    Science.gov (United States)

    Bouquet, Jerome; Soloski, Mark J.; Swei, Andrea; Cheadle, Chris; Federman, Scot; Billaud, Jean-Noel; Rebman, Alison W.; Kabre, Beniwende; Halpert, Richard; Boorgula, Meher

    2016-01-01

    ABSTRACT Lyme disease is a tick-borne illness caused by the bacterium Borrelia burgdorferi, and approximately 10 to 20% of patients report persistent symptoms lasting months to years despite appropriate treatment with antibiotics. To gain insights into the molecular basis of acute Lyme disease and the ensuing development of post-treatment symptoms, we conducted a longitudinal transcriptome study of 29 Lyme disease patients (and 13 matched controls) enrolled at the time of diagnosis and followed for up to 6 months. The differential gene expression signature of Lyme disease following the acute phase of infection persisted for at least 3 weeks and had fewer than 44% differentially expressed genes (DEGs) in common with other infectious or noninfectious syndromes. Early Lyme disease prior to antibiotic therapy was characterized by marked upregulation of Toll-like receptor signaling but lack of activation of the inflammatory T-cell apoptotic and B-cell developmental pathways seen in other acute infectious syndromes. Six months after completion of therapy, Lyme disease patients were found to have 31 to 60% of their pathways in common with three different immune-mediated chronic diseases. No differential gene expression signature was observed between Lyme disease patients with resolved illness to those with persistent symptoms at 6 months post-treatment. The identification of a sustained differential gene expression signature in Lyme disease suggests that a panel of selected human host-based biomarkers may address the need for sensitive clinical diagnostics during the “window period” of infection prior to the appearance of a detectable antibody response and may also inform the development of new therapeutic targets. PMID:26873097

  19. A meta-analysis of cerebrovascular disease and hyperhomocysteinaemia

    DEFF Research Database (Denmark)

    Nielsen, G M; Tvedegaard, K C; Andersen, Niels Trolle

    2000-01-01

    Hyperhomocysteinaemia has been identified as a risk factor for stroke and cerebrovascular disease in several studies. To evaluate the evidence we performed a meta-analysis. We found 21 studies searching Medline from 1966-July 1999 using the key words homocysteine, homocystine and cerebrovascular...... was used. The reports on 8 cross-sectional and 4 longitudinal studies gave data on the mean and standard deviations of plasma or serum homocysteine for both cases and controls, and these studies were included in the meta-analysis. The results of the 5 excluded studies all pointed to a positive relationship...

  20. Tract specific analysis in patients with sickle cell disease

    Science.gov (United States)

    Chai, Yaqiong; Coloigner, Julie; Qu, Xiaoping; Choi, Soyoung; Bush, Adam; Borzage, Matt; Vu, Chau; Lepore, Natasha; Wood, John

    2015-12-01

    Sickle cell disease (SCD) is a hereditary blood disorder in which the oxygen-carrying hemoglobin molecule in red blood cells is abnormal. It affects numerous people in the world and leads to a shorter life span, pain, anemia, serious infections and neurocognitive decline. Tract-Specific Analysis (TSA) is a statistical method to evaluate white matter alterations due to neurocognitive diseases, using diffusion tensor magnetic resonance images. Here, for the first time, TSA is used to compare 11 major brain white matter (WM) tracts between SCD patients and age-matched healthy subjects. Alterations are found in the corpus callosum (CC), the cortico-spinal tract (CST), inferior fronto-occipital fasciculus (IFO), inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF), and uncinated fasciculus (UNC). Based on previous studies on the neurocognitive functions of these tracts, the significant areas found in this paper might be related to several cognitive impairments and depression, both of which are observed in SCD patients.

  1. Causal mediation analysis for longitudinal data with exogenous exposure

    OpenAIRE

    Bind, M.-A. C.; Vanderweele, T. J.; Coull, B. A.; Schwartz, J. D.

    2015-01-01

    Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different type...

  2. Management of outpatients in France with stable coronary artery disease. Findings from the prospeCtive observational LongitudinAl RegIstry oF patients with stable coronary arterY disease (CLARIFY) registry.

    Science.gov (United States)

    Danchin, Nicolas; Ferrieres, Jean; Guenoun, Maxime; Cattan, Simon; Rushton-Smith, Sophie K; Greenlaw, Nicola; Ferrari, Roberto; Steg, Philippe Gabriel

    2014-01-01

    Improvements in the treatment of coronary artery disease mean that an increasing number of patients survive acute cardiovascular events and live as outpatients with or without anginal symptoms. To determine the characteristics and management of contemporary outpatients with stable coronary artery disease in Western Europe, and to compare France with the other Western European countries. CLARIFY (prospeCtive observational LongitudinAl RegIstry oF patients with stable coronary arterY disease) is an international, prospective, observational, longitudinal study. Between November 2009 and July 2010, 32,954 adult outpatients with stable coronary artery disease (defined as a history of documented myocardial infarction [of >3 months], prior coronary revascularization, chest pain with myocardial ischaemia, or coronary stenosis of>50% proven by angiography) were enrolled in 45 countries. The demographics and management of CLARIFY patients enrolled in France were compared with those enrolled in other Western European countries (Austria, Belgium, Denmark, Germany, Greece, Ireland, Italy, Netherlands, Portugal, Spain, Switzerland and the UK). Of the 14,726 patients enrolled in Western Europe (mean age 66.2 [10.2] years; 79.6% male), 2432 (16.5%) were from France. The use of aspirin was lower in France than in other Western European countries (74.5% vs. 86.9%, respectively), whereas use of thienopyridines (48.5% vs. 21.7%), oral anticoagulants (12.3% vs. 9.0%) and lipid-lowering drugs (95.8% vs. 92.5%) was higher. Beta-blockers were used in 73% of both groups. Angina was less prevalent in France (6.3% vs. 15.5%) and French patients showed higher levels of physical activity than their counterparts in Western Europe. The management of patients with stable CAD in France appears favourable, with good adherence to guideline-based therapies, but there remains room for improvement in terms of symptom and risk factor control. Copyright © 2014. Published by Elsevier Masson SAS.

  3. Epigenetic variability in conversion to psychosis: novel findings from an innovative longitudinal methylomic analysis.

    Science.gov (United States)

    Kebir, Oussama; Chaumette, Boris; Krebs, Marie-Odile

    2018-04-26

    Conversion to psychosis is a longitudinal process during which several epigenetic changes have been described. We tested the hypothesis that epigenetic variability in the methylomes of ultra-high risk (UHR) individuals may contribute to the risk of conversion. We studied a longitudinal cohort of UHR individuals (n = 39) and compared two groups (converters, n = 14 vs. non-converters, n = 25). A longitudinal methylomic study was conducted using Infinium HumanMethylation450 BeadChip covering half a million cytosine-phosphate-guanine (CpG) sites across the human genome from whole-blood samples. We used two statistical methods to investigate the variability of methylation probes. (i) The search for longitudinal variable methylation probes (VMPs) based on median comparisons identified two VMPs in converters only. The first CpG was located in the MACROD2 gene and the second CpG was in an intergenic region at 8q24.21. (ii) The detection of outliers using variance analysis related to private epimutations identified a dozen CpGs in converters only and highlighted two genes (RAC1 and SPHK1) from the sphingolipid signaling pathway. Our study is the first to support increased methylome variability during conversion to psychosis. We speculate that stochastic factors could increase DNA methylation variability and have a role in the complex pathophysiology of conversion to psychosis as well as in other psychiatric diseases.

  4. Diverging longitudinal changes in astrocytosis and amyloid PET in autosomal dominant Alzheimer's disease.

    Science.gov (United States)

    Rodriguez-Vieitez, Elena; Saint-Aubert, Laure; Carter, Stephen F; Almkvist, Ove; Farid, Karim; Schöll, Michael; Chiotis, Konstantinos; Thordardottir, Steinunn; Graff, Caroline; Wall, Anders; Långström, Bengt; Nordberg, Agneta

    2016-03-01

    Alzheimer's disease is a multifactorial dementia disorder characterized by early amyloid-β, tau deposition, glial activation and neurodegeneration, where the interrelationships between the different pathophysiological events are not yet well characterized. In this study, longitudinal multitracer positron emission tomography imaging of individuals with autosomal dominant or sporadic Alzheimer's disease was used to quantify the changes in regional distribution of brain astrocytosis (tracer (11)C-deuterium-L-deprenyl), fibrillar amyloid-β plaque deposition ((11)C-Pittsburgh compound B), and glucose metabolism ((18)F-fluorodeoxyglucose) from early presymptomatic stages over an extended period to clinical symptoms. The 52 baseline participants comprised autosomal dominant Alzheimer's disease mutation carriers (n = 11; 49.6 ± 10.3 years old) and non-carriers (n = 16; 51.1 ± 14.2 years old; 10 male), and patients with sporadic mild cognitive impairment (n = 17; 61.9 ± 6.4 years old; nine male) and sporadic Alzheimer's disease (n = 8; 63.0 ± 6.5 years old; five male); for confidentiality reasons, the gender of mutation carriers is not revealed. The autosomal dominant Alzheimer's disease participants belonged to families with known mutations in either presenilin 1 (PSEN1) or amyloid precursor protein (APPswe or APParc) genes. Sporadic mild cognitive impairment patients were further divided into (11)C-Pittsburgh compound B-positive (n = 13; 62.0 ± 6.4; seven male) and (11)C-Pittsburgh compound B-negative (n = 4; 61.8 ± 7.5 years old; two male) groups using a neocortical standardized uptake value ratio cut-off value of 1.41, which was calculated with respect to the cerebellar grey matter. All baseline participants underwent multitracer positron emission tomography scans, cerebrospinal fluid biomarker analysis and neuropsychological assessment. Twenty-six of the participants underwent clinical and imaging follow-up examinations after 2.8 ± 0.6 years. By using linear

  5. Composite marginal quantile regression analysis for longitudinal adolescent body mass index data.

    Science.gov (United States)

    Yang, Chi-Chuan; Chen, Yi-Hau; Chang, Hsing-Yi

    2017-09-20

    Childhood and adolescenthood overweight or obesity, which may be quantified through the body mass index (BMI), is strongly associated with adult obesity and other health problems. Motivated by the child and adolescent behaviors in long-term evolution (CABLE) study, we are interested in individual, family, and school factors associated with marginal quantiles of longitudinal adolescent BMI values. We propose a new method for composite marginal quantile regression analysis for longitudinal outcome data, which performs marginal quantile regressions at multiple quantile levels simultaneously. The proposed method extends the quantile regression coefficient modeling method introduced by Frumento and Bottai (Biometrics 2016; 72:74-84) to longitudinal data accounting suitably for the correlation structure in longitudinal observations. A goodness-of-fit test for the proposed modeling is also developed. Simulation results show that the proposed method can be much more efficient than the analysis without taking correlation into account and the analysis performing separate quantile regressions at different quantile levels. The application to the longitudinal adolescent BMI data from the CABLE study demonstrates the practical utility of our proposal. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Longitudinal decline in speech production in Parkinson's disease spectrum disorders.

    Science.gov (United States)

    Ash, Sharon; Jester, Charles; York, Collin; Kofman, Olga L; Langey, Rachel; Halpin, Amy; Firn, Kim; Dominguez Perez, Sophia; Chahine, Lama; Spindler, Meredith; Dahodwala, Nabila; Irwin, David J; McMillan, Corey; Weintraub, Daniel; Grossman, Murray

    2017-08-01

    We examined narrative speech production longitudinally in non-demented (n=15) and mildly demented (n=8) patients with Parkinson's disease spectrum disorder (PDSD), and we related increasing impairment to structural brain changes in specific language and motor regions. Patients provided semi-structured speech samples, describing a standardized picture at two time points (mean±SD interval=38±24months). The recorded speech samples were analyzed for fluency, grammar, and informativeness. PDSD patients with dementia exhibited significant decline in their speech, unrelated to changes in overall cognitive or motor functioning. Regression analysis in a subset of patients with MRI scans (n=11) revealed that impaired language performance at Time 2 was associated with reduced gray matter (GM) volume at Time 1 in regions of interest important for language functioning but not with reduced GM volume in motor brain areas. These results dissociate language and motor systems and highlight the importance of non-motor brain regions for declining language in PDSD. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. A Longitudinal Motor Characterisation of the HdhQ111 Mouse Model of Huntington's Disease.

    Science.gov (United States)

    Yhnell, Emma; Dunnett, Stephen B; Brooks, Simon P

    2016-05-31

    Huntington's disease (HD) is a rare, incurable neurodegenerative disorder caused by a CAG trinucleotide expansion with the first exon of the huntingtin gene. Numerous knock-in mouse models are currently available for modelling HD. However, before their use in scientific research, these models must be characterised to determine their face and predictive validity as models of the disease and their reliability in recapitulating HD symptoms. Manifest HD is currently diagnosed upon the onset of motor symptoms, thus we sought to longitudinally characterise the progression and severity of motor signs in the HdhQ111 knock-in mouse model of HD, in heterozygous mice. An extensive battery of motor tests including: rotarod, inverted lid test, balance beam, spontaneous locomotor activity and gait analysis were applied longitudinally to a cohort of HdhQ111 heterozygous mice in order to progressively assess motor function. A progressive failure to gain body weight was demonstrated from 11 months of age and motor problems in all measures of balance beam performance were shown in HdhQ111 heterozygous animals in comparison to wild type control animals from 9 months of age. A decreased latency to fall from the rotarod was demonstrated in HdhQ111 heterozygous animals in comparison to wild type animals, although this was not progressive with time. No genotype specific differences were demonstrated in any of the other motor tests included in the test battery. The HdhQ111 heterozygous mouse demonstrates a subtle and progressive motor phenotype that begins at 9 months of age. This mouse model represents an early disease stage and would be ideal for testing therapeutic strategies that require elongated lead-in times, such as viral gene therapies or striatal transplantation.

  8. Heart and skeletal muscle inflammation (HSMI disease diagnosed on a British Columbia salmon farm through a longitudinal farm study.

    Directory of Open Access Journals (Sweden)

    Emiliano Di Cicco

    Full Text Available Heart and skeletal muscle inflammation (HSMI is an emerging disease of marine-farmed Atlantic Salmon (Salmo salar, first recognized in 1999 in Norway, and later also reported in Scotland and Chile. We undertook a longitudinal study involving health evaluation over an entire marine production cycle on one salmon farm in British Columbia (Canada. In previous production cycles at this farm site and others in the vicinity, cardiac lesions not linked to a specific infectious agent or disease were identified. Histologic assessments of both live and moribund fish samples collected at the farm during the longitudinal study documented at the population level the development, peak, and recovery phases of HSMI. The fish underwent histopathological evaluation of all tissues, Twort's Gram staining, immunohistochemistry, and molecular quantification in heart tissue of 44 agents known or suspected to cause disease in salmon. Our analysis showed evidence of HSMI histopathological lesions over an 11-month timespan, with the prevalence of lesions peaking at 80-100% in sampled fish, despite mild clinical signs with no associated elevation in mortalities reported at the farm level. Diffuse mononuclear inflammation and myodegeneration, consistent with HSMI, was the predominant histologic observation in affected heart and skeletal muscle. Infective agent monitoring identified three agents at high prevalence in salmon heart tissue, including Piscine orthoreovirus (PRV, and parasites Paranucleospora theridion and Kudoa thyrsites. However, PRV alone was statistically correlated with the occurrence and severity of histopathological lesions in the heart. Immunohistochemical staining further localized PRV throughout HSMI development, with the virus found mainly within red blood cells in early cases, moving into the cardiomyocytes within or, more often, on the periphery of the inflammatory reaction during the peak disease, and reducing to low or undetectable levels later in

  9. Longitudinal Jitter Analysis of a Linear Accelerator Electron Gun

    Directory of Open Access Journals (Sweden)

    MingShan Liu

    2016-11-01

    Full Text Available We present measurements and analysis of the longitudinal timing jitter of a Beijing Electron Positron Collider (BEPCII linear accelerator electron gun. We simulated the longitudinal jitter effect of the gun using PARMELA to evaluate beam performance, including: beam profile, average energy, energy spread, and XY emittances. The maximum percentage difference of the beam parameters is calculated to be 100%, 13.27%, 42.24% and 65.01%, 86.81%, respectively. Due to this, the bunching efficiency is reduced to 54%. However, the longitudinal phase difference of the reference particle was 9.89°. The simulation results are in agreement with tests and are helpful to optimize the beam parameters by tuning the trigger timing of the gun during the bunching process.

  10. Longitudinal evaluation of bronchopulmonary disease in children with cystic fibrosis.

    Science.gov (United States)

    Farrell, Philip M; Li, Zhanhai; Kosorok, Michael R; Laxova, Anita; Green, Christopher G; Collins, Jannette; Lai, Hui-Chuan; Makholm, Linda M; Rock, Michael J; Splaingard, Mark L

    2003-09-01

    Children with cystic fibrosis (CF) develop bronchopulmonary disease at variable ages. Determining the epidemiology of chronic lung disease and quantifying its severity, however, have been difficult in infants and young children. As part of the Wisconsin CF Neonatal Screening Project, we were presented with an ideal opportunity to assess longitudinally the evolution of symptoms, signs, and quantitative measures of CF respiratory disease. After newborn screening test results led to early recognition, 64 patients diagnosed at a median age of 6.71 weeks were enrolled and studied systematically at a median age of 11.3 years to obtain clinical information, chest radiographs, and pulmonary function tests. Our observations revealed that a frequent cough by history is evident by 10.5 months of age in half the patients. Quantitative chest radiology (CXR scoring) demonstrated that potentially irreversible abnormalities are present in half the children by 2 years. The severity of Wisconsin and Brasfield CXR scores increased in association with respiratory infections. Longitudinal progression of Wisconsin CXR scores was related to age (P < 0.001), pancreatic insufficiency (P = 0.005), and respiratory secretion cultures positive for Staphylococus aureas (P = 0.039). In contrast, serial spirometry showed limited sensitivity, as did lung volume determinations; neither was satisfactory as repeated measures with acceptable quality control until after 7 years of age. Time to event analyses revealed that half the patients had % predicted FEF(25-75) and FEV(1)/FVC values greater than 80% until 10.7 and 9.9 years, respectively. We conclude that of the methods evaluated, quantitative chest radiology is currently the best procedure for frequent assessment of bronchopulmonary disease in CF, and that radiographic progression is evident in approximately 85% of patients by 5 years of age. Our results also suggest that bronchiectasis and other radiographic evidence of chronic infection are

  11. Longitudinal patterns of semantic and episodic memory in frontotemporal lobar degeneration and Alzheimer's disease.

    Science.gov (United States)

    Xie, Sharon X; Libon, David J; Wang, Xingmei; Massimo, Lauren; Moore, Peachie; Vesely, Luisa; Khan, Alea; Chatterjee, Anjan; Coslett, H Branch; Hurtig, Howard I; Liang, Tsao-Wei; Grossman, Murray

    2010-03-01

    The longitudinal assessment of episodic and semantic memory was obtained from 236 patients diagnosed with Alzheimer's disease (AD, n = 128) and with frontotemporal lobar degeneration (FTLD, n = 108), including patients with a social comportment/dysexecutive (SOC/EXEC) disorder, progressive nonfluent aphasia (PNFA), semantic dementia (SemD), and corticobasal syndrome (CBS). At the initial assessment, AD patients obtained a lower score on the delayed free recall test than other patients. Longitudinal analyses for delayed free recall found converging performance, with all patients reaching the same level of impairment as AD patients. On the initial evaluation for delayed recognition, AD patients also obtained lower scores than other groups. Longitudinal analyses for delayed recognition test performance found that AD patients consistently produced lower scores than other groups and no convergence between AD and other dementia groups was seen. For semantic memory, there were no initial between-group differences. However, longitudinal analyses for semantic memory revealed group differences over illness duration, with worse performance for SemD versus AD, PNFA, SOC/EXEC, and CBS patients. These data suggest the presence of specific longitudinal patterns of impairment for episodic and semantic memory in AD and FTLD patients suggesting that all forms of dementia do not necessarily converge into a single phenotype.

  12. Big data in multiple sclerosis: development of a web-based longitudinal study viewer in an imaging informatics-based eFolder system for complex data analysis and management

    Science.gov (United States)

    Ma, Kevin; Wang, Ximing; Lerner, Alex; Shiroishi, Mark; Amezcua, Lilyana; Liu, Brent

    2015-03-01

    In the past, we have developed and displayed a multiple sclerosis eFolder system for patient data storage, image viewing, and automatic lesion quantification results stored in DICOM-SR format. The web-based system aims to be integrated in DICOM-compliant clinical and research environments to aid clinicians in patient treatments and disease tracking. This year, we have further developed the eFolder system to handle big data analysis and data mining in today's medical imaging field. The database has been updated to allow data mining and data look-up from DICOM-SR lesion analysis contents. Longitudinal studies are tracked, and any changes in lesion volumes and brain parenchyma volumes are calculated and shown on the webbased user interface as graphical representations. Longitudinal lesion characteristic changes are compared with patients' disease history, including treatments, symptom progressions, and any other changes in the disease profile. The image viewer is updated such that imaging studies can be viewed side-by-side to allow visual comparisons. We aim to use the web-based medical imaging informatics eFolder system to demonstrate big data analysis in medical imaging, and use the analysis results to predict MS disease trends and patterns in Hispanic and Caucasian populations in our pilot study. The discovery of disease patterns among the two ethnicities is a big data analysis result that will help lead to personalized patient care and treatment planning.

  13. Analysis of longitudinal diffusion-weighted images in healthy and pathological aging: An ADNI study.

    Science.gov (United States)

    Kruggel, Frithjof; Masaki, Fumitaro; Solodkin, Ana

    2017-02-15

    The widely used framework of voxel-based morphometry for analyzing neuroimages is extended here to model longitudinal imaging data by exchanging the linear model with a linear mixed-effects model. The new approach is employed for analyzing a large longitudinal sample of 756 diffusion-weighted images acquired in 177 subjects of the Alzheimer's Disease Neuroimaging initiative (ADNI). While sample- and group-level results from both approaches are equivalent, the mixed-effect model yields information at the single subject level. Interestingly, the neurobiological relevance of the relevant parameter at the individual level describes specific differences associated with aging. In addition, our approach highlights white matter areas that reliably discriminate between patients with Alzheimer's disease and healthy controls with a predictive power of 0.99 and include the hippocampal alveus, the para-hippocampal white matter, the white matter of the posterior cingulate, and optic tracts. In this context, notably the classifier includes a sub-population of patients with minimal cognitive impairment into the pathological domain. Our classifier offers promising features for an accessible biomarker that predicts the risk of conversion to Alzheimer's disease. Data used in preparation of this article were obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database (adni.loni.usc.edu). As such, the investigators within the ADNI contributed to the design and implementation of ADNI and/or provided data but did not participate in analysis or writing of this report. A complete listing of ADNI investigators can be found at: http://adni.loni.usc.edu/wp-content/uploads/how to apply/ADNI Acknowledgement List.pdf. Significance statement This study assesses neuro-degenerative processes in the brain's white matter as revealed by diffusion-weighted imaging, in order to discriminate healthy from pathological aging in a large sample of elderly subjects. The analysis of time

  14. Longitudinal multigroup invariance analysis of the satisfaction with food-related life scale in university students.

    Science.gov (United States)

    Schnettler, Berta; Miranda, Horacio; Miranda-Zapata, Edgardo; Salinas-Oñate, Natalia; Grunert, Klaus G; Lobos, Germán; Sepúlveda, José; Orellana, Ligia; Hueche, Clementina; Bonilla, Héctor

    2017-06-01

    This study examined longitudinal measurement invariance in the Satisfaction with Food-related Life (SWFL) scale using follow-up data from university students. We examined this measure of the SWFL in different groups of students, separated by various characteristics. Through non-probabilistic longitudinal sampling, 114 university students (65.8% female, mean age: 22.5) completed the SWFL questionnaire three times, over intervals of approximately one year. Confirmatory factor analysis was used to examine longitudinal measurement invariance. Two types of analysis were conducted: first, a longitudinal invariance by time, and second, a multigroup longitudinal invariance by sex, age, socio-economic status and place of residence during the study period. Results showed that the 3-item version of the SWFL exhibited strong longitudinal invariance (equal factor loadings and equal indicator intercepts). Longitudinal multigroup invariance analysis also showed that the 3-item version of the SWFL displays strong invariance by socio-economic status and place of residence during the study period over time. Nevertheless, it was only possible to demonstrate equivalence of the longitudinal factor structure among students of both sexes, and among those older and younger than 22 years. Generally, these findings suggest that the SWFL scale has satisfactory psychometric properties for longitudinal measurement invariance in university students with similar characteristics as the students that participated in this research. It is also possible to suggest that satisfaction with food-related life is associated with sex and age. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Multi-modal neuroimaging in premanifest and early Huntington's disease: 18 month longitudinal data from the IMAGE-HD study.

    Science.gov (United States)

    Domínguez D, Juan F; Egan, Gary F; Gray, Marcus A; Poudel, Govinda R; Churchyard, Andrew; Chua, Phyllis; Stout, Julie C; Georgiou-Karistianis, Nellie

    2013-01-01

    IMAGE-HD is an Australian based multi-modal longitudinal magnetic resonance imaging (MRI) study in premanifest and early symptomatic Huntington's disease (pre-HD and symp-HD, respectively). In this investigation we sought to determine the sensitivity of imaging methods to detect macrostructural (volume) and microstructural (diffusivity) longitudinal change in HD. We used a 3T MRI scanner to acquire T1 and diffusion weighted images at baseline and 18 months in 31 pre-HD, 31 symp-HD and 29 controls. Volume was measured across the whole brain, and volume and diffusion measures were ascertained for caudate and putamen. We observed a range of significant volumetric and, for the first time, diffusion changes over 18 months in both pre-HD and symp-HD, relative to controls, detectable at the brain-wide level (volume change in grey and white matter) and in caudate and putamen (volume and diffusivity change). Importantly, longitudinal volume change in the caudate was the only measure that discriminated between groups across all stages of disease: far from diagnosis (>15 years), close to diagnosis (fractional anisotropy, FA), only longitudinal FA change was sensitive to group differences, but only after diagnosis. These findings further confirm caudate atrophy as one of the most sensitive and early biomarkers of neurodegeneration in HD. They also highlight that different tissue properties have varying schedules in their ability to discriminate between groups along disease progression and may therefore inform biomarker selection for future therapeutic interventions.

  16. Longitudinal multigroup invariance analysis of the satisfaction with food-related life scale in university students

    DEFF Research Database (Denmark)

    Schnettler, Berta; Miranda, Horacio; Miranda-Zapata, Edgardo

    2017-01-01

    This study examined longitudinal measurement invariance in the Satisfaction with Food-related Life (SWFL) scale using follow-up data from university students. We examined this measure of the SWFL in different groups of students, separated by various characteristics. Through non......-probabilistic longitudinal sampling, 114 university students (65.8% female, mean age: 22.5) completed the SWFL questionnaire three times, over intervals of approximately one year. Confirmatory factor analysis was used to examine longitudinal measurement invariance. Two types of analysis were conducted: first, a longitudinal...... students of both sexes, and among those older and younger than 22 years. Generally, these findings suggest that the SWFL scale has satisfactory psychometric properties for longitudinal measurement invariance in university students with similar characteristics as the students that participated...

  17. Comparing Longitudinal Profile Patterns of Mathematics and Reading in Early Child Longitudinal Study, Kindergarten: The Profile Analysis via Multidimensional Scaling (PAMS) Approach

    Science.gov (United States)

    Kim, Se-Kang

    2010-01-01

    The aim of the study is to compare longitudinal patterns from Mathematics and Reading data from the direct child assessment of Early Child Longitudinal Study, Kindergarten (ECLS-K, US Department of Education, National Center for Education Statistics 2006), utilizing Profile Analysis via Multidimensional Scaling (PAMS). PAMS has been used initially…

  18. Development of Inflammatory Bowel Disease Is Linked to a Longitudinal Restructuring of the Gut Metagenome in Mice

    Science.gov (United States)

    Sharpton, Thomas; Lyalina, Svetlana; Luong, Julie; Pham, Joey; Deal, Emily M.; Armour, Courtney; Gaulke, Christopher; Sanjabi, Shomyseh

    2017-01-01

    ABSTRACT The gut microbiome is linked to inflammatory bowel disease (IBD) severity and altered in late-stage disease. However, it is unclear how gut microbial communities change over the course of IBD development, especially in regard to function. To investigate microbiome-mediated disease mechanisms and discover early biomarkers of IBD, we conducted a longitudinal metagenomic investigation in an established mouse model of IBD, where damped transforming growth factor β (TGF-β) signaling in T cells leads to peripheral immune activation, weight loss, and severe colitis. IBD development is associated with abnormal gut microbiome temporal dynamics, including damped acquisition of functional diversity and significant differences in abundance trajectories for KEGG modules such as glycosaminoglycan degradation, cellular chemotaxis, and type III and IV secretion systems. Most differences between sick and control mice emerge when mice begin to lose weight and heightened T cell activation is detected in peripheral blood. However, levels of lipooligosaccharide transporter abundance diverge prior to immune activation, indicating that it could be a predisease indicator or microbiome-mediated disease mechanism. Taxonomic structure of the gut microbiome also significantly changes in association with IBD development, and the abundances of particular taxa, including several species of Bacteroides, correlate with immune activation. These discoveries were enabled by our use of generalized linear mixed-effects models to test for differences in longitudinal profiles between healthy and diseased mice while accounting for the distributions of taxon and gene counts in metagenomic data. These findings demonstrate that longitudinal metagenomics is useful for discovering the potential mechanisms through which the gut microbiome becomes altered in IBD. IMPORTANCE IBD patients harbor distinct microbial communities with functional capabilities different from those seen with healthy people

  19. Development of Inflammatory Bowel Disease Is Linked to a Longitudinal Restructuring of the Gut Metagenome in Mice.

    Science.gov (United States)

    Sharpton, Thomas; Lyalina, Svetlana; Luong, Julie; Pham, Joey; Deal, Emily M; Armour, Courtney; Gaulke, Christopher; Sanjabi, Shomyseh; Pollard, Katherine S

    2017-01-01

    The gut microbiome is linked to inflammatory bowel disease (IBD) severity and altered in late-stage disease. However, it is unclear how gut microbial communities change over the course of IBD development, especially in regard to function. To investigate microbiome-mediated disease mechanisms and discover early biomarkers of IBD, we conducted a longitudinal metagenomic investigation in an established mouse model of IBD, where damped transforming growth factor β (TGF-β) signaling in T cells leads to peripheral immune activation, weight loss, and severe colitis. IBD development is associated with abnormal gut microbiome temporal dynamics, including damped acquisition of functional diversity and significant differences in abundance trajectories for KEGG modules such as glycosaminoglycan degradation, cellular chemotaxis, and type III and IV secretion systems. Most differences between sick and control mice emerge when mice begin to lose weight and heightened T cell activation is detected in peripheral blood. However, levels of lipooligosaccharide transporter abundance diverge prior to immune activation, indicating that it could be a predisease indicator or microbiome-mediated disease mechanism. Taxonomic structure of the gut microbiome also significantly changes in association with IBD development, and the abundances of particular taxa, including several species of Bacteroides , correlate with immune activation. These discoveries were enabled by our use of generalized linear mixed-effects models to test for differences in longitudinal profiles between healthy and diseased mice while accounting for the distributions of taxon and gene counts in metagenomic data. These findings demonstrate that longitudinal metagenomics is useful for discovering the potential mechanisms through which the gut microbiome becomes altered in IBD. IMPORTANCE IBD patients harbor distinct microbial communities with functional capabilities different from those seen with healthy people. But is

  20. The longitudinal impact of depression on disability in Parkinson disease.

    Science.gov (United States)

    Pontone, Gregory M; Bakker, Catherine C; Chen, Shaojie; Mari, Zoltan; Marsh, Laura; Rabins, Peter V; Williams, James R; Bassett, Susan S

    2016-05-01

    Depression in Parkinson disease (PD) is a common problem that worsens quality of life and causes disability. However, little is known about the longitudinal impact of depression on disability in PD. This study examined the association between disability and DSM-IV-TR depression status across six years. Longitudinal cohort study with assessments at study entry, year two, four, and six conducted in the Morris K. Udall Parkinson Disease Research Center. Recruitment totaled 137 adult men and women with idiopathic PD in which up to six years of data on demographic, motor, and non-motor variables was collected. Movement disorder specialists used the structured interview for DSM-IV-TR depressive disorders and the Northwestern Disability Scale to assess depression and disability. A generalized linear mixed model was fitted with Northwestern Disability Scale score as the dependent variable to determine the effect of baseline depression status on disability. A total of 43 participants were depressed at baseline compared to 94 without depression. Depressed participants were more likely to be female, were less educated, were less likely to take dopamine agonists, and more likely to have motor fluctuations. Controlling for these variables, symptomatic depression predicted greater disability compared to both never depressed (p = 0.0133) and remitted depression (p = 0.0009). Disability associated with symptomatic depression at baseline was greater over the entire six-year period compared to participants with remitted depressive episodes or who were never depressed. Persisting depression is associated with a long-term adverse impact on daily functioning in PD. Adequate treatment or spontaneous remission of depression improves ADL function. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Natural History of Parkinson's Disease in the Province of Segovia: Disability in a 20 Years Longitudinal Study.

    Science.gov (United States)

    Duarte, Jacinto; García Olmos, Luis Miguel; Mendoza, Amelia; Martínez Pueyo, Ángel; Clavería, Luis Erik

    2015-01-01

    Parkinson's disease mainly affects the elderly population causing a progressive functional disability with motor, psychic, and cognitive deterioration. This study was carried out to evaluate disability caused by Parkinson's disease by analyzing the median time to reach Hoehn and Yahr stage III and to investigate predictor variables based on a 20-year longitudinal follow-up study. We examined 273 patients with Parkinson's disease recruited between 1978 and 1998. We performed a survival analysis using the Kaplan-Meier method to determine the time to disability and we used a Cox regression model to adjust prognosis factors. The median time to reach Hoehn and Yahr stage III was 7.73 years (95% CI: 5.95-8.05). Independent predictors of disability were: age at onset, the hazard ratio (HR) = 1.10, 95% CI: 1.08-1.12; UPDRS II (activities of daily living) HR = 1.08, 95% CI: 1.03-1.14; and akinesia and rigidity at onset HR = 1.55, 95% CI: 1.07-2.24. Patients with Parkinson's disease evolve gradually toward disability, and prognostic factors of this evolution were identified. © 2015 S. Karger AG, Basel.

  2. Multi-modal neuroimaging in premanifest and early Huntington's disease: 18 month longitudinal data from the IMAGE-HD study.

    Directory of Open Access Journals (Sweden)

    Juan F Domínguez D

    Full Text Available IMAGE-HD is an Australian based multi-modal longitudinal magnetic resonance imaging (MRI study in premanifest and early symptomatic Huntington's disease (pre-HD and symp-HD, respectively. In this investigation we sought to determine the sensitivity of imaging methods to detect macrostructural (volume and microstructural (diffusivity longitudinal change in HD. We used a 3T MRI scanner to acquire T1 and diffusion weighted images at baseline and 18 months in 31 pre-HD, 31 symp-HD and 29 controls. Volume was measured across the whole brain, and volume and diffusion measures were ascertained for caudate and putamen. We observed a range of significant volumetric and, for the first time, diffusion changes over 18 months in both pre-HD and symp-HD, relative to controls, detectable at the brain-wide level (volume change in grey and white matter and in caudate and putamen (volume and diffusivity change. Importantly, longitudinal volume change in the caudate was the only measure that discriminated between groups across all stages of disease: far from diagnosis (>15 years, close to diagnosis (<15 years and after diagnosis. Of the two diffusion metrics (mean diffusivity, MD; fractional anisotropy, FA, only longitudinal FA change was sensitive to group differences, but only after diagnosis. These findings further confirm caudate atrophy as one of the most sensitive and early biomarkers of neurodegeneration in HD. They also highlight that different tissue properties have varying schedules in their ability to discriminate between groups along disease progression and may therefore inform biomarker selection for future therapeutic interventions.

  3. Development of Inflammatory Bowel Disease Is Linked to a Longitudinal Restructuring of the Gut Metagenome in Mice

    OpenAIRE

    Sharpton, T; Lyalina, S; Luong, J; Pham, J; Deal, EM; Armour, C; Gaulke, C; Sanjabi, S; Pollard, KS

    2017-01-01

    ABSTRACT The gut microbiome is linked to inflammatory bowel disease (IBD) severity and altered in late-stage disease. However, it is unclear how gut microbial communities change over the course of IBD development, especially in regard to function. To investigate microbiome-mediated disease mechanisms and discover early biomarkers of IBD, we conducted a longitudinal metagenomic investigation in an established mouse model of IBD, where damped transforming growth factor ? (TGF-?) signaling in T ...

  4. Development of Inflammatory Bowel Disease is Linked to a Longitudinal Restructuring of the Gut Metagenome in Mice

    OpenAIRE

    Luong, Julie; Sharpton, Thomas; Pollard, Katherine; Sanjabi, Shomyseh; Gaulke, Christopher; Armour, Courtney; Deal, Emily; Pham, Joey; Loung, Julie; Lyalina, Svetlana; Sharpton, Thomas

    2017-01-01

    The gut microbiome is linked to inflammatory bowel disease (IBD) severity and altered in late stage disease. However, it is unclear how gut microbial communities change over the course of IBD development, especially in regards to function. To investigate microbiome mediated disease mechanisms and discover early biomarkers of IBD, we conducted a longitudinal metagenomic investigation in an established mouse model of IBD, where dampened TGF-β signaling in T cells leads to peripheral immune acti...

  5. A longitudinal study of neuromelanin-sensitive magnetic resonance imaging in Parkinson's disease.

    Science.gov (United States)

    Matsuura, Keita; Maeda, Masayuki; Tabei, Ken-Ichi; Umino, Maki; Kajikawa, Hiroyuki; Satoh, Masayuki; Kida, Hirotaka; Tomimoto, Hidekazu

    2016-10-28

    Neuromelanin-sensitive MR imaging (NMI) is an increasingly powerful tool for the diagnosis of Parkinson's disease (PD). This study was undertaken to evaluate longitudinal changes on NMI in PD patients. We examined longitudinal changes on NMI in 14 PD patients. The area and contrast ratio (CR) of the substantia nigra pars compacta (SNc) were comparatively analyzed. The total area and CR of the SNc upon follow-up NMI were significantly smaller than those on initial NMI (from 33.5±18.9 pixels and 6.35±2.86% to 21.5±16.7 pixels and 4.19±2.11%; Wilcoxon signed-rank test, pWilcoxon signed-rank test, p=0.002 and p=0.007, respectively). On a case-by-case basis, the area of the SNc invariably decreased upon follow-up NMI in all patients. We further demonstrated that the total area and CR of the SNc negatively correlated with disease duration (Pearson correlation coefficient, r=-0.63, p<0.001 and r=-0.41, p=0.031, respectively). In area analyses, our results demonstrated very high intraclass correlation coefficients for both intra- and inter-rater reliability. NMI is a useful and reliable tool for detecting neuropathological changes over time in PD patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. The longitudinal relationship between mental health disorders and chronic disease for older adults: a population-based study.

    Science.gov (United States)

    Chen, Chun-Min; Lee, I-Chen; Su, Yung-Yu; Mullan, Judy; Chiu, Herng-Chia

    2017-09-01

    Although mental health disorders in older adults are common, their relationship with chronic disease and the influence of chronic disease on the development of mental health disorders over time is not well understood. This longitudinal study investigated the change in status of mental health disorders and chronic disease, as well as their interrelationships, over time. Participants included community-dwelling older adults living in Taiwan, aged 65 years or older, who completed six waves of survey interviews. Mental health disorders were scored using the Short Psychiatric Evaluation Schedule, and chronic disease(s) status was recorded during consecutive biennial data collection waves. The autoregressive latent trajectory model and parallel latent growth curve model were used for data analysis. The study findings suggest that in older people pre-existing mental health disorders and/or chronic disease(s) will predispose them to developing significantly more mental health disorders and/or chronic diseases respectively. The study findings also suggest that pre-existing mental health disorders can significantly contribute to the development of chronic disease over time, and that pre-existing chronic disease(s) significantly can contribute to the development of mental health disorders over time, indicating a reciprocal interrelationship. Our study findings suggest that it in addition to monitoring and treating chronic disease(s) in older people, it is also important to monitor and treat their mental health disorders. Doing so will result in overall better health outcomes and will facilitate a better quality of life as they age. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  7. The association of periodontal disease with kidney function decline: a longitudinal retrospective analysis of the MrOS dental study.

    Science.gov (United States)

    Grubbs, Vanessa; Vittinghoff, Eric; Taylor, George; Kritz-Silverstein, Donna; Powe, Neil; Bibbins-Domingo, Kirsten; Ishani, Areef; Cummings, Steven R

    2016-03-01

    Identifying modifiable risk factors for chronic kidney disease (CKD) is essential for reducing its burden. Periodontal disease is common, modifiable and has been implicated as a novel potential CKD risk factor, but evidence of its association with kidney function decline over time is limited. In a longitudinal retrospective cohort of 761 elderly men with preserved kidney function [estimated glomerular filtration rate > 60 mL/min/1.73 m(2) using a calibrated creatinine and cystatin C (eGFRcr-cys) equation] at baseline, we performed multivariable Poisson's regression to examine the association of severe periodontal disease with incident CKD, defined as incident eGFRcr-cys 5% annualized) eGFRcr-cys decline. Severe periodontal disease was defined in two ways: (i) ≥5 mm proximal attachment loss in 30% of teeth examined (European Workshop in Periodontology Group C, European Workshop); and (ii) 2+ interproximal sites with attachment loss ≥6 mm and 1+ interproximal sites with probing depth ≥5 mm (Centers for Disease Control/American Academy of Periodontology, CDC/AAP). At baseline, the mean age was 73.4 (SD 4.8) years, the median eGFRcr-cys was 82.4 mL/min/1.73 m(2), and 35.5 and 25.4% of participants had severe periodontal disease by European Workshop and CDC/AAP criteria, respectively. After a mean follow-up of 4.9 years (SD 0.3), 56 (7.4%) participants had incident CKD. Severe periodontal disease was associated with a 2-fold greater rate of incident CKD [incidence rate ratio (IRR) 2.01 (1.21-3.44), P = 0.007] after adjusting for confounders compared with not severe periodontal disease by European Workshop criteria but did not reach statistical significance by CDC/AAP criteria [IRR 1.10 (0.63-1.91), P = 0.9]. Severe periodontal disease may be associated with incident clinically significant kidney function decline among a cohort of elderly men. © The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  8. Digitomotography in Parkinson's disease: a cross-sectional and longitudinal study.

    Directory of Open Access Journals (Sweden)

    Walter Maetzler

    Full Text Available Motor symptoms in Parkinson's disease (PD are usually assessed with semi-quantitative tests such as the Unified PD Rating Scale (UPDRS which are limited by subjectivity, categorical design, and low sensitivity. Particularly bradykinesia as assessed e.g. with speeded index finger tapping exhibits low validity measures. This exploratory study set out to (i assess whether force transducer-based objective and quantitative analysis of motor coordination in index finger tapping is able to distinguish between PD patients and controls, and (ii assess longitudinal changes. Sixteen early-stage and 17 mid-stage PD patients as well as 18 controls were included in the cross-sectional part of the study; thirteen, 16 and 16 individuals of the respective groups agreed in a reassessment 12 months later. Frequency, force, rhythmicity, regularity and laterality of speeded and metronome paced tapping were recorded by digitomotography using a quantitative motor system ("Q-Motor". Analysis of cross-sectional data revealed most consistent differences between PD patients and controls in variability of tap performance across modalities assessed. Among PD patients, variability of taps and the ability to keep a given rhythm were associated with UPDRS motor and finger tapping scores. After 12 months, laterality parameters were reduced but no other parameters changed significantly. This data suggests that digitomotography provides quantitative and objective measures capable to differentiate PD from non-PD in a small cohort, however, the value of the assessment to track PD progression has to be further evaluated in larger cohorts of patients.

  9. Presymptomatic and longitudinal neuroimaging in neurodegeneration--from snapshots to motion picture: a systematic review.

    Science.gov (United States)

    Schuster, Christina; Elamin, Marwa; Hardiman, Orla; Bede, Peter

    2015-10-01

    Recent quantitative neuroimaging studies have been successful in capturing phenotype and genotype-specific changes in dementia syndromes, amyotrophic lateral sclerosis, Parkinson's disease and other neurodegenerative conditions. However, the majority of imaging studies are cross-sectional, despite the obvious superiority of longitudinal study designs in characterising disease trajectories, response to therapy, progression rates and evaluating the presymptomatic phase of neurodegenerative conditions. The aim of this work is to perform a systematic review of longitudinal imaging initiatives in neurodegeneration focusing on methodology, optimal statistical models, follow-up intervals, attrition rates, primary study outcomes and presymptomatic studies. Longitudinal imaging studies were identified from 'PubMed' and reviewed from 1990 to 2014. The search terms 'longitudinal', 'MRI', 'presymptomatic' and 'imaging' were utilised in combination with one of the following degenerative conditions; Alzheimer's disease, amyotrophic lateral sclerosis/motor neuron disease, frontotemporal dementia, Huntington's disease, multiple sclerosis, Parkinson's disease, ataxia, HIV, alcohol abuse/dependence. A total of 423 longitudinal imaging papers and 103 genotype-based presymptomatic studies were identified and systematically reviewed. Imaging techniques, follow-up intervals and attrition rates showed significant variation depending on the primary diagnosis. Commonly used statistical models included analysis of annualised percentage change, mixed and random effect models, and non-linear cumulative models with acceleration-deceleration components. Although longitudinal imaging studies have the potential to provide crucial insights into the presymptomatic phase and natural trajectory of neurodegenerative processes a standardised design is required to enable meaningful data interpretation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under

  10. Relationship between white matter lesions and regional cerebral blood flow changes during longitudinal follow up in Alzheimer's disease.

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    Hanaoka, Takuya; Kimura, Noriyuki; Aso, Yasuhiro; Takemaru, Makoto; Kimura, Yuki; Ishibashi, Masato; Matsubara, Etsuro

    2016-07-01

    The aim of the present study was to evaluate the relationship between baseline white matter lesions (WML) and changes in regional cerebral blood flow during longitudinal follow up of patients with Alzheimer's disease (AD). A total of 38 patients with AD were included in the study (16 men, 22 women; mean age 77.8 years). All patients were evaluated using the Mini-Mental State Examination and brain perfusion single-photon emission computed tomography at baseline with an approximately 2-year follow up. The patients were divided into two subgroups according to the presence of WML on magnetic resonance imaging. Single-photon emission computed tomography data were analyzed using a voxel-by-voxel group analysis with Statistical Parametric Mapping 8 and region of interest analysis using FineSRT. Changes in Mini-Mental State Examination scores and regional cerebral blood flow were analyzed using the Wilcoxon signed-rank test. Mean Mini-Mental State Examination scores in AD patients with WML significantly decreased from 19.4 ± 4.8 to 15.5 ± 6.5 (P = 0.003). Statistical Parametric Mapping 8 and FineSRT analysis showed more severe and widespread regional cerebral blood flow reduction, mainly in the frontal and mesial temporal regions in AD patients with WML compared with those without WML. Baseline WML could predict a rapid progression of cognitive and brain functional impairment during longitudinal follow up in AD. Geriatr Gerontol Int 2016; 16: 836-842. © 2015 Japan Geriatrics Society.

  11. Striatal dopamine in Parkinson disease: A meta-analysis of imaging studies.

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    Kaasinen, Valtteri; Vahlberg, Tero

    2017-12-01

    A meta-analysis of 142 positron emission tomography and single photon emission computed tomography studies that have investigated striatal presynaptic dopamine function in Parkinson disease (PD) was performed. Subregional estimates of striatal dopamine metabolism are presented. The aromatic L-amino-acid decarboxylase (AADC) defect appears to be consistently smaller than the dopamine transporter and vesicular monoamine transporter 2 defects, suggesting upregulation of AADC function in PD. The correlation between disease severity and dopamine loss appears linear, but the majority of longitudinal studies point to a negative exponential progression pattern of dopamine loss in PD. Ann Neurol 2017;82:873-882. © 2017 American Neurological Association.

  12. An overview of longitudinal data analysis methods for neurological research.

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    Locascio, Joseph J; Atri, Alireza

    2011-01-01

    The purpose of this article is to provide a concise, broad and readily accessible overview of longitudinal data analysis methods, aimed to be a practical guide for clinical investigators in neurology. In general, we advise that older, traditional methods, including (1) simple regression of the dependent variable on a time measure, (2) analyzing a single summary subject level number that indexes changes for each subject and (3) a general linear model approach with a fixed-subject effect, should be reserved for quick, simple or preliminary analyses. We advocate the general use of mixed-random and fixed-effect regression models for analyses of most longitudinal clinical studies. Under restrictive situations or to provide validation, we recommend: (1) repeated-measure analysis of covariance (ANCOVA), (2) ANCOVA for two time points, (3) generalized estimating equations and (4) latent growth curve/structural equation models.

  13. An Overview of Longitudinal Data Analysis Methods for Neurological Research

    Directory of Open Access Journals (Sweden)

    Joseph J. Locascio

    2011-10-01

    Full Text Available The purpose of this article is to provide a concise, broad and readily accessible overview of longitudinal data analysis methods, aimed to be a practical guide for clinical investigators in neurology. In general, we advise that older, traditional methods, including (1 simple regression of the dependent variable on a time measure, (2 analyzing a single summary subject level number that indexes changes for each subject and (3 a general linear model approach with a fixed-subject effect, should be reserved for quick, simple or preliminary analyses. We advocate the general use of mixed-random and fixed-effect regression models for analyses of most longitudinal clinical studies. Under restrictive situations or to provide validation, we recommend: (1 repeated-measure analysis of covariance (ANCOVA, (2 ANCOVA for two time points, (3 generalized estimating equations and (4 latent growth curve/structural equation models.

  14. Longitudinal Assessment of Tau Pathology in Patients with Alzheimer's Disease Using [18F]THK-5117 Positron Emission Tomography.

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    Aiko Ishiki

    Full Text Available The formation of neurofibrillary tangles is believed to contribute to the neurodegeneration observed in Alzheimer's disease (AD. Postmortem studies have shown strong associations between the neurofibrillary pathology and both neuronal loss and the severity of cognitive impairment. However, the temporal changes in the neurofibrillary pathology and its association with the progression of the disease are not well understood. Tau positron emission tomography (PET imaging is expected to be useful for the longitudinal assessment of neurofibrillary pathology in the living brain. Here, we performed a longitudinal PET study using the tau-selective PET tracer [18F]THK-5117 in patients with AD and in healthy control subjects. Annual changes in [18F]THK-5117 binding were significantly elevated in the middle and inferior temporal gyri and in the fusiform gyrus of patients with AD. Compared to patients with mild AD, patients with moderate AD showed greater changes in the tau load that were more widely distributed across the cortical regions. Furthermore, a significant correlation was observed between the annual changes in cognitive decline and regional [18F]THK-5117 binding. These results suggest that the cognitive decline observed in patients with AD is attributable to the progression of neurofibrillary pathology. Longitudinal assessment of tau pathology will contribute to the assessment of disease progression and treatment efficacy.

  15. Longitudinal peripheral blood transcriptional analysis of a patient with severe Ebola virus disease.

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    Kash, John C; Walters, Kathie-Anne; Kindrachuk, Jason; Baxter, David; Scherler, Kelsey; Janosko, Krisztina B; Adams, Rick D; Herbert, Andrew S; James, Rebekah M; Stonier, Spencer W; Memoli, Matthew J; Dye, John M; Davey, Richard T; Chertow, Daniel S; Taubenberger, Jeffery K

    2017-04-12

    The 2013-2015 outbreak of Ebola virus disease in Guinea, Liberia, and Sierra Leone was unprecedented in the number of documented cases, but there have been few published reports on immune responses in clinical cases and their relationships with the course of illness and severity of Ebola virus disease. Symptoms of Ebola virus disease can include severe headache, myalgia, asthenia, fever, fatigue, diarrhea, vomiting, abdominal pain, and hemorrhage. Although experimental treatments are in development, there are no current U.S. Food and Drug Administration-approved vaccines or therapies. We report a detailed study of host gene expression as measured by microarray in daily peripheral blood samples collected from a patient with severe Ebola virus disease. This individual was provided with supportive care without experimental therapies at the National Institutes of Health Clinical Center from before onset of critical illness to recovery. Pearson analysis of daily gene expression signatures revealed marked gene expression changes in peripheral blood leukocytes that correlated with changes in serum and peripheral blood leukocytes, viral load, antibody responses, coagulopathy, multiple organ dysfunction, and then recovery. This study revealed marked shifts in immune and antiviral responses that preceded changes in medical condition, indicating that clearance of replicating Ebola virus from peripheral blood leukocytes is likely important for systemic viral clearance. Copyright © 2017, American Association for the Advancement of Science.

  16. The association between disease activity and NT-proBNP in 238 patients with rheumatoid arthritis: a 10-year longitudinal study

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    Provan, Sella A; Angel, Kristin; Ødegård, Sigrid; Mowinckel, Petter; Atar, Dan; Kvien, Tore K

    2008-01-01

    Introduction Disease activity in patients with rheumatoid arthritis (RA) is associated with increased cardiovascular morbidity and mortality, of which N-terminal pro-brain natriuretic peptide (NT-proBNP) is a predictor. Our objective was to examine the cross-sectional and longitudinal associations between markers of inflammation, measures of RA disease activity, medication used in the treatment of RA, and NT-proBNP levels (dependent variable). Methods Two hundred thirty-eight patients with RA of less than 4 years in duration were followed longitudinally with three comprehensive assessments of clinical and radiographic data over a 10-year period. Serum samples were frozen and later batch-analyzed for NT-proBNP levels and other biomarkers. Bivariate, multivariate, and repeated analyses were performed. Results C-reactive protein (CRP) levels at baseline were cross-sectionally associated with NT-proBNP levels after adjustment for age and gender (r2 adjusted = 0.23; P < 0.05). At the 10-year follow-up, risk factors for cardiovascular disease were recorded. Duration of RA and CRP levels were independently associated with NT-proBNP in the final model that was adjusted for gender, age, and creatinine levels (r2 adjusted = 0.38; P < 0.001). In the longitudinal analyses, which adjusted for age, gender, and time of follow-up, we found that repeated measures of CRP predicted NT-proBNP levels (P < 0.001). Conclusion CRP levels are linearly associated with levels of NT-proBNP in cross-sectional and longitudinal analyses of patients with RA. The independent associations of NT-proBNP levels and markers of disease activity with clinical cardiovascular endpoints need to be further investigated. PMID:18573197

  17. CHI: A contemporaneous health index for degenerative disease monitoring using longitudinal measurements.

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    Huang, Yijun; Meng, Qiang; Evans, Heather; Lober, William; Cheng, Yu; Qian, Xiaoning; Liu, Ji; Huang, Shuai

    2017-09-01

    In this paper, we develop a novel formulation for contemporaneous patient risk monitoring by exploiting the emerging data-rich environment in many healthcare applications, where an abundance of longitudinal data that reflect the degeneration of the health condition can be continuously collected. Our objective, and the developed formulation, is fundamentally different from many existing risk score models for different healthcare applications, which mostly focus on predicting the likelihood of a certain outcome at a pre-specified time. Rather, our formulation translates multivariate longitudinal measurements into a contemporaneous health index (CHI) that captures patient condition changes over the course of progression. Another significant feature of our formulation is that, CHI can be estimated with or without label information, different from other risk score models strictly based on supervised learning. To develop this formulation, we focus on the degenerative disease conditions, for which we could utilize the monotonic progression characteristic (either towards disease or recovery) to learn CHI. Such a domain knowledge leads us to a novel learning formulation, and on top of that, we further generalize this formulation with a capacity to incorporate label information if available. We further develop algorithms to mitigate the challenges associated with the nonsmooth convex optimization problem by first identifying its dual reformulation as a constrained smooth optimization problem, and then, using the block coordinate descent algorithm to iteratively solve the optimization with a derived efficient projection at each iteration. Extensive numerical studies are performed on both synthetic datasets and real-world applications on Alzheimer's disease and Surgical Site Infection, which demonstrate the utility and efficacy of the proposed method on degenerative conditions that include a wide range of applications. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Preliminary Analysis Using Multi-atlas Labeling Algorithms for Tracing Longitudinal Change

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    Eun Young eKim

    2015-07-01

    Full Text Available Multicenter longitudinal neuroimaging has great potential to provide efficient and consistent biomarkers for research of neurodegenerative diseases and aging. In rare disease studies it is of primary importance to have a reliable tool that performs consistently for data from many different collection sites to increase study power. A multi-atlas labeling algorithm is a powerful brain image segmentation approach that is becoming increasingly popular in image processing. The present study examined the performance of multi-atlas labeling tools for subcortical identification using two types of in-vivo image database: Traveling Human Phantom and PREDICT-HD. We compared the accuracy (Dice Similarity Coefficient; DSC and intraclass correlation; ICC, multicenter reliability (Coefficient of Variance; CV, and longitudinal reliability (volume trajectory smoothness and Akaike Information Criterion; AIC of three automated segmentation approaches: two multi-atlas labeling tools, MABMIS and MALF, and a machine-learning-based tool, BRAINSCut. In general, MALF showed the best performance (higher DSC, ICC, lower CV, AIC, and smoother trajectory with a couple of exceptions. First, the results of accumben, where BRAINSCut showed higher reliability, were still premature to discuss their reliability levels since their validity is still in doubt (DSC<0.7, ICC < 0.7. For caudate, BRAINSCut presented slightly better accuracy while MALF showed significantly smoother longitudinal trajectory. We discuss advantages and limitations of these performance variations and conclude that improved segmentation quality can be achieved using multi-atlas labeling methods. While multi-atlas labeling methods are likely to help improve overall segmentation quality, caution has to be taken when one chooses an approach, as our results suggest that segmentation outcome can vary depending on research interest.

  19. The Weather and Ménière's Disease: A Longitudinal Analysis in the UK.

    Science.gov (United States)

    Schmidt, Wiebke; Sarran, Christophe; Ronan, Natalie; Barrett, George; Whinney, David J; Fleming, Lora E; Osborne, Nicholas J; Tyrrell, Jessica

    2017-02-01

    Changes in the weather influence symptom severity in Ménière's disease (MD). MD is an unpredictable condition that significantly impacts on quality of life. It is suggested that fluctuations in the weather, especially atmospheric pressure may influence the symptoms of MD. However, to date, limited research has investigated the impact of the weather on MD. In a longitudinal study, a mobile phone application collected data from 397 individuals (277 females and 120 males with an average age of 50 yr) from the UK reporting consultant-diagnosed MD. Daily symptoms (vertigo, aural fullness, tinnitus, hearing loss, and attack prevalence) and GPS locations were collected; these data were linked with Met Office weather data (including atmospheric pressure, humidity, temperature, visibility, and wind speed). Symptom severity and attack prevalence were reduced on days when atmospheric pressure was higher. When atmospheric pressure was below 1,013 hectopascals, the risk of an attack was 1.30 (95% confidence interval: 1.10, 1.54); when the humidity was above 90%, the risk of an attack was 1.26 (95% confidence interval 1.06, 1.49). This study provides the strongest evidence to date that changes in atmospheric pressure and humidity are associated with symptom exacerbation in MD. Improving our understanding of the role of weather and other environmental triggers in Ménière's may reduce the uncertainty associated with living with this condition, significantly contributing to improved quality of life.

  20. Sample size determination for mediation analysis of longitudinal data.

    Science.gov (United States)

    Pan, Haitao; Liu, Suyu; Miao, Danmin; Yuan, Ying

    2018-03-27

    Sample size planning for longitudinal data is crucial when designing mediation studies because sufficient statistical power is not only required in grant applications and peer-reviewed publications, but is essential to reliable research results. However, sample size determination is not straightforward for mediation analysis of longitudinal design. To facilitate planning the sample size for longitudinal mediation studies with a multilevel mediation model, this article provides the sample size required to achieve 80% power by simulations under various sizes of the mediation effect, within-subject correlations and numbers of repeated measures. The sample size calculation is based on three commonly used mediation tests: Sobel's method, distribution of product method and the bootstrap method. Among the three methods of testing the mediation effects, Sobel's method required the largest sample size to achieve 80% power. Bootstrapping and the distribution of the product method performed similarly and were more powerful than Sobel's method, as reflected by the relatively smaller sample sizes. For all three methods, the sample size required to achieve 80% power depended on the value of the ICC (i.e., within-subject correlation). A larger value of ICC typically required a larger sample size to achieve 80% power. Simulation results also illustrated the advantage of the longitudinal study design. The sample size tables for most encountered scenarios in practice have also been published for convenient use. Extensive simulations study showed that the distribution of the product method and bootstrapping method have superior performance to the Sobel's method, but the product method was recommended to use in practice in terms of less computation time load compared to the bootstrapping method. A R package has been developed for the product method of sample size determination in mediation longitudinal study design.

  1. Self-Concept and Academic Achievement: A Meta-Analysis of Longitudinal Relations

    Science.gov (United States)

    Huang, Chiungjung

    2011-01-01

    The relation between self-concept and academic achievement was examined in 39 independent and longitudinal samples through the integration of meta-analysis and path analysis procedures. For relations with more than 3 independent samples, the mean observed correlations ranged from 0.20 to 0.27 between prior self-concept and subsequent academic…

  2. Sensitivity Analysis of Mixed Models for Incomplete Longitudinal Data

    Science.gov (United States)

    Xu, Shu; Blozis, Shelley A.

    2011-01-01

    Mixed models are used for the analysis of data measured over time to study population-level change and individual differences in change characteristics. Linear and nonlinear functions may be used to describe a longitudinal response, individuals need not be observed at the same time points, and missing data, assumed to be missing at random (MAR),…

  3. Application of pattern mixture models to address missing data in longitudinal data analysis using SPSS.

    Science.gov (United States)

    Son, Heesook; Friedmann, Erika; Thomas, Sue A

    2012-01-01

    Longitudinal studies are used in nursing research to examine changes over time in health indicators. Traditional approaches to longitudinal analysis of means, such as analysis of variance with repeated measures, are limited to analyzing complete cases. This limitation can lead to biased results due to withdrawal or data omission bias or to imputation of missing data, which can lead to bias toward the null if data are not missing completely at random. Pattern mixture models are useful to evaluate the informativeness of missing data and to adjust linear mixed model (LMM) analyses if missing data are informative. The aim of this study was to provide an example of statistical procedures for applying a pattern mixture model to evaluate the informativeness of missing data and conduct analyses of data with informative missingness in longitudinal studies using SPSS. The data set from the Patients' and Families' Psychological Response to Home Automated External Defibrillator Trial was used as an example to examine informativeness of missing data with pattern mixture models and to use a missing data pattern in analysis of longitudinal data. Prevention of withdrawal bias, omitted data bias, and bias toward the null in longitudinal LMMs requires the assessment of the informativeness of the occurrence of missing data. Missing data patterns can be incorporated as fixed effects into LMMs to evaluate the contribution of the presence of informative missingness to and control for the effects of missingness on outcomes. Pattern mixture models are a useful method to address the presence and effect of informative missingness in longitudinal studies.

  4. Baseline prevalence and longitudinal evolution of non-motor symptoms in early Parkinson's disease: the PPMI cohort.

    Science.gov (United States)

    Simuni, Tanya; Caspell-Garcia, Chelsea; Coffey, Christopher S; Weintraub, Daniel; Mollenhauer, Brit; Lasch, Shirley; Tanner, Caroline M; Jennings, Danna; Kieburtz, Karl; Chahine, Lana M; Marek, Kenneth

    2018-01-01

    To examine the baseline prevalence and longitudinal evolution in non-motor symptoms (NMS) in a prospective cohort of, at baseline, patients with de novo Parkinson's disease (PD) compared with healthy controls (HC). Parkinson's Progression Markers Initiative (PPMI) is a longitudinal, ongoing, controlled study of de novo PD participants and HC. NMS were rated using the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part I score and other validated NMS scales at baseline and after 2 years. Biological variables included cerebrospinal fluid (CSF) markers and dopamine transporter imaging. 423 PD subjects and 196 HC were enrolled and followed for 2 years. MDS-UPDRS Part I total mean (SD) scores increased from baseline 5.6 (4.1) to 7.7 (5.0) at year 2 in PD subjects (pbaseline NMS score was associated with female sex (p=0.008), higher baseline MDS-UPDRS Part II scores (pbaseline. There was no association with the dose or class of dopaminergic therapy. This study of NMS in early PD identified clinical and biological variables associated with both baseline burden and predictors of progression. The association of a greater longitudinal increase in NMS with lower baseline Aβ1-42 level is an important finding that will have to be replicated in other cohorts. ClinicalTrials.gov identifier: NCT01141023. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. The lower airway microbiota in early cystic fibrosis lung disease: a longitudinal analysis.

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    Frayman, Katherine B; Armstrong, David S; Carzino, Rosemary; Ferkol, Thomas W; Grimwood, Keith; Storch, Gregory A; Teo, Shu Mei; Wylie, Kristine M; Ranganathan, Sarath C

    2017-12-01

    In infants and young children with cystic fibrosis, lower airway infection and inflammation are associated with adverse respiratory outcomes. However, the role of lower airway microbiota in the pathogenesis of early cystic fibrosis lung disease remains uncertain. To assess the development of the lower airway microbiota over time in infants and young children with cystic fibrosis, and to explore its association with airway inflammation and pulmonary function at age 6 years. Serial, semi-annual bronchoscopies and bronchoalveolar lavage (BAL) procedures were performed in infants newly diagnosed with cystic fibrosis following newborn screening. Quantitative microbiological cultures and inflammatory marker (interleukin 8 and neutrophil elastase) measurements were undertaken contemporaneously. 16S ribosomal RNA gene sequencing was conducted on stored BAL samples. Spirometry results recorded at 6 years of age were extracted from medical records. Ninety-five BAL samples provided 16S ribosomal RNA gene data. These were collected from 48 subjects aged 1.2-78.3 months, including longitudinal samples from 27 subjects and 13 before age 6 months. The lower airway microbiota varied, but diversity decreased with advancing age. Detection of recognised cystic fibrosis bacterial pathogens was associated with reduced microbial diversity and greater lower airway inflammation. There was no association between the lower airway microbiota and pulmonary function at age 6 years. In infants with cystic fibrosis, the lower airway microbiota is dynamic. Dominance of the microbiota by recognised cystic fibrosis bacterial pathogens is associated with increased lower airway inflammation, however early microbial diversity is not associated with pulmonary function at 6 years of age. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  6. Incentivised chronic disease management and the inverse equity hypothesis: findings from a longitudinal analysis of Scottish primary care practice-level data.

    Science.gov (United States)

    Lowrie, Richard; McConnachie, Alex; Williamson, Andrea E; Kontopantelis, Evangelos; Forrest, Marie; Lannigan, Norman; Mercer, Stewart W; Mair, Frances S

    2017-04-11

    The inverse equity hypothesis asserts that new health policies initially widen inequality, then attenuate inequalities over time. Since 2004, the UK's pay-for-performance scheme for chronic disease management (CDM) in primary care general practices (the Quality and Outcomes Framework) has permitted practices to except (exclude) patients from attending annual CDM reviews, without financial penalty. Informed dissent (ID) is one component of exception rates, applied to patients who have not attended due to refusal or non-response to invitations. 'Population achievement' describes the proportion receiving care, in relation to those eligible to receive it, including excepted patients. Examination of exception reporting (including ID) and population achievement enables the equity impact of the UK pay-for-performance contract to be assessed. We conducted a longitudinal analysis of practice-level rates and of predictors of ID, overall exceptions and population achievement for CDM to examine whether the inverse equity hypothesis holds true. We carried out a retrospective, longitudinal study using routine primary care data, analysed by multilevel logistic regression. Data were extracted from 793 practices (83% of Scottish general practices) serving 4.4 million patients across Scotland from 2010/2011 to 2012/2013, for 29 CDM indicators covering 11 incentivised diseases. This provided 68,991 observations, representing a total of 15 million opportunities for exception reporting. Across all observations, the median overall exception reporting rate was 7.0% (7.04% in 2010-2011; 7.02% in 2011-2012 and 6.92% in 2012-2013). The median non-attendance rate due to ID was 0.9% (0.76% in 2010-2011; 0.88% in 2011-2012 and 0.96% in 2012-2013). Median population achievement was 83.5% (83.51% in 2010-2011; 83.41% in 2011-2012 and 83.63% in 2012-2013). The odds of ID reporting in 2012/2013 were 16.0% greater than in 2010/2011 (p rural practices reported lower levels of non-attendance due to

  7. Combined Circumferential and Longitudinal Left Ventricular Systolic Dysfunction in Patients with Rheumatoid Arthritis without Overt Cardiac Disease.

    Science.gov (United States)

    Cioffi, Giovanni; Viapiana, Ombretta; Ognibeni, Federica; Dalbeni, Andrea; Gatti, Davide; Mazzone, Carmine; Faganello, Giorgio; Di Lenarda, Andrea; Adami, Silvano; Rossini, Maurizio

    2016-07-01

    Patients with rheumatoid arthritis have an increased risk for cardiovascular disease. Because of accelerated atherosclerosis and changes in left ventricular (LV) geometry, circumferential and longitudinal (C&L) LV systolic dysfunction (LVSD) may be impaired in these patients despite preserved LV ejection fraction. The aim of this study was to determine the prevalence of and factors associated with combined C&L LVSD in patients with rheumatoid arthritis. One hundred ninety-eight outpatients with rheumatoid arthritis without overt cardiac disease were prospectively analyzed from January through June 2014 and compared with 198 matched control subjects. C&L systolic function was evaluated by stress-corrected midwall shortening (sc-MS) and tissue Doppler mitral annular peak systolic velocity (S'). Combined C&L LVSD was defined if sc-MS was cite either of them in the other one and, afterward, we just did not think about this point anymore. Of note, the idea to combine in the analysis longitudinal function came therefore well after the starting process of revision of the paper E and was, in some way inspired by a reviewer's comment. That is why we did not put both findings in the same paper. We think that our explanations provide the broad audience of your journal a perspective of transparency and our respect for the readers' right to understand how the work described in the paper J relates to other work by our research group. Giovanni Cioffi On behalf of all co-authors Ombretta Viapiana, Federica Ognibeni, Andrea Dalbeni, Davide Gatti, Carmine Mazzone, Giorgio Faganello, Andrea Di Lenarda, Silvano Adami, and Maurizio Rossini. Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

  8. Analysis of Longitudinal Waves in Rod-Type Piezoelectric Phononic Crystals

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    Longfei Li

    2016-04-01

    Full Text Available Phononic crystals can be used to control elastic waves due to their frequency bands. This paper analyzes the passive and active control as well as the dispersion properties of longitudinal waves in rod-type piezoelectric phononic crystals over large frequency ranges. Based on the Love rod theory for modeling the longitudinal wave motions in the constituent rods and the method of reverberation-ray matrix (MRRM for deriving the member transfer matrices of the constituent rods, a modified transfer matrix method (MTMM is proposed for the analysis of dispersion curves by combining with the Floquet–Bloch principle and for the calculation of transmission spectra. Numerical examples are provided to validate the proposed MTMM for analyzing the band structures in both low and high frequency ranges. The passive control of longitudinal-wave band structures is studied by discussing the influences of the electrode’s thickness, the Poisson’s effect and the elastic rod inserts in the unit cell. The influences of electrical boundaries (including electric-open, applied electric capacity, electric-short and applied feedback control conditions on the band structures are investigated to illustrate the active control scheme. From the calculated comprehensive frequency spectra over a large frequency range, the dispersion properties of the characteristic longitudinal waves in rod-type piezoelectric phononic crystals are summarized.

  9. Factors promoting health-related quality of life in people with rheumatic diseases: a 12 month longitudinal study

    Science.gov (United States)

    2011-01-01

    Background Rheumatic diseases have a significant adverse impact on the individual from physical, mental and social aspects, resulting in a low health-related quality of life (HRQL). There is a lack of longitudinal studies on HRQL in people with rheumatic diseases that focus on factors promoting HRQL instead of risk factors. The aim of this study was to investigate the associations between suggested health promoting factors at baseline and outcome in HRQL at a 12 month follow-up in people with rheumatic diseases. Methods A longitudinal cohort study was conducted in 185 individuals with rheumatic diseases with questionnaires one week and 12 months after rehabilitation in a Swedish rheumatology clinic. HRQL was assessed by SF-36 together with suggested health factors. The associations between SF-36 subscales and the health factors were analysed by multivariable logistic regressions. Results Factors predicting better outcome in HRQL in one or several SF-36 subscales were being younger or middle-aged, feeling painless, having good sleep structure, feeling rested after sleep, performing low effort of exercise more than twice per week, having strong sense of coherence (SOC), emotional support and practical assistance, higher educational level and work capacity. The most important factors were having strong SOC, feeling rested after sleep, having work capacity, being younger or middle-aged, and having good sleep structure. Conclusions This study identified several factors that promoted a good outcome in HRQL to people with rheumatic diseases. These health factors could be important to address in clinical work with rheumatic diseases in order to optimise treatment strategies. PMID:21599884

  10. Multilevel predictors of adolescent physical activity: a longitudinal analysis

    Directory of Open Access Journals (Sweden)

    Hearst Mary O

    2012-02-01

    Full Text Available Abstract Background To examine how factors from a social ecologic model predict physical activity (PA among adolescents using a longitudinal analysis. Methods Participants in this longitudinal study were adolescents (ages 10-16 at baseline and one parent enrolled in the Transdisciplinary Research on Energetics and Cancer-Identifying Determinants of Eating and Activity (TREC-IDEA and the Etiology of Childhood Obesity (ECHO. Both studies were designed to assess a socio-ecologic model of adolescent obesity risk. PA was collected using ActiGraph activity monitors at two time points 24 months apart. Other measures included objective height and weight, adolescent and parent questionnaires on multilevel psychological, behavioral and social determinants of PA, and a home PA equipment inventory. Analysis was conducted using SAS, including descriptive characteristics, bivariate and stepped multivariate mixed models, using baseline adjustment. Models were stratified by gender. Results There were 578 adolescents with complete data. Results suggest few statistically significant longitudinal associations with physical activity measured as minutes of MVPA or total counts from accelerometers. For boys, greater self-efficacy (B = 0.75, p = 0.01 and baseline MVPA (B = 0.55, p p = 0.01 and barriers (B = -0.32, p = 0.05 significantly predicted MVPA at follow-up in the full model. The full multilevel model explained 30% of the variance in PA among boys and 24% among girls. Conclusions PA change in adolescents is a complex issue that is not easily understood. Our findings suggest early PA habits are the most important predictor of PA levels in adolescence. Intervention may be necessary prior to middle school to maintain PA through adolescence.

  11. Longitudinal Diffusion Tensor Imaging-Based Assessment of Tract Alterations: An Application to Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Dobri Baldaranov

    2017-12-01

    Full Text Available Objective: The potential of magnetic resonance imaging (MRI as a technical biomarker for cerebral microstructural alterations in neurodegenerative diseases is under investigation. In this study, a framework for the longitudinal analysis of diffusion tensor imaging (DTI-based mapping was applied to the assessment of predefined white matter tracts in amyotrophic lateral sclerosis (ALS, as an example for a rapid progressive neurodegenerative disease.Methods: DTI was performed every 3 months in six patients with ALS (mean (M = 7.7; range 3 to 15 scans and in six controls (M = 3; range 2–5 scans with the identical scanning protocol, resulting in a total of 65 longitudinal DTI datasets. Fractional anisotropy (FA, mean diffusivity (MD, axonal diffusivity (AD, radial diffusivity (RD, and the ratio AD/RD were studied to analyze alterations within the corticospinal tract (CST which is a prominently affected tract structure in ALS and the tract correlating with Braak’s neuropathological stage 1. A correlation analysis was performed between progression rates based on DTI metrics and the revised ALS functional rating scale (ALS-FRS-R.Results: Patients with ALS showed an FA and AD/RD decline along the CST, while DTI metrics of controls did not change in longitudinal DTI scans. The FA and AD/RD decrease progression correlated significantly with ALS-FRS-R decrease progression.Conclusion: On the basis of the longitudinal assessment, DTI-based metrics can be considered as a possible noninvasive follow-up marker for disease progression in neurodegeneration. This finding was demonstrated here for ALS as a fast progressing neurodegenerative disease.

  12. Longitudinal Diffusion Tensor Imaging-Based Assessment of Tract Alterations: An Application to Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Baldaranov, Dobri; Khomenko, Andrei; Kobor, Ines; Bogdahn, Ulrich; Gorges, Martin; Kassubek, Jan; Müller, Hans-Peter

    2017-01-01

    Objective : The potential of magnetic resonance imaging (MRI) as a technical biomarker for cerebral microstructural alterations in neurodegenerative diseases is under investigation. In this study, a framework for the longitudinal analysis of diffusion tensor imaging (DTI)-based mapping was applied to the assessment of predefined white matter tracts in amyotrophic lateral sclerosis (ALS), as an example for a rapid progressive neurodegenerative disease. Methods : DTI was performed every 3 months in six patients with ALS (mean (M) = 7.7; range 3 to 15 scans) and in six controls ( M = 3; range 2-5 scans) with the identical scanning protocol, resulting in a total of 65 longitudinal DTI datasets. Fractional anisotropy (FA), mean diffusivity (MD), axonal diffusivity (AD), radial diffusivity (RD), and the ratio AD/RD were studied to analyze alterations within the corticospinal tract (CST) which is a prominently affected tract structure in ALS and the tract correlating with Braak's neuropathological stage 1. A correlation analysis was performed between progression rates based on DTI metrics and the revised ALS functional rating scale (ALS-FRS-R). Results : Patients with ALS showed an FA and AD/RD decline along the CST, while DTI metrics of controls did not change in longitudinal DTI scans. The FA and AD/RD decrease progression correlated significantly with ALS-FRS-R decrease progression. Conclusion : On the basis of the longitudinal assessment, DTI-based metrics can be considered as a possible noninvasive follow-up marker for disease progression in neurodegeneration. This finding was demonstrated here for ALS as a fast progressing neurodegenerative disease.

