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Sample records for intraindividual variability tools

  1. Focus on variability : New tools to study intra-individual variability in developmental data

    NARCIS (Netherlands)

    van Geert, P; van Dijk, M

    2002-01-01

    In accordance with dynamic systems theory, we assume that variability is an important developmental phenomenon. However, the standard methodological toolkit of the developmental psychologist offers few instruments for the study of variability. In this article we will present several new methods that

  2. Investigating Reliabilities of Intraindividual Variability Indicators

    Science.gov (United States)

    Wang, Lijuan; Grimm, Kevin J.

    2012-01-01

    Reliabilities of the two most widely used intraindividual variability indicators, "ISD[superscript 2]" and "ISD", are derived analytically. Both are functions of the sizes of the first and second moments of true intraindividual variability, the size of the measurement error variance, and the number of assessments within a burst. For comparison,…

  3. Intra-individual variability as a predictor of learning

    Directory of Open Access Journals (Sweden)

    Matija Svetina

    2004-05-01

    Full Text Available Learning is one of the most important aspects of children's behaviour. A new theory that emerged from evolutionary principles and information-processing models assumes learning to be run by two basic mechanisms: variability and selection. The theory is based on the underlying assumption that intra-individual variability of strategies that children use to solve a problem, is a core mechanism of learning change. This assumption was tested in the case of multiple classification (MC task. 30 6-year-old children were tested for intelligence, short-term memory, and MC. Procedure followed classical pre-test/learning/post-test scheme. Amount of learning was measured through percentage of correct answers before and after learning sessions, whereas intra-individual variability was assessed through children's explanations of their answers on MC problems. The results yielded intra-individual variability to explain learning changes beyond inter-individual differences in intelligence or short-term memory. Although the results rose some new questions to be considered in further research, the data supported the hypothesis of intra-individual variability as predictor of learning change.

  4. Age-Related Intraindividual Performance Variability with Practice

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    Miller, Suzanne Bonneau; Odell, Katharine H.

    2007-01-01

    Fluctuations in cognitive task performance in older individuals have been reported. To examine intraindividual variability as a function of practice, 34 younger and 34 older female participants, aged 20-30 years and 70-82 years, respectively, performed a reading span task 16 times over four sessions. Each individual's recall accuracy was analyzed…

  5. Using intraindividual variability to detect malingering in cognitive performance.

    Science.gov (United States)

    Strauss, E; Hultsch, D F; Hunter, M; Slick, D J; Patry, B; Levy-Bencheton, J

    1999-11-01

    The utility of measures for detecting malingering was evaluated using a simulation design in which half the participants were encouraged to do their best and half were asked to feign head injury. Particular attention was focused on the utility of repeated assessment (intraindividual variability) in discriminating the groups. Participants were tested on three occasions on measures commonly used to detect malingering including a specific symptom validity test (SVT). The results indicated that multiple measures of malingering obtained in single assessment (occasion one) discriminated the groups effectively. In addition, however, intraindividual variability in performance, particularly of indicators from the SVT, provided unique information beyond level of performance. The results suggest that response inconsistency across testing sessions may be a clinically useful measure for the detection of malingering.

  6. Using Derivative Estimates to Describe Intraindividual Variability at Multiple Time Scales

    Science.gov (United States)

    Deboeck, Pascal R.; Montpetit, Mignon A.; Bergeman, C. S.; Boker, Steven M.

    2009-01-01

    The study of intraindividual variability is central to the study of individuals in psychology. Previous research has related the variance observed in repeated measurements (time series) of individuals to traitlike measures that are logically related. Intraindividual measures, such as intraindividual standard deviation or the coefficient of…

  7. Modeling intraindividual variability with repeated measures data methods and applications

    CERN Document Server

    Hershberger, Scott L

    2013-01-01

    This book examines how individuals behave across time and to what degree that behavior changes, fluctuates, or remains stable.It features the most current methods on modeling repeated measures data as reported by a distinguished group of experts in the field. The goal is to make the latest techniques used to assess intraindividual variability accessible to a wide range of researchers. Each chapter is written in a ""user-friendly"" style such that even the ""novice"" data analyst can easily apply the techniques.Each chapter features:a minimum discussion of mathematical detail;an empirical examp

  8. Intraindividual variability in cognitive performance in persons with chronic fatigue syndrome.

    Science.gov (United States)

    Fuentes, K; Hunter, M A; Strauss, E; Hultsch, D F

    2001-05-01

    Studies of cognitive performance among persons with chronic fatigue syndrome (CFS) have yielded inconsistent results. We sought to contribute to findings in this area by examining intraindividual variability as well as level of performance in cognitive functioning. A battery of cognitive measures was administered to 14 CFS patients and 16 healthy individuals on 10 weekly occasions. Analyses comparing the two groups in terms of level of performance defined by latency and accuracy scores revealed that the CFS patients were slower but not less accurate than healthy persons. The CFS group showed greater intraindividual variability (as measured by intraindividual standard deviations and coefficients of variation) than the healthy group, although the results varied by task and time frame. Intraindividual variability was found to be stable across time and correlated across tasks at each testing occasion. Intraindividual variability also uniquely differentiated the groups. The present findings support the proposition that intraindividual variability is a meaningful indicator of cognitive functioning in CFS patients.

  9. Intraindividual variability as an indicator of malingering in head injury.

    Science.gov (United States)

    Strauss, Esther; Slick, Daniel J; Levy-Bencheton, Judi; Hunter, Michael; MacDonald, Stuart W S; Hultsch, David F

    2002-07-01

    The utility of various measures of malingering was evaluated using an analog design in which half the participants (composed of three groups: naive healthy people, professionals working with head-injured people, individuals who suffered a head injury but not currently in litigation) were asked to try their best and the remainder was asked to feign believable injury. Participants were assessed with the Reliable Digit Span (RDS) task, the Victoria Symptom Validity Test (VSVT), and the Computerized Dot Counting Test (CDCT) on three separate occasions in order to determine whether repeat administration of tests improves prediction. The results indicated that regardless of an individual's experience, consideration of both level of performance (particularly on forced-choice symptom validity tasks) and intraindividual variability holds considerable promise for the detection of malingering.

  10. Cognitive Intraindividual Variability and White Matter Integrity in Aging

    Directory of Open Access Journals (Sweden)

    Nathalie Mella

    2013-01-01

    Full Text Available The intraindividual variability (IIV of cognitive performance has been shown to increase with aging. While brain research has generally focused on mean performance, little is known about neural correlates of cognitive IIV. Nevertheless, some studies suggest that IIV relates more strongly than mean level of performance to the quality of white matter (WM. Our study aims to explore the relation between WM integrity and cognitive IIV by combining functional (fMRI and structural (diffusion tensor imaging, DTI imaging. Twelve young adults (aged 18–30 years and thirteen older adults (61–82 years underwent a battery of neuropsychological tasks, along with fMRI and DTI imaging. Their behavioral data were analyzed and correlated with the imaging data at WM regions of interest defined on the basis of (1 the fMRI-activated areas and (2 the Johns Hopkins University (JHU WM tractography atlas. For both methods, fractional anisotropy, along with the mean, radial, and axial diffusivity parameters, was computed. In accord with previous studies, our results showed that the DTI parameters were more related to IIV than to mean performance. Results also indicated that age differences in the DTI parameters were more pronounced in the regions activated primarily by young adults during a choice reaction-time task than in those also activated in older adults.

  11. Intraindividual variability as a marker of neurological dysfunction: a comparison of Alzheimer's disease and Parkinson's disease.

    Science.gov (United States)

    Burton, Catherine L; Strauss, Esther; Hultsch, David F; Moll, Alex; Hunter, Michael A

    2006-01-01

    Individuals with certain neurological conditions may demonstrate greater inconsistency (i.e., intraindividual variability) on cognitive tasks compared to healthy controls. Several researchers have suggested that intraindividual variability may be a behavioral marker of compromised neurobiological mechanisms associated with aging, disease, or injury. The present study sought to investigate whether intraindividual variability is associated with general nervous system compromise, or rather, with certain types of neurological disturbances by comparing healthy adults, adults with Alzheimer's disease (AD), and Parkinson's disease (PD). Participants were assessed on four separate occasions using measures of reaction time and memory. Results indicated that inconsistency was correlated with indices of severity of impairment suggesting a dose-response relationship between cognitive disturbance and intraindividual variability: the more severe the cognitive disturbance, the greater the inconsistency. However, participants with AD were more inconsistent than those with PD, with both groups being more variable than the healthy group, even when controlling for group differences in overall severity of cognitive impairment or cognitive decline. Consequently, intraindividual variability may index both the severity of cognitive impairment and the nature of the neurological disturbance.

  12. Intra-Individual Variability in ADHD, Autism Spectrum Disorders and Tourette's Syndrome

    Science.gov (United States)

    Geurts, Hilde M.; Grasman, Raoul P. P. P.; Verte, Sylvie; Oosterlaan, Jaap; Roeyers, Herbert; van Kammen, Serena M.; Sergeant, Joseph A.

    2008-01-01

    The potential for response variability to serve as an endophenotype for attention deficit hyperactivity disorders (ADHD) rests, in part, upon the development of reliable and valid methods to decompose variability. This study investigated the specificity of intra-individual variability (IIV) in 53 children with ADHD by comparing them with 25…

  13. Age and Sex Differences in Intra-Individual Variability in a Simple Reaction Time Task

    Science.gov (United States)

    Ghisletta, Paolo; Renaud, Olivier; Fagot, Delphine; Lecerf, Thierry; de Ribaupierre, Anik

    2018-01-01

    While age effects in reaction time (RT) tasks across the lifespan are well established for level of performance, analogous findings have started appearing also for indicators of intra-individual variability (IIV). Children are not only slower, but also display more variability than younger adults in RT. Yet, little is known about potential…

  14. Aerobic Fitness and Intra-Individual Variability of Neurocognition in Preadolescent Children

    Science.gov (United States)

    Moore, Robert Davis; Wu, Chien-Ting; Pontifex, Matthew B.; O'Leary, Kevin C.; Scudder, Mark R.; Raine, Lauren B.; Johnson, Christopher R.; Hillman, Charles H.

    2013-01-01

    This study examined behavioral and neuroelectric intra-individual variability (IIV) in preadolescent children during a task requiring variable amounts of cognitive control. The current study further examined whether IIV was moderated by aerobic fitness level. Participants performed a modified flanker task, comprised of congruent and incongruent…

  15. Intra-Individual Variability of Physical Activity in Older Adults With and Without Mild Alzheimer's Disease.

    Science.gov (United States)

    Watts, Amber; Walters, Ryan W; Hoffman, Lesa; Templin, Jonathan

    2016-01-01

    Physical activity shows promise for protection against cognitive decline in older adults with and without Alzheimer's disease (AD). To better understand barriers to adoption of physical activity in this population, a clear understanding of daily and weekly activity patterns is needed. Most accelerometry studies report average physical activity over an entire wear period without considering the potential importance of the variability of physical activity. This study evaluated individual differences in the amount and intra-individual variability of physical activity and determined whether these differences could be predicted by AD status, day of wear, age, gender, education, and cardiorespiratory capacity. Physical activity was measured via accelerometry (Actigraph GT3X+) over one week in 86 older adults with and without AD (n = 33 and n = 53, respectively). Mixed-effects location-scale models were estimated to evaluate and predict individual differences in the amount and intra-individual variability of physical activity. Results indicated that compared to controls, participants with AD averaged 21% less activity, but averaged non-significantly greater intra-individual variability. Women and men averaged similar amounts of physical activity, but women were significantly less variable. The amount of physical activity differed significantly across days of wear. Increased cardiorespiratory capacity was associated with greater average amounts of physical activity. Investigation of individual differences in the amount and intra-individual variability of physical activity provided insight into differences by AD status, days of monitor wear, gender, and cardiovascular capacity. All individuals regardless of AD status were equally consistent in their physical activity, which may have been due to a highly sedentary sample and/or the early disease stage of those participants with AD. These results highlight the value of considering individual differences in both the amount and

  16. Varieties of attention-deficit/hyperactivity disorder-related intra-individual variability

    NARCIS (Netherlands)

    Castellanos, F.X.; Sonuga-Barke, E.J.S.; Scheres, A.P.J.; Martino, A. Di; Hyde, C.; Walters, J.R.

    2005-01-01

    Intra-individual variability in behavior and functioning is ubiquitous among children with attention-deficit/hyperactivity disorder (ADHD), but it has not been systematically examined or integrated within causal models. This article seeks to provide a conceptual, methodologic, and analytic framework

  17. Inter- and Intra-individual variability following intermittent theta burst stimulation: implications for rehabilitation and recovery.

    Science.gov (United States)

    Hinder, Mark R; Goss, Emily L; Fujiyama, Hakuei; Canty, Alison J; Garry, Michael I; Rodger, Jennifer; Summers, Jeffery J

    2014-01-01

    The continued refinement of non-invasive brain stimulation (NBS) techniques is indicative of promising clinical and rehabilitative interventions that are able to modulate cortical excitability. Intermittent theta burst stimulation (iTBS) is one such technique that can increase cortical excitability, purportedly via LTP-like mechanisms. While iTBS may have the capacity to promote recovery after neurological injury, and to combat cognitive and motor decline, recent reports observed highly variable effects across individuals, questioning the efficacy of iTBS as a clinical tool. The aim of this study was to examine intra-individual reliability and inter-individual variability in responses to iTBS. Thirty healthy participants completed two experimental sessions of the iTBS protocol 1-3 weeks apart. Motor evoked potentials in response to single pulse TMS were used to assess corticospinal excitability prior to, and up to 36 min following, iTBS. At the group level, iTBS evoked statistically significant increases in motor cortical excitability across both sessions (P iTBS is capable of inducing relatively robust and consistent effects within and between young individuals. As such, the capacity for iTBS to be exploited in clinical and rehabilitative interventions should continue to be explored. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Intra-individual variability in tinnitus patients : current thoughts and perspectives.

    Science.gov (United States)

    Dauman, N; Erlandsson, S; Lundlin, L; Dauman, R

    2015-04-01

    Most tinnitus studies have attempted to compare groups of individuals, thus revealing inter-individuals differences, i.e., variations between compared subjects. For methodological reasons, inter-individual studies cannot take into account the variability of tinnitus experience, which has been known for decades to be relevant in daily practice with tinnitus patients. The concept of intra-individual variability has been promoted in the research literature, in order to shed light on this aspect of individual perception. In previous studies, unrelated to hearing, the concept of intra-individual variability implied inclusion of the environment (i.e., physical and social interactions) as a factor of individual performance. In tinnitus research, we believe that the concept of variability (within a person) could find a place beside the concept of variation (between groups of subjects). In this paper, four perspectives of tinnitus experiences from the clinical and research fields are described: (1) ENT consultation; (2) short-term group psychotherapy; (3) psychodynamic psychotherapy; and (4) clinical psychological research. Intra-individual variability stresses the importance of defining tinnitus in a dynamic way, contrary to the current definition of tinnitus as the perception of sound(s). In clinical practice, it is useful to embrace the perspective of the perceiver of tinnitus, and to include social and cultural circumstances as well as audiological/physical changes.

  19. Intraindividual variability in cognitive performance in older adults: comparison of adults with mild dementia, adults with arthritis, and healthy adults.

    Science.gov (United States)

    Hultsch, D F; MacDonald, S W; Hunter, M A; Levy-Bencheton, J; Strauss, E

    2000-10-01

    Intraindividual variability in latency and accuracy of cognitive performance across both trials and occasions was examined in 3 groups of older adults: healthy adults, adults with arthritis, and adults diagnosed with mild dementia. Participants completed 2 reaction-time and 2 episodic-memory tasks on 4 occasions. Results indicated that intraindividual variability in latency was greater in individuals diagnosed with mild dementia than in adults who were neurologically intact, regardless of their health status. Individual differences in variability were stable over time and across cognitive domains. Intraindividual variability was also related to level of performance and was uniquely predictive of neurological status, independent of level of performance. Results suggest that intraindividual variability may be a behavioral indicator of compromised neurological mechanisms.

  20. Intraindividual variability is related to cognitive change in older adults: evidence for within-person coupling.

    Science.gov (United States)

    Bielak, Allison A M; Hultsch, David F; Strauss, Esther; MacDonald, Stuart W S; Hunter, Michael A

    2010-09-01

    In this study, the authors addressed the longitudinal nature of intraindividual variability over 3 years. A sample of 304 community-dwelling older adults, initially between the ages of 64 and 92 years, completed 4 waves of annual testing on a battery of accuracy- and latency-based tests covering a wide range of cognitive complexity. Increases in response-time inconsistency on moderately and highly complex tasks were associated with increasing age, but there were significant individual differences in change across the entire sample. The time-varying covariation between cognition and inconsistency was significant across the 1-year intervals and remained stable across both time and age. On occasions when intraindividual variability was high, participants' cognitive performance was correspondingly low. The strength of the coupling relationship was greater for more fluid cognitive domains such as memory, reasoning, and processing speed than for more crystallized domains such as verbal ability. Variability based on moderately and highly complex tasks provided the strongest prediction. These results suggest that intraindividual variability is highly sensitive to even subtle changes in cognitive ability. (c) 2010 APA, all rights reserved.

  1. Intraindividual Stepping Reaction Time Variability Predicts Falls in Older Adults With Mild Cognitive Impairment

    OpenAIRE

    Bunce, D; Haynes, BI; Lord, SR; Gschwind, YJ; Kochan, NA; Reppermund, S; Brodaty, H; Sachdev, PS; Delbaere, K

    2017-01-01

    Background: Reaction time measures have considerable potential to aid neuropsychological assessment in a variety of health care settings. One such measure, the intraindividual reaction time variability (IIV), is of particular interest as it is thought to reflect neurobiological disturbance. IIV is associated with a variety of age-related neurological disorders, as well as gait impairment and future falls in older adults. However, although persons diagnosed with Mild Cognitive Impairment (MCI)...

  2. Intra-individual variability of ITS regions in entomopathogenic nematodes (Steinernematidae: Nematoda): implications for their taxonomy

    Czech Academy of Sciences Publication Activity Database

    Půža, Vladimír; Chundelová, Daniela; Nermuť, Jiří; Žurovcová, Martina; Mráček, Zdeněk

    2015-01-01

    Roč. 60, č. 4 (2015), s. 547-554 ISSN 1386-6141 R&D Projects: GA ČR GAP504/12/2352 Grant - others:GA JU(CZ) 052/2013/P Institutional support: RVO:60077344 Keywords : Steinernema * genetic diversity * intra-individual variability Subject RIV: EG - Zoology Impact factor: 1.767, year: 2015 http://link.springer.com/article/10.1007%2Fs10526-015-9664-5

  3. Both Reaction Time and Accuracy Measures of Intraindividual Variability Predict Cognitive Performance in Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Björn U. Christ

    2018-04-01

    Full Text Available Dementia researchers around the world prioritize the urgent need for sensitive measurement tools that can detect cognitive and functional change at the earliest stages of Alzheimer's disease (AD. Sensitive indicators of underlying neural pathology assist in the early detection of cognitive change and are thus important for the evaluation of early-intervention clinical trials. One method that may be particularly well-suited to help achieve this goal involves the quantification of intraindividual variability (IIV in cognitive performance. The current study aimed to directly compare two methods of estimating IIV (fluctuations in accuracy-based scores vs. those in latency-based scores to predict cognitive performance in AD. Specifically, we directly compared the relative sensitivity of reaction time (RT—and accuracy-based estimates of IIV to cognitive compromise. The novelty of the present study, however, centered on the patients we tested [a group of patients with Alzheimer's disease (AD] and the outcome measures we used (a measure of general cognitive function and a measure of episodic memory function. Hence, we compared intraindividual standard deviations (iSDs from two RT tasks and three accuracy-based memory tasks in patients with possible or probable Alzheimer's dementia (n = 23 and matched healthy controls (n = 25. The main analyses modeled the relative contributions of RT vs. accuracy-based measures of IIV toward the prediction of performance on measures of (a overall cognitive functioning, and (b episodic memory functioning. Results indicated that RT-based IIV measures are superior predictors of neurocognitive impairment (as indexed by overall cognitive and memory performance than accuracy-based IIV measures, even after adjusting for the timescale of measurement. However, one accuracy-based IIV measure (derived from a recognition memory test also differentiated patients with AD from controls, and significantly predicted episodic memory

  4. Intra-individual variability in cerebrovascular and respiratory chemosensitivity: Can we characterize a chemoreflex "reactivity profile"?

    Science.gov (United States)

    Borle, Kennedy J; Pfoh, Jamie R; Boulet, Lindsey M; Abrosimova, Maria; Tymko, Michael M; Skow, Rachel J; Varner, Amy; Day, Trevor A

    2017-08-01

    Intra-individual variability in the magnitude of human cerebrovascular and respiratory chemoreflex responses is largely unexplored. By comparing response magnitudes of cerebrovascular CO 2 reactivity (CVR; middle and posterior cerebral arteries; MCA, PCA), central (CCR; CO 2 ) and peripheral respiratory chemoreflexes (PCR; CO 2 and O 2 ), we tested the hypothesis that a within-individual reactivity magnitude profile could be characterized. The magnitudes of CVR and CCR were tested with hyperoxic rebreathing and PCR magnitudes were tested through transient respiratory tests (TT-CO 2 , hypercapnia; TT-N 2 , hypoxia). No significant intra-individual relationships were found between CCR vs. CVR (MCA and PCA), CCR vs. PCR (TT-N 2 or TT-CO 2 ) (r0.3) response magnitudes. Statistically significant relationships were found between MCA vs. PCA reactivity (r=0.45, Pvariability that exists in human cerebrovascular and respiratory chemoreflexes. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Cortical Brain Atrophy and Intra-Individual Variability in Neuropsychological Test Performance in HIV Disease

    Science.gov (United States)

    HINES, Lindsay J.; MILLER, Eric N.; HINKIN, Charles H.; ALGER, Jeffery R.; BARKER, Peter; GOODKIN, Karl; MARTIN, Eileen M.; MARUCA, Victoria; RAGIN, Ann; SACKTOR, Ned; SANDERS, Joanne; SELNES, Ola; BECKER, James T.

    2015-01-01

    Objective To characterize the relationship between dispersion-based intra-individual variability (IIVd) in neuropsychological test performance and brain volume among HIV seropositive and seronegative men and to determine the effects of cardiovascular risk and HIV infection on this relationship. Methods Magnetic Resonance Imaging (MRI) was used to acquire high-resolution neuroanatomic data from 147 men age 50 and over, including 80 HIV seropositive (HIV+) and 67 seronegative controls (HIV−) in this cross-sectional cohort study. Voxel Based Morphometry was used to derive volumetric measurements at the level of the individual voxel. These brain structure maps were analyzed using Statistical Parametric Mapping (SPM2). IIVd was measured by computing intra-individual standard deviations (ISD’s) from the standardized performance scores of five neuropsychological tests: Wechsler Memory Scale-III Visual Reproduction I and II, Logical Memory I and II, Wechsler Adult Intelligence Scale-III Letter Number Sequencing. Results Total gray matter (GM) volume was inversely associated with IIVd. Among all subjects, IIVd -related GM atrophy was observed primarily in: 1) the inferior frontal gyrus bilaterally, the left inferior temporal gyrus extending to the supramarginal gyrus, spanning the lateral sulcus; 2) the right superior parietal lobule and intraparietal sulcus; and, 3) dorsal/ventral regions of the posterior section of the transverse temporal gyrus. HIV status, biological, and cardiovascular disease (CVD) variables were not linked to IIVd -related GM atrophy. Conclusions IIVd in neuropsychological test performance may be a sensitive marker of cortical integrity in older adults, regardless of HIV infection status or CVD risk factors, and degree of intra-individual variability links with volume loss in specific cortical regions; independent of mean-level performance on neuropsychological tests. PMID:26303224

  6. Intra-individual gait pattern variability in specific situations: Implications for forensic gait analysis.

    Science.gov (United States)

    Ludwig, Oliver; Dillinger, Steffen; Marschall, Franz

    2016-07-01

    In this study, inter- and intra-individual gait pattern differences are examined in various gait situations by means of phase diagrams of the extremity angles (cyclograms). 8 test subjects walked along a walking distance of 6m under different conditions three times each: barefoot, wearing sneakers, wearing combat boots, after muscular fatigue, and wearing a full-face motorcycle helmet restricting vision. The joint angles of foot, knee, and hip were recorded in the sagittal plane. The coupling of movements was represented by time-adjusted cyclograms, and the inter- and intra-individual differences were captured by calculating the similarity between different gait patterns. Gait pattern variability was often greater between the defined test situations than between the individual test subjects. The results have been interpreted considering neurophysiological regulation mechanisms. Footwear, masking, and fatigue were interpreted as disturbance parameters, each being a cause for gait pattern variability and complicating the inference of identity of persons in video recordings. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Change in intraindividual variability over time as a key metric for defining performance-based cognitive fatigability.

    Science.gov (United States)

    Wang, Chao; Ding, Mingzhou; Kluger, Benzi M

    2014-03-01

    Cognitive fatigability is conventionally quantified as the increase over time in either mean reaction time (RT) or error rate from two or more time periods during sustained performance of a prolonged cognitive task. There is evidence indicating that these mean performance measures may not sufficiently reflect the response characteristics of cognitive fatigue. We hypothesized that changes in intraindividual variability over time would be a more sensitive and ecologically meaningful metric for investigations of fatigability of cognitive performance. To test the hypothesis fifteen young adults were recruited. Trait fatigue perceptions in various domains were assessed with the Multidimensional Fatigue Index (MFI). Behavioral data were then recorded during performance of a three-hour continuous cued Stroop task. Results showed that intraindividual variability, as quantified by the coefficient of variation of RT, increased linearly over the course of three hours and demonstrated a significantly greater effect size than mean RT or accuracy. Change in intraindividual RT variability over time was significantly correlated with relevant subscores of the MFI including reduced activity, reduced motivation and mental fatigue. While change in mean RT over time was also correlated with reduced motivation and mental fatigue, these correlations were significantly smaller than those associated with intraindividual RT variability. RT distribution analysis using an ex-Gaussian model further revealed that change in intraindividual variability over time reflects an increase in the exponential component of variance and may reflect attentional lapses or other breakdowns in cognitive control. These results suggest that intraindividual variability and its change over time provide important metrics for measuring cognitive fatigability and may prove useful for inferring the underlying neuronal mechanisms of both perceptions of fatigue and objective changes in performance. Copyright © 2014

  8. Intraindividual variability in reaction time before and after neoadjuvant chemotherapy in women diagnosed with breast cancer.

    Science.gov (United States)

    Yao, Christie; Rich, Jill B; Tirona, Kattleya; Bernstein, Lori J

    2017-12-01

    Women treated with chemotherapy for breast cancer experience subtle cognitive deficits. Research has focused on mean performance level, yet recent work suggests that within-person variability in reaction time performance may underlie cognitive symptoms. We examined intraindividual variability (IIV) in women diagnosed with breast cancer and treated with neoadjuvant chemotherapy. Patients (n = 28) were assessed at baseline before chemotherapy (T1), approximately 1 month after chemotherapy but prior to surgery (T2), and after surgery about 9 months post chemotherapy (T3). Healthy women of similar age and education (n = 20) were assessed at comparable time intervals. Using a standardized regression-based approach, we examined changes in mean performance level and IIV (eg, intraindividual standard deviation) on a Stroop task and self-report measures of cognitive function from T1 to T2 and T1 to T3. At T1, women with breast cancer were more variable than controls as task complexity increased. Change scores from T1 to T2 were similar between groups on all Stroop performance measures. From T1 to T3, controls improved more than women with breast cancer. IIV was more sensitive than mean reaction time in capturing group differences. Additional analyses showed increased cognitive symptoms reported by women with breast cancer from T1 to T3. Specifically, change in language symptoms was positively correlated with change in variability. Women with breast cancer declined in attention and inhibitory control relative to pretreatment performance. Future studies should include measures of variability, because they are an important sensitive indicator of change in cognitive function. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Intraindividual variability in vigilance performance: does degrading visual stimuli mimic age-related "neural noise"?

    Science.gov (United States)

    MacDonald, Stuart W S; Hultsch, David F; Bunce, David

    2006-07-01

    Intraindividual performance variability, or inconsistency, has been shown to predict neurological status, physiological functioning, and age differences and declines in cognition. However, potential moderating factors of inconsistency are not well understood. The present investigation examined whether inconsistency in vigilance response latencies varied as a function of time-on-task and task demands by degrading visual stimuli in three separate conditions (10%, 20%, and 30%). Participants were 24 younger women aged 21 to 30 years (M = 24.04, SD = 2.51) and 23 older women aged 61 to 83 years (M = 68.70, SD = 6.38). A measure of within-person inconsistency, the intraindividual standard deviation (ISD), was computed for each individual across reaction time (RT) trials (3 blocks of 45 event trials) for each condition of the vigilance task. Greater inconsistency was observed with increasing stimulus degradation and age, even after controlling for group differences in mean RTs and physical condition. Further, older adults were more inconsistent than younger adults for similar degradation conditions, with ISD scores for younger adults in the 30% condition approximating estimates observed for older adults in the 10% condition. Finally, a measure of perceptual sensitivity shared increasing negative associations with ISDs, with this association further modulated as a function of age but to a lesser degree by degradation condition. Results support current hypotheses suggesting that inconsistency serves as a marker of neurological integrity and are discussed in terms of potential underlying mechanisms.

  10. Intraindividual variability across cognitive tasks as a potential marker for prodromal Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Andrea Maria Kälin

    2014-07-01

    Full Text Available Recent studies have shown that increased cognitive intraindividual variability (IIV across accuracy scores from tests representing different cognitive domains (across-domain IIV might indicate prodromal Alzheimer’s disease (AD. Although IIV has been proposed to index cognitive control processes, IIV across accuracy scores from cognitive control tasks (within-domain IIV has not been examined in healthy controls subjects (HCS, mild cognitive impairment (MCI and AD patients in a single comparative study. This study examines the discriminative properties of within-domain IIV, and across-domain IIV in 149 HCS, 31 MCI and 26 AD. Three tasks representing different cognitive domains were identified to calculate across-domain IIV. Three other tasks representing cognitive control were identified to calculate within-domain IIV. The intraindividual standard deviation (ISD was calculated across accuracy scores. To compare IIV between groups, ANCOVAs with the covariates age, gender, education, and mean performance were computed. IIV scores in general were higher in AD vs. HCS (p< 0.01. Only across-domain IIV was higher in AD vs. MCI (p=0.001, and only within-domain IIV was higher in MCI vs. HCS (p=0.05. Within-domain IIV may constitute a cognitive marker for the detection of prodromal AD at the MCI stage, whereas across-domain IIV may detect beginning AD at the MCI stage.

  11. Intraindividual variability in reaction time predicts cognitive outcomes 5 years later.

    Science.gov (United States)

    Bielak, Allison A M; Hultsch, David F; Strauss, Esther; Macdonald, Stuart W S; Hunter, Michael A

    2010-11-01

    Building on results suggesting that intraindividual variability in reaction time (inconsistency) is highly sensitive to even subtle changes in cognitive ability, this study addressed the capacity of inconsistency to predict change in cognitive status (i.e., cognitive impairment, no dementia [CIND] classification) and attrition 5 years later. Two hundred twelve community-dwelling older adults, initially aged 64-92 years, remained in the study after 5 years. Inconsistency was calculated from baseline reaction time performance. Participants were assigned to groups on the basis of their fluctuations in CIND classification over time. Logistic and Cox regressions were used. Baseline inconsistency significantly distinguished among those who remained or transitioned into CIND over the 5 years and those who were consistently intact (e.g., stable intact vs. stable CIND, Wald (1) = 7.91, p < .01, Exp(β) = 1.49). Average level of inconsistency over time was also predictive of study attrition, for example, Wald (1) = 11.31, p < .01, Exp(β) = 1.24. For both outcomes, greater inconsistency was associated with a greater likelihood of being in a maladaptive group 5 years later. Variability based on moderately cognitively challenging tasks appeared to be particularly sensitive to longitudinal changes in cognitive ability. Mean rate of responding was a comparable predictor of change in most instances, but individuals were at greater relative risk of being in a maladaptive outcome group if they were more inconsistent rather than if they were slower in responding. Implications for the potential utility of intraindividual variability in reaction time as an early marker of cognitive decline are discussed. (c) 2010 APA, all rights reserved

  12. Neuroticism, intelligence, and intra-individual variability in elementary cognitive tasks: testing the mental noise hypothesis.

    Science.gov (United States)

    Colom, Roberto; Quiroga, Ma Angeles

    2009-08-01

    Some studies show positive correlations between intraindividual variability in elementary speed measures (reflecting processing efficiency) and individual differences in neuroticism (reflecting instability in behaviour). The so-called neural noise hypothesis assumes that higher levels of noise are related both to smaller indices of processing efficiency and greater levels of neuroticism. Here, we test this hypothesis measuring mental speed by means of three elementary cognitive tasks tapping similar basic processes but varying systematically their content (verbal, numerical, and spatial). Neuroticism and intelligence are also measured. The sample comprised 196 undergraduate psychology students. The results show that (1) processing efficiency is generally unrelated to individual differences in neuroticism, (2) processing speed and efficiency correlate with intelligence, and (3) only the efficiency index is genuinely related to intelligence when the colinearity between speed and efficiency is controlled.

  13. Intraindividual change and variability in daily stress processes: Findings from two measurement-burst diary studies

    Science.gov (United States)

    Sliwinski, Martin J.; Almeida, David M.; Smyth, Joshua; Stawski, Robert S.

    2010-01-01

    There is little longitudinal information on aging-related changes in emotional responses to negative events. The present manuscript examined intraindividual change and variability in the within-person coupling of daily stress and negative affect (NA) using data from two-measurement burst daily diary studies. Three main findings emerged. First, average reactivity to daily stress increased longitudinally, and this increase was evident across most the adult lifespan. Second, individual differences in emotional reactivity to daily stress exhibited long-term temporal stability, but this stability was greatest in midlife and decreased in old age. And third, reactivity to daily stress varied reliably within-persons (across-time), with individual exhibiting higher levels of reactivity during times when reporting high levels of global subject stress in previous month. Taken together, the present results emphasize the importance of modeling dynamic psychosocial and aging processes that operate across different time scales for understanding age-related changes in daily stress processes. PMID:20025399

  14. Intraindividual variability in physical and emotional functioning: comparison of adults with traumatic brain injuries and healthy adults.

    Science.gov (United States)

    Burton, Catherine L; Hultsch, David F; Strauss, Esther; Hunter, Michael A

    2002-08-01

    Recent research has shown that individuals with certain neurological conditions demonstrate greater intraindividual variability on cognitive tasks compared to healthy controls. The present study investigated intraindividual variability in the domains of physical functioning and affect/stress in three groups: adults with mild head injuries, adults with moderate/severe head injuries, and healthy adults. Participants were assessed on 10 occasions and results indicated that (a) individuals with head injuries demonstrated greater variability in dominant finger dexterity and right grip strength than the healthy controls; (b) increased variability tended to be associated with poorer performance/report both within and across tasks; and (c) increased variability on one task was associated with increased variability on other tasks. The findings suggest that increased variability in physical function, as well as cognitive function, represents an indicator of neurological compromise.

  15. Mean-Level Change and Intraindividual Variability in Self-Esteem and Depression among High-Risk Children

    Science.gov (United States)

    Kim, Jungmeen; Cicchetti, Dante

    2009-01-01

    This study investigated mean-level changes and intraindividual variability of self-esteem among maltreated (N = 142) and nonmaltreated (N = 109) school-aged children from low-income families. Longitudinal factor analysis revealed higher temporal stability of self-esteem among maltreated children compared to nonmaltreated children. Cross-domain…

  16. Beyond interference control impairment in ADHD: Evidence from increased intraindividual variability in the color-stroop test

    OpenAIRE

    BORELLA ERIKA; DE RIBAUPIERRE ANIK; CORNOLDI CESARE; CHICHERIO CHRISTIAN

    2012-01-01

    The present study investigates intraindividual variability (IIV) in the Color Stroop test and in a simple reaction time (SRT) task. Performance level and variability in reaction times (RTs)—quantified with different measures such as individual standard deviation (ISD) and coefficient of variation (ICV) as well as ex Gaussian parameters (mu sigma tau)—were analyzed in 24 children with attention deficit/hyperactivity disorder (ADHD) and 24 typically developing children (TDC). Children with ADHD...

  17. Intraindividual variability of boldness is repeatable across contexts in a wild lizard.

    Directory of Open Access Journals (Sweden)

    Laura Highcock

    Full Text Available Animals do not behave in exactly the same way when repeatedly tested in the same context or situation, even once systematic variation, such as habituation, has been controlled for. This unpredictability is called intraindividual variability (IIV and has been little studied in animals. Here we investigated how IIV in boldness (estimated by flight initiation distances changed across two seasons--the dry, non-breeding season and the wet, breeding season--in a wild population of the Namibian rock agama, Agama planiceps. We found significant differences in IIV both between individuals and seasons, and IIV was higher in the wet season, suggesting plasticity in IIV. Further, IIV was highly repeatable (r = 0.61 between seasons and we found strong negative correlations between consistent individual differences in flight initiation distances, i.e. their boldness, and individuals' IIVs. We suggest that to understand personality in animals, researchers should generate a personality 'profile' that includes not only the relative level of a trait (i.e. its personality, but also its plasticity and variability under natural conditions.

  18. Assessing intraindividual variability in sustained attention: reliability, relation to speed and accuracy, and practice effects

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    HAGEN C. FLEHMIG

    2007-06-01

    Full Text Available We investigated the psychometric properties of competing measures of sustained attention. 179 subjects were assessed twice within seven day's time with a test designed to measure sustained attention, or concentration, respectively. In addition to traditional performance indices [i.e., speed (MRT and accuracy (E%], we evaluated two intraindividual response time (RT variability measures: standard deviation (SDRT and coefficient of variation (CVRT. For the overall test, both indices were reliable. SDRT showed good to acceptable retest reliability for all subtests. For CVRT, retest reliability coefficients ranged from very good to not satisfactory. While the reversed-word recognition test proved highly reliable, the mental calculation test and the arrows test were not sufficiently reliable. CVRT was only slightly correlated but SDRT was highly correlated with MRT. In contrast to substantial practice gains for MRT, SDRT and E%, only CVRT proved to be stable. In conclusion, CVRT appears to be a potential index for assessing performance variability: it is reliable for the overall test, only moderately correlated with speed, and virtually not affected by practice. However, before applying CVRT in practical assessment settings, additional research is required to elucidate the impact of task-specific factors on the reliability of this performance measure.

  19. Intraindividual Variability in Basic Reaction Time Predicts Middle-Aged and Older Pilots’ Flight Simulator Performance

    Science.gov (United States)

    2013-01-01

    Objectives. Intraindividual variability (IIV) is negatively associated with cognitive test performance and is positively associated with age and some neurological disorders. We aimed to extend these findings to a real-world task, flight simulator performance. We hypothesized that IIV predicts poorer initial flight performance and increased rate of decline in performance among middle-aged and older pilots. Method. Two-hundred and thirty-six pilots (40–69 years) completed annual assessments comprising a cognitive battery and two 75-min simulated flights in a flight simulator. Basic and complex IIV composite variables were created from measures of basic reaction time and shifting and divided attention tasks. Flight simulator performance was characterized by an overall summary score and scores on communication, emergencies, approach, and traffic avoidance components. Results. Although basic IIV did not predict rate of decline in flight performance, it had a negative association with initial performance for most flight measures. After taking into account processing speed, basic IIV explained an additional 8%–12% of the negative age effect on initial flight performance. Discussion. IIV plays an important role in real-world tasks and is another aspect of cognition that underlies age-related differences in cognitive performance. PMID:23052365

  20. Intraindividual variability in basic reaction time predicts middle-aged and older pilots' flight simulator performance.

    Science.gov (United States)

    Kennedy, Quinn; Taylor, Joy; Heraldez, Daniel; Noda, Art; Lazzeroni, Laura C; Yesavage, Jerome

    2013-07-01

    Intraindividual variability (IIV) is negatively associated with cognitive test performance and is positively associated with age and some neurological disorders. We aimed to extend these findings to a real-world task, flight simulator performance. We hypothesized that IIV predicts poorer initial flight performance and increased rate of decline in performance among middle-aged and older pilots. Two-hundred and thirty-six pilots (40-69 years) completed annual assessments comprising a cognitive battery and two 75-min simulated flights in a flight simulator. Basic and complex IIV composite variables were created from measures of basic reaction time and shifting and divided attention tasks. Flight simulator performance was characterized by an overall summary score and scores on communication, emergencies, approach, and traffic avoidance components. Although basic IIV did not predict rate of decline in flight performance, it had a negative association with initial performance for most flight measures. After taking into account processing speed, basic IIV explained an additional 8%-12% of the negative age effect on initial flight performance. IIV plays an important role in real-world tasks and is another aspect of cognition that underlies age-related differences in cognitive performance.

  1. Neuronal Intra-Individual Variability Masks Response Selection Differences between ADHD Subtypes—A Need to Change Perspectives

    Directory of Open Access Journals (Sweden)

    Annet Bluschke

    2017-06-01

    Full Text Available Due to the high intra-individual variability in attention deficit/hyperactivity disorder (ADHD, there may be considerable bias in knowledge about altered neurophysiological processes underlying executive dysfunctions in patients with different ADHD subtypes. When aiming to establish dimensional cognitive-neurophysiological constructs representing symptoms of ADHD as suggested by the initiative for Research Domain Criteria, it is crucial to consider such processes independent of variability. We examined patients with the predominantly inattentive subtype (attention deficit disorder, ADD and the combined subtype of ADHD (ADHD-C in a flanker task measuring conflict control. Groups were matched for task performance. Besides using classic event-related potential (ERP techniques and source localization, neurophysiological data was also analyzed using residue iteration decomposition (RIDE to statistically account for intra-individual variability and S-LORETA to estimate the sources of the activations. The analysis of classic ERPs related to conflict monitoring revealed no differences between patients with ADD and ADHD-C. When individual variability was accounted for, clear differences became apparent in the RIDE C-cluster (analog to the P3 ERP-component. While patients with ADD distinguished between compatible and incompatible flanker trials early on, patients with ADHD-C seemed to employ more cognitive resources overall. These differences are reflected in inferior parietal areas. The study demonstrates differences in neuronal mechanisms related to response selection processes between ADD and ADHD-C which, according to source localization, arise from the inferior parietal cortex. Importantly, these differences could only be detected when accounting for intra-individual variability. The results imply that it is very likely that differences in neurophysiological processes between ADHD subtypes are underestimated and have not been recognized because intra-individual

  2. Sleep and Physiological Dysregulation: A Closer Look at Sleep Intraindividual Variability.

    Science.gov (United States)

    Bei, Bei; Seeman, Teresa E; Carroll, Judith E; Wiley, Joshua F

    2017-09-01

    Variable daily sleep (ie, higher intraindividual variability; IIV) is associated with negative health consequences, but potential physiological mechanisms are poorly understood. This study examined how the IIV of sleep timing, duration, and quality is associated with physiological dysregulation, with diurnal cortisol trajectories as a proximal outcome and allostatic load (AL) as a multisystem distal outcome. Participants are 436 adults (Mage ± standard deviation = 54.1 ± 11.7, 60.3% women) from the Midlife in the United States study. Sleep was objectively assessed using 7-day actigraphy. Diurnal cortisol was measured via saliva samples (four/day for 4 consecutive days). AL was measured using 23 biomarkers from seven systems (inflammatory, hypothalamic-pituitary-adrenal axis, metabolic glucose and lipid, cardiovascular, parasympathetic, sympathetic) using a validated bifactor model. Linear and quadratic effects of sleep IIV were estimated using a validated Bayesian model. Controlling for covariates, more variable sleep timing (p = .04 for risetime, p = .097 for bedtime) and total sleep time (TST; p = .02), but not mean sleep variables, were associated with flatter cortisol diurnal slope. More variable sleep onset latency and wake after sleep onset, later average bedtime, and shorter TST were associated with higher AL adjusting for age and sex (p-values sleep patterns were associated with blunted diurnal cortisol trajectories but not with higher multisystem physiological dysregulation. The associations between sleep IIV and overall health are likely complex, including multiple biopsychosocial determinants and require further investigation. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  3. Actigraphy Detects Greater Intra-Individual Variability During Gait in Non-Manifesting LRRK2 Mutation Carriers.

    Science.gov (United States)

    van den Heuvel, Lieneke; Lim, Andrew S; Visanji, Naomi P; Huang, Jana; Ghate, Taneera; Mestre, Tiago A; AlDakheel, Amaal; Connolly, Barbara S; Gasca-Salas, Carmen; Kern, Drew S; Jain, Jennifer; Slow, Elizabeth J; Pondal, Margarita; Faust-Socher, Achinoam; Rogaeva, Ekaterina; Tomlinson, George; Lang, Anthony E; Marras, Connie

    2018-01-01

    With recent advances in the search for disease-modifying therapies for Parkinson's disease (PD) the importance of identifying prodromal markers becomes greater. Non-manifesting LRRK2 mutation carriers (NMC) are at risk for developing PD, and provide a population in which to identify possible markers. The aim of this study was to test the hypothesis that NMC have differences in daily activity, fragmentation of sleep, arm swing asymmetry, and movement variability during walking, detectable by actigraphy, as compared to matched control subjects. Eleven NMC, fourteen PD patients (4 LRRK2-PD, 10 idiopathic PD (iPD)), and twenty-nine controls wore wristbands containing an accelerometer for seven days, and performed a daily walking task. Outcome measures included daily activity, fragmentation of activity, fragmentation of sleep, arm swing asymmetry during walking, and intra-individual variability. Compared to healthy controls, both NMC and LRRK2/iPD showed higher intra-individual variability in activity during walking compared to healthy controls. Individuals with LRRK2-PD/iPD, but not NMC, tend to have lower activity levels, more arm swing asymmetry and less increase of arm swing with transition from slow to faster walking speed compared to healthy controls. Higher intra-individual variability of gait-associated movements might be a useful biomarker of prodromal PD. These results encourage replication in a larger sample and longitudinal analysis is warranted.

  4. Selective attrition and intraindividual variability in response time moderate cognitive change.

    Science.gov (United States)

    Yao, Christie; Stawski, Robert S; Hultsch, David F; MacDonald, Stuart W S

    2016-01-01

    Selection of a developmental time metric is useful for understanding causal processes that underlie aging-related cognitive change and for the identification of potential moderators of cognitive decline. Building on research suggesting that time to attrition is a metric sensitive to non-normative influences of aging (e.g., subclinical health conditions), we examined reason for attrition and intraindividual variability (IIV) in reaction time as predictors of cognitive performance. Three hundred and four community dwelling older adults (64-92 years) completed annual assessments in a longitudinal study. IIV was calculated from baseline performance on reaction time tasks. Multilevel models were fit to examine patterns and predictors of cognitive change. We show that time to attrition was associated with cognitive decline. Greater IIV was associated with declines on executive functioning and episodic memory measures. Attrition due to personal health reasons was also associated with decreased executive functioning compared to that of individuals who remained in the study. These findings suggest that time to attrition is a useful metric for representing cognitive change, and reason for attrition and IIV are predictive of non-normative influences that may underlie instances of cognitive loss in older adults.

  5. Inter- and Intra-individual Variability in Response to Transcranial Direct Current Stimulation (tDCS) at Varying Current Intensities.

    Science.gov (United States)

    Chew, Taariq; Ho, Kerrie-Anne; Loo, Colleen K

    2015-01-01

    Translation of transcranial direct current stimulation (tDCS) from research to clinical practice is hindered by a lack of consensus on optimal stimulation parameters, significant inter-individual variability in response, and in sufficient intra-individual reliability data. Inter-individual differences in response to anodal tDCS at a range of current intensities were explored. Intra-individual reliability in response to anodal tDCS across two identical sessions was also investigated. Twenty-nine subjects participated in a crossover study. Anodal-tDCS using four different current intensities (0.2, 0.5, 1 and 2 mA), with an anode size of 16 cm2, was tested. The 0.5 mA condition was repeated to assess intra-individual variability. TMS was used to elicit 40 motor-evoked potentials (MEPs) before 10 min of tDCS, and 20 MEPs at four time-points over 30 min following tDCS. ANOVA revealed no main effect of TIME for all conditions except the first 0.5 mA condition, and no differences in response between the four current intensities. Cluster analysis identified two clusters for the 0.2 and 2 mA conditions only. Frequency distributions based on individual subject responses (excitatory, inhibitory or no response) to each condition indicate possible differential responses between individuals to different current intensities. Test-retest reliability was negligible (ICC(2,1) = -0.50). Significant inter-individual variability in response to tDCS across a range of current intensities was found. 2 mA and 0.2 mA tDCS were most effective at inducing a distinct response. Significant intra-individual variability in response to tDCS was also found. This has implications for interpreting results of single-session tDCS experiments. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  6. Intra-individual variability in information processing speed reflects white matter microstructure in multiple sclerosis.

    Science.gov (United States)

    Mazerolle, Erin L; Wojtowicz, Magdalena A; Omisade, Antonina; Fisk, John D

    2013-01-01

    Slowed information processing speed is commonly reported in persons with multiple sclerosis (MS), and is typically investigated using clinical neuropsychological tests, which provide sensitive indices of mean-level information processing speed. However, recent studies have demonstrated that within-person variability or intra-individual variability (IIV) in information processing speed may be a more sensitive indicator of neurologic status than mean-level performance on clinical tests. We evaluated the neural basis of increased IIV in mildly affected relapsing-remitting MS patients by characterizing the relation between IIV (controlling for mean-level performance) and white matter integrity using diffusion tensor imaging (DTI). Twenty women with relapsing-remitting MS and 20 matched control participants completed the Computerized Test of Information Processing (CTIP), from which both mean response time and IIV were calculated. Other clinical measures of information processing speed were also collected. Relations between IIV on the CTIP and DTI metrics of white matter microstructure were evaluated using tract-based spatial statistics. We observed slower and more variable responses on the CTIP in MS patients relative to controls. Significant relations between white matter microstructure and IIV were observed for MS patients. Increased IIV was associated with reduced integrity in more white matter tracts than was slowed information processing speed as measured by either mean CTIP response time or other neuropsychological test scores. Thus, despite the common use of mean-level performance as an index of cognitive dysfunction in MS, IIV may be more sensitive to the overall burden of white matter disease at the microstructural level. Furthermore, our study highlights the potential value of considering within-person fluctuations, in addition to mean-level performance, for uncovering brain-behavior relationships in neurologic disorders with widespread white matter pathology.

  7. Intraindividual variability in inhibitory function in adults with ADHD--an ex-Gaussian approach.

    Directory of Open Access Journals (Sweden)

    Dennis Gmehlin

    Full Text Available OBJECTIVE: Attention deficit disorder (ADHD is commonly associated with inhibitory dysfunction contributing to typical behavioral symptoms like impulsivity or hyperactivity. However, some studies analyzing intraindividual variability (IIV of reaction times in children with ADHD (cADHD question a predominance of inhibitory deficits. IIV is a measure of the stability of information processing and provides evidence that longer reaction times (RT in inhibitory tasks in cADHD are due to only a few prolonged responses which may indicate deficits in sustained attention rather than inhibitory dysfunction. We wanted to find out, whether a slowing in inhibitory functioning in adults with ADHD (aADHD is due to isolated slow responses. METHODS: Computing classical RT measures (mean RT, SD, ex-Gaussian parameters of IIV (which allow a better separation of reaction time (mu, variability (sigma and abnormally slow responses (tau than classical measures as well as errors of omission and commission, we examined response inhibition in a well-established GoNogo task in a sample of aADHD subjects without medication and healthy controls matched for age, gender and education. RESULTS: We did not find higher numbers of commission errors in aADHD, while the number of omissions was significantly increased compared with controls. In contrast to increased mean RT, the distributional parameter mu did not document a significant slowing in aADHD. However, subjects with aADHD were characterized by increased IIV throughout the entire RT distribution as indicated by the parameters sigma and tau as well as the SD of reaction time. Moreover, we found a significant correlation between tau and the number of omission errors. CONCLUSIONS: Our findings question a primacy of inhibitory deficits in aADHD and provide evidence for attentional dysfunction. The present findings may have theoretical implications for etiological models of ADHD as well as more practical implications for

  8. Intraindividual Stepping Reaction Time Variability Predicts Falls in Older Adults With Mild Cognitive Impairment.

    Science.gov (United States)

    Bunce, David; Haynes, Becky I; Lord, Stephen R; Gschwind, Yves J; Kochan, Nicole A; Reppermund, Simone; Brodaty, Henry; Sachdev, Perminder S; Delbaere, Kim

    2017-06-01

    Reaction time measures have considerable potential to aid neuropsychological assessment in a variety of health care settings. One such measure, the intraindividual reaction time variability (IIV), is of particular interest as it is thought to reflect neurobiological disturbance. IIV is associated with a variety of age-related neurological disorders, as well as gait impairment and future falls in older adults. However, although persons diagnosed with Mild Cognitive Impairment (MCI) are at high risk of falling, the association between IIV and prospective falls is unknown. We conducted a longitudinal cohort study in cognitively intact (n = 271) and MCI (n = 154) community-dwelling adults aged 70-90 years. IIV was assessed through a variety of measures including simple and choice hand reaction time and choice stepping reaction time tasks (CSRT), the latter administered as a single task and also with a secondary working memory task. Logistic regression did not show an association between IIV on the hand-held tasks and falls. Greater IIV in both CSRT tasks, however, did significantly increase the risk of future falls. This effect was specific to the MCI group, with a stronger effect in persons exhibiting gait, posture, or physiological impairment. The findings suggest that increased stepping IIV may indicate compromised neural circuitry involved in executive function, gait, and posture in persons with MCI increasing their risk of falling. IIV measures have potential to assess neurobiological disturbance underlying physical and cognitive dysfunction in old age, and aid fall risk assessment and routine care in community and health care settings. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Resting heart rate variability is associated with ex-Gaussian metrics of intra-individual reaction time variability.

    Science.gov (United States)

    Spangler, Derek P; Williams, DeWayne P; Speller, Lassiter F; Brooks, Justin R; Thayer, Julian F

    2018-03-01

    The relationships between vagally mediated heart rate variability (vmHRV) and the cognitive mechanisms underlying performance can be elucidated with ex-Gaussian modeling-an approach that quantifies two different forms of intra-individual variability (IIV) in reaction time (RT). To this end, the current study examined relations of resting vmHRV to whole-distribution and ex-Gaussian IIV. Subjects (N = 83) completed a 5-minute baseline while vmHRV (root mean square of successive differences; RMSSD) was measured. Ex-Gaussian (sigma, tau) and whole-distribution (standard deviation) estimates of IIV were derived from reaction times on a Stroop task. Resting vmHRV was found to be inversely related to tau (exponential IIV) but not to sigma (Gaussian IIV) or the whole-distribution standard deviation of RTs. Findings suggest that individuals with high vmHRV can better prevent attentional lapses but not difficulties with motor control. These findings inform the differential relationships of cardiac vagal control to the cognitive processes underlying human performance. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Intraindividual Variability across Neuropsychological Tests: Dispersion and Disengaged Lifestyle Increase Risk for Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Drew W. R. Halliday

    2018-03-01

    Full Text Available Objective: Increased intraindividual variability (IIV in function has been linked to various age-related outcomes including cognitive decline and dementia. Most studies have operationalized IIV as fluctuations across trials (e.g., response latencies for a single task, with comparatively few studies examining variability across multiple tasks for a given individual. In the present study, we derive a multivariable operationalization of dispersion across a broad profile of neuropsychological measures and use this index along with degree of engaged lifestyle to predict risk of cognitive impairment. Participants and Methods: Participants (n = 60 were community-dwelling older adults aged 65+ years (M = 74.1, SD = 6.5 participating in a cross-sectional investigation of risk factors for amnestic mild cognitive impairment (a-MCI and probable Alzheimer’s Disease (AD. Participants were classified into three subgroups based on test performance and clinical judgement. Healthy controls (n = 30 scored better than −1 SD relative to existing norms on all classification measures, in the absence of memory complaints or functional impairments. The a-MCI group (n = 23 had self- or informant-reported memory complaints and scored 1 SD or more below the mean for at least one memory task while scoring better than 1 SD below the mean for all other cognitive domains, in the absence of functional impairments. The AD group (n = 7 scored at least 2 SD below the mean for two cognitive domains (including memory with impairments in functioning. Measures spanned a range of cognitive domains (episodic memory, executive function, language, with the derived dispersion estimates reflecting variability across an individual’s neuropsychological profile relative to the group average. Further, an Activities Lifestyle Questionnaire, indexing social, cognitive, and physical behaviors, was administered to assess the protective benefits of engaged lifestyle. Results: Multinomial

  11. Plasma Beta-Trace Protein as a Marker of Residual Renal Function: The Effect of Different Hemodialysis Modalities and Intra-Individual Variability over Time

    Directory of Open Access Journals (Sweden)

    Amaryllis H. van Craenenbroeck

    2017-11-01

    Full Text Available Background/Aims: Beta-trace protein (BTP is a low-molecular-weight molecule, which may be used to assess residual renal function (RRF in dialysis patients. Here we evaluated the influence of hemodialysis (HD and hemodiafiltration (HDF on plasma BTP, and analyzed the inter- and intra-individual variability of plasma BTP over time in HD and peritoneal dialysis (PD patients. Methods: In 12 prevalent HD patients, the effect of a single session of low-flux HD, high-flux HD and HDF on plasma BTP was studied. Blood samples were taken at baseline, after 120 and 240 minutes, and at the start of the next dialysis session. In 13 HD patients and 10 PD patients, inter- and intra-individual variability over three months was studied (monthly and weekly, respectively. Plasma BTP was measured using a nephelometric method. Results: No significant decrease in plasma BTP was seen following a session of low-flux HD. Both high-flux HD and HDF resulted in a significant decrease immediately after dialysis (22% and 61% median decrease, respectively. A significant reduction of the molecule persisted only in HDF and a significant decrease (-15% was still found immediately before the start of the next dialysis session. In both HD and PD patients, the reproducibility over time was excellent with intra-class correlation coefficient of 0.96 (0.93-0.99 and 0.92 (0.86-0.99 respectively. In a small cohort of PD patients, fair agreement existed between mGFR (average of renal urea and creatinine clearance from a 24 hours urine collection and the BTP-based GFR estimation. Conclusion: BTP is a stable marker and a promising tool for RRF estimations in PD and HD patients. In patients receiving HDF, plasma levels of BTP should be interpreted with caution.

  12. Step-to-step spatiotemporal variables and ground reaction forces of intra-individual fastest sprinting in a single session.

    Science.gov (United States)

    Nagahara, Ryu; Mizutani, Mirai; Matsuo, Akifumi; Kanehisa, Hiroaki; Fukunaga, Tetsuo

    2018-06-01

    We aimed to investigate the step-to-step spatiotemporal variables and ground reaction forces during the acceleration phase for characterising intra-individual fastest sprinting within a single session. Step-to-step spatiotemporal variables and ground reaction forces produced by 15 male athletes were measured over a 50-m distance during repeated (three to five) 60-m sprints using a long force platform system. Differences in measured variables between the fastest and slowest trials were examined at each step until the 22nd step using a magnitude-based inferences approach. There were possibly-most likely higher running speed and step frequency (2nd to 22nd steps) and shorter support time (all steps) in the fastest trial than in the slowest trial. Moreover, for the fastest trial there were likely-very likely greater mean propulsive force during the initial four steps and possibly-very likely larger mean net anterior-posterior force until the 17th step. The current results demonstrate that better sprinting performance within a single session is probably achieved by 1) a high step frequency (except the initial step) with short support time at all steps, 2) exerting a greater mean propulsive force during initial acceleration, and 3) producing a greater mean net anterior-posterior force during initial and middle acceleration.

  13. Intraindividual variability of sleep/wake patterns in relation to child and adolescent functioning: A systematic review.

    Science.gov (United States)

    Becker, Stephen P; Sidol, Craig A; Van Dyk, Tori R; Epstein, Jeffery N; Beebe, Dean W

    2017-08-01

    Substantial research attention has been devoted to understanding the importance and impact of sleep in children and adolescents. Traditionally, this has focused on mean sleep variables (e.g., a child's "typical" or average sleep duration), yet research increasingly suggests that intraindividual variability (IIV) of sleep/wake patterns (sometimes referred to as sleep variability or night-to-night variability) regularly occurs and may have implications for adjustment. A systematic search of five electronic databases identified 52 empirical studies published between 2000 and 2015 that examined correlates of sleep IIV in children and adolescents, with a recent increase in the publication rate of such studies. Identified studies were often atheoretical and included post hoc analyses, though IIV in select aspects of sleep does appear to be associated with increasing age/pubertal status, non-White race, physical and neurodevelopmental conditions (e.g., attention-deficit/hyperactivity disorder; autism), psychopathology symptoms (e.g., anxiety, depression, inattention), body weight, stress, aspects of cognitive functioning, and poorer sleep functioning/habits. The limited intervention work examining sleep IIV in adolescents is promising, though studies are needed using more rigorous intervention designs. Clinical sleep recommendations may not only need to address overall sleep duration and sleep habits but also the stability of sleep duration and timing. It will be important for future research examining sleep IIV in children and adolescents to use a developmental framework in advancing theory pertaining to the causes, mechanisms, moderators, and outcomes of sleep IIV in youth, and a conceptual model is proposed to help guide such efforts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Evaluation of intra-individual test–re-test variability of uroflowmetry in healthy women and women suffering from stress, urge, and mixed urinary incontinence

    DEFF Research Database (Denmark)

    Lunacek, Libor; Gärtner, Marcel; Krhut, Jan

    2018-01-01

    Introduction and hypothesis: The objective was to evaluate the intra-individual variability of uroflowmetry (UFM) in healthy control subjects and women suffering from stress, urge, and mixed urinary incontinence. Methods: A total of 35 healthy controls (group A) and 105 women suffering from urinary...... incontinence were enrolled in the study. Thirty-five women suffered from stress urinary incontinence (group B), 35 women suffered from mixed urinary incontinence (group C), and 35 women with overactive bladder both dry and wet (group D). All participants were asked to perform UFM measurement three times......-individual difference in any of the recorded parameters was identified among the three UFM recordings in groups A, C, and D. The intra-individual variability of the following parameters reached statistical significance in patients suffering from stress urinary incontinence (group B): Qmax (p = 0.0016), Qave (p = 0...

  15. Prospective memory and intraindividual variability in ongoing task response times in an adult lifespan sample: the role of cue focality.

    Science.gov (United States)

    Ihle, Andreas; Ghisletta, Paolo; Kliegel, Matthias

    2017-03-01

    To contribute to the ongoing conceptual debate of what traditional mean-level ongoing task (OT) costs tell us about the attentional processes underlying prospective memory (PM), we investigated costs to intraindividual variability (IIV) in OT response times as a potentially sensitive indicator of attentional processes. Particularly, we tested whether IIV in OT responses may reflect controlled employment of attentional processes versus lapses of controlled attention, whether these processes differ across adulthood, and whether it is moderated by cue focality. We assessed 150 individuals (19-82 years) in a focal and a nonfocal PM condition. In addition, external measures of inhibition and working memory were assessed. In line with the predictions of the lapses-of-attention/inefficient-executive-control account, our data support the view that costs to IIV in OT trials of PM tasks reflect fluctuations in the efficiency of executive functioning, which was related to failures in prospective remembering, particularly in nonfocal PM tasks, potentially due to their increased executive demands. The additional value of considering costs to IIV over and beyond traditional mean-level OT costs in PM research is discussed.

  16. Intraindividual variability in executive functions but not speed of processing or conflict resolution predicts performance differences in gait speed in older adults.

    Science.gov (United States)

    Holtzer, Roee; Mahoney, Jeannette; Verghese, Joe

    2014-08-01

    The relationship between executive functions (EF) and gait speed is well established. However, with the exception of dual tasking, the key components of EF that predict differences in gait performance have not been determined. Therefore, the current study was designed to determine whether processing speed, conflict resolution, and intraindividual variability in EF predicted variance in gait performance in single- and dual-task conditions. Participants were 234 nondemented older adults (mean age 76.48 years; 55% women) enrolled in a community-based cohort study. Gait speed was assessed using an instrumented walkway during single- and dual-task conditions. The flanker task was used to assess EF. Results from the linear mixed effects model showed that (a) dual-task interference caused a significant dual-task cost in gait speed (estimate = 35.99; 95% CI = 33.19-38.80) and (b) of the cognitive predictors, only intraindividual variability was associated with gait speed (estimate = -.606; 95% CI = -1.11 to -.10). In unadjusted analyses, the three EF measures were related to gait speed in single- and dual-task conditions. However, in fully adjusted linear regression analysis, only intraindividual variability predicted performance differences in gait speed during dual tasking (B = -.901; 95% CI = -1.557 to -.245). Among the three EF measures assessed, intraindividual variability but not speed of processing or conflict resolution predicted performance differences in gait speed. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Age differences in coupling of intraindividual variability in mnemonic strategies and practice-related associative recall improvements.

