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  1. Method for mapping population-based case-control studies: an application using generalized additive models

    Directory of Open Access Journals (Sweden)

    Aschengrau Ann

    2006-06-01

    Full Text Available Abstract Background Mapping spatial distributions of disease occurrence and risk can serve as a useful tool for identifying exposures of public health concern. Disease registry data are often mapped by town or county of diagnosis and contain limited data on covariates. These maps often possess poor spatial resolution, the potential for spatial confounding, and the inability to consider latency. Population-based case-control studies can provide detailed information on residential history and covariates. Results Generalized additive models (GAMs provide a useful framework for mapping point-based epidemiologic data. Smoothing on location while controlling for covariates produces adjusted maps. We generate maps of odds ratios using the entire study area as a reference. We smooth using a locally weighted regression smoother (loess, a method that combines the advantages of nearest neighbor and kernel methods. We choose an optimal degree of smoothing by minimizing Akaike's Information Criterion. We use a deviance-based test to assess the overall importance of location in the model and pointwise permutation tests to locate regions of significantly increased or decreased risk. The method is illustrated with synthetic data and data from a population-based case-control study, using S-Plus and ArcView software. Conclusion Our goal is to develop practical methods for mapping population-based case-control and cohort studies. The method described here performs well for our synthetic data, reproducing important features of the data and adequately controlling the covariate. When applied to the population-based case-control data set, the method suggests spatial confounding and identifies statistically significant areas of increased and decreased odds ratios.

  2. Methods of Suicide among Cancer Patients: A Nationwide Population-Based Study

    Science.gov (United States)

    Chung, Kuo-Hsuan; Lin, Herng-Ching

    2010-01-01

    A 3-year nationwide population-based data set was used to explore methods of suicide (violent vs. nonviolent) and possible contributing factors among cancer patients in Taiwan. A total of 1,065 cancer inpatients who committed suicide were included as our study sample. The regression shows that those who had genitourinary cancer were 0.55 times (p…

  3. Consequences of population topology for studying gene flow using link-based landscape genetic methods.

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    van Strien, Maarten J

    2017-07-01

    Many landscape genetic studies aim to determine the effect of landscape on gene flow between populations. These studies frequently employ link-based methods that relate pairwise measures of historical gene flow to measures of the landscape and the geographical distance between populations. However, apart from landscape and distance, there is a third important factor that can influence historical gene flow, that is, population topology (i.e., the arrangement of populations throughout a landscape). As the population topology is determined in part by the landscape configuration, I argue that it should play a more prominent role in landscape genetics. Making use of existing literature and theoretical examples, I discuss how population topology can influence results in landscape genetic studies and how it can be taken into account to improve the accuracy of these results. In support of my arguments, I have performed a literature review of landscape genetic studies published during the first half of 2015 as well as several computer simulations of gene flow between populations. First, I argue why one should carefully consider which population pairs should be included in link-based analyses. Second, I discuss several ways in which the population topology can be incorporated in response and explanatory variables. Third, I outline why it is important to sample populations in such a way that a good representation of the population topology is obtained. Fourth, I discuss how statistical testing for link-based approaches could be influenced by the population topology. I conclude the article with six recommendations geared toward better incorporating population topology in link-based landscape genetic studies.

  4. The INTERPHONE study: design, epidemiological methods, and description of the study population

    DEFF Research Database (Denmark)

    Cardis, Elisabeth; Richardson, Lesley; Deltour, Isabelle

    2007-01-01

    . This paper describes the study design and methods and the main characteristics of the study population. INTERPHONE is the largest case-control study to date investigating risks related to mobile phone use and to other potential risk factors for the tumours of interest and includes 2,765 glioma, 2......The very rapid worldwide increase in mobile phone use in the last decade has generated considerable interest in the possible health effects of exposure to radio frequency (RF) fields. A multinational case-control study, INTERPHONE, was set-up to investigate whether mobile phone use increases...... the risk of cancer and, more specifically, whether the RF fields emitted by mobile phones are carcinogenic. The study focused on tumours arising in the tissues most exposed to RF fields from mobile phones: glioma, meningioma, acoustic neurinoma and parotid gland tumours. In addition to a detailed history...

  5. Nose profile morphology and accuracy study of nose profile estimation method in Scottish subadult and Indonesian adult populations.

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    Sarilita, Erli; Rynn, Christopher; Mossey, Peter A; Black, Sue; Oscandar, Fahmi

    2018-05-01

    This study investigated nose profile morphology and its relationship to the skull in Scottish subadult and Indonesian adult populations, with the aim of improving the accuracy of forensic craniofacial reconstruction. Samples of 86 lateral head cephalograms from Dundee Dental School (mean age, 11.8 years) and 335 lateral head cephalograms from the Universitas Padjadjaran Dental Hospital, Bandung, Indonesia (mean age 24.2 years), were measured. The method of nose profile estimation based on skull morphology previously proposed by Rynn and colleagues in 2010 (FSMP 6:20-34) was tested in this study. Following this method, three nasal aperture-related craniometrics and six nose profile dimensions were measured from the cephalograms. To assess the accuracy of the method, six nose profile dimensions were estimated from the three craniometric parameters using the published method and then compared to the actual nose profile dimensions.In the Scottish subadult population, no sexual dimorphism was evident in the measured dimensions. In contrast, sexual dimorphism of the Indonesian adult population was evident in all craniometric and nose profile dimensions; notably, males exhibited statistically significant larger values than females. The published method by Rynn and colleagues (FSMP 6:20-34, 2010) performed better in the Scottish subadult population (mean difference of maximum, 2.35 mm) compared to the Indonesian adult population (mean difference of maximum, 5.42 mm in males and 4.89 mm in females).In addition, regression formulae were derived to estimate nose profile dimensions based on the craniometric measurements for the Indonesian adult population. The published method is not sufficiently accurate for use on the Indonesian population, so the derived method should be used. The accuracy of the published method by Rynn and colleagues (FSMP 6:20-34, 2010) was sufficiently reliable to be applied in Scottish subadult population.

  6. A Pilot Study Using Mixed GPS/Narrative Interview Methods to Understand Geospatial Behavior in Homeless Populations.

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    North, Carol S; Wohlford, Sarah E; Dean, Denis J; Black, Melissa; Balfour, Margaret E; Petrovich, James C; Downs, Dana L; Pollio, David E

    2017-08-01

    Tracking the movements of homeless populations presents methodological difficulties, but understanding their movements in space and time is needed to inform optimal placement of services. This pilot study developed, tested, and refined methods to apply global positioning systems (GPS) technology paired with individual narratives to chronicle the movements of homeless populations. Detail of methods development and difficulties encountered and addressed, and geospatial findings are provided. A pilot sample of 29 adults was recruited from a low-demand homeless shelter in the downtown area of Fort Worth, Texas. Pre- and post-deployment interviews provided participant characteristics and planned and retrospectively-reported travels. Only one of the first eight deployments returned with sufficient usable data. Ultimately 19 participants returned the GPS device with >20 h of usable data. Protocol adjustments addressing methodological difficulties achieved 81 % of subsequent participants returning with sufficient usable data. This study established methods and demonstrated feasibility for tracking homeless population travels.

  7. Discontinuous Galerkin finite element method for solving population density functions of cortical pyramidal and thalamic neuronal populations.

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    Huang, Chih-Hsu; Lin, Chou-Ching K; Ju, Ming-Shaung

    2015-02-01

    Compared with the Monte Carlo method, the population density method is efficient for modeling collective dynamics of neuronal populations in human brain. In this method, a population density function describes the probabilistic distribution of states of all neurons in the population and it is governed by a hyperbolic partial differential equation. In the past, the problem was mainly solved by using the finite difference method. In a previous study, a continuous Galerkin finite element method was found better than the finite difference method for solving the hyperbolic partial differential equation; however, the population density function often has discontinuity and both methods suffer from a numerical stability problem. The goal of this study is to improve the numerical stability of the solution using discontinuous Galerkin finite element method. To test the performance of the new approach, interaction of a population of cortical pyramidal neurons and a population of thalamic neurons was simulated. The numerical results showed good agreement between results of discontinuous Galerkin finite element and Monte Carlo methods. The convergence and accuracy of the solutions are excellent. The numerical stability problem could be resolved using the discontinuous Galerkin finite element method which has total-variation-diminishing property. The efficient approach will be employed to simulate the electroencephalogram or dynamics of thalamocortical network which involves three populations, namely, thalamic reticular neurons, thalamocortical neurons and cortical pyramidal neurons. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Methods and background characteristics of the TOHNN study: a population-based study of oral health conditions in northern Norway

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    Holde, Gro Eirin; Oscarson, Nils; Tillberg, Anders; Marstrander, Peter; Jönsson, Birgitta

    2016-01-01

    Objectives The aim of the Tromstannen – Oral Health in Northern Norway (TOHNN) study was to investigate oral health and dental-related diseases in an adult population. This article provides an overview of the background of the study and a description of the sample characteristics and methods employed in data collection. Study design Cross-sectional population-based study including a questionnaire and clinical dental examination. Methods A randomly selected sample of 2,909 individuals (20–79 years old) drawn from the population register was invited to participate in the study. The data were collected between October 2013 and November 2014 in Troms County in northern Norway. The questionnaire focused on oral health-related behaviours and attitudes, oral health-related quality of life, sense of coherence, dental anxiety and symptoms from the temporomandibular joint. The dental examinations, including radiographs, were conducted by 11 dental teams in 5 dental offices. The examination comprised of registration of dental caries, full mouth periodontal status, temporomandibular disorders, mucosal lesions and height and weight. The participants were grouped by age (20–34, 35–49, 50–64 and 65–79) and ethnicity (Norwegian, Sámi, other European and other world). Results From the original sample of 2,909 individuals, 1,986 (68.3%) people participated, of whom 1,019 (51.3%) were women. The highest attendance rate was among women 20–34 years old (80.3%) and the lowest in the oldest age group of women (55.4%). There was no difference in response rate between rural and urban areas. There was a positive correlation between population size and household gross income (p population in Troms County. Due to the high participation rate, generalization both nationally and to the circumpolar area ought to be possible. PMID:26900910

  9. A new method for studying population genetics of cyst nematodes based on Pool-Seq and genomewide allele frequency analysis.

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    Mimee, Benjamin; Duceppe, Marc-Olivier; Véronneau, Pierre-Yves; Lafond-Lapalme, Joël; Jean, Martine; Belzile, François; Bélair, Guy

    2015-11-01

    Cyst nematodes are important agricultural pests responsible for billions of dollars of losses each year. Plant resistance is the most effective management tool, but it requires a close monitoring of population genetics. Current technologies for pathotyping and genotyping cyst nematodes are time-consuming, expensive and imprecise. In this study, we capitalized on the reproduction mode of cyst nematodes to develop a simple population genetic analysis pipeline based on genotyping-by-sequencing and Pool-Seq. This method yielded thousands of SNPs and allowed us to study the relationships between populations of different origins or pathotypes. Validation of the method on well-characterized populations also demonstrated that it was a powerful and accurate tool for population genetics. The genomewide allele frequencies of 23 populations of golden nematode, from nine countries and representing the five known pathotypes, were compared. A clear separation of the pathotypes and fine genetic relationships between and among global populations were obtained using this method. In addition to being powerful, this tool has proven to be very time- and cost-efficient and could be applied to other cyst nematode species. © 2015 Her Majesty the Queen in Right of Canada Molecular Ecology Resources © 2015 John Wiley & Sons Ltd Reproduced with the permission of the Minister of Agriculture and Agri-food.

  10. The Urban Environment and Childhood Asthma (URECA birth cohort study: design, methods, and study population

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    Sandel Megan T

    2009-05-01

    Full Text Available Abstract Background The incidence and morbidity of wheezing illnesses and childhood asthma is especially high in poor urban areas. This paper describes the study design, methods, and population of the Urban Environment and Childhood Asthma (URECA study, which was established to investigate the immunologic causes of asthma among inner-city children. Methods and Results URECA is an observational prospective study that enrolled pregnant women in central urban areas of Baltimore, Boston, New York City, and St. Louis and is following their offspring from birth through age 7 years. The birth cohort consists of 560 inner-city children who have at least one parent with an allergic disease or asthma, and all families live in areas in which at least 20% of the population has incomes below the poverty line. In addition, 49 inner-city children with no parental history of allergies or asthma were enrolled. The primary hypothesis is that specific urban exposures in early life promote a unique pattern of immune development (impaired antiviral and increased Th2 responses that increases the risk of recurrent wheezing and allergic sensitization in early childhood, and of asthma by age 7 years. To track immune development, cytokine responses of blood mononuclear cells stimulated ex vivo are measured at birth and then annually. Environmental assessments include allergen and endotoxin levels in house dust, pre- and postnatal maternal stress, and indoor air nicotine and nitrogen dioxide. Nasal mucous samples are collected from the children during respiratory illnesses and analyzed for respiratory viruses. The complex interactions between environmental exposures and immune development will be assessed with respect to recurrent wheeze at age 3 years and asthma at age 7 years. Conclusion The overall goal of the URECA study is to develop a better understanding of how specific urban exposures affect immune development to promote wheezing illnesses and asthma.

  11. Designs and Methods for Association Studies and Population Size Inference in Statistical Genetics

    DEFF Research Database (Denmark)

    Waltoft, Berit Lindum

    method provides a simple goodness of t test by comparing the observed SFS with the expected SFS under a given model of population size changes. By the use of Monte Carlo estimation the expected time between coalescent events can be estimated and the expected SFS can thereby be evaluated. Using......). The OR is interpreted as the eect of an exposure on the probability of being diseased at the end of follow-up, while the interpretation of the IRR is the eect of an exposure on the probability of becoming diseased. Through a simulation study, the OR from a classical case-control study is shown to be an inconsistent...... the classical chi-square statistics we are able to infer single parameter models. Multiple parameter models, e.g. multiple epochs, are harder to identify. By introducing the inference of population size back in time as an inverse problem, the second procedure applies the theory of smoothing splines to infer...

  12. Sample Size Calculations for Population Size Estimation Studies Using Multiplier Methods With Respondent-Driven Sampling Surveys.

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    Fearon, Elizabeth; Chabata, Sungai T; Thompson, Jennifer A; Cowan, Frances M; Hargreaves, James R

    2017-09-14

    While guidance exists for obtaining population size estimates using multiplier methods with respondent-driven sampling surveys, we lack specific guidance for making sample size decisions. To guide the design of multiplier method population size estimation studies using respondent-driven sampling surveys to reduce the random error around the estimate obtained. The population size estimate is obtained by dividing the number of individuals receiving a service or the number of unique objects distributed (M) by the proportion of individuals in a representative survey who report receipt of the service or object (P). We have developed an approach to sample size calculation, interpreting methods to estimate the variance around estimates obtained using multiplier methods in conjunction with research into design effects and respondent-driven sampling. We describe an application to estimate the number of female sex workers in Harare, Zimbabwe. There is high variance in estimates. Random error around the size estimate reflects uncertainty from M and P, particularly when the estimate of P in the respondent-driven sampling survey is low. As expected, sample size requirements are higher when the design effect of the survey is assumed to be greater. We suggest a method for investigating the effects of sample size on the precision of a population size estimate obtained using multipler methods and respondent-driven sampling. Uncertainty in the size estimate is high, particularly when P is small, so balancing against other potential sources of bias, we advise researchers to consider longer service attendance reference periods and to distribute more unique objects, which is likely to result in a higher estimate of P in the respondent-driven sampling survey. ©Elizabeth Fearon, Sungai T Chabata, Jennifer A Thompson, Frances M Cowan, James R Hargreaves. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 14.09.2017.

  13. Reliability of different mark-recapture methods for population size estimation tested against reference population sizes constructed from field data.

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    Annegret Grimm

    Full Text Available Reliable estimates of population size are fundamental in many ecological studies and biodiversity conservation. Selecting appropriate methods to estimate abundance is often very difficult, especially if data are scarce. Most studies concerning the reliability of different estimators used simulation data based on assumptions about capture variability that do not necessarily reflect conditions in natural populations. Here, we used data from an intensively studied closed population of the arboreal gecko Gehyra variegata to construct reference population sizes for assessing twelve different population size estimators in terms of bias, precision, accuracy, and their 95%-confidence intervals. Two of the reference populations reflect natural biological entities, whereas the other reference populations reflect artificial subsets of the population. Since individual heterogeneity was assumed, we tested modifications of the Lincoln-Petersen estimator, a set of models in programs MARK and CARE-2, and a truncated geometric distribution. Ranking of methods was similar across criteria. Models accounting for individual heterogeneity performed best in all assessment criteria. For populations from heterogeneous habitats without obvious covariates explaining individual heterogeneity, we recommend using the moment estimator or the interpolated jackknife estimator (both implemented in CAPTURE/MARK. If data for capture frequencies are substantial, we recommend the sample coverage or the estimating equation (both models implemented in CARE-2. Depending on the distribution of catchabilities, our proposed multiple Lincoln-Petersen and a truncated geometric distribution obtained comparably good results. The former usually resulted in a minimum population size and the latter can be recommended when there is a long tail of low capture probabilities. Models with covariates and mixture models performed poorly. Our approach identified suitable methods and extended options to

  14. Adaptive list sequential sampling method for population-based observational studies

    NARCIS (Netherlands)

    Hof, Michel H.; Ravelli, Anita C. J.; Zwinderman, Aeilko H.

    2014-01-01

    In population-based observational studies, non-participation and delayed response to the invitation to participate are complications that often arise during the recruitment of a sample. When both are not properly dealt with, the composition of the sample can be different from the desired

  15. Population control methods in stochastic extinction and outbreak scenarios.

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    Juan Segura

    Full Text Available Adaptive limiter control (ALC and adaptive threshold harvesting (ATH are two related control methods that have been shown to stabilize fluctuating populations. Large variations in population abundance can threaten the constancy and the persistence stability of ecological populations, which may impede the success and efficiency of managing natural resources. Here, we consider population models that include biological mechanisms characteristic for causing extinctions on the one hand and pest outbreaks on the other hand. These models include Allee effects and the impact of natural enemies (as is typical of forest defoliating insects. We study the impacts of noise and different levels of biological parameters in three extinction and two outbreak scenarios. Our results show that ALC and ATH have an effect on extinction and outbreak risks only for sufficiently large control intensities. Moreover, there is a clear disparity between the two control methods: in the extinction scenarios, ALC can be effective and ATH can be counterproductive, whereas in the outbreak scenarios the situation is reversed, with ATH being effective and ALC being potentially counterproductive.

  16. Population control methods in stochastic extinction and outbreak scenarios.

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    Segura, Juan; Hilker, Frank M; Franco, Daniel

    2017-01-01

    Adaptive limiter control (ALC) and adaptive threshold harvesting (ATH) are two related control methods that have been shown to stabilize fluctuating populations. Large variations in population abundance can threaten the constancy and the persistence stability of ecological populations, which may impede the success and efficiency of managing natural resources. Here, we consider population models that include biological mechanisms characteristic for causing extinctions on the one hand and pest outbreaks on the other hand. These models include Allee effects and the impact of natural enemies (as is typical of forest defoliating insects). We study the impacts of noise and different levels of biological parameters in three extinction and two outbreak scenarios. Our results show that ALC and ATH have an effect on extinction and outbreak risks only for sufficiently large control intensities. Moreover, there is a clear disparity between the two control methods: in the extinction scenarios, ALC can be effective and ATH can be counterproductive, whereas in the outbreak scenarios the situation is reversed, with ATH being effective and ALC being potentially counterproductive.

  17. A general method to determine sampling windows for nonlinear mixed effects models with an application to population pharmacokinetic studies.

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    Foo, Lee Kien; McGree, James; Duffull, Stephen

    2012-01-01

    Optimal design methods have been proposed to determine the best sampling times when sparse blood sampling is required in clinical pharmacokinetic studies. However, the optimal blood sampling time points may not be feasible in clinical practice. Sampling windows, a time interval for blood sample collection, have been proposed to provide flexibility in blood sampling times while preserving efficient parameter estimation. Because of the complexity of the population pharmacokinetic models, which are generally nonlinear mixed effects models, there is no analytical solution available to determine sampling windows. We propose a method for determination of sampling windows based on MCMC sampling techniques. The proposed method attains a stationary distribution rapidly and provides time-sensitive windows around the optimal design points. The proposed method is applicable to determine sampling windows for any nonlinear mixed effects model although our work focuses on an application to population pharmacokinetic models. Copyright © 2012 John Wiley & Sons, Ltd.

  18. Bacterial population in traditional sourdough evaluated by molecular methods

    NARCIS (Netherlands)

    Randazzo, C.L.; Heilig, G.H.J.; Restuccia, C.; Giudici, P.; Caggia, C.

    2005-01-01

    Aims: To study the microbial communities in artisanal sourdoughs, manufactured by traditional procedure in different areas of Sicily, and to evaluate the lactic acid bacteria (LAB) population by classical and culture-independent approaches. Methods and Results: Forty-five LAB isolates were

  19. Population Estimation with Mark and Recapture Method Program

    International Nuclear Information System (INIS)

    Limohpasmanee, W.; Kaewchoung, W.

    1998-01-01

    Population estimation is the important information which required for the insect control planning especially the controlling with SIT. Moreover, It can be used to evaluate the efficiency of controlling method. Due to the complexity of calculation, the population estimation with mark and recapture methods were not used widely. So that, this program is developed with Qbasic on the purpose to make it accuracy and easier. The program evaluation consists with 6 methods; follow Seber's, Jolly-seber's, Jackson's Ito's, Hamada's and Yamamura's methods. The results are compared with the original methods, found that they are accuracy and more easier to applied

  20. Sampling Methods and the Accredited Population in Athletic Training Education Research

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    Carr, W. David; Volberding, Jennifer

    2009-01-01

    Context: We describe methods of sampling the widely-studied, yet poorly defined, population of accredited athletic training education programs (ATEPs). Objective: There are two purposes to this study; first to describe the incidence and types of sampling methods used in athletic training education research, and second to clearly define the…

  1. The fairness, predictive validity and acceptability of multiple mini interview in an internationally diverse student population- a mixed methods study

    OpenAIRE

    Kelly, Maureen E.; Dowell, Jon; Husbands, Adrian; Newell, John; O'Flynn, Siun; Kropmans, Thomas; Dunne, Fidelma P.; Murphy, Andrew W.

    2014-01-01

    Background International medical students, those attending medical school outside of their country of citizenship, account for a growing proportion of medical undergraduates worldwide. This study aimed to establish the fairness, predictive validity and acceptability of Multiple Mini Interview (MMI) in an internationally diverse student population. Methods This was an explanatory sequential, mixed methods study. All students in First Year Medicine, National University of Ireland Galway 2012 we...

  2. Gastroesophageal Reflux Disease: A Population Based Study

    OpenAIRE

    Nwokediuko, Sylvester

    2009-01-01

    Background The prevalence of gastroesophageal reflux disease varies in different parts of the world. There are no population based studies in Nigeria. The main objectives of this study were to determine the prevalence and risk factors for gastroesophageal reflux disease in a population of Nigerian medical students. Methods The Carlsson-Dent questionnaire was administered to medical students in the clinical phase of their training at the University of Nigeria, Enugu Campus. Some putative risk ...

  3. A General Method for QTL Mapping in Multiple Related Populations Derived from Multiple Parents

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    Yan AO

    2009-03-01

    Full Text Available It's well known that incorporating some existing populations derived from multiple parents may improve QTL mapping and QTL-based breeding programs. However, no general maximum likelihood method has been available for this strategy. Based on the QTL mapping in multiple related populations derived from two parents, a maximum likelihood estimation method was proposed, which can incorporate several populations derived from three or more parents and also can be used to handle different mating designs. Taking a circle design as an example, we conducted simulation studies to study the effect of QTL heritability and sample size upon the proposed method. The results showed that under the same heritability, enhanced power of QTL detection and more precise and accurate estimation of parameters could be obtained when three F2 populations were jointly analyzed, compared with the joint analysis of any two F2 populations. Higher heritability, especially with larger sample sizes, would increase the ability of QTL detection and improve the estimation of parameters. Potential advantages of the method are as follows: firstly, the existing results of QTL mapping in single population can be compared and integrated with each other with the proposed method, therefore the ability of QTL detection and precision of QTL mapping can be improved. Secondly, owing to multiple alleles in multiple parents, the method can exploit gene resource more adequately, which will lay an important genetic groundwork for plant improvement.

  4. Use and misuse of mixed methods in population oral health research: A scoping review.

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    Gupta, A; Keuskamp, D

    2018-05-30

    Despite the known benefits of a mixed methods approach in health research, little is known of its use in the field of population oral health. To map the extent of literature using a mixed methods approach to examine population oral health outcomes. For a comprehensive search of all the available literature published in the English language, databases including PubMed, Dentistry and Oral Sciences Source (DOSS), CINAHL, Web of Science and EMBASE (including Medline) were searched using a range of keywords from inception to October 2017. Only peer-reviewed, population-based studies of oral health outcomes conducted among non-institutionalised participants and using mixed methods were considered eligible for inclusion. Only nine studies met the inclusion criteria and were included in the review. The most frequent oral health outcome investigated was caries experience. However, most studies lacked a theoretical rationale or framework for using mixed methods, or supporting the use of qualitative data. Concurrent triangulation with a convergent design was the most commonly used mixed methods typology for integrating quantitative and qualitative data. The tools used to collect quantitative and qualitative data were mostly limited to surveys and interviews. With growing complexity recognised in the determinants of oral disease, future studies addressing population oral health outcomes are likely to benefit from the use of mixed methods. Explicit consideration of theoretical framework and methodology will strengthen those investigations. Copyright© 2018 Dennis Barber Ltd.

  5. A phylogenetic method to perform genome-wide association studies in microbes that accounts for population structure and recombination.

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    Caitlin Collins

    2018-02-01

    Full Text Available Genome-Wide Association Studies (GWAS in microbial organisms have the potential to vastly improve the way we understand, manage, and treat infectious diseases. Yet, microbial GWAS methods established thus far remain insufficiently able to capitalise on the growing wealth of bacterial and viral genetic sequence data. Facing clonal population structure and homologous recombination, existing GWAS methods struggle to achieve both the precision necessary to reject spurious findings and the power required to detect associations in microbes. In this paper, we introduce a novel phylogenetic approach that has been tailor-made for microbial GWAS, which is applicable to organisms ranging from purely clonal to frequently recombining, and to both binary and continuous phenotypes. Our approach is robust to the confounding effects of both population structure and recombination, while maintaining high statistical power to detect associations. Thorough testing via application to simulated data provides strong support for the power and specificity of our approach and demonstrates the advantages offered over alternative cluster-based and dimension-reduction methods. Two applications to Neisseria meningitidis illustrate the versatility and potential of our method, confirming previously-identified penicillin resistance loci and resulting in the identification of both well-characterised and novel drivers of invasive disease. Our method is implemented as an open-source R package called treeWAS which is freely available at https://github.com/caitiecollins/treeWAS.

  6. Demographic Models for Projecting Population and Migration: Methods for African Historical Analysis

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    Patrick Manning

    2015-08-01

    Full Text Available This study presents methods for projecting population and migration over time in cases were empirical data are missing or undependable. The methods are useful for cases in which the researcher has details of population size and structure for a limited period of time (most obviously, the end point, with scattered evidence on other times. It enables estimation of population size, including its structure in age, sex, and status, either forward or backward in time. The program keeps track of all the details. The calculated data can be reported or sampled and compared to empirical findings at various times and places to expected values based on other procedures of estimation. The application of these general methods that is developed here is the projection of African populations backwards in time from 1950, since 1950 is the first date for which consistently strong demographic estimates are available for national-level populations all over the African continent. The models give particular attention to migration through enslavement, which was highly important in Africa from 1650 to 1900. Details include a sensitivity analysis showing relative significance of input variables and techniques for calibrating various dimensions of the projection with each other. These same methods may be applicable to quite different historical situations, as long as the data conform in structure to those considered here.

  7. High coffee consumption and different brewing methods in relation to postmenopausal endometrial cancer risk in the Norwegian women and cancer study: a population-based prospective study.

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    Gavrilyuk, Oxana; Braaten, Tonje; Skeie, Guri; Weiderpass, Elisabete; Dumeaux, Vanessa; Lund, Eiliv

    2014-03-25

    Coffee and its compounds have been proposed to inhibit endometrial carcinogenesis. Studies in the Norwegian population can be especially interesting due to the high coffee consumption and increasing incidence of endometrial cancer in the country. A total of 97 926 postmenopausal Norwegian women from the population-based prospective Norwegian Women and Cancer (NOWAC) Study, were included in the present analysis. We evaluated the general association between total coffee consumption and endometrial cancer risk as well as the possible impact of brewing method. Multivariate Cox regression analysis was used to estimate risks, and heterogeneity tests were performed to compare brewing methods. During an average of 10.9 years of follow-up, 462 incident endometrial cancer cases were identified. After multivariate adjustment, significant risk reduction was found among participants who drank ≥8 cups/day of coffee with a hazard ratio of 0.52 (95% confidence interval, CI 0.34-0.79). However, we did not observe a significant dose-response relationship. No significant heterogeneity in risk was found when comparing filtered and boiled coffee brewing methods. A reduction in endometrial cancer risk was observed in subgroup analyses among participants who drank ≥8 cups/day and had a body mass index ≥25 kg/m2, and in current smokers. These data suggest that in this population with high coffee consumption, endometrial cancer risk decreases in women consuming ≥8 cups/day, independent of brewing method.

  8. A two-stage cluster sampling method using gridded population data, a GIS, and Google EarthTM imagery in a population-based mortality survey in Iraq

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    Galway LP

    2012-04-01

    Full Text Available Abstract Background Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. Results We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. Conclusion Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings.

  9. A Genetic Study of Wild Populations and Evolution A Genetic Study of Wild Populations and Evolution

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    Hovanitz William

    1944-06-01

    Full Text Available The determination of the scientific basis of heredity within the last two decades and the verification of the principal conclusions in many different plants and animals has made possible the application of analytical methods in the study of variations in wild populations. As with the physical and chemical sciences, genetics has been enabled to make use of mathematics to compound (often theoretically out of simple units, the genes, the complexity known as an organism, much in the same way as a chemist compounds molecules with atoms and the physicist compounds atoms with protons and electrons. The determination of the scientific basis of heredity within the last two decades and the verification of the principal conclusions in many different plants and animals has made possible the application of analytical methods in the study of variations in wild populations. As with the physical and chemical sciences, genetics has been enabled to make use of mathematics to compound (often theoretically out of simple units, the genes, the complexity known as an organism, much in the same way as a chemist compounds molecules with atoms and the physicist compounds atoms with protons and electrons.

  10. [Epidemiological methods used in studies in the prevalence of Tourette syndrome].

    Science.gov (United States)

    Stefanoff, Paweł; Mazurek, Jacek

    2003-01-01

    Tourette syndrome (TS) prevalence was studied since the early 80-ies. Its clinical course is characterised by co-occurrence of motor and vocal tics. Results of previous epidemiological studies were surprisingly divergent: the prevalence varied from 0.5 to 115 cases per 10,000 population. The disease previously recognised as extremely rare and severe is now considered as quite common, with often moderate course. Selected methods used in studies of TS prevalence and analysis of their possible impact on study results are presented. The studies were divided into 3 groups: studies of the hospitalised population, large-scale screenings and studies involving school population, basing on characteristic and size of population, methods of selection of subjects, diagnostic and screening methods used. Studies of the hospitalised population involved patients with most severe symptoms, in different age groups, different methods of final diagnosis confirmation were used. TS prevalence varied from 0.5 up to 15 cases per 10,000 population. Procedures used in large-scale screening studies made possible the elimination of potential selection bias. Large populations were studied using transparent and repetitive confirmation of diagnoses. Their validity was additionally checked in parallel validity studies. TS prevalence was in the range 4.3 to 10 cases per 10,000 population. The highest TS prevalence was obtained in studies involving schoolchildren. Data were gathered from multiple sources: from parents, teachers and children, as well as from classroom observation. Diagnoses were made by experienced clinicians. TS prevalence obtained in school population studies was between 36.2 up to 115 per 10,000 population.

  11. Trust of Population within Social Relations System of the Population: A Case Study of Nasleg Administration in the Republic of Sakha (Yakutia)

    Science.gov (United States)

    Mikhaylova, Anna; Popova, Liudmila

    2016-01-01

    The research consists in studying the level of population's trust in nasleg administration (in the administrative-territorial unit) of MS "Khatyryksky nasleg" of Namsky ulus using the case study. The leading research methods for the problem are empirical methods that allow revealing the level of population's trust in administration. The…

  12. Density Estimation in Several Populations With Uncertain Population Membership

    KAUST Repository

    Ma, Yanyuan

    2011-09-01

    We devise methods to estimate probability density functions of several populations using observations with uncertain population membership, meaning from which population an observation comes is unknown. The probability of an observation being sampled from any given population can be calculated. We develop general estimation procedures and bandwidth selection methods for our setting. We establish large-sample properties and study finite-sample performance using simulation studies. We illustrate our methods with data from a nutrition study.

  13. Double Antibody Method for Immunoassay of Insulin. Its Application in Population Studies

    Energy Technology Data Exchange (ETDEWEB)

    Welborn, T. A.; Stenhouse, N. S.; Curnow, D. H.; Johnstone, Clare J. [Department of Medicine, Raine Foundation Medical Statistics Unit and Department of Pathology, University of Western Australia, Perth (Australia)

    1970-02-15

    The performance of a double-antibody Immunoassay technique over a period of two years is described, during which 3300 samples from population studies were analysed for insulin concentration. The method requires safeguards to ensure that complete separation of ''free'' from ''antibody-bound'' hormone is achieved, thus labelled gamma-globulin is used in the precise preliminary standardization of precipitating antibody. The dose-response curves for crystalline insulin standards over a range of concentration 0.2 to 16,0 ng (5 to 400 micro-International-Units)/ml are consistently nonlinear, but a close fit is obtained by a cubic function obtained empirically from multiple regression analysis, which also corrects satisfactorily for ''within-assay drift'' when large numbers of samples are involved. The coefficient of variation for pooled serum standards repetitively assayed ranged from 10 to 14%. Sources of ''between-assay variability'' of the serum standards include variable integrity of the labelled insulin and the slope of the standard curve. For quality control material, the need for standards of serum as well as crystalline insulin is stressed, Serum-insulin was measured in 3300 adults of the population of Busselton, approximately 1 h after a 50 g oral glucose load. The concentrations were distributed log-normally. Females had significantly higher 'one-hour' serum-insulin levels than males, and both sexes showed a moderate rise of values with age. Multiple regression analyses revealed that the major determinant of serum-insulin was the blood-sugar level, the independent relationship being such that at ''one-hour'' blood-sugar levels exceeding 160 - 180 mg/100 ml, a decline of insulin values occurred. Body-weight had a strong positive association, and height a negative relationship, with the ''one-hour'' serum-insulin. Males with coronary heart disease and hypertension showed elevated insulin levels under 60 years of age, whereas ''ideal'' males (with obesity

  14. Prevalence of polyhydramnios at a Danish hospital--a population-based study

    DEFF Research Database (Denmark)

    Bundgaard, Anne; Andersen, Betina Ristorp; Rode, Line

    2007-01-01

    BACKGROUND: The purpose of this study was to determine the incidence of polyhydramnios, the related maternal and perinatal morbidity, and to estimate the association between perinatal outcome and the degree of polyhydramnios in a Danish population. METHODS: The study population consisted of 168 w...

  15. Study of inter species diversity and population structure by molecular genetic method in Iranian Artemia

    OpenAIRE

    Hajirostamloo, Mahbobeh

    2005-01-01

    Artemia is a small crustacean that adapted to live in brine water and has been seen in different brine water sources in Iran. Considering the importance of genetic studies manifest inter population differences in species, to estimate genetic structure, detect difference at molecular level and separate different Artemia populations of Iran, also study of phylogenic relationships among them, samples of Artemia were collected from nine region: Urmia lake in West Azerbaijan, Sh...

  16. Ambit determination method in estimating rice plant population density

    Directory of Open Access Journals (Sweden)

    Abu Bakar, B.,

    2017-11-01

    Full Text Available Rice plant population density is a key indicator in determining the crop setting and fertilizer application rate. It is therefore essential that the population density is monitored to ensure that a correct crop management decision is taken. The conventional method of determining plant population is by manually counting the total number of rice plant tillers in a 25 cm x 25 cm square frame. Sampling is done by randomly choosing several different locations within a plot to perform tiller counting. This sampling method is time consuming, labour intensive and costly. An alternative fast estimating method was developed to overcome this issue. The method relies on measuring the outer circumference or ambit of the contained rice plants in a 25 cm x 25 cm square frame to determine the number of tillers within that square frame. Data samples of rice variety MR219 were collected from rice plots in the Muda granary area, Sungai Limau Dalam, Kedah. The data were taken at 50 days and 70 days after seeding (DAS. A total of 100 data samples were collected for each sampling day. A good correlation was obtained for the variety of 50 DAS and 70 DAS. The model was then verified by taking 100 samples with the latching strap for 50 DAS and 70 DAS. As a result, this technique can be used as a fast, economical and practical alternative to manual tiller counting. The technique can potentially be used in the development of an electronic sensing system to estimate paddy plant population density.

  17. A probabilistic method for testing and estimating selection differences between populations.

    Science.gov (United States)

    He, Yungang; Wang, Minxian; Huang, Xin; Li, Ran; Xu, Hongyang; Xu, Shuhua; Jin, Li

    2015-12-01

    Human populations around the world encounter various environmental challenges and, consequently, develop genetic adaptations to different selection forces. Identifying the differences in natural selection between populations is critical for understanding the roles of specific genetic variants in evolutionary adaptation. Although numerous methods have been developed to detect genetic loci under recent directional selection, a probabilistic solution for testing and quantifying selection differences between populations is lacking. Here we report the development of a probabilistic method for testing and estimating selection differences between populations. By use of a probabilistic model of genetic drift and selection, we showed that logarithm odds ratios of allele frequencies provide estimates of the differences in selection coefficients between populations. The estimates approximate a normal distribution, and variance can be estimated using genome-wide variants. This allows us to quantify differences in selection coefficients and to determine the confidence intervals of the estimate. Our work also revealed the link between genetic association testing and hypothesis testing of selection differences. It therefore supplies a solution for hypothesis testing of selection differences. This method was applied to a genome-wide data analysis of Han and Tibetan populations. The results confirmed that both the EPAS1 and EGLN1 genes are under statistically different selection in Han and Tibetan populations. We further estimated differences in the selection coefficients for genetic variants involved in melanin formation and determined their confidence intervals between continental population groups. Application of the method to empirical data demonstrated the outstanding capability of this novel approach for testing and quantifying differences in natural selection. © 2015 He et al.; Published by Cold Spring Harbor Laboratory Press.

  18. A method for estimating abundance of mobile populations using telemetry and counts of unmarked animals

    Science.gov (United States)

    Clement, Matthew; O'Keefe, Joy M; Walters, Brianne

    2015-01-01

    While numerous methods exist for estimating abundance when detection is imperfect, these methods may not be appropriate due to logistical difficulties or unrealistic assumptions. In particular, if highly mobile taxa are frequently absent from survey locations, methods that estimate a probability of detection conditional on presence will generate biased abundance estimates. Here, we propose a new estimator for estimating abundance of mobile populations using telemetry and counts of unmarked animals. The estimator assumes that the target population conforms to a fission-fusion grouping pattern, in which the population is divided into groups that frequently change in size and composition. If assumptions are met, it is not necessary to locate all groups in the population to estimate abundance. We derive an estimator, perform a simulation study, conduct a power analysis, and apply the method to field data. The simulation study confirmed that our estimator is asymptotically unbiased with low bias, narrow confidence intervals, and good coverage, given a modest survey effort. The power analysis provided initial guidance on survey effort. When applied to small data sets obtained by radio-tracking Indiana bats, abundance estimates were reasonable, although imprecise. The proposed method has the potential to improve abundance estimates for mobile species that have a fission-fusion social structure, such as Indiana bats, because it does not condition detection on presence at survey locations and because it avoids certain restrictive assumptions.

  19. Constructing stage-structured matrix population models from life tables: comparison of methods

    Directory of Open Access Journals (Sweden)

    Masami Fujiwara

    2017-10-01

    Full Text Available A matrix population model is a convenient tool for summarizing per capita survival and reproduction rates (collectively vital rates of a population and can be used for calculating an asymptotic finite population growth rate (λ and generation time. These two pieces of information can be used for determining the status of a threatened species. The use of stage-structured population models has increased in recent years, and the vital rates in such models are often estimated using a life table analysis. However, potential bias introduced when converting age-structured vital rates estimated from a life table into parameters for a stage-structured population model has not been assessed comprehensively. The objective of this study was to investigate the performance of methods for such conversions using simulated life histories of organisms. The underlying models incorporate various types of life history and true population growth rates of varying levels. The performance was measured by comparing differences in λ and the generation time calculated using the Euler-Lotka equation, age-structured population matrices, and several stage-structured population matrices that were obtained by applying different conversion methods. The results show that the discretization of age introduces only small bias in λ or generation time. Similarly, assuming a fixed age of maturation at the mean age of maturation does not introduce much bias. However, aggregating age-specific survival rates into a stage-specific survival rate and estimating a stage-transition rate can introduce substantial bias depending on the organism’s life history type and the true values of λ. In order to aggregate survival rates, the use of the weighted arithmetic mean was the most robust method for estimating λ. Here, the weights are given by survivorship curve after discounting with λ. To estimate a stage-transition rate, matching the proportion of individuals transitioning, with λ used

  20. Perception and prevalence of domestic violence in the study population

    OpenAIRE

    Shah, Sandeep H.; Rajani, Kajal; Kataria, Lakhan; Trivedi, Ashish; Patel, Sangita; Mehta, Kedar

    2012-01-01

    Background: Domestic violence is a major contributor to physical and mental ill health of the victim, and it is evident to some degree, in every society of the world. Objectives: 1) To study perception about domestic violence in the study population. 2) To compare prevalence of domestic violence within the three subgroups of the study population (i.e. spouses of psychotic patients, spouses of non-psychiatric patients and hospital staff). Materials and Methods: A cross-sectional study was cond...

  1. Population size estimation of men who have sex with men through the network scale-up method in Japan.

    Directory of Open Access Journals (Sweden)

    Satoshi Ezoe

    Full Text Available BACKGROUND: Men who have sex with men (MSM are one of the groups most at risk for HIV infection in Japan. However, size estimates of MSM populations have not been conducted with sufficient frequency and rigor because of the difficulty, high cost and stigma associated with reaching such populations. This study examined an innovative and simple method for estimating the size of the MSM population in Japan. We combined an internet survey with the network scale-up method, a social network method for estimating the size of hard-to-reach populations, for the first time in Japan. METHODS AND FINDINGS: An internet survey was conducted among 1,500 internet users who registered with a nationwide internet-research agency. The survey participants were asked how many members of particular groups with known population sizes (firepersons, police officers, and military personnel they knew as acquaintances. The participants were also asked to identify the number of their acquaintances whom they understood to be MSM. Using these survey results with the network scale-up method, the personal network size and MSM population size were estimated. The personal network size was estimated to be 363.5 regardless of the sex of the acquaintances and 174.0 for only male acquaintances. The estimated MSM prevalence among the total male population in Japan was 0.0402% without adjustment, and 2.87% after adjusting for the transmission error of MSM. CONCLUSIONS: The estimated personal network size and MSM prevalence seen in this study were comparable to those from previous survey results based on the direct-estimation method. Estimating population sizes through combining an internet survey with the network scale-up method appeared to be an effective method from the perspectives of rapidity, simplicity, and low cost as compared with more-conventional methods.

  2. Economic costs of minor depression: a population-based study.

    NARCIS (Netherlands)

    Cuijpers, P.; Smit, H.F.E.; Oostenbrink, J.; de Graaf, R.; ten Have, M.; Beekman, A.T.F.

    2007-01-01

    Objective: Although the clinical relevance of minor depression has been demonstrated in many studies, the economic costs are not well explored. In this study, we examine the economic costs of minor depression. Method: In a large-scale, population-based study in the Netherlands (n = 5504) the costs

  3. Economic costs of minor depression: a population-based study

    NARCIS (Netherlands)

    Cuijpers, P.; Smit, H.F.E.; Oostenbrink, J.; de Graaf, R.; ten Have, M.; Beekman, A.T.F.

    2006-01-01

    Objective: Although the clinical relevance of minor depression has been demonstrated in many studies, the economic costs are not well explored. In this study, we examine the economic costs of minor depression. Method: In a large-scale, population-based study in the Netherlands (n = 5504) the costs

  4. Relative accuracy of three common methods of parentage analysis in natural populations

    KAUST Repository

    Harrison, Hugo B.; Saenz Agudelo, Pablo; Planes, Serge; Jones, Geoffrey P.; Berumen, Michael L.

    2012-01-01

    Parentage studies and family reconstructions have become increasingly popular for investigating a range of evolutionary, ecological and behavioural processes in natural populations. However, a number of different assignment methods have emerged in common use and the accuracy of each may differ in relation to the number of loci examined, allelic diversity, incomplete sampling of all candidate parents and the presence of genotyping errors. Here, we examine how these factors affect the accuracy of three popular parentage inference methods (colony, famoz and an exclusion-Bayes' theorem approach by Christie (Molecular Ecology Resources, 2010a, 10, 115) to resolve true parent-offspring pairs using simulated data. Our findings demonstrate that accuracy increases with the number and diversity of loci. These were clearly the most important factors in obtaining accurate assignments explaining 75-90% of variance in overall accuracy across 60 simulated scenarios. Furthermore, the proportion of candidate parents sampled had a small but significant impact on the susceptibility of each method to either false-positive or false-negative assignments. Within the range of values simulated, colony outperformed FaMoz, which outperformed the exclusion-Bayes' theorem method. However, with 20 or more highly polymorphic loci, all methods could be applied with confidence. Our results show that for parentage inference in natural populations, careful consideration of the number and quality of markers will increase the accuracy of assignments and mitigate the effects of incomplete sampling of parental populations. © 2012 Blackwell Publishing Ltd.

  5. Relative accuracy of three common methods of parentage analysis in natural populations

    KAUST Repository

    Harrison, Hugo B.

    2012-12-27

    Parentage studies and family reconstructions have become increasingly popular for investigating a range of evolutionary, ecological and behavioural processes in natural populations. However, a number of different assignment methods have emerged in common use and the accuracy of each may differ in relation to the number of loci examined, allelic diversity, incomplete sampling of all candidate parents and the presence of genotyping errors. Here, we examine how these factors affect the accuracy of three popular parentage inference methods (colony, famoz and an exclusion-Bayes\\' theorem approach by Christie (Molecular Ecology Resources, 2010a, 10, 115) to resolve true parent-offspring pairs using simulated data. Our findings demonstrate that accuracy increases with the number and diversity of loci. These were clearly the most important factors in obtaining accurate assignments explaining 75-90% of variance in overall accuracy across 60 simulated scenarios. Furthermore, the proportion of candidate parents sampled had a small but significant impact on the susceptibility of each method to either false-positive or false-negative assignments. Within the range of values simulated, colony outperformed FaMoz, which outperformed the exclusion-Bayes\\' theorem method. However, with 20 or more highly polymorphic loci, all methods could be applied with confidence. Our results show that for parentage inference in natural populations, careful consideration of the number and quality of markers will increase the accuracy of assignments and mitigate the effects of incomplete sampling of parental populations. © 2012 Blackwell Publishing Ltd.