  13. Analysis on Longitudinal Dose according to Change of Field Width

    International Nuclear Information System (INIS)

    Jung, Won Seok; Shin, Ryung Mi; Oh, Byung Cheon; Jo, Jun Young; Kim, Gi Chul; Choi, Tae Gu; Back, Jong Geal

    2011-01-01

    To analyze the accuracy of tumor volume dose following field width change, to check the difference of dose change by using self-made moving car, and to evaluate practical delivery tumor dose when tomotherapy in the treatment of organ influenced by breathing. By using self-made moving car, the difference of longitudinal movement (0.0 cm, 1.0 cm, 1.5 cm, 2.0 cm) was applied and compared calculated dose with measured dose according to change of field width (1.05 cm, 2.50 cm, 5.02 cm) and apprehended margin of error. Then done comparative analysis in degree of photosensitivity of DQA film measured by using Gafchromic EBT film. Dose profile and Gamma histogram were used to measure degree of photosensitivity of DQA film. When field width were 1.05 cm, 2.50 cm, 5.02 cm, margin of error of dose delivery coefficient was -2.00%, -0.39%, -2.55%. In dose profile of Gafchromic EBT film's analysis, the movement of moving car had greater motion toward longitudinal direction and as field width was narrower, big error increased considerably at high dose part compared to calculated dose. The more field width was narrowed, gamma index had a large considerable influence of moving at gamma histogram. We could check the difference of longitudinal dose of moving organ. In order to small field width and minimize organ moving due to breathing, it is thought to be needed to develop breathing control unit and fixation tool.

  14. Regional Cerebral Disease Progression in Friedreich's Ataxia: A Longitudinal Diffusion Tensor Imaging Study.

    Science.gov (United States)

    Mascalchi, Mario; Toschi, Nicola; Giannelli, Marco; Ginestroni, Andrea; Della Nave, Riccardo; Tessa, Carlo; Piacentini, Silvia; Dotti, Maria Teresa; Aiello, Marco; Nicolai, Emanuele; Soricelli, Andrea; Salvi, Fabrizio; Diciotti, Stefano

    2016-01-01

    Imaging biomarkers of disease progression are desirable in inherited ataxias. MRI has demonstrated brain damage in Friedreich ataxia (FRDA) in form of regional atrophy of the medulla, peridentate cerebellar white matter (WM) and superior cerebellar peduncles (visible in T1-weighted images) and of change of microstructural characteristics of WM tracts of the brainstem, cerebellar peduncles, cerebellum, and supratentorial structures (visible through diffusion-weighted imaging). We explored the potential of brain MR morphometry and diffusion tensor imaging (DTI) to track the progression of neurodegeneration in FRDA. Eight patients (5F, 3M; age 13.4-41.2 years) and 8 healthy controls (2F, 6M; age 26.2-48.3 years) underwent 2 MRI examinations (mean 3.9 and 4.1 years apart, respectively) on the same 1.5T scanner. The protocol included 3D T1-weighted images and axial diffusion-weighted images (b-value 1,000 s/mm(2)) for calculating maps of fractional anisotropy, mean, axial and radial diffusivity, and mode of anisotropy. Tensor-based morphometry was used to investigate regional volume changes and tract-based spatial statistics was used to investigate microstructural changes in WM tracts. Longitudinal analyses showed no differences in regional volume changes but a significant difference in axial diffusivity changes in cerebral and corpus callosum WM of patients as compared to controls (mean longitudinal rate of change for axial diffusivity: -.02 × 10(-3) mm(2)/s/year in patients vs. .01 × 10(-3) mm(2)/s/year in controls). No correlation with number of triplets, disease duration, and worsening of the clinical deficit was observed. DTI can track brain microstructural changes in FRDA and can be considered a potential biomarker of disease progression. Copyright © 2015 by the American Society of Neuroimaging.

  15. Thyrotropin and free thyroxine levels and coronary artery disease: cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

    Science.gov (United States)

    de Miranda, E J F Peixoto; Bittencourt, M S; Staniak, H L; Sharovsky, R; Pereira, A C; Foppa, M; Santos, I S; Lotufo, P A; Benseñor, I M

    2018-03-15

    Data on the association between subclinical thyroid dysfunction and coronary artery disease (CAD) is scarce. We aimed to analyze the association between thyroid function and CAD using baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). We included subjects with normal thyroid function (0.4-4.0 mIU/L, and normal free thyroxine, FT4, or 0.8 to 1.9 ng/dL), subclinical hypothyroidism (SCHypo; TSH>4.0 mIU/L and normal FT4), and subclinical hyperthyroidism (SCHyper; TSH4, and segment severity score (SSS) >4 of coronary arteries as the dependent variables, and quintiles of TSH and FT4 as the independent variables, adjusted for demographical data and cardiovascular risk factors. We included 767 subjects, median age 58 years (IQR=55-63), 378 (49.3%) women, 697 euthyroid (90.9%), 57 (7.4%) with SCHypo, and 13 (1.7%) with SCHyper. No association between TSH and FT4 quintiles and CAD prevalence was noted. Similarly, no association between TSH levels and the extent or severity of CAD, represented by SIS>4 and SSS>4 were seen. Restricting analysis to euthyroid subjects did not alter the results. TSH levels were not significantly associated with the presence, extent, or severity of CAD in a middle-aged healthy population.

  16. Longitudinal changes in awareness over 36 months in patients with mild Alzheimer's disease

    DEFF Research Database (Denmark)

    Vogel, Asmus; Waldorff, Frans Boch; Waldemar, Gunhild

    2015-01-01

    MMSE, Neuropsychiatric Inventory (NPI-Q), and Cornell scale for Depression in Dementia also were applied. Results: At 12 months, 26% had lower awareness rating as compared to baseline and at 36 months lower awareness ratings were found in 39%. At both visits, 16% had higher awareness rating as compared......Background: Longitudinal changes in awareness in dementia have been studied with short follow-up time and mostly in small patient groups (including patients with moderate dementia). We investigated awareness in patients with mild Alzheimer’s disease (AD) over 36 months and studied if a decline...

  17. Scientific literature on infectious diseases affecting livestock animals, longitudinal worldwide bibliometric analysis.

    Science.gov (United States)

    Ducrot, Christian; Gautret, Marjolaine; Pineau, Thierry; Jestin, André

    2016-03-14

    The objectives of this bibliometric analysis of the scientific literature were to describe the research subjects and the international collaborations in the field of research on infectious diseases in livestock animals including fishes and honeybees. It was based on articles published worldwide from 2006 through 2013. The source of data was the Web of Science, Core collection(®) and only papers fully written in English were considered. Queries were built that combined 130 descriptors related to animal species and 1213 descriptors related to diseases and pathogens. To refine and assess the accuracy of the extracted database, supplementary filters were applied to discard non-specific terms and neighbouring topics, and numerous tests were carried out on samples. For pathogens, annotation was done using a thematic terminology established to link each disease with its corresponding pathogen, which was in turn classified according to its family. A total of 62,754 articles were published in this field during this 8-year period. The average annual growth rate of the number of papers was 5%. This represents the reference data to which we compared the average annual growth rate of articles produced in each of the sub-categories that we defined. Thirty-seven percent of the papers were dedicated to ruminant diseases. Poultry, pigs and fishes were covered by respectively 21, 13 and 14% of the total. Thirty-seven percent of papers concerned bacteria, 33% viruses, 19% parasites, 2% prions, the remaining being multi-pathogens. Research on virology, especially on pigs and poultry, is increasing faster than the average. There also is increasing interest in monogastric species, fish and bees. The average annual growth rate for Asia was 10%, which is high compared to 3% for Europe and 2% for the Americas, indicating that Asia is currently playing a leading role in this field. There is a well established network of international collaborations. For 75% of the papers, the co

  18. Bayesian Nonparametric Longitudinal Data Analysis.

    Science.gov (United States)

    Quintana, Fernando A; Johnson, Wesley O; Waetjen, Elaine; Gold, Ellen

    2016-01-01

    Practical Bayesian nonparametric methods have been developed across a wide variety of contexts. Here, we develop a novel statistical model that generalizes standard mixed models for longitudinal data that include flexible mean functions as well as combined compound symmetry (CS) and autoregressive (AR) covariance structures. AR structure is often specified through the use of a Gaussian process (GP) with covariance functions that allow longitudinal data to be more correlated if they are observed closer in time than if they are observed farther apart. We allow for AR structure by considering a broader class of models that incorporates a Dirichlet Process Mixture (DPM) over the covariance parameters of the GP. We are able to take advantage of modern Bayesian statistical methods in making full predictive inferences and about characteristics of longitudinal profiles and their differences across covariate combinations. We also take advantage of the generality of our model, which provides for estimation of a variety of covariance structures. We observe that models that fail to incorporate CS or AR structure can result in very poor estimation of a covariance or correlation matrix. In our illustration using hormone data observed on women through the menopausal transition, biology dictates the use of a generalized family of sigmoid functions as a model for time trends across subpopulation categories.

  19. What do medical students learn when they follow patients from hospital to community? A longitudinal qualitative study

    Directory of Open Access Journals (Sweden)

    Rukshini Puvanendran

    2012-07-01

    Full Text Available Context: Although longitudinal community-based care of patients provides opportunities for teaching patient centredness and chronic disease management, there is a paucity of literature assessing learning outcomes of these clerkships. This study examines learning outcomes among students participating in longitudinal community based follow-up of patients discharged from the hospital. Methods: The authors conducted a thematic analysis of 253 student narratives written by 44 third-year medical students reflecting on their longitudinal interactions with patients with chronic medical illnesses. The narratives were written over three periods: after acute hospital encounter, after a home visit and at the end of the 10-month follow-up. Analysis involved coding of theme content and counting of aggregate themes. Results: The most frequent theme was ‘chronic disease management’ (25% followed by ‘patient-centred care’ (22%, ‘health care systems’ (20.9%, ‘biomedical issues’ (19.7%, ‘community services’ (9.5% and ‘student's role conflict’ (2.3%. There was a shift in the relative frequency of the different themes, as students moved from hospital to community with their patients. Biomedical (44.3% and health systems (18.2% were the dominant themes following the acute hospitalization encounter. Chronic disease management (35.1% and patient centredness (31.8% were the dominant themes after the 10-month longitudinal follow-up. Conclusion: Longitudinal community-based interaction with patients resulted in learning about chronic disease management, patient centredness and health care systems over time. Students shifted from learning biomedical knowledge during the acute hospitalization, to focus on better understanding of long-term care and patient centredness, at the end of the module.

  20. The Weather and Ménière’s Disease: A Longitudinal Analysis in the UK

    Science.gov (United States)

    Schmidt, Wiebke; Sarran, Christophe; Ronan, Natalie; Barrett, George; Whinney, David J.; Fleming, Lora E.; Osborne, Nicholas J.; Tyrrell, Jessica

    2016-01-01

    Hypothesis Changes in the weather influence symptom severity in Ménière’s disease (MD). Background MD is an unpredictable condition that significantly impacts on quality of life. It is suggested that fluctuations in the weather, especially atmospheric pressure may influence the symptoms of MD. However, to date, limited research has investigated the impact of the weather on MD. Methods In a longitudinal study, a mobile phone application collected data from 397 individuals (277 females and 120 males with an average age of 50 yr) from the UK reporting consultant-diagnosed MD. Daily symptoms (vertigo, aural fullness, tinnitus, hearing loss, and attack prevalence) and GPS locations were collected; these data were linked with Met Office weather data (including atmospheric pressure, humidity, temperature, visibility, and wind speed). Results Symptom severity and attack prevalence were reduced on days when atmospheric pressure was higher. When atmospheric pressure was below 1,013 hectopascals, the risk of an attack was 1.30 (95% confidence interval: 1.10, 1.54); when the humidity was above 90%, the risk of an attack was 1.26 (95% confidence interval 1.06, 1.49). Conclusion This study provides the strongest evidence to date that changes in atmospheric pressure and humidity are associated with symptom exacerbation in MD. Improving our understanding of the role of weather and other environmental triggers in Ménière’s may reduce the uncertainty associated with living with this condition, significantly contributing to improved quality of life. PMID:27861300

  1. A Service Member's Self in Transition : A Longitudinal Case Study Analysis

    NARCIS (Netherlands)

    Grimell, Jan

    2017-01-01

    Adopting a narrative approach with a dialogical framework, a longitudinal case study is presented that describes a service member's self in transition from active service into the civilian population. An analysis and interpretation of the case study leads to the hypothesis that if a dominant

  2. Automated longitudinal intra-subject analysis (ALISA) for diffusion MRI tractography

    DEFF Research Database (Denmark)

    Aarnink, Saskia H; Vos, Sjoerd B; Leemans, Alexander

    2014-01-01

    the inter-subject and intra-subject automation in this situation are intended for subjects without gross pathology. In this work, we propose such an automated longitudinal intra-subject analysis (dubbed ALISA) approach, and assessed whether ALISA could preserve the same level of reliability as obtained....... The major disadvantage of manual FT segmentations, unfortunately, is that placing regions-of-interest for tract selection can be very labor-intensive and time-consuming. Although there are several methods that can identify specific WM fiber bundles in an automated way, manual FT segmentations across...... multiple subjects performed by a trained rater with neuroanatomical expertise are generally assumed to be more accurate. However, for longitudinal DTI analyses it may still be beneficial to automate the FT segmentation across multiple time points, but then for each individual subject separately. Both...

  3. Diet assessment in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil: Development of a food frequency questionnaire

    Directory of Open Access Journals (Sweden)

    Maria del Carmen Bisi Molina

    2013-04-01

    Full Text Available OBJECTIVE: The objective of this article is to present the development of the Food Frequency Questionaire used in the Longitudinal Study of Adult Health-Brazil and analyze how diet exposes individuals to cardiovascular diseases and type 2 diabetes Mellitus. METHODS: The Longitudinal Study of Adult Health-Brazil dietary assessment instrument is based on a previously validated Food Frequency Questionaire and the final list of items took into consideration a study done in the six Longitudinal Study of Adult Health-Brazil investigation centers. RESULTS: New foods/preparations were included in the Food Frequency Questionaire with their respective portions, totaling 114 items. The perspectives of dietary analysis and cardiovascular diseases and diabetes are presented in Longitudinal Study of Adult Health-Brazil. CONCLUSION: A new instrument was developed to cover the regional particularities of the study population.

  4. Evaluation of ventricular dysfunction using semi-automatic longitudinal strain analysis of four-chamber cine MR imaging.

    Science.gov (United States)

    Kawakubo, Masateru; Nagao, Michinobu; Kumazawa, Seiji; Yamasaki, Yuzo; Chishaki, Akiko S; Nakamura, Yasuhiko; Honda, Hiroshi; Morishita, Junji

    2016-02-01

    The aim of this study was to evaluate ventricular dysfunction using the longitudinal strain analysis in 4-chamber (4CH) cine MR imaging, and to investigate the agreement between the semi-automatic and manual measurements in the analysis. Fifty-two consecutive patients with ischemic, or non-ischemic cardiomyopathy and repaired tetralogy of Fallot who underwent cardiac MR examination incorporating cine MR imaging were retrospectively enrolled. The LV and RV longitudinal strain values were obtained by semi-automatically and manually. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff of the minimum longitudinal strain value for the detection of patients with cardiac dysfunction. The correlations between manual and semi-automatic measurements for LV and RV walls were analyzed by Pearson coefficient analysis. ROC analysis demonstrated the optimal cut-off of the minimum longitudinal strain values (εL_min) for diagnoses the LV and RV dysfunction at a high accuracy (LV εL_min = -7.8 %: area under the curve, 0.89; sensitivity, 83 %; specificity, 91 %, RV εL_min = -15.7 %: area under the curve, 0.82; sensitivity, 92 %; specificity, 68 %). Excellent correlations between manual and semi-automatic measurements for LV and RV free wall were observed (LV, r = 0.97, p cine MR imaging can evaluate LV and RV dysfunction with simply and easy measurements. The strain analysis could have extensive application in cardiac imaging for various clinical cases.

  5. MR image analysis: Longitudinal cardiac motion influences left ventricular measurements

    International Nuclear Information System (INIS)

    Berkovic, Patrick; Hemmink, Maarten; Parizel, Paul M.; Vrints, Christiaan J.; Paelinck, Bernard P.

    2010-01-01

    Background: Software for the analysis of left ventricular (LV) volumes and mass using border detection in short-axis images only, is hampered by through-plane cardiac motion. Therefore we aimed to evaluate software that involves longitudinal cardiac motion. Methods: Twenty-three consecutive patients underwent 1.5-Tesla cine magnetic resonance (MR) imaging of the entire heart in the long-axis and short-axis orientation with breath-hold steady-state free precession imaging. Offline analysis was performed using software that uses short-axis images (Medis MASS) and software that includes two-chamber and four-chamber images to involve longitudinal LV expansion and shortening (CAAS-MRV). Intraobserver and interobserver reproducibility was assessed by using Bland-Altman analysis. Results: Compared with MASS software, CAAS-MRV resulted in significantly smaller end-diastolic (156 ± 48 ml versus 167 ± 52 ml, p = 0.001) and end-systolic LV volumes (79 ± 48 ml versus 94 ± 52 ml, p < 0.001). In addition, CAAS-MRV resulted in higher LV ejection fraction (52 ± 14% versus 46 ± 13%, p < 0.001) and calculated LV mass (154 ± 52 g versus 142 ± 52 g, p = 0.004). Intraobserver and interobserver limits of agreement were similar for both methods. Conclusion: MR analysis of LV volumes and mass involving long-axis LV motion is a highly reproducible method, resulting in smaller LV volumes, higher ejection fraction and calculated LV mass.

  6. Statistical analysis of longitudinal quality of life data with missing measurements

    NARCIS (Netherlands)

    Zwinderman, A. H.

    1992-01-01

    The statistical analysis of longitudinal quality of life data in the presence of missing data is discussed. In cancer trials missing data are generated due to the fact that patients die, drop out, or are censored. These missing data are problematic in the monitoring of the quality of life during the

  7. Association analysis of whole genome sequencing data accounting for longitudinal and family designs.

    Science.gov (United States)

    Hu, Yijuan; Hui, Qin; Sun, Yan V

    2014-01-01

    Using the whole genome sequencing data and the simulated longitudinal phenotypes for 849 pedigree-based individuals from Genetic Analysis Workshop 18, we investigated various approaches to detecting the association of rare and common variants with blood pressure traits. We compared three strategies for longitudinal data: (a) using the baseline measurement only, (b) using the average from multiple visits, and (c) using all individual measurements. We also compared the power of using all of the pedigree-based data and the unrelated subset. The analyses were performed without knowledge of the underlying simulating model.

  8. Friendship Quality and School Achievement: A Longitudinal Analysis during Primary School

    Science.gov (United States)

    Zucchetti, Giulia; Candela, Filippo; Sacconi, Beatrice; Rabaglietti, Emanuela

    2015-01-01

    This study examined the longitudinal relationship between friendship quality (positive and negative) and school achievement among 228 school-age children (51% girls, M = 8.09, SD = 0.41). A three-wave cross-lagged analysis was used to determine the direction of influence between these domains across school years. Findings revealed that: (a) school…

  9. An approximate marginal logistic distribution for the analysis of longitudinal ordinal data

    NARCIS (Netherlands)

    Nooraee, Nazanin; Abegaz, Fentaw; Ormel, Johan; Wit, Ernst; van den Heuvel, Edwin R

    Subject-specific and marginal models have been developed for the analysis of longitudinal ordinal data. Subject-specific models often lack a population-average interpretation of the model parameters due to the conditional formulation of random intercepts and slopes. Marginal models frequently lack

  10. Bifurcation analysis and stability design for aircraft longitudinal motion with high angle of attack

    Directory of Open Access Journals (Sweden)

    Xin Qi

    2015-02-01

    Full Text Available Bifurcation analysis and stability design for aircraft longitudinal motion are investigated when the nonlinearity in flight dynamics takes place severely at high angle of attack regime. To predict the special nonlinear flight phenomena, bifurcation theory and continuation method are employed to systematically analyze the nonlinear motions. With the refinement of the flight dynamics for F-8 Crusader longitudinal motion, a framework is derived to identify the stationary bifurcation and dynamic bifurcation for high-dimensional system. Case study shows that the F-8 longitudinal motion undergoes saddle node bifurcation, Hopf bifurcation, Zero-Hopf bifurcation and branch point bifurcation under certain conditions. Moreover, the Hopf bifurcation renders series of multiple frequency pitch oscillation phenomena, which deteriorate the flight control stability severely. To relieve the adverse effects of these phenomena, a stabilization control based on gain scheduling and polynomial fitting for F-8 longitudinal motion is presented to enlarge the flight envelope. Simulation results validate the effectiveness of the proposed scheme.

  11. Longitudinal anterior-to-posterior shift of collateral channels in patients with moyamoya disease: an implication for its hemorrhagic onset.

    Science.gov (United States)

    Yamamoto, Shusuke; Hori, Satoshi; Kashiwazaki, Daina; Akioka, Naoki; Kuwayama, Naoya; Kuroda, Satoshi

    2018-03-23

    OBJECTIVE This study aimed to assess longitudinal changes in the collateral channels originating from the lenticulostriate artery (LSA), posterior communicating artery (PCoA), and anterior and posterior choroidal arteries (AChA and PChA, respectively) during disease progression and/or aging. The impact of collateral channels on onset type was also examined. METHODS This study included 71 involved hemispheres in 41 patients with moyamoya disease. The disease was categorized into 6 stages according to Suzuki's angiographic staging system. The degree of development of each moyamoya vessel was categorized into 3 grades. RESULTS The LSA started to dilate in stage 2, showed the most prominent development in stage 3, and decreased in more advanced stages (p PCoA started to dilate in stage 3 and showed the most prominent development in stage 4 (p = 0.03). The PChA started to dilate in stage 3 and showed the most prominent development in stages 4 to 5 (p PCoA (p = 0.02, R = 0.28) and PChA (p PCoA, AChA, and PChA more distinctly developed in hemispheres with intracerebral or intraventricular hemorrhage than in hemispheres with ischemic stroke or transient ischemic attack (p < 0.001, p = 0.03, and p = 0.03, respectively). CONCLUSIONS This study suggests that the collateral channels through moyamoya vessels longitudinally shift from the anterior to posterior component during disease progression and aging, which may be closely related to the onset of hemorrhagic stroke in adult moyamoya disease.

  12. The Association of Baseline and Longitudinal Change in Endothelial Microparticle Count with Mortality in Chronic Kidney Disease.

    Science.gov (United States)

    Green, Darren; Skeoch, Sarah; Alexander, M Yvonne; Kalra, Philip A; Parker, Ben

    2017-01-01

    Chronic kidney disease (CKD) is associated with a unique milieu of vascular pathology, and effective biomarkers of active vascular damage are lacking. A candidate biomarker is the quantification of circulating endothelial microparticles (EMPs). This study observed baseline and longitudinal EMP change (δEMP) and established the association of these with all-cause mortality and cardiovascular events in CKD. An observational study in adults with CKD (estimated glomerular filtration rate [eGFR] change was not. This may reflect disease-specific EMP behaviour and the limitation of EMP as a generalised biomarker in CKD. © 2017 S. Karger AG, Basel.

  13. Cardiovascular events in patients with atherothrombotic disease: a population-based longitudinal study in Taiwan.

    Directory of Open Access Journals (Sweden)

    Wen-Hsien Lee

    Full Text Available BACKGROUND: Atherothrombotic diseases including cerebrovascular disease (CVD, coronary artery disease (CAD, and peripheral arterial disease (PAD, contribute to the major causes of death in the world. Although several studies showed the association between polyvascular disease and poor cardiovascular (CV outcomes in Asian population, there was no large-scale study to validate this relationship in this population. METHODS AND RESULTS: This retrospective cohort study included patients with a diagnosis of CVD, CAD, or PAD from the database contained in the Taiwan National Health Insurance Bureau during 2001-2004. A total of 19954 patients were enrolled in this study. The atherothrombotic disease score was defined according to the number of atherothrombotic disease. The study endpoints included acute coronary syndrome (ACS, all strokes, vascular procedures, in hospital mortality, and so on. The event rate of ischemic stroke (18.2% was higher than that of acute myocardial infarction (5.7% in our patients (P = 0.0006. In the multivariate Cox regression analyses, the adjusted hazard ratios (HRs of each increment of atherothrombotic disease score in predicting ACS, all strokes, vascular procedures, and in hospital mortality were 1.41, 1.66, 1.30, and 1.14, respectively (P≦0.0169. CONCLUSIONS: This large population-based longitudinal study in patients with atherothrombotic disease demonstrated the risk of subsequent ischemic stroke was higher than that of subsequent AMI. In addition, the subsequent adverse CV events including ACS, all stroke, vascular procedures, and in hospital mortality were progressively increased as the increase of atherothrombotic disease score.

  14. Longitudinal decline of driving safety in Parkinson disease.

    Science.gov (United States)

    Uc, Ergun Y; Rizzo, Matthew; O'Shea, Amy M J; Anderson, Steven W; Dawson, Jeffrey D

    2017-11-07

    To longitudinally assess and predict on-road driving safety in Parkinson disease (PD). Drivers with PD (n = 67) and healthy controls (n = 110) drove a standardized route in an instrumented vehicle and were invited to return 2 years later. A professional driving expert reviewed drive data and videos to score safety errors. At baseline, drivers with PD performed worse on visual, cognitive, and motor tests, and committed more road safety errors compared to controls (median PD 38.0 vs controls 30.5; p < 0.001). A smaller proportion of drivers with PD returned for repeat testing (42.8% vs 62.7%; p < 0.01). At baseline, returnees with PD made fewer errors than nonreturnees with PD (median 34.5 vs 40.0; p < 0.05) and performed similar to control returnees (median 33). Baseline global cognitive performance of returnees with PD was better than that of nonreturnees with PD, but worse than for control returnees ( p < 0.05). After 2 years, returnees with PD showed greater cognitive decline and larger increase in error counts than control returnees (median increase PD 13.5 vs controls 3.0; p < 0.001). Driving error count increase in the returnees with PD was predicted by greater error count and worse visual acuity at baseline, and by greater interval worsening of global cognition, Unified Parkinson's Disease Rating Scale activities of daily living score, executive functions, visual processing speed, and attention. Despite drop out of the more impaired drivers within the PD cohort, returning drivers with PD, who drove like controls without PD at baseline, showed many more driving safety errors than controls after 2 years. Driving decline in PD was predicted by baseline driving performance and deterioration of cognitive, visual, and functional abnormalities on follow-up. © 2017 American Academy of Neurology.

  15. Association of non-alcoholic fatty liver disease with chronic kidney disease: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Giovanni Musso

    2014-07-01

    Full Text Available BACKGROUND: Chronic kidney disease (CKD is a frequent, under-recognized condition and a risk factor for renal failure and cardiovascular disease. Increasing evidence connects non-alcoholic fatty liver disease (NAFLD to CKD. We conducted a meta-analysis to determine whether the presence and severity of NAFLD are associated with the presence and severity of CKD. METHODS AND FINDINGS: English and non-English articles from international online databases from 1980 through January 31, 2014 were searched. Observational studies assessing NAFLD by histology, imaging, or biochemistry and defining CKD as either estimated glomerular filtration rate (eGFR <60 ml/min/1.73 m2 or proteinuria were included. Two reviewers extracted studies independently and in duplicate. Individual participant data (IPD were solicited from all selected studies. Studies providing IPD were combined with studies providing only aggregate data with the two-stage method. Main outcomes were pooled using random-effects models. Sensitivity and subgroup analyses were used to explore sources of heterogeneity and the effect of potential confounders. The influences of age, whole-body/abdominal obesity, homeostasis model of insulin resistance (HOMA-IR, and duration of follow-up on effect estimates were assessed by meta-regression. Thirty-three studies (63,902 participants, 16 population-based and 17 hospital-based, 20 cross-sectional, and 13 longitudinal were included. For 20 studies (61% of included studies, 11 cross-sectional and nine longitudinal, 29,282 participants, we obtained IPD. NAFLD was associated with an increased risk of prevalent (odds ratio [OR] 2.12, 95% CI 1.69-2.66 and incident (hazard ratio [HR] 1.79, 95% CI 1.65-1.95 CKD. Non-alcoholic steatohepatitis (NASH was associated with a higher prevalence (OR 2.53, 95% CI 1.58-4.05 and incidence (HR 2.12, 95% CI 1.42-3.17 of CKD than simple steatosis. Advanced fibrosis was associated with a higher prevalence (OR 5.20, 95% CI 3

  16. Longitudinal grey and white matter changes in frontotemporal dementia and Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Lars Frings

    Full Text Available Behavioural variant frontotemporal dementia (bvFTD and Alzheimer's disease (AD dementia are characterised by progressive brain atrophy. Longitudinal MRI volumetry may help to characterise ongoing structural degeneration and support the differential diagnosis of dementia subtypes. Automated, observer-independent atlas-based MRI volumetry was applied to analyse 102 MRI data sets from 15 bvFTD, 14 AD, and 10 healthy elderly control participants with consecutive scans over at least 12 months. Anatomically defined targets were chosen a priori as brain structures of interest. Groups were compared regarding volumes at clinic presentation and annual change rates. Baseline volumes, especially of grey matter compartments, were significantly reduced in bvFTD and AD patients. Grey matter volumes of the caudate and the gyrus rectus were significantly smaller in bvFTD than AD. The bvFTD group could be separated from AD on the basis of caudate volume with high accuracy (79% cases correct. Annual volume decline was markedly larger in bvFTD and AD than controls, predominantly in white matter of temporal structures. Decline in grey matter volume of the lateral orbitofrontal gyrus separated bvFTD from AD and controls. Automated longitudinal MRI volumetry discriminates bvFTD from AD. In particular, greater reduction of orbitofrontal grey matter and temporal white matter structures after 12 months is indicative of bvFTD.

  17. Loading Conditions and Longitudinal Strength

    DEFF Research Database (Denmark)

    Sørensen, Herman

    1995-01-01

    Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength.......Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength....

  18. Longitudinal cognitive decline in subcortical ischemic vascular disease--the LADIS Study

    DEFF Research Database (Denmark)

    Jokinen, Hanna; Kalska, Hely; Ylikoski, Raija

    2009-01-01

    BACKGROUND: Cross-sectional studies have indicated that subcortical ischemic vascular disease (SIVD), as defined according to imaging criteria, is associated with a specific clinical and cognitive profile. Much less is known about the long-term cognitive consequences of SIVD. The aim of the study...... was to investigate the longitudinal cognitive performance and incident dementia in subjects with and without SIVD in a sample of older adults with white matter lesions. METHODS: In the Leukoaraiosis and Disability (LADIS) study, 639 participants were examined with annual clinical and neuropsychological evaluations...... for 3 years. The subjects meeting the MRI criteria of SIVD at baseline were compared to the other subjects of the sample with linear mixed models. RESULTS: The overall level of cognitive performance over the follow-up period was inferior in multiple cognitive domains in SIVD subjects as compared...

  19. Profiles of Intrinsic and Extrinsic Motivations in Elementary School: A Longitudinal Analysis

    Science.gov (United States)

    Corpus, Jennifer Henderlong; Wormington, Stephanie V.

    2014-01-01

    The authors used a person-centered, longitudinal approach to identify and evaluate naturally occurring combinations of intrinsic and extrinsic motivations among 490 third- through fifth-grade students. Cluster analysis revealed 3 groups, characterized by high levels of both motivations ("high quantity"): high intrinsic motivation but low…

  20. Signs over time: Statistical and visual analysis of a longitudinal signed network

    NARCIS (Netherlands)

    de Nooy, W.

    2008-01-01

    This paper presents the design and results of a statistical and visual analysis of a dynamic signed network. In addition to prevalent approaches to longitudinal networks, which analyze series of cross-sectional data, this paper focuses on network data measured in continuous time in order to explain

  1. Identification of associations between genotypes and longitudinal phenotypes via temporally-constrained group sparse canonical correlation analysis.

    Science.gov (United States)

    Hao, Xiaoke; Li, Chanxiu; Yan, Jingwen; Yao, Xiaohui; Risacher, Shannon L; Saykin, Andrew J; Shen, Li; Zhang, Daoqiang

    2017-07-15

    Neuroimaging genetics identifies the relationships between genetic variants (i.e., the single nucleotide polymorphisms) and brain imaging data to reveal the associations from genotypes to phenotypes. So far, most existing machine-learning approaches are widely used to detect the effective associations between genetic variants and brain imaging data at one time-point. However, those associations are based on static phenotypes and ignore the temporal dynamics of the phenotypical changes. The phenotypes across multiple time-points may exhibit temporal patterns that can be used to facilitate the understanding of the degenerative process. In this article, we propose a novel temporally constrained group sparse canonical correlation analysis (TGSCCA) framework to identify genetic associations with longitudinal phenotypic markers. The proposed TGSCCA method is able to capture the temporal changes in brain from longitudinal phenotypes by incorporating the fused penalty, which requires that the differences between two consecutive canonical weight vectors from adjacent time-points should be small. A new efficient optimization algorithm is designed to solve the objective function. Furthermore, we demonstrate the effectiveness of our algorithm on both synthetic and real data (i.e., the Alzheimer's Disease Neuroimaging Initiative cohort, including progressive mild cognitive impairment, stable MCI and Normal Control participants). In comparison with conventional SCCA, our proposed method can achieve strong associations and discover phenotypic biomarkers across multiple time-points to guide disease-progressive interpretation. The Matlab code is available at https://sourceforge.net/projects/ibrain-cn/files/ . dqzhang@nuaa.edu.cn or shenli@iu.edu. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  2. A Longitudinal Study of Neurocognition in Dementia with Lewy Bodies Compared to Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Monica H. Breitve

    2018-03-01

    Full Text Available IntroductionThere are relatively few longitudinal studies on the differences in cognitive decline between Alzheimer’s disease (AD and dementia with Lewy bodies (DLB, and the majority of existing studies have suboptimal designs.AimWe investigated the differences in cognitive decline in AD compared to DLB over 4 years and cognitive domain predictors of progression.MethodsIn a longitudinal study, 266 patients with first-time diagnosis of mild dementia were included and followed annually. The patients were tested annually with neuropsychological tests and screening instruments [MMSE (Mini-Mental Status Examination, Clinical Dementia Rating (CDR, the second edition of California Verbal Learning Test (CVLT-II, Trail Making Test A & B (TMT A & B, Stroop test, Controlled Oral Word Associations Test (COWAT animal naming, Boston Naming Test, Visual Object and Space Perception Battery (VOSP Cubes and Silhouettes]. Longitudinal analyses were performed with linear mixed effects (LME models and Cox regression. Both specific neuropsychological tests and cognitive domains were analyzed.ResultsThis study sample comprised 119 AD and 67 DLB patients. In TMT A, the DLB patients had a faster decline over 4 years than patients with AD (p = 0.013. No other longitudinal differences in specific neuropsychological tests were found. Higher executive domain scores at baseline were associated with a longer time to reach severe dementia (CDR = 3 or death for the total sample (p = 0.032. High or low visuospatial function at baseline was not found to be associated with cognitive decline (MMSE or progression of dementia severity (CDR over time.ConclusionOver 4 years, patients with DLB had a faster decline in TMT A than patients with AD, but this should be interpreted cautiously. Beyond this, there was little support for faster decline in DLB patients neuropsychologically than in AD patients.

  3. Patterns of longitudinal neural activity linked to different cognitive profiles in Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Atsuko Nagano-Saito

    2016-11-01

    Full Text Available Mild cognitive impairment in Parkinson’s disease (PD has been linked with functional brain changes. Previously, using functional magnetic resonance imaging (fMRI, we reported reduced cortico-striatal activity in patients with PD who also had mild cognitive impairment (MCI versus those who did not (non-MCI. We followed up these patients to investigate the longitudinal effect on the neural activity. Twenty-four non-demented patients with Parkinson’s disease (non-MCI: 12, MCI; 12 were included in the study. Each participant underwent two fMRIs while performing the Wisconsin Card Sorting Task 20 months apart. The non-MCI patients recruited the usual cognitive corticostriatal loop at the first and second sessions (Time 1 and Time 2, respectively. However, decreased activity was observed in the cerebellum and occipital area and increased activity was observed in the medial prefrontal cortex and parietal lobe during planning set-shift at Time 2. Increased activity in the precuneus was also demonstrated while executing set-shifts at Time 2. The MCI patients revealed more activity in the frontal, parietal and occipital lobes during planning set-shifts, and in the parietal and occipital lobes, precuneus, and cerebellum, during executing set-shift at Time 2. Analysis regrouping of both groups of PD patients revealed that hippocampal and thalamic activity at Time 1 was associated with less cognitive decline over time. Our results reveal that functional alteration along the time-points differed between the non-MCI and MCI patients. They also underline the importance of preserving thalamic and hippocampal function with respect to cognitive decline over time.

  4. Changes in cognitive control in pre-manifest Huntington's disease examined using pre-saccadic EEG potentials - a longitudinal study.

    Science.gov (United States)

    Ness, Vanessa; Bestgen, Anne-Kathrin; Saft, Carsten; Beste, Christian

    2014-01-01

    It is well-known that Huntington's disease (HD) affects saccadic processing. However, saccadic dysfunctions in HD may be seen as a result of dysfunctional processes occurring at the oculomotor level prior to the execution of saccades, i.e., at a pre-saccadic level. Virtually nothing is known about possible changes in pre-saccadic processes in HD. This study examines pre-saccadic processing in pre-manifest HD gene mutation carriers (pre-HDs) by using clinically available EEG measures. Error rates, pre-saccadic EEG potentials and saccade onset EEG potentials were measured in 14 pre-HDs and case-matched controls performing prosaccades and antisaccades in a longitudinal study over a 15-month period. The results show that pre-saccadic potentials were changed in pre-HDs, relative to controls and also revealed changes across the 15-month longitudinal period. In particular, pre-saccadic ERP in pre-HDs were characterized by lower amplitudes and longer latencies, which revealed longitudinal changes. These changes were observed for anti-saccades, but not for pro-saccades. Overt saccadic trajectories (potentials) were not different to those in controls, showing that pre-saccadic processes are sensitive to subtle changes in fronto-striatal networks in pre-HDs. Deficits in pre-saccadic processes prior the execution of an erroneous anti-saccade can be seen as an effect of dysfunctional cognitive control in HD. This may underlie saccadic abnormalities and hence a major phenotype of HD. Pre-saccadic EEG potentials preceding erroneous anti-saccades are sensitive to pre-manifest disease progression in HD.

  5. Alteration of putaminal fractional anisotropy in Parkinson's disease. A longitudinal diffusion kurtosis imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Surova, Yulia; Widner, Haakan [Lund University, Department of Clinical Sciences, Lund (Sweden); Skaane University Hospital, Department of Neurology, Lund (Sweden); Nilsson, Markus [Skaane University Hospital, Center for Medical Imaging and Physiology, Lund (Sweden); Lampinen, Bjoern [Lund University, Lund University Bioimaging Center, Lund (Sweden); Laett, Jimmy [Lund University, Department of Medical Radiation Physics, Lund (Sweden); Hall, Sara; Hansson, Oskar [Lund University, Department of Clinical Sciences, Malmoe (Sweden); Skaane University Hospital, Memory Clinic, Lund (Sweden); Westen, Danielle van [Lund University, Department of Clinical Sciences, Lund (Sweden); Lund University, Lund University Bioimaging Center, Lund (Sweden)

    2018-03-15

    In Parkinson's disease (PD), pathological microstructural changes occur that may be detected using diffusion magnetic resonance imaging (dMRI). However, there are few longitudinal studies that explore the effect of disease progression on diffusion indices. We prospectively included 76 patients with PD and 38 healthy controls (HC), all of whom underwent diffusion kurtosis imaging (DKI) as part of the prospective Swedish BioFINDER study at baseline and 2 years later. Annualized rates of change in DKI parameters, including fractional anisotropy (FA), mean diffusivity (MD), and mean kurtosis (MK), were estimated in the gray matter (GM) by placing regions of interest (ROIs) in the basal ganglia and the thalamus, and in the white matter (WM) by tract-based spatial statistics (TBSS) analysis. When adjusting for potential confounding factors (age, gender, baseline-follow-up interval, and software upgrade of MRI scanner), only a decrease in FA in the putamen of PD patients (β = - 0.248, P <.01) over 2 years was significantly different from the changes observed in HC over the same time period. This 2-year decrease in FA in the putamen in PD correlated with higher l-dopa equivalent dose at baseline (Spearman's rho =.399, P <.0001). The study indicates that in PD microstructural changes in the putamen occur selectively over a 2-year period and can be detected with DKI. (orig.)

  6. The risk of falling into poverty after developing heart disease: a survival analysis.

    Science.gov (United States)

    Callander, Emily J; Schofield, Deborah J

    2016-07-15

    Those with a low income are known to have a higher risk of developing heart disease. However, the inverse relationship - falling into income poverty after developing heart disease has not been explored with longitudinal data. This paper aims to determine if those with heart disease have an elevated risk of falling into poverty. Survival analysis was conducted using the longitudinal Household Income and Labour Dynamics in Australia survey, between the years 2007 and 2012. The study focused on the Australian population aged 21 years and over in 2007 who were not already in poverty and did not already have heart disease, who were followed from 2007 to 2012. Cox regression models adjusting for age, sex and time-varying co-variates (marital status, home ownership and remoteness of area of residence) were constructed to assess the risk of falling into poverty. For those aged 20 who developed heart disease, the hazard ratio for falling into income poverty was 9.24 (95 % CI: 8.97-9.51) and for falling into multidimensional poverty the hazard ratio was 14.21 (95 % CI: 13.76-14.68); for those aged 40 the hazard ratio for falling into income poverty was 3.45 (95 % CI: 3.39-3.51) and for multidimensional poverty, 5.20 (95 % CI: 5.11-5.29); and for those aged 60 the hazard ratio for falling into income poverty was 1.29 (95 % CI: 1.28-1.30) and for multidimensional poverty, 1.52 (95 % CI: 1.51-1.54), relative those who never developed heart disease. The risk for both income and multidimensional poverty decreases with age up to the age of 70, over which, those who developed heart disease had a reduced risk of poverty. For those under the age of 70, developing heart disease is associated with an increased risk of falling into both income poverty and multidimensional poverty.

  7. Stability and Change in Work Values: A Meta-Analysis of Longitudinal Studies

    Science.gov (United States)

    Jin, Jing; Rounds, James

    2012-01-01

    A meta-analysis of longitudinal studies was conducted to investigate stability and change in work values across the life span. Both rank-order stability and mean-level change were investigated using an integrative classification for intrinsic, extrinsic, social and status work values (Ross, Schwartz, & Surkis, 1999). Results of rank-order…

  8. Serum Uric Acid and Progression of Kidney Disease: A Longitudinal Analysis and Mini-Review.

    Directory of Open Access Journals (Sweden)

    Ching-Wei Tsai

    Full Text Available Increasing evidence supports the association between hyperuricemia and incident chronic kidney disease (CKD; however, there are conflicting data regarding the role of hyperuricemia in the progression of CKD. This study retrospectively assessed the longitudinal association between uric acid (UA level and CKD progression in a Chinese population lived in Taiwan.Patients with physician diagnosis of hyperuricemia or receiving urate-lowering therapy between 2003 and 2005 were identified in the electronic medical records (EMR of a tertiary medical center and were followed up until December 31, 2011. Patients were divided into four UA categories at the cut-off 6, 8, and 10 mg/dL. CKD progression was estimated by the change of estimated glomerular filtration rate (eGFR in the linear mixed models. Kidney failure was defined as an eGFR less than 15 mL/min/1.73 m2 or requiring renal replacement therapy.A total of 739 patients were analyzed. In the full-adjusted model, patients with a baseline UA level ≥6 mg/dL had greater decline in eGFR ((β = -9.6, 95% CI -16.1, -3.1, comparing to those with a UA level less than 6 mg/dL. When stratifying patients into four UA categories, all three hyperuricemia categories (UA6-8, 8-10, ≥10 mg/dL associated with a greater decline in eGFR over the follow-up period with an increasing dose-response, comparing to the lowest UA category. The risk of progression to renal failure increased 7% (hazard ratio 1.07, 95% CI 1.00, 1.14 for each 1mg/dL increase in baseline UA level. The influences of hyperuricemia on eGFR decline and the risk of kidney failure were more prominent in patients without proteinuria than those with proteinuria.Our study showed a higher uric acid level is associated with a significant rapid decline in eGFR and a higher risk of kidney failure, particularly in patients without proteinuria. Our findings suggest hyperuricemia is a potential modifiable factor of CKD progression.

  9. A Longitudinal Study of Transitions Between Informal and Formal Care in Alzheimer Disease Using Multistate Models in the European ICTUS Cohort.

    NARCIS (Netherlands)

    Coley, N.; Gallini, A.; Gares, V.; Gardette, V.; Andrieu, S.; Olde Rikkert, M.G.M.; et al.,

    2015-01-01

    BACKGROUND: We aimed to describe longitudinal patterns of care in community-dwelling European patients with Alzheimer disease (AD), and determine patient-, caregiver-, and country-related predictors of transitions across different care levels. METHODS: Two-year follow-up data from ICTUS cohort (1375

  10. Analysis of baseline, average, and longitudinally measured blood pressure data using linear mixed models.

    Science.gov (United States)

    Hossain, Ahmed; Beyene, Joseph

    2014-01-01

    This article compares baseline, average, and longitudinal data analysis methods for identifying genetic variants in genome-wide association study using the Genetic Analysis Workshop 18 data. We apply methods that include (a) linear mixed models with baseline measures, (b) random intercept linear mixed models with mean measures outcome, and (c) random intercept linear mixed models with longitudinal measurements. In the linear mixed models, covariates are included as fixed effects, whereas relatedness among individuals is incorporated as the variance-covariance structure of the random effect for the individuals. The overall strategy of applying linear mixed models decorrelate the data is based on Aulchenko et al.'s GRAMMAR. By analyzing systolic and diastolic blood pressure, which are used separately as outcomes, we compare the 3 methods in identifying a known genetic variant that is associated with blood pressure from chromosome 3 and simulated phenotype data. We also analyze the real phenotype data to illustrate the methods. We conclude that the linear mixed model with longitudinal measurements of diastolic blood pressure is the most accurate at identifying the known single-nucleotide polymorphism among the methods, but linear mixed models with baseline measures perform best with systolic blood pressure as the outcome.

  11. Sibling analysis of adolescent intelligence and chronic diseases in older adulthood.

    Science.gov (United States)

    Jokela, Markus; Batty, G David; Deary, Ian J; Silventoinen, Karri; Kivimäki, Mika

    2011-07-01

    We examined whether associations of adolescent intelligence with chronic diseases in adulthood are explained by socioeconomic factors, health behaviors, or common sources of variance in intelligence and chronic disease risk. A prospective cohort study (Wisconsin Longitudinal Study) of high school graduates and their siblings with intelligence assessed in adolescence and chronic diseases reported in adulthood (n = 10,168; mean age 53.9 and n = 9051; mean age 64.8 in two follow-ups). After adjustment for age and sex, greater intelligence was associated with lower risk of heart disease (odds ratio per 1 SD advantage in intelligence 0.93; 95% confidence interval 0.87-0.99), circulation problems (0.85; 0.79-0.92), stroke (0.80; 0.70-0.91), and diabetes (0.88; 0.81-0.95). Participants' risk of stroke and circulation problems also was predicted by their sibling's intelligence, suggesting potential common causes for intelligence and cerebrovascular diseases. Sibling analysis provided no support for shared family environment in explaining associations between intelligence and disease outcomes because between-families and within-siblings regression models were not different. Adjusting for common risk factors had little impact on these associations. In contrast, adjusting for adult socioeconomic status attenuated the associations by 25%-100% (66% on average). Multiple mechanisms may link intelligence with occurrence of chronic diseases of major public health importance. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. An Overview of Longitudinal Data Analysis Methods for Neurological Research

    OpenAIRE

    Locascio, Joseph J.; Atri, Alireza

    2011-01-01

    The purpose of this article is to provide a concise, broad and readily accessible overview of longitudinal data analysis methods, aimed to be a practical guide for clinical investigators in neurology. In general, we advise that older, traditional methods, including (1) simple regression of the dependent variable on a time measure, (2) analyzing a single summary subject level number that indexes changes for each subject and (3) a general linear model approach with a fixed-subject effect, shoul...

  13. Longitudinal analysis of progression in glaucoma using spectral-domain optical coherence tomography.

    Science.gov (United States)

    Wessel, Julia M; Horn, Folkert K; Tornow, Ralf P; Schmid, Matthias; Mardin, Christian Y; Kruse, Friedrich E; Juenemann, Anselm G; Laemmer, Robert

    2013-05-01

    To compare the longitudinal loss of RNFL thickness measurements by SD-OCT in healthy individuals and glaucoma patients with or without progression concerning optic disc morphology. A total of 62 eyes, comprising 38 glaucomatous eyes with open angle glaucoma and 24 healthy controls, were included in the study (Erlangen Glaucoma Registry, NTC00494923). All patients were investigated annually over a period of 3 years by Spectralis SD-OCT measuring peripapillary RNFL thickness. By masked comparative analysis of photographs, the eyes were classified into nonprogressive and progressive glaucoma cases. Longitudinal loss of RNFL thickness was compared with morphological changes of optic disc morphology. Mixed model analysis of annual OCT scans revealed an estimated annual decrease of the RNFL thickness by 2.12 μm in glaucoma eyes with progression, whereas glaucoma eyes without progression in optic disc morphology lost 1.18 μm per year in RNFL thickness (P = 0.002). The rate of change in healthy eyes was 0.60 μm and thereby also significantly lower than in glaucoma eyes with progression (P < 0.001). The intrasession variability of three successive measurements without head repositioning was 1.5 ± 0.7 μm. The loss of mean RNFL thickness exceeded the intrasession variability in 60% of nonprogressive eyes, and in 85% of progressive eyes after 3 years. LONGITUDINAL MEASUREMENTS OF RNFL THICKNESS USING SD-OCT SHOW A MORE PRONOUNCED REDUCTION OF RNFL THICKNESS IN PATIENTS WITH PROGRESSION COMPARED WITH PATIENTS WITHOUT PROGRESSION IN GLAUCOMATOUS OPTIC DISC CHANGES. (www.clinicaltrials.gov number, NTC00494923.).

  14. Regulation and dysregulation of esophageal peristalsis by the integrated function of circular and longitudinal muscle layers in health and disease.

    Science.gov (United States)

    Mittal, Ravinder K

    2016-09-01

    Muscularis propria throughout the entire gastrointestinal tract including the esophagus is comprised of circular and longitudinal muscle layers. Based on the studies conducted in the colon and the small intestine, for more than a century, it has been debated whether the two muscle layers contract synchronously or reciprocally during the ascending contraction and descending relaxation of the peristaltic reflex. Recent studies in the esophagus and colon prove that the two muscle layers indeed contract and relax together in almost perfect synchrony during ascending contraction and descending relaxation of the peristaltic reflex, respectively. Studies in patients with various types of esophageal motor disorders reveal temporal disassociation between the circular and longitudinal muscle layers. We suggest that the discoordination between the two muscle layers plays a role in the genesis of esophageal symptoms, i.e., dysphagia and esophageal pain. Certain pathologies may selectively target one and not the other muscle layer, e.g., in eosinophilic esophagitis there is a selective dysfunction of the longitudinal muscle layer. In achalasia esophagus, swallows are accompanied by the strong contraction of the longitudinal muscle without circular muscle contraction. The possibility that the discoordination between two muscle layers plays a role in the genesis of esophageal symptoms, i.e., dysphagia and esophageal pain are discussed. The purpose of this review is to summarize the regulation and dysregulation of peristalsis by the coordinated and discoordinated function of circular and longitudinal muscle layers in health and diseased states.

  15. Metastatic spread pattern after curative colorectal cancer surgery. A retrospective, longitudinal analysis.

    Science.gov (United States)

    Augestad, K M; Bakaki, P M; Rose, J; Crawshaw, B P; Lindsetmo, R O; Dørum, L M; Koroukian, S M; Delaney, C P

    2015-10-01

    The most common sites of colorectal cancer (CRC) recurrence are the local tissues, liver or lungs. The objective was to identify risk factors associated with the primary CRC tumor and cancer recurrence in these anatomical sites. Retrospective, longitudinal analyses of data on CRC survivors. Multivariable Cox regression analysis was performed to examine the association between possible cofounders with recurrence to various anatomical sites. Data for 10,398CRC survivors (tumor location right colon=3870, left colon=2898, high rectum=2569, low rectum=1061) were analyzed; follow up time was up to five years. Mean age at curative surgery was 71.5 (SD 11.8) years, 20.2% received radio-chemotherapy, stage T3 (64.4%) and N0 (65.1%) were most common. Overall 1632 (15.7%) had cancer recurrence (Isolated liver n=412, 3,8%;  isolated lung n=252, 2,4%; isolated local n=223, 2.1%). Risk factors associated with recurrent CRC were identified, i.e. isolated liver metastases (male: Adjusted Hazard Ratio (AHR) 1,45; colon left: AHR 1,63; N2 disease: AHR 3,35; T2 disease: AHR 2,82), isolated lung metastases (colon left: AHR 1,53; rectum high: AHR 2,48; rectum low: AHR 2,65; N2 disease 3,76), and local recurrence (glands examined<12: AHR 1,51; CRM <3mm: AHR 1,60; rectum high: AHR 2,15; N2 disease: AHR 2,58) (all p values <0001). Our study finds that the site of the primary CRC tumor is associated with location of subsequent metastasis. Left sided colon cancers have increased risk of metastatic spread to the liver, whereas rectal cancers have increased risk of local recurrence and metastatic spread to the lungs. These results, in combination with other risk factors for CRC recurrence, should be taken into consideration when designing risk adapted post-treatment CRC surveillance programs. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Causal mediation analysis for longitudinal data with exogenous exposure.

    Science.gov (United States)

    Bind, M-A C; Vanderweele, T J; Coull, B A; Schwartz, J D

    2016-01-01

    Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different types of longitudinal measures of the mediator and outcome, we assume two generalized mixed-effects models for both the mediator and the outcome. The model for the mediator has subject-specific random intercepts and random exposure slopes for each cluster, and the outcome model has random intercepts and random slopes for the exposure, the mediator, and their interaction. We also expand our approach to settings with multiple mediators and derive the mediated effects, jointly through all mediators. Our method requires the absence of time-varying confounding with respect to the exposure and the mediator. This assumption is achieved in settings with exogenous exposure and mediator, especially when exposure and mediator are not affected by variables measured at earlier time points. We apply the methodology to data from the Normative Aging Study and estimate the direct and indirect effects, via DNA methylation, of air pollution, and temperature on intercellular adhesion molecule 1 (ICAM-1) protein levels. Our results suggest that air pollution and temperature have a direct effect on ICAM-1 protein levels (i.e. not through a change in ICAM-1 DNA methylation) and that temperature has an indirect effect via a change in ICAM-1 DNA methylation. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Bayesian Nonparametric Regression Analysis of Data with Random Effects Covariates from Longitudinal Measurements

    KAUST Repository

    Ryu, Duchwan

    2010-09-28

    We consider nonparametric regression analysis in a generalized linear model (GLM) framework for data with covariates that are the subject-specific random effects of longitudinal measurements. The usual assumption that the effects of the longitudinal covariate processes are linear in the GLM may be unrealistic and if this happens it can cast doubt on the inference of observed covariate effects. Allowing the regression functions to be unknown, we propose to apply Bayesian nonparametric methods including cubic smoothing splines or P-splines for the possible nonlinearity and use an additive model in this complex setting. To improve computational efficiency, we propose the use of data-augmentation schemes. The approach allows flexible covariance structures for the random effects and within-subject measurement errors of the longitudinal processes. The posterior model space is explored through a Markov chain Monte Carlo (MCMC) sampler. The proposed methods are illustrated and compared to other approaches, the "naive" approach and the regression calibration, via simulations and by an application that investigates the relationship between obesity in adulthood and childhood growth curves. © 2010, The International Biometric Society.

  18. Recommendations to improve imaging and analysis of brain lesion load and atrophy in longitudinal studies of multiple sclerosis

    DEFF Research Database (Denmark)

    Vrenken, H; Jenkinson, M; Horsfield, M A

    2013-01-01

    resonance image analysis methods for assessing brain lesion load and atrophy, this paper makes recommendations to improve these measures for longitudinal studies of MS. Briefly, they are (1) images should be acquired using 3D pulse sequences, with near-isotropic spatial resolution and multiple image......Focal lesions and brain atrophy are the most extensively studied aspects of multiple sclerosis (MS), but the image acquisition and analysis techniques used can be further improved, especially those for studying within-patient changes of lesion load and atrophy longitudinally. Improved accuracy...

  19. Two-year trajectory of fall risk in people with Parkinson’s disease: a latent class analysis

    Science.gov (United States)

    Paul, Serene S; Thackeray, Anne; Duncan, Ryan P; Cavanaugh, James T; Ellis, Theresa D; Earhart, Gammon M; Ford, Matthew P; Foreman, K Bo; Dibble, Leland E

    2015-01-01

    Objective To examine fall risk trajectories occurring naturally in a sample of individuals with early to middle stage Parkinson’s disease (PD). Design Latent class analysis, specifically growth mixture modeling (GMM) of longitudinal fall risk trajectories. Setting Not applicable. Participants 230 community-dwelling PD participants of a longitudinal cohort study who attended at least two of five assessments over a two year period. Interventions Not applicable. Main Outcome Measures Fall risk trajectory (low, medium or high risk) and stability of fall risk trajectory (stable or fluctuating). Fall risk was determined at 6-monthly intervals using a simple clinical tool based on fall history, freezing of gait, and gait speed. Results The GMM optimally grouped participants into three fall risk trajectories that closely mirrored baseline fall risk status (p=.001). The high fall risk trajectory was most common (42.6%) and included participants with longer and more severe disease and with higher postural instability and gait disability (PIGD) scores than the low and medium risk trajectories (pfall risk (posterior probability fall risk trajectories over two years. Further investigation is required to determine whether interventions to improve gait and balance may improve fall risk trajectories in people with PD. PMID:26606871

  20. Risk Factors for Nursing Home Placement in Alzheimer's Disease: A Longitudinal Study of Cognition, ADL, Service Utilization, and Cholinesterase Inhibitor Treatment

    Science.gov (United States)

    Wattmo, Carina; Wallin, Asa K.; Londos, Elisabet; Minthon, Lennart

    2011-01-01

    Purpose of the Study: To identify risk factors for early nursing home placement (NHP) in Alzheimer's disease (AD), focusing on the impact of longitudinal change in cognition, activities of daily living (ADL), service utilization, and cholinesterase inhibitor treatment (ChEI). Design and Methods: In an open, 3-year, prospective, multicenter study…

  1. Multiple Kernel Learning with Random Effects for Predicting Longitudinal Outcomes and Data Integration

    Science.gov (United States)

    Chen, Tianle; Zeng, Donglin

    2015-01-01

    Summary Predicting disease risk and progression is one of the main goals in many clinical research studies. Cohort studies on the natural history and etiology of chronic diseases span years and data are collected at multiple visits. Although kernel-based statistical learning methods are proven to be powerful for a wide range of disease prediction problems, these methods are only well studied for independent data but not for longitudinal data. It is thus important to develop time-sensitive prediction rules that make use of the longitudinal nature of the data. In this paper, we develop a novel statistical learning method for longitudinal data by introducing subject-specific short-term and long-term latent effects through a designed kernel to account for within-subject correlation of longitudinal measurements. Since the presence of multiple sources of data is increasingly common, we embed our method in a multiple kernel learning framework and propose a regularized multiple kernel statistical learning with random effects to construct effective nonparametric prediction rules. Our method allows easy integration of various heterogeneous data sources and takes advantage of correlation among longitudinal measures to increase prediction power. We use different kernels for each data source taking advantage of the distinctive feature of each data modality, and then optimally combine data across modalities. We apply the developed methods to two large epidemiological studies, one on Huntington's disease and the other on Alzheimer's Disease (Alzheimer's Disease Neuroimaging Initiative, ADNI) where we explore a unique opportunity to combine imaging and genetic data to study prediction of mild cognitive impairment, and show a substantial gain in performance while accounting for the longitudinal aspect of the data. PMID:26177419

  2. Two-level mixed modeling of longitudinal pedigree data for genetic association analysis

    DEFF Research Database (Denmark)

    Tan, Q.

    2013-01-01

    of follow-up. Approaches have been proposed to integrate kinship correlation into the mixed effect models to explicitly model the genetic relationship which have been proven as an efficient way for dealing with sample clustering in pedigree data. Although useful for adjusting relatedness in the mixed...... assess the genetic associations with the mean level and the rate of change in a phenotype both with kinship correlation integrated in the mixed effect models. We apply our method to longitudinal pedigree data to estimate the genetic effects on systolic blood pressure measured over time in large pedigrees......Genetic association analysis on complex phenotypes under a longitudinal design involving pedigrees encounters the problem of correlation within pedigrees which could affect statistical assessment of the genetic effects on both the mean level of the phenotype and its rate of change over the time...

  3. Indexing Combined with Statistical Deflation as a Tool for Analysis of Longitudinal Data.

    Science.gov (United States)

    Babcock, Judith A.

    Indexing is a tool that can be used with longitudinal, quantitative data for analysis of relative changes and for comparisons of changes among items. For greater accuracy, raw financial data should be deflated into constant dollars prior to indexing. This paper demonstrates the procedures for indexing, statistical deflation, and the use of…

  4. Longitudinal Research with Latent Variables

    CERN Document Server

    van Montfort, Kees; Satorra, Albert

    2010-01-01

    This book combines longitudinal research and latent variable research, i.e. it explains how longitudinal studies with objectives formulated in terms of latent variables should be carried out, with an emphasis on detailing how the methods are applied. Because longitudinal research with latent variables currently utilizes different approaches with different histories, different types of research questions, and different computer programs to perform the analysis, the book is divided into nine chapters. Starting from some background information about the specific approach, short history and the ma

  5. Qualitative Analysis of Mini Mental State Examination Pentagon in Vascular Dementia and Alzheimer's Disease: A Longitudinal Explorative Study.

    Science.gov (United States)

    Lo Buono, Viviana; Bonanno, Lilla; Corallo, Francesco; Foti, Maria; Palmeri, Rosanna; Angela, Marra; Di Lorenzo, Giuseppe; Todaro, Antonino; Bramanti, Placido; Bramanti, Alessia; Marino, Silvia

    2018-06-01

    Vascular dementia and Alzheimer's disease are the most diffuse forms of dementia. Sometimes, they are difficult to distinguish due to overlaps in symptomatology, pathophysiology, and comorbidity. Visual constructive apraxia is very common in dementia and impairment in these abilities can provide clinical information for differential diagnosis. All patients underwent Mini Mental State Examination (MMSE) at basal visit (T0) and after 1 year (T1). We analyzed differences in Qualitative Scoring Method for the Pentagon Copying Test and we explored the visual constructive apraxia evolution in these 2 types of dementia. In intragroup analysis, we found a significant difference in each group between T0 and T1 in MMSE score (P < .001) and total qualitative scores (P < .001). In intergroup analysis, at T0, we found significance difference in total qualitative scores (P < .001), in numbers of angles (P = .005), in distance/intersection (P < .001), in closure/opening (P = .01), in rotation (P < .001), and in closing-in (P < .001). At T1, we found significance difference in total qualitative scores (P < .001), in particular, in numbers of angles (P < .001), in distance/intersection (P < .001), in closure/opening (P < .001), in rotation (P < .001), and in closing-in (P < .001). The total score showed the highest classification accuracy (.90, 95%CI = .81-0.96) in differentiating patients with Alzheimer's disease from patients with vascular dementia. The optimal threshold value was k = 5. with .84 (95%CI = .69-0.93) sensitivity and .81 (95%CI = .64-0.93) specificity. Patients with vascular dementia showed more accuracy errors and graphic difficulties than patients with Alzheimer's disease. Qualitative analysis of copy provided a sensitive measure of visual constructive abilities in differentiating dementias, underlining a particularly vulnerability of visuoconstructive functions in vascular dementia compared

  6. Comparison of CTT and Rasch-based approaches for the analysis of longitudinal Patient Reported Outcomes.

    Science.gov (United States)

    Blanchin, Myriam; Hardouin, Jean-Benoit; Le Neel, Tanguy; Kubis, Gildas; Blanchard, Claire; Mirallié, Eric; Sébille, Véronique

    2011-04-15

    Health sciences frequently deal with Patient Reported Outcomes (PRO) data for the evaluation of concepts, in particular health-related quality of life, which cannot be directly measured and are often called latent variables. Two approaches are commonly used for the analysis of such data: Classical Test Theory (CTT) and Item Response Theory (IRT). Longitudinal data are often collected to analyze the evolution of an outcome over time. The most adequate strategy to analyze longitudinal latent variables, which can be either based on CTT or IRT models, remains to be identified. This strategy must take into account the latent characteristic of what PROs are intended to measure as well as the specificity of longitudinal designs. A simple and widely used IRT model is the Rasch model. The purpose of our study was to compare CTT and Rasch-based approaches to analyze longitudinal PRO data regarding type I error, power, and time effect estimation bias. Four methods were compared: the Score and Mixed models (SM) method based on the CTT approach, the Rasch and Mixed models (RM), the Plausible Values (PV), and the Longitudinal Rasch model (LRM) methods all based on the Rasch model. All methods have shown comparable results in terms of type I error, all close to 5 per cent. LRM and SM methods presented comparable power and unbiased time effect estimations, whereas RM and PV methods showed low power and biased time effect estimations. This suggests that RM and PV methods should be avoided to analyze longitudinal latent variables. Copyright © 2010 John Wiley & Sons, Ltd.

  7. Chronic disease prevalence in women and air pollution--A 30-year longitudinal cohort study.

    Science.gov (United States)

    To, Teresa; Zhu, Jingqin; Villeneuve, Paul J; Simatovic, Jacqueline; Feldman, Laura; Gao, Chenwei; Williams, Devon; Chen, Hong; Weichenthal, Scott; Wall, Claus; Miller, Anthony B

    2015-07-01

    Air pollution, such as fine particulate matter (PM2.5), can increase risk of adverse health events among people with heart disease, diabetes, asthma and chronic obstructive pulmonary disease (COPD) by aggravating these conditions. Identifying the influence of PM2.5 on prevalence of these conditions may help target interventions to reduce disease morbidity among high-risk populations. The objective of this study is to measure the association of exposure of PM2.5 with prevalence risk of various chronic diseases among a longitudinal cohort of women. Women from Ontario who enrolled in the Canadian National Breast Screening Study (CNBSS) from 1980 to 1985 (n = 29,549) were linked to provincial health administrative data from April 1, 1992 to March 31, 2013 to determine the prevalence of major chronic disease and conditions (heart disease, diabetes, asthma, COPD, acute myocardial infarction, angina, stroke and cancers). Exposure to PM2.5 was measured using satellite data collected from January 1, 1998 to December 31, 2006 and assigned to resident postal-code at time of entry into study. Poisson regression models were used to describe the relationship between exposure to ambient PM2.5 and chronic disease prevalence. Prevalence rate ratios (PRs) were estimated while adjusting for potential confounders: baseline age, smoking, BMI, marital status, education and occupation. Separate models were run for each chronic disease and condition. Congestive heart failure (PR = 1.31, 95% CI: 1.13, 1.51), diabetes (PR = 1.28, 95% CI: 1.16, 1.41), ischemic heart disease (PR = 1.22, 95% CI: 1.14, 1.30), and stroke (PR = 1.21, 95% CI: 1.09, 1.35) showed over a 20% increase in PRs per 10 μg/m(3) increase in PM2.5 after adjusting for risk factors. Risks were elevated in smokers and those with BMI greater than 30. This study estimated significant elevated prevalent rate ratios per unit increase in PM2.5 in nine of the ten chronic diseases studied. Copyright © 2015 Elsevier Ltd. All rights

  8. Longitudinal study of winter mortality disease in Sydney rock oysters Saccostrea glomerata.

    Science.gov (United States)

    Spiers, Zoe B; Gabor, Melinda; Fell, Shayne A; Carnegie, Ryan B; Dove, Michael; O'Connor, Wayne; Frances, Jane; Go, Jeffrey; Marsh, Ian B; Jenkins, Cheryl

    2014-07-24

    Winter mortality (WM) is a poorly studied disease affecting Sydney rock oysters Saccostrea glomerata in estuaries in New South Wales, Australia, where it can cause significant losses. WM is more severe in oysters cultured deeper in the water column and appears linked to higher salinities. Current dogma is that WM is caused by the microcell parasite Bonamia roughleyi, but evidence linking clinical signs and histopathology to molecular data identifying bonamiasis is lacking. We conducted a longitudinal study between February and November 2010 in 2 estuaries where WM has occurred (Georges and Shoalhaven Rivers). Results from molecular testing of experimental oysters for Bonamia spp. were compared to clinical disease signs and histopathology. Available environmental data from the study sites were also collated and compared. Oyster condition declined over the study period, coinciding with decreasing water temperatures, and was inversely correlated with the presence of histological lesions. While mortalities occurred in both estuaries, only oysters from the Georges River study site showed gross clinical signs and histological changes characteristic of WM (lesions were prevalent and intralesional microcell-like structures were sometimes noted). PCR testing for Bonamia spp. revealed the presence of an organism belonging to the B. exitiosa-B. roughleyi clade in some samples; however, the very low prevalence of this organism relative to histological changes and the lack of reactivity of affected oysters in subsequent in situ hybridisation experiments led us to conclude that this Bonamia sp. is not responsible for WM. Another aetiological agent and a confluence of environmental factors are a more likely explanation for the disease.

  9. Two-Year Trajectory of Fall Risk in People With Parkinson Disease: A Latent Class Analysis.

    Science.gov (United States)

    Paul, Serene S; Thackeray, Anne; Duncan, Ryan P; Cavanaugh, James T; Ellis, Theresa D; Earhart, Gammon M; Ford, Matthew P; Foreman, K Bo; Dibble, Leland E

    2016-03-01

    To examine fall risk trajectories occurring naturally in a sample of individuals with early to middle stage Parkinson disease (PD). Latent class analysis, specifically growth mixture modeling (GMM), of longitudinal fall risk trajectories. Assessments were conducted at 1 of 4 universities. Community-dwelling participants with PD of a longitudinal cohort study who attended at least 2 of 5 assessments over a 2-year follow-up period (N=230). Not applicable. Fall risk trajectory (low, medium, or high risk) and stability of fall risk trajectory (stable or fluctuating). Fall risk was determined at 6 monthly intervals using a simple clinical tool based on fall history, freezing of gait, and gait speed. The GMM optimally grouped participants into 3 fall risk trajectories that closely mirrored baseline fall risk status (P=.001). The high fall risk trajectory was most common (42.6%) and included participants with longer and more severe disease and with higher postural instability and gait disability (PIGD) scores than the low and medium fall risk trajectories (Pfall risk (posterior probability fall risk trajectories over 2 years. Further investigation is required to determine whether interventions to improve gait and balance may improve fall risk trajectories in people with PD. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  10. Multivariate mixed linear model analysis of longitudinal data: an information-rich statistical technique for analyzing disease resistance data

    Science.gov (United States)

    The mixed linear model (MLM) is currently among the most advanced and flexible statistical modeling techniques and its use in tackling problems in plant pathology has begun surfacing in the literature. The longitudinal MLM is a multivariate extension that handles repeatedly measured data, such as r...

  11. The State of PR Graduate Curriculum as We Know It: A Longitudinal Analysis

    Science.gov (United States)

    Briones, Rowena L.; Toth, Elizabeth L.

    2013-01-01

    This longitudinal content analysis study uses the Commission on Public Relations Education's 2006 report as a benchmark to determine whether master's education in public relations has evolved over the past decade. Findings show a lack of uniformity across the 75 programs studied. In addition, there is a lack of adherence to the Commission on…

  12. Time-dependent efficacy of longitudinal biomarker for clinical endpoint.

    Science.gov (United States)

    Kolamunnage-Dona, Ruwanthi; Williamson, Paula R

    2018-06-01

    Joint modelling of longitudinal biomarker and event-time processes has gained its popularity in recent years as they yield more accurate and precise estimates. Considering this modelling framework, a new methodology for evaluating the time-dependent efficacy of a longitudinal biomarker for clinical endpoint is proposed in this article. In particular, the proposed model assesses how well longitudinally repeated measurements of a biomarker over various time periods (0,t) distinguish between individuals who developed the disease by time t and individuals who remain disease-free beyond time t. The receiver operating characteristic curve is used to provide the corresponding efficacy summaries at various t based on the association between longitudinal biomarker trajectory and risk of clinical endpoint prior to each time point. The model also allows detecting the time period over which a biomarker should be monitored for its best discriminatory value. The proposed approach is evaluated through simulation and illustrated on the motivating dataset from a prospective observational study of biomarkers to diagnose the onset of sepsis.

  13. Detection of Obstructive Coronary Artery Disease Using Peak Systolic Global Longitudinal Strain Derived by Two-Dimensional Speckle-Tracking: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Liou, Kevin; Negishi, Kazuaki; Ho, Suyen; Russell, Elizabeth A; Cranney, Greg; Ooi, Sze-Yuan

    2016-08-01

    Global longitudinal strain (GLS) is well validated and has important applications in contemporary clinical practice. The aim of this analysis was to evaluate the accuracy of resting peak GLS in the diagnosis of obstructive coronary artery disease (CAD). A systematic literature search was performed through July 2015 using four databases. Data were extracted independently by two authors and correlated before analyses. Using a random-effect model, the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and summary area under the curve for GLS were estimated with their respective 95% CIs. Screening of 1,669 articles yielded 10 studies with 1,385 patients appropriate for inclusion in the analysis. The mean age and left ventricular ejection fraction were 59.9 years and 61.1%. On the whole, 54.9% and 20.9% of the patients had hypertension and diabetes, respectively. Overall, abnormal GLS detected moderate to severe CAD with a pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 74.4%, 72.1%, 2.9, and 0.35 respectively. The area under the curve and diagnostic odds ratio were 0.81 and 8.5. The mean values of GLS for those with and without CAD were -16.5% (95% CI, -15.8% to -17.3%) and -19.7% (95% CI, -18.8% to -20.7%), respectively. Subgroup analyses for patients with severe CAD and normal left ventricular ejection fractions yielded similar results. Current evidence supports the use of GLS in the detection of moderate to severe obstructive CAD in symptomatic patients. GLS may complement existing diagnostic algorithms and act as an early adjunctive marker of cardiac ischemia. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  14. Model selection for marginal regression analysis of longitudinal data with missing observations and covariate measurement error.

    Science.gov (United States)

    Shen, Chung-Wei; Chen, Yi-Hau

    2015-10-01

    Missing observations and covariate measurement error commonly arise in longitudinal data. However, existing methods for model selection in marginal regression analysis of longitudinal data fail to address the potential bias resulting from these issues. To tackle this problem, we propose a new model selection criterion, the Generalized Longitudinal Information Criterion, which is based on an approximately unbiased estimator for the expected quadratic error of a considered marginal model accounting for both data missingness and covariate measurement error. The simulation results reveal that the proposed method performs quite well in the presence of missing data and covariate measurement error. On the contrary, the naive procedures without taking care of such complexity in data may perform quite poorly. The proposed method is applied to data from the Taiwan Longitudinal Study on Aging to assess the relationship of depression with health and social status in the elderly, accommodating measurement error in the covariate as well as missing observations. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. A LONGITUDINAL ANALYSIS OF PARENTING PRACTICES, COUPLE SATISFACTION, AND CHILD BEHAVIOR PROBLEMS

    OpenAIRE

    Linville, Deanna; Chronister, Krista; Dishion, Tom; Todahl, Jeff; Miller, John; Shaw, Daniel; Gardner, Francis; Wilson, Melvin

    2010-01-01

    This longitudinal study examined the relationship between couple relationship satisfaction, parenting practices, parent depression, and child problem behaviors. The study participants (n = 148) were part of a larger experimental study that examined the effectiveness of a brief family-centered intervention, the Family Check-Up model. Regression analysis results indicated that our proposed model accounted for 38% of the variance in child problem behavior at Time 2, with child problem behavior a...

  16. Risk prediction for chronic kidney disease progression using heterogeneous electronic health record data and time series analysis.