    Science.gov (United States)

    Hertzog, Christopher; Lövdén, Martin; Lindenberger, Ulman; Schmiedek, Florian

    2017-09-01

    The importance of encoding strategies for associative recall is well established, but there have been no studies of aging and intraindividual variability (IAV) in strategy use during extended practice. We observed strategy use and cued-recall test performance over 101 days of practice in 101 younger adults (M = 25.6 years) and 103 older adults (M = 71.3 years) sandwiched by a pretest and posttest battery including an associative recall test. Each practice session included 2 lists of 12 number-noun paired-associate (PA) items (e.g., 23-DOGS), presented for brief exposures titrated to maintain below-ceiling performance throughout practice. Participants reported strategy use (e.g., rote repetition, imagery) after each test. Substantial IAV in strategy use was detected that was coupled with performance; lists studied with normatively effective strategies (e.g., imagery) generated higher PA recall than lists studied with less effective strategies (e.g., rote repetition). In comparison to younger adults, older adults' practice (a) relied more on repetition and less on effective strategies, (b) showed lower levels of IAV in effective strategy use, and (c) had lower within-person strategy-recall coupling, especially late in practice. Individual differences in pretest-posttest gains in PA recall were predicted by average level of effective strategy use in young adults but by strategy-recall coupling in older adults. Results are consistent with the hypothesis that experiencing variability in strategic outcomes during practice helps hone the effectiveness of strategic encoding behavior, and that older adults' reduced degree of pretest-posttest gains is influenced by lower likelihood of using and optimizing effective strategies through practice. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  18. Intraindividual variability across cognitive domains: investigation of dispersion levels and performance profiles in older adults.

    Science.gov (United States)

    Hilborn, Jennifer V; Strauss, Esther; Hultsch, David F; Hunter, Michael A

    2009-05-01

    A growing body of research suggests that substantial variability exists among cognitive abilities within individuals. This within-person variability across cognitive domains is termed dispersion. The present study investigated the relationship between aging and dispersion of cognitive functions both quantitatively (overall levels of dispersion) and qualitatively (patterns of dispersion) in a sample of 304 nondemented, older adults aged 64 to 92 years (M = 74.02). Quantitatively, higher levels of dispersion were observed in the old-old adults (aged 75-92 years) and those identified as having experienced cognitive decline, suggesting that dispersion level may serve as a marker of cognitive integrity. Qualitatively, three distinct dispersion profiles were identified through clustering methods, and these were found to be related to demographic, health, and performance characteristics of the individuals, suggesting that patterns of dispersion may be meaningful indicators of individual differences.

  19. Intraindividual Variability and Long-Term Changes of Thermal Quantitative Sensory Testing

    DEFF Research Database (Denmark)

    Krøigård, Thomas; Sothynathan, Isaivani; Sindrup, Søren H

    2015-01-01

    Thermal threshold examinations are widely used in the clinical setting and in studies to assess the function of the peripheral sensory nervous system. Little is known about the variation from one side of the body to the other and the long-term temporal changes and variability. In this study, 134...... and foot. Bilateral stimulations resulted in relative intertrial variations ranging from 19% to 40%. There was no significant temporal change for repeated measures. Analysis of the individual measurements of each subject at baseline and at 26 weeks, however, resulted in relatively large intertrial...

  20. Heritability of Intraindividual Mean and Variability of Positive and Negative Affect.

    Science.gov (United States)

    Zheng, Yao; Plomin, Robert; von Stumm, Sophie

    2016-12-01

    Positive affect (e.g., attentiveness) and negative affect (e.g., upset) fluctuate over time. We examined genetic influences on interindividual differences in the day-to-day variability of affect (i.e., ups and downs) and in average affect over the duration of a month. Once a day, 17-year-old twins in the United Kingdom ( N = 447) rated their positive and negative affect online. The mean and standard deviation of each individual's daily ratings across the month were used as the measures of that individual's average affect and variability of affect. Analyses revealed that the average of negative affect was significantly heritable (.53), but the average of positive affect was not; instead, the latter showed significant shared environmental influences (.42). Fluctuations across the month were significantly heritable for both negative affect (.54) and positive affect (.34). The findings support the two-factor theory of affect, which posits that positive affect is more situational and negative affect is more dispositional.

  1. Intra-individual response variability assessed by ex-gaussian analysis may be a new endophenotype for Attention Deficit / Hyperactivity Disorder

    Directory of Open Access Journals (Sweden)

    Marcela Patricia Henríquez-Henríquez

    2015-01-01

    Full Text Available Intra-individual variability of Response Times (RTisv is considered as potential endophenotype for Attentional Deficit/Hyperactivity Disorder (ADHD. Traditional methods for estimating RTisv lose information regarding Response Times (RTs distribution along the task, with eventual effects on statistical power. Ex-Gaussian analysis captures the dynamic nature of RTisv, estimating normal and exponential components for RT distribution, with specific phenomenological correlates. Here, we applied ex-Gaussian analysis to explore whether intra-individual variability of RTs agrees with criteria proposed by Gottesman and Gould for endophenotypes. Specifically, we evaluated if Normal and/or exponential components of RTs may a Present the stair-like distribution expected for endophenotypes (ADHD>Siblings>Typically Developing children (TD without familiar history of ADHD and b Represent a phenotypic correlate for previously described genetic risk variants. This is a pilot study including 55 subjects (20 ADHD-discordant sibling-pairs and 15 TD children, all aged between 8 and 13 years. Participants resolved a visual Go/Nogo with 10% Nogo probability. Ex-Gaussian distributions were fitted to individual RT data and compared among the three samples. In order to test whether intra-individual variability may represent a correlate for previously described genetic risk variants, VNTRs at DRD4 and SLC6A3 were identified in all sibling pairs following standard protocols. Groups were compared adjusting independent general linear models for the exponential and normal components from the ex-gaussian analysis. Identified trends were confirmed by the non-parametric Jonckheere-Terpstra test. Stair-like distributions were observed for μ (p=0.036 and σ (p=0.009. An additional DRD4-genotype X clinical status interaction was present for τ (p=0,014 reflecting a possible severity factor. Thus, Normal and exponential RTisv components are suitable as ADHD endophenotypes.

  2. Intra-individual variability in the urine concentrations of inhaled salmeterol in male subjects with reference to doping analysis – impact of urine specific gravity correction

    DEFF Research Database (Denmark)

    Hostrup, Morten; Kalsen, Anders; Hemmersbach, Peter

    2012-01-01

    and a-hydroxysalmeterol during visits one and two were 12.6 and 21.8%, respectively. The intra-individual variability of salmeterol and a-hydroxysalmeterol in the urine concentrations were significantly higher when uncorrected for USG with 43.0 and 43.7% versus 20.4% (p...Since 2010, the World Anti-Doping Agency (WADA) has introduced urinary thresholds for some beta2-agonists. In doping analysis urine samples of beta2-agonists are not corrected for the Urine Specific Gravity (USG) by the WADA laboratories. Several studies have observed high differences in the urine...

  3. Assessing inter- and intra-individual cognitive variability in patients at risk for cognitive impairment: the case of minimal hepatic encephalopathy.

    Science.gov (United States)

    Bisiacchi, Patrizia; Cona, Giorgia; Tarantino, Vincenza; Schiff, Sami; Montagnese, Sara; Amodio, Piero; Capizzi, Giovanna

    2014-12-01

    Recent evidence reveals that inter- and intra-individual variability significantly affects cognitive performance in a number of neuropsychological pathologies. We applied a flexible family of statistical models to elucidate the contribution of inter- and intra-individual variables on cognitive functioning in healthy volunteers and patients at risk for hepatic encephalopathy (HE). Sixty-five volunteers (32 patients with cirrhosis and 33 healthy volunteers) were assessed by means of the Inhibitory Control Task (ICT). A Generalized Additive Model for Location, Scale and Shape (GAMLSS) was fitted for jointly modeling the mean and the intra-variability of Reaction Times (RTs) as a function of socio-demographic and task related covariates. Furthermore, a Generalized Linear Mixed Model (GLMM) was fitted for modeling accuracy. When controlling for the covariates, patients without minimal hepatic encephalopathy (MHE) did not differ from patients with MHE in the low-demanding condition, both in terms of RTs and accuracy. Moreover, they showed a significant decline in accuracy compared to the control group. Compared to patients with MHE, patients without MHE showed faster RTs and higher accuracy only in the high-demanding condition. The results revealed that the application of GAMLSS and GLMM models are able to capture subtle cognitive alterations, previously not detected, in patients' subclinical pathologies.

  4. Intraindividual variability in cognitive performance in three groups of older adults: cross-domain links to physical status and self-perceived affect and beliefs.

    Science.gov (United States)

    Strauss, Esther; MacDonald, Stuart W S; Hunter, Michael; Moll, Alex; Hultsch, David F

    2002-11-01

    Intraindividual variability of physical status and affect/beliefs as well as their relations with cognition were examined in 3 groups of older adults: healthy elderly, individuals with a nonneurological health-related disturbance (arthritis) and people with neurological compromise (dementia). The findings showed that greater inconsistency in physical performance was observed in groups characterized by central nervous system dysfunction. By contrast, fluctuations in affect appeared to reflect other more transient sources, such as pain. In general, increased inconsistency in non-cognitive domains was associated with poorer cognitive function. There were cross-domain links between inconsistency in physical functioning and fluctuations in cognitive performance, although the nature of the links depended largely upon the neurological status of the individuals. Considered together, the result indicated that measures of cognitive as well as physical variability are important behavioral markers of neurological integrity.

  5. Now You’re With Me, Now You’re Not: Between-Session and Within-Session Intra-Individual Variability in Attention in Aphasia

    Directory of Open Access Journals (Sweden)

    Sarah Villard

    2015-05-01

    Full Text Available Introduction: Patients with aphasia (PWA have been found to exhibit impaired performance on attention tasks relative to healthy controls, even when tasks contain only non-linguistic stimuli (e.g. Robin & Rizzo, 1989. Additionally, our previous work has shown that PWA exhibit increased day-to-day, or between-session, intra-individual variability (BS-IIV on non-linguistic attention tasks (Villard & Kiran, 2015. The current study examines BS-IIV, as well as moment-to-moment, or within-session, intra-individual variability (WS-IIV, in performance on a series of non-linguistic and linguistic attention tasks. We theorize that BS-IIV and WS-IIV may be critical metrics for understanding attention processing in PWA. Methods: Data from 17 PWA and 17 age-matched healthy controls have been analyzed; data is expected from a total of 20 in each group. Each participant completed a series of five computerized experimental tasks of incrementally increasing demands/complexity. Task 1 measured non-linguistic sustained visual attention; Task 2 added visual distractor stimuli; Task 3 added non-linguistic target auditory stimuli, requiring integration of two modalities; Task 4 added lexical decision demands; and Task 5 added lexical-semantic processing demands. This series of five tasks was administered four times, on four different non-consecutive days. We hypothesized that increased task complexity would elicit increased BS-IIV and WS-IIV in attention for PWA but not for controls. Data Analysis: In order to examine BS-IIV and WS-IIV in reaction time (RT, coefficients of variation (COVs, or the standard deviation over the mean were calculated for each participant, on each task. Specifically, a COV representing BS-IIV in RT (BS-COV was calculated for each participant, each task, using data collected across the four sessions. Similarly, a COV representing WS-IIV in RT (WS-COV was calculated for each participant, each task, using data collected within a single session

  6. Reliability and short-term intra-individual variability of telomere length measurement using monochrome multiplexing quantitative PCR.

    Directory of Open Access Journals (Sweden)

    Sangmi Kim

    Full Text Available Studies examining the association between telomere length and cancer risk have often relied on measurement of telomere length from a single blood draw using a real-time PCR technique. We examined the reliability of telomere length measurement using sequential samples collected over a 9-month period.Relative telomere length in peripheral blood was estimated using a single tube monochrome multiplex quantitative PCR assay in blood DNA samples from 27 non-pregnant adult women (aged 35 to 74 years collected in 7 visits over a 9-month period. A linear mixed model was used to estimate the components of variance for telomere length measurements attributed to variation among women and variation between time points within women. Mean telomere length measurement at any single visit was not significantly different from the average of 7 visits. Plates had a significant systematic influence on telomere length measurements, although measurements between different plates were highly correlated. After controlling for plate effects, 64% of the remaining variance was estimated to be accounted for by variance due to subject. Variance explained by time of visit within a subject was minor, contributing 5% of the remaining variance.Our data demonstrate good short-term reliability of telomere length measurement using blood from a single draw. However, the existence of technical variability, particularly plate effects, reinforces the need for technical replicates and balancing of case and control samples across plates.

  7. Developmental Associations between Short-Term Variability and Long-Term Changes: Intraindividual Correlation of Positive and Negative Affect in Daily Life and Cognitive Aging

    Science.gov (United States)

    Hülür, Gizem; Hoppmann, Christiane A.; Ram, Nilam; Gerstorf, Denis

    2015-01-01

    Conceptual notions and empirical evidence suggest that the intraindividual correlation (iCorr) of positive affect (PA) and negative affect (NA) is a meaningful characteristic of affective functioning. PA and NA are typically negatively correlated within-person. Previous research has found that the iCorr of PA and NA is relatively stable over time…

  8. Intra-individual cognitive imbalance in ASD between perceptual reasoning and ambiguity-solving related to tool use: Comparison among children exhibiting ASD, AD/HD, and typical development.

    Science.gov (United States)

    Wakusawa, Keisuke; Nara, Chieko; Kubota, Yuki; Tomizawa, Yayoi; Taki, Yasuyuki; Sassa, Yuko; Kobayashi, Satoru; Suzuki-Muromoto, Sato; Hirose, Mieko; Yokoyama, Hiroyuki; Nara, Takahiro; Kure, Shigeo; Mori, Norio; Takei, Noriyoshi; Kawashima, Ryuta

    2018-01-01

    Several studies have suggested that objective deficits in the processing of abstract information in conjunction with an enhanced ability to process concrete information is a definitive characteristic of autism spectrum disorder (ASD). However, this cognitive imbalance is not necessarily clear in high-functioning autistic individuals who do not display absolute differences relative to typically developing (TD) populations. Thus, the purpose of this study was to identify this cognitive tendency in high-functioning autistic individuals using intra-individual cognitive comparisons. The reaction times (RTs) of TD children, children with ASD, and children with attention deficit hyperactivity disorder (AD/HD) (n=17 in each group, mean age=11.9years, age range=9.8-15.8years) were compared using the Which/How-to-Apply Tools (W/HAT) test, which consists of tasks requiring the adaptive use of novel tools and familiar tools in atypical and typical situations. Differences in RTs between the atypical and typical trials ([A-T]) were used to assess intra-individual cognitive imbalances. As predicted, the [A-T] scores of the ASD group were significantly higher than those of the TD group even though the RTs in the atypical and typical trials did not differ. Additionally, the [A-T] values were significantly higher in the ASD group than in the AD/HD group, which indicates that the cognitive imbalance was specific to ASD individuals. No significant interaction was detected between the trial and subject group. The findings of this study demonstrate that a cognitive imbalance in ASD individuals may enhance the current understanding of the pathophysiology of this disorder, which is found in a range of individuals, including those with obvious cortical dysfunction to those with only intra-individual imbalances. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  9. Atomoxetine could improve intra-individual variability in drug-naïve adults with attention-deficit/hyperactivity disorder comparably with methylphenidate: A head-to-head randomized clinical trial.

    Science.gov (United States)

    Ni, Hsing-Chang; Hwang Gu, Shoou-Lian; Lin, Hsiang-Yuan; Lin, Yu-Ju; Yang, Li-Kuang; Huang, Hui-Chun; Gau, Susan Shur-Fen

    2016-05-01

    Intra-individual variability in reaction time (IIV-RT) is common in individuals with attention-deficit/hyperactivity disorder (ADHD). It can be improved by stimulants. However, the effects of atomoxetine on IIV-RT are inconclusive. We aimed to investigate the effects of atomoxetine on IIV-RT, and directly compared its efficacy with methylphenidate in adults with ADHD. An 8-10 week, open-label, head-to-head, randomized clinical trial was conducted in 52 drug-naïve adults with ADHD, who were randomly assigned to two treatment groups: immediate-release methylphenidate (n=26) thrice daily (10-20 mg per dose) and atomoxetine once daily (n=26) (0.5-1.2 mg/kg/day). IIV-RT, derived from the Conners' continuous performance test (CCPT), was represented by the Gaussian (reaction time standard error, RTSE) and ex-Gaussian models (sigma and tau). Other neuropsychological functions, including response errors and mean of reaction time, were also measured. Participants received CCPT assessments at baseline and week 8-10 (60.4±6.3 days). We found comparable improvements in performances of CCPT between the immediate-release methylphenidate- and atomoxetine-treated groups. Both medications significantly improved IIV-RT in terms of reducing tau values with comparable efficacy. In addition, both medications significantly improved inhibitory control by reducing commission errors. Our results provide evidence to support that atomoxetine could improve IIV-RT and inhibitory control, of comparable efficacy with immediate-release methylphenidate, in drug-naïve adults with ADHD. Shared and unique mechanisms underpinning these medication effects on IIV-RT awaits further investigation. © The Author(s) 2016.

  10. No further gain can be achieved by calculating Disease Activity Score in 28 joints with high-sensitivity assay of C-reactive protein because of high intraindividual variability of C-reactive protein: A cross-sectional study and theoretical consideration.

    Science.gov (United States)

    Hansen, Inger M J; Emamifar, Amir; Andreasen, Rikke A; Antonsen, Steen

    2017-01-01

    Disease Activity Score in 28 joints (DAS28) is commonly used to evaluate disease activity of rheumatoid arthritis (RA) and is a guide to treatment decision.The aim of this study was to evaluate the impact of lower reporting limit for C-reactive protein (CRP), with respect to intraindividual biological variability, on the calculation of DAS28 and subsequent patient classification.This study consists of 2 sections: a theoretical consideration discussing the performance of CRP in calculating DAS28 taking intraindividual biological variation and lower reporting limit for CRP into account and a cross-sectional study of RA patients applying our theoretical results. Therefore, we calculated DAS28 twice, with the actual CRP values and CRP = 9 mg/L, the latter to elucidate the positive effects of reducing the lower reporting limit of CRP from <10 to <3 mg/L.Lower-reporting limit of <10 mg/L leads to overestimate DAS28. However, reducing lower reporting limit for CRP to <3 mg/L results in optimizing DAS28 calculation. Further lowering of reporting limit for CRP to <3 mg/L does not increase the precision of DAS28 owing to the relatively large intraindividual biological variation.Five hundred twelve patients were included. There was a significant difference between recalculated and patients DAS28 (P < 0.001). One hundred nine patients had DAS28 deviation (compatible to remission to low: 66, low to moderate: 39. and moderate to high: 4).Owing to significant impact of intraindividual biologic variation on DAS28 and patient classification, special attention should be paid to calculate DAS28 when CRP values are within normal range. Furthermore, we conclude that results of different studies evaluating DAS28 and treatment response are not comparable if the reporting limits of CRP are unknown.

  11. Intra-individual biological variation in sweat chloride concentrations in CF, CFTR dysfunction, and healthy pediatric subjects.

    Science.gov (United States)

    Cirilli, Natalia; Raia, Valeria; Rocco, Ilaria; De Gregorio, Fabiola; Tosco, Antonella; Salvadori, Laura; Sepe, Angela Ornella; Buzzetti, Roberto; Minicuci, Nadia; Castaldo, Giuseppe

    2018-04-02

    The sweat test is one of the main diagnostic tools used in newborn screening programs and as a confirmatory test, in case of suspect of Cystic Fibrosis (CF). Since sweat chloride (Cl) concentration is also considered an appropriate parameter to explore the efficacy of CFTR modulators in clinical trials, it is crucial to evaluate the biological variability of this test in healthy and pathological conditions. The aim of this pilot study was to determine the intra-individual biological variability of sweat Cl, both in healthy individuals and CF patients and to assess its correlation with diet, season, and menstrual cycle. Thirty-five out of 36 selected subjects (6-18 years) were enrolled by 2 CF care centers and assigned to 3 cohorts: CF, CFTR-related disorder (CFTR-RD) and healthy volunteers. Each participant was subjected to eight sweat tests in different conditions and time of the year. Data were analyzed using linear mixed effects models for repeated measures, taking also into account intra-individual correlations. We observed a high intra-individual variability of sweat Cl, with the lowest mean CV% values among CF patients (20.21 in CF, 29.74 in CFTR-RD, and 31.15 in healthy subjects). Gender and diet had no influence on sweat Cl variability, nor had pubertal age and menstrual phase. Results of this pilot study confirmed that sweat Cl variability is high in CF patients, although non-CF individuals displayed even higher mean CV% values. Season significantly influenced sweat test values only in CF patients, likely due to changes in their hydration status. © 2018 Wiley Periodicals, Inc.

  12. Intraindividual variation of triiodothyronine, thyroxine, thyrotropin and thyroxine-binding globulin in fasting serum from healthy men

    International Nuclear Information System (INIS)

    Liappis, N.; Hoffmann, U.; Rao, M.L.

    1986-01-01

    The concentrations of triiodothyronine, thyroxine, thyrotropin and thyroxine-binding globulin were determined in fasting serum from 11 healthy men (age 18-25 years) by radioimmunoassays conducted over a period of 4 weeks on 5 consecutive days per week. The concentrations of thyroxine and thyroxine-binding globulin were very consistent intraindividually, with coefficients of variation of 7.84% and 9.37%, respectively. The triiodothyronine and thyrotropin levels showed significant intraindividual variability with coefficients of variation of 18.38% and 51.85%, respectively. These results point to the type of difficulties encountered in judging serum values, namely intraindividual variations over a given period of time. (orig.) [de

  13. Analysis and Prediction of Micromilling Stability with Variable Tool Geometry

    Directory of Open Access Journals (Sweden)

    Ziyang Cao

    2014-11-01

    Full Text Available Micromilling can fabricate miniaturized components using micro-end mill at high rotational speeds. The analysis of machining stability in micromilling plays an important role in characterizing the cutting process, estimating the tool life, and optimizing the process. A numerical analysis and experimental method are presented to investigate the chatter stability in micro-end milling process with variable milling tool geometry. The schematic model of micromilling process is constructed and the calculation formula to predict cutting force and displacements is derived. This is followed by a detailed numerical analysis on micromilling forces between helical ball and square end mills through time domain and frequency domain method and the results are compared. Furthermore, a detailed time domain simulation for micro end milling with straight teeth and helical teeth end mill is conducted based on the machine-tool system frequency response function obtained through modal experiment. The forces and displacements are predicted and the simulation result between variable cutter geometry is deeply compared. The simulation results have important significance for the actual milling process.

  14. Intraindividual variation in levels of serum testosterone and other reproductive and adrenal hormones in men.

    Science.gov (United States)

    Brambilla, Donald J; O'Donnell, Amy B; Matsumoto, Alvin M; McKinlay, John B

    2007-12-01

    Estimates of intraindividual variation in hormone levels provide the basis for interpreting hormone measurements clinically and for developing eligibility criteria for trials of hormone replacement therapy. However, reliable systematic estimates of such variation are lacking. To estimate intraindividual variation of serum total, free and bioavailable testosterone (T), dihydrotestosterone (DHT), SHBG, LH, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), oestrone, oestradiol and cortisol, and the contributions of biological and assay variation to the total. Paired blood samples were obtained 1-3 days apart at entry and again 3 months and 6 months later (maximum six samples per subject). Each sample consisted of a pool of equal aliquots of two blood draws 20 min apart. Men aged 30-79 years were randomly selected from the respondents to the Boston Area Community Health Survey, a study of the health of the general population of Boston, MA, USA. Analysis was based on 132 men, including 121 who completed all six visits, 8 who completed the first two visits and 3 who completed the first four visits. Day-to-day and 3-month (long-term) intraindividual standard deviations, after transforming measurements to logarithms to eliminate the contribution of hormone level to intraindividual variation. Biological variation generally accounted for more of total intraindividual variation than did assay variation. Day-to-day biological variation accounted for more of the total than did long-term biological variation. Short-term variability was greater in hormones with pulsatile secretion (e.g. LH) than those that exhibit less ultradian variation. Depending on the hormone, the intraindividual standard deviations imply that a clinician can expect to see a difference exceeding 18-28% about half the time when two measurements are made on a subject. The difference will exceed 27-54% about a quarter of the time. Given the level of intraindividual variability in hormone

  15. Intra-individual variability in day-to-day and month-to-month measurements of physical activity and sedentary behaviour at work and in leisure-time among Danish adults.

    Science.gov (United States)

    Pedersen, E S L; Danquah, I H; Petersen, C B; Tolstrup, J S

    2016-12-03

    Accelerometers can obtain precise measurements of movements during the day. However, the individual activity pattern varies from day-to-day and there is limited evidence on measurement days needed to obtain sufficient reliability. The aim of this study was to examine variability in accelerometer derived data on sedentary behaviour and physical activity at work and in leisure-time during week days among Danish office employees. We included control participants (n = 135) from the Take a Stand! Intervention; a cluster randomized controlled trial conducted in 19 offices. Sitting time and physical activity were measured using an ActiGraph GT3X+ fixed on the thigh and data were processed using Acti4 software. Variability was examined for sitting time, standing time, steps and time spent in moderate-to-vigorous physical activity (MVPA) per day by multilevel mixed linear regression modelling. Results of this study showed that the number of days needed to obtain a reliability of 80% when measuring sitting time was 4.7 days for work and 5.5 days for leisure time. For physical activity at work, 4.0 days and 4.2 days were required to measure steps and MVPA, respectively. During leisure time, more monitoring time was needed to reliably estimate physical activity (6.8 days for steps and 5.8 days for MVPA). The number of measurement days needed to reliably estimate activity patterns was greater for leisure time than for work time. The domain specific variability is of great importance to researchers and health promotion workers planning to use objective measures of sedentary behaviour and physical activity. Clinical trials NCT01996176 .

  16. There Is No Further Gain from Calculating Disease Activity Score in 28 Joints with High Sensitivity Assays of C-Reactive Protein Because of High Intraindividual Variability of CRP: A Cross Sectional Study and Theoretical Consideration

    DEFF Research Database (Denmark)

    Jensen Hansen, Inger Marie; Asmussen Andreasen, Rikke; Antonsen, Steen

    Background/Purpose: The threshold for reporting of C-reactive protein (CRP) differs from laboratory to laboratory. Moreover, CRP values are affected by the intra individual biological variability.[1] With respect to disease activity score in 28 joints (DAS28) and Rheumatoid Arthritis (RA), precise...... threshold for reporting CRP is important due to the direct effects of CRP on calculating DAS28, patient classification and subsequent treatment decisions[2] Methods: This study consists of two sections: a theoretical consideration discussing the performance of CRP in calculating DAS28 with regard...... to the biological variation and reporting limit for CRP and a cross sectional study of all RA patients from our department (n=876) applying our theoretical results. In the second section, we calculate DAS28 twice with actual CRP and CRP=9, the latter to elucidate the positive consequences of changing the lower...

  17. There Is No Further Gain from Calculating Disease Activity Score in 28 Joints with High Sensitivity Assays of C-Reactive Protein Because of High Intraindividual Variability of CRP

    DEFF Research Database (Denmark)

    Jensen Hansen, Inger Marie; Asmussen Andreasen, Rikke; Antonsen, Steen

    2016-01-01

    Background/Purpose: The threshold for reporting of C-reactive protein (CRP) differs from laboratory to laboratory. Moreover, CRP values are affected by the intra individual biological variability.[1] With respect to disease activity score in 28 joints (DAS28) and Rheumatoid Arthritis (RA), precise...... threshold for reporting CRP is important due to the direct effects of CRP on calculating DAS28, patient classification and subsequent treatment decisions[2] Methods: This study consists of two sections: a theoretical consideration discussing the performance of CRP in calculating DAS28 with regard...... to the biological variation and reporting limit for CRP and a cross sectional study of all RA patients from our department (n=876) applying our theoretical results. In the second section, we calculate DAS28 twice with actual CRP and CRP=9, the latter to elucidate the positive consequences of changing the lower...

  18. Intra-individual variability in day-to-day and month-to-month measurements of physical activity and sedentary behaviour at work and in leisure-time among Danish adults

    DEFF Research Database (Denmark)

    Lunde Pedersen, Eva Sophie; Danquah, I H; Petersen, C B

    2016-01-01

    in accelerometer derived data on sedentary behaviour and physical activity at work and in leisure-time during week days among Danish office employees. METHODS: We included control participants (n = 135) from the Take a Stand! Intervention; a cluster randomized controlled trial conducted in 19 offices. Sitting time....... RESULTS: Results of this study showed that the number of days needed to obtain a reliability of 80% when measuring sitting time was 4.7 days for work and 5.5 days for leisure time. For physical activity at work, 4.0 days and 4.2 days were required to measure steps and MVPA, respectively. During leisure...... time, more monitoring time was needed to reliably estimate physical activity (6.8 days for steps and 5.8 days for MVPA). CONCLUSIONS: The number of measurement days needed to reliably estimate activity patterns was greater for leisure time than for work time. The domain specific variability is of great...

  19. Business Process Variability : A Tool for Declarative Template Design

    NARCIS (Netherlands)

    Bulanov, P.; Groefsema, H.; Aiello, M.

    2012-01-01

    To lower both implementation time and cost, many Business Process Management tools use process templates to implement highly recurring processes. However, in order for such templates to be used, a process has to adhere substantially to the template. Therefore, current practice for processes which

  20. A Tool for Estimating Variability in Wood Preservative Treatment Retention

    Science.gov (United States)

    Patricia K. Lebow; Adam M. Taylor; Timothy M. Young

    2015-01-01

    Composite sampling is standard practice for evaluation of preservative retention levels in preservative-treated wood. Current protocols provide an average retention value but no estimate of uncertainty. Here we describe a statistical method for calculating uncertainty estimates using the standard sampling regime with minimal additional chemical analysis. This tool can...

  1. Systems and software variability management concepts, tools and experiences

    CERN Document Server

    Capilla, Rafael; Kang, Kyo-Chul

    2013-01-01

    The success of product line engineering techniques in the last 15 years has popularized the use of software variability as a key modeling approach for describing the commonality and variability of systems at all stages of the software lifecycle. Software product lines enable a family of products to share a common core platform, while allowing for product specific functionality being built on top of the platform. Many companies have exploited the concept of software product lines to increase the resources that focus on highly differentiating functionality and thus improve their competitiveness

  2. Heart rate variability: a tool to explore the sleeping brain?

    OpenAIRE

    Chouchou, Florian; Desseilles, Martin

    2014-01-01

    Sleep is divided into two main sleep stages: (1) non-rapid eye movement sleep (non-REMS), characterized among others by reduced global brain activity; and (2) rapid eye movement sleep (REMS), characterized by global brain activity similar to that of wakefulness. Results of heart rate variability (HRV) analysis, which is widely used to explore autonomic modulation, have revealed higher parasympathetic tone during normal non-REMS and a shift toward sympathetic predominance during normal REMS. M...

  3. Variability of building environmental assessment tools on evaluating carbon emissions

    Energy Technology Data Exchange (ETDEWEB)

    Ng, S. Thomas, E-mail: tstng@hkucc.hku.hk; Chen Yuan, E-mail: chenyuan4@gmail.com; Wong, James M.W., E-mail: jmwwong@hku.hk

    2013-01-15

    With an increasing importance of sustainability in construction, more and more clients and designers employ building environmental assessment (BEA) tools to evaluate the environmental friendliness of their building facilities, and one important aspect of evaluation in the BEA models is the assessment of carbon emissions. However, in the absence of any agreed framework for carbon auditing and benchmarking, the results generated by the BEA tools might vary significantly which could lead to confusion or misinterpretation on the carbon performance of a building. This study thus aims to unveil the properties of and the standard imposed by the current BEA models on evaluating the life cycle carbon emissions. The analyses cover the (i) weighting of energy efficiency and emission levels among various environmental performance indicators; (ii) building life cycle stages in which carbon is taken into consideration; (iii) objectiveness of assessment; (iv) baseline set for carbon assessment; (v) mechanism for benchmarking the emission level; and (v) limitations of the carbon assessment approaches. Results indicate that the current BEA schemes focus primarily on operational carbon instead of the emissions generated throughout the entire building life cycle. Besides, the baseline and benchmark for carbon evaluation vary significantly among the BEA tools based on the analytical results of a hypothetical building. The findings point to the needs for a more transparent framework for carbon auditing and benchmarking in BEA modeling. - Highlights: Black-Right-Pointing-Pointer Carbon emission evaluation in building environmental assessment schemes are studied. Black-Right-Pointing-Pointer Simulative carbon emission is modeled for building environmental assessment schemes. Black-Right-Pointing-Pointer Carbon assessments focus primarily on operational stage instead of entire lifecycle. Black-Right-Pointing-Pointer Baseline and benchmark of carbon assessment vary greatly among BEA

  4. Variability of building environmental assessment tools on evaluating carbon emissions

    International Nuclear Information System (INIS)

    Ng, S. Thomas; Chen Yuan; Wong, James M.W.

    2013-01-01

    With an increasing importance of sustainability in construction, more and more clients and designers employ building environmental assessment (BEA) tools to evaluate the environmental friendliness of their building facilities, and one important aspect of evaluation in the BEA models is the assessment of carbon emissions. However, in the absence of any agreed framework for carbon auditing and benchmarking, the results generated by the BEA tools might vary significantly which could lead to confusion or misinterpretation on the carbon performance of a building. This study thus aims to unveil the properties of and the standard imposed by the current BEA models on evaluating the life cycle carbon emissions. The analyses cover the (i) weighting of energy efficiency and emission levels among various environmental performance indicators; (ii) building life cycle stages in which carbon is taken into consideration; (iii) objectiveness of assessment; (iv) baseline set for carbon assessment; (v) mechanism for benchmarking the emission level; and (v) limitations of the carbon assessment approaches. Results indicate that the current BEA schemes focus primarily on operational carbon instead of the emissions generated throughout the entire building life cycle. Besides, the baseline and benchmark for carbon evaluation vary significantly among the BEA tools based on the analytical results of a hypothetical building. The findings point to the needs for a more transparent framework for carbon auditing and benchmarking in BEA modeling. - Highlights: ► Carbon emission evaluation in building environmental assessment schemes are studied. ► Simulative carbon emission is modeled for building environmental assessment schemes. ► Carbon assessments focus primarily on operational stage instead of entire lifecycle. ► Baseline and benchmark of carbon assessment vary greatly among BEA schemes. ► A more transparent and comprehensive framework for carbon assessment is required.

  5. Heart rate variability: a tool to explore the sleeping brain?

    Directory of Open Access Journals (Sweden)

    Florian eChouchou

    2014-12-01

    Full Text Available Sleep is divided into two main sleep stages: 1 non-rapid eye movement sleep (non-REMS, characterized among others by reduced global brain activity; and 2 rapid eye movement sleep (REMS, characterized by global brain activity similar to that of wakefulness. Results of heart rate variability (HRV analysis, which is widely used to explore autonomic modulation, have revealed higher parasympathetic tone during normal non-REMS and a shift toward sympathetic predominance during normal REMS. Moreover, HRV analysis combined with brain imaging has identified close connectivity between autonomic cardiac modulation and activity in brain areas such as the amygdala and insular cortex during REMS, but no connectivity between brain and cardiac activity during non-REMS. There is also some evidence for an association between HRV and dream intensity and emotionality. Following some technical considerations, this review addresses how brain activity during sleep contributes to changes in autonomic cardiac activity, organized into three parts: 1 the knowledge on autonomic cardiac control, 2 differences in brain and autonomic activity between non-REMS and REMS, and 3 the potential of HRV analysis to explore the sleeping brain, and the implications for psychiatric disorders.

  6. Variability in Predictions from Online Tools: A Demonstration Using Internet-Based Melanoma Predictors.

    Science.gov (United States)

    Zabor, Emily C; Coit, Daniel; Gershenwald, Jeffrey E; McMasters, Kelly M; Michaelson, James S; Stromberg, Arnold J; Panageas, Katherine S

    2018-02-22

    Prognostic models are increasingly being made available online, where they can be publicly accessed by both patients and clinicians. These online tools are an important resource for patients to better understand their prognosis and for clinicians to make informed decisions about treatment and follow-up. The goal of this analysis was to highlight the possible variability in multiple online prognostic tools in a single disease. To demonstrate the variability in survival predictions across online prognostic tools, we applied a single validation dataset to three online melanoma prognostic tools. Data on melanoma patients treated at Memorial Sloan Kettering Cancer Center between 2000 and 2014 were retrospectively collected. Calibration was assessed using calibration plots and discrimination was assessed using the C-index. In this demonstration project, we found important differences across the three models that led to variability in individual patients' predicted survival across the tools, especially in the lower range of predictions. In a validation test using a single-institution data set, calibration and discrimination varied across the three models. This study underscores the potential variability both within and across online tools, and highlights the importance of using methodological rigor when developing a prognostic model that will be made publicly available online. The results also reinforce that careful development and thoughtful interpretation, including understanding a given tool's limitations, are required in order for online prognostic tools that provide survival predictions to be a useful resource for both patients and clinicians.

  7. Stimulant Treatment Reduces Lapses in Attention among Children with ADHD: The Effects of Methylphenidate on Intra-Individual Response Time Distributions

    Science.gov (United States)

    Spencer, Sarah V.; Hawk, Larry W., Jr.; Richards, Jerry B.; Shiels, Keri; Pelham, William E., Jr.; Waxmonsky, James G.

    2009-01-01

    Recent research has suggested that intra-individual variability in reaction time (RT) distributions of children with ADHD is characterized by a particularly large rightward skew that may reflect lapses in attention. The purpose of the study was to provide the first randomized, placebo-controlled test of the effects of the stimulant methylphenidate…

  8. Final report on LDRD project: Simulation/optimization tools for system variability analysis

    Energy Technology Data Exchange (ETDEWEB)

    R. L. Bierbaum; R. F. Billau; J. E. Campbell; K. D. Marx; R. J. Sikorski; B. M. Thompson; S. D. Wix

    1999-10-01

    >This work was conducted during FY98 (Proposal Number 98-0036) and FY99 (Proposal Number 99-0818) under the auspices of the Sandia National Laboratories Laboratory-Directed Research and Development (LDRD) program. Electrical simulation typically treats a single data point in the very large input space of component properties. For electrical simulation to reach its full potential as a design tool, it must be able to address the unavoidable variability and uncertainty in component properties. Component viability is strongly related to the design margin (and reliability) of the end product. During the course of this project, both tools and methodologies were developed to enable analysis of variability in the context of electrical simulation tools. Two avenues to link relevant tools were also developed, and the resultant toolset was applied to a major component.

  9. Tools for Assessing the Impacts of Climate Variability and Change on Wildfire Regimes in Forests

    Directory of Open Access Journals (Sweden)

    Hety Herawati

    2015-04-01

    Full Text Available Fire is an intrinsic element of many forest ecosystems; it shapes their ecological processes, determines species composition and influences landscape structure. However, wildfires may: have undesirable effects on biodiversity and vegetation coverage; produce carbon emissions to the atmosphere; release smoke affecting human health; and cause loss of lives and property. There have been increasing concerns about the potential impacts of climate variability and change on forest fires. Climate change can alter factors that influence the occurrence of fire ignitions, fuel availability and fuel flammability. This review paper aims to identify tools and methods used for gathering information about the impacts of climate variability and change on forest fires, forest fuels and the probability of fires. Tools to assess the impacts of climate variability and change on forest fires include: remote sensing, dynamic global vegetation and landscape models, integrated fire-vegetation models, fire danger rating systems, empirical models and fire behavior models. This review outlines each tool in terms of its characteristics, spatial and temporal resolution, limitations and applicability of the results. To enhance and improve tool performance, each must be continuously tested in all types of forest ecosystems.

  10. Geometric Parameters of Cutting Tools that Can be Used for Forming Sided Surfaces with Variable Profile

    Directory of Open Access Journals (Sweden)

    Razumov M.

    2017-03-01

    Full Text Available This article describes machining technology of polyhedral surfaces with varying profile, which is provided by planetary motion of multiblade block tools. The features of the technology and urgency of the problem is indicated. The purpose of the study is to determine the minimum value of the clearance angle of the tool. Also, the study is carried out about changing the value of the front and rear corners during the formation of polygonal surface using a planetary gear. The scheme of calculating the impact of various factors on the value of the minimum clearance angle of the tool and kinematic front and rear corners of the instrument is provided. The mathematical formula for calculating the minimum clearance angle of the tool is given. Also, given the formula for determining the front and rear corners of the tool during driving. This study can be used in the calculation of the design operations forming multifaceted external surfaces with a variable profile by using the planetary gear.

  11. ARTiiFACT: a tool for heart rate artifact processing and heart rate variability analysis.

    Science.gov (United States)

    Kaufmann, Tobias; Sütterlin, Stefan; Schulz, Stefan M; Vögele, Claus

    2011-12-01

    The importance of appropriate handling of artifacts in interbeat interval (IBI) data must not be underestimated. Even a single artifact may cause unreliable heart rate variability (HRV) results. Thus, a robust artifact detection algorithm and the option for manual intervention by the researcher form key components for confident HRV analysis. Here, we present ARTiiFACT, a software tool for processing electrocardiogram and IBI data. Both automated and manual artifact detection and correction are available in a graphical user interface. In addition, ARTiiFACT includes time- and frequency-based HRV analyses and descriptive statistics, thus offering the basic tools for HRV analysis. Notably, all program steps can be executed separately and allow for data export, thus offering high flexibility and interoperability with a whole range of applications.

  12. AAVSO Target Tool: A Web-Based Service for Tracking Variable Star Observations (Abstract)

    Science.gov (United States)

    Burger, D.; Stassun, K. G.; Barnes, C.; Kafka, S.; Beck, S.; Li, K.

    2018-06-01

    (Abstract only) The AAVSO Target Tool is a web-based interface for bringing stars in need of observation to the attention of AAVSOís network of amateur and professional astronomers. The site currently tracks over 700 targets of interest, collecting data from them on a regular basis from AAVSOís servers and sorting them based on priority. While the target tool does not require a login, users can obtain visibility times for each target by signing up and entering a telescope location. Other key features of the site include filtering by AAVSO observing section, sorting by different variable types, formatting the data for printing, and exporting the data to a CSV file. The AAVSO Target Tool builds upon seven years of experience developing web applications for astronomical data analysis, most notably on Filtergraph (Burger, D., et al. 2013, Astronomical Data Analysis Software and Systems XXII, Astronomical Society of the Pacific, San Francisco, 399), and is built using the web2py web framework based on the python programming language. The target tool is available at http://filtergraph.com/aavso.

  13. Intra-individual metameric variation expressed at the enamel-dentine junction of lower post-canine dentition of South African fossil hominins and modern humans.

    Science.gov (United States)

    Pan, Lei; Thackeray, John Francis; Dumoncel, Jean; Zanolli, Clément; Oettlé, Anna; de Beer, Frikkie; Hoffman, Jakobus; Duployer, Benjamin; Tenailleau, Christophe; Braga, José

    2017-08-01

    The aim of this study is to compare the degree and patterning of inter- and intra-individual metameric variation in South African australopiths, early Homo and modern humans. Metameric variation likely reflects developmental and taxonomical issues, and could also be used to infer ecological and functional adaptations. However, its patterning along the early hominin postcanine dentition, particularly among South African fossil hominins, remains unexplored. Using microfocus X-ray computed tomography (µXCT) and geometric morphometric tools, we studied the enamel-dentine junction (EDJ) morphology and we investigated the intra- and inter-individual EDJ metameric variation among eight australopiths and two early Homo specimens from South Africa, as well as 32 modern humans. Along post-canine dentition, shape changes between metameres represented by relative positions and height of dentine horns, outlines of the EDJ occlusal table are reported in modern and fossil taxa. Comparisons of EDJ mean shapes and multivariate analyses reveal substantial variation in the direction and magnitude of metameric shape changes among taxa, but some common trends can be found. In modern humans, both the direction and magnitude of metameric shape change show increased variability in M 2 -M 3 compared to M 1 -M 2 . Fossil specimens are clustered together showing similar magnitudes of shape change. Along M 2 -M 3 , the lengths of their metameric vectors are not as variable as those of modern humans, but they display considerable variability in the direction of shape change. The distalward increase of metameric variation along the modern human molar row is consistent with the odontogenetic models of molar row structure (inhibitory cascade model). Though much remains to be tested, the variable trends and magnitudes in metamerism in fossil hominins reported here, together with differences in the scale of shape change between modern humans and fossil hominins may provide valuable information

  14. Measurement Variability of Vertical Scanning Interferometry Tool Used for Orbiter Window Defect Assessment

    Science.gov (United States)

    Padula, Santo, II

    2009-01-01

    The ability to sufficiently measure orbiter window defects to allow for window recertification has been an ongoing challenge for the orbiter vehicle program. The recent Columbia accident has forced even tighter constraints on the criteria that must be met in order to recertify windows for flight. As a result, new techniques are being investigated to improve the reliability, accuracy and resolution of the defect detection process. The methodology devised in this work, which is based on the utilization of a vertical scanning interferometric (VSI) tool, shows great promise for meeting the ever increasing requirements for defect detection. This methodology has the potential of a 10-100 fold greater resolution of the true defect depth than can be obtained from the currently employed micrometer based methodology. An added benefit is that it also produces a digital elevation map of the defect, thereby providing information about the defect morphology which can be utilized to ascertain the type of debris that induced the damage. However, in order to successfully implement such a tool, a greater understanding of the resolution capability and measurement repeatability must be obtained. This work focused on assessing the variability of the VSI-based measurement methodology and revealed that the VSI measurement tool was more repeatable and more precise than the current micrometer based approach, even in situations where operator variation could affect the measurement. The analysis also showed that the VSI technique was relatively insensitive to the hardware and software settings employed, making the technique extremely robust and desirable

  15. CRITICAL RADAR: TOOL AND METHODOLOGY FOR EVALUATING CURRENT PROJECTS USING MULTIPLE VARIABLES

    Directory of Open Access Journals (Sweden)

    André M. Ferrari

    2017-06-01

    Full Text Available Many resources are invested in measurement processes of projects indicators without, however, give a clear view of which projects deserves the right attention at the right time. This paper proposes the use of statistics, through the analysis of multiple variables and their interrelationships, to give better basis to a critical assessment methodology of current projects used in a multinational mining company. The contribution of the research is to report the methodology called Critical Radar which is based on a graphical tool with simple operationalization that can support the decision making in complex environments, and has great flexibility across the different market scenarios and possible changes in companies guidelines. The tool has great potential to help evaluate current projects due to their characteristics of flexible use in different business areas; high degree of freedom for improvement; use of known market tool in its development; ease of viewing the results through charts and notes and user freedom to use any existing indicators in the company if complied with some statistical data quality characteristics.

  16. Sensitivity Analysis of Weather Variables on Offsite Consequence Analysis Tools in South Korea and the United States.

    Science.gov (United States)

    Kim, Min-Uk; Moon, Kyong Whan; Sohn, Jong-Ryeul; Byeon, Sang-Hoon

    2018-05-18

    We studied sensitive weather variables for consequence analysis, in the case of chemical leaks on the user side of offsite consequence analysis (OCA) tools. We used OCA tools Korea Offsite Risk Assessment (KORA) and Areal Location of Hazardous Atmospheres (ALOHA) in South Korea and the United States, respectively. The chemicals used for this analysis were 28% ammonia (NH₃), 35% hydrogen chloride (HCl), 50% hydrofluoric acid (HF), and 69% nitric acid (HNO₃). The accident scenarios were based on leakage accidents in storage tanks. The weather variables were air temperature, wind speed, humidity, and atmospheric stability. Sensitivity analysis was performed using the Statistical Package for the Social Sciences (SPSS) program for dummy regression analysis. Sensitivity analysis showed that impact distance was not sensitive to humidity. Impact distance was most sensitive to atmospheric stability, and was also more sensitive to air temperature than wind speed, according to both the KORA and ALOHA tools. Moreover, the weather variables were more sensitive in rural conditions than in urban conditions, with the ALOHA tool being more influenced by weather variables than the KORA tool. Therefore, if using the ALOHA tool instead of the KORA tool in rural conditions, users should be careful not to cause any differences in impact distance due to input errors of weather variables, with the most sensitive one being atmospheric stability.

  17. Sensitivity Analysis of Weather Variables on Offsite Consequence Analysis Tools in South Korea and the United States

    Directory of Open Access Journals (Sweden)

    Min-Uk Kim

    2018-05-01

    Full Text Available We studied sensitive weather variables for consequence analysis, in the case of chemical leaks on the user side of offsite consequence analysis (OCA tools. We used OCA tools Korea Offsite Risk Assessment (KORA and Areal Location of Hazardous Atmospheres (ALOHA in South Korea and the United States, respectively. The chemicals used for this analysis were 28% ammonia (NH3, 35% hydrogen chloride (HCl, 50% hydrofluoric acid (HF, and 69% nitric acid (HNO3. The accident scenarios were based on leakage accidents in storage tanks. The weather variables were air temperature, wind speed, humidity, and atmospheric stability. Sensitivity analysis was performed using the Statistical Package for the Social Sciences (SPSS program for dummy regression analysis. Sensitivity analysis showed that impact distance was not sensitive to humidity. Impact distance was most sensitive to atmospheric stability, and was also more sensitive to air temperature than wind speed, according to both the KORA and ALOHA tools. Moreover, the weather variables were more sensitive in rural conditions than in urban conditions, with the ALOHA tool being more influenced by weather variables than the KORA tool. Therefore, if using the ALOHA tool instead of the KORA tool in rural conditions, users should be careful not to cause any differences in impact distance due to input errors of weather variables, with the most sensitive one being atmospheric stability.

  18. Autonomic Differentiation Map: A Novel Statistical Tool for Interpretation of Heart Rate Variability

    Directory of Open Access Journals (Sweden)

    Daniela Lucini

    2018-04-01

    Full Text Available In spite of the large body of evidence suggesting Heart Rate Variability (HRV alone or combined with blood pressure variability (providing an estimate of baroreflex gain as a useful technique to assess the autonomic regulation of the cardiovascular system, there is still an ongoing debate about methodology, interpretation, and clinical applications. In the present investigation, we hypothesize that non-parametric and multivariate exploratory statistical manipulation of HRV data could provide a novel informational tool useful to differentiate normal controls from clinical groups, such as athletes, or subjects affected by obesity, hypertension, or stress. With a data-driven protocol in 1,352 ambulant subjects, we compute HRV and baroreflex indices from short-term data series as proxies of autonomic (ANS regulation. We apply a three-step statistical procedure, by first removing age and gender effects. Subsequently, by factor analysis, we extract four ANS latent domains that detain the large majority of information (86.94%, subdivided in oscillatory (40.84%, amplitude (18.04%, pressure (16.48%, and pulse domains (11.58%. Finally, we test the overall capacity to differentiate clinical groups vs. control. To give more practical value and improve readability, statistical results concerning individual discriminant ANS proxies and ANS differentiation profiles are displayed through peculiar graphical tools, i.e., significance diagram and ANS differentiation map, respectively. This approach, which simultaneously uses all available information about the system, shows what domains make up the difference in ANS discrimination. e.g., athletes differ from controls in all domains, but with a graded strength: maximal in the (normalized oscillatory and in the pulse domains, slightly less in the pressure domain and minimal in the amplitude domain. The application of multiple (non-parametric and exploratory statistical and graphical tools to ANS proxies defines

  19. Evaluation of tools for highly variable gene discovery from single-cell RNA-seq data.

    Science.gov (United States)

    Yip, Shun H; Sham, Pak Chung; Wang, Junwen

    2018-02-21

    Traditional RNA sequencing (RNA-seq) allows the detection of gene expression variations between two or more cell populations through differentially expressed gene (DEG) analysis. However, genes that contribute to cell-to-cell differences are not discoverable with RNA-seq because RNA-seq samples are obtained from a mixture of cells. Single-cell RNA-seq (scRNA-seq) allows the detection of gene expression in each cell. With scRNA-seq, highly variable gene (HVG) discovery allows the detection of genes that contribute strongly to cell-to-cell variation within a homogeneous cell population, such as a population of embryonic stem cells. This analysis is implemented in many software packages. In this study, we compare seven HVG methods from six software packages, including BASiCS, Brennecke, scLVM, scran, scVEGs and Seurat. Our results demonstrate that reproducibility in HVG analysis requires a larger sample size than DEG analysis. Discrepancies between methods and potential issues in these tools are discussed and recommendations are made.

  20. Antecedents of Teachers’ Emotions in the Classroom: An Intraindividual Approach

    Directory of Open Access Journals (Sweden)

    Eva Susann Becker

    2015-05-01

    Full Text Available Using a preexisting, but as yet empirically untested theoretical model, the present study investigated antecedents of teachers’ emotions in the classroom. More specifically, the relationships between students’ motivation and discipline and teachers’ enjoyment and anger were explored, as well as if these relationships are mediated by teachers’ subjective appraisals (goal conduciveness and coping potential. The study employed an intraindividual approach by collecting data through a diary. The sample consisted of 39 teachers who each participated with one of their 9th or 10th grade mathematics classes (N = 758 students. Both teachers and students filled out diaries for two to three weeks pertaining to 8.10 lessons on average (N = 316 lessons. Multilevel structural equation modeling revealed that students’ motivation and discipline explained 24% of variance in teachers’ enjoyment and 26% of variance in teachers’ anger. In line with theoretical assumptions, after introducing teachers’ subjective appraisals as a mediating mechanism into the model, the explained variance systematically increased to 65% and 61%, for teachers’ enjoyment and anger respectively. The effects of students’ motivation and discipline level on teachers’ emotions were partially mediated by teachers’ appraisals of goal conduciveness and coping potential. The findings imply that since teachers’ emotions depend to a large extent on subjective evaluations of a situation, teachers should be able to directly modify their emotional experiences during a lesson through cognitive reappraisals.

  1. Antecedents of teachers’ emotions in the classroom: an intraindividual approach

    Science.gov (United States)

    Becker, Eva S.; Keller, Melanie M.; Goetz, Thomas; Frenzel, Anne C.; Taxer, Jamie L.

    2015-01-01

    Using a preexisting, but as yet empirically untested theoretical model, the present study investigated antecedents of teachers’ emotions in the classroom. More specifically, the relationships between students’ motivation and discipline and teachers’ enjoyment and anger were explored, as well as if these relationships are mediated by teachers’ subjective appraisals (goal conduciveness and coping potential). The study employed an intraindividual approach by collecting data through a diary. The sample consisted of 39 teachers who each participated with one of their 9th or 10th grade mathematics classes (N = 758 students). Both teachers and students filled out diaries for 2–3 weeks pertaining to 8.10 lessons on average (N = 316 lessons). Multilevel structural equation modeling revealed that students’ motivation and discipline explained 24% of variance in teachers’ enjoyment and 26% of variance in teachers’ anger. In line with theoretical assumptions, after introducing teachers’ subjective appraisals as a mediating mechanism into the model, the explained variance systematically increased to 65 and 61%, for teachers’ enjoyment and anger respectively. The effects of students’ motivation and discipline level on teachers’ emotions were partially mediated by teachers’ appraisals of goal conduciveness and coping potential. The findings imply that since teachers’ emotions depend to a large extent on subjective evaluations of a situation, teachers should be able to directly modify their emotional experiences during a lesson through cognitive reappraisals. PMID:26042067

  2. Antecedents of teachers' emotions in the classroom: an intraindividual approach.

    Science.gov (United States)

    Becker, Eva S; Keller, Melanie M; Goetz, Thomas; Frenzel, Anne C; Taxer, Jamie L

    2015-01-01

    Using a preexisting, but as yet empirically untested theoretical model, the present study investigated antecedents of teachers' emotions in the classroom. More specifically, the relationships between students' motivation and discipline and teachers' enjoyment and anger were explored, as well as if these relationships are mediated by teachers' subjective appraisals (goal conduciveness and coping potential). The study employed an intraindividual approach by collecting data through a diary. The sample consisted of 39 teachers who each participated with one of their 9th or 10th grade mathematics classes (N = 758 students). Both teachers and students filled out diaries for 2-3 weeks pertaining to 8.10 lessons on average (N = 316 lessons). Multilevel structural equation modeling revealed that students' motivation and discipline explained 24% of variance in teachers' enjoyment and 26% of variance in teachers' anger. In line with theoretical assumptions, after introducing teachers' subjective appraisals as a mediating mechanism into the model, the explained variance systematically increased to 65 and 61%, for teachers' enjoyment and anger respectively. The effects of students' motivation and discipline level on teachers' emotions were partially mediated by teachers' appraisals of goal conduciveness and coping potential. The findings imply that since teachers' emotions depend to a large extent on subjective evaluations of a situation, teachers should be able to directly modify their emotional experiences during a lesson through cognitive reappraisals.

  3. Investigation of the Effect of Tool Edge Geometry upon Cutting Variables, Tool Wear and Burr Formation Using Finite Element Simulation — A Progress Report

    Science.gov (United States)

    Sartkulvanich, Partchapol; Al-Zkeri, Ibrahim; Yen, Yung-Chang; Altan, Taylan

    2004-06-01

    This paper summarizes some of the progress made on FEM simulations of metal cutting processes conducted at the Engineering Research Center (ERC/NSM). Presented research focuses on the performance of various cutting edge geometries (hone and chamfer edges) for different tool materials and specifically on: 1) the effect of round and chamfer edge geometries on the cutting variables in machining carbon steels and 2) the effect of the edge hone size upon the flank wear and burr formation behavior in face milling of A356-T6 aluminum alloy. In the second task, an innovative design of edge preparation with varying hone size around the tool nose is also explored using FEM. In order to model three-dimensional conventional turning and face milling with two-dimensional orthogonal cutting simulations, 2D simulation cross-sections consisting of the cutting speed direction and chip flow direction are selected at different locations along the tool nose radius. Then the geometries of the hone and chamfer edges and their associated tool angles as well as uncut chip thickness are determined on these planes and employed in cutting simulations. The chip flow direction on the tool rake face are obtained by examining the wear grooves on the experimental inserts or estimated by using Oxley's approximation theory of oblique cutting. Simulation results are compared with the available experimental results (e.g. cutting forces) both qualitatively and quantitatively.

  4. Investigation of the effect of tool edge geometry upon cutting variables, tool wear and burr formation using finite element simulation - A progress report

    International Nuclear Information System (INIS)

    Sartkulvanich, Partchapol; Al-Zkeri, Ibrahim; Yen Yungchang; Altan, Taylan

    2004-01-01

    This paper summarizes some of the progress made on FEM simulations of metal cutting processes conducted at the Engineering Research Center (ERC/NSM). Presented research focuses on the performance of various cutting edge geometries (hone and chamfer edges) for different tool materials and specifically on: 1) the effect of round and chamfer edge geometries on the cutting variables in machining carbon steels and 2) the effect of the edge hone size upon the flank wear and burr formation behavior in face milling of A356-T6 aluminum alloy. In the second task, an innovative design of edge preparation with varying hone size around the tool nose is also explored using FEM.In order to model three-dimensional conventional turning and face milling with two-dimensional orthogonal cutting simulations, 2D simulation cross-sections consisting of the cutting speed direction and chip flow direction are selected at different locations along the tool nose radius. Then the geometries of the hone and chamfer edges and their associated tool angles as well as uncut chip thickness are determined on these planes and employed in cutting simulations. The chip flow direction on the tool rake face are obtained by examining the wear grooves on the experimental inserts or estimated by using Oxley's approximation theory of oblique cutting. Simulation results are compared with the available experimental results (e.g. cutting forces) both qualitatively and quantitatively

  5. The impact of process variables and wear characteristics on the cutting tool performance using Finite Element Analysis

    OpenAIRE

    Jiang, Xiaoheng

    2016-01-01

    The frequent failure of cutting tool in the cutting process may cause a huge loss of money and time especially for hard to machine materials such as titanium alloys. Thus this study is mainly focused on the impact of wear characteristics and process variables on the cutting tool which is ignored by most of researchers. A thermo-mechanical finite element model of orthogonal metal cutting with segment chip formation is presented. This model can be used to predict the process performance in the ...

  6. A tool for protected area management: multivariate control charts 'cope' with rare variable communities.

    Science.gov (United States)

    Stringell, Thomas B; Bamber, Roger N; Burton, Mark; Lindenbaum, Charles; Skates, Lucie R; Sanderson, William G

    2013-06-01

    Performance assessment, impact detection, and the assessment of regulatory compliance are common scientific problems for the management of protected areas. Some habitats in protected areas, however, are rare and/or variable and are not often selected for study by ecologists because they preclude comparison with controls and high community variability makes meaningful change detection difficult. Shallow coastal saline lagoons are habitats that experience comparatively high levels of stress due to high physical variability. Lagoons are rare, declining habitats found in coastal regions throughout Europe (and elsewhere) where they are identified as one of the habitats most in need of protected area management. The infauna in the sediments of 25 lagoons were sampled. Temporal and spatial variation in three of these [protected] lagoons was investigated further over 5 years. In a multivariate analysis of community structure similarities were found between some lagoons, but in other cases communities were unique or specific to only two sites. The protected lagoons with these unique/specific communities showed significant temporal and spatial variation, yet none of the changes observed were attributed to human impacts and were interpreted as inherent variability. Multivariate control charts can operate without experimental controls and were used to assess community changes within the context of 'normal' lagoon variability. The aim of control chart analysis is to characterize background variability in a parameter and identify when a new observation deviates more than expected. In only 1 year was variability more than expected and corresponded with the coldest December in over 100 years. Multivariate control charts are likely to have wide application in the management of protected areas and other natural systems where variability and/or rarity preclude conventional analytical and experimental approaches but where assessments of condition, impact or regulatory compliance are

  7. Multi-Frequency Blazar Micro-Variability as a Tool to Investigate Relativistic Jets

    Directory of Open Access Journals (Sweden)

    James R. Webb

    2016-08-01

    Full Text Available For the past 12 years we have been studying optical micro-variability of a sample of 15 Blazars. We summarize the results of this study and draw some basic conclusions about the characteristics of micro-variability. The intermittency, the stochastic nature, and the similar profile shapes seen in micro-variations at different times and in different objects have led us to a possible model to explain the observed micro-variations. The model is based on a strong shock propagating down a relativistic jet and encountering turbulence which causes density or magnetic field enhancements. We use the theory of Kirk, Reiger, and Mastichiadis (1998 to describe the pulse of synchrotron emission emanating from individual density enhancements energized by the shock. By fitting these “pulses” to micro-variability observations, we obtain excellent fits to actual micro-variations. The model predicts that the spectral index changes as a function of pulse duration. This effect should be observable in multi-frequency micro-variability data. We present the theoretical model, model fits of our micro-variability light curves, and preliminary multi-frequency micro-variability observations that support this model. A further test that has yet to be carried out involves observing polarization changes in different pulses.

  8. Is Reaction Time Variability in ADHD Mainly at Low Frequencies?

    Science.gov (United States)

    Karalunas, Sarah L.; Huang-Pollock, Cynthia L.; Nigg, Joel T.

    2013-01-01

    Background: Intraindividual variability in reaction times (RT variability) has garnered increasing interest as an indicator of cognitive and neurobiological dysfunction in children with attention deficit hyperactivity disorder (ADHD). Recent theory and research has emphasized specific low-frequency patterns of RT variability. However, whether…

  9. VOLUMETRIC METHOD FOR EVALUATION OF BEACHES VARIABILITY BASED ON GIS-TOOLS

    Directory of Open Access Journals (Sweden)

    V. V. Dolotov

    2015-01-01

    Full Text Available In frame of cadastral beach evaluation the volumetric method of natural variability index is proposed. It base on spatial calculations with Cut-Fill method and volume accounting ofboththe common beach contour and specific areas for the each time.

  10. Variable Stars in (Not Only) Dwarf Galaxies : Key Tools to Constrain Distances and Stellar Content

    NARCIS (Netherlands)

    Fiorentino, G.; Koleva, M; Prugniel, P; Vauglin,

    2011-01-01

    The important role of Cepheid and RR Lyrae variable stars and what they teach us about dwarf galaxies is discussed. Despite ever improving star formation histories of Local Group dwarf galaxies uncertainties remain, in particular in the identification and characterisation of the oldest stellar

  11. Combining epidemiologic and biostatistical tools to enhance variable selection in HIV cohort analyses.

    Directory of Open Access Journals (Sweden)

    Christopher Rentsch

    Full Text Available BACKGROUND: Variable selection is an important step in building a multivariate regression model for which several methods and statistical packages are available. A comprehensive approach for variable selection in complex multivariate regression analyses within HIV cohorts is explored by utilizing both epidemiological and biostatistical procedures. METHODS: Three different methods for variable selection were illustrated in a study comparing survival time between subjects in the Department of Defense's National History Study and the Atlanta Veterans Affairs Medical Center's HIV Atlanta VA Cohort Study. The first two methods were stepwise selection procedures, based either on significance tests (Score test, or on information theory (Akaike Information Criterion, while the third method employed a Bayesian argument (Bayesian Model Averaging. RESULTS: All three methods resulted in a similar parsimonious survival model. Three of the covariates previously used in the multivariate model were not included in the final model suggested by the three approaches. When comparing the parsimonious model to the previously published model, there was evidence of less variance in the main survival estimates. CONCLUSIONS: The variable selection approaches considered in this study allowed building a model based on significance tests, on an information criterion, and on averaging models using their posterior probabilities. A parsimonious model that balanced these three approaches was found to provide a better fit than the previously reported model.