  6. Efficiency of two-phase methods with focus on a planned population-based case-control study on air pollution and stroke

    Directory of Open Access Journals (Sweden)

    Strömberg Ulf

    2007-11-01

    Full Text Available Abstract Background We plan to conduct a case-control study to investigate whether exposure to nitrogen dioxide (NO2 increases the risk of stroke. In case-control studies, selective participation can lead to bias and loss of efficiency. A two-phase design can reduce bias and improve efficiency by combining information on the non-participating subjects with information from the participating subjects. In our planned study, we will have access to individual disease status and data on NO2 exposure on group (area level for a large population sample of Scania, southern Sweden. A smaller sub-sample will be selected to the second phase for individual-level assessment on exposure and covariables. In this paper, we simulate a case-control study based on our planned study. We develop a two-phase method for this study and compare the performance of our method with the performance of other two-phase methods. Methods A two-phase case-control study was simulated with a varying number of first- and second-phase subjects. Estimation methods: Method 1: Effect estimation with second-phase data only. Method 2: Effect estimation by adjusting the first-phase estimate with the difference between the adjusted and unadjusted second-phase estimate. The first-phase estimate is based on individual disease status and residential address for all study subjects that are linked to register data on NO2-exposure for each geographical area. Method 3: Effect estimation by using the expectation-maximization (EM algorithm without taking area-level register data on exposure into account. Method 4: Effect estimation by using the EM algorithm and incorporating group-level register data on NO2-exposure. Results The simulated scenarios were such that, unbiased or marginally biased ( Conclusion In the setting described here, method 4 had the best performance in order to improve efficiency, while adjusting for varying participation rates across areas.

  7. Economic costs of minor depression: a population-based study

    NARCIS (Netherlands)

    Cuijpers, P.; Smit, H.F.E.; Oostenbrink, J.; Graaf, de R.; Have, M. ten; Beekman, A.T.F.

    2006-01-01

    Objective: Although the clinical relevance of minor depression has been demonstrated in many studies, the economic costs are not well explored. In this study, we examine the economic costs of minor depression. Method: In a large-scale, population-based study in the Netherlands (n ¼ 5504) the costs

  8. Explaining stasis: microevolutionary studies in natural populations.

    Science.gov (United States)

    Merilä, J; Sheldon, B C; Kruuk, L E

    2001-01-01

    Microevolution, defined as a change in the genetic constitution of a population over time, is considered to be of commonplace occurrence in nature. Its ubiquity can be inferred from the observation that quantitative genetic divergence among populations usually exceeds that to be expected due to genetic drift alone, and from numerous observations and experiments consistent with local adaptation. Experimental manipulations in natural populations have provided evidence that rapid evolutionary responses may occur in the wild. However, there are remarkably few cases where direct observations of natural populations have revealed microevolutionary changes occurring, despite the frequent demonstration of additive genetic variation and strong directional selection for particular traits. Those few cases where responses congruent with expectation have been demonstrated are restricted to changes over one generation. In this article we focus on possible explanations as to why heritable traits under apparently strong directional selection often fail to show the expected evolutionary response. To date, few of these explanations for apparent stasis have been amenable to empirical testing. We describe new methods, derived from procedures developed by animal breeding scientists, which can be used to address these explanations, and illustrate the approach with examples from long-term studies of collared flycatchers (Ficedula albicollis) and red deer (Cervus elaphus). Understanding why most intensively studied natural populations do not appear to be evolving is an important challenge for evolutionary biology.

  9. Economic costs of social phobia: a population-based study.

    NARCIS (Netherlands)

    Acarturk, C.; Smit, H.F.E.; de Graaf, R.; van Straten, A.; ten Have, M.; Cuijpers, P.

    2009-01-01

    Background: Information about the economic costs of social phobia is scant. In this study, we examine the economic costs of social phobia and subthreshold social phobia. Methods: Data were derived from the Netherlands Mental Health Survey and Incidence Study (NEMESIS) which is a population-based

  10. A Cross-Sectional Study on the Diet and Nutritional Status of Adolescent Girls in Zambézia Province, Mozambique (the ZANE Study): Design, Methods, and Population Characteristics

    Science.gov (United States)

    Freese, Riitta; Fidalgo, Lourdes; Selvester, Kerry; Ismael, Carina; Mutanen, Marja

    2014-01-01

    Background There is very little published work on dietary intake and nutritional status of Mozambicans. We conducted a population-based cross-sectional study on the diet and nutritional status of adolescent girls in different types of communities in Zambézia Province, Central Mozambique, in two distinct seasons. Objective The purpose of this paper is to present the design, methods, and study population characteristics of the Estudo do Estado Nutricional e da Dieta em Raparigas Adolescentes na Zambézia (the ZANE Study). Methods Data was collected in January-February 2010 ("hunger season") and in May-June 2010 ("harvest season"). A total of 551 girls in the age group 14-19 years old were recruited from one urban area and two districts (district towns and rural villages). The study protocol included a background interview, a 24-hour dietary recall interview, a food frequency questionnaire, anthropometric measurements, bioimpedance, hemoglobin measurement, and venous blood, urine, buccal cell, and fecal sampling. Results Adolescent motherhood was common in all study regions. Stunting prevalence for the total study population as a weighted percentage was 17.8% (95/549; 95% CI 14.3-22.0) with no regional differences. Overweight was found mainly in the urban area where the prevalence was 12.6% (20/159; 95% CI 7.5-17.6), thinness was rare. There were regional differences in the prevalence of malaria parasitemia and intestinal helminth infestation, but not human immunodeficiency virus. Conclusions The fully analyzed data from the ZANE Study will yield results useful for setting priorities in nutrition policy and further research on the diet and nutritional status in Mozambique and other countries with similar nutritional problems. Trial Registration ClinicalTrials.gov: NCT01944891; http://www.clinicaltrials.gov/ct2/show/NCT01944891 (Archived by WebCite at http://www.webcitation.org/6L9OUrsq8). PMID:24598035

  11. Association of STAT4 with rheumatoid arthritis - A replication study in three European populations : a replication study in three European populations

    NARCIS (Netherlands)

    Orozco, Gisela; Alizadeh, Behrooz Z.; Delgado-Vega, Angelica M.; Gonzalez-Gay, Miguel A.; Balsa, Alejandro; Pascual-Salcedo, Dora; Fernandez-Gutierrez, Benjamin; Gonzalez-Escribano, Maria F.; Petersson, Ingemar F.; van Riel, Piet L. C. M.; Barrera, Pilar; Coenen, Marieke J. H.; Radstake, Timothy R. D. J.; van Leeuwen, Miek A.; Wijmenga, Cisca; Koeleman, Bobby P. C.; Alarcon-Riquelme, Marta; Martin, Javier

    Objective. This study was undertaken to investigate the previously reported association of the STAT4 polymorphism rs7574865 with rheumatoid arthritis (RA) in 3 different European populations from Spain, Sweden, and The Netherlands, comprising a total of 2,072 patients and 2,474 controls. Methods.

  12. Estimation of the size of the female sex worker population in Rwanda using three different methods.

    Science.gov (United States)

    Mutagoma, Mwumvaneza; Kayitesi, Catherine; Gwiza, Aimé; Ruton, Hinda; Koleros, Andrew; Gupta, Neil; Balisanga, Helene; Riedel, David J; Nsanzimana, Sabin

    2015-10-01

    HIV prevalence is disproportionately high among female sex workers compared to the general population. Many African countries lack useful data on the size of female sex worker populations to inform national HIV programmes. A female sex worker size estimation exercise using three different venue-based methodologies was conducted among female sex workers in all provinces of Rwanda in August 2010. The female sex worker national population size was estimated using capture-recapture and enumeration methods, and the multiplier method was used to estimate the size of the female sex worker population in Kigali. A structured questionnaire was also used to supplement the data. The estimated number of female sex workers by the capture-recapture method was 3205 (95% confidence interval: 2998-3412). The female sex worker size was estimated at 3348 using the enumeration method. In Kigali, the female sex worker size was estimated at 2253 (95% confidence interval: 1916-2524) using the multiplier method. Nearly 80% of all female sex workers in Rwanda were found to be based in the capital, Kigali. This study provided a first-time estimate of the female sex worker population size in Rwanda using capture-recapture, enumeration, and multiplier methods. The capture-recapture and enumeration methods provided similar estimates of female sex worker in Rwanda. Combination of such size estimation methods is feasible and productive in low-resource settings and should be considered vital to inform national HIV programmes. © The Author(s) 2015.

  13. Are rapid population estimates accurate? A field trial of two different assessment methods.

    Science.gov (United States)

    Grais, Rebecca F; Coulombier, Denis; Ampuero, Julia; Lucas, Marcelino E S; Barretto, Avertino T; Jacquier, Guy; Diaz, Francisco; Balandine, Serge; Mahoudeau, Claude; Brown, Vincent

    2006-09-01

    Emergencies resulting in large-scale displacement often lead to populations resettling in areas where basic health services and sanitation are unavailable. To plan relief-related activities quickly, rapid population size estimates are needed. The currently recommended Quadrat method estimates total population by extrapolating the average population size living in square blocks of known area to the total site surface. An alternative approach, the T-Square, provides a population estimate based on analysis of the spatial distribution of housing units taken throughout a site. We field tested both methods and validated the results against a census in Esturro Bairro, Beira, Mozambique. Compared to the census (population: 9,479), the T-Square yielded a better population estimate (9,523) than the Quadrat method (7,681; 95% confidence interval: 6,160-9,201), but was more difficult for field survey teams to implement. Although applicable only to similar sites, several general conclusions can be drawn for emergency planning.

  14. Differential estimates of southern flying squirrel (Glaucomys volans) population structure based on capture method

    Science.gov (United States)

    Kevin S. Laves; Susan C. Loeb

    2005-01-01

    It is commonly assumed that population estimates derived from trapping small mammals are accurate and unbiased or that estimates derived from different capture methods are comparable. We captured southern flying squirrels (Glaucmrtys volam) using two methods to study their effect on red-cockaded woodpecker (Picoides bumah) reproductive success. Southern flying...

  15. A statistical method for testing epidemiological results, as applied to the Hanford worker population

    International Nuclear Information System (INIS)

    Brodsky, A.

    1979-01-01

    Some recent reports of Mancuso, Stewart and Kneale claim findings of radiation-produced cancer in the Hanford worker population. These claims are based on statistical computations that use small differences in accumulated exposures between groups dying of cancer and groups dying of other causes; actual mortality and longevity were not reported. This paper presents a statistical method for evaluation of actual mortality and longevity longitudinally over time, as applied in a primary analysis of the mortality experience of the Hanford worker population. Although available, this method was not utilized in the Mancuso-Stewart-Kneale paper. The author's preliminary longitudinal analysis shows that the gross mortality experience of persons employed at Hanford during 1943-70 interval did not differ significantly from that of certain controls, when both employees and controls were selected from families with two or more offspring and comparison were matched by age, sex, race and year of entry into employment. This result is consistent with findings reported by Sanders (Health Phys. vol.35, 521-538, 1978). The method utilizes an approximate chi-square (1 D.F.) statistic for testing population subgroup comparisons, as well as the cumulation of chi-squares (1 D.F.) for testing the overall result of a particular type of comparison. The method is available for computer testing of the Hanford mortality data, and could also be adapted to morbidity or other population studies. (author)

  16. Searching for rigour in the reporting of mixed methods population health research: a methodological review.

    Science.gov (United States)

    Brown, K M; Elliott, S J; Leatherdale, S T; Robertson-Wilson, J

    2015-12-01

    The environments in which population health interventions occur shape both their implementation and outcomes. Hence, when evaluating these interventions, we must explore both intervention content and context. Mixed methods (integrating quantitative and qualitative methods) provide this opportunity. However, although criteria exist for establishing rigour in quantitative and qualitative research, there is poor consensus regarding rigour in mixed methods. Using the empirical example of school-based obesity interventions, this methodological review examined how mixed methods have been used and reported, and how rigour has been addressed. Twenty-three peer-reviewed mixed methods studies were identified through a systematic search of five databases and appraised using the guidelines for Good Reporting of a Mixed Methods Study. In general, more detailed description of data collection and analysis, integration, inferences and justifying the use of mixed methods is needed. Additionally, improved reporting of methodological rigour is required. This review calls for increased discussion of practical techniques for establishing rigour in mixed methods research, beyond those for quantitative and qualitative criteria individually. A guide for reporting mixed methods research in population health should be developed to improve the reporting quality of mixed methods studies. Through improved reporting, mixed methods can provide strong evidence to inform policy and practice. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  17. Application of homotopy-perturbation method to nonlinear population dynamics models

    International Nuclear Information System (INIS)

    Chowdhury, M.S.H.; Hashim, I.; Abdulaziz, O.

    2007-01-01

    In this Letter, the homotopy-perturbation method (HPM) is employed to derive approximate series solutions of nonlinear population dynamics models. The nonlinear models considered are the multispecies Lotka-Volterra equations. The accuracy of this method is examined by comparison with the available exact and the fourth-order Runge-Kutta method (RK4)

  18. Application of Holt exponential smoothing and ARIMA method for data population in West Java

    Science.gov (United States)

    Supriatna, A.; Susanti, D.; Hertini, E.

    2017-01-01

    One method of time series that is often used to predict data that contains trend is Holt. Holt method using different parameters used in the original data which aims to smooth the trend value. In addition to Holt, ARIMA method can be used on a wide variety of data including data pattern containing a pattern trend. Data actual of population from 1998-2015 contains the trends so can be solved by Holt and ARIMA method to obtain the prediction value of some periods. The best method is measured by looking at the smallest MAPE and MAE error. The result using Holt method is 47.205.749 populations in 2016, 47.535.324 populations in 2017, and 48.041.672 populations in 2018, with MAPE error is 0,469744 and MAE error is 189.731. While the result using ARIMA method is 46.964.682 populations in 2016, 47.342.189 in 2017, and 47.899.696 in 2018, with MAPE error is 0,4380 and MAE is 176.626.

  19. The MOBILIZE Boston Study: Design and methods of a prospective cohort study of novel risk factors for falls in an older population

    Directory of Open Access Journals (Sweden)

    Hannan Marian T

    2008-07-01

    Full Text Available Abstract Background Falls are the sixth leading cause of death in elderly people in the U.S. Despite progress in understanding risk factors for falls, many suspected risk factors have not been adequately studied. Putative risk factors for falls such as pain, reductions in cerebral blood flow, somatosensory deficits, and foot disorders are poorly understood, in part because they pose measurement challenges, particularly for large observational studies. Methods The MOBILIZE Boston Study (MBS, an NIA-funded Program Project, is a prospective cohort study of a unique set of risk factors for falls in seniors in the Boston area. Using a door-to-door population-based recruitment, we have enrolled 765 persons aged 70 and older. The baseline assessment was conducted in 2 segments: a 3-hour home interview followed within 4 weeks by a 3-hour clinic examination. Measures included pain, cerebral hemodynamics, and foot disorders as well as established fall risk factors. For the falls follow-up, participants return fall calendar postcards to the research center at the end of each month. Reports of falls are followed-up with a telephone interview to assess circumstances and consequences of each fall. A second assessment is performed 18 months following baseline. Results Of the 2382 who met all eligibility criteria at the door, 1616 (67.8% agreed to participate and were referred to the research center for further screening. The primary reason for ineligibility was inability to communicate in English. Results from the first 600 participants showed that participants are largely representative of seniors in the Boston area in terms of age, sex, race and Hispanic ethnicity. The average age of study participants was 77.9 years (s.d. 5.5 and nearly two-thirds were women. The study cohort was 78% white and 17% black. Many participants (39% reported having fallen at least once in the year before baseline. Conclusion Our results demonstrate the feasibility of conducting

  20. Identification of individual foothill yellow-legged frogs (Rana boylii) using chin pattern photographs: a non-invasive and effective method for small population studies

    Science.gov (United States)

    K.R. Marlow; K.D. Wiseman; Clara Wheeler; J.E.  Drennan; R.E.  Jackman

    2016-01-01

    The ability to identify individual animals is a valuable tool in the study of amphibian population dynamics, movement ecology, social behavior, and habitat use. Numerous methods of marking amphibians have been employed including the use of passive integrated transponder (PIT) tags, radio-transmitters, elastomers, branding, and mutilation techniques such as toe...

  1. Preventable trauma deaths: from panel review to population based-studies

    Directory of Open Access Journals (Sweden)

    Vesconi Sergio

    2006-04-01

    Full Text Available Abstract Preventable trauma deaths are defined as deaths which could be avoided if optimal care has been delivered. Studies on preventable trauma deaths have been accomplished initially with panel reviews of pre-hospital and hospital charts. However, several investigators questioned the reliability and validity of this method because of low reproducibility of implicit judgments when they are made by different experts. Nevertheless, number of studies were published all around the world and ultimately gained some credibility, particularly in regions where comparisons were made before and after trauma system implementation with a resultant fall in mortality. During the last decade of century the method of comparing observed survival with probability of survival calculated from large trauma registries has obtained popularity. Preventable trauma deaths were identified as deaths occurred notwithstanding a high calculated probability of survival. In recent years, preventable trauma deaths studies have been replaced by population-based studies, which use databases representative of overall population, therefore with high epidemiologic value. These databases contain readily available information which carry out the advantage of objectivity and large numbers. Nowadays, population-based researches provide the strongest evidence regarding the effectiveness of trauma systems and trauma centers on patient outcomes.

  2. The North Jutland County Diabetic Retinopathy Study (NCDRS). Population characteristics

    DEFF Research Database (Denmark)

    Knudsen, L.L.; Lervang, H.H.; Lundbye-Christensen, Søren

    Abstract Purpose: Several population based studies have reported blood glucose levels and blood pressure to be risk factors for the development of proliferativ retinopathy and diabetic maculopathy. Despite their importance, these studies were initiated more than two decades ago and may therefore...... reflect the treatment and population composition of a previous era. Studies of the present diabetic population are therefore in demand. Methods: The present cross–section study included 656 type 1 and 328 type 2 diabetic subjects undergoing diabetic retinopathy screening. Crude prevalence rates...... for proliferative diabetic retinopathy, maculopathy, several specific lesions and non–ophthalmic findings were assessed together with their association to a simplified and internationally approved retinal grading. Results: The crude prevalence of proliferative retinopathy was found to be 5.6 % and 0.9 % for type 1...

  3. The North Jutland County Diabetic Retinopathy Study (NCDRS): population characteristics

    DEFF Research Database (Denmark)

    Knudsen, Lars Loumann; Lervang, Hans-Henrik; Lundbye-Christensen, Søren

    2006-01-01

    Background: Several population-based studies have reported blood glucose levels and blood pressure to be risk factors for the development of diabetic retinopathy. These studies were initiated more than two decades ago and may therefore reflect the treatment and population composition of a previous...... era, suggesting new studies of the present population with diabetes. Aim and methods: This cross-section study included 656 people with type 1 diabetes and 328 with type 2 diabetes. Crude prevalence rates of proliferative diabetic retinopathy, clinically significant macular oedema and several specific...... retinal lesions were assessed, together with their association to a simplified and internationally approved retinal grading. Results: The point prevalence of proliferative retinopathy was found to be 0.8% and 0.3% for type 1 and type 2 diabetes. Equivalent prevalence rates of clinically significant...

  4. A salutogenic approach to prevention of metabolic syndrome: a mixed methods population study.

    Science.gov (United States)

    Miettola, Juhani; Viljanen, Anna Maria

    2014-12-01

    To find a salutogenic approach for prevention of metabolic syndrome in primary care practice. An explanatory sequential mixed-methods procedure was used to find salutogenic approaches for lifestyle change by assessing individual need, potential, and personal motivation. Data from a population health survey and interviews that focused on a sense of coherence were analysed. Altogether 480 Finnish subjects participated in a population health survey, and 43 of them were interviewed. The 43 interviewees' data were included in the final analysis. With the health survey participants' liability for MetS was assessed, and the objective need for lifestyle intervention was determined. Through the focused interviews potential and personal motivation for lifestyle modification were explored. Finally the data of the 43 interviewed subjects were merged. Four possible lifestyle intervention approaches were identified for specific intervention. First, subjects with a strong sense of coherence only need encouragement to maintain a healthy lifestyle; second, professional support was found important for subjects with gaps in health awareness to improve health understanding; third, strengthening of social support for lifestyle change is necessary for subjects with various practical constraints in their everyday life; and fourth, strengthening of stress adaptation is important for subjects with redundant concerns about their health. Salutogenic client-centred lifestyle modification approaches should be part of primary care practice. Further, a cross-disciplinary approach is needed in primary care research and practice to combat the exploding lifestyle illnesses.

  5. [Use of psychoactive substances and contraceptive methods by the Brazilian urban population, 2005].

    Science.gov (United States)

    Bastos, Francisco I; Cunha, Cynthia B; Bertoni, Neilane

    2008-06-01

    To analyze the relationship between utilization patterns for condoms and other contraceptive methods and the consumption of alcohol and drugs. Exploratory study based on data from a probabilistic sample of 5,040 interviewees aged 16 to 65 years living in large urban regions of Brazil in 2005. The data were collected by means of questionnaires. The chi-square automatic interaction classification tree technique was used to study the use of condoms among interviewees of both sexes and other contraceptive methods among women, at the time of the last vaginal sexual intercourse. Among young and middle-aged adults of both sexes and young men in stable relationships, condom use was less frequent among those who said they used psychoactive substances (alcohol and/or illegal drugs). The possible modulating effect of psychoactive substances on contraceptive practices among mature women seems to be more straightforward, compared to the more subtle effects observed among younger women, for whom the different social classes they belonged to seemed to play a more important role. Despite the limitations resulting from an exploratory study, the fact that this was a representative sample of the urban population of Brazil and not from vulnerable populations, reinforces the need to implement integrated public policies directed towards the general population, with regard to preventing drug consumption, alcohol abuse, sexually transmitted infections, HIV/AIDS and unwanted pregnancy and promoting sexual and reproductive health.

  6. Validity and feasibility of a satellite imagery-based method for rapid estimation of displaced populations.

    Science.gov (United States)

    Checchi, Francesco; Stewart, Barclay T; Palmer, Jennifer J; Grundy, Chris

    2013-01-23

    Estimating the size of forcibly displaced populations is key to documenting their plight and allocating sufficient resources to their assistance, but is often not done, particularly during the acute phase of displacement, due to methodological challenges and inaccessibility. In this study, we explored the potential use of very high resolution satellite imagery to remotely estimate forcibly displaced populations. Our method consisted of multiplying (i) manual counts of assumed residential structures on a satellite image and (ii) estimates of the mean number of people per structure (structure occupancy) obtained from publicly available reports. We computed population estimates for 11 sites in Bangladesh, Chad, Democratic Republic of Congo, Ethiopia, Haiti, Kenya and Mozambique (six refugee camps, three internally displaced persons' camps and two urban neighbourhoods with a mixture of residents and displaced) ranging in population from 1,969 to 90,547, and compared these to "gold standard" reference population figures from census or other robust methods. Structure counts by independent analysts were reasonably consistent. Between one and 11 occupancy reports were available per site and most of these reported people per household rather than per structure. The imagery-based method had a precision relative to reference population figures of layout. For each site, estimates were produced in 2-5 working person-days. In settings with clearly distinguishable individual structures, the remote, imagery-based method had reasonable accuracy for the purposes of rapid estimation, was simple and quick to implement, and would likely perform better in more current application. However, it may have insurmountable limitations in settings featuring connected buildings or shelters, a complex pattern of roofs and multi-level buildings. Based on these results, we discuss possible ways forward for the method's development.

  7. Representativeness in population-based studies

    DEFF Research Database (Denmark)

    Drivsholm, Thomas Bo; Eplov, Lene Falgaard; Davidsen, Michael

    2006-01-01

    Decreasing rates of participation in population-based studies increasingly challenge the interpretation of study results, in both analytic and descriptive epidemiology. Consequently, estimates of possible differences between participants and non-participants are increasingly important...... for the interpretation of study results and generalization to the background population....

  8. Correction of population stratification in large multi-ethnic association studies.

    Directory of Open Access Journals (Sweden)

    David Serre

    2008-01-01

    Full Text Available The vast majority of genetic risk factors for complex diseases have, taken individually, a small effect on the end phenotype. Population-based association studies therefore need very large sample sizes to detect significant differences between affected and non-affected individuals. Including thousands of affected individuals in a study requires recruitment in numerous centers, possibly from different geographic regions. Unfortunately such a recruitment strategy is likely to complicate the study design and to generate concerns regarding population stratification.We analyzed 9,751 individuals representing three main ethnic groups - Europeans, Arabs and South Asians - that had been enrolled from 154 centers involving 52 countries for a global case/control study of acute myocardial infarction. All individuals were genotyped at 103 candidate genes using 1,536 SNPs selected with a tagging strategy that captures most of the genetic diversity in different populations. We show that relying solely on self-reported ethnicity is not sufficient to exclude population stratification and we present additional methods to identify and correct for stratification.Our results highlight the importance of carefully addressing population stratification and of carefully "cleaning" the sample prior to analyses to obtain stronger signals of association and to avoid spurious results.

  9. "The Theory was Beautiful Indeed": Rise, Fall and Circulation of Maximizing Methods in Population Genetics (1930-1980).

    Science.gov (United States)

    Grodwohl, Jean-Baptiste

    2017-08-01

    Describing the theoretical population geneticists of the 1960s, Joseph Felsenstein reminisced: "our central obsession was finding out what function evolution would try to maximize. Population geneticists used to think, following Sewall Wright, that mean relative fitness, W, would be maximized by natural selection" (Felsenstein 2000). The present paper describes the genesis, diffusion and fall of this "obsession", by giving a biography of the mean fitness function in population genetics. This modeling method devised by Sewall Wright in the 1930s found its heyday in the late 1950s and early 1960s, in the wake of Motoo Kimura's and Richard Lewontin's works. It seemed a reliable guide in the mathematical study of deterministic effects (the study of natural selection in populations of infinite size, with no drift), leading to powerful generalizations presenting law-like properties. Progress in population genetics theory, it then seemed, would come from the application of this method to the study of systems with several genes. This ambition came to a halt in the context of the influential objections made by the Australian mathematician Patrick Moran in 1963. These objections triggered a controversy between mathematically- and biologically-inclined geneticists, with affected both the formal standards and the aims of population genetics as a science. Over the course of the 1960s, the mean fitness method withered with the ambition of developing the deterministic theory. The mathematical theory became increasingly complex. Kimura re-focused his modeling work on the theory of random processes; as a result of his computer simulations, Lewontin became the staunchest critic of maximizing principles in evolutionary biology. The mean fitness method then migrated to other research areas, being refashioned and used in evolutionary quantitative genetics and behavioral ecology.

  10. Hard-to-reach populations of men who have sex with men and sex workers: a systematic review on sampling methods.

    Science.gov (United States)

    Barros, Ana B; Dias, Sonia F; Martins, Maria Rosario O

    2015-10-30

    In public health, hard-to-reach populations are often recruited by non-probabilistic sampling methods that produce biased results. In order to overcome this, several sampling methods have been improved and developed in the last years. The aim of this systematic review was to identify all current methods used to survey most-at-risk populations of men who have sex with men and sex workers. The review also aimed to assess if there were any relations between the study populations and the sampling methods used to recruit them. Lastly, we wanted to assess if the number of publications originated in middle and low human development (MLHD) countries had been increasing in the last years. A systematic review was conducted using electronic databases and a total of 268 published studies were included in the analysis. In this review, 11 recruitment methods were identified. Semi-probabilistic methods were used most commonly to survey men who have sex with men, and the use of the Internet was the method that gathered more respondents. We found that female sex workers were more frequently recruited through non-probabilistic methods than men who have sex with men (odds = 2.2; p review identified 11 methods used to sample men who have sex with men and female sex workers. There is an association between the type of sampling method and the population being studied. The number of studies based in middle and low human development countries has increased in the last 6 years of this study.

  11. The evaluation of a population based diffusion tensor image atlas using a ground truth method

    Science.gov (United States)

    Van Hecke, Wim; Leemans, Alexander; D'Agostino, Emiliano; De Backer, Steve; Vandervliet, Evert; Parizel, Paul M.; Sijbers, Jan

    2008-03-01

    Purpose: Voxel based morphometry (VBM) is increasingly being used to detect diffusion tensor (DT) image abnormalities in patients for different pathologies. An important requisite for these VBM studies is the use of a high-dimensional, non-rigid coregistration technique, which is able to align both the spatial and the orientational information. Recent studies furthermore indicate that high-dimensional DT information should be included during coregistration for an optimal alignment. In this context, a population based DTI atlas is created that preserves the orientational DT information robustly and contains a minimal bias towards any specific individual data set. Methods: A ground truth evaluation method is developed using a single subject DT image that is deformed with 20 deformation fields. Thereafter, an atlas is constructed based on these 20 resulting images. Thereby, the non-rigid coregistration algorithm is based on a viscous fluid model and on mutual information. The fractional anisotropy (FA) maps as well as the DT elements are used as DT image information during the coregistration algorithm, in order to minimize the orientational alignment inaccuracies. Results: The population based DT atlas is compared with the ground truth image using accuracy and precision measures of spatial and orientational dependent metrics. Results indicate that the population based atlas preserves the orientational information in a robust way. Conclusion: A subject independent population based DT atlas is constructed and evaluated with a ground truth method. This atlas contains all available orientational information and can be used in future VBM studies as a reference system.

  12. Harmonising measures of knee and hip osteoarthritis in population-based cohort studies

    DEFF Research Database (Denmark)

    Leyland, K M; Gates, L S; Nevitt, M

    2018-01-01

    OBJECTIVE: Population-based osteoarthritis (OA) cohorts provide vital data on risk factors and outcomes of OA, however the methods to define OA vary between cohorts. We aimed to provide recommendations for combining knee and hip OA data in extant and future population cohort studies, in order to ...

  13. ObStruct: a method to objectively analyse factors driving population structure using Bayesian ancestry profiles.

    Directory of Open Access Journals (Sweden)

    Velimir Gayevskiy

    Full Text Available Bayesian inference methods are extensively used to detect the presence of population structure given genetic data. The primary output of software implementing these methods are ancestry profiles of sampled individuals. While these profiles robustly partition the data into subgroups, currently there is no objective method to determine whether the fixed factor of interest (e.g. geographic origin correlates with inferred subgroups or not, and if so, which populations are driving this correlation. We present ObStruct, a novel tool to objectively analyse the nature of structure revealed in Bayesian ancestry profiles using established statistical methods. ObStruct evaluates the extent of structural similarity between sampled and inferred populations, tests the significance of population differentiation, provides information on the contribution of sampled and inferred populations to the observed structure and crucially determines whether the predetermined factor of interest correlates with inferred population structure. Analyses of simulated and experimental data highlight ObStruct's ability to objectively assess the nature of structure in populations. We show the method is capable of capturing an increase in the level of structure with increasing time since divergence between simulated populations. Further, we applied the method to a highly structured dataset of 1,484 humans from seven continents and a less structured dataset of 179 Saccharomyces cerevisiae from three regions in New Zealand. Our results show that ObStruct provides an objective metric to classify the degree, drivers and significance of inferred structure, as well as providing novel insights into the relationships between sampled populations, and adds a final step to the pipeline for population structure analyses.

  14. Frailty syndrome in an independent urban population in Brazil (FIBRA study: a cross-sectional populational study

    Directory of Open Access Journals (Sweden)

    Larissa Barradas Calado

    Full Text Available ABSTRACT: CONTEXT AND OBJECTIVE: Frailty is a multifactorial syndrome. The aim of this study was to determine the prevalence and characteristics of frailty syndrome in an elderly urban population. DESIGN AND SETTING: Cross-sectional study carried out at the homes of a randomized sample representing the independent elderly individuals of Ribeirão Preto, Brazil. METHODS: Sociodemographic characteristics, clinical data and criteria of the frailty phenotype were obtained at the subjects' homes; 385 individuals were evaluated. Frailty was defined based on detection of weight loss, exhaustion, weakness, slowness and low physical activity level. Individuals with three or more of these characteristics were classified as frail and those with one or two as pre-frail. Specific cutoff points for weakness, slowness and low physical activity level were calculated. RESULTS: The participants' mean age was 73.9 ± 6.5 years, and 64.7% were women. 12.5% had lost weight over the last year; 20.5% showed exhaustion, 17.1% slowness, 24.4% low physical activity level and 20.5% weakness. 9.1% were considered frail and 49.6% pre-frail. Frail subjects were older, attended more medical visits, had a higher chance of hospitalization within the last 12 months and had more cerebrovascular events, diabetes, neoplasms, osteoporosis and urinary and fecal incontinence. CONCLUSION: In this independent elderly population, there were numerous frail and pre-frail individuals. Frailty syndrome was associated with high morbidity. Cutoff points for weakness, slowness and low physical activity level should be adjusted for the population under study. It is essential to identify frail and pre-frail older individuals for appropriate interventions.

  15. The Characteristics of the Danish population in the Elderly-study

    DEFF Research Database (Denmark)

    Bilberg, Randi Marie; Andersen, Kjeld; Nielsen, Anette Søgaard

    the characteristics of the Danish population in the Elderly-study. Methods The study is a randomized controlled study and has so far enrolled 716 participants from Germany, USA, and Denmark and 341 are from Denmark. Participants are 60+ years old and fulfil the DSM-5 criteria for alcohol use disorder. The exclusions...

  16. Comparing methods of targeting obesity interventions in populations: An agent-based simulation.

    Science.gov (United States)

    Beheshti, Rahmatollah; Jalalpour, Mehdi; Glass, Thomas A

    2017-12-01

    Social networks as well as neighborhood environments have been shown to effect obesity-related behaviors including energy intake and physical activity. Accordingly, harnessing social networks to improve targeting of obesity interventions may be promising to the extent this leads to social multiplier effects and wider diffusion of intervention impact on populations. However, the literature evaluating network-based interventions has been inconsistent. Computational methods like agent-based models (ABM) provide researchers with tools to experiment in a simulated environment. We develop an ABM to compare conventional targeting methods (random selection, based on individual obesity risk, and vulnerable areas) with network-based targeting methods. We adapt a previously published and validated model of network diffusion of obesity-related behavior. We then build social networks among agents using a more realistic approach. We calibrate our model first against national-level data. Our results show that network-based targeting may lead to greater population impact. We also present a new targeting method that outperforms other methods in terms of intervention effectiveness at the population level.

  17. [Prospect and application of microsatellite population genetics in study of geoherbs].

    Science.gov (United States)

    Zhang, Wen-Jing; Zhang, Yong-Qing; Yuan, Qing-Jun; Huang, Lu-Qi; Jiang, Dan; Jing, Li

    2013-12-01

    The author introduces the basic concepts of microsatellite and population genetics and its characteristics, expounds the application of these theories for population genetic structure and genetic diversity, gene flow and evolutionary significant unit ESU division research. This paper discuss its applicationin study of genetic causes, origin of cultivation, different regional origins of geoherbs, aiming at providing a new theory and method for geoherbs.

  18. Life cycle and population growth rate of Caenorhabditis elegans studied by a new method.

    Science.gov (United States)

    Muschiol, Daniel; Schroeder, Fabian; Traunspurger, Walter

    2009-05-16

    The free-living nematode Caenorhabditis elegans is the predominant model organism in biological research, being used by a huge number of laboratories worldwide. Many researchers have evaluated life-history traits of C. elegans in investigations covering quite different aspects such as ecotoxicology, inbreeding depression and heterosis, dietary restriction/supplement, mutations, and ageing. Such traits include juvenile growth rates, age at sexual maturity, adult body size, age-specific fecundity/mortality, total reproduction, mean and maximum lifespan, and intrinsic population growth rates. However, we found that in life-cycle experiments care is needed regarding protocol design. Here, we test a recently developed method that overcomes some problems associated with traditional cultivation techniques. In this fast and yet precise approach, single individuals are maintained within hanging drops of semi-fluid culture medium, allowing the simultaneous investigation of various life-history traits at any desired degree of accuracy. Here, the life cycles of wild-type C. elegans strains N2 (Bristol, UK) and MY6 (Münster, Germany) were compared at 20 degrees C with 5 x 10(9) Escherichia coli ml-1 as food source. High-resolution life tables and fecundity schedules of the two strains are presented. Though isolated 700 km and 60 years apart from each other, the two strains barely differed in life-cycle parameters. For strain N2 (n = 69), the intrinsic rate of natural increase (r m d(-1)), calculated according to the Lotka equation, was 1.375, the net reproductive rate (R 0) 291, the mean generation time (T) 90 h, and the minimum generation time (T min) 73.0 h. The corresponding values for strain MY6 (n = 72) were r m = 1.460, R0 = 289, T = 84 h, and T min = 67.3 h. Peak egg-laying rates in both strains exceeded 140 eggs d(-1). Juvenile and early adulthood mortality was negligible. Strain N2 lived, on average, for 16.7 d, while strain MY6 died 2 days earlier; however

  19. Life cycle and population growth rate of Caenorhabditis elegans studied by a new method

    Directory of Open Access Journals (Sweden)

    Schroeder Fabian

    2009-05-01

    Full Text Available Abstract Background The free-living nematode Caenorhabditis elegans is the predominant model organism in biological research, being used by a huge number of laboratories worldwide. Many researchers have evaluated life-history traits of C. elegans in investigations covering quite different aspects such as ecotoxicology, inbreeding depression and heterosis, dietary restriction/supplement, mutations, and ageing. Such traits include juvenile growth rates, age at sexual maturity, adult body size, age-specific fecundity/mortality, total reproduction, mean and maximum lifespan, and intrinsic population growth rates. However, we found that in life-cycle experiments care is needed regarding protocol design. Here, we test a recently developed method that overcomes some problems associated with traditional cultivation techniques. In this fast and yet precise approach, single individuals are maintained within hanging drops of semi-fluid culture medium, allowing the simultaneous investigation of various life-history traits at any desired degree of accuracy. Here, the life cycles of wild-type C. elegans strains N2 (Bristol, UK and MY6 (Münster, Germany were compared at 20°C with 5 × 109 Escherichia coli ml-1 as food source. Results High-resolution life tables and fecundity schedules of the two strains are presented. Though isolated 700 km and 60 years apart from each other, the two strains barely differed in life-cycle parameters. For strain N2 (n = 69, the intrinsic rate of natural increase (rmd-1, calculated according to the Lotka equation, was 1.375, the net reproductive rate (R0 291, the mean generation time (T 90 h, and the minimum generation time (Tmin 73.0 h. The corresponding values for strain MY6 (n = 72 were rm = 1.460, R0 = 289, T = 84 h, and Tmin = 67.3 h. Peak egg-laying rates in both strains exceeded 140 eggs d-1. Juvenile and early adulthood mortality was negligible. Strain N2 lived, on average, for 16.7 d, while strain MY6 died 2 days

  20. Population based ranking of frameless CT-MRI registration methods

    Energy Technology Data Exchange (ETDEWEB)

    Opposits, Gabor; Kis, Sandor A.; Tron, Lajos; Emri, Miklos [Debrecen Univ. (Hungary). Dept. of Nuclear Medicine; Berenyi, Ervin [Debrecen Univ. (Hungary). Dept. of Biomedical Laboratory and Imaging Science; Takacs, Endre [Rotating Gamma Ltd., Debrecen (Hungary); Dobai, Jozsef G.; Bognar, Laszlo [Debrecen Univ., Medical Center (Hungary). Dept. of Neurosurgery; Szuecs, Bernadett [ScanoMed Ltd., Debrecen (Hungary)

    2015-07-01

    Clinical practice often requires simultaneous information obtained by two different imaging modalities. Registration algorithms are commonly used for this purpose. Automated procedures are very helpful in cases when the same kind of registration has to be performed on images of a high number of subjects. Radiotherapists would prefer to use the best automated method to assist therapy planning, however there are not accepted procedures for ranking the different registration algorithms. We were interested in developing a method to measure the population level performance of CT-MRI registration algorithms by a parameter of values in the [0,1] interval. Pairs of CT and MRI images were collected from 1051 subjects. Results of an automated registration were corrected manually until a radiologist and a neurosurgeon expert both accepted the result as good. This way 1051 registered MRI images were produced by the same pair of experts to be used as gold standards for the evaluation of the performance of other registration algorithms. Pearson correlation coefficient, mutual information, normalized mutual information, Kullback-Leibler divergence, L{sub 1} norm and square L{sub 2} norm (dis)similarity measures were tested for sensitivity to indicate the extent of (dis)similarity of a pair of individual mismatched images. The square Hellinger distance proved suitable to grade the performance of registration algorithms at population level providing the developers with a valuable tool to rank algorithms. The developed procedure provides an objective method to find the registration algorithm performing the best on the population level out of newly constructed or available preselected ones.

  1. Implementing a generic method for bias correction in statistical models using random effects, with spatial and population dynamics examples

    DEFF Research Database (Denmark)

    Thorson, James T.; Kristensen, Kasper

    2016-01-01

    Statistical models play an important role in fisheries science when reconciling ecological theory with available data for wild populations or experimental studies. Ecological models increasingly include both fixed and random effects, and are often estimated using maximum likelihood techniques...... configurations of an age-structured population dynamics model. This simulation experiment shows that the epsilon-method and the existing bias-correction method perform equally well in data-rich contexts, but the epsilon-method is slightly less biased in data-poor contexts. We then apply the epsilon......-method to a spatial regression model when estimating an index of population abundance, and compare results with an alternative bias-correction algorithm that involves Markov-chain Monte Carlo sampling. This example shows that the epsilon-method leads to a biologically significant difference in estimates of average...

  2. Assessment of the effect of population and diary sampling methods on estimation of school-age children exposure to fine particles.

    Science.gov (United States)

    Che, W W; Frey, H Christopher; Lau, Alexis K H

    2014-12-01

    Population and diary sampling methods are employed in exposure models to sample simulated individuals and their daily activity on each simulation day. Different sampling methods may lead to variations in estimated human exposure. In this study, two population sampling methods (stratified-random and random-random) and three diary sampling methods (random resampling, diversity and autocorrelation, and Markov-chain cluster [MCC]) are evaluated. Their impacts on estimated children's exposure to ambient fine particulate matter (PM2.5 ) are quantified via case studies for children in Wake County, NC for July 2002. The estimated mean daily average exposure is 12.9 μg/m(3) for simulated children using the stratified population sampling method, and 12.2 μg/m(3) using the random sampling method. These minor differences are caused by the random sampling among ages within census tracts. Among the three diary sampling methods, there are differences in the estimated number of individuals with multiple days of exposures exceeding a benchmark of concern of 25 μg/m(3) due to differences in how multiday longitudinal diaries are estimated. The MCC method is relatively more conservative. In case studies evaluated here, the MCC method led to 10% higher estimation of the number of individuals with repeated exposures exceeding the benchmark. The comparisons help to identify and contrast the capabilities of each method and to offer insight regarding implications of method choice. Exposure simulation results are robust to the two population sampling methods evaluated, and are sensitive to the choice of method for simulating longitudinal diaries, particularly when analyzing results for specific microenvironments or for exposures exceeding a benchmark of concern. © 2014 Society for Risk Analysis.

  3. Health state of population in vicinity of the Mochovce nuclear power plant. Epidemiologic study

    International Nuclear Information System (INIS)

    Celko, M.; Durov, M.; Letkovicova, M.; Holy, R.; Sedliak, D.; Zrubec, M.; Kristufek, P.; Machata, M.; Prikazsky, V.; Rehak, R.; Stehlikova, B.; Vladar, M.

    1999-01-01

    Results of epidemiologic study of health state of population in vicinity of the Mochovce nuclear power plant (Slovak Republic) are presented. This report is reported under the headings: (1) Introduction; (2) Basic information about Mochovce NPP; (3) Assessment of population exposition by environmental factors; (4) Basic conceptions and principles of epidemiologic study; (5) Demography and health state of population; (6) Characterisation of databases and data; (7) Description of demographic and health indicators; (8) Calculation of demographic and health indicators in vicinity of the Mochovce NPP and in control areas; (9) Calculated indicators; (10) Statistical methods and evaluation of calculated indicators; (11) Summary and conclusions; (12) References; Appendixes: Literature review of similar epidemiologic studies; Quantities and units in radiation protection; Definitions of indicators calculation - specification of method

  4. A review of population-based studies on hypertension in Ghana ...

    African Journals Online (AJOL)

    Background: Hypertension is becoming a common health problem worldwide with increasing life expectancy and increasing prevalence of risk factors. Epidemiological data on hypertension in Ghana is necessary to guide policy and develop effective interventions. Methods: A review of population-based studies on ...

  5. Methods to improve genomic prediction and GWAS using combined Holstein populations

    DEFF Research Database (Denmark)

    Li, Xiujin

    The thesis focuses on methods to improve GWAS and genomic prediction using combined Holstein populations and investigations G by E interaction. The conclusions are: 1) Prediction reliabilities for Brazilian Holsteins can be increased by adding Nordic and Frensh genotyped bulls and a large G by E...... interaction exists between populations. 2) Combining data from Chinese and Danish Holstein populations increases the power of GWAS and detects new QTL regions for milk fatty acid traits. 3) The novel multi-trait Bayesian model efficiently estimates region-specific genomic variances, covariances...