    Science.gov (United States)

    Perotte, Adler; Ranganath, Rajesh; Hirsch, Jamie S; Blei, David; Elhadad, Noémie

    2015-07-01

    As adoption of electronic health records continues to increase, there is an opportunity to incorporate clinical documentation as well as laboratory values and demographics into risk prediction modeling. The authors develop a risk prediction model for chronic kidney disease (CKD) progression from stage III to stage IV that includes longitudinal data and features drawn from clinical documentation. The study cohort consisted of 2908 primary-care clinic patients who had at least three visits prior to January 1, 2013 and developed CKD stage III during their documented history. Development and validation cohorts were randomly selected from this cohort and the study datasets included longitudinal inpatient and outpatient data from these populations. Time series analysis (Kalman filter) and survival analysis (Cox proportional hazards) were combined to produce a range of risk models. These models were evaluated using concordance, a discriminatory statistic. A risk model incorporating longitudinal data on clinical documentation and laboratory test results (concordance 0.849) predicts progression from state III CKD to stage IV CKD more accurately when compared to a similar model without laboratory test results (concordance 0.733, P<.001), a model that only considers the most recent laboratory test results (concordance 0.819, P < .031) and a model based on estimated glomerular filtration rate (concordance 0.779, P < .001). A risk prediction model that takes longitudinal laboratory test results and clinical documentation into consideration can predict CKD progression from stage III to stage IV more accurately than three models that do not take all of these variables into consideration. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association.

  17. High resolution molecular and histological analysis of renal disease progression in ZSF1 fa/faCP rats, a model of type 2 diabetic nephropathy.

    Science.gov (United States)

    Dower, Ken; Zhao, Shanrong; Schlerman, Franklin J; Savary, Leigh; Campanholle, Gabriela; Johnson, Bryce G; Xi, Li; Nguyen, Vuong; Zhan, Yutian; Lech, Matthew P; Wang, Ju; Nie, Qing; Karsdal, Morten A; Genovese, Federica; Boucher, Germaine; Brown, Thomas P; Zhang, Baohong; Homer, Bruce L; Martinez, Robert V

    2017-01-01

    ZSF1 rats exhibit spontaneous nephropathy secondary to obesity, hypertension, and diabetes, and have gained interest as a model system with potentially high translational value to progressive human disease. To thoroughly characterize this model, and to better understand how closely it recapitulates human disease, we performed a high resolution longitudinal analysis of renal disease progression in ZSF1 rats spanning from early disease to end stage renal disease. Analyses included metabolic endpoints, renal histology and ultrastructure, evaluation of a urinary biomarker of fibrosis, and transcriptome analysis of glomerular-enriched tissue over the course of disease. Our findings support the translational value of the ZSF1 rat model, and are provided here to assist researchers in the determination of the model's suitability for testing a particular mechanism of interest, the design of therapeutic intervention studies, and the identification of new targets and biomarkers for type 2 diabetic nephropathy.

  18. Use of Diffusion Spectrum imaging in preliminary longitudinal evaluation of Amyotrophic Lateral Sclerosis: development of an imaging biomarker

    Directory of Open Access Journals (Sweden)

    Kumar eAbhinav

    2014-04-01

    Full Text Available Previous diffusion tensor imaging (DTI studies have shown white matter pathology in ALS, predominantly in the motor pathways. Further these studies have shown that DTI can be used longitudinally to track pathology over time, making white matter pathology a candidate as an outcome measure in future trials. DTI has demonstrated application in group studies, however its derived indices, for example fractional anisotropy, are susceptible to partial volume effects, making its role questionable in examining individual progression. We hypothesize that changes in the white matter are present in ALS beyond the motor tracts, and that the affected pathways and associated pattern of disease progression can be tracked longitudinally using automated diffusion connectometry analysis. Connectometry analysis is based on diffusion spectrum imaging (DSI and overcomes the limitations of a conventional tractography approach and DTI. The identified affected white matter tracts can then be assessed in a targeted fashion using High definition fiber tractography (a novel white matter MR imaging technique. Changes in quantitative and qualitative markers over time could then be correlated with clinical progression.We illustrate these principles towards developing an imaging biomarker for demonstrating individual progression, by presenting results for five ALS patients, including with longitudinal data in two. Preliminary analysis demonstrated a number of changes bilaterally and asymmetrically in motoric and extramotoric white matter pathways. Further the limbic system was also affected possibly explaining the cognitive symptoms in ALS. In the two longitudinal subjects, the white matter changes were less extensive at baseline, although there was evidence of disease progression in a frontal pattern with a relatively spared postcentral gyrus, consistent with the known pathology in ALS.

  19. Determinants of exercise among children. II. A longitudinal analysis.

    Science.gov (United States)

    DiLorenzo, T M; Stucky-Ropp, R C; Vander Wal, J S; Gotham, H J

    1998-01-01

    Research has demonstrated that physical activity serves an important preventive function against the development of cardiovascular disease. The recognition that U.S. children are often sedentary, coupled with the observation that physical activity habits tend to persist into adulthood, has prompted the investigation of exercise determinants consistent with social learning theory. The purposes of the present study were to identify social learning variables relevant to children's exercise and to explore the longitudinal predictive value of the determinants. Data were collected from 111 families (N = 54 girls, N = 57 boys) who were interviewed in both Phase 1 (fifth and sixth grades) and Phase 2 (eight and ninth grades) of this study. Data from mothers (N = 111) were collected during both phases; data from 80 fathers were collected at Phase 2 only. The results of simultaneous stepwise regression analyses indicated that child's enjoyment of physical activity was the only consistent predictor of physical activity during Phase 1. At Phase 2, child's exercise knowledge, mother's physical activity, and child's and mother's friend modeling/support emerged as predictors for girls. For boys, child's self-efficacy for physical activity, exercise knowledge, parental modeling, and interest in sports media were important. Longitudinally, mother's self-efficacy, barriers to exercise, enjoyment of physical activity, and child's self-efficacy for physical activity were important for girls. Only child's exercise knowledge predicted boys' physical activity. The addition of information from fathers nearly doubled the explanatory power of the predictors for both genders. Socialization in the family unit exerts a tremendous influence on health-related behaviors such as exercise. The relative importance of determinants seems to differ for girls and boys and the pattern of these determinants appears to change over time.

  20. Enteric disease surveillance under the AFHSC-GEIS: Current efforts, landscape analysis and vision forward

    Directory of Open Access Journals (Sweden)

    Kasper Matthew R

    2011-03-01

    Full Text Available Abstract The mission of the Armed Forces Health Surveillance Center, Division of Global Emerging Infections Surveillance and Response System (AFHSC-GEIS is to support global public health and to counter infectious disease threats to the United States Armed Forces, including newly identified agents or those increasing in incidence. Enteric diseases are a growing threat to U.S. forces, which must be ready to deploy to austere environments where the risk of exposure to enteropathogens may be significant and where routine prevention efforts may be impractical. In this report, the authors review the recent activities of AFHSC-GEIS partner laboratories in regards to enteric disease surveillance, prevention and response. Each partner identified recent accomplishments, including support for regional networks. AFHSC/GEIS partners also completed a Strengths, Weaknesses, Opportunities and Threats (SWOT survey as part of a landscape analysis of global enteric surveillance efforts. The current strengths of this network include excellent laboratory infrastructure, equipment and personnel that provide the opportunity for high-quality epidemiological studies and test platforms for point-of-care diagnostics. Weaknesses include inconsistent guidance and a splintered reporting system that hampers the comparison of data across regions or longitudinally. The newly chartered Enterics Surveillance Steering Committee (ESSC is intended to provide clear mission guidance, a structured project review process, and central data management and analysis in support of rationally directed enteric disease surveillance efforts.

  1. Cognitive reserve in Parkinson's disease: a systematic review and meta-analysis.

    Science.gov (United States)

    Hindle, John V; Martyr, Anthony; Clare, Linda

    2014-01-01

    The concept of cognitive reserve is proposed to explain the mismatch between the degree of pathological changes and their clinical manifestations and has been used to help understand the variation in the rate of cognitive decline and the development of dementias. It is not clear whether this concept applies to cognitive performance, cognitive decline and dementia in Parkinson's disease (PD). A systematic review was conducted using the most commonly described proxies for cognitive reserve of education, occupation and leisure activities. Thirty four papers were found on education and cognition in PD but there were no studies of the other proxies of reserve. A random effects meta-analysis was used to assess the associations between education and cross-sectional cognitive assessments, longitudinal global cognitive decline and a long term dementia diagnosis. There was a significant association between higher education and cross-sectional performance of MMSE, global cognition, mild cognitive impairment, attention, executive function, visuospatial function and memory. There was a small but significant association between higher education and a reduced rate of cognitive decline. There was no association with a final dementia diagnosis. There was not enough information to perform an analysis on the rate and timing of transition to dementia. Higher levels of education are associated with significantly better cognitive performance and a small but significant slowing in cognitive decline but are not associated with a reduction in long-term dementia in PD. More detailed, standardized, longitudinal studies are required to study conclusively the effects cognitive reserve in PD. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Quantitative muscle MRI as an assessment tool for monitoring disease progression in LGMD2I: a multicentre longitudinal study.

    Directory of Open Access Journals (Sweden)

    Tracey A Willis

    Full Text Available Outcome measures for clinical trials in neuromuscular diseases are typically based on physical assessments which are dependent on patient effort, combine the effort of different muscle groups, and may not be sensitive to progression over short trial periods in slow-progressing diseases. We hypothesised that quantitative fat imaging by MRI (Dixon technique could provide more discriminating quantitative, patient-independent measurements of the progress of muscle fat replacement within individual muscle groups.To determine whether quantitative fat imaging could measure disease progression in a cohort of limb-girdle muscular dystrophy 2I (LGMD2I patients over a 12 month period.32 adult patients (17 male;15 female from 4 European tertiary referral centres with the homozygous c.826C>A mutation in the fukutin-related protein gene (FKRP completed baseline and follow up measurements 12 months later. Quantitative fat imaging was performed and muscle fat fraction change was compared with (i muscle strength and function assessed using standardized physical tests and (ii standard T1-weighted MRI graded on a 6 point scale.There was a significant increase in muscle fat fraction in 9 of the 14 muscles analyzed using the quantitative MRI technique from baseline to 12 months follow up. Changes were not seen in the conventional longitudinal physical assessments or in qualitative scoring of the T₁w images.Quantitative muscle MRI, using the Dixon technique, could be used as an important longitudinal outcome measure to assess muscle pathology and monitor therapeutic efficacy in patients with LGMD2I.

  3. Social Capital, Self-Esteem, and Use of Online Social Network Sites: A Longitudinal Analysis

    Science.gov (United States)

    Steinfield, Charles; Ellison, Nicole B.; Lampe, Cliff

    2008-01-01

    A longitudinal analysis of panel data from users of a popular online social network site, Facebook, investigated the relationship between intensity of Facebook use, measures of psychological well-being, and bridging social capital. Two surveys conducted a year apart at a large U.S. university, complemented with in-depth interviews with 18 Facebook…

  4. Frequency, prevalence, incidence and risk factors associated with visual hallucinations in a sample of patients with Parkinson's disease: a longitudinal 4-year study.

    Science.gov (United States)

    Gibson, G; Mottram, P G; Burn, D J; Hindle, J V; Landau, S; Samuel, M; Hurt, C S; Brown, R G; M Wilson, K C

    2013-06-01

    To examine the prevalence, incidence and risk factors associated with visual hallucinations (VHs) amongst people suffering from Parkinson's disease (PD). We recruited 513 patients with PD from movement disorder and PD clinics within three sites in the UK. Patients were interviewed using a series of standardised clinical rating scales at baseline, 12, 24 and 36 months. Data relating to VHs were collected using the North-East Visual Hallucinations Interview. Prevalence rates for VHs at each assessment were recorded. Associations were determined using multiple regression analysis. Cross-sectional prevalence rates for VHs at baseline, 12, 24 and 36 months indicated VHs in approximately 50% of patients. A cumulative frequency of 82.7% of cases at the end of the study period exhibited VHs. The incidence rate for VHs was 457 cases per 1000 population. Longer disease duration, greater impairment in activities of daily living and higher rates of anxiety were most commonly associated with VHs. No factors predictive of VHs could be ascertained. When examined longitudinally, VHs affect more patients than is commonly assumed in cross-sectional prevalence studies. Clinicians should routinely screen for VHs throughout the disease course. Disease duration, impairment in activities of daily living and anxiety presented as co-morbidities associated with VHs in PD, and therefore those presenting with VHs should be screened for anxiety disorder and vice versa. Copyright © 2012 John Wiley & Sons, Ltd.

  5. A tensor based morphometry study of longitudinal gray matter contraction in FTD

    Science.gov (United States)

    Brambati, Simona M.; Renda, Natasha C.; Rankin, Katherine P.; Rosen, Howard J.; Seeley, William W.; Ashburner, John; Weiner, Michael W.; Miller, Bruce L.; Gorno-Tempini, Maria Luisa

    2008-01-01

    Frontotemporal dementia (FTD) is a neurodegenerative disease characterized by progressive behavioural abnormalities and frontotemporal atrophy. Here we used tensor based morphometry (TBM) to identify regions of longitudinal progression of gray matter atrophy in FTD compared to controls. T1-weighted MRI images were acquired at presentation and 1-year follow-up from 12 patients with mild to moderate FTD and 12 healthy controls. Using TBM as implemented in SPM2, a voxel-wise estimation of regional tissue volume change was derived from the deformation field required to warp a subject’s late to early anatomical images. A whole brain analysis was performed, in which a level of significance of pBased on prior studies, a region of interest (ROI) analysis was also performed, including in the search area bilateral medial and orbital frontal regions, anterior cingulate gyrus, insula, amygdala and hippocampus. Within this ROI a level of significance of p<0.001 uncorrected was accepted. In the whole brain analysis, the anterior cingulate/paracingulate gyri were the only regions that showed significant atrophy change over 1 year. In the ROI analysis, the left ventro-medial frontal cortex, right medial superior frontal gyrus, anterior insulae and left amygdala/hippocampus showed significant longitudinal changes. In conclusion, limbic and paralimbic regions showed detectable gray matter contraction over 1 year in FTD, confirming the susceptibility of these regions to the disease and the consistency with their putative role in causing typical presenting behaviours. These results suggest that TBM might be useful in tracking progression of regional atrophy in FTD. PMID:17350290

  6. Accounting for dropout reason in longitudinal studies with nonignorable dropout.

    Science.gov (United States)

    Moore, Camille M; MaWhinney, Samantha; Forster, Jeri E; Carlson, Nichole E; Allshouse, Amanda; Wang, Xinshuo; Routy, Jean-Pierre; Conway, Brian; Connick, Elizabeth

    2017-08-01

    Dropout is a common problem in longitudinal cohort studies and clinical trials, often raising concerns of nonignorable dropout. Selection, frailty, and mixture models have been proposed to account for potentially nonignorable missingness by relating the longitudinal outcome to time of dropout. In addition, many longitudinal studies encounter multiple types of missing data or reasons for dropout, such as loss to follow-up, disease progression, treatment modifications and death. When clinically distinct dropout reasons are present, it may be preferable to control for both dropout reason and time to gain additional clinical insights. This may be especially interesting when the dropout reason and dropout times differ by the primary exposure variable. We extend a semi-parametric varying-coefficient method for nonignorable dropout to accommodate dropout reason. We apply our method to untreated HIV-infected subjects recruited to the Acute Infection and Early Disease Research Program HIV cohort and compare longitudinal CD4 + T cell count in injection drug users to nonusers with two dropout reasons: anti-retroviral treatment initiation and loss to follow-up.

  7. Depression as a risk factor for dementia and mild cognitive impairment: a meta-analysis of longitudinal studies.

    Science.gov (United States)

    Gao, Yuan; Huang, Changquan; Zhao, Kexiang; Ma, Louyan; Qiu, Xuan; Zhang, Lei; Xiu, Yun; Chen, Lin; Lu, Wei; Huang, Chunxia; Tang, Yong; Xiao, Qian

    2013-05-01

    This study examined whether depression was a risk factor for onset of dementia including Alzheimer's disease (AD), vascular dementia (VD) and any dementia, and mild cognitive impairment (MCI) by using a quantitative meta-analysis of longitudinal studies. EMBASE and MEDLINE were searched for articles published up to February 2011. All studies that examined the relationship between depression and the onset of dementia or MCI were included. Pooled relative risk was calculated using fixed-effects models. Twelve studies met our inclusion criteria for this meta-analysis. All subjects were without dementia or MCI at baseline. Four, two, five, and four studies compared the incidence of AD, VD, any dementia, and MCI between subjects with or without depression, respectively. After pooling all the studies, subjects with depression had higher incidence of AD (relative risk (RR):1.66, 95% confidence interval (CI): 1.29-2.14), VD (RR: 1.89, 95% CI: 1.19-3.01), any dementia (RR: 1.55, 95% CI: 1.31-2.83), and MCI (RR: 1.97, 95% CI: 1.53-2.54) than those without depression. The quantitative meta-analysis showed that depression was a major risk factor for incidence of dementia (including AD, VD, and any dementia) and MCI. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Longitudinal Diffusion Tensor Imaging Resembles Patterns of Pathology Progression in Behavioral Variant Frontotemporal Dementia (bvFTD

    Directory of Open Access Journals (Sweden)

    Jan Kassubek

    2018-03-01

    Full Text Available Objective: Recently, the characteristic longitudinal distribution pattern of the underlying phosphorylated TDP-43 (pTDP-43 pathology in the behavioral variant of frontotemporal dementia (bvFTD excluding Pick's disease (PiD across specific brain regions was described. The aim of the present study was to investigate whether in vivo investigations of bvFTD patients by use of diffusion tensor imaging (DTI were consistent with these proposed patterns of progression.Methods: Sixty-two bvFTD patients and 47 controls underwent DTI in a multicenter study design. Of these, 49 bvFTD patients and 34 controls had a follow-up scan after ~12 months. Cross-sectional and longitudinal alterations were assessed by a two-fold analysis, i.e., voxelwise comparison of fractional anisotropy (FA maps and a tract of interest-based (TOI approach, which identifies tract structures that could be assigned to brain regions associated with disease progression.Results: Whole brain-based spatial statistics showed white matter alterations predominantly in the frontal lobes cross-sectionally and longitudinally. The TOIs of bvFTD neuroimaging stages 1 and 2 (uncinate fascicle—bvFTD pattern I; corticostriatal pathway—bvFTD pattern II showed highly significant differences between bvFTD patients and controls. The corticospinal tract-associated TOI (bvFTD pattern III did not differ between groups, whereas the differences in the optic radiation (bvFTD pattern IV reached significance. The findings in the corticospinal tract were due to a “dichotomous” behavior of FA changes there.Conclusion: Longitudinal TOI analysis demonstrated a pattern of white matter pathways alterations consistent with patterns of pTDP-43 pathology.

  9. Maximizing the Potential of Longitudinal Cohorts for Research in Neurodegenerative Diseases: A Community Perspective

    Directory of Open Access Journals (Sweden)

    Catherine J. Moody

    2017-08-01

    Full Text Available Despite a wealth of activity across the globe in the area of longitudinal population cohorts, surprisingly little information is available on the natural biomedical history of a number of age-related neurodegenerative diseases (ND, and the scope for intervention studies based on these cohorts is only just beginning to be explored. The Joint Programming Initiative on Neurodegenerative Disease Research (JPND recently developed a novel funding mechanism to rapidly mobilize scientists to address these issues from a broad, international community perspective. Ten expert Working Groups, bringing together a diverse range of community members and covering a wide ND landscape [Alzheimer's, Parkinson's, frontotemporal degeneration, amyotrophic lateral sclerosis (ALS, Lewy-body and vascular dementia] were formed to discuss and propose potential approaches to better exploiting and coordinating cohort studies. The purpose of this work is to highlight the novel funding process along with a broad overview of the guidelines and recommendations generated by the ten groups, which include investigations into multiple methodologies such as cognition/functional assessment, biomarkers and biobanking, imaging, health and social outcomes, and pre-symptomatic ND. All of these were published in reports that are now publicly available online.

  10. Integration of Multilocus Genetic Risk into the Default Mode Network Longitudinal Trajectory during the Alzheimer's Disease Process.

    Science.gov (United States)

    Su, Fan; Shu, Hao; Ye, Qing; Xie, Chunming; Yuan, Baoyu; Zhang, Zhijun; Bai, Feng

    2017-01-01

    The aim of the study was to investigate the cognitive significance of the changes in default mode network (DMN) during the process of Alzheimer's disease (AD) and the genetic basis that drives the alteration. Eighty-seven subjects with mild cognitive impairment (MCI) and 131 healthy controls (HC) were employed at baseline, and they had the genetic risk scores (GRS) based on the GWAS-validated AD-related top loci. Eleven MCIs who converted to AD (c-MCIs), 32 subjects who remained stable (nc-MCIs), and 56 HCs participated in the follow-up analyses after an average of 35 months. Decreased functional connectivity (FC) within temporal cortex was identified for MCIs at baseline, which was partially determined by the GRS; moreover, compensations may occur within the frontal-parietal brain to maintain relatively intact cognition. During the follow-ups, c-MCIs exhibited more FC declines within the prefrontal-parietal lobes and parahippocampal gyrus/hippocampus than the HCs and nc-MCIs. The GRS did not significantly vary among the three groups, whereas associations were identified at risky alleles and FC declines in all AD spectra. Interestingly, the influence of APOEɛ4 varied as the disease progressed; APOEɛ4 was associated with longitudinal FC decreases only for HCs in the single variance-based analyses and deteriorated DMN integration in nc-MCIs by combining the effects of other loci. However, the GRS without APOEɛ4 predicted FC decline for converters. It is suggested that the integration of multilocus genetic risk predicted the longitudinal trajectory of DMN and may be used as a clinical strategy to track AD progression.

  11. Regression analysis of longitudinal data with correlated censoring and observation times.

    Science.gov (United States)

    Li, Yang; He, Xin; Wang, Haiying; Sun, Jianguo

    2016-07-01

    Longitudinal data occur in many fields such as the medical follow-up studies that involve repeated measurements. For their analysis, most existing approaches assume that the observation or follow-up times are independent of the response process either completely or given some covariates. In practice, it is apparent that this may not be true. In this paper, we present a joint analysis approach that allows the possible mutual correlations that can be characterized by time-dependent random effects. Estimating equations are developed for the parameter estimation and the resulted estimators are shown to be consistent and asymptotically normal. The finite sample performance of the proposed estimators is assessed through a simulation study and an illustrative example from a skin cancer study is provided.

  12. medplot: a web application for dynamic summary and analysis of longitudinal medical data based on R.

    Directory of Open Access Journals (Sweden)

    Črt Ahlin

    Full Text Available In biomedical studies the patients are often evaluated numerous times and a large number of variables are recorded at each time-point. Data entry and manipulation of longitudinal data can be performed using spreadsheet programs, which usually include some data plotting and analysis capabilities and are straightforward to use, but are not designed for the analyses of complex longitudinal data. Specialized statistical software offers more flexibility and capabilities, but first time users with biomedical background often find its use difficult. We developed medplot, an interactive web application that simplifies the exploration and analysis of longitudinal data. The application can be used to summarize, visualize and analyze data by researchers that are not familiar with statistical programs and whose knowledge of statistics is limited. The summary tools produce publication-ready tables and graphs. The analysis tools include features that are seldom available in spreadsheet software, such as correction for multiple testing, repeated measurement analyses and flexible non-linear modeling of the association of the numerical variables with the outcome. medplot is freely available and open source, it has an intuitive graphical user interface (GUI, it is accessible via the Internet and can be used within a web browser, without the need for installing and maintaining programs locally on the user's computer. This paper describes the application and gives detailed examples describing how to use the application on real data from a clinical study including patients with early Lyme borreliosis.

  13. Longitudinal changes in microstructural white matter metrics in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Chantel D. Mayo

    2017-01-01

    Conclusion: The current results indicate that sensitivity to white matter microstructure is a promising avenue for AD biomarker research. Additional longitudinal studies on both white and grey matter are warranted to further evaluate potential clinical utility.

  14. Biomarker clusters are differentially associated with longitudinal cognitive decline in late midlife

    Science.gov (United States)

    Racine, Annie M.; Koscik, Rebecca L.; Berman, Sara E.; Nicholas, Christopher R.; Clark, Lindsay R.; Okonkwo, Ozioma C.; Rowley, Howard A.; Asthana, Sanjay; Bendlin, Barbara B.; Blennow, Kaj; Zetterberg, Henrik; Gleason, Carey E.; Carlsson, Cynthia M.

    2016-01-01

    The ability to detect preclinical Alzheimer’s disease is of great importance, as this stage of the Alzheimer’s continuum is believed to provide a key window for intervention and prevention. As Alzheimer’s disease is characterized by multiple pathological changes, a biomarker panel reflecting co-occurring pathology will likely be most useful for early detection. Towards this end, 175 late middle-aged participants (mean age 55.9 ± 5.7 years at first cognitive assessment, 70% female) were recruited from two longitudinally followed cohorts to undergo magnetic resonance imaging and lumbar puncture. Cluster analysis was used to group individuals based on biomarkers of amyloid pathology (cerebrospinal fluid amyloid-β42/amyloid-β40 assay levels), magnetic resonance imaging-derived measures of neurodegeneration/atrophy (cerebrospinal fluid-to-brain volume ratio, and hippocampal volume), neurofibrillary tangles (cerebrospinal fluid phosphorylated tau181 assay levels), and a brain-based marker of vascular risk (total white matter hyperintensity lesion volume). Four biomarker clusters emerged consistent with preclinical features of (i) Alzheimer’s disease; (ii) mixed Alzheimer’s disease and vascular aetiology; (iii) suspected non-Alzheimer’s disease aetiology; and (iv) healthy ageing. Cognitive decline was then analysed between clusters using longitudinal assessments of episodic memory, semantic memory, executive function, and global cognitive function with linear mixed effects modelling. Cluster 1 exhibited a higher intercept and greater rates of decline on tests of episodic memory. Cluster 2 had a lower intercept on a test of semantic memory and both Cluster 2 and Cluster 3 had steeper rates of decline on a test of global cognition. Additional analyses on Cluster 3, which had the smallest hippocampal volume, suggest that its biomarker profile is more likely due to hippocampal vulnerability and not to detectable specific volume loss exceeding the rate of normal

  15. Power analysis to detect treatment effects in longitudinal clinical trials for Alzheimer's disease.

    Science.gov (United States)

    Huang, Zhiyue; Muniz-Terrera, Graciela; Tom, Brian D M

    2017-09-01

    Assessing cognitive and functional changes at the early stage of Alzheimer's disease (AD) and detecting treatment effects in clinical trials for early AD are challenging. Under the assumption that transformed versions of the Mini-Mental State Examination, the Clinical Dementia Rating Scale-Sum of Boxes, and the Alzheimer's Disease Assessment Scale-Cognitive Subscale tests'/components' scores are from a multivariate linear mixed-effects model, we calculated the sample sizes required to detect treatment effects on the annual rates of change in these three components in clinical trials for participants with mild cognitive impairment. Our results suggest that a large number of participants would be required to detect a clinically meaningful treatment effect in a population with preclinical or prodromal Alzheimer's disease. We found that the transformed Mini-Mental State Examination is more sensitive for detecting treatment effects in early AD than the transformed Clinical Dementia Rating Scale-Sum of Boxes and Alzheimer's Disease Assessment Scale-Cognitive Subscale. The use of optimal weights to construct powerful test statistics or sensitive composite scores/endpoints can reduce the required sample sizes needed for clinical trials. Consideration of the multivariate/joint distribution of components' scores rather than the distribution of a single composite score when designing clinical trials can lead to an increase in power and reduced sample sizes for detecting treatment effects in clinical trials for early AD.

  16. The influence of subjective aging on health and longevity: A meta-analysis of longitudinal data

    NARCIS (Netherlands)

    Westerhof, Gerben Johan; Miche, M.; Brothers, A.F.; Barrett, A.E.; Diehl, M.; Montepare, J.M.; Wahl, H.-W.; Wurm, S.

    2014-01-01

    Evidence is accumulating on the effects of subjective aging—that is, how individuals perceive their own aging process—on health and survival in later life. The goal of this article is to synthesize findings of existing longitudinal studies through a meta-analysis. A systematic search in PsycInfo,

  17. The effects of cognitive reserve and lifestyle on cognition and dementia in Parkinson's disease--a longitudinal cohort study.

    Science.gov (United States)

    Hindle, John V; Hurt, Catherine S; Burn, David J; Brown, Richard G; Samuel, Mike; Wilson, Kenneth C; Clare, Linda

    2016-01-01

    Cognitive reserve theory seeks to explain the observed mismatch between the degree of brain pathology and clinical manifestations. Early-life education, midlife social and occupational activities and later-life cognitive and social interactions are associated with a more favourable cognitive trajectory in older people. Previous studies of Parkinson's disease (PD) have suggested a possible role for the effects of cognitive reserve, but further research into different proxies for cognitive reserve and longitudinal studies is required. This study examined the effects of cognitive lifestyle on cross-sectional and longitudinal measures of cognition and dementia severity in people with PD. Baseline assessments of cognition, and of clinical, social and demographic information, were completed by 525 participants with PD. Cognitive assessments were completed by 323 participants at 4-year follow-up. Cognition was assessed using the measures of global cognition dementia severity. Cross-sectional and longitudinal serial analyses of covariance for cognition and binomial regression for dementia were performed. Higher educational level, socio-economic status and recent social engagement were associated with better cross-sectional global cognition. In those with normal cognition at baseline, higher educational level was associated with better global cognition after 4 years. Increasing age and low levels of a measure of recent social engagement were associated with an increased risk of dementia. Higher cognitive reserve has a beneficial effect on performance on cognitive tests and a limited effect on cognitive decline and dementia risk in PD. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Longitudinal follow-up of Zika virus RNA in semen of a traveller returning from Barbados to the Netherlands with Zika virus disease, March 2016

    NARCIS (Netherlands)

    C.B.E.M. Reusken (Chantal); S.D. Pas (Suzan); C.H. Geurts van Kessel (Corine); R. Mögling (Ramona); J.J.A. van Kampen (Jeroen); T. Langerak (Thomas); M.P.G. Koopmans D.V.M. (Marion); A.A. Eijck (Annemiek); E.C.M. van Gorp (Eric)

    2016-01-01

    textabstractWe report the longitudinal follow-up of Zika virus (ZIKV) RNA in semen of a traveller who developed ZIKV disease after return to the Netherlands from Barbados, March 2016. Persistence of ZIKV RNA in blood, urine, saliva and semen was followed until the loads reached undetectable levels.

  19. Longitudinal follow-up of Zika virus RNA in semen of a traveller returning from Barbados to the Netherlands with Zika virus disease, march 2016

    NARCIS (Netherlands)

    C.B.E.M. Reusken (Chantal); S.D. Pas (Suzan); C.H. Geurts van Kessel (Corine); R. Mögling (Ramona); J.J.A. van Kampen (Jeroen); T. Langerak (Thomas); M.P.G. Koopmans D.V.M. (Marion); A.A. Eijck (Annemiek); E.C.M. van Gorp (Eric)

    2016-01-01

    textabstractWe report the longitudinal follow-up of Zika virus (ZIKV) RNA in semen of a traveller who developed ZIKV disease after return to the Netherlands from Barbados, March 2016. Persistence of ZIKV RNA in blood, urine, saliva and semen was followed until the loads reached undetectable levels.

  20. Dataset of longitudinal analysis of tear cytokine levels, CD4, CD8 counts and HIV viral load in dry eye patients with HIV infection

    Directory of Open Access Journals (Sweden)

    Praveen Kumar Balne

    2017-04-01

    Full Text Available The data presented in this article shows the longitudinal analysis of tear fluid cytokine profiles, blood CD4 and CD8 counts and HIV viral load in 34 dry eye patients with HIV infection during the HAART therapy. Clinical samples were collected from HIV patients with dry eye disease at the time of presentation to the clinic (visit 1, three months (visit 2 and 6 months (visit 3 after the presentation. At each time point tear samples were evaluated for 41 cytokines using Luminex bead based multiplex assay and blood samples were tested for HIV viral load and CD4 and CD8 counts.

  1. Identifying the Alteration Patterns of Brain Functional Connectivity in Progressive Mild Cognitive Impairment Patients: A Longitudinal Whole-Brain Voxel-Wise Degree Analysis.

    Science.gov (United States)

    Deng, Yanjia; Liu, Kai; Shi, Lin; Lei, Yi; Liang, Peipeng; Li, Kuncheng; Chu, Winnie C W; Wang, Defeng

    2016-01-01

    Patients with mild cognitive impairment (MCI) are at high risk for developing Alzheimer's disease (AD), while some of them may remain stable over decades. The underlying mechanism is still not fully understood. In this study, we aimed to explore the connectivity differences between progressive MCI (PMCI) and stable MCI (SMCI) individuals on a whole-brain scale and on a voxel-wise basis, and we also aimed to reveal the differential dynamic alteration patterns between these two disease subtypes. The resting-state functional magnetic resonance images of PMCI and SMCI patients at baseline and year-one were obtained from the Alzheimer's Disease Neuroimaging Initiative dataset, and the progression was determined based on a 3-year follow-up. A whole-brain voxel-wise degree map that was calculated based on graph-theory was constructed for each subject, and then the cross-sectional and longitudinal analyses on the degree maps were performed between PMCI and SMCI patients. In longitudinal analyses, compared with SMCI group, PMCI group showed decreased long-range degree in the left middle occipital/supramarginal gyrus, while the short-range degree was increased in the left supplementary motor area and middle frontal gyrus and decreased in the right middle temporal pole. A significant longitudinal alteration of decreased short-range degree in the right middle occipital was found in PMCI group. Taken together with previous evidence, our current findings may suggest that PMCI, compared with SMCI, might be a "severe" presentation of disease along the AD continuum, and the rapidly reduced degree in the right middle occipital gyrus may have indicative value for the disease progression. Moreover, the cross-sectional comparison results and corresponding receiver-operator characteristic-curves analyses may indicate that the baseline degree difference is not a good predictor of disease progression in MCI patients. Overall, these findings may provide objective evidence and an indicator

  2. Identifying the Alternation Patterns of Brain Functional Connectivity in Progressive Mild Cognitive Impairment Patients: A Longitudinal Whole-brain Voxel-wise Degree Analysis

    Directory of Open Access Journals (Sweden)

    Yanjia Deng

    2016-08-01

    Full Text Available Patients with mild cognitive impairment (MCI are at high risk for developing Alzheimer’s disease (AD, while some of them may remain stable over decades. The underlying mechanism is still not fully understood. In this study, we aimed to explore the connectivity differences between progressive MCI (PMCI and stable MCI (SMCI individuals on a whole-brain scale and on a voxel-wise basis, and we also aimed to reveal the differential dynamic alternation patterns between these two disease subtypes. The resting-state functional magnetic resonance images of PMCI and SMCI patients at baseline and year-one were obtained from the Alzheimer’s Disease Neuroimaging Initiative dataset, and the progression was determined based on a three-year follow-up. A whole-brain voxel-wise degree map that was calculated based on graph-theory was constructed for each subject, and then the cross-sectional and longitudinal analyses on the degree maps were performed between PMCI and SMCI patients. In longitudinal analyses, compared with SMCI group, PMCI group showed decreased long-range degree in the left middle occipital/supramarginal gyrus, while the short-range degree was increased in the left supplementary motor area and middle frontal gyrus and decreased in the right middle temporal pole. A significant longitudinal alteration of decreased short-range degree in the right middle occipital was found in PMCI group. Taken together with previous evidence, our current findings may suggest that PMCI, compared with SMCI, might be a severe presentation of disease along the AD continuum, and the rapidly reduced degree in the right middle occipital gyrus may have indicative value for the disease progression. Moreover, the cross-sectional comparison results and corresponding receiver-operator characteristic-curves analyses may indicate that the baseline degree difference is not a good predictor of disease progression in MCI patients. Overall, these findings may provide objective

  3. Appearance of Abnormal Cardiothoracic Ratio of Fetuses with Hemoglobin Bart's Disease: Life Table Analysis.

    Science.gov (United States)

    Wanapirak, Chanane; Sirichotiyakul, Supatra; Luewan, Suchaya; Srisupundit, Kasemsri; Tongprasert, Fuanglada; Tongsong, Theera

    2017-10-01

    Objective  To determine the timeline of the first appearance of an increased CT ratio of fetuses with hemoglobin (Hb) Bart's disease. Materials and Methods  A prospective longitudinal study was conducted on pregnancies at risk for fetal Hb Bart's disease. Sonographic markers including cardiothoracic (CT) ratio and middle cerebral artery peak systolic velocity (MCA-PSV) were serially assessed and recorded from the first trimester. The definite diagnosis of fetal Hb Bart's disease based on DNA analysis (CVS), or fetal Hb typing (HPLC; cordocentesis) was performed at the first appearance of an increased CT ratio. Results  Of 275 pregnancies at risk, 64 fetuses were finally proven to be affected and life table analysis was performed. Most affected fetuses showed an increased CT ratio in late first trimester and early second trimester, with median time of the first appearance at 13 weeks and all affected fetuses were detected at 23 weeks or less. The CT ratio yielded a sensitivity of 100 % at a gestational age of 23 weeks with a false-positive rate of 8 %. MCA-PSV appeared later than CT ratio. Only 9.4 % of affected cases developed abnormal MCA-PSV before an increased CT ratio. Conclusion  The timeline of the first appearance of an increased CT ratio of fetuses with Hb Bart's disease was established. This may help us identify Hb Bart's disease among fetuses at risk in earlier gestation and proper schedules for serial ultrasound could be made more effectively. © Georg Thieme Verlag KG Stuttgart · New York.

  4. Clinical pharmacology quality assurance program: models for longitudinal analysis of antiretroviral proficiency testing for international laboratories.

    Science.gov (United States)

    DiFrancesco, Robin; Rosenkranz, Susan L; Taylor, Charlene R; Pande, Poonam G; Siminski, Suzanne M; Jenny, Richard W; Morse, Gene D

    2013-10-01

    Among National Institutes of Health HIV Research Networks conducting multicenter trials, samples from protocols that span several years are analyzed at multiple clinical pharmacology laboratories (CPLs) for multiple antiretrovirals. Drug assay data are, in turn, entered into study-specific data sets that are used for pharmacokinetic analyses, merged to conduct cross-protocol pharmacokinetic analysis, and integrated with pharmacogenomics research to investigate pharmacokinetic-pharmacogenetic associations. The CPLs participate in a semiannual proficiency testing (PT) program implemented by the Clinical Pharmacology Quality Assurance program. Using results from multiple PT rounds, longitudinal analyses of recovery are reflective of accuracy and precision within/across laboratories. The objectives of this longitudinal analysis of PT across multiple CPLs were to develop and test statistical models that longitudinally: (1) assess the precision and accuracy of concentrations reported by individual CPLs and (2) determine factors associated with round-specific and long-term assay accuracy, precision, and bias using a new regression model. A measure of absolute recovery is explored as a simultaneous measure of accuracy and precision. Overall, the analysis outcomes assured 97% accuracy (±20% of the final target concentration of all (21) drug concentration results reported for clinical trial samples by multiple CPLs). Using the Clinical Laboratory Improvement Act acceptance of meeting criteria for ≥2/3 consecutive rounds, all 10 laboratories that participated in 3 or more rounds per analyte maintained Clinical Laboratory Improvement Act proficiency. Significant associations were present between magnitude of error and CPL (Kruskal-Wallis P Kruskal-Wallis P < 0.001).

  5. Drug awareness in adolescents attending a mental health service: analysis of longitudinal data.

    Science.gov (United States)

    Arnau, Jaume; Bono, Roser; Díaz, Rosa; Goti, Javier

    2011-11-01

    One of the procedures used most recently with longitudinal data is linear mixed models. In the context of health research the increasing number of studies that now use these models bears witness to the growing interest in this type of analysis. This paper describes the application of linear mixed models to a longitudinal study of a sample of Spanish adolescents attending a mental health service, the aim being to investigate their knowledge about the consumption of alcohol and other drugs. More specifically, the main objective was to compare the efficacy of a motivational interviewing programme with a standard approach to drug awareness. The models used to analyse the overall indicator of drug awareness were as follows: (a) unconditional linear growth curve model; (b) growth model with subject-associated variables; and (c) individual curve model with predictive variables. The results showed that awareness increased over time and that the variable 'schooling years' explained part of the between-subjects variation. The effect of motivational interviewing was also significant.

  6. Large-scale identification of clinical and genetic predictors of motor progression in patients with newly diagnosed Parkinson's disease: a longitudinal cohort study and validation.

    Science.gov (United States)

    Latourelle, Jeanne C; Beste, Michael T; Hadzi, Tiffany C; Miller, Robert E; Oppenheim, Jacob N; Valko, Matthew P; Wuest, Diane M; Church, Bruce W; Khalil, Iya G; Hayete, Boris; Venuto, Charles S

    2017-11-01

    Better understanding and prediction of progression of Parkinson's disease could improve disease management and clinical trial design. We aimed to use longitudinal clinical, molecular, and genetic data to develop predictive models, compare potential biomarkers, and identify novel predictors for motor progression in Parkinson's disease. We also sought to assess the use of these models in the design of treatment trials in Parkinson's disease. A Bayesian multivariate predictive inference platform was applied to data from the Parkinson's Progression Markers Initiative (PPMI) study (NCT01141023). We used genetic data and baseline molecular and clinical variables from patients with Parkinson's disease and healthy controls to construct an ensemble of models to predict the annual rate of change in combined scores from the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) parts II and III. We tested our overall explanatory power, as assessed by the coefficient of determination (R 2 ), and replicated novel findings in an independent clinical cohort from the Longitudinal and Biomarker Study in Parkinson's disease (LABS-PD; NCT00605163). The potential utility of these models for clinical trial design was quantified by comparing simulated randomised placebo-controlled trials within the out-of-sample LABS-PD cohort. 117 healthy controls and 312 patients with Parkinson's disease from the PPMI study were available for analysis, and 317 patients with Parkinson's disease from LABS-PD were available for validation. Our model ensemble showed strong performance within the PPMI cohort (five-fold cross-validated R 2 41%, 95% CI 35-47) and significant-albeit reduced-performance in the LABS-PD cohort (R 2 9%, 95% CI 4-16). Individual predictive features identified from PPMI data were confirmed in the LABS-PD cohort. These included significant replication of higher baseline MDS-UPDRS motor score, male sex, and increased age, as well as a novel Parkinson's disease

  7. Quantitative longitudinal interrelationships between brain metabolism and amyloid deposition during a 2-year follow-up in patients with early Alzheimer's disease

    International Nuclear Information System (INIS)

    Foerster, Stefan; Yousefi, Behrooz H.; Wester, Hans-Juergen; Klupp, Elisabeth; Rominger, Axel; Foerstl, Hans; Kurz, Alexander; Grimmer, Timo; Drzezga, Alexander

    2012-01-01

    Similar regional anatomical distributions were reported for fibrillary amyloid deposition [measured by 11 C-Pittsburgh compound B (PIB) positron emission tomography (PET)] and brain hypometabolism [measured by 18 F-fluorodeoxyglucose (FDG) PET] in numerous Alzheimer's disease (AD) studies. However, there is a lack of longitudinal studies evaluating the interrelationships of these two different pathological markers in the same AD population. Our most recent AD study suggested that the longitudinal pattern of hypometabolism anatomically follows the pattern of amyloid deposition with temporal delay, which indicates that neuronal dysfunction may spread within the anatomical pattern of amyloid pathology. Based on this finding we now hypothesize that in early AD patients quantitative longitudinal decline in hypometabolism may be related to the amount of baseline amyloid deposition during a follow-up period of 2 years. Fifteen patients with mild probable AD underwent baseline (T1) and follow-up (T2) examination after 24 ± 2.1 months with [ 18 F]FDG PET, [ 11 C]PIB PET, structural T1-weighted MRI and neuropsychological testing [Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery]. Longitudinal cognitive measures and quantitative PET measures of amyloid deposition and metabolism [standardized uptake value ratios (SUVRs)] were obtained using volume of interest (VOI)-based approaches in the frontal-lateral-retrosplenial (FLR) network and in predefined bihemispheric brain regions after partial volume effect (PVE) correction of PET data. Statistical group comparisons (SUVRs and cognitive measures) between patients and 15 well-matched elderly controls who had undergone identical imaging procedures once as well as Pearson's correlation analyses within patients were performed. Group comparison revealed significant cognitive decline and increased mean PIB/decreased FDG SUVRs in the FLR network as well as in several AD-typical regions in

  8. Novel Longitudinal and Propensity Score Matched Analysis of Hands-On Cooking and Nutrition Education versus Traditional Clinical Education among 627 Medical Students

    Directory of Open Access Journals (Sweden)

    Dominique J. Monlezun

    2015-01-01

    Full Text Available Background. Physicians are inadequately equipped to respond to the global obesity and nutrition-associated chronic disease epidemics. We investigated superiority of simulation-based medical education with deliberate practice (SBME-DP hands-on cooking and nutrition elective in a medical school-based teaching kitchen versus traditional clinical education for medical students. Materials and Methods. A 59-question panel survey was distributed to an entire medical school twice annually from September 2012 to May 2014. Student diet and attitudes and competencies (DACs counseling patients on nutrition were compared using conditional multivariate logistic regression, propensity score-weighted, and longitudinal panel analyses. Inverse-variance weighted meta-analysis (IVWM was used for planned subgroup analysis by year and treatment estimates across the three methods. Results. Of the available 954 students, 65.72% (n=627 unique students were followed to produce 963 responses. 11.32% (n=109 of responses were from 84 subjects who participated in the elective. SBME-DP versus traditional education significantly improved fruit and vegetable diet (OR = 1.38, 95% CI: 1.07–1.79, p=0.013 and attitudes (OR = 1.81, 95% CI: 1.40–2.35, p<0.001 and competencies (OR = 1.72, 95% CI: 1.54–1.92, p<0.001. Conclusions. This study reports for the first time superiority longitudinally for SBME-DP style nutrition education for medical students which has since expanded to 13 schools.

  9. A Systematic Review and Meta-Analysis on the Strength and Consistency of the Associations between Dupuytren Disease and Diabetes Mellitus, Liver Disease, and Epilepsy.

    Science.gov (United States)

    Broekstra, Dieuwke C; Groen, Henk; Molenkamp, Sanne; Werker, Paul M N; van den Heuvel, Edwin R

    2018-03-01

    The role of diabetes mellitus, liver disease, and epilepsy as risk factors for Dupuytren disease remains unclear. In this systematic review and meta-analysis, the strength and consistency of these associations were examined. The MEDLINE, EMBASE, and Web of Science databases were searched for articles reporting an association between Dupuytren disease and diabetes mellitus, liver disease, and epilepsy published before September 26, 2016. The frequencies of Dupuytren disease and diabetes mellitus, liver disease, and epilepsy were extracted, as was information on potential confounders. Generalized linear mixed models were applied to estimate pooled odds ratios, adjusted for confounders. Heterogeneity between studies was quantified using an intraclass correlation coefficient and was accounted for by a random effect for study. One thousand two hundred sixty unique studies were identified, of which 32 were used in the meta-analyses. An association between Dupuytren disease and diabetes mellitus was observed (OR, 3.06; 95 percent CI, 2.69 to 3.48, adjusted for age), which was stronger for type 1 diabetes mellitus than for type 2 diabetes mellitus but was not statistically significant (p = 0.24). An association between Dupuytren disease and liver disease was observed (OR, 2.92; 95 percent CI, 2.08 to 4.12, adjusted for sex). Dupuytren disease and epilepsy were associated, yielding an OR of 2.80 (95 percent CI, 2.49 to 3.15). Heterogeneity between studies was moderate to low. These findings demonstrate an association between Dupuytren disease and diabetes mellitus, liver disease, and epilepsy. Prospective, longitudinal studies are needed to elucidate the pathways causing these associations.

  10. De Qeurvian Tenosynovitis: Clinical Outcomes of Surgical Treatment with Longitudinal and Transverse Incision

    Directory of Open Access Journals (Sweden)

    Arefah Dehghani Tafti

    2011-03-01

    Full Text Available AbstractObjectives: De Quervain disease is a mechanical tenosynovitis due to inadequacy volume between abductor pollicis longus, extensor pollicis brevis and their tunnel. Treatment methods include immobilization, steroid injections, and operation. For the first time Fritz De Quervain described surgical treatment of this disease. Since then, various ways of treatment have been reported. The purpose of this study is to compare the clinical outcomes of a longitudinal incision with a transverse incision in De Quervain disease.Methods: This was a randomized controlled clinical trial conducted in three hospitals in Iran, Yazd from March 2003 to September 2008. One hundred-twenty patients with De Quervain disease who did not respond to conservative treatment were operated with two different incisions. The patients were followed for three months to compare the surgical outcomes.Results: During a three month follow-up, a significant difference was shown between the two methods (p=0.03. Results of surgical treatment with longitudinal incision were excellent (only 5 hypertrophic scars, but there were 13 postoperative complaints with transverse incision.Conclusion: According to our findings, longitudinal incision in surgical treatment of De Quervain disease is better than transverse incision.

  11. Enabling Analysis of Big, Thick, Long, and Wide Data: Data Management for the Analysis of a Large Longitudinal and Cross-National Narrative Data Set.

    Science.gov (United States)

    Winskell, Kate; Singleton, Robyn; Sabben, Gaelle

    2018-03-01

    Distinctive longitudinal narrative data, collected during a critical 18-year period in the history of the HIV epidemic, offer a unique opportunity to examine how young Africans are making sense of evolving developments in HIV prevention and treatment. More than 200,000 young people from across sub-Saharan Africa took part in HIV-themed scriptwriting contests held at eight discrete time points between 1997 and 2014, creating more than 75,000 narratives. This article describes the data reduction and management strategies developed for our cross-national and longitudinal study of these qualitative data. The study aims to inform HIV communication practice by identifying cultural meanings and contextual factors that inform sexual behaviors and social practices, and also to help increase understanding of processes of sociocultural change. We describe our sampling strategies and our triangulating methodologies, combining in-depth narrative analysis, thematic qualitative analysis, and quantitative analysis, which are designed to enable systematic comparison without sacrificing ethnographic richness.

  12. Self-concept and academic achievement: a meta-analysis of longitudinal relations.

    Science.gov (United States)

    Huang, Chiungjung

    2011-10-01

    The relation between self-concept and academic achievement was examined in 39 independent and longitudinal samples through the integration of meta-analysis and path analysis procedures. For relations with more than 3 independent samples, the mean observed correlations ranged from .20 to .27 between prior self-concept and subsequent academic achievement and from .19 to .25 between prior academic achievement and subsequent self-concept. Globality/specificity of self-concept was the only significant moderating factor in the relation between (a) prior self-concept and subsequent academic achievement and (b) prior academic achievement and subsequent self-concept. As high self-concept is related to high academic performance and vice-versa, intervention programs that combine self-enhancement and skill development should be integrated. Copyright © 2011 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  13. Personality Predicts Mortality Risk: An Integrative Data Analysis of 15 International Longitudinal Studies.

    Science.gov (United States)

    Graham, Eileen K; Rutsohn, Joshua P; Turiano, Nicholas A; Bendayan, Rebecca; Batterham, Philip J; Gerstorf, Denis; Katz, Mindy J; Reynolds, Chandra A; Sharp, Emily S; Yoneda, Tomiko B; Bastarache, Emily D; Elleman, Lorien G; Zelinski, Elizabeth M; Johansson, Boo; Kuh, Diana; Barnes, Lisa L; Bennett, David A; Deeg, Dorly J H; Lipton, Richard B; Pedersen, Nancy L; Piccinin, Andrea M; Spiro, Avron; Muniz-Terrera, Graciela; Willis, Sherry L; Schaie, K Warner; Roan, Carol; Herd, Pamela; Hofer, Scott M; Mroczek, Daniel K

    2017-10-01

    This study examined the Big Five personality traits as predictors of mortality risk, and smoking as a mediator of that association. Replication was built into the fabric of our design: we used a Coordinated Analysis with 15 international datasets, representing 44,094 participants. We found that high neuroticism and low conscientiousness, extraversion, and agreeableness were consistent predictors of mortality across studies. Smoking had a small mediating effect for neuroticism. Country and baseline age explained variation in effects: studies with older baseline age showed a pattern of protective effects (HReffects for extraversion. This study demonstrated coordinated analysis as a powerful approach to enhance replicability and reproducibility, especially for aging-related longitudinal research.

  14. Thyrotropin levels are associated with chronic kidney disease among healthy subjects in cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

    Science.gov (United States)

    Peixoto de Miranda, Érique José F; Bittencourt, Márcio Sommer; Goulart, Alessandra C; Santos, Itamar S; de Oliveira Titan, Silvia Maria; Ladeira, Roberto Marini; Barreto, Sandhi Maria; Lotufo, Paulo A; Benseñor, Isabela Judith Martins

    2017-12-01

    Few studies have evaluated a possible relationship between thyrotropin levels and glomerular filtration rate (GFR) and albumin/creatinine ratio in euthyroid subjects. We aimed to analyze this association using baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Cross-sectionally, we included subjects with normal thyroid function and with subclinical hypothyroidism (SCH). We excluded individuals using medications that affect thyroid function. Linear and logistic regression models evaluated GFR estimated by Chronic Kidney Disease Epidemiology Collaboration (CKD-Epi) and albuminuria/creatinine ratio as dependent variables and thyrotropin quartiles in individuals with euthyroidism and SCH as independent variables, adjusted for demographical characteristics and diseases related to CKD. We included 13,193 subjects with a median age of 51 years [interquartile range, (IQR): 45-58], 6840 (51.8%) women, 12,416 (94.1%) euthyroid, and 777 (5.9%) with SCH. SCH subjects were characterized by higher age, triglycerides, frequency of white race, cardiovascular disease, CKD, and former smokers. In adjusted models, log-transformed TSH in euthyroid subjects was inversely and strongly associated with CKD (β = -2.181, 95% CI -2.714 to -1.648), P < 0.0001 for glomerular filtration rate and 4.528 (1.190-7.865) for albuminuria/creatinine ratio. Multivariate logistic models for euthyroid subjects showed an OR of 1.45 (95% CI 1.15-1.83) for GFR and of 1.95 (95% CI 1.08-3.54) for albuminuria/creatinine ratio in the fourth quartile of TSH using the first as the reference. Thyrotropin levels are independently associated with CKD in euthyroid subjects.

  15. The impact of removing financial incentives from clinical quality indicators: longitudinal analysis of four Kaiser Permanente indicators.

    NARCIS (Netherlands)

    Lester, H.; Schmittdiel, J.; Selby, J.; Fireman, B.; Campbell, S.M.; Lee, J.; Whippy, A.; Madvig, P.

    2010-01-01

    OBJECTIVE: To evaluate the effect of financial incentives on four clinical quality indicators common to pay for performance plans in the United Kingdom and at Kaiser Permanente in California. DESIGN: Longitudinal analysis. SETTING: 35 medical facilities of Kaiser Permanente Northern California,

  16. Connected speech as a marker of disease progression in autopsy-proven Alzheimer’s disease

    Science.gov (United States)

    Ahmed, Samrah; Haigh, Anne-Marie F.; de Jager, Celeste A.

    2013-01-01

    Although an insidious history of episodic memory difficulty is a typical presenting symptom of Alzheimer’s disease, detailed neuropsychological profiling frequently demonstrates deficits in other cognitive domains, including language. Previous studies from our group have shown that language changes may be reflected in connected speech production in the earliest stages of typical Alzheimer’s disease. The aim of the present study was to identify features of connected speech that could be used to examine longitudinal profiles of impairment in Alzheimer’s disease. Samples of connected speech were obtained from 15 former participants in a longitudinal cohort study of ageing and dementia, in whom Alzheimer’s disease was diagnosed during life and confirmed at post-mortem. All patients met clinical and neuropsychological criteria for mild cognitive impairment between 6 and 18 months before converting to a status of probable Alzheimer’s disease. In a subset of these patients neuropsychological data were available, both at the point of conversion to Alzheimer’s disease, and after disease severity had progressed from the mild to moderate stage. Connected speech samples from these patients were examined at later disease stages. Spoken language samples were obtained using the Cookie Theft picture description task. Samples were analysed using measures of syntactic complexity, lexical content, speech production, fluency and semantic content. Individual case analysis revealed that subtle changes in language were evident during the prodromal stages of Alzheimer’s disease, with two-thirds of patients with mild cognitive impairment showing significant but heterogeneous changes in connected speech. However, impairments at the mild cognitive impairment stage did not necessarily entail deficits at mild or moderate stages of disease, suggesting non-language influences on some aspects of performance. Subsequent examination of these measures revealed significant linear trends

  17. Overview of national attitudes toward nuclear energy: a longitudinal analysis

    International Nuclear Information System (INIS)

    Rankin, W.L.

    1982-01-01

    The purpose of this paper is to present a longitudinal overview of public attitudes toward nuclear power development in the United States. Over ten years of attitudinal data are now available for analysis of the stability of such attitudes over time. These data are useful to many people, including policy makers in government, nuclear industry decision makers, and public action groups that support and oppose nuclear power. This information is also useful in checking the claims of those who purport to be speaking for the public. The level of public acceptance for nuclear power in the near term and into the next century can only be estimated at this time. But this estimate can be based on nearly a decade of survey research

  18. Longitudinal Analysis of Academic Burnout in Korean Middle School Students.

    Science.gov (United States)

    Kim, Boyoung; Lee, Minyoung; Kim, Keunhwa; Choi, Hyunju; Lee, Sang Min

    2015-10-01

    The purpose of the study was to investigate the longitudinal relationships between the initial values and slopes of three dimensions of burnout syndrome (i.e. emotional exhaustion, cynicism and academic inefficacy). The study utilized four-wave longitudinal data from a total of 367 (81.6% response rate) middle school students in South Korea. Comprising a 6-month interval survey, the first survey was conducted in June 2010, the second in December 2010, the third in June 2011 and the fourth in December 2011. All participants were 13-year-olds at the first and second surveys, and 14-year-olds at the third and fourth surveys. The Maslach Burnout Inventory-Student Survey was used for each survey to assess the level of academic burnout. The longitudinal data were analysed using latent growth modelling. The results of the study indicated that high initial values (intercept) for emotional exhaustion were associated with a higher rate of increase (slope) in cynicism and academic inefficacy. On the other hand, high initial values for cynicism and academic inefficacy were associated with a lower rate of increase in the other dimensions. This longitudinal study should promote understanding of burned-out students and contribute to the literature by informing the design of prevention programmes for academic burnout. Copyright © 2014 John Wiley & Sons, Ltd.

  19. Longitudinal patterns of predominant asthma disease activity in pediatric patients enrolled in an asthma-specific disease management program.

    Science.gov (United States)

    Scott, Lyne; Nichols, Breck; Choi Kwong, Kenny Yat; Morphew, Tricia; Jones, Craig A

    2008-08-01

    To determine if patterns of predominant asthma disease activity are more closely related than baseline asthma severity to measures of morbidity (acute asthma attack, emergency room visit/hospitalization, missed school days, and/or steroid burst). Retrospective analysis was performed for inner-city Los Angeles asthmatic children (3 to 18 years of age) during their first year of enrollment in an asthma-specific disease management program. All measures of morbidity were more closely related to patterns of predominant disease activity than baseline severity. We conclude that patterns of predominant disease activity are a more significant predictor of asthma morbidity than is baseline severity.

  20. Genome-Wide Meta-Analysis of Longitudinal Alcohol Consumption Across Youth and Early Adulthood.

    Science.gov (United States)

    Adkins, Daniel E; Clark, Shaunna L; Copeland, William E; Kennedy, Martin; Conway, Kevin; Angold, Adrian; Maes, Hermine; Liu, Youfang; Kumar, Gaurav; Erkanli, Alaattin; Patkar, Ashwin A; Silberg, Judy; Brown, Tyson H; Fergusson, David M; Horwood, L John; Eaves, Lindon; van den Oord, Edwin J C G; Sullivan, Patrick F; Costello, E J

    2015-08-01

    The public health burden of alcohol is unevenly distributed across the life course, with levels of use, abuse, and dependence increasing across adolescence and peaking in early adulthood. Here, we leverage this temporal patterning to search for common genetic variants predicting developmental trajectories of alcohol consumption. Comparable psychiatric evaluations measuring alcohol consumption were collected in three longitudinal community samples (N=2,126, obs=12,166). Consumption-repeated measurements spanning adolescence and early adulthood were analyzed using linear mixed models, estimating individual consumption trajectories, which were then tested for association with Illumina 660W-Quad genotype data (866,099 SNPs after imputation and QC). Association results were combined across samples using standard meta-analysis methods. Four meta-analysis associations satisfied our pre-determined genome-wide significance criterion (FDR<0.1) and six others met our 'suggestive' criterion (FDR<0.2). Genome-wide significant associations were highly biological plausible, including associations within GABA transporter 1, SLC6A1 (solute carrier family 6, member 1), and exonic hits in LOC100129340 (mitofusin-1-like). Pathway analyses elaborated single marker results, indicating significant enriched associations to intuitive biological mechanisms, including neurotransmission, xenobiotic pharmacodynamics, and nuclear hormone receptors (NHR). These findings underscore the value of combining longitudinal behavioral data and genome-wide genotype information in order to study developmental patterns and improve statistical power in genomic studies.

  1. Comparison of longitudinal excursion of a nerve-phantom model using quantitative ultrasound imaging and motion analysis system methods: A convergent validity study.

    Science.gov (United States)

    Paquette, Philippe; El Khamlichi, Youssef; Lamontagne, Martin; Higgins, Johanne; Gagnon, Dany H

    2017-08-01

    Quantitative ultrasound imaging is gaining popularity in research and clinical settings to measure the neuromechanical properties of the peripheral nerves such as their capability to glide in response to body segment movement. Increasing evidence suggests that impaired median nerve longitudinal excursion is associated with carpal tunnel syndrome. To date, psychometric properties of longitudinal nerve excursion measurements using quantitative ultrasound imaging have not been extensively investigated. This study investigates the convergent validity of the longitudinal nerve excursion by comparing measures obtained using quantitative ultrasound imaging with those determined with a motion analysis system. A 38-cm long rigid nerve-phantom model was used to assess the longitudinal excursion in a laboratory environment. The nerve-phantom model, immersed in a 20-cm deep container filled with a gelatin-based solution, was moved 20 times using a linear forward and backward motion. Three light-emitting diodes were used to record nerve-phantom excursion with a motion analysis system, while a 5-cm linear transducer allowed simultaneous recording via ultrasound imaging. Both measurement techniques yielded excellent association ( r  = 0.99) and agreement (mean absolute difference between methods = 0.85 mm; mean relative difference between methods = 7.48 %). Small discrepancies were largely found when larger excursions (i.e. > 10 mm) were performed, revealing slight underestimation of the excursion by the ultrasound imaging analysis software. Quantitative ultrasound imaging is an accurate method to assess the longitudinal excursion of an in vitro nerve-phantom model and appears relevant for future research protocols investigating the neuromechanical properties of the peripheral nerves.

  2. The impact of unrecognized autoimmune rheumatic diseases on the incidence of preeclampsia and fetal growth restriction: a longitudinal cohort study.

    Science.gov (United States)

    Spinillo, Arsenio; Beneventi, Fausta; Locatelli, Elena; Ramoni, Vèronique; Caporali, Roberto; Alpini, Claudia; Albonico, Giulia; Cavagnoli, Chiara; Montecucco, Carlomaurizio

    2016-10-18

    The burden of pregnancy complications associated with well defined, already established systemic rheumatic diseases preexisting pregnancy such as rheumatoid arthritis, systemic lupus erythematosus or scleroderma is well known. Systemic rheumatic diseases are characterized by a long natural history with few symptoms, an undifferentiated picture or a remitting course making difficult a timely diagnosis. It has been suggested that screening measures for these diseases could be useful but the impact of unrecognized systemic rheumatic disorders on pregnancy outcome is unknown. The objective of the study was to evaluate the impact of previously unrecognized systemic autoimmune rheumatic on the incidence of preeclampsia and fetal growth restriction (FGR). A longitudinal cohort-study with enrolment during the first trimester of pregnancy of women attending routine antenatal care using a two-step approach with a self-reported questionnaire, autoantibody detection and clinical evaluation of antibody-positive subjects. The incidence of FGR and preeclampsia in subjects with newly diagnosed rheumatic diseases was compared to that of selected negative controls adjusting for potential confounders by logistic regression analysis. The prevalence of previously unrecognized systemic rheumatic diseases was 0.4 % for rheumatoid arthritis (19/5232), 0.25 % (13/5232) for systemic lupus erythematosus, 0.31 % (16/5232) for Sjögren's syndrome, 0.3 % for primary antiphospholipid syndrome (14/5232) and 0.11 % (6/5232) for other miscellaneous diseases. Undifferentiated connective tissue disease was diagnosed in an additional 131 subjects (2.5 %). The incidence of either FGR or preeclampsia was 6.1 % (36/594) among controls and 25.3 % (50/198) in subjects with unrecognized rheumatic diseases (excess incidence = 3.9 % (95 % CI = 2.6-9.6) or 34 % (95 % CI = 22-44) of all cases of FGR/preeclampsia). The incidence of small for gestational age infant (SGA) was higher among

  3. MRI allows for longitudinal quantitative analysis of body fat composition in rats: an analysis of sibutramine-associated changes at the group level.

    Science.gov (United States)

    Müller, Hans-Peter; Niessen, Heiko G; Kaulisch, Thomas; Ludolph, Albert C; Kassubek, Jan; Stiller, Detlef

    2013-09-01

    Body fat distribution changes are associated with multiple alterations in metabolism. Therefore, the assessment of body fat compartments by MRI in animal models is a promising approach to obesity research. Standard T1-weighted (T1w) whole body MRI was used here to quantify different effects in the subcutaneous and visceral fat compartments in rats under treatment with an anorexiant. Twenty rats on a high caloric diet were investigated by the identical MRI protocol at baseline and after seven weeks. Ten rats received a treatment with sibutramine, 10 rats served as vehicle control group. To longitudinally assess body fat components, MRI analysis was used with two approaches: 2D slicewise graphic analysis (SGA) was compared with an automated 3D analysis algorithm (3DA). At the group level, fat volume differences showed a longitudinal increase of subcutaneous and visceral fat volumes for the control group, whereas the sibutramine group showed stable subcutaneous fat volumes and decrease in visceral fat volumes. SGA and 3DA volume determination showed significant correlations for subcutaneous fat volume (C=0.85, psibutramine separate on the fat compartments in rats. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Parkinson's Disease Subtypes Identified from Cluster Analysis of Motor and Non-motor Symptoms.

    Science.gov (United States)

    Mu, Jesse; Chaudhuri, Kallol R; Bielza, Concha; de Pedro-Cuesta, Jesus; Larrañaga, Pedro; Martinez-Martin, Pablo

    2017-01-01

    Parkinson's disease is now considered a complex, multi-peptide, central, and peripheral nervous system disorder with considerable clinical heterogeneity. Non-motor symptoms play a key role in the trajectory of Parkinson's disease, from prodromal premotor to end stages. To understand the clinical heterogeneity of Parkinson's disease, this study used cluster analysis to search for subtypes from a large, multi-center, international, and well-characterized cohort of Parkinson's disease patients across all motor stages, using a combination of cardinal motor features (bradykinesia, rigidity, tremor, axial signs) and, for the first time, specific validated rater-based non-motor symptom scales. Two independent international cohort studies were used: (a) the validation study of the Non-Motor Symptoms Scale ( n = 411) and (b) baseline data from the global Non-Motor International Longitudinal Study ( n = 540). k -means cluster analyses were performed on the non-motor and motor domains (domains clustering) and the 30 individual non-motor symptoms alone (symptoms clustering), and hierarchical agglomerative clustering was performed to group symptoms together. Four clusters are identified from the domains clustering supporting previous studies: mild, non-motor dominant, motor-dominant, and severe. In addition, six new smaller clusters are identified from the symptoms clustering, each characterized by clinically-relevant non-motor symptoms. The clusters identified in this study present statistical confirmation of the increasingly important role of non-motor symptoms (NMS) in Parkinson's disease heterogeneity and take steps toward subtype-specific treatment packages.

  5. A longitudinal analysis of nanotechnology literature: 1976-2004

    International Nuclear Information System (INIS)

    Li Xin; Chen Hsinchun; Dang Yan; Lin Yiling; Larson, Catherine A.; Roco, Mihail C.

    2008-01-01

    Nanotechnology research and applications have experienced rapid growth in recent years. We assessed the status of nanotechnology research worldwide by applying bibliographic, content map, and citation network analysis to a data set of about 200,000 nanotechnology papers published in the Thomson Science Citation Index Expanded database (SCI) from 1976 to 2004. This longitudinal study shows a quasi-exponential growth of nanotechnology articles with an average annual growth rate of 20.7% after 1991. The United States had the largest contribution of nanotechnology research and China and Korea had the fastest growth rates. The largest institutional contributions were from the Chinese Academy of Sciences and the Russian Academy of Sciences. The high-impact papers generally described tools, theories, technologies, perspectives, and overviews of nanotechnology. From the top 20 institutions, based on the average number of paper citations in 1976-2004, 17 were in the Unites States, 2 in France and 1 in Germany. Content map analysis identified the evolution of the major topics researched from 1976 to 2004, including investigative tools, physical phenomena, and experiment environments. Both the country citation network and the institution citation network had relatively high clustering, indicating the existence of citation communities in the two networks, and specific patterns in forming citation communities. The United States, Germany, Japan, and China were major citation centers in nanotechnology research with close inter-citation relationships.

  6. A Semiparametric Marginalized Model for Longitudinal Data with Informative Dropout

    Directory of Open Access Journals (Sweden)

    Mengling Liu

    2012-01-01

    Full Text Available We propose a marginalized joint-modeling approach for marginal inference on the association between longitudinal responses and covariates when longitudinal measurements are subject to informative dropouts. The proposed model is motivated by the idea of linking longitudinal responses and dropout times by latent variables while focusing on marginal inferences. We develop a simple inference procedure based on a series of estimating equations, and the resulting estimators are consistent and asymptotically normal with a sandwich-type covariance matrix ready to be estimated by the usual plug-in rule. The performance of our approach is evaluated through simulations and illustrated with a renal disease data application.

  7. Modelling, simulation and applications of longitudinal train dynamics

    Science.gov (United States)

    Cole, Colin; Spiryagin, Maksym; Wu, Qing; Sun, Yan Quan

    2017-10-01

    Significant developments in longitudinal train simulation and an overview of the approaches to train models and modelling vehicle force inputs are firstly presented. The most important modelling task, that of the wagon connection, consisting of energy absorption devices such as draft gears and buffers, draw gear stiffness, coupler slack and structural stiffness is then presented. Detailed attention is given to the modelling approaches for friction wedge damped and polymer draft gears. A significant issue in longitudinal train dynamics is the modelling and calculation of the input forces - the co-dimensional problem. The need to push traction performances higher has led to research and improvement in the accuracy of traction modelling which is discussed. A co-simulation method that combines longitudinal train simulation, locomotive traction control and locomotive vehicle dynamics is presented. The modelling of other forces, braking propulsion resistance, curve drag and grade forces are also discussed. As extensions to conventional longitudinal train dynamics, lateral forces and coupler impacts are examined in regards to interaction with wagon lateral and vertical dynamics. Various applications of longitudinal train dynamics are then presented. As an alternative to the tradition single wagon mass approach to longitudinal train dynamics, an example incorporating fully detailed wagon dynamics is presented for a crash analysis problem. Further applications of starting traction, air braking, distributed power, energy analysis and tippler operation are also presented.

  8. Disease management programs for patients with asthma in Germany: a longitudinal population-based study.

    Science.gov (United States)

    Mehring, Michael; Donnachie, Ewan; Mutschler, Robert; Hofmann, Frank; Keller, Manfred; Schneider, Antonius

    2013-07-01

    The primary aim of the disease management program (DMP) for patients with asthma is to improve health outcomes and to reduce costs. Five years after its introduction in Germany, no consensus has yet been reached as to whether DMP has been effective in reaching these goals. To evaluate the DMP for asthma in Bavaria using routinely collected subject medical records. A longitudinal population-based study encompassing over 100,000 DMP participants between 2006 (when the program began) and 2010. The prescription rate of oral corticosteroids dropped from 15.7% in 2006 to 13.6% in 2007, and again from 7.5% in 2008 to 5.9% in 2010 (P management education increased from 4.4% to 23.4% (P management. The proportion of subjects requiring hospitalization decreased. Our results suggest that the German DMP for asthma has been effective in enhancing the quality of care in regard to an improved symptom frequency, adherence to guidelines, pharmacotherapy, and hospitalization.

  9. Gratitude uniquely predicts lower depression in chronic illness populations: A longitudinal study of inflammatory bowel disease and arthritis.

    Science.gov (United States)

    Sirois, Fuschia M; Wood, Alex M

    2017-02-01

    Although gratitude has been identified as a key clinically relevant trait for improving well-being, it is understudied within medical populations. The current study addressed this gap and extended previous and limited cross-sectional research by examining the longitudinal associations of gratitude to depression in 2 chronic illness samples, arthritis and inflammatory bowel disease (IBD). Two chronic illness samples, arthritis (N = 423) and IBD (N = 427), completed online surveys at Time 1 (T1). One hundred sixty-three people with arthritis and 144 people with IBD completed the 6-month follow-up survey (T2). Depression, gratitude, illness cognitions, perceived stress, social support, and disease-related variables were assessed at T1 and T2. At T2, 57.2% of the arthritis sample and 53.4% of the IBD sample met the cut off scores for significant depression. T1 gratitude was negatively associated with depressive symptoms at T1 and T2 in both samples (rs from -.43 to -.50). Regression analyses revealed that T1 gratitude remained a significant and unique predictor of lower T2 depression after controlling for T1 depression, relevant demographic variables, illness cognitions, changes in illness-relevant variables, and another positive psychological construct, thriving, in both samples. As the first investigation of the longitudinal associations of gratitude to psychological well-being in the context of chronic illness, the current study provides important evidence for the relevance of gratitude for health-related clinical populations. Further intervention-based research is warranted to more fully understand the potential benefits of gratitude for adjustment to chronic illness. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  10. A single-level random-effects cross-lagged panel model for longitudinal mediation analysis.

    Science.gov (United States)

    Wu, Wei; Carroll, Ian A; Chen, Po-Yi

    2017-12-06

    Cross-lagged panel models (CLPMs) are widely used to test mediation with longitudinal panel data. One major limitation of the CLPMs is that the model effects are assumed to be fixed across individuals. This assumption is likely to be violated (i.e., the model effects are random across individuals) in practice. When this happens, the CLPMs can potentially yield biased parameter estimates and misleading statistical inferences. This article proposes a model named a random-effects cross-lagged panel model (RE-CLPM) to account for random effects in CLPMs. Simulation studies show that the RE-CLPM outperforms the CLPM in recovering the mean indirect and direct effects in a longitudinal mediation analysis when random effects exist in the population. The performance of the RE-CLPM is robust to a certain degree, even when the random effects are not normally distributed. In addition, the RE-CLPM does not produce harmful results when the model effects are in fact fixed in the population. Implications of the simulation studies and potential directions for future research are discussed.

  11. A longitudinal evaluation of persons with disabilities: does a longitudinal definition help define who receives necessary care?

    Science.gov (United States)

    Chan, Leighton; Ciol, Marcia A; Shumway-Cook, Anne; Yorkston, Kathryn M; Dudgeon, Brian J; Asch, Steven M; Hoffman, Jeanne M

    2008-06-01

    To assess, using a longitudinal definition, the impact of disability on a broad range of objective health care quality indicators. Longitudinal cohort study following up with patients over several years. The first 2 interviews, 1 year apart, were used to determine each patient's disability status in activities of daily living (ADLs). Assessment of the health care indicators commenced after the second interview and continued throughout the survey period (an additional 1-3y). National survey. Participants (N=29,074) of the Medicare Current Beneficiary Survey (1992-2001) with no, increasing, decreasing, and stable ADL disability. Not applicable. The incidence of 5 avoidable outcomes, receipt of 3 preventive care measures, and adherence to 32 diagnostically based indicators assessing the quality of treatment for acute myocardial infarction [AMI], angina, breast cancer, cerebrovascular accident, transient ischemic attack, cholelithiasis, chronic obstructive pulmonary disease [COPD], congestive heart failure, depression, gastrointestinal bleeding, diabetes, and hypertension. For most indicators, less than 75% of eligible patients received necessary care, regardless of disability status. For 5 indicators, less than 50% of patients received appropriate treatment. In a logistic regression analysis that controlled for patient age, sex, race, and income, disability status was a significant factor in 7 quality measures (AMI, breast cancer, COPD, diabetes, angina, pneumonia, annual visits). Using a longitudinal definition of disability and objective health quality indicators, we found that disability status can be an important factor in determining receipt of quality health care in a broad range of diagnostic categories. However, the impact of disability status varies depending on the indicator measured. In this cohort of patients, the changing nature of a person's disability seems to have less impact than whether they ever have had any functional deficits.

  12. Morbidade em creche de Brasília: estudo longitudinal de incidência de enfermidades no ano de 1977 Morbidity in a Brasilia day care center: a longitudinal study of disease incidence in 1977

    Directory of Open Access Journals (Sweden)

    Ana Maria Low

    1980-12-01

    Full Text Available Foi feito estudo longitudinal de morbidade em creche de Brasília (Brasil freqüentada por crianças com bom estado nutricional. Foram admitidas na creche durante o ano de 1977 o total de 67 crianças (34 do sexo masculino e 33 do sexo feminino, com idade entre 3 e 21 meses. Infecções de vias aéreas superiores (25,4%, diarréia (23,6% e febre não esclarecida (18,4% representaram dois terços dos diagnósticos. A seguir, em ordem de freqüência, apareceram conjuntivite (15,5%, viroses da infância (7,9%, doenças de pele (3,8%, pequenos acidentes (2,6%, hepatite (2,6% e meningococcemia (0,3%. Houve um total de 343 episódios agudos, dando uma taxa de incidência de 14 enfermidades por criança por ano, independente de sexo e idade.A longitudinal morbidity study was carried out in a day care center in Brasilia (Brazil on a sample of 67 (34 male and 33 female, 3 to 21 months of age well-fed children from middle-class families. A pediatrician was on duty daily in the center. The incidence of disease was: upper respiratory, 25.4%; diarrhea, 23.6%; and undetermined fever, 18.4%. These represented 2/3 of the diagnoses. The other diseases found (and here listed in order of frequency were: conjunctivitis, 15.5%; childhood infections, 7.9%; skin diseases, 3.8%; accidents, 2.6%; hepatitis, 2.6%; and meningitis, 0.3%. There were a total of 343 acute illnesses, giving a mean incidence rate of 14 illnesses per child per year, independent of sex and age. Perhaps the incidence of illnesses would have been lower if the children had not been attending the center, a natural factor in the dissemination of communicable diseases.