  12. Predicting Intraindividual Changes in Teacher Burnout: The Role of Perceived School Environment and Motivational Factors

    Science.gov (United States)

    Fernet, Claude; Guay, Frederic; Senecal, Caroline; Austin, Stephanie

    2012-01-01

    Based on self-determination theory, this study proposes and tests a motivational model of intraindividual changes in teacher burnout (emotional exhaustion, depersonalization, and reduced personal accomplishment). Participants were 806 French-Canadian teachers in public elementary and high schools. Results show that changes in teachers' perceptions…

  13. Optimization method to determine mass transfer variables in a PWR crud deposition risk assessment tool

    International Nuclear Information System (INIS)

    Do, Chuong; Hussey, Dennis; Wells, Daniel M.; Epperson, Kenny

    2016-01-01

    Optimization numerical method was implemented to determine several mass transfer coefficients in a crud-induced power shift risk assessment code. The approach was to utilize a multilevel strategy that targets different model parameters that first changes the major order variables, mass transfer inputs, then calibrates the minor order variables, crud source terms, according to available plant data. In this manner, the mass transfer inputs are effectively simplified as 'dependent' on the crud source terms. Two optimization studies were performed using DAKOTA, a design and analysis toolkit, with the difference between the runs, being the number of model runs using BOA, allowed for adjusting the crud source terms, therefore, reducing the uncertainty with calibration. The result of the first case showed that the current best estimated values for the mass transfer coefficients, which were derived from first principle analysis, can be considered an optimized set. When the run limit of BOA was increased for the second case, an improvement in the prediction was obtained with the results deviating slightly from the best estimated values. (author)

  14. The boolean algebra with restricted variables as a tool for fault tree modularization

    International Nuclear Information System (INIS)

    Caldarola, L.; Wickenhaeuser, A.

    1981-08-01

    The number of minimal cut sets (m.c.s.) of very complex and highly interconnected fault trees can become extremely large (e.g. more than 10 7 ). In this case the usual analytical approach of dissecting the fault tree TOP variable into m.c.s. is not only computationally prohibitively expensive, but also meaningless because it does not offer any synthetic overview of system behavior. The method proposed in this paper overcomes the deficiencies of the analytical method. It is shown that, by applying boolean algebra with restricted variables (b.a.w.r.v.), the concept of fault tree modularization can be straightforwardly extended from a single gate to a set of gates. Thus, large fault trees are divided into smaller fault trees (modules), which are connected to each other according to a simple scheme. This scheme is represented by a block diagram in which each block is a module. The modules are analyzed separately by the m.c.s. method, and the results are combined according of the TOP event. The method allows the calculation of very large fault trees in a short time and offers a synthetic overview of systems behavior through the block diagram. Numerical examples are also included. Calculations have been carried out by using the computer code MUSTAMO, which is based on the theory developed in this paper. (orig.) [de

  15. Building Design Variables Usage as a Tool of Value Engineering During Designing

    Directory of Open Access Journals (Sweden)

    Sahid Nur

    2017-01-01

    Full Text Available The deployment of construction economics has become more desirable today, mainly due to need to establish how building costs are spent, and be able to come up with the most optimum alternatives. This research article therefore, explored 1 the various costs inputs called design variables used by design consultants, plus their underlying factors, 2 how the practice of value engineering (VE impacts on projects in Indonesia. A qualitative methodology, was used inform of a questionnaire, designed based on a 5 pointer liker scale approach, and distributed among 30 respondents consisting of consultants and clients in areas of Surakarta. The collected data was processed using statistical method of relative importance index, followed by descriptive analysis inform of bar and pie charts. The results obtained were that building plane shape (index 83.2, was mostly used, which itself depended on external features of building membrane and shape of building site (80.0 each, then other variables were building complexity (82.1; and building façade (77.9, meanwhile the least used was sharing walls (index 62.1, Lastly, VE was found to benefit the industry by producing designs which meet time, cost and quality targets, on the other hand material wastages and loss of confidence was reported once VE was neglected.

  16. Reducing variability of workforce as a tool to improve plan reliability

    DEFF Research Database (Denmark)

    Wandahl, Søren; Yicheng, S.; Zygmunt, K. J.

    Variability of flow is recognized as the greatest obstacle to production management. Since the work flow and labour flow are two dominators of work performance, it is important to manage them simultaneously. The objective of this paper is to examine whether by reducing the variance of a labour flow......, a plan reliability can be improved, therefore, three different construction labour data sets have been examined by utilizing Monte Carlo Simulation, to analyze the probability to finish simulated projects within a certain time. The research findings revealed that reducing variance in the workforce flow...... does not necessarily shorten the project length, nevertheless it increases probability to finish the tasks within a critical path duration. Additionally, it was concluded, that reducing the variance of crew allocation can improve the productivity....

  17. Reducing Variability of Workforce as a Tool to Improve Plan Reliability

    DEFF Research Database (Denmark)

    Shen, Yicheng; Zygmunt, Katarzyna Julia; Wandahl, Søren

    2017-01-01

    Variability of flow is recognized as one of the greatest obstacles to production management. Since the work flow and labour flow are two dominators of work performance, it is important to manage them simultaneously. The objective of this paper is to examine if an increased plan reliability could...... of the workforce flow does not necessarily shorten the project length, nevertheless it increases probability to finish the tasks within a critical path duration. Additionally, it was concluded, that reducing the variance of crew allocation can improve the productivity....... be reached by reducing the variance of a labour flow. Therefore, three different construction labour data sets have been examined by utilizing Monte Carlo Simulation, to analyze the probability to finish simulated projects within a certain time. The research findings revealed that reducing variance...

  18. GeneratorSE: A Sizing Tool for Variable-Speed Wind Turbine Generators

    Energy Technology Data Exchange (ETDEWEB)

    Sethuraman, Latha [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-22

    This report documents a set of analytical models employed by the optimization algorithms within the GeneratorSE framework. The initial values and boundary conditions employed for the generation of the various designs and initial estimates for basic design dimensions, masses, and efficiency for the four different models of generators are presented and compared with empirical data collected from previous studies and some existing commercial turbines. These models include designs applicable for variable-speed, high-torque application featuring direct-drive synchronous generators and low-torque application featuring induction generators. In all of the four models presented, the main focus of optimization is electromagnetic design with the exception of permanent-magnet and wire-wound synchronous generators, wherein the structural design is also optimized. Thermal design is accommodated in GeneratorSE as a secondary attribute by limiting the winding current densities to acceptable limits. A preliminary validation of electromagnetic design was carried out by comparing the optimized magnetic loading against those predicted by numerical simulation in FEMM4.2, a finite-element software for analyzing electromagnetic and thermal physics problems for electrical machines. For direct-drive synchronous generators, the analytical models for the structural design are validated by static structural analysis in ANSYS.

  19. The Variable Scale Evacuation Model (VSEM: a new tool for simulating massive evacuation processes during volcanic crises

    Directory of Open Access Journals (Sweden)

    J. M. Marrero

    2010-04-01

    Full Text Available Volcanic eruptions are among the most awesome and powerful displays of nature's force, constituting a major natural hazard for society (a single eruption can claim thousands of lives in an instant. Consequently, assessment and management of volcanic risk have become critically important goals of modern volcanology. Over recent years, numerous tools have been developed to evaluate volcanic risk and support volcanic crisis management: probabilistic analysis of future eruptions, hazard and risk maps, event trees, etc. However, there has been little improvement in the tools that may help Civil Defense officials to prepare Emergency Plans. Here we present a new tool for simulating massive evacuation processes during volcanic crisis: the Variable Scale Evacuation Model (VSEM. The main objective of the VSEM software is to optimize the evacuation process of Emergency Plans during volcanic crisis. For this, the VSEM allows the simulation of an evacuation considering different strategies depending on diverse impact scenarios. VSEM is able to calculate the required time for the complete evacuation taking into account diverse evacuation scenarios (number and type of population, infrastructure, road network, etc. and to detect high-risk or "blackspots" of the road network. The program is versatile and can work at different scales, thus being capable of simulating the evacuation of small villages as well as huge cities.

  20. Students' daily emotions in the classroom : Intra-individual variability and appraisal correlates

    NARCIS (Netherlands)

    Ahmed, Wondimu; van der Werf, Greetje; Minnaert, Alexander; Kuyper, Hans

    2010-01-01

    BACKGROUND: Recent literature on emotions in education has shown that competence- and value-related beliefs are important sources of students' emotions; nevertheless, the role of these antecedents in students' daily functioning in the classroom is not yet well-known. More importantly, to date we

  1. Intraindividual Variability in Adolescents' Perceived Relationship Satisfaction: The Role of Daily Conflict

    Science.gov (United States)

    Van Doorn, Muriel D.; Branje, Susan J. T.; Hox, Joop J.; Meeus, Wim H. J.

    2009-01-01

    A daily diary method was used to examine the daily dynamics of adolescent conflict and perceived relationship satisfaction with mothers, fathers, and best friends among a sample of 72 Dutch adolescents (M = 15.59 years). Multilevel analyses revealed that perceived relationship satisfaction with mothers, fathers, and best friends was lower on days…

  2. Intraindividual variability in adolescents' perceived relationship satisfaction: the role of daily conflict.

    Science.gov (United States)

    Van Doorn, Muriel D; Branje, Susan J T; Hox, Joop J; Meeus, Wim H J

    2009-07-01

    A daily diary method was used to examine the daily dynamics of adolescent conflict and perceived relationship satisfaction with mothers, fathers, and best friends among a sample of 72 Dutch adolescents (M = 15.59 years). Multilevel analyses revealed that perceived relationship satisfaction with mothers, fathers, and best friends was lower on days on which conflict occurred with mothers, fathers, and best friends than on days on which no conflict occurred. More specifically, perceived relationship satisfaction was highest in a particular relationship on days when no conflict occurred, second highest on days on which constructive conflict occurred, and lowest on days on which unconstructive conflict occurred. Whereas in adolescents' relationships with their parents, conflict and perceived relationship satisfaction were not found to be related to each other one day later, conflict with their best friends-and especially unconstructive conflict-was found to be related to higher perceived relationship satisfaction one day later.

  3. The Role of Affect in Intraindividual Variability in Task Performance for Young Learners

    Science.gov (United States)

    Butler, Yuko Goto

    2017-01-01

    Young learners (defined as children ages 5-12) of English as a foreign language are growing in number worldwide. At the policy level, foreign language (FL) programs for young learners are increasingly emphasizing the use of task-based language teaching (TBLT). In practice, however, designing and implementing tasks for young learners poses numerous…

  4. Inter- and intra-individual variability in the levels of plasma homovanillic acid in schizophrenic patients.

    Science.gov (United States)

    Zumárraga, Mercedes; Dávila, Ricardo; González-Torres, Miguel Angel; Anguiano, Juan B; Zabalo, María José; Basterreche, Nieves; Arrúe, Aurora; Zamalloa, María Isabel; Guimón, José

    2007-04-13

    Changes in the levels of homovanillic acid in blood plasma (pHVA) may reflect changes which occur in the brain. In healthy individuals, this concentration of pHVA is stable over time. Over the course of one month, we studied 98 acute schizophrenic patients who had not been taking any medication but were administered neuroleptics upon hospital admission, together with 23 chronic schizophrenic patients on long-term treatment from whom medication was withdrawn. Blood samples were taken at regular intervals from each individual and the concentration of plasma homovanillic acid was measured. We found relative stable values of pHVA with an intraclass correlation coefficient of 0.363 in acute patients and 0.638 (ppHVA and the presence of pharmacological stimuli, we found a certain reproducibility in the levels of this dopamine metabolite. These findings are consistent with the idea that the dopaminergic activity is characterized by a constitutive value which would be under genetic control. The higher stability observed in chronic patients may reflect a weaker, age-related dopaminergic plasticity; conversely, it may indicate that a lack of plasticity in response to a pharmacological stimulus may be an indicator of poorer prognosis.

  5. Bayesian nonparametric variable selection as an exploratory tool for discovering differentially expressed genes.

    Science.gov (United States)

    Shahbaba, Babak; Johnson, Wesley O

    2013-05-30

    High-throughput scientific studies involving no clear a priori hypothesis are common. For example, a large-scale genomic study of a disease may examine thousands of genes without hypothesizing that any specific gene is responsible for the disease. In these studies, the objective is to explore a large number of possible factors (e.g., genes) in order to identify a small number that will be considered in follow-up studies that tend to be more thorough and on smaller scales. A simple, hierarchical, linear regression model with random coefficients is assumed for case-control data that correspond to each gene. The specific model used will be seen to be related to a standard Bayesian variable selection model. Relatively large regression coefficients correspond to potential differences in responses for cases versus controls and thus to genes that might 'matter'. For large-scale studies, and using a Dirichlet process mixture model for the regression coefficients, we are able to find clusters of regression effects of genes with increasing potential effect or 'relevance', in relation to the outcome of interest. One cluster will always correspond to genes whose coefficients are in a neighborhood that is relatively close to zero and will be deemed least relevant. Other clusters will correspond to increasing magnitudes of the random/latent regression coefficients. Using simulated data, we demonstrate that our approach could be quite effective in finding relevant genes compared with several alternative methods. We apply our model to two large-scale studies. The first study involves transcriptome analysis of infection by human cytomegalovirus. The second study's objective is to identify differentially expressed genes between two types of leukemia. Copyright © 2012 John Wiley & Sons, Ltd.

  6. Integrated Variable-Fidelity Tool Set For Modeling and Simulation of Aeroservothermoelasticity -Propulsion (ASTE-P) Effects For Aerospace Vehicles Ranging From Subsonic to Hypersonic Flight, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed research program aims at developing a variable-fidelity software tool set for aeroservothermoelastic-propulsive (ASTE-P) modeling that can be routinely...

  7. Capturing the dynamics of response variability in the brain in ADHD

    Directory of Open Access Journals (Sweden)

    Janna van Belle

    2015-01-01

    Full Text Available ADHD is characterized by increased intra-individual variability in response times during the performance of cognitive tasks. However, little is known about developmental changes in intra-individual variability, and how these changes relate to cognitive performance. Twenty subjects with ADHD aged 7–24 years and 20 age-matched, typically developing controls participated in an fMRI-scan while they performed a go-no-go task. We fit an ex-Gaussian distribution on the response distribution to objectively separate extremely slow responses, related to lapses of attention, from variability on fast responses. We assessed developmental changes in these intra-individual variability measures, and investigated their relation to no-go performance. Results show that the ex-Gaussian measures were better predictors of no-go performance than traditional measures of reaction time. Furthermore, we found between-group differences in the change in ex-Gaussian parameters with age, and their relation to task performance: subjects with ADHD showed age-related decreases in their variability on fast responses (sigma, but not in lapses of attention (tau, whereas control subjects showed a decrease in both measures of variability. For control subjects, but not subjects with ADHD, this age-related reduction in variability was predictive of task performance. This group difference was reflected in neural activation: for typically developing subjects, the age-related decrease in intra-individual variability on fast responses (sigma predicted activity in the dorsal anterior cingulate gyrus (dACG, whereas for subjects with ADHD, activity in this region was related to improved no-go performance with age, but not to intra-individual variability. These data show that using more sophisticated measures of intra-individual variability allows the capturing of the dynamics of task performance and associated neural changes not permitted by more traditional measures.

  8. Magnetic Measurements as a Useful Tool for the Evaluation of Spatial Variability of the Arable Horizon Thickness

    Science.gov (United States)

    Fattakhova, Leysan; Shinkarev, Alexandr; Ryzhikh, Lyudmila; Kosareva, Lina

    2017-04-01

    In normal practice, the thickness of the arable horizon is determined on the basis of field morphological descriptions, allowing the subjectivity of perception and judgment at the crucial role of experience of the researcher. The subject of special interest are independent analytical and technically relatively simple in design approaches to the diagnosis of the lower boundary of the blended plowing the profiles part. Theoretical premises to use spectrophotometry and magnetometry to arable horizon depth diagnose is based on the concept of regular color and magnetic properties vertical differentiation in a profile of virgin soils. This work is devoted to the comparative assessment of the possibility to objectively and reliably diagnose the lower boundary of the arable horizon in gray forest soils by determining the color characteristics and the magnetic susceptibility of their layer-wise samples. It was shown with arable gray forest soil (Cutanic Luvisols (Anthric)) as example that the magnetic susceptibility profile distribution curves can provide more reliable and objective assessment of the arable horizon thickness spatial variability than the profile curves of the color characteristics in the CIELAB coordinates. Therefore, magnetic measurements can be a useful tool for the tillage erosion estimation in the monitoring of soil characteristics in connection with the development of precision agriculture technologies and the organizing of agricultural field plot experiments.

  9. Intra-individual gait patterns across different time-scales as revealed by means of a supervised learning model using kernel-based discriminant regression.

    Directory of Open Access Journals (Sweden)

    Fabian Horst

    Full Text Available Traditionally, gait analysis has been centered on the idea of average behavior and normality. On one hand, clinical diagnoses and therapeutic interventions typically assume that average gait patterns remain constant over time. On the other hand, it is well known that all our movements are accompanied by a certain amount of variability, which does not allow us to make two identical steps. The purpose of this study was to examine changes in the intra-individual gait patterns across different time-scales (i.e., tens-of-mins, tens-of-hours.Nine healthy subjects performed 15 gait trials at a self-selected speed on 6 sessions within one day (duration between two subsequent sessions from 10 to 90 mins. For each trial, time-continuous ground reaction forces and lower body joint angles were measured. A supervised learning model using a kernel-based discriminant regression was applied for classifying sessions within individual gait patterns.Discernable characteristics of intra-individual gait patterns could be distinguished between repeated sessions by classification rates of 67.8 ± 8.8% and 86.3 ± 7.9% for the six-session-classification of ground reaction forces and lower body joint angles, respectively. Furthermore, the one-on-one-classification showed that increasing classification rates go along with increasing time durations between two sessions and indicate that changes of gait patterns appear at different time-scales.Discernable characteristics between repeated sessions indicate continuous intrinsic changes in intra-individual gait patterns and suggest a predominant role of deterministic processes in human motor control and learning. Natural changes of gait patterns without any externally induced injury or intervention may reflect continuous adaptations of the motor system over several time-scales. Accordingly, the modelling of walking by means of average gait patterns that are assumed to be near constant over time needs to be reconsidered in the

  10. Intra-individual gait patterns across different time-scales as revealed by means of a supervised learning model using kernel-based discriminant regression.

    Science.gov (United States)

    Horst, Fabian; Eekhoff, Alexander; Newell, Karl M; Schöllhorn, Wolfgang I

    2017-01-01

    Traditionally, gait analysis has been centered on the idea of average behavior and normality. On one hand, clinical diagnoses and therapeutic interventions typically assume that average gait patterns remain constant over time. On the other hand, it is well known that all our movements are accompanied by a certain amount of variability, which does not allow us to make two identical steps. The purpose of this study was to examine changes in the intra-individual gait patterns across different time-scales (i.e., tens-of-mins, tens-of-hours). Nine healthy subjects performed 15 gait trials at a self-selected speed on 6 sessions within one day (duration between two subsequent sessions from 10 to 90 mins). For each trial, time-continuous ground reaction forces and lower body joint angles were measured. A supervised learning model using a kernel-based discriminant regression was applied for classifying sessions within individual gait patterns. Discernable characteristics of intra-individual gait patterns could be distinguished between repeated sessions by classification rates of 67.8 ± 8.8% and 86.3 ± 7.9% for the six-session-classification of ground reaction forces and lower body joint angles, respectively. Furthermore, the one-on-one-classification showed that increasing classification rates go along with increasing time durations between two sessions and indicate that changes of gait patterns appear at different time-scales. Discernable characteristics between repeated sessions indicate continuous intrinsic changes in intra-individual gait patterns and suggest a predominant role of deterministic processes in human motor control and learning. Natural changes of gait patterns without any externally induced injury or intervention may reflect continuous adaptations of the motor system over several time-scales. Accordingly, the modelling of walking by means of average gait patterns that are assumed to be near constant over time needs to be reconsidered in the context of

  11. Class Evolution Tree: A Graphical Tool to Support Decisions on the Number of Classes in Exploratory Categorical Latent Variable Modeling for Rehabilitation Research

    Science.gov (United States)

    Kriston, Levente; Melchior, Hanne; Hergert, Anika; Bergelt, Corinna; Watzke, Birgit; Schulz, Holger; von Wolff, Alessa

    2011-01-01

    The aim of our study was to develop a graphical tool that can be used in addition to standard statistical criteria to support decisions on the number of classes in explorative categorical latent variable modeling for rehabilitation research. Data from two rehabilitation research projects were used. In the first study, a latent profile analysis was…

  12. Interannual variations in length-of-day (LOD) as a tool to assess climate variability and climate change

    Science.gov (United States)

    Lehmann, E.

    2016-12-01

    On interannual time scales the atmosphere affects significantly fluctuations in the geodetic quantity of length-of-day (LOD). This effect is directly proportional to perturbations in the relative angular momentum of the atmosphere (AAM) computed from zonal winds. During El Niño events tropospheric westerlies increase due to elevated sea surface temperatures (SST) in the Pacific inducing peak anomalies in relative AAM and correspondingly, in LOD. However, El Niño events affect LOD variations differently strong and the causes of this varying effect are yet not clear. Here, we investigate the LOD-El Niño relationship in the 20th and 21st century (1982-2100) whether the quantity of LOD can be used as a geophysical tool to assess variability and change in a future climate. In our analysis we applied a windowed discrete Fourier transform on all de-seasonalized data to remove climatic signals outside of the El Niño frequency band. LOD (data: IERS) was related in space and time to relative AAM and SSTs (data: ERA-40 reanalysis, IPCC ECHAM05-OM1 20C, A1B). Results from mapped Pearson correlation coefficients and time frequency behavior analysis identified a teleconnection pattern that we term the EN≥65%-index. The EN≥65%-index prescribes a significant change in variation in length-of-day of +65% and more related to (1) SST anomalies of >2° in the Pacific Niño region (160°E-80°W, 5°S-5°N), (2) corresponding stratospheric warming anomalies of the quasi-biennial oscillation (QBO), and (3) strong westerly winds in the lower equatorial stratosphere. In our analysis we show that the coupled atmosphere-ocean conditions prescribed in the EN≥65%-index apply to the extreme El Niño events of 19982/83 and 1997/98, and to 75% of all El Niño events in the last third of the 21st century. At that period of time the EN≥65%-index describes a projected altered base state of the equatorial Pacific that shows almost continuous El Niño conditions under climate warming.

  13. Intraindividual comparison of gastric peristalsis after ingestion of a semiliquid and solid test meal

    International Nuclear Information System (INIS)

    Linke, R.; Tatsch, K.; Muenzing, W.; Vorderholzer, W.; Schindlbeck, N.; Hahn, K.

    1997-01-01

    Aim: Patients with various disorders of gastric function were studied with radiolabeled test meals of different consistency to elaborate the effect of ingested media on gastric peristalsis and emptying. Methods: In 12 patients parameters of gastric function were intraindividually compared after ingestion of a semiliquid and a solid test meal. In addition to the standard evaluation derived from time activity curves condensed images were established from two fixed time intervals (early and late period). These images were used to evaluate the amplitude and frequency of gastric contractions using Fourier analysis. Results: As expected gastric emptying was influenced by the consistency of the test meal. Mean emptying rates for the solid meal were significant lower than those for the semiliquid one (p [de

  14. Consistently Showing Your Best Side? Intra-individual Consistency in #Selfie Pose Orientation

    Science.gov (United States)

    Lindell, Annukka K.

    2017-01-01

    Painted and photographic portraits of others show an asymmetric bias: people favor their left cheek. Both experimental and database studies confirm that the left cheek bias extends to selfies. To date all such selfie studies have been cross-sectional; whether individual selfie-takers tend to consistently favor the same pose orientation, or switch between multiple poses, remains to be determined. The present study thus examined intra-individual consistency in selfie pose orientations. Two hundred selfie-taking participants (100 male and 100 female) were identified by searching #selfie on Instagram. The most recent 10 single-subject selfies for the each of the participants were selected and coded for type of selfie (normal; mirror) and pose orientation (left, midline, right), resulting in a sample of 2000 selfies. Results indicated that selfie-takers do tend to consistently adopt a preferred pose orientation (α = 0.72), with more participants showing an overall left cheek bias (41%) than would be expected by chance (overall right cheek bias = 31.5%; overall midline bias = 19.5%; no overall bias = 8%). Logistic regression modellng, controlling for the repeated measure of participant identity, indicated that sex did not affect pose orientation. However, selfie type proved a significant predictor when comparing left and right cheek poses, with a stronger left cheek bias for mirror than normal selfies. Overall, these novel findings indicate that selfie-takers show intra-individual consistency in pose orientation, and in addition, replicate the previously reported left cheek bias for selfies and other types of portrait, confirming that the left cheek bias also presents within individuals’ selfie corpora. PMID:28270790

  15. Variability of gastric emptying measurements in man employing standardized radiolabeled meals

    International Nuclear Information System (INIS)

    Brophy, C.M.; Moore, J.G.; Christian, P.E.; Egger, M.J.; Taylor, A.T.

    1986-01-01

    Radiolabeled liquid and solid portions of standardized 300-g meals were administered on four different study days to eight healthy subjects in an attempt to define the range of inter- and intrasubject variability in gastric emptying. Meal half emptying times, analysis of variance, and intraclass correlations were computed and compared within and between subjects. The mean solid half emptying time was 58 +/- 17 min (range 29-92), while the mean liquid half emptying time was 24 +/- 8 min (range 12-37). A nested random effects analysis of variance showed moderate intrasubject variability for solid emptying and high intrasubject variability for liquid emptying. The variability of solid and liquid emptying was comparable and relatively large when compared with other reports in the literature. The isotopic method for measuring gastric emptying is a valuable tool for investigating problems in gastric pathophysiology, particularly when differences between groups of subjects are sought. However, meal emptying time is a variable phenomenon in healthy subjects with significant inter- and intraindividual day-to-day differences. These day-to-day variations in gastric emptying must be considered in interpreting individual study results

  16. Variability of gastric emptying measurements in man employing standardized radiolabeled meals

    Energy Technology Data Exchange (ETDEWEB)

    Brophy, C.M.; Moore, J.G.; Christian, P.E.; Egger, M.J.; Taylor, A.T.

    1986-08-01

    Radiolabeled liquid and solid portions of standardized 300-g meals were administered on four different study days to eight healthy subjects in an attempt to define the range of inter- and intrasubject variability in gastric emptying. Meal half emptying times, analysis of variance, and intraclass correlations were computed and compared within and between subjects. The mean solid half emptying time was 58 +/- 17 min (range 29-92), while the mean liquid half emptying time was 24 +/- 8 min (range 12-37). A nested random effects analysis of variance showed moderate intrasubject variability for solid emptying and high intrasubject variability for liquid emptying. The variability of solid and liquid emptying was comparable and relatively large when compared with other reports in the literature. The isotopic method for measuring gastric emptying is a valuable tool for investigating problems in gastric pathophysiology, particularly when differences between groups of subjects are sought. However, meal emptying time is a variable phenomenon in healthy subjects with significant inter- and intraindividual day-to-day differences. These day-to-day variations in gastric emptying must be considered in interpreting individual study results.

  17. Stability and Variability in Young Children's Understanding of Floating and Sinking during One Single-Task Session

    Science.gov (United States)

    Meindertsma, Heidi B.; van Dijk, Marijn W. G.; Steenbeek, Henderien W.; van Geert, Paul L. C.

    2014-01-01

    Intraindividual variability is a key component in explaining children's development and learning. Studying this type of variability on the micro-timescale can help us understand real-time constructive processes and the subsequent long-term development. The aim of this article is to study the process of children's understanding of…

  18. Rapid decision support tool based on novel ecosystem service variables for retrofitting of permeable pavement systems in the presence of trees.

    Science.gov (United States)

    Scholz, Miklas; Uzomah, Vincent C

    2013-08-01

    The retrofitting of sustainable drainage systems (SuDS) such as permeable pavements is currently undertaken ad hoc using expert experience supported by minimal guidance based predominantly on hard engineering variables. There is a lack of practical decision support tools useful for a rapid assessment of the potential of ecosystem services when retrofitting permeable pavements in urban areas that either feature existing trees or should be planted with trees in the near future. Thus the aim of this paper is to develop an innovative rapid decision support tool based on novel ecosystem service variables for retrofitting of permeable pavement systems close to trees. This unique tool proposes the retrofitting of permeable pavements that obtained the highest ecosystem service score for a specific urban site enhanced by the presence of trees. This approach is based on a novel ecosystem service philosophy adapted to permeable pavements rather than on traditional engineering judgement associated with variables based on quick community and environment assessments. For an example case study area such as Greater Manchester, which was dominated by Sycamore and Common Lime, a comparison with the traditional approach of determining community and environment variables indicates that permeable pavements are generally a preferred SuDS option. Permeable pavements combined with urban trees received relatively high scores, because of their great potential impact in terms of water and air quality improvement, and flood control, respectively. The outcomes of this paper are likely to lead to more combined permeable pavement and tree systems in the urban landscape, which are beneficial for humans and the environment. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Effect Of Variable Practice On The Motor Learning Process In Manual Wheelchair Propulsion

    NARCIS (Netherlands)

    Leving, Marika T; Vegter, Riemer J K; de Groot, Sonja; van der Woude, Lucas H V

    Handrim wheelchair propulsion is a cyclic skill that needs to be learned during rehabilitation. It has been suggested that a higher intra-individual variability benefits the motor learning process of wheelchair propulsion. PURPOSE: The goal of the current study was to determine the effect of

  20. Variability of fasting and post-menthionine plasma homocysteine levels in normo- and hyperhomocysteinaemic individuals

    NARCIS (Netherlands)

    van den Berg, M.; de Jong, S.C.; Devilli, W.; Rauwerda, J.A.; Jakobs, C.A.J.M.; Pals, G.; Boers, G.H.J.; Stehouwer, C.D.A.

    1999-01-01

    To assess the variability of plasma homocysteine levels, fasting and post-methionine homocysteine levels were measured twice, at baseline and after follow-up of 1-4 months, in 16 individuals with normal and 26 with elevated homocysteine levels after methionine loading. The intra-individual

  1. Does Response Variability Predict Distractibility among Adults with Attention-Deficit/Hyperactivity Disorder?

    Science.gov (United States)

    Adams, Zachary W.; Roberts, Walter M.; Milich, Richard; Fillmore, Mark T.

    2011-01-01

    Increased intraindividual variability in response time (RTSD) has been observed reliably in attention-deficit/hyperactivity disorder (ADHD) and has often been used as a measure of inattention. RTSD is assumed to reflect attentional lapses and distractibility, though evidence for the validity of this connection is lacking. We assessed whether RTSD…

  2. Narrow intra-individual variation of maternal thyroid function in pregnancy based on a longitudinal study on 132 women

    DEFF Research Database (Denmark)

    Boas, M.; Forman, Julie Lyng; Juul, A.

    2009-01-01

    BACKGROUND: Adaptive alterations in maternal physiology cause changes in thyroid hormone levels throughout pregnancy, and precise biochemical evaluation is thus highly dependent on gestation-specific reference intervals and expected intra-individual variation. OBJECTIVE: The aim of the study...... was the assessment of the intra-individual variation as well as the longitudinal course of thyroid hormones during normal pregnancy and factors that influence the normal reference range for thyroid function. For this purpose, a longitudinal statistical model was applied. DESIGN: In a cohort of 132 pregnant women......, serial blood samples were obtained and ultrasound scans were performed throughout pregnancy. METHODS: Serum levels of TSH, free and total thyroxine (T(4)), free and total triiodothyronine (T(3)) as well as autoantibodies against thyroid peroxidase and thyroglobulin were measured in 979 serum samples...

  3. Thermal infrared imagery as a tool for analysing the variability of surface saturated areas at various temporal and spatial scales

    Science.gov (United States)

    Glaser, Barbara; Antonelli, Marta; Pfister, Laurent; Klaus, Julian

    2017-04-01

    Surface saturated areas are important for the on- and offset of hydrological connectivity within the hillslope-riparian-stream continuum. This is reflected in concepts such as variable contributing areas or critical source areas. However, we still lack a standardized method for areal mapping of surface saturation and for observing its spatiotemporal variability. Proof-of-concept studies in recent years have shown the potential of thermal infrared (TIR) imagery to record surface saturation dynamics at various temporal and spatial scales. Thermal infrared imagery is thus a promising alternative to conventional approaches, such as the squishy boot method or the mapping of vegetation. In this study we use TIR images to investigate the variability of surface saturated areas at different temporal and spatial scales in the forested Weierbach catchment (0.45 km2) in western Luxembourg. We took TIR images of the riparian zone with a hand-held FLIR infrared camera at fortnightly intervals over 18 months at nine different locations distributed over the catchment. Not all of the acquired images were suitable for a derivation of the surface saturated areas, as various factors influence the usability of the TIR images (e.g. temperature contrasts, shadows, fog). Nonetheless, we obtained a large number of usable images that provided a good insight into the dynamic behaviour of surface saturated areas at different scales. The images revealed how diverse the evolution of surface saturated areas can be throughout the hydrologic year. For some locations with similar morphology or topography we identified diverging saturation dynamics, while other locations with different morphology / topography showed more similar behaviour. Moreover, we were able to assess the variability of the dynamics of expansion / contraction of saturated areas within the single locations, which can help to better understand the mechanisms behind surface saturation development.

  4. Direct Aggression and Generalized Anxiety in Adolescence: Heterogeneity in Development and Intra-Individual Change.

    Science.gov (United States)

    Meeus, Wim; Van de Schoot, Rens; Hawk, Skyler T; Hale, William W; Branje, Susan

    2016-02-01

    Co-occurrence of aggression and anxiety might change during adolescence, or stay stable. We studied change and stability of four types of co-occurrence regarding direct aggression and anxiety in adolescence: an anxious and non-aggressive type, an aggressive and non-anxious type, a comorbid aggressive-anxious type and a no problems type. We applied a person-centered approach to assess increases and decreases of these types, and tested various models of intra-individual change of the types: the stability, acting out and failure models. We used data from a five-wave study of 923 early-to-middle and 390 middle-to-late adolescents (48.5 % male), thereby covering the ages of 12-20. We observed accelerated development in the older cohort: adolescents tended to grow faster out of the aggressive types in middle-to-late adolescence than in early-to-middle adolescence. We observed one other group-dependent pattern of heterogeneity in development, namely "gender differentiation": gender differences in aggression and generalized anxiety became stronger over time. We found support for two perspectives on intra-individual change of the four types, namely the stability and the acting out perspective. The no problems--and to a lesser extent the anxious--type proved to be stable across time. Acting out was found in early-to-middle adolescents, males, and adolescents with poorer-quality friendships. In all three groups, there were substantial transitions from the anxious type to the aggressive type during 4 years (between 20 and 41 %). Remarkably, acting out was most prevalent in subgroups that, generally speaking, are more vulnerable for aggressive behavior, namely early-to-middle adolescents and males. We interpret acting out as the attempt of adolescents to switch from anxiety to instrumental aggression, in order to become more visible and obtain an autonomous position in the adolescent world. Acting out contributed to the explanation of accelerated development and gender

  5. Adolescents' and Best Friend's Depressive Symptoms and Conflict Management: Intraindividual and Interpersonal Processes Over Time.

    Science.gov (United States)

    Boersma-van Dam, Elise; Hale, Bill; Koot, Hans; Meeus, Wim; Branje, Susan

    2016-12-12

    This 6-year longitudinal study examined the relation between 3 conflict management styles (i.e., problem solving, conflict engagement, and compliance) and depressive symptoms in adolescent-best friend relationships. Participants were 479 Dutch adolescents and their best friend who reported annually on depressive symptoms and conflict management styles toward each other. Bidirectional effects between conflict management styles and depressive symptoms were studied both within adolescents (intraindividual) and between adolescent best friends (interpersonal). A positive interpersonal effect of depressive symptoms of one dyad member on depressive symptoms of the other member was found. Similarly, higher positive problem solving and conflict engagement of one dyad member predicted respectively higher problem solving and conflict engagement of the other dyad member. Adolescents who reported more depressive symptoms reported more conflict engagement and compliance over time. In addition, for boys, higher levels of depressive symptoms of one dyad member were related to more problem solving by the other member over time. The current study contributed to the literature by showing that depressive symptoms and conflict management are related constructs in adolescents and that both intrapersonal and interpersonal processes contribute to this relation.

  6. Effects of visual feedback-induced variability on motor learning of handrim wheelchair propulsion.

    Science.gov (United States)

    Leving, Marika T; Vegter, Riemer J K; Hartog, Johanneke; Lamoth, Claudine J C; de Groot, Sonja; van der Woude, Lucas H V

    2015-01-01

    It has been suggested that a higher intra-individual variability benefits the motor learning of wheelchair propulsion. The present study evaluated whether feedback-induced variability on wheelchair propulsion technique variables would also enhance the motor learning process. Learning was operationalized as an improvement in mechanical efficiency and propulsion technique, which are thought to be closely related during the learning process. 17 Participants received visual feedback-based practice (feedback group) and 15 participants received regular practice (natural learning group). Both groups received equal practice dose of 80 min, over 3 weeks, at 0.24 W/kg at a treadmill speed of 1.11 m/s. To compare both groups the pre- and post-test were performed without feedback. The feedback group received real-time visual feedback on seven propulsion variables with instruction to manipulate the presented variable to achieve the highest possible variability (1st 4-min block) and optimize it in the prescribed direction (2nd 4-min block). To increase motor exploration the participants were unaware of the exact variable they received feedback on. Energy consumption and the propulsion technique variables with their respective coefficient of variation were calculated to evaluate the amount of intra-individual variability. The feedback group, which practiced with higher intra-individual variability, improved the propulsion technique between pre- and post-test to the same extent as the natural learning group. Mechanical efficiency improved between pre- and post-test in the natural learning group but remained unchanged in the feedback group. These results suggest that feedback-induced variability inhibited the improvement in mechanical efficiency. Moreover, since both groups improved propulsion technique but only the natural learning group improved mechanical efficiency, it can be concluded that the improvement in mechanical efficiency and propulsion technique do not always appear

  7. Acute Mental Discomfort Associated with Suicide Behavior in a Clinical Sample of Patients with Affective Disorders: Ascertaining Critical Variables Using Artificial Intelligence Tools.

    Science.gov (United States)

    Morales, Susana; Barros, Jorge; Echávarri, Orietta; García, Fabián; Osses, Alex; Moya, Claudia; Maino, María Paz; Fischman, Ronit; Núñez, Catalina; Szmulewicz, Tita; Tomicic, Alemka

    2017-01-01

    In efforts to develop reliable methods to detect the likelihood of impending suicidal behaviors, we have proposed the following. To gain a deeper understanding of the state of suicide risk by determining the combination of variables that distinguishes between groups with and without suicide risk. A study involving 707 patients consulting for mental health issues in three health centers in Greater Santiago, Chile. Using 345 variables, an analysis was carried out with artificial intelligence tools, Cross Industry Standard Process for Data Mining processes, and decision tree techniques. The basic algorithm was top-down, and the most suitable division produced by the tree was selected by using the lowest Gini index as a criterion and by looping it until the condition of belonging to the group with suicidal behavior was fulfilled. Four trees distinguishing the groups were obtained, of which the elements of one were analyzed in greater detail, since this tree included both clinical and personality variables. This specific tree consists of six nodes without suicide risk and eight nodes with suicide risk (tree decision 01, accuracy 0.674, precision 0.652, recall 0.678, specificity 0.670, F measure 0.665, receiver operating characteristic (ROC) area under the curve (AUC) 73.35%; tree decision 02, accuracy 0.669, precision 0.642, recall 0.694, specificity 0.647, F measure 0.667, ROC AUC 68.91%; tree decision 03, accuracy 0.681, precision 0.675, recall 0.638, specificity 0.721, F measure, 0.656, ROC AUC 65.86%; tree decision 04, accuracy 0.714, precision 0.734, recall 0.628, specificity 0.792, F measure 0.677, ROC AUC 58.85%). This study defines the interactions among a group of variables associated with suicidal ideation and behavior. By using these variables, it may be possible to create a quick and easy-to-use tool. As such, psychotherapeutic interventions could be designed to mitigate the impact of these variables on the emotional state of individuals, thereby reducing

  8. Malaria early warning tool: linking inter-annual climate and malaria variability in northern Guadalcanal, Solomon Islands.

    Science.gov (United States)

    Smith, Jason; Tahani, Lloyd; Bobogare, Albino; Bugoro, Hugo; Otto, Francis; Fafale, George; Hiriasa, David; Kazazic, Adna; Beard, Grant; Amjadali, Amanda; Jeanne, Isabelle

    2017-11-21

    Malaria control remains a significant challenge in the Solomon Islands. Despite progress made by local malaria control agencies over the past decade, case rates remain high in some areas of the country. Studies from around the world have confirmed important links between climate and malaria transmission. This study focuses on understanding the links between malaria and climate in Guadalcanal, Solomon Islands, with a view towards developing a climate-based monitoring and early warning for periods of enhanced malaria transmission. Climate records were sourced from the Solomon Islands meteorological service (SIMS) and historical malaria case records were sourced from the National Vector-Borne Disease Control Programme (NVBDCP). A declining trend in malaria cases over the last decade associated with improved malaria control was adjusted for. A stepwise regression was performed between climate variables and climate-associated malaria transmission (CMT) at different lag intervals to determine where significant relationships existed. The suitability of these results for use in a three-tiered categorical warning system was then assessed using a Mann-Whitney U test. Of the climate variables considered, only rainfall had a consistently significant relationship with malaria in North Guadalcanal. Optimal lag intervals were determined for prediction using R 2 skill scores. A highly significant negative correlation (R = - 0.86, R 2  = 0.74, p malaria transmission periods in January-June. Cross-validation emphasized the suitability of this relationship for forecasting purposes [Formula: see text]  as did Mann-Whitney U test results showing that rainfall below or above specific thresholds was significantly associated with above or below normal malaria transmission, respectively. This study demonstrated that rainfall provides the best predictor of malaria transmission in North Guadalcanal. This relationship is thought to be underpinned by the unique hydrological conditions

  9. Key indicator tools for shallow slope failure assessment using soil chemical property signatures and soil colour variables.

    Science.gov (United States)

    Othman, Rashidi; Hasni, Shah Irani; Baharuddin, Zainul Mukrim; Hashim, Khairusy Syakirin Has-Yun; Mahamod, Lukman Hakim

    2017-10-01

    Slope failure has become a major concern in Malaysia due to the rapid development and urbanisation in the country. It poses severe threats to any highway construction industry, residential areas, natural resources and tourism activities. The extent of damages that resulted from this catastrophe can be lessened if a long-term early warning system to predict landslide prone areas is implemented. Thus, this study aims to characterise the relationship between Oxisols properties and soil colour variables to be manipulated as key indicators to forecast shallow slope failure. The concentration of each soil property in slope soil was evaluated from two different localities that consist of 120 soil samples from stable and unstable slopes located along the North-South Highway (PLUS) and East-West Highway (LPT). Analysis of variance established highly significant difference (P shallow slope failure were high value of L*(62), low values of c* (20) and h* (66), low concentration of iron (53 mg kg -1 ) and aluminium oxide (37 mg kg -1 ), low soil TOC (0.5%), low CEC (3.6 cmol/kg), slightly acidic soil pH (4.9), high amount of sand fraction (68%) and low amount of clay fraction (20%).

  10. On Comparison of SimTandem with State-of-the-Art Peptide Identification Tools, Efficiency of Precursor Mass Filter and Dealing with Variable Modifications

    Directory of Open Access Journals (Sweden)

    Novák Jiří

    2013-12-01

    Full Text Available The similarity search in theoretical mass spectra generated from protein sequence databases is a widely accepted approach for identification of peptides from query mass spectra produced by shotgun proteomics. Growing protein sequence databases and noisy query spectra demand database indexing techniques and better similarity measures for the comparison of theoretical spectra against query spectra. We employ a modification of previously proposed parameterized Hausdorff distance for comparisons of mass spectra. The new distance outperforms the original distance, the angle distance and state-of-the-art peptide identification tools OMSSA and X!Tandem in the number of identified peptides even though the q-value is only 0.001. When a precursor mass filter is used as a database indexing technique, our method outperforms OMSSA in the speed of search. When variable modifications are not searched, the search time is similar to X!Tandem. We show that the precursor mass filter is an efficient database indexing technique for high-accuracy data even though many variable modifications are being searched. We demonstrate that the number of identified peptides is bigger when variable modifications are searched separately by more search runs of a peptide identification engine. Otherwise, the false discovery rates are affected by mixing unmodified and modified spectra together resulting in a lower number of identified peptides. Our method is implemented in the freely available application SimTandem which can be used in the framework TOPP based on OpenMS.

  11. The relationship between the structure of interindividual and intraindividual variability: A theoretical and empirical vindication of developmental systems theory

    NARCIS (Netherlands)

    Molenaar, P.C.M.; Huizenga, H.M.; Nesselroade, J.R.; Staudinger, U.M.

    2003-01-01

    (from the chapter) Proponents of the developmental systems theory (DST) have questioned the relevance of behavior genetics for the study of developmental processes. In this chapter, the criticism of DST will be reformulated in a way that is consistent with Wohlwill's thesis that the study of

  12. A longitudinal study of basal cortisol in infants : Intra-individual variability, circadian rhythm and developmental trends

    NARCIS (Netherlands)

    de Weerth, C.; Van Geert, P. L. C.

    2002-01-01

    Mothers with normally developing babies were visited in their homes during 13 consecutive weeks, when the babies were around 5-8 months of age. Basal salival cortisol measures were taken for both the baby and the mother on arrival. The infants' basal cortisol decreased linearly with age, was

  13. Integrated Variable-Fidelity Tool Set for Modeling and Simulation of Aeroservothermoelasticity-Propulsion (ASTE-P) Effects for Aerospace Vehicles Ranging From Subsonic to Hypersonic Flight, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed research program aims at developing a variable-fidelity software tool set for aeroservothermoelastic-propulsive (ASTE-P) modeling that can be routinely...

  14. Intraindividual right-left comparison of sonographic features in polycystic ovary syndrome (PCOS) diagnosis.

    Science.gov (United States)

    Köninger, Angela; Koch, Laura; Edimiris, Philippos; Nießen, Stefanie; Kasimir-Bauer, Sabine; Kimmig, Rainer; Strowitzki, Thomas; Schmidt, Börge

    2014-10-01

    Sonographic features of polycystic ovaries consist of elevated antral follicle count or ovarian volume of at least one ovary. The aim of this prospective cross-sectional study was to estimate intraindividual differences in sonographic measurements between the both ovaries of PCOS patients and controls and clinical consequences. Both ovaries of 85 PCOS patients and 48 controls were scanned transvaginally and agreement of sonographic measurements was analyzed using the Bland-Altman method. Concordance correlation coefficients (CCC) were computed. Mean differences between right and left ovaries were 0.24 (95% confidence interval [95% CI]: -0.32-0.80) follicles for AFC and 1.14 (95% CI: 0.34-1.92)ml for OV in the whole study population, 0.14 (95% CI: -0.68-0.96) follicles for AFC and 1.48 (95% CI: 0.39-2.58)ml for OV in PCOS patients, 0.42 (95% CI: -0.19-1.02) follicles for AFC and 0.53 (95% CI: -0.50-1.56)ml for OV in controls. Rather wide limits of agreement and low CCCs (ovaries for both sonographic measurements. Width between lower and upper limits of agreement was higher for PCOS patients than for controls. 23.5% of the PCOS patients showed polycystic ovarian morphology (PCOM) only in one ovary, resulting in 9.4% potentially missed PCOS diagnosis according to the Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group. Substantial differences in antral follicle count and ovarian volume between the right and left ovary were observed. In approximately 10% of the PCOS patients in our study only the examination of both ovaries has led to a reliable diagnosis of PCOS. In clinical practice it is recommended to scan both ovaries for a reliable diagnosis of abnormal sonographic findings in PCOM and PCOS diagnosis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Longitudinal Reliability of Self-Reported Age at Menarche in Adolescent Girls: Variability across Time and Setting

    Science.gov (United States)

    Dorn, Lorah D.; Sontag-Padilla, Lisa M.; Pabst, Stephanie; Tissot, Abbigail; Susman, Elizabeth J.

    2013-01-01

    Age at menarche is critical in research and clinical settings, yet there is a dearth of studies examining its reliability in adolescents. We examined age at menarche during adolescence, specifically, (a) average method reliability across 3 years, (b) test-retest reliability between time points and methods, (c) intraindividual variability of…

  16. Validation of the ICU-DaMa tool for automatically extracting variables for minimum dataset and quality indicators: The importance of data quality assessment.

    Science.gov (United States)

    Sirgo, Gonzalo; Esteban, Federico; Gómez, Josep; Moreno, Gerard; Rodríguez, Alejandro; Blanch, Lluis; Guardiola, Juan José; Gracia, Rafael; De Haro, Lluis; Bodí, María

    2018-04-01

    Big data analytics promise insights into healthcare processes and management, improving outcomes while reducing costs. However, data quality is a major challenge for reliable results. Business process discovery techniques and an associated data model were used to develop data management tool, ICU-DaMa, for extracting variables essential for overseeing the quality of care in the intensive care unit (ICU). To determine the feasibility of using ICU-DaMa to automatically extract variables for the minimum dataset and ICU quality indicators from the clinical information system (CIS). The Wilcoxon signed-rank test and Fisher's exact test were used to compare the values extracted from the CIS with ICU-DaMa for 25 variables from all patients attended in a polyvalent ICU during a two-month period against the gold standard of values manually extracted by two trained physicians. Discrepancies with the gold standard were classified into plausibility, conformance, and completeness errors. Data from 149 patients were included. Although there were no significant differences between the automatic method and the manual method, we detected differences in values for five variables, including one plausibility error and two conformance and completeness errors. Plausibility: 1) Sex, ICU-DaMa incorrectly classified one male patient as female (error generated by the Hospital's Admissions Department). Conformance: 2) Reason for isolation, ICU-DaMa failed to detect a human error in which a professional misclassified a patient's isolation. 3) Brain death, ICU-DaMa failed to detect another human error in which a professional likely entered two mutually exclusive values related to the death of the patient (brain death and controlled donation after circulatory death). Completeness: 4) Destination at ICU discharge, ICU-DaMa incorrectly classified two patients due to a professional failing to fill out the patient discharge form when thepatients died. 5) Length of continuous renal replacement

  17. OPTIMALISASI MRP PARAMATER PADA COMMON MATERIAL UNTUK MEMBERI NILAI TAMBAH PADA PROSES KANBAN DI PT UNELEC INDONESIA (UNINDO DENGAN SIMULASI PART-VARIABLE TOOLS

    Directory of Open Access Journals (Sweden)

    Budi Susatyo

    2016-02-01

    Full Text Available Part-Variable Tools merupakan  aplikasi kecil yang dibuat dengan Ms. Excel, untuk melakukan perhitungan dan usulan MRP parameter dengan mempergunakan data transaksi bahan baku paling sedikit 1 tahun kebelakang.”Common Material” adalah tipe bahan baku yang ada di PT UNINDO yang harus selalu tersedia dalam kotak (bin di Gudang Persediaan dan sumber kebutuhan akan bahan baku ini diminta oleh karyawan Gudang. Permintaan jumlah kuantitinya berdasarkan jumlah akutal yang ada dibandingkan dengan nilai level permintaan kembali (ROP yang tertera pada KARTU KANBAN. Nilai ROP tersebut merupakan parameter MRP yang digunakan dalam perhitungan kebutuhan material.Perhitungan MRP dibutuhkan untuk meningkatkan kualitas, produktifitas, dan efisiensi, perbaikan komunikasi, dan menurunkan biaya-biaya dan hal hal yang tidak diperlukan serta mendekati keinginan konsumen dengan meminimalkan waktu tunggu ( Kootaneel, 2013  

  18. In-process tool rotational speed variation with constant heat input in friction stir welding of AZ31 sheets with variable thickness

    Science.gov (United States)

    Buffa, Gianluca; Campanella, Davide; Forcellese, Archimede; Fratini, Livan; Simoncini, Michela

    2017-10-01

    In the present work, friction stir welding experiments on AZ31 magnesium alloy sheets, characterized by a variable thickness along the welding line, were carried out. The approach adapted during welding consisted in maintaining constant the heat input to the joint. To this purpose, the rotational speed of the pin tool was increased with decreasing thickness and decreased with increasing thickness in order to obtain the same temperatures during welding. The amount by which the rotational speed was changed as a function of the sheet thickness was defined on the basis of the results given by FEM simulations of the FSW process. Finally, the effect of the in-process variation of the tool rotational speed on the mechanical and microstructural properties of FSWed joints was analysed by comparing both the nominal stress vs. nominal strain curves and microstructure of FSWed joints obtained in different process conditions. It was observed that FSW performed by keeping constant the heat input to the joint leads to almost coincident results both in terms of the curve shape, ultimate tensile strength and ultimate elongation values, and microstructure.

  19. The Macaque Social Responsiveness Scale (mSRS: A Rapid Screening Tool for Assessing Variability in the Social Responsiveness of Rhesus Monkeys (Macaca mulatta.

    Directory of Open Access Journals (Sweden)

    Eric J Feczko

    Full Text Available Understanding the biological mechanisms underlying human neuropsychiatric disorders, such as autism spectrum disorder (ASD, has been hindered by the lack of a robust, translational animal model. Rhesus monkeys (Macaca mulatta display many of the same social behaviors that are affected in ASD, making them an excellent animal species in which to model social impairments. However, the social impairments associated with ASD may reflect extreme ends of a continuous distribution of traits. Thus, to validate the rhesus monkey as an animal model for studying social impairments that has strong translational relevance for ASD, researchers need an easily-implemented measurement tool that can quantify variation in social behavior dimensionally. The Social Responsiveness Scale (SRS is a 65-item survey that identifies both typical and atypical social behaviors in humans that covary with ASD symptom severity. A chimpanzee SRS has already been validated and the current study adapted this tool for use in the rhesus monkey (mSRS. Fifteen raters completed the mSRS for 105 rhesus monkeys living at the Yerkes National Primate Research Center. The mSRS scores showed a unimodal distribution with a positive skew that identified 6 statistical outliers. Inter-rater reliability was very strong, but only 17 of the 36 questions showed positive intra-item reliability. The results of an exploratory factor analysis identified 3 factors that explained over 60% of the variance, with 12 items significantly loading onto the primary factor. These items reflected behaviors associated with social avoidance, social anxiety or inflexibility and social confidence. These initial findings are encouraging and suggest that variability in the social responsiveness of rhesus monkeys can be quantified using the mSRS: a tool that has strong translational relevance for human disorders. With further modification, the mSRS may provide an promising new direction for research on the biological

  20. Sleep and circadian variability in people with delayed sleep-wake phase disorder versus healthy controls.

    Science.gov (United States)

    Burgess, Helen J; Park, Margaret; Wyatt, James K; Rizvydeen, Muneer; Fogg, Louis F

    2017-06-01

    To compare sleep and circadian variability in adults with delayed sleep-wake phase disorder (DSWPD) to healthy controls. Forty participants (22 DSWPD, 18 healthy controls) completed a ten-day protocol, consisting of DLMO assessments on two consecutive nights, a five-day study break, followed by two more DLMO assessments. All participants were instructed to sleep within one hour of their self-reported average sleep schedule for the last four days of the study break. We analyzed the participants' wrist actigraphy data during these four days to examine intraindividual variability in sleep timing, duration and efficiency. We also examined shifts in the DLMO from before and after the study break. Under the same conditions, people with DSWPD had significantly more variable wake times and total sleep time than healthy controls (p ≤ 0.015). Intraindividual variability in sleep onset time and sleep efficiency was similar between the two groups (p ≥ 0.30). The DLMO was relatively stable across the study break, with only 11% of controls but 27% of DSWPDs showed more than a one hour shift in the DLMO. Only in the DSWPD sample was greater sleep variability associated with a larger shift in the DLMO (r = 0.46, p = 0.03). These results suggest that intraindividual variability in sleep can be higher in DSWPD versus healthy controls, and this may impact variability in the DLMO. DSWPD patients with higher intraindividual variability in sleep are more likely to have a shifting DLMO, which could impact sleep symptoms and the optimal timing of light and/or melatonin treatment for DSWPD. Circadian Phase Assessments at Home, http://clinicaltrials.gov/show/NCT01487252, NCT01487252. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Intra-individual comparison of different contrast media concentrations (300 mg, 370 mg and 400 mg iodine) in MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Behrendt, Florian F.; Keil, Sebastian; Plumhans, Cedric; Guenther, Rolf W. [RWTH Aachen University, Department of Diagnostic Radiology, University Hospital, Aachen (Germany); Pietsch, Hubertus; Jost, Gregor; Sieber, Martin A.; Seidensticker, Peter [Bayer Schering Pharma AG, Berlin (Germany); Mahnken, Andreas H. [RWTH Aachen University, Department of Diagnostic Radiology, University Hospital, Aachen (Germany); RWTH Aachen University, Applied Medical Engineering, Helmholtz-Institute for Biomedical Engineering, Aachen (Germany)

    2010-07-15

    To compare intra-individual contrast enhancement in multi-detector-row computed tomography (MDCT) using contrast media (CM) containing 300, 370 and 400 mg iodine per ml (mgI/ml). Six pigs underwent repeated chest MDCT using three different CM (iopromide 300, iopromide 370, iomeprol 400). An identical iodine delivery (IDR) rate of 1.5 gI/s and a constant total iodine dose of 300 mg/kg body weight were used. Dynamic CT were acquired at the level of the pulmonary artery, and the ascending and descending aorta. After the time enhancement curves were computed, the pulmonary and aortic peak enhancement, time to peak and plateau time above 300 HU were calculated. Intra-individual peak contrast enhancement was significantly higher for the 300 mgI/ml contrast medium compared with the 370 and 400 mgI/ml media: pulmonary trunk 595 HU vs 516 HU (p = 0.0093) vs 472HU (p = 0.0005), and aorta 505 HU vs 454 HU (p = 0.0008) vs 439 HU (p = 0.0001), respectively. Comparison of time to peaks showed no significant difference. Plateau times were significantly longer for the 300 mgI/ml than for the 370 and 400 mgI/ml CM at all anatomical sites. Given normalised IDR and total iodine burden, the use of CM with a standard concentration with 300 mg iodine/ml provides improved contrast enhancement compared with highly concentrated CM in the chest. (orig.)

  2. Enhancement of abdominal structures on MRI at 1.5 and 3 T: a retrospective intraindividual crossover comparison

    Energy Technology Data Exchange (ETDEWEB)

    AlObaidy, Mamdoh [King Faisal Specialist Hospital and Research Center, Department of Radiology, Riyadh (Saudi Arabia); University of North Carolina at Chapel Hill, Department of Radiology, Chapel Hill, NC (United States); Ramalho, Miguel; Velloni, Fernanda; Matos, Antonio P.; Herman, Kevin; Semelka, Richard C. [University of North Carolina at Chapel Hill, Department of Radiology, Chapel Hill, NC (United States)

    2017-04-15

    To quantitatively compare the extent of enhancement of abdominal structures on MRI in an intraindividual fashion at 1.5 and 3 T. HIPAA-compliant, retrospective, longitudinal, intraindividual, crossover study, with waived informed consent, of consecutive individuals scanned at both 1.5 and 3 T closed-bore magnets using gadobenate dimeglumine during different phases of enhancement at tightly controlled arterial phase timing. Quantitative ROI measurements and qualitative sub-phase arterial phase assignments were independently performed by two radiologists. Qualitative discrepancies were resolved by a senior radiologist. Final population included 60 patients [41 female and 19 male; age, 49.35 ± 18.31 years (range 16-81); weight, 78.88 ± 20.3 kg (range 44.5-136)]. Similar enhancement peak patterns were noted at both field strengths. Interobserver agreement of quantitative evaluations was substantial. Significantly higher amplitudes of enhancement peaks were noted for all abdominal solid organs during all phases at 3 T, except for the pancreas (p = 0.17-0.30). Significantly higher amplitudes of enhancement peaks of the abdominal aorta at 1.5 T were noted. Similar peak patterns of enhancement for abdominal structures were observed at 1.5 and 3 T, with solid abdominal organs showing a higher percentage enhancement at 3 T, while unexpectedly higher aortic higher percentage enhancement was observed at 1.5 T. (orig.)

  3. Quantification and variability in colonic volume with a novel magnetic resonance imaging method

    DEFF Research Database (Denmark)

    Nilsson, M; Sandberg, Thomas Holm; Poulsen, Jakob Lykke

    2015-01-01

    Background: Segmental distribution of colorectal volume is relevant in a number of diseases, but clinical and experimental use demands robust reliability and validity. Using a novel semi-automatic magnetic resonance imaging-based technique, the aims of this study were to describe: (i) inter......-individual and intra-individual variability of segmental colorectal volumes between two observations in healthy subjects and (ii) the change in segmental colorectal volume distribution before and after defecation. Methods: The inter-individual and intra-individual variability of four colorectal volumes (cecum...... (p = 0.02). Conclusions & Inferences: Imaging of segmental colorectal volume, morphology, and fecal accumulation is advantageous to conventional methods in its low variability, high spatial resolution, and its absence of contrast-enhancing agents and irradiation. Hence, the method is suitable...

  4. The virtual lover: variable and easily guided 3D fish animations as an innovative tool in mate-choice experiments with sailfin mollies-II. Validation.

    Science.gov (United States)

    Gierszewski, Stefanie; Müller, Klaus; Smielik, Ievgen; Hütwohl, Jan-Marco; Kuhnert, Klaus-Dieter; Witte, Klaudia

    2017-02-01

    The use of computer animation in behavioral research is a state-of-the-art method for designing and presenting animated animals to live test animals. The major advantages of computer animations are: (1) the creation of animated animal stimuli with high variability of morphology and even behavior; (2) animated stimuli provide highly standardized, controlled and repeatable testing procedures; and (3) they allow a reduction in the number of live test animals regarding the 3Rs principle. But the use of animated animals should be attended by a thorough validation for each test species to verify that behavior measured with live animals toward virtual animals can also be expected with natural stimuli. Here we present results on the validation of a custom-made simulation for animated 3D sailfin mollies Poecilia latipinna and show that responses of live test females were as strong to an animated fish as to a video or a live male fish. Movement of an animated stimulus was important but female response was stronger toward a swimming 3D fish stimulus than to a "swimming" box. Moreover, male test fish were able to discriminate between animated male and female stimuli; hence, rendering the animated 3D fish a useful tool in mate-choice experiments with sailfin mollies.

  5. Inter- and intra-individual differences in skin hydration and surface lipids measured with mid-infrared spectroscopy

    Science.gov (United States)

    Ezerskaia, A.; Pereira, S. F.; Urbach, H. P.; Varghese, B.

    2016-03-01

    Skin health is characterized by heterogeneous system of water and lipids in upper layers providing protection from external environment and preventing loss of vital components of the body. Skin hydration (moisture) and sebum (skin surface lipids) are considered to be important factors in skin health; a right balance between these components is an indication of healthy skin and plays a central role in protecting and preserving skin integrity. In this manuscript we present inter- and intra-individual variation in skin hydration and surface lipids measured with a home-built experimental prototype based on infrared spectroscopy. Results show good agreement with measurements performed by commercially available instruments Corneometer and Sebumeter used for skin hydration and sebum measurements respectively.

  6. Variable-density groundwater flow simulations and particle tracking. Numerical modelling using DarcyTools. Preliminary site description of the Simpevarp area, version 1.1

    Energy Technology Data Exchange (ETDEWEB)

    Follin, Sven [SF GeoLogic AB, Stockholm (Sweden); Stigsson, Martin; Berglund, Sten [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Svensson, Urban [Computer-aided Fluid Engineering AB, Norrkoeping (Sweden)

    2004-12-01

    SKB is conducting site investigations for a high-level nuclear waste repository in fractured crystalline rocks at two coastal areas in Sweden, Forsmark and Simpevarp. The investigations started in 2002 and have been planned since the late 1990s. The work presented here investigates the possibility of using hydrogeochemical measurements in deep boreholes to reduce parameter uncertainty in a regional modelling of groundwater flow in fractured rock. The work was conducted with the aim of improving the palaeohydrogeological understanding of the Simpevarp area and to give recommendations to the preparations of the next version of the Preliminary Site Description (1.2). The study is based on a large number of numerical simulations of transient variable density groundwater flow through a strongly heterogeneous and anisotropic medium. The simulations were conducted with the computer code DarcyTools, the development of which has been funded by SKB. DarcyTools is a flexible porous media code specifically designed to treat groundwater flow and salt transport in sparsely fractured crystalline rock and it is noted that some of the features presented in this report are still under development or subjected to testing and verification. The simulations reveal the sensitivity of the results to different hydrogeological modelling assumptions, e.g. the sensitivity to the initial groundwater conditions at 10,000 BC, the size of the model domain and boundary conditions, and the hydraulic properties of deterministically and stochastically modelled deformation zones. The outcome of these simulations was compared with measured salinities and calculated relative proportions of different water types (mixing proportions) from measurements in two deep core drilled boreholes in the Laxemar subarea. In addition to the flow simulations, the statistics of flow related transport parameters were calculated for particle flowpaths from repository depth to ground surface for two subareas within the

  7. Variable-density groundwater flow simulations and particle tracking. Numerical modelling using DarcyTools. Preliminary site description of the Simpevarp area, version 1.1

    International Nuclear Information System (INIS)

    Follin, Sven; Stigsson, Martin; Berglund, Sten; Svensson, Urban

    2004-12-01

    SKB is conducting site investigations for a high-level nuclear waste repository in fractured crystalline rocks at two coastal areas in Sweden, Forsmark and Simpevarp. The investigations started in 2002 and have been planned since the late 1990s. The work presented here investigates the possibility of using hydrogeochemical measurements in deep boreholes to reduce parameter uncertainty in a regional modelling of groundwater flow in fractured rock. The work was conducted with the aim of improving the palaeohydrogeological understanding of the Simpevarp area and to give recommendations to the preparations of the next version of the Preliminary Site Description (1.2). The study is based on a large number of numerical simulations of transient variable density groundwater flow through a strongly heterogeneous and anisotropic medium. The simulations were conducted with the computer code DarcyTools, the development of which has been funded by SKB. DarcyTools is a flexible porous media code specifically designed to treat groundwater flow and salt transport in sparsely fractured crystalline rock and it is noted that some of the features presented in this report are still under development or subjected to testing and verification. The simulations reveal the sensitivity of the results to different hydrogeological modelling assumptions, e.g. the sensitivity to the initial groundwater conditions at 10,000 BC, the size of the model domain and boundary conditions, and the hydraulic properties of deterministically and stochastically modelled deformation zones. The outcome of these simulations was compared with measured salinities and calculated relative proportions of different water types (mixing proportions) from measurements in two deep core drilled boreholes in the Laxemar subarea. In addition to the flow simulations, the statistics of flow related transport parameters were calculated for particle flowpaths from repository depth to ground surface for two subareas within the

  8. Effects of estradiol and progesterone on the variability of the micronucleus assay

    International Nuclear Information System (INIS)

    Baeyens, Ans; Vandersickel, Veerle; Thierens, Hubert; Ridder, Leo De; Vral, Anne

    2005-01-01

    To investigate chromosomal radiosensitivity of lymphocytes the micronucleus (MN) assay has been used for many years. The results of these studies suggest the use of the MN assay as a biomarker for cancer predisposition. However, the MN assay has still some limitations associated with the reproducibility and sensitivity. Especially a high intra-individual variability has been observed. An explanation for this high intra-individual variability is not yet available. In literature it is suggested that the high variability among females is attributable to hormonal status. In this study we investigated if the high intra-individual variability in micronucleus formation in lymphocytes of females after in vitro exposure to ionising radiation is caused by variations in hormone levels of estradiol (E2) and progesterone (PROG). For this, the MN assay was performed on blood samples of 18 healthy women during 7 consecutive weeks while the estradiol and progesterone levels were determined at the same time. The MN assay was also examined in cultures of isolated blood lymphocytes with estradiol or progesterone levels added in vitro. The results demonstrated that estradiol and progesterone levels have no influence on the variations in radiation-induced MN yields observed in blood samples of healthy women. These conclusions were confirmed by the 'in vitro' experiments as no correlation between the MN yields and the concentrations of hormones (estradiol or progesterone) added in vitro to isolated lymphocytes cultures was observed

  9. Preliminary evaluations related to the ranges of hematological and biochemical variables in hospitalized patients with stroke

    Directory of Open Access Journals (Sweden)

    Ahmad Chitsaz

    2013-01-01

    Conclusions: Any considerable alter in patients′ biochemical and hematological figures (BS, Hgb, Plt and Lymph may necessitate further attention related to inter- and intra-individual variability in clinical supervision and drug′s assortment. Therefore, success in treatment could be achieved by the close management of clinical, biochemical, hematological, and pharmacological manifestation. To reduce disability, mortality, and morbidity in Iranian stroke population further clinical studies are needed to correlate drugs and laboratory markers to associated clinical events in order.