  6. A mixed methods study to investigate needs assessment for knee pain and disability: population and individual perspectives

    Directory of Open Access Journals (Sweden)

    Ong Bie

    2007-07-01

    Full Text Available Abstract Background The new Musculoskeletal Services Framework outlines the importance of health care needs assessment. Our aim was to provide a model for this for knee pain and disability, describing felt need (individual assessment of a need for health care and expressed need (demand for health care. This intelligence is required by health care planners in order to implement the new Framework. Methods A multi-method approach was used. A population survey (n = 5784 was administered to adults aged 50+ registered with 3 general practices. The questionnaire contained a Knee Pain Screening Tool to identify the prevalence of knee pain and health care use in the population, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC. Survey responders who scored "severe" or "extreme" on at least one item on the pain or physical function scale on the WOMAC were categorised into "severe" groups. Qualitative interviews were undertaken with 22 survey responders to explore in detail the experience of living with knee pain and disability. A sample of interviewees (n = 10 completed an open format patient diary to explore the experience of knee pain in everyday life. Results The 12-month period prevalence of knee pain was 49.5%, of which half was severe. Severe difficulties were reported with domestic duties, bending, bathing, climbing stairs and getting in or out of a car. Some self-care is occurring. The majority (53% of responders with severe pain or disability had not consulted their GP in the last 12 months. The qualitative study revealed reasons for this including a perception that knee pain is part of normal ageing, little effective prevention and treatment is available and the use of medications causes side effects and dependency. Conclusion This study adds to previous work by highlighting a gap between felt and expressed need and the reasons for this mismatch. There is evidence of self-management, but also missed opportunities for

  7. Childhood disability in Malawi: a population based assessment using the key informant method.

    Science.gov (United States)

    Tataryn, Myroslava; Polack, Sarah; Chokotho, Linda; Mulwafu, Wakisa; Kayange, Petros; Banks, Lena Morgon; Noe, Christiane; Lavy, Chris; Kuper, Hannah

    2017-11-28

    Epidemiological data on childhood disability are lacking in Low and Middle Income countries (LMICs) such as Malawi, hampering effective service planning and advocacy. The Key Informant Method (KIM) is an innovative, cost-effective method for generating population data on the prevalence and causes of impairment in children. The aim of this study was to use the Key Informant Method to estimate the prevalence of moderate/severe, hearing, vision and physical impairments, intellectual impairments and epilepsy in children in two districts in Malawi and to estimate the associated need for rehabilitation and other services. Five hundred key informants (KIs) were trained to identify children in their communities who may have the impairment types included in this study. Identified children were invited to attend a screening camp where they underwent assessment by medical professionals for moderate/severe hearing, vision and physical impairments, intellectual impairments and epilepsy. Approximately 15,000 children were identified by KIs as potentially having an impairment of whom 7220 (48%) attended a screening camp. The estimated prevalence of impairments/epilepsy was 17.3/1000 children (95% CI: 16.9-17.7). Physical impairment (39%) was the commonest impairment type followed by hearing impairment (27%), intellectual impairment (26%), epilepsy (22%) and vision impairment (4%). Approximately 2100 children per million population could benefit from physiotherapy and occupational therapy and 300 per million are in need of a wheelchair. An estimated 1800 children per million population have hearing impairment caused by conditions that could be prevented or treated through basic primary ear care. Corneal opacity was the leading cause of vision impairment. Only 50% of children with suspected epilepsy were receiving medication. The majority (73%) of children were attending school, but attendance varied by impairment type and was lowest among children with multiple impairments (38

  8. Comparison of Three Plot Selection Methods for Estimating Change in Temporally Variable, Spatially Clustered Populations.

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, William L. [Bonneville Power Administration, Portland, OR (US). Environment, Fish and Wildlife

    2001-07-01

    Monitoring population numbers is important for assessing trends and meeting various legislative mandates. However, sampling across time introduces a temporal aspect to survey design in addition to the spatial one. For instance, a sample that is initially representative may lose this attribute if there is a shift in numbers and/or spatial distribution in the underlying population that is not reflected in later sampled plots. Plot selection methods that account for this temporal variability will produce the best trend estimates. Consequently, I used simulation to compare bias and relative precision of estimates of population change among stratified and unstratified sampling designs based on permanent, temporary, and partial replacement plots under varying levels of spatial clustering, density, and temporal shifting of populations. Permanent plots produced more precise estimates of change than temporary plots across all factors. Further, permanent plots performed better than partial replacement plots except for high density (5 and 10 individuals per plot) and 25% - 50% shifts in the population. Stratified designs always produced less precise estimates of population change for all three plot selection methods, and often produced biased change estimates and greatly inflated variance estimates under sampling with partial replacement. Hence, stratification that remains fixed across time should be avoided when monitoring populations that are likely to exhibit large changes in numbers and/or spatial distribution during the study period. Key words: bias; change estimation; monitoring; permanent plots; relative precision; sampling with partial replacement; temporary plots.

  9. Quantification of rat retinal growth and vascular population changes after single and split doses of proton irradiation: translational study using stereology methods

    Science.gov (United States)

    Mao, Xiao W.; Archambeau, John O.; Kubinova, Lucie; Boyle, Soames; Petersen, Georgia; Grove, Roger; Nelson, G. A. (Principal Investigator)

    2003-01-01

    This study quantified architectural and population changes in the rat retinal vasculature after proton irradiation using stereology. A 100 MeV conformal proton beam delivered 8, 14, 20 and 28 Gy as single and split doses to the whole eye. The vascular networks were prepared from retinal digests. Stereological methods were used to obtain the area of the retina and unbiased estimates of microvessel/artery/vein endothelial, pericyte and smooth muscle population, and vessel length. The retinal area increased progressively in the unirradiated, age-matched controls and in the retinas irradiated with 8 and 14 Gy, indicating uniform progressive retinal growth. No growth occurred after 20 and 28 Gy. Regression analysis of total endothelial cell number in all vessels (arteries, veins and capillaries) after irradiation documented a progressive time- and dose-dependent cell loss occurring over 15 to 24 months. The difference from controls was significant (Ppopulations after split doses. At 10 Gy, the rate of endothelial cell loss, a dose parameter used to characterize the time- and dose-dependent loss of the endothelial population, was doubled.

  10. Counting hard-to-count populations: the network scale-up method for public health

    Science.gov (United States)

    Bernard, H Russell; Hallett, Tim; Iovita, Alexandrina; Johnsen, Eugene C; Lyerla, Rob; McCarty, Christopher; Mahy, Mary; Salganik, Matthew J; Saliuk, Tetiana; Scutelniciuc, Otilia; Shelley, Gene A; Sirinirund, Petchsri; Weir, Sharon

    2010-01-01

    Estimating sizes of hidden or hard-to-reach populations is an important problem in public health. For example, estimates of the sizes of populations at highest risk for HIV and AIDS are needed for designing, evaluating and allocating funding for treatment and prevention programmes. A promising approach to size estimation, relatively new to public health, is the network scale-up method (NSUM), involving two steps: estimating the personal network size of the members of a random sample of a total population and, with this information, estimating the number of members of a hidden subpopulation of the total population. We describe the method, including two approaches to estimating personal network sizes (summation and known population). We discuss the strengths and weaknesses of each approach and provide examples of international applications of the NSUM in public health. We conclude with recommendations for future research and evaluation. PMID:21106509

  11. Stroke Awareness in the General Population: A Study from Jordan ...

    African Journals Online (AJOL)

    Purpose: To assess the awareness level of the Jordanian general population regarding the definition, risk factors, signs and symptoms, and consequences of stroke. Methods: This was a cross-sectional study. The questionnaire was handed to participants by trained students, the participants were chosen randomly from ...

  12. A Comparison of Multiple Methods for Estimating Parasitemia of Hemogregarine Hemoparasites (Apicomplexa: Adeleorina) and Its Application for Studying Infection in Natural Populations

    Science.gov (United States)

    Maia, João P.; Harris, D. James; Carranza, Salvador; Gómez-Díaz, Elena

    2014-01-01

    Identifying factors influencing infection patterns among hosts is critical for our understanding of the evolution and impact of parasitism in natural populations. However, the correct estimation of infection parameters depends on the performance of detection and quantification methods. In this study, we designed a quantitative PCR (qPCR) assay targeting the 18 S rRNA gene to estimate prevalence and intensity of Hepatozoon infection and compared its performance with microscopy and PCR. Using qPCR, we also compared various protocols that differ in the biological source and the extraction methods. Our results show that the qPCR approach on DNA extracted from blood samples, regardless of the extraction protocol, provided the most sensitive estimates of Hepatozoon infection parameters; while allowed us to differentiate between mixed infections of Adeleorinid (Hepatozoon) and Eimeriorinid (Schellackia and Lankesterella), based on the analysis of melting curves. We also show that tissue and saline methods can be used as low-cost alternatives in parasitological studies. The next step was to test our qPCR assay in a biological context, and for this purpose we investigated infection patterns between two sympatric lacertid species, which are naturally infected with apicomplexan hemoparasites, such as the genera Schellackia (Eimeriorina) and Hepatozoon (Adeleorina). From a biological standpoint, we found a positive correlation between Hepatozoon intensity of infection and host body size within each host species, being significantly higher in males, and higher in the smaller sized host species. These variations can be associated with a number of host intrinsic factors, like hormonal and immunological traits, that require further investigation. Our findings are relevant as they pinpoint the importance of accounting for methodological issues to better estimate infection in parasitological studies, and illustrate how between-host factors can influence parasite distributions in

  13. A comparison of multiple methods for estimating parasitemia of hemogregarine hemoparasites (apicomplexa: adeleorina and its application for studying infection in natural populations.

    Directory of Open Access Journals (Sweden)

    João P Maia

    Full Text Available Identifying factors influencing infection patterns among hosts is critical for our understanding of the evolution and impact of parasitism in natural populations. However, the correct estimation of infection parameters depends on the performance of detection and quantification methods. In this study, we designed a quantitative PCR (qPCR assay targeting the 18 S rRNA gene to estimate prevalence and intensity of Hepatozoon infection and compared its performance with microscopy and PCR. Using qPCR, we also compared various protocols that differ in the biological source and the extraction methods. Our results show that the qPCR approach on DNA extracted from blood samples, regardless of the extraction protocol, provided the most sensitive estimates of Hepatozoon infection parameters; while allowed us to differentiate between mixed infections of Adeleorinid (Hepatozoon and Eimeriorinid (Schellackia and Lankesterella, based on the analysis of melting curves. We also show that tissue and saline methods can be used as low-cost alternatives in parasitological studies. The next step was to test our qPCR assay in a biological context, and for this purpose we investigated infection patterns between two sympatric lacertid species, which are naturally infected with apicomplexan hemoparasites, such as the genera Schellackia (Eimeriorina and Hepatozoon (Adeleorina. From a biological standpoint, we found a positive correlation between Hepatozoon intensity of infection and host body size within each host species, being significantly higher in males, and higher in the smaller sized host species. These variations can be associated with a number of host intrinsic factors, like hormonal and immunological traits, that require further investigation. Our findings are relevant as they pinpoint the importance of accounting for methodological issues to better estimate infection in parasitological studies, and illustrate how between-host factors can influence parasite

  14. A comparison of multiple methods for estimating parasitemia of hemogregarine hemoparasites (apicomplexa: adeleorina) and its application for studying infection in natural populations.

    Science.gov (United States)

    Maia, João P; Harris, D James; Carranza, Salvador; Gómez-Díaz, Elena

    2014-01-01

    Identifying factors influencing infection patterns among hosts is critical for our understanding of the evolution and impact of parasitism in natural populations. However, the correct estimation of infection parameters depends on the performance of detection and quantification methods. In this study, we designed a quantitative PCR (qPCR) assay targeting the 18 S rRNA gene to estimate prevalence and intensity of Hepatozoon infection and compared its performance with microscopy and PCR. Using qPCR, we also compared various protocols that differ in the biological source and the extraction methods. Our results show that the qPCR approach on DNA extracted from blood samples, regardless of the extraction protocol, provided the most sensitive estimates of Hepatozoon infection parameters; while allowed us to differentiate between mixed infections of Adeleorinid (Hepatozoon) and Eimeriorinid (Schellackia and Lankesterella), based on the analysis of melting curves. We also show that tissue and saline methods can be used as low-cost alternatives in parasitological studies. The next step was to test our qPCR assay in a biological context, and for this purpose we investigated infection patterns between two sympatric lacertid species, which are naturally infected with apicomplexan hemoparasites, such as the genera Schellackia (Eimeriorina) and Hepatozoon (Adeleorina). From a biological standpoint, we found a positive correlation between Hepatozoon intensity of infection and host body size within each host species, being significantly higher in males, and higher in the smaller sized host species. These variations can be associated with a number of host intrinsic factors, like hormonal and immunological traits, that require further investigation. Our findings are relevant as they pinpoint the importance of accounting for methodological issues to better estimate infection in parasitological studies, and illustrate how between-host factors can influence parasite distributions in

  15. Comparison of association mapping methods in a complex pedigreed population

    DEFF Research Database (Denmark)

    Sahana, Goutam; Guldbrandtsen, Bernt; Janss, Luc

    2010-01-01

    to collect SNP signals in intervals, to avoid the scattering of a QTL signal over multiple neighboring SNPs. Methods not accounting for genetic background (full pedigree information) performed worse, and methods using haplotypes were considerably worse with a high false-positive rate, probably due...... to the presence of low-frequency haplotypes. It was necessary to account for full relationships among individuals to avoid excess false discovery. Although the methods were tested on a cattle pedigree, the results are applicable to any population with a complex pedigree structure...

  16. Long-term response to genomic selection: effects of estimation method and reference population structure for different genetic architectures.

    Science.gov (United States)

    Bastiaansen, John W M; Coster, Albart; Calus, Mario P L; van Arendonk, Johan A M; Bovenhuis, Henk

    2012-01-24

    Genomic selection has become an important tool in the genetic improvement of animals and plants. The objective of this study was to investigate the impacts of breeding value estimation method, reference population structure, and trait genetic architecture, on long-term response to genomic selection without updating marker effects. Three methods were used to estimate genomic breeding values: a BLUP method with relationships estimated from genome-wide markers (GBLUP), a Bayesian method, and a partial least squares regression method (PLSR). A shallow (individuals from one generation) or deep reference population (individuals from five generations) was used with each method. The effects of the different selection approaches were compared under four different genetic architectures for the trait under selection. Selection was based on one of the three genomic breeding values, on pedigree BLUP breeding values, or performed at random. Selection continued for ten generations. Differences in long-term selection response were small. For a genetic architecture with a very small number of three to four quantitative trait loci (QTL), the Bayesian method achieved a response that was 0.05 to 0.1 genetic standard deviation higher than other methods in generation 10. For genetic architectures with approximately 30 to 300 QTL, PLSR (shallow reference) or GBLUP (deep reference) had an average advantage of 0.2 genetic standard deviation over the Bayesian method in generation 10. GBLUP resulted in 0.6% and 0.9% less inbreeding than PLSR and BM and on average a one third smaller reduction of genetic variance. Responses in early generations were greater with the shallow reference population while long-term response was not affected by reference population structure. The ranking of estimation methods was different with than without selection. Under selection, applying GBLUP led to lower inbreeding and a smaller reduction of genetic variance while a similar response to selection was

  17. Bacterial population in traditional sourdough evaluated by molecular methods.

    Science.gov (United States)

    Randazzo, C L; Heilig, H; Restuccia, C; Giudici, P; Caggia, C

    2005-01-01

    To study the microbial communities in artisanal sourdoughs, manufactured by traditional procedure in different areas of Sicily, and to evaluate the lactic acid bacteria (LAB) population by classical and culture-independent approaches. Forty-five LAB isolates were identified both by phenotypic and molecular methods. The restriction fragment length polymorphism and 16S ribosomal DNA gene sequencing gave evidence of a variety of species with the dominance of Lactobacillus sanfranciscensis and Lactobacillus pentosus, in all sourdoughs tested. Culture-independent method, such as denaturing gradient gel electrophoresis (DGGE) of the V6-V8 regions of the 16S rDNA, was applied for microbial community fingerprint. The DGGE profiles revealed the dominance of L. sanfranciscensis species. In addition, Lactobacillus-specific primers were used to amplify the V1-V3 regions of the 16S rDNA. DGGE profiles flourished the dominance of L. sanfranciscensis and Lactobacillus fermentum in the traditional sourdoughs, and revealed that the closely related species Lactobacillus kimchii and Lactobacillus alimentarius were not discriminated. Lactobacillus-specific PCR-DGGE analysis is a rapid tool for rapid detection of Lactobacillus species in artisanal sourdough. This study reports a characterization of Lactobacillus isolates from artisanal sourdoughs and highlights the value of DGGE approach to detect uncultivable Lactobacillus species.

  18. Comparison between ARIMA and DES Methods of Forecasting Population for Housing Demand in Johor

    Directory of Open Access Journals (Sweden)

    Alias Ahmad Rizal

    2016-01-01

    Full Text Available Forecasting accuracy is a primary criterion in selecting appropriate method of prediction. Even though there are various methods of forecasting however not all of these methods are able to predict with good accuracy. This paper presents an evaluation of two methods of population forecasting for housing demand. These methods are Autoregressive Integrated Moving Average (ARIMA and Double Exponential Smoothing (DES. Both of the methods are principally adopting univariate time series analysis which uses past and present data for forecasting. Secondary data obtained from Department of Statistics, Malaysia was used to forecast population for housing demand in Johor. Forecasting processes had generated 14 models to each of the methods and these models where evaluated using Mean Absolute Percentage Error (MAPE. It was found that 14 of Double Exponential Smoothing models and also 14 of ARIMA models had resulted to 1.674% and 5.524% of average MAPE values respectively. Hence, the Double Exponential Smoothing method outperformed the ARIMA method by reducing 4.00 % in forecasting model population for Johor state. These findings help researchers and government agency in selecting appropriate forecasting model for housing demand.

  19. Methods for calculating population dose from atmospheric dispersion of radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, B L; Jow, H N; Lee, I S [Pittsburgh Univ., PA (USA)

    1978-06-01

    Curves are computed from which population dose (man-rem) due to dispersal of radioactivity from a point source can be calculated in the gaussian plume model by simple multiplication, and methods of using them and their limitations are considered. Illustrative examples are presented.

  20. SAS Macros for Calculation of Population Attributable Fraction in a Cohort Study Design

    Directory of Open Access Journals (Sweden)

    Maarit A. Laaksonen

    2011-08-01

    Full Text Available The population attributable fraction (PAF is a useful measure for quantifying the impact of exposure to certain risk factors on a particular outcome at the population level. Recently, new model-based methods for the estimation of PAF and its confidence interval for different types of outcomes in a cohort study design have been proposed. In this paper, we introduce SAS macros implementing these methods and illustrate their application with a data example on the impact of different risk factors on type 2 diabetes incidence.

  1. Development and evaluation of a new method for sampling and monitoring the symphylid population in pineapple.

    Science.gov (United States)

    Soler, Alain; Gaude, Jean-Marie; Marie-Alphonsine, Paul-Alex; Vinatier, Fabrice; Dole, Bernard; Govindin, Jean-Claude; Fournier, Patrick; Queneherve, Patrick

    2011-09-01

    Symphylids (Hanseniella sp.) are polyphagous soilborne parasites. Today, symphylid populations on pineapple are monitored by observing root symptoms and the presence of symphylids at the bottom of basal leaves. The authors developed a reliable method with a bait and trap device to monitor symphylid populations in pineapple or fallow crops. The spatial distribution of the symphylid populations was evaluated using the variance/mean ratios and spatial analyses based on Moran's and Geary's indices. The method has been tested to monitor symphylid populations at different developmental stages of pineapple. Adding potato baits to the soil samples increased the trapping efficiency of symphylids when compared with 'soil only' and 'bait only' methods. The handling of the samples is also facilitated by the new device. Results showed that the vertical distribution of symphylids may be uniform deeply inside the soil profile under pineapple, up to 50 cm. Results showed that symphylid populations are highly aggregated, showing a spot area about 4-6 m wide for their development. The new method allows better and easier evaluation of symphylid populations. It may be very useful in the evaluation of new IPM methods to control symphylids under pineapple. Copyright © 2011 Society of Chemical Industry.

  2. Incidence of symptomatic osteochondritis dissecans lesions of the knee : A population-based study in Olmsted County

    NARCIS (Netherlands)

    Pareek, A.; Sanders, T. L.; Wu, I. T.; Larson, D. R.; Saris, D. B.F.; Krych, A.J.

    2017-01-01

    Objective: To (1) define population-based incidence of knee Osteochondritis dissecans (OCD) lesions using the population of Olmsted County, (2) examine trends over time, and (3) evaluate rate of surgical management over time. Method: Study population included 302 individuals who were diagnosed with

  3. Population studies of echinoderms and growth and mortality of sea cucumbers

    International Nuclear Information System (INIS)

    Ebert, T.A.

    1979-01-01

    Progress is reported on the following studies: methods of collecting sea cucumbers; determination of growth rates of plates of the calcareous ring; use of growth parameters and a length-frequency distribution to estimate mortality and population turnover; movement of materials through the atoll ecosystem; and autoradiographic studies on spines of sea urchins

  4. An Improved Real-Coded Population-Based Extremal Optimization Method for Continuous Unconstrained Optimization Problems

    Directory of Open Access Journals (Sweden)

    Guo-Qiang Zeng

    2014-01-01

    Full Text Available As a novel evolutionary optimization method, extremal optimization (EO has been successfully applied to a variety of combinatorial optimization problems. However, the applications of EO in continuous optimization problems are relatively rare. This paper proposes an improved real-coded population-based EO method (IRPEO for continuous unconstrained optimization problems. The key operations of IRPEO include generation of real-coded random initial population, evaluation of individual and population fitness, selection of bad elements according to power-law probability distribution, generation of new population based on uniform random mutation, and updating the population by accepting the new population unconditionally. The experimental results on 10 benchmark test functions with the dimension N=30 have shown that IRPEO is competitive or even better than the recently reported various genetic algorithm (GA versions with different mutation operations in terms of simplicity, effectiveness, and efficiency. Furthermore, the superiority of IRPEO to other evolutionary algorithms such as original population-based EO, particle swarm optimization (PSO, and the hybrid PSO-EO is also demonstrated by the experimental results on some benchmark functions.

  5. Study Circles as a Method of Informing the Adult Population on Radioactivity

    International Nuclear Information System (INIS)

    Kralj, M.

    2002-01-01

    Public acceptance of the radioactive waste disposal facilities is difficult to achieve. Analysis of the reasons that underlie public rejection of radioactive waste disposal facilities shows that people are not adequately informed about the proposal. They also have a lot of prejudices due to the lack of knowledge and understanding about basic facts on radioactivity and environmental processes. ARAO has proposed that the topic of radioactivity and radioactive waste be included in the program of study circles in order to promote knowledge and understanding of these issues among the adult population in several Slovenian communities. Study circles are self-organized adult learning groups in the local community environment. Two study circles were initially proposed: one in Krsko, the community with a nuclear facility, and one in Radovljica, a community without a nuclear facility. Because of troubles with the unexpected politicization of nuclear issues, the study circle in Krsko was postponed to the later term, so that only the study circle in the community without the nuclear installation was active. The members were found by personal invitations. They worked on different issues dealing with radiation, mainly with the application of radiation and radioactive substances in medicine. Through the study circle activities the interest in radiation issues increased. The members reported that they disseminated their interest and acquired knowledge to their family members and friends. Our experience shows that self-learning in small groups, promoting discussions and the confrontation of different opinions, results in an increase in objective knowledge. Therefore, study circles can provide a good basis for confidence building in the nuclear technology.(author)

  6. Psychiatric morbidity among rural and slum female population: A comparative study

    Directory of Open Access Journals (Sweden)

    Jhunu Shamsun Nahar

    2016-08-01

    Full Text Available Background: Psychiatric disorders are more prevalent among women than men worldwide. The lifetime risk of depres­sion and dysthymia are twice as common in women as men. Rural women usually undergoes more stressful situations and also scores more on stress scale than that of urban and slum population. Objectives: The research objectives of this study are: 1 To find out the prevalence of psychiatric disorders among the study population. 2 To compare the disorders among the rural and slum female population. 3 To find out the influence of existing socio-demographic factors on psychiatric disorders. Method: This is a community-based study, which is also cross sectional and descriptive in nature. The sample for the main study constituted 366 randomly selected respondents. A two-staged screening procedure was carried in the study. First, the total population was studied by screening test-Self Reporting Questionnaire (SRQ to divide the sample into 'screen positive' and 'screen negative' subjects. In the second stage, full assessment of a mixture of all 'screen positive' and 25% 'screen negative' was carried out by structured clinical interview for diagnosis (SCID-NP. Later SCID filled by the respondents was assessed by consultant psychiatrists by using DSMIV in order to put exact clinical diagnosis. Stress was scored according to Presumptive Stressful Life Events Scale (PSLE. The total duration of the study was from July 2010 to June 2011. Results: Higher prevalence of psychiatric morbidity was found among rural sample (22.8% than slum (10.90% population. Regarding pattern of psychiatric disorders among rural sample (22.8% than slum (10.9% population.See the PDF for the rest of the abstract.

  7. The value of some Corsican sub-populations for genetic association studies

    Directory of Open Access Journals (Sweden)

    Vona Giuseppe

    2008-07-01

    Full Text Available Abstract Background Genetic isolates with a history of a small founder population, long-lasting isolation and population bottlenecks represent exceptional resources in the identification of disease genes. In these populations the disease allele reveals Linkage Disequilibrium (LD with markers over significant genetic intervals, therefore facilitating disease locus identification. In a previous study we examined the LD extension on the Xq13 region in three Corsican sub-populations from the inner mountainous region of the island. On the basis of those previous results we have proposed a multistep procedure to carry out studies aimed at the identification of genes involved in complex diseases in Corsica. A prerequisite to carry out the proposed multi-step procedure was the presence of different degrees of LD on the island and a common genetic derivation of the different Corsican sub-populations. In order to evaluate the existence of these conditions in the present paper we extended the analysis to the Corsican coastal populations. Methods Samples were analyzed using seven dinucleotide microsatellite markers on chromosome Xq13-21: DXS983, DXS986, DXS8092, DXS8082, DXS1225, DXS8037 and DXS995 spanning approximately 4.0 cM (13.3 Mb. We have also investigated the distribution of the DXS1225-DXS8082 haplotype which has been recently proposed as a good marker of population genetic history due to its low recombination rate. Results the results obtained indicate a decrease of LD on the island from the central mountainous toward the coastal sub-populations. In addition the analysis of the DXS1225-DXS8082 haplotype revealed: 1 the presence of a particular haplotype with high frequency; 2 the derivation from a common genetic pool of the sub-populations examined in the present study. Conclusion These results indicate the Corsican sub-populations useful for the fine mapping of genes contributing to complex diseases.

  8. Comparison of Drive Counts and Mark-Resight As Methods of Population Size Estimation of Highly Dense Sika Deer (Cervus nippon Populations.

    Directory of Open Access Journals (Sweden)

    Kazutaka Takeshita

    Full Text Available Assessing temporal changes in abundance indices is an important issue in the management of large herbivore populations. The drive counts method has been frequently used as a deer abundance index in mountainous regions. However, despite an inherent risk for observation errors in drive counts, which increase with deer density, evaluations of the utility of drive counts at a high deer density remain scarce. We compared the drive counts and mark-resight (MR methods in the evaluation of a highly dense sika deer population (MR estimates ranged between 11 and 53 individuals/km2 on Nakanoshima Island, Hokkaido, Japan, between 1999 and 2006. This deer population experienced two large reductions in density; approximately 200 animals in total were taken from the population through a large-scale population removal and a separate winter mass mortality event. Although the drive counts tracked temporal changes in deer abundance on the island, they overestimated the counts for all years in comparison to the MR method. Increased overestimation in drive count estimates after the winter mass mortality event may be due to a double count derived from increased deer movement and recovery of body condition secondary to the mitigation of density-dependent food limitations. Drive counts are unreliable because they are affected by unfavorable factors such as bad weather, and they are cost-prohibitive to repeat, which precludes the calculation of confidence intervals. Therefore, the use of drive counts to infer the deer abundance needs to be reconsidered.

  9. Does adversity early in life affect general population suicide rates? a cross-national study

    OpenAIRE

    Ritesh Bhandarkar; Ajit Shah

    2011-01-01

    Abstract: Background: Adversity early in life has been suggested as a protective factor for elderly suicides. However, studies examining this relationship in general population suicide rates are scarce. Methods: The relationship between general population suicide rates and four proxy measures of adversity earlier in life was examined using data from the World Health Organization and the United Nations data banks. Results: General population suicide rates were negatively correlated with the pe...

  10. Disregarding population specificity: its influence on the sex assessment methods from the tibia

    Czech Academy of Sciences Publication Activity Database

    Kotěrová, A.; Velemínská, J.; Dupej, J.; Brzobohatá, Hana; Pilný, A.; Brůžek, J.

    2017-01-01

    Roč. 131, č. 1 (2017), s. 251-261 ISSN 0937-9827 Institutional support: RVO:67985912 Keywords : forensic anthropology population data * sex determination * tibia * population specificity * discriminant function analysis * GAME method Subject RIV: AC - Archeology, Anthropology, Ethnology OBOR OECD: Archaeology Impact factor: 2.382, year: 2016

  11. Genotyping faecal samples of Bengal tiger Panthera tigris tigris for population estimation: A pilot study

    Directory of Open Access Journals (Sweden)

    Singh Lalji

    2006-10-01

    Full Text Available Abstract Background Bengal tiger Panthera tigris tigris the National Animal of India, is an endangered species. Estimating populations for such species is the main objective for designing conservation measures and for evaluating those that are already in place. Due to the tiger's cryptic and secretive behaviour, it is not possible to enumerate and monitor its populations through direct observations; instead indirect methods have always been used for studying tigers in the wild. DNA methods based on non-invasive sampling have not been attempted so far for tiger population studies in India. We describe here a pilot study using DNA extracted from faecal samples of tigers for the purpose of population estimation. Results In this study, PCR primers were developed based on tiger-specific variations in the mitochondrial cytochrome b for reliably identifying tiger faecal samples from those of sympatric carnivores. Microsatellite markers were developed for the identification of individual tigers with a sibling Probability of Identity of 0.005 that can distinguish even closely related individuals with 99.9% certainty. The effectiveness of using field-collected tiger faecal samples for DNA analysis was evaluated by sampling, identification and subsequently genotyping samples from two protected areas in southern India. Conclusion Our results demonstrate the feasibility of using tiger faecal matter as a potential source of DNA for population estimation of tigers in protected areas in India in addition to the methods currently in use.

  12. A genetic association study of the IGF-1 gene and radiological osteoarthritis in a population-based cohort study (the Rotterdam study)

    NARCIS (Netherlands)

    Meulenbelt, I.; Bijkerk, C.; Miedema, H.S.; Breedveld, F.C.; Hofman, A.; Valkenburg, H.A.; Pols, H.A.P.; Slagboom, P.E.; Duijn, C.M. van

    1998-01-01

    Objective - A genetic association study was performed to investigate whether radiographical osteoarthritis (ROA) was associated with specific genotypes of the insulin-like growth factor I (IGF-1) gene. Methods - Subjects aged 55-65 years were selected from a population-based study of which ROA at

  13. A method to assess the population-level consequences of wind energy facilities on bird and bat species: Chapter

    Science.gov (United States)

    Diffendorfer, James E.; Beston, Julie A.; Merrill, Matthew; Stanton, Jessica C.; Corum, Margo D.; Loss, Scott R.; Thogmartin, Wayne E.; Johnson, Douglas H.; Erickson, Richard A.; Heist, Kevin W.

    2016-01-01

    For this study, a methodology was developed for assessing impacts of wind energy generation on populations of birds and bats at regional to national scales. The approach combines existing methods in applied ecology for prioritizing species in terms of their potential risk from wind energy facilities and estimating impacts of fatalities on population status and trend caused by collisions with wind energy infrastructure. Methods include a qualitative prioritization approach, demographic models, and potential biological removal. The approach can be used to prioritize species in need of more thorough study as well as to identify species with minimal risk. However, the components of this methodology require simplifying assumptions and the data required may be unavailable or of poor quality for some species. These issues should be carefully considered before using the methodology. The approach will increase in value as more data become available and will broaden the understanding of anthropogenic sources of mortality on bird and bat populations.

  14. Respondent-driven sampling (rds as a new method to access vulnerable populations to hiv: its application in men who have sex with men

    Directory of Open Access Journals (Sweden)

    John H. Estrada M

    2010-11-01

    Full Text Available Approximately 30 million people are living with hiv all around the world in 2010. The most vulnerable hiv/aids groups are sex workers, intravenous drug users, transgender people and population of men who have sex with men (msm. Up to now, the surveillance and behavioral studies on sexual transmitted diseases (sti and hiv have been conducted using intentional sampling methods like the snowball methodology, but this kind of sampling does not achieve representation and does not represent a conclusive method for the study of hidden populations in order to extend and apply its results to the general population. Furthermore, it is necessary to add to this limitation the lack of knowledge about the size of these groups that must face situations of stigma and discrimination. A decade ago a new method was designed to sample hidden and hard to reach populations based on Markov theories and on chain recruitment. This new method is known as respondent-driven sampling (rds and it has been used in several behavioral and hiv prevalence studies. This review article presents the background, the theoretical support and a description of the method. It also analyzes some studies carried out using this new methodology.

  15. Stochastic weighted particle methods for population balance equations with coagulation, fragmentation and spatial inhomogeneity

    International Nuclear Information System (INIS)

    Lee, Kok Foong; Patterson, Robert I.A.; Wagner, Wolfgang; Kraft, Markus

    2015-01-01

    Graphical abstract: -- Highlights: •Problems concerning multi-compartment population balance equations are studied. •A class of fragmentation weight transfer functions is presented. •Three stochastic weighted algorithms are compared against the direct simulation algorithm. •The numerical errors of the stochastic solutions are assessed as a function of fragmentation rate. •The algorithms are applied to a multi-dimensional granulation model. -- Abstract: This paper introduces stochastic weighted particle algorithms for the solution of multi-compartment population balance equations. In particular, it presents a class of fragmentation weight transfer functions which are constructed such that the number of computational particles stays constant during fragmentation events. The weight transfer functions are constructed based on systems of weighted computational particles and each of it leads to a stochastic particle algorithm for the numerical treatment of population balance equations. Besides fragmentation, the algorithms also consider physical processes such as coagulation and the exchange of mass with the surroundings. The numerical properties of the algorithms are compared to the direct simulation algorithm and an existing method for the fragmentation of weighted particles. It is found that the new algorithms show better numerical performance over the two existing methods especially for systems with significant amount of large particles and high fragmentation rates.

  16. Stochastic weighted particle methods for population balance equations with coagulation, fragmentation and spatial inhomogeneity

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kok Foong [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge CB2 3RA (United Kingdom); Patterson, Robert I.A.; Wagner, Wolfgang [Weierstrass Institute for Applied Analysis and Stochastics, Mohrenstraße 39, 10117 Berlin (Germany); Kraft, Markus, E-mail: mk306@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge CB2 3RA (United Kingdom); School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459 (Singapore)

    2015-12-15

    Graphical abstract: -- Highlights: •Problems concerning multi-compartment population balance equations are studied. •A class of fragmentation weight transfer functions is presented. •Three stochastic weighted algorithms are compared against the direct simulation algorithm. •The numerical errors of the stochastic solutions are assessed as a function of fragmentation rate. •The algorithms are applied to a multi-dimensional granulation model. -- Abstract: This paper introduces stochastic weighted particle algorithms for the solution of multi-compartment population balance equations. In particular, it presents a class of fragmentation weight transfer functions which are constructed such that the number of computational particles stays constant during fragmentation events. The weight transfer functions are constructed based on systems of weighted computational particles and each of it leads to a stochastic particle algorithm for the numerical treatment of population balance equations. Besides fragmentation, the algorithms also consider physical processes such as coagulation and the exchange of mass with the surroundings. The numerical properties of the algorithms are compared to the direct simulation algorithm and an existing method for the fragmentation of weighted particles. It is found that the new algorithms show better numerical performance over the two existing methods especially for systems with significant amount of large particles and high fragmentation rates.

  17. Genetic study of scheduled caste populations of Tamil Nadu

    Indian Academy of Sciences (India)

    Their traditional occupations are sweeping ... computed by gene counting method. ... method. Population relationships were also analysed via. PCA, using SPSS 11.0 version. .... series volume V, Anthropological survey of India, Oxford Uni-.

  18. Comparative study of different methods used in assessment of population exposure to external environmental radiation

    International Nuclear Information System (INIS)

    Niewiadomski, T.

    1979-08-01

    Doses received by individuals and population from terrestial radiation sources were estimated using three approaches, 1) measurements of dose rates, 2) calculations on the basis of spectrometric analysis of the soil or local radiation field and 3) integrating dosimeters. The 1st approach was carried out by means of pressurised ionization chambers, scintillation counters or GM counters properly calibrated, and also by supplying individuals with dosimetric or radiometric instruments. The data for calculation assessment was based on measurements of dose rates both outdoors and indoors and often taken from spectrometric analysis of natural radionuclide. Several equations and calculation factors have been derived and computer programs developed for calculating the concentration of radionuclides in question and for estimating dose rates in π or 2π geometries. Integrating measurements were carried out using TL dosimeters. To assess the reliability of the methods, comparative measurements were carried out at statistically representative number of locations using a wide choice of techniques. The detailed methods used and the equipment are described in the research programme as well as the results of the measurements. The most reliable results are these obtained when measurements are carried out over a long period of time, e.g. one year

  19. Population studies of sporadic cerebral amyloid angiopathy and dementia: a systematic review

    Directory of Open Access Journals (Sweden)

    Wharton Stephen B

    2009-01-01

    Full Text Available Abstract Background Deposition of amyloid-β (Aβ in vessel walls of the brain as cerebral amyloid angiopathy (CAA could be a major factor in the pathogenesis of dementia. Here we investigate the relationship between dementia and the prevalence of CAA in older populations. We searched the literature for prospective population-based epidemiological clinicopathological studies, free of the biases of other sampling techniques, which were used as a comparison. Methods To identify population-based studies assessing CAA and dementia, a previous systematic review of population-based clinicopathological studies of ageing and dementia was employed. To identify selected-sample studies, PsychInfo (1806–April Week 3 2008, OVID MEDLINE (1950–April Week 2 2008 and Pubmed (searched 21 April 2008 databases were searched using the term "amyloid angiopathy". These databases were also employed to search for any population-based studies not included in the previous systematic review. Studies were included if they reported the prevalence of CAA relative to a dementia classification (clinical or neuropathological. Results Four population-based studies were identified. They showed that on average 55–59% of those with dementia displayed CAA (of any severity compared to 28–38% of the non-demented. 37–43% of the demented displayed severe CAA in contrast to 7–24% of the non-demented. There was no overlap in the range of these averages and they were less variable and lower than those reported in 38 selected sample studies (demented v non-demented: 32–100 v 0–77% regardless of severity; 0–50 v 0–11% for severe only. Conclusion CAA prevalence in populations is consistently higher in the demented as compared to the non-demented. This supports a significant role for CAA in the pathogenesis of dementia.

  20. Estimating population cause-specific mortality fractions from in-hospital mortality: validation of a new method.

    Directory of Open Access Journals (Sweden)

    Christopher J L Murray

    2007-11-01

    Full Text Available Cause-of-death data for many developing countries are not available. Information on deaths in hospital by cause is available in many low- and middle-income countries but is not a representative sample of deaths in the population. We propose a method to estimate population cause-specific mortality fractions (CSMFs using data already collected in many middle-income and some low-income developing nations, yet rarely used: in-hospital death records.For a given cause of death, a community's hospital deaths are equal to total community deaths multiplied by the proportion of deaths occurring in hospital. If we can estimate the proportion dying in hospital, we can estimate the proportion dying in the population using deaths in hospital. We propose to estimate the proportion of deaths for an age, sex, and cause group that die in hospital from the subset of the population where vital registration systems function or from another population. We evaluated our method using nearly complete vital registration (VR data from Mexico 1998-2005, which records whether a death occurred in a hospital. In this validation test, we used 45 disease categories. We validated our method in two ways: nationally and between communities. First, we investigated how the method's accuracy changes as we decrease the amount of Mexican VR used to estimate the proportion of each age, sex, and cause group dying in hospital. Decreasing VR data used for this first step from 100% to 9% produces only a 12% maximum relative error between estimated and true CSMFs. Even if Mexico collected full VR information only in its capital city with 9% of its population, our estimation method would produce an average relative error in CSMFs across the 45 causes of just over 10%. Second, we used VR data for the capital zone (Distrito Federal and Estado de Mexico and estimated CSMFs for the three lowest-development states. Our estimation method gave an average relative error of 20%, 23%, and 31% for

  1. Error baseline rates of five sample preparation methods used to characterize RNA virus populations.

    Directory of Open Access Journals (Sweden)

    Jeffrey R Kugelman

    Full Text Available Individual RNA viruses typically occur as populations of genomes that differ slightly from each other due to mutations introduced by the error-prone viral polymerase. Understanding the variability of RNA virus genome populations is critical for understanding virus evolution because individual mutant genomes may gain evolutionary selective advantages and give rise to dominant subpopulations, possibly even leading to the emergence of viruses resistant to medical countermeasures. Reverse transcription of virus genome populations followed by next-generation sequencing is the only available method to characterize variation for RNA viruses. However, both steps may lead to the introduction of artificial mutations, thereby skewing the data. To better understand how such errors are introduced during sample preparation, we determined and compared error baseline rates of five different sample preparation methods by analyzing in vitro transcribed Ebola virus RNA from an artificial plasmid-based system. These methods included: shotgun sequencing from plasmid DNA or in vitro transcribed RNA as a basic "no amplification" method, amplicon sequencing from the plasmid DNA or in vitro transcribed RNA as a "targeted" amplification method, sequence-independent single-primer amplification (SISPA as a "random" amplification method, rolling circle reverse transcription sequencing (CirSeq as an advanced "no amplification" method, and Illumina TruSeq RNA Access as a "targeted" enrichment method. The measured error frequencies indicate that RNA Access offers the best tradeoff between sensitivity and sample preparation error (1.4-5 of all compared methods.

  2. Error baseline rates of five sample preparation methods used to characterize RNA virus populations

    Science.gov (United States)

    Kugelman, Jeffrey R.; Wiley, Michael R.; Nagle, Elyse R.; Reyes, Daniel; Pfeffer, Brad P.; Kuhn, Jens H.; Sanchez-Lockhart, Mariano; Palacios, Gustavo F.

    2017-01-01

    Individual RNA viruses typically occur as populations of genomes that differ slightly from each other due to mutations introduced by the error-prone viral polymerase. Understanding the variability of RNA virus genome populations is critical for understanding virus evolution because individual mutant genomes may gain evolutionary selective advantages and give rise to dominant subpopulations, possibly even leading to the emergence of viruses resistant to medical countermeasures. Reverse transcription of virus genome populations followed by next-generation sequencing is the only available method to characterize variation for RNA viruses. However, both steps may lead to the introduction of artificial mutations, thereby skewing the data. To better understand how such errors are introduced during sample preparation, we determined and compared error baseline rates of five different sample preparation methods by analyzing in vitro transcribed Ebola virus RNA from an artificial plasmid-based system. These methods included: shotgun sequencing from plasmid DNA or in vitro transcribed RNA as a basic “no amplification” method, amplicon sequencing from the plasmid DNA or in vitro transcribed RNA as a “targeted” amplification method, sequence-independent single-primer amplification (SISPA) as a “random” amplification method, rolling circle reverse transcription sequencing (CirSeq) as an advanced “no amplification” method, and Illumina TruSeq RNA Access as a “targeted” enrichment method. The measured error frequencies indicate that RNA Access offers the best tradeoff between sensitivity and sample preparation error (1.4−5) of all compared methods. PMID:28182717

  3. An evaluation of the methods of determining excited state population distributions from sputtering sources

    International Nuclear Information System (INIS)

    Snowdon, K.J.; Andresen, B.; Veje, E.

    1978-01-01

    The method of calculating relative initial level populations of excited states of sputtered atoms is developed in principle and compared with those in current use. The reason that the latter, although mathematically different, have generally led to similar population distributions is outlined. (Auth.)

  4. The COLOFOL trial: study design and comparison of the study population with the source cancer population

    Directory of Open Access Journals (Sweden)

    Hansdotter Andersson P

    2016-01-01

    Full Text Available Pernilla Hansdotter Andersson,1 Peer Wille-Jørgensen,2 Erzsébet Horváth-Puhó,3 Sune Høirup Petersen,2 Anna Martling,4 Henrik Toft Sørensen,3 Ingvar Syk1 On behalf of the COLOFOL Study Group 1Department of Surgery, Skåne University Hospital, Malmö, Sweden; 2Abdominal Disease Center K, Bispebjerg University Hospital, Copenhagen, Denmark; 3Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 4Department of Molecular Medicine and Surgery, Karolinska Institutet, Solna, Sweden Introduction: The COLOFOL trial, a prospective randomized multicenter trial comparing two follow-up regimes after curative surgical treatment for colorectal cancer, focuses on detection of asymptomatic recurrences. This paper aims to describe the design and recruitment procedure in the COLOFOL trial, comparing demographic characteristics between randomized patients and eligible patients not included in the study. Materials and methods: COLOFOL was designed as a pragmatic trial with wide inclusion criteria and few exclusion criteria, in order to obtain a sample reflecting the general patient population. To be eligible, patients had to be 75 years or younger and curatively resected for stage II or III colorectal cancer. Exclusion criteria were hereditary colorectal cancer, no signed consent, other malignancy, and life expectancy less than 2 years due to concomitant disease. In four of the 24 participating centers, we scrutinized hospital inpatient data to identify all colorectal cancer patients who underwent surgery, in order to ascertain all eligible patients who were not included in the study and to compare them with enrolled patients. Results: Of a total of 4,445 eligible patients, 2,509 patients were randomized (56.4% inclusion rate. A total of 1,221 eligible patients were identified in the scrutinized hospitals, of which 684 (56% were randomized. No difference in age or sex distribution was observed between randomized and nonrandomized

  5. Molecular Markers for Genetic Diversity Studies of European Hare (Lepus europaeus Pallas, 1778 Populations

    Directory of Open Access Journals (Sweden)

    Noémi Soós

    2015-05-01

    Full Text Available The purpose of this article is to give an overview of different molecular techniques which have been used in studies concerning population genetic issues of Lepus species and specifically of L. europaeus. The importance of these researches is ever-growing as the European populations of the brown hare have suffered several falloffs as a consequent upon both natural and anthropogenic effects. With developing tools and techniques molecular genetics have become the centrepiece of population genetics and conservation biology. Nucleic acid methods based on both bi- and uniparentally inherited DNA (allozymes, microsatellites, Y chromosome, mtDNA are often used to study genetic structure, diversity and phylogeography of different species’ populations due to their effectiveness in identifying genetic variability

  6. Lattice Boltzmann method with the cell-population equilibrium

    International Nuclear Information System (INIS)

    Zhou Xiaoyang; Cheng Bing; Shi Baochang

    2008-01-01

    The central problem of the lattice Boltzmann method (LBM) is to construct a discrete equilibrium. In this paper, a multi-speed 1D cell-model of Boltzmann equation is proposed, in which the cell-population equilibrium, a direct non-negative approximation to the continuous Maxwellian distribution, plays an important part. By applying the explicit one-order Chapman–Enskog distribution, the model reduces the transportation and collision, two basic evolution steps in LBM, to the transportation of the non-equilibrium distribution. Furthermore, 1D dam-break problem is performed and the numerical results agree well with the analytic solutions

  7. Infertility experience and health differentials - a population-based comparative study on infertile and non-infertile women (the HUNT Study)

    DEFF Research Database (Denmark)

    Rostad, Berit; Schmidt, Lone; Sundby, Johanne

    2014-01-01

    between infertility and health and life satisfaction. DESIGN: Cross-sectional population-based health study, conducted between 2006 and 2008. SETTING: All women in a county in Norway were invited. The current material is restricted to women aged 20-49 years. POPULATION: A total of 9200 women participated......OBJECTIVE: Studies suggest that health complaints, distress and poor life satisfaction are associated with infertility experience. Research on health consequences of infertility experience in women has relied heavily on clinic-based samples. This population-based study investigates the association....... METHODS: Health measures were compared between women with infertility experience (infertile women) and women without infertility experience (non-infertile women). Disparities in health and life satisfaction among the infertile women were assessed. MAIN OUTCOME MEASURES: Self-reported health, functional...