  13. Changes in consumption of added sugars from age 13 to 30 years: a systematic review and meta-analysis of longitudinal studies.

    Science.gov (United States)

    Winpenny, E M; Penney, T L; Corder, K; White, M; van Sluijs, E M F

    2017-11-01

    Added sugar intake during adolescence has been associated with weight gain and cardiometabolic risk factors. Moreover, dietary habits may persist into adulthood, increasing chronic disease risk in later life. This systematic review investigated changes in intake of added sugars between the ages of 13 and 30 years. Literature databases were searched for longitudinal studies of diet during adolescence or early adulthood. Retrieved articles were screened for studies including multiple measures of intake of sugars or sugary foods from cohort participants between the ages of 13 and 30. Data were analysed using random-effects meta-analysis, by the three main nutrient and food group categories identified (PROSPERO: CRD42015030126). Twenty-four papers reported longitudinal data on intake of added sugar or sucrose (n = 6), sugar-sweetened beverages (SSBs) (n = 20) and/or confectionery (n = 9). Meta-analysis showed a non-significant per year of age decrease in added sugar or sucrose intake (-0.15% total energy intake (95%CI -0.41; 0.12)), a decrease in confectionery consumption (-0.20 servings/week (95%CI -0.41; -0.001)) and a non-significant decrease in SSB consumption (-0.15 servings/week (95%CI -0.32; 0.02)). Taken together, the overall decrease in added sugar intake observed from adolescence to early adulthood may suggest opportunities for intervention to further improve dietary choices within this age range. © 2017 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of World Obesity Federation.

  14. Decreasing Sports Activity with Increasing Age? Findings from a 20-Year Longitudinal and Cohort Sequence Analysis

    Science.gov (United States)

    Breuer, Christoph; Wicker, Pamela

    2009-01-01

    According to cross-sectional studies in sport science literature, decreasing sports activity with increasing age is generally assumed. In this paper, the validity of this assumption is checked by applying more effective methods of analysis, such as longitudinal and cohort sequence analyses. With the help of 20 years' worth of data records from the…

  15. Methotrexate in ocular manifestations of Behcet's disease: a longitudinal study up to 15 years.

    Science.gov (United States)

    Davatchi, Fereydoun; Shams, Hormoz; Shahram, Farhad; Nadji, Abdolhadi; Chams-Davatchi, Cheyda; Sadeghi Abdollahi, Bahar; Faezi, Tahereh; Akhlaghi, Massoomeh; Ashofteh, Farimah

    2013-10-01

    Ocular manifestations of Behcet's disease (BD) need aggressive treatment to prevent severe loss of vision or blindness. Cytotoxic drugs are the main therapeutic agents and the first line treatment. Methotrexate is the least toxic, used mainly for posterior uveitis. We present here the outcome of eye lesions with methotrexate and prednisolone, in a longitudinal study of up to 15 years, on 682 patients (5447 eye-years of follow-up). Methotrexate was started at 7.5-15 mg/week. Prednisolone was added at 0.5 mg/kg/daily, then adjusted as needed. (i) fulfilling the International Criteria for Behcet's Disease; and (ii) having active posterior uveitis (PU). Visual acuity (VA) was calculated on a scale of 10. Activity indexes were calculated for PU and retinal vasculitis (RV) for each eye. Total Inflammatory Activity Index (TIAI) demonstrating the inflammatory index of both eyes of the patient, and Total Adjusted Disease Activity Index (TADAI) showing both TIAI + VA were also calculated. Overall results: the mean VA improvement was 0.4 (P < 001), PU 1.2 (P < 0.001) and RV 0.6 (P < 0.001). VA improved in 46.5%, PU in 75.4%, and RV in 53.7% of eyes. TIAI improved in 74% of patients and TADAI in 69.4%. VA was aggravated in 37.2%, PU in 11.1%, and RV in 30.3% of eyes. TIAI was aggravated in 17.4% and TADAI in 21.6% of the patients. The remaining kept their baseline values. All parameters improved, PU better than RV. Improvement of VA was the least, mainly due to secondary cataracts. © 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  16. Association Between Change in Body Mass Index, Unified Parkinson's Disease Rating Scale Scores, and Survival Among Persons With Parkinson Disease: Secondary Analysis of Longitudinal Data From NINDS Exploratory Trials in Parkinson Disease Long-term Study 1.

    Science.gov (United States)

    Wills, Anne-Marie A; Pérez, Adriana; Wang, Jue; Su, Xiao; Morgan, John; Rajan, Suja S; Leehey, Maureen A; Pontone, Gregory M; Chou, Kelvin L; Umeh, Chizoba; Mari, Zoltan; Boyd, James

    2016-03-01

    Greater body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) is associated with improved survival among persons with Huntington disease or amyotrophic lateral sclerosis. Weight loss is common among persons with Parkinson disease (PD) and is associated with worse quality of life. To explore the association between change in BMI, Unified Parkinson's Disease Rating Scale (UPDRS) motor and total scores, and survival among persons with PD and to test whether there is a positive association between BMI at randomization and survival. Secondary analysis (from May 27, 2014, to October 13, 2015) of longitudinal data (3-6 years) from 1673 participants who started the National Institute of Neurological Disorders and Stroke Exploratory Trials in PD Long-term Study-1 (NET-PD LS-1). This was a double-blind randomized placebo-controlled clinical trial of creatine monohydrate (10 g/d) that was performed at 45 sites throughout the United States and Canada. Participants with early (within 5 years of diagnosis) and treated (receiving dopaminergic therapy) PD were enrolled from March 2007 to May 2010 and followed up until September 2013. Change across time in motor UPDRS score, change across time in total UPDRS score, and time to death. Generalized linear mixed models were used to estimate the effect of BMI on the change in motor and total UPDRS scores after controlling for covariates. Survival was analyzed using Cox proportional hazards models of time to death. A participant's BMI was measured at randomization, and BMI trajectory groups were classified according to whether participants experienced weight loss ("decreasing BMI"), weight stability ("stable BMI"), or weight gain ("increasing BMI") during the study. Of the 1673 participants (mean [SD] age, 61.7 [9.6] years; 1074 [64.2%] were male), 158 (9.4%) experienced weight loss (decreasing BMI), whereas 233 (13.9%) experienced weight gain (increasing BMI). After adjusting for covariates, we

  17. Hearing Impairment Affects Dementia Incidence. An Analysis Based on Longitudinal Health Claims Data in Germany

    Science.gov (United States)

    Teipel, Stefan; Óvári, Attila; Kilimann, Ingo; Witt, Gabriele; Doblhammer, Gabriele

    2016-01-01

    Recent research has revealed an association between hearing impairment and dementia. The objective of this study is to determine the effect of hearing impairment on dementia incidence in a longitudinal study, and whether ear, nose, and throat (ENT) specialist care, care level, institutionalization, or depression mediates or moderates this pathway. The present study used a longitudinal sample of 154,783 persons aged 65 and older from claims data of the largest German health insurer; containing 14,602 incident dementia diagnoses between 2006 and 2010. Dementia and hearing impairment diagnoses were defined according to International Classification of Diseases, Tenth Revision, codes. We used a Kaplan Meier estimator and performed Cox proportional hazard models to explore the effect of hearing impairment on dementia incidence, controlling for ENT specialist care, care level, institutionalization, and depression. Gender, age, and comorbidities were controlled for as potential confounders. Patients with bilateral (HR = 1.43, pimpairment had higher risks of dementia incidence than patients without hearing impairment. We found no significant effect for unilateral hearing impairment and other diseases of the ear. The effect of hearing impairment was only partly mediated through ENT specialist utilization. Significant interaction between hearing impairment and specialist care, care level, and institutionalization, respectively, indicated moderating effects. We discuss possible explanations for these effects. This study underlines the importance of the association between hearing impairment and dementia. Preserving hearing ability may maintain social participation and may reduce the burden associated with dementia. The particular impact of hearing aid use should be the subject of further investigations, as it offers potential intervention on the pathway to dementia. PMID:27391486

  18. Cerebrospinal fluid biomarker supported diagnosis of Creutzfeldt–Jakob disease and rapid dementias: a longitudinal multicentre study over 10 years

    Science.gov (United States)

    Sanchez-Juan, Pascual; Gawinecka, Joanna; Green, Alison; Ladogana, Anna; Pocchiari, Maurizio; Sanchez-Valle, Raquel; Mitrova, Eva; Sklaviadis, Theodor; Kulczycki, Jerzy; Slivarichova, Dana; Saiz, Albert; Calero, Miguel; Knight, Richard; Aguzzi, Adriano; Laplanche, Jean-Louis; Peoc’h, Katell; Schelzke, Gabi; Karch, Andre; van Duijn, Cornelia M.; Zerr, Inga

    2012-01-01

    To date, cerebrospinal fluid analysis, particularly protein 14-3-3 testing, presents an important approach in the identification of Creutzfeldt–Jakob disease cases. However, one special point of criticism of 14-3-3 testing is the specificity in the differential diagnosis of rapid dementia. The constant observation of increased cerebrospinal fluid referrals in the national surveillance centres over the last years raises the concern of declining specificity due to higher number of cerebrospinal fluid tests performed in various neurological conditions. Within the framework of a European Community supported longitudinal multicentre study (‘cerebrospinal fluid markers’) we analysed the spectrum of rapid progressive dementia diagnoses, their potential influence on 14-3-3 specificity as well as results of other dementia markers (tau, phosphorylated tau and amyloid-β1–42) and evaluated the specificity of 14-3-3 in Creutzfeldt–Jakob disease diagnosis for the years 1998–2008. A total of 29 022 cerebrospinal fluid samples were analysed for 14-3-3 protein and other cerebrospinal fluid dementia markers in patients with rapid dementia and suspected Creutzfeldt–Jakob disease in the participating centres. In 10 731 patients a definite diagnosis could be obtained. Protein 14-3-3 specificity was analysed for Creutzfeldt–Jakob disease with respect to increasing cerebrospinal fluid tests per year and spectrum of differential diagnosis. Ring trials were performed to ensure the comparability between centres during the reported time period. Protein 14-3-3 test specificity remained high and stable in the diagnosis of Creutzfeldt–Jakob disease during the observed time period across centres (total specificity 92%; when compared with patients with definite diagnoses only: specificity 90%). However, test specificity varied with respect to differential diagnosis. A high 14-3-3 specificity was obtained in differentiation to other neurodegenerative diseases (95–97%) and non

  19. Cerebrospinal fluid biomarker supported diagnosis of Creutzfeldt-Jakob disease and rapid dementias: a longitudinal multicentre study over 10 years.

    Science.gov (United States)

    Stoeck, Katharina; Sanchez-Juan, Pascual; Gawinecka, Joanna; Green, Alison; Ladogana, Anna; Pocchiari, Maurizio; Sanchez-Valle, Raquel; Mitrova, Eva; Sklaviadis, Theodor; Kulczycki, Jerzy; Slivarichova, Dana; Saiz, Albert; Calero, Miguel; Knight, Richard; Aguzzi, Adriano; Laplanche, Jean-Louis; Peoc'h, Katell; Schelzke, Gabi; Karch, Andre; van Duijn, Cornelia M; Zerr, Inga

    2012-10-01

    To date, cerebrospinal fluid analysis, particularly protein 14-3-3 testing, presents an important approach in the identification of Creutzfeldt-Jakob disease cases. However, one special point of criticism of 14-3-3 testing is the specificity in the differential diagnosis of rapid dementia. The constant observation of increased cerebrospinal fluid referrals in the national surveillance centres over the last years raises the concern of declining specificity due to higher number of cerebrospinal fluid tests performed in various neurological conditions. Within the framework of a European Community supported longitudinal multicentre study ('cerebrospinal fluid markers') we analysed the spectrum of rapid progressive dementia diagnoses, their potential influence on 14-3-3 specificity as well as results of other dementia markers (tau, phosphorylated tau and amyloid-β(1-42)) and evaluated the specificity of 14-3-3 in Creutzfeldt-Jakob disease diagnosis for the years 1998-2008. A total of 29 022 cerebrospinal fluid samples were analysed for 14-3-3 protein and other cerebrospinal fluid dementia markers in patients with rapid dementia and suspected Creutzfeldt-Jakob disease in the participating centres. In 10 731 patients a definite diagnosis could be obtained. Protein 14-3-3 specificity was analysed for Creutzfeldt-Jakob disease with respect to increasing cerebrospinal fluid tests per year and spectrum of differential diagnosis. Ring trials were performed to ensure the comparability between centres during the reported time period. Protein 14-3-3 test specificity remained high and stable in the diagnosis of Creutzfeldt-Jakob disease during the observed time period across centres (total specificity 92%; when compared with patients with definite diagnoses only: specificity 90%). However, test specificity varied with respect to differential diagnosis. A high 14-3-3 specificity was obtained in differentiation to other neurodegenerative diseases (95-97%) and non

  20. Mortality among immigrants in England and Wales by major causes of death, 1971-2012: A longitudinal analysis of register-based data.

    Science.gov (United States)

    Wallace, Matthew; Kulu, Hill

    2015-12-01

    Recent research has found a migrant mortality advantage among immigrants relative to the UK-born population living in England and Wales. However, while all-cause mortality is useful to show differences in mortality between immigrants and the host population, it can mask variation in mortality patterns from specific causes of death. This study analyses differences in the causes of death among immigrants living in England and Wales. We extend previous research by applying competing-risks survival analysis to study a large-scale longitudinal dataset from 1971 to 2012 to directly compare causes of death. We confirm low all-cause mortality among nearly all immigrants, except immigrants from Scotland, Northern Ireland and the Republic of Ireland (who have high mortality). In most cases, low all-cause mortality among immigrants is driven by lower mortality from chronic diseases (in nearly all cases by lower cancer mortality and in some cases by lower mortality from cardiovascular diseases (CVD)). This low all-cause mortality often coexists with low respiratory disease mortality and among non-western immigrants, coexists with high mortality from infectious diseases; however, these two causes of death contribute little to mortality among immigrants. For men, CVD is the leading cause of death (particularly among South Asians). For women, cancer is the leading cause of death (except among South Asians, for whom CVD is also the leading cause). Differences in CVD mortality over time remain constant between immigrants relative to UK-born, but immigrant cancer patterns shows signs of some convergence to the cancer mortality among the UK-born (though cancer mortality is still low among immigrants by age 80). The study provides the most up-to-date, reliable UK-based analysis of immigrant mortality. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Patient safety in the clinical laboratory: a longitudinal analysis of specimen identification errors.

    Science.gov (United States)

    Wagar, Elizabeth A; Tamashiro, Lorraine; Yasin, Bushra; Hilborne, Lee; Bruckner, David A

    2006-11-01

    Patient safety is an increasingly visible and important mission for clinical laboratories. Attention to improving processes related to patient identification and specimen labeling is being paid by accreditation and regulatory organizations because errors in these areas that jeopardize patient safety are common and avoidable through improvement in the total testing process. To assess patient identification and specimen labeling improvement after multiple implementation projects using longitudinal statistical tools. Specimen errors were categorized by a multidisciplinary health care team. Patient identification errors were grouped into 3 categories: (1) specimen/requisition mismatch, (2) unlabeled specimens, and (3) mislabeled specimens. Specimens with these types of identification errors were compared preimplementation and postimplementation for 3 patient safety projects: (1) reorganization of phlebotomy (4 months); (2) introduction of an electronic event reporting system (10 months); and (3) activation of an automated processing system (14 months) for a 24-month period, using trend analysis and Student t test statistics. Of 16,632 total specimen errors, mislabeled specimens, requisition mismatches, and unlabeled specimens represented 1.0%, 6.3%, and 4.6% of errors, respectively. Student t test showed a significant decrease in the most serious error, mislabeled specimens (P patient safety projects. Trend analysis demonstrated decreases in all 3 error types for 26 months. Applying performance-improvement strategies that focus longitudinally on specimen labeling errors can significantly reduce errors, therefore improving patient safety. This is an important area in which laboratory professionals, working in interdisciplinary teams, can improve safety and outcomes of care.

  2. Training, Innovation and Business Performance: An Analysis of the Business Longitudinal Survey.

    Science.gov (United States)

    Dockery, A. Michael

    This paper uses the Australian Bureau of Statistics' Business Longitudinal Survey to explore relationships between training, innovation, and firm performance for Australian businesses with less than 200 employees. The longitudinal nature of the data is used to test various hypotheses about the nature of the link between training, business changes,…

  3. Joint modelling of longitudinal CEA tumour marker progression and survival data on breast cancer

    Science.gov (United States)

    Borges, Ana; Sousa, Inês; Castro, Luis

    2017-06-01

    This work proposes the use of Biostatistics methods to study breast cancer in patients of Braga's Hospital Senology Unit, located in Portugal. The primary motivation is to contribute to the understanding of the progression of breast cancer, within the Portuguese population, using a more complex statistical model assumptions than the traditional analysis that take into account a possible existence of a serial correlation structure within a same subject observations. We aim to infer which risk factors aect the survival of Braga's Hospital patients, diagnosed with breast tumour. Whilst analysing risk factors that aect a tumour markers used on the surveillance of disease progression the Carcinoembryonic antigen (CEA). As survival and longitudinal processes may be associated, it is important to model these two processes together. Hence, a joint modelling of these two processes to infer on the association of these was conducted. A data set of 540 patients, along with 50 variables, was collected from medical records of the Hospital. A joint model approach was used to analyse these data. Two dierent joint models were applied to the same data set, with dierent parameterizations which give dierent interpretations to model parameters. These were used by convenience as the ones implemented in R software. Results from the two models were compared. Results from joint models, showed that the longitudinal CEA values were signicantly associated with the survival probability of these patients. A comparison between parameter estimates obtained in this analysis and previous independent survival[4] and longitudinal analysis[5][6], lead us to conclude that independent analysis brings up bias parameter estimates. Hence, an assumption of association between the two processes in a joint model of breast cancer data is necessary. Results indicate that the longitudinal progression of CEA is signicantly associated with the probability of survival of these patients. Hence, an assumption of

  4. Quantitative longitudinal interrelationships between brain metabolism and amyloid deposition during a 2-year follow-up in patients with early Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Foerster, Stefan [Technische Universitaet Muenchen, Department of Nuclear Medicine, Munich (Germany); Technische Universitaet Muenchen, TUM-Neuroimaging Center (TUM-NIC), Munich (Germany); Technische Universitaet Muenchen (TUM), Klinik und Poliklinik fuer Nuklearmedizin, Klinikum rechts der Isar, Munich (Germany); Yousefi, Behrooz H.; Wester, Hans-Juergen; Klupp, Elisabeth [Technische Universitaet Muenchen, Department of Nuclear Medicine, Munich (Germany); Rominger, Axel [Ludwig Maximilians Universitaet Muenchen, Department of Nuclear Medicine, Munich (Germany); Foerstl, Hans; Kurz, Alexander; Grimmer, Timo [Technische Universitaet Muenchen, Department of Psychiatry and Psychotherapy, Munich (Germany); Drzezga, Alexander [Technische Universitaet Muenchen, Department of Nuclear Medicine, Munich (Germany); Technische Universitaet Muenchen, TUM-Neuroimaging Center (TUM-NIC), Munich (Germany)

    2012-12-15

    Similar regional anatomical distributions were reported for fibrillary amyloid deposition [measured by {sup 11}C-Pittsburgh compound B (PIB) positron emission tomography (PET)] and brain hypometabolism [measured by {sup 18}F-fluorodeoxyglucose (FDG) PET] in numerous Alzheimer's disease (AD) studies. However, there is a lack of longitudinal studies evaluating the interrelationships of these two different pathological markers in the same AD population. Our most recent AD study suggested that the longitudinal pattern of hypometabolism anatomically follows the pattern of amyloid deposition with temporal delay, which indicates that neuronal dysfunction may spread within the anatomical pattern of amyloid pathology. Based on this finding we now hypothesize that in early AD patients quantitative longitudinal decline in hypometabolism may be related to the amount of baseline amyloid deposition during a follow-up period of 2 years. Fifteen patients with mild probable AD underwent baseline (T1) and follow-up (T2) examination after 24 {+-} 2.1 months with [{sup 18}F]FDG PET, [{sup 11}C]PIB PET, structural T1-weighted MRI and neuropsychological testing [Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery]. Longitudinal cognitive measures and quantitative PET measures of amyloid deposition and metabolism [standardized uptake value ratios (SUVRs)] were obtained using volume of interest (VOI)-based approaches in the frontal-lateral-retrosplenial (FLR) network and in predefined bihemispheric brain regions after partial volume effect (PVE) correction of PET data. Statistical group comparisons (SUVRs and cognitive measures) between patients and 15 well-matched elderly controls who had undergone identical imaging procedures once as well as Pearson's correlation analyses within patients were performed. Group comparison revealed significant cognitive decline and increased mean PIB/decreased FDG SUVRs in the FLR network as well as

  5. Item Response Theory as an Efficient Tool to Describe a Heterogeneous Clinical Rating Scale in De Novo Idiopathic Parkinson's Disease Patients.

    Science.gov (United States)

    Buatois, Simon; Retout, Sylvie; Frey, Nicolas; Ueckert, Sebastian

    2017-10-01

    This manuscript aims to precisely describe the natural disease progression of Parkinson's disease (PD) patients and evaluate approaches to increase the drug effect detection power. An item response theory (IRT) longitudinal model was built to describe the natural disease progression of 423 de novo PD patients followed during 48 months while taking into account the heterogeneous nature of the MDS-UPDRS. Clinical trial simulations were then used to compare drug effect detection power from IRT and sum of item scores based analysis under different analysis endpoints and drug effects. The IRT longitudinal model accurately describes the evolution of patients with and without PD medications while estimating different progression rates for the subscales. When comparing analysis methods, the IRT-based one consistently provided the highest power. IRT is a powerful tool which enables to capture the heterogeneous nature of the MDS-UPDRS.

  6. Evaluation of longitudinal 12 and 24 month cognitive outcomes in premanifest and early Huntington's disease.

    Science.gov (United States)

    Stout, Julie C; Jones, Rebecca; Labuschagne, Izelle; O'Regan, Alison M; Say, Miranda J; Dumas, Eve M; Queller, Sarah; Justo, Damian; Santos, Rachelle Dar; Coleman, Allison; Hart, Ellen P; Dürr, Alexandra; Leavitt, Blair R; Roos, Raymund A; Langbehn, Doug R; Tabrizi, Sarah J; Frost, Chris

    2012-07-01

    Deterioration of cognitive functioning is a debilitating symptom in many neurodegenerative diseases, such as Huntington's disease (HD). To date, there are no effective treatments for the cognitive problems associated with HD. Cognitive assessment outcomes will have a central role in the efforts to develop treatments to delay onset or slow the progression of the disease. The TRACK-HD study was designed to build a rational basis for the selection of cognitive outcomes for HD clinical trials. There were a total of 349 participants, including controls (n=116), premanifest HD (n=117) and early HD (n=116). A standardised cognitive assessment battery (including nine cognitive tests comprising 12 outcome measures) was administered at baseline, and at 12 and 24 months, and consisted of a combination of paper and pencil and computerised tasks selected to be sensitive to cortical-striatal damage or HD. Each cognitive outcome was analysed separately using a generalised least squares regression model. Results are expressed as effect sizes to permit comparisons between tasks. 10 of the 12 cognitive outcomes showed evidence of deterioration in the early HD group, relative to controls, over 24 months, with greatest sensitivity in Symbol Digit, Circle Tracing direct and indirect, and Stroop word reading. In contrast, there was very little evidence of deterioration in the premanifest HD group relative to controls. The findings describe tests that are sensitive to longitudinal cognitive change in HD and elucidate important considerations for selecting cognitive outcomes for clinical trials of compounds aimed at ameliorating cognitive decline in HD.

  7. Longitudinal dynamics in storage rings

    International Nuclear Information System (INIS)

    Colton, E.P.

    1986-01-01

    The single-particle equations of motion are derived for charged particles in a storage ring. Longitudinal space charge is included in the potential assuming an infinitely conducting circular beam pipe with a distributed inductance. The framework uses Hamilton's equations with the canonical variables phi and W. The Twiss parameters for longitudinal motion are also defined for the small amplitude synchrotron oscillations. The space-charge Hamiltonian is calculated for both parabolic bunches and ''matched'' bunches. A brief analysis including second-harmonic rf contributions is also given. The final sections supply calculations of dynamical quantities and particle simulations with the space-charge effects neglected

  8. A longitudinal analysis of prenatal exposure to methylmercury and fatty acids in the Seychelles.

    Science.gov (United States)

    Stokes-Riner, Abbie; Thurston, Sally W; Myers, Gary J; Duffy, Emeir M; Wallace, Julie; Bonham, Maxine; Robson, Paula; Shamlaye, Conrad F; Strain, J J; Watson, Gene; Davidson, Philip W

    2011-01-01

    Maternal fish consumption during pregnancy exposes the fetus simultaneously to methylmercury (MeHg) and long chain polyunsaturated fatty acids (LCPUFA). Data from the Seychelles Child Development Nutrition Study (SCDNS) showed a negative association of MeHg with child development when children were 30 months of age, only when controlling for LCPUFA. Concomitantly, n-3 LCPUFA were found to have a significant positive association only at 9 months. These findings suggest that the effects of MeHg and LCPUFA may vary with age over the first few years of life. We address this by including outcomes at two ages and adjusting for the child's age at testing. A longitudinal analysis utilizing linear mixed models was performed to assess the associations of maternal hair total mercury (THg, a biomarker for MeHg) and maternal LCPUFA with children's Bayley Scales of Infant Development Psychomotor Developmental Index (BSID-II PDI) at 9 and 30 months of age, and to determine whether these associations change over time. Data from 228 children were included. Maternal hair MeHg had a negative effect on BSID PDI, while maternal n-3 LCPUFA had a positive effect. These effects did not change significantly from 9 to 30 months in this analysis. The longitudinal analysis provides increased power for estimating the relationships of prenatal MeHg and LCPUFA exposures during child development. Significant associations of these exposures in opposite directions confirm the importance of LCPUFA in development and the need to adjust for maternal nutrition when studying prenatal MeHg exposure. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Longitudinal CSF biomarkers in patients with early Parkinson disease and healthy controls.

    Science.gov (United States)

    Mollenhauer, Brit; Caspell-Garcia, Chelsea J; Coffey, Christopher S; Taylor, Peggy; Shaw, Leslie M; Trojanowski, John Q; Singleton, Andy; Frasier, Mark; Marek, Kenneth; Galasko, Douglas

    2017-11-07

    To analyze longitudinal levels of CSF biomarkers in drug-naive patients with Parkinson disease (PD) and healthy controls (HC), examine the extent to which these biomarker changes relate to clinical measures of PD, and identify what may influence them. CSF α-synuclein (α-syn), total and phosphorylated tau (t- and p-tau), and β-amyloid 1-42 (Aβ42) were measured at baseline and 6 and 12 months in 173 patients with PD and 112 matched HC in the international multicenter Parkinson's Progression Marker Initiative. Baseline clinical and demographic variables, PD medications, neuroimaging, and genetic variables were evaluated as potential predictors of CSF biomarker changes. CSF biomarkers were stable over 6 and 12 months, and there was a small but significant increase in CSF Aβ42 in both patients with patients with PD and HC from baseline to 12 months. The t-tau remained stable. The p-tau increased marginally more in patients with PD than in HC. α-syn remained relatively stable in patients with PD and HC. Ratios of p-tau/t-tau increased, while t-tau/Aβ42 decreased over 12 months in patients with PD. CSF biomarker changes did not correlate with changes in Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale motor scores or dopamine imaging. CSF α-syn levels at 12 months were lower in patients with PD treated with dopamine replacement therapy, especially dopamine agonists. These core CSF biomarkers remained stable over 6 and 12 months in patients with early PD and HC. PD medication use may influence CSF α-syn. Novel biomarkers are needed to better profile progressive neurodegeneration in PD. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

  10. Cluster analysis of behavioural weight management strategies and associations with weight change in young women: a longitudinal analysis.

    Science.gov (United States)

    Madigan, C D; Daley, A J; Kabir, E; Aveyard, P; Brown, W

    2015-11-01

    Maintaining a healthy weight is important for the prevention of many chronic diseases. Little is known about the strategies used by young women to manage their weight, or the effectiveness of these in preventing weight gain. We aimed to identify clusters of weight control strategies used by women and to determine the average annual weight change among women in each cluster from 2000 to 2009. Latent cluster analysis of weight control strategies reported by 8125 participants in the Australian Longitudinal Study of Women's Health. Analyses were performed in March-November 2014. Weight control strategies were used by 79% of the women, and four unique clusters were found. The largest cluster group (39.7%) was named dieters as 90% had been on a diet in the past year, and half of these women had lost 5 kg on purpose. Women cut down on size of meals, fats and sugars and took part in vigorous physical activity. Additionally 20% had used a commercial programme. The next largest cluster (30.2%) was the healthy living group who followed the public health messages of 'eat less and move more'. The do nothing group (20%) did not actively control their weight whereas the perpetual dieters group (10.7%) used all strategies, including unhealthy behaviours. On average women gained 700 g per year (over 9 years); however, the perpetual dieters group gained significantly more weight (210 g) than the do nothing group (Phealth guidelines on health eating and physical activity.

  11. Studies of generalized elemental imbalances in neurological disease patients using INAA [instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Ehmann, W.D.; Vance, D.E.; Khare, S.S.; Kasarskis, E.J.; Markesbery, W.R.

    1988-01-01

    Evidence has been presented in the literature to implicate trace elements in the etiology of several age-related neurological diseases. Most of these studies are based on brain analyses. Using instrumental neutron activation analysis (INAA), we have observed trace element imbalances in brains of patients with Alzheimer's disease, amyotrophic lateral sclerosis (ALS), and Picks's disease. The most prevalent elemental imbalances found in the brain were for bromine, mercury, and the alkali metals. In this study the authors report INAA studies of trace elements in nonneural tissues from Alzheimer's disease and ALS patients. Samples from household relatives were collected for use as controls wherever possible. Hair samples were washed according to the International Atomic Energy Agency recommended procedure. Fingernail samples were scraped with a quartz knife prior to washing by the same procedure. For ALS patients, blood samples were also collected. These data indicate that elemental imbalances in Alzheimer's disease and ALS are not restricted to the brain. Many elements perturbed in the brain are also altered in the several nonneural tissues examined to date. The imbalances in different tissues, however, are not always in the same direction. The changes observed may represent causes, effects, or simply epiphenomena. Longitudinal studies of nonneural tissues and blood, as well as tissue microprobe analyses at the cellular and subcellular level, will be required in order to better assess the role of trace elements in the etiology of these diseases

  12. Analysis of critically refracted longitudinal waves

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Ning, E-mail: npei@iastate.edu; Bond, Leonard J., E-mail: npei@iastate.edu [Center for Nondestructive Evaluation, Iowa State University, Ames, IA 50011 (United States)

    2015-03-31

    Fabrication processes, such as, welding, forging, and rolling can induce residual stresses in metals that will impact product performance and phenomena such as cracking and corrosion. To better manage residual stress tools are needed to map their distribution. The critically refracted ultrasonic longitudinal (LCR) wave is one such approach that has been used for residual stress characterization. It has been shown to be sensitive to stress and less sensitive to the effects of the texture of the material. Although the LCR wave is increasingly widely applied, the factors that influence the formation of the LCR beam are seldom discussed. This paper reports a numerical model used to investigate the transducers' parameters that can contribute to the directionality of the LCR wave and hence enable performance optimization when used for industrial applications. An orthogonal test method is used to study the transducer parameters which influence the LCR wave beams. This method provides a design tool that can be used to study and optimize multiple parameter experiments and it can identify which parameter or parameters are of most significance. The simulation of the sound field in a 2-D 'water-steel' model is obtained using a Spatial Fourier Analysis method. The effects of incident angle, standoff, the aperture and the center frequency of the transducer were studied. Results show that the aperture of the transducer, the center frequency and the incident angle are the most important factors in controlling the directivity of the resulting LCR wave fields.

  13. An analysis of the effects of aeroelasticity on static longitudinal stability and control of a swept-back-wing airplane

    Science.gov (United States)

    Skoog, Richard B

    1951-01-01

    A theoretical analysis of the effects of aeroelasticity on the stick-fixed static longitudinal stability and elevator angle required for balance of an airplane is presented together with calculated effects for a swept-wing bomber of relatively high flexibility. Although large changes in stability due to certain parameters are indicated for the example airplane, the over-all stability change after considering all parameters was quite small, compared to the individual effects, due to the counterbalancing of wing and tail contributions. The effect of flexibility on longitudinal control for the example airplane was found to be of little real importance.

  14. Exposure to violent video games and aggression in German adolescents: a longitudinal analysis.

    Science.gov (United States)

    Möller, Ingrid; Krahé, Barbara

    2009-01-01

    The relationship between exposure to violent electronic games and aggressive cognitions and behavior was examined in a longitudinal study. A total of 295 German adolescents completed the measures of violent video game usage, endorsement of aggressive norms, hostile attribution bias, and physical as well as indirect/relational aggression cross-sectionally, and a subsample of N=143 was measured again 30 months later. Cross-sectional results at T1 showed a direct relationship between violent game usage and aggressive norms, and an indirect link to hostile attribution bias through aggressive norms. In combination, exposure to game violence, normative beliefs, and hostile attribution bias predicted physical and indirect/relational aggression. Longitudinal analyses using path analysis showed that violence exposure at T1 predicted physical (but not indirect/relational) aggression 30 months later, whereas aggression at T1 was unrelated to later video game use. Exposure to violent games at T1 influenced physical (but not indirect/relational) aggression at T2 via an increase of aggressive norms and hostile attribution bias. The findings are discussed in relation to social-cognitive explanations of long-term effects of media violence on aggression. Copyright 2008 Wiley-Liss, Inc.

  15. Longitudinal Modeling of Functional Decline Associated with Pathologic Alzheimer's Disease in Older Persons without Cognitive Impairment.

    Science.gov (United States)

    Wang, Dai; Schultz, Tim; Novak, Gerald P; Baker, Susan; Bennett, David A; Narayan, Vaibhav A

    2018-01-01

    Therapeutic research on Alzheimer's disease (AD) has moved to intercepting the disease at the preclinical phase. Most drugs in late development have focused on the amyloid hypothesis. To understand the magnitude of amyloid-related functional decline and to identify the functional domains sensitive to decline in a preclinical AD population. Data were from the Religious Orders Study and the Rush Memory and Aging Project. Cognitive decline was measured by a modified version of the Alzheimer's Disease Cooperative Study Preclinical Alzheimer Cognitive Composite. The trajectories of functional decline, as measured by the instrumental and basic activities of daily living, were longitudinally modeled in 484 participants without cognitive impairment at baseline and having both a final clinical and a postmortem neuropathology assessment of AD. Individuals with different final clinical diagnoses had different trajectories of cognitive and functional decline. Individuals with AD dementia, minor cognitive impairment, and no cognitive impairment had the most, intermediate, and least declines. While individuals with pathologic AD had significantly more cognitive decline over time than those without, the magnitude of difference in functional decline between these two groups was small. Functional domains such as handling finance and handling medications were more sensitive to decline. Demonstrating the functional benefit of an amyloid-targeting drug represents a significant challenge as elderly people experience functional decline due to a wide range of reasons with limited manifestation attributable to AD neuropathology. More sensitive functional scales focusing on the functional domains sensitive to decline in preclinical AD are needed.

  16. Hierarchical linear modeling of longitudinal pedigree data for genetic association analysis

    DEFF Research Database (Denmark)

    Tan, Qihua; B Hjelmborg, Jacob V; Thomassen, Mads

    2014-01-01

    -effect models to explicitly model the genetic relationship. These have proved to be an efficient way of dealing with sample clustering in pedigree data. Although current algorithms implemented in popular statistical packages are useful for adjusting relatedness in the mixed modeling of genetic effects...... associated with blood pressure with estimated inflation factors of 0.99, suggesting that our modeling of random effects efficiently handles the genetic relatedness in pedigrees. Application to simulated data captures important variants specified in the simulation. Our results show that the method is useful......Genetic association analysis on complex phenotypes under a longitudinal design involving pedigrees encounters the problem of correlation within pedigrees, which could affect statistical assessment of the genetic effects. Approaches have been proposed to integrate kinship correlation into the mixed...

  17. Quality of life in patients with depression, panic syndrome, other anxiety syndrome, alcoholism and chronic somatic diseases: a longitudinal study in Slovenian primary care patients.

    Science.gov (United States)

    Cerne, Anja; Rifel, Janez; Rotar-Pavlic, Danica; Svab, Igor; Selic, Polona; Kersnik, Janko

    2013-01-01

    To analyse the correlates between the quality of life and chronic diseases and socio-demographic characteristics of patients in family medicine with a special emphasis on depression, panic syndrome, other anxiety syndrome and alcoholism. In a longitudinal study, the data set of 516 family practice attendees recruited from 60 family practices was analysed. Depression, panic syndrome, other anxiety syndrome and alcoholism were diagnosed using appropriate diagnostic interviews. Quality of life was assessed using the SF-12 questionnaire, measuring a mental health score and a physical health score. Data about the number of chronic somatic diseases were obtained from the patients' medical records. Physical health score was negatively associated with higher age (β = -0.25, p chronic somatic diseases (β = -0.10, p chronic somatic diseases as they are associated with poorer quality of life.

  18. Longitudinal Patterns of Glycemic Control and Blood Pressure in Pregnant Women with Type 1 Diabetes Mellitus: Phenotypes from Functional Data Analysis.

    Science.gov (United States)

    Szczesniak, Rhonda D; Li, Dan; Duan, Leo L; Altaye, Mekibib; Miodovnik, Menachem; Khoury, Jane C

    2016-11-01

    Objective  To identify phenotypes of type 1 diabetes control and associations with maternal/neonatal characteristics based on blood pressure (BP), glucose, and insulin curves during gestation, using a novel functional data analysis approach that accounts for sparse longitudinal patterns of medical monitoring during pregnancy. Methods  We performed a retrospective longitudinal cohort study of women with type 1 diabetes whose BP, glucose, and insulin requirements were monitored throughout gestation as part of a program-project grant. Scores from sparse functional principal component analysis (fPCA) were used to classify gestational profiles according to the degree of control for each monitored measure. Phenotypes created using fPCA were compared with respect to maternal and neonatal characteristics and outcome. Results  Most of the gestational profile variation in the monitored measures was explained by the first principal component (82-94%). Profiles clustered into three subgroups of high, moderate, or low heterogeneity, relative to the overall mean response. Phenotypes were associated with baseline characteristics, longitudinal changes in glycohemoglobin A1 and weight, and to pregnancy-related outcomes. Conclusion  Three distinct longitudinal patterns of glucose, insulin, and BP control were found. By identifying these phenotypes, interventions can be targeted for subgroups at highest risk for compromised outcome, to optimize diabetes management during pregnancy. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  19. Social Activity and Cognitive Functioning Over Time: A Coordinated Analysis of Four Longitudinal Studies

    Directory of Open Access Journals (Sweden)

    Cassandra L. Brown

    2012-01-01

    Full Text Available Social activity is typically viewed as part of an engaged lifestyle that may help mitigate the deleterious effects of advanced age on cognitive function. As such, social activity has been examined in relation to cognitive abilities later in life. However, longitudinal evidence for this hypothesis thus far remains inconclusive. The current study sought to clarify the relationship between social activity and cognitive function over time using a coordinated data analysis approach across four longitudinal studies. A series of multilevel growth models with social activity included as a covariate is presented. Four domains of cognitive function were assessed: reasoning, memory, fluency, and semantic knowledge. Results suggest that baseline social activity is related to some, but not all, cognitive functions. Baseline social activity levels failed to predict rate of decline in most cognitive abilities. Changes in social activity were not consistently associated with cognitive functioning. Our findings do not provide consistent evidence that changes in social activity correspond to immediate benefits in cognitive functioning, except perhaps for verbal fluency.

  20. Longitudinal analysis of the behavioral phenotype in a novel transgenic rat model of early stages of Alzheimer's disease.

    Science.gov (United States)

    Galeano, Pablo; Martino Adami, Pamela V; Do Carmo, Sonia; Blanco, Eduardo; Rotondaro, Cecilia; Capani, Francisco; Castaño, Eduardo M; Cuello, A Claudio; Morelli, Laura

    2014-01-01

    Intraneuronal accumulation of amyloid β (iAβ) has been linked to mild cognitive impairment that may precede Alzheimer's disease (AD) onset. This neuropathological trait was recently mimicked in a novel animal model of AD, the hemizygous transgenic McGill-R-Thy1-APP (Tg(+/-)) rat. The characterization of the behavioral phenotypes in this animal model could provide a baseline of efficacy for earlier therapeutic interventions. The aim of the present study was to undertake a longitudinal study of Aβ accumulation and a comprehensive behavioral evaluation of this transgenic rat model. We assessed exploratory activity, anxiety-related behaviors, recognition memory, working memory, spatial learning and reference memory at 3, 6, and 12 months of age. In parallel, we measured Aβ by ELISA, Western blots and semiquantitative immunohistochemistry in hippocampal samples. SDS-soluble Aβ peptide accumulated at low levels (~9 pg/mg) without differences among ages. However, Western blots showed SDS-resistant Aβ oligomers (~30 kDa) at 6 and 12 months, but not at 3 months. When compared to wild-type (WT), male Tg(+/-) rats exhibited a spatial reference memory deficit in the Morris Water Maze (MWM) as early as 3 months of age, which persisted at 6 and 12 months. In addition, Tg(+/-) rats displayed a working memory impairment in the Y-maze and higher anxiety levels in the Open Field (OF) at 6 and 12 months of age, but not at 3 months. Exploratory activity in the OF was similar to that of WT at all-time points. Spatial learning in the MWM and the recognition memory, as assessed by the Novel Object Recognition Test, were unimpaired at any time point. The data from the present study demonstrate that the hemizygous transgenic McGill-R-Thy1-APP rat has a wide array of behavioral and cognitive impairments from young adulthood to middle-age. The low Aβ burden and early emotional and cognitive deficits in this transgenic rat model supports its potential use for drug discovery purposes in

  1. Longitudinal Analysis of Personal and Work-Related Factors Associated With Turnover Among Nurses

    NARCIS (Netherlands)

    Estryn-Behar, Madeleine; van der Heijden, Beatrice; Fry, Clementine; Hasselhorn, Hans Martin

    2010-01-01

    AB Background: Although many scholars have acknowledged the relationship between personal and work-related factors associated with job search and actual turnover, there is a lack of longitudinal designs that test this relationship empirically. Objectives: This longitudinal study examines specific

  2. Multimorbidity and Persistent Depression among Veterans with Diabetes, Heart Disease, and Hypertension

    Science.gov (United States)

    Findley, Patricia; Shen, Chan; Sambamoorthi, Usha

    2011-01-01

    This study investigated the association between multimorbidity and persistent depression among cohorts of veterans with diabetes, heart disease, or hypertension. The retrospective longitudinal analysis used national administrative data on around 1.38 million Veteran Health Administration clinic users merged with Medicare claims data.…

  3. Multi-longitudinal-mode micro-laser model

    Science.gov (United States)

    Staliunas, Kestutis

    2017-10-01

    We derive a convenient model for broad aperture micro-lasers, such as microchip lasers, broad area semiconductor lasers, or VCSELs, taking into account several longitudinal mode families. We provide linear stability analysis, and show characteristic spatio-temporal dynamics in such multi-longitudinal mode laser models. Moreover, we derive the coupled mode model in the presence of intracavity refraction index modulation (intracavity photonic crystal). Contribution to the Topical Issue "Theory and Applications of the Lugiato-Lefever Equation", edited by Yanne K. Chembo, Damia Gomila, Mustapha Tlidi, Curtis R. Menyuk.

  4. Longitudinal Patterns of Change in Systolic Blood Pressure and Incidence of Cardiovascular Disease: The Atherosclerosis Risk in Communities Study.

    Science.gov (United States)

    Petruski-Ivleva, Natalia; Viera, Anthony J; Shimbo, Daichi; Muntner, Paul; Avery, Christy L; Schneider, Andrea L C; Couper, David; Kucharska-Newton, Anna

    2016-06-01

    Elevated blood pressure in midlife contributes significantly to the risk of cardiovascular disease. However, patterns of blood pressure increase may differ among individuals and may result in differential risk. Our goal was to examine the contribution of longitudinal patterns of blood pressure change to incidence of heart failure, coronary heart disease, stroke, and cardiovascular disease mortality. Latent class growth models were used to identify patterns of change in blood pressure across 4 clinical examinations (1987-1998) among 9845 Atherosclerosis Risk in Communities (ARIC) cohort participants (mean age, 53.7 [SD 5.7] years). Patterns of change in systolic blood pressure included slowly and steeply increasing, a decreasing and a sustained elevated blood pressure. Changes in diastolic and mid-blood pressure (½ systolic+½ diastolic) were less pronounced. The association of blood pressure pattern group membership with incidence of clinical outcomes was examined in follow-up from the fourth clinical examination (1996-1998) to December 31, 2011, using Poisson regression models adjusted for demographic and metabolic characteristics, and hypertension medication use. A gradient of rates of all events was observed across the identified patterns. Associations were attenuated after adjustment for covariates. Cumulative systolic blood pressure load, rather than the temporal pattern of change in systolic blood pressure itself, plays a role in determining the risk of cardiovascular disease, in particular, of heart failure and cardiovascular disease mortality, independent of blood pressure level measured at one point in time. © 2016 American Heart Association, Inc.

  5. Prevalence and characteristics of dementia in Parkinson disease

    DEFF Research Database (Denmark)

    Aarsland, Dag; Andersen, Kjeld; Larsen, Jan P

    2003-01-01

    Few longitudinal studies of dementia in Parkinson disease (PD) have been reported, and the proportion of patients with PD who eventually develop dementia is unknown.......Few longitudinal studies of dementia in Parkinson disease (PD) have been reported, and the proportion of patients with PD who eventually develop dementia is unknown....

  6. Micro-Mechanical Analysis About Kink Band in Carbon Fiber/Epoxy Composites Under Longitudinal Compression

    Science.gov (United States)

    Zhang, Mi; Guan, Zhidong; Wang, Xiaodong; Du, Shanyi

    2017-10-01

    Kink band is a typical phenomenon for composites under longitudinal compression. In this paper, theoretical analysis and finite element simulation were conducted to analyze kink angle as well as compressive strength of composites. Kink angle was considered to be an important character throughout longitudinal compression process. Three factors including plastic matrix, initial fiber misalignment and rotation due to loading were considered for theoretical analysis. Besides, the relationship between kink angle and fiber volume fraction was improved and optimized by theoretical derivation. In addition, finite element models considering fiber stochastic strength and Drucker-Prager constitutive model for matrix were conducted in ABAQUS to analyze kink band formation process, which corresponded with the experimental results. Through simulation, the loading and failure procedure can be evidently divided into three stages: elastic stage, softening stage, and fiber break stage. It also shows that kink band is a result of fiber misalignment and plastic matrix. Different values of initial fiber misalignment angle, wavelength and fiber volume fraction were considered to explore the effects on compressive strength and kink angle. Results show that compressive strength increases with the decreasing of initial fiber misalignment angle, the decreasing of initial fiber misalignment wavelength and the increasing of fiber volume fraction, while kink angle decreases in these situations. Orthogonal array in statistics was also built to distinguish the effect degree of these factors. It indicates that initial fiber misalignment angle has the largest impact on compressive strength and kink angle.

  7. Persistence and clearance of Ebola virus RNA from seminal fluid of Ebola virus disease survivors: a longitudinal analysis and modelling study

    Directory of Open Access Journals (Sweden)

    Daouda Sissoko, MD

    2017-01-01

    Full Text Available Summary: Background: By January, 2016, all known transmission chains of the Ebola virus disease (EVD outbreak in west Africa had been stopped. However, there is concern about persistence of Ebola virus in the reproductive tract of men who have survived EVD. We aimed to use biostatistical modelling to describe the dynamics of Ebola virus RNA load in seminal fluid, including clearance parameters. Methods: In this longitudinal study, we recruited men who had been discharged from three Ebola treatment units in Guinea between January and July, 2015. Participants provided samples of seminal fluid at follow-up every 3–6 weeks, which we tested for Ebola virus RNA using quantitative real-time RT-PCR. Representative specimens from eight participants were then inoculated into immunodeficient mice to test for infectivity. We used a linear mixed-effect model to analyse the dynamics of virus persistence in seminal fluid over time. Findings: We enrolled 26 participants and tested 130 seminal fluid specimens; median follow up was 197 days (IQR 187–209 days after enrolment, which corresponded to 255 days (228–287 after disease onset. Ebola virus RNA was detected in 86 semen specimens from 19 (73% participants. Median duration of Ebola virus RNA detection was 158 days after onset (73–181; maximum 407 days at end of follow-up. Mathematical modelling of the quantitative time-series data showed a mean clearance rate of Ebola virus RNA from seminal fluid of −0·58 log units per month, although the clearance kinetic varied greatly between participants. Using our biostatistical model, we predict that 50% and 90% of male survivors clear Ebola virus RNA from seminal fluid at 115 days (90% prediction interval 72–160 and 294 days (212–399 after disease onset, respectively. We also predicted that the number of men positive for Ebola virus RNA in affected countries would decrease from about 50 in January 2016, to fewer than 1 person by July, 2016. Infectious

  8. Time-Course Gene Set Analysis for Longitudinal Gene Expression Data.

    Directory of Open Access Journals (Sweden)

    Boris P Hejblum

    2015-06-01

    Full Text Available Gene set analysis methods, which consider predefined groups of genes in the analysis of genomic data, have been successfully applied for analyzing gene expression data in cross-sectional studies. The time-course gene set analysis (TcGSA introduced here is an extension of gene set analysis to longitudinal data. The proposed method relies on random effects modeling with maximum likelihood estimates. It allows to use all available repeated measurements while dealing with unbalanced data due to missing at random (MAR measurements. TcGSA is a hypothesis driven method that identifies a priori defined gene sets with significant expression variations over time, taking into account the potential heterogeneity of expression within gene sets. When biological conditions are compared, the method indicates if the time patterns of gene sets significantly differ according to these conditions. The interest of the method is illustrated by its application to two real life datasets: an HIV therapeutic vaccine trial (DALIA-1 trial, and data from a recent study on influenza and pneumococcal vaccines. In the DALIA-1 trial TcGSA revealed a significant change in gene expression over time within 69 gene sets during vaccination, while a standard univariate individual gene analysis corrected for multiple testing as well as a standard a Gene Set Enrichment Analysis (GSEA for time series both failed to detect any significant pattern change over time. When applied to the second illustrative data set, TcGSA allowed the identification of 4 gene sets finally found to be linked with the influenza vaccine too although they were found to be associated to the pneumococcal vaccine only in previous analyses. In our simulation study TcGSA exhibits good statistical properties, and an increased power compared to other approaches for analyzing time-course expression patterns of gene sets. The method is made available for the community through an R package.

  9. Longitudinal analysis of categorical epidemiological data: a study of Three Mile Island.

    Science.gov (United States)

    Fienberg, S E; Bromet, E J; Follmann, D; Lambert, D; May, S M

    1985-11-01

    The accident at the Three Mile Island nuclear power plant in 1979 led to an unprecedented set of events with potentially life threatening implications. This paper focusses on the analysis of a longitudinal study of the psychological well-being of the mothers of young children living within 10 miles of the plant. The initial analyses of the data utilize loglinear/logit model techniques from the contingency table literature, and involve the fitting of a sequence of logit models. The inadequancies of these analyses are noted, and a new class of mixture models for logistic response structures is introduced to overcome the noted shortcomings. The paper includes a brief outline of the methodology relevant for the fitting of these models using the method of maximum likelihood, and then the model is applied to the TMI data. The paper concludes with a discussion of some of the substantive implications of the mixture model analysis.

  10. Assessment of significance of features acquired from thyroid ultrasonograms in Hashimoto's disease

    Directory of Open Access Journals (Sweden)

    Koprowski Robert

    2012-08-01

    Full Text Available Abstract Introduction This paper concerns the analysis of the features obtained from thyroid ultrasound images in left and right transverse and longitudinal sections. In the image analysis, the thyroid lobe is treated as a texture for healthy subjects and patients with Hashimoto’s disease. The applied methods of analysis and image processing were profiled to obtain 10 features of the image. Then, their significance in the classification was shown. Material In this study, the examined group consisted of 29 healthy subjects aged 18 to 60 and 65 patients with Hashimoto's disease. For each subject, four ultrasound images were taken. They were all in transverse and longitudinal sections of the right and left lobe of the thyroid, which gave 376 images in total. Method 10 different features obtained from each ultrasound image were suggested. The analyzed thyroid lobe was marked automatically or manually with a rectangular element. Results The analysis of 10 features and the creation for each one of them their own decision tree configuration resulted in distinguishing 3 most significant features. The results of the quality of classification show accuracy above 94% for a non-trimmed decision tree.

  11. Statistical analysis of longitudinal network data with changing composition

    NARCIS (Netherlands)

    Huisman, M; Snijders, TAB; Snijders, Tom A.B.

    2003-01-01

    Markov chains can be used for the modeling of complex longitudinal network data. One class of probability models to model the evolution of social networks are stochastic actor-oriented models for network change proposed by Snijders. These models are continuous-time Markov chain models that are

  12. Physical Activity and Personality Development over Twenty Years: Evidence from Three Longitudinal Samples.

    Science.gov (United States)

    Stephan, Yannick; Sutin, Angelina R; Luchetti, Martina; Bosselut, Grégoire; Terracciano, Antonio

    2018-04-01

    A physically inactive lifestyle is associated with maladaptive patterns of personality development over relatively short follow-up periods. The present study extends existing research by examining whether this association persists over 20 years. Participants (total N = 8,723) were drawn from the Wisconsin Longitudinal Study Graduates and Siblings samples and the Midlife in the United States Study. Controlling for demographic factors and disease burden, baseline physical inactivity was related to steeper declines in conscientiousness in all three samples and a meta-analysis (β=-.06). The meta-analysis further showed that lower physical activity was associated with declines in openness (β=-.05), extraversion (β=-.03), and agreeableness (β=-.03). These findings provide evidence that a physically inactive lifestyle is associated with long-term detrimental personality trajectories.

  13. Association between earthquake events and cholera outbreaks: a cross-country 15-year longitudinal analysis.

    Science.gov (United States)

    Sumner, Steven A; Turner, Elizabeth L; Thielman, Nathan M

    2013-12-01

    Large earthquakes can cause population displacement, critical sanitation infrastructure damage, and increased threats to water resources, potentially predisposing populations to waterborne disease epidemics such as cholera. Problem The risk of cholera outbreaks after earthquake disasters remains uncertain. A cross-country analysis of World Health Organization (WHO) cholera data that would contribute to this discussion has yet to be published. A cross-country longitudinal analysis was conducted among 63 low- and middle-income countries from 1995-2009. The association between earthquake disasters of various effect sizes and a relative spike in cholera rates for a given country was assessed utilizing fixed-effects logistic regression and adjusting for gross domestic product per capita, water and sanitation level, flooding events, percent urbanization, and under-five child mortality. Also, the association between large earthquakes and cholera rate increases of various degrees was assessed. Forty-eight of the 63 countries had at least one year with reported cholera infections during the 15-year study period. Thirty-six of these 48 countries had at least one earthquake disaster. In adjusted analyses, country-years with ≥10,000 persons affected by an earthquake had 2.26 times increased odds (95 CI, 0.89-5.72, P = .08) of having a greater than average cholera rate that year compared to country-years having earthquake. The association between large earthquake disasters and cholera infections appeared to weaken as higher levels of cholera rate increases were tested. A trend of increased risk of greater than average cholera rates when more people were affected by an earthquake in a country-year was noted. However these findings did not reach statistical significance at traditional levels and may be due to chance. Frequent large-scale cholera outbreaks after earthquake disasters appeared to be relatively uncommon.

  14. The Exploding Spark: Workplace Violence in an Infectious Disease Hospital—A Longitudinal Study

    Directory of Open Access Journals (Sweden)

    Nicola Magnavita

    2013-01-01

    Full Text Available Objectives. Workplace violence (WV is an important occupational hazard for healthcare workers (HCWs. Methods. A longitudinal study was carried out on HCWs from an infectious disease hospital. Work-related stress, anxiety, and depression were measured at baseline in 2003, and they were reassessed in 2005, along with the assaults that occurred in the previous year. Results. One-year prevalences of 6.2% and 13.9% were reported for physical and verbal aggressions, respectively. Perpetrators were mainly patients. The professional groups most frequently attacked were physicians, followed by nurses. Workers with job strain at baseline had a significant risk of being subject to aggression (OR 7.7; CI 95%, 3.3–17.9 in the following year. The relationship between job strain and subsequent WV remained significant even after correction for anxiety, depression, and other confounders. Conversely, experiencing WV was associated with a high risk of job strain and effort-reward imbalance in the following year. The final levels of anxiety and depression were predicted using regression models that included physical aggression among predictive variables. Conclusions. WV is the spark that sets off a problematic work situation. Effective prevention of WV can only be achieved within the framework of an overall improvement in the quality of work.

  15. Longitudinal analysis of quality of life in patients with undifferentiated connective tissue diseases

    Directory of Open Access Journals (Sweden)

    Iudici M

    2017-02-01

    Full Text Available Michele Iudici, Rosaria Irace, Antonella Riccardi, Giovanna Cuomo, Serena Vettori, Gabriele Valentini Rheumatology Section, Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy Introduction/objectives: To prospectively assess the quality of life (QoL of patients affected by undifferentiated connective tissue diseases (UCTDs and to identify factors associated with changes over time.Patients and methods: A total of 46 consecutive UCTD patients completed the Short-Form 36 (SF-36 questionnaire at presentation and then yearly. At each 6-month visit, all patients underwent a detailed history taking and a laboratory and physical assessment, in order to follow the evolution of the disease over time and to assess the the co-existence of fibromyalgia.Results: At presentation, scores lower than the average of the general population were detected in 34 (74% and 41 (89% patients in the physical and mental domains, respectively. No difference between patients with and without Raynaud’s phenomenon was detected. Fibromyalgia was the only independent variable associated with an impaired physical component summary score (p = 0.0009. No patient feature was found to be associated with the basal mental component summary score. During 24 months of follow-up, a significant improvement (ie, a change ≥5 from baseline in physical component summary and mental component summary scores was observed in 14 (33.3% and 20 (43.4% patients, respectively. Patients who significantly improved in the physical domain more frequently had a history of glucocorticoids intake (p < 0.001, while those who improved in the mental component more frequently had a history of either glucocorticoids (p = 0.043 or immunosuppressors (p = 0.037 intake during follow-up.Conclusion: UCTD patients perceive a worse QoL, regardless of Raynaud’s phenomenon Fibromyalgia is one of the major contributors of physical QoL, whereas no factor influencing

  16. Longitudinal changes in white matter disease and cognition in the first year of the Alzheimer disease neuroimaging initiative

    NARCIS (Netherlands)

    Carmichael, Owen; Schwarz, Christopher; Drucker, David; Fletcher, Evan; Harvey, Danielle; Beckett, Laurel; Jack, Clifford R.; Weiner, Michael; Decarli, Charles; Abdi, Herve; Abeliovich, Asa; Abellan van Kan, Gabor; Abner, Erin; Acharya, Deepa; Adams, Nicholas; Adler, Daniel; Agrusti, Antonella; Agyemang, Alex; Ahdidan, Jamila; Ahn, Jae Eun; Aisen, Paul; Aksu, Yaman; Al-Akhras, Mousa; Alarcon, Marcelo; Alberca, Roman; Alexander, Gene; Alexander, Daniel; Almeida, Fabio; Anand, Rishi; Anand, Shyam; Andrew, Marilee; Anjum, Ayesha; Aoyama, Eiji; Ard, Michael Colin; Arfanakis, Konstantinos; Armor, Tom; Arnold, Steven; Asatryan, Albert; Ashe-McNalley, Cody; Ashiga, Hirokazu; Assareh, Arezoo; Aubry, Florent; Avants, Brian; Avinash, Gopal; Awasthi, Sukrati; Ayan-Oshodi, Mosun; Bagci, Ulas; Bai, Shuyang; Baker, John; Banks, Sarah; Bard, Jonathan; Barnes, Josephine; Barret, Olivier; Bartzokis, George; Barua, Neil; Bauer, Corinna; Becker, James; Bednar, Martin; Beg, Mirza Faisal; Bek, Stephan; Bernard, Charlotte; Bertram, Lars; Bhagwagar, Zubin; Biffi, Alessandro; Bilgic, Basar; Bishnoi, Mahesh; Bishop, Courtney; Bittner, Daniel; Black, Ronald; Blennow, Kaj; Bogorodzki, Piotr; Bokde, Arun; Bonner-Jackson, Aaron; Boppana, Madhu; Bourgeat, Pierrick; Bowes, Mike; Bowman, Gene; Bowman, DuBois; Braskie, Meredith; Brewer, James; Brickman, Adam; Broadbent, Steve; Brooks, David; Browndyke, Jeffrey; Bruat, Vanessa; Brunton, Simon; Buchert, Ralph; Buchsbaum, Monte; Buckley, Chris; Burger, Cyrill; Burns, Jeffrey; Burton, David; Butman, John; Cabeza, Rafael; Cairns, Nigel; Callhoff, Johanna; Calvini, Piero; Campbell, Aaron; Cantillon, Marc; Capella, Heraldo; Cardona-Sanclemente, Luis Eduardo; Carle, Adam; Carmasin, Jeremy; Carranza-Ath, Fredy; Casanova, Ramon; Cash, David; Cella, Massimo; Celsis, Pierre; Chan, Lung Tat Andrew; Chaney, Megan; Chanu, Pascal; Chao, Linda; Charil, Arnaud; Chemali, Zeina; Chen, Baojiang; Chen, Kewei; Chen, Ting; Chen, Minhua; Chen, Gennan; Chen, Rong; Cheng, Wei-Chen; Chertkow, Howard; Chiang, Gloria; Chiba, Koji; Chisholm, Jane; Cho, Youngsang; Choe, John; Choubey, Suresh; Christensen, Anette Luther; Clark, Chris; Clark, David; Clarkson, Matt; Clayton, David; Clunie, David; Coimbra, Alexandre; Compton, David; Crane, Paul; Crans, Gerald; Croop, Robert; Crowther, Daniel; Crum, William; Cui, Yue; Curry, Charles; Curtis, Steven; Cutter, Gary; Daiello, Lori; Dake, Michael; Dale, Anders; Damato, Vito Domenico; Darby, Eveleen; Darkner, Sune; Davatzikos, Christos; Dave, Jay; David, Renaud; Davidson, Julie; de Bruijne, Marleen; de Meyer, Geert; de Nunzio, Giorgio; de Santi, Susan; Dechairo, Bryan; DeDuck, Kristina; Dejkam, Arsalan; Delfino, Manuel; Delpassand, Ebrahim; Deniz, Oscar; Denney, Douglas; DeOrchis, Vincent; Depy Carron, Delphine; deToledo-Morrell, Leyla; Devanand, Davangere; Devanarayan, Viswanath; Diaz, Gloria; Diaz-Arrastia, Ramon; Dickerson, Bradford; Dinov, Ivo; Dodge, Hiroko; Donohue, Michael; Dowling, Maritza; Drzezga, Alex; Duan, Xujun; Duchesne, Simon; Duff, Kevin; Dukart, Jurgen; Durazzo, Timothy; Dykstra, Kevin; Earl, Nancy; Edula, Goutham; Ekin, Ahmet; Engelman, Corinne; Epstein, Noam; Erten-Lyons, Deniz; Eskildsen, Simon; Falcone, Guido; Fan, Yong; Farnum, Michael; Farrer, Lindsay; Farzan, Ali; Feldman, Howard; Feng, Yan; Fennema-Notestine, Christine; Fernandes, Michel; Fernandez, Elsa; Ferrarini, Luca; Ferreira, Luiz; Ferrer, Eugene; Figurski, Michal; Filipovych, Roman; Finch, Stephen; Finlay, Daniel; Fiot, Jean-Baptiste; Flenniken, Derek; Fletcher, P. Thomas; Flynn Longmire, Crystal; Forman, Mark; Forsythe, Alan; Fox-Bosetti, Sabrina; Francis, Alexander L.; Franco-Villalobos, Conrado; Franko, Edit; Freeman, Stefanie; Friedrich, Christoph M.; Friesenhahn, Michel; Frings, Lars; Frisoni, Giovanni; Fritzsche, Klaus; Fujimoto, Yoko; Fujiwara, Ken; Fullerton, Terence; Furney, Simon; Gallins, Paul; Gamst, Anthony; Gan, Ke; Garcia, Maria Teresa; Garcia-Linares, Antonio; Garg, Gaurav; Gaser, Christian; Gastineau, Edward; Gavidia, Giovana; Gazdzinski, Stefan; Ge, Qi; Gemme, Gianluca; German, Dwight; Ghassabi, Zeinab; Gil, Juan E.; Gill, Ryan; Gitelman, Darren; Gleason, Carey; Godbey, Michael; Goghari, Vina; Gold, Michael; Goldberg, Terry; Gomeni, Roberto; Gong, Shangwenyan; Gonzales, Celedon; Gordon, Brian; Gorriz, Juan Manuel; Grachev, Igor; Grandey, Emily; Grasela, Thaddeus; Gratt, Jeremy; Gray, Katherine; Greenberg, Barry; Gregg, Keith; Gregory, Erik; Greicius, Michael; Greve, Douglas; Grill, Joshua; Gross, Alan; Guo, Lianghao; Guo, Hongbin; Guo, Jeffrey; Habeck, Christian; Hai, Yizhen; Haight, Thaddeus; Hakansson, Kristina; Hammarstrom, Per; Hampel, Harald; Han, Tony; Han, Jian; Hanif, Muhammad; Hanna, Yousef; Hardy, Peter; Hasan, Md Kamrul; Hazart, Aurelien; Hazel, James; He, Yong; He, Huiguang; Head, Denise; Heckemann, Rolf; Heidebrink, Judith; Henderson, David; Henrard, Sebastien; Herholz, Karl; Hernandez, Monica; Hess, Christopher; Hobart, Jeremy; Hoffman, John; Holder, Daniel; Honigberg, Lee; Horsfield, Mark; Hsu, Wei-Wen; Hsu, Ailing; Hu, Zhenghui; Hu, Zhiwei; Hu, Xiaolan; Hu, William; Huang, Shu-Pang; Huang, Chun-Jung; Huang, Fude; Huang, Yifan; Huang, Juebin; Huang, Chingwen; Hubbard, Rebecca; Huentelman, Matthew; Hui, Shen; Huppertz, Hans-Jurgen; Hurko, Orest; Hurt, Stephen; Huyck, Susan; Hwang, Scott; Hyun, JungMoon; Ifeachor, Emmanuel; Iglesias, Martina; Ikari, Yasuhiko; Immermann, Fred; Inoue, Lurdes; Insel, Philip; Irizarry, Michael; Irungu, Benson mwangi; Ishibashi, Taro; Ishii, Kenji; Ismail, Shahina; Ito, Kaori; Ito, Momoyo; Iwatsubo, Takeshi; Iyer, Madhumitha; Jacobson, Mark; Jacobson, Alex; Jafari, Aria; Jafari-Khouzani, Kourosh; Jaffe, Carl; Jagust, William; Jara, Hernan; Jaros, Mark; Jefferson, Angela; Jiang, Tianzi; Johnson, David K.; Juengling, Freimut; Juh, Rahyeong; Julin, Per; Bhaskar, Uday; Kadish, Bill; Kahle-Wrobleski, Kristin; Kallam, Hanimi Reddy; Kalpathy-Cramer, Jayashree; Karageorgiou, Elissaios; Karantzoulis, Stella; Karasev, Peter; Kauwe, John; Kawakami, Hirofumi; Kazimipoor, Borhan; Kelleher, Thomas; Kennedy, Richard; Kerr, Douglas; Kerrouche, Nacer; Khalil, Iya; Khalil, Andre; Khatry, Deepak; Kihel, Badra; Killeen, Neil; Killiany, Ron; Kim, Hyewon; Kim, Heeyoung; Kim, Yeonhee; Kim, Jong Hun; Kimberg, Daniel; Kimura, Tokunori; King, Richard; Kirby, Justin; Kita, Hiroshi; Klimas, Michael; Klopfenstein, Erin; Kobayashi, Dione; Koikkalainen, Juha; Kokomoor, Anders; Kolasny, Anthony; Kondo, Yusuke; Koppel, Jeremy; Korolev, Igor; Kotran, Nickolas; Kouassi, Alex; Koutsouleris, Nikolaos; Kozma, Lynn; Kramer, Joel; Kratzer, Martina; Kuceyeski, Amy; Kuhn, Felix Pierre; Kulkarni, Mauktik; Kumar, Sreedhar; Kuo, Hsun Ting; Kuo, Julie; Kurosawa, Ken; Kwon, Oh Hun; Laforet, Genevieve; Lai, Song; Lakatos, Anita; Landau, Susan; Landen, Jaren; Lane, Richard; Langbaum, Jessica; Lanius, Vivian; Lavault, Romain; Laxamana, Joel; Le, Trung; Leahy, Richard; Lee, Noah; Lee, Vita; Lee, Joseph H.; Lee, Jong-Min; Lee, Dongsoo; Lee, Junyoung; Lefkimmiatis, Stamatis; Lemaitre, Herve; Lenz, Robert; Lester, Gayle; Levey, Allan; Li, Rui; Li, Wenjun; Li, Shanshan; Li, Lexin; Li, Shi-jiang; Li, Gang; Li, Lin; Li, Yi; Li, Jinhe; Li, Chin-Shang; Liang, Peipeng; Liang, Lichen; Liao, Yuan-Lin; Lin, Mingkuan; Lin, Lan; Lin, Ling-chih; Liu, Tao; Liu, Meijie; Liu, Yuan; Liu, Dazhong; Liu, Pu; Liu, Songling; Liu, Xiuwen; Liu, Tianming; Lo, Raymond; Logovinsky, Veronika; Lois, Augusto; Long, Xiaojing; Long, Ziyi; Looi, Jeffrey; Lu, Yuan; Lu, Po-Haong; Lukic, Ana; Lull, Juan J.; Lynch, John; Ma, Lei; Mackin, Scott; Magda, Sebastian; Maglio, Silvio; Mak, Henry Ka-Fung; Malave, Vicente; Mandal, Pravat; Mangin, Jean-Francois; Manohar, Deepak; Mansouri, Chemseddine; Mantri, Ninad; Manzour, Amir; Marambaud, Philippe; Marchewka, Artur; Marek, Kenneth; Markind, Samuel; Marshall, Gad; Martin, Jacob; Mather, Mara; Mathis, Chester; Matoug, Sofia; Matsuo, Yoshiyuki; Matthews, Dawn; Mayo, Agustin; McEvoy, Linda; McGeown, William; McIntyre, John; McQuail, Joseph; Meadowcroft, Mark; Meda, Shashwath; Mehta, Nirav; Mele, Valeria; Mendonca, Brian; Menendez, Manuel; Meredith, Jere; Merrill, David; Mesulam, Marek-Marsel; Meyer, Carsten; Mez, Jesse; Mickael, Guedj; Miftahof, Roustem; Mikhno, Arthur; Miller, David; Min, Ye; Miri, Roham; Mirza, Mubeena; Mitsis, Effie; Mohan, Ananth; Monno, Laura; Montana, Giovanni; Moore, Dana; Birgani, Parmida Moradi; Moratal, David; Morimoto, Bruce; Mortamet, Benedicte; Motyl, Rafal; Mueller, Notger; Mukherjee, Shubhabrata; Mulder, Emma; Murphy, Michael; Murray, Brian; Musiek, Erik; Myers, Amanda; Najafi, Shahla; Nazeri, Arash; Nettiksimmons, Jasmine; Neu, Scott; Neves, Simone; Ng, Yen-Bee; Nguyen, Danh; Nguyen, Nghi; Nguyen Xuan, Tuong; Nielsen, Casper; Nuneez Benjumea, Francisco; O'Neil, Alison; Obisesan, Thomas; Oh, Dong Hoon; Oh, Joonmi; Okonkwo, Ozioma; Olde Rikkert, Marcel; Ollesch, Julian; Olmos, Salvador; Ostrowitzki, Susanne; Oswald, Annahita; Ott, Brian; Ourselin, Sebastien; Ouyang, Gaoxiang; Paiva, Renata; Pan, Zhifang; Pande, Yogesh; Pardoe, Heath; Park, Kee Hyung; Park, Hyunjin; Parsey, Ramin; Parveen, Riswana; Paskavitz, James; Patel, Yogen; Patil, Manasi; Paul, Robert; Pawlak, Mikolaj; Peavy, Guerry; Peng, Yahong; Pepin, Jean louis; Perea, Rodrigo; Perneczky, Robert; Petitti, Diana; Petrella, Jeffrey; Peyrat, Jean-Marc; Pezoa, Jorge; Pham, Chi-Tuan; Phillips, Nicole; Piovezan, Mauro; Podhorski, Adam; Pollari, Mika; Pontecorvo, Michael; Poppenk, Jordan; Posner, Holly; Potkin, Steven; Poulin, Stephane; Prasad, Gautam; Prenger, Kurt; Prieto, Elena; Prince, Jerry; Puchakayala, Shashidhar Reddy; Qin, Wei; Qiu, Ruolun; Qiu, Wendy; Qiu, Anqi; Qualls, Constance Dean; Rabie, Huwaida; Rajeesh, Rajeesh; Rajeesh, J. Rajeesh; Rallabandi, V. P. Subramanyam; Ramage, Amy; Randolph, Christopher; Raniga, Parnesh; Rao, Divya; Rao, Anil; Raubertas, Richard; Ray, Debashis; Razak, Hana; Redolfi, Alberto; Reid, Andrew; Reilhac, Anthonin; Reinsberger, Claus; Restrepo, Lucas; Retico, Alessandra; Rezaeitabar, Yousef; Richards, John; Richter, Mirco; Riddle, William; Ries, Michele; Rincon, Mariano; Rischall, Matt; Robieson, Weining; Rocha-Rego, Vanessa; Rogalski, Emily; Rogers, Elizabeth; Rojas, Ignacio; Romero, Klaus; Rosand, Jonathan; Rosen, Ori; Rosen, Allyson; Rosenberg, Paul; Ross, David; Ross, Joel; Rousseau, Francois; Rowe, Christopher; Rubin, Daniel; Ruiz, Agustin; Rusinek, Henry; Ryan, Laurie; Saad, Ahmed; Sabbagh, Marway; Sabuncu, Mert; Sachs, Michael; Sacuiu, Simona; Sadeghi, Ali; Said, Yasmine; Saint-Aubert, Laure; Sakata, Muneyuki; Salat, David; Salmon, David; Salomi, Sharmila; Salter, Hugh; Samwald, Matthias; Sanchez, Luciano; Sanjo, Nobuo; Sankaranarayanan, Preethi; Sato, Shinji; Sato, Hajime; Saumier, Daniel; Savio, Alexandre; Sawada, Ikuhisa; Saykin, Andrew; Schaffer, J. David; Scharre, Douglas; Schlosser, Gretchen; Schmand, Ben; Schmansky, Nick; Schmidt, Mark; Schneider, Lon; Schramm, Hauke; Schuerch, Markus; Schwartz, Eben; Schwartz, Craig; Schwarz, Adam; Seethamraju, Ravi; Seixas, Flavio; Selnes, Per; Senjem, Matthew; Senlin, Wang; Seo, Sang Won; Sethuraman, Gopalan; Sevigny, Jeffrey; Sfikas, Giorgos; Shahbaba, Babak; Shams, Soheil; Shankle, William; Shattuck, David; Shaw, Leslie; Sheela, Jaba; Shen, Weijia; Shera, David; Sherman, John; Sherman, Michelle; Sherva, Richard; Shimizu, Keiji; Shuler, Catherine; Shulman, Joshua; Siegel, Rene; Siemers, Eric; Silveira, Margarida; Silver, Michael; Silverman, Daniel; Simmons, Andy; Simpson, Ivor; Singh, Simer Preet; Singh, Nikhil; Siuciak, Judy; Sjogren, Niclas; Skup, Martha; Small, Gary; Smith, Benjamin; Smith, Michael; Smith, Charles; Smyth, Timothy; Snow, Sarah; Soares, Holly; Soldea, Octavian; Solomon, Paul; Solomon, Alan; Song, Mingli; Song, Changhong; Sorensen, Greg; Soudah, Eduardo; Spampinato, Maria Vittoria; Spenger, Christian; Sperling, Reisa; Spiegel, Rene; Spies, Lothar; Squarcia, Sandro; Squire, Larry; Staff, Roger; Stern, Yaakov; Strittmatter, Stephen; Styren, Scot; Sugishita, Morihiro; Sugishita, Kazuyuki; Sukkar, Rafid; Sun, Jia; Sun, Yu; Sundell, Karen; Suri, Muhammad; Swan, Melanie; Takagi, Toshihisa; Takahasi, Tetsuhiko; Takeuchi, Tomoko; Tang, Songyuan; Tanner, William; Tao, Wenwen; Tao, Dacheng; Tariot, Pierre; Tarjoman, Mana; Tatsuoka, Curtis; Taylor-Reinwald, Lisa; Terlizzi, Rita; Thiele, Frank; Thomas, Ronald; Thomas, Benjamin; Thompson, Paul; Thompson, Wesley; Thornton-Wells, Tricia; Thurfjell, Lennart; Titeux, Laurence; Tolli, Tuomas; Toma, Ahmed; Tomita, Naoki; Toro, Roberto; Tosun, Duygu; Toussaint, Paule; Toyoshiba, Hiroyoshi; Tractenberg, Rochelle E.; Trittschuh, Emily; Truran, Diana; Tsechpenakis, Gavriil; Tucker-Drob, Elliot; Tung, Joyce; Uesugi, Humito; Ullrich, Lauren; Umadevi Venkataraju, Kannan; Umar, Nisser; Uzunbas, Gokhan; Valdivia, Fernando; van Horn, John; van Leemput, Koen; van Train, Kenneth; van Zeeland, Ashley; Vargas, Gabriel; Vasanawala, Minal; Vemuri, Prashanthi; Verwaerde, Philippe; Videbaek, Charlotte; Vidoni, Eric; Vigneron, Vincent; Villanueva-Meyer, Javier; Visser, Pieter Jelle; Vitolo, Ottavio; Vlassenko, Andrei; Volkau, Ihar; Vounou, Maria; Wade, Sara; Walhovd, Kristine B.; Wallace, Douglas; Wan, Hong; Wang, Angela; Wang, Li-San; Wang, Yongmei Michelle; Wang, Yaping; Wang, Alex; Wang, Lubin; Wang, Yalin; Wang, Tiger; Wang, Yue; Wang, Huanli; Wang, Huali; Ward, Michael; Warfield, Simon; Waring, Stephen; Webb, David; Wei, Lili; Wen, Shu-Hui; Wenjing, Li; Wenzel, Fabian; Westlye, Lars T.; Whitcher, Brandon; Whitwell, Jennifer; WilliamFaltaos, Demiana; Williams, David; Wilmot, Beth; Wingo, Thomas; Winkler, Andreas; Wiste, Heather; Wolfson, Tanya; Wolke, Ira; Wolz, Robin; Woo, Jongwook; Woo, Ellen; Woods, Lynn; Worth, Andrew; Worth, Eric; Wouters, Hans; Wu, Liang; Wu, Xiaoling; Wu, Yi Gen; Wu, Teresa; Wyman, Bradley; Wyss-Coray, Tony; Xiao, Liu; Xu, Guofan; Xu, Jun; Yamane, Tomohiko; Yamashita, Fumio; Yamazawa, Maki; Yan, Yunyi; Yan, Pingkun; Yang, Qing X.; Yang, Zhitong; Ye, Byoung Seok; Ye, Jieping; Yee, Laura; Yesavage, Jerome; Yip, WaiKuan; Yoo, Bongin; Yuan, Kai; Yushkevich, Paul; Zagorodnov, Vitali; Zagorski, Michael; Zawadzki, Rezi; Zeitzer, Jamie; Zhang, Linda; Zhang, Lijun; Zhang, Tianhao; Zhang, Huixiong; Zhang, Bin; Zhang, Kurt; Zhao, Qinying; Zhao, Peng; Zhen, Xiantong; Zheng, Yuanjie; Zhijun, Yao; Zhou, Sheng; Zhou, Bin; Zhou, Luping; Zhu, Wanlin; Zhu, Hongtu; Zou, Heng

    2010-01-01

    To evaluate relationships between magnetic resonance imaging (MRI)-based measures of white matter hyperintensities (WMHs), measured at baseline and longitudinally, and 1-year cognitive decline using a large convenience sample in a clinical trial design with a relatively mild profile of

  17.  Association between hepatitis B virus and chronic kidney disease: a systematic review and meta-analysis.

    Science.gov (United States)

    Fabrizi, Fabrizio; Donato, Francesca M; Messa, Piergiorgio

     Background. Hepatitis B virus infection and chronic kidney disease are prevalent and remain a major public health problem worldwide. It remains unclear how infection with hepatitis B virus impacts on the development and progression of chronic kidney disease. To evaluate the effect of infection with HBV on the risk of chronic kidney disease in the general population. We conducted a systematic review of the published medical literature to determine if hepatitis B infection is associated with increased likelihood of chronic kidney disease. We used the random effects model of DerSimonian and Laird to generate a summary estimate of the relative risk for chronic kidney disease (defined by reduced glomerular filtration rate and/or detectable proteinuria) with hepatitis B virus across the published studies. Meta-regression and stratified analysis were also conducted. We identified 16 studies (n = 394,664 patients) and separate meta-analyses were performed according to the outcome. The subset of longitudinal studies addressing ESRD (n = 2; n = 91,656) gave a pooled aHR 3.87 (95% CI, 1.48; 6.25, P chronic kidney disease (including end-stage renal disease). No relationship occurred between HBV positive status and prevalent chronic disease (n = 7, n = 109,889 unique patients); adjusted odds ratio, were 1.07 (95% CI, 0.89; 1.25) and 0.93 (95% CI, 0.76; 1.10), respectively. HBV infection is possibly associated with a risk of developing reduced glomerular filtration rate in the general population; no link between HBV sero-positive status and frequency of chronic kidney disease or proteinuria was noted in cross-sectional surveys.