  10. Variability of ferritin measurements in chronic kidney disease; implications for iron management.

    Science.gov (United States)

    Ford, Bradley A; Coyne, Daniel W; Eby, Charles S; Scott, Mitchell G

    2009-01-01

    Serum ferritin levels are a proxy measure of iron stores; and existing guidelines for managing anemia in hemodialysis patients suggest that serum ferritin concentrations should be maintained at >200 ng/ml. The KDOQI recommendations further state there is insufficient evidence advocating routine intravenous iron when ferritin levels exceed 500 ng/ml. Here we determined the interassay differences and short-term intraindividual variability of serum ferritin measurements in patients on chronic hemodialysis to illustrate how these variances may affect treatment decisions. Intermethod variations of up to 150 ng/ml were found comparing six commonly used ferritin assays that evaluated thirteen pools of serum from hemodialysis and nonhemodialysis patients. The intraindividual variability for ferritin in 60 stable hemodialysis patients ranged between 2-62% measured over an initial two-week period and from 3-52% when factored over a six-week period. Our results suggests that single serum ferritin values should not be used to guide clinical decisions regarding treatment of chronic hemodialysis patients with intravenous iron due to significant analytical and intraindividual variability.

  11. Persistent Organic Pollutants in Norwegian Men from 1979 to 2007: Intraindividual Changes, Age–Period–Cohort Effects, and Model Predictions

    Science.gov (United States)

    Breivik, Knut; Fuskevåg, Ole-Martin; Nieboer, Evert; Odland, Jon Øyvind; Sandanger, Torkjel Manning

    2013-01-01

    Background: Longitudinal monitoring studies of persistent organic pollutants (POPs) in human populations are important to better understand changes with time and age, and for future predictions. Objectives: We sought to describe serum POP time trends on an individual level, investigate age–period–cohort effects, and compare predicted polychlorinated biphenyl (PCB) concentrations to measured values. Methods: Serum was sampled in 1979, 1986, 1994, 2001, and 2007 from a cohort of 53 men in Northern Norway and analyzed for 41 POPs. Time period, age, and birth cohort effects were assessed by graphical analyses and mixed-effect models. We derived the predicted concentrations of four PCBs for each sampling year using the CoZMoMAN model. Results: The median decreases in summed serum POP concentrations (lipid-adjusted) in 1986, 1994, 2001, and 2007 relative to 1979 were –22%, –52%, –54%, and –68%, respectively. We observed substantial declines in all POP groups with the exception of chlordanes. Time period (reflected by sampling year) was the strongest descriptor of changes in PCB-153 concentrations. Predicted PCB-153 concentrations were consistent with measured concentrations in the study population. Conclusions: Our results suggest substantial intraindividual declines in serum concentrations of legacy POPs from 1979 to 2007 in men from Northern Norway. These changes are consistent with reduced environmental exposure during these 30 years and highlight the relation between historic emissions and POP concentrations measured in humans. Observed data and interpretations are supported by estimates from the CoZMoMAN emission-based model. A longitudinal decrease in concentrations with age was evident for all birth cohorts. Overall, our findings support the relevance of age–period–cohort effects to human biomonitoring of environmental contaminants. Citation: Nøst TH, Breivik K, Fuskevåg OM, Nieboer E, Odland JØ, Sandanger TM. 2013. Persistent organic pollutants

  12. Handheld mechanical nociceptive threshold testing in dairy cows - intra-individual variation, inter-observer agreement and variation over time.

    Science.gov (United States)

    Raundal, Peter M; Andersen, Pia H; Toft, Nils; Forkman, Björn; Munksgaard, Lene; Herskin, Mette S

    2014-11-01

    To examine the use of handheld methodology to assess mechanical nociceptive threshold (MNT) on cows kept loose-housed. Prospective randomized partial cross-over experimental study. A one-factor (test day) design was used to evaluate MNT over time. One hundred and fifteen healthy, loose-housed Danish Holstein cattle. We evaluated intra-individual variation, inter-observer agreement and variation over time of MNT using two handheld devices and two stimulation sites. Mechanical, ramped stimulations were performed with an algometer (6.5 mm diameter steel probe, 0-10.0 kgf) or an electronic von Frey device (plastic tip with diameter 0.8 mm, 0-1000 gf). Each cow received 5-6 consecutive stimulations within a 2 × 5 cm skin area on the dorsal or lateral aspect of the left third metatarsus until an avoidance reaction occurred. We investigated the difference in precision [expressed as coefficient of variation (CV)] between the combinations of devices and stimulation sites. The inter-observer agreement and the difference in MNT between test day 1, 3, 7, 10 and 24 were investigated for selected combinations. Data were analysed in mixed models and Bland-Altman as relevant. The CVs did not differ [range 0.34-0.52 (p = 0.1)]. Difference between observers (95% limits) was 0.2 kgf (2.8) and 4 gf (369) for the algometer and von Frey device, respectively. Mechanical nociceptive threshold increased from 361 on test day one to 495 gf on test day 24 (p < 0.01). All methods showed a high degree of intra-individual variation, and no combination of device and stimulation site showed superior precision. Mean difference between observers was low, and MNT was not consistent over time. Further development of the methods is required before they can be used in research to investigate possible relations between claw lesions and hyperalgesia. © 2014 The Authors Veterinary Anaesthesia and Analgesia published by John Wiley & Sons Ltd on behalf of Association of Veterinary Anaesthetists and the

  13. Building Trust and Feeling Well: Examining Intraindividual and Interpersonal Outcomes and Underlying Mechanisms of Listening

    Science.gov (United States)

    Lloyd, Karina J.; Boer, Diana; Kluger, Avraham N.; Voelpel, Sven C.

    2015-01-01

    We investigated perceived listening quality in relation to individual (self-clarity and emotional well-being) and dyadic variables (social attraction and trust). Specifically, we proposed that the link between perceived listening quality and emotional well-being is mediated by self-clarity, and that the link between perceived listening and trust…

  14. The intra-individual reproducibility of flash-evoked potentials in a sample of children.

    Science.gov (United States)

    Schellberg, D; Gasser, T; Köhler, W

    1987-07-01

    Visual evoked potentials (VEPs) to flash stimuli were recorded twice from 26 children aged 10-13 years, with an intersession interval of about 10 months. Test-retest reliability was poor for recordings taken from scalp locations overlying non-specific cortex and somewhat better for specific cortex. The size of consistency coefficients (i.e. correlations within session) showed that noise and artefacts were not the decisive factors which lower reliability. A comparison with retest correlations of broad band parameters of the EEG at rest for the same sample showed, to our surprise, smaller retest reliability for VEP parameters. Variability of the VEP in children over time seems to be a substantial as its well-known inter-individual variability.

  15. Predicting intraindividual changes in learning strategies: The effects of previous achievement

    OpenAIRE

    Buško, Vesna; Mujagić, Amela

    2013-01-01

    Socio-cognitive models of self-regulated learning (e.g., Pintrich, 2000) emphasize contextualized nature oflearning process, and within-person variation in learning processes, along with between-person variability in selfregulation.Previous studies about contextual nature of learning strategies have mostly focused on the effects ofdifferent contextual factors on interindividual differences in learning strategies utilization. However, less attentionwas given to the question about contextual ef...

  16. Short interactive workshops reduce variability in contouring treatment volumes for spine stereotactic body radiation therapy: Experience with the ESTRO FALCON programme and EduCase™ training tool.

    Science.gov (United States)

    De Bari, Berardino; Dahele, Max; Palmu, Miika; Kaylor, Scott; Schiappacasse, Luis; Guckenberger, Matthias

    2017-11-20

    We report the results of 4, 2-h contouring workshops on target volume definition for spinal stereotactic radiotherapy. They combined traditional teaching methods with a web-based contouring/contour-analysis platform and led to a significant reduction in delineation variability. Short, interactive workshops can reduce interobserver variability in spine SBRT target volume delineation. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Individualized exergame training improves postural control in advanced degenerative spinocerebellar ataxia: A rater-blinded, intra-individually controlled trial.

    Science.gov (United States)

    Schatton, Cornelia; Synofzik, Matthis; Fleszar, Zofia; Giese, Martin A; Schöls, Ludger; Ilg, Winfried

    2017-06-01

    Treatment options are rare in degenerative ataxias, especially in advanced, multisystemic disease. Exergame training might offer a novel treatment strategy, but its effectiveness has not been investigated in advanced stages. We examined the effectiveness of a 12-week home-based training with body-controlled videogames in 10 young subjects with advanced degenerative ataxia unable or barely able to stand. Training was structured in two 6-weeks phases, allowing to adapt the training according to individual training progress. Rater-blinded clinical assessment (Scale for the Assessment and Rating of Ataxia; SARA), individual goal-attainment scoring (GAS), and quantitative movement analysis were performed two weeks before training, immediately prior to training, and after training phases 1 and 2 (intra-individual control design). This study is registered with ClinicalTrials.gov, NCT02874911). After intervention, ataxia symptoms were reduced (SARA -2.5 points, p training (p = 0.04). Goal attainment during daily living was higher than expected (GAS: 0.45). Movement analysis revealed reduced body sway while sitting (p training-induced improvements in posture control mechanisms. This study provides first evidence that, even in advanced stages, subjects with degenerative ataxia may benefit from individualized training, with effects translating into daily living and improving underlying control mechanisms. The proposed training strategy can be performed at home, is motivating and facilitates patient self-empowerment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. MRI in multiple sclerosis: an intra-individual, randomized and multicentric comparison of gadobutrol with gadoterate meglumine at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Saake, Marc; Weibart, Marina; Doerfler, Arnd [University of Erlangen-Nuremberg, Department of Neuroradiology, Erlangen (Germany); Langner, Soenke; Hosten, Norbert [University Medicine Greifswald, Institute for Diagnostic Radiology and Neuroradiology, Greifswald (Germany); Schwenke, Carsten [SCO:SSiS, Statistical Consulting, Berlin (Germany); Jansen, Olav [University of Kiel, Department of Radiology and Neuroradiology, Kiel (Germany)

    2016-03-15

    To compare contrast effects of gadobutrol with gadoterate meglumine for brain MRI in multiple sclerosis (MS) in a multicentre, randomized, prospective, intraindividual study at 3 T. Institutional review board approval was obtained. Patients with known or suspected active MS lesions were included. Two identical MRIs were performed using randomized contrast agent order. Four post-contrast T1 sequences were acquired (start time points 0, 3, 6 and 9 min). If no enhancing lesion was present in first MRI, second MRI was cancelled. Quantitative (number and signal intensity of enhancing lesions) and qualitative parameters (time points of first and all lesions enhancing; subjective preference regarding contrast enhancement and lesion delineation; global preference) were evaluated blinded. Seventy-four patients (male, 26; mean age, 35 years) were enrolled in three centres. In 45 patients enhancing lesions were found. Number of enhancing lesions increased over time for both contrast agents without significant difference (median 2 for both). Lesions signal intensity was significantly higher for gadobutrol (p < 0.05 at time points 3, 6 and 9 min). Subjective preference rating showed non-significant tendency in favour of gadobutrol. Both gadobutrol and gadoterate meglumine can be used for imaging of acute inflammatory MS lesions. However, gadobutrol generates higher lesion SI. (orig.)

  19. Intraindividual, randomized comparison of the macrocyclic contrast agents gadobutrol and gadoterate meglumine in breast magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fallenberg, Eva M.; Renz, Diane M.; Hamm, Bernd [Charite - Universitaetsmedizin Berlin, Campus Virchow-Klinikum, Department of Radiology, Berlin (Germany); Karle, Bettina [Clinic of Radiation Therapy, Helios Clinics, Berlin (Germany); Schwenke, Carsten [SCOSSIS Statistical Consulting, Berlin (Germany); Ingod-Heppner, Barbara [Charite Universitaetsmedizin, Campus Charite Mitte, Institute of Pathology, Berlin (Germany); Reles, Angela [Charite Universitaetsmedizin, Charite-Partner-Practice, Interdisciplinary Breast Center, Berlin (Germany); Engelken, Florian J. [Charite - Universitaetsmedizin Berlin, Charite Campus Mitte, Department of Radiology, Berlin (Germany); Huppertz, Alexander; Taupitz, Matthias [Charite - Universitaetsmedizin Berlin, Campus Benjamin Franklin, Department of Radiology, Berlin (Germany)

    2014-09-25

    To compare intraindividually two macrocyclic contrast agents - gadobutrol and gadoterate meglumine (Gd-DOTA) - for dynamic and quantitative assessment of relative enhancement (RE) in benign and malignant breast lesions. This was an ethically approved, prospective, single-centre, randomized, crossover study in 52 women with suspected breast lesions referred for magnetic resonance imaging (MRI). Each patient underwent one examination with gadobutrol and one with Gd-DOTA (0.1 mmol/kg BW) on a 1.5 T system 1 - 7 days apart. Dynamic, T1-weighted, 3D gradient echo sequences were acquired under identical conditions. Quantitative evaluation with at least three regions of interest (ROI) per lesion was performed. Primary endpoint was RE during the initial postcontrast phase after the first and second dynamic acquisition, and peak RE. All lesions were histologically proven; differences between the examinations were evaluated. Forty-five patients with a total of 11 benign and 34 malignant lesions were assessed. Mean RE was significantly higher for gadobutrol than Gd-DOTA (p < 0.0001). Gadobutrol showed significantly less washout (64.4 %) than Gd-DOTA (75.4 %) in malignant lesions (p = 0.048) Gadobutrol has higher RE values compared with Gd-DOTA, whereas Gd-DOTA shows more marked washout in malignant lesions. This might improve the detection of breast lesions and influence the specificity of breast MRI-imaging. (orig.)

  20. Effects of visual feedback-induced variability on motor learning of handrim wheelchair propulsion.

    Directory of Open Access Journals (Sweden)

    Marika T Leving

    Full Text Available It has been suggested that a higher intra-individual variability benefits the motor learning of wheelchair propulsion. The present study evaluated whether feedback-induced variability on wheelchair propulsion technique variables would also enhance the motor learning process. Learning was operationalized as an improvement in mechanical efficiency and propulsion technique, which are thought to be closely related during the learning process.17 Participants received visual feedback-based practice (feedback group and 15 participants received regular practice (natural learning group. Both groups received equal practice dose of 80 min, over 3 weeks, at 0.24 W/kg at a treadmill speed of 1.11 m/s. To compare both groups the pre- and post-test were performed without feedback. The feedback group received real-time visual feedback on seven propulsion variables with instruction to manipulate the presented variable to achieve the highest possible variability (1st 4-min block and optimize it in the prescribed direction (2nd 4-min block. To increase motor exploration the participants were unaware of the exact variable they received feedback on. Energy consumption and the propulsion technique variables with their respective coefficient of variation were calculated to evaluate the amount of intra-individual variability.The feedback group, which practiced with higher intra-individual variability, improved the propulsion technique between pre- and post-test to the same extent as the natural learning group. Mechanical efficiency improved between pre- and post-test in the natural learning group but remained unchanged in the feedback group.These results suggest that feedback-induced variability inhibited the improvement in mechanical efficiency. Moreover, since both groups improved propulsion technique but only the natural learning group improved mechanical efficiency, it can be concluded that the improvement in mechanical efficiency and propulsion technique do not

  1. Intra- and inter-individual variability of Aspergillus fumigatus reactive T-cell frequencies in healthy volunteers in dependency of mould exposure in residential and working environment.

    Science.gov (United States)

    Wurster, Sebastian; Weis, Philipp; Page, Lukas; Helm, Johanna; Lazariotou, Maria; Einsele, Hermann; Ullmann, Andrew J

    2017-10-01

    Invasive aspergillosis remains a deadly disease in immunocompromised patients, whereas the combination of an exaggerated immune response and continuous exposure lead to various hyperinflammatory diseases. This pilot study aimed to gain an overview of the intra- and inter-individual variability in Aspergillus fumigatus reactive T-helper cells in healthy adults and the correlation with environmental mould exposure. In this flow cytometric study, the frequencies of CD154 + A. fumigatus reactive T cells were evaluated in 70 healthy volunteers. All subjects completed a standardised questionnaire addressing their mould exposure. Subjects with intensive mould exposure in their professional or residential surrounding demonstrated considerably higher mean frequencies of A. fumigatus reactive T-helper and T-memory cells. Comparative evaluation of multiple measurements over time demonstrated relatively conserved reactive T-cell frequencies in the absence of major changes to the exposure profile, whereas those frequently exposed in professional environment or with changes to their risk score demonstrated a marked dependency of antigen reactive T-cell frequencies on recent mould exposure. This pilot study was the first to provide data on the intra-individual variability in A. fumigatus reactive T-cell frequencies and its linkage to mould encounter. Fungus reactive T cells are to be considered a valued tool for the assessment of environmental mould exposure. © 2017 Blackwell Verlag GmbH.

  2. Intraindividual differences in motivation and cognition in students with and without learning disabilities.

    Science.gov (United States)

    Pintrich, P R; Anderman, E M; Klobucar, C

    1994-01-01

    The present study examines several cognitive and motivational variables that distinguish children with learning disabilities (n = 19) from children without learning disabilities (n = 20). The total sample included 30 males and 9 females and was composed of white, fifth-grade students from a middle-class community in the Midwest. Results showed that although the students with learning disabilities displayed lower levels of metacognitive knowledge and reading comprehension, they did not differ from the students without learning disabilities on self-efficacy, intrinsic orientation, or anxiety. In addition, they did not show any signs of learned helplessness, although they did tend to attribute success and failure to external causes more often than the students without learning disabilities. Using a cluster analysis that grouped individuals, we found that differences in the motivational and cognitive variables cut across a priori categories of children with and without learning disabilities. Three clusters were formed: one with high comprehension, motivation, and metacognition (mostly children without learning disabilities); one with low levels of comprehension and metacognition but high intrinsic motivation (all children with learning disabilities); and one with low intrinsic motivation but average comprehension, metacognition, and attributional style (approximately equal numbers of children with and without learning disabilities). Implications for diagnosis and intervention for students with learning disabilities are discussed.

  3. Variable importance in latent variable regression models

    NARCIS (Netherlands)

    Kvalheim, O.M.; Arneberg, R.; Bleie, O.; Rajalahti, T.; Smilde, A.K.; Westerhuis, J.A.

    2014-01-01

    The quality and practical usefulness of a regression model are a function of both interpretability and prediction performance. This work presents some new graphical tools for improved interpretation of latent variable regression models that can also assist in improved algorithms for variable

  4. Intraindividual Increase of Homeostatic Sleep Pressure Across Acute and Chronic Sleep Loss: A High-Density EEG Study.

    Science.gov (United States)

    Maric, Angelina; Lustenberger, Caroline; Werth, Esther; Baumann, Christian R; Poryazova, Rositsa; Huber, Reto

    2017-09-01

    To compare intraindividually the effects of acute sleep deprivation (ASD) and chronic sleep restriction (CSR) on the homeostatic increase in slow wave activity (SWA) and to relate it to impairments in basic cognitive functioning, that is, vigilance. The increase in SWA after ASD (40 hours of wakefulness) and after CSR (seven nights with time in bed restricted to 5 hours per night) relative to baseline sleep was assessed in nine healthy, male participants (age = 18-26 years) by high-density electroencephalography. The SWA increase during the initial part of sleep was compared between the two conditions of sleep loss. The increase in SWA was related to the increase in lapses of vigilance in the psychomotor vigilance task (PVT) during the preceding days. While ASD induced a stronger increase in initial SWA than CSR, the increase was globally correlated across the two conditions in most electrodes. The increase in initial SWA was positively associated with the increase in PVT lapses. The individual homeostatic response in SWA is globally preserved across acute and chronic sleep loss, that is, individuals showing a larger increase after ASD also do so after CSR and vice versa. Furthermore, the increase in SWA is globally correlated to vigilance impairments after sleep loss over both conditions. Thus, the increase in SWA might therefore provide a physiological marker for individual differences in performance impairments after sleep loss. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  5. Photodynamic therapy is more effective than imiquimod for actinic keratosis in organ transplant recipients: a randomized intraindividual controlled trial.

    Science.gov (United States)

    Togsverd-Bo, K; Halldin, C; Sandberg, C; Gonzalez, H; Wennberg, A M; Sørensen, S S; Wulf, H C; Haedersdal, M

    2018-04-01

    Actinic keratoses (AKs) in solid organ transplant recipients (OTRs) are difficult-to-treat premalignancies and comparison of topical therapies is therefore warranted. In an intraindividual study to compare the efficacy and safety of field treatment with methyl aminolaevulinate photodynamic therapy (MAL-PDT) and imiquimod (IMIQ) for AKs in OTRs. OTRs (n = 35) with 572 AKs (grade I-III) in two similar areas on the face, scalp, dorsal hands or forearms were included. All patients received one MAL-PDT and one IMIQ session (three applications per week for 4 weeks) in each study area according to randomization. Treatments were repeated after 2 months (IMIQ) and 3 months (PDT) in skin with incomplete AK response. Outcome measures were complete lesion response (CR), skin reactions, laboratory results and treatment preference. The majority of study areas received two treatment sessions (PDT n = 25 patients; IMIQ n = 29 patients). At 3 months after two treatments, skin treated with PDT achieved a higher rate of CR (AK I-III median 78%; range 50-100) compared with IMIQ-treated skin areas (median 61%, range 33-100; P AKs were seen in PDT-treated skin vs. IMIQ-treated skin (0·7 vs. 1·5 AKs, P = 0·04). Patients developed more intense inflammatory skin reactions following PDT, which resolved more rapidly compared with IMIQ (median 10 days vs. 18 days, P 47) and cosmesis (P > 0·30) were similar for PDT and IMIQ. Compared with IMIQ, PDT treatment obtained a higher rate of AK clearance at 3-month follow-up and achieved shorter-lasting, but more intense, short-term skin reactions. © 2017 British Association of Dermatologists.

  6. Intraindividual comparison of myocardial delayed enhancement MR imaging using gadobenate dimeglumine at 1.5 T and 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Klumpp, Bernhard D.; Seeger, Achim; Fenchel, Michael; Kramer, Ulrich; Claussen, Claus D.; Miller, Stephan [Eberhard Karls University Tuebingen, Department for Diagnostic Radiology, Tuebingen (Germany); Sandstede, Joern [Roentgenzentrum, Hamburg (Germany); Lodemann, Klaus P. [Bracco Altana Pharma, Konstanz (Germany); Hoevelborn, Tobias [Eberhard Karls University Tuebingen, Department for Cardiology, Tuebingen (Germany)

    2009-05-15

    For contrast-enhanced imaging techniques relying on strong T1 weighting, 3 T provides increased contrast compared with 1.5 T. The aim of our study was the intraindividual comparison of delayed enhancement MR imaging at 1.5 T and at 3 T. Twenty patients with myocardial infarction were examined at 1.5 T and 3 T. Fifteen minutes after injection of contrast agent (0.1 mmol gadobenate dimeglumine per kg body weight), inversion recovery gradient recalled echo (IR-GRE) sequences were acquired (1.5 T/3 T: TR 11.0/9.9 ms, TE 4.4/4.9 ms, flip 30 /30 , slice thickness 6/6 mm) to assess myocardial viability. Two observers rated image quality (Wilcoxon signed rank test). Quantification of hyperenhanced myocardium and standardized SNR/CNR measurements were performed (Student's t test). There was no significant difference with respect to image quality (1.5 T/3 T: 3.5/3.3, p = 0.34, reader 1; 2.4/2.7, p = 0.12, reader 2) and infarction size (760 {+-} 566/828 {+-} 677 mm{sup 2} at 1.5 T, 808 {+-} 639/826 {+-} 726 mm{sup 2} at 3 T, reader 1/reader 2, p > 0.05). Mean SNR in hyperenhanced/normal myocardium was 19.2/6.2 at 1.5 T and 29.5/8.8 at 3 T (p < 0.05). Mean CNR was 14.3 at 1.5 T and 26.0 at 3 T (p < 0.05). Delayed enhancement MR imaging at 3 T is a robust procedure yielding superior tissue contrast at 3 T compared with 1.5 T which is, however, not reflected by increased image quality. (orig.)

  7. The Area of Secondary Hyperalgesia following Heat Stimulation in Healthy Male Volunteers: Inter- and Intra-Individual Variance and Reproducibility.

    Directory of Open Access Journals (Sweden)

    Morten Sejer Hansen

    Full Text Available Clinical pain models can be applied when investigating basic physiologic pain responses in healthy volunteers. Several pain models exist; however, only few have been adequately validated. Our primary aim with this prospective study was to investigate the intra- and inter-individual variation in secondary hyperalgesia elicited by brief thermal sensitization (45°C for 3 min in healthy volunteers.Fifty healthy volunteers were included. Areas of secondary hyperalgesia following brief thermal sensitization were investigated by 2 observers on 4 experimental days, with a minimum interval of 7 days. Additionally, heat pain detection threshold and pain during thermal stimulation (45°C for 1 min., and the psychological tests Pain Catastrophizing Scale and Hospital Anxiety and Depression Score were applied.For areas of secondary hyperalgesia, an intra-observer intra-person correlation of 0.85, 95% CI [0.78, 0.90], an intra-observer inter-person correlation of 0.03, 95% CI [0.00, 0.16], and a coefficient of variation of 0.17, 95% CI [0.14, 0.21] was demonstrated. Four percent of the study population had areas of secondary hyperalgesia both below the 1st and above the 3rd quartile considering all included participants. Heat pain detection threshold predicted area of secondary hyperalgesia with an adjusted R2 of 0.20 (P = 0.0006.We have demonstrated a low intra-individual, and a high inter-individual variation in thermally induced secondary hyperalgesia. We conclude that brief thermal sensitization produce secondary hyperalgesia with a high level of reproducibility, which can be applied to investigate different phenotypes related to secondary hyperalgesia in healthy volunteers.clinicaltrials.gov NCT02166164.

  8. An fMRI Study of Intra-Individual Functional Topography in the Human Cerebellum

    Directory of Open Access Journals (Sweden)

    Catherine J. Stoodley

    2010-01-01

    Full Text Available Neuroimaging studies report cerebellar activation during both motor and non-motor paradigms, and suggest a functional topography within the cerebellum. Sensorimotor tasks activate the anterior lobe, parts of lobule VI, and lobule VIII, whereas higher-level tasks activate lobules VI and VII in the posterior lobe. To determine whether these activation patterns are evident at a single-subject level, we conducted functional magnetic resonance imaging (fMRI during five tasks investigating sensorimotor (finger tapping, language (verb generation, spatial (mental rotation, working memory (N-back, and emotional processing (viewing images from the International Affective Picture System. Finger tapping activated the ipsilateral anterior lobe (lobules IV-V as well as lobules VI and VIII. Activation during verb generation was found in right lobules VII and VIIIA. Mental rotation activated left-lateralized clusters in lobules VII-VIIIA, VI-Crus I, and midline VIIAt. The N-back task showed bilateral activation in right lobules VI-Crus I and left lobules VIIB-VIIIA. Cerebellar activation was evident bilaterally in lobule VI while viewing arousing vs. neutral images. This fMRI study provides the first proof of principle demonstration that there is topographic organization of motor execution vs. cognitive/emotional domains within the cerebellum of a single individual, likely reflecting the anatomical specificity of cerebro-cerebellar circuits underlying different task domains. Inter-subject variability of motor and non-motor topography remains to be determined.

  9. Future time perspective and promotion focus as determinants of intraindividual change in work motivation.

    Science.gov (United States)

    Kooij, Dorien T A M; Bal, P Matthijs; Kanfer, Ruth

    2014-06-01

    In the near future, workforces will increasingly consist of older workers. At the same time, research has demonstrated that work-related growth motives decrease with age. Although this finding is consistent with life span theories, such as the selection optimization and compensation (SOC) model, we know relatively little about the process variables that bring about this change in work motivation. Therefore, we use a 4-wave study design to examine the mediating role of future time perspective and promotion focus in the negative association between age and work-related growth motives. Consistent with the SOC model, we found that future time perspective was negatively associated with age, which, in turn, was associated with lower promotion focus, lower work-related growth motive strength, and lower motivation to continue working. These findings have important theoretical implications for the literature on aging and work motivation, and practical implications for how to motivate older workers. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  10. Positional variability of a tandem applicator system in HDR brachytherapy for primary treatment of cervix cancer. Analysis of the anatomic pelvic position and comparison of the applicator positions during five insertions

    International Nuclear Information System (INIS)

    Wulf, J.; Popp, K.; Oppitz, U.; Baier, K.; Flentje, M.

    2004-01-01

    Purpose: evaluation of the inter- and intraindividual applicator variability of multiple high-dose-rate (HDR) brachytherapy applications for primary treatment of cancer of the uterine cervix. Material and methods: retrospective analysis of 460 pairs of orthogonal X-ray films for conventional treatment in 92 patients with five intrauterine applications using an HDR tandem applicator. Measurement of the position of the applicator origin relative to a bony reference system in three dimensions. Evaluation of the differences of the applicator position in all 460 applications (interindividual variability), of the five applications in a single patient (intraindividual variability) and of the intraindividual variability relative to the applicator position at the first application. Results: the position of the applicator origin in the pelvis ranged from 23 mm cranial and 55 mm caudal to the top of femoral heads, 23 mm right and 27 mm left to the pelvic midline, and 6-53 mm dorsal to the mid of the femoral heads. Standard deviation (SD) of interindividual applicator variability was 12.9 mm (minimum/maximum -55/+23 mm, mean -13.6 mm) in longitudinal, 5.1 mm (-27/+23 mm, mean 1.6 mm) in lateral, and 7.6 mm (6/53 mm, mean 26 mm) in anterior-posterior [AP] direction. SD of intraindividual variability was 5.5 mm (-21/+23 mm, mean 0 mm) in longitudinal, 2.5 mm (-17/+19 mm, mean 0 mm) in lateral, and 4.2 mm (-15/+18 mm, mean 0 mm) in AP direction compared to intraindividual variability relative to the first insertion with an SD of 8.9 mm (-23/+36 mm, mean 2.8 mm) in longitudinal, 4.0 mm (-11/+23 mm, mean 0 mm) in lateral, and 6.8 mm (-27/+17 mm, mean -0.8 mm) in AP direction. Conclusion: intraindividual applicator variability is significantly smaller than interindividual variability. Applicator-related procedures such as midline shielding or dose matching of tele- and brachytherapy should be performed with information on at least one individual applicator position. (orig.)

  11. Positional variability of a tandem applicator system in HDR brachytherapy for primary treatment of cervix cancer. Analysis of the anatomic pelvic position and comparison of the applicator positions during five insertions

    Energy Technology Data Exchange (ETDEWEB)

    Wulf, J.; Popp, K.; Oppitz, U.; Baier, K.; Flentje, M. [Dept. of Radiotherapy, Univ. of Wuerzburg (Germany)

    2004-04-01

    Purpose: evaluation of the inter- and intraindividual applicator variability of multiple high-dose-rate (HDR) brachytherapy applications for primary treatment of cancer of the uterine cervix. Material and methods: retrospective analysis of 460 pairs of orthogonal X-ray films for conventional treatment in 92 patients with five intrauterine applications using an HDR tandem applicator. Measurement of the position of the applicator origin relative to a bony reference system in three dimensions. Evaluation of the differences of the applicator position in all 460 applications (interindividual variability), of the five applications in a single patient (intraindividual variability) and of the intraindividual variability relative to the applicator position at the first application. Results: the position of the applicator origin in the pelvis ranged from 23 mm cranial and 55 mm caudal to the top of femoral heads, 23 mm right and 27 mm left to the pelvic midline, and 6-53 mm dorsal to the mid of the femoral heads. Standard deviation (SD) of interindividual applicator variability was 12.9 mm (minimum/maximum -55/+23 mm, mean -13.6 mm) in longitudinal, 5.1 mm (-27/+23 mm, mean 1.6 mm) in lateral, and 7.6 mm (6/53 mm, mean 26 mm) in anterior-posterior [AP] direction. SD of intraindividual variability was 5.5 mm (-21/+23 mm, mean 0 mm) in longitudinal, 2.5 mm (-17/+19 mm, mean 0 mm) in lateral, and 4.2 mm (-15/+18 mm, mean 0 mm) in AP direction compared to intraindividual variability relative to the first insertion with an SD of 8.9 mm (-23/+36 mm, mean 2.8 mm) in longitudinal, 4.0 mm (-11/+23 mm, mean 0 mm) in lateral, and 6.8 mm (-27/+17 mm, mean -0.8 mm) in AP direction. Conclusion: intraindividual applicator variability is significantly smaller than interindividual variability. Applicator-related procedures such as midline shielding or dose matching of tele- and brachytherapy should be performed with information on at least one individual applicator position. (orig.)

  12. The virtual lover: variable and easily guided 3D fish animations as an innovative tool in mate-choice experiments with sailfin mollies-I. Design and implementation.

    Science.gov (United States)

    Müller, Klaus; Smielik, Ievgen; Hütwohl, Jan-Marco; Gierszewski, Stefanie; Witte, Klaudia; Kuhnert, Klaus-Dieter

    2017-02-01

    Animal behavior researchers often face problems regarding standardization and reproducibility of their experiments. This has led to the partial substitution of live animals with artificial virtual stimuli. In addition to standardization and reproducibility, virtual stimuli open new options for researchers since they are easily changeable in morphology and appearance, and their behavior can be defined. In this article, a novel toolchain to conduct behavior experiments with fish is presented by a case study in sailfin mollies Poecilia latipinna . As the toolchain holds many different and novel features, it offers new possibilities for studies in behavioral animal research and promotes the standardization of experiments. The presented method includes options to design, animate, and present virtual stimuli to live fish. The designing tool offers an easy and user-friendly way to define size, coloration, and morphology of stimuli and moreover it is able to configure virtual stimuli randomly without any user influence. Furthermore, the toolchain brings a novel method to animate stimuli in a semiautomatic way with the help of a game controller. These created swimming paths can be applied to different stimuli in real time. A presentation tool combines models and swimming paths regarding formerly defined playlists, and presents the stimuli onto 2 screens. Experiments with live sailfin mollies validated the usage of the created virtual 3D fish models in mate-choice experiments.

  13. Development of a software tool using deterministic logic for the optimization of cochlear implant processor programming.

    Science.gov (United States)

    Govaerts, Paul J; Vaerenberg, Bart; De Ceulaer, Geert; Daemers, Kristin; De Beukelaer, Carina; Schauwers, Karen

    2010-08-01

    An intelligent agent, Fitting to Outcomes eXpert, was developed to optimize and automate Cochlear implant (CI) programming. The current article describes the rationale, development, and features of this tool. Cochlear implant fitting is a time-consuming procedure to define the value of a subset of the available electric parameters based primarily on behavioral responses. It is comfort-driven with high intraindividual and interindividual variability both with respect to the patient and to the clinician. Its validity in terms of process control can be questioned. Good clinical practice would require an outcome-driven approach. An intelligent agent may help solve the complexity of addressing more electric parameters based on a range of outcome measures. A software application was developed that consists of deterministic rules that analyze the map settings in the processor together with psychoacoustic test results (audiogram, A(section sign)E phoneme discrimination, A(section sign)E loudness scaling, speech audiogram) obtained with that map. The rules were based on the daily clinical practice and the expertise of the CI programmers. The data transfer to and from this agent is either manual or through seamless digital communication with the CI fitting database and the psychoacoustic test suite. It recommends and executes modifications to the map settings to improve the outcome. Fitting to Outcomes eXpert is an operational intelligent agent, the principles of which are described. Its development and modes of operation are outlined, and a case example is given. Fitting to Outcomes eXpert is in use for more than a year now and seems to be capable to improve the measured outcome. It is argued that this novel tool allows a systematic approach focusing on outcome, reducing the fitting time, and improving the quality of fitting. It introduces principles of artificial intelligence in the process of CI fitting.

  14. Twitter as a Potential Disaster Risk Reduction Tool. Part III: Evaluating Variables that Promoted Regional Twitter Use for At-risk Populations During the 2013 Hattiesburg F4 Tornado.

    Science.gov (United States)

    Cooper, Guy Paul; Yeager, Violet; Burkle, Frederick M; Subbarao, Italo

    2015-06-29

    Study goals attempt to identify the variables most commonly associated with successful tweeted messages and determine which variables have the most influence in promoting exponential dissemination of information (viral spreading of the message) and trending (becoming popular) in the given disaster affected region. Part II describes the detailed extraction and triangulation filtration methodological approach to acquiring twitter data for the 2013 Hattiesburg Tornado. The data was then divided into two 48 hour windows before and after the tornado impact with a 2 hour pre-tornado buffer to capture tweets just prior to impact. Criteria-based analysis was completed for Tweets and users. The top 100 pre-Tornado and post-Tornado retweeted users were compared to establish the variability among the top retweeted users during the 4 day span.  Pre-Tornado variables that were correlated to higher retweeted rates include total user tweets (0.324), and total times message retweeted (0.530).  Post-Tornado variables that were correlated to higher retweeted rates include total hashtags in a retweet (0.538) and hashtags #Tornado (0.378) and #Hattiesburg (0.254). Overall hashtags usage significantly increased during the storm. Pre-storm there were 5,763 tweets with a hashtag and post-storm there was 13,598 using hashtags. Twitter's unique features allow it to be considered a unique social media tool applicable for emergency managers and public health officials for rapid and accurate two way communication.  Additionally, understanding how variables can be properly manipulated plays a key role in understanding how to use this social media platform for effective, accurate, and rapid mass information communication.

  15. Dealing with randomness and vagueness in business and management sciences: the fuzzy-probabilistic approach as a tool for the study of statistical relationships between imprecise variables

    Directory of Open Access Journals (Sweden)

    Fabrizio Maturo

    2016-06-01

    Full Text Available In practical applications relating to business and management sciences, there are many variables that, for their own nature, are better described by a pair of ordered values (i.e. financial data. By summarizing this measurement with a single value, there is a loss of information; thus, in these situations, data are better described by interval values rather than by single values. Interval arithmetic studies and analyzes this type of imprecision; however, if the intervals has no sharp boundaries, fuzzy set theory is the most suitable instrument. Moreover, fuzzy regression models are able to overcome some typical limitation of classical regression because they do not need the same strong assumptions. In this paper, we present a review of the main methods introduced in the literature on this topic and introduce some recent developments regarding the concept of randomness in fuzzy regression.

  16. Intraindividual comparison of T1 relaxation times after gadobutrol and Gd-DTPA administration for cardiac late enhancement imaging

    Energy Technology Data Exchange (ETDEWEB)

    Doeblin, Patrick, E-mail: Patrick.doeblin@charite.de [Department of Cardiology, Charité – Universitätsmedizin Berlin, Charité Campus Benjamin Franklin, Berlin (Germany); Schilling, Rene, E-mail: rene.schilling@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Wagner, Moritz, E-mail: moritz.wagner@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Luhur, Reny, E-mail: renyluhur@yahoo.com [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Huppertz, Alexander, E-mail: alexander.huppertz@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Imaging Science Institute, Charité, Berlin (Germany); Hamm, Bernd, E-mail: bernd.hamm@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Taupitz, Matthias, E-mail: matthias.taupitz@harite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); and others

    2014-04-15

    Purpose: To evaluate T1-relaxation times of chronic myocardial infarction (CMI) using gadobutrol and gadopentetate dimeglumine (Gd-DTPA) over time and to determine the optimal imaging window for late enhancement imaging with both contrast agents. Material and methods: Twelve patients with CMI were prospectively included and examined on a 1.5 T magnetic resonance (MR) system using relaxivity-adjusted doses of gadobutrol (0.15 mmol/kg) and Gd-DTPA (0.2 mmol/kg) in random order. T1-relaxation times of remote myocardium (RM), infarcted myocardium (IM), and left ventricular cavity (LVC) were assessed from short-axis TI scout imaging using the Look–Locker approach and compared intraindividually using a Wilcoxon paired signed-rank test (α < 0.05). Results: Within 3 min of contrast agent administration (CA), IM showed significantly lower T1-relaxation times than RM with both contrast agents, indicating beginning cardiac late enhancement. Differences between gadobutrol and Gd-DTPA in T1-relaxation times of IM and RM were statistically not significant through all time points. However, gadobutrol led to significantly higher T1-relaxation times of LVC than Gd-DTPA from 6 to 9 min (220 ± 15 ms vs. 195 ± 30 ms p < 0.01) onwards, resulting in a significantly greater ΔT1 of IM to LVC at 9–12 min (−20 ± 35 ms vs. 0 ± 35 ms, p < 0.05) and 12–15 min (−25 ± 45 ms vs. −10 ± 60 ms, p < 0.05). Using Gd-DTPA, comparable ΔT1 values were reached only after 25–35 min. Conclusion: This study indicates good delineation of IM to RM with both contrast agents as early as 3 min after administration. However, we found significant differences in T1 relaxation times with greater ΔT1 IM–LVC using 0.15 mmol/kg gadobutrol compared to 0.20 mmol/kg Gd-DTPA after 9–15 min post-CA suggesting earlier differentiability of IM and LVC using gadobutrol.

  17. Contrast enhancement in multidetector-row computed tomography (MDCT) of the abdomen: intraindividual comparison of contrast media containing 300 mg versus 370 mg iodine per ml

    International Nuclear Information System (INIS)

    Behrendt, F.F.; Mahnken, A.H.; Keil, S.; Das, M.; Hohl, C.; Guenther, R.W.; Muehlenbruch, G.; Bauer, D.; Seidensticker, P.; Jost, E.; Wildberger, J.E.

    2008-01-01

    The purpose of this study was to intraindividually evaluate the difference in intraluminal vessel and parenchyma contrast enhancement of two different iodine concentrations in multidetector-row computed tomography (MDCT) of the abdomen. Eighty-three patients underwent baseline and follow-up MDCT-scanning (Somatom Sensation 16; Siemens, Forchheim, Germany) of the abdomen using contrast media containing 370 mg iodine/ml (protocol A; Ultravist 370, Bayer Schering Pharma, Berlin, Germany) and 300 mg iodine/ml (protocol B; Ultravist 300). The total iodine load (37 g iodine) and the iodine delivery rate (1.29 g iodine/s) were identical for both protocols. Contrast enhancement in the portal venous phase was measured in the abdominal aorta, inferior vena cava, portal vein, liver, spleen, pancreas and kidney. Mean attenuation values were compared using paired t-test. Intraindividual comparison revealed no statistically significant differences of the mean attenuation values between protocols A and B for all anatomic sites: abdominal aorta, inferior vena cava, portal vein, liver, spleen, pancreas and kidney (all P > 0.05). Given an injection protocol with constant total iodine load and constant iodine delivery rate, the iodine concentration of contrast media does not significantly influence abdominal contrast enhancement in the portal venous phase. (orig.)

  18. Intraindividual comparison of two different skin care conceptions in patients undergoing radiotherapy of the head-and-neck region. Creme or powder?

    International Nuclear Information System (INIS)

    Schreck, U.; Paulsen, F.; Bamberg, M.; Budach, W.

    2002-01-01

    Objectives: This study evaluated for the first time in intraindividual comparison the conception of care with creme or powder. Acute skin reactions on the left and right side of the neck during symmetrically performed radiotherapy and subjective impairment were assessed. Patients and Methods: Twelve patients receiving radiotherapy of the head-and-neck region up to 50, 60, 66 and 72 Gy, respectively, were asked to treat one side of the neck with creme, the contralateral side with powder after random assignment. Objective and subjective assessment and photodocumentation were performed at therapy onset and weekly during therapy. The photodocumentation provides an impressive course of acute skin reactions under these care concepts. Results: Altogether we saw no relevant difference in favor of care with creme or powder according to objective as well as subjective assessment criteria (Figures 2 and 3). In this intraindividual comparison the results are independent from interindividual different sensitivity to radiotherapy, total dose or fractionation. Therefore the small patient number is a minor limitation for evidence. Our results are in accordance to trials comparing other care concepts. Conclusions: A relevant effect concerning onset and degree of acute skin reactions or differences in symptom relief could not be demonstrated. Both conceptions are to be regarded equal in terms of subjective symptom relief and in extent of acute skin reactions. The lack of differences may be explained by the fact that the underlying pathophysiological processes cannot be influenced by topical agents. (orig.)

  19. Symbolic dynamics of heart rate variability - a promising tool to investigate cardiac sympathovagal control in attention deficit/hyperactivity disorder (ADHD)?

    Science.gov (United States)

    Tonhajzerova, Ingrid; Farsky, Ivan; Mestanik, Michal; Visnovcova, Zuzana; Mestanikova, Andrea; Hrtanek, Igor; Ondrejka, Igor

    2016-06-01

    We aimed to evaluate complex cardiac sympathovagal control in attention deficit/hyperactivity disorder (ADHD) by using heart rate variability (HRV) nonlinear analysis - symbolic dynamics. We examined 29 boys with untreated ADHD and 25 healthy boys (age 8-13 years). ADHD symptoms were evaluated by ADHD-RS-IV scale. ECG was recorded in 3 positions: baseline supine position, orthostasis, and clinostasis. Symbolic dynamics indices were used for the assessment of complex cardiac sympathovagal regulation: normalised complexity index (NCI), normalised unpredictability index (NUPI), and pattern classification measures (0V%, 1V%, 2LV%, 2UV%). The results showed that HRV complexity was significantly reduced at rest (NUPI) and during standing position (NCI, NUPI) in ADHD group compared to controls. Cardiac-linked sympathetic index 0V% was significantly higher during all posture positions and cardiovagal index 2LV% was significantly lower to standing in boys suffering from ADHD. Importantly, ADHD symptom inattention positively correlated with 0V%, and negatively correlated with NCI, NUPI. Concluding, symbolic dynamics revealed impaired complex neurocardiac control characterised by potential cardiac beta-adrenergic overactivity and vagal deficiency at rest and to posture changes in boys suffering from ADHD that is correlated with inattention. We suggest that symbolic dynamics indices could represent promising cardiac biomarkers in ADHD.

  20. A Tool for the Quantitative Anthropology of Music: Use of the nPVI Equation to Analyze Rhythmic Variability within Long-term Historical Patterns in Music

    Directory of Open Access Journals (Sweden)

    Joseph R Daniele

    2017-01-01

    Full Text Available The development of musical style across time and geography is of particular interest to historians and musicologists, yet quantitative evidence to support these trends has been lacking. This paper illustrates a novel application of the nPVI ('normalized pairwise variability index' equation to probe and quantify the rhythmic components of music over time. The nPVI equation quantifies the average difference between adjacent events in a sequence (e.g. musical notes in a melody, successive vowels in a spoken sentence. Building upon an earlier finding that German/Austrian composer nPVI values increased steadily from 1600 to 1950 (while Italian composers showed no such increase, the nPVI 'distribution' of themes from individual composers was quantitatively explored. Interestingly, the proportion of 'low nPVI' or 'Italianate' themes decreases rapidly with time while 'high nPVI' (more Germanic themes concomitantly increase in frequency. 'Middle range nPVIs' exhibit a constant incidence, arguing for a replacement of 'low nPVIs' (Italianate with 'high nPVIs' over a short time instead of a more modest, long-term progressive shift. Thus, the precise rhythmic components of complex stylistic shifts in music can be quantitatively extracted from music and support the historical record and theory.

  1. Characterization of a single-chain variable fragment recognizing a linear epitope of aβ: a biotechnical tool for studies on Alzheimer's disease?

    Directory of Open Access Journals (Sweden)

    Silke Dornieden

    Full Text Available Alzheimer's disease (AD is a progressive neurodegenerative disorder with devastating effects. Currently, therapeutic options are limited to symptomatic treatment. For more than a decade, research focused on immunotherapy for the causal treatment of AD. However, clinical trials with active immunization using Aβ encountered severe complications, for example meningoencephalitis. Consequently, attention focused on passive immunization using antibodies. As an alternative to large immunoglobulins (IgGs, Aβ binding single-chain variable fragments (scFvs were used for diagnostic and therapeutic research approaches. scFvs can be expressed in E. coli and may provide improved pharmacokinetic properties like increased blood-brain barrier permeability or reduced side-effects in vivo. In this study, we constructed an scFv from an Aβ binding IgG, designated IC16, which binds the N-terminal region of Aβ (Aβ(1-8. scFv-IC16 was expressed in E. coli, purified and characterized with respect to its interaction with different Aβ species and its influence on Aβ fibril formation. We were able to show that scFv-IC16 strongly influenced the aggregation behavior of Aβ and could be applied as an Aβ detection probe for plaque staining in the brains of transgenic AD model mice. The results indicate potential for therapy and diagnosis of AD.

  2. Response variability of different anodal transcranial direct current stimulation intensities across multiple sessions.

    Science.gov (United States)

    Ammann, Claudia; Lindquist, Martin A; Celnik, Pablo A

    It is well known that transcranial direct current stimulation (tDCS) is capable of modulating corticomotor excitability. However, a source of growing concern has been the observed inter- and intra-individual variability of tDCS-responses. Recent studies have assessed whether individuals respond in a predictable manner across repeated sessions of anodal tDCS (atDCS). The findings of these investigations have been inconsistent, and their methods have some limitations (i.e. lack of sham condition or testing only one tDCS intensity). To study inter- and intra-individual variability of atDCS effects at two different intensities on primary motor cortex (M1) excitability. Twelve subjects participated in a crossover study testing 7-min atDCS over M1 in three separate conditions (2 mA, 1 mA, sham) each repeated three times separated by 48 h. Motor evoked potentials were recorded before and after stimulation (up to 30min). Time of testing was maintained consistent within participants. To estimate the reliability of tDCS effects across sessions, we calculated the Intra-class Correlation Coefficient (ICC). AtDCS at 2 mA, but not 1 mA, significantly increased cortical excitability at the group level in all sessions. The overall ICC revealed fair to high reliability of tDCS effects for multiple sessions. Given that the distribution of responses showed important variability in the sham condition, we established a Sham Variability-Based Threshold to classify responses and to track individual changes across sessions. Using this threshold an intra-individual consistent response pattern was then observed only for the 2 mA condition. 2 mA anodal tDCS results in consistent intra- and inter-individual increases of M1 excitability. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Frequency analysis of heart rate variability: a useful assessment tool of linearly polarized near-infrared irradiation to stellate ganglion area for burning mouth syndrome.

    Science.gov (United States)

    Momota, Yukihiro; Takano, Hideyuki; Kani, Koichi; Matsumoto, Fumihiro; Motegi, Katsumi; Aota, Keiko; Yamamura, Yoshiko; Omori, Mayuko; Tomioka, Shigemasa; Azuma, Masayuki

    2013-03-01

    Burning mouth syndrome (BMS) is characterized by the following subjective complaints without distinct organic changes: burning sensation in mouth or chronic pain of tongue. BMS is also known as glossodynia; both terms are used equivalently in Japan. Although the real cause of BMS is still unknown, it has been pointed out that BMS is related to some autonomic abnormality, and that stellate ganglion near-infrared irradiation (SGR) corrects the autonomic abnormality. Frequency analysis of heart rate variability (HRV) is expected to be useful for assessing autonomic abnormality. This study investigated whether frequency analysis of HRV could reveal autonomic abnormality associated with BMS, and whether autonomic changes were corrected after SGR. Eight subjects received SGR; the response to SGR was assessed by frequency analysis of HRV. No significant difference of autonomic activity concerning low-frequency (LF) norm, high-frequency (HF) norm, and low-frequency/high-frequency (LF/HF) was found between SGR effective and ineffective groups. Therefore, we proposed new parameters: differential normalized low frequency (D LF norm), differential normalized high frequency (D HF norm), and differential low-frequency/high-frequency (D LF/HF), which were defined as differentials between original parameters just before and after SGR. These parameters as indexes of responsiveness of autonomic nervous system (ANS) revealed autonomic changes in BMS, and BMS seems to be related to autonomic instability rather than autonomic imbalance. Frequency analysis of HRV revealed the autonomic instability associated with BMS and enabled tracing of autonomic changes corrected with SGR. It is suggested that frequency analysis of HRV is very useful in follow up of BMS and for determination of the therapeutic efficacy of SGR. Wiley Periodicals, Inc.

  4. The Association of Glucose Variability and Home Discharge Among Survivors of Critical Illness Managed With a Computerized Decision-Support Tool for Glycemic Control.

    Science.gov (United States)

    Oud, Lavi; Spellman, Craig

    2014-03-01

    In-intensive care unit (ICU) glucose variability (GV) is associated with increased mortality. However, the impact of GV on hospital survivors' morbidity and associated changes in destination at time of hospital discharge are unknown. We studied a retrospective patient cohort in a medical/surgical ICU, requiring insulin infusion, using computer-guided insulin dosing software. Standard deviation (Glu SD ) and coefficient of variation (Glu CV ) were used as GV measures. We examined rates of home discharge (H) in the whole cohort and selected subgroups across GV quartiles, between patients with and without H, determinants of H, and determinants of GV and its association with patients' ICU length of stay (LOS). A total of 351 patients met study criteria. The association of GV and H varied among examined subgroups. H increased with GV quartile (Glu SD ; P = .004). GV was higher in patients with H than non-H (Glu SD 36.1 vs 30.0 mg/dl, respectively; P = .002). Increased GV was not a predictor of reduced H on multivariate analysis. GV was inversely associated with patients' ICU LOS in all examined subgroups. Increased number of hypoglycemic events and time to attain target glycemia were independent predictors of reduced H. GV was not associated with adverse impact on H in the present cohort, and its prognostic impact should be considered in the context of ICU LOS of examined patient populations. Further studies are needed to examine the morbidity effects of GV and other glycemia-related measures among hospital survivors of critical illness across varying ICU populations, glycemic control approaches, and glycemic targets. © 2014 Diabetes Technology Society.

  5. Climatic controls of the interannual to decadal variability in Saudi Arabian dust activity: Towards the development of a seasonal prediction tool

    Science.gov (United States)

    Yu, Y.; Notaro, M.; Liu, Z.; Alkolibi, F.; Fadda, E.; Bakhrjy, F.

    2013-12-01

    Atmospheric dust significantly influences the climate system, as well as human life in Saudi Arabia. Skillful seasonal prediction of dust activity with climatic variables will help prevent some negative social impacts of dust storms. Yet, the climatic regulators on Saudi Arabian dust activity remain largely unaddressed. Remote sensing and station observations show consistent seasonal cycles in Saudi Arabian dust activity, which peaks in spring and summer. The climatic controls on springtime and summertime Saudi Arabian dust activity during 1975-2010 are studied using observational and reanalysis data. Empirical Orthogonal Function (EOF) of the observed Saudi Arabian dust storm frequency shows a dominant homogeneous pattern across the country, which has distinct interannual and decadal variations, as revealed by the power spectrum. Regression and correlation analyses reveal that Saudi Arabian dust activity is largely tied to precipitation on the Arabian Peninsula in spring and northwesterly (Shamal) wind in summer. On the seasonal-interannual time scale, warm El Niño-Southern Oscillation (ENSO) phase (El Niño) in winter-to-spring inhibits spring dust activity by increasing the precipitation over the Rub'al Khali Desert, a major dust source region on the southern Arabian Peninsula; warm ENSO and warm Indian Ocean Basin Mode (IOBM) in winter-to-spring favor less summer dust activity by producing anomalously low sea-level pressure over eastern north Africa and Arabian Peninsula, which leads to the reduced Shamal wind speed. The decadal variation in dust activity is likely associated with the Atlantic Multidecadal Oscillation (AMO), which impacts Sahel rainfall and North African dust, and likely dust transport to Saudi Arabia. The Pacific Decadal Oscillation (PDO) and tropical Indian Ocean SST also have influence on the decadal variation in Saudi Arabian dust activity, by altering precipitation over the Arabian Peninsula and summer Shamal wind speed. Using eastern

  6. Inter- and Intra-Individual Variability in the Process of Change in the Use of Analogical Strategies to Solve Geometric Tasks in Children: A Microgenetic Analysis

    Science.gov (United States)

    Tunteler, Erika; Pronk, Christine M. E.; Resing, Wilma C. M.

    2008-01-01

    This study focused on unprompted changes in children's analogical reasoning on geometric tasks and the additional effect of a short training procedure. Participants were 36 grade 1 level children (M = 6;8 years) divided over a not-trained and a trained condition. The study was a 5-sessions migrogenetic procedure, with a follow-up test session…

  7. Variability modifies life satisfaction's association with mortality risk in older adults

    Science.gov (United States)

    Boehm, Julia K.; Winning, Ashley; Segerstrom, Suzanne; Kubzansky, Laura D.

    2015-01-01

    Life satisfaction is associated with greater longevity, but its variability across time has not been examined relative to longevity. We investigated whether mean levels of life satisfaction across time, variability in life satisfaction across time, and their interaction were associated with mortality over 9 years of follow-up. Participants were 4,458 Australians initially ≥50 years old. During the follow-up, 546 people died. Adjusting for age, greater mean life satisfaction was associated with reduced risk and greater variability in life satisfaction was associated with increased risk of mortality. These findings were qualified by a significant interaction such that individuals with low mean satisfaction and high variability in satisfaction had the greatest risk of mortality over the follow-up period. In combination with mean levels of life satisfaction, variability in life satisfaction is relevant for mortality risk among older adults. Considering intraindividual variability provides additional insight into associations between psychological characteristics and health. PMID:26048888

  8. Effect of a new moisturizing lotion on immediate and cumulative skin hydration: Two randomized, intra-individual, vehicle- and comparator-controlled studies.

    Science.gov (United States)

    Nogueira, Alessandra; Sidou, Farzaneh; Brocard, Sylvie

    2011-08-01

    Moisturizers increase skin hydration and can serve as adjunctive care in dermatologic conditions such as xerosis, psoriasis vulgaris, atopic dermatitis and ichthyosis, in which dry skin is implicated. A non-irritating hydrating lotion (CDA lotion) was recently developed. We assessed the effect of CDA lotion on skin hydration in two randomized, evaluator-blind and intra-individual comparison studies. After a single application, CDA lotion induced significantly greater hydration than the non-treated control for at least 24 hours (p skin hydration up to 3 days after treatment cessation (p skin dryness score up to 7 days after treatment cessation (p hydration effects of CDA lotion were also compared to those of several currently available moisturizing products. In summary, application of CDA lotion increases skin hydration and alleviates the condition of skin dryness.

  9. Requirements and Tools for Variability Management

    NARCIS (Netherlands)

    Aiello, Marco; Bulanov, Pavel; Groefsema, Heerko

    2010-01-01

    Explicit and software-supported Business Process Management has become the core infrastructure of any medium and large organization that has a need to be efficient and effective. The number of processes of a single organization can be very high, furthermore, they might be very similar, be in need of

  10. Variability Bugs:

    DEFF Research Database (Denmark)

    Melo, Jean

    . Although many researchers suggest that preprocessor-based variability amplifies maintenance problems, there is little to no hard evidence on how actually variability affects programs and programmers. Specifically, how does variability affect programmers during maintenance tasks (bug finding in particular......)? How much harder is it to debug a program as variability increases? How do developers debug programs with variability? In what ways does variability affect bugs? In this Ph.D. thesis, I set off to address such issues through different perspectives using empirical research (based on controlled...... experiments) in order to understand quantitatively and qualitatively the impact of variability on programmers at bug finding and on buggy programs. From the program (and bug) perspective, the results show that variability is ubiquitous. There appears to be no specific nature of variability bugs that could...

  11. The renal protective effect of angiotensin receptor blockers depends on intra-individual response variation in multiple risk markers

    DEFF Research Database (Denmark)

    Schievink, Bauke; de Zeeuw, Dick; Parving, Hans-Henrik

    2015-01-01

    , haemoglobin, cholesterol and uric acid after 6 months of losartan treatment were assessed in the RENAAL database. Improvement in predictive performance of renal outcomes (ESRD or doubling serum creatinine) for each individual using ARB-induced changes in all risk markers was assessed by the relative...... integrative discrimination index (RIDI). RESULTS: SBP response showed high variability (mean -5.7 mmHg, 5(th) to 95(th) percentile -36.5 to +24.0 mmHg) between individuals. Changes in off-target parameters also showed high variability between individuals. No congruency was observed between responses...

  12. Intraindividuální komparace vybraných koordinačních ukazatelů bruslařského kroku na ledě a při in-line

    OpenAIRE

    Hospůdka, Jakub

    2010-01-01

    4 Summary: Title: Intraindividual comparison of selected indicators of coordinating steps on the ice skating and in-line. Objective: Assessment of coordination relationship rate of the skating forward during ice hockey and inline skating. Methods: Surface electromyography combinated with kinematography analysis used synchronized video recording. Results: Kinesiological content of movement during ice skating and inline skating is not the same. The general stereotype of the skating step is sign...

  13. iDermatoPath - a novel software tool for mitosis detection in H&E-stained tissue sections of malignant melanoma.

    Science.gov (United States)

    Andres, C; Andres-Belloni, B; Hein, R; Biedermann, T; Schäpe, A; Brieu, N; Schönmeyer, R; Yigitsoy, M; Ring, J; Schmidt, G; Harder, N

    2017-07-01

    Malignant Melanoma (MM) is characterized by a growing incidence and a high malignant potential. Besides well-defined prognostic factors such as tumour thickness and ulceration, the Mitotic Rate (MR) was included in the AJCC recommendations for diagnosis and treatment of MM. In daily routine, the identification of a single mitosis can be difficult on haematoxylin and eosin slides alone. Several studies showed a big inter- and intra-individual variability in detecting the MR in MM even by very experienced investigators, thus raising the question for a computer-assisted method. The objective was to develop a software system for mitosis detection in MM on H&E slides based on machine learning for diagnostic support. We developed a computer-aided staging support system based on image analysis and machine learning on the basis of 59 MM specimens. Our approach automatically detects tumour regions, identifies mitotic nuclei and classifies them with respect to their diagnostic relevance. A convenient user interface enables the investigator to browse through the proposed mitoses for fast and efficient diagnosing. A quantitative evaluation on manually labelled ground truth data revealed that the tumour region detection yields a medium spatial overlap index (dice coefficient) of 0.72. For the mitosis detection, we obtained high accuracies of above 83%. On the technical side, the developed iDermatoPath software tool provides a novel approach for mitosis detection in MM, which can be further improved using more training data such as dermatopathologist annotations. On the practical side, a first evaluation of the clinical utility was positive, albeit this approach provides most benefit for difficult cases in a research setting. Assuming all slides to be digitally processed and reported in the near future, this method could become a helpful additional tool for the pathologist. © 2017 European Academy of Dermatology and Venereology.