  8. Accuracy, precision, and economic efficiency for three methods of thrips (Thysanoptera: Thripidae) population density assessment.

    Science.gov (United States)

    Sutherland, Andrew M; Parrella, Michael P

    2011-08-01

    Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a major horticultural pest and an important vector of plant viruses in many parts of the world. Methods for assessing thrips population density for pest management decision support are often inaccurate or imprecise due to thrips' positive thigmotaxis, small size, and naturally aggregated populations. Two established methods, flower tapping and an alcohol wash, were compared with a novel method, plant desiccation coupled with passive trapping, using accuracy, precision and economic efficiency as comparative variables. Observed accuracy was statistically similar and low (37.8-53.6%) for all three methods. Flower tapping was the least expensive method, in terms of person-hours, whereas the alcohol wash method was the most expensive. Precision, expressed by relative variation, depended on location within the greenhouse, location on greenhouse benches, and the sampling week, but it was generally highest for the flower tapping and desiccation methods. Economic efficiency, expressed by relative net precision, was highest for the flower tapping method and lowest for the alcohol wash method. Advantages and disadvantages are discussed for all three methods used. If relative density assessment methods such as these can all be assumed to accurately estimate a constant proportion of absolute density, then high precision becomes the methodological goal in terms of measuring insect population density, decision making for pest management, and pesticide efficacy assessments.

  9. Suicide after traumatic brain injury: a population study

    DEFF Research Database (Denmark)

    Teasdale, T W; Engberg, A W

    2001-01-01

    OBJECTIVES: To determine the rates of suicide among patients who have had a traumatic brain injury. METHODS: From a Danish population register of admissions to hospital covering the years 1979-93 patients were selected who had had either a concussion (n=126 114), a cranial fracture (n=7560......), or a cerebral contusion or traumatic intracranial haemorrhage (n=11 766). All cases of deaths by the end of the study period were identified. RESULTS: In the three diagnostic groups there had been 750 (0.59%), 46 (0.61%), and 99 (0.84%) cases of suicide respectively. Standardised mortality ratios, stratified...... by sex and age, showed that the incidence of suicide among the three diagnostic groups was increased relative to the general population (3.0, 2.7, and 4.1 respectively). In all diagnosis groups the ratios were higher for females than for males, and lower for patients injured before the age of 21 or after...

  10. Characterizing Adult Sleep Behavior Over 20 Years-The Population-Based Doetinchem Cohort Study

    NARCIS (Netherlands)

    Zomers, Margot L; Hulsegge, Gerben; van Oostrom, Sandra H; Proper, Karin I.; Verschuren, W M Monique; Picavet, H. Susan J

    2017-01-01

    Study Objectives: To describe sleep duration patterns of adults over a 20-year period; to compare sociodemographic, lifestyle, and health characteristics across these patterns; and to relate the patterns to sleep quality. Methods: The study population consisted of 3695 adults aged 20 to 59 years at

  11. The etiology of autistic traits in preschoolers : a population-based twin study

    NARCIS (Netherlands)

    de Zeeuw, E.L.; van Beijsterveldt, Catharina E M; Hoekstra, Rosa A; Bartels, Meike; Boomsma, Dorret I

    2017-01-01

    BACKGROUND: Autism Spectrum Disorders (ASD) are highly heritable, but the exact etiological mechanisms underlying the condition are still unclear. METHODS: Using a multiple rater twin design in a large sample of general population preschool twins, this study aimed to (a) estimate the contribution of

  12. Artificial nests as an alternative to studies of arboreal small mammal populations: a five-year study in the Atlantic Forest, Brazil

    Directory of Open Access Journals (Sweden)

    Diogo Loretto

    2011-06-01

    Full Text Available Despite the great diversity of Brazilian Atlantic forest small mammals, natural history of most species is unknown due to their cryptic and nocturnal habits, but also due to the inadequacy of methods to capture some species, especially those of arboreal habits. A new technique, based on the use of artificial nests (AN to record arboreal marsupials, is presented. Artificial nests were combined with traditional live traps to study the population ecology of four didelphid marsupial species. After 62 months of monitoring, 119 individuals were recorded 243 times (total success = 5.2%. Only 26 individuals (22% were recorded by both AN and live trap methods, and two of the four species were never captured by live traps, only by AN. Live traps alone would have provided biased data of the structure of small mammal assemblages, creating artificial tendencies in population dynamics of many species. Detectability estimates based on mark-recapture data could correct bias resulting from the use only live traps, but these estimates require that at least some individuals of each age class or stage are captured. Only the combination of AN and live traps can produce more accurate data on population dynamics and assemblage structure. This study demonstrates that artificial nests represent a new method that should be combined with live traps in studies of small mammal assemblages and populations.

  13. On estimation of time-dependent attributable fraction from population-based case-control studies.

    Science.gov (United States)

    Zhao, Wei; Chen, Ying Qing; Hsu, Li

    2017-09-01

    Population attributable fraction (PAF) is widely used to quantify the disease burden associated with a modifiable exposure in a population. It has been extended to a time-varying measure that provides additional information on when and how the exposure's impact varies over time for cohort studies. However, there is no estimation procedure for PAF using data that are collected from population-based case-control studies, which, because of time and cost efficiency, are commonly used for studying genetic and environmental risk factors of disease incidences. In this article, we show that time-varying PAF is identifiable from a case-control study and develop a novel estimator of PAF. Our estimator combines odds ratio estimates from logistic regression models and density estimates of the risk factor distribution conditional on failure times in cases from a kernel smoother. The proposed estimator is shown to be consistent and asymptotically normal with asymptotic variance that can be estimated empirically from the data. Simulation studies demonstrate that the proposed estimator performs well in finite sample sizes. Finally, the method is illustrated by a population-based case-control study of colorectal cancer. © 2017, The International Biometric Society.

  14. Study design and statistical analysis of data in human population studies with the micronucleus assay.

    Science.gov (United States)

    Ceppi, Marcello; Gallo, Fabio; Bonassi, Stefano

    2011-01-01

    The most common study design performed in population studies based on the micronucleus (MN) assay, is the cross-sectional study, which is largely performed to evaluate the DNA damaging effects of exposure to genotoxic agents in the workplace, in the environment, as well as from diet or lifestyle factors. Sample size is still a critical issue in the design of MN studies since most recent studies considering gene-environment interaction, often require a sample size of several hundred subjects, which is in many cases difficult to achieve. The control of confounding is another major threat to the validity of causal inference. The most popular confounders considered in population studies using MN are age, gender and smoking habit. Extensive attention is given to the assessment of effect modification, given the increasing inclusion of biomarkers of genetic susceptibility in the study design. Selected issues concerning the statistical treatment of data have been addressed in this mini-review, starting from data description, which is a critical step of statistical analysis, since it allows to detect possible errors in the dataset to be analysed and to check the validity of assumptions required for more complex analyses. Basic issues dealing with statistical analysis of biomarkers are extensively evaluated, including methods to explore the dose-response relationship among two continuous variables and inferential analysis. A critical approach to the use of parametric and non-parametric methods is presented, before addressing the issue of most suitable multivariate models to fit MN data. In the last decade, the quality of statistical analysis of MN data has certainly evolved, although even nowadays only a small number of studies apply the Poisson model, which is the most suitable method for the analysis of MN data.

  15. Feeding methods, sleep arrangement, and infant sleep patterns: a Chinese population-based study.

    Science.gov (United States)

    Huang, Xiao-Na; Wang, Hui-Shan; Chang, Jen-Jen; Wang, Lin-Hong; Liu, Xi-Cheng; Jiang, Jing-Xiong; An, Lin

    2016-02-01

    Findings from prior research into the effect of feeding methods on infant sleep are inconsistent. The objectives of this study were to examine infants' sleep patterns by feeding methods and sleep arrangement from birth to eight months old. This longitudinal cohort study enrolled 524 pregnant women at 34-41 weeks of gestation and their infants after delivery in 2006 and followed up until eight months postpartum. The study subjects were recruited from nine women and children hospitals in nine cities in China (Beijing, Chongqing, Wuhan, Changsha, Nanning, Xiamen, Xi'an, Jinan, and Hailin). Participating infants were followed up weekly during the first month and monthly from the second to the eighth month after birth. Twenty-four hour sleep diaries recording infants' sleeping and feeding methods were administered based on caregiver's self-report. Multivariable mixed growth curve models were fitted to estimate the effects of feeding methods and sleep arrangement on infants' sleep patterns over time, controlling for maternal and paternal age, maternal and paternal education level, household income, supplementation of complementary food, and infant birth weight and length. Exclusively formula fed infants had the greatest sleep percentage/24 h, followed by exclusively breast milk fed infants and partially breast milk fed infants (Psleep percentage and night waking frequency between exclusively formula and exclusively breast milk fed infants weakened over time as infants developed. In addition, compared to infants with bed-sharing sleep arrangement, those with room sharing sleep arrangement had greater daytime and 24-hour infant sleep percentage, whereas those with sleeping alone sleep arrangement had greater nighttime sleep percentage. Our data based on caregiver's self-report suggested that partial breastfeeding and bed-sharing may be associated with less sleep in infants. Health care professionals need to work with parents of newborns to develop coping strategies that

  16. Methods of estimating population exposures from Plowshare applications

    Energy Technology Data Exchange (ETDEWEB)

    Kaye, S V; Rohwer, P S [Health Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1969-07-01

    When estimating doses to populations it is necessary to divide the total population into groups that have parameters of similar type and magnitude in order to identify critical population groups. Age groups constitute the most basic and generally useful way of dividing the total population for estimating dose. Models for estimating dose, particularly the internal dose from inhalation and ingestion of radioactivity, should be written as a function of age. The importance of considering age-dependency is emphasized by the fact that some of the internal dose parameters change by much as a factor of ten for some radionuclides when comparing a one year old with an adult. A computer code called INREM has been written which can consider all internal dose parameters as a function of age. The major imitation in using this computer code for all radionuclides is the paucity of age-dependent input data for many radionuclides. Tritium, iodine, cesium, and strontium have been studied in detail with INREM and the results and interpretations are discussed. Another code, EXREM, computes the external dose rates and cumulative doses from both beta particles and gamma photons from submersion in a radioactive cloud, submersion in contaminated water and exposure above a contaminated land surface. This code can consider up to 25 Plowshare detonations and a variety of combinations for calculating doses and dose rates in relation to a detonation schedule. The importance of using both INREM and EXREM to estimate the total dose to a population group is stressed. (author)

  17. Methods of estimating population exposures from Plowshare applications

    International Nuclear Information System (INIS)

    Kaye, S.V.; Rohwer, P.S.

    1969-01-01

    When estimating doses to populations it is necessary to divide the total population into groups that have parameters of similar type and magnitude in order to identify critical population groups. Age groups constitute the most basic and generally useful way of dividing the total population for estimating dose. Models for estimating dose, particularly the internal dose from inhalation and ingestion of radioactivity, should be written as a function of age. The importance of considering age-dependency is emphasized by the fact that some of the internal dose parameters change by much as a factor of ten for some radionuclides when comparing a one year old with an adult. A computer code called INREM has been written which can consider all internal dose parameters as a function of age. The major imitation in using this computer code for all radionuclides is the paucity of age-dependent input data for many radionuclides. Tritium, iodine, cesium, and strontium have been studied in detail with INREM and the results and interpretations are discussed. Another code, EXREM, computes the external dose rates and cumulative doses from both beta particles and gamma photons from submersion in a radioactive cloud, submersion in contaminated water and exposure above a contaminated land surface. This code can consider up to 25 Plowshare detonations and a variety of combinations for calculating doses and dose rates in relation to a detonation schedule. The importance of using both INREM and EXREM to estimate the total dose to a population group is stressed. (author)

  18. Screening for type 2 diabetes in a high-risk population: Study design and feasibility of a population-based randomized controlled trial

    NARCIS (Netherlands)

    B. Klijs (Bart); S.J. Otto (Suzie); R.J. Heine (Robert); Y. van der Graaf (Yolanda); J.J. Lous (Jan); H.J. de Koning (Harry)

    2012-01-01

    textabstractBackground: We describe the design and present the results of the first year of a population-based study of screening for type 2 diabetes in individuals at high risk of developing the disease. High risk is defined as having abdominal obesity. Methods. Between 2006 and 2007, 79,142

  19. Primary mucinous carcinoma of the skin: a population-based study

    DEFF Research Database (Denmark)

    Breiting, L.; Dahlstrom, K.; Breiting, V.

    2008-01-01

    Background Primary mucinous carcinoma of the skin (PMCS) is a rare malignant tumor deriving from the sweat glands. It is typically located on the head and is often mistaken for a metastasis from a more common primary tumor of the breast or gastrointestinal tract. We present the first population......-based study of PMCS. Materials and methods Data on PMCS was obtained from the Danish Cancer Registry, which has recorded incident cases of cancer on a nationwide basis since 1943. We extracted all patients diagnosed 1978-2003 with PMCS. Results Fifteen cases of PMCS have been registered during the study...... or PMCS related deaths were reported. Conclusion PMCS is a rare, slow-growing tumor which rarely metastasizes and is associated with low mortality. The age-standardized incidence rate, based on data from a population-based cancer registry of high quality and validity, is less than 0.1 per million. However...

  20. Enabling the participation of marginalized populations: case studies from a health service organization in Ontario, Canada.

    Science.gov (United States)

    Montesanti, Stephanie R; Abelson, Julia; Lavis, John N; Dunn, James R

    2017-08-01

    We examined efforts to engage marginalized populations in Ontario Community Health Centers (CHCs), which are primary health care organizations serving 74 high-risk communities. Qualitative case studies of community participation in four Ontario CHCs were carried out through key informant interviews with CHC staff to identify: (i) the approaches, strategies and methods used in participation initiatives aimed specifically at engaging marginalized populations in the planning of and decision making for health services; and (ii) the challenges and enablers for engaging these populations. The marginalized populations involved in the community participation initiatives studied included Low-German Speaking Mennonites in a rural town, newcomer immigrants and refugees in an urban downtown city, immigrant and francophone seniors in an inner city and refugee women in an inner city. Our analysis revealed that enabling the participation of marginalized populations requires CHCs to attend to the barriers experienced by marginalized populations that constrain their participation. Key informants outlined the features of a 'community development approach' that they rely on to address the barriers to marginalized peoples' involvement by strengthening their skills, abilities and leadership in capacity-building activities. The community development approach also shaped the participation methods that were used in the engagement process of CHCs. However, key informants also described the challenges of applying this approach, influenced by the cultural values of some groups, which shaped their willingness and motivation to participate. This study provides further insight into the approach, strategies and methods used in the engagement process to enable the participation of marginalized populations, which may be transferable to other health services settings. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Evidence for Association of the E23K Variant of KCNJ11 Gene with Type 2 Diabetes in Tunisian Population: Population-Based Study and Meta-Analysis

    OpenAIRE

    Lasram, Khaled; Ben Halim, Nizar; Hsouna, Sana; Kefi, Rym; Arfa, Imen; Ghazouani, Welid; Jamoussi, Henda; Benrahma, Houda; Kharrat, Najla; Rebai, Ahmed; Ben Ammar, Slim; Bahri, Sonia; Barakat, Abdelhamid; Abid, Abdelmajid; Abdelhak, Sonia

    2014-01-01

    Aims. Genetic association studies have reported the E23K variant of KCNJ11 gene to be associated with Type 2 diabetes. In Arab populations, only four studies have investigated the role of this variant. We aimed to replicate and validate the association between the E23K variant and Type 2 diabetes in Tunisian and Arab populations. Methods. We have performed a case-control association study including 250 Tunisian patients with Type 2 diabetes and 267 controls. Allelic association has also been ...

  2. Theoretical study of atomic structure of Zpopulations in a hot plasma and population inversions

    International Nuclear Information System (INIS)

    Guennou, Helene.

    1983-05-01

    This thesis presents a theoretical method for atomic-structure calculations (energy levels, wave functions, oscillator strengths): it is a modified Hartree-Fock method including the spin-orbit interaction in the variationnal process. Two applications are first described: one concerning the resonance lines of the Krypton isoelectronic sequence, the other having for purpose the interpretation of Lsub(α) and Lsub(β) satellites in Copper. A description is made of an original collisional-radiative model, which makes use of the preceding method, and allows to calculate the populations of a great number of ionic excited levels in a plasma. This model is used in a detailed study of the Al 10+ Lithium -like ion spectrum. It is able to explain the apparition of inversion populations for some special electronic densities and temperatures, for example between the levels corresponding to the transitions observed at 103.8, 105.7 and 154.7 A [fr

  3. Pneumococcal serotypes and mortality following invasive pneumococcal disease: a population-based cohort study

    DEFF Research Database (Denmark)

    Harboe, Zitta B; Thomsen, Reimar W; Riis, Anders

    2009-01-01

    BACKGROUND: Pneumococcal disease is a leading cause of morbidity and mortality worldwide. The aim of this study was to investigate the association between specific pneumococcal serotypes and mortality from invasive pneumococcal disease (IPD). METHODS AND FINDINGS: In a nationwide population-based...

  4. Epidemiology of multiple congenital anomalies in Europe: A EUROCAT population-based registry study

    DEFF Research Database (Denmark)

    Calzolari, Elisa; Barisic, Ingeborg; Loane, Maria

    2014-01-01

    BACKGROUND: This study describes the prevalence, associated anomalies, and demographic characteristics of cases of multiple congenital anomalies (MCA) in 19 population-based European registries (EUROCAT) covering 959,446 births in 2004 and 2010. METHODS: EUROCAT implemented a computer algorithm f...

  5. Screening for type 2 diabetes in a high-risk population: study design and feasibility of a population-based randomized controlled trial

    NARCIS (Netherlands)

    Klijs, B.; Otto, S.J.; Heine, R.J.; van der Graaf, Y.; Lous, J.J.; Koning, H.J.

    2012-01-01

    Background: We describe the design and present the results of the first year of a population-based study of screening for type 2 diabetes in individuals at high risk of developing the disease. High risk is defined as having abdominal obesity. Methods. Between 2006 and 2007, 79,142 inhabitants of two

  6. Study on the IFNL4 gene ss469415590 variant in Ukrainian population

    Directory of Open Access Journals (Sweden)

    Kucherenko A. M.

    2014-09-01

    Full Text Available Aim. To determine genotype and allele disribution for the IFNL4 gene ss469415590 and examine it for linkage with the IL28B gene rs12979860 in Ukrainian population. Methods. The studied group consisted of 100 unrelated donors of Eastern European origin representing the population of Ukraine. Genotyping for the IFNL4 gene ss469415590 was performed using the amplification-refractory mutation system PCR. Genotyping for the IL28B gene rs12979860 was performed by the PCR-based restriction fragment length polymorphism assay. Results. Genotype frequencies for both studied variants showed no significant deviation from those expected according to Hardy-Weinberg equilibrium. Allelic distribution for ss469415590 was: TT – 0.665, G – 0.335. Allelic frequencies of rs12979860 were: C – 0.655, T – 0.345. The results of likelihood ratio test indicated a linkage disequilibrium between the studied variants (p > 0.0001, the major alleles ss469415590 TT and rs12979860 C were in phase. The genetic structure of Ukrainian population in terms of two studied polymorphic variants is similar to the European population presented in the «1000 genomes» project. Conclusions. Considering a tight linkage revealed in Ukrainian population between the ss469415590 variant and rs12979860, a crucial genetic marker of chronic hepatitis C treatment efficiency, this polymorphism might be a promising target for further investigation as a pharmacogenetic marker.

  7. Variations in suicide method and in suicide occurrence by season and day of the week in Russia and the Nenets Autonomous Okrug, Northwestern Russia: a retrospective population-based mortality study.

    Science.gov (United States)

    Sumarokov, Yury A; Brenn, Tormod; Kudryavtsev, Alexander V; Nilssen, Odd

    2015-09-23

    Suicide is an important world health issue, especially in territories inhabited by indigenous people. This investigated differences in suicide rates, suicide methods, and suicide occurrence by month and day of the week among the indigenous and non-indigenous populations of the Nenets Autonomous Okrug (NAO) and to compare the findings from the NAO with national Russian statistics. In this retrospective population-based mortality study we investigated all suicides that occurred in the NAO in 2002-2012 (N = 252). Suicide method and the month and day of the week suicide occurred was taken from autopsy reports and disaggregated by ethnic group (indigenous and non-indigenous) and sex. Data from the NAO were then compared with national data from the Russian Federal Statistics Service (Rosstat). Hanging was the most common suicide method in the NAO in both indigenous and non-indigenous populations. The proportion of suicides by hanging among males was lower in the NAO than in national data (69.3 vs 86.2 %), but the inverse was true for females (86.5 vs 74.9 %). Suicide by firearm and by cutting was significantly higher among the indigenous population in the NAO when compared with national data. Peaks in suicide occurrence were observed in May and September in the NAO, whereas national data showed only one peak in May. Suicide occurrence in the indigenous population of the NAO was highest in April, while the non-indigenous population showed peaks in May and September. Suicide occurrence in the NAO was highest on Fridays; in national data this occurrence was highest on Mondays. We showed different relative frequencies of suicide by hanging, cutting, and firearm, as well as different suicide occurrence by month and day of the week in the NAO compared with Russia as a whole. These results can be used to plan suicide prevention activities in the Russian Arctic.

  8. Complementary methods to estimate population size of Antillean Manatees (Sirenia: Trichechidae at Cienaga de Paredes, Santander, Colombia

    Directory of Open Access Journals (Sweden)

    G.K. Arevalo-Gonzalez

    2014-06-01

    Full Text Available Information on manatee population size in Colombia is limited. This study was aimed at determining manatee population size in the Cienaga de Paredes (Colombia by three different methods: boat-based surveys, side-scan Sonar (SSS surveys and local interviews. Manatees were counted during breathing events by direct observation during the dry season, with the number of sightings per hour (NSH and maximum number of simultaneous sightings (MNSS used as occurrence indices. In 2002, we obtained an average NSH of 27.62 (SD=12.34 and the MNSS was 18; in 2010 the values were 55.71 (SD=29.79 and four respectively. Using linear-transect SSS data we estimated a population size of 12 individuals (%CV=27.3. The local community claimed that no hunting or entanglements had taken place in the area for over 20 years. These methods have pros and cons in terms of investment, effort, efficiency and community involvement, and their efficiency may vary in different seasons. Applying them in a complementary way and at greater spatial and temporal scales could enhance the accuracy of results.

  9. Comparison between ARIMA and DES Methods of Forecasting Population for Housing Demand in Johor

    OpenAIRE

    Alias Ahmad Rizal; Zainun Noor Yasmin; Abdul Rahman Ismail

    2016-01-01

    Forecasting accuracy is a primary criterion in selecting appropriate method of prediction. Even though there are various methods of forecasting however not all of these methods are able to predict with good accuracy. This paper presents an evaluation of two methods of population forecasting for housing demand. These methods are Autoregressive Integrated Moving Average (ARIMA) and Double Exponential Smoothing (DES). Both of the methods are principally adopting univariate time series analysis w...

  10. Geometric and morphometric analysis of fish scales to identity genera, species and populations case study: the Cyprinid family

    Directory of Open Access Journals (Sweden)

    Seyedeh Narjes Tabatabei

    2014-01-01

    Full Text Available Using fish scale to identity species and population is a rapid, safe and low cost method. Hence, this study was carried out to investigate the possibility of using geometric and morphometric methods in fish scales for rapid identification of species and populations and compare the efficiency of applying few and/or high number of landmark points. For this purpose, scales of one population of Luciobarbus capito, four populations of Alburnoides eichwaldii and two populations of Rutilus frisii kutum, all belonging to cyprinid family, were examined. On two-dimensional images of the scales 7 and 23 landmark points were digitized in two separate times using TpsDig2, respectively. Landmark data after generalized procrustes analysis were analyzed using Principal Component Analysis (PCA, Canonical Variate Analysis (CVA and Cluster Analysis. The results of both methods (using 7 and 23 landmark points showed significant differences of the shape of scales among the three species studied (P0.05. The results also showed that few number of landmarks could display the differences between scale shapes. According to the results of this study, it could be stated that the scale of each species had unique shape patterns which could be utilized as a species identification key.

  11. Ongoing challenges to finding people with Parkinson's disease for epidemiological studies: a comparison of population-level case ascertainment methods.

    Science.gov (United States)

    Harris, M Anne; Koehoorn, Mieke; Teschke, Kay

    2011-07-01

    Locating Parkinson's disease cases for epidemiological studies has long been challenging. Self reports, secondary records of physician diagnosis and drug tracer methods each exhibit known disadvantages but have rarely been compared directly. Prescriptions of levodopa have in some studies been considered to comprise a reasonable proxy for Parkinson's disease diagnosis. We tested this assumption by comparing three methods of population-level case ascertainment. We compared the number of Parkinson's disease cases in British Columbia derived from self-reports in the 2001 Canadian Community Health Survey to those obtained from administrative records of filled levodopa prescriptions and to Parkinson's disease diagnoses from physician visit billing and hospital discharge records in 1996 and 2005. We directly compared a case definition based on levodopa prescriptions with a definition based on records of physician diagnosis by calculating positive predictive value and sensitivity. Crude prevalence estimates ranged from approximately 100 to 200 per 100,000. Levodopa-based case definitions overestimated prevalence, while physician- and hospital-record-based case definitions provided lower prevalence estimates compared to survey derived estimates. The proportion of levodopa users with a diagnosis of Parkinson's disease declined from 62% to 52% between 1996 and 2005. This decrease was most dramatic among women (64%-44%) and those under age 65 (54%-39%). Sex and age trends suggest increasing use of levodopa among patients with conditions other than Parkinson's disease, such as restless legs syndrome. Increased non-Parkinson's levodopa use decreases the efficiency of levodopa as a Parkinson's disease case tracer. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Methods for environmental change; an exploratory study

    NARCIS (Netherlands)

    Nell Gottlieb; Robert Panne; Chris Smerecnik; Gerjo Kok

    2012-01-01

    Background: While the interest of health promotion researchers in change methods directed at the target population has a long tradition, interest in change methods directed at the environment is still developing. In this survey, the focus is on methods for environmental change; especially about how

  13. Population coding and decoding in a neural field: a computational study.

    Science.gov (United States)

    Wu, Si; Amari, Shun-Ichi; Nakahara, Hiroyuki

    2002-05-01

    This study uses a neural field model to investigate computational aspects of population coding and decoding when the stimulus is a single variable. A general prototype model for the encoding process is proposed, in which neural responses are correlated, with strength specified by a gaussian function of their difference in preferred stimuli. Based on the model, we study the effect of correlation on the Fisher information, compare the performances of three decoding methods that differ in the amount of encoding information being used, and investigate the implementation of the three methods by using a recurrent network. This study not only rediscovers main results in existing literatures in a unified way, but also reveals important new features, especially when the neural correlation is strong. As the neural correlation of firing becomes larger, the Fisher information decreases drastically. We confirm that as the width of correlation increases, the Fisher information saturates and no longer increases in proportion to the number of neurons. However, we prove that as the width increases further--wider than (sqrt)2 times the effective width of the turning function--the Fisher information increases again, and it increases without limit in proportion to the number of neurons. Furthermore, we clarify the asymptotic efficiency of the maximum likelihood inference (MLI) type of decoding methods for correlated neural signals. It shows that when the correlation covers a nonlocal range of population (excepting the uniform correlation and when the noise is extremely small), the MLI type of method, whose decoding error satisfies the Cauchy-type distribution, is not asymptotically efficient. This implies that the variance is no longer adequate to measure decoding accuracy.

  14. Confidence intervals for population allele frequencies: the general case of sampling from a finite diploid population of any size.

    Science.gov (United States)

    Fung, Tak; Keenan, Kevin

    2014-01-01

    The estimation of population allele frequencies using sample data forms a central component of studies in population genetics. These estimates can be used to test hypotheses on the evolutionary processes governing changes in genetic variation among populations. However, existing studies frequently do not account for sampling uncertainty in these estimates, thus compromising their utility. Incorporation of this uncertainty has been hindered by the lack of a method for constructing confidence intervals containing the population allele frequencies, for the general case of sampling from a finite diploid population of any size. In this study, we address this important knowledge gap by presenting a rigorous mathematical method to construct such confidence intervals. For a range of scenarios, the method is used to demonstrate that for a particular allele, in order to obtain accurate estimates within 0.05 of the population allele frequency with high probability (> or = 95%), a sample size of > 30 is often required. This analysis is augmented by an application of the method to empirical sample allele frequency data for two populations of the checkerspot butterfly (Melitaea cinxia L.), occupying meadows in Finland. For each population, the method is used to derive > or = 98.3% confidence intervals for the population frequencies of three alleles. These intervals are then used to construct two joint > or = 95% confidence regions, one for the set of three frequencies for each population. These regions are then used to derive a > or = 95%% confidence interval for Jost's D, a measure of genetic differentiation between the two populations. Overall, the results demonstrate the practical utility of the method with respect to informing sampling design and accounting for sampling uncertainty in studies of population genetics, important for scientific hypothesis-testing and also for risk-based natural resource management.

  15. Confidence intervals for population allele frequencies: the general case of sampling from a finite diploid population of any size.

    Directory of Open Access Journals (Sweden)

    Tak Fung

    Full Text Available The estimation of population allele frequencies using sample data forms a central component of studies in population genetics. These estimates can be used to test hypotheses on the evolutionary processes governing changes in genetic variation among populations. However, existing studies frequently do not account for sampling uncertainty in these estimates, thus compromising their utility. Incorporation of this uncertainty has been hindered by the lack of a method for constructing confidence intervals containing the population allele frequencies, for the general case of sampling from a finite diploid population of any size. In this study, we address this important knowledge gap by presenting a rigorous mathematical method to construct such confidence intervals. For a range of scenarios, the method is used to demonstrate that for a particular allele, in order to obtain accurate estimates within 0.05 of the population allele frequency with high probability (> or = 95%, a sample size of > 30 is often required. This analysis is augmented by an application of the method to empirical sample allele frequency data for two populations of the checkerspot butterfly (Melitaea cinxia L., occupying meadows in Finland. For each population, the method is used to derive > or = 98.3% confidence intervals for the population frequencies of three alleles. These intervals are then used to construct two joint > or = 95% confidence regions, one for the set of three frequencies for each population. These regions are then used to derive a > or = 95%% confidence interval for Jost's D, a measure of genetic differentiation between the two populations. Overall, the results demonstrate the practical utility of the method with respect to informing sampling design and accounting for sampling uncertainty in studies of population genetics, important for scientific hypothesis-testing and also for risk-based natural resource management.

  16. The establishment of tocopherol reference intervals for Hungarian adult population using a validated HPLC method.

    Science.gov (United States)

    Veres, Gábor; Szpisjak, László; Bajtai, Attila; Siska, Andrea; Klivényi, Péter; Ilisz, István; Földesi, Imre; Vécsei, László; Zádori, Dénes

    2017-09-01

    Evidence suggests that decreased α-tocopherol (the most biologically active substance in the vitamin E group) level can cause neurological symptoms, most likely ataxia. The aim of the current study was to first provide reference intervals for serum tocopherols in the adult Hungarian population with appropriate sample size, recruiting healthy control subjects and neurological patients suffering from conditions without symptoms of ataxia, myopathy or cognitive deficiency. A validated HPLC method applying a diode array detector and rac-tocol as internal standard was utilized for that purpose. Furthermore, serum cholesterol levels were determined as well for data normalization. The calculated 2.5-97.5% reference intervals for α-, β/γ- and δ-tocopherols were 24.62-54.67, 0.81-3.69 and 0.29-1.07 μm, respectively, whereas the tocopherol/cholesterol ratios were 5.11-11.27, 0.14-0.72 and 0.06-0.22 μmol/mmol, respectively. The establishment of these reference intervals may improve the diagnostic accuracy of tocopherol measurements in certain neurological conditions with decreased tocopherol levels. Moreover, the current study draws special attention to the possible pitfalls in the complex process of the determination of reference intervals as well, including the selection of study population, the application of internal standard and method validation and the calculation of tocopherol/cholesterol ratios. Copyright © 2017 John Wiley & Sons, Ltd.

  17. A population-based prospective study of optic neuritis

    DEFF Research Database (Denmark)

    Soelberg, K; Jarius, S; Skejoe, Hanne Pernille Bro

    2017-01-01

    BACKGROUND: Optic neuritis (ON) is often associated with multiple sclerosis (MS). Early diagnosis is critical to optimal patient management. OBJECTIVE: To estimate the incidence of acute ON and the rates of conversion to MS and antibody-mediated ON. METHOD: Population-based prospective study......-specific incidence was 3.28 (2.44-4.31) per 100,000 person years, 2.02 for men and 4.57 for women. At follow-up, 20 patients met the diagnostic criteria for MS, MRI lesions disseminated in space and time in 17/20 patients. AQP4-IgG was detected in none, MOG-IgG was detected in two patients. CONCLUSION...

  18. Moderate alcohol consumption may protect against overt autoimmune hypothyroidism: a population-based casecontrol study

    DEFF Research Database (Denmark)

    Carl, Allan; Pedersen, Inge Blow; Knudsen, Nils

    2012-01-01

    OBJECTIVE: Alcohol consumption is an important protective risk factor for many autoimmune diseases. We wished to study the association between alcohol consumption and autoimmune hypothyroidism. DESIGN: Population-based, case-control study, 1997-2001, Denmark. METHODS: Patients with newly diagnose......, or region of inhabitancy. CONCLUSIONS: Alcohol consumption seems to confer considerable protection against development of overt autoimmune hypothyroidism irrespective of sex and type of alcohol consumed.......OBJECTIVE: Alcohol consumption is an important protective risk factor for many autoimmune diseases. We wished to study the association between alcohol consumption and autoimmune hypothyroidism. DESIGN: Population-based, case-control study, 1997-2001, Denmark. METHODS: Patients with newly diagnosed...... of alcohol per week were as follows: 0 units/week, 1.98 (1.21-3.33); 11-20 units/week, 0.41 (0.20-0.83); and ≥21 units/week, 0.90 (0.41-2.00). Similar results were found for maximum previous alcohol consumption during a calendar year. No interaction was found with type of alcohol consumed (wine vs beer), sex...

  19. Genetic classification of populations using supervised learning.

    Directory of Open Access Journals (Sweden)

    Michael Bridges

    2011-05-01

    Full Text Available There are many instances in genetics in which we wish to determine whether two candidate populations are distinguishable on the basis of their genetic structure. Examples include populations which are geographically separated, case-control studies and quality control (when participants in a study have been genotyped at different laboratories. This latter application is of particular importance in the era of large scale genome wide association studies, when collections of individuals genotyped at different locations are being merged to provide increased power. The traditional method for detecting structure within a population is some form of exploratory technique such as principal components analysis. Such methods, which do not utilise our prior knowledge of the membership of the candidate populations. are termed unsupervised. Supervised methods, on the other hand are able to utilise this prior knowledge when it is available.In this paper we demonstrate that in such cases modern supervised approaches are a more appropriate tool for detecting genetic differences between populations. We apply two such methods, (neural networks and support vector machines to the classification of three populations (two from Scotland and one from Bulgaria. The sensitivity exhibited by both these methods is considerably higher than that attained by principal components analysis and in fact comfortably exceeds a recently conjectured theoretical limit on the sensitivity of unsupervised methods. In particular, our methods can distinguish between the two Scottish populations, where principal components analysis cannot. We suggest, on the basis of our results that a supervised learning approach should be the method of choice when classifying individuals into pre-defined populations, particularly in quality control for large scale genome wide association studies.

  20. Genetic classification of populations using supervised learning.

    LENUS (Irish Health Repository)

    Bridges, Michael

    2011-01-01

    There are many instances in genetics in which we wish to determine whether two candidate populations are distinguishable on the basis of their genetic structure. Examples include populations which are geographically separated, case-control studies and quality control (when participants in a study have been genotyped at different laboratories). This latter application is of particular importance in the era of large scale genome wide association studies, when collections of individuals genotyped at different locations are being merged to provide increased power. The traditional method for detecting structure within a population is some form of exploratory technique such as principal components analysis. Such methods, which do not utilise our prior knowledge of the membership of the candidate populations. are termed unsupervised. Supervised methods, on the other hand are able to utilise this prior knowledge when it is available.In this paper we demonstrate that in such cases modern supervised approaches are a more appropriate tool for detecting genetic differences between populations. We apply two such methods, (neural networks and support vector machines) to the classification of three populations (two from Scotland and one from Bulgaria). The sensitivity exhibited by both these methods is considerably higher than that attained by principal components analysis and in fact comfortably exceeds a recently conjectured theoretical limit on the sensitivity of unsupervised methods. In particular, our methods can distinguish between the two Scottish populations, where principal components analysis cannot. We suggest, on the basis of our results that a supervised learning approach should be the method of choice when classifying individuals into pre-defined populations, particularly in quality control for large scale genome wide association studies.

  1. Paediatric population neuroimaging and the Generation R Study

    DEFF Research Database (Denmark)

    White, Tonya; Muetzel, Ryan L.; El Marroun, Hanan

    2018-01-01

    Paediatric population neuroimaging is an emerging field that falls at the intersection between developmental neuroscience and epidemiology. A key feature of population neuroimaging studies involves large-scale recruitment that is representative of the general population. One successful approach f...

  2. Determining adult type 2 diabetes-related health care needs in an indigenous population from rural Guatemala: a mixed-methods preliminary study

    Directory of Open Access Journals (Sweden)

    Chary Anita

    2012-12-01

    Full Text Available Abstract Background In Guatemala, diabetes is an emerging public health concern. Guatemala has one of the largest indigenous populations in Latin America, and this population frequently does not access the formal health care system. Therefore, knowledge about the emergence of diabetes in this population is limited. Methods Interview participants (n=23 were recruited from a convenience sample of indigenous adults with type 2 diabetes at one rural diabetes clinic in Guatemala. A structured interview was used to assess knowledge about diabetes and its complications; access to diabetes-related health care and treatment; dietary and lifestyle changes; and family and social supports for individuals living with diabetes. Interviews were supplemented with two group interviews with community leaders and health care providers. Thematic analysis was used to produce insights into diabetes knowledge, attitudes, and practices. In addition, a chart review of the clinic’s electronic medical record identified all adult patients (n=80 presenting in one calendar year for a first-time diabetic consultation. Sociodemographic and clinical variables were extracted and summarized from these records. Results Salient demographic factors in both the structured interview and chart review samples included low educational levels and high indigenous language preference. In the interview sample, major gaps in biomedical knowledge about diabetes included understanding the causes, chronicity, and long-term end-organ complications of diabetes. Medication costs, medical pluralism, and limited social supports for dietary and lifestyles changes were major practical barriers to disease management. Quantitative data from medical records review revealed high rates of poor glycemic control, overweight and obesity, and medication prescription. Conclusions This study provides a preliminary sketch of type 2 diabetes in an indigenous Guatemalan population. Combined qualitative and

  3. PINP: a new method of tagging neuronal populations for identification during in vivo electrophysiological recording.

    Directory of Open Access Journals (Sweden)

    Susana Q Lima

    Full Text Available Neural circuits are exquisitely organized, consisting of many different neuronal subpopulations. However, it is difficult to assess the functional roles of these subpopulations using conventional extracellular recording techniques because these techniques do not easily distinguish spikes from different neuronal populations. To overcome this limitation, we have developed PINP (Photostimulation-assisted Identification of Neuronal Populations, a method of tagging neuronal populations for identification during in vivo electrophysiological recording. The method is based on expressing the light-activated channel channelrhodopsin-2 (ChR2 to restricted neuronal subpopulations. ChR2-tagged neurons can be detected electrophysiologically in vivo since illumination of these neurons with a brief flash of blue light triggers a short latency reliable action potential. We demonstrate the feasibility of this technique by expressing ChR2 in distinct populations of cortical neurons using two different strategies. First, we labeled a subpopulation of cortical neurons-mainly fast-spiking interneurons-by using adeno-associated virus (AAV to deliver ChR2 in a transgenic mouse line in which the expression of Cre recombinase was driven by the parvalbumin promoter. Second, we labeled subpopulations of excitatory neurons in the rat auditory cortex with ChR2 based on projection target by using herpes simplex virus 1 (HSV1, which is efficiently taken up by axons and transported retrogradely; we find that this latter population responds to acoustic stimulation differently from unlabeled neurons. Tagging neurons is a novel application of ChR2, used in this case to monitor activity instead of manipulating it. PINP can be readily extended to other populations of genetically identifiable neurons, and will provide a useful method for probing the functional role of different neuronal populations in vivo.

  4. THE STUDY OF INDONESIA’S READINESS TO COPE WITH DEMOGRAPHIC BONUS: A REVIEW OF POPULATION LAW

    Directory of Open Access Journals (Sweden)

    Edie Toet Hendratno

    2015-09-01

    Full Text Available The shift from a population mapping to investigate the population bonus on demographic aspect enhances the economic value this study might contribute for. Indonesian population as the fourth largest number requires some policies to cope with the millennium challenges. Improving nationwide database maintains government on-going strategy to manage its population that is expected to serve all stakeholders for any quest towards economic development. The study uses mixed method with the explanatory sequential strategy. The qualitative approach is used, using social network analysis, supported by desk study, in-depth interview, focus group discussion, and literature studies. This study attempts to provide for improvement to the extant regulations on identity card, mostly electronic-KTP. Demographic bonus is an interesting topic given that the younger the population, the higher the employment demand rate will be. Having systematic database bank and access is expected to alleviate the challenge on high population growth rate in Indonesia. Besides, recommendations are addressed to the policy maker (the Government, mostly on the review or amendment of the extant regulations that might not in line with the database systematic improvements. The study is a primary thesis from a review of population law, using multidisciplinary approach, i.e. population economics (demography, legal study, and public policy that can be used as a testing basis to answer further demographic bonus from an exploration of other scientific inquiries.

  5. Genealogy construction in a historically isolated population: application to genetic studies of rheumatoid arthritis in the Pima Indian.

    Science.gov (United States)

    Lin, J P; Hirsch, R; Jacobsson, L T; Scott, W W; Ma, L D; Pillemer, S R; Knowler, W C; Kastner, D L; Bale, S J

    1999-01-01

    Due to the characteristics of complex traits, many traits may not be amenable to traditional epidemiologic methods. We illustrate an approach that defines an isolated population as the "unit" for carrying out studies of complex disease. We provide an example using the Pima Indians, a relatively isolated population, in which the incidence and prevalence of Type 2 diabetes, gallbladder disease, and rheumatoid arthritis (RA) are significantly increased compared with the general U.S. population. A previous study of RA in the Pima utilizing traditional methods failed to detect a genetic effect on the occurrence of the disease. Our approach involved constructing a genealogy for this population and using a genealogic index to investigate familial aggregation. We developed an algorithm to identify biological relationships among 88 RA cases versus 4,000 subsamples of age-matched individuals from the same population. Kinship coefficients were calculated for all possible pairs of RA cases, and similarly for the subsamples. The sum of the kinship coefficient among all combination of RA pairs, 5.92, was significantly higher than the average of the 4,000 subsamples, 1.99 (p genealogy can be anticipated to provide valuable information for the genetic study of diseases other than RA. Defining an isolated population as the "unit" in which to assess familial aggregation may be advantageous, especially if there are a limited number of cases in the study population.

  6. Piloting a Non-Invasive Genetic Sampling Method for Evaluating Population-Level Benefits of Wildlife Crossing Structures

    Directory of Open Access Journals (Sweden)

    Anthony P. Clevenger

    2010-03-01

    Full Text Available Intuitively, wildlife crossing structures should enhance the viability of wildlife populations. Previous research has demonstrated that a broad range of species will use crossing structures, however, questions remain as to whether these measures actually provide benefits to populations. To assess this, studies will need to determine the number of individuals using crossings, their sex, and their genetic relationships. Obtaining empirical data demonstrating population-level benefits for some species can be problematic and challenging at best. Molecular techniques now make it possible to identify species, individuals, their sex, and their genetic relatedness from hair samples collected through non-invasive genetic sampling (NGS. We describe efforts to pilot a method to assess potential population-level benefits of wildlife crossing structures. We tested the feasibility of a prototype NGS system designed to sample hair from black bears (Ursus americanus and grizzly bears (U. arctos at two wildlife underpasses. The piloted hair-sampling method did not deter animal use of the trial underpasses and was effective at sampling hair from more than 90% of the bear crossing events at the underpasses. Hair samples were also obtained from non-target carnivore species, including three out of five (60% cougar (Puma concolor crossing events. Individual identification analysis revealed that three female and two male grizzly bears used one wildlife underpass, whereas two female and three male black bears were identified as using the other underpass. Of the 36 hair samples from bears analyzed, five failed, resulting in an 87% extraction success rate, and six more were only identified to species. Overall, 70% of the hair samples from bears collected in the field had sufficient DNA for extraction purposes. Preliminary data from our NGS suggest the technique can be a reliable method to assess the population-level benefits of Banff wildlife crossings. Furthermore, NGS

  7. A New Method for Deriving the Stellar Birth Function of Resolved Stellar Populations.

    Science.gov (United States)

    Gennaro, M.; Tchernyshyov, K.; Brown, T. M.; Gordon, K. D.

    2015-07-01

    We present a new method for deriving the stellar birth function (SBF) of resolved stellar populations. The SBF (stars born per unit mass, time, and metallicity) is the combination of the initial mass function (IMF), the star formation history (SFH), and the metallicity distribution function (MDF). The framework of our analysis is that of Poisson Point Processes (PPPs), a class of statistical models suitable when dealing with points (stars) in a multidimensional space (the measurement space of multiple photometric bands). The theory of PPPs easily accommodates the modeling of measurement errors as well as that of incompleteness. Our method avoids binning stars in the color-magnitude diagram and uses the whole likelihood function for each data point; combining the individual likelihoods allows the computation of the posterior probability for the population's SBF. Within the proposed framework it is possible to include nuisance parameters, such as distance and extinction, by specifying their prior distributions and marginalizing over them. The aim of this paper is to assess the validity of this new approach under a range of assumptions, using only simulated data. Forthcoming work will show applications to real data. Although it has a broad scope of possible applications, we have developed this method to study multi-band Hubble Space Telescope observations of the Milky Way Bulge. Therefore we will focus on simulations with characteristics similar to those of the Galactic Bulge. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at STScI, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  8. Underwater methods for study of salmonids in the Intermountain West

    Science.gov (United States)

    Russell F. Thurow

    1994-01-01

    This guide describes underwater methods using snorkeling gear to study fish populations in flowing waters of the Intermountain West. It outlines procedures for estimating salmonid abundance and habitat use and provides criteria for identifying and estimating the size of fish underwater.