  18. Longitudinal course of cortical thickness decline in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Schuster, Christina; Kasper, Elisabeth; Machts, Judith; Bittner, Daniel; Kaufmann, Jörn; Benecke, Reiner; Teipel, Stefan; Vielhaber, Stefan; Prudlo, Johannes

    2014-10-01

    To determine longitudinal rates of cortical atrophy in classical Amyotrophic lateral sclerosis (ALS) and ALS variants. Rates of cortical thinning were determined between 2 scans, 3-15 months apart, in 77 ALS patients: 51 classical, 12 upper motor neuron (UMN), and 14 lower motor neuron (LMN) ALS variants. Cortical thickness at the first assessment was compared with 60 healthy controls matched by age and gender. Atrophy rates were compared between patient sub-groups and correlated with disease duration, progression, and severity. Using a cross-sectional analysis, we found a significant difference in cortical thickness between ALS patients and controls in the motor and extra-motor areas (left medial orbito frontal gyrus, left inferior parietal gyrus, bilateral insular cortex, right fusiform gyrus, bilateral precuneus). Using a longitudinal analysis, we found a significant decline of cortical thickness in frontal, temporal, and parietal regions over the course of the study in ALS patients. Effects were independent of the clinical subtype, with exception of the precentral gyrus (p gyrus, the UMN-dominant subjects exhibited intermediate rates of atrophy, and the classical ALS patients exhibited no such change. Atrophy of the precentral gyrus in classical ALS indicates a floor effect at the first assessment, resulting in a lack of further atrophy over time. Structural loss of the precentral gyrus appears to be an early sign of classical ALS. Over time, patterns of cortical thinning in extra-motor areas can be identified in ALS, regardless of the phenotype.

  19. Comparison of endothelial changes and power settings between torsional and longitudinal phacoemulsification.

    Science.gov (United States)

    Reuschel, Anna; Bogatsch, Holger; Barth, Thomas; Wiedemann, Renate

    2010-11-01

    To compare the intraoperative and postoperative outcomes of conventional longitudinal phacoemulsification and torsional phacoemulsification. Department of Ophthalmology, University of Leipzig, Germany. Randomized single-center clinical trial. Eyes with senile cataract were randomized to have phacoemulsification using the Infiniti Vision System and the torsional mode (OZil) or conventional longitudinal mode. Primary outcomes were corrected distance visual acuity (CDVA) and central endothelial cell density (ECD), calculated according to the Conference on Harmonisation-E9 Guidelines in which missing values were substituted by the median in each group (primary analysis) and the loss was then calculated using actual data (secondary analysis). Secondary outcomes were ultrasound (US) time, cumulative dissipated energy (CDE), and percentage total equivalent power in position 3. Postoperative follow-up was at 3 months. The mean preoperative CDVA was 0.41 logMAR in the torsional group and 0.38 logMAR in the longitudinal group, improving to 0.07 logMAR postoperatively in both groups. The mean ECD loss was 7.2% ± 4.6% in the torsional group (72 patients) and 7.1% ± 4.4% in the longitudinal group (76 patients), with no statistically significant differences in the primary analysis (P = .342) or secondary analysis (P = .906). The mean US time, CDE, and percentage total equivalent power in position 3 were statistically significantly lower in the torsional group (98 patients) than in the longitudinal group (94 patients) (P<.001). The torsional mode was as safe as the longitudinal mode in phacoemulsification for age-related cataract. Copyright © 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  20. Haplotype-based association analysis of general cognitive ability in Generation Scotland, the English Longitudinal Study of Ageing, and UK Biobank [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    David M. Howard

    2017-08-01

    Full Text Available Background: Cognitive ability is a heritable trait with a polygenic architecture, for which several associated variants have been identified using genotype-based and candidate gene approaches. Haplotype-based analyses are a complementary technique that take phased genotype data into account, and potentially provide greater statistical power to detect lower frequency variants. Methods: In the present analysis, three cohort studies (ntotal = 48,002 were utilised: Generation Scotland: Scottish Family Health Study (GS:SFHS, the English Longitudinal Study of Ageing (ELSA, and the UK Biobank. A genome-wide haplotype-based meta-analysis of cognitive ability was performed, as well as a targeted meta-analysis of several gene coding regions. Results: None of the assessed haplotypes provided evidence of a statistically significant association with cognitive ability in either the individual cohorts or the meta-analysis. Within the meta-analysis, the haplotype with the lowest observed P-value overlapped with the D-amino acid oxidase activator (DAOA gene coding region. This coding region has previously been associated with bipolar disorder, schizophrenia and Alzheimer’s disease, which have all been shown to impact upon cognitive ability. Another potentially interesting region highlighted within the current genome-wide association analysis (GS:SFHS: P = 4.09 x 10-7, was the butyrylcholinesterase (BCHE gene coding region. The protein encoded by BCHE has been shown to influence the progression of Alzheimer’s disease and its role in cognitive ability merits further investigation. Conclusions: Although no evidence was found for any haplotypes with a statistically significant association with cognitive ability, our results did provide further evidence that the genetic variants contributing to the variance of cognitive ability are likely to be of small effect.

  1. SELECTIVE MODAL ANALYSIS OF POWER FLOW OSCILLATION IN LARGE SCALE LONGITUDINAL POWER SYSTEMS

    Directory of Open Access Journals (Sweden)

    Wirindi -

    2009-06-01

    Full Text Available Novel selective modal analysis for the determination of low frequency power flow oscillation behaviour based on eigenvalues with corresponding damping ratio, cumulative damping index, and participation factors is proposed. The power system being investigated consists of three large longitudinally interconnected areas with some weak tie lines. Different modes, such as exciter modes, inter area modes, and local modes of the dominant poles are fully studied to find out the significant level of system damping and other factors producing power flow instability. The nature of the energy exchange between area is determined and strategic power flow stability improvement is developed and tested.

  2. Secondary Analysis of National Longitudinal Transition Study 2 Data

    Science.gov (United States)

    Hicks, Tyler A.; Knollman, Greg A.

    2015-01-01

    This review examines published secondary analyses of National Longitudinal Transition Study 2 (NLTS2) data, with a primary focus upon statistical objectives, paradigms, inferences, and methods. Its primary purpose was to determine which statistical techniques have been common in secondary analyses of NLTS2 data. The review begins with an…

  3. Power analysis on the time effect for the longitudinal Rasch model.

    Science.gov (United States)

    Feddag, M L; Blanchin, M; Hardouin, J B; Sebille, V

    2014-01-01

    Statistics literature in the social, behavioral, and biomedical sciences typically stress the importance of power analysis. Patient Reported Outcomes (PRO) such as quality of life and other perceived health measures (pain, fatigue, stress,...) are increasingly used as important health outcomes in clinical trials or in epidemiological studies. They cannot be directly observed nor measured as other clinical or biological data and they are often collected through questionnaires with binary or polytomous items. The Rasch model is the well known model in the item response theory (IRT) for binary data. The article proposes an approach to evaluate the statistical power of the time effect for the longitudinal Rasch model with two time points. The performance of this method is compared to the one obtained by simulation study. Finally, the proposed approach is illustrated on one subscale of the SF-36 questionnaire.

  4. Quality of life among prostate cancer patients: A prospective longitudinal population-based study

    International Nuclear Information System (INIS)

    Schaake, Wouter; Groot, Martijn de; Krijnen, Wim P.; Langendijk, Johannes A.; Bergh, Alfons C.M. van den

    2013-01-01

    Purpose: To investigate the course of quality of life (QoL) among prostate cancer patients treated with external beam radiotherapy and to compare the results with QoL of a normal age-matched reference population. Patients and methods: The study population was composed of 227 prostate cancer patients, treated with radiotherapy. The EORTC QLQ-C30 was used to assess QoL before radiotherapy and six months, one year, two years and three years after completion of radiotherapy. Mixed model analyses were used to investigate longitudinal changes in QoL. QoL of prostate cancer patients was compared to that of a normative cohort using a multivariate analysis of covariance. Results: A significant decline in QoL was observed after radiotherapy (p < 0.001). The addition of hormonal therapy to radiotherapy was associated with a lower level of role functioning. Patients with coronary heart disease and or chronic obstructive pulmonary disease or asthma had a significantly worse course in QoL. Although statistically significant, all differences were classified as small or trivial. Conclusion: Prostate cancer patients experience a small worsening of QoL as compared with baseline and as compared with a normal reference population. As co-morbidity modulates patients’ post-treatment QoL, a proper assessment of co-morbidity should be included in future longitudinal analyses on QoL

  5. Longitudinal assessment of short-term memory deterioration in a logopenic variant primary progressive aphasia with post-mortem confirmed Alzheimer's Disease pathology.

    Science.gov (United States)

    Tree, Jeremy; Kay, Janice

    2015-09-01

    In the field of dementia research, there are reports of neurodegenerative cases with a focal loss of language, termed primary progressive aphasia (PPA). Currently, this condition has been further sub-classified, with the most recent sub-type dubbed logopenic variant (PPA-LV). As yet, there remains somewhat limited evaluation of the characteristics of this condition, with no studies providing longitudinal assessment accompanied by post-mortem examination. Moreover, a key characteristic of the PPA-LV case is a deterioration of phonological short-term memory, but again little work has scrutinized the nature of this impairment over time. The current study seeks to redress these oversights and presents detailed longitudinal examination of language and memory function in a case of PPA-LV, with special focus on tests linked to components of phonological short-term memory function. Our findings are then considered with reference to a contemporary model of the neuropsychology of phonological short-term memory. Additionally, post-mortem examinations indicated Alzheimer's disease type pathology, providing further evidence that the PPA-LV presentation may reflect an atypical presentation of this condition. © 2014 The British Psychological Society.

  6. High-Sensitivity Troponin: A Clinical Blood Biomarker for Staging Cardiomyopathy in Fabry Disease.

    Science.gov (United States)

    Seydelmann, Nora; Liu, Dan; Krämer, Johannes; Drechsler, Christiane; Hu, Kai; Nordbeck, Peter; Schneider, Andreas; Störk, Stefan; Bijnens, Bart; Ertl, Georg; Wanner, Christoph; Weidemann, Frank

    2016-05-31

    High-sensitivity troponin (hs-TNT), a biomarker of myocardial damage, might be useful for assessing fibrosis in Fabry cardiomyopathy. We performed a prospective analysis of hs-TNT as a biomarker for myocardial changes in Fabry patients and a retrospective longitudinal follow-up study to assess longitudinal hs-TNT changes relative to fibrosis and cardiomyopathy progression. For the prospective analysis, hs-TNT from 75 consecutive patients with genetically confirmed Fabry disease was analyzed relative to typical Fabry-associated echocardiographic findings and total myocardial fibrosis as measured by late gadolinium enhancement (LE) on magnetic resonance imaging. Longitudinal data (3.9±2.0 years), including hs-TNT, LE, and echocardiographic findings from 58 Fabry patients, were retrospectively collected. Hs-TNT level positively correlated with LE (linear correlation coefficient, 0.72; odds ratio, 32.81 [95% CI, 3.56-302.59]; P=0.002); patients with elevated baseline hs-TNT (>14 ng/L) showed significantly increased LE (median: baseline, 1.9 [1.1-3.3] %; follow-up, 3.2 [2.3-4.9] %; PFabry disease and a qualified predictor of cardiomyopathy progression. Thus, hs-TNT could be helpful for staging and follow-up of Fabry patients. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  7. New perspectives in monitoring lung inflammation: analysis of exhaled breath condensate

    National Research Council Canada - National Science Library

    Montuschi, Paolo

    2005-01-01

    ... diseases might be relevant to differential diagnosis. Given its noninvasiveness, this method might be suitable for longitudinal studies in patients with lung disease, including children. This book provides an introduction to the analysis of exhaled breath condensate. To provide an overview of lung inflammation, basic and clinical pharmacology of leukotrie...

  8. Statistical analysis of entropy generation in longitudinally finned tube heat exchanger with shell side nanofluid by a single phase approach

    Directory of Open Access Journals (Sweden)

    Konchada Pavan Kumar

    2016-06-01

    Full Text Available The presence of nanoparticles in heat exchangers ascertained increment in heat transfer. The present work focuses on heat transfer in a longitudinal finned tube heat exchanger. Experimentation is done on longitudinal finned tube heat exchanger with pure water as working fluid and the outcome is compared numerically using computational fluid dynamics (CFD package based on finite volume method for different flow rates. Further 0.8% volume fraction of aluminum oxide (Al2O3 nanofluid is considered on shell side. The simulated nanofluid analysis has been carried out using single phase approach in CFD by updating the user-defined functions and expressions with thermophysical properties of the selected nanofluid. These results are thereafter compared against the results obtained for pure water as shell side fluid. Entropy generated due to heat transfer and fluid flow is calculated for the nanofluid. Analysis of entropy generation is carried out using the Taguchi technique. Analysis of variance (ANOVA results show that the inlet temperature on shell side has more pronounced effect on entropy generation.

  9. A Longitudinal Analysis of Television Advertising Effects on Adolescents.

    Science.gov (United States)

    Moore, Roy L.; Moschis, George P.

    A longitudinal study examined both the short term and the long term effects of television advertising on the development of adolescents' consumption-related orientations. Questionnaires were administered to 556 adolescents in a number of schools in a southern state; a second wave of questionnaires was administered to a subsample of 230 of these…

  10. Longitudinal analysis of HIV risk behaviour patterns and their ...

    African Journals Online (AJOL)

    The goal of this study was to identify various HIV risk behaviours among tuberculosis (TB) patients in a longitudinal study design in South Africa. In 42 public primary healthcare facilities in three districts in three provinces, adult new TB and TB retreatment patients with hazardous or harmful alcohol use were interviewed ...

  11. Effects of prediabetes mellitus alone or plus hypertension on subsequent occurrence of cardiovascular disease and diabetes mellitus: longitudinal study.

    Science.gov (United States)

    Qiu, Miaoyan; Shen, Weili; Song, Xiaomin; Ju, Liping; Tong, Wenxin; Wang, Haiyan; Zheng, Sheng; Jin, Yan; Wu, Yixin; Wang, Weiqing; Tian, Jingyan

    2015-03-01

    Whether prediabetes mellitus alone or combined with other disorders means a higher risk for cardiovascular disease (CVD) is still controversial. This study aimed to investigate the association between prediabetes mellitus and CVD and diabetes mellitus and to explore whether prediabetes mellitus alone or combined with other syndromes, such as hypertension, could promote CVD risks significantly. This longitudinal population-based study of 1609 residents from Shanghai in Southern China was conducted between 2002 and 2014. Participants with a history of CVD at baseline were excluded from analysis. Multivariate log-binomial regression models were used to adjust possible coexisting factors. Incidence of CVD during follow-up was 10.1%. After adjusting for age, sex, and other factors, the association between prediabetes mellitus and CVD was not observed. When hypertension was incorporated in stratifying factors, adjusted CVD risk was elevated significantly (odds ratio, 2.41; 95% confidence interval, 1.25-4.64) in prediabetes mellitus and hypertension combined group, and coexistence of diabetes mellitus and hypertension made CVD risk highly significantly increased, reaching 3.43-fold higher than the reference group. Blood glucose level within prediabetic range is significantly associated with elevated risks for diabetes mellitus after multivariable adjustment, but only when it is concurrent with other disorders, such as hypertension, it will significantly increase CVD risk. © 2015 American Heart Association, Inc.

  12. The Latent Curve ARMA (P, Q) Panel Model: Longitudinal Data Analysis in Educational Research and Evaluation

    Science.gov (United States)

    Sivo, Stephen; Fan, Xitao

    2008-01-01

    Autocorrelated residuals in longitudinal data are widely reported as common to longitudinal data. Yet few, if any, researchers modeling growth processes evaluate a priori whether their data have this feature. Sivo, Fan, and Witta (2005) found that not modeling autocorrelated residuals present in longitudinal data severely biases latent curve…

  13. Explaining the increasing heritability of cognitive ability across development: a meta-analysis of longitudinal twin and adoption studies.

    Science.gov (United States)

    Briley, Daniel A; Tucker-Drob, Elliot M

    2013-09-01

    Genes account for increasing proportions of variation in cognitive ability across development, but the mechanisms underlying these increases remain unclear. We conducted a meta-analysis of longitudinal behavioral genetic studies spanning infancy to adolescence. We identified relevant data from 16 articles with 11 unique samples containing a total of 11,500 twin and sibling pairs who were all reared together and measured at least twice between the ages of 6 months and 18 years. Longitudinal behavioral genetic models were used to estimate the extent to which early genetic influences on cognition were amplified over time and the extent to which innovative genetic influences arose with time. Results indicated that in early childhood, innovative genetic influences predominate but that innovation quickly diminishes, and amplified influences account for increasing heritability following age 8 years.

  14. Clustering of unhealthy behaviors in the aerobics center longitudinal study.

    Science.gov (United States)

    Héroux, Mariane; Janssen, Ian; Lee, Duck-chul; Sui, Xuemei; Hebert, James R; Blair, Steven N

    2012-04-01

    Clustering of unhealthy behaviors has been reported in previous studies; however the link with all-cause mortality and differences between those with and without chronic disease requires further investigation. To observe the clustering effects of unhealthy diet, fitness, smoking, and excessive alcohol consumption in adults with and without chronic disease and to assess all-cause mortality risk according to the clustering of unhealthy behaviors. Participants were 13,621 adults (aged 20-84) from the Aerobics Center Longitudinal Study. Four health behaviors were observed (diet, fitness, smoking, and drinking). Baseline characteristics of the study population and bivariate relations between pairs of the health behaviors were evaluated separately for those with and without chronic disease using cross-tabulation and a chi-square test. The odds of partaking in unhealthy behaviors were also calculated. Latent class analysis (LCA) was used to assess clustering. Cox regression was used to assess the relationship between the behaviors and mortality. The four health behaviors were related to each other. LCA results suggested that two classes existed. Participants in class 1 had a higher probability of partaking in each of the four unhealthy behaviors than participants in class 2. No differences in health behavior clustering were found between participants with and without chronic disease. Mortality risk increased relative to the number of unhealthy behaviors participants engaged in. Unhealthy behaviors cluster together irrespective of chronic disease status. Such findings suggest that multi-behavioral intervention strategies can be similar in those with and without chronic disease.

  15. A Randomized Longitudinal Factorial Design to Assess Malaria Vector Control and Disease Management Interventions in Rural Tanzania

    Directory of Open Access Journals (Sweden)

    Randall A. Kramer

    2014-05-01

    Full Text Available The optimization of malaria control strategies is complicated by constraints posed by local health systems, infrastructure, limited resources, and the complex interactions between infection, disease, and treatment. The purpose of this paper is to describe the protocol of a randomized factorial study designed to address this research gap. This project will evaluate two malaria control interventions in Mvomero District, Tanzania: (1 a disease management strategy involving early detection and treatment by community health workers using rapid diagnostic technology; and (2 vector control through community-supported larviciding. Six study villages were assigned to each of four groups (control, early detection and treatment, larviciding, and early detection and treatment plus larviciding. The primary endpoint of interest was change in malaria infection prevalence across the intervention groups measured during annual longitudinal cross-sectional surveys. Recurring entomological surveying, household surveying, and focus group discussions will provide additional valuable insights. At baseline, 962 households across all 24 villages participated in a household survey; 2,884 members from 720 of these households participated in subsequent malariometric surveying. The study design will allow us to estimate the effect sizes of different intervention mixtures. Careful documentation of our study protocol may also serve other researchers designing field-based intervention trials.

  16. A randomized longitudinal factorial design to assess malaria vector control and disease management interventions in rural Tanzania.

    Science.gov (United States)

    Kramer, Randall A; Mboera, Leonard E G; Senkoro, Kesheni; Lesser, Adriane; Shayo, Elizabeth H; Paul, Christopher J; Miranda, Marie Lynn

    2014-05-16

    The optimization of malaria control strategies is complicated by constraints posed by local health systems, infrastructure, limited resources, and the complex interactions between infection, disease, and treatment. The purpose of this paper is to describe the protocol of a randomized factorial study designed to address this research gap. This project will evaluate two malaria control interventions in Mvomero District, Tanzania: (1) a disease management strategy involving early detection and treatment by community health workers using rapid diagnostic technology; and (2) vector control through community-supported larviciding. Six study villages were assigned to each of four groups (control, early detection and treatment, larviciding, and early detection and treatment plus larviciding). The primary endpoint of interest was change in malaria infection prevalence across the intervention groups measured during annual longitudinal cross-sectional surveys. Recurring entomological surveying, household surveying, and focus group discussions will provide additional valuable insights. At baseline, 962 households across all 24 villages participated in a household survey; 2,884 members from 720 of these households participated in subsequent malariometric surveying. The study design will allow us to estimate the effect sizes of different intervention mixtures. Careful documentation of our study protocol may also serve other researchers designing field-based intervention trials.

  17. The Relationship Between Job Satisfaction and Productivity-Related Costs: A Longitudinal Analysis.

    Science.gov (United States)

    Arnold, Amélie E; Coffeng, Jennifer K; Boot, Cécile R L; van der Beek, Allard J; van Tulder, Maurits W; Nieboer, Dagmar; van Dongen, Johanna M

    2016-09-01

    The aim of this study was to examine the longitudinal relationship between job satisfaction and total productivity-related costs, and between job satisfaction and absenteeism and presenteeism costs separately. A secondary aim was to explore whether these relationships differed across job types. Linear generalized estimating equation analyses were used to explore the longitudinal relationships. To explore whether the relationships differed across job types, stratified analyses were performed. A significant relationship was found between job satisfaction and total productivity-related costs [β = &OV0556;-273; 95% confidence interval (95% CI): -407 to -200] and between job satisfaction and presenteeism costs (β = &OV0556;-276; 95% CI: -367 to -235), but not between job satisfaction and absenteeism costs. These relationships differed across job types. Higher levels of job satisfaction were longitudinally related to lower total productivity-related costs and presenteeism costs, but not to lower absenteeism costs. These relationships seem to differ across job types.

  18. Longitudinal myelitis associated with yellow fever vaccination.

    Science.gov (United States)

    Chaves, M; Riccio, P; Patrucco, L; Rojas, J I; Cristiano, E

    2009-07-01

    Severe adverse reaction to yellow fever (YF) vaccine includes the yellow fever vaccine-associated neurotropic disease. This terminology includes postvaccinal encephalitis, acute disseminated encephalomyelitis, and Guillain-Barré syndrome. The objective of this communication is to report a patient who received a YF vaccine in Argentina and subsequently developed longitudinal myelitis with a symptom that had previously gone unreported in the literature. A 56-year-old man began with progressive paraparesia, urinary retention, and constipation 48 h previous to admission. The patient received YF vaccine 45 days prior to the onset of the symptoms. There was no history of other immunization or relevant condition. MR of the spine showed longitudinal intramedullary hyperintense signal (D5-12) without gadolinium enhancement. A high concentration of YFV-specific IgM vaccine antibody was found in the cerebrospinal fluid (CSF). Serological tests for other flavivirus were negative. A diagnosis of longitudinal myelitis without encephalitis associated with YF vaccine was performed and symptoms improved 5 days later. This is the first report dealing with longitudinal myelitis as a serious adverse event associated with YF vaccination in which confirmation of the presence of antibodies in CSF was found. To date, it is also the first report with serological confirmation in Argentina and in South America. We consider that the present investigation will raise awareness in the region in the reporting of adverse events related to YF vaccine and improve our knowledge of adverse reactions to the vaccine.

  19. Transition in adolescents across time, disease and gender

    DEFF Research Database (Denmark)

    Aagaard, Hanne; Ludvigsen, Mette Spliid; Svanholm, Jette Rolf

    interview with the adolescent at outpatient clinics at Aarhus University Hospital. Follow-up is planned at 15 and 18 years of age. A comparative approach is employed to show central characteristics across time, disease and gender. Results: Results from analysis inspired by Ricoeur's phenomenological......Background: Despite a growing number of studies on transition to adulthood in adolescents, literature is scarce on qualitative, longitudinal studies of transitions in adolescents with severe chronic diseases. The aim is to study transition in adolescents with cystic fibrosis, congenital heart...... diseases and chronic kidney diseases. We specifically focus on the adolescents’ experiences, 'what is important to them', 'what characterises their interaction with health care staff' and 'the communication between the adolescents and health care staff as perceived by the adolescents'. Methods...

  20. Multilevel Cross-Dependent Binary Longitudinal Data

    KAUST Repository

    Serban, Nicoleta

    2013-10-16

    We provide insights into new methodology for the analysis of multilevel binary data observed longitudinally, when the repeated longitudinal measurements are correlated. The proposed model is logistic functional regression conditioned on three latent processes describing the within- and between-variability, and describing the cross-dependence of the repeated longitudinal measurements. We estimate the model components without employing mixed-effects modeling but assuming an approximation to the logistic link function. The primary objectives of this article are to highlight the challenges in the estimation of the model components, to compare two approximations to the logistic regression function, linear and exponential, and to discuss their advantages and limitations. The linear approximation is computationally efficient whereas the exponential approximation applies for rare events functional data. Our methods are inspired by and applied to a scientific experiment on spectral backscatter from long range infrared light detection and ranging (LIDAR) data. The models are general and relevant to many new binary functional data sets, with or without dependence between repeated functional measurements.

  1. Retinal thickness as a marker of disease progression in longitudinal observation of patients with Wolfram syndrome.

    Science.gov (United States)

    Zmyslowska, Agnieszka; Fendler, Wojciech; Waszczykowska, Arleta; Niwald, Anna; Borowiec, Maciej; Jurowski, Piotr; Mlynarski, Wojciech

    2017-11-01

    Wolfram syndrome (WFS) is a recessively inherited monogenic form of diabetes coexisting with optic atrophy and neurodegenerative disorders with no currently recognized markers of disease progression. The aim of the study was to evaluate retinal parameters by using optical coherence tomography (OCT) in WFS patients after 2 years of follow-up and analysis of the parameters in relation to visual acuity. OCT parameters and visual acuity were measured in 12 WFS patients and 31 individuals with type 1 diabetes. Total thickness of the retinal nerve fiber layer (RNFL), average retinal thickness and total retinal volume decreased in comparison with previous OCT examination. Significant decreases were noted for RNFL (average difference -17.92 µm 95% CI -30.74 to -0.10; p = 0.0157), macular average thickness (average difference -5.38 µm 95% CI -10.63 to -2.36; p = 0.0067) and total retinal volume (average difference -0.15 mm 3 95% CI -0.30 to -0.07; p = 0.0070). Central thickness remained unchanged (average difference 1.5 µm 95% CI -7.61 to 10.61; p = 0.71). Visual acuity of WFS patients showed a strong negative correlation with diabetes duration (R = -0.82; p = 0.0010). After division of WFS patients into two groups (with low-vision and blind patients), all OCT parameters except for the RNFL value were lower in blind WFS patients. OCT measures structural parameters and can precede visual acuity loss. The OCT study in WFS patients should be performed longitudinally, and serial retinal examinations may be helpful as a potential end point for future clinical trials.

  2. Restoration of longitudinal images.

    Science.gov (United States)

    Hu, Y; Frieden, B R

    1988-01-15

    In this paper, a method of restoring longitudinal images is developed. By using the transfer function for longitudinal objects, and inverse filtering, a longitudinal image may be restored. The Fourier theory and sampling theorems for transverse images cannot be used directly in the longitudinal case. A modification and reasonable approximation are introduced. We have numerically established a necessary relationship between just-resolved longitudinal separation (after inverse filtering), noise level, and the taking conditions of object distance and lens diameter. An empirical formula is also found to well-fit the computed results. This formula may be of use for designing optical systems which are to image longitudinal details, such as in robotics or microscopy.

  3. Persistence and clearance of Ebola virus RNA from seminal fluid of Ebola virus disease survivors: a longitudinal analysis and modelling study.

    Science.gov (United States)

    Sissoko, Daouda; Duraffour, Sophie; Kerber, Romy; Kolie, Jacques Seraphin; Beavogui, Abdoul Habib; Camara, Alseny-Modet; Colin, Géraldine; Rieger, Toni; Oestereich, Lisa; Pályi, Bernadett; Wurr, Stephanie; Guedj, Jeremie; Nguyen, Thi Huyen Tram; Eggo, Rosalind M; Watson, Conall H; Edmunds, W John; Bore, Joseph Akoi; Koundouno, Fara Raymond; Cabeza-Cabrerizo, Mar; Carter, Lisa L; Kafetzopoulou, Liana Eleni; Kuisma, Eeva; Michel, Janine; Patrono, Livia Victoria; Rickett, Natasha Y; Singethan, Katrin; Rudolf, Martin; Lander, Angelika; Pallasch, Elisa; Bockholt, Sabrina; Rodríguez, Estefanía; Di Caro, Antonino; Wölfel, Roman; Gabriel, Martin; Gurry, Céline; Formenty, Pierre; Keïta, Sakoba; Malvy, Denis; Carroll, Miles W; Anglaret, Xavier; Günther, Stephan

    2017-01-01

    By January, 2016, all known transmission chains of the Ebola virus disease (EVD) outbreak in west Africa had been stopped. However, there is concern about persistence of Ebola virus in the reproductive tract of men who have survived EVD. We aimed to use biostatistical modelling to describe the dynamics of Ebola virus RNA load in seminal fluid, including clearance parameters. In this longitudinal study, we recruited men who had been discharged from three Ebola treatment units in Guinea between January and July, 2015. Participants provided samples of seminal fluid at follow-up every 3-6 weeks, which we tested for Ebola virus RNA using quantitative real-time RT-PCR. Representative specimens from eight participants were then inoculated into immunodeficient mice to test for infectivity. We used a linear mixed-effect model to analyse the dynamics of virus persistence in seminal fluid over time. We enrolled 26 participants and tested 130 seminal fluid specimens; median follow up was 197 days (IQR 187-209 days) after enrolment, which corresponded to 255 days (228-287) after disease onset. Ebola virus RNA was detected in 86 semen specimens from 19 (73%) participants. Median duration of Ebola virus RNA detection was 158 days after onset (73-181; maximum 407 days at end of follow-up). Mathematical modelling of the quantitative time-series data showed a mean clearance rate of Ebola virus RNA from seminal fluid of -0·58 log units per month, although the clearance kinetic varied greatly between participants. Using our biostatistical model, we predict that 50% and 90% of male survivors clear Ebola virus RNA from seminal fluid at 115 days (90% prediction interval 72-160) and 294 days (212-399) after disease onset, respectively. We also predicted that the number of men positive for Ebola virus RNA in affected countries would decrease from about 50 in January 2016, to fewer than 1 person by July, 2016. Infectious virus was detected in 15 of 26 (58%) specimens tested in mice. Time

  4. The Mutual Relationship Between Men's Drinking and Depression: A 4-Year Longitudinal Analysis.

    Science.gov (United States)

    Lee, Soo Bi; Chung, Sulki; Lee, HaeKook; Seo, Jeong Seok

    2018-03-17

    The purpose of the current study was to examine the longitudinal reciprocal relationship between depression and drinking among male adults from the general population. This study used a panel dataset from the Korean Welfare Panel (from 2011 to 2014). The subjects were 2511 male adults aged between 20 and 65 years. Based on the Korean Version of the Alcohol Use Disorders Identification Test (AUDIT-K) scores, 2191 subjects were categorized as the control group (AUDIT-K AUDIT-K ≥ 12). An autoregressive cross-lagged modelling analysis was performed to investigate the mutual relationship between problem drinking and depression measured consecutively over time. The results indicated that alcohol drinking and depression were stable over time. In the control group, there was no significant causal relationship between problem drinking and depression while in the problem drinking group, drinking in the previous year significantly influenced depression in the following second, third and fourth years. This study compared normal versus problem drinkers and showed a 4-year mutual causal relationship between depression and drinking. No longitudinal interaction between drinking and depression occurred in normal drinkers, while drinking intensified depression over time in problem drinkers. This study found that problem drinking was a risk factor for development of depression. Therefore, more attention should be given to problem alcohol use in the general population and evaluation of past alcohol use history in patients with depressive disorders.

  5. Shapes related to longitudinal studies of disease

    DEFF Research Database (Denmark)

    Erleben, Lene Lillemark

    investigated four different proximity markers which lead to significantly improved marker values between NC and AD after correction for whole brain and hippocampus volume. Based on the different proximity markers we have chosen the surface connectivity marker that gave the best separation to investigate......This dissertation investigates novel markers for cardiovascular diseases (CVD) and Alzheimer's disease (AD). Both CVD and AD are among the large diseases counted in morbidity and mortality in the western world, which makes them huge and increasing problems. By investigating and learning....... The first part of this dissertation studies the growth patterns of atherosclerotic calcified deposits in the lumbar aorta based on x-ray images over an 8-year time period. We have been able to find simple growth patterns that explain how the calcifications evolve. The calcifications grew on average 41 % (p...

  6. Comparative analysis of maximum renal longitudinal length with positional changes on ultrasound with multiplanar reconstructed MR image in Korea Adults

    International Nuclear Information System (INIS)

    Jang, Yun Hee; Cho, Bum Sang; Kang, Min Ho; Kang, Woo Young; Lee, Jisun; Kim, Yook; Lee, Soo Hyun; Lee, Soo Jung; Lee, Jin Yong

    2016-01-01

    The purpose of this study was to determine a suitable position in which the measured length on ultrasound is close to the true renal length obtained through a multiplanar reconstructed MR image. A total of 33 individuals (males: 15, females: 18) without any underlying renal disease were included in the present study. Renal length was measured as the longest axis at the level of the renal hilum in three positions-supine, lateral decubitus, and prone, respectively. With a 3.0 T MR scanner, 3D eTHRIVE was acquired. Subsequently, the maximum longitudinal length of both the kidneys was measured through multiplanar reconstructed MR images. Paired t-test was used to compare the renal length obtained from ultrasonographic measurement with the length obtained through multiplanar reconstructed MR images. Our study demonstrated significant difference between sonographic renal length in three positions and renal length through MRI (p < 0.001). However, the longest longitudinal length of right kidney among the measured three values by ultrasound was statistically similar to the renal length measured by reconstructed MR image. Among them, the lateral decubitus position showed the strongest correlation with true renal length (right: 0.887; left: 0.849). We recommend measurement of the maximum renal longitudinal length in all possible positions on ultrasonography. If not allowed, the best measurement is on the lateral decubitus showing the strongest correlation coefficient with true renal length

  7. Comparative analysis of maximum renal longitudinal length with positional changes on ultrasound with multiplanar reconstructed MR image in Korea Adults

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Yun Hee; Cho, Bum Sang; Kang, Min Ho; Kang, Woo Young; Lee, Jisun; Kim, Yook; Lee, Soo Hyun; Lee, Soo Jung [Dept. of Radiology, Chungbuk National University Hospital, Cheongju (Korea, Republic of); Lee, Jin Yong [Public Health Medical Service, Seoul National University Boramae Medical Center, Seoul (Korea, Republic of)

    2016-07-15

    The purpose of this study was to determine a suitable position in which the measured length on ultrasound is close to the true renal length obtained through a multiplanar reconstructed MR image. A total of 33 individuals (males: 15, females: 18) without any underlying renal disease were included in the present study. Renal length was measured as the longest axis at the level of the renal hilum in three positions-supine, lateral decubitus, and prone, respectively. With a 3.0 T MR scanner, 3D eTHRIVE was acquired. Subsequently, the maximum longitudinal length of both the kidneys was measured through multiplanar reconstructed MR images. Paired t-test was used to compare the renal length obtained from ultrasonographic measurement with the length obtained through multiplanar reconstructed MR images. Our study demonstrated significant difference between sonographic renal length in three positions and renal length through MRI (p < 0.001). However, the longest longitudinal length of right kidney among the measured three values by ultrasound was statistically similar to the renal length measured by reconstructed MR image. Among them, the lateral decubitus position showed the strongest correlation with true renal length (right: 0.887; left: 0.849). We recommend measurement of the maximum renal longitudinal length in all possible positions on ultrasonography. If not allowed, the best measurement is on the lateral decubitus showing the strongest correlation coefficient with true renal length.

  8. Long-term effect of coffee consumption on autosomal dominant polycystic kidneys disease progression: results from the Suisse ADPKD, a Prospective Longitudinal Cohort Study.

    Science.gov (United States)

    Girardat-Rotar, Laura; Puhan, Milo A; Braun, Julia; Serra, Andreas L

    2018-02-01

    Previous in vitro experiments of human polycystic kidney disease (PKD) cells reported that caffeine is a risk factor for the promotion of cyst enlargement in patients with autosomal dominant PKD (ADPKD). The relentless progression of ADPKD inclines the majority of physicians to advocate minimization of caffeine consumption despite the absence of clinical data supporting such a recommendation so far. This is the first clinical study to assess prospectively the association between coffee consumption and disease progression in a longitudinal ADPKD cohort. Information on coffee consumption and disease progression was collected at each follow-up visit using standardized measurement methods. The main model for the outcomes, kidney size (height-adjusted total kidney volume, htTKV) and kidney function (estimated glomerular filtration rate, eGFR), was a linear mixed model. Patients entered the on-going Swiss ADPKD study between 2006 and June 2014 and had at least 1 visit every year. The sample size of the study population was 151 with a median follow-up of 4 visits per patient and a median follow-up time of 4.38 years. After multivariate adjustment for age, smoking, hypertension, sex, body mass index and an interaction term (coffee*visit), coffee drinkers did not have a statistically significantly different kidney size compared to non-coffee drinkers (difference of -33.03 cm 3 height adjusted TKV, 95% confidence interval (CI) from -72.41 to 6.34, p = 0.10). After the same adjustment, there was no statistically significant difference in eGFR between coffee and non-coffee drinkers (2.03 ml/min/1.73 m 2 , 95% CI from -0.31 to 4.31, p = 0.089). Data derived from our prospective longitudinal study do not confirm that drinking coffee is a risk factor for ADPKD progression.

  9. Collaboration in sensor network research: an in-depth longitudinal analysis of assortative mixing patterns.

    Science.gov (United States)

    Pepe, Alberto; Rodriguez, Marko A

    2010-09-01

    Many investigations of scientific collaboration are based on statistical analyses of large networks constructed from bibliographic repositories. These investigations often rely on a wealth of bibliographic data, but very little or no other information about the individuals in the network, and thus, fail to illustrate the broader social and academic landscape in which collaboration takes place. In this article, we perform an in-depth longitudinal analysis of a relatively small network of scientific collaboration (N = 291) constructed from the bibliographic record of a research centerin the development and application of wireless and sensor network technologies. We perform a preliminary analysis of selected structural properties of the network, computing its range, configuration and topology. We then support our preliminary statistical analysis with an in-depth temporal investigation of the assortative mixing of selected node characteristics, unveiling the researchers' propensity to collaborate preferentially with others with a similar academic profile. Our qualitative analysis of mixing patterns offers clues as to the nature of the scientific community being modeled in relation to its organizational, disciplinary, institutional, and international arrangements of collaboration.

  10. An in-depth longitudinal analysis of mixing patterns in a small scientific collaboration network

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Marko A [Los Alamos National Laboratory; Pepe, Alberto [UCLA

    2009-01-01

    Many investigations of scientific collaboration are based on large-scale statistical analyses of networks constructed from bibliographic repositories. These investigations often rely on a wealth of bibliographic data, but very little or no other information about the individuals in the network, and thus, fail to illustate the broader social and academic landscape in which collaboration takes place. In this article, we perform an in-depth longitudinal analysis of a small-scale network of scientific collaboration (N = 291) constructed from the bibliographic record of a research center involved in the development and application of sensor network technologies. We perform a preliminary analysis of selected structural properties of the network, computing its range, configuration and topology. We then support our preliminary statistical analysis with an in-depth temporal investigation of the assortativity mixing of these node characteristics: academic department, affiliation, position, and country of origin of the individuals in the network. Our qualitative analysis of mixing patterns offers clues as to the nature of the scientific community being modeled in relation to its organizational, disciplinary, institutional, and international arrangements of collaboration.

  11. Cardiac strain findings in children with latent rheumatic heart disease detected by echocardiographic screening.

    Science.gov (United States)

    Beaton, Andrea; Richards, Hedda; Ploutz, Michelle; Gaur, Lasya; Aliku, Twalib; Lwabi, Peter; Ensing, Greg; Sable, Craig

    2017-08-01

    Identification of patients with latent rheumatic heart disease by echocardiography presents a unique opportunity to prevent disease progression. Myocardial strain is a more sensitive indicator of cardiac performance than traditional measures of systolic function. The objective of this study was to test the hypothesis that abnormalities in myocardial strain may be present in children with latent rheumatic heart disease. Standard echocardiography images with electrocardiogram gating were obtained from Ugandan children found to have latent rheumatic heart disease as well as control subjects. Traditional echocardiography measures of systolic function were obtained, and offline global longitudinal strain analysis was performed. Comparison between groups was performed using strain as a continuous (Mann-Whitney U-test) and categorical (cut-off 5th percentile for age) variable. Our study included 14 subjects with definite rheumatic heart disease, 13 with borderline rheumatic heart disease, and 112 control subjects. None of the subjects had abnormal left ventricular size or ejection fraction. Global longitudinal strain was lower than the 5th percentile in 44% of the subjects with any rheumatic heart disease (p=0.002 versus controls) and 57% of the subjects with definite rheumatic heart disease (p=0.03). The mean absolute strain values were significantly lower when comparing subjects with any rheumatic heart disease with controls (20.4±3.95 versus 22.4±4.35, p=0.025) and subjects with definite rheumatic heart disease with controls (19.9±4.25 versus 22.4±4.35, p=0.033). Global longitudinal strain is decreased in subjects with rheumatic heart disease in the absence of abnormal systolic function. Larger studies with longer-term follow-up are required to determine whether there is a role for strain to help better understand the pathophysiology of latent rheumatic heart disease.

  12. Intimate Partner Violence and Welfare Participation: A Longitudinal Causal Analysis

    Science.gov (United States)

    Cheng, Tyrone C.

    2013-01-01

    This longitudinal study examined the temporal-ordered causal relationship between intimate partner violence (IPV), five mental disorders (depression, generalized anxiety disorder, social phobia, panic attack, posttraumatic stress disorder [PTSD]), alcohol abuse/dependence, drug abuse/ dependence, treatment seeking (from physician, counselor, and…

  13. Physical Activity and Personality Development over Twenty Years: Evidence from Three Longitudinal Samples

    Science.gov (United States)

    Stephan, Yannick; Sutin, Angelina R.; Luchetti, Martina; Bosselut, Grégoire; Terracciano, Antonio

    2018-01-01

    A physically inactive lifestyle is associated with maladaptive patterns of personality development over relatively short follow-up periods. The present study extends existing research by examining whether this association persists over 20 years. Participants (total N = 8,723) were drawn from the Wisconsin Longitudinal Study Graduates and Siblings samples and the Midlife in the United States Study. Controlling for demographic factors and disease burden, baseline physical inactivity was related to steeper declines in conscientiousness in all three samples and a meta-analysis (β=−.06). The meta-analysis further showed that lower physical activity was associated with declines in openness (β=−.05), extraversion (β=−.03), and agreeableness (β=−.03). These findings provide evidence that a physically inactive lifestyle is associated with long-term detrimental personality trajectories. PMID:29651189

  14. Progressive microstructural changes of the occipital cortex in Huntington's disease.

    Science.gov (United States)

    Odish, Omar F F; Reijntjes, Robert H A M; van den Bogaard, Simon J A; Roos, Raymund A C; Leemans, Alexander

    2018-02-28

    In this study we longitudinally investigated the rate of microstructural alterations in the occipital cortex in different stages of Huntington's disease (HD) by applying an automated atlas-based approach to diffusion MRI data. Twenty-two premanifest (preHD), 10 early manifest HD (early HD) and 24 healthy control subjects completed baseline and two year follow-up scans. The preHD group was stratified based on the predicted years to disease onset into a far (preHD-A) and near (preHD-B) to disease onset group. Clinical and behavioral measures were collected per assessment time point. An automated atlas-based DTI analysis approach was used to obtain the mean, axial and radial diffusivities of the occipital cortex. We found that the longitudinal rate of diffusivity change in the superior occipital gyrus (SOG), middle occipital gyrus (MOG), and inferior occipital gyrus (IOG) was significantly higher in early HD compared to both preHD and controls (all p's ≤ 0.005), which can be interpreted as an increased rate of microstructural degeneration. Furthermore, the change rate in the diffusivity of the MOG could significantly discriminate between preHD-B compared to preHD-A and the other groups (all p's ≤ 0.04). Finally, we found an inverse correlation between the Stroop Word Reading task and diffusivities in the SOG and MOG (all p's ≤ 0.01). These findings suggest that measures obtained from the occipital cortex can serve as sensitive longitudinal biomarkers for disease progression in preHD-B and early HD. These could in turn be used to assess potential effects of proposed disease modifying therapies.

  15. Dynamic thresholds and a summary ROC curve: Assessing prognostic accuracy of longitudinal markers.

    Science.gov (United States)

    Saha-Chaudhuri, P; Heagerty, P J

    2018-04-19

    Cancer patients, chronic kidney disease patients, and subjects infected with HIV are routinely monitored over time using biomarkers that represent key health status indicators. Furthermore, biomarkers are frequently used to guide initiation of new treatments or to inform changes in intervention strategies. Since key medical decisions can be made on the basis of a longitudinal biomarker, it is important to evaluate the potential accuracy associated with longitudinal monitoring. To characterize the overall accuracy of a time-dependent marker, we introduce a summary ROC curve that displays the overall sensitivity associated with a time-dependent threshold that controls time-varying specificity. The proposed statistical methods are similar to concepts considered in disease screening, yet our methods are novel in choosing a potentially time-dependent threshold to define a positive test, and our methods allow time-specific control of the false-positive rate. The proposed summary ROC curve is a natural averaging of time-dependent incident/dynamic ROC curves and therefore provides a single summary of net error rates that can be achieved in the longitudinal setting. Copyright © 2018 John Wiley & Sons, Ltd.

  16. Using administrative data for longitudinal substance abuse research.

    Science.gov (United States)

    Evans, Elizabeth; Grella, Christine E; Murphy, Debra A; Hser, Yih-Ing

    2010-04-01

    The utilization of administrative data in substance abuse research has become more widespread than ever. This selective review synthesizes recent extant research from 31 articles to consider what has been learned from using administrative data to conduct longitudinal substance abuse research in four overlapping areas: (1) service access and utilization, (2) underrepresented populations, (3) treatment outcomes, and (4) cost analysis. Despite several notable limitations, administrative data contribute valuable information, particularly in the investigation of service system interactions and outcomes among substance abusers as they unfold and influence each other over the long term. This critical assessment of the advantages and disadvantages of using existing administrative data within a longitudinal framework should stimulate innovative thinking regarding future applications of administrative data for longitudinal substance abuse research purposes.

  17. Longitudinal beta-binomial modeling using GEE for overdispersed binomial data.

    Science.gov (United States)

    Wu, Hongqian; Zhang, Ying; Long, Jeffrey D

    2017-03-15

    Longitudinal binomial data are frequently generated from multiple questionnaires and assessments in various scientific settings for which the binomial data are often overdispersed. The standard generalized linear mixed effects model may result in severe underestimation of standard errors of estimated regression parameters in such cases and hence potentially bias the statistical inference. In this paper, we propose a longitudinal beta-binomial model for overdispersed binomial data and estimate the regression parameters under a probit model using the generalized estimating equation method. A hybrid algorithm of the Fisher scoring and the method of moments is implemented for computing the method. Extensive simulation studies are conducted to justify the validity of the proposed method. Finally, the proposed method is applied to analyze functional impairment in subjects who are at risk of Huntington disease from a multisite observational study of prodromal Huntington disease. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  18. Longitudinal evaluation of leukocyte transcripts in killer whales (Orcinus Orca)

    Science.gov (United States)

    Sitt, Tatjana; Bowen, Lizabeth; Lee, Chia-Shan; Blanchard, Myra; McBain, James; Dold, Christopher; Stott, Jeffrey L.

    2016-01-01

    Early identification of illness and/or presence of environmental and/or social stressors in free-ranging and domestic cetaceans is a priority for marine mammal health care professionals. Incorporation of leukocyte gene transcript analysis into the diagnostic tool kit has the potential to augment classical diagnostics based upon ease of sample storage and shipment, inducible nature and well-defined roles of transcription and associated downstream actions. Development of biomarkers that could serve to identify “insults” and potentially differentiate disease etiology would be of great diagnostic value. To this end, a modest number of peripheral blood leukocyte gene transcripts were selected for application to a domestic killer whale population with a focus on broad representation of inducible immunologically relevant genes. Normalized leukocyte transcript values, longitudinally acquired from 232 blood samples derived from 26 clinically healthy whales, were not visibly influenced temporally nor by sex or the specific Park in which they resided. Stability in leukocyte transcript number during periods of health enhances their potential use in diagnostics through identification of outliers. Transcript levels of two cytokine genes, IL-4 and IL-17, were highly variable within the group as compared to the other transcripts. IL-4 transcripts were typically absent. Analysis of transcript levels on the other genes of interest, on an individual animal basis, identified more outliers than were visible when analyzed in the context of the entire population. The majority of outliers (9 samples) were low, though elevated transcripts were identified for IL-17 from 2 animals and one each for Cox-2 and IL-10. The low number of outliers was not unexpected as sample selection was intentionally directed towards animals that were clinically healthy at the time of collection. Outliers may reflect animals experiencing subclinical disease that is transient and self-limiting. The

  19. Longitudinal relationships among posturography and gait measures in multiple sclerosis.

    Science.gov (United States)

    Fritz, Nora E; Newsome, Scott D; Eloyan, Ani; Marasigan, Rhul Evans R; Calabresi, Peter A; Zackowski, Kathleen M

    2015-05-19

    Gait and balance dysfunction frequently occurs early in the multiple sclerosis (MS) disease course. Hence, we sought to determine the longitudinal relationships among quantitative measures of gait and balance in individuals with MS. Fifty-seven ambulatory individuals with MS (28 relapsing-remitting, 29 progressive) were evaluated using posturography, quantitative sensorimotor and gait measures, and overall MS disability with the Expanded Disability Status Scale at each session. Our cohort's age was 45.8 ± 10.4 years (mean ± SD), follow-up time 32.8 ± 15.4 months, median Expanded Disability Status Scale score 3.5, and 56% were women. Poorer performance on balance measures was related to slower walking velocity. Two posturography measures, the anterior-posterior sway and sway during static eyes open, feet apart conditions, were significant contributors to walk velocity over time (approximate R(2) = 0.95), such that poorer performance on the posturography measures was related to slower walking velocity. Similarly, the anterior-posterior sway and sway during static eyes closed, feet together conditions were also significant contributors to the Timed 25-Foot Walk performance over time (approximate R(2) = 0.83). This longitudinal cohort study establishes a strong relationship between clinical gait measures and posturography. The data show that increases in static posturography and reductions in dynamic posturography are associated with a decline in walk velocity and Timed 25-Foot Walk performance over time. Furthermore, longitudinal balance measures predict future walking performance. Quantitative walking and balance measures are important additions to clinical testing to explore longitudinal change and understand fall risk in this progressive disease population. © 2015 American Academy of Neurology.

  20. Does oral language underpin the development of later behavior problems? A longitudinal meta-analysis.

    Science.gov (United States)

    Chow, Jason C; Ekholm, Erik; Coleman, Heather

    2018-05-24

    The purpose of this article is to estimate the overall weighted mean effect of the relation between early language skills and later behavior problems in school-aged children. A systematic literature search yielded 19,790 unduplicated reports, and a structured search strategy and identification procedure yielded 25 unique data sets, with 114 effect sizes for analysis. Eligible reports were then coded, and effect sizes were extracted and synthesized via robust variance estimation and random-effects meta-analytic techniques. The overall correlation between early language and later behavior problems was negative and small (r = -.14, 95% confidence interval [CI] [-.16, -.11]), and controlling for demographic variables did not reduce the magnitude of the inverse relationship between language skill and problem behavior (r = -.16). Moderator analyses identified receptive language, parent-reported behavior measures, gender, and age as significant predictors of the association between language and behavior. This article corroborates the consistent findings of previous meta-analytic and longitudinal studies and further identifies areas, particularly around measurement, for future research. Furthermore, prospective longitudinal evaluations of the relations between language deficits and behavior problems with different types of measures (teacher-/parent-report, direct assessment, classroom observation) is warranted. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  1. PARAMETRIC ANALYSIS OF LONGITUDINAL STABILITY UNMANNED AERIAL VEHICLE

    Directory of Open Access Journals (Sweden)

    Ievgen Udartsev

    2013-10-01

    Full Text Available 1024x768 We consider the aerodynamic characteristics of unmanned aircraft container type, which were obtained in a wind tunnel and refined amended by soot blowing elements propeller system and the influence of the earth's surface. The estimation of longitudinal static stability and its dependence on altitude, damping, coordinates of center of gravity, shoulder horizontal tail, wings rejection of mechanization. The variation of these parameters enables to optimize balancing system with minimal losses. Normal 0 false false false

  2. Longitudinal burnout-collaboration patterns in Japanese medical care workers at special needs schools: a latent class growth analysis

    Science.gov (United States)

    Kanayama, Mieko; Suzuki, Machiko; Yuma, Yoshikazu

    2016-01-01

    The present study aimed to identify and characterize potential burnout types and the relationship between burnout and collaboration over time. Latent class growth analysis and the growth mixture model were used to identify and characterize heterogeneous patterns of longitudinal stability and change in burnout, and the relationship between burnout and collaboration. We collected longitudinal data at three time points based on Japanese academic terms. The 396 study participants included academic teachers, yogo teachers, and registered nurses in Japanese special needs schools. The best model included four types of both burnout and collaboration in latent class growth analysis with intercept, slope, and quadratic terms. The four types of burnout were as follows: low stable, moderate unstable, high unstable, and high decreasing. They were identified as involving inverse collaboration function. The results indicated that there could be dynamic burnout types, namely moderate unstable, high unstable, and high decreasing, when focusing on growth trajectories in latent class analyses. The finding that collaboration was dynamic for dynamic burnout types and stable for stable burnout types is of great interest. This was probably related to the inverse relationship between the two constructs. PMID:27366107

  3. A genome-wide longitudinal transcriptome analysis of the aging model Podospora anserina.

    Science.gov (United States)

    Philipp, Oliver; Hamann, Andrea; Servos, Jörg; Werner, Alexandra; Koch, Ina; Osiewacz, Heinz D

    2013-01-01

    Aging of biological systems is controlled by various processes which have a potential impact on gene expression. Here we report a genome-wide transcriptome analysis of the fungal aging model Podospora anserina. Total RNA of three individuals of defined age were pooled and analyzed by SuperSAGE (serial analysis of gene expression). A bioinformatics analysis identified different molecular pathways to be affected during aging. While the abundance of transcripts linked to ribosomes and to the proteasome quality control system were found to decrease during aging, those associated with autophagy increase, suggesting that autophagy may act as a compensatory quality control pathway. Transcript profiles associated with the energy metabolism including mitochondrial functions were identified to fluctuate during aging. Comparison of wild-type transcripts, which are continuously down-regulated during aging, with those down-regulated in the long-lived, copper-uptake mutant grisea, validated the relevance of age-related changes in cellular copper metabolism. Overall, we (i) present a unique age-related data set of a longitudinal study of the experimental aging model P. anserina which represents a reference resource for future investigations in a variety of organisms, (ii) suggest autophagy to be a key quality control pathway that becomes active once other pathways fail, and (iii) present testable predictions for subsequent experimental investigations.

  4. A genome-wide longitudinal transcriptome analysis of the aging model Podospora anserina.

    Directory of Open Access Journals (Sweden)

    Oliver Philipp

    Full Text Available Aging of biological systems is controlled by various processes which have a potential impact on gene expression. Here we report a genome-wide transcriptome analysis of the fungal aging model Podospora anserina. Total RNA of three individuals of defined age were pooled and analyzed by SuperSAGE (serial analysis of gene expression. A bioinformatics analysis identified different molecular pathways to be affected during aging. While the abundance of transcripts linked to ribosomes and to the proteasome quality control system were found to decrease during aging, those associated with autophagy increase, suggesting that autophagy may act as a compensatory quality control pathway. Transcript profiles associated with the energy metabolism including mitochondrial functions were identified to fluctuate during aging. Comparison of wild-type transcripts, which are continuously down-regulated during aging, with those down-regulated in the long-lived, copper-uptake mutant grisea, validated the relevance of age-related changes in cellular copper metabolism. Overall, we (i present a unique age-related data set of a longitudinal study of the experimental aging model P. anserina which represents a reference resource for future investigations in a variety of organisms, (ii suggest autophagy to be a key quality control pathway that becomes active once other pathways fail, and (iii present testable predictions for subsequent experimental investigations.

  5. Self-control and early adolescent antisocial behavior: A longitudinal analysis

    NARCIS (Netherlands)

    de Kemp, R.A.T.; Vermulst, A.A.; Finkenauer, C.; Scholte, R.H.J.; Overbeek, G.; Rommes, E.W.M.; Engels, R.C.M.E.

    2009-01-01

    The article discusses a three-wave longitudinal study that investigates the relationship between self-control and aggressive and delinquent behavior of early adolescent boys and girls. The sample consists of 1,012 Dutch adolescents (mean age = 12.3) in their first year of secondary education.

  6. The dorsal tectal longitudinal column (TLCd): a second longitudinal column in the paramedian region of the midbrain tectum.

    Science.gov (United States)

    Aparicio, M-Auxiliadora; Saldaña, Enrique

    2014-03-01

    The tectal longitudinal column (TLC) is a longitudinally oriented, long and narrow nucleus that spans the paramedian region of the midbrain tectum of a large variety of mammals (Saldaña et al. in J Neurosci 27:13108-13116, 2007). Recent analysis of the organization of this region revealed another novel nucleus located immediately dorsal, and parallel, to the TLC. Because the name "tectal longitudinal column" also seems appropriate for this novel nucleus, we suggest the TLC described in 2007 be renamed the "ventral tectal longitudinal column (TLCv)", and the newly discovered nucleus termed the "dorsal tectal longitudinal column (TLCd)". This work represents the first characterization of the rat TLCd. A constellation of anatomical techniques was used to demonstrate that the TLCd differs from its surrounding structures (TLCv and superior colliculus) cytoarchitecturally, myeloarchitecturally, neurochemically and hodologically. The distinct expression of vesicular amino acid transporters suggests that TLCd neurons are GABAergic. The TLCd receives major projections from various areas of the cerebral cortex (secondary visual mediomedial area, and granular and dysgranular retrosplenial cortices) and from the medial pretectal nucleus. It densely innervates the ipsilateral lateral posterior and laterodorsal nuclei of the thalamus. Thus, the TLCd is connected with vision-related neural centers. The TLCd may be unique as it constitutes the only known nucleus made of GABAergic neurons dedicated to providing massive inhibition to higher order thalamic nuclei of a specific sensory modality.

  7. The Analysis of the Disease Spectrum in China

    Directory of Open Access Journals (Sweden)

    Xin Zhang

    2014-01-01

    Full Text Available Analysis of the related risks of disease provides a scientific basis for disease prevention and treatment, hospital management, and policy formulation by the changes in disease spectrum of patients in hospital. Retrospective analysis was made to the first diagnosis, age, gender, daily average cost of hospitalized patients, and other factors in the First Affiliated Hospital of Nanjing Medical University during 2006–2013. The top 4 cases were as follows: cardiovascular disease, malignant tumors, lung infections, and noninsulin dependent diabetes mellitus. By the age of disease analysis, we found a younger age trend of cardiovascular disease, and the age of onset of cancer or diabetes was somewhat postponed. The average daily cost of hospitalization and the average daily cost of the main noncommunicable diseases were both on the rise. Noncommunicable diseases occupy an increasingly important position in the constitution of the disease, and they caused an increasing medical burden. People should pay attention to health from the aspects of lifestyle changing. Hospitals should focus on building the appropriate discipline. On the other hand, an integrated government response is required to tackle key risks. Multiple interventions are needed to lower the burden of these diseases and to improve national health.

  8. Associations between Obesity and Spinal Diseases: A Medical Expenditure Panel Study Analysis

    Directory of Open Access Journals (Sweden)

    Binwu Sheng

    2017-02-01

    Full Text Available Background: The link between body weight status and spinal diseases has been suggested by a number of cross-sectional and cohort studies with a limited range of patient populations. No population-representative samples have been used to examine the link between obesity and spinal diseases. The present study is based on a nationally representative sample drawn from the Medical Expenditure Panel Survey. Methods: Using the cross-sectional sample of the 2014 Medical Expenditure Panel Study, we built four weighted logistic regression analyses of the associations between body weight status and the following four spinal diseases: low back pain, spondylosis, other cervical disorders and intervertebral disc disorder (IDD. Each respondent’s body weight status was used as the key independent variable with three categories: normal/underweight, overweight, and obese. We controlled for marital status, gender, age, smoking status, household income, health insurance coverage, educational attainment and the use of health services for other major categories of diseases. Results: A total sample of 23,048 respondents was used in our analysis. Overweight and obese respondents, as compared to normal/underweight respondents, were more likely to develop lower back problems (Overweight: logged odds = 0.218, p < 0.01; Obese: logged odds = 0.395, p < 0.001 and IDD (Overweight: logged odds = 0.441, p < 0.05; Obese: logged odds = 0.528, p < 0.001. The associations between bodyweight status and spondylitis were statistically insignificant (Overweight: logged odds = 0.281, p = 0.442; Obese: logged odds = 0.680, p = 0.104. The associations between body weight status and other cervical disorders (Overweight: logged odds = −0.116, p = 0.304; Obese: logged odds = −0.160, p = 0.865 were statistically insignificant. Conclusions: As the first study using a national sample to study bodyweight and spinal diseases, our paper supports the hypothesis that obesity adds to the burden

  9. Defining SNAP by cross-sectional and longitudinal definitions of neurodegeneration.

    Science.gov (United States)

    Wisse, L E M; Das, S R; Davatzikos, C; Dickerson, B C; Xie, S X; Yushkevich, P A; Wolk, D A

    2018-01-01

    Suspected non-Alzheimer's pathophysiology (SNAP) is a biomarker driven designation that represents a heterogeneous group in terms of etiology and prognosis. SNAP has only been identified by cross-sectional neurodegeneration measures, whereas longitudinal measures might better reflect "active" neurodegeneration and might be more tightly linked to prognosis. We compare neurodegeneration defined by cross-sectional 'hippocampal volume' only (SNAP/L-) versus both cross-sectional and longitudinal 'hippocampal atrophy rate' (SNAP/L+) and investigate how these definitions impact prevalence and the clinical and biomarker profile of SNAP in Mild Cognitive Impairment (MCI). 276 MCI patients from ADNI-GO/2 were designated amyloid "positive" (A+) or "negative" (A-) based on their florbetapir scan and neurodegeneration 'positive' or 'negative' based on cross-sectional hippocampal volume and longitudinal hippocampal atrophy rate. 74.1% of all SNAP participants defined by the cross-sectional definition of neurodegeneration also met the longitudinal definition of neurodegeneration, whereas 25.9% did not. SNAP/L+ displayed larger white matter hyperintensity volume, a higher conversion rate to dementia over 5 years and a steeper decline on cognitive tasks compared to SNAP/L- and the A- CN group. SNAP/L- had more abnormal values on neuroimaging markers and worse performance on cognitive tasks than the A- CN group, but did not show a difference in dementia conversion rate or longitudinal cognition. Using a longitudinal definition of neurodegeneration in addition to a cross-sectional one identifies SNAP participants with significant cognitive decline and a worse clinical prognosis for which cerebrovascular disease may be an important driver.

  10. A comparative analysis of longitudinal computed tomography and histopathology for evaluating the potential of mesenchymal stem cells in mitigating radiation-induced pulmonary fibrosis.

    Science.gov (United States)

    Perez, Jessica R; Lee, Sangkyu; Ybarra, Norma; Maria, Ola; Serban, Monica; Jeyaseelan, Krishinima; Wang, Li Ming; Seuntjens, Jan; Naqa, Issam El

    2017-08-22

    Radiation-induced pulmonary fibrosis (RIPF) is a debilitating side effect that occurs in up to 30% of thoracic irradiations in breast and lung cancer patients. RIPF remains a major limiting factor to dose escalation and an obstacle to applying more promising new treatments for cancer cure. Limited treatment options are available to mitigate RIPF once it occurs, but recently, mesenchymal stem cells (MSCs) and a drug treatment stimulating endogenous stem cells (GM-CSF) have been investigated for their potential in preventing this disease onset. In a pre-clinical rat model, we contrasted the application of longitudinal computed tomography (CT) imaging and classical histopathology to quantify RIPF and to evaluate the potential of MSCs in mitigating RIPF. Our results on histology demonstrate promises when MSCs are injected endotracheally (but not intravenously). While our CT analysis highlights the potential of GM-CSF treatment. Advantages and limitations of both analytical methods are contrasted in the context of RIPF.

  11. Machine Learning-based Individual Assessment of Cortical Atrophy Pattern in Alzheimer's Disease Spectrum: Development of the Classifier and Longitudinal Evaluation.

    Science.gov (United States)

    Lee, Jin San; Kim, Changsoo; Shin, Jeong-Hyeon; Cho, Hanna; Shin, Dae-Seock; Kim, Nakyoung; Kim, Hee Jin; Kim, Yeshin; Lockhart, Samuel N; Na, Duk L; Seo, Sang Won; Seong, Joon-Kyung

    2018-03-07

    To develop a new method for measuring Alzheimer's disease (AD)-specific similarity of cortical atrophy patterns at the individual-level, we employed an individual-level machine learning algorithm. A total of 869 cognitively normal (CN) individuals and 473 patients with probable AD dementia who underwent high-resolution 3T brain MRI were included. We propose a machine learning-based method for measuring the similarity of an individual subject's cortical atrophy pattern with that of a representative AD patient cohort. In addition, we validated this similarity measure in two longitudinal cohorts consisting of 79 patients with amnestic-mild cognitive impairment (aMCI) and 27 patients with probable AD dementia. Surface-based morphometry classifier for discriminating AD from CN showed sensitivity and specificity values of 87.1% and 93.3%, respectively. In the longitudinal validation study, aMCI-converts had higher atrophy similarity at both baseline (p < 0.001) and first year visits (p < 0.001) relative to non-converters. Similarly, AD patients with faster decline had higher atrophy similarity than slower decliners at baseline (p = 0.042), first year (p = 0.028), and third year visits (p = 0.027). The AD-specific atrophy similarity measure is a novel approach for the prediction of dementia risk and for the evaluation of AD trajectories on an individual subject level.

  12. Longitudinal study of arteriogenesis with swept source optical coherence tomography and hyperspectral imaging

    Science.gov (United States)

    Poole, Kristin M.; Patil, Chetan A.; Nelson, Christopher E.; McCormack, Devin R.; Madonna, Megan C.; Duvall, Craig L.; Skala, Melissa C.

    2014-03-01

    Peripheral arterial disease (PAD) is an atherosclerotic disease of the extremities that leads to high rates of myocardial infarction and stroke, increased mortality, and reduced quality of life. PAD is especially prevalent in diabetic patients, and is commonly modeled by hind limb ischemia in mice to study collateral vessel development and test novel therapies. Current techniques used to assess recovery cannot obtain quantitative, physiological data non-invasively. Here, we have applied hyperspectral imaging and swept source optical coherence tomography (OCT) to study longitudinal changes in blood oxygenation and vascular morphology, respectively, intravitally in the diabetic mouse hind limb ischemia model. Additionally, recommended ranges for controlling physiological variability in blood oxygenation with respect to respiration rate and body core temperature were determined from a control animal experiment. In the longitudinal study with diabetic mice, hyperspectral imaging data revealed the dynamics of blood oxygenation recovery distally in the ischemic footpad. In diabetic mice, there is an early increase in oxygenation that is not sustained in the long term. Quantitative analysis of vascular morphology obtained from Hessian-filtered speckle variance OCT volumes revealed temporal dynamics in vascular density, total vessel length, and vessel diameter distribution in the adductor muscle of the ischemic limb. The combination of hyperspectral imaging and speckle variance OCT enabled acquisition of novel functional and morphological endpoints from individual animals, and provides a more robust platform for future preclinical evaluations of novel therapies for PAD.

  13. Crohn's disease in Japan: diagnostic criteria and epidemiology.

    Science.gov (United States)

    Yao, T; Matsui, T; Hiwatashi, N

    2000-10-01

    New diagnostic criteria for Crohn's disease and a review of Japanese epidemiologic studies are presented. New diagnostic criteria for Crohn's disease were established by the Research Committee of Inflammatory Bowel Disease, set up by the Japanese Ministry of Health and Welfare. For a definite diagnosis one of the following three conditions is required: 1) longitudinal ulcer or luminal deformity induced by longitudinal ulcer or cobblestone pattern, 2) intestinal small aphthous ulcerations arranged in a longitudinal fashion for at least three months plus noncaseating granulomas, and 3) multiple small aphthous ulcerations in both the upper and lower digestive tract not necessarily with longitudinal arrangement, for at least three months, plus noncaseating granulomas. Moreover, ulcerative colitis, ischemic enterocolitis, and acute infectious enterocolitis should be excluded. Data from the Japanese Ministry of Health and Welfare, in addition to data collected from two study groups, these being the two largest studies in Japan, are reviewed with regard to epidemiology. The number of patients with Crohn's disease has increased remarkably. The prevalence and the annual incidence of patients with Crohn's disease in Japan were estimated to be approximately 2.9 and 0.6 per 10(5) population in 1986, respectively, and 13.5 and 1.2 per 10(5) population in 1998. Characteristic features of Crohn's disease in Japan are that the male-female ratio exceeds 2, and that there is no second peak of incidence in the age group of 55 to 65 years. Clinically, Crohn's disease with only multiple small aphthous ulcerations, which is the earliest stage of the disease that is diagnosable, was found in 5 percent of patients.

  14. Regional 18F-Fluorodeoxyglucose Hypometabolism is Associated with Higher Apathy Scores Over Time in Early Alzheimer Disease.

    Science.gov (United States)

    Gatchel, Jennifer R; Donovan, Nancy J; Locascio, Joseph J; Becker, J Alex; Rentz, Dorene M; Sperling, Reisa A; Johnson, Keith A; Marshall, Gad A

    2017-07-01

    Apathy is among the earliest and most pervasive neuropsychiatric symptoms in prodromal and mild Alzheimer disease (AD) dementia that correlates with functional impairment and disease progression. We investigated the association of apathy with regional 18F-fluorodeoxyglucose (FDG) metabolism in cognitively normal, mild cognitive impairment, and AD dementia subjects from the Alzheimer's Disease Neuroimaging Initiative database. Cross-sectional and longitudinal studies. 57 North American research sites. 402 community dwelling elders. Apathy was assessed using the Neuropsychiatric Inventory Questionnaire. Baseline FDG metabolism in five regions implicated in the neurobiology of apathy and AD was investigated in relationship to apathy at baseline (cross-sectional general linear model) and longitudinally (mixed random/fixed effect model). Covariates included age, sex, diagnosis, apolipoprotein E genotype, premorbid intelligence, cognition, and antidepressant use. Cross-sectional analysis revealed that posterior cingulate hypometabolism, diagnosis, male sex, and antidepressant use were associated with higher apathy scores. Longitudinal analysis revealed that the interaction of supramarginal hypometabolism and time, posterior cingulate hypometabolism, and antidepressant use were associated with higher apathy scores across time; only supramarginal hypometabolism was positively related to rate of increase of apathy. Results support an association of apathy with hypometabolism in parietal regions commonly affected in early stages of AD, rather than medial frontal regions implicated in the neurobiology of apathy in later stages. Further work is needed to substantiate whether this localization is specific to apathy rather than to disease stage, and to investigate the potential role of AD proteinopathies in the pathogenesis of apathy. Copyright © 2017 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  15. Longitudinal Analysis of Somatic Cell Count for Joint Genetic Evaluation of Mastitis and Recovery Liability

    DEFF Research Database (Denmark)

    Welderufael, Berihu Gebremedhin; de Koning, D J; Janss, Luc

    Abstract Text: Better models of genetic evaluation for mastitis can be developed through longitudinal analysis of somatic cell count (SCC) which usually is used as a proxy for mastitis. Mastitis and recovery data with weekly observations of SCC were simulated for daughter groups of 60 and 240 per...... sire. Data were created to define cases: 1 if SCC was above a pre-specified boundary, else 0. A transition from below to above the boundary indicates probability to contract mastitis, and the other way indicates recovery. The MCMCglmm package was used to estimate breeding values. In the 60 daughters...