  14. Handheld mechanical nociceptive threshold testing in dairy cows – intra-individual variation, inter-observer agreement and variation over time

    Science.gov (United States)

    Raundal, Peter M; Andersen, Pia H; Toft, Nils; Forkman, Björn; Munksgaard, Lene; Herskin, Mette S

    2014-01-01

    Objective To examine the use of handheld methodology to assess mechanical nociceptive threshold (MNT) on cows kept loose-housed. Study design Prospective randomized partial cross-over experimental study. A one-factor (test day) design was used to evaluate MNT over time. Animals One hundred and fifteen healthy, loose-housed Danish Holstein cattle. Methods We evaluated intra-individual variation, inter-observer agreement and variation over time of MNT using two handheld devices and two stimulation sites. Mechanical, ramped stimulations were performed with an algometer (6.5 mm diameter steel probe, 0–10.0 kgf) or an electronic von Frey device (plastic tip with diameter 0.8 mm, 0–1000 gf). Each cow received 5–6 consecutive stimulations within a 2 × 5 cm skin area on the dorsal or lateral aspect of the left third metatarsus until an avoidance reaction occurred. We investigated the difference in precision [expressed as coefficient of variation (CV)] between the combinations of devices and stimulation sites. The inter-observer agreement and the difference in MNT between test day 1, 3, 7, 10 and 24 were investigated for selected combinations. Data were analysed in mixed models and Bland-Altman as relevant. Results The CVs did not differ [range 0.34–0.52 (p = 0.1)]. Difference between observers (95% limits) was 0.2 kgf (2.8) and 4 gf (369) for the algometer and von Frey device, respectively. Mechanical nociceptive threshold increased from 361 on test day one to 495 gf on test day 24 (p < 0.01). Conclusion and clinical relevance All methods showed a high degree of intra-individual variation, and no combination of device and stimulation site showed superior precision. Mean difference between observers was low, and MNT was not consistent over time. Further development of the methods is required before they can be used in research to investigate possible relations between claw lesions and hyperalgesia. PMID:24734991

  15. Variability of insulin-stimulated myocardial glucose uptake in healthy elderly subjects

    DEFF Research Database (Denmark)

    Kofoed, Klaus F; Hove, Jens D; Freiberg, Jacob

    2002-01-01

    The aim of this study was to assess regional and global variability of insulin-stimulated myocardial glucose uptake in healthy elderly subjects and to evaluate potentially responsible factors. Twenty men with a mean age of 64 years, no history of cardiovascular disease, and normal blood pressure...... rest and hyperaemic blood flow during dipyridamole infusion were measured with nitrogen-13 ammonia and positron emission tomography in 16 left ventricular myocardial segments. Intra-individual and inter-individual variability of insulin-stimulated myocardial glucose uptake [relative dispersion...... = (standard deviation/mean)] was 13% and 29% respectively. Although inter-individual variability of glucose uptake and blood flow at rest was of the same magnitude, no correlation was found between these measures. Regional and global insulin-stimulated myocardial glucose uptake correlated linearly with whole...

  16. Water baths for farmed mink: intra-individual consistency and inter-individual variation in swimming behaviour, and effects on stereotyped behaviour

    Directory of Open Access Journals (Sweden)

    J. MONONEN

    2008-12-01

    Full Text Available Swimming behaviour and effects of water baths on stereotyped behaviour in farmed mink (Mustela vison were studied in three experiments. The singly-housed mink had access from their home cages to extra cages with 20.5 litre water baths. Two short-term experiments aimed to investigate how quickly adult and juvenile mink start using and how consistently they use water baths over 10 days, and whether the extent of the use correlates between dams and their females kits. A four-month experiment was designed to compare the development of stereotyped behaviour in juvenile mink housed with and without swimming opportunity. The behavioural analyses were based on several 24-hour video recordings carried out in all three experiments. There were obvious inter-individual differences and intra-individual consistency in swimming frequency and time. Farmed mink’s motivation to swim can be assessed in short-term experiments, and measurement of water losses from the swimming baths and use of instantaneous sampling with 10 min sampling intervals provide quite reliable measures of the amount of swimming. The bath use of the juveniles correlated with that of their dams, indicating that an individual mink’s eagerness to swim may have a genetic component. The lower amount of stereotyped behaviour in mink housed with water baths indicates that long-term access to baths may alleviate frustration in singly-housed juvenile farmed mink.;

  17. Intraindividual evaluation of the influence of iterative reconstruction and filter kernel on subjective and objective image quality in computed tomography of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Buhk, J.H. [Univ. Medical Center, Hamburg-Eppendorf (Germany). Dept. of Neuroradiology; Laqmani, A.; Schultzendorff, H.C. von; Hammerle, D.; Adam, G.; Regier, M. [Univ. Medical Center, Hamburg-Eppendorf (Germany). Dept. of Diagnostic and Interventional Radiology; Sehner, S. [Univ. Medical Center, Hamburg-Eppendorf (Germany). Inst. of Medical Biometry and Epidemiology; Fiehler, J. [Univ. Medical Center, Hamburg-Eppendorf (Germany). Neuroradiology; Nagel, H.D. [Dr. HD Nagel, Science and Technology for Radiology, Buchholz (Germany)

    2013-08-15

    Objectives: To intraindividually evaluate the potential of 4th generation iterative reconstruction (IR) on brain CT with regard to subjective and objective image quality. Methods: 31 consecutive raw data sets of clinical routine native sequential brain CT scans were reconstructed with IR level 0 (= filtered back projection), 1, 3 and 4; 3 different brain filter kernels (smooth/standard/sharp) were applied respectively. Five independent radiologists with different levels of experience performed subjective image rating. Detailed ROI analysis of image contrast and noise was performed. Statistical analysis was carried out by applying a random intercept model. Results: Subjective scores for the smooth and the standard kernels were best at low IR levels, but both, in particular the smooth kernel, scored inferior with an increasing IR level. The sharp kernel scored lowest at IR 0, while the scores substantially increased at high IR levels, reaching significantly best scores at IR 4. Objective measurements revealed an overall increase in contrast-to-noise ratio at higher IR levels, which was highest when applying the soft filter kernel. The absolute grey-white contrast decreased with an increasing IR level and was highest when applying the sharp filter kernel. All subjective effects were independent of the raters' experience and the patients' age and sex. Conclusion: Different combinations of IR level and filter kernel substantially influence subjective and objective image quality of brain CT. (orig.)

  18. Examining the Interplay of Processes Across Multiple Time-Scales: Illustration With the Intraindividual Study of Affect, Health, and Interpersonal Behavior (iSAHIB).

    Science.gov (United States)

    Ram, Nilam; Conroy, David E; Pincus, Aaron L; Lorek, Amy; Rebar, Amanda; Roche, Michael J; Coccia, Michael; Morack, Jennifer; Feldman, Josh; Gerstorf, Denis

    Human development is characterized by the complex interplay of processes that manifest at multiple levels of analysis and time-scales. We introduce the Intraindividual Study of Affect, Health and Interpersonal Behavior (iSAHIB) as a model for how multiple time-scale study designs facilitate more precise articulation of developmental theory. Combining age heterogeneity, longitudinal panel, daily diary, and experience sampling protocols, the study made use of smartphone and web-based technologies to obtain intensive longitudinal data from 150 persons age 18-89 years as they completed three 21-day measurement bursts ( t = 426 bursts, t = 8,557 days) wherein they provided reports on their social interactions ( t = 64,112) as they went about their daily lives. We illustrate how multiple time-scales of data can be used to articulate bioecological models of development and the interplay among more 'distal' processes that manifest at 'slower' time-scales (e.g., age-related differences and burst-to-burst changes in mental health) and more 'proximal' processes that manifest at 'faster' time-scales (e.g., changes in context that progress in accordance with the weekly calendar and family influence processes).

  19. Intra-individual comparison of image contrast in SPIO-enhanced liver MRI at 1.5T and 3.0T

    International Nuclear Information System (INIS)

    Falkenhausen, Marcus von; Meyer, Carsten; Lutterbey, Goetz; Morakkabati, Nuschin; Bloemer, Renate; Willinek, Winfried A.; Kuhl, Christiane K.; Schild, Hans H.; Walter, Oliver; Gieseke, Juergen

    2007-01-01

    The purpose of the study was to examine if the higher susceptibility at 3.0 Tesla (T) compared to 1.5 T will affect the contrast in MR imaging of the liver after application of superparamagnetic iron oxide particles (SPIO). The study was approved by our institutional review board and informed consent was obtained. Seventeen healthy volunteers were examined in a prospective, intra-individual comparative study within one day on a 1.5 T and a 3.0 T MRI system. T2 weighted TSE sequences were acquired after bolus injection of a SPIO contrast agent. Image contrast and signal to noise ratio (SNR) were compared between the field strengths. Image contrast was calculated between the liver tissue and the kidneys / spleen / muscles and fluids. The students'T-test was used for statistical analysis. No influence of the higher field strength could be observed on image contrast except for the liver / muscle contrast. This was due to a distinct SNR increase of the muscle tissue at 3.0 T as a result of their relaxation properties. The higher susceptibility at 3.0 T compared to 1.5 T does not translate into a stronger signal attenuation of the SPIO enhanced liver parenchyma. (orig.)

  20. Pancreatic Duct in Autoimmune Pancreatitis: Intraindividual Comparison of Magnetic Resonance Pancreatography at 1.5 T and 3.0 T.

    Science.gov (United States)

    Kim, Jin Hee; Byun, Jae Ho; Kim, Myung-Hwan; Lee, Sung Koo; Kim, Song Cheol; Kim, Hyoung Jung; Lee, Seung Soo; Kim, So Yeon; Lee, Moon-Gyu

    2017-08-01

    The aim of this study was to intraindividually compare magnetic resonance pancreatography (MRP) image quality at 1.5 T and 3.0 T when demonstrating main pancreatic duct (MPD) abnormalities in patients with autoimmune pancreatitis (AIP). Thirty prospectively enrolled patients with AIP underwent MRP at both 1.5 T and 3.0 T followed by endoscopic retrograde pancreatography before treatment. Two readers independently analyzed the MRP images and graded the visualization of MPD strictures and full-length MPD, using endoscopic retrograde pancreatography as the reference standard, as well as overall image artifacts on a 4-point scale. The contrast between the MPD and periductal area was calculated using a region-of-interest measurement. Visualization scores of MPD strictures and full-length MPD, and summed scores of each qualitative analysis, were significantly greater at 3.0-T MRP than at 1.5-T MRP for both readers (P ≤ 0.02). There were less image artifacts at 3.0 T compared with 1.5 T (P ≤ 0.052). The contrast between the MPD and periductal area was significantly greater at 3.0-T MRP than at 1.5-T MRP (P 3.0 T was superior to 1.5-T MRP for demonstrating MPD abnormalities in AIP, with better image contrast and fewer image artifacts. Consequently, 3.0-T MRP may be useful for the diagnosis and management of patients with AIP.

  1. Intra-individual comparison of image contrast in SPIO-enhanced liver MRI at 1.5T and 3.0T

    Energy Technology Data Exchange (ETDEWEB)

    Falkenhausen, Marcus von; Meyer, Carsten; Lutterbey, Goetz; Morakkabati, Nuschin; Bloemer, Renate; Willinek, Winfried A.; Kuhl, Christiane K.; Schild, Hans H. [University of Bonn, Department of Radiology, Bonn (Germany); Walter, Oliver [Leibniz-Institute for Science Education, Kiel (Germany); Gieseke, Juergen [University of Bonn, Department of Radiology, Bonn (Germany); Philips Medical Systems, Hamburg (Germany)

    2007-05-15

    The purpose of the study was to examine if the higher susceptibility at 3.0 Tesla (T) compared to 1.5 T will affect the contrast in MR imaging of the liver after application of superparamagnetic iron oxide particles (SPIO). The study was approved by our institutional review board and informed consent was obtained. Seventeen healthy volunteers were examined in a prospective, intra-individual comparative study within one day on a 1.5 T and a 3.0 T MRI system. T2 weighted TSE sequences were acquired after bolus injection of a SPIO contrast agent. Image contrast and signal to noise ratio (SNR) were compared between the field strengths. Image contrast was calculated between the liver tissue and the kidneys / spleen / muscles and fluids. The students'T-test was used for statistical analysis. No influence of the higher field strength could be observed on image contrast except for the liver / muscle contrast. This was due to a distinct SNR increase of the muscle tissue at 3.0 T as a result of their relaxation properties. The higher susceptibility at 3.0 T compared to 1.5 T does not translate into a stronger signal attenuation of the SPIO enhanced liver parenchyma. (orig.)

  2. Intraindividual evaluation of the influence of iterative reconstruction and filter kernel on subjective and objective image quality in computed tomography of the brain

    International Nuclear Information System (INIS)

    Buhk, J.H.

    2013-01-01

    Objectives: To intraindividually evaluate the potential of 4th generation iterative reconstruction (IR) on brain CT with regard to subjective and objective image quality. Methods: 31 consecutive raw data sets of clinical routine native sequential brain CT scans were reconstructed with IR level 0 (= filtered back projection), 1, 3 and 4; 3 different brain filter kernels (smooth/standard/sharp) were applied respectively. Five independent radiologists with different levels of experience performed subjective image rating. Detailed ROI analysis of image contrast and noise was performed. Statistical analysis was carried out by applying a random intercept model. Results: Subjective scores for the smooth and the standard kernels were best at low IR levels, but both, in particular the smooth kernel, scored inferior with an increasing IR level. The sharp kernel scored lowest at IR 0, while the scores substantially increased at high IR levels, reaching significantly best scores at IR 4. Objective measurements revealed an overall increase in contrast-to-noise ratio at higher IR levels, which was highest when applying the soft filter kernel. The absolute grey-white contrast decreased with an increasing IR level and was highest when applying the sharp filter kernel. All subjective effects were independent of the raters' experience and the patients' age and sex. Conclusion: Different combinations of IR level and filter kernel substantially influence subjective and objective image quality of brain CT. (orig.)

  3. Diagnosis of cerebral metastases by means of standard doses of Gadobutrol versus a high-dose protocol. Intraindividual evaluation of a phase-II high-dose study

    International Nuclear Information System (INIS)

    Vogl, T.J.; Friebe, C.E.; Balzer, T.; Mack, M.G.; Steiner, S.; Schedel, H.; Pegios, W.; Lanksch, W.; Banzer, D.; Felix, R.

    1995-01-01

    In a clinical phase-II study 20 patients who had been diagnosed as having brain metastases with CT or MRT were studied prospectively with Gadobutrol, a new nonionic, low osmolality contrast agent. Each patient received an initial injection of 0.1 mmol/kg body weight and an additional dose of 0.2 mmol/kg Gadobutrol 10 min later. Spinecho images were obtained before and after the two applications of Gadobutrol. Dynamic scanning (Turbo-FLASH) was performed for 3 min after each injection of the contrast agent. Both quantitative and qualitative data were intraindividually evaluated. The primary tumor was a bronchial carcinoma in 11 cases; in 9 other cases there were different primary tumors. Forty-eight hours after the use of Gadobutrol there were no adverse signs in the clinical examination, vital signs or blood and urine chemistry. Statistical analysis (Friedman test and Wilcoxon test) of the C/N ratios between tumor and white matter, percentage enhancement, and visual assessment rating revealed statistically significant superiority of high-dose Gadobutrol injection in comparison to the standard dose. The percentage enhancement increased on average from 104% after 0.1 mmol/kg to 162% after 0.3 mmol/kg Gadobutrol. Qualitative delineation and contrast of the lesions increased significantly. The use of high-dose Gadobutrol improved the detection of 36 additional lesions in 6 patients. (orig./VHE) [de

  4. Pulsating variables

    International Nuclear Information System (INIS)

    1989-01-01

    The study of stellar pulsations is a major route to the understanding of stellar structure and evolution. At the South African Astronomical Observatory (SAAO) the following stellar pulsation studies were undertaken: rapidly oscillating Ap stars; solar-like oscillations in stars; 8-Scuti type variability in a classical Am star; Beta Cephei variables; a pulsating white dwarf and its companion; RR Lyrae variables and galactic Cepheids. 4 figs

  5. Cognitive Variability

    Science.gov (United States)

    Siegler, Robert S.

    2007-01-01

    Children's thinking is highly variable at every level of analysis, from neural and associative levels to the level of strategies, theories, and other aspects of high-level cognition. This variability exists within people as well as between them; individual children often rely on different strategies or representations on closely related problems…

  6. Simulation tools

    CERN Document Server

    Jenni, F

    2006-01-01

    In the last two decades, simulation tools made a significant contribution to the great progress in development of power electronics. Time to market was shortened and development costs were reduced drastically. Falling costs, as well as improved speed and precision, opened new fields of application. Today, continuous and switched circuits can be mixed. A comfortable number of powerful simulation tools is available. The users have to choose the best suitable for their application. Here a simple rule applies: The best available simulation tool is the tool the user is already used to (provided, it can solve the task). Abilities, speed, user friendliness and other features are continuously being improved—even though they are already powerful and comfortable. This paper aims at giving the reader an insight into the simulation of power electronics. Starting with a short description of the fundamentals of a simulation tool as well as properties of tools, several tools are presented. Starting with simplified models ...

  7. Low luminance/eyes closed and monochromatic stimulations reduce variability of flash visual evoked potential latency

    Directory of Open Access Journals (Sweden)

    Senthil Kumar Subramanian

    2013-01-01

    Full Text Available Context: Visual evoked potentials are useful in investigating the physiology and pathophysiology of the human visual system. Flash visual evoked potential (FVEP, though technically easier, has less clinical utility because it shows great variations in both latency and amplitude for normal subjects. Aim: To study the effect of eye closure, low luminance, and monochromatic stimulation on the variability of FVEPs. Subjects and Methods: Subjects in self-reported good health in the age group of 18-30 years were divided into three groups. All participants underwent FVEP recording with eyes open and with white light at 0.6 J luminance (standard technique. Next recording was done in group 1 with closed eyes, group 2 with 1.2 and 20 J luminance, and group 3 with red and blue lights, while keeping all the other parameters constant. Two trials were given for each eye, for each technique. The same procedure was repeated at the same clock time on the following day. Statistical Analysis: Variation in FVEP latencies between the individuals (interindividual variability and the variations within the same individual for four trials (intraindividual variability were assessed using coefficient of variance (COV. The technique with lower COV was considered the better method. Results: Recording done with closed eyes, 0.6 J luminance, and monochromatic light (blue > red showed lower interindividual and intraindividual variability in P2 and N2 as compared to standard techniques. Conclusions: Low luminance flash stimulations and monochromatic light will reduce FVEP latency variability and may be clinically useful modifications of FVEP recording technique.

  8. Intra-individual comparison of magnesium citrate and sodium phosphate for bowel preparation at CT colonography: Automated volumetric analysis of residual fluid for quality assessment

    International Nuclear Information System (INIS)

    Bannas, P.; Bakke, J.; Munoz del Rio, A.; Pickhardt, P.J.

    2014-01-01

    Aim: To perform an objective, intra-individual comparison of residual colonic fluid volume and attenuation associated with the current front-line laxative magnesium citrate (MgC) versus the former front-line laxative sodium phosphate (NaP) at CT colonography (CTC). Materials and methods: This retrospective Health Insurance and Portability and Accountability Act-compliant study had institutional review board approval; informed consent was waived. The study cohort included 250 asymptomatic adults (mean age at index 56.1 years; 124 male/126 female) who underwent CTC screening twice over a 5 year interval. Colon catharsis at initial and follow-up screening employed single-dose NaP and double-dose MgC, respectively, allowing for intra-patient comparison. Automated volumetric analysis of residual colonic fluid volume and attenuation was performed on all 500 CTC studies. Colonic fluid volume <200 ml and mean attenuation between 300–900 HU were considered optimal. Paired t-test and McNemar's test were used to compare differences. Results: Residual fluid volumes <200 ml were recorded in 192 examinations (76.8%) following MgC and in 204 examinations (81.6%) following NaP (p = 0.23). The mean total residual fluid volume was 155 ± 114 ml for MgC and 143 ± 100 ml for NaP (p = 0.01). The attenuation range of 300–900 HU was significantly more frequent for MgC (n = 220, 88%) than for NaP (n = 127, 50.8%; p < 0.001). Mean fluid attenuation was significantly lower for MgC (700 ± 165 HU) than for NaP (878 ± 155 HU; p < 0.001). Concomitant presence of both optimal fluid volume and attenuation was significantly more frequent for MgC 65.2% than for NaP (38%; p < 0.001). Conclusions: Objective intra-individual comparison using automated volumetric analysis suggests that the replacement of NaP by MgC as the front-line laxative for CTC has not compromised overall examination quality. - Highlights: • Automated volumetric analysis provides

  9. Intraindividual comparison of gastric peristalsis after ingestion of a semiliquid and solid test meal; Intraindividueller Vergleich der Magenperistaltik nach Gabe von semiliquiden und festen Testmahlzeiten

    Energy Technology Data Exchange (ETDEWEB)

    Linke, R. [Muenchen Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Tatsch, K. [Muenchen Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Muenzing, W. [Muenchen Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Vorderholzer, W. [Muenchen Univ. (Germany). Medizinische Klinik Innenstadt; Schindlbeck, N. [Muenchen Univ. (Germany). Medizinische Klinik Innenstadt; Hahn, K. [Muenchen Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    1997-06-01

    Aim: Patients with various disorders of gastric function were studied with radiolabeled test meals of different consistency to elaborate the effect of ingested media on gastric peristalsis and emptying. Methods: In 12 patients parameters of gastric function were intraindividually compared after ingestion of a semiliquid and a solid test meal. In addition to the standard evaluation derived from time activity curves condensed images were established from two fixed time intervals (early and late period). These images were used to evaluate the amplitude and frequency of gastric contractions using Fourier analysis. Results: As expected gastric emptying was influenced by the consistency of the test meal. Mean emptying rates for the solid meal were significant lower than those for the semiliquid one (p<0,01). The amplitude and frequency of gastric contractions, however, did not depend on the consistency of the test meal. Within the course of the examination contraction amplitudes significantly increased (p<0,05) from the early to the late period using both, solid as well as semiliquid test meals. The frequency of gastric contractions remained unchanged. Conclusion: As shown by an intraindividual data comparison amplitude and frequency of gastric contractions seem to be independent of the consistency of ingested test meals whereas gastric emptying is significantly influenced by the administered media. Semiliquid meals offer advantages with respect to the shorter examination time and simpler preparation and therefore may be preferred for routine use. Since amplitudes seem to vary within the observation period standardized acquisition protocols are recommended for the evaluation of this parameter. (orig.) [Deutsch] Ziel: An einem heterogenen Kollektiv von Patienten mit gastrointestinalen Beschwerden wurde der Einfluss von Testspeisen unterschiedlicher Konsistenz auf Peristaltik und Entleerungsrate des Magens untersucht. Methodik: Bei 12 Patienten wurde nach Gabe von

  10. A prospective intra-individual evaluation of silk compared to Biobrane for the treatment of superficial burns of the hand and face.

    Science.gov (United States)

    Schiefer, Jennifer Lynn; Arens, Elena; Grigutsch, Daniel; Rath, Rebekka; Hoffmann, Alexandra; Fuchs, Paul Christian; Schulz, Alexandra

    2017-05-01

    An ever-increasing number of commercially available dressings have been applied to treat superficial burns with the aim to reduce pain and inflammation and lead to a fast wound healing and scar reduction. Nevertheless the search for cheap and effective wound dressing proceeds. Dressilk ® consisting of silkworm silk showed good results for wound healing in regards to scarring, biocompatibility and reduction of inflammation and pain. Therefore it seemed to be an interesting product for the treatment of superficial burns. In a prospective intra-individual study the healing of superficial burns was evaluated after the treatment with Dressilk ® and Biobrane ® in 30 patients with burns of the hand and face. During wound healing pain, active bleeding, exudation, dressing change and inflammation were evaluated using the Verbal Rating Scale 1-10. Three months later scar appearance was assessed by VSS (Vancouver Scar Scale) and POSAS (Patient and Observer Scar Scale). With regard to re-epithelialization, pain, inflammation and acute bleeding both dressings were equivalent. High subjective satisfaction rates were reported for both Dressilk ® and Biobrane ® dressings in regard to comfort and mobility of the face. Biobrane ® , applied as a glove was subjectively preferred for burns of the hand. Regarding their cost efficiency Dressilk ® was clearly superior to Biobrane ® . Long-term results were similar. The "ideal" wound dressing maximizes patients' comfort while reducing pain and promoting wound healing. Dressilk ® and Biobrane ® both provided an effective and safe healing environment, showing low overall complication rates with respect to infection and exudation on superficial burns of the hand and face. Therefore Dressilk ® , being clearly superior to Biobrane ® in cost efficiency is an interesting alternative especially for the treatment of superficial burns of faces. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  11. Exact monitoring of aortic diameters in Marfan patients without gadolinium contrast: intraindividual comparison of 2D SSFP imaging with 3D CE-MRA and echocardiography

    International Nuclear Information System (INIS)

    Veldhoen, Simon; Behzadi, Cyrus; Derlin, Thorsten; Henes, Frank Oliver; Adam, Gerhard; Bannas, Peter; Rybczinsky, Meike; Kodolitsch, Yskert von; Sheikhzadeh, Sara; Bley, Thorsten Alexander

    2015-01-01

    To assess whether ECG-gated non-contrast 2D steady-state free precession (SSFP) imaging allows for exact monitoring of aortic diameters in Marfan syndrome (MFS) patients using non-ECG-gated contrast-enhanced 3D magnetic resonance angiography (CE-MRA) and echocardiography for intraindividual comparison. Non-ECG-gated CE-MRA and ECG-gated non-contrast SSFP at 1.5 T were prospectively performed in 50 patients. Two readers measured aortic diameters on para-sagittal images identically aligned with the aortic arch at the sinuses of Valsalva, sinotubular junction, ascending/descending aorta and aortic arch. Image quality was assessed on a three-point scale. Aortic root diameters acquired by echocardiography were used as reference. Intra- and interobserver variances were smaller for SSFP at the sinuses of Valsalva (p = 0.002; p = 0.002) and sinotubular junction (p = 0.014; p = 0.043). Image quality was better in SSFP than in CE-MRA at the sinuses of Valsalva (p < 0.0001), sinotubular junction (p < 0.0001) and ascending aorta (p = 0.02). CE-MRA yielded higher diameters than SSFP at the sinuses of Valsalva (mean bias, 2.5 mm; p < 0.0001), and comparison with echocardiography confirmed a higher bias for CE-MRA (7.2 ± 3.4 mm vs. SSFP, 4.7 ± 2.6 mm). ECG-gated non-contrast 2D SSFP imaging provides superior image quality with higher validity compared to non-ECG-gated contrast-enhanced 3D imaging. Since CE-MRA requires contrast agents with potential adverse effects, non-contrast SSFP imaging is an appropriate alternative for exact and riskless aortic monitoring of MFS patients. (orig.)

  12. Exact monitoring of aortic diameters in Marfan patients without gadolinium contrast: intraindividual comparison of 2D SSFP imaging with 3D CE-MRA and echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Simon [University Medical Center Wuerzburg, Department of Diagnostic and Interventional Radiology, Bavaria (Germany); University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Behzadi, Cyrus; Derlin, Thorsten; Henes, Frank Oliver; Adam, Gerhard; Bannas, Peter [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Rybczinsky, Meike; Kodolitsch, Yskert von; Sheikhzadeh, Sara [University Medical Center Hamburg-Eppendorf, Department of General and Interventional Cardiology, Hamburg (Germany); Bley, Thorsten Alexander [University Medical Center Wuerzburg, Department of Diagnostic and Interventional Radiology, Bavaria (Germany)

    2014-10-15

    To assess whether ECG-gated non-contrast 2D steady-state free precession (SSFP) imaging allows for exact monitoring of aortic diameters in Marfan syndrome (MFS) patients using non-ECG-gated contrast-enhanced 3D magnetic resonance angiography (CE-MRA) and echocardiography for intraindividual comparison. Non-ECG-gated CE-MRA and ECG-gated non-contrast SSFP at 1.5 T were prospectively performed in 50 patients. Two readers measured aortic diameters on para-sagittal images identically aligned with the aortic arch at the sinuses of Valsalva, sinotubular junction, ascending/descending aorta and aortic arch. Image quality was assessed on a three-point scale. Aortic root diameters acquired by echocardiography were used as reference. Intra- and interobserver variances were smaller for SSFP at the sinuses of Valsalva (p = 0.002; p = 0.002) and sinotubular junction (p = 0.014; p = 0.043). Image quality was better in SSFP than in CE-MRA at the sinuses of Valsalva (p < 0.0001), sinotubular junction (p < 0.0001) and ascending aorta (p = 0.02). CE-MRA yielded higher diameters than SSFP at the sinuses of Valsalva (mean bias, 2.5 mm; p < 0.0001), and comparison with echocardiography confirmed a higher bias for CE-MRA (7.2 ± 3.4 mm vs. SSFP, 4.7 ± 2.6 mm). ECG-gated non-contrast 2D SSFP imaging provides superior image quality with higher validity compared to non-ECG-gated contrast-enhanced 3D imaging. Since CE-MRA requires contrast agents with potential adverse effects, non-contrast SSFP imaging is an appropriate alternative for exact and riskless aortic monitoring of MFS patients. (orig.)

  13. Evening cortisol is associated with intra-individual instability in daytime napping in nursing home residents with dementia: an allostatic load perspective.

    Science.gov (United States)

    Woods, Diana Lynn; Yefimova, Maria

    2012-10-01

    Circadian rhythm disruption, reflected in alterations in sleep-wake activity and daytime napping behavior, is consistently reported in nursing home (NH) residents with dementia. This disruption may be reflected in day-to-day instability. The concept of allostatic load (AL), a measure of cumulative biological burden over a lifetime, may be a helpful model for understanding cortisol diurnal rhythm and daytime napping activity in this population. The purpose of this study was to examine the association between intra-individual daytime napping episodes and basal cortisol diurnal rhythm in NH residents with dementia in the context of AL. U sing a within-individual longitudinal design (N = 51), the authors observed and recorded daytime napping activity every 20 min for 10 hr per day across 4 consecutive days. The authors obtained saliva samples 4 times each day (upon participants' waking and within 1 hr, 6 hr, and 12 hr of participants' wake time) for cortisol analysis. The authors categorized participants as high changers (HCs; day-to-day instability in napping activity) or low changers (LCs; day-to-day stability). There were no significant differences in resident characteristics between groups. There was a significant difference between HCs and LCs in napping episodes (F = 4.86, p = .03), with an interaction effect of evening cortisol on napping episodes in the HC group (F = 10.161, p = .001). NH residents with unstable day-to-day napping episodes are more responsive to alterations in evening cortisol, an index of a dysregulated hypothalamic-pituitary-adrenal (HPA) axis. They may also be more amenable to environmental intervention, an avenue for further research.

  14. Randomized double-blinded placebo-controlled intra-individual trial on topical treatment with a 1,25-dihydroxyvitamin D₃ analogue in polymorphic light eruption.

    Science.gov (United States)

    Gruber-Wackernagel, A; Bambach, I; Legat, F J; Hofer, A; Byrne, S N; Quehenberger, F; Wolf, P

    2011-07-01

    Polymorphic light eruption (PLE) is a very frequent photodermatosis whose pathogenesis may involve resistance to ultraviolet (UV)-induced immune suppression. Similar to UV radiation, calcitriol (1,25-dihydroxyvitamin D₃) and its analogues such as calcipotriol have been shown to exhibit immunosuppressive properties. We performed a randomized double-blinded placebo-controlled intraindividual half-body trial (NCT00871052) to investigate the preventive effect of a calcipotriol-containing cream in PLE. Thirteen patients with PLE (10 women, three men; mean age 37 years) pretreated their skin on two symmetrically located test fields with calcipotriol or placebo cream twice daily for 7 days before the start of photoprovocation testing with solar-simulated UV radiation. We established a specific PLE test score [AA + SI + 0·4 P (range 0-12), where AA is affected area score (range 0-4), SI is skin infiltration score (range 0-4) and P is pruritus score on a visual analogue scale (range 0-10)] to quantify PLE severity. Photoprovocation led to PLE lesions in 12/13 (92%) patients. As shown by the PLE test score, compared with placebo calcipotrial pretreatment significantly reduced PLE symptoms in average by 32% (95% confidence interval 21-44%; P = 0·0022, exact Wilcoxon signed-rank test) throughout the observation period starting at 48 h until 144 h after the first photoprovocation exposure. At 48, 72 and 144 h calcipotriol pretreatment resulted in a lower PLE test score in 7 (58%), 9 (75%) and 10 (83%) of the 12 cases, respectively. Considering all time points together, calcipotriol diminished the PLE test score in all 12 photoprovocable patients (P = 0·0005; Wilcoxon signed-rank test). These results suggest a potential therapeutic benefit of topical 1,25-dihydroxyvitamin D₃ analogues as prophylactic treatment in patients with PLE. © 2011 The Authors. BJD © 2011 British Association of Dermatologists 2011.

  15. Reconciling the Log-Linear and Non-Log-Linear Nature of the TSH-Free T4 Relationship: Intra-Individual Analysis of a Large Population.

    Science.gov (United States)

    Rothacker, Karen M; Brown, Suzanne J; Hadlow, Narelle C; Wardrop, Robert; Walsh, John P

    2016-03-01

    The TSH-T4 relationship was thought to be inverse log-linear, but recent cross-sectional studies report a complex, nonlinear relationship; large, intra-individual studies are lacking. Our objective was to analyze the TSH-free T4 relationship within individuals. We analyzed data from 13 379 patients, each with six or more TSH/free T4 measurements and at least a 5-fold difference between individual median TSH and minimum or maximum TSH. Linear and nonlinear regression models of log TSH on free T4 were fitted to data from individuals and goodness of fit compared by likelihood ratio testing. Comparing all models, the linear model achieved best fit in 31% of individuals, followed by quartic (27%), cubic (15%), null (12%), and quadratic (11%) models. After eliminating least favored models (with individuals reassigned to best fitting, available models), the linear model fit best in 42% of participants, quartic in 43%, and null model in 15%. As the number of observations per individual increased, so did the proportion of individuals in whom the linear model achieved best fit, to 66% in those with more than 20 observations. When linear models were applied to all individuals and averaged according to individual median free T4 values, variations in slope and intercept indicated a nonlinear log TSH-free T4 relationship across the population. The log TSH-free T4 relationship appears linear in some individuals and nonlinear in others, but is predominantly linear in those with the largest number of observations. A log-linear relationship within individuals can be reconciled with a non-log-linear relationship in a population.

  16. Pharmacokinetic variability of long-acting stimulants in the treatment of children and adults with attention-deficit hyperactivity disorder.

    Science.gov (United States)

    Ermer, James C; Adeyi, Ben A; Pucci, Michael L

    2010-12-01

    Methylphenidate- and amfetamine-based stimulants are first-line pharmacotherapies for attention-deficit hyperactivity disorder, a common neurobehavioural disorder in children and adults. A number of long-acting stimulant formulations have been developed with the aim of providing once-daily dosing, employing various means to extend duration of action, including a transdermal delivery system, an osmotic-release oral system, capsules with a mixture of immediate- and delayed-release beads, and prodrug technology. Coefficients of variance of pharmacokinetic measures can estimate the levels of pharmacokinetic variability based on the measurable variance between different individuals receiving the same dose of stimulant (interindividual variability) and within the same individual over multiple administrations (intraindividual variability). Differences in formulation clearly impact pharmacokinetic profiles. Many medications exhibit wide interindividual variability in clinical response. Stimulants with low levels of inter- and intraindividual variability may be better suited to provide consistent levels of medication to patients. The pharmacokinetic profile of stimulants using pH-dependent bead technology can vary depending on food consumption or concomitant administration of medications that alter gastric pH. While delivery of methylphenidate with the transdermal delivery system would be unaffected by gastrointestinal factors, intersubject variability is nonetheless substantial. Unlike the beaded formulations and, to some extent (when considering total exposure) the osmotic-release formulation, systemic exposure to amfetamine with the prodrug stimulant lisdexamfetamine dimesylate appears largely unaffected by such factors, likely owing to its dependence on systemic enzymatic cleavage of the precursor molecule, which occurs primarily in the blood involving red blood cells. The high capacity but as yet unidentified enzymatic system for conversion of lisdexamfetamine

  17. Performance variability is related to change in cognition: evidence from the Victoria Longitudinal Study.

    Science.gov (United States)

    MacDonald, Stuart W S; Hultsch, David F; Dixon, Roger A

    2003-09-01

    Performance variability across repeated task administrations may be an important indicator of age-related cognitive functioning. In the present investigation, the authors examined whether age differences and change in inconsistency were related to 6-year (3 occasion) cognitive change. Inconsistency scores were computed from 4 reaction time tasks performed by 446 older adults (54-89 years). Replicating previous cross-sectional results, greater inconsistency was observed for older participants even after controlling for differences in response speed. New longitudinal results demonstrated (a) associations between inconsistency at baseline measurement and 6-year change in cognitive performance; (b) longitudinal change in inconsistency; and (c) intraindividual covariation between 6-year change in inconsistency and 6-year change in level of cognitive function. These findings support the view that performance variability serves as a marker of cognitive aging.

  18. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  19. Variable stars

    International Nuclear Information System (INIS)

    Feast, M.W.; Wenzel, W.; Fernie, J.D.; Percy, J.R.; Smak, J.; Gascoigne, S.C.B.; Grindley, J.E.; Lovell, B.; Sawyer Hogg, H.B.; Baker, N.; Fitch, W.S.; Rosino, L.; Gursky, H.

    1976-01-01

    A critical review of variable stars is presented. A fairly complete summary of major developments and discoveries during the period 1973-1975 is given. The broad developments and new trends are outlined. Essential problems for future research are identified. (B.R.H. )

  20. Inter- and intra-individual variation in allele-specific DNA methylation and gene expression in children conceived using assisted reproductive technology.

    Directory of Open Access Journals (Sweden)

    Nahid Turan

    2010-07-01

    Full Text Available Epidemiological studies have reported a higher incidence of rare disorders involving imprinted genes among children conceived using assisted reproductive technology (ART, suggesting that ART procedures may be disruptive to imprinted gene methylation patterns. We examined intra- and inter-individual variation in DNA methylation at the differentially methylated regions (DMRs of the IGF2/H19 and IGF2R loci in a population of children conceived in vitro or in vivo. We found substantial variation in allele-specific methylation at both loci in both groups. Aberrant methylation of the maternal IGF2/H19 DMR was more common in the in vitro group, and the overall variance was also significantly greater in the in vitro group. We estimated the number of trophoblast stem cells in each group based on approximation of the variance of the binomial distribution of IGF2/H19 methylation ratios, as well as the distribution of X chromosome inactivation scores in placenta. Both of these independent measures indicated that placentas of the in vitro group were derived from fewer stem cells than the in vivo conceived group. Both IGF2 and H19 mRNAs were significantly lower in placenta from the in vitro group. Although average birth weight was lower in the in vitro group, we found no correlation between birth weight and IGF2 or IGF2R transcript levels or the ratio of IGF2/IGF2R transcript levels. Our results show that in vitro conception is associated with aberrant methylation patterns at the IGF2/H19 locus. However, very little of the inter- or intra-individual variation in H19 or IGF2 mRNA levels can be explained by differences in maternal DMR DNA methylation, in contrast to the expectations of current transcriptional imprinting models. Extraembryonic tissues of embryos cultured in vitro appear to be derived from fewer trophoblast stem cells. It is possible that this developmental difference has an effect on placental and fetal growth.

  1. In-phase and out-of-phase gradient-echo imaging in abdominal studies: intra-individual comparison of three different techniques

    International Nuclear Information System (INIS)

    Ramalho, Miguel; Heredia, Vasco; Campos, Rafael O. P. de; Azevedo, Rafael M.; Semelka, Richard C.; Dale, Brian M.

    2012-01-01

    Background: T1-weighted gradient-echo in-phase and out-of-phase imaging is an essential component of comprehensive abdominal MR exams. It is useful for the study of fat-containing lesions and to identify various disease states related to the presence of fat in the liver. Purpose: To compare three T1-weighted in-phase and out-of-phase (IP/OP) gradient-echo imaging sequences in an intra-individual fashion, and to determine whether advantages exist for each of these sequences for various patient types. Material and Methods: One hundred and eighteen consecutive subjects (74 men, 44 women; mean age 53.9 ± 13.8 years) who had MRI examinations containing all three different IP/OP sequences (two-dimensional spoiled gradient-echo [2D-GRE], three-dimensional gradient-echo [3D-GRE], and magnetization-prepared gradient-recall echo [MP-GRE]) were included. Two different reviewers independently and blindly qualitatively evaluated IP/OP sequences to determine image quality, extent of artifacts, lesion detectability and conspicuity, and subjective grading of liver steatosis for the various sequences. Quantitative analysis was also performed. Qualitative and quantitative data were subjected to statistical analysis. Results: Respiratory ghosting, parallel imaging, and truncation artifacts as well as shading and blurring were more pronounced with 3D-GRE IP/OP imaging. Overall image quality was higher with 2D-GRE (P < 0.05). Detectability of low-fluid content lesions was lower with IP/OP MP-GRE sequences. MP-GRE sequences had the lowest SNRs (P < 0.001). Liver-to-spleen and liver-to-lesion CNRs were significantly lower with 3D-GRE and MP-GR, respectively (P < 0.001). Fat liver indexes showed strongly positive correlation between all sequences. Conclusion: Currently, 2D-GRE remains the best approach for clinical IP/OP imaging. The good image quality of MP-GRE sequences acquired in a free-breathing manner should recommend its use in patients unable to suspend breathing

  2. Patient Satisfaction After Femoral Arterial Access Site Closure Using the ExoSeal® Vascular Closure Device Compared to Manual Compression: A Prospective Intra-individual Comparative Study

    International Nuclear Information System (INIS)

    Pieper, Claus Christian; Thomas, Daniel; Nadal, Jennifer; Willinek, Winfried A.; Schild, Hans Heinz; Meyer, Carsten

    2016-01-01

    PurposeTo intra-individually compare discomfort levels and patient satisfaction after arterial access closure using the ExoSeal ® vascular closure device (VCD) and manual compression (MC) in a prospective study design.MethodsPatients undergoing two planned interventions from 07/2013 to 09/2014 could participate in the study. Access closure was performed with an ExoSeal ® -VCD in one and MC in the other intervention. Patients were clinically and sonographically examined and were given questionnaires 1 day after intervention [groin- and back-pain during bedrest (100-point visual analog scale; 0: no pain); comfortability of bedrest (10-point Likert scale, 1: comfortable), satisfaction with closure (10-point Likert scale, 1: very satisfied)]. Results were analyzed in a cross-over design.Results48 patients (29 male, median age 62.5 (32–88) years) were included. An ExoSeal ® -VCD was used first in 25 cases. As four of these subsequently refused MC as second intervention, data from 44 patients could be analyzed. All closures were technically successful (successful device deployment) without major complications. Groin- and back-pain after VCD-use/MC was 0 (0–15) vs. 10 (0–80) and 0 (0–75) vs. 25 (0–90), respectively (p < 0.0001). Bedrest after VCD-use was more comfortable than after MC [1 (range 1–7) vs. 6 (2–10); p < 0.0001]. Satisfaction with the closure procedure and with the intervention in general was higher after VCD-use compared to MC [1 (1–3) vs. 5 (2–10) and 1 (1–2) vs. 2 (1–4), respectively; p < 0.0001].ConclusionIntra-individual comparison showed pain levels and discomfort to be significantly lower after ExoSeal ® use compared to MC. VCD closure was associated with higher satisfaction both with the closure itself and with the intervention in general

  3. Intra-individual comparison of CAIPIRINHA VIBE technique with conventional VIBE sequences in contrast-enhanced MRI of focal liver lesions

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, M.H., E-mail: MoritzAlbrecht@gmx.net [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Bodelle, B., E-mail: boris.bodelle@kgu.de [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Varga-Szemes, A., E-mail: vargaasz@musc.edu [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Dewes, P., E-mail: patricia.dewes@kgu.de [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Bucher, A.M., E-mail: andreas.bucher@kgu.de [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Ball, B.D., E-mail: BallBr@musc.edu [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); De Cecco, C.N., E-mail: dececco@musc.edu [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U.J., E-mail: schoepf@musc.edu [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Zhu, X., E-mail: zhuxun@shzu.edu.cn [Shihezi University, Department of Psychology, Beisi Road, Xinjiang (China); Zangos, S., E-mail: Zangos@em.uni-frankfurt.de [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Gruber-Rouh, T., E-mail: tatjanagruber2004@yahoo.de [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Wichmann, J.L., E-mail: dochwichmann@gmail.com [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); and others

    2017-01-15

    Purpose: To evaluate the impact of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) volume interpolated breath-hold examination (VIBE) magnetic resonance imaging (MRI) technique on image quality, reader confidence, and inter-observer agreement for the assessment of focal liver lesions in comparison with the standard VIBE approach. Material and methods: In this IRB-approved intra-individual comparison study, abdominal arterial and portal-venous contrast-enhanced MRI studies were retrospectively analyzed in 38 patients with malignant liver lesions. Each patient underwent both CAIPIRINHA and conventional VIBE 3 T MRI within 3 months, showing stable disease. Images were evaluated using 5-point rating scales by two blinded radiologists with more than 20 and 5 years of experience in MRI, respectively. Readers scored dignity of liver lesions and assessed which liver segments were affected by malignancy (ranging from 1 = definitely benign/not affected to 5 = definitely malignant/affected by malignancy). Readers also rated overall image quality, sharpness of intrahepatic veins, and diagnostic confidence (ranging from 1 = poor to 5 = excellent). Results: Reviewers achieved a higher inter-observer reliability using CAIPIRINHA when they reported which liver segments were affected by malignancy compared to traditional VIBE series (κ = 0.62 and 0.54, respectively, p < 0.05). Similarly, CAIPIRINHA showed a slightly higher inter-rater agreement for the dignity of focal liver lesions versus the standard VIBE images (κ = 0.50 and 0.49, respectively, p < 0.05). CAIPIRINHA series also scored higher in comparison to standard VIBE sequences (mean scores: image quality, 4.2 and 3.5; sharpness of intrahepatic vessels, 3.8 and 3.2, respectively, p < 0.05) for both reviewers and allowed for higher subjective diagnostic confidence (ratings, 3.8 and 3.2, respectively, p < 0.05). Conclusion: Compared to the standard VIBE approach, CAIPIRINHA VIBE technique

  4. In-phase and out-of-phase gradient-echo imaging in abdominal studies: intra-individual comparison of three different techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ramalho, Miguel; Heredia, Vasco; Campos, Rafael O. P. de; Azevedo, Rafael M.; Semelka, Richard C. (Dept. of Radiology, Univ. of North Carolina at Chapel Hill (United States)); Dale, Brian M. (Siemens Medical Systems, Morrisville (United States)), email: richsem@med.unc.edu

    2012-05-15

    Background: T1-weighted gradient-echo in-phase and out-of-phase imaging is an essential component of comprehensive abdominal MR exams. It is useful for the study of fat-containing lesions and to identify various disease states related to the presence of fat in the liver. Purpose: To compare three T1-weighted in-phase and out-of-phase (IP/OP) gradient-echo imaging sequences in an intra-individual fashion, and to determine whether advantages exist for each of these sequences for various patient types. Material and Methods: One hundred and eighteen consecutive subjects (74 men, 44 women; mean age 53.9 +- 13.8 years) who had MRI examinations containing all three different IP/OP sequences (two-dimensional spoiled gradient-echo [2D-GRE], three-dimensional gradient-echo [3D-GRE], and magnetization-prepared gradient-recall echo [MP-GRE]) were included. Two different reviewers independently and blindly qualitatively evaluated IP/OP sequences to determine image quality, extent of artifacts, lesion detectability and conspicuity, and subjective grading of liver steatosis for the various sequences. Quantitative analysis was also performed. Qualitative and quantitative data were subjected to statistical analysis. Results: Respiratory ghosting, parallel imaging, and truncation artifacts as well as shading and blurring were more pronounced with 3D-GRE IP/OP imaging. Overall image quality was higher with 2D-GRE (P < 0.05). Detectability of low-fluid content lesions was lower with IP/OP MP-GRE sequences. MP-GRE sequences had the lowest SNRs (P < 0.001). Liver-to-spleen and liver-to-lesion CNRs were significantly lower with 3D-GRE and MP-GR, respectively (P < 0.001). Fat liver indexes showed strongly positive correlation between all sequences. Conclusion: Currently, 2D-GRE remains the best approach for clinical IP/OP imaging. The good image quality of MP-GRE sequences acquired in a free-breathing manner should recommend its use in patients unable to suspend breathing

  5. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress.

    Science.gov (United States)

    Wawrzyniak, Andrew J; Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-05-01

    Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. © 2016 The Authors. Psychophysiology published by Wiley Periodicals, Inc. on behalf of Society for Psychophysiological Research.

  6. Image Quality of 3rd Generation Spiral Cranial Dual-Source CT in Combination with an Advanced Model Iterative Reconstruction Technique: A Prospective Intra-Individual Comparison Study to Standard Sequential Cranial CT Using Identical Radiation Dose.

    Science.gov (United States)

    Wenz, Holger; Maros, Máté E; Meyer, Mathias; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O; Flohr, Thomas; Leidecker, Christianne; Groden, Christoph; Scharf, Johann; Henzler, Thomas

    2015-01-01

    To prospectively intra-individually compare image quality of a 3rd generation Dual-Source-CT (DSCT) spiral cranial CT (cCT) to a sequential 4-slice Multi-Slice-CT (MSCT) while maintaining identical intra-individual radiation dose levels. 35 patients, who had a non-contrast enhanced sequential cCT examination on a 4-slice MDCT within the past 12 months, underwent a spiral cCT scan on a 3rd generation DSCT. CTDIvol identical to initial 4-slice MDCT was applied. Data was reconstructed using filtered backward projection (FBP) and 3rd-generation iterative reconstruction (IR) algorithm at 5 different IR strength levels. Two neuroradiologists independently evaluated subjective image quality using a 4-point Likert-scale and objective image quality was assessed in white matter and nucleus caudatus with signal-to-noise ratios (SNR) being subsequently calculated. Subjective image quality of all spiral cCT datasets was rated significantly higher compared to the 4-slice MDCT sequential acquisitions (pspiral compared to sequential cCT datasets with mean SNR improvement of 61.65% (p*Bonferroni0.05spiral cCT with an advanced model IR technique significantly improves subjective and objective image quality compared to a standard sequential cCT acquisition acquired at identical dose levels.

  7. Variability of gastric emptying time using standardized radiolabeled meals

    International Nuclear Information System (INIS)

    Christian, P.E.; Brophy, C.M.; Egger, M.J.; Taylor, A.; Moore, J.G.

    1984-01-01

    To define the range of inter- and intra-subject variability on gastric emptying measurements, eight healthy male subjects (ages 19-40) received meals on four separate occasions. The meal consisted of 150 g of beef stew labeled with Tc-99m SC labeled liver (600 μCi) and 150 g of orange juice containing In-111 DTPA (100 μCi) as the solid- and liquid-phase markers respectively. Images of the solid and liquid phases were obtained at 20 min intervals immediately after meal ingestion. The stomach region was selected from digital images and data were corrected for radionuclide interference, radioactive decay and the geometric mean of anterior and posterior counts. More absolute variability was seen with the solid than the liquid marker emptying for the group. The mean solid half-emptying time was 58 +- 17 min (range 29-92) while the mean liquid half-emptying time was 24 +- 8 min (range 12-37). A nested random effects analysis of variance showed moderate intra-subject variability for solid half-emptying times (rho = 0.4594), and high intra-subject variability was implied by a low correlation (rho = 0.2084) for liquid half-emptying. The average inter-subject differences were 58.3% of the total variance for solids (rho = 0.0017). For liquids, the inter-subject variability was 69.1% of the total variance, but was only suggestive of statistical significance (rho = 0.0666). The normal half emptying time for gastric emptying of liquids and solids is a variable phenomenon in healthy subjects and has great inter- and intra-individual day-to-day differences

  8. Variability of gastric emptying time using standardized radiolabeled meals

    Energy Technology Data Exchange (ETDEWEB)

    Christian, P.E.; Brophy, C.M.; Egger, M.J.; Taylor, A.; Moore, J.G.

    1984-01-01

    To define the range of inter- and intra-subject variability on gastric emptying measurements, eight healthy male subjects (ages 19-40) received meals on four separate occasions. The meal consisted of 150 g of beef stew labeled with Tc-99m SC labeled liver (600 ..mu..Ci) and 150 g of orange juice containing In-111 DTPA (100 ..mu..Ci) as the solid- and liquid-phase markers respectively. Images of the solid and liquid phases were obtained at 20 min intervals immediately after meal ingestion. The stomach region was selected from digital images and data were corrected for radionuclide interference, radioactive decay and the geometric mean of anterior and posterior counts. More absolute variability was seen with the solid than the liquid marker emptying for the group. The mean solid half-emptying time was 58 +- 17 min (range 29-92) while the mean liquid half-emptying time was 24 +- 8 min (range 12-37). A nested random effects analysis of variance showed moderate intra-subject variability for solid half-emptying times (rho = 0.4594), and high intra-subject variability was implied by a low correlation (rho = 0.2084) for liquid half-emptying. The average inter-subject differences were 58.3% of the total variance for solids (rho = 0.0017). For liquids, the inter-subject variability was 69.1% of the total variance, but was only suggestive of statistical significance (rho = 0.0666). The normal half emptying time for gastric emptying of liquids and solids is a variable phenomenon in healthy subjects and has great inter- and intra-individual day-to-day differences.

  9. Fatigue shifts and scatters heart rate variability in elite endurance athletes.

    Directory of Open Access Journals (Sweden)

    Laurent Schmitt

    Full Text Available PURPOSE: This longitudinal study aimed at comparing heart rate variability (HRV in elite athletes identified either in 'fatigue' or in 'no-fatigue' state in 'real life' conditions. METHODS: 57 elite Nordic-skiers were surveyed over 4 years. R-R intervals were recorded supine (SU and standing (ST. A fatigue state was quoted with a validated questionnaire. A multilevel linear regression model was used to analyze relationships between heart rate (HR and HRV descriptors [total spectral power (TP, power in low (LF and high frequency (HF ranges expressed in ms(2 and normalized units (nu] and the status without and with fatigue. The variables not distributed normally were transformed by taking their common logarithm (log10. RESULTS: 172 trials were identified as in a 'fatigue' and 891 as in 'no-fatigue' state. All supine HR and HRV parameters (Beta±SE were significantly different (P<0.0001 between 'fatigue' and 'no-fatigue': HRSU (+6.27±0.61 bpm, logTPSU (-0.36±0.04, logLFSU (-0.27±0.04, logHFSU (-0.46±0.05, logLF/HFSU (+0.19±0.03, HFSU(nu (-9.55±1.33. Differences were also significant (P<0.0001 in standing: HRST (+8.83±0.89, logTPST (-0.28±0.03, logLFST (-0.29±0.03, logHFST (-0.32±0.04. Also, intra-individual variance of HRV parameters was larger (P<0.05 in the 'fatigue' state (logTPSU: 0.26 vs. 0.07, logLFSU: 0.28 vs. 0.11, logHFSU: 0.32 vs. 0.08, logTPST: 0.13 vs. 0.07, logLFST: 0.16 vs. 0.07, logHFST: 0.25 vs. 0.14. CONCLUSION: HRV was significantly lower in 'fatigue' vs. 'no-fatigue' but accompanied with larger intra-individual variance of HRV parameters in 'fatigue'. The broader intra-individual variance of HRV parameters might encompass different changes from no-fatigue state, possibly reflecting different fatigue-induced alterations of HRV pattern.

  10. Authoring Tools

    Science.gov (United States)

    Treviranus, Jutta

    Authoring tools that are accessible and that enable authors to produce accessible Web content play a critical role in web accessibility. Widespread use of authoring tools that comply to the W3C Authoring Tool Accessibility Guidelines (ATAG) would ensure that even authors who are neither knowledgeable about nor particularly motivated to produce accessible content do so by default. The principles and techniques of ATAG are discussed. Some examples of accessible authoring tools are described including authoring tool content management components such as TinyMCE. Considerations for creating an accessible collaborative environment are also covered. As part of providing accessible content, the debate between system-based personal optimization and one universally accessible site configuration is presented. The issues and potential solutions to address the accessibility crisis presented by the advent of rich internet applications are outlined. This challenge must be met to ensure that a large segment of the population is able to participate in the move toward the web as a two-way communication mechanism.

  11. Complex variables

    CERN Document Server

    Flanigan, Francis J

    2010-01-01

    A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion

  12. Tool steels

    DEFF Research Database (Denmark)

    Højerslev, C.

    2001-01-01

    On designing a tool steel, its composition and heat treatment parameters are chosen to provide a hardened and tempered martensitic matrix in which carbides are evenly distributed. In this condition the matrix has an optimum combination of hardness andtoughness, the primary carbides provide...... resistance against abrasive wear and secondary carbides (if any) increase the resistance against plastic deformation. Tool steels are alloyed with carbide forming elements (Typically: vanadium, tungsten, molybdenumand chromium) furthermore some steel types contains cobalt. Addition of alloying elements...... serves primarily two purpose (i) to improve the hardenabillity and (ii) to provide harder and thermally more stable carbides than cementite. Assuming proper heattreatment, the properties of a tool steel depends on the which alloying elements are added and their respective concentrations....

  13. Management Tools

    Science.gov (United States)

    1987-01-01

    Manugistics, Inc. (formerly AVYX, Inc.) has introduced a new programming language for IBM and IBM compatible computers called TREES-pls. It is a resource management tool originating from the space shuttle, that can be used in such applications as scheduling, resource allocation project control, information management, and artificial intelligence. Manugistics, Inc. was looking for a flexible tool that can be applied to many problems with minimal adaptation. Among the non-government markets are aerospace, other manufacturing, transportation, health care, food and beverage and professional services.

  14. Design tools

    Science.gov (United States)

    Anton TenWolde; Mark T. Bomberg

    2009-01-01

    Overall, despite the lack of exact input data, the use of design tools, including models, is much superior to the simple following of rules of thumbs, and a moisture analysis should be standard procedure for any building envelope design. Exceptions can only be made for buildings in the same climate, similar occupancy, and similar envelope construction. This chapter...

  15. Determining anthropometric variables as a tool in the preparation of furniture and designs of interior spaces: the case of children 6 to 11 years old of Vicosa, State of Minas Gerais, Brazil.

    Science.gov (United States)

    Zanuncio, Sharinna Venturim; Mafra, Simone Caldas Tavares; Antônio, Carlos Emílio Barbosa; Filho, Jugurta Lisboa; Vidigal Guimarães, Elza Maria; da Silva, Vania Eugênia; de Souza, Amaury Paulo; Minette, Luciano José

    2012-01-01

    The adequacy of facilities and the individual securities in their different age groups is importance to ensure greater functionality to them, allowing full development of daily activities. For this to occur more efficiently it is necessary the use of ergonomics which can ensure more comfort and safety for end users of products and spaces. The present study aimed to measure body dimensions of a representative sample of children aged 6 to 11 years old, children of graduate and pos graduate students, faculty and staff of the Federal University of Vicosa and also residents of the city of Vicosa, State of Minas Gerais, Brazil, coming from different municipalities of State of Minas Gerais, to organize a database that will provide the furniture industry, anthropometric variables more appropriate to design products for both the leisure activities, and for the school sector. To realize this research we used the methodology proposed by the authors Panero and Zelnik, based on samples distributed in six age groups, and providing a measurement of 10 variables. By applying the methodology to the field was possible to compare the observed data, with the tables of the aforementioned authors. The main results revealed a significant variation of the 10 variables analyzed, and it is believed that this variation could lead to possible flaws in the designs of products that use the data from these authors. The completion of the study provided data on Vicosa considered more appropriate for the design of products and environments for the population of the study, considering age and region, of Brazil (State of Minas Gerais) and it is believed that the future may expand to the Brazilian population, with the progress of study of this nature.

  16. Visualization of Variation and Variability

    NARCIS (Netherlands)

    Busking, S.

    2014-01-01

    As datasets grow in size and complexity, the importance of comparison as a tool for analysis is growing. We define comparison as the act of analyzing variation or variability based on two or more specific instances of the data. This thesis explores a number of cases spread across the range of

  17. Variable collimator

    International Nuclear Information System (INIS)

    Richey, J.B.; McBride, T.R.; Covic, J.

    1979-01-01

    This invention describes an automatic variable collimator which controls the width and thickness of X-ray beams in X-ray diagnostic medical equipment, and which is particularly adapted for use with computerized axial tomographic scanners. A two-part collimator is provided which shapes an X-ray beam both prior to its entering an object subject to radiographic analysis and after the attenuated beam has passed through the object. Interposed between a source of radiation and the object subject to radiographic analysis is a first or source collimator. The source collimator causes the X-ray beam emitted by the source of radiation to be split into a plurality of generally rectangular shaped beams. Disposed within the source collimator is a movable aperture plate which may be used to selectively vary the thickness of the plurality of generally rectangular shaped beams transmitted through the source collimator. A second or receiver collimator is interposed between the object subject to radiographic analysis and a series of radiation detectors. The receiver collimator is disposed to receive the attenuated X-ray beams passing through the object subject to radiographic analysis. Located within the receiver collimator are a plurality of movable aperture plates adapted to be displaced relative to a plurality of fixed aperture plates for the purpose of varying the width and thickness of the attenuated X-ray beams transmitted through the object subject to radiographic analysis. The movable aperture plates of the source and receiver collimators are automatically controlled by circuitry which is provided to allow remote operation of the movable aperture plates

  18. Psychobiological Factors Affecting Cortisol Variability in Human-Dog Dyads.

    Directory of Open Access Journals (Sweden)

    Iris Schöberl

    Full Text Available Stress responses within dyads are modulated by interactions such as mutual emotional support and conflict. We investigated dyadic psychobiological factors influencing intra-individual cortisol variability in response to different challenging situations by testing 132 owners and their dogs in a laboratory setting. Salivary cortisol was measured and questionnaires were used to assess owner and dog personality as well as owners' social attitudes towards the dog and towards other humans. We calculated the individual coefficient of variance of cortisol (iCV = sd/mean*100 over the different test situations as a parameter representing individual variability of cortisol concentration. We hypothesized that high cortisol variability indicates efficient and adaptive coping and a balanced individual and dyadic social performance. Female owners of male dogs had lower iCV than all other owner gender-dog sex combinations (F = 14.194, p<0.001, whereas owner Agreeableness (NEO-FFI scaled positively with owner iCV (F = 4.981, p = 0.028. Dogs of owners high in Neuroticism (NEO-FFI and of owners who were insecure-ambivalently attached to their dogs (FERT, had low iCV (F = 4.290, p = 0.041 and F = 5.948, p = 0.016, as had dogs of owners with human-directed separation anxiety (RSQ or dogs of owners with a strong desire of independence (RSQ (F = 7.661, p = 0.007 and F = 9.192, p = 0.003. We suggest that both owner and dog social characteristics influence dyadic cortisol variability, with the human partner being more influential than the dog. Our results support systemic approaches (i.e. considering the social context in science and in counselling.

  19. FDG-PET-based radiotherapy planning in lung cancer. Optimum breathing protocol and patient positioning - an intraindividual comparison; FDG-PET-basierte Bestrahlungsplanung von nicht kleinzelligen Bronchialkarzinomen. Optimales Atemprotokoll und Patientenpositionierung - ein intraindividueller Vergleich

    Energy Technology Data Exchange (ETDEWEB)

    Grgic, A.; Schaefer-Schuler, A.; Kirsch, C.M.; Hellwig, D. [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Nuklearmedizin; Nestle, U. [Universitaetsklinikum Freiburg (Germany). Klinik fuer Strahlenheilkunde; Kremp, S. [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Strahlentherapie und Radioonkologie

    2008-12-15

    FDG-PET and PET / CT is increasingly used for radiotherapy (RT) planning in non-small-cell lung carcinoma (NSCLC). The planning process is often based on separately-acquired FDG-PET / CT and planning CT. We compared intraindividual differences between PET acquired in diagnostic and radiotherapy treatment position coregistered with planning CTs acquired using different breathing protocols. Sixteen patients with NSCLC underwent two PET acquisitions (diagnostic position-D-PET, radiotherapy position-RT-PET) and three planning-CT acquisitions (expiration-EXP, inspiration-INS, mid-breathhold-MID) on the same day. All scans were rigidly coregistered resulting in six fused datasets: D-INS, D-EXP, D-MID, RT-INS, RT-EXP and RT-MID. Fusion accuracy was assessed by three readers at eight anatomical landmarks: lung apices, aortic arch, heart, spine, sternum, carina, diaphragm and tumor using an alignment score ranging from 1 (no alignment) to 5 (exact alignment). RT-PET showed better alignment with any CT than D-PET (p < 0.001). With regard to breathing, RT-MID showed the best mean alignment score (3.7 {+-} 1.0) followed by RT-EXP (3.5 {+-} 0.9) and RT-INS (3.0 {+-} 0.8), all differences being significant (p < 0.001). Comparing the alignment scores with regard to anatomical landmarks, the largest deviations were found at diaphragm, heart and apices. Overall, there was a fair agreement (? = 0.48; p < 0.001) among the three readers. Significantly better fusion of PET and planning-CT can be reached with PET acquired in RT-position. The best intraindividual fusion results are obtained with the planning-CT performed during mid-breathhold. Our data justify the acquisition of a separate planning-PET in RT-treatment position if only a diagnostic PET-scan is available. (orig.)