  9. A moment projection method for population balance dynamics with a shrinkage term

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shaohua [Department of Mechanical Engineering, National University of Singapore, Engineering Block EA, Engineering Drive 1, 117576 (Singapore); Yapp, Edward K.Y.; Akroyd, Jethro; Mosbach, Sebastian [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA (United Kingdom); Xu, Rong [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore); Yang, Wenming [Department of Mechanical Engineering, National University of Singapore, Engineering Block EA, Engineering Drive 1, 117576 (Singapore); Kraft, Markus, E-mail: mk306@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA (United Kingdom); School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore)

    2017-02-01

    A new method of moments for solving the population balance equation is developed and presented. The moment projection method (MPM) is numerically simple and easy to implement and attempts to address the challenge of particle shrinkage due to processes such as oxidation, evaporation or dissolution. It directly solves the moment transport equation for the moments and tracks the number of the smallest particles using the algorithm by Blumstein and Wheeler (1973) . The performance of the new method is measured against the method of moments (MOM) and the hybrid method of moments (HMOM). The results suggest that MPM performs much better than MOM and HMOM where shrinkage is dominant. The new method predicts mean quantities which are almost as accurate as a high-precision stochastic method calculated using the established direct simulation algorithm (DSA).

  10. Male Contraception: Research, New Methods, and Implications for Marginalized Populations.

    Science.gov (United States)

    Plana, Olivia

    2017-07-01

    The majority of research on contraception has focused on manipulating the female reproductive system. Recent studies have identified novel contraceptives for males, including hormonal- and nonhormonal-based therapeutics. Although these new contraceptives are still undergoing clinical trials, their development and potential future use in society necessitate serious consideration of their implications for reproductive health. Through my analysis of the research conducted on male contraception over time and the current therapeutics available, it is clear that male contraception has the potential to shift societal gender dynamics and provide males with greater control over their own reproduction. This article also identifies the implications of these novel contraceptives for marginalized populations, especially men of color and men of lower socioeconomic positions. To overcome barriers to contraception among these populations, public policy efforts are needed in order to motivate the development of programs that facilitate coverage of these new male contraceptives by health plans and to increase their availability to underserved communities. Health care providers will be responsible for educating patients about these novel male contraception options and the need to continue using existing methods (e.g., condoms) in order to prevent sexually transmitted infections. This article analyzes the research conducted on male contraception and identifies the implications of these novel therapeutics for marginalized groups of men in the United States to identify the interventions that will be necessary to help ensure that all men have access to these promising scientific innovations.

  11. Density Estimation in Several Populations With Uncertain Population Membership

    KAUST Repository

    Ma, Yanyuan; Hart, Jeffrey D.; Carroll, Raymond J.

    2011-01-01

    sampled from any given population can be calculated. We develop general estimation procedures and bandwidth selection methods for our setting. We establish large-sample properties and study finite-sample performance using simulation studies. We illustrate

  12. Methods for decreasing population doses due to medical use of ionizing radiations

    International Nuclear Information System (INIS)

    Marej, A.N.

    1984-01-01

    The problem of radiation safety of population as regard to irradiation of a great contingents of people due to diagnosis procedures, carried out using X-ray and radiological methods of examination, is considered. It is shown, that prevention from excessive irradiation of population due to X-ray radiodiagnostic procedures is possible by realization the complex of activities, including legislative, organizational, technical and other measures. Human exposure doses in diagnosis most not exceed permissible ones, established on the basis of cost-benefit criterion. The necessity of the maximum limitation of exposure of pregnant women and children is emphasized

  13. A Qualitative Study to Assess Factors Supporting Tobacco Use in A Homeless Population

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    Maribeth Porter

    2017-02-01

    Full Text Available Purpose: Homeless adults have a higher prevalence of smoking compared to the general population. Most tobacco cessation efforts have focused on the general population, with limited attention paid to this vulnerable population. In this study, homeless adults as well as shelter staff were interviewed to understand their attitudes and beliefs about smoking and smoking cessation, and receptiveness to smoking cessation interventions. Methods: Semi-structured, one-on-one interviews were audio recorded and transcribed for 13 homeless adult smokers and 9 staff recruited from a homeless shelter in Charleston, South Carolina. Transcripts were analyzed in a systematic manner by independent investigators trained in grounded theory. The constant comparison method was used to code, categorize and synthesize the qualitative data. Results: The majority of smokers interviewed expressed the desire to stop smoking, but felt that stress from being homeless was a barrier to quitting. When asked about different tobacco cessation methods, there was no preferred method and there was skepticism regarding actual effectiveness of different methods, since many had previously been unsuccessful when tried by these smokers. Shelter staff acknowledged that tobacco cessation was important, but did not see it as a priority for shelter residents. Even though cessation medications are available in the shelter clinic, very few of the smokers or shelter staff interviewed were aware of the availability of these medications. Conclusions: This study suggests that adult smokers in a homeless shelter are interested in quitting smoking and receptive toward assistance, but that lack of awareness and perceived importance of cessation among staff is a significant barrier. Providing training to staff and encouraging them to take a proactive approach to tobacco cessation may be an area to focus future cessation interventions.

  14. Occupational risk and chronic kidney disease: a population-based study in the United States adult population

    Directory of Open Access Journals (Sweden)

    Rubinstein S

    2013-03-01

    Full Text Available Sofia Rubinstein,1 Chengwei Wang,1 Wenchun Qu2 1Department of Medicine, Nassau University Medical Center, East Meadow, NY, USA; 2Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN, USA Objective: Previous studies on occupational risk for chronic kidney disease (CKD have analyzed a limited range of occupations and focused on nephrotoxins. The primary purpose of this study was to examine the relative risk for the occurrence of CKD between different occupations in the US adult population. Materials and methods: This was a population-based survey study of 91,340 participants in the US, who completed the National Health Interview Survey, 2004 through 2008. The outcome variable, CKD, was defined as having weakening/failing kidneys in the past 12 months, as diagnosed by a physician. The predictor variable, occupation, was obtained using the census occupational codes, regrouped according to North American Industrial Classification System. Results: After controlling for age, gender, hypertension, and education, and with the category Life, Physical, and Social Science Occupations as a reference group, the likelihood of developing CKD was 4.3 times higher in respondents working in Building, Grounds Cleaning and Maintenance Occupations, 4.4 times higher in Healthcare Practitioners and Technical Occupations, 4.7 times higher in Transportation and Material Moving Occupations and in Computer and Mathematical Occupations, 4.8 times higher in Production Occupations, 5.3 times higher in Food Preparation and Serving Related Occupations, and 6.1 times higher in Healthcare Support Occupations and in Legal Occupations. Conclusion: This study identified occupation groups in US adult population with increased risk for CKD. Alleviation of workplace stress is suggested as a goal for behavioral intervention in high-risk occupations. Keywords: CKD, risk factors, occupations

  15. A Comparative Rugoscopic Study of the Dentate and Edentulous Individuals in the South Indian Population

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    Jagdish Prasad Rajguru

    2014-01-01

    Full Text Available This study analyzes the rugae pattern in dentulous and edentulous patients and also evaluates the association of rugae pattern between males and females. Aims and Objectives. This study aims to investigate rugae patterns in dentulous and edentulous patients of both sexes in South Indian population and to find whether palatoscopy is a useful tool in human identification. Materials and Methods. Four hundred outpatients from Sree Balaji Dental College and Hospital, Chennai, were included in the study. The study group was equally divided between the sexes, which was further categorized into 100 dentulous and edentulous patients, respectively. Results. The edentulous male showed the highest mean of wavy pattern and total absence of circular pattern while the edentulous female group showed the highest mean of curved pattern and total absence of nonspecific pattern, while dentate population showed similar value as that of the overall population such as straight, wavy, and curved patterns. Conclusion. The present study concludes that there is similar rugae pattern of distribution between male and female dentate population while there is varied pattern between the sexes of edentulous population. However, the most predominant patterns were straight, wavy, and circular patterns.

  16. [Psychiatric comorbidities in transsexualism: Study of a Lebanese transgender population].

    Science.gov (United States)

    Ibrahim, C; Haddad, R; Richa, S

    2016-12-01

    The question of whether gender dysphoria is associated with psychiatric comorbidity has been addressed in several studies. Several cohort studies have shown that psychiatric comorbidity is one of the main features of poor prognosis following sex change therapy. Gender dysphoria is rare, with an estimated prevalence of 0.001% to 0.002% globally. The literature shows a high prevalence of psychiatric comorbidities in people with gender dysphoria, and that they are more common in male to female transsexuals. Data on long-term mortality show that transsexuals present a 51 % increase in mortality compared to the general population. This is mainly attributed to a six-fold increase in the number of suicides and a higher rate of psychiatric disorders and risky behaviors leading to HIV infection and substance abuse. Assess psychiatric comorbidity in a population of Lebanese transgender individuals and compare it to the general population. The hypothesis of our study is that the Lebanese transgenders suffer from more psychiatric comorbidities than the general population. Our second objective was to determine the specific mental health needs of this population in order to adapt our services to their medical needs and their specific concerns. Our objective was to acquire 20 transgender participants and 20 control subjects. We chose a snowball sampling method. The evaluation consisted of three questionnaires including a general demographic questionnaire, the MINI 5.0.0 Arabic version for axis I disorders and the SCID-II for axis II disorders. The mean age of both groups was 23.55 years. Fifty-five percent (n=11) transgender participants had active suicidal thoughts against 0 % in controls. Within the group of transgender, 45 % (n=9) had a major depressive episode, 5 % (n=1) had a generalized anxiety disorder, 5 % (n=1) had a posttraumatic stress disorder and 10 % (n=2) had a major depressive episode with comorbid posttraumatic stress disorder. We noted a significant

  17. THE LIFE QUALITY OF BUYNAKSK CITY INHABITANTS, REPUBLIC OF DAGESTAN (POPULATION STUDY

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    G. M. Abdurakhmanov

    2017-01-01

    Full Text Available Aim. We studied the life quality indicators of the population in Buynaksk city, Dagestan, in a random representative sample of 315 people (155 women and 160 men aged between 18 and 76 years. Respondents were divided into 3 age groups (up to 35 years, 35-50 years and 50 years and older.Methods. The study was performed using a common health survey – Medical Outcomes Study-Short Form-36 (SF-36 in accordance with the requirements of the International Quality of Life Assessment Project (IQOLA.Results. We conducted a comparative analysis of age dynamics of population quality of life, as well as the male and female population of the study sample. The highest quality of life indicators are found on the scales of social (SF and physical functioning (PF – 83.4 and 82.9 points, respectively, the lowest – on the scale of general health (GH– 58.6. In general, with aging, there is a decrease of life quality among both male and female population. The most marked age-related changes are observed on the scale of role-physical functioning (RF and physical functioning (PF – 54.2 and 48.0% respectively and the least marked on the scale of mental health – 4.4%. The value of the integral index of quality of life in population-based study in Buynaksk city, Republic of Dagestan was 583.4.Conclusion. The research findings might be used in planning, developing and evaluating the effectiveness of various reforms, health and socio-economic programs being implemented in the region as well as to improve the quality of life and well-being. 

  18. Prevalence of widespread pain and associations with work status: a population study

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    Henriksson KG

    2008-07-01

    Full Text Available Abstract Background This population study based on a representative sample from a Swedish county investigates the prevalence, duration, and determinants of widespread pain (WSP in the population using two constructs and estimates how WSP affects work status. In addition, this study investigates the prevalence of widespread pain and its relationship to pain intensity, gender, age, income, work status, citizenship, civil status, urban residence, and health care seeking. Methods A cross-sectional survey using a postal questionnaire was sent to a representative sample (n = 9952 of the target population (284,073 people, 18–74 years in a county (Östergötland in the southern Sweden. The questionnaire was mailed and followed by two postal reminders when necessary. Results The participation rate was 76.7% (n = 7637; the non-participants were on the average younger, earned less money, and male. Women had higher prevalences of pain in 10 different predetermined anatomical regions. WSP was generally chronic (90–94% and depending on definition of WSP the prevalence varied between 4.8–7.4% in the population. Women had significantly higher prevalence of WSP than men and the age effect appeared to be stronger in women than in men. WSP was a significant negative factor – together with age 50–64 years, low annual income, and non-Nordic citizen – for work status in the community and in the group with chronic pain. Chronic pain but not the spreading of pain was related to health care seeking in the population. Conclusion This study confirms earlier studies that report high prevalences of widespread pain in the population and especially among females and with increasing age. Widespread pain is associated with prominent effects on work status.

  19. Identifying risk for dementia across populations: A study on the prevalence of dementia in tribal elderly population of Himalayan region in Northern India

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    Sunil Kumar Raina

    2013-01-01

    Full Text Available Introduction: Studies have suggested that dementia is differentially distributed across populations with a lower prevalence in developing regions than the developed ones. A comparison in the prevalence of dementia across populations may provide an insight into its risk factors. Keeping this in view, a study was planned to evaluate the prevalence of dementia in tribal elderly population. Materials and Methods: A cross-sectional comprehensive two-phase survey of all residents aged 60 years and older was conducted. Phase one involved screening of all individuals aged 60 and above with the help of a cognitive screen specifically developed for the tribal population. Phase two involved clinical examination of individuals who were suspected of dementia as per the developed cognitive screening test. Results: The results revealed that no individual above 60 years of age in the studied population was diagnosed as a case of dementia. Thereby, pointing out at some unknown factors, which are responsible for prevention of dementia. Discussion: The differences between the prevalence rate in this study and other studies in India appear to be a function of a valid regional difference. Environmental, phenotypic and genetic factors may contribute to regional and racial variations in dementia. Societies living in isolated hilly and tribal areas seem less predisposed to dementia, particularly age related neurodegenerative and vascular dementia, which are the most common causes for dementia in elderly. This may be because some environmental risk factors are much less prevalent in these settings.

  20. Population-based study on use of chemotherapy in men with castration resistant prostate cancer

    OpenAIRE

    Lissbrant, Ingela Franck; Garmo, Hans; Widmark, Anders; Stattin, P?r

    2013-01-01

    Background. Chemotherapy prolongs life and relieves symptoms in men with castration resistant prostate cancer (CRPC). There is limited information on a population level on the use of chemotherapy for CRPC. Material and methods. To assess the use of chemotherapy in men with CRPC we conducted a register-based nationwide population-based study in Prostate Cancer data Base Sweden (PCBaSe) and a nationwide in-patient drug register (SALT database) between May 2009 and December 2010. We assumed that...

  1. Development of a Late-Life Dementia Prediction Index with Supervised Machine Learning in the Population-Based CAIDE Study.

    Science.gov (United States)

    Pekkala, Timo; Hall, Anette; Lötjönen, Jyrki; Mattila, Jussi; Soininen, Hilkka; Ngandu, Tiia; Laatikainen, Tiina; Kivipelto, Miia; Solomon, Alina

    2017-01-01

    This study aimed to develop a late-life dementia prediction model using a novel validated supervised machine learning method, the Disease State Index (DSI), in the Finnish population-based CAIDE study. The CAIDE study was based on previous population-based midlife surveys. CAIDE participants were re-examined twice in late-life, and the first late-life re-examination was used as baseline for the present study. The main study population included 709 cognitively normal subjects at first re-examination who returned to the second re-examination up to 10 years later (incident dementia n = 39). An extended population (n = 1009, incident dementia 151) included non-participants/non-survivors (national registers data). DSI was used to develop a dementia index based on first re-examination assessments. Performance in predicting dementia was assessed as area under the ROC curve (AUC). AUCs for DSI were 0.79 and 0.75 for main and extended populations. Included predictors were cognition, vascular factors, age, subjective memory complaints, and APOE genotype. The supervised machine learning method performed well in identifying comprehensive profiles for predicting dementia development up to 10 years later. DSI could thus be useful for identifying individuals who are most at risk and may benefit from dementia prevention interventions.

  2. An application of the variable-r method to subpopulation growth rates in a 19th century agricultural population

    Directory of Open Access Journals (Sweden)

    Corey Sparks

    2009-07-01

    Full Text Available This paper presents an analysis of the differential growth rates of the farming and non-farming segments of a rural Scottish community during the 19th and early 20th centuries using the variable-r method allowing for net migration. Using this method, I find that the farming population of Orkney, Scotland, showed less variability in their reproduction and growth rates than the non-farming population during a period of net population decline. I conclude by suggesting that the variable-r method can be used in general cases where the relative growth of subpopulations or subpopulation reproduction is of interest.

  3. POPULATION STUDIES OF CZECH HUCUL HORSES

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    Hana Vostrá Vydrová

    2015-09-01

    Full Text Available Population studies were carried out analysis Czech Hucul breed based on pedigree information of animals registered in the Studbook. Pedigree records collected from the year 1834 to 2013 comprised information on 9455 animals used in the analyses. The pedigree depth of the analysed individuals was up to 19 generations. The mean value of inbreeding coefficient was 5.35% (with maximum value 30%. The proportion of inbreed animals was high (98%. The average rate of inbreeding in the reference population was lower than 1%, and the respective estimates of effective population sizes were 54. The presented paper is indicating that genetic diversity in the Czech Hucul breeds is still relatively high and conservation programs should be continued.

  4. Dietary Patterns Associated with Alzheimer’s Disease: Population Based Study

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    Katarzyna Gustaw-Rothenberg

    2009-04-01

    Full Text Available Recently dietary pattern analysis has emerged as a way for examining diet-disease relations in Alzheimer’s disease. In contrast with the conventional approach, which focuses on a single nutrient or a few nutrients or foods, this method considers overall eating patterns. We examined the dietary patterns defined by factor analysis using data collected with a food-frequency questionnaire in people with Alzheimer’s disease (AD as compared to healthy controls. The diet data were obtained during population based study of the prevalence of Alzheimer’s disease in a population in Poland. Stratified sampling and random selection strategies were combined to obtain a representative population for screening (age group > 55. From the population screened three times, 71 people were diagnosed with Alzheimer’s according to DSM-IV, and were recruited for further diet risk factors assessment. A group of people with Alzheimer disease (n = 71; F/M 42/29 and the same number of healthy, age and gender matched control were recruited for the study. Patients and their caregivers as well as controls were presented with a food frequency questionnaire based on the 12 food groups. Factor analysis (principal component was used to derive food patterns. The analysis was conducted using the factor procedure. The factors were rotated by an orthogonal transformation (Varimax rotation to achieve simpler structure with greater interpretability. Using factor analysis, we identified major eating patterns, one for Alzheimer’s patients and a different one for control group. The AD dietary pattern, FACTOR AD was characterized by a high intake of meat, butter, high-fat dairy products, eggs, and refined sugar, whereas the other pattern, (FACTOR C was characterized by a high intake of grains and vegetables. These data indicate the existence of dietary patterns defined by factor analysis with data from a food frequency questionnaire, characteristic for Alzheimer’s disease in a

  5. Methods and representativeness of a European survey in children and adolescents: the KIDSCREEN study

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    von Rueden Ursula

    2007-07-01

    Full Text Available Abstract Background The objective of the present study was to compare three different sampling and questionnaire administration methods used in the international KIDSCREEN study in terms of participation, response rates, and external validity. Methods Children and adolescents aged 8–18 years were surveyed in 13 European countries using either telephone sampling and mail administration, random sampling of school listings followed by classroom or mail administration, or multistage random sampling of communities and households with self-administration of the survey materials at home. Cooperation, completion, and response rates were compared across countries and survey methods. Data on non-respondents was collected in 8 countries. The population fraction (PF, respondents in each sex-age, or educational level category, divided by the population in the same category from Eurostat census data and population fraction ratio (PFR, ratio of PF and their corresponding 95% confidence intervals were used to analyze differences by country between the KIDSCREEN samples and a reference Eurostat population. Results Response rates by country ranged from 18.9% to 91.2%. Response rates were highest in the school-based surveys (69.0%–91.2%. Sample proportions by age and gender were similar to the reference Eurostat population in most countries, although boys and adolescents were slightly underrepresented (PFR Conclusion School-based sampling achieved the highest overall response rates but also produced slightly more biased samples than the other methods. The results suggest that the samples were sufficiently representative to provide reference population values for the KIDSCREEN instrument.

  6. Regression toward the mean – a detection method for unknown population mean based on Mee and Chua's algorithm

    Directory of Open Access Journals (Sweden)

    Lüdtke Rainer

    2008-08-01

    Full Text Available Abstract Background Regression to the mean (RTM occurs in situations of repeated measurements when extreme values are followed by measurements in the same subjects that are closer to the mean of the basic population. In uncontrolled studies such changes are likely to be interpreted as a real treatment effect. Methods Several statistical approaches have been developed to analyse such situations, including the algorithm of Mee and Chua which assumes a known population mean μ. We extend this approach to a situation where μ is unknown and suggest to vary it systematically over a range of reasonable values. Using differential calculus we provide formulas to estimate the range of μ where treatment effects are likely to occur when RTM is present. Results We successfully applied our method to three real world examples denoting situations when (a no treatment effect can be confirmed regardless which μ is true, (b when a treatment effect must be assumed independent from the true μ and (c in the appraisal of results of uncontrolled studies. Conclusion Our method can be used to separate the wheat from the chaff in situations, when one has to interpret the results of uncontrolled studies. In meta-analysis, health-technology reports or systematic reviews this approach may be helpful to clarify the evidence given from uncontrolled observational studies.

  7. Oral Hygiene Levels in Children of Tribal Population of Eastern Ghats: An Epidemiological Study

    OpenAIRE

    Raju, P Krishnam; Vasanti, D; Kumar, J Raghavendra; Niranjani, K; Kumar, M S Saravana

    2015-01-01

    Background: Oral hygiene has been given due importance since ages. Different cultures have been using different methods for the maintenance of good oral hygiene. The study was done to find out the oral hygiene levels in children of tribal population and to correlate the brushing methods used and the oral hygiene levels. Methodology: A total of 5129 children of 5-12 years age (boys 2778, girls 2351) were checked for the simplified oral hygiene index in the study. Results: The overall oral hygi...

  8. Dental age estimation using Willems method: A digital orthopantomographic study

    Directory of Open Access Journals (Sweden)

    Rezwana Begum Mohammed

    2014-01-01

    Full Text Available In recent years, age estimation has become increasingly important in living people for a variety of reasons, including identifying criminal and legal responsibility, and for many other social events such as a birth certificate, marriage, beginning a job, joining the army, and retirement. Objectives: The aim of this study was to assess the developmental stages of left seven mandibular teeth for estimation of dental age (DA in different age groups and to evaluate the possible correlation between DA and chronological age (CA in South Indian population using Willems method. Materials and Methods: Digital Orthopantomogram of 332 subjects (166 males, 166 females who fit the study and the criteria were obtained. Assessment of mandibular teeth (from central incisor to the second molar on left quadrant development was undertaken and DA was assessed using Willems method. Results and Discussion: The present study showed a significant correlation between DA and CA in both males (r = 0.71 and females (r = 0.88. The overall mean difference between the estimated DA and CA for males was 0.69 ± 2.14 years (P 0.05. Willems method underestimated the mean age of males by 0.69 years and females by 0.08 years and showed that females mature earlier than males in selected population. The mean difference between DA and CA according to Willems method was 0.39 years and is statistically significant (P < 0.05. Conclusion: This study showed significant relation between DA and CA. Thus, digital radiographic assessment of mandibular teeth development can be used to generate mean DA using Willems method and also the estimated age range for an individual of unknown CA.

  9. A study of lip prints among Pondicherry population.

    Science.gov (United States)

    Kumar, G Sathish; Vezhavendhan, N; Vendhan, Priya

    2012-07-01

    Cheiloscopy is a forensic investigation that deals with the examination of the system of furrows on the red part of human lips. Like fingerprint, lip print is also unique for every individual. But most of the crime-detecting agencies are unaware of the importance of lip print and it is not commonly attempted in identification of the suspects. The aim of the present study is to determine the predominant lip print pattern among Pondicherry population, India, and also to determine its uniqueness. The study comprised of 60 students (30 males and 30 females), aged from 17 to 25 years, from Pondicherry population, India. A dark-colored lipstick was applied with a single stroke and the students were asked to rub both the lips to spread the applied lipstick, after which a lip print was made on butter paper. The lip print was visualized with magnifying lens. Percentage calculation method was used to identify the predominant lip pattern. One-sample T test was done to identify the statistical significance within the different types of lip pattern with P value print and Type III appears to be the most predominant pattern in males, followed by the Type II, Type IV, Type I and Type V patterns. In females, Type II appears to be the most predominant pattern followed by the Type IV, Type I, Type III and Type V patterns.

  10. Thyroid Dysfunction in an Adult Female Population: A population-based study of Latin American Vertebral Osteoporosis Study (LAVOS) - Puerto Rico Site Hypothyroidism in LAVOS-Puerto Rico site

    Science.gov (United States)

    González-Rodríguez, Loida A.; Felici-Giovanini, Marcos E; Haddock, Lillian

    2013-01-01

    Objective To determine the prevalence of hypothyroidism in an adult female population in Puerto Rico and to determine the relationship between hypothyroidism, bone mineral density and vertebral and non-vertebral fractures in this population. Methods Data from the 400 subjects database of the Latin American Vertebral Osteoporosis Study (LAVOS), Puerto Rico site was reviewed. Patient’s medical history, anthropometric data, current medications, laboratories, and DXA results was extracted. Subjects with thyroid dysfunction were identified based on their previous medical history and levels of TSH. Bone Mineral Density was classified using the World Health Organization criteria. Crude prevalence of thyroid dysfunction were estimated with a confidence of 95% and weighted by the population distribution by age, according to the distribution by age group in the 2000 census. Bone mineral densities and prevalence of vertebral and non-vertebral fractures were compared among the groups. Results The weighted prevalence of hyperthyroidism in this population was 0.0043% (95% CI: −0.0021%, 0.0107%). The weighted prevalence of hypothyroidism was 24.2% (95% CI: 19.9%, 28.4%). Increased prevalence of hypothyroidism was found in participants 70 years or older. The mean BMD at spine, hip and femoral neck was similar among the groups. No difference in the proportion of participants with vertebral and non-vertebral fractures was found among the groups. Conclusion Our study found a high prevalence of hypothyroidism among adult postmenopausal females in Puerto Rico. No association between hypothyroidism and decreased bone mineral densities, vertebral or non-vertebral fractures was found in this population. PMID:23781620

  11. Ethno- medico - botanical studies of Badaga population In the Nilgiri district of Tamilnadu, South India

    Science.gov (United States)

    Manikandan, P. N. Arul

    2008-01-01

    The study grains to explore ethno-medicobotany of Badaga population in the Nilgiri hills of Tamilnadu, South India. Ethno botanical field survey and personal discussion methods have been adopted in the collection of data. A list of 71 flowering plants belonging to 42 families, 67 genera and 70 species are employed by the Badaga popu-lation in their native system of medicine for therapeutic purposes. In reviewing ethnomedical information, data on folk herbal remedies and their various methods of applications for treating a wide range of ailments have been furnished. A brief description of plants, their habitat, family and local Badaga names are outlined here. PMID:22557279

  12. A framework for comparative evaluation of dosimetric methods to triage a large population following a radiological event

    International Nuclear Information System (INIS)

    Flood, Ann Barry; Nicolalde, Roberto J.; Demidenko, Eugene; Williams, Benjamin B.; Shapiro, Alla; Wiley, Albert L.; Swartz, Harold M.

    2011-01-01

    Background: To prepare for a possible major radiation disaster involving large numbers of potentially exposed people, it is important to be able to rapidly and accurately triage people for treatment or not, factoring in the likely conditions and available resources. To date, planners have had to create guidelines for triage based on methods for estimating dose that are clinically available and which use evidence extrapolated from unrelated conditions. Current guidelines consequently focus on measuring clinical symptoms (e.g., time-to-vomiting), which may not be subject to the same verification of standard methods and validation processes required for governmental approval processes of new and modified procedures. Biodosimeters under development have not yet been formally approved for this use. Neither set of methods has been tested in settings involving large-scale populations at risk for exposure. Objective: To propose a framework for comparative evaluation of methods for such triage and to evaluate biodosimetric methods that are currently recommended and new methods as they are developed. Methods: We adapt the NIH model of scientific evaluations and sciences needed for effective translational research to apply to biodosimetry for triaging very large populations following a radiation event. We detail criteria for translating basic science about dosimetry into effective multi-stage triage of large populations and illustrate it by analyzing 3 current guidelines and 3 advanced methods for biodosimetry. Conclusions: This framework for evaluating dosimetry in large populations is a useful technique to compare the strengths and weaknesses of different dosimetry methods. It can help policy-makers and planners not only to compare the methods' strengths and weaknesses for their intended use but also to develop an integrated approach to maximize their effectiveness. It also reveals weaknesses in methods that would benefit from further research and evaluation.

  13. A framework for comparative evaluation of dosimetric methods to triage a large population following a radiological event

    Energy Technology Data Exchange (ETDEWEB)

    Flood, Ann Barry, E-mail: Ann.B.Flood@Dartmouth.Edu [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Nicolalde, Roberto J., E-mail: Roberto.J.Nicolalde@Dartmouth.Edu [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Demidenko, Eugene, E-mail: Eugene.Demidenko@Dartmouth.Edu [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Williams, Benjamin B., E-mail: Benjamin.B.Williams@Dartmouth.Edu [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States); Shapiro, Alla, E-mail: Alla.Shapiro@fda.hhs.gov [Food and Drug Administration (FDA), Rockville, MD (United States); Wiley, Albert L., E-mail: Albert.Wiley@orise.orau.gov [Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States); Swartz, Harold M., E-mail: Harold.M.Swartz@Dartmouth.Edu [Dartmouth Physically Based Biodosimetry Center for Medical Countermeasures Against Radiation (Dart-Dose CMCR), Dartmouth Medical School, Hanover, NH 03768 (United States)

    2011-09-15

    Background: To prepare for a possible major radiation disaster involving large numbers of potentially exposed people, it is important to be able to rapidly and accurately triage people for treatment or not, factoring in the likely conditions and available resources. To date, planners have had to create guidelines for triage based on methods for estimating dose that are clinically available and which use evidence extrapolated from unrelated conditions. Current guidelines consequently focus on measuring clinical symptoms (e.g., time-to-vomiting), which may not be subject to the same verification of standard methods and validation processes required for governmental approval processes of new and modified procedures. Biodosimeters under development have not yet been formally approved for this use. Neither set of methods has been tested in settings involving large-scale populations at risk for exposure. Objective: To propose a framework for comparative evaluation of methods for such triage and to evaluate biodosimetric methods that are currently recommended and new methods as they are developed. Methods: We adapt the NIH model of scientific evaluations and sciences needed for effective translational research to apply to biodosimetry for triaging very large populations following a radiation event. We detail criteria for translating basic science about dosimetry into effective multi-stage triage of large populations and illustrate it by analyzing 3 current guidelines and 3 advanced methods for biodosimetry. Conclusions: This framework for evaluating dosimetry in large populations is a useful technique to compare the strengths and weaknesses of different dosimetry methods. It can help policy-makers and planners not only to compare the methods' strengths and weaknesses for their intended use but also to develop an integrated approach to maximize their effectiveness. It also reveals weaknesses in methods that would benefit from further research and evaluation.

  14. Clinical prediction in defined populations: a simulation study investigating when and how to aggregate existing models

    Directory of Open Access Journals (Sweden)

    Glen P. Martin

    2017-01-01

    Full Text Available Abstract Background Clinical prediction models (CPMs are increasingly deployed to support healthcare decisions but they are derived inconsistently, in part due to limited data. An emerging alternative is to aggregate existing CPMs developed for similar settings and outcomes. This simulation study aimed to investigate the impact of between-population-heterogeneity and sample size on aggregating existing CPMs in a defined population, compared with developing a model de novo. Methods Simulations were designed to mimic a scenario in which multiple CPMs for a binary outcome had been derived in distinct, heterogeneous populations, with potentially different predictors available in each. We then generated a new ‘local’ population and compared the performance of CPMs developed for this population by aggregation, using stacked regression, principal component analysis or partial least squares, with redevelopment from scratch using backwards selection and penalised regression. Results While redevelopment approaches resulted in models that were miscalibrated for local datasets of less than 500 observations, model aggregation methods were well calibrated across all simulation scenarios. When the size of local data was less than 1000 observations and between-population-heterogeneity was small, aggregating existing CPMs gave better discrimination and had the lowest mean square error in the predicted risks compared with deriving a new model. Conversely, given greater than 1000 observations and significant between-population-heterogeneity, then redevelopment outperformed the aggregation approaches. In all other scenarios, both aggregation and de novo derivation resulted in similar predictive performance. Conclusion This study demonstrates a pragmatic approach to contextualising CPMs to defined populations. When aiming to develop models in defined populations, modellers should consider existing CPMs, with aggregation approaches being a suitable modelling

  15. A Tractable Method for Describing Complex Couplings between Neurons and Population Rate.

    Science.gov (United States)

    Gardella, Christophe; Marre, Olivier; Mora, Thierry

    2016-01-01

    Neurons within a population are strongly correlated, but how to simply capture these correlations is still a matter of debate. Recent studies have shown that the activity of each cell is influenced by the population rate, defined as the summed activity of all neurons in the population. However, an explicit, tractable model for these interactions is still lacking. Here we build a probabilistic model of population activity that reproduces the firing rate of each cell, the distribution of the population rate, and the linear coupling between them. This model is tractable, meaning that its parameters can be learned in a few seconds on a standard computer even for large population recordings. We inferred our model for a population of 160 neurons in the salamander retina. In this population, single-cell firing rates depended in unexpected ways on the population rate. In particular, some cells had a preferred population rate at which they were most likely to fire. These complex dependencies could not be explained by a linear coupling between the cell and the population rate. We designed a more general, still tractable model that could fully account for these nonlinear dependencies. We thus provide a simple and computationally tractable way to learn models that reproduce the dependence of each neuron on the population rate.

  16. [A study of population pharmacokinetics of linezolid in Chinese].

    Science.gov (United States)

    Zhang, L; Bai, N; Liu, Y N; Wang, R

    2016-12-12

    Objective: To study the population pharmacokinetic (PPK) profiles of linezolid in Chinese healthy volunteers and infected patients. Methods: Linezolid 600 mg was administered to 31 Chinese healthy volunteers with a single dose and to 57 infected patients every 12 h for at least 5 doses. High performance liquid chromatography was applied to determine the plasma concentration of linezolid. Nonlinear mixed-effects modeling method was applied to analyze the PPK profiles. Results: For healthy volunteers with single dose of linezolid, 2-compartment with linear elimination model was the most appropriate structural pharmacokinetic model. The population typical value of apparent volume of central compartment was 26.99 L, volume of peripheral compartment was 22.22 L, apparent clearance of central compartment was 7.99 L/h, and clearance of peripheral compartment was 101.28 L/h. For each 1 kg deviation of weight from the mean value, 0.62 L of volume of peripheral compartment was correlated. For Chinese infected patients with multiple doses of linezolid, 1-compartment with linear elimination model was the most appropriate structural pharmacokinetic model. The population typical value of apparent volume was 38.85 L, and apparent clearance was 4.70 L/h. For each 1 kg deviation of weight from the mean value, 0.79 L of volume, as well as 0.04 L/h of clearance were correlated. For each 1 year deviation of age from the mean value, -0.045 L/h of clearance was correlated. Conclusions: The pharmacokinetic profiles of linezolid in Chinese simulate a 2-compartment with linear elimination model when single dose is administrated, and the weight is linearly positive-correlated to volume. While a 1-compartment with linear elimination model is appropriate when multiple doses are administrated, and the weight is linearly positive-correlated to volume and clearance, but the age is linearly negative-correlated to clearance.

  17. Increased migraine risk in osteoporosis patients: a nationwide population-based study

    OpenAIRE

    Wu, Chieh-Hsin; Zhang, Zi-Hao; Wu, Ming-Kung; Wang, Chiu-Huan; Lu, Ying-Yi; Lin, Chih-Lung

    2016-01-01

    Background Osteoporosis and migraine are both important public health problems and may have overlapping pathophysiological mechanisms. The aim of this study was to use a Taiwanese population-based dataset to assess migraine risk in osteoporosis patients. Methods The Taiwan National Health Insurance Research Database was used to analyse data for 40,672 patients aged ?20?years who had been diagnosed with osteoporosis during 1996?2010. An additional 40,672 age-matched patients without osteoporos...

  18. Tobacco usage among tribal population of Nilgiris, Tamil Nadu - a cross sectional study

    Directory of Open Access Journals (Sweden)

    Vikneshan Murugaboopathy

    2018-03-01

    Full Text Available Background Tobacco use is attributed for deaths of 3.5 to 4 million people globally, which is expected to increase to about 10 million during 2020 and around more than two-third will be occurring in developing countries as they are showing an increasing trends of tobacco use. Anti-tobacco messages or campaigns do not reach the Tribal regions. Tobacco use is ingrained in many of the cultural practices of tribal people. This study aimed to assess the prevalence of tobacco usage among tribal populations of Nilgiris region, Tamil Nadu. Methods A cross sectional study was conducted among 4 villages of Conoor and Kothagiri districts of nilgiris region. A total of 363 people were screened and their tobacco usage status was assessed using Interview method. A trained interviewer along with help of community leader collected information about the usage of tobacco among the populations. Oral health status and presence of oral mucosal lesions were also recorded. Results Smokeless tobacco usage was high among the subjects. Majority of the males between 21-40 years were having both smoking and smokeless tobacco. Bidis was the most common form of smoking tobacco and gutka was the commonest smokeless tobacco used. More than 32% females in the age group of 30-45 years were tobacco users. Conclusions Tobacco usage was high among the tribal populations. Interestingly, the number of tobacco users among females was more prevalent. Customized tobacco cessation education programs has to be carried out for effective control of tobacco usage among the tribal population of Nilgiris region.

  19. Prevalence of renal artery stenosis in subjects with moderate hypertension. A population-based study

    DEFF Research Database (Denmark)

    Andersen, Ulrik B; Borglykke, Anders; Jørgensen, Torben

    2011-01-01

    Abstract Aim. To examine the prevalence of significant renal artery stenosis (RAS) in subjects with moderate to severe hypertension. Materials and methods. Subjects aged 50-66 years with blood pressure >160/100 mmHg or receiving antihypertensive treatment were selected from the population study...

  20. Association of STAT4 with rheumatoid arthritis: a replication study in three European populations.

    NARCIS (Netherlands)

    Orozco, G.; Alizadeh, B.Z.; Delgado-Vega, A.M.; Gonzalez-Gay, M.A.; Balsa, A.; Pascual-Salcedo, D.; Fernandez-Gutierrez, B.; Gonzalez-Escribano, M.F.; Petersson, I.F.; Riel, P.L.C.M. van; Barrera, P.; Coenen, M.J.H.; Radstake, T.R.D.J.; Leeuwen, M.A. van; Wijmenga, C.; Koeleman, B.P.; Alarcon-Riquelme, M.E.; Martin, J.

    2008-01-01

    OBJECTIVE: This study was undertaken to investigate the previously reported association of the STAT4 polymorphism rs7574865 with rheumatoid arthritis (RA) in 3 different European populations from Spain, Sweden, and The Netherlands, comprising a total of 2,072 patients and 2,474 controls. METHODS:

  1. Searching for Rigour in the Reporting of Mixed Methods Population Health Research: A Methodological Review

    Science.gov (United States)

    Brown, K. M.; Elliott, S. J.; Leatherdale, S. T.; Robertson-Wilson, J.

    2015-01-01

    The environments in which population health interventions occur shape both their implementation and outcomes. Hence, when evaluating these interventions, we must explore both intervention content and context. Mixed methods (integrating quantitative and qualitative methods) provide this opportunity. However, although criteria exist for establishing…

  2. Methods for estimating population coverage of mass distribution programmes: a review of practices in relation to trachoma control.

    Science.gov (United States)

    Cromwell, Elizabeth A; Ngondi, Jeremiah; McFarland, Deborah; King, Jonathan D; Emerson, Paul M

    2012-10-01

    In the context of trachoma control, population coverage with mass drug administration (MDA) using antibiotics is measured using routine data. Due to the limitations of administrative records as well as the potential for bias from incomplete or incorrect records, a literature review of coverage survey methods applied in neglected tropical disease control programmes and immunisation outreach was conducted to inform the design of coverage surveys for trachoma control. Several methods were identified, including the '30 × 7' survey method for the Expanded Programme on Immunization (EPI 30×7), other cluster random sampling (CRS) methods, lot quality assurance sampling (LQAS), purposive sampling and routine data. When compared against one another, the EPI and other CRS methods produced similar population coverage estimates, whilst LQAS, purposive sampling and use of administrative data did not generate estimates consistent with CRS. In conclusion, CRS methods present a consistent approach for MDA coverage surveys despite different methods of household selection. They merit use until standard guidelines are available. CRS methods should be used to verify population coverage derived from LQAS, purposive sampling methods and administrative reports. Copyright © 2012 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  3. Digital radiographic evaluation of mandibular third molar for age estimation in young adults and adolescents of South Indian population using modified Demirjian's method.

    Science.gov (United States)

    Mohammed, Rezwana Begum; Koganti, Ravichandra; Kalyan, Siva V; Tircouveluri, Saritha; Singh, Johar Rajvinder; Srinivasulu, Enganti

    2014-09-01

    In recent years, it has become increasingly important to determine the age of living people for a variety of reasons, including identifying criminal and legal responsibility and for many other social events such as birth certificate, marriage, beginning a job, joining the army and retirement. The aim of this study was to assess the developmental stages of mandibular third molar for estimation of dental age (DA) in different age groups and to evaluate the possible correlation between DA and chronological age (CA) in South Indian population. Digital orthopantomography of 330 subjects (165 males, 165 females) who fit the study and the criteria were obtained. Assessment of mandibular third molar development was performed using Demirjian et al., modified method and DA was assessed using tooth specific stages. The present study showed a significant correlation between DA and CA in both males and females. Third molar development commenced around 9 years and root completion takes place around 18.9 years in males and in females 9 years and 18.6 years respectively. Demirjian modified method underestimated the mean age of males by 0.8 years and females by 0.5 years and also showed that females mature earlier than males in selected population. Digital radiographic assessment of mandibular third molar development can be used to generate mean DA using Demirjian modified method and also the estimated age range for an individual of unknown CA. Since the Demirjian method is based on French-Canadian population, to enhance the accuracy of forensic age estimates based on third molar development, the use of population-specific standards is recommended.

  4. ERECTOR SPINAE AND SCOLIOSIS IN A POPULATION WITH CEREBRAL PALSY: A PRELIMINARY STUDY

    Directory of Open Access Journals (Sweden)

    OSAMA J. ALÍ-MORELL

    Full Text Available ABSTRACT Objective: To verify the relation of muscular response to the vestibular stimulation of the erector spinae, specifically longissimus thoracis and iliocostalis lumborum, with the origin of scoliosis in a population of individuals with level V cerebral palsy of the Gross Motor Function Classification System (GMFCS. Methods: Cross-sectional study of 12 individuals aged between four and 14 years. The muscular activity of the longissimus thoracis and iliocostalis lumborum was recorded by electromyography in the presence of anteroposterior and lateral imbalances, comparing it with that obtained in sitting position without imbalances. Scoliosis was assessed by radiological study following Cobb method. Results: Statistically significant differences were found between correct responses of both muscles to anteroposterior imbalances and absence of right thoracolumbar scoliosis (p=0.005; p=0.028, left thoracic scoliosis (p=0.005; p=0.046 and right lumbar scoliosis (p=0.005; p=0.046. Conclusions: The symmetry of muscular responses to anteroposterior imbalances, both of longissimus thoracis and iliocostalis lumborum, seems to be one of the factors that prevent the development of spine deviations in this population. Level of evidence: IV. Type of Study: Case series

  5. A principled dimension-reduction method for the population density approach to modeling networks of neurons with synaptic dynamics.

    Science.gov (United States)

    Ly, Cheng

    2013-10-01

    The population density approach to neural network modeling has been utilized in a variety of contexts. The idea is to group many similar noisy neurons into populations and track the probability density function for each population that encompasses the proportion of neurons with a particular state rather than simulating individual neurons (i.e., Monte Carlo). It is commonly used for both analytic insight and as a time-saving computational tool. The main shortcoming of this method is that when realistic attributes are incorporated in the underlying neuron model, the dimension of the probability density function increases, leading to intractable equations or, at best, computationally intensive simulations. Thus, developing principled dimension-reduction methods is essential for the robustness of these powerful methods. As a more pragmatic tool, it would be of great value for the larger theoretical neuroscience community. For exposition of this method, we consider a single uncoupled population of leaky integrate-and-fire neurons receiving external excitatory synaptic input only. We present a dimension-reduction method that reduces a two-dimensional partial differential-integral equation to a computationally efficient one-dimensional system and gives qualitatively accurate results in both the steady-state and nonequilibrium regimes. The method, termed modified mean-field method, is based entirely on the governing equations and not on any auxiliary variables or parameters, and it does not require fine-tuning. The principles of the modified mean-field method have potential applicability to more realistic (i.e., higher-dimensional) neural networks.

  6. Development and evaluation of a new method for sampling and monitoring the symphylid population in pineapple

    OpenAIRE

    Soler, A.; Gaude, J. M.; Marie-Alphonsine, P. A.; Vinatier, F.; Dole, B.; Govindin, J. C.; Fournier, P.; Quénéhervé, Patrick

    2011-01-01

    BACKGROUND: Symphylids (Hanseniella sp.) are polyphagous soilborne parasites. Today, symphylid populations on pineapple are monitored by observing root symptoms and the presence of symphylids at the bottom of basal leaves. The authors developed a reliable method with a bait and trap device to monitor symphylid populations in pineapple or fallow crops. The spatial distribution of the symphylid populations was evaluated using the variance/mean ratios and spatial analyses based on Moran's and Ge...

  7. Modifiable etiological factors and the burden of stroke from the Rotterdam study: a population-based cohort study.

    Directory of Open Access Journals (Sweden)

    Michiel J Bos

    2014-04-01

    Full Text Available BACKGROUND: Stroke prevention requires effective treatment of its causes. Many etiological factors for stroke have been identified, but the potential gain of effective intervention on these factors in terms of numbers of actually prevented strokes remains unclear because of the lack of data from cohort studies. We assessed the impact of currently known potentially modifiable etiological factors on the occurrence of stroke. METHODS AND FINDINGS: This population-based cohort study was based on 6,844 participants of the Rotterdam Study who were aged ≥55 y and free from stroke at baseline (1990-1993. We computed population attributable risks (PARs for individual risk factors and for risk factors in combination to estimate the proportion of strokes that could theoretically be prevented by the elimination of etiological factors from the population. The mean age at baseline was 69.4 y (standard deviation 6.3 y. During follow-up (mean follow-up 12.9 y, standard deviation 6.3 y, 1,020 strokes occurred. The age- and sex-adjusted combined PAR of prehypertension/hypertension, smoking, diabetes mellitus, atrial fibrillation, coronary disease, and overweight/obesity was 0.51 (95% CI 0.41-0.62 for any stroke; hypertension and smoking were the most important etiological factors. C-reactive protein, fruit and vegetable consumption, and carotid intima-media thickness in combination raised the total PAR by 0.06. The PAR was 0.55 (95% CI 0.41-0.68 for ischemic stroke and 0.70 (95% CI 0.45-0.87 for hemorrhagic stroke. The main limitations of our study are that our study population comprises almost exclusively Caucasians who live in a middle and high income area, and that risk factor awareness is higher in a study cohort than in the general population. CONCLUSIONS: About half of all strokes are attributable to established causal and modifiable factors. This finding encourages not only intervention on established etiological factors, but also further study of less

  8. Celebrity suicides and their differential influence on suicides in the general population: a national population-based study in Korea.