  16. Ethical Code Effectiveness in Football Clubs: A Longitudinal Analysis

    OpenAIRE

    Constandt, Bram; De Waegeneer, Els; Willem, Annick

    2017-01-01

    As football (soccer) clubs are facing different ethical challenges, many clubs are turning to ethical codes to counteract unethical behaviour. However, both in- and outside the sport field, uncertainty remains about the effectiveness of these ethical codes. For the first time, a longitudinal study design was adopted to evaluate code effectiveness. Specifically, a sample of non-professional football clubs formed the subject of our inquiry. Ethical code effectiveness was...

  17. Late life changes in mental health: a longitudinal study of 9683 women.

    Science.gov (United States)

    Leigh, Lucy; Byles, Julie E; Chojenta, Catherine; Pachana, Nancy A

    2016-10-01

    To identify latent subgroups of women in late life who are alike in terms of their mental health trajectories. Longitudinal data are for 9683 participants in the 1921-1926 cohort of the Australian Longitudinal Study on Women's Health, who completed at least two surveys between 1999 (aged 73-78 years) and 2008 (aged 82-87 years). Mental health was measured using the five-item mental health inventory (MHI-5). Latent profile analysis uncovered patterns of change in MHI-5 scores. Three patterns of change were identified for women who were still alive in 2008 (n = 7061), and three similar patterns for deceased women (n = 2622): (1) 'poor mental health' representing women with low MHI-5 scores, (2) 'good mental health' and (3) 'excellent' mental health, where scores remained very high. Deceased women had lower mental health scores for each class. Remote areas of residence, higher education, single marital status, higher Body Mass Index (BMI) and falls were the covariates associated with mental health in the survivor group. For the deceased group, education, BMI and falls were significant. Arthritis, stroke, heart disease, bronchitis/emphysema, diabetes and osteoporosis were associated with worse mental health for both groups, while asthma increased these odds significantly for the survivor group only. Hypertension and cancer were not significant predictors of poor mental health. The results show associations between chronic disease and level of mental health in older age, but no evidence of a large decline in mental health in the period prior to death.

  18. Analysis of the proton longitudinal structure function from the gluon distribution function

    International Nuclear Information System (INIS)

    Boroun, G.R.; Rezaei, B.

    2012-01-01

    We make a critical, next-to-leading order, study of the relationship between the longitudinal structure function F L and the gluon distribution proposed in Cooper-Sarkar et al. (Z. Phys. C 39:281, 1988; Acta Phys. Pol. B 34:2911 2003), which is frequently used to extract the gluon distribution from the proton longitudinal structure function at small x. The gluon density is obtained by expanding at particular choices of the point of expansion and compared with the hard Pomeron behavior for the gluon density. Comparisons with H1 data are made and predictions for the proposed best approach are also provided. (orig.)

  19. Longitudinal Associations between Triglycerides and Metabolic Syndrome Components in a Beijing Adult Population, 2007-2012.

    Science.gov (United States)

    Tao, Li-Xin; Yang, Kun; Liu, Xiang-Tong; Cao, Kai; Zhu, Hui-Ping; Luo, Yan-Xia; Guo, Jin; Wu, Li-Juan; Li, Xia; Guo, Xiu-Hua

    2016-01-01

    Longitudinal associations between triglycerides (TG) and other metabolic syndrome (MetS) components have rarely been reported. The purpose was to investigate the longitudinal association between TG and other MetS components with time. The longitudinal study was established in 2007 on individuals who attended health check-ups at Beijing Tongren Hospital and Beijing Xiaotangshan Hospital. Data used in this study was based on 7489 participants who had at least three health check-ups over a period of 5-year follow up. Joint model was used to explore longitudinal associations between TG and other MetS components after adjusted for age. There were positive correlations between TG and other MetS components except for high density lipoprotein (HDL), and the correlations increased with time. A negative correlation was displayed between TG and HDL, and the correlation also increased with time. Among all five pairs of TG and other MetS components, the marginal correlation between TG and body mass index (BMI) was the largest for both men and women. The marginal correlation between TG and fasting plasma glucose was the smallest for men, while the marginal correlation between TG and diastolic blood pressure was the smallest for women. The longitudinal association between TG and other MetS components increased with time. Among five pairs of TG and other MetS components, the longitudinal correlation between TG and BMI was the largest. It is important to closely monitor subjects with high levels of TG and BMI in health check-up population especially for women, because these two components are closely associated with development of hypertension, diabetes, cardiovascular disease and other metabolic diseases.

  20. Elastic stability of biaxially loaded longitudinally stiffened composite structures.

    Science.gov (United States)

    Viswanathan, A. V.; Tamekuni, M.; Tripp, L. L.

    1973-01-01

    A linear analysis method is presented for the elastic stability of structures of uniform cross section, that may be idealized as an assemblage of laminated plate-strips, flat and curved, and beams. Each plate-strip and beam covers the entire length of the structure and is simply supported on the edges normal to the longitudinal axis. Arbitrary boundary conditions may be specified on any external longitudinal side of plate-strips. The structure or selected plate-strips may be loaded in any desired combination of inplane biaxial loads. The analysis simultaneously considers all modes of instability and is applicable for the buckling of laminated composite structures. Some numerical results are presented to indicate possible applications.

  1. Longitudinal AddiQoL scores may identify higher risk for adrenal crises in Addison's disease.

    Science.gov (United States)

    Meyer, Gesine; Koch, Maike; Herrmann, Eva; Bojunga, Jörg; Badenhoop, Klaus

    2018-05-01

    Several studies have shown a reduced quality of life (QoL) in patients with Addison's disease (AD), but investigations of QoL over a long-term course are lacking. Adrenal crises (AC) are life-threatening complications in AD. The purpose of this prospective study was to test whether the repeated use of QoL-questionnaires can detect prodromal periods of an AC. 110 patients with AD were asked to complete the disease specific-QoL questionnaire AddiQoL and a short questionnaire about adverse events once monthly over a period of ten months. AC was defined if at least two of the following symptoms were reported: (a) hypotension, (b) nausea or vomiting, (c) severe fatigue, (d) documented hyponatremia, hyperkalemia, or hypoglycemia, and subsequent parenteral glucocorticoid administration was carried out. Prevalence of AC was 10.9/100 patient years. AddiQoL scores in patients with AC showed a trend (p = 0,08) to a wider fluctuation over time. Subjective precrises not meeting the criteria for AC were reported by 31 patients who had significantly lower AddiQoL scores (p = 0,018). These are the first data showing the course of QoL during a period of ten months in patients with AD. Incidence of AC exceeds previous data. Our data show, that subjective precrises in AD associate with lower QoL. AC, as well as precrises affect intraindividual AddiQol-scores over time with a trend to a stronger fluctuation. Longitudinal AddiQol scores and self-reporting of precrises via patient diaries are additional clinical tools to identify higher risk for critical events.

  2. Longitudinal Bunch Position Control for the Super-B Accelerator

    International Nuclear Information System (INIS)

    Bertsche, Kirk; Rivetta, Claudio; Sullivam, Michael K.; SLAC; Drago, Alessandro; Frascati

    2009-01-01

    The use of normal conducting cavities and an ion-clearing gap will cause a significant RF accelerating voltage gap transient and longitudinal phase shift of the individual bunches along the bunch train in both rings of the SuperB accelerator. Small relative centroid position shifts between bunches of the colliding beams will have a large adverse impact on the luminosity due to the small β* y at the interaction point (IP). We investigate the possibility of minimizing the relative longitudinal position shift between bunches by reducing the gap transient in each ring and matching the longitudinal bunch positions of the two rings at the IP using feedback/feedforward techniques in the LLRF. The analysis is conducted assuming maximum use of the klystron power installed in the system

  3. Longitudinal Meta-analysis

    NARCIS (Netherlands)

    Hox, J.J.; Maas, C.J.M.; Lensvelt-Mulders, G.J.L.M.

    2004-01-01

    The goal of meta-analysis is to integrate the research results of a number of studies on a specific topic. Characteristic for meta-analysis is that in general only the summary statistics of the studies are used and not the original data. When the published research results to be integrated

  4. Employee identification before and after an internal merger: a longitudinal analysis

    NARCIS (Netherlands)

    Bartels, J.; Pruyn, A.T.H.; Jong, de M.D.T.

    2009-01-01

    Earlier studies have shown that perceived external prestige (PEP) and communication climate influence employees' overall organizational identification. This paper presents the results of a longitudinal study into the determinants of organizational identification at two organizational levels during

  5. Employee indentification before and after an internal merger: A longitudinal analysis

    NARCIS (Netherlands)

    Bartels, J.; Pruyn, Adriaan T.H.; de Jong, Menno D.T.

    2009-01-01

    Earlier studies have shown that perceived external prestige (PEP) and communication climate influence employees' overall organizational identification. This paper presents the results of a longitudinal study into the determinants of organizational identification at two organizational levels during

  6. The Effect of Disease-Modifying Drugs on Brain Atrophy in Relapsing-Remitting Multiple Sclerosis: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Pierre Branger

    Full Text Available The quantification of brain atrophy in relapsing-remitting multiple sclerosis (RRMS may serve as a marker of disease progression and treatment response. We compared the association between first-line (FL or second-line (SL disease-modifying drugs (DMDs and brain volume changes over time in RRMS.We reviewed clinical trials in RRMS between January 1, 1995 and June 1, 2014 that assessed the effect of DMDs and reported data on brain atrophy in Medline, Embase, the Cochrane database and meeting abstracts. First, we designed a meta-analysis to directly compare the percentage brain volume change (PBVC between FLDMDs and SLDMDs at 24 months. Second, we conducted an observational and longitudinal linear regression analysis of a 48-month follow-up period. Sensitivity analyses considering PBVC between 12 and 48 months were also performed.Among the 272 studies identified, 117 were analyzed and 35 (18,140 patients were included in the analysis. Based on the meta-analysis, atrophy was greater for the use of an FLDMD than that of an SLDMD at 24 months (primary endpoint mean difference, -0.86; 95% confidence interval: -1.57--0.15; P = 0.02. Based on the linear regression analysis, the annual PBVC significantly differed between SLDMDs and placebo (-0.27%/y and -0.50%/y, respectively, P = 0.046 but not between FLDMDs (-0.33%/y and placebo (P = 0.11 or between FLDMDs and SLDMDs (P = 0.49. Based on sensitivity analysis, the annual PBVC was reduced for SLDMDs compared with placebo (-0.14%/y and -0.56%/y, respectively, P<0.001 and FLDMDs (-0.46%/y, P<0.005, but no difference was detected between FLDMDs and placebo (P = 0.12.SLDMDs were associated with reduced PBVC slope over time in RRMS, regardless of the period considered. These results provide new insights into the mechanisms underlying atrophy progression in RRMS.

  7. Longitudinal erythronychia: individual or multiple linear red bands of the nail plate: a review of clinical features and associated conditions.

    Science.gov (United States)

    Cohen, Philip R

    2011-08-01

    Longitudinal erythronychia is a linear red band on the nail plate that originates at the proximal nail fold, traverses the lunula, and extends to the free edge of the nail plate. Longitudinal erythronychia is classified based upon the number of nails affected and the number of red streaks present on each nail as follows: type Ia (monodactylous - single band), type Ib (monodactylous - bifid bands), type IIa (polydactylous - single band), and type IIb (polydactylous - multiple bands). Associated morphologic findings that can be present at the distal tip of the nail with longitudinal erythronychia include fragility, onycholysis, splinter hemorrhage, splitting, subungual keratosis, thinning, and V-shaped nick. Some patients with longitudinal erythronychia seek medical evaluation because of pain in the associated distal digit; however, the linear red nail plate dyschromia is often asymptomatic and the individual is concerned about the cosmetic appearance or distal nail fragility. Longitudinal erythronychia can be a clinical manifestation of an underlying local or systemic condition. Benign tumors (glomus tumor, onychopapilloma, and warty dyskeratoma), malignant neoplasms (malignant melanoma and squamous cell carcinoma), and other conditions (hemiplegia and postsurgical scar) can be associated with monodactylous longitudinal erythronychia or it may be idiopathic or the initial stage of polydactylous longitudinal erythronychia-associated systemic conditions. Polydactylous longitudinal erythronychia is most commonly reported in patients with Darier disease (keratosis follicularis); other associated conditions include acantholytic dyskeratotic epidermal nevus, acantholytic epidermolysis bullosa, acrokeratosis verruciformis of Hopf, amyloidosis, graft-versus-host disease, lichen planus, and pseudobulbar syndrome. Polydactylous longitudinal erythronychia has also been observed as an idiopathic finding. Biopsy of the nail matrix and nail bed may be necessary to establish the

  8. Floquet stability analysis of the longitudinal dynamics of two hovering model insects

    Science.gov (United States)

    Wu, Jiang Hao; Sun, Mao

    2012-01-01

    Because of the periodically varying aerodynamic and inertial forces of the flapping wings, a hovering or constant-speed flying insect is a cyclically forcing system, and, generally, the flight is not in a fixed-point equilibrium, but in a cyclic-motion equilibrium. Current stability theory of insect flight is based on the averaged model and treats the flight as a fixed-point equilibrium. In the present study, we treated the flight as a cyclic-motion equilibrium and used the Floquet theory to analyse the longitudinal stability of insect flight. Two hovering model insects were considered—a dronefly and a hawkmoth. The former had relatively high wingbeat frequency and small wing-mass to body-mass ratio, and hence very small amplitude of body oscillation; while the latter had relatively low wingbeat frequency and large wing-mass to body-mass ratio, and hence relatively large amplitude of body oscillation. For comparison, analysis using the averaged-model theory (fixed-point stability analysis) was also made. Results of both the cyclic-motion stability analysis and the fixed-point stability analysis were tested by numerical simulation using complete equations of motion coupled with the Navier–Stokes equations. The Floquet theory (cyclic-motion stability analysis) agreed well with the simulation for both the model dronefly and the model hawkmoth; but the averaged-model theory gave good results only for the dronefly. Thus, for an insect with relatively large body oscillation at wingbeat frequency, cyclic-motion stability analysis is required, and for their control analysis, the existing well-developed control theories for systems of fixed-point equilibrium are no longer applicable and new methods that take the cyclic variation of the flight dynamics into account are needed. PMID:22491980

  9. Modest alcohol consumption decreases the risk of fatty liver disease or nonalcoholic fatty liver disease: a Meta-analysis

    Directory of Open Access Journals (Sweden)

    Guo-li CAO

    2016-08-01

    Full Text Available Objective  To evaluate the association between modest alcohol consumption and the risk of fatty liver disease (FLD or nonalcoholic fatty liver disease (NAFLD. Methods  PubMed, EMBASE, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI, Wanfang Digital Journal Full-text Database, and database for Chinese Technical Periodicals (VIP till Nov. 2015 were searched for the studies in evaluating the effect of alcohol consumption on FLD or NAFLD. The quality assessment of included studies was performed according to the combined evaluation for cross-sectional studies and Newcastle-Ottawa scale (NOS for cohort studies. A meta-analysis was performed using Stata12.0 software. Results  A total of 16 studies including 13 cross-sectional studies, 2 cross-sectional following longitudinal studies, and 1 cohort study with 76 967 participants were selected finally. The results of Meta-analysis were as follows. Minimal and light alcohol consumptions reduced the risk for FLD or NAFLD by 17% and 27%, respectively, and moderate alcohol consumption was marginally associated with decreased risk for FLD or NAFLD. The results of subgroup analysis by gender showed that (1 Minimal and light alcohol consumptions reduced the risk of FLD or NAFLD by 29% and 33%, respectively, but moderate alcohol consumption was not statistically significant in reducing the risk of FLD or NAFLD in females compared with controls; (2 Light alcohol consumption reduced the risk of FLD or NAFLD by 23%, but minimal and moderate alcohol consumptions were not statistically significant in reducing the risk of FLD or NAFLD in male compared with controls; (3 Light and moderate alcohol consumptions in Asian males reduced the risk of FLD or NAFLD by 29.7% and 30.3%, respectively. Conclusions  Modest alcohol consumptions may not increase the risk of FLD or NAFLD. Inversely, minimal and light alcohol consumptions in female reduce the risk of FLD or NAFLD remarkably

  10. Longitudinal burnout-collaboration patterns in Japanese medical care workers at special needs schools: a latent class growth analysis

    Directory of Open Access Journals (Sweden)

    Kanayama M

    2016-06-01

    Full Text Available Mieko Kanayama,1 Machiko Suzuki,1 Yoshikazu Yuma2 1Department of Human Health Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan; 2Department of Human Development Education, Graduate School of Education, Hyogo University of Teacher Education, Kato, Hyogo, Japan Abstract: The present study aimed to identify and characterize potential burnout types and the relationship between burnout and collaboration over time. Latent class growth analysis and the growth mixture model were used to identify and characterize heterogeneous patterns of longitudinal stability and change in burnout, and the relationship between burnout and collaboration. We collected longitudinal data at three time points based on Japanese academic terms. The 396 study participants included academic teachers, yogo teachers, and registered nurses in Japanese special needs schools. The best model included four types of both burnout and collaboration in latent class growth analysis with intercept, slope, and quadratic terms. The four types of burnout were as follows: low stable, moderate unstable, high unstable, and high decreasing. They were identified as involving inverse collaboration function. The results indicated that there could be dynamic burnout types, namely moderate unstable, high unstable, and high decreasing, when focusing on growth trajectories in latent class analyses. The finding that collaboration was dynamic for dynamic burnout types and stable for stable burnout types is of great interest. This was probably related to the inverse relationship between the two constructs. Keywords: burnout, collaboration, latent class growth analysis, interprofessional care, special needs schools

  11. Quantitative MR characterization of disease activity in the knee in children with juvenile idiopathic arthritis: a longitudinal pilot study

    International Nuclear Information System (INIS)

    Workie, Dagnachew W.; Graham, T.B.; Laor, Tal; Racadio, Judy M.; Rajagopal, Akila; O'Brien, Kendall J.; Bommer, Wendy A.; Shire, Norah J.; Dardzinski, Bernard J.

    2007-01-01

    The development of a quantifiable and noninvasive method of monitoring disease activity and response to therapy is vital for arthritis management. The purpose of this study was to investigate the utility of quantitative dynamic contrast-enhanced MRI (DCE-MRI) based on pharmacokinetic (PK) modeling to evaluate disease activity in the knee and correlate the results with the clinical assessment in children with juvenile idiopathic arthritis (JIA). A group of 17 children with JIA underwent longitudinal clinical and laboratory assessment and DCE-MRI of the knee at enrollment, 3 months, and 12 months. A PK model was employed using MRI signal enhancement data to give three parameters, K trans ' (min -1 ), k ep (min -1 ), and V p ' and to calculate synovial volume. The PK parameters, synovial volumes, and clinical and laboratory assessments in most children were significantly decreased (P < 0.05) at 12 months when compared to the enrollment values. There was excellent correlation between the PK and synovial volume and the clinical and laboratory assessments. Differences in MR and clinical parameter values in individual subjects illustrate persistent synovitis when in clinical remission. A decrease in PK parameter values obtained from DCE-MRI in children with JIA likely reflects diminution of disease activity. This technique may be used as an objective follow-up measure of therapeutic efficacy in patients with JIA. MR imaging can detect persistent synovitis in patients considered to be in clinical remission. (orig.)

  12. Tensions in mentoring medical students toward self-directed and reflective learning in a longitudinal portfolio-based mentoring system - An activity theory analysis.

    Science.gov (United States)

    Heeneman, Sylvia; de Grave, Willem

    2017-04-01

    In medical education, students need to acquire skills to self-direct(ed) learning (SDL), to enable their development into self-directing and reflective professionals. This study addressed the mentor perspective on how processes in the mentor-student interaction influenced development of SDL. n = 22 mentors of a graduate-entry medical school with a problem-based curriculum and longitudinal mentoring system were interviewed (n = 1 recording failed). Using activity theory (AT) as a theoretical framework, thematic analysis was applied to the interview data to identify important themes. Four themes emerged: centered around the role of the portfolio, guiding of students' SDL in the context of assessment procedures, mentor-role boundaries and longitudinal development of skills by both the mentor and mentee. Application of AT showed that in the interactions between themes tensions or supportive factors could emerge for activities in the mentoring process. The mentors' perspective on coaching and development of reflection and SDL of medical students yielded important insights into factors that can hinder or support students' SDL, during a longitudinal mentor-student interaction. Coaching skills of the mentor, the interaction with a portfolio and the context of a mentor community are important factors in a longitudinal mentor-student interaction that can translate to students' SDL skills.

  13. Longitudinal trends and subgroup analysis in publication patterns for preclinical data of newly approved drugs.

    Science.gov (United States)

    Köster, Ursula; Nolte, Ingo; Michel, Martin C

    2016-02-01

    Having observed a large variation in the number and type of original preclinical publications for newly registered drugs, we have explored whether longitudinal trends and/or factors specific for certain drugs or their manufacturers may explain such variation. Our analysis is based on 1954 articles related to 170 newly approved drugs. The number of preclinical publications per compound declined from a median of 10.5 in 1991 to 3 in 2011. A similar trend was observed for the number of in vivo studies in general, but not in the subset of in vivo studies in animal models of disease. The percentage of compounds with studies using isolated human cells or cell lines almost doubled over time from 37 to 72%. Number of publications did not exhibit major differences between compounds intended for human versus veterinary use, therapeutic areas, small molecules versus biologicals, or innovator versus follow-up compounds; however, some companies may publish fewer studies per compound than others. However, there were qualitative differences in the types of models being used depending on the therapeutic area; specifically, compounds for use in oncology very often used isolated cells and cell lines, often from human origin. We conclude that the large variation in number and type of reported preclinical data is not easily explained. We propose that pharmaceutical companies should consistently provide a comprehensive documentation of the preclinical data they generate as part of their development programs in the public domain to enable a better understanding of the drugs they intend to market.

  14. Interaction between Social/Psychosocial Factors and Genetic Variants on Body Mass Index: A Gene-Environment Interaction Analysis in a Longitudinal Setting.

    Science.gov (United States)

    Zhao, Wei; Ware, Erin B; He, Zihuai; Kardia, Sharon L R; Faul, Jessica D; Smith, Jennifer A

    2017-09-29

    Obesity, which develops over time, is one of the leading causes of chronic diseases such as cardiovascular disease. However, hundreds of BMI (body mass index)-associated genetic loci identified through large-scale genome-wide association studies (GWAS) only explain about 2.7% of BMI variation. Most common human traits are believed to be influenced by both genetic and environmental factors. Past studies suggest a variety of environmental features that are associated with obesity, including socioeconomic status and psychosocial factors. This study combines both gene/regions and environmental factors to explore whether social/psychosocial factors (childhood and adult socioeconomic status, social support, anger, chronic burden, stressful life events, and depressive symptoms) modify the effect of sets of genetic variants on BMI in European American and African American participants in the Health and Retirement Study (HRS). In order to incorporate longitudinal phenotype data collected in the HRS and investigate entire sets of single nucleotide polymorphisms (SNPs) within gene/region simultaneously, we applied a novel set-based test for gene-environment interaction in longitudinal studies (LGEWIS). Childhood socioeconomic status (parental education) was found to modify the genetic effect in the gene/region around SNP rs9540493 on BMI in European Americans in the HRS. The most significant SNP (rs9540488) by childhood socioeconomic status interaction within the rs9540493 gene/region was suggestively replicated in the Multi-Ethnic Study of Atherosclerosis (MESA) ( p = 0.07).

  15. Interaction between Social/Psychosocial Factors and Genetic Variants on Body Mass Index: A Gene-Environment Interaction Analysis in a Longitudinal Setting

    Directory of Open Access Journals (Sweden)

    Wei Zhao

    2017-09-01

    Full Text Available Obesity, which develops over time, is one of the leading causes of chronic diseases such as cardiovascular disease. However, hundreds of BMI (body mass index-associated genetic loci identified through large-scale genome-wide association studies (GWAS only explain about 2.7% of BMI variation. Most common human traits are believed to be influenced by both genetic and environmental factors. Past studies suggest a variety of environmental features that are associated with obesity, including socioeconomic status and psychosocial factors. This study combines both gene/regions and environmental factors to explore whether social/psychosocial factors (childhood and adult socioeconomic status, social support, anger, chronic burden, stressful life events, and depressive symptoms modify the effect of sets of genetic variants on BMI in European American and African American participants in the Health and Retirement Study (HRS. In order to incorporate longitudinal phenotype data collected in the HRS and investigate entire sets of single nucleotide polymorphisms (SNPs within gene/region simultaneously, we applied a novel set-based test for gene-environment interaction in longitudinal studies (LGEWIS. Childhood socioeconomic status (parental education was found to modify the genetic effect in the gene/region around SNP rs9540493 on BMI in European Americans in the HRS. The most significant SNP (rs9540488 by childhood socioeconomic status interaction within the rs9540493 gene/region was suggestively replicated in the Multi-Ethnic Study of Atherosclerosis (MESA (p = 0.07.

  16. Income inequality is associated with adolescent fertility in Brazil: a longitudinal multilevel analysis of 5,565 municipalities.

    Science.gov (United States)

    Chiavegatto Filho, Alexandre D P; Kawachi, Ichiro

    2015-02-07

    Brazil has one of the highest adolescent fertility rates in the world. Income inequality has been frequently linked to overall adolescent health, but studies that analyzed its association with adolescent fertility have been performed only in developed countries. Brazil, in the past decade, has presented a rare combination of increasing per capita income and decreasing income inequality, which could influence future desirable pathways for other countries. We analyzed every live birth from 2000 and from 2010 in each of the 5,565 municipalities of Brazil, a total of 6,049,864 births, which included 1,247,145 (20.6%) births from women aged 15 to 19. Income inequality was assessed by the Gini Coefficient and adolescent fertility by the ratio between the number of live births from women aged 15 to 19 and the number of women aged 15 to 19, calculated for each municipality. We first applied multilevel models separately for 2000 and 2010 to test the cross-sectional association between income inequality and adolescent fertility. We then fitted longitudinal first-differences multilevel models to control for time-invariant effects. We also performed a sensitivity analysis to include only municipality with satisfactory birth record coverage. Our results indicate a consistent and positive association between income inequality and adolescent fertility. After controlling for per capita income, college access, youth homicide rate and adult fertility, higher income inequality was significantly associated with higher adolescent fertility for both 2000 and 2010. The longitudinal multilevel models found similar results. The sensitivity analysis indicated that the results for the association between income inequality and adolescent fertility were robust. Adult fertility was also significantly associated with adolescent fertility in the cross-sectional and longitudinal models. Income inequality is expected to be a leading concern for most countries in the near future. Our results suggest

  17. Exploring Longitudinal Risk-return Relationships

    DEFF Research Database (Denmark)

    Andersen, Torben J.; Bettis, Richard A.

    2015-01-01

    We study a longitudinal fit model of adaptation and its association with the longitudinal risk-return relationship. The model allows the firm to adjust its position in response to partial learning about a changing environment characterized by two path-dependent processes—a random walk and a stoch......We study a longitudinal fit model of adaptation and its association with the longitudinal risk-return relationship. The model allows the firm to adjust its position in response to partial learning about a changing environment characterized by two path-dependent processes—a random walk...... can lead to the inverse longitudinal risk-return relationships observed empirically. We discuss this apparent paradox and the possible resolution between mindless and conscious behavior as plausible causes of the longitudinal Bowman Paradox....

  18. Life satisfaction and longitudinal changes in physical activity, diabetes and obesity among patients with cardiovascular diseases.

    Science.gov (United States)

    Baumann, Michèle; Tchicaya, Anastase; Lorentz, Nathalie; Le Bihan, Etienne

    2017-12-02

    Patients with cardiovascular disease who underwent coronary angiography at the National Institute of Cardiac Surgery and Cardiological Intervention (INCCI) in Luxembourg were surveyed for cardiovascular risk factors (CVRF) (hypertension, hypercholesterolemia, diabetes, obesity, physical inactivity, tobacco consumption). In 2013/14, their life satisfaction (LS) was also assessed. Our aim was to analyse the relationships between LS on one hand and longitudinal changes in CVRF between 2008/09 and 2013/14 and socioeconomic factors on the other. 1289 patients completed a self-administered questionnaire. Life Satisfaction, originally recorded on a 1 to 10 scale of complete satisfaction was dichotomized into two groups: ≤ 7 and. >7. We then performed logistic multiple regressions. The event on which the probability was modelled, was LS > 7. Data were adjusted on age, sex and income. Longitudinal changes in CVRF were assessed by their presence or absence in 2008/09 and 2013/14 (categories: 'no-no'; 'no-yes'; 'yes-no'; 'yes-yes'). Physical activity in 2008/09 and 2013/14 was associated with a lower LS (OR = 0.469). The same pattern was observed for obesity and physical inactivity: lower LS was related to the presence of these risks (yes-yes; no-yes) in 2013/14 (mean OR for obesity and physical inactivity in 2013/14: 0.587 and 0.485 respectively), whereas their presence or absence in 2008/09 was not related to LS. Finally, patients who suffered from diabetes in 2008 were more likely to experience a decline in LS, particularly if their diabetes was less severe in 2013/14 (OR = 0.462). The lowest LS was observed when obesity or physical inactivity was present in 2013/14, newly or otherwise. The same trend was seen in diabetes among patients who had it in 2008/9, but were less severely affected in 2013/14. In secondary prevention, CVD-related upheavals could be minimised if professionals and patients became 'Partners in Healthcare' to better adhere to healthy

  19. Accuracy of Consecutive Fecal Calprotectin Measurements to Predict Relapse in Inflammatory Bowel Disease Patients Under Maintenance With Anti-TNF Therapy: A Prospective Longitudinal Cohort Study.

    Science.gov (United States)

    Ferreiro-Iglesias, Rocio; Barreiro-de Acosta, Manuel; Lorenzo-Gonzalez, Aurelio; Dominguez-Muñoz, Juan E

    2018-03-01

    Predicting relapse in inflammatory bowel disease (IBD) patients could allow early changes in therapy. We aimed at evaluating the accuracy of consecutive fecal calprotectin (FC) measurements to predict flares in IBD patients under maintenance treatment with anti-tumor necrosis factor (TNF) drugs. A prospective longitudinal cohort study with 16-month follow-up period was designed. IBD patients in clinical remission for at least 6 months under anti-TNF therapy were included. FC was quantified at 4-month intervals for 1 year, and patients were clinically evaluated for relapse at 2-month intervals. Diagnostic accuracy of FC for predicting relapse was evaluated by receiver-operating characteristic curve analysis. In total, 95 of 106 included patients finalized the study and were analyzed (median age 44 y, 50.5% female, 75% with Crohn's disease). A total of 30 patients (31.6%) had a relapse over follow-up. FC concentration was significantly higher in patients who relapsed (477 μg/g) than in patients who maintained in remission (65 μg/g) (Ppredict remission was 130 μg/g (negative predictive value of 100%), and 300 μg/g to predict relapse (positive predictive value of 78.3%). FC is a good predictor of clinical relapse and a particularly good predictor of remission over the following 4 months in patients with IBD on maintenance therapy with anti-TNF drugs. FC levels 300 μg/g allow predicting relapse with a high probability at any time over the following 4 months.

  20. Defining disease beyond conceptual analysis: an analysis of conceptual analysis in philosophy of medicine.

    Science.gov (United States)

    Lemoine, Maël

    2013-08-01

    Conceptual analysis of health and disease is portrayed as consisting in the confrontation of a set of criteria--a "definition"--with a set of cases, called instances of either "health" or "disease." Apart from logical counter-arguments, there is no other way to refute an opponent's definition than by providing counter-cases. As resorting to intensional stipulation (stipulation of meaning) is not forbidden, several contenders can therefore be deemed to have succeeded. This implies that conceptual analysis alone is not likely to decide between naturalism and normativism. An alternative to this approach would be to examine whether the concept of disease can be naturalized.

  1. Accuracy of accelerated cine MR imaging at 3 Tesla in longitudinal follow-up of cardiac function

    International Nuclear Information System (INIS)

    Sandner, Torleif A.; Huber, Armin M.; Theisen, Daniel; Reiser, Maximilian F.; Wintersperger, Bernd J.; Houck, Philip; Runge, Val M.; Sincleair, Spencer

    2008-01-01

    The ability of fast, parallel-imaging-based cine magnetic resonance (MR) to monitor global cardiac function in longitudinal exams at 3 Tesla was evaluated. Seventeen patients with chronic cardiac disease underwent serial cine MR imaging exams (n=3) at 3 Tesla. Data were acquired in short-axis orientation using cine steady-state free precession (SSFP) with a spatial resolution of 2.5 x 1.9 mm 2 at 45 ms temporal resolution. Multislice imaging (three slices/breath-hold) was performed using TSENSE acceleration (R=3) and standard single-slice cine (non-TSENSE) was performed at identical locations in consecutive breath-holds. End-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF) and myocardial mass (MM) of both cine approaches were compared for individual time-points as well as for longitudinal comparison. TSENSE-cine did not show significant differences for EDV (2.6 ml; P=.79), ESV (2.2 ml; P=0.81), EF (-0.3%; P=0.95) and MM (2.4 g; P=0.72) in comparison with non-TSENSE. Longitudinal ANOVA analysis did not reveal significant differences for any parameter, neither for non-TSENSE data (all P>0.7) nor for TSENSE data (all P>0.9). Multifactorial ANOVA showed non-significant differences (all P>0.7) at comparable data variances. Data acquisition was significantly shortened using TSENSE. Threefold accelerated multislice cine at 3 Tesla allows accurate assessment of volumetric LV data and accurate longitudinal monitoring of global LV function at a substantially shorter overall examination time. (orig.)

  2. A Study of the Factors Associated with Risk for Development of Pressure Ulcers: A Longitudinal Analysis.

    Science.gov (United States)

    Thomas, Elizebeth; Vinodkumar, Sudhaya; Mathew, Silvia; Setia, Maninder Singh

    2015-01-01

    Pressure ulcers (PUs) are prevalent in hospitalized patients; they may cause clinical, psychological, and economic problems in these patients. Previous studies are cross-sectional, have used pooled data, or cox-regression models to assess the risk for developing PU. However, PU risk scores change over time and models that account for time varying variables are useful for cohort analysis of data. The present longitudinal study was conducted to compare the risk of PU between surgical and nonsurgical patients, and to evaluate the factors associated with the development of these ulcers over a period of time. We evaluated 290 hospitalized patients over a 4 months period. The main outcomes for our analysis were: (1) Score on the pressure risk assessment scale; and (2) the proportion of individuals who were at severe risk for developing PUs. We used random effects models for longitudinal analysis of the data. The mean PU score was significantly higher in the nonsurgical patients compared with surgical patients at baseline (15.23 [3.86] vs. 9.33 [4.57]; P 20 at baseline and were considered as being at high-risk for PU; the proportion was significantly higher among the nonsurgical patients compared with the surgical patients (14% vs. 4%, P = 0.003). In the adjusted models, there was no difference for severe risk for PU between surgical and nonsurgical patients (odds ratios [ORs]: 0.37, 95% confidence interval [CI]: 0.01-12.80). An additional day in the ward was associated with a significantly higher likelihood of being at high-risk for PU (OR: 1.47, 95% CI: 1.16-1.86). There were no significant differences between patients who were admitted for surgery compared with those who were not. An additional day in the ward, however, is important for developing a high-risk score for PU on the monitoring scale, and these patients require active interventions.

  3. Effect of exposure to evening light on sleep initiation in the elderly: a longitudinal analysis for repeated measurements in home settings.

    Science.gov (United States)

    Obayashi, Kenji; Saeki, Keigo; Iwamoto, Junko; Okamoto, Nozomi; Tomioka, Kimiko; Nezu, Satoko; Ikada, Yoshito; Kurumatani, Norio

    2014-05-01

    Epidemiologic data have demonstrated associations of sleep-onset insomnia with a variety of diseases, including depression, dementia, diabetes and cardiovascular diseases. Sleep initiation is controlled by the suprachiasmatic nucleus of the hypothalamus and endogenous melatonin, both of which are influenced by environmental light. Exposure to evening light is hypothesized to cause circadian phase delay and melatonin suppression before bedtime, resulting in circadian misalignment and sleep-onset insomnia; however, whether exposure to evening light disturbs sleep initiation in home settings remains unclear. In this longitudinal analysis of 192 elderly individuals (mean age: 69.9 years), we measured evening light exposure and sleep-onset latency for 4 days using a wrist actigraph incorporating a light meter and an accelerometer. Mixed-effect linear regression analysis for repeated measurements was used to evaluate the effect of evening light exposure on subsequent sleep-onset latency. The median intensity of evening light exposure and the median sleep-onset latency were 27.3 lux (interquartile range, 17.9-43.4) and 17 min (interquartile range, 7-33), respectively. Univariate models showed significant associations between sleep-onset latency and age, gender, daytime physical activity, in-bed time, day length and average intensity of evening and nighttime light exposures. In a multivariate model, log-transformed average intensity of evening light exposure was significantly associated with log-transformed sleep-onset latency independent of the former potential confounding factors (regression coefficient, 0.133; 95% CI, 0.020-0.247; p = 0.021). Day length and nighttime light exposure were also significantly associated with log-transformed sleep-onset latency (p = 0.001 and p < 0.001, respectively). In conclusion, exposure to evening light in home setting prolongs subsequent sleep-onset latency in the elderly.

  4. The association between mood and anxiety disorders, and coronary heart disease in Brazil: A cross-sectional analysis on the Brazilian longitudinal study of adult health (ELSA-Brasil

    Directory of Open Access Journals (Sweden)

    Andrew eKemp

    2015-02-01

    Full Text Available Background: Associations between major depressive disorder and coronary heart disease (CHD have been established, and these associations increase risk of future morbidity and mortality. Prior research has been carried out in high-income countries. Here we examine associations between the mood and anxiety disorders, and coronary heart disease in a large cohort at baseline from Brazil, a country facing a variety of challenges that may affect these associations.Methods: Participants included 15,105 civil servants aged 35 to 74 at baseline (2008-10 from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil. CHD (N=721 included self-reported angina pectoris (n=305, myocardial infarction (MI (n=259 and coronary revascularization (n=239. Hierarchical logistic regression analyses were conducted to estimate odds ratios and confidence intervals. Results: Major findings indicate that comorbid major depressive disorder and anxiety disorders (n=434 are associated with a 3-fold increase in CHD, major depressive disorder alone (n=170 with a 2-fold increase in CHD, while generalised anxiety disorder alone (n=1,394 and mixed anxiety and depression disorder (MADD; n=1,844 – symptoms present, but diagnostic threshold not reached – are associated with a 1.5-fold increase in CHD, after full adjustment for covariates. Conclusions: The association with CHD is greatest in those with psychiatric comorbidity, while associations were also observed in major depressive disorder and generalised anxiety disorder without comorbidity. While findings are limited by the cross-sectional design of the study, given the known risks associated with comorbidity of the mood and anxiety disorders with CHD, findings reinforce the importance of comprehensive health assessment in Brazil.

  5. Gray matter concentration and effective connectivity changes in Alzheimer's disease: a longitudinal structural MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xingfeng; Coyle, Damien; Maguire, Liam; Watson, David R.; McGinnity, Thomas M. [University of Ulster, Intelligent Systems Research Centre, Magee Campus, Derry, Northern Ireland (United Kingdom)

    2011-10-15

    Understanding disease progression in Alzheimer's disease (AD) awaits the resolution of three fundamental questions: first, can we identify the location of ''seed'' regions where neuropathology is first present? Some studies have suggested the medial temporal lobe while others have suggested the hippocampus. Second, are there similar atrophy rates within affected regions in AD? Third, is there evidence of causality relationships between different affected regions in AD progression ?To address these questions, we conducted a longitudinal MRI study to investigate the gray matter (GM) changes in AD progression. Abnormal brain regions were localized by a standard voxel-based morphometry method, and the absolute atrophy rate in these regions was calculated using a robust regression method. Primary foci of atrophy were identified in the hippocampus and middle temporal gyrus (MTG). A model based upon the Granger causality approach was developed to investigate the cause-effect relationship over time between these regions based on GM concentration. Results show that in the earlier stages of AD, primary pathological foci are in the hippocampus and entorhinal cortex. Subsequently, atrophy appears to subsume the MTG. The causality results show that there is in fact little difference between AD and age-matched healthy control in terms of hippocampus atrophy, but there are larger differences in MTG, suggesting that local pathology in MTG is the predominant progressive abnormality during intermediate stages of AD development. (orig.)

  6. Maternal Alcohol Consumption During the Perinatal and Early Parenting Period: A Longitudinal Analysis.

    Science.gov (United States)

    Liu, Weiwei; Mumford, Elizabeth A; Petras, Hanno

    2016-02-01

    Despite potential health risks for women and children, one in five women report alcohol use during pregnancy and a significant proportion of those who quit during pregnancy return to drinking post-delivery. This study seeks to understand the longitudinal patterns of alcohol consumption before, during pregnancy and post-delivery, and the role of maternal characteristics for purposes of informing prevention design. General growth mixture models were used to describe the average developmental patterns of maternal weekly drinking quantity at six time points, from preconception through child entering kindergarten, as well as heterogeneity in these patterns among 9100 mothers from the Early Childhood Longitudinal Study representing the 2001 US national birth cohort. Four distinct classes of mothers were defined by their longitudinal alcohol consumption patterns: Low Probability Drinkers (50.3 %), Escalating Risk Drinkers (12.0 %), Escalating Low Risk Drinkers (27.4 %), and Early Parenting Quitters (10.2 %). Heterogeneous covariate associations were observed. For example, mothers who gave birth after age 36 were twice as likely to be Escalating Risk Drinkers and Escalating Low Risk Drinkers (vs Low Probability Drinkers), but not more likely to be Early Parenting Quitters, when compared to mothers who gave birth between the ages of 26 and 35. There is significant heterogeneity in maternal longitudinal alcohol use patterns during the perinatal period. Baseline maternal characteristics and behavior associated with these heterogeneous patterns provide valuable tools to identify potential risky drinkers during this critical time period and may be synthesized to tailor pre- and postnatal clinical counseling protocols.

  7. Transformation of QSPA plasma streams in longitudinal magnetic field

    International Nuclear Information System (INIS)

    Makhlaj, V.A.; Bandura, A.N.; Chebotarev, V.V.; Kulik, N.V.; Wuerz, H.

    2002-01-01

    The main aim of this work is analysis of efficiency of QSPA powerful plasma streams transportation in longitudinal magnetic field in dependence on operational mode of accelerator and plasma stream parameters

  8. Microprobe PIXE analysis and EDX analysis on the brain of patients with Alzheimer's disease

    International Nuclear Information System (INIS)

    Yumoto, S.; Horino, Y.; Mokuno, Y.; Fujii, K.; Kakimi, S.; Mizutani, T.; Matsushima, H.; Ishikawa, A.

    1996-01-01

    To investigate the cause of Alzheimer's disease (senile dementia of Alzheimer's disease type), we examined aluminium (Al) in the brain (hippocampus) of patients with Alzheimer's disease using heavy ion (5 MeV Si 3+ ) microprobe particle-induced X-ray emission (PIXE) analysis. Heavy ion microprobes (3 MeV Si 2+ ) have several times higher sensitivity for Al detection than 2 MeV proton microprobes. We also examined Al in the brain of these patients by energy dispersive X-ray spectroscopy (EDX). (1) Al was detected in the cell nuclei isolated from the brain of patients with Alzheimer's disease using 5 MeV Si 3+ microprobe PIXE analysis, and EDX analysis. (2) EDX analysis demonstrated high levels of Al in the nucleolus of nerve cells in frozen sections prepared from the brain of these patients. Our results support the theory that Alzheimer's disease is caused by accumulation of Al in the nuclei of brain cells. (author)

  9. An alpha-synuclein MRM assay with diagnostic potential for Parkinson's disease and monitoring disease progression

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Li [Department of Pathology, University of Washington, Seattle WA USA; Stewart, Tessandra [Department of Pathology, University of Washington, Seattle WA USA; Shi, Min [Department of Pathology, University of Washington, Seattle WA USA; Pottiez, Gwenael [Department of Pathology, University of Washington, Seattle WA USA; Dator, Romel [Department of Pathology, University of Washington, Seattle WA USA; Wu, Rui [Department of Pathology, University of Washington, Seattle WA USA; Department of Pathology, No. 3 Hospital of Beijing University, Beijing China; Aro, Patrick [Department of Pathology, University of Washington, Seattle WA USA; Schuster, Robert J. [Department of Pathology, University of Washington, Seattle WA USA; Ginghina, Carmen [Department of Pathology, University of Washington, Seattle WA USA; Pan, Catherine [Department of Pathology, University of Washington, Seattle WA USA; Gao, Yuqian [Pacific Northwest National Laboratory, Richland WA USA; Qian, Weijun [Pacific Northwest National Laboratory, Richland WA USA; Zabetian, Cyrus P. [Parkinson' s Disease Research and Geriatric Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle WA USA; Department of Neurology, University of Washington School of Medicine, Seattle WA USA; Hu, Shu-Ching [Department of Neurology, University of Washington School of Medicine, Seattle WA USA; Quinn, Joseph F. [Department of Neurology, Oregon Health and Science University, Portland OR USA; Zhang, Jing [Department of Pathology, University of Washington, Seattle WA USA; Department of Pathology, Peking University Health Science Centre and Third Hospital, Beijing 100083 China

    2017-04-19

    Aim: The alpha-synuclein (α-syn) level in human cerebrospinal fluid (CSF), as measured by immunoassays, is promising as a Parkinson’s disease (PD) biomarker. However, the levels of total α-syn are inconsistent among studies with large cohorts and different measurement platforms. Total α-syn level also does not correlate with disease severity or progression. Here, we developed a highly sensitive Multiple Reaction Monitoring (MRM) method to measure absolute CSF α-syn peptide concentrations without prior enrichment or fractionation, aiming to discover new candidate biomarkers. Results: Six peptides covering 73% of protein sequence were reliably identified, and two were consistently quantified in cross-sectional and longitudinal cohorts. Absolute concentration of α-syn in human CSF was determined to be 2.1ng/mL. A unique α-syn peptide, TVEGAGSIAAATGFVK (81-96), displayed excellent correlation with previous immunoassay results in two independent PD cohorts (p < 0.001), correlated with disease severity, and its changes significantly tracked the disease progression longitudinally. Conclusions: An MRM assay to quantify human CSF α-syn was developed and optimized. Sixty clinical samples from cross-sectional and longitudinal PD cohorts were analyzed with this approach. Although further larger-scale validation is needed, the results suggest that α-syn peptide could serve as a promising biomarker in PD diagnosis and progression.

  10. Self-Efficacy as a Longitudinal Predictor of Perceived Cognitive Impairment in Individuals with Multiple Sclerosis

    Science.gov (United States)

    Hughes, Abbey J.; Beier, Meghan; Hartoonian, Narineh; Turner, Aaron P.; Amtmann, Dagmar; Ehde, Dawn M.

    2015-01-01

    Objective Self-efficacy plays an important role in symptom management and may be predictive of perceived cognitive impairment (PCI) for individuals with multiple sclerosis (MS). The primary aim of this study was to determine if self-efficacy longitudinally predicts two types of PCI in MS: general cognitive functioning and executive functioning. The secondary aim was to assess whether self-efficacy mediates the relationships between depression, fatigue, and PCI. Design Longitudinal analysis of self-report survey data collected over three years. Hierarchical regression analyses examined the relationship between self-efficacy and PCI, adjusting for depression and fatigue. Additional analyses tested self-efficacy as a mediator between depression, fatigue, and PCI. Setting Community-dwelling individuals with MS. Participants 233 individuals (age range 22-83 years) were recruited from a larger longitudinal survey study of 562 individuals with MS. Interventions Not applicable. Main Outcome Measures Primary outcome measures were the Applied Cognition General Concerns (ACGC) and Executive Function (ACEF) domains of the Quality of Life in Neurological Disorders (NeuroQoL) measures. Results Self-efficacy was significantly correlated with PCI at baseline (r = .40 to .53) and three years later (r = .36 to .44). In multivariate regression analyses, self-efficacy was a significant longitudinal predictor of PCI, both for general cognitive functioning (β = .20, p Self-efficacy partially mediated the relationships between depression, fatigue, and PCI. Conclusions Self-efficacy may influence how individuals with MS will perceive their cognitive functioning over time. Interventions that target self-efficacy, particularly early in the disease course, may lead to improvements in PCI, as well as improvements in fatigue and depression. PMID:25597915

  11. A novel joint analysis framework improves identification of differentially expressed genes in cross disease transcriptomic analysis

    Directory of Open Access Journals (Sweden)

    Wenyi Qin

    2018-02-01

    Full Text Available Abstract Motivation Detecting differentially expressed (DE genes between disease and normal control group is one of the most common analyses in genome-wide transcriptomic data. Since most studies don’t have a lot of samples, researchers have used meta-analysis to group different datasets for the same disease. Even then, in many cases the statistical power is still not enough. Taking into account the fact that many diseases share the same disease genes, it is desirable to design a statistical framework that can identify diseases’ common and specific DE genes simultaneously to improve the identification power. Results We developed a novel empirical Bayes based mixture model to identify DE genes in specific study by leveraging the shared information across multiple different disease expression data sets. The effectiveness of joint analysis was demonstrated through comprehensive simulation studies and two real data applications. The simulation results showed that our method consistently outperformed single data set analysis and two other meta-analysis methods in identification power. In real data analysis, overall our method demonstrated better identification power in detecting DE genes and prioritized more disease related genes and disease related pathways than single data set analysis. Over 150% more disease related genes are identified by our method in application to Huntington’s disease. We expect that our method would provide researchers a new way of utilizing available data sets from different diseases when sample size of the focused disease is limited.

  12. Acquisition patterns of financial products : A longitudinal investigation

    NARCIS (Netherlands)

    Paas, Leonard J.; Bijmolt, Tammo H. A.; Vermunt, Jeroen K.

    Acquisition pattern analysis investigates orders in which households acquire products. Extant empirical studies employ cross-sectional data, providing limited insight into acquisition orders and no insight into timing of product acquisitions. We use an extensive longitudinal database for studying

  13. [A case of MM1+2 Creutzfeldt-Jakob disease with a longitudinal study of EEG and MRI].

    Science.gov (United States)

    Katsube, Mizuho; Shiota, Yuri; Harada, Takayuki; Shibata, Hiroshi; Nagai, Atsushi

    2013-11-01

    We report a case of definite MM1 + 2 sporadic Creutzfeldt-Jakob disease (sCJD). A 66-year-old woman was admitted to our hospital with memory disturbance and disorientation for three months. On admission she presented a progressive cognitive insufficiency. Electroencephalography (EEG) revealed a frontal intermittent rhythmical delta activity (FIRDA) and the brain magnetic resonance imaging (MRI) showed high signal intensities in cerebral cortex on diffusion weighted images (DWI). After four months from the onset, she reached the akinetic mutism state followed by myoclonus. Follow up examination revealed that periodic synchronous discharge (PSD) was found in EEG, and DWI revealed enlargement of high signal intensity lesions in cerebral cortex. At seven months from the onset, PSD and high signal intensities of cortex became unclear with disappearance of myoclonus, and brain white matter lesions were evident on MRI. Serial studies of EEG and MRI revealed that PSD generalized from frontal lobe dominant pattern, while high signal intensity lesions of cortex diffusely increased on DWI. At ten months from the onset patient died. Pathological examination in brain showed moderate and diffuse neuronal cell loss and gliosis in cerebral cortex corresponding with DWI changes. The genotype at codon 129 of the prion protein (PrP) was homozygous methionine (MM) and the type of protease-resistant PrP (PrPres) was the mixed type of 1 and 2 in Western blot analysis. It has been rare to analyze the changes of EEG and MRI in the entire stage and to investigate pathological finding in the case of sCJD-MM1 + 2. A longitudinal examination of EEG and MRI is useful for early diagnosis of CJD. Also we could correlate these findings with clinical and histopathological phenotype.

  14. Caregiver perception of apathy in persons with mild cognitive impairment or Alzheimer's disease: a longitudinal study.

    Science.gov (United States)

    Pfeifer, Livia; Horn, Andrea B; Maercker, Andreas; Forstmeier, Simon

    2017-05-01

    Discrepancy between self- and caregiver apathy ratings was examined longitudinally for persons with mild cognitive impairment or Alzheimer's disease. Particular focus was on the distinction between the positive and negative caregiver bias and its predictive value for a clinical diagnosis of apathy. Apathy rating discrepancy was based on the apathy evaluation scale. Dyads were categorized depending on whether the caregiver reported fewer deficits (positive caregiver bias) or more deficits (negative caregiver bias) than the cognitively impaired person did. Caregiver ratings and rating discrepancy showed a significant increase from baseline to follow-up. By contrast, self- and clinician ratings showed no change across the two time points. Ratings with a negative caregiver bias remained stable, while those with a positive caregiver bias showed a significant increase in the caregiver ratings but also a significant decrease in the self-ratings. A negative caregiver bias at baseline was significantly related to greater likelihood of having clinical apathy at follow-up, adjusted for an array of control variables. Positive and negative caregiver bias should be distinguished, as they seem to reflect distinct dyadic processes and are relevant for clinical outcome. Furthermore, negative rating discrepancies can be considered a risk factor for developing apathy.

  15. Budget Impact Analysis to Estimate the Cost Dynamics of Treating Refractory Gastroesophageal Reflux Disease With Radiofrequency Energy: a Payer Perspective.

    Science.gov (United States)

    Gregory, David; Scotti, Dennis J; Buck, Daniel; Triadafilopoulos, George

    2016-05-01

    A minimally invasive endoscopic treatment that utilizes radio-frequency energy (RFE) has received increased attention as an appropriate middle-ground approach in the treatment of refractory gastroesophageal reflux disease (GERD) and as an alternative to complicated and invasive surgical procedures. The objective of this study was to develop a longitudinal budget impact analysis from the payer perspective to estimate the direct medical costs of treatment for the refractory GERD patient population and to estimate the budgetary impact of further extending the RFE treatment option to other target populations. A retrospective analysis of claims designed to assess the longitudinal costs and budget impact on payer expenditures associated with managing and treating GERD surgically (Nissen fundoplication [NF]), endoscopically (RFE), or medically was performed. Both Medicare and commercially insured claims databases were interrogated for such population-level analyses. At current adoption rates (less than 1% of procedures), RFE demonstrated overall cost savings ranging from 7.3% to 50.5% in the 12-month time period following the index procedure (inclusive of procedure costs) when compared to medical management and fundoplication across the commercial and Medicare patient populations. Increasing the total number of RFE procedures to 2% of total cases performed generated per-member, per-month (PMPM) savings of $0.28 in the Medicare population and $0.37 in the commercially insured population. Further increases yielded higher PMPM savings. Adding to the clinical importance of RFE in filling the gap between medical and surgical management, this economic analysis demonstrates to payers that the adoption of RFE can create notable savings to their plans when compared to surgery or medical management.

  16. How do innovators stay innovative? A longitudinal case analysis

    OpenAIRE

    Tuzovic, Sven; Wirtz, Jochen; Heracleous, Loizos Th.

    2018-01-01

    Purpose – How can some companies be the innovation leader in their industry over prolonged periods of time, while others cannot? The purpose of this study is to understand a firm’s capability to be a successful serial innovator and to generate a constant stream of industry-leading innovations.\\ud \\ud Design/Methodology/Approach – The paper uses a longitudinal case study approach to gain an understanding of what and how Singapore Airlines (SIA) sustained service innovation for over 30 years. T...

  17. Normative changes in interests from adolescence to adulthood: A meta-analysis of longitudinal studies.

    Science.gov (United States)

    Hoff, Kevin A; Briley, Daniel A; Wee, Colin J M; Rounds, James

    2018-04-01

    Vocational interests predict a variety of important outcomes and are among the most widely applied individual difference constructs in psychology and education. Despite over 90 years of research, little is known about the longitudinal development of interests. In this meta-analysis, the authors investigate normative changes in interests through adolescence and young adulthood. Effect sizes were aggregated from 49 longitudinal studies reporting mean-level changes in vocational interests, containing 98 total samples and 20,639 participants. Random effects meta-analytic regression models were used to assess age-related changes and gender differences across Holland's (1959, 1997) RIASEC categories and composite dimensions (people, things, data, and ideas). Results showed that mean-level interest scores generally increase with age, but effect sizes varied across interest categories and developmental periods. Adolescence was defined by two broad patterns of change: interest scores generally decreased during early adolescence, but then increased during late adolescence. During young adulthood, the most striking changes were found across the people and things orientations. Interests involving people tended to increase (artistic, social, and enterprising), whereas interests involving things either decreased (conventional) or remained constant (realistic and investigative). Gender differences associated with occupational stereotypes reached a lifetime peak during early adolescence, then tended to decrease in all subsequent age periods. Overall findings suggest there are normative changes in vocational interests from adolescence to adulthood, with important implications for developmental theories and the applied use of interests. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  18. DETERMINANTS OF HEALTHCARE EXPENDITURE ON HUMAN CAPITAL AND ECONOMIC GROWTH IN BANGLADESH: A LONGITUDINAL DATA ANALYSIS FROM 1995-2010

    OpenAIRE

    SHONGKOUR ROY

    2014-01-01

    The objective of this study was to examine the determinants of healthcare expenditure in Bangladesh between 1995 and 2010 byapplying the World development indicator data. First, I developed an empirical model for longitudinal data analysis to determinant thehealthcare expenditure under the human capital and economic growth. Next, I explored the dynamic relationships among healthcareexpenditure, human capital and economic growth usingOLSmodel. The expenditure in private healthcare was 2.3% and...

  19. Gait analysis in patients with chronic obstructive pulmonary disease: a systematic review.

    Science.gov (United States)

    Zago, Matteo; Sforza, Chiarella; Bonardi, Daniela Rita; Guffanti, Enrico Eugenio; Galli, Manuela

    2018-03-01

    Gait instability is a major fall-risk factor in patients with chronic obstructive pulmonary disease (COPD). Clinical gait analysis is a reliable tool to predict fall onsets. However, controversy still exists on gait impairments associated with COPD. Thus, the aims of this review were to evaluate the current understanding of spatiotemporal, kinematic and kinetic gait features in patients with COPD. In line with PRISMA guidelines, a systematic literature search was performed throughout Web of Science, PubMed Medline, Scopus, PEDro and Scielo databases. We considered observational cross-sectional studies evaluating gait features in patients with COPD as their primary outcome. Risk of bias and applicability of these papers were assessed according to the QUADAS-2 tool. Seven articles, cross-sectional studies published from 2011 to 2017, met the inclusion criteria. Sample size of patients with COPD ranged 14-196 (mean age range: 64-75 years). The main reported gait abnormalities were reduced step length and cadence, and altered variability of spatiotemporal parameters. Only subtle biomechanical changes were reported at the ankle level. A convincing mechanistic link between such gait impairments and falls in patients with COPD is still lacking. The paucity of studies, small sample sizes, gender and disease status pooling were the main risk of biases affecting the results uncertainty. Two research directions emerged: stricter cohorts characterization in terms of COPD phenotype and longitudinal studies. Quantitative assessment of gait would identify abnormalities and sensorimotor postural deficiencies that in turn may lead to better falling prevention strategies in COPD. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Accuracy and Uncertainty Analysis of Intelligent Techniques for Predicting the Longitudinal Dispersion Coefficient in Rivers

    Directory of Open Access Journals (Sweden)

    Abbas Akbarzadeh

    2010-09-01

    Full Text Available Accurate prediction of longitudinal dispersion coefficient (LDC can be useful for the determination of pollutants concentration distribution in natural rivers. However, the uncertainty associated with the results obtained from forecasting models has a negative effect on pollutant management in water resources. In this research, appropriate models are first developed using ANN and ANFIS techniques to predict the LDC in natural streams. Then, an uncertainty analysis is performed for ANN and ANFIS models based on Monte-Carlo simulation. The input parameters of the models are related to hydraulic variables and stream geometry. Results indicate that ANN is a suitable model for predicting the LDC, but it is also associated with a high level of uncertainty. However, results of uncertainty analysis show that ANFIS model has less uncertainty; i.e. it is the best model for forecasting satisfactorily the LDC in natural streams.

  1. Longitudinal study of fingerprint recognition.

    Science.gov (United States)

    Yoon, Soweon; Jain, Anil K

    2015-07-14

    Human identification by fingerprints is based on the fundamental premise that ridge patterns from distinct fingers are different (uniqueness) and a fingerprint pattern does not change over time (persistence). Although the uniqueness of fingerprints has been investigated by developing statistical models to estimate the probability of error in comparing two random samples of fingerprints, the persistence of fingerprints has remained a general belief based on only a few case studies. In this study, fingerprint match (similarity) scores are analyzed by multilevel statistical models with covariates such as time interval between two fingerprints in comparison, subject's age, and fingerprint image quality. Longitudinal fingerprint records of 15,597 subjects are sampled from an operational fingerprint database such that each individual has at least five 10-print records over a minimum time span of 5 y. In regard to the persistence of fingerprints, the longitudinal analysis on a single (right index) finger demonstrates that (i) genuine match scores tend to significantly decrease when time interval between two fingerprints in comparison increases, whereas the change in impostor match scores is negligible; and (ii) fingerprint recognition accuracy at operational settings, nevertheless, tends to be stable as the time interval increases up to 12 y, the maximum time span in the dataset. However, the uncertainty of temporal stability of fingerprint recognition accuracy becomes substantially large if either of the two fingerprints being compared is of poor quality. The conclusions drawn from 10-finger fusion analysis coincide with the conclusions from single-finger analysis.

  2. Longitudinal behavioral analysis during dental care of children aged 0 to 3 years

    Directory of Open Access Journals (Sweden)

    Robson Frederico Cunha

    2009-09-01

    Full Text Available "When" and "how" the dentist intervenes have repercussions on children's physical and emotional patterns. The objective of the present study was to conduct a longitudinal behavioral analysis during dental care of babies aged 0 to 3 years. A total of 216 patients seen at the Baby Clinic of the School of Dentistry at Araçatuba, São Paulo State University (UNESP, were selected. The selection criterion was attendance at ten dental care sessions at bimonthly intervals for routine procedures such as clinical examination and oral hygiene. There was a predominance of cooperative behavior compared to uncooperative behavior when each visit was analyzed separately. The behavior of the patients must have been directly influenced by their psychomotor development. Constant attendance and exposure of the baby to non-stressful dental stimuli are factors that favor a cooperative behavior.

  3. A longitudinal study of urea cycle disorders.

    Science.gov (United States)

    Batshaw, Mark L; Tuchman, Mendel; Summar, Marshall; Seminara, Jennifer

    2014-01-01

    The Urea Cycle Disorders Consortium (UCDC) is a member of the NIH funded Rare Diseases Clinical Research Network and is performing a longitudinal study of 8 urea cycle disorders (UCDs) with initial enrollment beginning in 2006. The consortium consists of 14 sites in the U.S., Canada and Europe. This report summarizes data mining studies of 614 patients with UCDs enrolled in the UCDC's longitudinal study protocol. The most common disorder is ornithine transcarbamylase deficiency, accounting for more than half of the participants. We calculated the overall prevalence of urea cycle disorders to be 1/35,000, with 2/3rds presenting initial symptoms after the newborn period. We found the mortality rate to be 24% in neonatal onset cases and 11% in late onset cases. The most common precipitant of clinical hyperammonemic episodes in the post-neonatal period was intercurrent infections. Elevations in both blood ammonia and glutamine appeared to be biomarkers for neurocognitive outcome. In terms of chronic treatment, low protein diet appeared to result in normal weight but decreased linear growth while N-scavenger therapy with phenylbutyrate resulted in low levels of branched chain amino acids. Finally, we found an unexpectedly high risk for hepatic dysfunction in patients with ornithine transcarbamylase deficiency. This natural history study illustrates how a collaborative study of a rare genetic disorder can result in an improved understanding of morbidity and disease outcome. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Regional vulnerability of longitudinal cortical association connectivity

    Directory of Open Access Journals (Sweden)

    Rafael Ceschin

    2015-01-01

    Full Text Available Preterm born children with spastic diplegia type of cerebral palsy and white matter injury or periventricular leukomalacia (PVL, are known to have motor, visual and cognitive impairments. Most diffusion tensor imaging (DTI studies performed in this group have demonstrated widespread abnormalities using averaged deterministic tractography and voxel-based DTI measurements. Little is known about structural network correlates of white matter topography and reorganization in preterm cerebral palsy, despite the availability of new therapies and the need for brain imaging biomarkers. Here, we combined novel post-processing methodology of probabilistic tractography data in this preterm cohort to improve spatial and regional delineation of longitudinal cortical association tract abnormalities using an along-tract approach, and compared these data to structural DTI cortical network topology analysis. DTI images were acquired on 16 preterm children with cerebral palsy (mean age 5.6 ± 4 and 75 healthy controls (mean age 5.7 ± 3.4. Despite mean tract analysis, Tract-Based Spatial Statistics (TBSS and voxel-based morphometry (VBM demonstrating diffusely reduced fractional anisotropy (FA reduction in all white matter tracts, the along-tract analysis improved the detection of regional tract vulnerability. The along-tract map-structural network topology correlates revealed two associations: (1 reduced regional posterior–anterior gradient in FA of the longitudinal visual cortical association tracts (inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, optic radiation, posterior thalamic radiation correlated with reduced posterior–anterior gradient of intra-regional (nodal efficiency metrics with relative sparing of frontal and temporal regions; and (2 reduced regional FA within frontal–thalamic–striatal white matter pathways (anterior limb/anterior thalamic radiation, superior longitudinal fasciculus and cortical spinal tract

  5. The Longitudinal Interplay of Maternal Warmth and Adolescents' Self-Disclosure in Predicting Maternal Knowledge

    Science.gov (United States)

    Blodgett Salafia, Elizabeth H.; Gondoli, Dawn M.; Grundy, Amber M.

    2009-01-01

    This study examined the longitudinal associations among maternal warmth, adolescents' self-disclosure, and maternal knowledge during the transition to adolescence. Three years of self-report data were collected from 131 married mothers and their adolescents. Results from longitudinal analysis using adolescent reports indicated that greater…

  6. Pooling Data from Multiple Longitudinal Studies: The Role of Item Response Theory in Integrative Data Analysis

    Science.gov (United States)

    Curran, Patrick J.; Hussong, Andrea M.; Cai, Li; Huang, Wenjing; Chassin, Laurie; Sher, Kenneth J.; Zucker, Robert A.

    2010-01-01

    There are a number of significant challenges encountered when studying development over an extended period of time including subject attrition, changing measurement structures across group and developmental period, and the need to invest substantial time and money. Integrative data analysis is an emerging set of methodologies that overcomes many of the challenges of single sample designs through the pooling of data drawn from multiple existing developmental studies. This approach is characterized by a host of advantages, but this also introduces several new complexities that must be addressed prior to broad adoption by developmental researchers. In this paper we focus on methods for fitting measurement models and creating scale scores using data drawn from multiple longitudinal studies. We present findings from the analysis of repeated measures of internalizing symptomatology that were pooled from three existing developmental studies. We describe and demonstrate each step in the analysis and we conclude with a discussion of potential limitations and directions for future research. PMID:18331129

  7. Pediatric Acute Longitudinal Extensive Transverse Myelitis Secondary to Neuroborreliosis

    Directory of Open Access Journals (Sweden)

    Sana Khan

    2015-07-01

    Full Text Available Lyme neuroborreliosis has several different clinical manifestations in children, of which facial nerve palsies, meningitis and radiculopathies are the most common. Transverse myelitis (TM secondary to Lyme disease has been reported in rare occasions, typically presenting with severe weakness, sensory abnormalities and autonomic dysfunction. We present the case of a 16-year-old male who developed acute left peripheral facial palsy and longitudinal extensive TM secondary to Lyme disease. Remarkably, the patient reported only mild symptoms with severe back pain in the absence of profound signs of myelopathy. We reviewed the medical literature and analyzed the clinical features of pediatric patients with Borrelia burgdorferi-related TM.

  8. Application of the Levenshtein Distance Metric for the Construction of Longitudinal Data Files

    Science.gov (United States)

    Doran, Harold C.; van Wamelen, Paul B.

    2010-01-01

    The analysis of longitudinal data in education is becoming more prevalent given the nature of testing systems constructed for No Child Left Behind Act (NCLB). However, constructing the longitudinal data files remains a significant challenge. Students move into new schools, but in many cases the unique identifiers (ID) that should remain constant…

  9. Development of a Conceptual Model of Disease Progression for Use in Economic Modeling of Chronic Obstructive Pulmonary Disease.

    Science.gov (United States)

    Tabberer, Maggie; Gonzalez-McQuire, Sebastian; Muellerova, Hana; Briggs, Andrew H; Rutten-van Mölken, Maureen P M H; Chambers, Mike; Lomas, David A

    2017-05-01

    To develop and validate a new conceptual model (CM) of chronic obstructive pulmonary disease (COPD) for use in disease progression and economic modeling. The CM identifies and describes qualitative associations between disease attributes, progression and outcomes. A literature review was performed to identify any published CMs or literature reporting the impact and association of COPD disease attributes with outcomes. After critical analysis of the literature, a Steering Group of experts from the disciplines of health economics, epidemiology and clinical medicine was convened to develop a draft CM, which was refined using a Delphi process. The refined CM was validated by testing for associations between attributes using data from the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE). Disease progression attributes included in the final CM were history and occurrence of exacerbations, lung function, exercise capacity, signs and symptoms (cough, sputum, dyspnea), cardiovascular disease comorbidities, 'other' comorbidities (including depression), body composition (body mass index), fibrinogen as a biomarker, smoking and demographic characteristics (age, gender). Mortality and health-related quality of life were determined to be the most relevant final outcome measures for this model, intended to be the foundation of an economic model of COPD. The CM is being used as the foundation for developing a new COPD model of disease progression and to provide a framework for the analysis of patient-level data. The CM is available as a reference for the implementation of further disease progression and economic models.

  10. Like a virgin (mother): analysis of data from a longitudinal, US population representative sample survey

    OpenAIRE

    Herring, Amy H; Attard, Samantha M; Gordon-Larsen, Penny; Joyner, William H; Halpern, Carolyn T

    2013-01-01

    Objective To estimate the incidence of self report of pregnancy without sexual intercourse (virgin pregnancy) and factors related to such reporting, in a population representative group of US adolescents and young adults. Design Longitudinal, population representative sample survey. Setting Nationally representative, multiethnic National Longitudinal Study of Adolescent Health, United States. Participants 7870 women enrolled at wave I (1995) and completing the most recent wave of data collect...

  11. Predictive Biomarkers of Gastroesophageal Reflux Disease and Barrett's Esophagus in World Trade Center Exposed Firefighters: a 15 Year Longitudinal Study.

    Science.gov (United States)

    Haider, Syed H; Kwon, Sophia; Lam, Rachel; Lee, Audrey K; Caraher, Erin J; Crowley, George; Zhang, Liqun; Schwartz, Theresa M; Zeig-Owens, Rachel; Liu, Mengling; Prezant, David J; Nolan, Anna

    2018-02-15

    Gastroesophageal reflux disease (GERD) and Barrett's Esophagus (BE), which are prevalent in the World Trade Center (WTC) exposed and general populations, negatively impact quality of life and cost of healthcare. GERD, a risk factor of BE, is linked to obstructive airways disease (OAD). We aim to identify serum biomarkers of GERD/BE, and assess the respiratory and clinical phenotype of a longitudinal cohort of never-smoking, male, WTC-exposed rescue workers presenting with pulmonary symptoms. Biomarkers collected soon after WTC-exposure were evaluated in optimized predictive models of GERD/BE. In the WTC-exposed cohort, the prevalence of BE is at least 6 times higher than in the general population. GERD/BE cases had similar lung function, D LCO , bronchodilator response and long-acting β-agonist use compared to controls. In confounder-adjusted regression models, TNF-α ≥ 6 pg/mL predicted both GERD and BE. GERD was also predicted by C-peptide ≥ 360 pg/mL, while BE was predicted by fractalkine ≥ 250 pg/mL and IP-10 ≥ 290 pg/mL. Finally, participants with GERD had significantly increased use of short-acting β-agonist compared to controls. Overall, biomarkers sampled prior to GERD/BE presentation showed strong predictive abilities of disease development. This study frames future investigations to further our understanding of aerodigestive pathology due to particulate matter exposure.

  12. Effect of traffic pollution on respiratory and allergic disease in adults: cross-sectional and longitudinal analyses

    Directory of Open Access Journals (Sweden)

    Whyatt Duncan

    2009-08-01

    Full Text Available Abstract Background Epidemiological research into the role of traffic pollution on chronic respiratory and allergic disease has focused primarily on children. Studies in adults, in particular those based on objective outcomes such as bronchial hyperresponsiveness, skin sensitisation, and lung function, are limited. Methods We have used an existing cohort of 2644 adults aged 18–70 living in Nottingham, UK, for whom baseline health and demographic data were collected in 1991 and computed two markers of exposure to traffic: distance between the home and nearest main road and modelled outdoor nitrogen dioxide (NO2 concentration at the home location. Using multiple regression techniques, we analysed cross-sectional associations with bronchial hyperresponsiveness, FEV1, spirometry-defined COPD, skin test positivity, total IgE and questionnaire-reported wheeze, asthma, eczema and hayfever in 2599 subjects, and longitudinal associations with decline in FEV1 in 1329 subjects followed-up nine years later in 2000. Results There were no significant cross-sectional associations between home proximity to the roadside or NO2 level on any of the outcomes studied (adjusted OR of bronchial hyperresponsiveness in relation to living ≤150 m vs >150 m from a road = 0.92, 95% CI 0.68 to 1.24. Furthermore, neither exposure was associated with a significantly greater decline in FEV1 over time (adjusted mean difference in ΔFEV1 for living ≤150 m vs >150 m of a road = 10.03 ml, 95% CI, -33.98 to 54.04. Conclusion This study found no evidence to suggest that living in close proximity to traffic is a major determinant of asthma, allergic disease or COPD in adults.

  13. Effect of longitudinal profile on the seismic anaysis of concrete gravity dams

    International Nuclear Information System (INIS)

    El-Nady, A.; Ghobarah, A.; Aziz, T.S.

    1992-01-01

    The traditional three-dimensional analysis of concrete gravity dams is expensive and very difficult. An alternate approach is to divide the dam into substructures. Each monolith is considered as a substructure and its degrees of freedom are reduced to those on the contact surfaces with the adjacent monoliths as well as a few Ritz vectors. Using this procedure high accuracy was achieved using a reasonable number of degrees of freedom. The analysis is carried out in the frequency domain to account for the frequency dependent parameters in the reservoir substructure. The procedure was tested and compared to typical three-dimensional analysis and was found to give high accuracy. A simplified cross section of gravity dams with different longitudinal profiles was studied using the substructuring procedure as well as a typical two-dimensional analysis. The results obtained show a significant variation in dynamic properties of the dam from that calculated assuming two-dimensional analysis. Furthermore, the response of the dam varies significantly when including the effect of longitudinal profile of the structure. It is concluded that the two-dimensional representation of the structure may substantially overestimate the response of the dam, depending on its longitudinal profile, especially when keyed joints are used in the construction. 13 refs., 5 figs., 4 tabs

  14. A longitudinal analysis of the effects of different patterns of employment and unemployment on school-leavers.

    Science.gov (United States)

    Feather, N T; O'Brien, G E

    1986-11-01

    Large samples of young employed and unemployed respondents in metropolitan Adelaide, South Australia, completed questionnaires on two occasions one year apart. A wide range of variables was assessed that included measures of aspects of the self-concept, Protestant Ethic values, desired work values, stress symptoms, life satisfaction, unemployment disappointment, job need, employment value, external control and attributions for youth unemployment. There was little evidence from longitudinal analyses of change scores that a shift from employment to unemployment or the reverse transition had significant effects on psychological well-being, but unemployment attributions were affected. The shift from employment to unemployment led to less internal and more external causal attributions for youth unemployment; the reverse transition had the opposite effects. Cross-sectional comparisons of findings from the employed and unemployed samples replicated previous results that were consistent with the conclusion that many of the obtained differences were present when respondents were still at school. Variables assumed to reflect employment importance did not have moderating effects on psychological well-being when employed and unemployed groups were compared in either longitudinal or cross-sectional analyses but they were involved in significant associations with other measures. Results suggested the need for more empirical and conceptual analysis of the concepts of psychological well-being and employment importance.

  15. The neural determinants of age-related changes in fluid intelligence: a pre-registered, longitudinal analysis in UK Biobank

    Science.gov (United States)

    Kievit, Rogier A.; Fuhrmann, Delia; Henson, Richard N. A.