  20. Longitudinal intra- and inter-individual variability in young swimmers' performance and determinant competition factors

    Directory of Open Access Journals (Sweden)

    Jorge Estrela Morais

    2014-09-01

    Full Text Available The main purpose of this study was to follow-up the intra- and inter-individual variability of young swimmers' performance and determinant factors over two competitive seasons. Thirty young swimmers (14 boys: 12.33±0.65 years-old; 16 girls: 11.15±0.55 years-old were followed-up throughout two consecutive seasons (seven evaluation moments. Performance (100m freestyle, anthropometric, kinematic, hydrodynamic and efficiency features were evaluated. A gender and skill-level effect was observed. Boys improved in a higher amount (% comparing to girls. Overall, swimmers in skill-level 2 (both genders presented a higher intra-individual variability. Performance and anthropometrics showed a significant inter-individual variability in most moments, but hydrodynamics, kinematics and efficiency did not. Within each skill-level hydrodynamics, kinematics and efficiency were the variables that showed a high inter-individual variability. As a gender and skill-level effect was noticed in an age-group of young swimmers, coaches and practitioners should put the focus in specific and customized training plans for each skill-level of swimmers.

  1. Continuous performance task in ADHD: Is reaction time variability a key measure?

    Science.gov (United States)

    Levy, Florence; Pipingas, Andrew; Harris, Elizabeth V; Farrow, Maree; Silberstein, Richard B

    2018-01-01

    To compare the use of the Continuous Performance Task (CPT) reaction time variability (intraindividual variability or standard deviation of reaction time), as a measure of vigilance in attention-deficit hyperactivity disorder (ADHD), and stimulant medication response, utilizing a simple CPT X-task vs an A-X-task. Comparative analyses of two separate X-task vs A-X-task data sets, and subgroup analyses of performance on and off medication were conducted. The CPT X-task reaction time variability had a direct relationship to ADHD clinician severity ratings, unlike the CPT A-X-task. Variability in X-task performance was reduced by medication compared with the children's unmedicated performance, but this effect did not reach significance. When the coefficient of variation was applied, severity measures and medication response were significant for the X-task, but not for the A-X-task. The CPT-X-task is a useful clinical screening test for ADHD and medication response. In particular, reaction time variability is related to default mode interference. The A-X-task is less useful in this regard.

  2. Breath acetone concentration; biological variability and the influence of diet

    International Nuclear Information System (INIS)

    Španěl, Patrik; Dryahina, Kseniya; Rejšková, Alžběta; Chippendale, Thomas W E; Smith, David

    2011-01-01

    Previous measurements of acetone concentrations in the exhaled breath of healthy individuals and the small amount of comparable data for individuals suffering from diabetes are briefly reviewed as a prelude to the presentation of new data on the sporadic and wide variations of breath acetone that occur in ostensibly healthy individuals. Data are also presented which show that following a ketogenic diet taken by eight healthy individuals their breath acetone concentrations increased up to five times over the subsequent 6 h. Similarly, the breath acetone increased six and nine times when a low carbohydrate diet was taken by two volunteers and remained high for the several days for which the diet was continued. These new data, together with the previous data, clearly indicate that diet and natural intra-individual biological and diurnal variability result in wide variations in breath acetone concentration. This places an uncertainty in the use of breath acetone alone to monitor blood glucose and glycaemic control, except and unless the individual acts as their own control and is cognizant of the need for dietary control. (note)

  3. Visit-to-visit cholesterol variability correlates with coronary atheroma progression and clinical outcomes.

    Science.gov (United States)

    Clark, Donald; Nicholls, Stephen J; St John, Julie; Elshazly, Mohamed B; Kapadia, Samir R; Tuzcu, E Murat; Nissen, Steven E; Puri, Rishi

    2018-04-21

    Utilizing serial intravascular ultrasonography (IVUS), we aimed to exam the association of intra-individual lipid variability, coronary atheroma progression, and clinical outcomes. We performed a post hoc patient-level analysis of nine clinical trials involving 4976 patients with coronary artery disease who underwent serial coronary IVUS in the setting of a range of medical therapies. We assessed the associations between progression in percent atheroma volume (ΔPAV), clinical outcomes, and visit-to-visit lipid variability including low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, total cholesterol (TC)/HDL-C, and apolipoprotein B (ApoB). Variability of lipid parameters was measured using intra-individual standard deviation over 3, 6, 12, 18, and 24 months. Atherogenic lipoprotein variability significantly associated with ΔPAV [odds ratio (95% confidence interval; P-value), LDL-C: 1.09 (1.02, 1.17, P = 0.01); non-HDL-C: 1.10 (1.02, 1.18, P = 0.01); TC/HDL-C: 1.14 (1.06, 1.24, P = 0.001); ApoB: 1.13 (1.03, 1.24, P = 0.01)]. Survival curves revealed significant stepwise relationships between cumulative major adverse cardiovascular events and increasing quartiles of atherogenic lipoprotein variability at 24-months follow-up (log-rank P C). Stronger associations were noted between achieved lipoprotein levels and ΔPAV [LDL-C: 1.27 (1.17, 1.39; P C: 1.32 (1.21, 1.45; P C: 1.31 (1.19, 1.45; P < 0.001); ApoB: 1.20 (1.07, 1.35; P = 0.003)]. Greater visit-to-visit variability in atherogenic lipoprotein levels significantly associates with coronary atheroma progression and clinical outcomes, although the association between achieved atherogenic lipoproteins and atheroma progression appears stronger. These data highlight the importance of achieving low and consistent atherogenic lipoprotein levels to promote plaque regression and improve clinical outcomes.

  4. Platelet-rich plasma differs according to preparation method and human variability.

    Science.gov (United States)

    Mazzocca, Augustus D; McCarthy, Mary Beth R; Chowaniec, David M; Cote, Mark P; Romeo, Anthony A; Bradley, James P; Arciero, Robert A; Beitzel, Knut

    2012-02-15

    Varying concentrations of blood components in platelet-rich plasma preparations may contribute to the variable results seen in recently published clinical studies. The purposes of this investigation were (1) to quantify the level of platelets, growth factors, red blood cells, and white blood cells in so-called one-step (clinically used commercial devices) and two-step separation systems and (2) to determine the influence of three separate blood draws on the resulting components of platelet-rich plasma. Three different platelet-rich plasma (PRP) separation methods (on blood samples from eight subjects with a mean age [and standard deviation] of 31.6 ± 10.9 years) were used: two single-spin processes (PRPLP and PRPHP) and a double-spin process (PRPDS) were evaluated for concentrations of platelets, red and white blood cells, and growth factors. Additionally, the effect of three repetitive blood draws on platelet-rich plasma components was evaluated. The content and concentrations of platelets, white blood cells, and growth factors for each method of separation differed significantly. All separation techniques resulted in a significant increase in platelet concentration compared with native blood. Platelet and white blood-cell concentrations of the PRPHP procedure were significantly higher than platelet and white blood-cell concentrations produced by the so-called single-step PRPLP and the so-called two-step PRPDS procedures, although significant differences between PRPLP and PRPDS were not observed. Comparing the results of the three blood draws with regard to the reliability of platelet number and cell counts, wide variations of intra-individual numbers were observed. Single-step procedures are capable of producing sufficient amounts of platelets for clinical usage. Within the evaluated procedures, platelet numbers and numbers of white blood cells differ significantly. The intra-individual results of platelet-rich plasma separations showed wide variations in

  5. Analysis of the in vivo confocal Raman spectral variability in human skin

    Science.gov (United States)

    Mogilevych, Borys; dos Santos, Laurita; Rangel, Joao L.; Grancianinov, Karen J. S.; Sousa, Mariane P.; Martin, Airton A.

    2015-06-01

    Biochemical composition of the skin changes in each layer and, therefore, the skin spectral profile vary with the depth. In this work, in vivo Confocal Raman spectroscopy studies were performed at different skin regions and depth profile (from the surface down to 10 μm) of the stratum corneum, to verify the variability and reproducibility of the intra- and interindividual Raman data. The Raman spectra were collected from seven healthy female study participants using a confocal Raman system from Rivers Diagnostic, with 785 nm excitation line and a CCD detector. Measurements were performed in the volar forearm region, at three different points at different depth, with the step of 2 μm. For each depth point, three spectra were acquired. Data analysis included the descriptive statistics (mean, standard deviation and residual) and Pearson's correlation coefficient calculation. Our results show that inter-individual variability is higher than intraindividual variability, and variability inside the SC is higher than on the skin surface. In all these cases we obtained r values, higher than 0.94, which correspond to high correlation between Raman spectra. It reinforces the possibility of the data reproducibility and direct comparison of in vivo results obtained with different study participants of the same age group and phototype.

  6. Introducing Product Lines through Open Source Tools

    OpenAIRE

    Haugen, Øystein

    2008-01-01

    We present an approach to introducing product lines to companies that lower their initial risk by applying open source tools and a smooth learning curve into the use and creation of domain specific modeling combined with standardized variability modeling.

  7. Biologic variability and correlation of platelet function testing in healthy dogs.

    Science.gov (United States)

    Blois, Shauna L; Lang, Sean T; Wood, R Darren; Monteith, Gabrielle

    2015-12-01

    Platelet function tests are influenced by biologic variability, including inter-individual (CVG ) and intra-individual (CVI ), as well as analytic (CVA ) variability. Variability in canine platelet function testing is unknown, but if excessive, would make it difficult to interpret serial results. Additionally, the correlation between platelet function tests is poor in people, but not well described in dogs. The aims were to: (1) identify the effect of variation in preanalytic factors (venipuncture, elapsed time until analysis) on platelet function tests; (2) calculate analytic and biologic variability of adenosine diphosphate (ADP) and arachidonic acid (AA)-induced thromboelastograph platelet mapping (TEG-PM), ADP-, AA-, and collagen-induced whole blood platelet aggregometry (WBA), and collagen/ADP and collagen/epinephrine platelet function analysis (PFA-CADP, PFA-CEPI); and (3) determine the correlation between these variables. In this prospective observational trial, platelet function was measured once every 7 days, for 4 consecutive weeks, in 9 healthy dogs. In addition, CBC, TEG-PM, WBA, and PFA were performed. Overall coefficients of variability ranged from 13.3% to 87.8% for the platelet function tests. Biologic variability was highest for AA-induced maximum amplitude generated during TEG-PM (MAAA; CVG = 95.3%, CVI = 60.8%). Use of population-based reference intervals (RI) was determined appropriate only for PFA-CADP (index of individuality = 10.7). There was poor correlation between most platelet function tests. Use of population-based RI appears inappropriate for most platelet function tests, and tests poorly correlate with one another. Future studies on biologic variability and correlation of platelet function tests should be performed in dogs with platelet dysfunction and those treated with antiplatelet therapy. © 2015 American Society for Veterinary Clinical Pathology.

  8. Assessment of metabolic phenotypic variability in children’s urine using 1H NMR spectroscopy

    Science.gov (United States)

    Maitre, Léa; Lau, Chung-Ho E.; Vizcaino, Esther; Robinson, Oliver; Casas, Maribel; Siskos, Alexandros P.; Want, Elizabeth J.; Athersuch, Toby; Slama, Remy; Vrijheid, Martine; Keun, Hector C.; Coen, Muireann

    2017-04-01

    The application of metabolic phenotyping in clinical and epidemiological studies is limited by a poor understanding of inter-individual, intra-individual and temporal variability in metabolic phenotypes. Using 1H NMR spectroscopy we characterised short-term variability in urinary metabolites measured from 20 children aged 8-9 years old. Daily spot morning, night-time and pooled (50:50 morning and night-time) urine samples across six days (18 samples per child) were analysed, and 44 metabolites quantified. Intraclass correlation coefficients (ICC) and mixed effect models were applied to assess the reproducibility and biological variance of metabolic phenotypes. Excellent analytical reproducibility and precision was demonstrated for the 1H NMR spectroscopic platform (median CV 7.2%). Pooled samples captured the best inter-individual variability with an ICC of 0.40 (median). Trimethylamine, N-acetyl neuraminic acid, 3-hydroxyisobutyrate, 3-hydroxybutyrate/3-aminoisobutyrate, tyrosine, valine and 3-hydroxyisovalerate exhibited the highest stability with over 50% of variance specific to the child. The pooled sample was shown to capture the most inter-individual variance in the metabolic phenotype, which is of importance for molecular epidemiology study design. A substantial proportion of the variation in the urinary metabolome of children is specific to the individual, underlining the potential of such data to inform clinical and exposome studies conducted early in life.

  9. Progression paths in children's problem solving: The influence of dynamic testing, initial variability, and working memory.

    Science.gov (United States)

    Resing, Wilma C M; Bakker, Merel; Pronk, Christine M E; Elliott, Julian G

    2017-01-01

    The current study investigated developmental trajectories of analogical reasoning performance of 104 7- and 8-year-old children. We employed a microgenetic research method and multilevel analysis to examine the influence of several background variables and experimental treatment on the children's developmental trajectories. Our participants were divided into two treatment groups: repeated practice alone and repeated practice with training. Each child received an initial working memory assessment and was subsequently asked to solve figural analogies on each of several sessions. We examined children's analogical problem-solving behavior and their subsequent verbal accounts of their employed solving processes. We also investigated the influence of verbal and visual-spatial working memory capacity and initial variability in strategy use on analogical reasoning development. Results indicated that children in both treatment groups improved but that gains were greater for those who had received training. Training also reduced the influence of children's initial variability in the use of analogical strategies with the degree of improvement in reasoning largely unrelated to working memory capacity. Findings from this study demonstrate the value of a microgenetic research method and the use of multilevel analysis to examine inter- and intra-individual change in problem-solving processes. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Tool path in torus tool CNC machining

    Directory of Open Access Journals (Sweden)

    XU Ying

    2016-10-01

    Full Text Available This paper is about tool path in torus tool CNC machining.The mathematical model of torus tool is established.The tool path planning algorithm is determined through calculation of the cutter location,boundary discretization,calculation of adjacent tool path and so on,according to the conversion formula,the cutter contact point will be converted to the cutter location point and then these points fit a toolpath.Lastly,the path planning algorithm is implemented by using Matlab programming.The cutter location points for torus tool are calculated by Matlab,and then fit these points to a toolpath.While using UG software,another tool path of free surface is simulated of the same data.It is drew compared the two tool paths that using torus tool is more efficient.

  11. Estimating variation in stomatal frequency at intra-individual, intra-site, and inter-taxonomic levels in populations of the Leonardoxa africana (Fabaceae) complex over environmental gradients in Cameroon

    Science.gov (United States)

    Finsinger, Walter; Dos Santos, Thibaut; McKey, Doyle

    2013-07-01

    Variation of stomatal frequency (stomatal density and stomatal index) includes genetically-based, potentially-adaptive variation, and variation due to phenotypic plasticity, the degree of which may be fundamental to the ability to maintain high water-use efficiency and thus to deal with environmental change. We analysed stomatal frequency and morphology (pore length, pore width) in leaves from several individuals from nine populations of four sub-species of the Leonardoxa africana complex. The dataset represents a hierarchical sampling wherein factors are nested within each level (leaves in individuals, individuals in sites, etc.), allowing estimation of the contribution of different levels to overall variation, using variance-component analysis. SI showed significant variation among sites ("site" is largely confounded with "sub-species"), being highest in the sub-species localized in the highest-elevation site. However, most of the observed variance was accounted for at intra-site and intra-individual levels. This variance could reflect great phenotypic plasticity, presumably in response to highly local variation in micro-environmental conditions.

  12. An assessment of hair cortisol among postpartum Brazilian mothers and infants from a high-risk community in São Paulo: Intra-individual stability and association in mother-infant dyads.

    Science.gov (United States)

    Liu, Cindy H; Fink, Günther; Brentani, Helena; Brentani, Alexandra

    2017-11-01

    This study examined maternal-infant synchrony of hair cortisol at 12 months after birth and the intra-individual stability of maternal hair cortisol in the postpartum period. Participants were selected from an ongoing São Paulo birth cohort project, where families are considered to be "high-risk" due to their chronic stress experiences, with the majority living in slums (favelas). Cortisol was collected through 3-cm segments of hair samples, with values representing approximate levels of cortisol from 9 to 12 months for mothers and children and 6 to 12 months for mothers. Maternal and infant cortisol values reflecting chronic stress 9-12 months after birth were highly correlated (r = .61, p cortisol levels (6-9 months) and child cortisol levels at 9-12 months (r = .51, p cortisol values showed stability over time (r = .79, p cortisol in other mother-child dyads, suggesting stronger synchrony under high-risk contexts where families are faced with challenging circumstances. © 2017 Wiley Periodicals, Inc.

  13. Bilateral ce-MR angiography of the hands at 3.0 T and 1.5 T: intraindividual comparison of quantitative and qualitative image parameters in healthy volunteers

    International Nuclear Information System (INIS)

    Winterer, Jan T.; Markl, Michael; Frydrychowicz, Alexander; Bley, Thorsten A.; Langer, Mathias; Moske-Eick, Olaf

    2008-01-01

    The purpose of this study was to determine the benefit of bilateral contrast-enhanced MR angiography (ce-MRA) of the hands at 3.0 Tesla (T) compared with an established 1.5-T technique in healthy volunteers. Intraindividual bilateral ce-MRA of the hands was performed at 1.5 T and 3.0 T in 14 healthy volunteers using a timed ultra-fast GRE sequence featuring parallel acquisition. The evaluation comprised measurement of the vessel signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), rating of the image quality and the assessment of artefacts and venous contamination. At 3.0 T, SNR improved up to 95% and CNR up to 129%. The image quality of the larger inflow arteries, the palm arches and common digital arteries was good or sufficient at either magnetic field strengths. However, 3.0-T MRA was clearly superior in the depiction of the digital arteries. Ce-MRA of the hand clearly profits from the use of 3.0 T. Compared with 1.5 T, a substantial increase of CNR is found resulting in a significantly better delineation of the small digital arteries. Saturation affects more the SNR of the perivascular tissue than the contrast-enhanced blood, and thus leads to a marked increase of CNR at 3.0. (orig.)

  14. APT: Aperture Photometry Tool

    Science.gov (United States)

    Laher, Russ

    2012-08-01

    Aperture Photometry Tool (APT) is software for astronomers and students interested in manually exploring the photometric qualities of astronomical images. It has a graphical user interface (GUI) which allows the image data associated with aperture photometry calculations for point and extended sources to be visualized and, therefore, more effectively analyzed. Mouse-clicking on a source in the displayed image draws a circular or elliptical aperture and sky annulus around the source and computes the source intensity and its uncertainty, along with several commonly used measures of the local sky background and its variability. The results are displayed and can be optionally saved to an aperture-photometry-table file and plotted on graphs in various ways using functions available in the software. APT is geared toward processing sources in a small number of images and is not suitable for bulk processing a large number of images, unlike other aperture photometry packages (e.g., SExtractor). However, APT does have a convenient source-list tool that enables calculations for a large number of detections in a given image. The source-list tool can be run either in automatic mode to generate an aperture photometry table quickly or in manual mode to permit inspection and adjustment of the calculation for each individual detection. APT displays a variety of useful graphs, including image histogram, and aperture slices, source scatter plot, sky scatter plot, sky histogram, radial profile, curve of growth, and aperture-photometry-table scatter plots and histograms. APT has functions for customizing calculations, including outlier rejection, pixel “picking” and “zapping,” and a selection of source and sky models. The radial-profile-interpolation source model, accessed via the radial-profile-plot panel, allows recovery of source intensity from pixels with missing data and can be especially beneficial in crowded fields.

  15. Useful design tools?

    DEFF Research Database (Denmark)

    Jensen, Jesper Ole

    2005-01-01

    vague and contested concept of sustainability into concrete concepts and building projects. It describes a typology of tools: process tools, impact assessment tools, multi-criteria tools and tools for monitoring. It includes a Danish paradigmatic case study of stakeholder participation in the planning...... of a new sustainable settlement. The use of design tools is discussed in relation to innovation and stakeholder participation, and it is stressed that the usefulness of design tools is context dependent....

  16. CoC GIS Tools (GIS Tool)

    Data.gov (United States)

    Department of Housing and Urban Development — This tool provides a no-cost downloadable software tool that allows users to interact with professional quality GIS maps. Users access pre-compiled projects through...

  17. Attention Measures of Accuracy, Variability, and Fatigue Detect Early Response to Donepezil in Alzheimer's Disease: A Randomized, Double-blind, Placebo-Controlled Pilot Trial.

    Science.gov (United States)

    Vila-Castelar, Clara; Ly, Jenny J; Kaplan, Lillian; Van Dyk, Kathleen; Berger, Jeffrey T; Macina, Lucy O; Stewart, Jennifer L; Foldi, Nancy S

    2018-04-09

    Donepezil is widely used to treat Alzheimer's disease (AD), but detecting early response remains challenging for clinicians. Acetylcholine is known to directly modulate attention, particularly under high cognitive conditions, but no studies to date test whether measures of attention under high load can detect early effects of donepezil. We hypothesized that load-dependent attention tasks are sensitive to short-term treatment effects of donepezil, while global and other domain-specific cognitive measures are not. This longitudinal, randomized, double-blind, placebo-controlled pilot trial (ClinicalTrials.gov Identifier: NCT03073876) evaluated 23 participants newly diagnosed with AD initiating de novo donepezil treatment (5 mg). After baseline assessment, participants were randomized into Drug (n = 12) or Placebo (n = 11) groups, and retested after approximately 6 weeks. Cognitive assessment included: (a) attention tasks (Foreperiod Effect, Attentional Blink, and Covert Orienting tasks) measuring processing speed, top-down accuracy, orienting, intra-individual variability, and fatigue; (b) global measures (Alzheimer's Disease Assessment Scale-Cognitive Subscale, Mini-Mental Status Examination, Dementia Rating Scale); and (c) domain-specific measures (memory, language, visuospatial, and executive function). The Drug but not the Placebo group showed benefits of treatment at high-load measures by preserving top-down accuracy, improving intra-individual variability, and averting fatigue. In contrast, other global or cognitive domain-specific measures could not detect treatment effects over the same treatment interval. The pilot-study suggests that attention measures targeting accuracy, variability, and fatigue under high-load conditions could be sensitive to short-term cholinergic treatment. Given the central role of acetylcholine in attentional function, load-dependent attentional measures may be valuable cognitive markers of early treatment response.

  18. Intra-individual, randomised comparison of the MRI contrast agents gadobutrol versus gadoteridol in patients with primary and secondary brain tumours, evaluated in a blinded read

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, M. [Klinikum Luenen St. Marien-Hospital, Department of Diagnostic and Interventional Radiology and Neuroradiology, Luenen (Germany); Schulte-Altedorneburg, G. [Staedtisches Klinikum Muenchen Harlaching, Department of Diagnostic and Interventional Radiology, Neuroradiology and Nuclear Medicine, Muenchen (Germany); Piontek, M.; Heuser, L. [Universitaetsklinikum Knappschaftskrankenhaus GmbH, Department of Diagnostic and Interventional Radiology, Neuroradiology and Nuclear Medicine, Bochum (Germany); Hentsch, A. [Radiologisches Institut Hohenzollernstrasse, Koblenz (Germany); Spangenberg, P. [Universitaetsklinikum Knappschaftskrankenhaus GmbH, Department of Neurosurgery, Bochum (Germany); Schwenke, C. [SCO:SSiS, Berlin (Germany); Harders, A. [Universitaetsklinikum Knappschaftskrankenhaus GmbH, Department of Neurosurgery Knappschaftskrankenhaus, Bochum (Germany)

    2013-12-15

    To prove that 1.0 M gadobutrol provides superior contrast enhancement and MRI image characteristics of primary and secondary brain tumours compared with 0.5 M gadoteridol, thereby providing superior diagnostic information. Brain MRI was performed in two separate examinations in patients scheduled for neurosurgery. Independent injections of 1.0 M gadobutrol and 0.5 M gadoteridol at doses of 0.1 mmol Gd/kg body weight were administered per patient in randomised order. Evaluation was performed in an off-site blinded read. Fifty-one patients in the full analysis set (FAS) were eligible for efficacy analysis and 44 for the per-protocol analysis. For the primary efficacy variable ''preference in contrast enhancement for one contrast agent or the other'', the rate of ''gadobutrol preferred'' was estimated at 0.73 (95 % confidence interval 0.61; 0.83), showing significant superiority of gadobutrol over gadoteridol. Calculated lesion-to-brain contrast and the results of all qualitative secondary efficacy variables were also in favour of gadobutrol. Keeping a sufficient time delay after contrast application proved to be essential to get optimal image quality. Compared with 0.5 M gadoteridol, 1.0 M gadobutrol was proven to have significantly superior contrast enhancement characteristics in a routine MRI protocol of primary and secondary brain tumours. (orig.)

  19. Intra-individual, randomised comparison of the MRI contrast agents gadobutrol versus gadoteridol in patients with primary and secondary brain tumours, evaluated in a blinded read

    International Nuclear Information System (INIS)

    Koenig, M.; Schulte-Altedorneburg, G.; Piontek, M.; Heuser, L.; Hentsch, A.; Spangenberg, P.; Schwenke, C.; Harders, A.

    2013-01-01

    To prove that 1.0 M gadobutrol provides superior contrast enhancement and MRI image characteristics of primary and secondary brain tumours compared with 0.5 M gadoteridol, thereby providing superior diagnostic information. Brain MRI was performed in two separate examinations in patients scheduled for neurosurgery. Independent injections of 1.0 M gadobutrol and 0.5 M gadoteridol at doses of 0.1 mmol Gd/kg body weight were administered per patient in randomised order. Evaluation was performed in an off-site blinded read. Fifty-one patients in the full analysis set (FAS) were eligible for efficacy analysis and 44 for the per-protocol analysis. For the primary efficacy variable ''preference in contrast enhancement for one contrast agent or the other'', the rate of ''gadobutrol preferred'' was estimated at 0.73 (95 % confidence interval 0.61; 0.83), showing significant superiority of gadobutrol over gadoteridol. Calculated lesion-to-brain contrast and the results of all qualitative secondary efficacy variables were also in favour of gadobutrol. Keeping a sufficient time delay after contrast application proved to be essential to get optimal image quality. Compared with 0.5 M gadoteridol, 1.0 M gadobutrol was proven to have significantly superior contrast enhancement characteristics in a routine MRI protocol of primary and secondary brain tumours. (orig.)

  20. The power tool

    International Nuclear Information System (INIS)

    HAYFIELD, J.P.

    1999-01-01

    POWER Tool--Planning, Optimization, Waste Estimating and Resourcing tool, a hand-held field estimating unit and relational database software tool for optimizing disassembly and final waste form of contaminated systems and equipment

  1. The EPICS process variable Gateway Version 2

    International Nuclear Information System (INIS)

    Evans, K.

    2005-01-01

    The EPICS Process Variable Gateway is both a Channel Access Server and Channel Access Client that provides a means for many clients, typically on different subnets, to access a process variable while making only one connection to the server that owns the process variable. It also provides additional access security beyond that implemented on the server. It thus protects critical servers while providing suitably restricted access to needed process variables. The original version of the Gateway worked with EPICS Base 3.13 but required a special version, since the changes necessary for its operation were never incorporated into EPICS Base. Version 2 works with any standard EPICS Base 3.14.6 or later and has many improvements in both performance and features over the older version. The Gateway is now used at many institutions and has become a stable, high-performance application. It is capable of handling tens of thousands of process variables with hundreds of thousands of events per second. It has run for over three months in a production environment without having to be restarted. It has many internal process variables that can be used to monitor its state using standard EPICS client tools, such as MEDM and StripTool. Other internal process variables can be used to stop the Gateway, make several kinds of reports, or change the access security without stopping the Gateway. It can even be started on remote workstations from MEDM by using a Secure Shell script. This paper will describe the new Gateway and how it is used. The Gateway is both a server (like an EPICS Input/Output Controller (IOC)) and a client (like the EPICS Motif Editor and Display Manager (MEDM), StripTool, and others). Clients connect to the server side, and the client side connects to IOCs and other servers, possibly other Gateways. See Fig. 1. There are perhaps three principal reasons for using the Gateway: (1) it allows many clients to access a process variable while making only one connection to

  2. The neutron porosity tool

    International Nuclear Information System (INIS)

    Oelgaard, P.L.

    1988-01-01

    The report contains a review of available information on neutron porosity tools with the emphasis on dual thermal-neutron-detector porosity tools and epithermal-neutron-detector porosity tools. The general principle of such tools is discussed and theoretical models are very briefly reviewed. Available data on tool designs are summarized with special regard to the source-detector distance. Tool operational data, porosity determination and correction of measurements are briefly discussed. (author) 15 refs

  3. Preset pivotal tool holder

    Science.gov (United States)

    Asmanes, Charles

    1979-01-01

    A tool fixture is provided for precise pre-alignment of a radiused edge cutting tool in a tool holder relative to a fixed reference pivot point established on said holder about which the tool holder may be selectively pivoted relative to the fixture base member to change the contact point of the tool cutting edge with a workpiece while maintaining the precise same tool cutting radius relative to the reference pivot point.

  4. Light induced intraspecific variability in response to thermal stress in the hard coral Stylophora pistillata

    Directory of Open Access Journals (Sweden)

    Arjen Tilstra

    2017-10-01

    Full Text Available Recent research suggests that prior exposure of several months to elevated irradiance induces enhanced thermal tolerance in scleractinian corals. While this tolerance has been reported at the species level, individual coral colonies may react differently due to individual variability in thermal tolerance. As thermal anomalies are predicted to become common in the upcoming future, intraspecific variation may be key to the survival of coral populations. In order to study light-history based thermal stress responses on individual colonies, we developed a preliminary microcosm experiment where three randomly chosen, aquacultured colonies of the model coral Stylophora pistillata were exposed to two irradiance treatments (200 and 400 μmol photons m−2 s−1 for 31 days, followed by artificially induced heat stress (∼33.4 °C. We found different responses to occur at both the intraspecific and the intracolonial levels, as indicated by either equal, less severe, delayed, and/or even non-necrotic responses of corals previously exposed to the irradiance of 400 compared to 200 μmol photons m−2 s−1. In addition, all individual colonies revealed light-enhanced calcification. Finally, elevated irradiance resulted in a lower chlorophyll a concentration in one colony compared to the control treatment, and the same colony displayed more rapid bleaching compared to the other ones. Taken together, this study highlights the potential importance of intra-individual variability in physiological responses of scleractinian corals and provides recommendations for improving methodological designs for future studies.

  5. Daily variability in working memory is coupled with negative affect: the role of attention and motivation.

    Science.gov (United States)

    Brose, Annette; Schmiedek, Florian; Lövdén, Martin; Lindenberger, Ulman

    2012-06-01

    Across days, individuals experience varying levels of negative affect, control of attention, and motivation. We investigated whether this intraindividual variability was coupled with daily fluctuations in working memory (WM) performance. In 100 days, 101 younger individuals worked on a spatial N-back task and rated negative affect, control of attention, and motivation. Results showed that individuals differed in how reliably WM performance fluctuated across days, and that subjective experiences were primarily linked to performance accuracy. WM performance was lower on days with higher levels of negative affect, reduced control of attention, and reduced task-related motivation. Thus, variables that were found to predict WM in between-subjects designs showed important relationships to WM at the within-person level. In addition, there was shared predictive variance among predictors of WM. Days with increased negative affect and reduced performance were also days with reduced control of attention and reduced motivation to work on tasks. These findings are in line with proposed mechanisms linking negative affect and cognitive performance.

  6. Biologic variability of N-terminal pro-brain natriuretic peptide in adult healthy cats.

    Science.gov (United States)

    Harris, Autumn N; Estrada, Amara H; Gallagher, Alexander E; Winter, Brandy; Lamb, Kenneth E; Bohannon, Mary; Hanscom, Jancy; Mainville, Celine A

    2017-02-01

    Objectives The biologic variability of N-terminal pro-brain natriuretic peptide (NT-proBNP) and its impact on diagnostic utility is unknown in healthy cats and those with cardiac disease. The purpose of this study was to determine the biologic variation of NT-proBNP within-day and week-to-week in healthy adult cats. Methods Adult cats were prospectively evaluated by complete blood count (CBC), biochemistry, total thyroxine, echocardiography, electrocardiography and blood pressure, to exclude underlying systemic or cardiac disease. Adult healthy cats were enrolled and blood samples were obtained at 11 time points over a 6 week period (0, 2 h, 4 h, 6 h, 8 h, 10 h and at weeks 2, 3, 4, 5 and 6). The intra-individual (coefficient of variation [CV I ]) biologic variation along with index of individuality and reference change values (RCVs) were calculated. Univariate models were analyzed and included comparison of the six different time points for both daily and weekly samples. This was followed by a Tukey's post-hoc adjustment, with a P value of cats. Further research is warranted to evaluate NT-proBNP variability, particularly how serial measurements of NT-proBNP may be used in the diagnosis and management of cats with cardiac disease.

  7. Feeling old today? Daily health, stressors, and affect explain day-to-day variability in subjective age.

    Science.gov (United States)

    Kotter-Grühn, Dana; Neupert, Shevaun D; Stephan, Yannick

    2015-01-01

    Subjective age is an important correlate of health, well-being, and longevity. So far, little is known about short-term variability in subjective age and the circumstances under which individuals feel younger/older in daily life. This study examined whether (a) older adults' felt age fluctuates on a day-to-day basis, (b) daily changes in health, stressors, and affect explain fluctuations in felt age, and (c) the daily associations between felt age and health, stressors, or affect are time-ordered. Using an eight-day daily diary approach, N = 43 adults (60-96 years, M = 74.65, SD = 8.19) filled out daily questionnaires assessing subjective age, health, daily stressors, and affect. Data were analysed using multilevel modelling. Subjective age, health, daily stressors, affect. Intra-individual variability in felt age was not explained by time but by short-term variability in other variables. Specifically, on days when participants experienced more than average health problems, stress, or negative affect they felt older than on days with average health, stress, or negative affect. No time-ordered effects were found. Bad health, many stressors, and negative affective experiences constitute circumstances under which older adults feel older than they typically do. Thus, daily measures of subjective age could be markers of health and well-being.

  8. An Integrated Workflow To Assess Technical and Biological Variability of Cell Population Frequencies in Human Peripheral Blood by Flow Cytometry.

    Science.gov (United States)

    Burel, Julie G; Qian, Yu; Lindestam Arlehamn, Cecilia; Weiskopf, Daniela; Zapardiel-Gonzalo, Jose; Taplitz, Randy; Gilman, Robert H; Saito, Mayuko; de Silva, Aruna D; Vijayanand, Pandurangan; Scheuermann, Richard H; Sette, Alessandro; Peters, Bjoern

    2017-02-15

    In the context of large-scale human system immunology studies, controlling for technical and biological variability is crucial to ensure that experimental data support research conclusions. In this study, we report on a universal workflow to evaluate both technical and biological variation in multiparameter flow cytometry, applied to the development of a 10-color panel to identify all major cell populations and T cell subsets in cryopreserved PBMC. Replicate runs from a control donation and comparison of different gating strategies assessed the technical variability associated with each cell population and permitted the calculation of a quality control score. Applying our panel to a large collection of PBMC samples, we found that most cell populations showed low intraindividual variability over time. In contrast, certain subpopulations such as CD56 T cells and Temra CD4 T cells were associated with high interindividual variability. Age but not gender had a significant effect on the frequency of several populations, with a drastic decrease in naive T cells observed in older donors. Ethnicity also influenced a significant proportion of immune cell population frequencies, emphasizing the need to account for these covariates in immune profiling studies. We also exemplify the usefulness of our workflow by identifying a novel cell-subset signature of latent tuberculosis infection. Thus, our study provides a universal workflow to establish and evaluate any flow cytometry panel in systems immunology studies. Copyright © 2017 by The American Association of Immunologists, Inc.

  9. Handbook of latent variable and related models

    CERN Document Server

    Lee, Sik-Yum

    2011-01-01

    This Handbook covers latent variable models, which are a flexible class of models for modeling multivariate data to explore relationships among observed and latent variables.- Covers a wide class of important models- Models and statistical methods described provide tools for analyzing a wide spectrum of complicated data- Includes illustrative examples with real data sets from business, education, medicine, public health and sociology.- Demonstrates the use of a wide variety of statistical, computational, and mathematical techniques.

  10. Cartas de control para monitorear variables multinomiales

    Directory of Open Access Journals (Sweden)

    Luz Marcela Restrepo-Tamayo

    2014-07-01

    Full Text Available Background: The control as a tool for monitoring the quality of a product, allows to study the stability of processes over time, contrasting two hypothesis, which states that the process is in stable condition and the other denies it. Its use has been massive for continuous variables but not for categorical variables, why it is imperative to design such tools for such variables. Objective: To propose two (2 control charts for variables multinomial processes based on the p-value test result for homogeneity of proportions using the chi square test for uniform processing variables and approximation Wilson - Hilferty for variables chi square. Methods: The performance of proposed charts via simulation is estimated considering a Phase II process and considering the first category increments of 2%, 4% and 6% in the control stage. Results: The multinomial control chart using Wilson-Hilferty approximation for variables chi square, from the transformation of value-p, has poor performance compared to the control charts using p-value processing and using chi-square p-value, as they have less ability to detect small changes. Conclusion: We propose two control charts to monitor multinomial variables and once studied via simulation, based on the average run length (ARL and the probability of rejecting the null hypothesis of equal proportions, we recommend the control chart using value-p, or equivalently, the control chart processing using chi square p-value.

  11. Understanding Process in Group-Based Intervention Delivery: Social Network Analysis and Intra-entity Variability Methods as Windows into the "Black Box".

    Science.gov (United States)

    Molloy Elreda, Lauren; Coatsworth, J Douglas; Gest, Scott D; Ram, Nilam; Bamberger, Katharine

    2016-11-01

    Although the majority of evidence-based programs are designed for group delivery, group process and its role in participant outcomes have received little empirical attention. Data were collected from 20 groups of participants (94 early adolescents, 120 parents) enrolled in an efficacy trial of a mindfulness-based adaptation of the Strengthening Families Program (MSFP). Following each weekly session, participants reported on their relations to group members. Social network analysis and methods sensitive to intraindividual variability were integrated to examine weekly covariation between group process and participant progress, and to predict post-intervention outcomes from levels and changes in group process. Results demonstrate hypothesized links between network indices of group process and intervention outcomes and highlight the value of this unique analytic approach to studying intervention group process.

  12. Photometric variability in earthshine observations.

    Science.gov (United States)

    Langford, Sally V; Wyithe, J Stuart B; Turner, Edwin L

    2009-04-01

    The identification of an extrasolar planet as Earth-like will depend on the detection of atmospheric signatures or surface non-uniformities. In this paper we present spatially unresolved flux light curves of Earth for the purpose of studying a prototype extrasolar terrestrial planet. Our monitoring of the photometric variability of earthshine revealed changes of up to 23% per hour in the brightness of Earth's scattered light at around 600 nm, due to the removal of specular reflection from the view of the Moon. This variability is accompanied by reddening of the spectrum and results from a change in surface properties across the continental boundary between the Indian Ocean and Africa's east coast. Our results based on earthshine monitoring indicate that specular reflection should provide a useful tool in determining the presence of liquid water on extrasolar planets via photometric observations.

  13. Value of 100 kVp scan with sinogram-affirmed iterative reconstruction algorithm on a single-source CT system during whole-body CT for radiation and contrast medium dose reduction: an intra-individual feasibility study.

    Science.gov (United States)

    Nagayama, Y; Nakaura, T; Oda, S; Tsuji, A; Urata, J; Furusawa, M; Tanoue, S; Utsunomiya, D; Yamashita, Y

    2018-02-01

    To perform an intra-individual investigation of the usefulness of a contrast medium (CM) and radiation dose-reduction protocol using single-source computed tomography (CT) combined with 100 kVp and sinogram-affirmed iterative reconstruction (SAFIRE) for whole-body CT (WBCT; chest-abdomen-pelvis CT) in oncology patients. Forty-three oncology patients who had undergone WBCT under both 120 and 100 kVp protocols at different time points (mean interscan intervals: 98 days) were included retrospectively. The CM doses for the 120 and 100 kVp protocols were 600 and 480 mg iodine/kg, respectively; 120 kVp images were reconstructed with filtered back-projection (FBP), whereas 100 kVp images were reconstructed with FBP (100 kVp-F) and the SAFIRE (100 kVp-S). The size-specific dose estimate (SSDE), iodine load and image quality of each protocol were compared. The SSDE and iodine load of 100 kVp protocol were 34% and 21%, respectively, lower than of 120 kVp protocol (SSDE: 10.6±1.1 versus 16.1±1.8 mGy; iodine load: 24.8±4versus 31.5±5.5 g iodine, p<0.01). Contrast enhancement, objective image noise, contrast-to-noise-ratio, and visual score of 100 kVp-S were similar to or better than of 120 kVp protocol. Compared with the 120 kVp protocol, the combined use of 100 kVp and SAFIRE in WBCT for oncology assessment with an SSCT facilitated substantial reduction in the CM and radiation dose while maintaining image quality. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  14. Effect of automated tube voltage selection, integrated circuit detector and advanced iterative reconstruction on radiation dose and image quality of 3rd generation dual-source aortic CT angiography: An intra-individual comparison.

    Science.gov (United States)

    Mangold, Stefanie; De Cecco, Carlo N; Wichmann, Julian L; Canstein, Christian; Varga-Szemes, Akos; Caruso, Damiano; Fuller, Stephen R; Bamberg, Fabian; Nikolaou, Konstantin; Schoepf, U Joseph

    2016-05-01

    To compare, on an intra-individual basis, the effect of automated tube voltage selection (ATVS), integrated circuit detector and advanced iterative reconstruction on radiation dose and image quality of aortic CTA studies using 2nd and 3rd generation dual-source CT (DSCT). We retrospectively evaluated 32 patients who had undergone CTA of the entire aorta with both 2nd generation DSCT at 120kV using filtered back projection (FBP) (protocol 1) and 3rd generation DSCT using ATVS, an integrated circuit detector and advanced iterative reconstruction (protocol 2). Contrast-to-noise ratio (CNR) was calculated. Image quality was subjectively evaluated using a five-point scale. Radiation dose parameters were recorded. All studies were considered of diagnostic image quality. CNR was significantly higher with protocol 2 (15.0±5.2 vs 11.0±4.2; p<.0001). Subjective image quality analysis revealed no significant differences for evaluation of attenuation (p=0.08501) but image noise was rated significantly lower with protocol 2 (p=0.0005). Mean tube voltage and effective dose were 94.7±14.1kV and 6.7±3.9mSv with protocol 2; 120±0kV and 11.5±5.2mSv with protocol 1 (p<0.0001, respectively). Aortic CTA performed with 3rd generation DSCT, ATVS, integrated circuit detector, and advanced iterative reconstruction allow a substantial reduction of radiation exposure while improving image quality in comparison to 120kV imaging with FBP. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Reproducibility, stability, and biological variability of thrombin generation using calibrated automated thrombography in healthy dogs.

    Science.gov (United States)

    Cuq, Benoît; Blois, Shauna L; Wood, R Darren; Monteith, Gabrielle; Abrams-Ogg, Anthony C; Bédard, Christian; Wood, Geoffrey A

    2018-06-01

    Thrombin plays a central role in hemostasis and thrombosis. Calibrated automated thrombography (CAT), a thrombin generation assay, may be a useful test for hemostatic disorders in dogs. To describe CAT results in a group of healthy dogs, and assess preanalytical variables and biological variability. Forty healthy dogs were enrolled. Lag time (Lag), time to peak (ttpeak), peak thrombin generation (peak), and endogenous thrombin potential (ETP) were measured. Direct jugular venipuncture and winged-needle catheter-assisted saphenous venipuncture were used to collect samples from each dog, and results were compared between methods. Sample stability at -80°C was assessed over 12 months in a subset of samples. Biological variability of CAT was assessed via nested ANOVA using samples obtained weekly from a subset of 9 dogs for 4 consecutive weeks. Samples for CAT were stable at -80°C over 12 months of storage. Samples collected via winged-needle catheter venipuncture showed poor repeatability compared to direct venipuncture samples; there was also poor agreement between the 2 sampling methods. Intra-individual variability of CAT parameters was below 25%; inter-individual variability ranged from 36.9% to 78.5%. Measurement of thrombin generation using CAT appears to be repeatable in healthy dogs, and samples are stable for at least 12 months when stored at -80°C. Direct venipuncture sampling is recommended for CAT. Low indices of individuality suggest that subject-based reference intervals are more suitable when interpreting CAT results. © 2018 American Society for Veterinary Clinical Pathology.

  16. Effects of Sex on Intra-Individual Variance in Urinary Solutes in Stone-Formers Collected from a Single Clinical Laboratory.

    Directory of Open Access Journals (Sweden)

    Guy M L Perry

    Full Text Available Our work in a rodent model of urinary calcium suggests genetic and gender effects on increased residual variability in urine chemistries. Based on these findings, we hypothesized that sex would similarly be associated with residual variation in human urine solutes. Sex-related effects on residuals might affect the establishment of physiological baselines and error in medical assays.We tested the effects of sex on residual variation in urine chemistry by estimating coefficients of variation (CV for urinary solutes in paired sequential 24-h urines (≤72 hour interval in 6,758 females and 9,024 males aged 16-80 submitted to a clinical laboratory.Females had higher CVs than males for urinary phosphorus overall at the False Discovery Rate (P0.3. Males had higher CVs for citrate (P<0.01 from ages 16-45 and females higher CVs for citrate (P<0.01 from ages 56-80, suggesting effects of an extant oestral cycle on residual variance.Our findings indicate the effects of sex on residual variance of the excretion of urinary solutes including phosphorus and citrate; differences in CV by sex might reflect dietary lability, differences in the fidelity of reporting or genetic differentiation in renal solute consistency. Such an effect could complicate medical analysis by the addition of random error to phenotypic assays. Renal analysis might require explicit incorporation of heterogeneity among factorial effects, and for sex in particular.

  17. Aperture Photometry Tool

    Science.gov (United States)

    Laher, Russ R.; Gorjian, Varoujan; Rebull, Luisa M.; Masci, Frank J.; Fowler, John W.; Helou, George; Kulkarni, Shrinivas R.; Law, Nicholas M.

    2012-07-01

    Aperture Photometry Tool (APT) is software for astronomers and students interested in manually exploring the photometric qualities of astronomical images. It is a graphical user interface (GUI) designed to allow the image data associated with aperture photometry calculations for point and extended sources to be visualized and, therefore, more effectively analyzed. The finely tuned layout of the GUI, along with judicious use of color-coding and alerting, is intended to give maximal user utility and convenience. Simply mouse-clicking on a source in the displayed image will instantly draw a circular or elliptical aperture and sky annulus around the source and will compute the source intensity and its uncertainty, along with several commonly used measures of the local sky background and its variability. The results are displayed and can be optionally saved to an aperture-photometry-table file and plotted on graphs in various ways using functions available in the software. APT is geared toward processing sources in a small number of images and is not suitable for bulk processing a large number of images, unlike other aperture photometry packages (e.g., SExtractor). However, APT does have a convenient source-list tool that enables calculations for a large number of detections in a given image. The source-list tool can be run either in automatic mode to generate an aperture photometry table quickly or in manual mode to permit inspection and adjustment of the calculation for each individual detection. APT displays a variety of useful graphs with just the push of a button, including image histogram, x and y aperture slices, source scatter plot, sky scatter plot, sky histogram, radial profile, curve of growth, and aperture-photometry-table scatter plots and histograms. APT has many functions for customizing the calculations, including outlier rejection, pixel “picking” and “zapping,” and a selection of source and sky models. The radial-profile-interpolation source

  18. Dutch Risk Assessment tools

    NARCIS (Netherlands)

    Venema, A.

    2015-01-01

    The ‘Risico- Inventarisatie- en Evaluatie-instrumenten’ is the name for the Dutch risk assessment (RA) tools. A RA tool can be used to perform a risk assessment including an evaluation of the identified risks. These tools were among the first online risk assessment tools developed in Europe. The

  19. New QC 7 tools

    International Nuclear Information System (INIS)

    1982-03-01

    This book tells of new QC with 7 tools which includes TQC and new QC with 7 tools which is for better propel, what is QC method to think? what is new QC 7 tool ? like KJ law, PDPC law, arrow and diagram law, and matrix diagram law, application of new QC 7 tools such as field to apply, application of new QC 7 tools for policy management the method of new QC 7 tools including related regulations KJ law, matrix and data analysis, PDPC law and education and introduction of new QC 7 tools.

  20. A Core Language for Separate Variability Modeling

    DEFF Research Database (Denmark)

    Iosif-Lazăr, Alexandru Florin; Wasowski, Andrzej; Schaefer, Ina

    2014-01-01

    Separate variability modeling adds variability to a modeling language without requiring modifications of the language or the supporting tools. We define a core language for separate variability modeling using a single kind of variation point to define transformations of software artifacts in object...... hierarchical dependencies between variation points via copying and flattening. Thus, we reduce a model with intricate dependencies to a flat executable model transformation consisting of simple unconditional local variation points. The core semantics is extremely concise: it boils down to two operational rules...

  1. Analytic functions of several complex variables

    CERN Document Server

    Gunning, Robert C

    2009-01-01

    The theory of analytic functions of several complex variables enjoyed a period of remarkable development in the middle part of the twentieth century. After initial successes by Poincaré and others in the late 19th and early 20th centuries, the theory encountered obstacles that prevented it from growing quickly into an analogue of the theory for functions of one complex variable. Beginning in the 1930s, initially through the work of Oka, then H. Cartan, and continuing with the work of Grauert, Remmert, and others, new tools were introduced into the theory of several complex variables that resol

  2. 42 Variability Bugs in the Linux Kernel

    DEFF Research Database (Denmark)

    Abal, Iago; Brabrand, Claus; Wasowski, Andrzej

    2014-01-01

    Feature-sensitive verification pursues effective analysis of the exponentially many variants of a program family. However, researchers lack examples of concrete bugs induced by variability, occurring in real large-scale systems. Such a collection of bugs is a requirement for goal-oriented research...... provide self-contained simplified C99 versions of the bugs, facilitating understanding and tool evaluation. Our study provides insights into the nature and occurrence of variability bugs in a large C software system, and shows in what ways variability affects and increases the complexity of software bugs....

  3. Age differences in big five behavior averages and variabilities across the adult life span: moving beyond retrospective, global summary accounts of personality.

    Science.gov (United States)

    Noftle, Erik E; Fleeson, William

    2010-03-01

    In 3 intensive cross-sectional studies, age differences in behavior averages and variabilities were examined. Three questions were posed: Does variability differ among age groups? Does the sizable variability in young adulthood persist throughout the life span? Do past conclusions about trait development, based on trait questionnaires, hold up when actual behavior is examined? Three groups participated: young adults (18-23 years), middle-aged adults (35-55 years), and older adults (65-81 years). In 2 experience-sampling studies, participants reported their current behavior multiple times per day for 1- or 2-week spans. In a 3rd study, participants interacted in standardized laboratory activities on 8 occasions. First, results revealed a sizable amount of intraindividual variability in behavior for all adult groups, with average within-person standard deviations ranging from about half a point to well over 1 point on 6-point scales. Second, older adults were most variable in Openness, whereas young adults were most variable in Agreeableness and Emotional Stability. Third, most specific patterns of maturation-related age differences in actual behavior were more greatly pronounced and differently patterned than those revealed by the trait questionnaire method. When participants interacted in standardized situations, personality differences between young adults and middle-aged adults were larger, and older adults exhibited a more positive personality profile than they exhibited in their everyday lives.

  4. Variability or conservation of hepatitis C virus hypervariable region 1?

    Indian Academy of Sciences (India)

    The hypervariable region 1 (HVR1) of the E2 protein of hepatitis C virus (HCV) is highly heterogeneous in its primary sequence and is responsible for significant inter- and intra-individual variation of the infecting virus, which may represent an important pathogenetic mechanism leading to immune escape and persistent ...

  5. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ; SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and

  6. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2010-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ;SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and can

  7. [Blood pressure variability: clinical interest or simple curiosity?].

    Science.gov (United States)

    Ciaroni, Stefano

    2007-03-14

    Blood pressure variability is a physiological phenomenon influenced by many internal and external factors. This variability could be also influenced by pathological conditions such as arterial hypertension. Two forms must be mainly distinguished: the blood pressure variability at long and short-term. The latter could only be studied by continuous recordings. In this article will be analysed the interest of measuring blood pressure variability, its cardiovascular prognosis and the therapeutic tools when it is increased.

  8. Roles of Variables in Three Programming Paradigms

    Science.gov (United States)

    Sajaniemi, J.; Ben-Ari, M.; Byckling, P.; Gerdt, P.; Kulikova, Y.

    2006-01-01

    Roles can be assigned to occurrences of variables in programs according to a small number of stereotypical patterns of use. Studies on explicitly teaching roles to novices learning programming have shown that roles are an excellent pedagogical tool for clarifying the structure and meaning of programs and that their use improves students'…

  9. Political Discourse and Its Sociolinguistic Variables

    Science.gov (United States)

    Reyes-Rodriguez, Antonio

    2008-01-01

    Linguistically, political discourses have generally been discussed within qualitative approaches (e.g., Blackledge, 2005; Chilton, 2004; Chomsky, 2004; van Dijk, 2005; Wodak, 2002). This paper presents tools to design a quantitative research relating political speech with sociolinguistic variables. Notions such as Accommodation Theory (Giles &…

  10. Quantum engineering of continuous variable quantum states

    International Nuclear Information System (INIS)

    Sabuncu, Metin

    2009-01-01

    Quantum information with continuous variables is a field attracting increasing attention recently. In continuous variable quantum information one makes use of the continuous information encoded into the quadrature of a quantized light field instead of binary quantities such as the polarization state of a single photon. This brand new research area is witnessing exciting theoretical and experimental achievements such as teleportation, quantum computation and quantum error correction. The rapid development of the field is mainly due higher optical data rates and the availability of simple and efficient manipulation tools in continuous-variable quantum information processing. We in this thesis extend the work in continuous variable quantum information processing and report on novel experiments on amplification, cloning, minimal disturbance and noise erasure protocols. The promising results we obtain in these pioneering experiments indicate that the future of continuous variable quantum information is bright and many advances can be foreseen. (orig.)

  11. Quantum engineering of continuous variable quantum states

    Energy Technology Data Exchange (ETDEWEB)

    Sabuncu, Metin

    2009-10-29

    Quantum information with continuous variables is a field attracting increasing attention recently. In continuous variable quantum information one makes use of the continuous information encoded into the quadrature of a quantized light field instead of binary quantities such as the polarization state of a single photon. This brand new research area is witnessing exciting theoretical and experimental achievements such as teleportation, quantum computation and quantum error correction. The rapid development of the field is mainly due higher optical data rates and the availability of simple and efficient manipulation tools in continuous-variable quantum information processing. We in this thesis extend the work in continuous variable quantum information processing and report on novel experiments on amplification, cloning, minimal disturbance and noise erasure protocols. The promising results we obtain in these pioneering experiments indicate that the future of continuous variable quantum information is bright and many advances can be foreseen. (orig.)

  12. High-pitch computed tomography of the lung in pediatric patients. An intraindividual comparison of image quality and radiation dose to conventional 64-MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Tsiflikas, I.; Thomas, C.; Ketelsen, D.; Claussen, C.D.; Schaefer, J.F. [University Hospital of Tuebingen (Germany). Diagnostic and Interventional Radiology; Seitz, G.; Warmann, S. [University Hospital of Tuebingen (Germany). Pediatric Surgery

    2014-06-15

    Purpose: The aim of this study was to investigate frequencies of typical artifacts in low-dose pediatric lung examinations using high-pitch computed tomography (HPCT) compared to MDCT, and to estimate the effective radiation dose (E{sub eff}). Materials and Methods: Institutional review board approval for this retrospective study was obtained. 35 patients (17 boys, 18 girls; mean age 112 ± 69 months) were included and underwent MDCT and follow-up scan by HPCT or vice versa (mean follow-up time 87 days), using the same tube voltage and current. The total artifact score (0-8) was defined as the sum of artifacts arising from movement, breathing or pulsation of the heart or pulmonary vessels (0 - no; 1 - moderate; 2 - severe artifacts). E{sub eff} was estimated according to the European Guidelines on Quality Criteria for Multislice Computed Tomography. The Mann-Whitney U test was used to analyze differences between the patient groups. The Spearman's rank correlation coefficient was used for correlation of ordinal variables. Results: The scan time was significantly lower for HPCT compared to MDCT (0.72 ± 0.13 s vs. 3.65 ± 0.81s; p < 0.0001). In 28 of 35 (80 %) HPCT examinations no artifacts were visible, whereas in MDCT artifacts occurred in all examinations. The frequency of pulsation artifacts and breathing artifacts was higher in MDCT compared to HPCT (100% vs. 17% and 31% vs. 6%). The total artifact score significantly correlated with the patient's age in MDCT (r=-0.42; p=0.01), but not in HPCT (r=-0.32; p=0.07). The estimated E{sub eff} was significantly lower in HPCT than in MDCT (1.29±0.31 vs. 1.47±0.37 mSv; p < 0.0001). Conclusion: Our study indicates that the use of HPCT has advantages for pediatric lung imaging with a reduction of breathing and pulsation artifacts. Moreover, the estimated E{sub eff} was lower. In addition, examinations can be performed without sedation or breath-hold without losing image quality. (orig.)

  13. Software reference for SaTool - a Tool for Structural Analysis of Automated Systems

    DEFF Research Database (Denmark)

    Lorentzen, Torsten; Blanke, Mogens

    2004-01-01

    This software reference details the functions of SaTool – a tool for structural analysis of technical systems. SaTool is intended used as part of an industrial systems design cycle. Structural analysis is a graph-based technique where principal relations between variables express the system’s...... of the graph. SaTool makes analysis of the structure graph to provide knowledge about fundamental properties of the system in normal and faulty conditions. Salient features of SaTool include rapid analysis of possibility to diagnose faults and ability to make autonomous recovery should faults occur........ The list of such variables and functional relations constitute the system’s structure graph. Normal operation means all functional relations are intact. Should faults occur, one or more functional relations cease to be valid. In a structure graph, this is seen as the disappearance of one or more nodes...

  14. Variable mechanical ventilation.

    Science.gov (United States)

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini, Luiz Alberto; Friedman, Gilberto

    2017-01-01

    To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE®, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". A total of 36 studies were selected. Of these, 24 were original studies, including 21 experimental studies and three clinical studies. Several experimental studies reported the beneficial effects of distinct variable ventilation strategies on lung function using different models of lung injury and healthy lungs. Variable ventilation seems to be a viable strategy for improving gas exchange and respiratory mechanics and preventing lung injury associated with mechanical ventilation. However, further clinical studies are necessary to assess the potential of variable ventilation strategies for the clinical improvement of patients undergoing mechanical ventilation.

  15. [Inter-and intra-operator variability in the analysis of semen parameters: results from a quality control program].

    Science.gov (United States)

    Daoud, Salima; Chakroun-Feki, Nozha; Sellami, Afifa; Ammar-Keskes, Leila; Rebai, Tarek

    2016-01-01

    Semen analysis is a key part of male infertility investigation. The necessity of quality management implementation in the andrology laboratory has been recognized in order to ensure the reliability of its results. The aim of this study was to evaluate intra- and inter-individual variability in the assessment of semen parameters in our laboratory through a quality control programme. Four participants from the laboratory with different experience levels have participated in this study. Semen samples of varying quality were assessed for sperm motility, concentration and morphology and the results were used to evaluate inter-participant variability. In addition, replicates of each semen sample were analyzed to determine intra-individual variability for semen parameters analysis. The average values of inter-participant coefficients of variation for sperm motility, concentration and morphology were 12.8%, 19.8% and 48.9% respectively. The mean intra-participant coefficients of variation were, respectively, 6.9%, 12.3% and 42.7% for sperm motility, concentration and morphology. Despite some random errors of under- or overestimation, the overall results remained within the limits of acceptability for all participants. Sperm morphology assessment was particularly influenced by the participant's level of experience. The present data emphasize the need for appropriate training of the laboratory staff and for regular participation in internal quality control programmes in order to improve the reliability of laboratory results.

  16. The Effects of Exercise Intensity vs. Metabolic State on the Variability and Magnitude of Left Ventricular Twist Mechanics during Exercise.

    Directory of Open Access Journals (Sweden)

    Craig Armstrong

    Full Text Available Increased left ventricular (LV twist and untwisting rate (LV twist mechanics are essential responses of the heart to exercise. However, previously a large variability in LV twist mechanics during exercise has been observed, which complicates the interpretation of results. This study aimed to determine some of the physiological sources of variability in LV twist mechanics during exercise. Sixteen healthy males (age: 22 ± 4 years, [Formula: see text]O2peak: 45.5 ± 6.9 ml∙kg-1∙min-1, range of individual anaerobic threshold (IAT: 32-69% of [Formula: see text]O2peak were assessed at rest and during exercise at: i the same relative exercise intensity, 40%peak, ii at 2% above IAT, and, iii at 40%peak with hypoxia (40%peak+HYP. LV volumes were not significantly different between exercise conditions (P > 0.05. However, the mean margin of error of LV twist was significantly lower (F2,47 = 2.08, P 0.05. Overall, LV twist mechanics were linearly related to rate pressure product. During exercise, the intra-individual variability of LV twist mechanics is smaller at the same relative exercise intensity compared with IAT. However, the absolute magnitude (degrees of LV twist mechanics appears to be associated with the prevailing rate pressure product. Exercise tests that evaluate LV twist mechanics should be standardised by relative exercise intensity and rate pressure product be taken into account when interpreting results.

  17. The Effects of Exercise Intensity vs. Metabolic State on the Variability and Magnitude of Left Ventricular Twist Mechanics during Exercise

    Science.gov (United States)

    Armstrong, Craig; Samuel, Jake; Yarlett, Andrew; Cooper, Stephen-Mark; Stembridge, Mike; Stöhr, Eric J.

    2016-01-01

    Increased left ventricular (LV) twist and untwisting rate (LV twist mechanics) are essential responses of the heart to exercise. However, previously a large variability in LV twist mechanics during exercise has been observed, which complicates the interpretation of results. This study aimed to determine some of the physiological sources of variability in LV twist mechanics during exercise. Sixteen healthy males (age: 22 ± 4 years, V˙O2peak: 45.5 ± 6.9 ml∙kg-1∙min-1, range of individual anaerobic threshold (IAT): 32–69% of V˙O2peak) were assessed at rest and during exercise at: i) the same relative exercise intensity, 40%peak, ii) at 2% above IAT, and, iii) at 40%peak with hypoxia (40%peak+HYP). LV volumes were not significantly different between exercise conditions (P > 0.05). However, the mean margin of error of LV twist was significantly lower (F2,47 = 2.08, P 0.05). Overall, LV twist mechanics were linearly related to rate pressure product. During exercise, the intra-individual variability of LV twist mechanics is smaller at the same relative exercise intensity compared with IAT. However, the absolute magnitude (degrees) of LV twist mechanics appears to be associated with the prevailing rate pressure product. Exercise tests that evaluate LV twist mechanics should be standardised by relative exercise intensity and rate pressure product be taken into account when interpreting results. PMID:27100099

  18. Wilmar Planning Tool, user guide

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Helge V.

    2006-01-15

    This is a short user guide to the Wilmar Planning Tool developed in the project Wind Power Integration in Liberalised Electricity Markets (WILMAR) supported by EU (Contract No. ENK5-CT-2002-00663). A User Shell implemented in an Excel workbook controls the Wilmar Planning Tool. All data are contained in Access databases that communicate with various sub-models through text files that are exported from or imported to the databases. In the User Shell various scenario variables and control parameters are set, and export of model data from the input database, activation of the models, as well as import of model results to the output database are triggered from the shell. (au)

  19. Motor origins of tool use.

    Science.gov (United States)

    Kahrs, Björn A; Jung, Wendy P; Lockman, Jeffrey J

    2013-01-01

    The current study examines the developmental trajectory of banging movements and its implications for tool use development. Twenty (6- to 15-month-old) infants wore reflective markers while banging a handled cube; movements were recorded at 240 Hz. Results indicated that through the second half-year, banging movements undergo developmental changes making them ideally suited for instrumental hammering and pounding. Younger infants were inefficient and variable when banging the object: Their hands followed circuitous paths of great lengths at high velocities. By 1 year, infants showed consistent and efficient straight up-down hand trajectories of smaller magnitude and velocity, allowing for precise aiming and delivering dependable levels of force. The findings suggest that tool use develops gradually from infants' existing manual behaviors. © 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.

  20. Wilmar Planning Tool, user guide

    International Nuclear Information System (INIS)

    Larsen, Helge V.

    2006-01-01

    This is a short user guide to the Wilmar Planning Tool developed in the project Wind Power Integration in Liberalised Electricity Markets (WILMAR) supported by EU (Contract No. ENK5-CT-2002-00663). A User Shell implemented in an Excel workbook controls the Wilmar Planning Tool. All data are contained in Access databases that communicate with various sub-models through text files that are exported from or imported to the databases. In the User Shell various scenario variables and control parameters are set, and export of model data from the input database, activation of the models, as well as import of model results to the output database are triggered from the shell. (au)

  1. Nanocomposites for Machining Tools

    Directory of Open Access Journals (Sweden)

    Daria Sidorenko

    2017-10-01

    Full Text Available Machining tools are used in many areas of production. To a considerable extent, the performance characteristics of the tools determine the quality and cost of obtained products. The main materials used for producing machining tools are steel, cemented carbides, ceramics and superhard materials. A promising way to improve the performance characteristics of these materials is to design new nanocomposites based on them. The application of micromechanical modeling during the elaboration of composite materials for machining tools can reduce the financial and time costs for development of new tools, with enhanced performance. This article reviews the main groups of nanocomposites for machining tools and their performance.

  2. Tool grinding machine

    Science.gov (United States)

    Dial, Sr., Charles E.

    1980-01-01

    The present invention relates to an improved tool grinding mechanism for grinding single point diamond cutting tools to precise roundness and radius specifications. The present invention utilizes a tool holder which is longitudinally displaced with respect to the remainder of the grinding system due to contact of the tool with the grinding surface with this displacement being monitored so that any variation in the grinding of the cutting surface such as caused by crystal orientation or tool thickness may be compensated for during the grinding operation to assure the attainment of the desired cutting tool face specifications.