    Science.gov (United States)

    Myung, Woojae; Won, Hong-Hee; Fava, Maurizio; Mischoulon, David; Yeung, Albert; Lee, Dongsoo; Kim, Doh Kwan; Jeon, Hong Jin

    2015-04-01

    Although evidence suggests that there is an increase in suicide rates in the general population following celebrity suicide, the rates are heterogeneous across celebrities and countries. It is unclear which is the more vulnerable population according to the effect sizes of celebrity suicides to general population. All suicide victims in the general population verified by the Korea National Statistical Office and suicides of celebrity in South Korea were included for 7 years from 2005 to 2011. Effect sizes were estimated by comparing rates of suicide in the population one month before and after each celebrity suicide. The associations between suicide victims and celebrities were examined. Among 94,845 suicide victims, 17,209 completed suicide within one month after 13 celebrity suicides. Multivariate logistic regression analyses revealed that suicide victims who died after celebrity suicide were significantly likely to be of age 20-39, female, and to die by hanging. These qualities were more strongly associated among those who followed celebrity suicide with intermediate and high effect sizes than lower. Younger suicide victims were significantly associated with higher effect size, female gender, white collar employment, unmarried status, higher education, death by hanging, and night-time death. Characteristics of celebrities were significantly associated with those of general population in hanging method and gender. Individuals who commit suicide after a celebrity suicide are likely to be younger, female, and prefer hanging as method of suicide, which are more strongly associated in higher effect sizes of celebrity suicide.

  9. Use of antimicrobial drugs in general hospitals. I. Description of population and definition of methods.

    Science.gov (United States)

    Townsend, T R; Shapiro, M; Rosner, B; Kass, E H

    1979-06-01

    The patterns of use of antimicrobial drugs in a random sample of general hosptials in Pennsylvania were studied. The sample was tested for validity, and all deaths and discharges were analyzed for 10 random days drawn across the year spanning July 1973 to June 1974. Methods were developed for abstracting the hospital records and for determining the reproducibility of the findings of the physician and nonphysician chart reviewers. More than 99% of the requested charts were available. In the 5,288 charts reviewed, most of the required data were readily available. The study population was 84% white and 58% female; most patients were in hospitals that had more than 300 beds and that were located in towns with populations of greater than 10,000. In 41% of the 2,070 antimicrobial courses administered to almost 30% of the patients, an explicit clinical statement of why the drug was being given could be found in the chart. The information for review was found in clinical charts, but in half of the charts, the information required was not on face sheets and discharge summaries.

  10. Potential rapd markers for population studies in tree legumes

    International Nuclear Information System (INIS)

    Gomez, S.M.; Ramasubramanian, T.; Mohankumar, S.

    2011-01-01

    RAPDs were quite efficient in bringing out the diversity at DNA level among non-edible legumes viz., Acacia nilotica, Adenanthera pavonina, Prosopis juliflora, Pithecolobium dulce, Clitoria ternatea and Pongamia pinnata. The RAPD primer index reveals the information content of the RAPD primer per se. Of the 82 primers tested, OPE 8, OPI 6, OPL 2, OPL 16, OPI 18, OPI 13, OPI 14, OPP 1, OPE 20 and OPI 4 with comparatively higher primer index were more informative and can be used for further DNA finger printing and population studies in tree legumes. CTAB protocol was found to be superior in isolating genomic DNA of good quality. The 260/280 ratios varied between 1.70 and 2.09. Though the genomic DNA isolated by potassium acetate method was found to be intact in 0.8% agarose gel, the yield was significantly lower than the modified CTAB method. (author)

  11. Lifestyle Characteristics and Gastroesophageal Reflux Disease: A Population-Based Study in Albania

    Directory of Open Access Journals (Sweden)

    Lulzim Çela

    2013-01-01

    Full Text Available Aim. We aimed to assess the prevalence and lifestyle correlates of gastroesophageal reflux disease (GERD in the adult population of Albania, a Mediterranean country in Southeast Europe which has experienced major behavioral changes in the past two decades. Methods. A cross-sectional study, conducted in 2012, included a population-representative sample of 845 individuals (≥18 years residing in Tirana (345 men, mean age: ; 500 women, mean age: ; response rate: 84.5%. Assessment of GERD was based on Montreal definition. Covariates included socioeconomic characteristics, lifestyle factors, and body mass index. Logistic regression was used to assess the association of socioeconomic characteristics and lifestyle factors with GERD. Results. The overall prevalence of GERD was 11.9%. There were no significant sex differences, but a higher prevalence among the older participants. In fully adjusted models, there was a positive relationship of GERD with smoking, physical inactivity, fried food consumption, and obesity, but not so for alcohol intake and meat consumption. Conclusion. We obtained important evidence on the prevalence and lifestyle correlates of GERD in a Western Balkans' country. Smoking, physical inactivity, and obesity were strong “predictors” of GERD in this population. Findings from this study should be replicated in prospective studies in Albania and other transitional settings.

  12. Comparative performance of different stochastic methods to simulate drug exposure and variability in a population.

    Science.gov (United States)

    Tam, Vincent H; Kabbara, Samer

    2006-10-01

    Monte Carlo simulations (MCSs) are increasingly being used to predict the pharmacokinetic variability of antimicrobials in a population. However, various MCS approaches may differ in the accuracy of the predictions. We compared the performance of 3 different MCS approaches using a data set with known parameter values and dispersion. Ten concentration-time profiles were randomly generated and used to determine the best-fit parameter estimates. Three MCS methods were subsequently used to simulate the AUC(0-infinity) of the population, using the central tendency and dispersion of the following in the subject sample: 1) K and V; 2) clearance and V; 3) AUC(0-infinity). In each scenario, 10000 subject simulations were performed. Compared to true AUC(0-infinity) of the population, mean biases by various methods were 1) 58.4, 2) 380.7, and 3) 12.5 mg h L(-1), respectively. Our results suggest that the most realistic MCS approach appeared to be based on the variability of AUC(0-infinity) in the subject sample.

  13. Accurate and fast methods to estimate the population mutation rate from error prone sequences

    Directory of Open Access Journals (Sweden)

    Miyamoto Michael M

    2009-08-01

    Full Text Available Abstract Background The population mutation rate (θ remains one of the most fundamental parameters in genetics, ecology, and evolutionary biology. However, its accurate estimation can be seriously compromised when working with error prone data such as expressed sequence tags, low coverage draft sequences, and other such unfinished products. This study is premised on the simple idea that a random sequence error due to a chance accident during data collection or recording will be distributed within a population dataset as a singleton (i.e., as a polymorphic site where one sampled sequence exhibits a unique base relative to the common nucleotide of the others. Thus, one can avoid these random errors by ignoring the singletons within a dataset. Results This strategy is implemented under an infinite sites model that focuses on only the internal branches of the sample genealogy where a shared polymorphism can arise (i.e., a variable site where each alternative base is represented by at least two sequences. This approach is first used to derive independently the same new Watterson and Tajima estimators of θ, as recently reported by Achaz 1 for error prone sequences. It is then used to modify the recent, full, maximum-likelihood model of Knudsen and Miyamoto 2, which incorporates various factors for experimental error and design with those for coalescence and mutation. These new methods are all accurate and fast according to evolutionary simulations and analyses of a real complex population dataset for the California seahare. Conclusion In light of these results, we recommend the use of these three new methods for the determination of θ from error prone sequences. In particular, we advocate the new maximum likelihood model as a starting point for the further development of more complex coalescent/mutation models that also account for experimental error and design.

  14. Impact of Rainfall, Land-Cover and Population Growth on Groundwater - A Case Study From Karnataka State, India

    Science.gov (United States)

    Srivastav, R. K.; Chinnapa Reddy, A. R.

    2015-12-01

    Recent trends in climate, land-use pattern and population has affected almost every portable water resources in the world. Due to depleting surface water and untimely distribution of precipitation, the demand to use groundwater has increased considerably. Further recent studies have shown that the groundwater stress is more in developing countries like India. This study focuses on understanding the impacts of three major factors (i.e., rainfall, land-cover and population growth) effecting the groundwater levels. For this purpose, the correlation between the trends in groundwater time series is compared with trends in rainfall, land-cover and population growth. To detect the trends in time series, two statistical methods namely, least square method and Mann-Kendall method, are adopted. The results were analyzed based on the measurements from 1800 observation wells in the Karnataka state, India. The data is obtained for a total of 9 year time period ranging from 2005 to 2013. A gridded precipitation data of 0.5o× 0.5o over the entire region is used. The change in land-cover and population data was approximately obtained from the local governing bodies. The early results show significant correlation between rainfall and groundwater time series trends. The outcomes will assess the vulnerability of groundwater levels under changing physical and hydroclimatic conditions, especially under climate change.

  15. Outline-based morphometrics, an overlooked method in arthropod studies?

    Science.gov (United States)

    Dujardin, Jean-Pierre; Kaba, D; Solano, P; Dupraz, M; McCoy, K D; Jaramillo-O, N

    2014-12-01

    Modern methods allow a geometric representation of forms, separating size and shape. In entomology, as well as in many other fields involving arthropod studies, shape variation has proved useful for species identification and population characterization. In medical entomology, it has been applied to very specific questions such as population structure, reinfestation of insecticide-treated areas and cryptic species recognition. For shape comparisons, great importance is given to the quality of landmarks in terms of comparability. Two conceptually and statistically separate approaches are: (i) landmark-based morphometrics, based on the relative position of a few anatomical "true" or "traditional" landmarks, and (ii) outline-based morphometrics, which captures the contour of forms through a sequence of close "pseudo-landmarks". Most of the studies on insects of medical, veterinary or economic importance make use of the landmark approach. The present survey makes a case for the outline method, here based on elliptic Fourier analysis. The collection of pseudo-landmarks may require the manual digitization of many points and, for this reason, might appear less attractive. It, however, has the ability to compare homologous organs or structures having no landmarks at all. This strength offers the possibility to study a wider range of anatomical structures and thus, a larger range of arthropods. We present a few examples highlighting its interest for separating close or cryptic species, or characterizing conspecific geographic populations, in a series of different vector organisms. In this simple application, i.e. the recognition of close or cryptic forms, the outline approach provided similar scores as those obtained by the landmark-based approach. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Diagnosis of Dementia by Machine learning methods in Epidemiological studies: a pilot exploratory study from south India.

    Science.gov (United States)

    Bhagyashree, Sheshadri Iyengar Raghavan; Nagaraj, Kiran; Prince, Martin; Fall, Caroline H D; Krishna, Murali

    2018-01-01

    There are limited data on the use of artificial intelligence methods for the diagnosis of dementia in epidemiological studies in low- and middle-income country (LMIC) settings. A culture and education fair battery of cognitive tests was developed and validated for population based studies in low- and middle-income countries including India by the 10/66 Dementia Research Group. We explored the machine learning methods based on the 10/66 battery of cognitive tests for the diagnosis of dementia based in a birth cohort study in South India. The data sets for 466 men and women for this study were obtained from the on-going Mysore Studies of Natal effect of Health and Ageing (MYNAH), in south India. The data sets included: demographics, performance on the 10/66 cognitive function tests, the 10/66 diagnosis of mental disorders and population based normative data for the 10/66 battery of cognitive function tests. Diagnosis of dementia from the rule based approach was compared against the 10/66 diagnosis of dementia. We have applied machine learning techniques to identify minimal number of the 10/66 cognitive function tests required for diagnosing dementia and derived an algorithm to improve the accuracy of dementia diagnosis. Of 466 subjects, 27 had 10/66 diagnosis of dementia, 19 of whom were correctly identified as having dementia by Jrip classification with 100% accuracy. This pilot exploratory study indicates that machine learning methods can help identify community dwelling older adults with 10/66 criterion diagnosis of dementia with good accuracy in a LMIC setting such as India. This should reduce the duration of the diagnostic assessment and make the process easier and quicker for clinicians, patients and will be useful for 'case' ascertainment in population based epidemiological studies.

  17. Recurrent bacteraemia: A 10-year regional population-based study of clinical and microbiological risk factors

    DEFF Research Database (Denmark)

    Jensen, U.S.; Knudsen, J.D.; Andersen, Christian Østergaard

    2010-01-01

    Background: A population-based nested case-control study was conducted in order to characterize patient factors and microbial species associated with recurrent bacteraemia. Methods: All patients with bacteraemia in a Danish region during 1996-2006 were investigated. Recurrence was defined based o...

  18. Sleep disturbances in an arctic population: The Tromsø Study

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    Straand Jørund

    2008-05-01

    Full Text Available Abstract Background Prevalence estimates for insomnia range from 10 to 50% in the adult general population. Sleep disturbances cause great impairment in quality of life, which might even rival or exceed the impairment in other chronic medical disorders. The economic implications and use of health-care services related to chronic insomnia represent a clinical concern as well as a pronounced public health problem. Hypnotics are frequently prescribed for insomnia, but alcohol and over-the-counter sleep aids seem to be more widely used by insomniacs than prescription medications. Despite the complex relationship between insomnia and physical and mental health factors, the condition appears to be underrecognized and undertreated by health care providers, probably due to the generally limited knowledge of the causes and natural development of insomnia. Methods/Design The Tromsø Study is an ongoing population-based cohort study with five previous health studies undertaken between 1974 and 2001. This protocol outlines a planned study within the sixth Tromsø Study (Tromsø VI, aiming at; 1 describing sleep patterns in a community-based sample representative of the general population of northern Norway, and 2 examining outcome variables of sleep disturbances against possible explanatory and confounding variables, both within a cross-sectional approach, as well as retrospectively in a longitudinal study – exploring sleep patterns in subjects who have attended two or more of the previous Tromsø studies between 1974 and 2009. First, we plan to perform a simple screening in order to identify those participants with probable sleep disturbances, and secondly to investigate these sleep disturbances further, using an extensive sleep-questionnaire. We will also collect biological explanatory variables, i.e. blood samples, weight, height and blood pressure. We plan to merge data on an individual level from the Tromsø VI Study with data from the Norwegian

  19. Epidemiological methods for research with drug misusers: review of methods for studying prevalence and morbidity

    Directory of Open Access Journals (Sweden)

    Dunn John

    1999-01-01

    Full Text Available Epidemiological studies of drug misusers have until recently relied on two main forms of sampling: probability and convenience. The former has been used when the aim was simply to estimate the prevalence of the condition and the latter when in depth studies of the characteristics, profiles and behaviour of drug users were required, but each method has its limitations. Probability samples become impracticable when the prevalence of the condition is very low, less than 0.5% for example, or when the condition being studied is a clandestine activity such as illicit drug use. When stratified random samples are used, it may be difficult to obtain a truly representative sample, depending on the quality of the information used to develop the stratification strategy. The main limitation of studies using convenience samples is that the results cannot be generalised to the whole population of drug users due to selection bias and a lack of information concerning the sampling frame. New methods have been developed which aim to overcome some of these difficulties, for example, social network analysis, snowball sampling, capture-recapture techniques, privileged access interviewer method and contact tracing. All these methods have been applied to the study of drug misuse. The various methods are described and examples of their use given, drawn from both the Brazilian and international drug misuse literature.

  20. Progression to impaired glucose regulation and diabetes in the population-based Inter99 study

    DEFF Research Database (Denmark)

    Engberg, Susanne; Vistisen, Dorte; Lau, Cathrine

    2009-01-01

    Objective: To estimate the progression rates to impaired glucose regulation (impaired fasting glucose or impaired glucose tolerance) and diabetes in the Danish population-based Inter99 study and in a high-risk subpopulation, separately. Research Design and Methods: From a population-based primary...... glucose regulation using the current World Health Organization classification criteria were calculated for the first time in a large European population-based study. The progression rates to diabetes show the same pattern as seen in the few similar European studies....... prevention study, the Inter99 study, 4,615 individuals without diabetes at baseline and with relevant follow-up data were divided into a low- and a high-risk group based on a risk estimate of ischemic heart disease or the presence of risk factors (smoking, hypertension, hypercholesterolemia, obesity...... estimated directly from baseline to 5-year follow-up for all the participants, and from baseline through 1- and 3-, to 5-year follow-up for the high-risk individuals, separately. Results: In the combined low- and high-risk group, 2.1 per 100 person-years progressed from normal glucose tolerance to impaired...

  1. Fast and reliable methods for extracting functional connectivity in large populations

    DEFF Research Database (Denmark)

    Roudi, Yasser; Tyrcha, Joanna; Hertz, John

    2009-01-01

    in that time bin, and 1 if it has emitted one spike or more. One then can construct an Ising model, P(s )=Z-1exp{h.s+sJs} for the spike patterns with the same means and pair correlations as the data, using Boltzmann learning, which is in principle exact.  The elements Jij , of the matrix J can be considered...... to be functional couplings. However, Boltzmann learning is prohibitively time-consuming for large networks. Here, we compare the results from five fast approximate methods for finding the couplings with those from Boltzmann learning.      We used data from a simulated network of spiking neurons operating...... in a balanced state of asynchronous firing with a mean rate of ~10 Hz for excitatory neurons. Employing a bin size of 10 ms, we performed Boltzmann learning to fit Ising models for populations of size N up to 200 excitatory neurons chosen randomly from the 800 in the simulated network.  We studied the following...

  2. Setting population targets for mammals using body mass as a predictor of population persistence.

    Science.gov (United States)

    Hilbers, Jelle P; Santini, Luca; Visconti, Piero; Schipper, Aafke M; Pinto, Cecilia; Rondinini, Carlo; Huijbregts, Mark A J

    2017-04-01

    Conservation planning and biodiversity assessments need quantitative targets to optimize planning options and assess the adequacy of current species protection. However, targets aiming at persistence require population-specific data, which limit their use in favor of fixed and nonspecific targets, likely leading to unequal distribution of conservation efforts among species. We devised a method to derive equitable population targets; that is, quantitative targets of population size that ensure equal probabilities of persistence across a set of species and that can be easily inferred from species-specific traits. In our method, we used models of population dynamics across a range of life-history traits related to species' body mass to estimate minimum viable population targets. We applied our method to a range of body masses of mammals, from 2 g to 3825 kg. The minimum viable population targets decreased asymptotically with increasing body mass and were on the same order of magnitude as minimum viable population estimates from species- and context-specific studies. Our approach provides a compromise between pragmatic, nonspecific population targets and detailed context-specific estimates of population viability for which only limited data are available. It enables a first estimation of species-specific population targets based on a readily available trait and thus allows setting equitable targets for population persistence in large-scale and multispecies conservation assessments and planning. © 2016 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

  3. EpiReumaPt: how to perform a national population based study - a practical guide

    OpenAIRE

    Gouveia, Nélia; Rodrigues, Ana M.; Ramiro, Sofia; Machado, Pedro; Da Costa, Leonor Pereira; Mourão, Ana Filipa; Silva, Inês; Rego, Tânia; Laires, Pedro; André, Rui; Mauricio, Luís; Romeu, José Carlos; Tavares, Viviana; Cerol, Jorge; Canhão, Helena

    2015-01-01

    BACKGROUND: The aim of this article was to describe and discuss several strategies and standard operating procedures undertaken in the EpiReumaPt study - which was the first Portuguese, national, cross-sectional population-based study of Rheumatic and Musculoskeletal Diseases (RMD). METHODS: The technical procedures, legal issues, management and practical questions were studied, analyzed and discussed with relevant stakeholders. During the 1st phase of EpiReumaPt the coordination team and Cen...

  4. Evidence for Association of the E23K Variant of KCNJ11 Gene with Type 2 Diabetes in Tunisian Population: Population-Based Study and Meta-Analysis

    Science.gov (United States)

    Lasram, Khaled; Ben Halim, Nizar; Hsouna, Sana; Kefi, Rym; Arfa, Imen; Ghazouani, Welid; Jamoussi, Henda; Benrahma, Houda; Kharrat, Najla; Rebai, Ahmed; Ben Ammar, Slim; Bahri, Sonia; Barakat, Abdelhamid; Abid, Abdelmajid; Abdelhak, Sonia

    2014-01-01

    Aims. Genetic association studies have reported the E23K variant of KCNJ11 gene to be associated with Type 2 diabetes. In Arab populations, only four studies have investigated the role of this variant. We aimed to replicate and validate the association between the E23K variant and Type 2 diabetes in Tunisian and Arab populations. Methods. We have performed a case-control association study including 250 Tunisian patients with Type 2 diabetes and 267 controls. Allelic association has also been evaluated by 2 meta-analyses including all population-based studies among Tunisians and Arabs (2 and 5 populations, resp.). Results. A significant association between the E23K variant and Type 2 diabetes was found (OR = 1.6, 95% CI = 1.14–2.27, and P = 0.007). Furthermore, our meta-analysis has confirmed the significant role of the E23K variant in susceptibility of Type 2 diabetes in Tunisian and Arab populations (OR = 1.29, 95% CI = 1.15–1.46, and P < 10−3 and OR = 1.33, 95% CI = 1.13–1.56, and P = 0.001, resp.). Conclusion. Both case-control and meta-analyses results revealed the significant association between the E23K variant of KCNJ11 and Type 2 diabetes among Tunisians and Arabs. PMID:25165692

  5. Evidence for Association of the E23K Variant of KCNJ11 Gene with Type 2 Diabetes in Tunisian Population: Population-Based Study and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Khaled Lasram

    2014-01-01

    Full Text Available Aims. Genetic association studies have reported the E23K variant of KCNJ11 gene to be associated with Type 2 diabetes. In Arab populations, only four studies have investigated the role of this variant. We aimed to replicate and validate the association between the E23K variant and Type 2 diabetes in Tunisian and Arab populations. Methods. We have performed a case-control association study including 250 Tunisian patients with Type 2 diabetes and 267 controls. Allelic association has also been evaluated by 2 meta-analyses including all population-based studies among Tunisians and Arabs (2 and 5 populations, resp.. Results. A significant association between the E23K variant and Type 2 diabetes was found (OR = 1.6, 95% CI = 1.14–2.27, and P=0.007. Furthermore, our meta-analysis has confirmed the significant role of the E23K variant in susceptibility of Type 2 diabetes in Tunisian and Arab populations (OR = 1.29, 95% CI = 1.15–1.46, and P<10-3 and OR = 1.33, 95% CI = 1.13–1.56, and P=0.001, resp.. Conclusion. Both case-control and meta-analyses results revealed the significant association between the E23K variant of KCNJ11 and Type 2 diabetes among Tunisians and Arabs.

  6. Prevalence, incidence and mortality of type 2 diabetes mellitus revisited : A prospective population-based study in The Netherlands (ZODIAC-1)

    NARCIS (Netherlands)

    Ubink-Veltmaat, LJ; Bilo, HJG; Groenier, KH; Houweling, ST; Rischen, RO; Meyboom-de Jong, B

    2003-01-01

    Background: To present actual data to estimate prevalence, incidence and mortality of known type 2 diabetes mellitus in all age categories in The Netherlands. Methods: Prospective population-based study between 1998 and 2000 in The Netherlands. Baseline population of 155,774 patients, registered

  7. A comparison of methods for calculating population exposure estimates of daily weather for health research

    Directory of Open Access Journals (Sweden)

    Dear Keith BG

    2006-09-01

    Full Text Available Abstract Background To explain the possible effects of exposure to weather conditions on population health outcomes, weather data need to be calculated at a level in space and time that is appropriate for the health data. There are various ways of estimating exposure values from raw data collected at weather stations but the rationale for using one technique rather than another; the significance of the difference in the values obtained; and the effect these have on a research question are factors often not explicitly considered. In this study we compare different techniques for allocating weather data observations to small geographical areas and different options for weighting averages of these observations when calculating estimates of daily precipitation and temperature for Australian Postal Areas. Options that weight observations based on distance from population centroids and population size are more computationally intensive but give estimates that conceptually are more closely related to the experience of the population. Results Options based on values derived from sites internal to postal areas, or from nearest neighbour sites – that is, using proximity polygons around weather stations intersected with postal areas – tended to include fewer stations' observations in their estimates, and missing values were common. Options based on observations from stations within 50 kilometres radius of centroids and weighting of data by distance from centroids gave more complete estimates. Using the geographic centroid of the postal area gave estimates that differed slightly from the population weighted centroids and the population weighted average of sub-unit estimates. Conclusion To calculate daily weather exposure values for analysis of health outcome data for small areas, the use of data from weather stations internal to the area only, or from neighbouring weather stations (allocated by the use of proximity polygons, is too limited. The most

  8. Menstrual pad, a cervical cancer screening tool, a population-based study in rural India.

    Science.gov (United States)

    Budukh, Atul; Palayekar, Vrushali; Maheshwari, Amita; Deodhar, Kedar; Purwar, Pallavi; Bagal, Sonali; Vadigoppula, Ashok; Lokhande, Manoj; Panse, Nandkumar; Dikshit, Rajesh; Badwe, Rajendra

    2017-07-12

    In the rural areas of India, women generally use a piece of old cloth as a menstrual device. The aim of this study was to detect human papilloma virus (HPV) from menstrual blood on the menstrual pad and assess whether this could be a useful screening tool for cervical cancer. In Jamkhed area of rural Maharashtra, (population A), we collected menstrual pads from women who provided consent in the 30-50 year age group. The women who had provided menstrual pads underwent HC2 testing. We standardized the method for extracting DNA by PCR from the menstrual pad. The women who tested HPV positive, on the basis of HC2/PCR testing, underwent colposcopy. In the rural population of Pune area of Maharashtra state (population B), menstrual pads were collected. HPV was tested using the PCR method. HPV-positive women and a few HPV-negative women, selected randomly, underwent colposcopy and HC2 testing. In population A, 164 women provided their used menstrual pads and also underwent an HC2 screening test. Of these, six (3.2%) cases were reported as HPV positive. In population B, 365 women provided their used menstrual pads for HPV testing, of which 18 (4.9%) cases were diagnosed as HPV positive. The women who tested HPV positive, on the basis of PCR testing, and 10% randomly selected HPV-negative cases (37) and 18 women who voluntary requested testing underwent colposcopy and HC2 testing. The sensitivity of menstrual pad HPV testing compared with gold standard HC2 testing was 83% [95% confidence interval (CI): 0.47-0.97], 67% (95% CI: 0.30-0.91) and specificity was 99% (95% CI: 0.96-0.99), 88% (95% CI: 0.77-0.94) in population A and population B, respectively. The sensitivity of diagnosing CIN lesion was 83% (95% CI: 0.44-0.97) and specificity was 95% (95% CI: 0.91-0.97). On the basis of the sensitivity and specificity results, and the completely noninvasive, simple and convenient method of detecting HPV, menstrual pad might be considered a cervical cancer screening tool in rural

  9. Innovative research methods for studying treatments for rare diseases: methodological review.

    Science.gov (United States)

    Gagne, Joshua J; Thompson, Lauren; O'Keefe, Kelly; Kesselheim, Aaron S

    2014-11-24

    To examine methods for generating evidence on health outcomes in patients with rare diseases. Methodological review of existing literature. PubMed, Embase, and Academic Search Premier searched for articles describing innovative approaches to randomized trial design and analysis methods and methods for conducting observational research in patients with rare diseases. We assessed information related to the proposed methods, the specific rare disease being studied, and outcomes from the application of the methods. We summarize methods with respect to their advantages in studying health outcomes in rare diseases and provide examples of their application. We identified 46 articles that proposed or described methods for studying patient health outcomes in rare diseases. Articles covered a wide range of rare diseases and most (72%) were published in 2008 or later. We identified 16 research strategies for studying rare disease. Innovative clinical trial methods minimize sample size requirements (n=4) and maximize the proportion of patients who receive active treatment (n=2), strategies crucial to studying small populations of patients with limited treatment choices. No studies describing unique methods for conducting observational studies in patients with rare diseases were identified. Though numerous studies apply unique clinical trial designs and considerations to assess patient health outcomes in rare diseases, less attention has been paid to innovative methods for studying rare diseases using observational data. © Gagne et al 2014.

  10. Replication of genome wide association studies on hepatocellular carcinoma susceptibility loci in a Chinese population.

    Directory of Open Access Journals (Sweden)

    Kangmei Chen

    Full Text Available BACKGROUND: Genome-wide association studies (GWAS have identified three loci (rs17401966 in KIF1B, rs7574865 in STAT4, rs9275319 in HLA-DQ as being associated with hepatitis B virus-related hepatocellular carcinoma (HBV-related HCC in a Chinese population, two loci (rs2596542 in MICA, rs9275572 located between HLA-DQA and HLA-DQB with hepatitis C virus-related HCC (HCV-related HCC in a Japanese population. In the present study, we sought to determine whether these SNPs are predictive for HBV-related HCC development in other Chinese population as well. METHOD AND FINDINGS: We genotyped 4 SNPs, rs2596542, rs9275572, rs17401966, rs7574865, in 506 HBV-related HCC patients and 772 chronic hepatitis B (CHB patients in Han Chinese by TaqMan methods. Odds ratio(ORand 95% confidence interval (CI were calculated by logistic regression. In our case-control study, significant association between rs9275572 and HCC were observed (P = 0.02, OR = 0.73, 95% CI = 0.56-0.95. In the further haplotype analysis between rs2596542 at 6p21.33 and rs9275572 at 6p21.3, G-A showed a protective effect on HBV-related HCC occurrence (P<0.001, OR = 0.66, 95% CI = 0.52-0.84. CONCLUSION: These findings provided convincing evidence that rs9275572 significantly associated with HBV-related HCC.

  11. An alternative method for assessing early mortality in contemporary populations.

    Science.gov (United States)

    Wiley, A S; Pike, I L

    1998-11-01

    Biological anthropologists are interested in a population's early mortality rates for a variety of reasons. Early mortality (infant or juvenile) is of obvious importance to those interested in demography, but early mortality statistics are useful for life history analysis, paleodemography, and human adaptability studies, among others. In general, the form of mortality statistics is derived from demography, where chronological age is the gold standard for statistical calculation and comparison. However, there are numerous problems associated with the collection, analysis, and interpretation of early mortality statistics based on age, particularly for anthropological research, which is often conducted in small or non-calendrical-age numerate populations. The infant mortality rate (IMR), for example, is notoriously difficult to determine in populations where accurate accounting of age is not routine, and yet it is widely used in demography, public health, medicine, and social science research. Here we offer an alternative to age-based early mortality statistics that makes use of human biologists' interest in, and skill at, assessing human growth and development. Our proposal is to use developmental stages of juveniles instead of relying exclusively on age as the basis for mortality statistics. Death or survival according to a developmental stage (such as crawling or weaning) may provide more accurate data that are also more closely related to the cause of death. Developmental stages have the added advantage of putting infants and children back at the center of the discussion of early mortality by focusing on their activities in relation to their environment. A case study from the Turkana population of Kenya illustrates the use of developmental stages in describing early mortality.

  12. Minerals Intake Distributions in a Large Sample of Iranian at-Risk Population Using the National Cancer Institute Method: Do They Meet Their Requirements?

    Science.gov (United States)

    Heidari, Zahra; Feizi, Awat; Azadbakht, Leila; Sarrafzadegan, Nizal

    2015-01-01

    Minerals are required for the body's normal function. The current study assessed the intake distribution of minerals and estimated the prevalence of inadequacy and excess among a representative sample of healthy middle aged and elderly Iranian people. In this cross-sectional study, the second follow up to the Isfahan Cohort Study (ICS), 1922 generally healthy people aged 40 and older were investigated. Dietary intakes were collected using 24 hour recalls and two or more consecutive food records. Distribution of minerals intake was estimated using traditional (averaging dietary intake days) and National Cancer Institute (NCI) methods, and the results obtained from the two methods, were compared. The prevalence of minerals intake inadequacy or excess was estimated using the estimated average requirement (EAR) cut-point method, the probability approach and the tolerable upper intake levels (UL). There were remarkable differences between values obtained using traditional and NCI methods, particularly in the lower and upper percentiles of the estimated intake distributions. A high prevalence of inadequacy of magnesium (50 - 100 %), calcium (21 - 93 %) and zinc (30 - 55 % for males > 50 years) was observed. Significant gender differences were found regarding inadequate intakes of calcium (21 - 76 % for males vs. 45 - 93 % for females), magnesium (92 % vs. 100 %), iron (0 vs. 15 % for age group 40 - 50 years) and zinc (29 - 55 % vs. 0 %) (all; p < 0.05). Severely imbalanced intakes of magnesium, calcium and zinc were observed among the middle-aged and elderly Iranian population. Nutritional interventions and population-based education to improve healthy diets among the studied population at risk are needed.

  13. Matrix population models from 20 studies of perennial plant populations

    Science.gov (United States)

    Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.

    2012-01-01

    Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the 'Testing Matrix Models' working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.

  14. Normalized Mini-Mental State Examination for assessing cognitive change in population-based brain aging studies.

    Science.gov (United States)

    Philipps, Viviane; Amieva, Hélène; Andrieu, Sandrine; Dufouil, Carole; Berr, Claudine; Dartigues, Jean-François; Jacqmin-Gadda, Hélène; Proust-Lima, Cécile

    2014-01-01

    The Mini-Mental State Examination (MMSE) is widely used in population-based longitudinal studies to quantify cognitive change. However, its poor metrological properties, mainly ceiling/floor effects and varying sensitivity to change, have largely restricted its usefulness. We propose a normalizing transformation that corrects these properties, and makes possible the use of standard statistical methods to analyze change in MMSE scores. The normalizing transformation designed to correct at best the metrological properties of MMSE was estimated and validated on two population-based studies (n = 4,889, 20-year follow-up) by cross-validation. The transformation was also validated on two external studies with heterogeneous samples mixing normal and pathological aging, and samples including only demented subjects. The normalizing transformation provided correct inference in contrast with models analyzing the change in crude MMSE that most often lead to biased estimates of risk factors and incorrect conclusions. Cognitive change can be easily and properly assessed with the normalized MMSE using standard statistical methods such as linear (mixed) models. © 2014 S. Karger AG, Basel.

  15. Measuring populism: comparing two methods of content analysis

    NARCIS (Netherlands)

    Rooduijn, M.; Pauwels, T.

    2011-01-01

    The measurement of populism - particularly over time and space - has received only scarce attention. In this research note two different ways to measure populism are compared: a classical content analysis and a computer-based content analysis. An analysis of political parties in the United Kingdom,

  16. Level of colorectal cancer awareness: a cross sectional exploratory study among multi-ethnic rural population in Malaysia

    OpenAIRE

    Su, Tin Tin; Goh, Jun Yan; Tan, Jackson; Muhaimah, Abdul Rahim; Pigeneswaren, Yoganathan; Khairun, Nasirin Sallamun; Normazidah, Abdul Wahab; Tharisini, Devi Kunasekaran; Majid, Hazreen Abd

    2013-01-01

    Background This paper presents the level of colorectal cancer awareness among multi-ethnic rural population in Malaysia. Methods A rural-based cross sectional survey was carried out in Perak state in Peninsular Malaysia in March 2011. The survey recruited a population-representative sample using multistage sampling. Altogether 2379 participants were included in this study. Validated bowel/colorectal cancer awareness measure questionnaire was used to assess the level of colorectal cancer aware...

  17. A comparison of two methods for prediction of response and rates of inbreeding in selected populations with the results obtained in two selection experiments

    Directory of Open Access Journals (Sweden)

    Verrier Etienne

    2005-05-01

    Full Text Available Abstract Selection programmes are mainly concerned with increasing genetic gain. However, short-term progress should not be obtained at the expense of the within-population genetic variability. Different prediction models for the evolution within a small population of the genetic mean of a selected trait, its genetic variance and its inbreeding have been developed but have mainly been validated through Monte Carlo simulation studies. The purpose of this study was to compare theoretical predictions to experimental results. Two deterministic methods were considered, both grounded on a polygenic additive model. Differences between theoretical predictions and experimental results arise from differences between the true and the assumed genetic model, and from mathematical simplifications applied in the prediction methods. Two sets of experimental lines of chickens were used in this study: the Dutch lines undergoing true truncation mass selection, the other lines (French undergoing mass selection with a restriction on the representation of the different families. This study confirmed, on an experimental basis, that modelling is an efficient approach to make useful predictions of the evolution of selected populations although the basic assumptions considered in the models (polygenic additive model, normality of the distribution, base population at the equilibrium, etc. are not met in reality. The two deterministic methods compared yielded results that were close to those observed in real data, especially when the selection scheme followed the rules of strict mass selection: for instance, both predictions overestimated the genetic gain in the French experiment, whereas both predictions were close to the observed values in the Dutch experiment.

  18. Population models and simulation methods: The case of the Spearman rank correlation.

    Science.gov (United States)

    Astivia, Oscar L Olvera; Zumbo, Bruno D

    2017-11-01

    The purpose of this paper is to highlight the importance of a population model in guiding the design and interpretation of simulation studies used to investigate the Spearman rank correlation. The Spearman rank correlation has been known for over a hundred years to applied researchers and methodologists alike and is one of the most widely used non-parametric statistics. Still, certain misconceptions can be found, either explicitly or implicitly, in the published literature because a population definition for this statistic is rarely discussed within the social and behavioural sciences. By relying on copula distribution theory, a population model is presented for the Spearman rank correlation, and its properties are explored both theoretically and in a simulation study. Through the use of the Iman-Conover algorithm (which allows the user to specify the rank correlation as a population parameter), simulation studies from previously published articles are explored, and it is found that many of the conclusions purported in them regarding the nature of the Spearman correlation would change if the data-generation mechanism better matched the simulation design. More specifically, issues such as small sample bias and lack of power of the t-test and r-to-z Fisher transformation disappear when the rank correlation is calculated from data sampled where the rank correlation is the population parameter. A proof for the consistency of the sample estimate of the rank correlation is shown as well as the flexibility of the copula model to encompass results previously published in the mathematical literature. © 2017 The British Psychological Society.

  19. Young people’s risk of suicide attempts in relation to parental death: A population-based register study

    DEFF Research Database (Denmark)

    Christiansen, Erik; Jakobsen, Ida Skytte

    2011-01-01

    Background:  The objective of this study was to examine the association between the death of a biological parent and subsequent suicide attempts by young people (aged 10–22 years), and to explore sociodemographic factors as modifying factors in the process. Methods:  The study used a nested case......–control design. The full study population was obtained from the Danish longitudinal registers and included all individuals born between 1983 and 1989 (n = 403,431 individuals). The 3,465 registered suicide attempters from that group were matched with 75,300 population-based control subjects. Potentially...

  20. A Comparison of Internet-Based Participant Recruitment Methods: Engaging the Hidden Population of Cannabis Users in Research

    Directory of Open Access Journals (Sweden)

    Elizabeth Clare Temple

    2011-01-01

    Full Text Available While a growing number of researchers are embracing Internet-based data collection methods, the adoption of Internet-based recruitment methods has been relatively slow. This may be because little is known regarding the relative strengths and weaknesses of different methods of Internet-based participant recruitment, nor how these different recruitment strategies impact on the data collected. These issues are addressed in this article with reference to a study comparing the effectiveness of three Internet-based strategies in recruiting cannabis users for an online study. Consideration of the recruitment data leads us to recommend that researchers use multipronged Internet-based recruitment campaigns with appropriately detailed recruitment messages tailored to the population of interest and located carefully to ensure they reach the intended audience. Further, we suggest that building rapport directly with potential participants, or utilising derived rapport and implicit endorsements, is an important aspect of successful Internet-based participant recruitment strategies.

  1. Econometric studies of urban population density: a survey.

    Science.gov (United States)

    Mcdonald, J F

    1989-01-01

    This paper presents the 1st reasonably comprehensive survey of empirical research of urban population densities since the publication of the book by Edmonston in 1975. The survey summarizes contributions to empirical knowledge that have been made since 1975 and points toward possible areas for additional research. The paper also provides a brief interpretative intellectual history of the topic. It begins with a personal overview of research in the field. The next section discusses econometric issues that arise in the estimation of population density functions in which density is a function only of a distance to the central business district of the urban area. Section 4 summarizes the studies of a single urban area that went beyond the estimation of simple distance-density functions, and Section 5 discusses studies that sought to explain the variations across urban areas in population density patterns. McDonald refers to the standard theory of urban population density throughout the paper. This basic model is presented in the textbook by Mills and Hamilton and it is assumed that the reader is familiar with the model.

  2. A MORPHOLOGICAL STUDY OF HUMAN THYROID GLAND IN THE POPULATION OF NORTH - EASTERN REGION OF INDIA

    Directory of Open Access Journals (Sweden)

    Debabani

    2015-06-01

    Full Text Available BACKGROUND : Due to the high incidence of thyroid disorders in the North - Eastern population of India a study was undertaken in Guwahati Medical College to see the age related changes in the morphology of the gland in the ca davers of this region. AIM : The study was done to compare the dimensions of the thyroid gland in this population with different studies around the world to see if it can throw any light why thyroid disorders are more common in this population and help clin icians to deal better. MATERIALS AND METHOD : The specimens were divided into three groups according to their ages. Twenty (21 specimens (both male and female were taken from each age group. Statistical analysis was done by paired t - test and t was taken a s significant if the value of t was greater than 2.18. SUMMARY : A study of all together of 63 specimen were taken up to see if any morphological differences in dimension exists in various age groups viz. pediatrics , adults and elderly and co relate with fi ndings of previous workers and was statistically analyzed. CONCLUSION : The study showed that there was no morphological difference of this population with that of previous studies done in other parts of the world. Perhaps a histological study in molecular level will throw more light why this stratum of population is so vulnerable to thyroid disorders.

  3. Identification of dietary patterns in urban population of Argentina: study on diet-obesity relation in population-based prevalence study.

    Science.gov (United States)

    Pou, Sonia Alejandra; Del Pilar Díaz, María; De La Quintana, Ana Gabriela; Forte, Carla Antonella; Aballay, Laura Rosana

    2016-12-01

    In Argentina, obesity prevalence rose from 14.6% in 2005 to 20.8% in 2013. Although the number of studies on noncommunicable diseases and dietary patterns as a unique dietary exposure measure has increased, information on this topic remains scarce in developing countries. This is the first population-based study investigating the association between diet and obesity using a dietary pattern approach in Argentina. We aimed (a) to identify current dietary patterns of the population of Córdoba city, (b) to investigate its association with obesity prevalence, and (c) to identify and describe dietary patterns from the subgroup of people with obesity. The Córdoba Obesity and Diet Study (CODIES) was conducted in Córdoba city by using a random sample of n = 4,327 subjects between 2005 and 2012. Empirically derived dietary patterns were identified through principal component factor analysis. A multiple logistic regression analysis was used to investigate the association of dietary patterns with obesity. Four dietary patterns were identified, called " Starchy-Sugar ", " Prudent ", " Western ", and " Sugary drinks ". High scores for the " Western " pattern (with strongest factor loading on meats/eggs, processed meats, and alcohol) showed a positive association with obesity (OR: 1.33, 95% CI: 1.06-1.67, for third versus first tertile of factor score). " Meats/Cheeses " and " Snacks/Alcohol " patterns emerged in people with obesity. The findings suggest that high adherence to the " Western " pattern promoted obesity in this urban population. In addition, people with obesity showed characteristic dietary patterns that differ from those identified in the overall population.

  4. Comparison of gene-based rare variant association mapping methods for quantitative traits in a bovine population with complex familial relationships.

    Science.gov (United States)

    Zhang, Qianqian; Guldbrandtsen, Bernt; Calus, Mario P L; Lund, Mogens Sandø; Sahana, Goutam

    2016-08-17

    There is growing interest in the role of rare variants in the variation of complex traits due to increasing evidence that rare variants are associated with quantitative traits. However, association methods that are commonly used for mapping common variants are not effective to map rare variants. Besides, livestock populations have large half-sib families and the occurrence of rare variants may be confounded with family structure, which makes it difficult to disentangle their effects from family mean effects. We compared the power of methods that are commonly applied in human genetics to map rare variants in cattle using whole-genome sequence data and simulated phenotypes. We also studied the power of mapping rare variants using linear mixed models (LMM), which are the method of choice to account for both family relationships and population structure in cattle. We observed that the power of the LMM approach was low for mapping a rare variant (defined as those that have frequencies lower than 0.01) with a moderate effect (5 to 8 % of phenotypic variance explained by multiple rare variants that vary from 5 to 21 in number) contributing to a QTL with a sample size of 1000. In contrast, across the scenarios studied, statistical methods that are specialized for mapping rare variants increased power regardless of whether multiple rare variants or a single rare variant underlie a QTL. Different methods for combining rare variants in the test single nucleotide polymorphism set resulted in similar power irrespective of the proportion of total genetic variance explained by the QTL. However, when the QTL variance is very small (only 0.1 % of the total genetic variance), these specialized methods for mapping rare variants and LMM generally had no power to map the variants within a gene with sample sizes of 1000 or 5000. We observed that the methods that combine multiple rare variants within a gene into a meta-variant generally had greater power to map rare variants compared

  5. The Etruscans: a population-genetic study

    DEFF Research Database (Denmark)

    Vernesi, Cristiano; Caramelli, David; Dupanloup, Isabelle

    2004-01-01

    The origins of the Etruscans, a non-Indo-European population of preclassical Italy, are unclear. There is broad agreement that their culture developed locally, but the Etruscans' evolutionary and migrational relationships are largely unknown. In this study, we determined mitochondrial DNA sequences...... a culture but also a mitochondrial gene pool. Genetic distances and sequence comparisons show closer evolutionary relationships with the eastern Mediterranean shores for the Etruscans than for modern Italian populations. All mitochondrial lineages observed among the Etruscans appear typically European...... or West Asian, but only a few haplotypes were found to have an exact match in a modern mitochondrial database, raising new questions about the Etruscans' fate after their assimilation into the Roman state....

  6. High prevalence of sarcopenia among binge drinking elderly women: a nationwide population-based study

    OpenAIRE

    Yoo, Jun-Il; Ha, Yong-Chan; Lee, Young-Kyun; Hana-Choi,; Yoo, Moon-Jib; Koo, Kyung-Hoi

    2017-01-01

    Background Alcohol consumption is considered a risk factor for sarcopenia, but the association between alcohol consumption and the prevalence of sarcopenia has not been evaluated in detail. This study was to identify the relationship between alcohol drinking patterns and the prevalence of sarcopenia in the elderly Korean population. Methods The cross-sectional study was performed using data from the Korea National Health and Nutrition Examination Survey. Participants were excluded if they wer...

  7. Chronic Physical Illness and Mental Health in Children. Results from a Large-Scale Population Study

    Science.gov (United States)

    Hysing, Mari; Elgen, Irene; Gillberg, Christopher; Lie, Stein Atle; Lundervold, Astri J.