    2018-01-01

    Background: Fluid intelligence declines with advancing age, starting in early adulthood. Within-subject declines in fluid intelligence are highly correlated with contemporaneous declines in the ability to live and function independently. To support healthy aging, the mechanisms underlying these declines need to be better understood. Methods: In this pre-registered analysis, we applied latent growth curve modelling to investigate the neural determinants of longitudinal changes in fluid intelligence across three time points in 185,317 individuals (N=9,719 two waves, N=870 three waves) from the UK Biobank (age range: 39-73 years). Results: We found a weak but significant effect of cross-sectional age on the mean fluid intelligence score, such that older individuals scored slightly lower. However, the mean longitudinal slope was positive, rather than negative, suggesting improvement across testing occasions. Despite the considerable sample size, the slope variance was non-significant, suggesting no reliable individual differences in change over time. This null-result is likely due to the nature of the cognitive test used. In a subset of individuals, we found that white matter microstructure (N=8839, as indexed by fractional anisotropy) and grey-matter volume (N=9931) in pre-defined regions-of-interest accounted for complementary and unique variance in mean fluid intelligence scores. The strongest effects were such that higher grey matter volume in the frontal pole and greater white matter microstructure in the posterior thalamic radiations were associated with higher fluid intelligence scores. Conclusions: In a large preregistered analysis, we demonstrate a weak but significant negative association between age and fluid intelligence. However, we did not observe plausible longitudinal patterns, instead observing a weak increase across testing occasions, and no significant individual differences in rates of change, likely due to the suboptimal task design. Finally

  16. The neural determinants of age-related changes in fluid intelligence: a pre-registered, longitudinal analysis in UK Biobank.

    Science.gov (United States)

    Kievit, Rogier A; Fuhrmann, Delia; Borgeest, Gesa Sophia; Simpson-Kent, Ivan L; Henson, Richard N A

    2018-01-01

    Background:  Fluid intelligence declines with advancing age, starting in early adulthood. Within-subject declines in fluid intelligence are highly correlated with contemporaneous declines in the ability to live and function independently. To support healthy aging, the mechanisms underlying these declines need to be better understood. Methods:  In this pre-registered analysis, we applied latent growth curve modelling to investigate the neural determinants of longitudinal changes in fluid intelligence across three time points in 185,317 individuals (N=9,719 two waves, N=870 three waves) from the UK Biobank (age range: 39-73 years). Results:  We found a weak but significant effect of cross-sectional age on the mean fluid intelligence score, such that older individuals scored slightly lower. However, the mean longitudinal slope was positive, rather than negative, suggesting improvement across testing occasions. Despite the considerable sample size, the slope variance was non-significant, suggesting no reliable individual differences in change over time. This null-result is likely due to the nature of the cognitive test used. In a subset of individuals, we found that white matter microstructure (N=8839, as indexed by fractional anisotropy) and grey-matter volume (N=9931) in pre-defined regions-of-interest accounted for complementary and unique variance in mean fluid intelligence scores. The strongest effects were such that higher grey matter volume in the frontal pole and greater white matter microstructure in the posterior thalamic radiations were associated with higher fluid intelligence scores. Conclusions:  In a large preregistered analysis, we demonstrate a weak but significant negative association between age and fluid intelligence. However, we did not observe plausible longitudinal patterns, instead observing a weak increase across testing occasions, and no significant individual differences in rates of change, likely due to the suboptimal task design

  17. Vocal fold immobility: a longitudinal analysis of etiology over 20 years.

    Science.gov (United States)

    Rosenthal, Laura H Swibel; Benninger, Michael S; Deeb, Robert H

    2007-10-01

    To determine the current etiology of vocal fold immobility, identify changing trends over the last 20 years, and compare results to historical reports. The present study is a retrospective analysis of all patients seen within a tertiary care institution between 1996 and 2005 with vocal fold immobility. The results were combined with a previous study of patients within the same institution from 1985 through 1995. Results were compared to the literature. The medical records of all patients assigned a primary or additional diagnostic code for vocal cord paralysis were obtained from the electronic database. Eight hundred twenty-seven patients were available for analysis (435 from the most recent cohort), which is substantially larger than any reported series to date. Vocal fold immobility was most commonly associated with a surgical procedure (37%). Nonthyroid surgeries (66%), such as anterior cervical approaches to the spine and carotid endarterectomies, have surpassed thyroid surgery (33%) as the most common iatrogenic causes. These data represent a change from historical figures in which extralaryngeal malignancies were considered the major cause of unilateral immobility. Thyroidectomy continues to cause the majority (80%) of iatrogenic bilateral vocal fold immobility and 30% of all bilateral immobility. This 20-year longitudinal assessment revealed that the etiology of unilateral vocal fold immobility has changed such that there has been a shift from extralaryngeal malignancies to nonthyroid surgical procedures as the major cause. Thyroid surgery remains the most common cause of bilateral vocal fold immobility.

  18. A Pluralistic, Longitudinal Method

    DEFF Research Database (Denmark)

    Evers, Winie; Marroun, Sana; Young, Louise

    2017-01-01

    There is recognition in business markets of the need for connected relationships to enable the survival and growth of firms. Finding new ways to collaborate enables firms to better seek opportunities and challenges and enhance network capability. However the traditional methods used to research...... and analysis. Longitudinal research considers a Danish advertising and communication firm looking for new ideas by involving their network in order to help them to compete in their environment of rapid globalization and emergence of new technologies. A five stage research design considered how network...

  19. GWAS with longitudinal phenotypes : performance of approximate procedures

    NARCIS (Netherlands)

    Sikorska, Karolina; Mostafavi, Nahid; Uitterlinden, André; Rivadeneira, Fernando; Eilers, Paul HC; Lesaffre, Emmanuel

    2015-01-01

    Analysis of genome-wide association studies with longitudinal data using standard procedures, such as linear mixed model (LMM) fitting, leads to discouragingly long computation times. There is a need to speed up the computations significantly. In our previous work (Sikorska et al: Fast linear mixed

  20. GWAS with longitudinal phenotypes: Performance of approximate procedures

    NARCIS (Netherlands)

    K. Sikorska (Karolina); N.M. Montazeri (Nahid Mostafavi); A.G. Uitterlinden (André); F. Rivadeneira Ramirez (Fernando); P.H.C. Eilers (Paul); E.M.E.H. Lesaffre (Emmanuel)

    2015-01-01

    textabstractAnalysis of genome-wide association studies with longitudinal data using standard procedures, such as linear mixed model (LMM) fitting, leads to discouragingly long computation times. There is a need to speed up the computations significantly. In our previous work (Sikorska et al: Fast

  1. Longitudinal study of prognostic factors in established periodontitis patients.

    Science.gov (United States)

    Machtei, E E; Dunford, R; Hausmann, E; Grossi, S G; Powell, J; Cummins, D; Zambon, J J; Genco, R J

    1997-02-01

    Numerous indicators for disease progression have been described in the last decade. The purpose of this study was to examine, longitudinally, a large battery of clinical, microbiological, and immunological indicators, to try to determine whether the presence of one or a combination of these parameters at baseline, would correlate positively with increased attachment and or bone loss (true prognostic factors). Following initial screening, 79 patients with established periodontitis were monitored longitudinally for one year. Whole mouth clinical measurements, plaque gingival and calculus indices, together with pocket depth and attachment level measurements, were repeated every three months. Full mouth radiographic survey, performed at baseline and 12 months, served to determine changes in crestal bone height using an image enhancement technique. Subgingival plaque samples were taken at baseline and every 3 months. Immunofluorescence assays were performed for the a battery of target microorganisms. Serum and GCF samples for IgG subclasses analysis were obtained at each visit and assayed using ELISA techniques. Likewise blood, samples were also drawn at each visit for a quantitative analysis of serum cotinine level. The overall mean attachment loss (AL) and bone loss (BL) were almost identical (0.159 mm and 0.164 mm, respectively). Individual patients variation was large (-0.733 to +1.004 mm). An overall 6.89% of sites were active; individual patients' means ranged from 0-28.9%. Mean pocket depth (PD) showed minimal change over the study period (-0.033 mm) thus suggesting that most if not all the AL was accompained by concomitant gingival recession. Smokers exhibited greater AL and radiographic BL compared to non-smokers. Likewise, patients' cotinine level showed direct correlation with outcomes of progressive periodontal breakdown. Past severity of periodontal involvement, as reflected in the patients baseline PD, AL and crestal bone height, showed good correlation

  2. Longitudinal structure function from logarithmic slopes of F2 at low x

    Science.gov (United States)

    Boroun, G. R.

    2018-01-01

    Using Laplace transform techniques, I calculate the longitudinal structure function FL(x ,Q2) from the scaling violations of the proton structure function F2(x ,Q2) and make a critical study of this relationship between the structure functions at leading order (LO) up to next-to-next-to leading order (NNLO) analysis at small x . Furthermore, I consider heavy quark contributions to the relation between the structure functions, which leads to compact formula for Nf=3 +Heavy . The nonlinear corrections to the longitudinal structure function at LO up to NNLO analysis are shown in the Nf=4 (light quark flavor) based on the nonlinear corrections at R =2 and R =4 GeV-1 . The results are compared with experimental data of the longitudinal proton structure function FL in the range of 6.5 ≤Q2≤800 GeV2 .

  3. Colorimetric and longitudinal analysis of leukocoria in recreational photographs of children with retinoblastoma.

    Directory of Open Access Journals (Sweden)

    Alireza Abdolvahabi

    Full Text Available Retinoblastoma is the most common primary intraocular tumor in children. The first sign that is often reported by parents is the appearance of recurrent leukocoria (i.e., "white eye" in recreational photographs. A quantitative definition or scale of leukocoria--as it appears during recreational photography--has not been established, and the amount of clinical information contained in a leukocoric image (collected by a parent remains unknown. Moreover, the hypothesis that photographic leukocoria can be a sign of early stage retinoblastoma has not been tested for even a single patient. This study used commercially available software (Adobe Photoshop® and standard color space conversion algorithms (operable in Microsoft Excel® to quantify leukocoria in actual "baby pictures" of 9 children with retinoblastoma (that were collected by parents during recreational activities i.e., in nonclinical settings. One particular patient with bilateral retinoblastoma ("Patient Zero" was photographed >7, 000 times by his parents (who are authors of this study over three years: from birth, through diagnosis, treatment, and remission. This large set of photographs allowed us to determine the longitudinal and lateral frequency of leukocoria throughout the patient's life. This study establishes: (i that leukocoria can emerge at a low frequency in early-stage retinoblastoma and increase in frequency during disease progression, but decrease upon disease regression, (ii that Hue, Saturation and Value (i.e., HSV color space are suitable metrics for quantifying the intensity of retinoblastoma-linked leukocoria; (iii that different sets of intraocular retinoblastoma tumors can produce distinct leukocoric reflections; and (iv the Saturation-Value plane of HSV color space represents a convenient scale for quantifying and classifying pupillary reflections as they appear during recreational photography.

  4. Cognitive/affective and somatic/affective symptoms of depression in patients with heart disease and their association with cardiovascular prognosis : a meta-analysis

    NARCIS (Netherlands)

    Azevedo, R. de Miranda; Roest, A. M.; Hoen, P. W.; de Jonge, P.

    2014-01-01

    Background. Several prospective longitudinal studies have suggested that somatic/affective depressive symptoms, but not cognitive/affective depressive symptoms, are related to prognosis in patients with heart disease, but findings have been inconsistent. The aim of this study was to investigate the

  5. Childhood trauma and suicide attempt: A meta-analysis of longitudinal studies from the last decade.

    Science.gov (United States)

    Zatti, Cleonice; Rosa, Virgínia; Barros, Alcina; Valdivia, Lucianne; Calegaro, Vitor Crestani; Freitas, Lúcia Helena; Ceresér, Keila Maria Mendes; Rocha, Neusa Sica da; Bastos, Andre Goettems; Schuch, Felipe Barreto

    2017-10-01

    Childhood trauma (CT) is a modifiable risk factor for lifetime suicide attempts (SA). However, the extent to which each type of CT increases SA risk is unclear. This study aimed to conduct a meta-analysis of longitudinal studies published in the last 10 years about the relationship between CT and lifetime SA risk. The PUBMED, PsycINFO, ISI, and EMBASE databases were searched for cohort studies that reported AS during follow-up and included an assessment of CT. A meta-analysis was conducted to identify potential effects of each type of CT on SA. Seven unique studies were included for review. Sexual (n=6, OR=3.73, 95%CI 2.94-4.75, pbroken home were not significantly associated with further SA. The modes of CT that most contribute to SA in later life are physical, emotional, and sexual abuse and physical neglect, in descending order. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Multilingualism and fMRI: Longitudinal Study of Second Language Acquisition

    Science.gov (United States)

    Andrews, Edna; Frigau, Luca; Voyvodic-Casabo, Clara; Voyvodic, James; Wright, John

    2013-01-01

    BOLD fMRI is often used for the study of human language. However, there are still very few attempts to conduct longitudinal fMRI studies in the study of language acquisition by measuring auditory comprehension and reading. The following paper is the first in a series concerning a unique longitudinal study devoted to the analysis of bi- and multilingual subjects who are: (1) already proficient in at least two languages; or (2) are acquiring Russian as a second/third language. The focus of the current analysis is to present data from the auditory sections of a set of three scans acquired from April, 2011 through April, 2012 on a five-person subject pool who are learning Russian during the study. All subjects were scanned using the same protocol for auditory comprehension on the same General Electric LX 3T Signa scanner in Duke University Hospital. Using a multivariate analysis of covariance (MANCOVA) for statistical analysis, proficiency measurements are shown to correlate significantly with scan results in the Russian conditions over time. The importance of both the left and right hemispheres in language processing is discussed. Special attention is devoted to the importance of contextualizing imaging data with corresponding behavioral and empirical testing data using a multivariate analysis of variance. This is the only study to date that includes: (1) longitudinal fMRI data with subject-based proficiency and behavioral data acquired in the same time frame; and (2) statistical modeling that demonstrates the importance of covariate language proficiency data for understanding imaging results of language acquisition. PMID:24961428

  7. Multilingualism and fMRI: Longitudinal Study of Second Language Acquisition

    Directory of Open Access Journals (Sweden)

    John Wright

    2013-05-01

    Full Text Available BOLD fMRI is often used for the study of human language. However, there are still very few attempts to conduct longitudinal fMRI studies in the study of language acquisition by measuring auditory comprehension and reading. The following paper is the first in a series concerning a unique longitudinal study devoted to the analysis of bi- and multilingual subjects who are: (1 already proficient in at least two languages; or (2 are acquiring Russian as a second/third language. The focus of the current analysis is to present data from the auditory sections of a set of three scans acquired from April, 2011 through April, 2012 on a five-person subject pool who are learning Russian during the study. All subjects were scanned using the same protocol for auditory comprehension on the same General Electric LX 3T Signa scanner in Duke University Hospital. Using a multivariate analysis of covariance (MANCOVA for statistical analysis, proficiency measurements are shown to correlate significantly with scan results in the Russian conditions over time. The importance of both the left and right hemispheres in language processing is discussed. Special attention is devoted to the importance of contextualizing imaging data with corresponding behavioral and empirical testing data using a multivariate analysis of variance. This is the only study to date that includes: (1 longitudinal fMRI data with subject-based proficiency and behavioral data acquired in the same time frame; and (2 statistical modeling that demonstrates the importance of covariate language proficiency data for understanding imaging results of language acquisition.

  8. Multilingualism and fMRI: Longitudinal Study of Second Language Acquisition.

    Science.gov (United States)

    Andrews, Edna; Frigau, Luca; Voyvodic-Casabo, Clara; Voyvodic, James; Wright, John

    2013-05-28

    BOLD fMRI is often used for the study of human language. However, there are still very few attempts to conduct longitudinal fMRI studies in the study of language acquisition by measuring auditory comprehension and reading. The following paper is the first in a series concerning a unique longitudinal study devoted to the analysis of bi- and multilingual subjects who are: (1) already proficient in at least two languages; or (2) are acquiring Russian as a second/third language. The focus of the current analysis is to present data from the auditory sections of a set of three scans acquired from April, 2011 through April, 2012 on a five-person subject pool who are learning Russian during the study. All subjects were scanned using the same protocol for auditory comprehension on the same General Electric LX 3T Signa scanner in Duke University Hospital. Using a multivariate analysis of covariance (MANCOVA) for statistical analysis, proficiency measurements are shown to correlate significantly with scan results in the Russian conditions over time. The importance of both the left and right hemispheres in language processing is discussed. Special attention is devoted to the importance of contextualizing imaging data with corresponding behavioral and empirical testing data using a multivariate analysis of variance. This is the only study to date that includes: (1) longitudinal fMRI data with subject-based proficiency and behavioral data acquired in the same time frame; and (2) statistical modeling that demonstrates the importance of covariate language proficiency data for understanding imaging results of language acquisition.

  9. Longitudinal data analysis in support of functional stability concepts for leachate management at closed municipal landfills

    International Nuclear Information System (INIS)

    Gibbons, Robert D.; Morris, Jeremy W.F.; Prucha, Christopher P.; Caldwell, Michael D.; Staley, Bryan F.

    2014-01-01

    Highlights: • Longitudinal data analysis using a mixed-effects regression model. • Dataset consisted of a total of 1402 samples from 101 closed municipal landfills. • Target analytes and classes generally showed predictable degradation trends. • Validates historical studies focused on macro organic indicators such as BOD. • BOD can serve as “gateway” indicator for planning leachate management. - Abstract: Landfill functional stability provides a target that supports no environmental threat at the relevant point of exposure in the absence of active control systems. With respect to leachate management, this study investigates “gateway” indicators for functional stability in terms of the predictability of leachate characteristics, and thus potential threat to water quality posed by leachate emissions. Historical studies conducted on changes in municipal solid waste (MSW) leachate concentrations over time (longitudinal analysis) have concentrated on indicator compounds, primarily chemical oxygen demand (COD) and biochemical oxygen demand (BOD). However, validation of these studies using an expanded database and larger constituent sets has not been performed. This study evaluated leachate data using a mixed-effects regression model to determine the extent to which leachate constituent degradation can be predicted based on waste age or operational practices. The final dataset analyzed consisted of a total of 1402 samples from 101 MSW landfills. Results from the study indicated that all leachate constituents exhibit a decreasing trend with time in the post-closure period, with 16 of the 25 target analytes and aggregate classes exhibiting a statistically significant trend consistent with well-studied indicators such as BOD. Decreasing trends in BOD concentration after landfill closure can thus be considered representative of trends for many leachate constituents of concern

  10. Longitudinal data analysis in support of functional stability concepts for leachate management at closed municipal landfills

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, Robert D., E-mail: rdg@uchicago.edu [Center for Health Statistics, University of Chicago, 5841 S. Maryland Avenue, Chicago, IL 60637 (United States); Morris, Jeremy W.F., E-mail: jmorris@geosyntec.com [Geosyntec Consultants, 10220 Old Columbia Road, Suite A, Columbia, MD 21046 (United States); Prucha, Christopher P., E-mail: cprucha@wm.com [Groundwater Protection Program, Waste Management, 1550 Balmer Road, Box 200, Model City, NY 14107 (United States); Caldwell, Michael D., E-mail: mcaldwell@wm.com [Groundwater Protection Program, Waste Management, 3623 Wilson Road, Humble, TX 77396 (United States); Staley, Bryan F., E-mail: BStaley@erefdn.org [Environmental Research and Education Foundation, 3301 Benson Drive, Suite 301, Raleigh, NC 27609 (United States)

    2014-09-15

    Highlights: • Longitudinal data analysis using a mixed-effects regression model. • Dataset consisted of a total of 1402 samples from 101 closed municipal landfills. • Target analytes and classes generally showed predictable degradation trends. • Validates historical studies focused on macro organic indicators such as BOD. • BOD can serve as “gateway” indicator for planning leachate management. - Abstract: Landfill functional stability provides a target that supports no environmental threat at the relevant point of exposure in the absence of active control systems. With respect to leachate management, this study investigates “gateway” indicators for functional stability in terms of the predictability of leachate characteristics, and thus potential threat to water quality posed by leachate emissions. Historical studies conducted on changes in municipal solid waste (MSW) leachate concentrations over time (longitudinal analysis) have concentrated on indicator compounds, primarily chemical oxygen demand (COD) and biochemical oxygen demand (BOD). However, validation of these studies using an expanded database and larger constituent sets has not been performed. This study evaluated leachate data using a mixed-effects regression model to determine the extent to which leachate constituent degradation can be predicted based on waste age or operational practices. The final dataset analyzed consisted of a total of 1402 samples from 101 MSW landfills. Results from the study indicated that all leachate constituents exhibit a decreasing trend with time in the post-closure period, with 16 of the 25 target analytes and aggregate classes exhibiting a statistically significant trend consistent with well-studied indicators such as BOD. Decreasing trends in BOD concentration after landfill closure can thus be considered representative of trends for many leachate constituents of concern.

  11. Advantages and disadvantages : longitudinal vs. repeated cross-section surveys

    Science.gov (United States)

    1996-06-20

    The benefits of a longitudinal analysis over a repeated cross-sectional study include increased statistical power and the capability to estimate a greater range of conditional probabilities. With the Puget Sound Transportation Panel (PSTP), and any s...

  12. Typology of alcohol users based on longitudinal patterns of drinking.

    Science.gov (United States)

    Harrington, Magdalena; Velicer, Wayne F; Ramsey, Susan

    2014-03-01

    Worldwide, alcohol is the most commonly used psychoactive substance. However, heterogeneity among alcohol users has been widely recognized. This paper presents a typology of alcohol users based on an implementation of idiographic methodology to examine longitudinal daily and cyclic (weekly) patterns of alcohol use at the individual level. A secondary data analysis was performed on the pre-intervention data from a large randomized control trial. A time series analysis was performed at the individual level, and a dynamic cluster analysis was employed to identify homogenous longitudinal patterns of drinking behavior at the group level. The analysis employed 180 daily observations of alcohol use in a sample of 177 alcohol users. The first order autocorrelations ranged from -.76 to .72, and seventh order autocorrelations ranged from -.27 to .79. Eight distinct profiles of alcohol users were identified, each characterized by a unique configuration of first and seventh autoregressive terms and longitudinal trajectories of alcohol use. External validity of the profiles confirmed the theoretical relevance of different patterns of alcohol use. Significant differences among the eight subtypes were found on gender, marital status, frequency of drug use, lifetime alcohol dependence, family history of alcohol use and the Short Index of Problems. Our findings demonstrate that individuals can have very different temporal patterns of drinking behavior. The daily and cyclic patterns of alcohol use may be important for designing tailored interventions for problem drinkers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Arterial stiffness and its relationship to clinic and ambulatory blood pressure: a longitudinal study in non-dialysis chronic kidney disease.

    Science.gov (United States)

    Agarwal, Rajiv

    2017-11-01

    Both arterial stiffness and systolic blood pressure (BP) are established cardiovascular risk factors, yet little is known about their interrelationship in chronic kidney disease (CKD). The goal of this prospective study was to describe the trajectory of aortic pulse wave velocity (PWV) and BP and to compare the longitudinal interrelationship of BP (clinic and 24 h ambulatory recording) with the PWV. Clinic BP was taken in two ways: at the time of the measurement of the PWV (Clinic-S) and as an average of triplicate measurements on three separate occasions within 1 week (Clinic-M). 24 h ambulatory BP was measured using a validated monitor and PWV was measured in the aorta using an echo-Doppler technique. Among 255 veterans with CKD followed for over up to 4 years, the rate of change of log PWV was inversely related to the baseline PWV; the trajectories were variable among individuals and the net population change was no different from zero. In contrast, systolic BP significantly increased, but linearly, and a strong relationship was seen between cross-sectional and longitudinal changes in Clinic-M systolic BP and log PWV. In contrast, a longitudinal relationship between Clinic-S and log PWV was absent. In the case of 24-h ambulatory BP, a strong cross-sectional change was seen between awake and 24 h systolic BP but not between sleep BP and log PWV. In conclusion, among people with CKD, the PWV changes over time and is inversely related to the baseline PWV. An average of clinic BP measurements taken over three visits, but not single measurements, are useful to assess the PWV and its change over time. Differences exist between ambulatory BP monitoring recording during the sleep and awake states in their ability to predict the PWV. Taken together, these data support the view that among those with CKD not on dialysis, targeting clinic BP taken on multiple occasions using a standardized methodology or daytime ambulatory systolic BP may slow the progression of arterial

  14. Sequential inflammatory processes define human progression from M. tuberculosis infection to tuberculosis disease.

    Science.gov (United States)

    Scriba, Thomas J; Penn-Nicholson, Adam; Shankar, Smitha; Hraha, Tom; Thompson, Ethan G; Sterling, David; Nemes, Elisa; Darboe, Fatoumatta; Suliman, Sara; Amon, Lynn M; Mahomed, Hassan; Erasmus, Mzwandile; Whatney, Wendy; Johnson, John L; Boom, W Henry; Hatherill, Mark; Valvo, Joe; De Groote, Mary Ann; Ochsner, Urs A; Aderem, Alan; Hanekom, Willem A; Zak, Daniel E

    2017-11-01

    Our understanding of mechanisms underlying progression from Mycobacterium tuberculosis infection to pulmonary tuberculosis disease in humans remains limited. To define such mechanisms, we followed M. tuberculosis-infected adolescents longitudinally. Blood samples from forty-four adolescents who ultimately developed tuberculosis disease (“progressors”) were compared with those from 106 matched controls, who remained healthy during two years of follow up. We performed longitudinal whole blood transcriptomic analyses by RNA sequencing and plasma proteome analyses using multiplexed slow off-rate modified DNA aptamers. Tuberculosis progression was associated with sequential modulation of immunological processes. Type I/II interferon signalling and complement cascade were elevated 18 months before tuberculosis disease diagnosis, while changes in myeloid inflammation, lymphoid, monocyte and neutrophil gene modules occurred more proximally to tuberculosis disease. Analysis of gene expression in purified T cells also revealed early suppression of Th17 responses in progressors, relative to M. tuberculosis-infected controls. This was confirmed in an independent adult cohort who received BCG re-vaccination; transcript expression of interferon response genes in blood prior to BCG administration was associated with suppression of IL-17 expression by BCG-specific CD4 T cells 3 weeks post-vaccination. Our findings provide a timeline to the different immunological stages of disease progression which comprise sequential inflammatory dynamics and immune alterations that precede disease manifestations and diagnosis of tuberculosis disease. These findings have important implications for developing diagnostics, vaccination and host-directed therapies for tuberculosis. Clincialtrials.gov, NCT01119521.

  15. Stability of longitudinal bunch length feedback for heavy-ion synchrotrons

    Directory of Open Access Journals (Sweden)

    D. Lens

    2013-03-01

    Full Text Available In heavy-ion synchrotrons such as the SIS18 at Helmholtzzentrum für Schwerionenforschung, Helmholtz Centre for Heavy Ion Research (GSI, coherent oscillations of the particle bunches are damped by rf feedback systems to increase the stability and to improve the beam quality. In the longitudinal direction, important modes are the coherent longitudinal dipole and quadrupole oscillation. In this paper we present a new and rigorous approach to analyze the longitudinal feedback to damp these modes. The results are applied to the rf feedback loop at GSI that damps the quadrupole mode. The stability analysis is compared with simulations and is in good agreement with results of a beam experiment. Finally, we summarize practical implications for the operation of the feedback system regarding performance and stability.

  16. Microprobe PIXE analysis and EDX analysis on the brain of patients with Alzheimer`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Yumoto, S. [Tokyo Univ. (Japan). Faculty of Medicine; Horino, Y.; Mokuno, Y.; Fujii, K.; Kakimi, S.; Mizutani, T.; Matsushima, H.; Ishikawa, A.

    1996-12-31

    To investigate the cause of Alzheimer`s disease (senile dementia of Alzheimer`s disease type), we examined aluminium (Al) in the brain (hippocampus) of patients with Alzheimer`s disease using heavy ion (5 MeV Si{sup 3+}) microprobe particle-induced X-ray emission (PIXE) analysis. Heavy ion microprobes (3 MeV Si{sup 2+}) have several times higher sensitivity for Al detection than 2 MeV proton microprobes. We also examined Al in the brain of these patients by energy dispersive X-ray spectroscopy (EDX). (1) Al was detected in the cell nuclei isolated from the brain of patients with Alzheimer`s disease using 5 MeV Si{sup 3+} microprobe PIXE analysis, and EDX analysis. (2) EDX analysis demonstrated high levels of Al in the nucleolus of nerve cells in frozen sections prepared from the brain of these patients. Our results support the theory that Alzheimer`s disease is caused by accumulation of Al in the nuclei of brain cells. (author)

  17. A longitudinal assessment of changes in bacterial community composition associated with the development of periodontal disease in dogs.

    Science.gov (United States)

    Wallis, Corrin; Marshall, Mark; Colyer, Alison; O'Flynn, Ciaran; Deusch, Oliver; Harris, Stephen

    2015-12-31

    Periodontal disease is the most widespread oral disease in dogs. Whilst the involvement of bacteria in the aetiology of periodontitis is well established the role of individual species and their complex interactions with the host is not well understood. The objective of this research was therefore to perform a longitudinal study in dogs to identify the changes that occur in subgingival bacterial communities during the transition from mild gingivitis to the early stages of periodontitis (dogs every six weeks for up to 60 weeks. The microbial composition of plaque samples was determined using 454-pyrosequencing of the 16S rDNA. A group of aerobic Gram negative species, including Bergeyella zoohelcum COT-186, Moraxella sp. COT-017, Pasteurellaceae sp. COT-080, and Neisseria shayeganii COT-090 decreased in proportion as teeth progressed to mild periodontitis. In contrast, there was less evidence that increases in the proportion of individual species were associated with the onset of periodontitis, although a number of species (particularly members of the Firmicutes) became more abundant as gingivitis severity increased. There were small increases in Shannon diversity, suggesting that plaque community membership remains relatively stable but that bacterial proportions change during progression into periodontitis. This is the first study to demonstrate the temporal dynamics of the canine oral microbiota; it showed that periodontitis results from a microbial succession predominantly characterised by a reduction of previously abundant, health associated taxa. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Longitudinal analysis of music education on executive functions in primary school children

    NARCIS (Netherlands)

    Jaschke, A.C.; Honing, H.; Scherder, E.J.A.

    Background: Research on the effects of music education on cognitive abilities has generated increasing interest across the scientific community. Nonetheless, longitudinal studies investigating the effects of structured music education on cognitive sub-functions are still rare. Prime candidates for

  19. Safe RESIDential Environments? A longitudinal analysis of the influence of crime-related safety on walking

    OpenAIRE

    Foster, Sarah; Hooper, Paula; Knuiman, Matthew; Christian, Hayley; Bull, Fiona; Giles-Corti, Billie

    2016-01-01

    Background Numerous cross-sectional studies have investigated the premise that the perception of crime will cause residents to constrain their walking; however the findings to date are inconclusive. In contrast, few longitudinal or prospective studies have examined the impact of crime-related safety on residents walking behaviours. This study used longitudinal data to test whether there is a causal relationship between crime-related safety and walking in the local neighbourhood. Methods Parti...

  20. Vitamin D levels and risk for periodontal disease: A systematic review.

    Science.gov (United States)

    Pinto, J P N S; Goergen, J; Muniz, F W M G; Haas, A N

    2018-06-01

    To evaluate the existing evidence supporting or refuting the following questions: (i) Do patients with lower vitamin D levels have higher risk for periodontal disease? (ii) Are periodontal treatment outcomes improved by the adjuvant supplementation of vitamin D or by elevated serum vitamin D levels? MEDLINE, SCOPUS, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched up to September 2017. Studies were included if they had measured serum vitamin D levels or vitamin D intake and any periodontal parameter. Overall, 27 studies were included (13 cross-sectional studies, 6 case-control studies, 5 cohort studies, 2 randomized clinical trials and 1 case series study). Sixty-five percent of the cross-sectional studies reported significant associations between low vitamin D levels and poor periodontal parameters. None of the observational longitudinal studies found that periodontal disease progression could be attributed to lower vitamin D levels. No interventional studies that evaluated the use of vitamin D supplementation as a solely adjuvant to periodontal treatment was found. No meta-analysis was performed due to high variability across studies. The data to support or refute the association between vitamin D levels and periodontal disease are inconclusive at the moment. More rigorously designed longitudinal studies with standardized definitions of periodontal disease and vitamin D are necessary. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Longitudinal acoustic instabilities in slender solid propellant rockets : linear analysis

    OpenAIRE

    García Schafer, Juan Esteban; Liñán Martínez, Amable

    2001-01-01

    To describe the acoustic instabilities in the combustion chambers of laterally burning solid propellant rockets the interaction of the mean flow with the acoustic waves is analysed, using multiple scale techniques, for realistic cases in which the combustion chamber is slender and the nozzle area is small compared with the cross-sectional area of the chamber. Associated with the longitudinal acoustic oscillations we find vorticity and entropy waves, with a wavelength typically small compared ...

  2. Clinical analysis of spinal cord injury with or without cervical ossification of the posterior longitudinal ligament, spondylosis, and canal stenosis in elderly head injury patients

    International Nuclear Information System (INIS)

    Nakae, Ryuta; Onda, Hidetaka; Yokobori, Shoji; Araki, Takashi; Fuse, Akira; Toda, Shigeki; Kushimoto, Shigeki; Yokota, Hiroyuki; Teramoto, Akira

    2010-01-01

    Patients with degenerative diseases of the cervical spine, such as ossification of the posterior longitudinal ligament, spondylosis, and canal stenosis, sometimes present with acute spinal cord injury caused by minor trauma. However, the relative risk of cervical cord injury with these diseases is unknown. The clinical and radiological features of 94 elderly patients with head injury, 57 men and 37 women aged from 65 to 98 years (mean 76.6 years), were retrospectively analyzed to assess the association of spinal cord injury with degenerative cervical diseases. Degenerative cervical diseases were present in 25 patients, and spinal cord injury was more common in the patients with degenerative diseases (11/25 patients) than in the patients without such diseases (3/69 patients; relative risk=10.2). The incidence of degenerative cervical diseases seems to be increasing in Japan because life expectancy has increased and the elderly are a rapidly growing part of the population. A fall while walking or cycling is a common mechanism of head injury and/or cervical cord injury in the elderly. To decrease the occurrence of cervical myelopathy, prevention by increasing social awareness and avoiding traffic accidents and falls is important. (author)

  3. Longitudinal prediction of sexually transmitted diseases among adolescents: results from a national survey.

    Science.gov (United States)

    Crosby, R; Leichliter, J S; Brackbill, R

    2000-05-01

    Although adolescent use of condoms has been increasing, incidence of sexually transmitted diseases (STDs) among young people remains high. To identify adolescent behavioral risk factors for acquiring STDs, this study assessed adolescent self-reports of acquired chlamydia, gonorrhea, syphilis, and trichomoniasis within 1 year after a baseline interview. We used data from the National Longitudinal Survey of Adolescent Health for this study. Data were collected in the homes of survey respondents, using audio-computer-assisted self-interview (audio-CASI) technology and interviews. Participants were enrolled in grades 7-11 from 134 U.S. schools. A cohort of 4593 sexually experienced adolescents was followed for 1 year. We conducted separate analyses for both genders. About 3.1% of the male adolescents and nearly 4.7% of the female adolescents reported having had at least one STD after the baseline interview. For both genders, self-reported STD infection before baseline interview was the best predictor of self-reported STD infection 1 year after baseline interview. Female adolescents were more likely to report diagnosis with an STD after baseline if they self-identified as a minority race (other than Asian) and perceived that their mother did not disapprove of their having sex. Female adolescents were less likely to report STDs if they perceived that adults care about them. No additional variables predicted STD diagnosis after baseline for male adolescents. We conclude that past history of STD infection is the most important indicator of subsequent STD infection among adolescents. Thus, this study suggests the benefit of specific clinical efforts designed to promote preventive behavior among adolescents newly diagnosed with an STD.

  4. Vascular disease and risk factors are associated with cognitive decline in the alzheimer disease spectrum.

    Science.gov (United States)

    Lorius, Natacha; Locascio, Joseph J; Rentz, Dorene M; Johnson, Keith A; Sperling, Reisa A; Viswanathan, Anand; Marshall, Gad A

    2015-01-01

    We investigated the relationship between vascular disease and risk factors versus cognitive decline cross-sectionally and longitudinally in normal older control, mild cognitive impairment, and mild Alzheimer disease (AD) dementia subjects. A total of 812 participants (229 normal older control, 395 mild cognitive impairment, 188 AD) underwent cognitive testing, brain magnetic resonance imaging, and clinical evaluations at baseline and over a period of 3 years. General linear, longitudinal mixed-effects, and Cox proportional hazards models were used. Greater homocysteine level and white matter hyperintensity volume were associated with processing speed impairment (homocysteine: P=0.02; white matter hyperintensity: Prisk factors with cognitive impairment at baseline and over time in the AD spectrum in a sample that was selected to have low vascular burden at baseline.

  5. Clinical management and burden of bipolar disorder: a multinational longitudinal study (WAVE-bd Study

    Directory of Open Access Journals (Sweden)

    Moreno-Manzanaro Miriam

    2011-04-01

    Full Text Available Abstract Background Studies in bipolar disorder (BD to date are limited in their ability to provide a whole-disease perspective - their scope has generally been confined to a single disease phase and/or a specific treatment. Moreover, most clinical trials have focused on the manic phase of disease, and not on depression, which is associated with the greatest disease burden. There are few longitudinal studies covering both types of patients with BD (I and II and the whole course of the disease, regardless of patients' symptomatology. Therefore, the Wide AmbispectiVE study of the clinical management and burden of Bipolar Disorder (WAVE-bd (NCT01062607 aims to provide reliable information on the management of patients with BD in daily clinical practice. It also seeks to determine factors influencing clinical outcomes and resource use in relation to the management of BD. Methods WAVE-bd is a multinational, multicentre, non-interventional, longitudinal study. Approximately 3000 patients diagnosed with BD type I or II with at least one mood event in the preceding 12 months were recruited at centres in Austria, Belgium, Brazil, France, Germany, Portugal, Romania, Turkey, Ukraine and Venezuela. Site selection methodology aimed to provide a balanced cross-section of patients cared for by different types of providers of medical aid (e.g. academic hospitals, private practices in each country. Target recruitment percentages were derived either from scientific publications or from expert panels in each participating country. The minimum follow-up period will be 12 months, with a maximum of 27 months, taking into account the retrospective and the prospective parts of the study. Data on demographics, diagnosis, medical history, clinical management, clinical and functional outcomes (CGI-BP and FAST scales, adherence to treatment (DAI-10 scale and Medication Possession Ratio, quality of life (EQ-5D scale, healthcare resources, and caregiver burden (BAS scale

  6. Longitudinal motion in high current ion beams: a self-consistent phase space distribution with an envelope equation

    International Nuclear Information System (INIS)

    Neuffer, D.

    1979-03-01

    Many applications of particle acceleration, such as heavy ion fusion, require longitudinal bunching of a high intensity particle beam to extremely high particle currents with correspondingly high space charge forces. This requires a precise analysis of longitudinal motion including stability analysis. Previous papers have treated the longitudinal space charge force as strictly linear, and have not been self-consistent; that is, they have not displayed a phase space distribution consistent with this linear force so that the transport of the phase space distribution could be followed, and departures from linearity could be analyzed. This is unlike the situation for transverse phase space where the Kapchinskij--Vladimirskij (K--V) distribution can be used as the basis of an analysis of transverse motion. In this paper a self-consistent particle distribution in longitudinal phase space is derived which is a solution of the Vlasov equation and an envelope equation for this solution is derived

  7. Test-Retest Reliability of Diffusion Tensor Imaging in Huntington's Disease.

    Science.gov (United States)

    Cole, James H; Farmer, Ruth E; Rees, Elin M; Johnson, Hans J; Frost, Chris; Scahill, Rachael I; Hobbs, Nicola Z

    2014-03-21

    Diffusion tensor imaging (DTI) has shown microstructural abnormalities in patients with Huntington's Disease (HD) and work is underway to characterise how these abnormalities change with disease progression. Using methods that will be applied in longitudinal research, we sought to establish the reliability of DTI in early HD patients and controls. Test-retest reliability, quantified using the intraclass correlation coefficient (ICC), was assessed using region-of-interest (ROI)-based white matter atlas and voxelwise approaches on repeat scan data from 22 participants (10 early HD, 12 controls). T1 data was used to generate further ROIs for analysis in a reduced sample of 18 participants. The results suggest that fractional anisotropy (FA) and other diffusivity metrics are generally highly reliable, with ICCs indicating considerably lower within-subject compared to between-subject variability in both HD patients and controls. Where ICC was low, particularly for the diffusivity measures in the caudate and putamen, this was partly influenced by outliers. The analysis suggests that the specific DTI methods used here are appropriate for cross-sectional research in HD, and give confidence that they can also be applied longitudinally, although this requires further investigation. An important caveat for DTI studies is that test-retest reliability may not be evenly distributed throughout the brain whereby highly anisotropic white matter regions tended to show lower relative within-subject variability than other white or grey matter regions.

  8. Longitudinal Research in Social Science: Some Theoretical Challenges

    Directory of Open Access Journals (Sweden)

    Thomas K. Burch

    2001-12-01

    Full Text Available Every advance carries with it potential problems, and longitudinal analysis is no exception. This paper focuses on the problems related to the massive amounts of data generated by longitudinal surveys. It is argued that a proliferation of data may be to the good but it will not necessarily lead to better scientific knowledge. Most demographers think the logical positivist way that theory arises out of empirical generalisations, but massive empirical investigations have only led to disappointing theoretical outcomes in demography. This paper discusses one way out of this impasse - to adopt a different view of theory, a model-based view of science. Theoretical models based on empirical generalisation should become the main representational device in science.

  9. Leveraging electronic health records to support chronic disease management: the need for temporal data views.

    Science.gov (United States)

    Samal, Lipika; Wright, Adam; Wong, Bang T; Linder, Jeffrey A; Bates, David W

    2011-01-01

    The ageing population worldwide is increasingly acquiring multiple chronic diseases. The complex management of chronic diseases could be improved with electronic health records (EHRs) tailored to chronic disease care, but most EHRs in use today do not adequately support longitudinal data management. A key aspect of chronic disease management is that it takes place over long periods, but the way that most EHRs display longitudinal data makes it difficult to trend changes over time and slows providers as they review each patient's unique course. We present five clinical scenarios illustrating longitudinal data needs in complex chronic disease management. These scenarios may function as example cases for software development. For each scenario, we describe and illustrate improvements in temporal data views. Two potential solutions are visualisation for numerical data and disease-oriented text summaries for non-numerical data. We believe that development and widespread implementation of improved temporal data views in EHRs will improve the efficiency and quality of chronic disease management in primary care.

  10. Adolescence and Later Life Disease Burden: Quantifying the Contribution of Adolescent Tobacco Initiation From Longitudinal Cohorts.

    Science.gov (United States)

    Viner, Russell M; Hargreaves, Dougal S; Motta, Janaina Vieira Dos Santos; Horta, Bernardo; Mokdad, Ali H; Patton, George

    2017-08-01

    Adolescence is a time of initiation of behaviors leading to noncommunicable diseases (NCDs). We use tobacco to illustrate a novel method for assessing the contribution of adolescence to later burden. Data on initiation of regular smoking during adolescence (10-19 years) and current adult smoking were obtained from the 1958 British Birth Cohort, the U.S. National Longitudinal Study of Adolescent Health (Add Health), the Pelotas 1982 Birth Cohort, and the Victorian Adolescent Health Cohort Study. We estimated an "adolescent attributable fraction" (AAF) by calculating the proportion of persisting adult daily smoking initiated 155 countries using contemporary surveillance data. In the 1958 British Birth Cohort, 81.6% of daily smokers at age 50 years initiated adolescent initiation. The adjusted AAF was 69.1. Proportions of smokers initiating Adolescent Health Cohort Study; and 70.9%, 5.8%, and 56.9% in Pelotas males and 89.9%, 6.4%, and 75.9% in females. Initiation adolescent smoking initiation to adult smoking burden is high, suggesting a need to formulate and implement effective actions to reduce smoking initiation in adolescents. Similar trends in other NCD risks suggest that adolescents will be central to future efforts to control NCDs. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  11. Regression analysis of sparse asynchronous longitudinal data.

    Science.gov (United States)

    Cao, Hongyuan; Zeng, Donglin; Fine, Jason P

    2015-09-01

    We consider estimation of regression models for sparse asynchronous longitudinal observations, where time-dependent responses and covariates are observed intermittently within subjects. Unlike with synchronous data, where the response and covariates are observed at the same time point, with asynchronous data, the observation times are mismatched. Simple kernel-weighted estimating equations are proposed for generalized linear models with either time invariant or time-dependent coefficients under smoothness assumptions for the covariate processes which are similar to those for synchronous data. For models with either time invariant or time-dependent coefficients, the estimators are consistent and asymptotically normal but converge at slower rates than those achieved with synchronous data. Simulation studies evidence that the methods perform well with realistic sample sizes and may be superior to a naive application of methods for synchronous data based on an ad hoc last value carried forward approach. The practical utility of the methods is illustrated on data from a study on human immunodeficiency virus.

  12. A Longitudinal Analysis of the Influence of a Peer Run Warm Line Phone Service on Psychiatric Recovery.

    Science.gov (United States)

    Dalgin, Rebecca Spirito; Dalgin, M Halim; Metzger, Scott J

    2018-05-01

    This article focuses on the impact of a peer run warm line as part of the psychiatric recovery process. It utilized data including the Recovery Assessment Scale, community integration measures and crisis service usage. Longitudinal statistical analysis was completed on 48 sets of data from 2011, 2012, and 2013. Although no statistically significant differences were observed for the RAS score, community integration data showed increases in visits to primary care doctors, leisure/recreation activities and socialization with others. This study highlights the complexity of psychiatric recovery and that nonclinical peer services like peer run warm lines may be critical to the process.

  13. Effect of longitudinal stiffening on bridge girder webs at incremental launching stage

    Directory of Open Access Journals (Sweden)

    Carlos Graciano

    2015-01-01

    Full Text Available Patch loading is a predominant load case at incremental bridge launching. Bridge girder webs are frequently provided with longitudinal stiffeners to increase in-service shear and bending strength, and its effect has been included in design codes. However, no straightforward rules are given to account for the influence of such stiffeners on improving the patch loading resistance. This paper presents a review of some available formulae found in the literature to estimate the girder ultimate strength including the provisions of the European, American and Colombian design codes. Additionally, a nonlinear finite element analysis is conducted on three case studies related to actual launched bridges. The case studies are also used to study the influence of the longitudinal stiffener and girder depth on the girder capacity. Different load-displacement responses are observed depending on the girder depth. Finally, the finite element analysis shows to what extent the longitudinal stiffeners can increase the patch loading capacity of bridge girder webs during launching.

  14. Alzheimer Disease Cerebrospinal Fluid Biomarkers Moderate Baseline Differences and Predict Longitudinal Change in Attentional Control and Episodic Memory Composites in the Adult Children Study.

    Science.gov (United States)

    Aschenbrenner, Andrew J; Balota, David A; Fagan, Anne M; Duchek, Janet M; Benzinger, Tammie L S; Morris, John C

    2015-09-01

    Cognitive measures that are sensitive to biological markers of Alzheimer disease (AD) pathology are needed to (a) facilitate preclinical staging, (b) identify individuals who are at the highest risk for developing clinical symptoms, and (c) serve as endpoints for evaluating the efficacy of interventions. The present study assesses the utility of two cognitive composite scores of attentional control and episodic memory as markers for preclinical AD pathology in a group of cognitively normal older adults (N = 238), as part of the Adult Children Study. All participants were given a baseline cognitive assessment and follow-up assessments every 3 years over an 8-year period, as well as a lumbar puncture within 2 years of the initial assessment to collect cerebrospinal fluid (CSF) and amyloid tracer Pittsburgh compound-B scan for amyloid imaging. Results indicated that attentional control was correlated with levels of Aβ42 at the initial assessment whereas episodic memory was not. Longitudinally, individuals with high CSF tau exhibited a decline in both attention and episodic memory over the course of the study. These results indicate that measures of attentional control and episodic memory can be used to evaluate cognitive decline in preclinical AD and provide support that CSF tau may be a key mechanism driving longitudinal cognitive change.

  15. An image-based model of brain volume biomarker changes in Huntington's disease.

    Science.gov (United States)

    Wijeratne, Peter A; Young, Alexandra L; Oxtoby, Neil P; Marinescu, Razvan V; Firth, Nicholas C; Johnson, Eileanoir B; Mohan, Amrita; Sampaio, Cristina; Scahill, Rachael I; Tabrizi, Sarah J; Alexander, Daniel C

    2018-05-01

    Determining the sequence in which Huntington's disease biomarkers become abnormal can provide important insights into the disease progression and a quantitative tool for patient stratification. Here, we construct and present a uniquely fine-grained model of temporal progression of Huntington's disease from premanifest through to manifest stages. We employ a probabilistic event-based model to determine the sequence of appearance of atrophy in brain volumes, learned from structural MRI in the Track-HD study, as well as to estimate the uncertainty in the ordering. We use longitudinal and phenotypic data to demonstrate the utility of the patient staging system that the resulting model provides. The model recovers the following order of detectable changes in brain region volumes: putamen, caudate, pallidum, insula white matter, nonventricular cerebrospinal fluid, amygdala, optic chiasm, third ventricle, posterior insula, and basal forebrain. This ordering is mostly preserved even under cross-validation of the uncertainty in the event sequence. Longitudinal analysis performed using 6 years of follow-up data from baseline confirms efficacy of the model, as subjects consistently move to later stages with time, and significant correlations are observed between the estimated stages and nonimaging phenotypic markers. We used a data-driven method to provide new insight into Huntington's disease progression as well as new power to stage and predict conversion. Our results highlight the potential of disease progression models, such as the event-based model, to provide new insight into Huntington's disease progression and to support fine-grained patient stratification for future precision medicine in Huntington's disease.

  16. Usefulness of abdominal ultrasonography in the analysis of endoscopic activity in patients with Crohn's disease: changes following treatment with immunomodulators and/or anti-TNF antibodies.

    Science.gov (United States)

    Moreno, Nadia; Ripollés, Tomás; Paredes, José María; Ortiz, Inmaculada; Martínez, María Jesús; López, Antonio; Delgado, Fructuoso; Moreno-Osset, Eduardo

    2014-09-01

    The objective of this study was to analyze the accuracy of abdominal ultrasonography (AUS) in the assessment of mucosal healing in patients with Crohn's disease (CD) receiving immunomodulators and/or biological treatment, with ileocolonoscopy as the reference standard. Thirty patients were included in a prospective longitudinal study. All patients underwent ileocolonoscopy and AUS before and after a minimum of one year of treatment. The Crohn's Disease Endoscopic Inflammatory Index of Severity (CDEIS) was used for endoscopic assessment whereas AUS was analyzed by means of bowel wall thickness, color Doppler grade and percentage of increase of parietal enhancement after contrast injection. In the segmental analysis, endoscopic healing was found in 71.2% of the segments and AUS findings were normalized in 62.8%, with a significant correlation between the two techniques (κ=0.76, pimmunomodulators and/or biological drugs in Crohn's disease. AUS is a highly accurate technique for evaluating the healing of the intestinal mucosa. Copyright © 2014 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.

  17. Measurement of the longitudinal parameters of an electron beam in a storage ring

    International Nuclear Information System (INIS)

    Krinsky, S.

    1989-01-01

    We discuss the determination of the longitudinal parameters of a bunched beam of electrons or positrons circulating in a storage ring. From the analysis of the beam current observed at a fixed azimuthal location, one can learn much about the longitudinal behavior. We present an elementary analysis of the time-dependence of the current. In particular, we discuss the determination of the average current, bunch length, synchrotron oscillation frequency, and the coherent synchrotron oscillation modes associated with longitudinal instabilities. A brief discussion is also given of the incoherent synchrotron oscillations, or Schottky noise. We review the electromagnetic field traveling with a charge in uniform motion, and introduce some of the most common devices used to detect this field: capacitive pick-up, stripline monitor, and DC beam current transformer. Our paper is organized as follows: We discuss the analysis of the time-dependence of the beam current. Then, the measurement of the current is considered. Finally, we describe some measurements of energy spread and bunch lengthening made recently at SLAC on the SLC damping ring. 12 refs., 6 figs

  18. Meta-analysis: Coeliac disease and hypertransaminasaemia.

    Science.gov (United States)

    Sainsbury, A; Sanders, D S; Ford, A C

    2011-07-01

    There may be a positive association between coeliac disease and serum hypertransaminasaemia but evidence is conflicting. To conduct a systematic review and meta-analysis to determine the prevalence of coeliac disease in adults presenting with cryptogenic serum hypertransaminasaemia and the prevalence of hypertransaminasaemia in patients with newly diagnosed coeliac disease. MEDLINE and EMBASE were searched up to August 2010. Case series and case-control studies recruiting adults with either cryptogenic hypertransaminasaemia that applied serological tests for coeliac disease and/or distal duodenal biopsy to participants or newly diagnosed biopsy-proven coeliac disease that assessed serum transaminases were eligible. The pooled prevalence of coeliac disease in individuals presenting with abnormal serum transaminases and the pooled prevalence of hypertransaminasaemia in newly diagnosed coeliac disease were calculated with 95% confidence intervals (CI). Eleven eligible studies were identified. Pooled prevalences of positive coeliac serology and biopsy-proven coeliac disease in cryptogenic hypertransaminasaemia were 6% (95% CI 3% to 10%) and 4% (95% CI 1% to 7%) respectively. Pooled prevalence of abnormal serum transaminases in newly diagnosed coeliac disease was 27% (95% CI 13% to 44%). Exclusion of gluten led to normalisation of serum transaminase levels in 63% to 90% of patients within 1 year. Undetected coeliac disease is a potential cause for cryptogenic hypertransaminasaemia in 3% to 4% of cases. More than 20% of individuals with newly diagnosed coeliac disease may have abnormal serum transaminases and these normalise on a gluten-free diet in the majority of cases. © 2011 Blackwell Publishing Ltd.

  19. An Analysis of the Effects of Wing Aspect Ratio and Tail Location on Static Longitudinal Stability Below the Mach Number of Lift Divergence

    Science.gov (United States)

    Axelson, John A.; Crown, J. Conrad

    1948-01-01

    An analysis is presented of the influence of wing aspect ratio and tail location on the effects of compressibility upon static longitudinal stability. The investigation showed that the use of reduced wing aspect ratios or short tail lengths leads to serious reductions in high-speed stability and the possibility of high-speed instability.

  20. Research on FBG-based longitudinal-acousto-optic modulator with Fourier mode coupling method.

    Science.gov (United States)

    Li, Zhuoxuan; Pei, Li; Liu, Chao; Ning, Tigang; Yu, Shaowei

    2012-10-20

    Fourier mode coupling model was first applied to achieve the spectra property of a fiber Bragg grating (FBG)-based longitudinal-acousto-optic modulator. Compared with traditional analysis algorithms, such as the transfer matrix method, the Fourier mode coupling model could improve the computing efficiency up to 100 times with a guarantee of accuracy. In this paper, based on the theoretical analysis of this model, the spectra characteristics of the modulator in different frequencies and acoustically induced strains were numerically simulated. In the experiment, a uniform FBG was modulated by acoustic wave (AW) at 12 different frequencies. In particular, the modulator responses at 563 and 885.5 KHz with three different lead zirconate titanate (PZT) loads applied were plotted for illustration, and the linear fitting of experimental data demonstrated a good match with the simulation result. The acoustic excitation of the longitudinal wave is obtained using a conic silica horn attached to the surface of a shear-mode PZT plate paralleled to the fiber axis. This way of generating longitudinal AW with a transversal PZT may shed light on the optimal structural design for the FBG-based longitudinal-acousto-optic modulator.

  1. Economic effectiveness of disease management programs: a meta-analysis.

    Science.gov (United States)

    Krause, David S

    2005-04-01

    The economic effectiveness of disease management programs, which are designed to improve the clinical and economic outcomes for chronically ill individuals, has been evaluated extensively. A literature search was performed with MEDLINE and other published sources for the period covering January 1995 to September 2003. The search was limited to empirical articles that measured the direct economic outcomes for asthma, diabetes, and heart disease management programs. Of the 360 articles and presentations evaluated, only 67 met the selection criteria for meta-analysis, which included 32,041 subjects. Although some studies contained multiple measurements of direct economic outcomes, only one average effect size per study was included in the meta-analysis. Based on the studies included in the research, a meta-analysis provided a statistically significant answer to the question of whether disease management programs are economically effective. The magnitude of the observed average effect size for equally weighted studies was 0.311 (95% CI = 0.272-0.350). Statistically significant differences of effect sizes by study design, disease type and intensity of disease management program interventions were not found after a moderating variable, disease severity, was taken into consideration. The results suggest that disease management programs are more effective economically with severely ill enrollees and that chronic disease program interventions are most effective when coordinated with the overall level of disease severity. The findings can be generalized, which may assist health care policy makers and practitioners in addressing the issue of providing economically effective care for the growing number of individuals with chronic illness.

  2. Estimators for longitudinal latent exposure models: examining measurement model assumptions.

    Science.gov (United States)

    Sánchez, Brisa N; Kim, Sehee; Sammel, Mary D

    2017-06-15

    Latent variable (LV) models are increasingly being used in environmental epidemiology as a way to summarize multiple environmental exposures and thus minimize statistical concerns that arise in multiple regression. LV models may be especially useful when multivariate exposures are collected repeatedly over time. LV models can accommodate a variety of assumptions but, at the same time, present the user with many choices for model specification particularly in the case of exposure data collected repeatedly over time. For instance, the user could assume conditional independence of observed exposure biomarkers given the latent exposure and, in the case of longitudinal latent exposure variables, time invariance of the measurement model. Choosing which assumptions to relax is not always straightforward. We were motivated by a study of prenatal lead exposure and mental development, where assumptions of the measurement model for the time-changing longitudinal exposure have appreciable impact on (maximum-likelihood) inferences about the health effects of lead exposure. Although we were not particularly interested in characterizing the change of the LV itself, imposing a longitudinal LV structure on the repeated multivariate exposure measures could result in high efficiency gains for the exposure-disease association. We examine the biases of maximum likelihood estimators when assumptions about the measurement model for the longitudinal latent exposure variable are violated. We adapt existing instrumental variable estimators to the case of longitudinal exposures and propose them as an alternative to estimate the health effects of a time-changing latent predictor. We show that instrumental variable estimators remain unbiased for a wide range of data generating models and have advantages in terms of mean squared error. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  3. Centrifugal Expansion of Fundus Autofluorescence Patterns in Stargardt Disease Over Time

    Science.gov (United States)

    Cukras, Catherine A.; Wong, Wai T.; Caruso, Rafael; Cunningham, Denise; Zein, Wadih; Sieving, Paul

    2012-01-01

    Objective Changing lipofuscin and melanin content in RPE cells has been hypothesized to contribute to Stargardt disease pathogenesis. Longitudinal study of autofluorescence in Stargardt disease which reflect changing fluorophore compositions can reveal aspects of disease progression not previously evident. Method We examined the temporal-spatial patterns of fundus autofluorescence with excitation at both 488 nm (standard fundus autofluorescence, FAF) and 795nm (near infrared autofluorescence, NIA) in a longitudinal case series involving 8 eyes of 4 patients (range of follow-up = 11 to 57 months; mean = 39 months). Image processing was performed to analyze spatial and temporal cross-modality associations. Results Longitudinal FAF imaging of fleck lesions revealed hyperautofluorescent lesions that extended in a centrifugal direction from the fovea with time. Patterns of spread were non-random and followed a radial path that leaves behind a trail of diminishing autofluorescence. Longitudinal NIA imaging also demonstrated centrifugal lesion spread, but with fewer hyperautofluorescent lesions, suggestive of more transient hyperautofluorescence and more rapid decay at longer wavelengths. FAF and NIA abnormalities were spatially correlated to each other, and together reflect systematic progressions in fleck distribution and fluorophore composition occurring during the natural history of the disease. Conclusion Stargardt disease fleck lesions do not evolve randomly in location but instead follow consistent patterns of radial expansion and a systematic decay of autofluorescence that reflect changing lipofuscin and melanin compositions in RPE cells. These progressive foveal-to-peripheral changes are helpful in elucidating molecular and cellular mechanisms underlying Stargardt disease and may constitute potential outcome measures in clinical trials. PMID:21987580

  4. Centrifugal expansion of fundus autofluorescence patterns in Stargardt disease over time.

    Science.gov (United States)

    Cukras, Catherine A; Wong, Wai T; Caruso, Rafael; Cunningham, Denise; Zein, Wadih; Sieving, Paul A

    2012-02-01

    To study the longitudinal changes in autofluorescence in Stargardt disease to reveal aspects of disease progression not previously evident. Changes in autofluorescence reflect changing fluorophore compositions of lipofuscin and melanin in retinal pigment epithelial cells, which has been hypothesized to contribute to Stargardt disease pathogenesis. We examined the temporospatial patterns of fundus autofluorescence with excitation at both 488 nm (standard fundus autofluorescence) and 795 nm (near-infrared autofluorescence) in a longitudinal case series involving 8 eyes of 4 patients (range of follow-up, 11-57 months; mean, 39 months). Image processing was performed to analyze spatial and temporal cross-modality associations. Longitudinal fundus autofluorescence imaging of fleck lesions revealed hyperautofluorescent lesions that extended in a centrifugal direction from the fovea with time. Patterns of spread were nonrandom and followed a radial path that left behind a trail of diminishing autofluorescence. Longitudinal near-infrared autofluorescence imaging also demonstrated centrifugal lesion spread but with fewer hyperautofluorescent lesions, suggestive of more transient hyperautofluorescence and more rapid decay at longer wavelengths. Fundus autofluorescence and near-infrared autofluorescence abnormalities were spatially correlated with each other, and together they reflect systematic progressions in fleck distribution and fluorophore composition occurring during the natural history of the disease. Stargardt disease fleck lesions do not evolve randomly in location but instead follow consistent patterns of radial expansion and a systematic decay of autofluorescence that reflect changing lipofuscin and melanin compositions in retinal pigment epithelial cells. These progressive foveal-to-peripheral changes are helpful in elucidating molecular and cellular mechanisms underlying Stargardt disease and may constitute potential outcome measures in clinical trials.

  5. Clinical and Biological Insights from the University of California San Francisco Prospective and Longitudinal Cohort.

    Science.gov (United States)

    Benn, Bryan S; Lehman, Zoe; Kidd, Sharon A; Ho, Melissa; Sun, Sara; Ramstein, Joris; Arger, Nicholas K; Nguyen, Christine P; Su, Robert; Gomez, Antonio; Gelfand, Jeffrey M; Koth, Laura L

    2017-10-01

    Sarcoidosis is a systemic inflammatory disease characterized by non-necrotizing granulomas in involved organs, most commonly the lung. Description of patient characteristics in the Western United States is limited. Furthermore, blood-based measures that relate to clinical sarcoidosis phenotypes are lacking. We present an analysis of a prospective, longitudinal sarcoidosis cohort at a Northern Californian academic medical center. We enrolled 126 sarcoidosis subjects and 64 healthy controls and recorded baseline demographic and clinical characteristics. We used regression models to identify factors independently associated with pulmonary physiology. We tested whether blood transcript levels at study entry could relate to longitudinal changes in pulmonary physiology. White, non-Hispanics composed ~70% of subjects. Hispanics and Blacks had a diagnostic biopsy at an age ~7 years younger than whites. Obstructive, but not restrictive, physiology characterized Scadding Stage IV patients. Subjects reporting use of immunosuppression had worse FEV1%p, FVC%p, and DLCO%p compared to subjects never treated, regardless of Scadding stage. We defined sarcoidosis disease activity by a drop in pulmonary function over 36 months and found that subjects meeting this definition had significant repression of blood gene transcripts related to T cell receptor signaling pathways, referred to as the "TCR factor." Obstructive pulmonary physiology defined Stage IV patients which were mostly white, non-Hispanics. Genes comprising the composite gene expression score, TCR factor, may represent a blood-derived measure of T-cell activity and an indirect measure of active sarcoidosis inflammation. Validation of this measure could translate into individualized treatment for sarcoidosis patients.

  6. Reliability measures of functional magnetic resonance imaging in a longitudinal evaluation of mild cognitive impairment.

    Science.gov (United States)

    Zanto, Theodore P; Pa, Judy; Gazzaley, Adam

    2014-01-01

    As the aging population grows, it has become increasingly important to carefully characterize amnestic mild cognitive impairment (aMCI), a preclinical stage of Alzheimer's disease (AD). Functional magnetic resonance imaging (fMRI) is a valuable tool for monitoring disease progression in selectively vulnerable brain regions associated with AD neuropathology. However, the reliability of fMRI data in longitudinal studies of older adults with aMCI is largely unexplored. To address this, aMCI participants completed two visual working tasks, a Delayed-Recognition task and a One-Back task, on three separate scanning sessions over a three-month period. Test-retest reliability of the fMRI blood oxygen level dependent (BOLD) activity was assessed using an intraclass correlation (ICC) analysis approach. Results indicated that brain regions engaged during the task displayed greater reliability across sessions compared to regions that were not utilized by the task. During task-engagement, differential reliability scores were observed across the brain such that the frontal lobe, medial temporal lobe, and subcortical structures exhibited fair to moderate reliability (ICC=0.3-0.6), while temporal, parietal, and occipital regions exhibited moderate to good reliability (ICC=0.4-0.7). Additionally, reliability across brain regions was more stable when three fMRI sessions were used in the ICC calculation relative to two fMRI sessions. In conclusion, the fMRI BOLD signal is reliable across scanning sessions in this population and thus a useful tool for tracking longitudinal change in observational and interventional studies in aMCI. © 2013.

  7. Longitudinal validity and responsiveness of the Food Allergy Quality of Life Questionnaire - Parent Form in children 0-12 years following positive and negative food challenges

    NARCIS (Netherlands)

    DunnGalvin, A.; Cullinane, C.; Daly, D. A.; Flokstra-de Blok, B. M. J.; Dubois, A. E. J.; Hourihane, J. O'B.

    P>Background There are no published studies of longitudinal health-related quality of life (HRQL) assessments of food-allergic children using a disease-specific measure. Objective This study assessed the longitudinal measurement properties of the Food Allergy Quality of Life Questionnaire - Parent

  8. Multifractal Detrended Fluctuation Analysis of Human gait Diseases

    Directory of Open Access Journals (Sweden)

    Srimonti eDutta

    2013-10-01

    Full Text Available IIn this paper multifractal detrended fluctuation analysis is used to study the human gait time series for normal and diseased sets. It is observed that long range correlation is primarily responsible for the origin of multifractality. The study reveals that the degree of multifractality is more for normal set compared to diseased set. However the method fails to distinguish between the two diseased sets.

  9. Diagnosing the EAP needs of Turkish medical students: A longitudinal critical needs analysis

    Directory of Open Access Journals (Sweden)

    Neslihan Önder Özdemir

    2014-10-01

    Full Text Available This study uses a longitudinal critical needs analysis to diagnose the English for academic purposes (EAP needs of Turkish medical students seeking proficiency in medical English and contribute to needs analysis methodology. The data were collected from medical students and specialists. To obtain valid and reliable information about medical students’ needs, three types of instruments were used: ethnographic methods, including sustained observation and participation in a research setting; reflective journals; and a questionnaire and in-depth interview. The questionnaire design was based on essays collected from the students during their study, and the items were constructed from the students’ own words. To the best of my knowledge, this study is the first attempt in the literature to triangulate both methods and data with a focus on critical pedagogy to diagnose EAP needs. The findings are the result of the triangulation of data and methodology to ensure the reliability and validity of the findings. A total of 525 subjects participated in the research (186 participants in the pilot study and 339 participants in the main study. The findings revealed medical students’ expectations of their English for specific purposes (ESP instructor, students’ shortcomings, and the problems and strategies they use while learning medical English. The interview data analysis sought to determine whether higher education students can be a reliable source to consult for their own educational needs in higher education. The methodology followed here can be replicated in other mainstream classrooms.

  10. Longitudinal micro-CT as an outcome measure of interstitial lung disease in TNF-transgenic mice.

    Directory of Open Access Journals (Sweden)

    Richard D Bell

    Full Text Available Rheumatoid arthritis associated interstitial lung disease (RA-ILD is a debilitating condition with poor survival prognosis. High resolution computed tomography (CT is a common clinical tool to diagnose RA-ILD, and is increasingly being adopted in pre-clinical studies. However, murine models recapitulating RA-ILD are lacking, and CT outcomes for inflammatory lung disease have yet to be formally validated. To address this, we validate μCT outcomes for ILD in the tumor necrosis factor transgenic (TNF-Tg mouse model of RA.Cross sectional μCT was performed on cohorts of male TNF-Tg mice and their WT littermates at 3, 4, 5.5 and 12 months of age (n = 4-6. Lung μCT outcomes measures were determined by segmentation of the μCT datasets to generate Aerated and Tissue volumes. After each scan, lungs were obtained for histopathology and 3 sections stained with hematoxylin and eosin. Automated histomorphometry was performed to quantify the tissue area (nuclei, cytoplasm, and extracellular matrix and aerated area (white space within the tissue sections. Spearman's correlation coefficients were used to evaluate the extent of association between μCT imaging and histopathology endpoints.TNF-Tg mice had significantly greater tissue volume, total lung volume and mean intensity at all timepoints compared to age matched WT littermates. Histomorphometry also demonstrated a significant increase in tissue area at 3, 4, and 5.5 months of age in TNF-Tg mice. Lung tissue volume was correlated with lung tissue area (ρ = 0.81, p<0.0001, and normalize lung aerated volume was correlated with normalized lung air area (ρ = 0.73, p<0.0001.We have validated in vivo μCT as a quantitative biomarker of ILD in mice. Further, development of longitudinal measures is critical for dissecting pathologic progression of ILD, and μCT is a useful non-invasive method to study lung inflammation in the TNF-Tg mouse model.

  11. Diagnostic power of longitudinal strain at rest for the detection of obstructive coronary artery disease in patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Zuo, Houjuan; Yan, Jiangtao; Zeng, Hesong; Li, Wenyu; Li, Pengcheng; Liu, Zhengxiang; Cui, Guanglin; Lv, Jiagao; Wang, Daowen; Wang, Hong

    2015-01-01

    Global longitudinal strain (GLS) measured by 2-D speckle-tracking echocardiography (2-D STE) at rest has been recognized as a sensitive parameter in the detection of significant coronary artery disease (CAD). However, the diagnostic power of 2-D STE in the detection of significant CAD in patients with diabetes mellitus is unknown. Two-dimensional STE features were studied in total of 143 consecutive patients who underwent echocardiography and coronary angiography. Left ventricular global and segmental peak systolic longitudinal strains (PSLSs) were quantified by speckle-tracking imaging. In the presence of obstructive CAD (defined as stenosis ≥75%), global PSLS was significantly lower in patients with diabetes mellitus than in patients without (16.65 ± 2.29% vs. 17.32 ± 2.27%, p diabetes mellitus (cutoff value: -18.35%, sensitivity: 78.8%, specificity: 77.5%). However, global PSLS could detect obstructive CAD in diabetic patients at a lower cutoff value with inadequate sensitivity and specificity (cutoff value: -17.15%; sensitivity: 61.1%, specificity: 52.9%). In addition, the results for segmental PSLS were similar to those for global PSLS. In conclusion, global and segmental PSLSs at rest were significantly lower in patients with both obstructive CAD and diabetes mellitus than in patients with obstructive CAD only; thus, PSLSs at rest might not be a useful parameter in the detection of obstructive CAD in patients with diabetes mellitus. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  12. A Longitudinal Analysis of Adolescent Decision-Making with the Iowa Gambling Task

    Science.gov (United States)

    Almy, Brandon; Kuskowski, Michael; Malone, Stephen M.; Myers, Evan; Luciana, Monica

    2018-01-01

    Many researchers have used the standard Iowa Gambling Task (IGT) to assess decision-making in adolescence given increased risk-taking during this developmental period. Most studies are cross-sectional and do not observe behavioral trajectories over time, limiting interpretation. This longitudinal study investigated healthy adolescents' and young…

  13. Long-term impact of a chronic disease management program on hospital utilization and cost in an Australian population with heart disease or diabetes.

    Science.gov (United States)

    Hamar, G Brent; Rula, Elizabeth Y; Coberley, Carter; Pope, James E; Larkin, Shaun

    2015-04-22

    To evaluate the longitudinal value of a chronic disease management program, My Health Guardian (MHG), in reducing hospital utilization and costs over 4 years. The MHG program provides individualized support via telephonic nurse outreach and online tools for self-management, behavior change and well-being. In follow up to an initial 18-month analysis of MHG, the current study evaluated program impact over 4 years. A matched-cohort analysis retrospectively compared MHG participants with heart disease or diabetes (treatment, N = 4,948) to non-participants (comparison, N = 28,520) on utilization rates (hospital admission, readmission, total bed days) and hospital claims cost savings. Outcomes were evaluated using regression analyses, controlling for remaining demographic, disease, and pre-program admissions or cost differences between the study groups. Over the 4 year period, program participation resulted in significant reductions in hospital admissions (-11.4%, P hospital claims was $3,549 over 4-years; savings values for each program year were significant and increased with time (P = 0.003 to P hospital utilization and costs for individuals with heart disease or diabetes and demonstrate the increasing program effect with continued participation over time.

  14. Child adiposity and maternal feeding practices: a longitudinal analysis.

    Science.gov (United States)

    Webber, Laura; Cooke, Lucy; Hill, Claire; Wardle, Jane

    2010-12-01

    Parental control has been hypothesized to cause weight gain in children by weakening self-regulatory processes. However, most studies that link control with weight have been cross-sectional, and therefore causation is uncertain. It remains possible that parental control is a response to child overweight rather than a cause. We investigated the direction of the association between parental feeding practices and children's adiposity in a longitudinal study. Three subscales of the Child Feeding Questionnaire (CFQ) that measure "pressure," "restriction," and "monitoring" were completed by 213 mothers of 7-9-y-old children as part of the Physical Exercise and Appetite in CHildren Study (PEACHES) and repeated by 113 mothers 3 y later. Baseline and follow-up anthropometric measurements [body mass index (BMI); fat mass index (FMI), and waist circumference (WC)] were made by researchers when the children were aged 7-9 y and 10-11 y. Regression analyses showed no association between any of the CFQ scales at baseline and change in child adiposity. In contrast, higher child BMI at baseline predicted a smaller decrease in follow-up CFQ "monitoring" (P = 0.003) and a larger decrease in "pressure to eat" (P = 0.04) after baseline scores were controlled for. Similar results were observed for FMI and WC, although they did not reach significance for WC. There were no significant longitudinal associations between child adiposity and the CFQ "restriction" subscale. The results were more consistent with a "child-responsive" model whereby a mother's choice of feeding practice is influenced by her child's weight status rather than her feeding practices influencing the child's weight gain.

  15. A Multilevel, Longitudinal Analysis of Middle School Math and Language Achievement

    Directory of Open Access Journals (Sweden)

    Keith Zvoch

    2003-07-01

    Full Text Available The performance of schools in a large urban school district was examined using achievement data from a longitudinally matched cohort of middle school students. Schools were evaluated in terms of the mean achievement and mean growth of students in mathematics and language arts. Application of multilevel, longitudinal models to student achievement data revealed that 1 school performance varied across both outcome measures in both subject areas, 2 significant proportions of variation were associated with school-to-school differences in performance, 3 evaluations of school performance differed depending on whether school mean achievement or school mean growth in achievement was examined, and 4 school mean achievement was a weak predictor of school mean growth. These results suggest that assessments of school performance depend on choices of how data are modeled and analyzed. In particular, the present study indicates that schools with low mean scores are not always “poor performing” schools. Use of student growth rates to evaluate school performance enables schools that would otherwise be deemed low performing to demonstrate positive effects on student achievement. Implications for state accountability systems are discussed.

  16. A study of the HEB longitudinal dynamics

    International Nuclear Information System (INIS)

    Larson, D.J.

    1993-12-01

    A study of the High Energy Booster (HEB) longitudinal dynamics is presented. Full derivations of ramp dependent longitudinal variables are given. The formulas assume that the input magnetic field and beam longitudinal emittance are known as a function of time, and that either the rf voltage or the rf bucket area are known as a function of time. Once these three inputs are specified, the formulas can be used to calculate values for all other longitudinal dynamics variables. The formulas have been incorporated into a single computer code named ELVIRA: Evaluation of Longitudinal Variables in Relativistic Accelerators. The ELVIRA code is documented here in detail. The ELVIRA code is used under two initial longitudinal emittance assumptions to plot ramp functions for the longitudinal dynamics design of the HEB as of May 5, 1992

  17. Protocol for the modeling the epidemiologic transition study: a longitudinal observational study of energy balance and change in body weight, diabetes and cardiovascular disease risk

    Directory of Open Access Journals (Sweden)

    Luke Amy

    2011-12-01

    Full Text Available Abstract Background The prevalence of obesity has increased in societies of all socio-cultural backgrounds. To date, guidelines set forward to prevent obesity have universally emphasized optimal levels of physical activity. However there are few empirical data to support the assertion that low levels of energy expenditure in activity is a causal factor in the current obesity epidemic are very limited. Methods/Design The Modeling the Epidemiologic Transition Study (METS is a cohort study designed to assess the association between physical activity levels and relative weight, weight gain and diabetes and cardiovascular disease risk in five population-based samples at different stages of economic development. Twenty-five hundred young adults, ages 25-45, were enrolled in the study; 500 from sites in Ghana, South Africa, Seychelles, Jamaica and the United States. At baseline, physical activity levels were assessed using accelerometry and a questionnaire in all participants and by doubly labeled water in a subsample of 75 per site. We assessed dietary intake using two separate 24-hour recalls, body composition using bioelectrical impedance analysis, and health history, social and economic indicators by questionnaire. Blood pressure was measured and blood samples collected for measurement of lipids, glucose, insulin and adipokines. Full examination including physical activity using accelerometry, anthropometric data and fasting glucose will take place at 12 and 24 months. The distribution of the main variables and the associations between physical activity, independent of energy intake, glucose metabolism and anthropometric measures will be assessed using cross-section and longitudinal analysis within and between sites. Discussion METS will provide insight on the relative contribution of physical activity and diet to excess weight, age-related weight gain and incident glucose impairment in five populations' samples of young adults at different stages

  18. Joint analysis of longitudinal feed intake and single recorded production traits in pigs using a novel horizontal model

    DEFF Research Database (Denmark)

    Shirali, M.; Strathe, A. B.; Mark, T.