  3. Improved tool grinding machine

    Science.gov (United States)

    Dial, C.E. Sr.

    The present invention relates to an improved tool grinding mechanism for grinding single point diamond cutting tools to precise roundness and radius specifications. The present invention utilizes a tool holder which is longitudinally displaced with respect to the remainder of the grinding system due to contact of the tool with the grinding surface with this displacement being monitored so that any variation in the grinding of the cutting surface such as caused by crystal orientation or tool thicknesses may be compensated for during the grinding operation to assure the attainment of the desired cutting tool face specifications.

  4. Integrated Wind Power Planning Tool

    DEFF Research Database (Denmark)

    Rosgaard, M. H.; Giebel, Gregor; Nielsen, T. S.

    2012-01-01

    model to be developed in collaboration with ENFOR A/S; a danish company that specialises in forecasting and optimisation for the energy sector. This integrated prediction model will allow for the description of the expected variability in wind power production in the coming hours to days, accounting......This poster presents the current state of the public service obligation (PSO) funded project PSO 10464, with the working title "Integrated Wind Power Planning Tool". The project commenced October 1, 2011, and the goal is to integrate a numerical weather prediction (NWP) model with purely...

  5. The tools of mathematical reasoning

    CERN Document Server

    Lakins, Tamara J

    2016-01-01

    This accessible textbook gives beginning undergraduate mathematics students a first exposure to introductory logic, proofs, sets, functions, number theory, relations, finite and infinite sets, and the foundations of analysis. The book provides students with a quick path to writing proofs and a practical collection of tools that they can use in later mathematics courses such as abstract algebra and analysis. The importance of the logical structure of a mathematical statement as a framework for finding a proof of that statement, and the proper use of variables, is an early and consistent theme used throughout the book.

  6. Cataclysmic Variable Stars

    Science.gov (United States)

    Hellier, Coel

    2001-01-01

    Cataclysmic variable stars are the most variable stars in the night sky, fluctuating in brightness continually on timescales from seconds to hours to weeks to years. The changes can be recorded using amateur telescopes, yet are also the subject of intensive study by professional astronomers. That study has led to an understanding of cataclysmic variables as binary stars, orbiting so closely that material transfers from one star to the other. The resulting process of accretion is one of the most important in astrophysics. This book presents the first account of cataclysmic variables at an introductory level. Assuming no previous knowledge of the field, it explains the basic principles underlying the variability, while providing an extensive compilation of cataclysmic variable light curves. Aimed at amateur astronomers, undergraduates, and researchers, the main text is accessible to those with no mathematical background, while supplementary boxes present technical details and equations.

  7. Understanding Brown Dwarf Variability

    Science.gov (United States)

    Marley, Mark S.

    2013-01-01

    Surveys of brown dwarf variability continue to find that roughly half of all brown dwarfs are variable. While variability is observed amongst all types of brown dwarfs, amplitudes are typically greatest for L-T transition objects. In my talk I will discuss the possible physical mechanisms that are responsible for the observed variability. I will particularly focus on comparing and contrasting the effects of changes in atmospheric thermal profile and cloud opacity. The two different mechanisms will produce different variability signatures and I will discuss the extent to which the current datasets constrain both mechanisms. By combining constraints from studies of variability with existing spectral and photometric datasets we can begin to construct and test self-consistent models of brown dwarf atmospheres. These models not only aid in the interpretation of existing objects but also inform studies of directly imaged giant planets.

  8. Tools of online Marketing

    OpenAIRE

    Hossain, M. S.; Rahman, M. F.

    2017-01-01

    Abstract Online marketing is the most crucial issue in the modern marketing era but there was no previous research that could identify the tools of internet marketing before this study and it was the first study on the field of online marketing tools. This research was descriptive in nature and it has attempted to identify the major tools of internet marketing from the concepts of traditional marketing tools. Worldwide network is known as Internet that can exchange information between use...

  9. OOTW COST TOOLS

    Energy Technology Data Exchange (ETDEWEB)

    HARTLEY, D.S.III; PACKARD, S.L.

    1998-09-01

    This document reports the results of a study of cost tools to support the analysis of Operations Other Than War (OOTW). It recommends the continued development of the Department of Defense (DoD) Contingency Operational Support Tool (COST) as the basic cost analysis tool for 00TWS. It also recommends modifications to be included in future versions of COST and the development of an 00TW mission planning tool to supply valid input for costing.

  10. Detecting intraannual dietary variability in wild mountain gorillas by stable isotope analysis of feces.

    Science.gov (United States)

    Blumenthal, Scott A; Chritz, Kendra L; Rothman, Jessica M; Cerling, Thure E

    2012-12-26

    We use stable isotope ratios in feces of wild mountain gorillas (Gorilla beringei) to test the hypothesis that diet shifts within a single year, as measured by dry mass intake, can be recovered. Isotopic separation of staple foods indicates that intraannual changes in the isotopic composition of feces reflect shifts in diet. Fruits are isotopically distinct compared with other staple foods, and peaks in fecal δ(13)C values are interpreted as periods of increased fruit feeding. Bayesian mixing model results demonstrate that, although the timing of these diet shifts match observational data, the modeled increase in proportional fruit feeding does not capture the full shift. Variation in the isotopic and nutritional composition of gorilla foods is largely independent, highlighting the difficulty for estimating nutritional intake with stable isotopes. Our results demonstrate the potential value of fecal sampling for quantifying short-term, intraindividual dietary variability in primates and other animals with high temporal resolution even when the diet is composed of C(3) plants.

  11. Selecting candidate predictor variables for the modelling of post ...

    African Journals Online (AJOL)

    Objectives: The objective of this project was to determine the variables most likely to be associated with post- .... (as defined subjectively by the research team) in global .... ed on their lack of knowledge of wealth scoring tools. ... HIV serology.

  12. Laboratory development of wind turbine simulator using variable ...

    African Journals Online (AJOL)

    user

    1*Department of Electronics Engineering, Prof. ... In this paper variable speed induction motor drive using scalar control is interfaced in wind energy conversion ... the wind turbine simulator is used as a necessary tool in research laboratories.

  13. Pro Tools HD

    CERN Document Server

    Camou, Edouard

    2013-01-01

    An easy-to-follow guide for using Pro Tools HD 11 effectively.This book is ideal for anyone who already uses ProTools and wants to learn more, or is new to Pro Tools HD and wants to use it effectively in their own audio workstations.

  14. Nanocomposites for Machining Tools

    DEFF Research Database (Denmark)

    Sidorenko, Daria; Loginov, Pavel; Mishnaevsky, Leon

    2017-01-01

    Machining tools are used in many areas of production. To a considerable extent, the performance characteristics of the tools determine the quality and cost of obtained products. The main materials used for producing machining tools are steel, cemented carbides, ceramics and superhard materials...

  15. The nebular variables

    CERN Document Server

    Glasby, John S

    1974-01-01

    The Nebular Variables focuses on the nebular variables and their characteristics. Discussions are organized by type of nebular variable, namely, RW Aurigae stars, T Orionis stars, T Tauri stars, and peculiar nebular objects. Topics range from light variations of the stars to their spectroscopic and physical characteristics, spatial distribution, interaction with nebulosity, and evolutionary features. This volume is divided into four sections and consists of 25 chapters, the first of which provides general information on nebular variables, including their stellar associations and their classifi

  16. Ultrasonic variables affecting inspection

    International Nuclear Information System (INIS)

    Lautzenheiser, C.E.; Whiting, A.R.; McElroy, J.T.

    1977-01-01

    There are many variables which affect the detection of the effects and reproducibility of results when utilizing ultrasonic techniques. The most important variable is the procedure, as this document specifies, to a great extent, the controls that are exercised over the other variables. The most important variable is personnel with regards to training, qualification, integrity, data recording, and data analysis. Although the data is very limited, these data indicate that, if the procedure is carefully controlled, reliability of defect detection and reproducibility of results are both approximately 90 percent for reliability of detection, this applies to relatively small defects as reliability increases substantially as defect size increases above the recording limit. (author)

  17. Patient Satisfaction After Femoral Arterial Access Site Closure Using the ExoSeal{sup ®} Vascular Closure Device Compared to Manual Compression: A Prospective Intra-individual Comparative Study

    Energy Technology Data Exchange (ETDEWEB)

    Pieper, Claus Christian, E-mail: claus.christian.pieper@ukb.uni-bonn.de; Thomas, Daniel, E-mail: daniel.thomas@ukb.uni-bonn.de [University of Bonn, Department of Radiology (Germany); Nadal, Jennifer, E-mail: jennifer.nadal@ukb.uni-bonn.de [University of Bonn, Institute for Medical Biometry, Informatics and Epidemiology (Germany); Willinek, Winfried A., E-mail: w.willinek@bk-trier.de; Schild, Hans Heinz, E-mail: hans.schild@ukb.uni-bonn.de; Meyer, Carsten, E-mail: carsten.meyer@ukb.uni-bonn.de [University of Bonn, Department of Radiology (Germany)

    2016-01-15

    PurposeTo intra-individually compare discomfort levels and patient satisfaction after arterial access closure using the ExoSeal{sup ®} vascular closure device (VCD) and manual compression (MC) in a prospective study design.MethodsPatients undergoing two planned interventions from 07/2013 to 09/2014 could participate in the study. Access closure was performed with an ExoSeal{sup ®}-VCD in one and MC in the other intervention. Patients were clinically and sonographically examined and were given questionnaires 1 day after intervention [groin- and back-pain during bedrest (100-point visual analog scale; 0: no pain); comfortability of bedrest (10-point Likert scale, 1: comfortable), satisfaction with closure (10-point Likert scale, 1: very satisfied)]. Results were analyzed in a cross-over design.Results48 patients (29 male, median age 62.5 (32–88) years) were included. An ExoSeal{sup ®}-VCD was used first in 25 cases. As four of these subsequently refused MC as second intervention, data from 44 patients could be analyzed. All closures were technically successful (successful device deployment) without major complications. Groin- and back-pain after VCD-use/MC was 0 (0–15) vs. 10 (0–80) and 0 (0–75) vs. 25 (0–90), respectively (p < 0.0001). Bedrest after VCD-use was more comfortable than after MC [1 (range 1–7) vs. 6 (2–10); p < 0.0001]. Satisfaction with the closure procedure and with the intervention in general was higher after VCD-use compared to MC [1 (1–3) vs. 5 (2–10) and 1 (1–2) vs. 2 (1–4), respectively; p < 0.0001].ConclusionIntra-individual comparison showed pain levels and discomfort to be significantly lower after ExoSeal{sup ®} use compared to MC. VCD closure was associated with higher satisfaction both with the closure itself and with the intervention in general.

  18. Less is better? Intraindividual and interindividual comparison between 0.075 mmol/kg of gadobenate dimeglumine and 0.1 mmol/kg of gadoterate meglumine for cranial MRI

    Energy Technology Data Exchange (ETDEWEB)

    Khouri Chalouhi, Katia, E-mail: khouri.katia@gmail.com [Scuola di Specializzazione in Radiodiagnostica, Università degli Studi di Milano, Via Festa del Perdono 7, 20122 Milan (Italy); Papini, Giacomo D.E., E-mail: docgde@gmail.com [Unità di Radiologia, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan (Italy); Bandirali, Michele, E-mail: michele.bandirali@hotmail.it [Scuola di Specializzazione in Radiodiagnostica, Università degli Studi di Milano, Via Festa del Perdono 7, 20122 Milan (Italy); Sconfienza, Luca M., E-mail: io@lucasconfienza.it [Unità di Radiologia, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan (Italy); Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Morandi 30, 20097 San Donato Milanese, Milano (Italy); Di Leo, Giovanni, E-mail: gianni.dileo77@gmail.com [Unità di Radiologia, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan (Italy); Sardanelli, Francesco, E-mail: francesco.sardanelli@unimi.it [Unità di Radiologia, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan (Italy); Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Via Morandi 30, 20097 San Donato Milanese, Milano (Italy)

    2014-07-15

    Purpose: To retrospectively compare a reduced dose (RD) (0.075 mmol/kg) of gadobenate dimeglumine (RD-gadobenate) with standard single dose (SSD) (0.1 mmol/kg) of gadoterate meglumine (SSD-gadoterate) for cranial MRI. Materials and methods: Thirty-one patients (12 males; aged 52 ± 16 years) underwent cranial MRI with SSD-gadoterate and repeated the examination with RD-gadobenate after a median interval of 10 months. Signal-to-noise ratio (SNR) was obtained on contrast-enhanced images for enhancing lesions (n = 10) as well as for right and left transverse venous sinuses, internal carotid arteries, and parotid glands. Moreover, a consecutive series of 100 cranial MRI with SSD-gadoterate (49 males; aged 51 ± 19 years) was compared with a consecutive series of 100 cranial MRI with RD-gadobenate (45 males; aged 54 ± 18 years). Two blinded neuroradiologists (R1, R2) judged contrast enhancement as sufficient, good, or optimal. Wilcoxon, Mann–Whitney, χ{sup 2}, and Cohen κ statistics were used. Results: At intraindividual analysis, median SNR ranged 57–88 for SSD-gadoterate and 79–99 for RD-gadobenate, the latter being systematically higher, the difference being significant for both transverse venous sinuses (p ≤ 0.011), not significant for both internal carotid arteries and both parotid glands, and enhancing lesions (p ≤ 0.101). The two series of interindividual analysis were not significantly different for gender/age (p > 0.415). Contrast enhancement was optimal in 59% (R1) and 76% (R2) of patients using RD-gadobenate, in 39% (R1) and 49% (R2) of patients using SSD-gadoterate (p ≤ 0.016), with substantial reproducibility (κ ≥ 0.606). Conclusion: Both analyses showed an equal or better contrast enhancement when using RD-gadobenate compared to SSD-gadoterate for routine cranial MRI. The high relaxivity of gadobenate allowed for a 25% dose reduction.

  19. Simultaneous analysis of naphthols, phenanthrols, and 1-hydroxypyrene in urine as biomarkers of polycyclic aromatic hydrocarbon exposure: intraindividual variance in the urinary metabolite excretion profiles caused by intervention with {beta}-naphthoflavone induction in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Elovaara, Eivor; Mikkola, Jouni [Laboratory of Toxicokinetics and Metabolism, Department of Industrial Hygiene and Toxicology, Finnish Institute of Occupational Health, 00250, Helsinki (Finland); Vaeaenaenen, Virpi [Chemistry Laboratory, Department of Industrial Hygiene and Toxicology, Finnish Institute of Occupational Health, 00250, Helsinki (Finland)

    2003-04-01

    . This intervention study clarifies intraindividual variation in PAH metabolism and provides useful information for the development of new methods applicable in the biomonitoring of PAH exposure in humans. (orig.)

  20. Less is better? Intraindividual and interindividual comparison between 0.075 mmol/kg of gadobenate dimeglumine and 0.1 mmol/kg of gadoterate meglumine for cranial MRI

    International Nuclear Information System (INIS)

    Khouri Chalouhi, Katia; Papini, Giacomo D.E.; Bandirali, Michele; Sconfienza, Luca M.; Di Leo, Giovanni; Sardanelli, Francesco

    2014-01-01

    Purpose: To retrospectively compare a reduced dose (RD) (0.075 mmol/kg) of gadobenate dimeglumine (RD-gadobenate) with standard single dose (SSD) (0.1 mmol/kg) of gadoterate meglumine (SSD-gadoterate) for cranial MRI. Materials and methods: Thirty-one patients (12 males; aged 52 ± 16 years) underwent cranial MRI with SSD-gadoterate and repeated the examination with RD-gadobenate after a median interval of 10 months. Signal-to-noise ratio (SNR) was obtained on contrast-enhanced images for enhancing lesions (n = 10) as well as for right and left transverse venous sinuses, internal carotid arteries, and parotid glands. Moreover, a consecutive series of 100 cranial MRI with SSD-gadoterate (49 males; aged 51 ± 19 years) was compared with a consecutive series of 100 cranial MRI with RD-gadobenate (45 males; aged 54 ± 18 years). Two blinded neuroradiologists (R1, R2) judged contrast enhancement as sufficient, good, or optimal. Wilcoxon, Mann–Whitney, χ 2 , and Cohen κ statistics were used. Results: At intraindividual analysis, median SNR ranged 57–88 for SSD-gadoterate and 79–99 for RD-gadobenate, the latter being systematically higher, the difference being significant for both transverse venous sinuses (p ≤ 0.011), not significant for both internal carotid arteries and both parotid glands, and enhancing lesions (p ≤ 0.101). The two series of interindividual analysis were not significantly different for gender/age (p > 0.415). Contrast enhancement was optimal in 59% (R1) and 76% (R2) of patients using RD-gadobenate, in 39% (R1) and 49% (R2) of patients using SSD-gadoterate (p ≤ 0.016), with substantial reproducibility (κ ≥ 0.606). Conclusion: Both analyses showed an equal or better contrast enhancement when using RD-gadobenate compared to SSD-gadoterate for routine cranial MRI. The high relaxivity of gadobenate allowed for a 25% dose reduction

  1. Pickering tool management system

    International Nuclear Information System (INIS)

    Wong, E.H.; Green, A.H.

    1997-01-01

    Tools were being deployed in the station with no process in effect to ensure that they are maintained in good repair so as to effectively support the performance of Maintenance activities. Today's legal requirements require that all employers have a process in place to ensure that tools are maintained in a safe condition. This is specified in the Ontario Health and Safety Act. The Pickering Tool Management System has been chosen as the process at Pickering N.D to manage tools. Tools are identified by number etching and bar codes. The system is a Windows application installed on several file servers

  2. Machine tool structures

    CERN Document Server

    Koenigsberger, F

    1970-01-01

    Machine Tool Structures, Volume 1 deals with fundamental theories and calculation methods for machine tool structures. Experimental investigations into stiffness are discussed, along with the application of the results to the design of machine tool structures. Topics covered range from static and dynamic stiffness to chatter in metal cutting, stability in machine tools, and deformations of machine tool structures. This volume is divided into three sections and opens with a discussion on stiffness specifications and the effect of stiffness on the behavior of the machine under forced vibration c

  3. Variable volume combustor

    Science.gov (United States)

    Ostebee, Heath Michael; Ziminsky, Willy Steve; Johnson, Thomas Edward; Keener, Christopher Paul

    2017-01-17

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a linear actuator so as to maneuver the micro-mixer fuel nozzles axially along the liner.

  4. Collective variables and dissipation

    International Nuclear Information System (INIS)

    Balian, R.

    1984-09-01

    This is an introduction to some basic concepts of non-equilibrium statistical mechanics. We emphasize in particular the relevant entropy relative to a given set of collective variables, the meaning of the projection method in the Liouville space, its use to establish the generalized transport equations for these variables, and the interpretation of dissipation in the framework of information theory

  5. Variability: A Pernicious Hypothesis.

    Science.gov (United States)

    Noddings, Nel

    1992-01-01

    The hypothesis of greater male variability in test results is discussed in its historical context, and reasons feminists have objected to the hypothesis are considered. The hypothesis acquires political importance if it is considered that variability results from biological, rather than cultural, differences. (SLD)

  6. Reinforcing Saccadic Amplitude Variability

    Science.gov (United States)

    Paeye, Celine; Madelain, Laurent

    2011-01-01

    Saccadic endpoint variability is often viewed as the outcome of neural noise occurring during sensorimotor processing. However, part of this variability might result from operant learning. We tested this hypothesis by reinforcing dispersions of saccadic amplitude distributions, while maintaining constant their medians. In a first experiment we…

  7. POVMs and hidden variables

    International Nuclear Information System (INIS)

    Stairs, Allen

    2007-01-01

    Recent results by Paul Busch and Adan Cabello claim to show that by appealing to POVMs, non-contextual hidden variables can be ruled out in two dimensions. While the results of Busch and Cabello are mathematically correct, interpretive problems render them problematic as no hidden variable proofs

  8. Interdependence Among Organizational Variables

    Science.gov (United States)

    Knowles, M. C.

    1975-01-01

    The interrelationship between a set of organizational variables was investigated at 14 work organizations within a company. The variables were production, quality, costs, job satisfaction of operatives, job satisfaction of supervisors, work anxiety, accidents, absence, labor turnover, and industrial unrest. (Author)

  9. DATA COLLECTION METHOD FOR PEDESTRIAN MOVEMENT VARIABLES

    Directory of Open Access Journals (Sweden)

    Hajime Inamura

    2000-01-01

    Full Text Available The need of tools for design and evaluation of pedestrian areas, subways stations, entrance hall, shopping mall, escape routes, stadium etc lead to the necessity of a pedestrian model. One approach pedestrian model is Microscopic Pedestrian Simulation Model. To be able to develop and calibrate a microscopic pedestrian simulation model, a number of variables need to be considered. As the first step of model development, some data was collected using video and the coordinate of the head path through image processing were also taken. Several numbers of variables can be gathered to describe the behavior of pedestrian from a different point of view. This paper describes how to obtain variables from video taking and simple image processing that can represent the movement of pedestrians and its variables

  10. Variability of skin autofluorescence measurement over 6 and 12 weeks and the influence of benfotiamine treatment.

    Science.gov (United States)

    Stirban, Alin; Pop, Alexandra; Fischer, Annelie; Heckermann, Sascha; Tschoepe, Diethelm

    2013-09-01

    Measurements of skin autofluorescence (SAF) allow for a simple and noninvasive quantification of tissue advanced glycation end-products (AGEs), a marker linked to the risk of diabetes complications. The aim of this study was to test the repeatability of SAF over 6 and 12 weeks and to test whether benfotiamine, a thiamine prodrug suggested to reduce AGEs formation under hyperglycemic conditions, is able to attenuate SAF when administered over 6 weeks. In a double-blind, placebo-controlled, randomized, crossover study, 22 patients with type 2 diabetes mellitus (T2DM) received 900 mg/day benfotiamine or placebo for 6 weeks (washout period of 6 weeks between). At the beginning and at the end of each treatment period, SAF was assessed in the fasting state, as well as 2, 4, and 6 h following a mixed test meal. The respective intra-individual and inter-individual variability of fasting SAF was 6.9% and 24.5% within 6 weeks and 10.9% and 23.1% within 12 weeks. The respective variability calculated for triplicate comparisons was 9.9% and 27.7%. A short-term therapy with benfotiamine did not influence SAF significantly, nor did we find a significant postprandial SAF increase. In patients with T2DM, repeated, timely spaced SAF measurements have an intra-subject variability of below 11%. Using these data, sample sizes were calculated for interventional studies aiming at reducing SAF. Benfotiamine treatment for 6 weeks did not significantly influence SAF; for this, a longer-term therapy is probably needed.

  11. Interseason variability in isokinetic strength and poor correlation with Nordic hamstring eccentric strength in football players.

    Science.gov (United States)

    van Dyk, N; Witvrouw, E; Bahr, R

    2018-04-25

    In elite sport, the use of strength testing to establish muscle function and performance is common. Traditionally, isokinetic strength tests have been used, measuring torque during concentric and eccentric muscle action. A device that measures eccentric hamstring muscle strength while performing the Nordic hamstring exercise is now also frequently used. The study aimed to investigate the variability of isokinetic muscle strength over time, for example, between seasons, and the relationship between isokinetic testing and the new Nordic hamstring exercise device. All teams (n = 18) eligible to compete in the premier football league in Qatar underwent a comprehensive strength assessment during their periodic health evaluation at Aspetar Orthopaedic and Sports Medicine Hospital in Qatar. Isokinetic strength was investigated for measurement error, and correlated to Nordic hamstring exercise strength. Of the 529 players included, 288 players had repeated tests with 1/2 seasons between test occasions. Variability (measurement error) between test occasions was substantial, as demonstrated by the measurement error (approximately 25 Nm, 15%), whether separated by 1 or 2 seasons. Considering hamstring injuries, the same pattern was observed among injured (n = 60) and uninjured (n = 228) players. A poor correlation (r = .35) was observed between peak isokinetic hamstring eccentric torque and Nordic hamstring exercise peak force. The strength imbalance between limbs calculated for both test modes was not correlated (r = .037). There is substantial intraindividual variability in all isokinetic test measures, whether separated by 1 or 2 seasons, irrespective of injury. Also, eccentric hamstring strength and limb-to-limb imbalance were poorly correlated between the isokinetic and Nordic hamstring exercise tests. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. A standardized approach to study human variability in isometric thermogenesis during low-intensity physical activity

    Directory of Open Access Journals (Sweden)

    Delphine eSarafian

    2013-07-01

    Full Text Available Limitations of current methods: The assessment of human variability in various compartments of daily energy expenditure (EE under standardized conditions is well defined at rest (as basal metabolic rate and thermic effect of feeding, and currently under validation for assessing the energy cost of low-intensity dynamic work. However, because physical activities of daily life consist of a combination of both dynamic and isometric work, there is also a need to develop standardized tests for assessing human variability in the energy cost of low-intensity isometric work.Experimental objectives: Development of an approach to study human variability in isometric thermogenesis by incorporating a protocol of intermittent leg press exercise of varying low-intensity isometric loads with measurements of EE by indirect calorimetry. Results: EE was measured in the seated position with the subject at rest or while intermittently pressing both legs against a press-platform at 5 low-intensity isometric loads (+5, +10, + 15, +20 and +25 kg force, each consisting of a succession of 8 cycles of press (30 s and rest (30 s. EE, integrated over each 8-min period of the intermittent leg press exercise, was found to increase linearly across the 5 isometric loads with a correlation coefficient (r > 0.9 for each individual. The slope of this EE-Load relationship, which provides the energy cost of this standardized isometric exercise expressed per kg force applied intermittently (30 s in every min, was found to show good repeatability when assessed in subjects who repeated the same experimental protocol on 3 separate days: its low intra-individual coefficient of variation (CV of ~ 10% contrasted with its much higher inter-individual CV of 35%; the latter being mass-independent but partly explained by height. Conclusion: This standardized approach to study isometric thermogenesis opens up a new avenue for research in EE phenotyping and metabolic predisposition to obesity

  13. Soil variability in engineering applications

    Science.gov (United States)

    Vessia, Giovanna

    2014-05-01

    Natural geomaterials, as soils and rocks, show spatial variability and heterogeneity of physical and mechanical properties. They can be measured by in field and laboratory testing. The heterogeneity concerns different values of litho-technical parameters pertaining similar lithological units placed close to each other. On the contrary, the variability is inherent to the formation and evolution processes experienced by each geological units (homogeneous geomaterials on average) and captured as a spatial structure of fluctuation of physical property values about their mean trend, e.g. the unit weight, the hydraulic permeability, the friction angle, the cohesion, among others. The preceding spatial variations shall be managed by engineering models to accomplish reliable designing of structures and infrastructures. Materon (1962) introduced the Geostatistics as the most comprehensive tool to manage spatial correlation of parameter measures used in a wide range of earth science applications. In the field of the engineering geology, Vanmarcke (1977) developed the first pioneering attempts to describe and manage the inherent variability in geomaterials although Terzaghi (1943) already highlighted that spatial fluctuations of physical and mechanical parameters used in geotechnical designing cannot be neglected. A few years later, Mandelbrot (1983) and Turcotte (1986) interpreted the internal arrangement of geomaterial according to Fractal Theory. In the same years, Vanmarcke (1983) proposed the Random Field Theory providing mathematical tools to deal with inherent variability of each geological units or stratigraphic succession that can be resembled as one material. In this approach, measurement fluctuations of physical parameters are interpreted through the spatial variability structure consisting in the correlation function and the scale of fluctuation. Fenton and Griffiths (1992) combined random field simulation with the finite element method to produce the Random

  14. Two methods for studying the X-ray variability

    NARCIS (Netherlands)

    Yan, Shu-Ping; Ji, Li; Méndez, Mariano; Wang, Na; Liu, Siming; Li, Xiang-Dong

    2016-01-01

    The X-ray aperiodic variability and quasi-periodic oscillation (QPO) are the important tools to study the structure of the accretion flow of X-ray binaries. However, the origin of the complex X-ray variability from X-ray binaries remains yet unsolved. We proposed two methods for studying the X-ray

  15. First International Workshop on Variability in Software Architecture (VARSA 2011)

    NARCIS (Netherlands)

    Galster, Matthias; Avgeriou, Paris; Weyns, Danny; Mannisto, Tomi

    2011-01-01

    Variability is the ability of a software artifact to be changed for a specific context. Mechanisms to accommodate variability include software product lines, configuration wizards and tools in commercial software, configuration interfaces of software components, or the dynamic runtime composition of

  16. Rapidly variable relatvistic absorption

    Science.gov (United States)

    Parker, M.; Pinto, C.; Fabian, A.; Lohfink, A.; Buisson, D.; Alston, W.; Jiang, J.

    2017-10-01

    I will present results from the 1.5Ms XMM-Newton observing campaign on the most X-ray variable AGN, IRAS 13224-3809. We find a series of nine absorption lines with a velocity of 0.24c from an ultra-fast outflow. For the first time, we are able to see extremely rapid variability of the UFO features, and can link this to the X-ray variability from the inner accretion disk. We find a clear flux dependence of the outflow features, suggesting that the wind is ionized by increasing X-ray emission.

  17. Open Health Tools: Tooling for Interoperable Healthcare

    Directory of Open Access Journals (Sweden)

    Skip McGaughey

    2008-11-01

    Full Text Available The Open Health Tools initiative is creating an ecosystem focused on the production of software tooling that promotes the exchange of medical information across political, geographic, cultural, product, and technology lines. At its core, OHT believes that the availability of high-quality tooling that interoperates will propel the industry forward, enabling organizations and vendors to build products and systems that effectively work together. This will ?raise the interoperability bar? as a result of having tools that just work. To achieve these lofty goals, careful consideration must be made to the constituencies that will be most affected by an OHT-influenced world. This document outlines a vision of OHT?s impact to these stakeholders. It does not explain the OHT process itself or how the OHT community operates. Instead, we place emphasis on the impact of that process within the health industry. The catchphrase ?code is king? underpins this document, meaning that the manifestation of any open source community lies in the products and technology it produces.

  18. Improvement of the variable storage coefficient method with water surface gradient as a variable

    Science.gov (United States)

    The variable storage coefficient (VSC) method has been used for streamflow routing in continuous hydrological simulation models such as the Agricultural Policy/Environmental eXtender (APEX) and the Soil and Water Assessment Tool (SWAT) for more than 30 years. APEX operates on a daily time step and ...

  19. Eternity Variables to Simulate Specifications

    NARCIS (Netherlands)

    Hesselink, WH; Boiten, EA; Moller, B

    2002-01-01

    Simulation of specifications is introduced as a unification and generalization of refinement mappings, history variables, forward simulations, prophecy variables, and backward simulations. Eternity variables are introduced as a more powerful alternative for prophecy variables and backward

  20. Scheme Program Documentation Tools

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2004-01-01

    are separate and intended for different documentation purposes they are related to each other in several ways. Both tools are based on XML languages for tool setup and for documentation authoring. In addition, both tools rely on the LAML framework which---in a systematic way---makes an XML language available...... as named functions in Scheme. Finally, the Scheme Elucidator is able to integrate SchemeDoc resources as part of an internal documentation resource....

  1. Annual Research Review: Reaction time variability in ADHD and autism spectrum disorders: measurement and mechanisms of a proposed trans-diagnostic phenotype

    Science.gov (United States)

    Karalunas, Sarah L.; Geurts, Hilde M.; Konrad, Kerstin; Bender, Stephan; Nigg, Joel T.

    2014-01-01

    Background Intraindividual variability in reaction time (RT) has received extensive discussion as an indicator of cognitive performance, a putative intermediate phenotype of many clinical disorders, and a possible trans-diagnostic phenotype that may elucidate shared risk factors for mechanisms of psychiatric illnesses. Scope and Methodology Using the examples of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD), we discuss RT variability. We first present a new meta-analysis of RT variability in ASD with and without comorbid ADHD. We then discuss potential mechanisms that may account for RT variability and statistical models that disentangle the cognitive processes affecting RTs. We then report a second meta-analysis comparing ADHD and non-ADHD children on diffusion model parameters. We consider how findings inform the search for neural correlates of RT variability. Findings Results suggest that RT variability is increased in ASD only when children with comorbid ADHD are included in the sample. Furthermore, RT variability in ADHD is explained by moderate to large increases (d = 0.63–0.99) in the ex-Gaussian parameter τ and the diffusion parameter drift rate, as well as by smaller differences (d = 0.32) in the diffusion parameter of nondecision time. The former may suggest problems in state regulation or arousal and difficulty detecting signal from noise, whereas the latter may reflect contributions from deficits in motor organization or output. The neuroimaging literature converges with this multicomponent interpretation and also highlights the role of top-down control circuits. Conclusion We underscore the importance of considering the interactions between top-down control, state regulation (e.g. arousal), and motor preparation when interpreting RT variability and conclude that decomposition of the RT signal provides superior interpretive power and suggests mechanisms convergent with those implicated using other cognitive

  2. Agreement Workflow Tool (AWT)

    Data.gov (United States)

    Social Security Administration — The Agreement Workflow Tool (AWT) is a role-based Intranet application used for processing SSA's Reimbursable Agreements according to SSA's standards. AWT provides...

  3. Instant Spring Tool Suite

    CERN Document Server

    Chiang, Geoff

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. A tutorial guide that walks you through how to use the features of Spring Tool Suite using well defined sections for the different parts of Spring.Instant Spring Tool Suite is for novice to intermediate Java developers looking to get a head-start in enterprise application development using Spring Tool Suite and the Spring framework. If you are looking for a guide for effective application development using Spring Tool Suite, then this book is for you.

  4. Chimera Grid Tools

    Science.gov (United States)

    Chan, William M.; Rogers, Stuart E.; Nash, Steven M.; Buning, Pieter G.; Meakin, Robert

    2005-01-01

    Chimera Grid Tools (CGT) is a software package for performing computational fluid dynamics (CFD) analysis utilizing the Chimera-overset-grid method. For modeling flows with viscosity about geometrically complex bodies in relative motion, the Chimera-overset-grid method is among the most computationally cost-effective methods for obtaining accurate aerodynamic results. CGT contains a large collection of tools for generating overset grids, preparing inputs for computer programs that solve equations of flow on the grids, and post-processing of flow-solution data. The tools in CGT include grid editing tools, surface-grid-generation tools, volume-grid-generation tools, utility scripts, configuration scripts, and tools for post-processing (including generation of animated images of flows and calculating forces and moments exerted on affected bodies). One of the tools, denoted OVERGRID, is a graphical user interface (GUI) that serves to visualize the grids and flow solutions and provides central access to many other tools. The GUI facilitates the generation of grids for a new flow-field configuration. Scripts that follow the grid generation process can then be constructed to mostly automate grid generation for similar configurations. CGT is designed for use in conjunction with a computer-aided-design program that provides the geometry description of the bodies, and a flow-solver program.

  5. Easy QC 7 tools

    International Nuclear Information System (INIS)

    1981-04-01

    This book explains method of QC 7 tools, mind for using QC 7 tools, effect of QC 7 tools application, giving descriptions of graph, pareto's diagram like application writing way and using method of pareto's diagram, characteristic diagram, check sheet such as purpose and subject of check, goals and types of check sheet, and using point of check sheet, histogram like application and using method, and stratification, scatterplot, control chart, promotion method and improvement and cases of practice of QC tools.

  6. Java Power Tools

    CERN Document Server

    Smart, John

    2008-01-01

    All true craftsmen need the best tools to do their finest work, and programmers are no different. Java Power Tools delivers 30 open source tools designed to improve the development practices of Java developers in any size team or organization. Each chapter includes a series of short articles about one particular tool -- whether it's for build systems, version control, or other aspects of the development process -- giving you the equivalent of 30 short reference books in one package. No matter which development method your team chooses, whether it's Agile, RUP, XP, SCRUM, or one of many other

  7. Easy QC 7 tools

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1981-04-15

    This book explains method of QC 7 tools, mind for using QC 7 tools, effect of QC 7 tools application, giving descriptions of graph, pareto's diagram like application writing way and using method of pareto's diagram, characteristic diagram, check sheet such as purpose and subject of check, goals and types of check sheet, and using point of check sheet, histogram like application and using method, and stratification, scatterplot, control chart, promotion method and improvement and cases of practice of QC tools.

  8. Qlikview Audit Tool (QLIKVIEW) -

    Data.gov (United States)

    Department of Transportation — This tool supports the cyclical financial audit process. Qlikview supports large volumes of financial transaction data that can be mined, summarized and presented to...

  9. Variable Attitude Test Stand

    Data.gov (United States)

    Federal Laboratory Consortium — The Variable Attitude Test Stand designed and built for testing of the V-22 tilt rotor aircraft propulsion system, is used to evaluate the effect of aircraft flight...

  10. Several complex variables

    International Nuclear Information System (INIS)

    Field, M.J.

    1976-01-01

    Topics discussed include the elementary of holomorphic functions of several complex variables; the Weierstrass preparation theorem; meromorphic functions, holomorphic line bundles and divisors; elliptic operators on compact manifolds; hermitian connections; the Hodge decomposition theorem. ( author)

  11. Variable-Rate Premiums

    Data.gov (United States)

    Pension Benefit Guaranty Corporation — These interest rates are used to value vested benefits for variable rate premium purposes as described in PBGC's regulation on Premium Rates (29 CFR Part 4006) and...

  12. Variable Pricing Feasibility Assessment

    National Research Council Canada - National Science Library

    2004-01-01

    ...) and Willard Bishop Consulting (Barrington, IL) to evaluate the practicality of using a variable pricing system within DeCA to maintain an average of 30 percent customer savings and lower appropriated fund costs...

  13. Evolution of variable stars

    International Nuclear Information System (INIS)

    Becker, S.A.

    1986-08-01

    Throughout the domain of the H R diagram lie groupings of stars whose luminosity varies with time. These variable stars can be classified based on their observed properties into distinct types such as β Cephei stars, δ Cephei stars, and Miras, as well as many other categories. The underlying mechanism for the variability is generally felt to be due to four different causes: geometric effects, rotation, eruptive processes, and pulsation. In this review the focus will be on pulsation variables and how the theory of stellar evolution can be used to explain how the various regions of variability on the H R diagram are populated. To this end a generalized discussion of the evolutionary behavior of a massive star, an intermediate mass star, and a low mass star will be presented. 19 refs., 1 fig., 1 tab

  14. Calculus of one variable

    CERN Document Server

    Grossman, Stanley I

    1986-01-01

    Calculus of One Variable, Second Edition presents the essential topics in the study of the techniques and theorems of calculus.The book provides a comprehensive introduction to calculus. It contains examples, exercises, the history and development of calculus, and various applications. Some of the topics discussed in the text include the concept of limits, one-variable theory, the derivatives of all six trigonometric functions, exponential and logarithmic functions, and infinite series.This textbook is intended for use by college students.

  15. Software Testing Requires Variability

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    2003-01-01

    Software variability is the ability of a software system or artefact to be changed, customized or configured for use in a particular context. Variability in software systems is important from a number of perspectives. Some perspectives rightly receive much attention due to their direct economic...... impact in software production. As is also apparent from the call for papers these perspectives focus on qualities such as reuse, adaptability, and maintainability....

  16. Suspended graphene variable capacitor

    OpenAIRE

    AbdelGhany, M.; Mahvash, F.; Mukhopadhyay, M.; Favron, A.; Martel, R.; Siaj, M.; Szkopek, T.

    2016-01-01

    The tuning of electrical circuit resonance with a variable capacitor, or varactor, finds wide application with the most important being wireless telecommunication. We demonstrate an electromechanical graphene varactor, a variable capacitor wherein the capacitance is tuned by voltage controlled deflection of a dense array of suspended graphene membranes. The low flexural rigidity of graphene monolayers is exploited to achieve low actuation voltage in an ultra-thin structure. Large arrays compr...

  17. The induction on a continuous variable

    International Nuclear Information System (INIS)

    Zhang Jingzhong.

    1989-06-01

    Mathematical induction is a useful tool. But it could be used to prove only the proposition with form P(n) for the natural number n. Could the natural number n be replaced by a continuous variable x? Yes, and then we have the continuous induction. The continuous induction is very easy to grasp by the students who have learned mathematical induction. And it can be used to prove many basic propositions in the elementary calculus. (author)

  18. EPR design tools. Integrated data processing tools

    International Nuclear Information System (INIS)

    Kern, R.

    1997-01-01

    In all technical areas, planning and design have been supported by electronic data processing for many years. New data processing tools had to be developed for the European Pressurized Water Reactor (EPR). The work to be performed was split between KWU and Framatome and laid down in the Basic Design contract. The entire plant was reduced to a logical data structure; the circuit diagrams and flowsheets of the systems were drafted, the central data pool was established, the outlines of building structures were defined, the layout of plant components was planned, and the electrical systems were documented. Also building construction engineering was supported by data processing. The tasks laid down in the Basic Design were completed as so-called milestones. Additional data processing tools also based on the central data pool are required for the phases following after the Basic Design phase, i.e Basic Design Optimization; Detailed Design; Management; Construction, and Commissioning. (orig.) [de

  19. Data Tools and Apps

    Science.gov (United States)

    Employment and Payroll Survey of Business Owners Work from Home Our statistics highlight trends in household statistics from multiple surveys. Data Tools & Apps Main American FactFinder Census Business Builder My ). Business Dynamics Statistics This tool shows tabulations on establishments, firms, and employment with

  20. Evaluating meeting support tools

    NARCIS (Netherlands)

    Post, W.M.; Huis in 't Veld, M. M.A.; Boogaard, S.A.A. van den

    2007-01-01

    Many attempts are underway for developing meeting support tools, but less attention is paid to the evaluation of meetingware. This article describes the development and testing of an instrument for evaluating meeting tools. First, we specified the object of evaluation -meetings- by means of a set of

  1. Maailma suurim tool

    Index Scriptorium Estoniae

    2000-01-01

    AS Tartu näitused, Tartu Kunstikool ja ajakiri 'Diivan' korraldavad 9.-11. III Tartu messikeskuse I paviljonis näituse 'Tool 2000'. Eksponeeritakse 2000 tooli, mille hulgast valitakse TOP 12. Messikeskuse territooriumile on kavas püstitada maailma suurim tool. Samal ajal II paviljonis kaksikmess 'Sisustus 2000' ja 'Büroo 2000'.

  2. Design mentoring tool.

    Science.gov (United States)

    2011-01-01

    In 2004 a design engineer on-line mentoring tool was developed and implemented The purpose of the tool was to assist senior engineers : mentoring new engineers to the INDOT design process and improve their technical competency. This approach saves se...

  3. Evaluating meeting support tools

    NARCIS (Netherlands)

    Post, W.M.; Huis in't Veld, M.A.A.; Boogaard, S.A.A. van den

    2008-01-01

    Many attempts are underway for developing meeting support tools, but less attention is paid to the evaluation of meetingware. This article describes the development and testing of an instrument for evaluating meeting tools. First, we specified the object of evaluation - meetings - by means of a set

  4. Tool Storage Problem Solved!

    Science.gov (United States)

    Klenke, Andrew M.; Dell, Tim W.

    2007-01-01

    Graduates of the automotive technology program at Pittsburg State University (PSU) generally enter the workforce in some type of automotive management role. As a result, the program does not require students to purchase their own tools, and it does not have room for all 280 majors to roll around a personal tool chest. Each instructor must maintain…

  5. Benchmarking Tool Kit.

    Science.gov (United States)

    Canadian Health Libraries Association.

    Nine Canadian health libraries participated in a pilot test of the Benchmarking Tool Kit between January and April, 1998. Although the Tool Kit was designed specifically for health libraries, the content and approach are useful to other types of libraries as well. Used to its full potential, benchmarking can provide a common measuring stick to…

  6. Expert tool use

    DEFF Research Database (Denmark)

    Thorndahl, Kathrine Liedtke; Ravn, Susanne

    2017-01-01

    on a case study of elite rope skipping, we argue that the phenomenological concept of incorporation does not suffice to adequately describe how expert tool users feel when interacting with their tools. By analyzing a combination of insights gained from participant observation of 11 elite rope skippers......According to some phenomenologists, a tool can be experienced as incorporated when, as a result of habitual use or deliberate practice, someone is able to manipulate it without conscious effort. In this article, we specifically focus on the experience of expertise tool use in elite sport. Based...... and autoethnographic material from one former elite skipper, we take some initial steps toward the development of a more nuanced understanding of the concept of incorporation; one that is able to accommodate the experiences of expert tool users. In sum, our analyses indicate that the possibility for experiencing...

  7. Language Management Tools

    DEFF Research Database (Denmark)

    Sanden, Guro Refsum

    This paper offers a review of existing literature on the topic of language management tools – the means by which language is managed – in multilingual organisations. By drawing on a combination of sociolinguistics and international business and management studies, a new taxonomy of language...... management tools is proposed, differentiating between three categories of tools. Firstly, corporate policies are the deliberate control of issues pertaining to language and communication developed at the managerial level of a firm. Secondly, corporate measures are the planned activities the firm’s leadership...... may deploy in order to address the language needs of the organisation. Finally, front-line practices refer to the use of informal, emergent language management tools available to staff members. The language management tools taxonomy provides a framework for operationalising the management of language...

  8. OOTW Force Design Tools

    Energy Technology Data Exchange (ETDEWEB)

    Bell, R.E.; Hartley, D.S.III; Packard, S.L.

    1999-05-01

    This report documents refined requirements for tools to aid the process of force design in Operations Other Than War (OOTWs). It recommends actions for the creation of one tool and work on other tools relating to mission planning. It also identifies the governmental agencies and commands with interests in each tool, from whom should come the user advisory groups overseeing the respective tool development activities. The understanding of OOTWs and their analytical support requirements has matured to the point where action can be taken in three areas: force design, collaborative analysis, and impact analysis. While the nature of the action and the length of time before complete results can be expected depends on the area, in each case the action should begin immediately. Force design for OOTWs is not a technically difficult process. Like force design for combat operations, it is a process of matching the capabilities of forces against the specified and implied tasks of the operation, considering the constraints of logistics, transport and force availabilities. However, there is a critical difference that restricts the usefulness of combat force design tools for OOTWs: the combat tools are built to infer non-combat capability requirements from combat capability requirements and cannot reverse the direction of the inference, as is required for OOTWs. Recently, OOTWs have played a larger role in force assessment, system effectiveness and tradeoff analysis, and concept and doctrine development and analysis. In the first Quadrennial Defense Review (QDR), each of the Services created its own OOTW force design tool. Unfortunately, the tools address different parts of the problem and do not coordinate the use of competing capabilities. These tools satisfied the immediate requirements of the QDR, but do not provide a long-term cost-effective solution.

  9. Time variability of C-reactive protein: implications for clinical risk stratification.

    Directory of Open Access Journals (Sweden)

    Peter Bogaty

    Full Text Available C-reactive protein (CRP is proposed as a screening test for predicting risk and guiding preventive approaches in coronary artery disease (CAD. However, the stability of repeated CRP measurements over time in subjects with and without CAD is not well defined. We sought to determine the stability of serial CRP measurements in stable subjects with distinct CAD manifestations and a group without CAD while carefully controlling for known confounders.We prospectively studied 4 groups of 25 stable subjects each 1 a history of recurrent acute coronary events; 2 a single myocardial infarction ≥7 years ago; 3 longstanding CAD (≥7 years that had never been unstable; 4 no CAD. Fifteen measurements of CRP were obtained to cover 21 time-points: 3 times during one day; 5 consecutive days; 4 consecutive weeks; 4 consecutive months; and every 3 months over the year. CRP risk threshold was set at 2.0 mg/L. We estimated variance across time-points using standard descriptive statistics and Bayesian hierarchical models.Median CRP values of the 4 groups and their pattern of variability did not differ substantially so all subjects were analyzed together. The median individual standard deviation (SD CRP values within-day, within-week, between-weeks and between-months were 0.07, 0.19, 0.36 and 0.63 mg/L, respectively. Forty-six percent of subjects changed CRP risk category at least once and 21% had ≥4 weekly and monthly CRP values in both low and high-risk categories.Considering its large intra-individual variability, it may be problematic to rely on CRP values for CAD risk prediction and therapeutic decision-making in individual subjects.

  10. Purposeful selection of variables in logistic regression

    Directory of Open Access Journals (Sweden)

    Williams David Keith

    2008-12-01

    Full Text Available Abstract Background The main problem in many model-building situations is to choose from a large set of covariates those that should be included in the "best" model. A decision to keep a variable in the model might be based on the clinical or statistical significance. There are several variable selection algorithms in existence. Those methods are mechanical and as such carry some limitations. Hosmer and Lemeshow describe a purposeful selection of covariates within which an analyst makes a variable selection decision at each step of the modeling process. Methods In this paper we introduce an algorithm which automates that process. We conduct a simulation study to compare the performance of this algorithm with three well documented variable selection procedures in SAS PROC LOGISTIC: FORWARD, BACKWARD, and STEPWISE. Results We show that the advantage of this approach is when the analyst is interested in risk factor modeling and not just prediction. In addition to significant covariates, this variable selection procedure has the capability of retaining important confounding variables, resulting potentially in a slightly richer model. Application of the macro is further illustrated with the Hosmer and Lemeshow Worchester Heart Attack Study (WHAS data. Conclusion If an analyst is in need of an algorithm that will help guide the retention of significant covariates as well as confounding ones they should consider this macro as an alternative tool.

  11. Eutrophication Modeling Using Variable Chlorophyll Approach

    International Nuclear Information System (INIS)

    Abdolabadi, H.; Sarang, A.; Ardestani, M.; Mahjoobi, E.

    2016-01-01

    In this study, eutrophication was investigated in Lake Ontario to identify the interactions among effective drivers. The complexity of such phenomenon was modeled using a system dynamics approach based on a consideration of constant and variable stoichiometric ratios. The system dynamics approach is a powerful tool for developing object-oriented models to simulate complex phenomena that involve feedback effects. Utilizing stoichiometric ratios is a method for converting the concentrations of state variables. During the physical segmentation of the model, Lake Ontario was divided into two layers, i.e., the epilimnion and hypolimnion, and differential equations were developed for each layer. The model structure included 16 state variables related to phytoplankton, herbivorous zooplankton, carnivorous zooplankton, ammonium, nitrate, dissolved phosphorus, and particulate and dissolved carbon in the epilimnion and hypolimnion during a time horizon of one year. The results of several tests to verify the model, close to 1 Nash-Sutcliff coefficient (0.98), the data correlation coefficient (0.98), and lower standard errors (0.96), have indicated well-suited model’s efficiency. The results revealed that there were significant differences in the concentrations of the state variables in constant and variable stoichiometry simulations. Consequently, the consideration of variable stoichiometric ratios in algae and nutrient concentration simulations may be applied in future modeling studies to enhance the accuracy of the results and reduce the likelihood of inefficient control policies.

  12. Pulsating red variables

    International Nuclear Information System (INIS)

    Whitelock, P.A.

    1990-01-01

    The observational characteristics of pulsating red variables are reviewed with particular emphasis on the Miras. These variables represent the last stage in the evolution of stars on the Asymptotic Giant Branch (AGB). A large fraction of the IRAS sources in the Bulge are Mira variables and a subset of these are also OH/IR sources. Their periods range up to 720 days, though most are between 360 and 560 days. At a given period those stars with the highest pulsation amplitudes have the highest mass-loss rates; this is interpreted as evidence for a causal connection between mass-loss and pulsation. It is suggested that once an AGB star has become a Mira it will evolve with increasing pulsation amplitude and mass-loss, but with very little change of luminosity or logarithmic period. 26 refs

  13. Variable stator radial turbine

    Science.gov (United States)

    Rogo, C.; Hajek, T.; Chen, A. G.

    1984-01-01

    A radial turbine stage with a variable area nozzle was investigated. A high work capacity turbine design with a known high performance base was modified to accept a fixed vane stagger angle moveable sidewall nozzle. The nozzle area was varied by moving the forward and rearward sidewalls. Diffusing and accelerating rotor inlet ramps were evaluated in combinations with hub and shroud rotor exit rings. Performance of contoured sidewalls and the location of the sidewall split line with respect to the rotor inlet was compared to the baseline. Performance and rotor exit survey data are presented for 31 different geometries. Detail survey data at the nozzle exit are given in contour plot format for five configurations. A data base is provided for a variable geometry concept that is a viable alternative to the more common pivoted vane variable geometry radial turbine.

  14. Benford's law and continuous dependent random variables

    Science.gov (United States)

    Becker, Thealexa; Burt, David; Corcoran, Taylor C.; Greaves-Tunnell, Alec; Iafrate, Joseph R.; Jing, Joy; Miller, Steven J.; Porfilio, Jaclyn D.; Ronan, Ryan; Samranvedhya, Jirapat; Strauch, Frederick W.; Talbut, Blaine

    2018-01-01

    Many mathematical, man-made and natural systems exhibit a leading-digit bias, where a first digit (base 10) of 1 occurs not 11% of the time, as one would expect if all digits were equally likely, but rather 30%. This phenomenon is known as Benford's Law. Analyzing which datasets adhere to Benford's Law and how quickly Benford behavior sets in are the two most important problems in the field. Most previous work studied systems of independent random variables, and relied on the independence in their analyses. Inspired by natural processes such as particle decay, we study the dependent random variables that emerge from models of decomposition of conserved quantities. We prove that in many instances the distribution of lengths of the resulting pieces converges to Benford behavior as the number of divisions grow, and give several conjectures for other fragmentation processes. The main difficulty is that the resulting random variables are dependent. We handle this by using tools from Fourier analysis and irrationality exponents to obtain quantified convergence rates as well as introducing and developing techniques to measure and control the dependencies. The construction of these tools is one of the major motivations of this work, as our approach can be applied to many other dependent systems. As an example, we show that the n ! entries in the determinant expansions of n × n matrices with entries independently drawn from nice random variables converges to Benford's Law.

  15. 40 Variability Bugs in the Linux Kernel

    DEFF Research Database (Denmark)

    Abal Rivas, Iago; Brabrand, Claus; Wasowski, Andrzej

    2014-01-01

    Feature-sensitive verification is a recent field that pursues the effective analysis of the exponential number of variants of a program family. Today researchers lack examples of concrete bugs induced by variability, and occurring in real large-scale software. Such a collection of bugs is a requi......Feature-sensitive verification is a recent field that pursues the effective analysis of the exponential number of variants of a program family. Today researchers lack examples of concrete bugs induced by variability, and occurring in real large-scale software. Such a collection of bugs...... the outcome of our analysis into a database. In addition, we provide self-contained simplified C99 versions of the bugs, facilitating understanding and tool evaluation. Our study provides insights about the nature and occurrence of variability bugs in a large C software system, and shows in what ways...

  16. Internal variables in thermoelasticity

    CERN Document Server

    Berezovski, Arkadi

    2017-01-01

    This book describes an effective method for modeling advanced materials like polymers, composite materials and biomaterials, which are, as a rule, inhomogeneous. The thermoelastic theory with internal variables presented here provides a general framework for predicting a material’s reaction to external loading. The basic physical principles provide the primary theoretical information, including the evolution equations of the internal variables. The cornerstones of this framework are the material representation of continuum mechanics, a weak nonlocality, a non-zero extra entropy flux, and a consecutive employment of the dissipation inequality. Examples of thermoelastic phenomena are provided, accompanied by detailed procedures demonstrating how to simulate them.

  17. Resiliencia y variables sociodemograficas

    OpenAIRE

    Calero Martinez, Edgar David

    2015-01-01

    En el presente trabajo se aborda la definición de una de las variables dentro de lo que se denomina Capital psicológico positivo, la Resiliencia, sus principales características y algunas de las variables socio demográficas que en el estudio pretenden ver el nivel de relación existente entre cada una de ellas (indirecta o directamente) en el proceso resiliente de una persona para posteriores discusiones y su implicación dentro de la gestión empresarial y sus direcciones futuras.

  18. A Comparison of Pseudo-Maximum Likelihood and Asymptotically Distribution-Free Dynamic Factor Analysis Parameter Estimation in Fitting Covariance-Structure Models to Block-Toeplitz Representing Single-Subject Multivariate Time-Series

    NARCIS (Netherlands)

    Molenaar, P.C.M.; Nesselroade, J.R.

    1998-01-01

    The study of intraindividual variability pervades empirical inquiry in virtually all subdisciplines of psychology. The statistical analysis of multivariate time-series data - a central product of intraindividual investigations - requires special modeling techniques. The dynamic factor model (DFM),

  19. Electricity of machine tool

    International Nuclear Information System (INIS)

    Gijeon media editorial department

    1977-10-01

    This book is divided into three parts. The first part deals with electricity machine, which can taints from generator to motor, motor a power source of machine tool, electricity machine for machine tool such as switch in main circuit, automatic machine, a knife switch and pushing button, snap switch, protection device, timer, solenoid, and rectifier. The second part handles wiring diagram. This concludes basic electricity circuit of machine tool, electricity wiring diagram in your machine like milling machine, planer and grinding machine. The third part introduces fault diagnosis of machine, which gives the practical solution according to fault diagnosis and the diagnostic method with voltage and resistance measurement by tester.

  20. Machine tool evaluation

    International Nuclear Information System (INIS)

    Lunsford, B.E.

    1976-01-01

    Continued improvement in numerical control (NC) units and the mechanical components used in the construction of today's machine tools, necessitate the use of more precise instrumentation to calibrate and determine the capabilities of these systems. It is now necessary to calibrate most tape-control lathes to a tool-path positioning accuracy of +-300 microinches in the full slide travel and, on some special turning and boring machines, a capability of +-100 microinches must be achieved. The use of a laser interferometer to determine tool-path capabilities is described

  1. Machine Tool Software

    Science.gov (United States)

    1988-01-01

    A NASA-developed software package has played a part in technical education of students who major in Mechanical Engineering Technology at William Rainey Harper College. Professor Hack has been using (APT) Automatically Programmed Tool Software since 1969 in his CAD/CAM Computer Aided Design and Manufacturing curriculum. Professor Hack teaches the use of APT programming languages for control of metal cutting machines. Machine tool instructions are geometry definitions written in APT Language to constitute a "part program." The part program is processed by the machine tool. CAD/CAM students go from writing a program to cutting steel in the course of a semester.

  2. Behavioral variability and consistency: Experimental bases for a psychological theory of personality (Variabilidad y Consistencia individual: Bases experimentales de la teoría de la personalidad

    Directory of Open Access Journals (Sweden)

    José Santacreu Mas

    2013-04-01

    Full Text Available The aim of this paper is to explain how and why individual differences emerge despite accounting for biological andsocio-cultural differences, why people behave differently in the same context, and how behavior becomes stable and consistent. We review the experimental work on variability and stereotypy. In animal research, in contrast to expectations, there is interindividual variability in behavior under extreme environmental control. In addition, intraindividual consistency (stereotypy is detected in animals whose behavior is not fully adjusted to the contingencies. The differences in what is learned (the kind of contingency relations among laboratory animals can be explained by: a the differences between effective contingencies and programmed contingencies, and b the relationship between exploration and rate of reinforcement. In experimental studies in humans, learning differences in identical environments depend, further to the above, onwhat was previously learned by the individual (experience and education and the thoroughness and internal consistency of task instructions. From these concepts, we propose a psychological theory of personality that explains: (a how we learn different relationships from the same experience; (b how behavioral individual differences emerge (variability; and (cwhy each individual’s behavior becomes stable and consistent.

  3. Biological Sampling Variability Study

    Energy Technology Data Exchange (ETDEWEB)

    Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-11-08

    There are many sources of variability that exist in the sample collection and analysis process. This paper addresses many, but not all, sources of variability. The main focus of this paper was to better understand and estimate variability due to differences between samplers. Variability between days was also studied, as well as random variability within each sampler. Experiments were performed using multiple surface materials (ceramic and stainless steel), multiple contaminant concentrations (10 spores and 100 spores), and with and without the presence of interfering material. All testing was done with sponge sticks using 10-inch by 10-inch coupons. Bacillus atrophaeus was used as the BA surrogate. Spores were deposited using wet deposition. Grime was coated on the coupons which were planned to include the interfering material (Section 3.3). Samples were prepared and analyzed at PNNL using CDC protocol (Section 3.4) and then cultured and counted. Five samplers were trained so that samples were taken using the same protocol. Each sampler randomly sampled eight coupons each day, four coupons with 10 spores deposited and four coupons with 100 spores deposited. Each day consisted of one material being tested. The clean samples (no interfering materials) were run first, followed by the dirty samples (coated with interfering material). There was a significant difference in recovery efficiency between the coupons with 10 spores deposited (mean of 48.9%) and those with 100 spores deposited (mean of 59.8%). There was no general significant difference between the clean and dirty (containing interfering material) coupons or between the two surface materials; however, there was a significant interaction between concentration amount and presence of interfering material. The recovery efficiency was close to the same for coupons with 10 spores deposited, but for the coupons with 100 spores deposited, the recovery efficiency for the dirty samples was significantly larger (65

  4. INTER-EXAMINER VARIABILITY

    African Journals Online (AJOL)

    Objective: To establish whether inter-examiner variability is still a significant factor for the undergraduate orthopaedic clinical ... D. The scores for each student were tabulated and the range, mean, and pass rate determined for each of the examiners. ... has not the heart to reject the man”, consistently gave higher scores (1).

  5. Several real variables

    CERN Document Server

    Kantorovitz, Shmuel

    2016-01-01

    This undergraduate textbook is based on lectures given by the author on the differential and integral calculus of functions of several real variables. The book has a modern approach and includes topics such as: •The p-norms on vector space and their equivalence •The Weierstrass and Stone-Weierstrass approximation theorems •The differential as a linear functional; Jacobians, Hessians, and Taylor's theorem in several variables •The Implicit Function Theorem for a system of equations, proved via Banach’s Fixed Point Theorem •Applications to Ordinary Differential Equations •Line integrals and an introduction to surface integrals This book features numerous examples, detailed proofs, as well as exercises at the end of sections. Many of the exercises have detailed solutions, making the book suitable for self-study. Several Real Variables will be useful for undergraduate students in mathematics who have completed first courses in linear algebra and analysis of one real variable.

  6. Variability in GPS sources

    NARCIS (Netherlands)

    Jauncey, DL; King, EA; Bignall, HE; Lovell, JEJ; Kedziora-Chudczer, L; Tzioumis, AK; Tingay, SJ; Macquart, JP; McCulloch, PM

    2003-01-01

    Flux density monitoring data at 2.3 and 8.4 GHz is presented for a sample of 33 southern hemisphere GPS sources, drawn from the 2.7 GHz Parkes survey. This monitoring data, together with VLBI monitoring data, shows that a small fraction of these sources, similar to10%, vary. Their variability falls

  7. All Those Independent Variables.

    Science.gov (United States)

    Meacham, Merle L.

    This paper presents a case study of a sixth grade remedial math class which illustrates the thesis that only the "experimental attitude," not the "experimental method," is appropriate in the classroom. The thesis is based on the fact that too many independent variables exist in a classroom situation to allow precise measurement. The case study…

  8. Variable speed generators

    CERN Document Server

    Boldea, Ion

    2005-01-01

    With the deregulation of electrical energy production and distribution, says Boldea (Polytechnical Institute, Timisoara, Romania) producers are looking for ways to tailor their electricity for different markets. Variable-speed electric generators are serving that purpose, up to the 400 megavolt ampere unit size, in Japan since 1996 and Germany sinc

  9. Surfing wave climate variability

    Science.gov (United States)

    Espejo, Antonio; Losada, Iñigo J.; Méndez, Fernando J.

    2014-10-01

    International surfing destinations are highly dependent on specific combinations of wind-wave formation, thermal conditions and local bathymetry. Surf quality depends on a vast number of geophysical variables, and analyses of surf quality require the consideration of the seasonal, interannual and long-term variability of surf conditions on a global scale. A multivariable standardized index based on expert judgment is proposed for this purpose. This index makes it possible to analyze surf conditions objectively over a global domain. A summary of global surf resources based on a new index integrating existing wave, wind, tides and sea surface temperature databases is presented. According to general atmospheric circulation and swell propagation patterns, results show that west-facing low to middle-latitude coasts are more suitable for surfing, especially those in the Southern Hemisphere. Month-to-month analysis reveals strong seasonal variations in the occurrence of surfable events, enhancing the frequency of such events in the North Atlantic and the North Pacific. Interannual variability was investigated by comparing occurrence values with global and regional modes of low-frequency climate variability such as El Niño and the North Atlantic Oscillation, revealing their strong influence at both the global and the regional scale. Results of the long-term trends demonstrate an increase in the probability of surfable events on west-facing coasts around the world in recent years. The resulting maps provide useful information for surfers, the surf tourism industry and surf-related coastal planners and stakeholders.

  10. Game development tool essentials

    CERN Document Server

    Berinstein, Paula; Ardolino, Alessandro; Franco, Simon; Herubel, Adrien; McCutchan, John; Nedelcu, Nicusor; Nitschke, Benjamin; Olmstead, Don; Robinet, Fabrice; Ronchi, Christian; Turkowski, Rita; Walter, Robert; Samour, Gustavo

    2014-01-01

    Offers game developers new techniques for streamlining the critical game tools pipeline. Inspires game developers to share their secrets and improve the productivity of the entire industry. Helps game industry practitioners compete in a hyper-competitive environment.

  11. Tool Inventory and Replacement

    Science.gov (United States)

    Bear, W. Forrest

    1976-01-01

    Vocational agriculture teachers are encouraged to evaluate curriculum offerings, the new trends in business and industry, and develop a master tool purchase and replacement plan over a 3- to 5-year period. (HD)

  12. ATO Resource Tool -

    Data.gov (United States)

    Department of Transportation — Cru-X/ART is a shift management tool designed for?use by operational employees in Air Traffic Facilities.? Cru-X/ART is used for shift scheduling, shift sign in/out,...