    2007-01-01

    Background: The aim of the present study was to evaluate the sensitivity and specificity of the Strengths and Difficulties Questionnaire (SDQ) in detecting emotional and behavioural problems among children with chronic illness (CI). Methods: Parents and teachers of a population of primary school children in Norway (n = 9430) completed a…

  8. A population-based study of cognitive impairment in socially vulnerable adults in Argentina. The Matanza Riachuelo study preliminary results

    Science.gov (United States)

    Bartoloni, Leonardo; Blatt, Graciela; Insua, Iván; Furman, Mariano; González, María Agustina; Hermann, Bárbara; Kesselman, Mariana; Massautis, Alicia; Reinado, Alejandra; Senas, Patricia; Yavitz, Claudia; Lejarraga, Horacio; Nunes, Fernando; Arizaga, Raúl Luciano; Allegri, Ricardo F

    2014-01-01

    Population aging has taken place intensively worldwide, even in developing countries. These countries have population groups with low resources and basic unmet needs that are frequently omitted from epidemiological studies. Objective The purpose of this study was to determine the prevalence of cognitive impairment (CI) and dementia in an economic and socially vulnerable population from Argentina. Methods A door-to-door observational population-based survey among adults over 60 years of cognitive impairment and dementia in the social vulnerable area of the Matanza Riachuelo Basin, in the suburban area of Buenos Aires, Argentina was conducted. Trained psychologists interviewed subjects and a proxy informant. A standardized protocol including a socio-demographic questionnaire, the Mini-Mental State Examination, the Geriatric Depression Scale and a functional inventory for IADL and ADL was administered. Diagnoses were divided into three general categories: normal cognitive function, cognitive impairment-no dementia (CIND) and dementia. Results and Conclusions A total of 2437 elderly persons were assessed, of which 73.6% fulfilled inclusion criteria. The prevalence of CI among those over 60 was 26.4% (18.1% CIND and 8.3% dementia) with higher prevalence of dementia in younger individuals than rates reported in developed counties, probably due to low control of vascular risk factors. This information can help inform health public decisions in the generation of programs and plans for the prevention, diagnosis and treatment of cognitive impairment in this type of socially vulnerable population. PMID:29213923

  9. Testing the Latino paradox in Latin America: A population-based study of Intra-regional immigrants in Chile

    OpenAIRE

    Cabieses,Baltica; Tunstall,Helena; Pickett,Kate

    2013-01-01

    Background: Several studies in high-income countries report better health status of immigrants compared to the local population ("healthy migrant" effect), regardless of their socioeconomic deprivation. This is known as the Latino paradox. Aim: To test the Latino paradox within Latin America by assessing the health of international immigrants to Chile, most of them from Latin American countries, and comparing them to the Chilean-born. Material and Methods: Secondary data analysis of the popul...

  10. Prevalence of metabolic syndrome in Central America: a cross-sectional population-based study

    Directory of Open Access Journals (Sweden)

    Roy A. Wong-McClure

    2015-09-01

    Full Text Available OBJECTIVE: To report the prevalence of metabolic syndrome (MetS as found by the Central American Diabetes Initiative (CAMDI study for five major Central American populations: Belize (national; Costa Rica (San José; Guatemala (Guatemala City; Honduras (Tegucigalpa; and Nicaragua (Managua. METHODS: Study data on 6 185 adults aged 20 years or older with anthropometric and laboratory determination of MetS from population-based surveys were analyzed. Overall, the survey response rate was 82.0%. MetS prevalence was determined according to criteria from the Adult Treatment Panel III of the National Cholesterol Education Program. The study's protocol was reviewed and approved by the bioethical committee of each country studied. RESULTS: The overall standardized prevalence of MetS in the Central American region was 30.3% (95% confidence interval (CI: 27.1-33.4. There was wide variability by gender and work conditions, with higher prevalence among females and unpaid workers. The standardized percentage of the population free of any component of MetS was lowest in Costa Rica (9.0%; CI: 6.5-11.4 and highest in Honduras (21.1%; CI: 16.4-25.9. CONCLUSIONS: Overall prevalence of MetS in Central America is high. Strengthening surveillance of chronic diseases and establishing effective programs for preventing cardiovascular diseases might reduce the risk of MetS in Central America.

  11. Human population studies and the World Health Organization.

    Science.gov (United States)

    de Chadarevian, Soraya

    2015-01-01

    This essay draws attention to the role of the WHO in shaping research agendas in the biomedical sciences in the postwar era. It considers in particular the genetic studies of human populations that were pursued under the aegis of the WHO from the late 1950s to 1970s. The study provides insights into how human and medical genetics entered the agenda of the WHO. At the same time, the population studies become a focus for tracking changing notions of international relations, cooperation, and development and their impact on research in biology and medicine in the post-World War I era. After a brief discussion of the early history of the WHO and its position in Cold War politics, the essay considers the WHO program in radiation protection and heredity and how the genetic study of "vanishing" human populations and a world-wide genetic study of newborns fitted this broader agenda. It then considers in more detail the kind of support offered by the WHO for these projects. The essay highlights the role of single individuals in taking advantage of WHO support for pushing their research agendas while establishing a trend towards cooperative international projects in biology.

  12. Data Quality in the Application of Tailored Calendar Methods in Hard-to-Reach Populations

    NARCIS (Netherlands)

    Navarra, M.Q.; Vaart, van der W.; Niehof, Anke

    2012-01-01

    Abstract A tailored calendar method was used to collect retrospective data from hard-to-reach populations: people with very low levels of income, education and literacy that live in complex societal situations and have low trust in authorities. Recognizing the serious threats to data quality in

  13. A prospective observational study of skin to subarachnoid space depth in the Indian population

    Directory of Open Access Journals (Sweden)

    Smita Prakash

    2014-01-01

    Full Text Available Background and Aims: A pre-puncture estimate of skin to subarachnoid space depth (SSD may guide spinal needle placement and reduce complications associated with lumbar puncture. Our aim was to determine (1 The SSD in Indian males, females, parturients and the overall population; (2 To derive formulae for predicting SSD and (3 To determine which previously suggested formula best suited our population. Methods: In this prospective, observational study, 800 adult Indian patients undergoing surgery under spinal anaesthesia were divided into three groups: Males (Group M, females (Group F and parturients (Group PF. SSD was measured after lumbar puncture. The relationship between SSD and patient characteristics was studied and statistical models were used to derive formula for predicting SSD. Statistical analysis included One-way ANOVA with post hoc analysis, forward stepwise multivariate regression analysis and paired t-tests. Results: Mean SSD was 4.71 ± 0.70 cm in the overall population. SSD in adult males (4.81 ± 0.68 cm was significantly longer than that observed in females (4.55 ± 0.66 cm but was comparable with SSD in parturients (4.73 ± 0.73 cm. Formula for predicting SSD in the overall population was 2.71 + 0.09 × Body Mass Index (BMI. Stocker′s formula when applied correlated best with the observed SSD. Formulae were derived for the three groups. Conclusions: We found gender-based differences in SSD, with SSD in males being significantly greater than that observed in the female population. SSD correlated with BMI in the parturient and the overall population. Amongst the previously proposed formulae, Stocker′s formula was most accurate in predicting SSD in our population.

  14. Practical Bias Correction in Aerial Surveys of Large Mammals: Validation of Hybrid Double-Observer with Sightability Method against Known Abundance of Feral Horse (Equus caballus) Populations.

    Science.gov (United States)

    Lubow, Bruce C; Ransom, Jason I

    2016-01-01

    Reliably estimating wildlife abundance is fundamental to effective management. Aerial surveys are one of the only spatially robust tools for estimating large mammal populations, but statistical sampling methods are required to address detection biases that affect accuracy and precision of the estimates. Although various methods for correcting aerial survey bias are employed on large mammal species around the world, these have rarely been rigorously validated. Several populations of feral horses (Equus caballus) in the western United States have been intensively studied, resulting in identification of all unique individuals. This provided a rare opportunity to test aerial survey bias correction on populations of known abundance. We hypothesized that a hybrid method combining simultaneous double-observer and sightability bias correction techniques would accurately estimate abundance. We validated this integrated technique on populations of known size and also on a pair of surveys before and after a known number was removed. Our analysis identified several covariates across the surveys that explained and corrected biases in the estimates. All six tests on known populations produced estimates with deviations from the known value ranging from -8.5% to +13.7% and corrected by our statistical models. Our results validate the hybrid method, highlight its potentially broad applicability, identify some limitations, and provide insight and guidance for improving survey designs.

  15. An econometric method for estimating population parameters from non-random samples: An application to clinical case finding.

    Science.gov (United States)

    Burger, Rulof P; McLaren, Zoë M

    2017-09-01

    The problem of sample selection complicates the process of drawing inference about populations. Selective sampling arises in many real world situations when agents such as doctors and customs officials search for targets with high values of a characteristic. We propose a new method for estimating population characteristics from these types of selected samples. We develop a model that captures key features of the agent's sampling decision. We use a generalized method of moments with instrumental variables and maximum likelihood to estimate the population prevalence of the characteristic of interest and the agents' accuracy in identifying targets. We apply this method to tuberculosis (TB), which is the leading infectious disease cause of death worldwide. We use a national database of TB test data from South Africa to examine testing for multidrug resistant TB (MDR-TB). Approximately one quarter of MDR-TB cases was undiagnosed between 2004 and 2010. The official estimate of 2.5% is therefore too low, and MDR-TB prevalence is as high as 3.5%. Signal-to-noise ratios are estimated to be between 0.5 and 1. Our approach is widely applicable because of the availability of routinely collected data and abundance of potential instruments. Using routinely collected data to monitor population prevalence can guide evidence-based policy making. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Evaluating manta ray mucus as an alternative DNA source for population genetics study: underwater-sampling, dry-storage and PCR success

    Science.gov (United States)

    Maxwell, Elisabeth A.; Marshall, Andrea D.; Christensen, Ana B.

    2015-01-01

    Sharks and rays are increasingly being identified as high-risk species for extinction, prompting urgent assessments of their local or regional populations. Advanced genetic analyses can contribute relevant information on effective population size and connectivity among populations although acquiring sufficient regional sample sizes can be challenging. DNA is typically amplified from tissue samples which are collected by hand spears with modified biopsy punch tips. This technique is not always popular due mainly to a perception that invasive sampling might harm the rays, change their behaviour, or have a negative impact on tourism. To explore alternative methods, we evaluated the yields and PCR success of DNA template prepared from the manta ray mucus collected underwater and captured and stored on a Whatman FTA™ Elute card. The pilot study demonstrated that mucus can be effectively collected underwater using toothbrush. DNA stored on cards was found to be reliable for PCR-based population genetics studies. We successfully amplified mtDNA ND5, nuclear DNA RAG1, and microsatellite loci for all samples and confirmed sequences and genotypes being those of target species. As the yields of DNA with the tested method were low, further improvements are desirable for assays that may require larger amounts of DNA, such as population genomic studies using emerging next-gen sequencing. PMID:26413431

  17. Wealth Inequality and Mental Disability Among the Chinese Population: A Population Based Study.

    Science.gov (United States)

    Wang, Zhenjie; Du, Wei; Pang, Lihua; Zhang, Lei; Chen, Gong; Zheng, Xiaoying

    2015-10-19

    In the study described herein, we investigated and explored the association between wealth inequality and the risk of mental disability in the Chinese population. We used nationally represented, population-based data from the second China National Sample Survey on Disability, conducted in 2006. A total of 1,724,398 study subjects between the ages of 15 and 64, including 10,095 subjects with mental disability only, were used for the analysis. Wealth status was estimated by a wealth index that was derived from a principal component analysis of 10 household assets and four other variables related to wealth. Logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence interval (CI) for mental disability for each category, with the lowest quintile category as the referent. Confounding variables under consideration were age, gender, residence area, marital status, ethnicity, education, current employment status, household size, house type, homeownership and living arrangement. The distribution of various types and severities of mental disability differed significantly by wealth index category in the present population. Wealth index category had a positive association with mild mental disability (p for trend disability (p for trend disability when all severities of mental disability were taken into consideration. This study's results suggest that wealth is a significant factor in the distribution of mental disability and it might have different influences on various types and severities of mental disability.

  18. Estimation of the effective population size (Ne) and its application in the management of small populations

    DEFF Research Database (Denmark)

    Jimenez Mena, Belen

    2016-01-01

    Effective population size (Ne) is an important concept to understand the evolution of a population. In conservation, Ne is used to assess the threat status of a population, evaluate its genetic viability in the future and set conservation priorities. An accurate estimation of Ne is thus essential....... The main objective of this thesis was to better understand how the estimation of Ne using molecular markers can be improved for use in conservation genetics. As a first step, we undertook a simulation study where three different methods to estimate Ne were investigated. We explored how well these three...... methods performed under different scenarios. This study showed that all three methods performed better when the number of unlinked loci used to make the estimation increased and the minimum number of loci need for an accurate estimation of Ne was 100 SNPs. A general assumption in the estimation of Ne...

  19. Association study of STAT4 polymorphisms and type 1 diabetes in Northeastern Chinese Han population.

    Science.gov (United States)

    Bi, C; Li, B; Cheng, Z; Hu, Y; Fang, Z; Zhai, A

    2013-03-01

    Type 1 diabetes (T1D) is an organ-specific, T-cell-mediated disease resulting from the selective destruction of pancreatic β cells. The signal transducer and activator of transcription 4 (STAT4) gene is one of the most interesting genes for the pathogenesis of autoimmune diseases, including T1D. In this study, a case-control study was conducted in a Han population in northeastern China comparing the genotypes of T1D patients to healthy controls for the presence of two single-nucleotide polymorphisms (SNPs) in the STAT4 gene. The study population comprised of 410 T1D patients and 407 healthy individuals. Two SNPs (rs7574865 and rs3024866) of STAT4 were genotyped with Multiplex SNaPShot method. Data were analyzed with spss 13.0 to determine if a statistical association existed between these genotypes and T1D. One of the two SNPs (rs7574865) was strongly associated with T1D in Northeastern Chinese population compared to healthy controls (P < 0.05), whereas the other tested SNP (rs3024866) demonstrated no significant relationship. In conclusion, the STAT4 gene may play an important role in facilitating susceptibility to T1D in this Han Chinese population. © 2013 John Wiley & Sons A/S.

  20. Incidence of anogenital warts in Germany: a population-based cohort study

    Directory of Open Access Journals (Sweden)

    Mikolajczyk Rafael T

    2010-12-01

    Full Text Available Abstract Background Human papilloma virus (HPV types 6 and 11 account for 90 percent of anogenital warts (AGW. Assessment of a potential reduction of the incidence of AGW following introduction of HPV vaccines requires population-based incidence rates. The aim of this study was to estimate incidence rates of AGW in Germany, stratified by age, sex, and region. Additionally, the medical practitioner (gynaecologist, dermatologist, urologist etc. who made the initial diagnosis of AGW was assessed. Methods Retrospective cohort study in a population aged 10 to 79 years in a population-based healthcare insurance database. The database included more than 14 million insurance members from all over Germany during the years 2004-2006. A case of AGW was considered incident if a disease-free period of twelve months preceded the diagnosis. To assess regional variation, analyses were performed by federal state. Results The estimated incidence rate was 169.5/100,000 person-years for the German population aged 10 to 79 years. Most cases occurred in the 15 to 40 years age group. The incidence rate was higher and showed a peak at younger ages in females than in males. The highest incidence rates for both sexes were observed in the city-states Berlin, Hamburg and Bremen. In females, initial diagnosis of AGW was most frequently made by a gynaecologist (71.7%, whereas in males, AGW were most frequently diagnosed by a dermatologist (44.8% or urologist (25.1%. Conclusions Incidence of AGW in Germany is comparable with findings for other countries. As expected, most cases occurred in the younger age groups. The frequency of diagnoses of AGW differs between sexes and women and men receive treatment by doctors of different specialties.

  1. Columbia River Stock Identification Study; Validation of Genetic Method, 1980-1981 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Milner, George B.; Teel, David J.; Utter, Fred M. (Northwest and Alaska Fisheries Science Center, Coastal Zone and Estuarine Studies Division, Seattle, WA)

    1981-06-01

    The reliability of a method for obtaining maximum likelihood estimate of component stocks in mixed populations of salmonids through the frequency of genetic variants in a mixed population and in potentially contributing stocks was tested in 1980. A data base of 10 polymorphic loci from 14 hatchery stocks of spring chinook salmon of the Columbia River was used to estimate proportions of these stocks in four different blind'' mixtures whose true composition was only revealed subsequent to obtaining estimates. The accuracy and precision of these blind tests have validated the genetic method as a valuable means for identifying components of stock mixtures. Properties of the genetic method were further examined by simulation studies using the pooled data of the four blind tests as a mixed fishery. Replicated tests with samples sizes between 100 and 1,000 indicated that actual standard deviations on estimated contributions were consistently lower than calculated standard deviations; this difference diminished as sample size increased. It is recommended that future applications of the method be preceded by simulation studies that will identify appropriate levels of sampling required for acceptable levels of accuracy and precision. Variables in such studies include the stocks involved, the loci used, and the genetic differentiation among stocks. 8 refs., 6 figs., 4 tabs.

  2. Influence of population versus convenience sampling on sample characteristics in studies of cognitive aging.

    Science.gov (United States)

    Brodaty, Henry; Mothakunnel, Annu; de Vel-Palumbo, Melissa; Ames, David; Ellis, Kathryn A; Reppermund, Simone; Kochan, Nicole A; Savage, Greg; Trollor, Julian N; Crawford, John; Sachdev, Perminder S

    2014-01-01

    We examined whether differences in findings of studies examining mild cognitive impairment (MCI) were associated with recruitment methods by comparing sample characteristics in two contemporaneous Australian studies, using population-based and convenience sampling. The Sydney Memory and Aging Study invited participants randomly from the electoral roll in defined geographic areas in Sydney. The Australian Imaging, Biomarkers and Lifestyle Study of Ageing recruited cognitively normal (CN) individuals via media appeals and MCI participants via referrals from clinicians in Melbourne and Perth. Demographic and cognitive variables were harmonized, and similar diagnostic criteria were applied to both samples retrospectively. CN participants recruited via convenience sampling were younger, better educated, more likely to be married and have a family history of dementia, and performed better cognitively than those recruited via population-based sampling. MCI participants recruited via population-based sampling had better memory performance and were less likely to carry the apolipoprotein E ε4 allele than clinically referred participants but did not differ on other demographic variables. A convenience sample of normal controls is likely to be younger and better functioning and that of an MCI group likely to perform worse than a purportedly random sample. Sampling bias should be considered when interpreting findings. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Study design and the estimation of the size of key populations at risk of HIV: lessons from Viet Nam.

    Science.gov (United States)

    Safarnejad, Ali; Groot, Wim; Pavlova, Milena

    2018-01-30

    Estimation of the size of populations at risk of HIV is a key activity in the surveillance of the HIV epidemic. The existing framework for considering future research needs may provide decision-makers with a basis for a fair process of deciding on the methods of the estimation of the size of key populations at risk of HIV. This study explores the extent to which stakeholders involved with population size estimation agree with this framework, and thus, the study updates the framework. We conducted 16 in-depth interviews with key informants from city and provincial governments, NGOs, research institutes, and the community of people at risk of HIV. Transcripts were analyzed and reviewed for significant statements pertaining to criteria. Variations and agreement around criteria were analyzed, and emerging criteria were validated against the existing framework. Eleven themes emerged which are relevant to the estimation of the size of populations at risk of HIV in Viet Nam. Findings on missing criteria, inclusive participation, community perspectives and conflicting weight and direction of criteria provide insights for an improved framework for the prioritization of population size estimation methods. The findings suggest that the exclusion of community members from decision-making on population size estimation methods in Viet Nam may affect the validity, use, and efficiency of the evidence generated. However, a wider group of decision-makers, including community members among others, may introduce diverse definitions, weight and direction of criteria. Although findings here may not apply to every country with a transitioning economy or to every emerging epidemic, the principles of fair decision-making, value of community participation in decision-making and the expected challenges faced, merit consideration in every situation.

  4. A method for analyzing changing prison populations: explaining the growth of the elderly in prison.

    Science.gov (United States)

    Luallen, Jeremy; Kling, Ryan

    2014-12-01

    For the past several decades, the U.S. prison system has witnessed a steady and persistent increase in the ages of prison populations. Given the additional costs and burdens placed on prisons as they house older inmates, this aging trend has generated intense interest among policy makers and academics who seek to understand why prison populations are getting older. This article presents a method for evaluating drivers influencing the change in age distributions among prisoners. We define a methodological approach and demonstrate its application using prison data from four states reporting to the Bureau of Justice Statistics' National Corrections Reporting Program. We find that since 2000, the primary driver of overall growth in the elderly populations in prison (defined as inmates over 50) is the increasing admission age of offenders entering prison. Moreover, changes in offense mix and sentence length/time served over the last decade have had significantly less influence on the age composition of prison populations. We also find that the impact of explanatory factors varies across states and offense types. For example, prison admission and exit rates explain much of the change in elderly drug offenders in New York, but not elderly violent offenders, where admission age plays a much stronger explanatory role. Our analysis offers an effective demonstration that supports the use of this method as an important and informative first step toward understanding components of change that affect the problem of prison aging. © The Author(s) 2014.

  5. Study population, questionnaire, data management and sample description

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    Chiara de Waure

    2015-06-01

    Full Text Available INTRODUCTION: This article describes methodological issues of the "Sportello Salute Giovani" project ("Youth Health Information Desk", a multicenter study aimed at assessing the health status and attitudes and behaviours of university students in Italy. MATERIALS AND METHODS: The questionnaire used to carry out the study was adapted from the Italian health behaviours in school-aged children (HBSC project and consisted of 93 items addressing: demographics; nutritional habits and status; physical activity; lifestyles; reproductive and preconception health; health and satisfaction of life; attitudes and behaviours toward academic study and new technologies. The questionnaire was administered to a pool of 12 000 students from 18 to 30 years of age who voluntary decided to participate during classes held at different Italian faculties or at the three "Sportello Salute Giovani" centers which were established in the three sites of the Università Cattolica del Sacro Cuore (Catholic University of the Sacred Heart of Rome. RESULTS: The final study sample was composed by 8516 university students. The mean age of responders was 22.2 (Standard Deviation 2.0 and 5702 (67.0% were females. According to the distribution in age classes, 3601 (43.3% belonged to the 18-21 one, 3796 (44.5% to the 22-24 class and 1019 (12.2% to the 25-30 class. With respect to socio-economic status, data were available for 8410 responders and showed that 50.3% of students belonged to the middle class. DISCUSSION: The project took into consideration a large number of individuals from different regions of the country and therefore may be considered representative of the general population of Italian university students. Furthermore, it is the first to address, at the same time, several issues, in particular attitudes and behaviours toward health, in Italian university students. CONCLUSION: The analysis of data from such a large sample of university students sets the basis for

  6. Statistical Methods for Population Genetic Inference Based on Low-Depth Sequencing Data from Modern and Ancient DNA

    DEFF Research Database (Denmark)

    Korneliussen, Thorfinn Sand

    Due to the recent advances in DNA sequencing technology genomic data are being generated at an unprecedented rate and we are gaining access to entire genomes at population level. The technology does, however, not give direct access to the genetic variation and the many levels of preprocessing...... that is required before being able to make inferences from the data introduces multiple levels of uncertainty, especially for low-depth data. Therefore methods that take into account the inherent uncertainty are needed for being able to make robust inferences in the downstream analysis of such data. This poses...... a problem for a range of key summary statistics within populations genetics where existing methods are based on the assumption that the true genotypes are known. Motivated by this I present: 1) a new method for the estimation of relatedness between pairs of individuals, 2) a new method for estimating...

  7. Study on frequency of dental developmental alterations in a MEXICAN school-based population

    OpenAIRE

    Ledesma Montes, Constantino; Garcés Ortíz, Maricela; Salcido García, Juan Francisco; Hernández Flores, Florentino

    2016-01-01

    Background The aim of this study was to know the distribution of dental developmental alterations in the population requesting stomatological attention at the Admission and Diagnosis Clinic of our institution in Mexico City. Material and Methods We reviewed the archives and selected those files with developmental dental alterations. Analyzed data were diagnoses, age, gender, location and number of involved teeth. Results Of the 3.522 patients reviewed, 179 (5.1%) harbored 394 developmental de...

  8. A rangewide population genetic study of trumpeter swans

    Science.gov (United States)

    Oyler-McCance, S.J.; Ransler, F.A.; Berkman, L.K.; Quinn, T.W.

    2007-01-01

    For management purposes, the range of naturally occurring trumpeter swans (Cygnus buccinator) has been divided into two populations, the Pacific Coast Population (PP) and the Rocky Mountain Population (RMP). Little is known about the distribution of genetic variation across the species' range despite increasing pressure to make difficult management decisions regarding the two populations and flocks within them. To address this issue, we used rapidly evolving genetic markers (mitochondrial DNA sequence and 17 nuclear microsatellite loci) to elucidate the underlying genetic structure of the species. Data from both markers revealed a significant difference between the PP and RMP with the Yukon Territory as a likely area of overlap. Additionally, we found that the two populations have somewhat similar levels of genetic diversity (PP is slightly higher) suggesting that the PP underwent a population bottleneck similar to a well-documented one in the RMP. Both genetic structure and diversity results reveal that the Tri-State flock, a suspected unique, non-migratory flock, is not genetically different from the Canadian flock of the RMP and need not be treated as a unique population from a genetic standpoint. Finally, trumpeter swans appear to have much lower mitochondrial DNA variability than other waterfowl studied thus far which may suggest a previous, species-wide bottleneck. ?? 2007 Springer Science+Business Media, Inc.

  9. Does childhood cancer affect parental divorce rates? A population-based study.

    Science.gov (United States)

    Syse, Astri; Loge, Jon H; Lyngstad, Torkild H

    2010-02-10

    PURPOSE Cancer in children may profoundly affect parents' personal relationships in terms of psychological stress and an increased care burden. This could hypothetically elevate divorce rates. Few studies on divorce occurrence exist, so the effect of childhood cancers on parental divorce rates was explored. PATIENTS AND METHODS Data on the entire Norwegian married population, age 17 to 69 years, with children age 0 to 20 years in 1974 to 2001 (N = 977,928 couples) were retrieved from the Cancer Registry, the Central Population Register, the Directorate of Taxes, and population censuses. Divorce rates for 4,590 couples who were parenting a child with cancer were compared with those of otherwise similar couples by discrete-time hazard regression models. Results Cancer in a child was not associated with an increased risk of parental divorce overall. An increased divorce rate was observed with Wilms tumor (odds ratio [OR], 1.52) but not with any of the other common childhood cancers. The child's age at diagnosis, time elapsed from diagnosis, and death from cancer did not influence divorce rates significantly. Increased divorce rates were observed for couples in whom the mothers had an education greater than high school level (OR, 1.16); the risk was particularly high shortly after diagnosis, for CNS cancers and Wilms tumors, for couples with children 0 to 9 years of age at diagnosis, and after a child's death. CONCLUSION This large, registry-based study shows that cancer in children is not associated with an increased parental divorce rate, except with Wilms tumors. Couples in whom the wife is highly educated appear to face increased divorce rates after a child's cancer, and this may warrant additional study.

  10. Age-Specific Bacteriological Profile of Pediatric Septicemia; A Population- Based Study

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    Seyyed Shahin Eftekhari

    2017-06-01

    Full Text Available Background Septicemia is a life-threatening condition particularly among pediatric population. Early initiating a proper empiric antimicrobial treatment prior to definite isolation of the pathogen through blood culture has pivotal role in reducing further mortality and morbidity. The aim of this study was to evaluate the epidemiological properties of a distinct Iranian population by patients’ age and gender throughout the year. Materials and Methods As a retrospective study between March 2013 and March 2017, all consecutive patients referred to the Hazrat Masumeh hospital of Qom-Iran with suspicious of septicemia were reviewed. Patients with prior history of antibiotic consumption as well as patients over 6 years of age were excluded; incomplete hospital records were also excluded from further evaluations. Prespecified data-extraction forms were used to collect data including characteristics of patients and the results of antibiogram. Results Total of 378 patients were enrolled in this study and 200 of them were boys (52.91%. Escherichia coli (11.6% and Klebsiella (9.5% were the most common isolated pathogens (Gram-negative after coagulase-negatives. Escherichia coli, Citrobacter (Gram-negative, and Staph. Aureus (Gram-positive were the most common pathogens among age group of 0-1 year. Winter had the greatest outbreak of bacteremia (29.1% and the autumn had the least incidence (21.4%. The least and the most antimicrobial resistance were associated with Imipenem (1.8% and Ampicillin (78.78%, respectively. Conclusion Escherichia coliand Klebsiella were the most common isolated bacteria in patients suspected to bacteremia in our region. Imipenem and Ampicillin had the least and the most antimicrobial resistance in our population, respectively.

  11. Population versus hospital controls for case-control studies on cancers in Chinese hospitals

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    Li Lin

    2011-12-01

    Full Text Available Abstract Background Correct control selection is crucial to the internal validity of case-control studies. Little information exists on differences between population and hospital controls in case-control studies on cancers in Chinese hospital setting. Methods We conducted three parallel case-control studies on leukemia, breast and colorectal cancers in China between 2009 and 2010, using population and hospital controls to separately match 540 incident cases by age, gender and residency at a 1:1 ratio. Demographic and lifestyle factors were measured using a validated questionnaire in face-to-face interview. Odds ratios (ORs and 95% confidence intervals (CIs were obtained using conditional logistic regression analyses. Results The two control groups had closely similar exposure distributions of 15 out of 16 factors, with the only exception being that hospital controls were less likely to have a BMI ≥ 25 (OR = 0.71, 95% CI: 0.54, 0.93. For exposure of green tea drinking, the adjusted ORs (95% CIs comparing green tealeaves intake ≥ 1000 grams annually with non-drinkers were 0.51 (0.31, 0.83 and 0.21 (0.27, 0.74 for three cancers combined, 0.06 (0.01, 0.61 and 0.07 (0.01, 0.47 for breast cancer, 0.52 (0.29, 0.94 and 0.45 (0.25, 0.82 for colorectal cancer, 0.65 (0.08, 5.63 and 0.57 (0.07, 4.79 for leukemia using hospital and population controls respectively. Conclusions The study found that hospital controls were comparable with population controls for most demographic characteristics and lifestyle factors measured, but there was a slight difference between the two control groups. Hospital outpatients provide a satisfactory control group in hospital-based case-control study in the Chinese hospital setting.

  12. Intimate partner violence in Europe: design and methods of a multinational study.

    Science.gov (United States)

    Costa, Diogo; Soares, Joaquim J F; Lindert, Jutta; Hatzidimitriadou, Eleni; Karlsso, Andreas; Sundin, Örjan; Toth, Olga; Ioannidi-Kapolou, Ellisabeth; Degomme, Olivier; Cervilla, Jorge; Barros, Henrique

    2013-01-01

    To describe the design, methods, procedures and characteristics of the population involved in a study designed to compare Intimate Partner Violence (IPV) in eight European countries. Women and men aged 18-65, living in Ghent-Belgium (n = 245), Stuttgart-Germany (n = 546), Athens-Greece (n = 548), Budapest-Hungary (n = 604), Porto-Portugal (n = 635), Granada-Spain (n = 138), Östersund-Sweden (n = 592), London-United Kingdom (n = 571), were sampled and administered a common questionnaire. Chi-square goodness of fit and five-age strata population fractions ratios for sex and education were computed to evaluate samples' representativeness. Differences in the age distributions were found among women from Sweden and Portugal and among men from Belgium, Hungary, Portugal and Sweden. Over-recruitment of more educated respondents was noted in all sites. The use of a common research protocol with the same structured questionnaire is likely to provide accurate estimates of the general population IPV frequency, despite limitations in probabilistic sampling and restrictions in methods of administration. Copyright © 2012 SESPAS. Published by Elsevier Espana. All rights reserved.

  13. The association between systemic inflammatory cellular levels and lung function: a population-based study.

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    Tricia McKeever

    Full Text Available BACKGROUND: Lower lung function is associated with an elevated systemic white cell count in men. However, these observations have not been demonstrated in a representative population that includes females and may be susceptible to confounding by recent airway infections or recent cigarette smoking. We tested the hypothesis that lung function is inversely associated with systemic white cell count in a population-based study. METHODS: The study population consisted adults aged 17-90+ years who participated in the Third National Health and Nutrition Examination Survey who did not report a recent cough, cold or acute illness in a non-smoking and smoking population. RESULTS: In non-smoking adults with the highest quintile of the total white cell count had a FEV(1 125.3 ml lower than those in the lowest quintile (95% confidence interval CI: -163.1 to -87.5. Adults with the highest quintile of the total white cell count had a FVC 151.1 ml lower than those in the lowest quintile (95% confidence interval CI: -195.0 to -107.2. Similar associations were observed for granulocytes, mononuclear cells and lymphocytes. In current smokers, similar smaller associations observed for total white cell count, granulocytes and mononuclear cells. CONCLUSIONS: Systemic cellular inflammation levels are inversely associated with lung function in a population of both non-smokers and smokers without acute illnesses. This may contribute to the increased mortality observed in individuals with a higher baseline white cell count.

  14. A hypothetical study of populations under constant mortality and fertility.

    Science.gov (United States)

    Gupta, R B

    1976-03-01

    28 countries with different characteristics have been selected in order to observe the amount of time it takes for these different countries to reach stable age distributions. The individual populations by sex and age were projected for 150 years in 5-year intervals with the present constant mortality and fertility schedules by component method. Observations have been made by considering the following characteristics of population when it has acquired stability: age distribution; the rate of growth, birthrate, and mortality rate; the population change; the intrinsic rate of growth, birthrate and mortality rate; and approximate time taken to stabilize the population. The initial age distribution has a significant part in the amount of time it takes for a population to acquire stability, and its intrinsic rate of growth is mostly dependent upon the existing age distribution of that population. The time taken for a country's population to become stable depends upon the age distribution, fertility and mortality schedules at the beginning. It has been observed that countries having a higher intrinsic rate of growth take comparatively less time in acquiring stability than the countries having a lower intrinsic rate of growth. The mortality and fertility schedules of a country is another important phenomenon. The populations of the different countries at the point of stability were growing according to their rates of growth. No specific trend of population growth could be found among the groups of countries. Time taken for stabilizing the population is completely based upon age distributions, fertility and mortality schedules a particular country was having at the beginning. The range of time taken for different countries to acquire stability generally ranged from 100 to 135 years. Among the different countries the relationship for the time it takes to acquire stability has not been established. This is a hypothetical approach in order to obtain some idea as to how a

  15. Skeeter Buster: a stochastic, spatially explicit modeling tool for studying Aedes aegypti population replacement and population suppression strategies.

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    Krisztian Magori

    2009-09-01

    of genetic control methods. Skeeter Buster is therefore an important tool to model Ae. aegypti populations and the outcome of vector control measures.

  16. The prevalence of diagnosed chronic conditions and multimorbidity in Australia: A method for estimating population prevalence from general practice patient encounter data.

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    Christopher Harrison

    Full Text Available To estimate the prevalence of common chronic conditions and multimorbidity among patients at GP encounters and among people in the Australian population. To assess the extent to which use of each individual patient's GP attendance over the previous year, instead of the average for their age-sex group, affects the precision of national population prevalence estimates of diagnosed chronic conditions.A sub-study (between November 2012 and March 2016 of the Bettering the Evaluation and Care of Health program, a continuous national study of GP activity. Each of 1,449 GPs provided data for about 30 consecutive patients (total 43,501 indicating for each, number of GP attendances in previous year and all diagnosed chronic conditions, using their knowledge of the patient, patient self-report, and patient's health record.Hypertension (26.5% was the most prevalent diagnosed chronic condition among patients surveyed, followed by osteoarthritis (22.7%, hyperlipidaemia (16.6%, depression (16.3%, anxiety (11.9%, gastroesophageal reflux disease (GORD (11.3%, chronic back pain (9.7% and Type 2 diabetes (9.6%. After adjustment, we estimated population prevalence of hypertension as 12.4%, 9.5% osteoarthritis, 8.2% hyperlipidaemia, 8.0% depression, 5.8% anxiety and 5.2% asthma. Estimates were significantly lower than those derived using the previous method. About half (51.6% the patients at GP encounters had two or more diagnosed chronic conditions and over one third (37.4% had three or more. Population estimates were: 25.7% had two or more diagnosed chronic conditions and 15.8% had three or more.Of the three approaches we have tested to date, this study provides the most accurate method for estimation of population prevalence of chronic conditions using the GP as an expert interviewer, by adjusting for each patient's reported attendance.

  17. A study of biodiversity using DSS method and seed storage protein comparison of populations in two species of Achillea L. in the west of Iran

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    Hajar Salehi

    2013-11-01

    Full Text Available Intarspecific and interspecific variations are the main reserves of biodiversity and both are important sources of speciation. On this basis, identifing and recognizing the intra and interspecific variations is important in order to recognition of biodiversity. This research was done to study biodiversity and electrophoresis comparison of seed storage proteins in the populations of the two species of the genus Achillea in Hamadan and Kurdistan provinces using of the method of determination of special station (DSS. For this purpose, 12 and 9 special stations were selected for the species A. tenuifolia and A. biebresteinii using the data published in the related flora. Seed storage proteins were extracted and then studied using electrophoresis techniques (SDS-PAGE. In survey of all special stations, 120 plant species were distinguished as associated species. The results of the floristic data for the both species determined six distinctive groups that indicated the existence of intraspecific diversity in this species. The result of analysis of ecological data and seed storage proteins for the two species was in accordance with the floristic data and showed six distinctive groups. The existence of the bands of no. 4, 5, 8, 12 and 13 in the special stations of A. tenuifolia and the bands of 14, 15 and 16 in the special stations of A. biebresteinii o separated the populations of the species in two quite different and distinctive groups.

  18. Hand Grip Strength: age and gender stratified normative data in a population-based study

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    Taylor Anne W

    2011-04-01

    Full Text Available Abstract Background The North West Adelaide Health Study is a representative longitudinal cohort study of people originally aged 18 years and over. The aim of this study was to describe normative data for hand grip strength in a community-based Australian population. Secondary aims were to investigate the relationship between body mass index (BMI and hand grip strength, and to compare Australian data with international hand grip strength norms. Methods The sample was randomly selected and recruited by telephone interview. Overall, 3 206 (81% of those recruited participants returned to the clinic during the second stage (2004-2006 which specifically focused on the collection of information relating to musculoskeletal conditions. Results Following the exclusion of 435 participants who had hand pain and/or arthritis, 1366 men and 1312 women participants provided hand grip strength measurement. The study population was relatively young, with 41.5% under 40 years; and their mean BMI was 28.1 kg/m2 (SD 5.5. Higher hand grip strength was weakly related to higher BMI in adults under the age of 30 and over the age of 70, but inversely related to higher BMI between these ages. Australian norms from this sample had amongst the lowest of the hand grip strength of the internationally published norms, except those from underweight populations. Conclusions This population demonstrated higher BMI and lower grip strength in younger participants than much of the international published, population data. A complete exploration of the relationship between BMI and hand grip strength was not fully explored as there were very few participants with BMI in the underweight range. The age and gender grip strength values are lower in younger adults than those reported in international literature.

  19. Mental health in war-affected populations

    NARCIS (Netherlands)

    Scholte, W.F.

    2013-01-01

    This book addresses mental health problems in populations in nonwestern war-affected regions, and methods to mitigate these problems through interventions focusing on social reintegration. It describes a number of studies among war-affected populations in widely different areas: refugees from the

  20. Lithium and renal and upper urinary tract tumors - results from a nationwide population-based study

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Gerds, Thomas Alexander; Feldt-Rasmussen, Bo

    2015-01-01

    OBJECTIVES: A recent alarming finding suggested an increased risk of renal tumors among long-term lithium users. The objectives of the present study were to estimate rates of renal and upper urinary tract tumors (RUT), malignant and benign, among individuals exposed to successive prescriptions...... for lithium, anticonvulsants, and other psychotropic agents used for bipolar disorder, and among unexposed individuals. METHODS: This was a nationwide, population-based longitudinal study including time-specific data from all individuals exposed to lithium (n = 24,272) or anticonvulsants (n = 386,255), all...... individuals with a diagnosis of bipolar disorder (n = 9,651), and a randomly selected sample of 1,500,000 from the Danish population. The study period was from 1995 to 2012, inclusive. Outcomes were hazard rate ratios (HR) for RUT in three groups: (i) combined malignant and benign, (ii) malignant, and (iii...

  1. Epidemiological studies of some populations exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Weeks, J.L.

    1985-08-01

    During 1984 September 19 and 20, a meeting was held at the Whiteshell Nuclear Research Establishment, Pinawa, Manitoba to discuss current epidemiological studies of populations exposed to low levels of ionizing radiation. Twelve representatives from three countries attended the meeting and eleven papers were extensively discussed. The majority of these papers described studies of populations occupationally exposed to radiation. The report contains summaries of the papers presented and of the discussions that took place

  2. Population dynamics

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    Cooch, E. G.

    2004-06-01

    focused on estimation of survival rate (arguably, use of data from marked individuals has been used for estimation of survival more than any other parameter, save perhaps abundance, it is only one of many transitions in the life cycle. Others discussed include transitions between age or size classes, breeding states, and physical locations. The demographic consequences of these transitions can be captured by matrix population models, and such models provide a natural link connecting multi–stage mark–recapture methods and population dynamics. The utility of the matrix approach for both prospective, and retrospective, analysis of variation in the dynamics of populations is well–known; such comparisons of results of prospective and retrospective analysis is fundamental to considerations of conservation management (sensu Caswell, 2000. What is intriguing is the degree to which these methods can be combined, or contrasted, with more direct estimation of one or more measures of the trajectory of a population (e.g., Sandercock & Beissinger, 2002. The five additional papers presented in the population dynamics session clearly reflected these considerations. In particular, the three papers submitted for this volume indicate the various ways in which complex empirical data can be analyzed, and often combined with more classical modeling approaches, to provide more robust insights to the dynamics of the study population. The paper by Francis & Saurola (2004 is an example of rigorous analysis and modeling applied to a large, carefully collected dataset from a long–term study of the biology of the Tawny Owl. Using a combination of live encounters and dead recoveries, the authors were able to separate the relative contributions of various processes (emigration, mortality on variation in survival rates. These analyses were combined with periodic matrix models to explore comparisons of direct estimation of changes in population size (based on both census and mark

  3. Mental health consultations in a prison population: a descriptive study

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    Rustad Aase-Bente

    2006-06-01

    Full Text Available Abstract Background The psychiatric morbidity among prison inmates is substantially higher than in the general population. We do, however, have insufficient knowledge about the extent of psychiatric treatment provided in our prisons. The aim of the present study was to give a comprehensive description of all non-pharmacological interventions provided by the psychiatric health services to a stratified sample of prison inmates. Methods Six medium/large prisons (n = 928 representing 1/3 of the Norwegian prison population and with female and preventive detention inmates over-sampled, were investigated cross-sectionally. All non-pharmacological psychiatric interventions, excluding pure correctional programs, were recorded. Those receiving interventions were investigated further and compared to the remaining prison population. Results A total of 230 of the 928 inmates (25 % had some form of psychiatric intervention: 184 (20 % were in individual psychotherapy, in addition 40 (4 % received ad hoc interventions during the registration week. Group therapy was infrequent (1 %. The psychotherapies were most often of a supportive (62 % or behavioural-cognitive (26 % nature. Dynamic, insight-oriented psychotherapies were infrequent (8 %. Concurrent psychopharmacological treatment was prevalent (52 %. Gender and age did not correlate with psychiatric interventions, whereas prisoner category (remanded, sentenced, or preventive detention did (p Conclusion Our results pertain only to prisons with adequate primary and mental health services and effective diversion from prison of individuals with serious mental disorders. Given these important limitations, we do propose that the service estimates found may serve as a rough guideline to the minimum number of sessions a prison's psychiatric health services should be able to fulfil in order to serve the inmates psychiatric needs. The results rely on the specialist services' own estimates only. Future studies should

  4. Fertility rates and perinatal outcomes of adolescent pregnancies: a retrospective population-based study

    OpenAIRE

    Souza, Maria de Lourdes de; Lynn, Fiona Ann; Johnston, Linda; Tavares, Eduardo Cardoso Teixeira; Brüggemann, Odaléa Maria; Botelho, Lúcio José

    2017-01-01

    ABSTRACT Objective: analyze trends in fertility rates and associations with perinatal outcomes for adolescents in Santa Catarina, Brazil. Methods: a population-based study covering 2006 to 2013 was carried out to evaluate associations between perinatal outcomes and age groups, using odds ratios, and Chi-squared tests. Results: differences in the fertility rate among female adolescents across regions and time period were observed, ranging from 40.9 to 72.0 per 1,000 in mothers aged 15-19 ye...

  5. Hepatoblastoma incidence in Taiwan: A population-based study

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    Giun-Yi Hung

    2018-06-01

    Full Text Available Background: The incidence of hepatoblastoma is not well known in Taiwan. The goal of this study was to investigate the incidence rates of hepatoblastoma by age and sex. Methods: The data of patients with hepatoblastoma diagnosed from 1995 to 2012 were obtained from the population-based Taiwan Cancer Registry. Incidence rates of hepatoblastoma according to sex and age were analyzed. This study employed the published methods of International Agency for Research on Cancer to calculate the age-standardized incidence rates (ASIRs, standard errors, 95% confidence intervals (CIs, and standardized incidence rate ratios (SIRRs. Results: In total, 211 patients were diagnosed with hepatoblastoma during the 18-year study period. The ASIR was 0.76 per million person-years. Hepatoblastoma was predominantly diagnosed in children (n = 184, 87.2%. By contrast, adolescents/adults (n = 10, 4.7% and elderly people (n = 17, 8.1% were rarely affected. The incidence peaked at ages 0–4 years with corresponding ASIR of 7.3 per million person-years. A significant male predilection was only found in children and elderly people, with male-to-female SIRRs of 1.23 and 1.89, respectively. During 1995–2012, the overall incidence of hepatoblastoma significantly increased only in children (annual percent change: 7.4%, 95% CI 3.9%–11.1%, p < 0.05 and specifically in boys (annual percent change: 6.5%, 95% CI 1.9%–11.2%, p < 0.05. Conclusion: Only 27 patients aged ≥ 15 years with hepatoblastoma were identified in this study, the existence of adult hepatoblastoma still requires novel molecular tools to elucidate. The association between the upward trend of hepatoblastoma incidence in boys and increased survival of prematurity in Taiwan warrants further investigations. Keywords: Hepatoblastoma, Incidence, Taiwan

  6. Estimating glomerular filtration rate in a population-based study

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    Anoop Shankar

    2010-07-01

    Full Text Available Anoop Shankar1, Kristine E Lee2, Barbara EK Klein2, Paul Muntner3, Peter C Brazy4, Karen J Cruickshanks2,5, F Javier Nieto5, Lorraine G Danforth2, Carla R Schubert2,5, Michael Y Tsai6, Ronald Klein21Department of Community Medicine, West Virginia University School of Medicine, Morgantown, WV, USA; 2Department of Ophthalmology and Visual Sciences, 4Department of Medicine, 5Department of Population Health Sciences, University of Wisconsin, School of Medicine and Public Health, Madison, WI, USA; 3Department of Community Medicine, Mount Sinai School of Medicine, NY, USA; 6Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USABackground: Glomerular filtration rate (GFR-estimating equations are used to determine the prevalence of chronic kidney disease (CKD in population-based studies. However, it has been suggested that since the commonly used GFR equations were originally developed from samples of patients with CKD, they underestimate GFR in healthy populations. Few studies have made side-by-side comparisons of the effect of various estimating equations on the prevalence estimates of CKD in a general population sample.Patients and methods: We examined a population-based sample comprising adults from Wisconsin (age, 43–86 years; 56% women. We compared the prevalence of CKD, defined as a GFR of <60 mL/min per 1.73 m2 estimated from serum creatinine, by applying various commonly used equations including the modification of diet in renal disease (MDRD equation, Cockcroft–Gault (CG equation, and the Mayo equation. We compared the performance of these equations against the CKD definition of cystatin C >1.23 mg/L.Results: We found that the prevalence of CKD varied widely among different GFR equations. Although the prevalence of CKD was 17.2% with the MDRD equation and 16.5% with the CG equation, it was only 4.8% with the Mayo equation. Only 24% of those identified to have GFR in the range of 50–59 mL/min per 1

  7. Multi-population Genomic Relationships for Estimating Current Genetic Variances Within and Genetic Correlations Between Populations.