    2017-01-01

    - and first-order Legendre polynomials of age on test, respectively. The fixed effect and random residual variance were estimated for each weekly FI trait. Residual feed intake (RFI) was derived from the conditional distribution of FI given the breeding values of ADG100 and LMP. The heritability of FI varied......A novel Horizontal model is presented for multitrait analysis of longitudinal traits through random regression analysis combined with single recorded traits. Weekly ADFI on test for Danish Duroc, Landrace, and Yorkshire boars were available from the national test station and were collected from 30...... to 100 kg BW. Single recorded production traits of ADG from birth to 30 kg BW (ADG30), ADG from 30 to 100 kg BW (ADG100), and lean meat percentage (LMP) were available from breeding herds or the national test station. The Horizontal model combined random regression analysis of feed intake (FI...

  19. Evaluation of elastix-based propagated align algorithm for VOI- and voxel-based analysis of longitudinal F-18-FDG PET/CT data from patients with non-small cell lung cancer (NSCLC)

    OpenAIRE

    Kerner, Gerald S. M. A.; Fischer, Alexander; Koole, Michel J. B.; Pruim, Jan; Groen, Harry J. M.

    2015-01-01

    Background: Deformable image registration allows volume of interest (VOI)- and voxel-based analysis of longitudinal changes in fluorodeoxyglucose (FDG) tumor uptake in patients with non-small cell lung cancer (NSCLC). This study evaluates the performance of the elastix toolbox deformable image registration algorithm for VOI and voxel-wise assessment of longitudinal variations in FDG tumor uptake in NSCLC patients. Methods: Evaluation of the elastix toolbox was performed using F-18-FDG PET/CT ...

  20. Optimization and Analysis of a U-Shaped Linear Piezoelectric Ultrasonic Motor Using Longitudinal Transducers.

    Science.gov (United States)

    Yu, Hongpeng; Quan, Qiquan; Tian, Xinqi; Li, He

    2018-03-07

    A novel U-shaped piezoelectric ultrasonic motor that mainly focused on miniaturization and high power density was proposed, fabricated, and tested in this work. The longitudinal vibrations of the transducers were excited to form the elliptical movements on the driving feet. Finite element method (FEM) was used for design and analysis. The resonance frequencies of the selected vibration modes were tuned to be very close to each other with modal analysis and the movement trajectories of the driving feet were gained with transient simulation. The vibration modes and the mechanical output abilities were tested to evaluate the proposed motor further by a prototype. The maximum output speed was tested to be 416 mm/s, the maximum thrust force was 21 N, and the maximum output power was 5.453 W under frequency of 29.52 kHz and voltage of 100 V rms . The maximum output power density of the prototype reached 7.59 W/kg, which was even greater than a previous similar motor under the exciting voltage of 200 V rms . The proposed motor showed great potential for linear driving of large thrust force and high power density.

  1. Enhancing Brain Lesions during Acute Optic Neuritis and/or Longitudinally Extensive Transverse Myelitis May Portend a Higher Relapse Rate in Neuromyelitis Optica Spectrum Disorders.

    Science.gov (United States)

    Orman, G; Wang, K Y; Pekcevik, Y; Thompson, C B; Mealy, M; Levy, M; Izbudak, I

    2017-05-01

    Neuromyelitis optica spectrum disorders are inflammatory demyelinating disorders with optic neuritis and/or longitudinally extensive transverse myelitis episodes. We now know that neuromyelitis optica spectrum disorders are associated with antibodies to aquaporin-4, which are highly concentrated on astrocytic end-feet at the blood-brain barrier. Immune-mediated disruption of the blood-brain barrier may manifest as contrast enhancement on brain MR imaging. We aimed to delineate the extent and frequency of contrast enhancement on brain MR imaging within 1 month of optic neuritis and/or longitudinally extensive transverse myelitis attacks and to correlate contrast enhancement with outcome measures. Brain MRIs of patients with neuromyelitis optica spectrum disorders were evaluated for patterns of contrast enhancement (periependymal, cloudlike, leptomeningeal, and so forth). The Fisher exact test was used to evaluate differences between the proportion of contrast enhancement in patients who were seropositive and seronegative for aquaporin-4 antibodies. The Mann-Whitney test was used to compare the annualized relapse rate and disease duration between patients with and without contrast enhancement and with and without seropositivity. Brain MRIs of 77 patients were evaluated; 59 patients (10 males, 49 females) were scanned within 1 month of optic neuritis and/or longitudinally extensive transverse myelitis attacks and were included in the analysis. Forty-eight patients were seropositive, 9 were seronegative, and 2 were not tested for aquaporin-4 antibodies. Having brain contrast enhancement of any type during an acute attack was significantly associated with higher annualized relapse rates ( P = .03) and marginally associated with shorter disease duration ( P = .05). Having periependymal contrast enhancement was significantly associated with higher annualized relapse rates ( P = .03). Brain MRIs of patients with neuromyelitis optica spectrum disorders with contrast

  2. A Longitudinal Analysis of Students' Motives for Communicating with Their Instructors

    Science.gov (United States)

    Myers, Scott A.

    2017-01-01

    This study utilized the longitudinal survey research design using students' motives to communicate with their instructors as a test case. Participants were 282 undergraduate students enrolled in introductory communication courses at a large Mid-Atlantic university who completed the Student Communication Motives scale at three points (Time 1:…

  3. The Use of Longitudinal Analysis to Identify More and Less Effective Schools.

    Science.gov (United States)

    Goldberg, Zandra S.; Spartz, James L.

    Three longitudinal studies of student achievement test data were conducted to examine the extent to which the variation in student achievement can be explained by differences in student background (including socioeconomic and prior achievement data) and school resources. This model assumes that achievement test performance may be predicted by…

  4. Analysis of Exhaled Breath for Disease Detection

    Science.gov (United States)

    Amann, Anton; Miekisch, Wolfram; Schubert, Jochen; Buszewski, Bogusław; Ligor, Tomasz; Jezierski, Tadeusz; Pleil, Joachim; Risby, Terence

    2014-06-01

    Breath analysis is a young field of research with great clinical potential. As a result of this interest, researchers have developed new analytical techniques that permit real-time analysis of exhaled breath with breath-to-breath resolution in addition to the conventional central laboratory methods using gas chromatography-mass spectrometry. Breath tests are based on endogenously produced volatiles, metabolites of ingested precursors, metabolites produced by bacteria in the gut or the airways, or volatiles appearing after environmental exposure. The composition of exhaled breath may contain valuable information for patients presenting with asthma, renal and liver diseases, lung cancer, chronic obstructive pulmonary disease, inflammatory lung disease, or metabolic disorders. In addition, oxidative stress status may be monitored via volatile products of lipid peroxidation. Measurement of enzyme activity provides phenotypic information important in personalized medicine, whereas breath measurements provide insight into perturbations of the human exposome and can be interpreted as preclinical signals of adverse outcome pathways.

  5. A Longitudinal Study on Learner Career Advancement in MOOCs

    Science.gov (United States)

    Wang, Yuan; Paquette, Luc; Baker, Ryan

    2014-01-01

    In this paper, we present progress towards a longitudinal study of the post-course career advancement of MOOC learners. We present initial results and analysis plans for how to link this to in-course behaviour, towards better understanding the goals of all MOOC learners.

  6. Monitoring the newly qualified nurses in Sweden: the Longitudinal Analysis of Nursing Education (LANE study

    Directory of Open Access Journals (Sweden)

    Wallin Lars

    2010-04-01

    Full Text Available Abstract Background The Longitudinal Analysis of Nursing Education (LANE study was initiated in 2002, with the aim of longitudinally examining a wide variety of individual and work-related variables related to psychological and physical health, as well as rates of employee and occupational turnover, and professional development among nursing students in the process of becoming registered nurses and entering working life. The aim of this paper is to present the LANE study, to estimate representativeness and analyse response rates over time, and also to describe common career pathways and life transitions during the first years of working life. Methods Three Swedish national cohorts of nursing students on university degree programmes were recruited to constitute the cohorts. Of 6138 students who were eligible for participation, a total of 4316 consented to participate and responded at baseline (response rate 70%. The cohorts will be followed prospectively for at least three years of their working life. Results Sociodemographic data in the cohorts were found to be close to population data, as point estimates only differed by 0-3% from population values. Response rates were found to decline somewhat across time, and this decrease was present in all analysed subgroups. During the first year after graduation, nearly all participants had qualified as nurses and had later also held nursing positions. The most common reason for not working was due to maternity leave. About 10% of the cohorts who graduated in 2002 and 2004 intended to leave the profession one year after graduating, and among those who graduated in 2006 the figure was almost twice as high. Intention to leave the profession was more common among young nurses. In the cohort who graduated in 2002, nearly every fifth registered nurse continued to further higher educational training within the health professions. Moreover, in this cohort, about 2% of the participants had left the nursing

  7. Influence of the measurement method of features in ultrasound images of the thyroid in the diagnosis of Hashimoto’s disease

    Directory of Open Access Journals (Sweden)

    Koprowski Robert

    2012-11-01

    Full Text Available Abstract Introduction This paper shows the influence of a measurement method of features in the diagnosis of Hashimoto’s disease. Sensitivity of the algorithm to changes in the parameters of the ROI, namely shift, resizing and rotation, has been presented. The obtained results were also compared to the methods known from the literature in which decision trees or average gray level thresholding are used. Material In the study, 288 images obtained from patients with Hashimoto’s disease and 236 images from healthy subjects have been analyzed. For each person, an ultrasound examination of the left and right thyroid lobe in transverse and longitudinal sections has been performed. Method With the use of the developed algorithm, a discriminant analysis has been conducted for the following five options: linear, diaglinear, quadratic, diagquadratic and mahalanobis. The left and right thyroid lobes have been analyzed both together and separately in transverse and longitudinal sections. In addition, the algorithm enabled to analyze specificity and sensitivity as well as the impact of sensitivity of ROI shift, repositioning and rotation on the measured features. Results and summary The analysis has shown that the highest accuracy was obtained for the longitudinal section (LD with the method of linear, yielding sensitivity = 76%, specificity = 95% and accuracy ACC = 84%. The conducted sensitivity assessment confirms that changes in the position and size of the ROI have little effect on sensitivity and specificity. The analysis of all cases, that is, images of the left and right thyroid lobes in transverse and longitudinal sections, has shown specificity ranging from 60% to 95% and sensitivity from 62% to 89%. Additionally, it was shown that the value of ACC for the method using decision trees as a classifier is equal to 84% for the analyzed data. Thresholding of average brightness of the ROI gave ACC equal to 76%.

  8. Mesenchymal stem cells can modulate longitudinal changes in cortical thickness and its related cognitive decline in patients with multiple system atrophy

    Science.gov (United States)

    Sunwoo, Mun Kyung; Yun, Hyuk Jin; Song, Sook K.; Ham, Ji Hyun; Hong, Jin Yong; Lee, Ji E.; Lee, Hye S.; Sohn, Young H.; Lee, Jong-Min; Lee, Phil Hyu

    2014-01-01

    Multiple system atrophy (MSA) is an adult-onset, sporadic neurodegenerative disease. Because the prognosis of MSA is fatal, neuroprotective or regenerative strategies may be invaluable in MSA treatment. Previously, we obtained clinical and imaging evidence that mesenchymal stem cell (MSC) treatment could have a neuroprotective role in MSA patients. In the present study, we evaluated the effects of MSC therapy on longitudinal changes in subcortical deep gray matter volumes and cortical thickness and their association with cognitive performance. Clinical and imaging data were obtained from our previous randomized trial of autologous MSC in MSA patients. During 1-year follow-up, we assessed longitudinal differences in automatic segmentation-based subcortical deep gray matter volumes and vertex-wise cortical thickness between placebo (n = 15) and MSC groups (n = 11). Next, we performed correlation analysis between the changes in cortical thickness and changes in the Korean version of the Montreal Cognitive Assessment (MoCA) scores and cognitive performance of each cognitive subdomain using a multiple, comparison correction. There were no significant differences in age at baseline, age at disease onset, gender ratio, disease duration, clinical severity, MoCA score, or education level between the groups. The automated subcortical volumetric analysis revealed that the changes in subcortical deep gray matter volumes of the caudate, putamen, and thalamus did not differ significantly between the groups. The areas of cortical thinning over time in the placebo group were more extensive, including the frontal, temporal, and parietal areas, whereas these areas in the MSC group were less extensive. Correlation analysis indicated that declines in MoCA scores and phonemic fluency during the follow-up period were significantly correlated with cortical thinning of the frontal and posterior temporal areas and anterior temporal areas in MSA patients, respectively. In contrast, no

  9. Longitudinal Associations of Leptin and Adiponectin with Heart Rate Variability in Children

    Directory of Open Access Journals (Sweden)

    Roos Van De Wielle

    2017-07-01

    Full Text Available For early prevention of cardiovascular disease, early detection and risk factor insights are necessary. The autonomic balance reflects cardiovascular risk and can be measured by heart rate variability (HRV. Therefore, our purpose is to examine associations between HRV and the energy-related biomarkers leptin and adiponectin in children. Participants of this study were Belgian children recruited for the longitudinal ChiBS study (year 2010–2012. HRV was measured and fasting blood samples were taken in 249 children at baseline (4.4–11.0 y and 223 children at follow-up (6.7–12.2 y. Cross-sectional and longitudinal linear regression analyses were separated by sex and adjusted for age, socio-economic status, body fat%, negative emotions, puberty, and mean heart rate. Leptin was a negative cross-sectional and longitudinal predictor of parasympathetic activity in boys; while leptin in girls was cross-sectionally associated with higher LF and LF/HF suggesting sympathetic predominance. Adiponectin was a negative cross-sectional and longitudinal predictor of parasympathetic activity in boys; but when adjusting for mean heart rate, this effect disappeared and adiponectin was a positive cross-sectional and longitudinal predictor of parasympathetic activity in girls. These results stress the importance of considering sex differences and adjustment for heart rate in testing HRV predictors. Leptin seemed disadvantageous for the autonomic balance, while adiponectin seemed advantageous for the autonomic balance in girls only. More research is needed to see whether leptin and adiponectin are interesting in cardiovascular screening/prevention or in determining the cardiovascular gain during weight loss follow-up.

  10. Azimuthal asymmetries in semi-inclusive deep-inelastic hadron muoproduction on longitudinally polarized protons

    Energy Technology Data Exchange (ETDEWEB)

    Sirtl, Stefan

    2016-06-27

    In recent years, measuring azimuthal asymmetries in semi-inclusive deep-inelastic scattering (SIDIS) off polarized targets emerged as a powerful tool to investigate the nucleon spin structure, one of the main objectives of the COMPASS physics program. The two-stage COMPASS spectrometer at the CERN SPS is characterized by a large acceptance and a broad kinematic coverage. It makes use of a tertiary longitudinally polarized high-energetic μ{sup +} beam, impinging on a transversely or longitudinally polarized ammonia target. This thesis is dedicated to the analysis of both leading and subleading longitudinal target spin dependent asymmetries arising in the SIDIS cross section of one hadron and hadron pair production. The results provide new insights to the longitudinal spin structure of the nucleon, addressing the role of spin-orbit couplings and quark-gluon correlations in the framework of collinear or transverse momentum dependent factorization.

  11. Applying the Nominal Response Model within a Longitudinal Framework to Construct the Positive Family Relationships Scale

    Science.gov (United States)

    Preston, Kathleen Suzanne Johnson; Parral, Skye N.; Gottfried, Allen W.; Oliver, Pamella H.; Gottfried, Adele Eskeles; Ibrahim, Sirena M.; Delany, Danielle

    2015-01-01

    A psychometric analysis was conducted using the nominal response model under the item response theory framework to construct the Positive Family Relationships scale. Using data from the Fullerton Longitudinal Study, this scale was constructed within a long-term longitudinal framework spanning middle childhood through adolescence. Items tapping…

  12. Progression of brain atrophy in the early stages of Parkinson's disease: a longitudinal tensor-based morphometry study in de novo patients without cognitive impairment.

    Science.gov (United States)

    Tessa, Carlo; Lucetti, Claudio; Giannelli, Marco; Diciotti, Stefano; Poletti, Michele; Danti, Sabrina; Baldacci, Filippo; Vignali, Claudio; Bonuccelli, Ubaldo; Mascalchi, Mario; Toschi, Nicola

    2014-08-01

    The presence of brain atrophy and its progression in early Parkinson's disease (PD) are still a matter of debate, particularly in patients without cognitive impairment. The aim of this longitudinal study was to assess whether PD patients who remain cognitively intact develop progressive atrophic changes in the early stages of the disease. For this purpose, we employed high-resolution T1-weighted MR imaging to compare 22 drug-naïve de novo PD patients without cognitive impairment to 17 age-matched control subjects, both at baseline and at three-year follow-up. We used tensor-based morphometry to explore the presence of atrophic changes at baseline and to compute yearly atrophy rates, after which we performed voxel-wise group comparisons using threshold-free cluster enhancement. At baseline, we did not observe significant differences in regional atrophy in PD patients with respect to control subjects. In contrast, PD patients showed significantly higher yearly atrophy rates in the prefrontal cortex, anterior cingulum, caudate nucleus, and thalamus when compared to control subjects. Our results indicate that even cognitively preserved PD patients show progressive cortical and subcortical atrophic changes in regions related to cognitive functions and that these changes are already detectable in the early stages of the disease. Copyright © 2014 Wiley Periodicals, Inc.

  13. X-ray analysis in lung leptospira disease

    International Nuclear Information System (INIS)

    Deng Shiyong; Peng Shi; He Guoman

    2006-01-01

    Objective: To analysis the X-ray signs and subtype of the lung leptospira disease, and improve the undersdand, reduce the error diagnosis of this diseases. Methods: 40 cases of lung leptospira disease were evaluated about the check X-ray sings and clinical data, the check X-ray sings were dynamic observated and typed, and 40 cases had a diagnostic treatment. Results: There were various X-ray changes of lung leptospira disease. in 40 cases, 12 cases (30%) pulmonary marking, 21 cases (52%) little lesions, and 7 cases(18%) lager lesions, respectively. The patients who were correctly diagnosed made a recovery after effective treatment, the patients who were error diagnosed died because of multiple system organ damage. Conclusion: The check X-ray signs in lung leptospira disease have some characteristics. It may play an important role in improving this disease' diagnosis combining the dynamic observation of check X-ray sings with clinical data. (authors)

  14. Effect of longitudinal vibration of fluid-filled pipe with elastic wall on sound transmission character

    Directory of Open Access Journals (Sweden)

    DONG Peng

    2017-01-01

    Full Text Available When one end of a fluid-filled pipe with an elastic wall is fixed and a harmonic force effect acts on the other end,a steady longitudinal vibration will be produced. Compared to the pipeline resonance mode,the amplitude of the steady longitudinal vibration of an elastic pipe is greater,and the effect on the sound is also greater. The study of the steady longitudinal vibration of pipes can better describe the effects of fluid-filled pipelines on the radiation sound field of the pipe opening. Through the contrast between the analysis calculation of the equivalent beam model and the experimental results,the accuracy of the equivalent beam model for the calculation of the steady longitudinal vibration of pipelines is verified,and a method of isolating the steady longitudinal vibration state is proposed and verified.

  15. Capabilities of R Package mixAK for Clustering Based on Multivariate Continuous and Discrete Longitudinal Data

    Directory of Open Access Journals (Sweden)

    Arnošt Komárek

    2014-09-01

    Full Text Available R package mixAK originally implemented routines primarily for Bayesian estimation of finite normal mixture models for possibly interval-censored data. The functionality of the package was considerably enhanced by implementing methods for Bayesian estimation of mixtures of multivariate generalized linear mixed models proposed in Komrek and Komrkov (2013. Among other things, this allows for a cluster analysis (classification based on multivariate continuous and discrete longitudinal data that arise whenever multiple outcomes of a different nature are recorded in a longitudinal study. This package also allows for a data-driven selection of a number of clusters as methods for selecting a number of mixture components were implemented. A model and clustering methodology for multivariate continuous and discrete longitudinal data is overviewed. Further, a step-by-step cluster analysis based jointly on three longitudinal variables of different types (continuous, count, dichotomous is given, which provides a user manual for using the package for similar problems.

  16. Substance abuse and quality of life among severely mentally ill consumers: a longitudinal modelling analysis.

    Science.gov (United States)

    Urbanoski, Karen A; Cairney, John; Adlaf, Edward; Rush, Brian

    2007-10-01

    Evidence suggests that substance abuse negatively affects both psychiatric symptom severity and quality of life (QOL) in people with severe mental illness (SMI). However, these relationships have not been examined simultaneously, nor have they been characterized over time. Thus, it is difficult to appreciate the extent to which substance abuse exerts an enduring effect on psychiatric symptoms and distress and/or QOL in this population. The purpose of this study is to test a conceptual model linking these factors together. Subjects were participants in a longitudinal evaluation of community mental healthcare in Ontario (n = 133). Comprehensive consumer assessments were conducted at treatment entry, and at 9 and 18 months. Subjects were receiving intensive case management or assertive community treatment throughout the 18-month study period. Structural equation modelling was used to examine the concurrent and longitudinal relationships between substance abuse, symptoms and distress, and QOL. The prevalence of substance abuse was 55.0%. The SEM analysis suggested that substance abuse at baseline was associated with elevated symptomatology and distress and lower QOL, and that these effects endured after 18 months of treatment. Psychiatric symptoms and distress mediated the negative relationship between substance abuse and QOL. The mediating role played by symptom and distress levels in the relationship between substance abuse and QOL suggests the importance of closely monitoring changes in these factors among SMI patients with substance problems. Tracking symptom severity and distress levels over time will allow service providers to intervene and potentially improve the QOL of individuals with SMI.

  17. Bolted flanged connections subjected to longitudinal bending moments

    International Nuclear Information System (INIS)

    Blach, A.E.

    1992-01-01

    Flanges in piping systems and also pressure vessel flanges on tall columns are often subjected to longitudinal bending moments of considerable magnitude, be it from thermal expansion stresses in piping systems or from wind or seismic loadings on tall vertical pressure vessels. Except for the ASME Code, Section III, Subsections NB, NC, and ND, other pressure vessel and piping codes do not contain design ASME Nuclear Power Plant Code (Section III), an empirical formula is given, expressing a longitudinal bending moment in bolted flanged connections in terms of an equivalent internal pressure to be added to the design pressure of the flange. In this paper, an attempt is made to analyse the stresses on flanges and bolting due to external bending moments and to compare flange thicknesses thus obtained with thicknesses required using the equivalent design pressure specified in Subsections NB, NC, and ND. A design method is proposed, based on analysis and experimental work, which may be suitable for flange bending moment analysis when the rules of the Nuclear Power Plant Code are not mandatory. (orig.)

  18. The ONS Longitudinal Study--a prestigious past and a bright future.

    Science.gov (United States)

    Goldring, Shayla; Newman, Jim

    2010-01-01

    This issue of Population Trends includes a number of articles and reports resulting from research based on the ONS Longitudinal Study (ONS LS). They have been drawn together in one issue to highlight the value of this type of study for demographic research.2009 marked the 35th anniversary of the establishment of the ONS LS. The study now contains data from the last four censuses (1971 to 2001), linked to vital events data since 1971, for a sample of one per cent of the population of England and Wales.More recently, sister studies have been established in Scotland and Northern Ireland. The Scottish Longitudinal Study (SLS) started with 1991 Census data and the Northern Ireland Longitudinal Study (NILS)started with 2001 Census data.The lead article in this issue comes from an exemplar project that was established to explore how to utilise the three studies to carry out UK-wide longitudinal analysis. Two different methods were used to analyse socio-economic and country level differences in health and mortality across the studies. The article summarises the results of this analysis, reports on the relative strengths of the different methods used, and draws attention to a number of new resources that have been developed by the project researchers as aids to using all three studies.This is an excellent example of collaborative working across the UK, involving researchers from the Centre for Longitudinal Study Information and User Support (CeLSIUS) at the London School of Hygiene and Tropical Medicine, the Longitudinal Studies Centre - Scotland (LSCS) at the University of St.Andrews and the Northern Ireland Longitudinal Study - Research Support Unit (NILS-RSU) at Queen's University Belfast. The project also involved collaboration between ONS, the General Register Office for Scotland (GROS) and the Northern Ireland Statistics and Research Agency (NISRA) to ensure the secure transfer and handling of data from the three studies so that it could be brought together in one

  19. Cancer and autoimmunity: Harnessing longitudinal cohorts to probe the link.

    Science.gov (United States)

    Egiziano, Giordano; Bernatsky, Sasha; Shah, Ami A

    2016-02-01

    In many autoimmune rheumatic diseases, there is an increased risk of cancer compared to the general population. While reasons for this increased risk have not been elucidated, it has been hypothesized that the link between cancer and autoimmunity may be bidirectional. For instance, chronic inflammation and damage from the rheumatic disease or its therapies may trigger malignant transformation; conversely, antitumor immune responses targeting cancers may become cross-reactive resulting in autoimmunity. In rare rheumatic diseases, longitudinal observational studies can play a critical role in studying these complex relationships, thereby enabling investigators to quantify the extent of cancer risk, identify unique clinical phenotypes associated with cancer, investigate the biological link between these conditions, and define optimal strategies for screening and treatment of the underlying cancer. In this review, we discuss recent data on cancer in the rheumatic diseases and suggest a research agenda to address several gaps in our current knowledge base. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. The importance of longitudinal studies in family medicine: experiences of two practice-based research networks.

    NARCIS (Netherlands)

    Weel, C. van; Weel-Baumgarten, E.M. van; Mold, J.

    2006-01-01

    BACKGROUND: For evidence-based decision making in family practice, it is essential to know the long-term (natural) course of common diseases and their outcomes under care and treatment. This article, based on a research methodology workshop, aims to raise awareness and interest in longitudinal

  1. Longitudinal recovery following distal radial fractures managed with volar plate fixation.

    Science.gov (United States)

    Stinton, S B; Graham, P L; Moloney, N A; Maclachlan, L R; Edgar, D W; Pappas, E

    2017-12-01

    To synthesise the literature and perform a meta-analysis detailing the longitudinal recovery in the first two years following a distal radius fracture (DRF) managed with volar plate fixation. Three databases were searched to identify relevant articles. Following eligibility screening and quality assessment, data were extracted and outcomes were assimilated at the post-operative time points of interest. A state-of-the-art longitudinal mixed-effects meta-analysis model was employed to analyse the data. The search identified 5698 articles, of which 46 study reports met the selection criteria. High levels of disability and impairment were reported in the immediate post-operative period with subsequently a rapid initial improvement followed by more gradual improvement for up to one year. The results highlight that the period associated with the greatest physical recovery is in the first three months and suggest that the endpoint of treatment outcomes is best measured at one year post-surgery. Clinically meaningful improvements in outcomes can be expected for 12 months, after which progress plateaus and reaches normal values. This paper adopted a novel approach to meta-analyses in that the research question was of a longitudinal nature, which required a unique method of statistical analysis. Cite this article: Bone Joint J 2017;99-B:1665-76. ©2017 The British Editorial Society of Bone & Joint Surgery.

  2. A New Approach to Assess Lifetime Dietary Patterns Finds Lower Consumption of Animal Foods with Aging in a Longitudinal Analysis of a Health-Oriented Adventist Population

    Science.gov (United States)

    Martins, Marcia C. T.; Jaceldo-Siegl, Karen; Fan, Jing; Mashchak, Andrew

    2017-01-01

    Life-course diet patterns may impact risk of disease, but little is known about dietary trends with aging. In a retrospective longitudinal analysis we estimated lifetime intake of animal products and adherence to vegetarian dietary patterns among 51,082 Adventist Health Study-2 (AHS-2) subjects using data from a reliable life-course dietary (meats, dairy, eggs) questionnaire. Results showed a marked tendency to consume fewer animal products (in total) in older years and to reduce consumption of meat, poultry and fish, but not eggs or dairy. Among the 29% of elderly subjects who during their lifetime kept the same dietary pattern (LTS) were: LTS-vegans (1.1%), LTS-lacto-ovo vegetarians (31.2%), LTS-pesco vegetarians (0.49%), LTS-semi vegetarians (3.7%), and LTS-non-vegetarians (63.5%). Among the 71% of switchers were “Converters” (59.7%) who moved towards and “Reverters” (9.1%) who moved away from vegetarian diets, and Multiverters (31.2%), who had moved in both directions. LTS-non-vegetarians, and also reverters, were more overweight and showed a less healthy lifestyle than others. We conclude that the dietary patterns are dynamic with strong trends to reduce animal foods and to adopt more vegetarian patterns with aging. The disease experience of subjects with different lifetime dietary patterns can be compared. PMID:29027960

  3. Data-driven identification of intensity normalization region based on longitudinal coherency of 18F-FDG metabolism in the healthy brain.

    Science.gov (United States)

    Zhang, Huiwei; Wu, Ping; Ziegler, Sibylle I; Guan, Yihui; Wang, Yuetao; Ge, Jingjie; Schwaiger, Markus; Huang, Sung-Cheng; Zuo, Chuantao; Förster, Stefan; Shi, Kuangyu

    2017-02-01

    analysis strategies (subject-based and age-cohort averaging). In addition, the proposed new intensity normalization method using the paracentral lobule generates significantly higher differentiation from the age-associated changes than other intensity normalization methods. Proper intensity normalization can enhance the longitudinal coherency of normal brain glucose metabolism. The paracentral lobule followed by the cerebellar tonsil are shown to be the two most stable intensity normalization regions concerning age-dependent brain metabolism. This may provide the potential to better differentiate disease-related changes from age-related changes in brain metabolism, which is of relevance in the diagnosis of neurodegenerative disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Cross-sectional and longitudinal associations of motor fluctuations and non-motor predominance with cerebrospinal τ and Aβ as well as dementia-risk in Parkinson's disease.

    Science.gov (United States)

    Modreanu, Raluca; Cerquera, Sonia Catalina; Martí, María José; Ríos, José; Sánchez-Gómez, Almudena; Cámara, Ana; Fernández, Manel; Compta, Yaroslau

    2017-02-15

    Experimental, neuropathological and cerebrospinal fluid (CSF) studies support τ and amyloid-β (Aβ) relevance in Parkinson's disease (PD) related dementia. Lesser motor fluctuations (MFs) and non-motor features have also been related to PD-dementia. Yet, little is known about the association of MFs and non-motor symptoms with CSF τ and Aβ in PD. We hypothesized that lesser MFs and non-motor predominance are related to these CSF markers and dementia-risk in PD. We studied 58 PD patients (dementia at baseline, n=21; dementia at 18-months, n=35) in whom CSF Aβ and τ had been determined with ELISA techniques. MFs and a number of non-motor symptoms (apathy, anxiety, irritability, depression, visual hallucinations, spatial disorientation, memory complaints) over disease course were dichotomized as absent-mild vs. moderate-severe by retrospective clinical chart review blind to CSF findings. Non-motor predominance was defined as ≥3 non-motor symptoms (after the cohort-median of non-motor symptoms per patient) with ≥2 being moderate-severe and ≥1 having been present from onset, with all these being more disabling overall than motor features. Cross-sectionally, CSF biomarkers were non-parametrically compared according to dichotomized MFs and non-motor predominance. Longitudinally, dementia was the outcome (dependent variable), CSF markers, MFs and non-motor predominance were the predictors (independent variables), and potential modifiers as age, sex, and memory complaints were the covariates in binary regression models. Absent-mild MFs were associated with higher CSF τ markers and shorter time-to-dementia, while non-motor predominance and decreasing CSF Aβ independently increased longitudinal dementia-risk. In summary, absent-mild MFs, non-motor predominance and CSF τ and Aβ might define endophenotypes related to the timing or risk of dementia in PD. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Spinal cord injury and Parkinson's disease: a population-based, propensity score-matched, longitudinal follow-up study.

    Science.gov (United States)

    Yeh, T-S; Huang, Y-P; Wang, H-I; Pan, S-L

    2016-12-01

    To investigate whether patients with spinal cord injury (SCI) are at an increased risk of developing Parkinson's disease (PD). A population-based, propensity score-matched, longitudinal follow-up cohort study. The study was conducted using the National Health Insurance (NHI) Research Database. A total of 10 125 patients with at least 2 ambulatory visits with a diagnosis of SCI in 2001 were enrolled in the SCI group. The non-SCI group comprised 10 125 propensity score-matched patients without SCI. The propensity scores were computed using a logistic regression model that included age, sex, comorbidities and socioeconomic status. The PD-free survival rates of the two groups were estimated using the Kaplan-Meier method. Stratified Cox proportional hazard regression was used to estimate the effect of SCI on subsequent occurrence of PD. During the 3-year follow-up period, 99 subjects in the SCI group and 59 in the non-SCI group developed PD. The hazard ratio of PD for the SCI group compared with the non-SCI group was 1.65 (95% confidence interval 1.16-2.33, P=0.0049). The PD-free survival rate for the SCI group was lower than that for the non-SCI group (P=0.0017). This study shows that SCI is associated with a subsequent increased risk of PD. Further studies are needed to elucidate the mechanism underlying this association.

  6. Effectiveness of diffusion tensor imaging in differentiating early-stage subcortical ischemic vascular disease, Alzheimer's disease and normal ageing.

    Directory of Open Access Journals (Sweden)

    Min-Chien Tu

    Full Text Available To describe and compare diffusion tensor imaging (DTI parameters between patients with subcortical ischemic vascular disease (SIVD and Alzheimer's disease (AD diagnosed using structuralized neuropsychiatric assessments, and investigate potential neuronal substrates related to cognitive performance.Thirty-five patients with SIVD, 40 patients with AD, and 33 cognitively normal control (NC subjects matched by age and education level were consecutively recruited and underwent cognitive function assessments and DTI examinations. Comparisons among these three subgroups with regards to cognitive performance and DTI parameters including fractional anisotropy (FA and mean diffusivity (MD values were performed. Partial correlation analysis after controlling for age and education was used to evaluate associations between cognitive performance and DTI parameters.With regards to cognitive performance, the patients with SIVD had lower total scores in frontal assessment battery (FAB compared to those with AD (p < 0.05 in the context of comparable Mini-Mental Status Examination and Cognitive Abilities Screening Instrument scores. With regards to DTI parameters, there were more regions of significant differences in FA among these three subgroups compared with MD. Compared with NC group, the patients with SIVD had significant global reductions in FA (p < 0.001 ~ 0.05, while significant reductions in FA among the patients with AD were regionally confined within the left superior longitudinal fasciculus, genu and splenium of the corpus callosum, and bilateral forceps major, and the anterior thalamic radiation, uncinate fasciculus, and cingulum of the left side (p < 0.01 ~ 0.05. Analysis of FA values within the left forceps major, left anterior thalamic radiation, and genu of the corpus callosum revealed a 71.8% overall correct classification (p < 0.001 with sensitivity of 69.4%, specificity of 73.8%, positive predictive value of 69.4%, and negative predictive value

  7. Engagement in Pleasant Leisure Activities and Blood Pressure: A 5-Year Longitudinal Study in Alzheimer Caregivers.

    Science.gov (United States)

    Mausbach, Brent T; Romero-Moreno, Rosa; Bos, Taylor; von Känel, Roland; Ziegler, Michael G; Allison, Matthew A; Mills, Paul J; Dimsdale, Joel E; Ancoli-Israel, Sonia; Losada, Andrés; Márquez-González, María; Patterson, Thomas L; Grant, Igor

    2017-09-01

    Elevated blood pressure is a significant public health concern, particularly given its association with cardiovascular disease risk, including stroke. Caring for a loved one with Alzheimer disease has been associated with physical health morbidity, including higher blood pressure. Engagement in adaptive coping strategies may help prevent blood pressure elevation in this population. This 5-year longitudinal study examined whether greater participation in pleasant leisure activities was associated with reduced blood pressure in caregivers. Participants were 126 in-home spousal Alzheimer's caregivers (M [SD] age = 74.2 [7.9] years) that completed five yearly assessments. Linear mixed-effects models analysis was used to examine the longitudinal relationship between pleasant leisure activities and caregivers' blood pressure, after adjusting for demographic and health characteristics. Greater engagement in pleasant leisure activities was associated with reduced mean arterial blood pressure (B = -0.08, SE = 0.04, p = .040). Follow-up analyses indicated that engagement in activities was significantly associated with reduced diastolic (B = -0.07, SE = 0.03, p = .030) but not systolic blood pressure (B = -0.10, SE = 0.06, p = .114). In addition, mean arterial blood pressure was significantly reduced when caregiving duties ended because of placement of care recipients in nursing homes (B = -3.10, SE = 1.11, p = .005) or death of the care recipient (B = -2.64, SE = 1.14, p = .021). Greater engagement in pleasant leisure activities was associated with lowered caregivers' blood pressure over time. Participation in pleasant leisure activities may have cardiovascular health benefits for Alzheimer's caregivers.

  8. Alzheimer Disease Cerebrospinal Fluid Biomarkers Moderate Baseline Differences and Predict Longitudinal Change in Attentional Control and Episodic Memory Composites in the Adult Children Study

    Science.gov (United States)

    Aschenbrenner, Andrew J.; Balota, David A.; Fagan, Anne M.; Duchek, Janet M.; Benzinger, Tammie L.S.; Morris, John C.

    2015-01-01

    Objective Cognitive measures that are sensitive to biological markers of Alzheimer disease (AD) pathology are needed in order to (a) facilitate preclinical staging, (b) identify individuals who are at the highest risk for developing clinical symptoms and (c) serve as endpoints for evaluating the efficacy of interventions. The present study assesses the utility of two cognitive composite scores of attentional control and episodic memory as markers for preclinical AD pathology in a group of cognitively normal older adults (N = 238), as part of the Adult Children Study. Method All participants were given a baseline cognitive assessment and follow-up assessments every 3 years over an 8-year period, as well as a lumbar puncture within two years of the initial assessment to collect cerebrospinal fluid (CSF) and a PET-PIB scan for amyloid imaging. Results Results indicated that attentional control was correlated with levels of Aβ42 at the initial assessment whereas episodic memory was not. Longitudinally, individuals with high CSF tau exhibited a decline in both attention and episodic memory over the course of the study. Conclusion These results indicate that measures of attentional control and episodic memory can be utilized to evaluate cognitive decline in preclinical AD and provide support that CSF tau may be a key mechanism driving longitudinal cognitive change. PMID:26416094

  9. Forecasting and Analyzing the Disease Burden of Aged Population in China, Based on the 2010 Global Burden of Disease Study

    Directory of Open Access Journals (Sweden)

    Chengzhen Bao

    2015-06-01

    Full Text Available Background: Forecasting the disease burden of the elderly will contribute to make a comprehensive assessment about physical and mental status of the elderly in China and provide a basis for reducing the negative consequences of aging society to a minimum. Methods: This study collected data from a public database online provided by Global Burden of Disease Study 2010. Grey model GM (1, 1 was used to forecast all-cause and disease-specific rates of disability adjusted life years (DALYs in 2015 and 2020. Results: After cross-sectional and longitudinal analysis, we found that non-communicable diseases (NCDs were still the greatest threats in the elderly, followed by injuries. As for 136 predicted causes, more than half of NCDs increased obviously with age, less than a quarter of communicable, material, neonatal, and nutritional disorders or injuries had uptrend. Conclusions: The findings display the health condition of the Chinese elderly in the future, which will provide critical information for scientific and sociological researches on preventing and reducing the risks of aging society.

  10. On Longitudinal Spectral Coherence

    DEFF Research Database (Denmark)

    Kristensen, Leif

    1979-01-01

    It is demonstrated that the longitudinal spectral coherence differs significantly from the transversal spectral coherence in its dependence on displacement and frequency. An expression for the longitudinal coherence is derived and it is shown how the scale of turbulence, the displacement between ...... observation sites and the turbulence intensity influence the results. The limitations of the theory are discussed....

  11. Intelligent control for braking-induced longitudinal vibration responses of floating-type railway bridges

    Science.gov (United States)

    Qu, Wei-Lian; Qin, Shun-Quan; Tu, Jian-Weia; Liu, Jia; Zhou, Qiang; Cheng, Haibin; Pi, Yong-Lin

    2009-12-01

    This paper presents an intelligent control method and its engineering application in the control of braking-induced longitudinal vibration of floating-type railway bridges. Equations of motion for the controlled floating-type railway bridges have been established based on the analysis of the longitudinal vibration responses of floating-type railway bridges to train braking and axle-loads of moving trains. For engineering applications of the developed theory, a full-scale 500 kN smart magnetorheologic (MR) damper has been designed, fabricated and used to carry out experiments on the intelligent control of braking-induced longitudinal vibration. The procedure for using the developed intelligent method in conjunction with the full-scale 500 kN MR dampers has been proposed and used to control the longitudinal vibration responses of the deck of floating-type railway bridges induced by train braking and axle-loads of moving trains. This procedure has been applied to the longitudinal vibration control of the Tian Xingzhou highway and railway cable-stayed bridge over the Yangtze River in China. The simulated results have shown that the intelligent control system using the smart MR dampers can effectively control the longitudinal response of the floating-type railway bridge under excitations of braking and axle-loads of moving trains.

  12. Intelligent control for braking-induced longitudinal vibration responses of floating-type railway bridges

    International Nuclear Information System (INIS)

    Qu, Wei-Lian; Tu, Jian-Weia; Liu, Jia; Zhou, Qiang; Qin, Shun-Quan; Cheng, Haibin; Pi, Yong-Lin

    2009-01-01

    This paper presents an intelligent control method and its engineering application in the control of braking-induced longitudinal vibration of floating-type railway bridges. Equations of motion for the controlled floating-type railway bridges have been established based on the analysis of the longitudinal vibration responses of floating-type railway bridges to train braking and axle-loads of moving trains. For engineering applications of the developed theory, a full-scale 500 kN smart magnetorheologic (MR) damper has been designed, fabricated and used to carry out experiments on the intelligent control of braking-induced longitudinal vibration. The procedure for using the developed intelligent method in conjunction with the full-scale 500 kN MR dampers has been proposed and used to control the longitudinal vibration responses of the deck of floating-type railway bridges induced by train braking and axle-loads of moving trains. This procedure has been applied to the longitudinal vibration control of the Tian Xingzhou highway and railway cable-stayed bridge over the Yangtze River in China. The simulated results have shown that the intelligent control system using the smart MR dampers can effectively control the longitudinal response of the floating-type railway bridge under excitations of braking and axle-loads of moving trains

  13. Analysis of Dose Response for Circulatory Disease After Radiotherapy for Benign Disease

    Energy Technology Data Exchange (ETDEWEB)

    Little, Mark P., E-mail: mark.little@nih.gov [Radiation Epidemiology Branch, National Cancer Institute, Executive Plaza South, Rockville, Maryland (United States); Kleinerman, Ruth A. [Radiation Epidemiology Branch, National Cancer Institute, Executive Plaza South, Rockville, Maryland (United States); Stovall, Marilyn; Smith, Susan A. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mabuchi, Kiyohiko [Radiation Epidemiology Branch, National Cancer Institute, Executive Plaza South, Rockville, Maryland (United States)

    2012-12-01

    Purpose: To assess the shape of the dose-response for various circulatory disease endpoints, and modifiers by age and time since exposure. Methods and Materials: This was an analysis of the US peptic ulcer data testing for heterogeneity of radiogenic risk by circulatory disease endpoint (ischemic heart, cerebrovascular, other circulatory disease). Results: There were significant excess risks for all circulatory disease, with an excess relative risk Gy{sup -1} of 0.082 (95% CI 0.031-0.140), and ischemic heart disease, with an excess relative risk Gy{sup -1} of 0.102 (95% CI 0.039-0.174) (both p = 0.01), and indications of excess risk for stroke. There were no statistically significant (p > 0.2) differences between risks by endpoint, and few indications of curvature in the dose-response. There were significant (p < 0.001) modifications of relative risk by time since exposure, the magnitude of which did not vary between endpoints (p > 0.2). Risk modifications were similar if analysis was restricted to patients receiving radiation, although the relative risks were slightly larger and the risk of stroke failed to be significant. The slopes of the dose-response were generally consistent with those observed in the Japanese atomic bomb survivors and in occupationally and medically exposed groups. Conclusions: There were excess risks for a variety of circulatory diseases in this dataset, with significant modification of risk by time since exposure. The consistency of the dose-response slopes with those observed in radiotherapeutically treated groups at much higher dose, as well as in lower dose-exposed cohorts such as the Japanese atomic bomb survivors and nuclear workers, implies that there may be little sparing effect of fractionation of dose or low-dose-rate exposure.

  14. Impact of Perinatally Acquired HIV Disease Upon Longitudinal Changes in Memory and Executive Functioning.

    Science.gov (United States)

    Malee, Kathleen M; Chernoff, Miriam C; Sirois, Patricia A; Williams, Paige L; Garvie, Patricia A; Kammerer, Betsy L; Harris, Lynnette L; Nozyce, Molly L; Yildirim, Cenk; Nichols, Sharon L

    2017-08-01

    Little is known regarding effects of perinatally acquired HIV infection (PHIV) on longitudinal change in memory and executive functioning (EF) during adolescence despite the importance of these skills for independence in adulthood. PHIV (n = 144) and perinatally HIV-exposed uninfected youth (PHEU, n = 79), ages 12-17, completed standardized tests of memory and EF at baseline and 2 years later. Changes from baseline for each memory and EF outcome were compared between PHEU and PHIV youth with (PHIV/C, n = 39) and without (PHIV/non-C, n = 105) history of CDC class C (AIDS-defining) diagnoses. Among PHIV youth, associations of baseline and past disease severity with memory and EF performance at follow-up were evaluated using adjusted linear regression models. Participants were primarily black (79%); 16% were Hispanic; 55% were female. Mean memory and EF scores at follow-up generally fell in the low-average to average range. Pairwise comparison of adjusted mean change from baseline to follow-up revealed significantly greater change for PHIV/non-C compared with PHEU youth in only one verbal recognition task, with a difference in mean changes for PHIV/non-C versus PHEU of -0.99 (95% CI: -1.80 to -0.19; P = 0.02). Among youth with PHIV, better immunologic status at baseline was positively associated with follow-up measures of verbal recall and recognition and cognitive inhibition/flexibility. Past AIDS-defining diagnoses and higher peak viral load were associated with lower performance across multiple EF tasks at follow-up. Youth with PHIV demonstrated stable memory and EF during a 2-year period of adolescence, allowing cautious optimism regarding long-term outcomes.

  15. Personality traits and chronic disease: implications for adult personality development.

    Science.gov (United States)

    Sutin, Angelina R; Zonderman, Alan B; Ferrucci, Luigi; Terracciano, Antonio

    2013-11-01

    Personality traits have been associated with chronic disease. Less is known about the longitudinal relation between personality and disease and whether chronic disease is associated with changes in personality. Method. Participants from the Baltimore Longitudinal Study of Aging (N = 2,008) completed the Revised NEO Personality Inventory and a standard medical interview at regularly scheduled visits; the Charlson Comorbidity Index, a weighted sum of 19 serious diseases, was derived from this interview. Using data from 6,685 visits, we tested whether personality increased risk of disease and whether disease was associated with personality change. Measured concurrently, neuroticism and conscientiousness were associated with greater disease burden. The impulsiveness facet of neuroticism was the strongest predictor of developing disease across the follow-up period: For every standard deviation increase in impulsiveness, there was a 26% increased risk of developing disease and a 36% increased risk of getting more ill. Personality traits changed only modestly with disease: As participants developed chronic illnesses, they became more conservative (decreased openness). Discussion. This research indicates that personality traits confer risk for disease, in part, through health-risk behaviors. These traits, however, were relatively resistant to the effect of serious disease.

  16. Alcohol consumption and risk of fatty liver disease: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Guoli Cao

    2016-10-01

    Full Text Available Background Observational studies have shown inconsistent results regarding alcohol consumption and risk of fatty liver. We performed a meta-analysis of published literature to investigate the association between alcohol consumption and fatty liver disease (FLD. Methods We searched Medline, Embase, Web of Science, and several Chinese databases, identifying studies that reported an association between alcohol consumption and the risk of FLD. Results A total of 16 studies with 76,608 participants including 13 cross-sectional studies, two cross-sectional following longitudinal studies, and one cohort study met the inclusion criteria. For light to moderate alcohol consumption (LMAC, there was a 22.6% reduction in risk of FLD (odds ratio [OR] = 0.774, 95% confidence interval CI [0.695–0.862], P <0.001, and subgroup analysis showed that a greater reduction in risk of FLD was found in the female drinkers (30.2% and the drinkers with BMI ≥25 kg/m2(31.3% compared with the male drinkers (22.6% and the drinkers with BMI <25 kg/m2(21.3%, respectively. For heavy alcohol consumption, there was no significant influence on risk of FLD (OR = 0.869, 95% CI [0.553–1.364], P = 0.541 in Japanese women, but there was a 33.7% reduction in risk of FLD (OR = 0.663, 95% CI [0.574–0.765], P < 0.001 in Japanese men and a significant increased risk of FLD (OR = 1.785, 95% CI [1.064–2.996], P = 0.028 in Germans. Conclusion LMAC is associated with a significant protective effect on FLD in the studied population, especially in the women and obese population. However, the effect of heavy alcohol consumption on FLD remains unclear due to limited studies and small sample sizes.

  17. A longitudinal analysis of regional brain volumes in macaques exposed to X-irradiation in early gestation.

    Directory of Open Access Journals (Sweden)

    Kristina Aldridge

    Full Text Available Early gestation represents a period of vulnerability to environmental insult that has been associated with adult psychiatric disease. However, little is known about how prenatal perturbation translates into adult brain dysfunction. Here, we use a longitudinal study design to examine the effects of disruption of early gestational neurogenesis on brain volume in the non-human primate.Five Rhesus macaques were exposed to x-irradiation in early gestation (E30-E41, and four control monkeys were sham-irradiated at comparable ages. Whole brain magnetic resonance imaging was performed at 6 months, 12 months, and 3 and 5 years of age. Volumes of whole cerebrum, cortical gray matter, caudate, putamen, and thalamus were estimated using semi-automated segmentation methods and high dimensional brain mapping. Volume reductions spanning all ages were observed in irradiated monkeys in the putamen (15-24%, p = 0.01 and in cortical gray matter (6-15%, p = 0.01. Upon covarying for whole cerebral volume, group differences were reduced to trend levels (putamen: p = 0.07; cortical gray matter: p = 0.08. No group-by-age effects were significant.Due to the small number of observations, the conclusions drawn from this study must be viewed as tentative. Early gestational irradiation may result in non-uniform reduction of gray matter, mainly affecting the putamen and cerebral cortex. This may be relevant to understanding how early prenatal environmental insult could lead to brain morphological differences in neurodevelopmental diseases.

  18. A retrospective analysis of longitudinal changes in bone mineral content in cystic fibrosis.

    Science.gov (United States)

    Chirita-Emandi, Adela; Shepherd, Sheila; Kyriakou, Andreas; McNeilly, Jane D; Dryden, Carol; Corrigan, Donna; Devenny, Anne; Ahmed, Syed Faisal

    2017-08-28

    We aimed to describe the longitudinal changes in bone mineral content and influencing factors, in children with cystic fibrosis (CF). One hundred children (50 females) had dual X-ray absorptiometry (DXA) performed. Of these, 48 and 24 children had two to three scans, respectively over 10 years of follow-up. DXA data were expressed as lumbar spine bone mineral content standard deviation score (LSBMCSDS) adjusted for age, gender, ethnicity and bone area. Markers of disease, anthropometry and bone biochemistry were collected retrospectively. Baseline LSBMCSDS was >0.5 SDS in 13% children, between -0.5; 0.5 SDS, in 50% and ≤-0.5 in the remainder. Seventy-eight percent of the children who had baseline LSBMCSDS >-0.5, and 35% of the children with poor baseline (LSBMCSDS0.5), showed decreasing values in subsequent assessments. However, mean LS BMC SDS did not show a significant decline in subsequent assessments (-0.51; -0.64; -0.56; p=0.178). Lower forced expiratory volume in 1 s percent (FEV1%) low body mass index standard deviation scores (BMI SDS) and vitamin D were associated with reduction in BMC. Bone mineral content as assessed by DXA is sub-optimal and decreases with time in most children with CF and this study has highlighted parameters that can be addressed to improve bone health.

  19. Framework for Infectious Disease Analysis: A comprehensive and integrative multi-modeling approach to disease prediction and management.

    Science.gov (United States)

    Erraguntla, Madhav; Zapletal, Josef; Lawley, Mark

    2017-12-01

    The impact of infectious disease on human populations is a function of many factors including environmental conditions, vector dynamics, transmission mechanics, social and cultural behaviors, and public policy. A comprehensive framework for disease management must fully connect the complete disease lifecycle, including emergence from reservoir populations, zoonotic vector transmission, and impact on human societies. The Framework for Infectious Disease Analysis is a software environment and conceptual architecture for data integration, situational awareness, visualization, prediction, and intervention assessment. Framework for Infectious Disease Analysis automatically collects biosurveillance data using natural language processing, integrates structured and unstructured data from multiple sources, applies advanced machine learning, and uses multi-modeling for analyzing disease dynamics and testing interventions in complex, heterogeneous populations. In the illustrative case studies, natural language processing from social media, news feeds, and websites was used for information extraction, biosurveillance, and situation awareness. Classification machine learning algorithms (support vector machines, random forests, and boosting) were used for disease predictions.

  20. Mesenchymal stem cells can modulate longitudinal changes in cortical thickness and its related cognitive decline in patients with multiple system atrophy

    Directory of Open Access Journals (Sweden)

    Mun Kyung eSunwoo

    2014-06-01

    Full Text Available Multiple system atrophy (MSA is an adult-onset sporadic neurodegenerative disease. Because the prognosis of MSA is fatal, neuroprotective or regenerative strategies may be invaluable in MSA treatment. Previously, we obtained clinical and imaging evidence that mesenchymal stem cell (MSC treatment could have a neuroprotective role in MSA patients. In the present study, we evaluated the effects of MSC therapy on longitudinal changes in subcortical deep grey matter volumes and cortical thickness and their association with cognitive performance. Clinical and imaging data were obtained from our previous randomized trial of autologous MSC in MSA patients. During 1-year follow-up, we assessed longitudinal differences in subcortical deep grey matter volumes and cortical thickness between placebo (n=15 and MSC groups (n=11. Next, we performed correlation analysis between the changes in cortical thickness and changes in the Korean version of the Montreal Cognitive Assessment (MoCA scores and detailed cognitive performance. There were no significant differences in age, gender ratio, disease duration, clinical severity, MoCA score, or education level between the groups. The subcortical volumetric analysis revealed that the changes in deep grey matter volumes of the caudate, putamen, and thalamus did not differ significantly between the groups. The areas of cortical thinning over time in the placebo group were more extensive, including the frontal, temporal, and parietal areas, whereas these areas in the MSC group were less extensive. Correlation analysis indicated that declines in MoCA scores and phonemic fluency were significantly correlated with cortical thinning of the frontal and posterior temporal areas and anterior temporal areas in MSA patients, respectively. These results suggest that MSC treatment in patients with MSA may modulate cortical thinning over time and related cognitive performance, inferring a future therapeutic candidate for cognitive

  1. Occupational exposure and risk of chronic obstructive pulmonary disease: a systematic review and meta-analysis.

    Science.gov (United States)

    Alif, Sheikh M; Dharmage, Shyamali C; Bowatte, Gayan; Karahalios, Amalia; Benke, Geza; Dennekamp, Martine; Mehta, Amar J; Miedinger, David; Künzli, Nino; Probst-Hensch, Nicole; Matheson, Melanie C

    2016-08-01

    Due to contradictory literature we have performed a systematic review and meta-analyse of population-based studies that have used Job Exposure Matrices to assess occupational exposure and risk of Chronic Obstructive Pulmonary Disease (COPD). Two researchers independently searched databases for published articles using predefined inclusion criteria. Study quality was assessed, and results pooled for COPD and chronic bronchitis for exposure to biological dust, mineral dust, and gases/fumes using a fixed and random effect model. Five studies met predetermined inclusion criteria. The meta-analysis showed low exposure to mineral dust, and high exposure to gases/fumes were associated with an increased risk of COPD. We also found significantly increased the risk of chronic bronchitis for low and high exposure to biological dust and mineral dust. Expert commentary: The relationship between occupational exposure assessed by the JEM and the risk of COPD and chronic bronchitis shows significant association with occupational exposure. However, the heterogeneity of the meta-analyses suggests more wide population-based studies with older age groups and longitudinal phenotype assessment of COPD to clarify the role of occupational exposure to COPD risk.

  2. Optimization analysis of convective–radiative longitudinal fins with temperature-dependent properties and different section shapes and materials

    International Nuclear Information System (INIS)

    Mosayebidorcheh, S.; Hatami, M.; Mosayebidorcheh, T.; Ganji, D.D.

    2015-01-01

    Graphical abstract: Temperature distribution along the fins obtained for different material and section shapes. - Highlights: • The steady state thermal analysis of longitudinal fins is presented. • The properties of fins are assumed as a function of temperature. • The rectangular, convex, triangular and concave profiles are considered for fin shape. • Least Square Method (LSM) is used for solving the governing equation. • Thermal optimization of fin geometry is presented based on maximum value of heat transfer. - Abstract: The main aim of this study is to obtain an optimum design point for fin geometry, so that heat transfer rate reaches to a maximum value in a constant fin volume. Effect of fin thicknesses ratio (τ), convection coefficient power index (m), profile power parameter (n), base thickness (δ) and fin material are evaluated in the fin optimization point for heat transfer rate, effectiveness and efficiency. It’s assumed that the thickness of longitudinal fins varies with length in a special profile, so four different shapes (rectangular, convex, triangular and concave) are considered. In present study, temperature-dependent heat generation, convection and radiation are considered and an analytical technique based on the least square method is proposed for the solution methodology. Results show that by increasing the fin thicknesses ratio, maximum heat transfer rate decreases and Copper among the other materials has the most heat transfer rate in a constant volume.

  3. Longitudinal joint specifications and performance.

    Science.gov (United States)

    2012-08-01

    Deterioration of longitudinal joints is widely recognized as one of the major factors contributing to failure of asphalt pavements. Finding : ways to improve the durability of longitudinal joints will lead to improved service lives and lower life cyc...

  4. Multidimensionality of Longitudinal Data: Unlocking the Age-Happiness Puzzle

    OpenAIRE

    Ning Li

    2014-01-01

    In social and economic analysis of longitudinal data, the socio-economic variables that are statistically significant in pooled data regressions sometimes become insignificant after individual fixed effects are controlled for. This phenomenon has been observed in the analysis of the relationship between age and happiness. The discrepancy in results between regressions with and without controlling for individual fixed effects is sometimes known as a mystery in the research of age and happiness...

  5. Generation of Natural-Language Textual Summaries from Longitudinal Clinical Records.

    Science.gov (United States)

    Goldstein, Ayelet; Shahar, Yuval

    2015-01-01

    Physicians are required to interpret, abstract and present in free-text large amounts of clinical data in their daily tasks. This is especially true for chronic-disease domains, but holds also in other clinical domains. We have recently developed a prototype system, CliniText, which, given a time-oriented clinical database, and appropriate formal abstraction and summarization knowledge, combines the computational mechanisms of knowledge-based temporal data abstraction, textual summarization, abduction, and natural-language generation techniques, to generate an intelligent textual summary of longitudinal clinical data. We demonstrate our methodology, and the feasibility of providing a free-text summary of longitudinal electronic patient records, by generating summaries in two very different domains - Diabetes Management and Cardiothoracic surgery. In particular, we explain the process of generating a discharge summary of a patient who had undergone a Coronary Artery Bypass Graft operation, and a brief summary of the treatment of a diabetes patient for five years.

  6. Item Response Theory to Quantify Longitudinal Placebo and Paliperidone Effects on PANSS Scores in Schizophrenia.

    Science.gov (United States)

    Krekels, Ehj; Novakovic, A M; Vermeulen, A M; Friberg, L E; Karlsson, M O

    2017-08-01

    As biomarkers are lacking, multi-item questionnaire-based tools like the Positive and Negative Syndrome Scale (PANSS) are used to quantify disease severity in schizophrenia. Analyzing composite PANSS scores as continuous data discards information and violates the numerical nature of the scale. Here a longitudinal analysis based on Item Response Theory is presented using PANSS data from phase III clinical trials. Latent disease severity variables were derived from item-level data on the positive, negative, and general PANSS subscales each. On all subscales, the time course of placebo responses were best described with Weibull models, and dose-independent functions with exponential models to describe the onset of the full effect were used to describe paliperidone's effect. Placebo and drug effect were most pronounced on the positive subscale. The final model successfully describes the time course of treatment effects on the individual PANSS item-levels, on all PANSS subscale levels, and on the total score level. © 2017 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

  7. Chinese social media analysis for disease surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaohui [Wuhan Univ., Wuhan (China); Yang, Nanhai [Wuhan Univ., Wuhan (China); Wang, Zhibo [Wuhan Univ., Wuhan (China); East China Institute of Technology, Nanchang (China); Hu, Cheng [Wuhan Univ., Wuhan (China); Zhu, Weiping [Wuhan Univ., Wuhan (China); Li, Hanjie [Wuhan Univ., Wuhan (China); Ji, Yujie [Wuhan Univ., Wuhan (China); Liu, Cheng [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-11

    Here, it is reported that there are hundreds of thou- sands of deaths caused by seasonal flu all around the world every year. More other diseases such as chickenpox, malaria, etc. are also serious threats to people’s physical and mental health. There are 250,000–500,000 deaths every year around the world. Therefore proper techniques for disease surveillance are highly demanded. Recently, social media analysis is regarded as an efficient way to achieve this goal, which is feasible since growing number of people have been posting their health information on social media such as blogs, personal websites, etc. Previous work on social media analysis mainly focused on English materials but hardly considered Chinese materials, which hinders the application of such technique to Chinese peo- ple. In this paper, we proposed a new method of Chinese social media analysis for disease surveillance. More specifically, we compared different kinds of methods in the process of classification and then proposed a new way to process Chinese text data. The Chinese Sina micro-blog data collected from September to December 2013 are used to validate the effectiveness of the proposed method. The results show that a high classification precision of 87.49 % in average has been obtained. Comparing with the data from the authority, Chinese National Influenza Center, we can predict the outbreak time of flu 5 days earlier.

  8. Modeling and experimental analysis of the linear ultrasonic motor with in-plane bending and longitudinal mode.

    Science.gov (United States)

    Wan, Zhijian; Hu, Hong

    2014-03-01

    A novel linear ultrasonic motor based on in-plane longitudinal and bending mode vibration is presented in this paper. The stator of the motor is composed of a metal plate and eight piezoelectric ceramic patches. There are four long holes in the plate, designed for consideration of the longitudinal and bending mode coupling. The corresponding model is developed to optimize the mechanical and electrical coupling of the stator, which causes an ellipse motion at the contact tip of the stator when the composite vibrations with longitudinal and bending are excited. Its harmonic and transient responses are simulated and inspected. A prototype based on the model is fabricated and used to conduct experiments. Results show that the amplitude of the stator's contact tips is significantly increased, which helps to amplify the driving force and speed of the motor. It is therefore feasible to implement effective linear movement using the developed prototype. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Evaluation of longitudinal loading of tank trains during motion in longitudinal changes of gradient

    Directory of Open Access Journals (Sweden)

    S.V. Myamlin

    2013-06-01

    Full Text Available Purpose. To research the tank train longitudinal loading during motion by track sections with changes of gradient. The trains of different length that consist of bogie tank wagons should be examined. Influence of cargo type on longitudinal loading of train during motion in concave section of track should be evaluated. Methodology. The level of the largest longitudinal forces was estimated by mathematical simulation. It was assumed that change of gradient is formed by two grades with baffle platforms, length 50 meters, so that the algebraic difference of limiting grades vary from 10‰ to 40‰, pitch 10‰. The initial speeds were 40, 60, 80, 100, 120 km/h. For evaluation of the longitudinal loading the regulating braking and motion "by coasting" was considered. For evaluation of buffing loads the entry to the concave gradient change of expanded train is considered, and in order to determine the quasi-static forces the compressed train is considered. Findings. As a result of calculations the dependencies of maximal longitudinal forces in the trains on the cargo type, the algebraic difference of the grades, the number of tank wagons, the initial speed, motion modes, and initial gaps condition in the train were obtained. Originality. The longitudinal loading of freight cars of different length formed by the similar bogie tank wagons with one locomotive was obtained. The locomotive is placed in the train head during motion in concave track sections with various algebraic difference of the grades "on coasting" and during the regulating braking mode. The obtained results can be used for parameters standardization of profile elevation of the track. Practical value. The obtained results show that during operation of tank trains on track sections of complex breakage the most dangerous is regulating braking of preliminary compressed trains during entering on concave parts of track. Level of the greatest buffing and quasi-static longitudinal forces is

  10. Cognitive function and advanced kidney disease: longitudinal trends and impact on decision-making.

    Science.gov (United States)

    Iyasere, Osasuyi; Okai, David; Brown, Edwina

    2017-02-01

    Background: Cognitive impairment commonly affects renal patients. But little is known about the influence of dialysis modality on cognitive trends or the influence of cognitive impairment on decision-making in renal patients. This study evaluated cognitive trends amongst chronic kidney disease (CKD), haemodialysis (HD) and peritoneal dialysis (PD) patients. The relationship between cognitive impairment and decision-making capacity (DMC) was also assessed. Methods: Patients were recruited from three outpatient clinics. Cognitive function was assessed 4-monthly for up to 2 years, using the Montreal Cognitive Assessment (MoCA) tool. Cognitive trends were assessed using mixed model analysis. DMC was assessed using the Macarthur Competency Assessment tool (MacCAT-T). MacCAT-T scores were compared between patients with cognitive impairment (MoCA cognitive impairment had lower MacCAT-T compared with those without [median (interquartile range) 19 (17.9-19.6) versus 17.4 (16.3-18.4); P = 0.049]. Conclusions: Cognition declines faster in dialysis patients compared with CKD patients and in HD patients compared with PD patients. Cognitive impairment affects DMC in patients with advanced kidney disease.

  11. Eating patterns in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil): an exploratory analysis.

    Science.gov (United States)

    Cardoso, Letícia de Oliveira; Carvalho, Marilia Sá; Cruz, Oswaldo Gonçalves; Melere, Cristiane; Luft, Vivian Cristine; Molina, Maria Del Carmen Bisi; Faria, Carolina Perim de; Benseñor, Isabela M; Matos, Sheila Maria Alvim; Fonseca, Maria de Jesus Mendes da; Griep, Rosane Harter; Chor, Dóra

    2016-01-01

    The food consumption of 15,071 public employees was analyzed in six Brazilian cities participating in the baseline for Brazilian Longitudinal Study of Adult Health (ELSA-Brasil, 2008-2010) with the aim of identifying eating patterns and their relationship to socio-demographic variables. Multiple correspondence and cluster analysis were applied. Four patterns were identified, with their respective frequencies: "traditional" (48%); "fruits and vegetables" (25%); "pastry shop" (24%); and "diet/light" (5%) The "traditional" and "pastry shop" patterns were more frequent among men, younger individuals, and those with less schooling. "Fruits and vegetables" and "diet/light" were more frequent in women, older individuals, and those with more schooling. Our findings show the inclusion of new items in the "traditional" pattern and the appearance of the "low sugar/low fat" pattern among the eating habits of Brazilian workers, and signal socio-demographic and regional differences.

  12. The effects of work organization on the health of immigrant manual workers: A longitudinal analysis.

    Science.gov (United States)

    Arcury, Thomas A; Chen, Haiying; Mora, Dana C; Walker, Francis O; Cartwright, Michael S; Quandt, Sara A

    2016-01-01

    This analysis uses a longitudinal design to examine the associations of work organization and health outcomes among Latino manual workers. Participants included 247 Latino workers who completed baseline and 1-year follow-up interviews and clinical examinations. Health outcome measures were epicondylitis, rotator cuff syndrome, back pain, and depressive symptoms. Independent measures were measures of job demand, job control, and job support. Workers commonly experienced rotator cuff syndrome (6.5%), back pain (8.9%), and depressive symptoms (11.2%); fewer experienced epicondylitis (2.4%). Psychological demand was associated with rotator cuff syndrome; awkward position and decision latitude were associated with back pain. Decreased skill variety but increased decision latitude was associated with elevated depressive symptoms. Work context factors are important for health outcomes among vulnerable workers. Further research is needed to expand upon this work, particularly cultural perspectives on job support.

  13. A longitudinal analysis of bibliometric and impact factor trends among the core international journals of nursing, 1977-2008.

    Science.gov (United States)

    Smith, Derek R

    2010-12-01

    Although bibliometric analysis affords significant insight into the progression and distribution of information within a particular research field, detailed longitudinal studies of this type are rare within the field of nursing. This study aimed to investigate, from a bibliometric perspective, the progression and trends of core international nursing journals over the longest possible time period. A detailed bibliometric analysis was undertaken among 7 core international nursing periodicals using custom historical data sourced from the Thomson Reuters Journal Citation Reports®. In the 32 years between 1977 and 2008, the number of citations received by these 7 journals increased over 700%. A sustained and statistically significant (pnursing. Impressive and continual impact factor gains suggest that published nursing research is being increasingly seen, heard and cited in the international academic community. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Numerical Analysis on Longitudinal Location Optimization of Vortex Generator in Compact Heat Exchangers

    DEFF Research Database (Denmark)

    Gorji, M.; Mirgolbababei, H.; Barari, Amin

    2011-01-01

    In this paper, numerical, curvilinear and turbulent model has been used to investigate the effect of vortex generator's longitudinal displacement on heat transfer and fluid flow in different Reynolds numbers ranging from 500 to 3000. The numerical model has been validated with experimental results...

  15. [A cost-benefit analysis of occupational disease reporting in China].

    Science.gov (United States)

    Tang, X Z; Zeng, Q; Liu, D S

    2017-03-20

    Objective: To perform a cost-benefit analysis of the occupational disease reporting system in China, and to provide a basis for effective resource allocation. Methods: The data on the cost of occupational diseases were collected from China Health Statistics Yearbook 2013, the estimated benefit data were collected from published articles in China and foreign countries, and the probability data were collected from the occupational diseasereports published by health and family planning administrative departments. Adecision-making tree was used for the cost-benefit analysis. Results: The estimated cost of occupational disease reporting was about 102.47 million yuan/year, consisting of a cost of reporting in national medical institutions of 1.25 million yuan/year, a management cost of 30.35 million yuan/year, a management cost in local public health institutions of 69.80 million yuan/year, a management cost in national public health institutions of 370 thousand yuan/year, and a cost of construction and maintenance of reporting system of 700 thousand yuan/year. The results of the decision tree analysis showed that when an occupational disease monitoring system was established, the incremental input for occupational disease monitoring and prevention/control was 2.1 billion yuan/year, the output was 6.5 billion yuan/year, and the benefit of occupational disease reporting system was 4.4 billion yuan/year. Conclusion: The benefit of occupational disease reporting system depends on the cost-benefit of occupational disease prevention and control measures, and proper prevention and control measures are extremely important for improving the benefit of occupational disease reporting system.

  16. Rivastigmine in Alzheimer's disease and Parkinson's disease dementia: an ADAS-cog factor analysis.

    Science.gov (United States)

    Weintraub, Daniel; Somogyi, Monique; Meng, Xiangyi

    2011-09-01

    Rivastigmine treatment is associated with significant improvements on the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog) in patients with mild-to-moderate Alzheimer's disease (AD) and Parkinson's disease dementia (PDD). Both AD and PDD are purported to have different profiles of cognitive impairment, which may respond differentially to rivastigmine treatment. This was a retrospective analysis of 3 randomized, double-blind, rivastigmine trial databases (Investigation of transDermal Exelon in ALzheimer's disease [IDEAL; AD], EXelon in PaRkinson's disEaSe dementia Study [EXPRESS; PDD], and Alzheimer's Disease with ENA 713 [ADENA; AD]). Factor analyses of the 11 baseline ADAS-cog items derived the same factors in the 2 diseases, that is, "memory" and "language". Rivastigmine-treated AD and PDD patients showed significant improvements (P < .0001 versus placebo) on both factors. For both AD and PDD, rivastigmine had a numerically greater effect on memory than language. Treatment effect sizes were numerically greater in PDD compared with AD. Rivastigmine treatment is associated with improvement in memory and language in AD and PDD. The numerically greater response in PDD is consistent with greater cholinergic deficits in this disease state.

  17. Statistical analysis of medical data using SAS

    CERN Document Server

    Der, Geoff

    2005-01-01

    An Introduction to SASDescribing and Summarizing DataBasic InferenceScatterplots Correlation: Simple Regression and SmoothingAnalysis of Variance and CovarianceMultiple RegressionLogistic RegressionThe Generalized Linear ModelGeneralized Additive ModelsNonlinear Regression ModelsThe Analysis of Longitudinal Data IThe Analysis of Longitudinal Data II: Models for Normal Response VariablesThe Analysis of Longitudinal Data III: Non-Normal ResponseSurvival AnalysisAnalysis Multivariate Date: Principal Components and Cluster AnalysisReferences

  18. Longitudinal Alterations of Frontoparietal and Frontotemporal Networks Predict Future Creative Cognitive Ability.

    Science.gov (United States)

    Chen, Qunlin; Beaty, Roger E; Wei, Dongtao; Yang, Junyi; Sun, Jiangzhou; Liu, Wei; Yang, Wenjing; Zhang, Qinglin; Qiu, Jiang

    2018-01-01

    Creative cognition is important to academic performance and career success during late adolescence and adulthood. However, there is a lack of longitudinal data on whether brain structural development could predict improvements in creative thinking, and how such changes interact with other cognitive abilities to support creative performance. Here we examined longitudinal alterations of brain structure and their relation to creative cognitive ability in a sample of 159 healthy young adults who were scanned using magnetic resonance imaging 2-3 times over the course of 3 years. The most robust predictor of future creative ability was the right dorsolateral prefrontal cortex (DLPFC), which in conjunction with baseline creative capacity showed a 31% prediction rate. Longitudinal analysis revealed that slower decreases in gray matter density within left frontoparietal and right frontotemporal clusters predicted enhanced creative ability. Moreoever, the relationship between longitudinal alterations within frontal-related clusters and improved creative ability was moderated by the right DLPFC and working memory ability. We conclude that continuous goal-directed planning and accumulated knowledge are implemented in the right DLPFC and temporal areas, respectively, which in turn support longitudinal gains in creative cognitive ability. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. A longitudinal multilevel CFA-MTMM model for interchangeable and structurally different methods

    Science.gov (United States)

    Koch, Tobias; Schultze, Martin; Eid, Michael; Geiser, Christian

    2014-01-01

    One of the key interests in the social sciences is the investigation of change and stability of a given attribute. Although numerous models have been proposed in the past for analyzing longitudinal data including multilevel and/or latent variable modeling approaches, only few modeling approaches have been developed for studying the construct validity in longitudinal multitrait-multimethod (MTMM) measurement designs. The aim of the present study was to extend the spectrum of current longitudinal modeling approaches for MTMM analysis. Specifically, a new longitudinal multilevel CFA-MTMM model for measurement designs with structurally different and interchangeable methods (called Latent-State-Combination-Of-Methods model, LS-COM) is presented. Interchangeable methods are methods that are randomly sampled from a set of equivalent methods (e.g., multiple student ratings for teaching quality), whereas structurally different methods are methods that cannot be easily replaced by one another (e.g., teacher, self-ratings, principle ratings). Results of a simulation study indicate that the parameters and standard errors in the LS-COM model are well recovered even in conditions with only five observations per estimated model parameter. The advantages and limitations of the LS-COM model relative to other longitudinal MTMM modeling approaches are discussed. PMID:24860515

  20. Predicting longitudinal trajectories of health probabilities with random-effects multinomial logit regression.

    Science.gov (United States)

    Liu, Xian; Engel, Charles C

    2012-12-20

    Researchers often encounter longitudinal health data characterized with three or more ordinal or nominal categories. Random-effects multinomial logit models are generally applied to account for potential lack of independence inherent in such clustered data. When parameter estimates are used to describe longitudinal processes, however, random effects, both between and within individuals, need to be retransformed for correctly predicting outcome probabilities. This study attempts to go beyond existing work by developing a retransformation method that derives longitudinal growth trajectories of unbiased health probabilities. We estimated variances of the predicted probabilities by using the delta method. Additionally, we transformed the covariates' regression coefficients on the multinomial logit function, not substantively meaningful, to the conditional effects on the predicted probabilities. The empirical illustration uses the longitudinal data from the Asset and Health Dynamics among the Oldest Old. Our analysis compared three sets of the predicted probabilities of three health states at six time points, obtained from, respectively, the retransformation method, the best linear unbiased prediction, and the fixed-effects approach. The results demonstrate that neglect of retransforming random errors in the random-effects multinomial logit model results in severely biased longitudinal trajectories of health probabilities as well as overestimated effects of covariates on the probabilities. Copyright © 2012 John Wiley & Sons, Ltd.