  13. Water Budget Tool

    Science.gov (United States)

    If you're designing a new landscape or rethinking your current one, the WaterSense Water Budget Tool will tell you if you have designed a landscape that will use an appropriate amount of water for your climate.

  14. Neighborhood Mapping Tool

    Data.gov (United States)

    Department of Housing and Urban Development — This tool assists the public and Choice Neighborhoods applicants to prepare data to submit with their grant application by allowing applicants to draw the exact...

  15. Sequence History Update Tool

    Science.gov (United States)

    Khanampompan, Teerapat; Gladden, Roy; Fisher, Forest; DelGuercio, Chris

    2008-01-01

    The Sequence History Update Tool performs Web-based sequence statistics archiving for Mars Reconnaissance Orbiter (MRO). Using a single UNIX command, the software takes advantage of sequencing conventions to automatically extract the needed statistics from multiple files. This information is then used to populate a PHP database, which is then seamlessly formatted into a dynamic Web page. This tool replaces a previous tedious and error-prone process of manually editing HTML code to construct a Web-based table. Because the tool manages all of the statistics gathering and file delivery to and from multiple data sources spread across multiple servers, there is also a considerable time and effort savings. With the use of The Sequence History Update Tool what previously took minutes is now done in less than 30 seconds, and now provides a more accurate archival record of the sequence commanding for MRO.

  16. Microgrid Analysis Tools Summary

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Antonio [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Haase, Scott G [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mathur, Shivani [Formerly NREL

    2018-03-05

    The over-arching goal of the Alaska Microgrid Partnership is to reduce the use of total imported fuel into communities to secure all energy services by at least 50% in Alaska's remote microgrids without increasing system life cycle costs while also improving overall system reliability, security, and resilience. One goal of the Alaska Microgrid Partnership is to investigate whether a combination of energy efficiency and high-contribution (from renewable energy) power systems can reduce total imported energy usage by 50% while reducing life cycle costs and improving reliability and resiliency. This presentation provides an overview of the following four renewable energy optimization tools. Information is from respective tool websites, tool developers, and author experience. Distributed Energy Resources Customer Adoption Model (DER-CAM) Microgrid Design Toolkit (MDT) Renewable Energy Optimization (REopt) Tool Hybrid Optimization Model for Electric Renewables (HOMER).

  17. Financing Alternatives Comparison Tool

    Science.gov (United States)

    FACT is a financial analysis tool that helps identify the most cost-effective method to fund a wastewater or drinking water management project. It produces a comprehensive analysis that compares various financing options.

  18. Breastfeeding assessment tools

    International Nuclear Information System (INIS)

    Bizouerne, Cécile; Kerac, Marko; Macgrath, Marie

    2014-01-01

    Full text: Breastfeeding plays a major role in reducing the global burden of child mortality and under-nutrition. Whilst many programmes aim to support breastfeeding and prevent feeding problems occurring, interventions are also needed once they have developed. In this situation, accurate assessment of a problem is critical to inform prognosis and enables tailored, appropriate treatment. The presentation will present a review, which aims to identify breastfeeding assessment tools/checklists for use in assessing malnourished infants in poor resource settings. The literature review identified 24 breastfeeding assessment tools, and 41 validation studies. Evidence underpinning most of the tools was mainly low quality, and conducted in high-income countries and hospital settings. The presentation will describe the main findings of the literature review and propose recommendations for improving existing tools in order to appropriately assess malnourished infants and enable early, appropriate intervention and treatment of malnutrition. (author)

  19. Personal Wellness Tools

    Science.gov (United States)

    ... of Personal Stories Peers Celebrating Art Peers Celebrating Music Be Vocal Support Locator DBSA In-Person Support ... With this tool, you can track key health trends related to the following: Overall mood Mood disorder ...

  20. Cash Reconciliation Tool

    Data.gov (United States)

    US Agency for International Development — CART is a cash reconciliation tool that allows users to reconcile Agency cash disbursements with Treasury fund balances; track open unreconciled items; and create an...

  1. Chemical Data Access Tool

    Data.gov (United States)

    U.S. Environmental Protection Agency — This tool is intended to aid individuals interested in learning more about chemicals that are manufactured or imported into the United States. Health and safety...

  2. Tools and their uses

    CERN Document Server

    1973-01-01

    Teaches names, general uses, and correct operation of all basic hand and power tools, fasteners, and measuring devices you are likely to need. Also, grinding, metal cutting, soldering, and more. 329 illustrations.

  3. Chatter and machine tools

    CERN Document Server

    Stone, Brian

    2014-01-01

    Focussing on occurrences of unstable vibrations, or Chatter, in machine tools, this book gives important insights into how to eliminate chatter with associated improvements in product quality, surface finish and tool wear. Covering a wide range of machining processes, including turning, drilling, milling and grinding, the author uses his research expertise and practical knowledge of vibration problems to provide solutions supported by experimental evidence of their effectiveness. In addition, this book contains links to supplementary animation programs that help readers to visualise the ideas detailed in the text. Advancing knowledge in chatter avoidance and suggesting areas for new innovations, Chatter and Machine Tools serves as a handbook for those desiring to achieve significant reductions in noise, longer tool and grinding wheel life and improved product finish.

  4. Learning Design Tools

    NARCIS (Netherlands)

    Griffiths, David; Blat, Josep; Garcia, Rocío; Vogten, Hubert; Kwong, KL

    2005-01-01

    Griffiths, D., Blat, J., Garcia, R., Vogten, H. & Kwong, KL. (2005). Learning Design Tools. In: Koper, R. & Tattersall, C., Learning Design: A Handbook on Modelling and Delivering Networked Education and Training (pp. 109-136). Berlin-Heidelberg: Springer Verlag.

  5. Clean Energy Finance Tool

    Science.gov (United States)

    State and local governments interested in developing a financing program can use this Excel tool to support energy efficiency and clean energy improvements for large numbers of buildings within their jurisdiction.

  6. Mapping Medicare Disparities Tool

    Data.gov (United States)

    U.S. Department of Health & Human Services — The CMS Office of Minority Health has designed an interactive map, the Mapping Medicare Disparities Tool, to identify areas of disparities between subgroups of...

  7. Recovery Action Mapping Tool

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Recovery Action Mapping Tool is a web map that allows users to visually interact with and query actions that were developed to recover species listed under the...

  8. Friction stir welding tool

    Science.gov (United States)

    Tolle,; Charles R. , Clark; Denis E. , Barnes; Timothy, A [Ammon, ID

    2008-04-15

    A friction stir welding tool is described and which includes a shank portion; a shoulder portion which is releasably engageable with the shank portion; and a pin which is releasably engageable with the shoulder portion.

  9. Response variability in Attention-Deficit/Hyperactivity Disorder: a neuronal and glial energetics hypothesis.

    Science.gov (United States)

    Russell, Vivienne A; Oades, Robert D; Tannock, Rosemary; Killeen, Peter R; Auerbach, Judith G; Johansen, Espen B; Sagvolden, Terje

    2006-08-23

    Current concepts of Attention-Deficit/Hyperactivity Disorder (ADHD) emphasize the role of higher-order cognitive functions and reinforcement processes attributed to structural and biochemical anomalies in cortical and limbic neural networks innervated by the monoamines, dopamine, noradrenaline and serotonin. However, these explanations do not account for the ubiquitous findings in ADHD of intra-individual performance variability, particularly on tasks that require continual responses to rapid, externally-paced stimuli. Nor do they consider attention as a temporal process dependent upon a continuous energy supply for efficient and consistent function. A consideration of this feature of intra-individual response variability, which is not unique to ADHD but is also found in other disorders, leads to a new perspective on the causes and potential remedies of specific aspects of ADHD. We propose that in ADHD, astrocyte function is insufficient, particularly in terms of its formation and supply of lactate. This insufficiency has implications both for performance and development: H1) In rapidly firing neurons there is deficient ATP production, slow restoration of ionic gradients across neuronal membranes and delayed neuronal firing; H2) In oligodendrocytes insufficient lactate supply impairs fatty acid synthesis and myelination of axons during development. These effects occur over vastly different time scales: those due to deficient ATP (H1) occur over milliseconds, whereas those due to deficient myelination (H2) occur over months and years. Collectively the neural outcomes of impaired astrocytic release of lactate manifest behaviourally as inefficient and inconsistent performance (variable response times across the lifespan, especially during activities that require sustained speeded responses and complex information processing). Multi-level and multi-method approaches are required. These include: 1) Use of dynamic strategies to evaluate cognitive performance under

  10. CMS offline web tools

    International Nuclear Information System (INIS)

    Metson, S; Newbold, D; Belforte, S; Kavka, C; Bockelman, B; Dziedziniewicz, K; Egeland, R; Elmer, P; Eulisse, G; Tuura, L; Evans, D; Fanfani, A; Feichtinger, D; Kuznetsov, V; Lingen, F van; Wakefield, S

    2008-01-01

    We describe a relatively new effort within CMS to converge on a set of web based tools, using state of the art industry techniques, to engage with the CMS offline computing system. CMS collaborators require tools to monitor various components of the computing system and interact with the system itself. The current state of the various CMS web tools is described along side current planned developments. The CMS collaboration comprises of nearly 3000 people from all over the world. As well as its collaborators, its computing resources are spread all over globe and are accessed via the LHC grid to run analysis, large scale production and data transfer tasks. Due to the distributed nature of collaborators effective provision of collaborative tools is essential to maximise physics exploitation of the CMS experiment, especially when the size of the CMS data set is considered. CMS has chosen to provide such tools over the world wide web as a top level service, enabling all members of the collaboration to interact with the various offline computing components. Traditionally web interfaces have been added in HEP experiments as an afterthought. In the CMS offline we have decided to put web interfaces, and the development of a common CMS web framework, on an equal footing with the rest of the offline development. Tools exist within CMS to transfer and catalogue data (PhEDEx and DBS/DLS), run Monte Carlo production (ProdAgent) and submit analysis (CRAB). Effective human interfaces to these systems are required for users with different agendas and practical knowledge of the systems to effectively use the CMS computing system. The CMS web tools project aims to provide a consistent interface to all these tools

  11. Quality management tool

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tae Hun

    2011-09-15

    This book introduces basic conception of quality with characteristic, price, cost, and function, basic conception on quality management, introduction and operation of quality management, quality guaranteed and claim like handling of claim of goods, standards, and quality guaranteed method, basic tools of quality management such as Pareto diagram, characteristic diagram, cause-and-effect, fish born diagram check sheet histogram scatter diagram graph and stratification new seven tools of QC, quality deployment function and measurement system.

  12. Quality management tool

    International Nuclear Information System (INIS)

    Lee, Tae Hun

    2011-09-01

    This book introduces basic conception of quality with characteristic, price, cost, and function, basic conception on quality management, introduction and operation of quality management, quality guaranteed and claim like handling of claim of goods, standards, and quality guaranteed method, basic tools of quality management such as Pareto diagram, characteristic diagram, cause-and-effect, fish born diagram check sheet histogram scatter diagram graph and stratification new seven tools of QC, quality deployment function and measurement system.

  13. Stochastic tools in turbulence

    CERN Document Server

    Lumey, John L

    2012-01-01

    Stochastic Tools in Turbulence discusses the available mathematical tools to describe stochastic vector fields to solve problems related to these fields. The book deals with the needs of turbulence in relation to stochastic vector fields, particularly, on three-dimensional aspects, linear problems, and stochastic model building. The text describes probability distributions and densities, including Lebesgue integration, conditional probabilities, conditional expectations, statistical independence, lack of correlation. The book also explains the significance of the moments, the properties of the

  14. CMS offline web tools

    Energy Technology Data Exchange (ETDEWEB)

    Metson, S; Newbold, D [H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Belforte, S; Kavka, C [INFN, Sezione di Trieste (Italy); Bockelman, B [University of Nebraska Lincoln, Lincoln, NE (United States); Dziedziniewicz, K [CERN, Geneva (Switzerland); Egeland, R [University of Minnesota Twin Cities, Minneapolis, MN (United States); Elmer, P [Princeton (United States); Eulisse, G; Tuura, L [Northeastern University, Boston, MA (United States); Evans, D [Fermilab MS234, Batavia, IL (United States); Fanfani, A [Universita degli Studi di Bologna (Italy); Feichtinger, D [PSI, Villigen (Switzerland); Kuznetsov, V [Cornell University, Ithaca, NY (United States); Lingen, F van [California Institute of Technology, Pasedena, CA (United States); Wakefield, S [Blackett Laboratory, Imperial College, London (United Kingdom)

    2008-07-15

    We describe a relatively new effort within CMS to converge on a set of web based tools, using state of the art industry techniques, to engage with the CMS offline computing system. CMS collaborators require tools to monitor various components of the computing system and interact with the system itself. The current state of the various CMS web tools is described along side current planned developments. The CMS collaboration comprises of nearly 3000 people from all over the world. As well as its collaborators, its computing resources are spread all over globe and are accessed via the LHC grid to run analysis, large scale production and data transfer tasks. Due to the distributed nature of collaborators effective provision of collaborative tools is essential to maximise physics exploitation of the CMS experiment, especially when the size of the CMS data set is considered. CMS has chosen to provide such tools over the world wide web as a top level service, enabling all members of the collaboration to interact with the various offline computing components. Traditionally web interfaces have been added in HEP experiments as an afterthought. In the CMS offline we have decided to put web interfaces, and the development of a common CMS web framework, on an equal footing with the rest of the offline development. Tools exist within CMS to transfer and catalogue data (PhEDEx and DBS/DLS), run Monte Carlo production (ProdAgent) and submit analysis (CRAB). Effective human interfaces to these systems are required for users with different agendas and practical knowledge of the systems to effectively use the CMS computing system. The CMS web tools project aims to provide a consistent interface to all these tools.

  15. Tides and Decadal Variability

    Science.gov (United States)

    Ray, Richard D.

    2003-01-01

    This paper reviews the mechanisms by which oceanic tides and decadal variability in the oceans are connected. We distinguish between variability caused by tides and variability observed in the tides themselves. Both effects have been detected at some level. The most obvious connection with decadal timescales is through the 18.6-year precession of the moon's orbit plane. This precession gives rise to a small tide of the same period and to 18.6-year modulations in the phase and amplitudes of short-period tides. The 18.6-year "node tide" is very small, no more than 2 cm anywhere, and in sea level data it is dominated by the ocean's natural Variability. Some authors have naively attributed climate variations with periods near 19 years directly to the node tide, but the amplitude of the tide is too small for this mechanism to be operative. The more likely explanation (Loder and Garrett, JGR, 83, 1967-70, 1978) is that the 18.6-y modulations in short-period tides, especially h e principal tide M2, cause variations in ocean mixing, which is then observed in temperature and other climatic indicators. Tidally forced variability has also been proposed by some authors, either in response to occasional (and highly predictable) tidal extremes or as a nonlinear low-frequency oscillation caused by interactions between short-period tides. The former mechanism can produce only short-duration events hardly more significant than normal tidal ranges, but the latter mechanism can in principle induce low-frequency oscillations. The most recent proposal of this type is by Keeling and Whorf, who highlight the 1800-year spectral peak discovered by Bond et al. (1997). But the proposal appears contrived and should be considered, in the words of Munk et al. (2002), "as the most likely among unlikely candidates."

  16. Didactic tools for understanding respiratory physiology

    International Nuclear Information System (INIS)

    Kehoe, P Donnelly; Bratovich, C; Perrone, Ms; Castells, L Mendez

    2007-01-01

    The challenges in Bioengineering are not only the application of engineering knowledge to the measurement of physiological variables, but also the simulation of biological systems. Experience has shown that the physiology of the respiratory system involves a set of concepts that cannot be effectively taught without the help of a group of didactic tools that contribute to the measurement of characteristic specific variables and to the simulation of the system itself. This article describes a series of tools designed to optimize the teaching of the respiratory system, including the use of spirometers and software developed entirely by undergraduate Bioengineering students from Universidad Nacional de Entre Rios (UNER). The impact these resources have caused on the understanding of the topic and how each of them has facilitated the interpretation of the concepts by the students is also discussed

  17. Tools used for hand deburring

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, L.K.

    1981-03-01

    This guide is designed to help in quick identification of those tools most commonly used to deburr hand size or smaller parts. Photographs and textual descriptions are used to provide rapid yet detailed information. The data presented include the Bendix Kansas City Division coded tool number, tool description, tool crib in which the tool can be found, the maximum and minimum inventory requirements, the cost of each tool, and the number of the illustration that shows the tool.

  18. Physics analysis tools

    International Nuclear Information System (INIS)

    Kunz, P.F.

    1991-04-01

    There are many tools used in analysis in High Energy Physics (HEP). They range from low level tools such as a programming language to high level such as a detector simulation package. This paper will discuss some aspects of these tools that are directly associated with the process of analyzing HEP data. Physics analysis tools cover the whole range from the simulation of the interactions of particles to the display and fitting of statistical data. For purposes of this paper, the stages of analysis is broken down to five main stages. The categories are also classified as areas of generation, reconstruction, and analysis. Different detector groups use different terms for these stages thus it is useful to define what is meant by them in this paper. The particle generation stage is a simulation of the initial interaction, the production of particles, and the decay of the short lived particles. The detector simulation stage simulates the behavior of an event in a detector. The track reconstruction stage does pattern recognition on the measured or simulated space points, calorimeter information, etc., and reconstructs track segments of the original event. The event reconstruction stage takes the reconstructed tracks, along with particle identification information and assigns masses to produce 4-vectors. Finally the display and fit stage displays statistical data accumulated in the preceding stages in the form of histograms, scatter plots, etc. The remainder of this paper will consider what analysis tools are available today, and what one might expect in the future. In each stage, the integration of the tools with other stages and the portability of the tool will be analyzed

  19. Variable Permanent Magnet Quadrupole

    International Nuclear Information System (INIS)

    Mihara, T.; Iwashita, Y.; Kyoto U.; Kumada, M.; NIRS, Chiba; Spencer, C.M.; SLAC

    2007-01-01

    A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments

  20. On Complex Random Variables

    Directory of Open Access Journals (Sweden)

    Anwer Khurshid

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE In this paper, it is shown that a complex multivariate random variable  is a complex multivariate normal random variable of dimensionality if and only if all nondegenerate complex linear combinations of  have a complex univariate normal distribution. The characteristic function of  has been derived, and simpler forms of some theorems have been given using this characterization theorem without assuming that the variance-covariance matrix of the vector  is Hermitian positive definite. Marginal distributions of  have been given. In addition, a complex multivariate t-distribution has been defined and the density derived. A characterization of the complex multivariate t-distribution is given. A few possible uses of this distribution have been suggested.

  1. Technological Capability's Predictor Variables

    Directory of Open Access Journals (Sweden)

    Fernanda Maciel Reichert

    2011-03-01

    Full Text Available The aim of this study was to identify the factors that influence in configuration of the technological capability of companies in sectors with medium-low technological intensity. To achieve the goal proposed in this article a survey was carried out. Based on the framework developed by Lall (1992 which classifies firms in basic, intermediate and advanced level of technological capability; it was found that the predominant technological capability is intermediate, with 83.7% of respondent companies (plastics companies in Brazil. It is believed that the main contribution of this study is the finding that the dependent variable named “Technological Capability” can be explained at a rate of 65% by six variables: development of new processes; selection of the best equipment supplier; sales of internally developed new technology to third parties; design and manufacture of equipment; study of the work methods and perform inventory control; and improvement of product quality.

  2. Variable Kernel Density Estimation

    OpenAIRE

    Terrell, George R.; Scott, David W.

    1992-01-01

    We investigate some of the possibilities for improvement of univariate and multivariate kernel density estimates by varying the window over the domain of estimation, pointwise and globally. Two general approaches are to vary the window width by the point of estimation and by point of the sample observation. The first possibility is shown to be of little efficacy in one variable. In particular, nearest-neighbor estimators in all versions perform poorly in one and two dimensions, but begin to b...

  3. TEC variability over Havana

    International Nuclear Information System (INIS)

    Lazo, B.; Alazo, K.; Rodriguez, M.; Calzadilla, A.

    2003-01-01

    The variability of total electron content (TEC) measured over Havana using ATS-6, SMS-1 and GOES-3 geosynchronous satellite signals has been investigated for low, middle and high solar activity periods from 1974 to 1982. The obtained results show that standard deviation is smooth during nighttime hours and maximum at noon or postnoon hours. Strong solar activity dependence of standard deviation with a maximum values during HSA has been found. (author)

  4. Fleet Tools; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-04-01

    From beverage distributors to shipping companies and federal agencies, industry leaders turn to the National Renewable Energy Laboratory (NREL) to help green their fleet operations. Cost, efficiency, and reliability are top priorities for fleets, and NREL partners know the lab’s portfolio of tools can pinpoint fuel efficiency and emissions-reduction strategies that also support operational the bottom line. NREL is one of the nation’s foremost leaders in medium- and heavy-duty vehicle research and development (R&D) and the go-to source for credible, validated transportation data. NREL developers have drawn on this expertise to create tools grounded in the real-world experiences of commercial and government fleets. Operators can use this comprehensive set of technology- and fuel-neutral tools to explore and analyze equipment and practices, energy-saving strategies, and other operational variables to ensure meaningful performance, financial, and environmental benefits.

  5. Short timescale variability in the faint sky variability survey

    NARCIS (Netherlands)

    Morales-Rueda, L.; Groot, P.J.; Augusteijn, T.; Nelemans, G.A.; Vreeswijk, P.M.; Besselaar, E.J.M. van den

    2006-01-01

    We present the V-band variability analysis of the Faint Sky Variability Survey (FSVS). The FSVS combines colour and time variability information, from timescales of 24 minutes to tens of days, down to V = 24. We find that �1% of all point sources are variable along the main sequence reaching �3.5%

  6. Articulatory variability in cluttering.

    Science.gov (United States)

    Hartinger, Mariam; Mooshammer, Christine

    2008-01-01

    In order to investigate the articulatory processes of the hasty and mumbled speech in cluttering, the kinematic variability was analysed by means of electromagnetic midsagittal articulography. In contrast to persons with stuttering, those with cluttering improve their intelligibility by concentrating on their speech task. Variability has always been an important criterion in comparable studies of stuttering and is discussed in terms of the stability of the speech motor system. The aim of the current study was to analyse the spatial and temporal variability in the speech of three persons with cluttering (PWC) and three control speakers. All participants were native speakers of German. The speech material consisted of repetitive CV syllables and loan words such as 'emotionalisieren', because PWC have the severest problems with long words with a complex syllable structure. The results showed a significantly higher coefficient of variation for PWC in loan word production, both in the temporal and in the spatial domain, whereas the means of displacements and durations did not differ between groups. These findings were discussed in terms of the effects of the linguistic complexity, since for the syllable repetition task, no significant differences between PWC and controls were found. Copyright 2008 S. Karger AG, Basel.

  7. Phytoscreening with SPME: Variability Analysis.

    Science.gov (United States)

    Limmer, Matt A; Burken, Joel G

    2015-01-01

    Phytoscreening has been demonstrated at a variety of sites over the past 15 years as a low-impact, sustainable tool in delineation of shallow groundwater contaminated with chlorinated solvents. Collection of tree cores is rapid and straightforward, but low concentrations in tree tissues requires sensitive analytics. Solid-phase microextraction (SPME) is amenable to the complex matrix while allowing for solvent-less extraction. Accurate quantification requires the absence of competitive sorption, examined here both in laboratory experiments and through comprehensive examination of field data. Analysis of approximately 2,000 trees at numerous field sites also allowed testing of the tree genus and diameter effects on measured tree contaminant concentrations. Collectively, while these variables were found to significantly affect site-adjusted perchloroethylene (PCE) concentrations, the explanatory power of these effects was small (adjusted R(2) = 0.031). 90th quantile chemical concentrations in trees were significantly reduced by increasing Henry's constant and increasing hydrophobicity. Analysis of replicate tree core data showed no correlation between replicate relative standard deviation (RSD) and wood type or tree diameter, with an overall median RSD of 30%. Collectively, these findings indicate SPME is an appropriate technique for sampling and analyzing chlorinated solvents in wood and that phytoscreening is robust against changes in tree type and diameter.

  8. Judging the Neonatal Abstinence Syndrome Assessment Tools to Guide Future Tool Development: The use of Clinimetrics as Opposed to Psychometrics.

    Science.gov (United States)

    Westgate, Philip M; Gomez-Pomar, Enrique

    2017-01-01

    In the face of the current Neonatal Abstinence Syndrome (NAS) epidemic, there is considerable variability in the assessment and management of infants with NAS. In this manuscript, we particularly focus on NAS assessment, with special attention given to the popular Finnegan Neonatal Abstinence Score (FNAS). A major instigator of the problem of variable practices is that multiple modified versions of the FNAS exist and continue to be proposed, including shortened versions. Furthermore, the validity of such assessment tools has been questioned, and as a result, the need for better tools has been suggested. The ultimate purpose of this manuscript, therefore, is to increase researchers' and clinicians' understanding on how to judge the usefulness of NAS assessment tools in order to guide future tool development and to reduce variable practices. In short, we suggest that judgment of NAS assessment tools should be made on a clinimetrics viewpoint as opposed to psychometrically. We provide examples, address multiple issues that must be considered, and discuss future tool development. Furthermore, we urge researchers and clinicians to come together, utilizing their knowledge and experience, to assess the utility and practicality of existing assessment tools and to determine if one or more new or modified tools are needed with the goal of increased agreement on the assessment of NAS in practice.

  9. Judging the Neonatal Abstinence Syndrome Assessment Tools to Guide Future Tool Development: The use of Clinimetrics as Opposed to Psychometrics

    Directory of Open Access Journals (Sweden)

    Philip M. Westgate

    2017-09-01

    Full Text Available In the face of the current Neonatal Abstinence Syndrome (NAS epidemic, there is considerable variability in the assessment and management of infants with NAS. In this manuscript, we particularly focus on NAS assessment, with special attention given to the popular Finnegan Neonatal Abstinence Score (FNAS. A major instigator of the problem of variable practices is that multiple modified versions of the FNAS exist and continue to be proposed, including shortened versions. Furthermore, the validity of such assessment tools has been questioned, and as a result, the need for better tools has been suggested. The ultimate purpose of this manuscript, therefore, is to increase researchers’ and clinicians’ understanding on how to judge the usefulness of NAS assessment tools in order to guide future tool development and to reduce variable practices. In short, we suggest that judgment of NAS assessment tools should be made on a clinimetrics viewpoint as opposed to psychometrically. We provide examples, address multiple issues that must be considered, and discuss future tool development. Furthermore, we urge researchers and clinicians to come together, utilizing their knowledge and experience, to assess the utility and practicality of existing assessment tools and to determine if one or more new or modified tools are needed with the goal of increased agreement on the assessment of NAS in practice.

  10. About hidden influence of predictor variables: Suppressor and mediator variables

    Directory of Open Access Journals (Sweden)

    Milovanović Boško

    2013-01-01

    Full Text Available In this paper procedure for researching hidden influence of predictor variables in regression models and depicting suppressor variables and mediator variables is shown. It is also shown that detection of suppressor variables and mediator variables could provide refined information about the research problem. As an example for applying this procedure, relation between Atlantic atmospheric centers and air temperature and precipitation amount in Serbia is chosen. [Projekat Ministarstva nauke Republike Srbije, br. 47007

  11. New Conceptual Design Tools

    DEFF Research Database (Denmark)

    Pugnale, Alberto; Holst, Malene Kirstine; Kirkegaard, Poul Henning

    2010-01-01

    hand, the main software houses are trying to introduce powerful and effective user-friendly applications in the world of building designers, that are more and more able to fit their specific requirements; on the other hand, some groups of expert users with a basic programming knowledge seem to deal......This paper aims to discuss recent approaches in using more and more frequently computer tools as supports for the conceptual design phase of the architectural project. The present state-of-the-art about software as conceptual design tool could be summarized in two parallel tendencies. On the one...... with the problem of software as conceptual design tool by means of 'scripting', in other words by self-developing codes able to solve specific and well defined design problems. Starting with a brief historical recall and the discussion of relevant researches and practical experiences, this paper investigates...

  12. Assembly tool design

    International Nuclear Information System (INIS)

    Kanamori, Naokazu; Nakahira, Masataka; Ohkawa, Yoshinao; Tada, Eisuke; Seki, Masahiro

    1996-06-01

    The reactor core of the International Thermonuclear Experimental Reactor (ITER) is assembled with a number of large and asymmetric components within a tight tolerance in order to assure the structural integrity for various loads and to provide the tritium confinement. In addition, the assembly procedure should be compatible with remote operation since the core structures will be activated by 14-MeV neutrons once it starts operation and thus personal access will be prohibited. Accordingly, the assembly procedure and tool design are quite essential and should be designed from the beginning to facilitate remote operation. According to the ITER Design Task Agreement, the Japan Atomic Energy Research Institute (JAERI) has performed design study to develop the assembly procedures and associated tool design for the ITER tokamak assembly. This report describes outlines of the assembly tools and the remaining issues obtained in this design study. (author)

  13. RSP Tooling Technology

    Energy Technology Data Exchange (ETDEWEB)

    None

    2001-11-20

    RSP Tooling{trademark} is a spray forming technology tailored for producing molds and dies. The approach combines rapid solidification processing and net-shape materials processing in a single step. The general concept involves converting a mold design described by a CAD file to a tooling master using a suitable rapid prototyping (RP) technology such as stereolithography. A pattern transfer is made to a castable ceramic, typically alumina or fused silica (Figure 1). This is followed by spray forming a thick deposit of a tooling alloy on the pattern to capture the desired shape, surface texture, and detail. The resultant metal block is cooled to room temperature and separated from the pattern. The deposit's exterior walls are machined square, allowing it to be used as an insert in a standard mold base. The overall turnaround time for tooling is about 3 to 5 days, starting with a master. Molds and dies produced in this way have been used in high volume production runs in plastic injection molding and die casting. A Cooperative Research and Development Agreement (CRADA) between the Idaho National Engineering and Environmental Laboratory (INEEL) and Grupo Vitro has been established to evaluate the feasibility of using RSP Tooling technology for producing molds and dies of interest to Vitro. This report summarizes results from Phase I of this agreement, and describes work scope and budget for Phase I1 activities. The main objective in Phase I was to demonstrate the feasibility of applying the Rapid Solidification Process (RSP) Tooling method to produce molds for the manufacture of glass and other components of interest to Vitro. This objective was successfully achieved.

  14. CMS tracker visualization tools

    CERN Document Server

    Zito, G; Osborne, I; Regano, A

    2005-01-01

    This document will review the design considerations, implementations and performance of the CMS Tracker Visualization tools. In view of the great complexity of this sub-detector (more than 50 millions channels organized in 16540 modules each one of these being a complete detector), the standard CMS visualization tools (IGUANA and IGUANACMS) that provide basic 3D capabilities and integration within CMS framework, respectively, have been complemented with additional 2D graphics objects. Based on the experience acquired using this software to debug and understand both hardware and software during the construction phase, we propose possible future improvements to cope with online monitoring and event analysis during data taking.

  15. CMS tracker visualization tools

    Energy Technology Data Exchange (ETDEWEB)

    Mennea, M.S. [Dipartimento Interateneo di Fisica ' Michelangelo Merlin' e INFN sezione di Bari, Via Amendola 173 - 70126 Bari (Italy); Osborne, I. [Northeastern University, 360 Huntington Avenue, Boston, MA 02115 (United States); Regano, A. [Dipartimento Interateneo di Fisica ' Michelangelo Merlin' e INFN sezione di Bari, Via Amendola 173 - 70126 Bari (Italy); Zito, G. [Dipartimento Interateneo di Fisica ' Michelangelo Merlin' e INFN sezione di Bari, Via Amendola 173 - 70126 Bari (Italy)]. E-mail: giuseppe.zito@ba.infn.it

    2005-08-21

    This document will review the design considerations, implementations and performance of the CMS Tracker Visualization tools. In view of the great complexity of this sub-detector (more than 50 millions channels organized in 16540 modules each one of these being a complete detector), the standard CMS visualization tools (IGUANA and IGUANACMS) that provide basic 3D capabilities and integration within CMS framework, respectively, have been complemented with additional 2D graphics objects. Based on the experience acquired using this software to debug and understand both hardware and software during the construction phase, we propose possible future improvements to cope with online monitoring and event analysis during data taking.

  16. The GNEMRE Dendro Tool.

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, Bion John

    2007-10-01

    The GNEMRE Dendro Tool provides a previously unrealized analysis capability in the field of nuclear explosion monitoring. Dendro Tool allows analysts to quickly and easily determine the similarity between seismic events using the waveform time-series for each of the events to compute cross-correlation values. Events can then be categorized into clusters of similar events. This analysis technique can be used to characterize historical archives of seismic events in order to determine many of the unique sources that are present. In addition, the source of any new events can be quickly identified simply by comparing the new event to the historical set.

  17. Authoring Issues beyond Tools

    Science.gov (United States)

    Spierling, Ulrike; Szilas, Nicolas

    Authoring is still considered a bottleneck in successful Interactive Storytelling and Drama. The claim for intuitive authoring tools is high, especially for tools that allow storytellers and artists to define dynamic content that can be run with an AI-based story engine. We explored two concrete authoring processes in depth, using various Interactive Storytelling prototypes, and have provided feedback from the practical steps. The result is a presentation of general issues in authoring Interactive Storytelling, rather than of particular problems with a specific system that could be overcome by 'simply' designing the right interface. Priorities for future developments are also outlined.

  18. CMS tracker visualization tools

    International Nuclear Information System (INIS)

    Mennea, M.S.; Osborne, I.; Regano, A.; Zito, G.

    2005-01-01

    This document will review the design considerations, implementations and performance of the CMS Tracker Visualization tools. In view of the great complexity of this sub-detector (more than 50 millions channels organized in 16540 modules each one of these being a complete detector), the standard CMS visualization tools (IGUANA and IGUANACMS) that provide basic 3D capabilities and integration within CMS framework, respectively, have been complemented with additional 2D graphics objects. Based on the experience acquired using this software to debug and understand both hardware and software during the construction phase, we propose possible future improvements to cope with online monitoring and event analysis during data taking

  19. Coach assessment tool

    OpenAIRE

    Härkönen, Niko; Klicznik, Roman

    2014-01-01

    The Coach Assessment Tool was created to assist coaches of all sports for their own development. The starting point to develop the tool is the fact that coaching clinics solely focus on the technical and tactial skills of the sport. The education for coaches is lacking to teach the importance of the coach´s behavior towards their athletes. The question is how to teach properly the task in hand to increase the athlete´s performance considering the coach´s behavior. Nevertheless,...

  20. Individual Movement Variability Magnitudes Are Explained by Cortical Neural Variability.

    Science.gov (United States)

    Haar, Shlomi; Donchin, Opher; Dinstein, Ilan

    2017-09-13

    Humans exhibit considerable motor variability even across trivial reaching movements. This variability can be separated into specific kinematic components such as extent and direction that are thought to be governed by distinct neural processes. Here, we report that individual subjects (males and females) exhibit different magnitudes of kinematic variability, which are consistent (within individual) across movements to different targets and regardless of which arm (right or left) was used to perform the movements. Simultaneous fMRI recordings revealed that the same subjects also exhibited different magnitudes of fMRI variability across movements in a variety of motor system areas. These fMRI variability magnitudes were also consistent across movements to different targets when performed with either arm. Cortical fMRI variability in the posterior-parietal cortex of individual subjects explained their movement-extent variability. This relationship was apparent only in posterior-parietal cortex and not in other motor system areas, thereby suggesting that individuals with more variable movement preparation exhibit larger kinematic variability. We therefore propose that neural and kinematic variability are reliable and interrelated individual characteristics that may predispose individual subjects to exhibit distinct motor capabilities. SIGNIFICANCE STATEMENT Neural activity and movement kinematics are remarkably variable. Although intertrial variability is rarely studied, here, we demonstrate that individual human subjects exhibit distinct magnitudes of neural and kinematic variability that are reproducible across movements to different targets and when performing these movements with either arm. Furthermore, when examining the relationship between cortical variability and movement variability, we find that cortical fMRI variability in parietal cortex of individual subjects explained their movement extent variability. This enabled us to explain why some subjects

  1. Cancer Data and Statistics Tools

    Science.gov (United States)

    ... Educational Campaigns Initiatives Stay Informed Cancer Data and Statistics Tools Recommend on Facebook Tweet Share Compartir Cancer Statistics Tools United States Cancer Statistics: Data Visualizations The ...

  2. Incident Information Management Tool

    CERN Document Server

    Pejovic, Vladimir

    2015-01-01

    Flaws of\tcurrent incident information management at CMS and CERN\tare discussed. A new data\tmodel for future incident database is\tproposed and briefly described. Recently developed draft version of GIS-­‐based tool for incident tracking is presented.

  3. Hypercard Another Computer Tool.

    Science.gov (United States)

    Geske, Joel

    1991-01-01

    Describes "Hypercard," a computer application package usable in all three modes of instructional computing: tutor, tool, and tutee. Suggests using Hypercard in scholastic journalism programs to teach such topics as news, headlines, design, photography, and advertising. Argues that the ability to access, organize, manipulate, and comprehend…

  4. Organisational skills and tools.

    Science.gov (United States)

    Wicker, Paul

    2009-04-01

    While this article mainly applies to practitioners who have responsibilities for leading teams or supervising practitioners, many of the skills and tools described here may also apply to students or junior practitioners. The purpose of this article is to highlight some of the main points about organisation, some of the organisational skills and tools that are available, and some examples of how these skills and tools can be used to make practitioners more effective at organising their workload. It is important to realise that organising work and doing work are two completely different things and shouldn't be mixed up. For example, it would be very difficult to start organising work in the middle of a busy operating list: the organisation of the work must come before the work starts and therefore preparation is often an important first step in organising work. As such, some of the tools and skills described in this article may need to be used hours or even days prior to the actual work taking place.

  5. Tools for Authentication

    International Nuclear Information System (INIS)

    White, G.

    2008-01-01

    Many recent Non-proliferation and Arms Control software projects include a software authentication component. In this context, 'authentication' is defined as determining that a software package performs only its intended purpose and performs that purpose correctly and reliably over many years. In addition to visual inspection by knowledgeable computer scientists, automated tools are needed to highlight suspicious code constructs both to aid the visual inspection and to guide program development. While many commercial tools are available for portions of the authentication task, they are proprietary, and have limited extensibility. An open-source, extensible tool can be customized to the unique needs of each project (projects can have both common and custom rules to detect flaws and security holes). Any such extensible tool must be based on a complete language compiler infrastructure, that is, one that can parse and digest the full language through its standard grammar. ROSE is precisely such a compiler infrastructure developed within DOE. ROSE is a robust source-to-source analysis and optimization infrastructure currently addressing large, million-line DOE applications in C, C++, and FORTRAN. This year, it has been extended to support the automated analysis of binaries. We continue to extend ROSE to address a number of security-specific requirements and apply it to software authentication for Non-proliferation and Arms Control projects. We will give an update on the status of our work

  6. Methodologies, languages and tools

    International Nuclear Information System (INIS)

    Amako, Katsuya

    1994-01-01

    This is a summary of the open-quotes Methodologies, Languages and Toolsclose quotes session in the CHEP'94 conference. All the contributions to methodologies and languages are relevant to the object-oriented approach. Other topics presented are related to various software tools in the down-sized computing environment

  7. Tools for Authentication

    Energy Technology Data Exchange (ETDEWEB)

    White, G

    2008-07-09

    Many recent Non-proliferation and Arms Control software projects include a software authentication component. In this context, 'authentication' is defined as determining that a software package performs only its intended purpose and performs that purpose correctly and reliably over many years. In addition to visual inspection by knowledgeable computer scientists, automated tools are needed to highlight suspicious code constructs both to aid the visual inspection and to guide program development. While many commercial tools are available for portions of the authentication task, they are proprietary, and have limited extensibility. An open-source, extensible tool can be customized to the unique needs of each project (projects can have both common and custom rules to detect flaws and security holes). Any such extensible tool must be based on a complete language compiler infrastructure, that is, one that can parse and digest the full language through its standard grammar. ROSE is precisely such a compiler infrastructure developed within DOE. ROSE is a robust source-to-source analysis and optimization infrastructure currently addressing large, million-line DOE applications in C, C++, and FORTRAN. This year, it has been extended to support the automated analysis of binaries. We continue to extend ROSE to address a number of security-specific requirements and apply it to software authentication for Non-proliferation and Arms Control projects. We will give an update on the status of our work.

  8. [Tools for assisting diagnosis].

    Science.gov (United States)

    Roux, Magali; Asset, Sonya; Medjebar, Samir

    2017-11-01

    Connected objects are revolutionising practices, fulfil patients' needs for autonomy and the need to deploy healthcare provision beyond healthcare facilities. This article illustrates how these tools can be used in the case of epilepsy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  9. Requirements for enrichment tools

    NARCIS (Netherlands)

    Boer, A.; Winkels, R.; Trompper, M.

    2016-01-01

    This report gives a high level overview of requirements for Enrichment tools in the Openlaws.eu project. Openlaws.eu aims to initiate a platform and develop a vision for Big Open Legal Data (BOLD): an open framework for legislation, case law, and legal literature from across Europe.

  10. C-TOOL

    DEFF Research Database (Denmark)

    Taghizadeh-Toosi, Arezoo; Christensen, Bent Tolstrup; Hutchings, Nicholas John

    2014-01-01

    Soil organic carbon (SOC) is a significant component of the global carbon (C) cycle. Changes in SOC storage affect atmospheric CO2 concentrations on decadal to centennial timescales. The C-TOOL model was developed to simulate farm- and regional-scale effects of management on medium- to long...

  11. Tools for Climate Services

    Science.gov (United States)

    Hartmann, H. C.

    2007-05-01

    Full realization of socio-economic benefits of from public investments in climate services remains incomplete because decision makers have difficulty: 1) interpreting individual products, 2) appropriately judging information credibility, and 3) linking different types of information, both conceptually and practically. Addressing these barriers is as important as improving the science leading to improved information. The challenge is creating flexible climate information products and tools that can accommodate unique user needs; the goal is a systemic change in the nature of information delivery and use. The underlying assumption is not that climate information is good and useful, and simply needs to be communicated effectively. Rather, a number of conditions must be met before decision makers can make informed choices about whether to use particular information in a specific situation. Several case studies, of varying success, illustrate user-centric strategies for developing decision support tools: a forecast evaluation tool, a climate information management system, and a hydrologic alert system. However, tools alone will not bridge the barriers in climate services, with training and other capacity- building activities remaining important activities.

  12. Sight Application Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    Bronevetsky, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-09-17

    The scale and complexity of scientific applications makes it very difficult to optimize, debug and extend them to support new capabilities. We have developed a tool that supports developers’ efforts to understand the logical flow of their applications and interactions between application components and hardware in a way that scales with application complexity and parallelism.

  13. Tool voor verdeling rivierwater

    NARCIS (Netherlands)

    Hellegers, P.J.G.J.

    2011-01-01

    In het stroomgebied van de Inkomati-rivier in zuidelijk Afrika, maken partijen uit drie landen aanspraak op het rivierwater. LEI, Alterra en adviesbureau WaterWatch ontwikkelden met lokale partners een tool die betrokkenen laat zien wat ander landgebruik betekent voor de beschikbaarheid van dat

  14. The science writing tool

    Science.gov (United States)

    Schuhart, Arthur L.

    This is a two-part dissertation. The primary part is the text of a science-based composition rhetoric and reader called The Science Writing Tool. This textbook has seven chapters dealing with topics in Science Rhetoric. Each chapter includes a variety of examples of science writing, discussion questions, writing assignments, and instructional resources. The purpose of this text is to introduce lower-division college science majors to the role that rhetoric and communication plays in the conduct of Science, and how these skills contribute to a successful career in Science. The text is designed as a "tool kit," for use by an instructor constructing a science-based composition course or a writing-intensive Science course. The second part of this part of this dissertation reports on student reactions to draft portions of The Science Writing Tool text. In this report, students of English Composition II at Northern Virginia Community College-Annandale were surveyed about their attitudes toward course materials and topics included. The findings were used to revise and expand The Science Writing Tool.

  15. Big Data Visualization Tools

    OpenAIRE

    Bikakis, Nikos

    2018-01-01

    Data visualization is the presentation of data in a pictorial or graphical format, and a data visualization tool is the software that generates this presentation. Data visualization provides users with intuitive means to interactively explore and analyze data, enabling them to effectively identify interesting patterns, infer correlations and causalities, and supports sense-making activities.

  16. Rapid Tooling via Stereolithography

    OpenAIRE

    Montgomery, Eva

    2006-01-01

    Approximately three years ago, composite stereolithography (SL) resins were introduced to the marketplace, offering performance features beyond what traditional SL resins could offer. In particular, the high heat deflection temperatures and high stiffness of these highly filled resins have opened the door to several new rapid prototyping (RP) applications, including wind tunnel test modelling and, more recently, rapid tooling.

  17. Tools of the Trade

    Science.gov (United States)

    Porterfield, Kitty; Carnes, Meg

    2010-01-01

    People have known principals who are intellectual giants on issues of instruction and who have a great love of children but who stumble in leadership roles because they either do not or cannot communicate what they know. Good communication skills are among the most important tools a leader carries in his or her toolbox. Not only does good…

  18. Verification of Simulation Tools

    International Nuclear Information System (INIS)

    Richard, Thierry

    2015-01-01

    Before qualifying a simulation tool, the requirements shall first be clearly identified, i.e.: - What type of study needs to be carried out? - What phenomena need to be modeled? This phase involves writing a precise technical specification. Once the requirements are defined, the most adapted product shall be selected from the various software options available on the market. Before using a particular version of a simulation tool to support the demonstration of nuclear safety studies, the following requirements shall be met. - An auditable quality assurance process complying with development international standards shall be developed and maintained, - A process of verification and validation (V and V) shall be implemented. This approach requires: writing a report and/or executive summary of the V and V activities, defining a validated domain (domain in which the difference between the results of the tools and those of another qualified reference is considered satisfactory for its intended use). - Sufficient documentation shall be available, - A detailed and formal description of the product (software version number, user configuration, other settings and parameters) in the targeted computing environment shall be available. - Source codes corresponding to the software shall be archived appropriately. When these requirements are fulfilled, the version of the simulation tool shall be considered qualified for a defined domain of validity, in a given computing environment. The functional verification shall ensure that: - the computer architecture of the tool does not include errors, - the numerical solver correctly represents the physical mathematical model, - equations are solved correctly. The functional verification can be demonstrated through certification or report of Quality Assurance. The functional validation shall allow the user to ensure that the equations correctly represent the physical phenomena in the perimeter of intended use. The functional validation can

  19. Understanding Solar Cycle Variability

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, R. H.; Schüssler, M., E-mail: cameron@mps.mpg.de [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)

    2017-07-10

    The level of solar magnetic activity, as exemplified by the number of sunspots and by energetic events in the corona, varies on a wide range of timescales. Most prominent is the 11-year solar cycle, which is significantly modulated on longer timescales. Drawing from dynamo theory, together with the empirical results of past solar activity and similar phenomena for solar-like stars, we show that the variability of the solar cycle can be essentially understood in terms of a weakly nonlinear limit cycle affected by random noise. In contrast to ad hoc “toy models” for the solar cycle, this leads to a generic normal-form model, whose parameters are all constrained by observations. The model reproduces the characteristics of the variable solar activity on timescales between decades and millennia, including the occurrence and statistics of extended periods of very low activity (grand minima). Comparison with results obtained with a Babcock–Leighton-type dynamo model confirm the validity of the normal-mode approach.

  20. Extended Testability Analysis Tool

    Science.gov (United States)

    Melcher, Kevin; Maul, William A.; Fulton, Christopher

    2012-01-01

    The Extended Testability Analysis (ETA) Tool is a software application that supports fault management (FM) by performing testability analyses on the fault propagation model of a given system. Fault management includes the prevention of faults through robust design margins and quality assurance methods, or the mitigation of system failures. Fault management requires an understanding of the system design and operation, potential failure mechanisms within the system, and the propagation of those potential failures through the system. The purpose of the ETA Tool software is to process the testability analysis results from a commercial software program called TEAMS Designer in order to provide a detailed set of diagnostic assessment reports. The ETA Tool is a command-line process with several user-selectable report output options. The ETA Tool also extends the COTS testability analysis and enables variation studies with sensor sensitivity impacts on system diagnostics and component isolation using a single testability output. The ETA Tool can also provide extended analyses from a single set of testability output files. The following analysis reports are available to the user: (1) the Detectability Report provides a breakdown of how each tested failure mode was detected, (2) the Test Utilization Report identifies all the failure modes that each test detects, (3) the Failure Mode Isolation Report demonstrates the system s ability to discriminate between failure modes, (4) the Component Isolation Report demonstrates the system s ability to discriminate between failure modes relative to the components containing the failure modes, (5) the Sensor Sensor Sensitivity Analysis Report shows the diagnostic impact due to loss of sensor information, and (6) the Effect Mapping Report identifies failure modes that result in specified system-level effects.

  1. Spray-formed tooling

    Science.gov (United States)

    McHugh, K. M.; Key, J. F.

    The United States Council for Automotive Research (USCAR) has formed a partnership with the Idaho National Engineering Laboratory (INEL) to develop a process for the rapid production of low-cost tooling based on spray forming technology developed at the INEL. Phase 1 of the program will involve bench-scale system development, materials characterization, and process optimization. In Phase 2, prototype systems will be designed, constructed, evaluated, and optimized. Process control and other issues that influence commercialization will be addressed during this phase of the project. Technology transfer to USCAR, or a tooling vendor selected by USCAR, will be accomplished during Phase 3. The approach INEL is using to produce tooling, such as plastic injection molds and stamping dies, combines rapid solidification processing and net-shape materials processing into a single step. A bulk liquid metal is pressure-fed into a de Laval spray nozzle transporting a high velocity, high temperature inert gas. The gas jet disintegrates the metal into fine droplets and deposits them onto a tool pattern made from materials such as plastic, wax, clay, ceramics, and metals. The approach is compatible with solid freeform fabrication techniques such as stereolithography, selective laser sintering, and laminated object manufacturing. Heat is extracted rapidly, in-flight, by convection as the spray jet entrains cool inert gas to produce undercooled and semi-solid droplets. At the pattern, the droplets weld together while replicating the shape and surface features of the pattern. Tool formation is rapid; deposition rates in excess of 1 ton/h have been demonstrated for bench-scale nozzles.

  2. Context matters! sources of variability in weekend physical activity among families: a repeated measures study

    Directory of Open Access Journals (Sweden)

    Robert J. Noonan

    2017-04-01

    Full Text Available Abstract Background Family involvement is an essential component of effective physical activity (PA interventions in children. However, little is known about the PA levels and characteristics of PA among families. This study used a repeated measures design and multiple data sources to explore the variability and characteristics of weekend PA among families. Methods Families (including a ‘target’ child aged 9–11 years, their primary caregiver(s and siblings aged 6–8 years were recruited through primary schools in Liverpool, UK. Participants completed a paper-based PA diary and wore an ActiGraph GT9X accelerometer on their left wrist for up to 16 weekend days. ActiGraph.csv files were analysed using the R-package GGIR version 1.1–4. Mean minutes of moderate-to-vigorous PA (MVPA for each weekend of measurement were calculated using linear mixed models, and variance components were estimated for participant (inter-individual, weekend of measurement, and residual error (intra-individual. Intraclass correlation coefficients (ICC were calculated from the proportion of total variance accounted for by inter-individual sources, and used as a measure of reliability. Diary responses were summed to produce frequency counts. To offer contextual insight into weekend PA among family units, demographic, accelerometer, and diary data were combined to form two case studies representative of low and high active families. Results Twenty-five participants from 7 families participated, including 7 ‘target’ children (mean age 9.3 ± 1.1 years, 4 boys, 6 siblings (mean age 7.2 ± 0.7 years; 4 boys and 12 adults (7 mothers and 5 fathers. There was a high degree of variability in target children’s (ICC = 0.55, siblings (ICC = 0.38, and mothers’ MVPA (ICC = 0.58, but not in fathers’ MVPA (ICC = 0.83. Children’s weekend PA was mostly unstructured in nature and undertaken with friends, whereas a greater proportion of parents’ weekend

  3. Climate variability and change

    International Nuclear Information System (INIS)

    Manton, M.

    2006-01-01

    When Australia's climate should not be definite barrier to the population reaching 30 million by 2050, it is recognised that our climate has limited the development of the nation over the past 200 years. Indeed in 1911, based on a comparison of the climate and development between the US and Australia. Griffith Taylor predicted that Australia's population would be 19 million at the end of the 20th century, which is a pretty good 90-year forecast. The climate constraint is not only due to much of the country being semi-arid with an annual rainfall below 400 millimetres, but also due to the large year-to-year variability of rainfall across the country

  4. Variable cycle engine

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, A.P.; Sprunger, E.V.

    1980-09-16

    A variable cycle turboshaft engine includes a remote fan system and respective high and low pressure systems for selectively driving the fan system in such a manner as to provide VTOL takeoff capability and minimum specific fuel consumption (SFC) at cruise and loiter conditions. For takeoff the fan system is primarily driven by the relatively large low pressure system whose combustor receives the motive fluid from a core bypass duct and, for cruise and loiter conditions, the fan system is driven by both a relatively small high pressure core and the low pressure system with its combustor inoperative. A mixer is disposed downstream of the high pressure system for mixing the relatively cold air from the bypass duct and the relatively hot air from the core prior to its flow to the low pressure turbine.

  5. Web Tools: The Second Generation

    Science.gov (United States)

    Pascopella, Angela

    2008-01-01

    Web 2.0 tools and technologies, or second generation tools, help districts to save time and money, and eliminate the need to transfer or move files back and forth across computers. Many Web 2.0 tools help students think critically and solve problems, which falls under the 21st-century skills. The second-generation tools are growing in popularity…

  6. Statistical variability of hydro-meteorological variables as indicators ...

    African Journals Online (AJOL)

    Statistical variability of hydro-meteorological variables as indicators of climate change in north-east Sokoto-Rima basin, Nigeria. ... water resources development including water supply project, agriculture and tourism in the study area. Key word: Climate change, Climatic variability, Actual evapotranspiration, Global warming ...

  7. Pneumatic soil removal tool

    International Nuclear Information System (INIS)

    Neuhaus, J.E.

    1992-01-01

    A soil removal tool is provided for removing radioactive soil, rock and other debris from the bottom of an excavation, while permitting the operator to be located outside of a containment for that excavation. The tool includes a fixed jaw, secured to one end of an elongate pipe, which cooperates with a movable jaw pivotably mounted on the pipe. Movement of the movable jaw is controlled by a pneumatic cylinder mounted on the pipe. The actuator rod of the pneumatic cylinder is connected to a collar which is slidably mounted on the pipe and forms part of the pivotable mounting assembly for the movable jaw. Air is supplied to the pneumatic cylinder through a handle connected to the pipe, under the control of an actuator valve mounted on the handle, to provide movement of the movable jaw. 3 figs

  8. Building energy analysis tool

    Science.gov (United States)

    Brackney, Larry; Parker, Andrew; Long, Nicholas; Metzger, Ian; Dean, Jesse; Lisell, Lars

    2016-04-12

    A building energy analysis system includes a building component library configured to store a plurality of building components, a modeling tool configured to access the building component library and create a building model of a building under analysis using building spatial data and using selected building components of the plurality of building components stored in the building component library, a building analysis engine configured to operate the building model and generate a baseline energy model of the building under analysis and further configured to apply one or more energy conservation measures to the baseline energy model in order to generate one or more corresponding optimized energy models, and a recommendation tool configured to assess the one or more optimized energy models against the baseline energy model and generate recommendations for substitute building components or modifications.

  9. Remote vehicle survey tool

    International Nuclear Information System (INIS)

    Armstrong, G.A.; Burks, B.L.; Kress, R.L.; Wagner, D.G.; Ward, C.R.

    1993-01-01

    The Remote Vehicle Survey Tool (RVS7) is a color graphical display tool for viewing remotely acquired scientific data. The RVST displays the data in the form of a color two-dimensional world model map. The world model map allows movement of the remote vehicle to be tracked by the operator and the data from sensors to be graphically depicted in the interface. Linear and logarithmic meters, dual channel oscilloscopes, and directional compasses are used to display sensor information. The RVST is user-configurable by the use of ASCII text files. The operator can configure the RVST to work with any remote data acquisition system and teleoperated or autonomous vehicle. The modular design of the RVST and its ability to be quickly configured for varying system requirements make the RVST ideal for remote scientific data display in all environmental restoration and waste management programs

  10. Pneumatic soil removal tool

    Science.gov (United States)

    Neuhaus, John E.

    1992-01-01

    A soil removal tool is provided for removing radioactive soil, rock and other debris from the bottom of an excavation, while permitting the operator to be located outside of a containment for that excavation. The tool includes a fixed jaw, secured to one end of an elongate pipe, which cooperates with a movable jaw pivotably mounted on the pipe. Movement of the movable jaw is controlled by a pneumatic cylinder mounted on the pipe. The actuator rod of the pneumatic cylinder is connected to a collar which is slidably mounted on the pipe and forms part of the pivotable mounting assembly for the movable jaw. Air is supplied to the pneumatic cylinder through a handle connected to the pipe, under the control of an actuator valve mounted on the handle, to provide movement of the movable jaw.

  11. Communication tools in Canada

    International Nuclear Information System (INIS)

    Cowper, D.

    1995-01-01

    This document deals with the means and tools that are used for communicating with elected representatives. First, messages need to be simple, few in number and accurate. It is also advised to seek a first briefing because there is some information to be given, and not because some help is needed. On top of that, contacts should be made often enough to assure of a continued interest. (TEC)

  12. The GEDI Performance Tool

    Science.gov (United States)

    Hancock, S.; Armston, J.; Tang, H.; Patterson, P. L.; Healey, S. P.; Marselis, S.; Duncanson, L.; Hofton, M. A.; Kellner, J. R.; Luthcke, S. B.; Sun, X.; Blair, J. B.; Dubayah, R.

    2017-12-01

    NASA's Global Ecosystem Dynamics Investigation will mount a multi-track, full-waveform lidar on the International Space Station (ISS) that is optimised for the measurement of forest canopy height and structure. GEDI will use ten laser tracks, two 10 mJ "power beams" and eight 5 mJ "coverage beams" to produce global (51.5oS to 51.5oN) maps of above ground biomass (AGB), canopy height, vegetation structure and other biophysical parameters. The mission has a requirement to generate a 1 km AGB map with 80% of pixels with ≤ 20% standard error or 20 Mg·ha-1, whichever is greater. To assess performance and compare to mission requirements, an end-to-end simulator has been developed. The simulator brings together tools to propagate the effects of measurement and sampling error on GEDI data products. The simulator allows us to evaluate the impact of instrument performance, ISS orbits, processing algorithms and losses of data that may occur due to clouds, snow, leaf-off conditions, and areas with an insufficient signal-to-noise ratio (SNR). By evaluating the consequences of operational decisions on GEDI data products, this tool provides a quantitative framework for decision-making and mission planning. Here we demonstrate the performance tool by using it to evaluate the trade-off between measurement and sampling error on the 1 km AGB data product. Results demonstrate that the use of coverage beams during the day (lowest GEDI SNR case) over very dense forests (>95% canopy cover) will result in some measurement bias. Omitting these low SNR cases increased the sampling error. Through this an SNR threshold for a given expected canopy cover can be set. The other applications of the performance tool are also discussed, such as assessing the impact of decisions made in the AGB modelling and signal processing stages on the accuracy of final data products.

  13. Program Management Tool

    Science.gov (United States)

    Gawadiak, Yuri; Wong, Alan; Maluf, David; Bell, David; Gurram, Mohana; Tran, Khai Peter; Hsu, Jennifer; Yagi, Kenji; Patel, Hemil

    2007-01-01

    The Program Management Tool (PMT) is a comprehensive, Web-enabled business intelligence software tool for assisting program and project managers within NASA enterprises in gathering, comprehending, and disseminating information on the progress of their programs and projects. The PMT provides planning and management support for implementing NASA programmatic and project management processes and requirements. It provides an online environment for program and line management to develop, communicate, and manage their programs, projects, and tasks in a comprehensive tool suite. The information managed by use of the PMT can include monthly reports as well as data on goals, deliverables, milestones, business processes, personnel, task plans, monthly reports, and budgetary allocations. The PMT provides an intuitive and enhanced Web interface to automate the tedious process of gathering and sharing monthly progress reports, task plans, financial data, and other information on project resources based on technical, schedule, budget, and management criteria and merits. The PMT is consistent with the latest Web standards and software practices, including the use of Extensible Markup Language (XML) for exchanging data and the WebDAV (Web Distributed Authoring and Versioning) protocol for collaborative management of documents. The PMT provides graphical displays of resource allocations in the form of bar and pie charts using Microsoft Excel Visual Basic for Application (VBA) libraries. The PMT has an extensible architecture that enables integration of PMT with other strategic-information software systems, including, for example, the Erasmus reporting system, now part of the NASA Integrated Enterprise Management Program (IEMP) tool suite, at NASA Marshall Space Flight Center (MSFC). The PMT data architecture provides automated and extensive software interfaces and reports to various strategic information systems to eliminate duplicative human entries and minimize data integrity

  14. Social Data Analytics Tool

    DEFF Research Database (Denmark)

    Hussain, Abid; Vatrapu, Ravi

    2014-01-01

    This paper presents the design, development and demonstrative case studies of the Social Data Analytics Tool, SODATO. Adopting Action Design Framework [1], the objective of SODATO [2] is to collect, store, analyze, and report big social data emanating from the social media engagement of and social...... media conversations about organizations. We report and discuss results from two demonstrative case studies that were conducted using SODATO and conclude with implications and future work....

  15. MICROCONTROLLER PIN CONFIGURATION TOOL

    OpenAIRE

    Bhaskar Joshi; F. Mohammed Rizwan; Dr. Rajashree Shettar

    2012-01-01

    Configuring the micro controller with large number of pins is tedious. Latest Infine on microcontroller contains more than 200 pins and each pin has classes of signals. Therefore the complexity of the microcontroller is growing. It evolves looking into thousands of pages of user manual. For a user it will take days to configure the microcontroller with the peripherals. We need an automated tool to configure the microcontroller so that the user can configure the microcontroller without having ...

  16. Fluid sampling tool

    Science.gov (United States)

    Garcia, A.R.; Johnston, R.G.; Martinez, R.K.

    1999-05-25

    A fluid sampling tool is described for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall. 6 figs.

  17. Frequency Response Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    Etingov, Pavel V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kosterev, Dmitry [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dai, T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    Frequency response has received a lot of attention in recent years at the national level, which culminated in the development and approval of North American Electricity Reliability Corporation (NERC) BAL-003-1 Frequency Response and Frequency Bias Setting Reliability Standard. This report is prepared to describe the details of the work conducted by Pacific Northwest National Laboratory (PNNL) in collaboration with the Bonneville Power Administration and Western Electricity Coordinating Council (WECC) Joint Synchronized Information Subcommittee (JSIS) to develop a frequency response analysis tool (FRAT). The document provides the details on the methodology and main features of the FRAT. The tool manages the database of under-frequency events and calculates the frequency response baseline. Frequency response calculations are consistent with frequency response measure (FRM) in NERC BAL-003-1 for an interconnection and balancing authority. The FRAT can use both phasor measurement unit (PMU) data, where available, and supervisory control and data acquisition (SCADA) data. The tool is also capable of automatically generating NERC Frequency Response Survey (FRS) forms required by BAL-003-1 Standard.

  18. Dynamic Contingency Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    2016-01-14

    The Dynamic Contingency Analysis Tool (DCAT) is an open-platform and publicly available methodology to help develop applications that aim to improve the capabilities of power system planning engineers to assess the impact and likelihood of extreme contingencies and potential cascading events across their systems and interconnections. Outputs from the DCAT will help find mitigation solutions to reduce the risk of cascading outages in technically sound and effective ways. The current prototype DCAT implementation has been developed as a Python code that accesses the simulation functions of the Siemens PSS/E planning tool (PSS/E). It has the following features: It uses a hybrid dynamic and steady-state approach to simulating the cascading outage sequences that includes fast dynamic and slower steady-state events. It integrates dynamic models with protection scheme models for generation, transmission, and load. It models special protection systems (SPSs)/remedial action schemes (RASs) and automatic and manual corrective actions. Overall, the DCAT attempts to bridge multiple gaps in cascading-outage analysis in a single, unique prototype tool capable of automatically simulating and analyzing cascading sequences in real systems using multiprocessor computers.While the DCAT has been implemented using PSS/E in Phase I of the study, other commercial software packages with similar capabilities can be used within the DCAT framework.

  19. Fluid sampling tool

    Science.gov (United States)

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    1999-05-25

    A fluid sampling tool for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall.

  20. An Analysis of Social Class Classification Based on Linguistic Variables

    Institute of Scientific and Technical Information of China (English)

    QU Xia-sha

    2016-01-01

    Since language is an influential tool in social interaction, the relationship of speech and social factors, such as social class, gender, even age is worth studying. People employ different linguistic variables to imply their social class, status and iden-tity in the social interaction. Thus the linguistic variation involves vocabulary, sounds, grammatical constructions, dialects and so on. As a result, a classification of social class draws people’s attention. Linguistic variable in speech interactions indicate the social relationship between people. This paper attempts to illustrate three main linguistic variables which influence the social class, and further sociolinguistic studies need to be more concerned about.