    Science.gov (United States)

    Wientjes, Yvonne C J; Bijma, Piter; Vandenplas, Jérémie; Calus, Mario P L

    2017-10-01

    Different methods are available to calculate multi-population genomic relationship matrices. Since those matrices differ in base population, it is anticipated that the method used to calculate genomic relationships affects the estimate of genetic variances, covariances, and correlations. The aim of this article is to define the multi-population genomic relationship matrix to estimate current genetic variances within and genetic correlations between populations. The genomic relationship matrix containing two populations consists of four blocks, one block for population 1, one block for population 2, and two blocks for relationships between the populations. It is known, based on literature, that by using current allele frequencies to calculate genomic relationships within a population, current genetic variances are estimated. In this article, we theoretically derived the properties of the genomic relationship matrix to estimate genetic correlations between populations and validated it using simulations. When the scaling factor of across-population genomic relationships is equal to the product of the square roots of the scaling factors for within-population genomic relationships, the genetic correlation is estimated unbiasedly even though estimated genetic variances do not necessarily refer to the current population. When this property is not met, the correlation based on estimated variances should be multiplied by a correction factor based on the scaling factors. In this study, we present a genomic relationship matrix which directly estimates current genetic variances as well as genetic correlations between populations. Copyright © 2017 by the Genetics Society of America.

  8. Evaluating manta ray mucus as an alternative DNA source for population genetics study: underwater-sampling, dry-storage and PCR success

    Directory of Open Access Journals (Sweden)

    Tom Kashiwagi

    2015-08-01

    Full Text Available Sharks and rays are increasingly being identified as high-risk species for extinction, prompting urgent assessments of their local or regional populations. Advanced genetic analyses can contribute relevant information on effective population size and connectivity among populations although acquiring sufficient regional sample sizes can be challenging. DNA is typically amplified from tissue samples which are collected by hand spears with modified biopsy punch tips. This technique is not always popular due mainly to a perception that invasive sampling might harm the rays, change their behaviour, or have a negative impact on tourism. To explore alternative methods, we evaluated the yields and PCR success of DNA template prepared from the manta ray mucus collected underwater and captured and stored on a Whatman FTA™ Elute card. The pilot study demonstrated that mucus can be effectively collected underwater using toothbrush. DNA stored on cards was found to be reliable for PCR-based population genetics studies. We successfully amplified mtDNA ND5, nuclear DNA RAG1, and microsatellite loci for all samples and confirmed sequences and genotypes being those of target species. As the yields of DNA with the tested method were low, further improvements are desirable for assays that may require larger amounts of DNA, such as population genomic studies using emerging next-gen sequencing.

  9. Comparative study of paediatric prescription drug utilization between the spanish and immigrant population

    Science.gov (United States)

    2009-01-01

    Background The immigrant population has increased greatly in Spain in recent years to the point where immigrants made up 12% of the infant population in 2008. There is little information available on the profile of this group with regard to prescription drug utilization in universal public health care systems such as that operating in Spain. This work studies the overall and specific differences in prescription drug utilization between the immigrant and Spanish population. Methods Use was made of the Aragonese Health Service databases for 2006. The studied population comprises 159,908 children aged 0-14 years, 13.6% of whom are foreign nationals. Different utilization variables were calculated for each group. Prescription-drug consumption is measured in Defined Daily Doses (DDD) and DDD/1000 persons/day/(DID). Results A total of 833,223 prescriptions were studied. Utilization is lower for immigrant children than in Spanish children for both DID (66.27 v. 113.67) and average annual expense (€21.55 v. €41.14). Immigrant children consume fewer prescription drugs than Spanish children in all of the therapy groups, with the most prescribed (in DID) being: respiratory system, anti-infectives for systemic use, nervous system, sensory organs. Significant differences were observed in relation to the type of drugs and the geographical background of immigrants. Conclusion Prescription drug utilization is much greater in Spanish children than in immigrant children, particularly with reference to bronchodilators (montelukast and terbutaline) and attention-disorder hyperactivity drugs such as methylphenidate. There are important differences regarding drug type and depending on immigrants' geographical backgrounds that suggest there are social, cultural and access factors underlying these disparities. PMID:19995453

  10. Comparative study of paediatric prescription drug utilization between the spanish and immigrant population

    Directory of Open Access Journals (Sweden)

    Macipe-Costa Rosa

    2009-12-01

    Full Text Available Abstract Background The immigrant population has increased greatly in Spain in recent years to the point where immigrants made up 12% of the infant population in 2008. There is little information available on the profile of this group with regard to prescription drug utilization in universal public health care systems such as that operating in Spain. This work studies the overall and specific differences in prescription drug utilization between the immigrant and Spanish population. Methods Use was made of the Aragonese Health Service databases for 2006. The studied population comprises 159,908 children aged 0-14 years, 13.6% of whom are foreign nationals. Different utilization variables were calculated for each group. Prescription-drug consumption is measured in Defined Daily Doses (DDD and DDD/1000 persons/day/(DID. Results A total of 833,223 prescriptions were studied. Utilization is lower for immigrant children than in Spanish children for both DID (66.27 v. 113.67 and average annual expense (€21.55 v. €41.14. Immigrant children consume fewer prescription drugs than Spanish children in all of the therapy groups, with the most prescribed (in DID being: respiratory system, anti-infectives for systemic use, nervous system, sensory organs. Significant differences were observed in relation to the type of drugs and the geographical background of immigrants. Conclusion Prescription drug utilization is much greater in Spanish children than in immigrant children, particularly with reference to bronchodilators (montelukast and terbutaline and attention-disorder hyperactivity drugs such as methylphenidate. There are important differences regarding drug type and depending on immigrants' geographical backgrounds that suggest there are social, cultural and access factors underlying these disparities.

  11. Incidence rates and risk factors of bipolar disorder in the general population: a population-based cohort study

    NARCIS (Netherlands)

    Kroon, Jojanneke S.; Wohlfarth, Tamar D.; Dieleman, Jeanne; Sutterland, Arjen L.; Storosum, Jitschak G.; Denys, Damiaan; de Haan, Lieuwe; Sturkenboom, Mirjam C. J. M.

    2013-01-01

    To estimate the incidence rates (IRs) of bipolar I and bipolar II disorders in the general population according to sociodemographic population characteristics. A cohort study (during the years 1996-2007) was conducted in a general practitioners research database with a longitudinal electronic record

  12. Predictors of medication use in the Roma population in Spain: a population-based national study.

    Science.gov (United States)

    Martín-Pérez, M; Hernández Barrera, V; López de Andrés, A; Jiménez-Trujillo, I; Jiménez-García, R; Carrasco-Garrido, P

    2015-05-01

    To describe the prevalence of prescribed and self-medicated use of medication in the Spanish Roma population, and identify the associated factors. Descriptive cross-sectional study. Data from the first National Health Survey conducted on the Roma population in Spain were used. The sample comprised 1000 Spanish Roma adults of both sexes aged ≥16 years. Answers (yes/no) to the question, 'In the last two weeks have you taken the following medicines [in reference to a list of medicines that might be used by the population] and were they prescribed for you by a doctor?' were used to ascertain 'medication use'. 'Self-medication' referred to use of these medicines without medical prescription. Using multivariate logistic regression models, odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to identify associated factors. The overall prevalence of medication use in the Roma population for both sexes was 69.1%, and 38.7% was self-medicated. Females reported higher use of medication than males (75.1% vs 62.3%); however, self-medication was higher among males. Analgesics and antipyretics were used most often (35.8%). Among males, the variables that were independently and significantly associated with a higher probability of medication use were: age; negative perception of health; presence of chronic disease (OR 2.81; 95% CI 1.67-4.73); and medical visits (OR 4.51; 95% CI 2.54-8.01). The variables were the same among females, except for age. A high percentage of the Spanish Roma population use medication, and a significant proportion of them self-medicate. The presence of chronic diseases, a negative perception of health and medical consultations were associated with increased use of medication in the study population. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  13. Methodology of a study on the French population exposure to 50 Hz magnetic fields

    International Nuclear Information System (INIS)

    Bedja, M.; Magne, I.; Souques, M.; Lambrozo, J.; Le Brusquet, L.; Fleury, G.; Azoulay, A.; Deschamps, F.; Carlsberg, A.

    2010-01-01

    The characterisation of population exposure to a 50-Hz magnetic field (MF) is important for assessing health effects of electromagnetic fields. With the aim of estimating and characterising the exposure of the French population to 50-Hz MFs, two representative samples of the population were made. A random selection method based on the distribution of households in different regions of France was used. The samples were carried out starting from a random polling of telephone numbers of households (listed, unlisted fixed phones and cell phones only). A total of 95 362 telephone numbers were dialed to have 2148 volunteers (1060 children and 1088 adults). They all agreed to carrying an EMDEX II meter, measuring and recording MFs, and to filling out a timetable for a 24-hour period. In this article, the methodology of the sample selection and the collection of all necessary information for the realisation of this study are presented. (authors)

  14. A Field Evaluation of the Time-of-Detection Method to Estimate Population Size and Density for Aural Avian Point Counts

    Directory of Open Access Journals (Sweden)

    Mathew W. Alldredge

    2007-12-01

    Full Text Available The time-of-detection method for aural avian point counts is a new method of estimating abundance, allowing for uncertain probability of detection. The method has been specifically designed to allow for variation in singing rates of birds. It involves dividing the time interval of the point count into several subintervals and recording the detection history of the subintervals when each bird sings. The method can be viewed as generating data equivalent to closed capture-recapture information. The method is different from the distance and multiple-observer methods in that it is not required that all the birds sing during the point count. As this method is new and there is some concern as to how well individual birds can be followed, we carried out a field test of the method using simulated known populations of singing birds, using a laptop computer to send signals to audio stations distributed around a point. The system mimics actual aural avian point counts, but also allows us to know the size and spatial distribution of the populations we are sampling. Fifty 8-min point counts (broken into four 2-min intervals using eight species of birds were simulated. Singing rate of an individual bird of a species was simulated following a Markovian process (singing bouts followed by periods of silence, which we felt was more realistic than a truly random process. The main emphasis of our paper is to compare results from species singing at (high and low homogenous rates per interval with those singing at (high and low heterogeneous rates. Population size was estimated accurately for the species simulated, with a high homogeneous probability of singing. Populations of simulated species with lower but homogeneous singing probabilities were somewhat underestimated. Populations of species simulated with heterogeneous singing probabilities were substantially underestimated. Underestimation was caused by both the very low detection probabilities of all distant

  15. Studying Intense Pulsed Light Method Along With Corticosteroid Injection in Treating Keloid Scars

    OpenAIRE

    Shamsi Meymandi, Simin; Rezazadeh, Azadeh; Ekhlasi, Ali

    2014-01-01

    Background: Results of various studies suggest that the hypertrophic and keloid scars are highly prevalent in the general population and are irritating both physically and mentally. Objective: Considering the variety of existing therapies, intense pulsed light (IPL) method along with corticosteroid injection was evaluated in treating these scars. Materials and Methods: 86 subjects were included in this clinical trial. Eight sessions of therapeutic intervention were done with IPL along with co...

  16. Recommended methods for monitoring change in bird populations by counting and capture of migrants

    Science.gov (United States)

    David J. T. Hussell; C. John Ralph

    2005-01-01

    Counts and banding captures of spring or fall migrants can generate useful information on the status and trends of the source populations. To do so, the counts and captures must be taken and recorded in a standardized and consistent manner. We present recommendations for field methods for counting and capturing migrants at intensively operated sites, such as bird...

  17. Dasymetric high resolution population distribution estimates for improved decision making, with a case study of sea-level rise vulnerability in Boca Raton, Florida

    Science.gov (United States)

    Ziegler, Hannes Moritz

    Planners and managers often rely on coarse population distribution data from the census for addressing various social, economic, and environmental problems. In the analysis of physical vulnerabilities to sea-level rise, census units such as blocks or block groups are coarse relative to the required decision-making application. This study explores the benefits offered from integrating image classification and dasymetric mapping at the household level to provide detailed small area population estimates at the scale of residential buildings. In a case study of Boca Raton, FL, a sea-level rise inundation grid based on mapping methods by NOAA is overlaid on the highly detailed population distribution data to identify vulnerable residences and estimate population displacement. The enhanced spatial detail offered through this method has the potential to better guide targeted strategies for future development, mitigation, and adaptation efforts.

  18. A simulation study of how simple mark-recapture methods can be combined with destructive sub-sampling to facilitate surveys of flying insects

    DEFF Research Database (Denmark)

    Nachman, Gøsta Støger; Skovgård, Henrik; Pedersen, Henrik Skovgård

    2012-01-01

    Mark-recapture techniques are used for studies of animal populations. With only three sampling occasions, both Bailey's triple-catch (BTC) and Jolly-Seber's (J-S) stochastic method can be applied. As marking and handling of fragile organisms may harm them, and thereby affect their chances of being...... to compare the subsampling method with the ordinary mark-recapture methods. Model-generated populations were sampled with and without subsampling to provide estimates of population size, loss, and dilution rates. The estimated parameters were compared with their true values to identify biases associated...... with the sampling methods, using 81 different combinations of population size, dilution rate, loss rate, and sampling effort. Each combination was replicated 1,000 times. In no cases did subsampling perform more poorly than the ordinary methods. J-S was slightly more accurate than BTC to estimate the population...

  19. Factors associated with the utilization of primary care emergency centers in a Spanish region with high population dispersion: a mixed-methods study.

    Science.gov (United States)

    Sanz-Barbero, Belén; Otero-García, Laura; Blasco-Hernández, Teresa; San Sebastián, Miguel

    2014-09-03

    Adequate access to primary care emergency centers is particularly important in rural areas isolated from urban centers. However, variability in utilization of emergency services located in primary care centers among inhabitants of nearby geographical areas is understudied. The objectives of this study are twofold: 1) to analyze the association between the availability of municipal emergency care centers and utilization of primary care emergency centers (PCEC), in a Spanish region with high population dispersion; and 2) to determine healthcare providers' perceptions regarding PCEC utilization. A mixed-methods study was conducted. Quantitative phase: multilevel logistic regression modeling using merged data from the 2003 Regional Health Survey of Castile and Leon and the 2001 census data (Spain). Qualitative phase:14 in-depth- interviews of rural-based PCEC providers. Having PCEC as the only emergency center in the municipality was directly associated with its utilization (p use. PCEC users were considered to be predominantly workers and students with scheduling conflicts with rural primary care opening hours. The location of emergency care centers is associated with PCEC utilization. Increasing access to primary care by extending hours may be an important step toward optimal PCEC utilization. Further research would determine whether lower PCEC use by certain groups is associated with disparities in access to care.

  20. Ischemic heart disease in HIV-infected and HIV-uninfected individuals: a population-based cohort study

    DEFF Research Database (Denmark)

    Obel, N; Thomsen, Henrik F.; Kronborg, G

    2007-01-01

    BACKGROUND: There are concerns about highly active antiretroviral therapy (HAART) causing a progressive increase in the risk of ischemic heart disease. We examined this issue in a nationwide cohort study of patients with human immunodeficiency virus (HIV) infection and a population-based control...... group. METHODS: We determined the rate of first hospitalization for ischemic heart disease in all Danish patients with HIV infection (3953 patients) from 1 January 1995 through 31 December 2004 and compared this rate with that for 373,856 subjects in a population-based control group. Data on first...... hospitalization for ischemic heart disease and comorbidity were obtained from the Danish National Hospital Registry for all study participants. We used Cox's regression to compute the hospitalization rate ratio as an estimate of relative risk, adjusting for comorbidity. RESULTS: Although the difference...

  1. C-reactive protein implications in new-onset hypertension in a healthy population initially aged 65 years : the Proof study

    NARCIS (Netherlands)

    Dauphinot, Virginie; Roche, Frederic; Kossovsky, Michel P.; Schott, Anne-Marie; Pichot, Vincent; Gaspoz, Jean-Michel; Gosse, Philippe; Barthelemy, Jean-Claude

    Background Because inflammation is known to be related with several cardiovascular diseases, we sought to determine whether C-reactive protein (CRP) might precede the onset of hypertension. Methods The study population was selected from the Proof study cohort including 1011 individuals initially

  2. Java project on periodontal diseases : a study on transmission of Porphyromonas gingivalis in a remote Indonesian population

    NARCIS (Netherlands)

    van Winkelhoff, A. J.; Rijnsburger, M. C.; Abbas, F.; Timmerman, M. F.; van der Weijden, G. A.; Winkel, E. G.; van der Velden, U.

    Aim: To study transmission of Porphyromonas gingivalis in a population living in a remote area in Southern Java, Indonesia. Material and Methods: Subgingival plaque samples from 167 subjects with varying degrees of periodontal breakdown were obtained and cultured for the presence of P. gingivalis.

  3. Asthma exacerbation and proximity of residence to major roads: a population-based matched case-control study among the pediatric Medicaid population in Detroit, Michigan

    Directory of Open Access Journals (Sweden)

    Wahl Robert

    2011-04-01

    Full Text Available Abstract Background The relationship between asthma and traffic-related pollutants has received considerable attention. The use of individual-level exposure measures, such as residence location or proximity to emission sources, may avoid ecological biases. Method This study focused on the pediatric Medicaid population in Detroit, MI, a high-risk population for asthma-related events. A population-based matched case-control analysis was used to investigate associations between acute asthma outcomes and proximity of residence to major roads, including freeways. Asthma cases were identified as all children who made at least one asthma claim, including inpatient and emergency department visits, during the three-year study period, 2004-06. Individually matched controls were randomly selected from the rest of the Medicaid population on the basis of non-respiratory related illness. We used conditional logistic regression with distance as both categorical and continuous variables, and examined non-linear relationships with distance using polynomial splines. The conditional logistic regression models were then extended by considering multiple asthma states (based on the frequency of acute asthma outcomes using polychotomous conditional logistic regression. Results Asthma events were associated with proximity to primary roads with an odds ratio of 0.97 (95% CI: 0.94, 0.99 for a 1 km increase in distance using conditional logistic regression, implying that asthma events are less likely as the distance between the residence and a primary road increases. Similar relationships and effect sizes were found using polychotomous conditional logistic regression. Another plausible exposure metric, a reduced form response surface model that represents atmospheric dispersion of pollutants from roads, was not associated under that exposure model. Conclusions There is moderately strong evidence of elevated risk of asthma close to major roads based on the results obtained

  4. Asthma exacerbation and proximity of residence to major roads: a population-based matched case-control study among the pediatric Medicaid population in Detroit, Michigan

    Science.gov (United States)

    2011-01-01

    Background The relationship between asthma and traffic-related pollutants has received considerable attention. The use of individual-level exposure measures, such as residence location or proximity to emission sources, may avoid ecological biases. Method This study focused on the pediatric Medicaid population in Detroit, MI, a high-risk population for asthma-related events. A population-based matched case-control analysis was used to investigate associations between acute asthma outcomes and proximity of residence to major roads, including freeways. Asthma cases were identified as all children who made at least one asthma claim, including inpatient and emergency department visits, during the three-year study period, 2004-06. Individually matched controls were randomly selected from the rest of the Medicaid population on the basis of non-respiratory related illness. We used conditional logistic regression with distance as both categorical and continuous variables, and examined non-linear relationships with distance using polynomial splines. The conditional logistic regression models were then extended by considering multiple asthma states (based on the frequency of acute asthma outcomes) using polychotomous conditional logistic regression. Results Asthma events were associated with proximity to primary roads with an odds ratio of 0.97 (95% CI: 0.94, 0.99) for a 1 km increase in distance using conditional logistic regression, implying that asthma events are less likely as the distance between the residence and a primary road increases. Similar relationships and effect sizes were found using polychotomous conditional logistic regression. Another plausible exposure metric, a reduced form response surface model that represents atmospheric dispersion of pollutants from roads, was not associated under that exposure model. Conclusions There is moderately strong evidence of elevated risk of asthma close to major roads based on the results obtained in this population

  5. The population-based Barcelona-Asymptomatic Intracranial Atherosclerosis Study (ASIA: rationale and design

    Directory of Open Access Journals (Sweden)

    Pera Guillem

    2011-02-01

    Full Text Available Abstract Background Large-artery intracranial atherosclerosis may be the most frequent cause of ischemic stroke worldwide. Traditional approaches have attempted to target the disease when it is already symptomatic. However, early detection of intracranial atherosclerosis may allow therapeutic intervention while the disease is still asymptomatic. The prevalence and natural history of asymptomatic intracranial atherosclerosis in Caucasians remain unclear. The aims of the Barcelona-ASymptomatic Intracranial Atherosclerosis (ASIA study are (1 to determine the prevalence of ASIA in a moderate-high vascular risk population, (2 to study its prognostic impact on the risk of suffering future major ischemic events, and (3 to identify predictors of the development, progression and clinical expression of this condition. Methods/Design Cross-over and cohort, population-based study. A randomly selected representative sample of 1,503 subjects with a mild-moderate-high vascular risk (as defined by a REGICOR score ≥ 5% and with neither a history of cerebrovascular nor ischemic heart disease will be studied. At baseline, all individuals will undergo extracranial and transcranial Color-Coded Duplex (TCCD ultrasound examinations to detect presence and severity of extra and intracranial atherosclerosis. Intracranial stenoses will be assessed by magnetic resonance angiography (MRA. Clinical and demographic variables will be recorded and blood samples will be drawn to investigate clinical, biological and genetic factors associated with the presence of ASIA. A long-term clinical and sonographic follow-up will be conducted thereafter to identify predictors of disease progression and of incident vascular events. Discussion The Barcelona-ASIA is a population-based study aiming to evaluate the prevalence and clinical importance of asymptomatic intracranial large-artery atherosclerosis in Caucasians. The ASIA project may provide a unique scientific resource to better

  6. Psychiatric disorders in long-term sickness absence -- a population-based cross-sectional study

    DEFF Research Database (Denmark)

    Søgaard, Hans Jørgen; Bech, Per

    2009-01-01

    AIMS: The study estimates the incidence of psychiatric disorders in long-term sickness absence (LSA; more than eight weeks of continuous sickness absence) over one year. The study is the first accounting for everybody on LSA by linking a psychiatric assessment for all persons on LSA to public...... registers. METHODS: In a Danish population of 120,000 inhabitants all 2,414 incident persons on LSA within one year were posted a questionnaire, of whom 1,121 (46.4%) responded. In a two phase design the 1,121 sick-listed persons were screened for psychiatric disorders. Phase 2 consisted of 844 people...

  7. Potential for parasite-induced biases in aquatic invertebrate population studies

    Science.gov (United States)

    Fisher, Justin D.L.; Mushet, David M.; Stockwell, Craig A.

    2014-01-01

    Recent studies highlight the need to include estimates of detection/capture probability in population studies. This need is particularly important in studies where detection and/or capture probability is influenced by parasite-induced behavioral alterations. We assessed potential biases associated with sampling a population of the amphipod Gammarus lacustris in the presence of Polymorphus spp. acanthocephalan parasites shown to increase positive phototaxis in their amphipod hosts. We trapped G. lacustris at two water depths (benthic and surface) and compared number of captures and number of parasitized individuals at each depth. While we captured the greatest number of G. lacustris individuals in benthic traps, parasitized individuals were captured most often in surface traps. These results reflect the phototaxic movement of infected individuals from benthic locations to sunlit surface waters. We then explored the influence of varying infection rates on a simulated population held at a constant level of abundance. Simulations resulted in increasingly biased abundance estimates as infection rates increased. Our results highlight the need to consider parasite-induced biases when quantifying detection and/or capture probability in studies of aquatic invertebrate populations.

  8. [An analytical framework for the study of population and development interrelationships].

    Science.gov (United States)

    Ochoa, L H

    1977-01-01

    When studying the relationship between population dynamics and socioeconomic development, 4 important considerations must guide the inquiry. Changes in growth of population or distribution of population, the determinants of such change, the consequences and implications of such change and the political implications of such change must always be recognized and analyzed. This study, then, aims at a more complete evaluation and analysis of the interrelationships between nutrition and development by bringing into focus the many networks which exist between demographic factors, food supply, the agricultural reality on a national level and political factors. Demographic, nutritional and agricultural data are presented in support of the study's most forceful assertion which states that if population and agricultural production growth rates are increasing proportionately, but yet half of the national population is still starving, the problem is not strictly demographic in nature. The author proposes that more stress be given to the distribution of nutrition and the quality of nutrition in future population and nutritional planning, since these are indeed the keys to economic and social development.

  9. PERSONAL NETWORK SAMPLING, OUTDEGREE ANALYSIS AND MULTILEVEL ANALYSIS - INTRODUCING THE NETWORK CONCEPT IN STUDIES OF HIDDEN POPULATIONS

    NARCIS (Netherlands)

    SPREEN, M; ZWAAGSTRA, R

    1994-01-01

    Populations, such as heroin and cocaine users, the homeless and the like (hidden populations), are among the most difficult populations to which to apply classic random sampling procedures. A frequently used data collection method for these hidden populations is the snowball procedure. The

  10. Cancer survival in Cixian of China, 2003-2013: a population-based study.

    Science.gov (United States)

    Li, Dongfang; Li, Daojuan; Song, Guohui; Liang, Di; Chen, Chao; Zhang, Yachen; Gao, Zhaoyu; He, Yutong

    2018-04-01

    Cixian is one of the high-risk areas for upper gastrointestinal cancer in China and the world. From 2005, comprehensive population-based screening for upper gastrointestinal cancers has been conducted in Cixian. The aim of this study was to investigate population-based cancer survival from 2003 to 2013 and to explore the effect of screening on upper gastrointestinal cancer survival in Cixian. Observed survival was estimated using the life table method. The expected survival from the general population was calculated using all-cause mortality data from the population of Cixian with the EdererII method. Cixian cancer registry, with a total coverage of 6.88 million person years, recorded 19,628 cancer patients diagnosed during 2003-2013. In Cixian, from 2003 to 2013, there were 19,628 newly cancer cases and 13,984 cancer deaths, with an incidence rate of 285.37/100,000 and mortality rate of 203.31/100,000. The overall five-year relative cancer survival for patients diagnosed in Cixian in 2003-2013 was 22.53%. The relative survival for all cancers combined in Cixian had an overall upward trend from 2003 to 2013. Among upper gastrointestinal cancer in Cixian, the five-year relative survival for cardia gastric cancer was highest at 30.42%, followed by oesophageal cancer at 25.37% and noncardia gastric cancer at 18.93%. In 2013, the five-year relative survival for oesophageal cancer, cardia gastric cancer, and noncardia gastric cancer patients aged 45-69 years was 39.97% (95% CI: 34.52-45.43%), 51.74% (95% CI: 42.09-60.86%), and 37.43% (95% CI: 26.93-48.17%), respectively, the absolute values increasing 14.11%, 16.71%, and 14.92% compared with that in 2003. There is an increasing trend in overall survival for upper gastrointestinal cancer with early screening and treatment of cancer in Cixian. © 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  11. Bladder cancer in cancer patients: population-based estimates from a large Swedish study

    OpenAIRE

    Bermejo, J Lorenzo; Sundquist, J; Hemminki, K

    2009-01-01

    Background: This study quantified the risk of urinary bladder neoplasms in cancer patients taking into account the age at first diagnosis, the gender of the patients and the lead time between diagnoses. Methods: We used standardised incidence ratios (SIRs) to compare the incidence of bladder tumours in 967?767 cancer patients with the incidence rate in the general Swedish population. A total of 3324 male and 1560 female patients developed bladder tumours at least 1 year after first cancer dia...

  12. Risk perception among women receiving genetic counseling: a population-based follow-up study

    DEFF Research Database (Denmark)

    Mikkelsen, Ellen M; Sunde, Lone; Johansen, Christoffer

    2007-01-01

    -up study of 213 women who received genetic counseling for hereditary breast and ovarian cancer, 319 women who underwent mammography (Reference Group I), and a random sample of 1070 women from the general population (Reference Group II). RESULTS: Women who received genetic counseling decreased...... counseling, compared to a reduction of 5% (p=0.03) and 2% (p=0.01) in Reference Groups I and II, respectively. Risk communicated only in words, inaccurate risk perception at baseline, and presence of a familial mutation appeared to be predictors of inaccurate risk perception 12 months after counseling......BACKGROUND: We aimed to explore the impact of genetic counseling on perceived personal lifetime risk of breast cancer, the accuracy of risk perception, and possible predictors of inaccurate risk perception 1 year following counseling. METHODS: We conducted a population-based prospective follow...

  13. Characteristics of pregnant illicit drug users and associations between cannabis use and perinatal outcome in a population-based study.

    NARCIS (Netherlands)

    Gelder, M.M.H.J. van; Reefhuis, J.; Caton, A.R.; Werler, M.M.; Druschel, C.M.; Roeleveld, N.

    2010-01-01

    BACKGROUND: According to the 2004 National Survey on Drug Use and Health, 4.6% of American women reported use of an illicit drug during pregnancy. Previous studies on illicit drug use during pregnancy and perinatal outcomes showed inconsistent results. METHODS: This population-based study included

  14. A population-based nested case control study on recurrent pneumonias in children with severe generalized cerebral palsy: ethical considerations of the design and representativeness of the study sample

    Directory of Open Access Journals (Sweden)

    Benninga Marc A

    2005-07-01

    Full Text Available Abstract Background In children with severe generalized cerebral palsy, pneumonias are a major health issue. Malnutrition, dysphagia, gastro-oesophageal reflux, impaired respiratory function and constipation are hypothesized risk factors. Still, no data are available on the relative contribution of these possible risk factors in the described population. This paper describes the initiation of a study in 194 children with severe generalized cerebral palsy, on the prevalence and on the impact of these hypothesized risk factors of recurrent pneumonias. Methods/Design A nested case-control design with 18 months follow-up was chosen. Dysphagia, respiratory function and constipation will be assessed at baseline, malnutrition and gastro-oesophageal reflux at the end of the follow-up. The study population consists of a representative population sample of children with severe generalized cerebral palsy. Inclusion was done through care-centres in a predefined geographical area and not through hospitals. All measurements will be done on-site which sets high demands on all measurements. If these demands were not met in "gold standard" methods, other methods were chosen. Although the inclusion period was prolonged, the desired sample size of 300 children was not met. With a consent rate of 33%, nearly 10% of all eligible children in the Netherlands are included (n = 194. The study population is subtly different from the non-participants with regard to severity of dysphagia and prevalence rates of pneumonias and gastro-oesophageal reflux. Discussion Ethical issues complicated the study design. Assessment of malnutrition and gastro-oesophageal reflux at baseline was considered unethical, since these conditions can be easily treated. Therefore, we postponed these diagnostics until the end of the follow-up. In order to include a representative sample, all eligible children in a predefined geographical area had to be contacted. To increase the consent rate, on

  15. The National Women's Health Study: assembly and description of a population-based reproductive cohort

    Directory of Open Access Journals (Sweden)

    Prior Susan

    2004-08-01

    Full Text Available Abstract Background Miscarriage is a common event but is remarkably difficult to measure in epidemiological studies. Few large-scale population-based studies have been conducted in the UK. Methods This was a population-based two-stage postal survey of reproductive histories of adult women living in the United Kingdom in 2001, sampled from the electronic electoral roll. In Stage 1 a short "screening" questionnaire was sent to over 60,000 randomly selected women in order to identify those aged 55 and under who had ever been pregnant or ever attempted to achieve a pregnancy, from whom a brief reproductive history was requested. Stage 2 involved a more lengthy questionnaire requesting detailed information on every pregnancy (and fertility problems, and questions relating to socio-demographic, behavioural and other factors for the most recent pregnancy in order to examine risk factors for miscarriage. Data on stillbirth, multiple birth and maternal age are compared to national data in order to assess response bias. Results The response rate was 49% for Stage 1 and 73% for the more targeted Stage 2. A total of 26,050 questionnaires were returned in Stage 1. Of the 17,748 women who were eligible on the grounds of age, 27% reported that they had never been pregnant and had never attempted to conceive a child. The remaining 13,035 women reported a total of 30,661 pregnancies. Comparison of key reproductive indicators (stillbirth and multiple birth rates and maternal age at first birth with national statistics showed that the data look remarkably similar to the general population. Conclusions This study has enabled the assembly of a large population-based dataset of women's reproductive histories which appears unbiased compared to the general UK population and which will enable investigation of hard-to-measure outcomes such as miscarriage and infertility.

  16. Cigarette smoking, nicotine dependence and anxiety disorders: a systematic review of population-based, epidemiological studies

    Directory of Open Access Journals (Sweden)

    Moylan Steven

    2012-10-01

    Full Text Available Abstract Background Multiple studies have demonstrated that rates of smoking and nicotine dependence are increased in individuals with anxiety disorders. However, significant variability exists in the epidemiological literature exploring this relationship, including study design (cross-sectional versus prospective, the population assessed (random sample versus clinical population and diagnostic instrument utilized. Methods We undertook a systematic review of population-based observational studies that utilized recognized structured clinical diagnostic criteria (Diagnostic and Statistical Manual of Mental Disorders (DSM or International Classification of Diseases (ICD for anxiety disorder diagnosis to investigate the relationship between cigarette smoking, nicotine dependence and anxiety disorders. Results In total, 47 studies met the predefined inclusion criteria, with 12 studies providing prospective information and 5 studies providing quasiprospective information. The available evidence suggests that some baseline anxiety disorders are a risk factor for initiation of smoking and nicotine dependence, although the evidence is heterogeneous and many studies did not control for the effect of comorbid substance use disorders. The identified evidence however appeared to more consistently support cigarette smoking and nicotine dependence as being a risk factor for development of some anxiety disorders (for example, panic disorder, generalized anxiety disorder, although these findings were not replicated in all studies. A number of inconsistencies in the literature were identified. Conclusions Although many studies have demonstrated increased rates of smoking and nicotine dependence in individuals with anxiety disorders, there is a limited and heterogeneous literature that has prospectively examined this relationship in population studies using validated diagnostic criteria. The most consistent evidence supports smoking and nicotine dependence as

  17. Reliability of third molar development for age estimation in Gujarati population: A comparative study.

    Science.gov (United States)

    Gandhi, Neha; Jain, Sandeep; Kumar, Manish; Rupakar, Pratik; Choyal, Kanaram; Prajapati, Seema

    2015-01-01

    Age assessment may be a crucial step in postmortem profiling leading to confirmative identification. In children, Demirjian's method based on eight developmental stages was developed to determine maturity scores as a function of age and polynomial functions to determine age as a function of score. Of this study was to evaluate the reliability of age estimation using Demirjian's eight teeth method following the French maturity scores and Indian-specific formula from developmental stages of third molar with the help of orthopantomograms using the Demirjian method. Dental panoramic tomograms from 30 subjects each of known chronological age and sex were collected and were evaluated according to Demirjian's criteria. Age calculations were performed using Demirjian's formula and Indian formula. Statistical analysis used was Chi-square test and ANOVA test and the P values obtained were statistically significant. There was an average underestimation of age with both Indian and Demirjian's formulas. The mean absolute error was lower using Indian formula hence it can be applied for age estimation in present Gujarati population. Also, females were ahead of achieving dental maturity than males thus completion of dental development is attained earlier in females. Greater accuracy can be obtained if population-specific formulas considering the ethnic and environmental variation are derived performing the regression analysis.

  18. The importance of studying inherited hematological disorders in ancient Anatolian populations

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    Yeşim Doğan Alakoç

    2011-12-01

    Full Text Available Before analysis of DNA from ancient remains was possible, anthropologists studied evolution and migration patterns using data obtained from population genetic studies on modern populations combined with data obtained from morphological evaluations of ancient remains. Currently, DNA analysis of ancient populations is making a valuable contribution to these efforts. Researchers that perform ancient DNA analysis prefer to study polymorphisms on the Y chromosome or mitochondrial DNA because the results are easier to statistically evaluate. To evaluate polymorphisms on diploid genomes, which are more informative, only mutations that have been extensively examined in modern populations should be chosen. The most extensively evaluated mutations are those related to prevalent inherited disorders. As such, beta-thalassemia, sickle cell anemia, FVL mutation of globin and the factor V genes are good candidates for DNA studies in ancient populations. These mutations are common in Anatolia, host to many civilizations since the Paleolithic period. This history makes Anatolia a good place for conducting research that could enhance our understanding of human evolution and migration patterns.

  19. Prevalence and causes of visual impairment in a Brazilian population: The Botucatu Eye Study

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    Cordeiro Ricardo

    2009-08-01

    Full Text Available Abstract Background This paper reports population-based data on the prevalence and causes of visual impairment among children and adults in Botucatu, Brazil. Methods A population-based cross-sectional study was conducted involving a random start point and then systematic sampling of an urban Brazilian population in the city of Botucatu. There were approximately 3 300 individuals aged 1 to 91 years who were eligible to participate in the study. Of this sample, 2485 (75.3% underwent ophthalmic examination. The ophthalmic examination included uncorrected (presenting and best corrected distance visual acuity using standardized protocols. The primary cause of decreased visual acuity was identified for all patients with visual impairment. Results Presenting low vision and presenting blindness were found in 5.2% (95% CI: 4.3–6.1 and 2.2% (95% CI: 1.6–2.8 of the population, respectively. Unilateral presenting low vision and unilateral presenting blindness were found in 8.3% (95% CI: 7.2–9.5 and 3.7% (95% CI: 2.9–4.4 of the population respectively. Best corrected low vision was found in 1.3% of the population (95% CI: 0.9–1.7 and best corrected blindness was discovered in 0.4% of people (95% CI: 0.2–0.7. The main cause of presenting low vision was refractive error (72.3% and cataract was the most prevalent cause of blindness (50%. Conclusion The main causes of low vision and blindness in this Brazilian city were uncorrected refractive errors, cataract, and retinal diseases. Programs to further reduce the burden of visual impairment need to be targeted toward the correction of refractive error and surgery for cataracts.

  20. Outcomes in type 1 diabetic pregnancies: a nationwide, population-based study

    DEFF Research Database (Denmark)

    Jensen, Dorte; Damm, Peter; Moelsted-Pedersen, Lars

    2004-01-01

    The aim of this study was to compare pregnancy outcomes in type 1 diabetic pregnancies with the background population.......The aim of this study was to compare pregnancy outcomes in type 1 diabetic pregnancies with the background population....

  1. Design of PREVENCION: a population-based study of cardiovascular disease in Peru.

    Science.gov (United States)

    Medina-Lezama, Josefina; Chirinos, Julio A; Zea Díaz, Humberto; Morey, Oscar; Bolanos, Juan F; Munoz-Atahualpa, Edgar; Chirinos-Pacheco, Julio

    2005-11-02

    Latin America is undergoing the epidemiologic transition that occurred earlier in developed countries, and is likely to face a gigantic epidemic of heart disease in the next few years unless urgent action is taken. The first essential component of any effective cardiovascular disease (CVD) control program is to establish reliable estimates of cardiovascular disease-related morbidity and mortality. However, such data from population-based studies in Latin America are still lacking. In this paper, we present the design and operation of PREVENCION (Estudio Peruano de Prevalencia de Enfermedades Cardiovasculares, for Peruvian Study of the Prevalence of Cardiovascular diseases). PREVENCION is an ongoing population-based study on a representative sample of the civilian non-institutionalized population of the second largest city in Peru. Its population is comparable to the rest of the Peruvian urban population and closely resembles other Latin American populations in countries such as Bolivia and Ecuador. Our study will contribute to the enormous task of understanding and preventing CVD in Latin America.

  2. Association Between Educational Level and Risk of Cancer in HIV-infected Individuals and the Background Population: Population-based Cohort Study 1995-2011.

    Science.gov (United States)

    Legarth, Rebecca; Omland, Lars H; Dalton, Susanne O; Kronborg, Gitte; Larsen, Carsten S; Pedersen, Court; Pedersen, Gitte; Gerstoft, Jan; Obel, Niels

    2015-11-15

    Human immunodeficiency virus (HIV)-infected individuals have increased risk of cancer. To our knowledge, no previous study has examined the impact of socioeconomic position on risk and prognosis of cancer in HIV infection. Population-based cohort-study, including HIV-infected individuals diagnosed (without intravenous drug abuse or hepatitis C infection) (n = 3205), and a background population cohort matched by age, gender, and country of birth (n = 22 435) were analyzed. Educational level (low or high) and cancer events were identified in Danish national registers. Cumulative incidences, incidence rate ratios (IRRs), and survival using Kaplan-Meier methods were estimated. Low educational level was associated with increased risk of cancer among HIV-infected individuals compared to population controls: all (adjusted-IRRs: 1.4 [95% confidence interval {CI}, 1.1-1.7] vs 1.1 [95% CI, .9-1.2]), tobacco- and alcohol-related (2.1 [95% CI, 1.3-3.4] vs 1.3 [95% CI, 1.1-1.6]), and other (1.7 [95% CI, 1.1-2.8] vs 0.9 [95% CI, .7-1.0]). Educational level was not associated with infection-related or ill-defined cancers. One-year-survival was not associated with educational level, but HIV-infected individuals with low educational level had lower 5-year-survival following infection-related and ill-defined cancers. Education is associated with risk and prognosis of some cancers in HIV infection, and diverges from what is observed in the background population. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Optimal cutoff for the evaluation of insulin resistance through triglyceride-glucose index: A cross-sectional study in a Venezuelan population.

    Science.gov (United States)

    Salazar, Juan; Bermúdez, Valmore; Calvo, María; Olivar, Luis Carlos; Luzardo, Eliana; Navarro, Carla; Mencia, Heysa; Martínez, María; Rivas-Ríos, José; Wilches-Durán, Sandra; Cerda, Marcos; Graterol, Modesto; Graterol, Rosemily; Garicano, Carlos; Hernández, Juan; Rojas, Joselyn

    2017-01-01

    Background: Insulin resistance (IR) evaluation is a fundamental goal in clinical and epidemiological research. However, the most widely used methods are difficult to apply to populations with low incomes. The triglyceride-glucose index (TGI) emerges as an alternative to use in daily clinical practice. Therefore the objective of this study was to determine an optimal cutoff point for the TGI in an adult population from Maracaibo, Venezuela. Methods: This is a sub-study of Maracaibo City Metabolic Syndrome Prevalence Study, a descriptive, cross-sectional study with random and multi-stage sampling. For this analysis, 2004 individuals of both genders ≥18 years old with basal insulin determination and triglycerides triglyceride (mg / dl) x Fasting glucose (mg / dl)] / 2. Results: The TGI in the general population was 4.6±0.3 (male: 4.66±0.34 vs. female: 4.56±0.33, p=8.93x10 -10 ). The optimal cutoff point was 4.49, with a sensitivity of 82.6% and specificity of 82.1% (AUC=0.889, 95% CI: 0.854-0.924). There were no significant differences in the predictive capacity of the index when evaluated according to gender and age groups. Those individuals with TGI≥4.5 had higher HOMA2-IR averages than those with TGI index to determine atypical metabolic phenotypes, type 2 diabetes mellitus and even cardiovascular risk in our population.

  4. Mammary carcinoma – current diagnostic methods and symptomatology in imaging studies

    International Nuclear Information System (INIS)

    Popiel, Monika; Mróz-Klimas, Danuta; Kasprzak, Renata; Furmanek, Mariusz

    2012-01-01

    Breast cancer is the most common neoplasm of the female population and its incidence is constantly rising. Social campaigns educating the public about the importance of the problem have been conducted for the past several years. Women are encouraged to self-examine on a monthly basis. Women aged 50–69 years can have an x-ray mammography performed once every 2 years as part of a prophylactic screening program. Ultrasound studies or MR mammography are adjuvant or, in some cases, alternative to x-ray mammography. Nuclear medicine techniques with application of oncophilic markers and receptor studies (this publication will not cover nuclear medicine methods) are not routinely used. Other techniques, such as computed tomography and conventional radiography are of no significance in the diagnostics of mammary cancer. However, together with isotopic methods, they are helpful in staging of the disease. X-ray mammography is, up to date, the only method with proven value in decreasing mortality. It is also the best available method for visualization of microcalicifications. Ultrasound examination is complementary to x-ray mammography as it is a cheap, easily available method of imaging mammary glands with higher glandular tissue content. It is also the most commonly used modality aiding in targeted biopsy of mammary gland. To date, MR mammography, characterized by the highest sensitivity in cancer diagnostics, remained a method reserved for “special tasks”. MR is used for prophylaxis mainly in a population of women with particularly high risk of the disease and in cases where x-ray and ultrasound examinations are insufficient. Picture of mammary carcinoma in imaging studies is heterogeneous. However, it most often presents as an irregularly demarcated mass. Moreover, each modality can aid in visualization of additional features of a lesion such as typical shape of microcalcifications in x-ray mammography, characteristic pattern of contrast enhancement in MR examination

  5. Perfluorocarbons and Gilbert syndrome (phenotype) in the C8 Health Study Population

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Hongmin [Cancer Center, School of Public Health, West Virginia University, Morgantown, WV 265050-9190 (United States); Department of Epidemiology and Statistics, School of Public Health, Hebei United University, Hebei 063000 (China); Ducatman, Alan [Department of Occupational and Environmental Health, School of Public Health, West Virginia University (United States); Department of Medicine, School of Medicine, West Virginia University (United States); Clinical Translational Science Institute, West Virginia University (United States); Zhang, Jianjun [Department of Biostatistics, School Public Health, West Virginia University (United States)

    2014-11-15

    Background: Gilbert syndrome (GS) is an inherited defect of bilirubin conjugation, most commonly caused by a gene mutation for the enzyme UGT1A. GS is known to affect the metabolism and excretion of drugs and xenobiotics. Perfluorocarbon compounds (PFCs) are bio-persistent environmental contaminants that affect metabolic regulation. In this study, we examined the associations of GS phenotype and serum PFCs in the C8 Health Study Population. Materials and methods: Using 2005–2006 data from a large PFC-exposure population survey, we compared serum PFCs concentrations between GS and non GS clinical phenotypes, in a cross sectional design, adjusting for standard risk factors, including age, BMI, smoking status, socioeconomic status and gender. Results: Among 10 PFC compounds considered, only perfluorohexanoic acid (PFHxA) was seen at a significantly higher concentration in GS men and women. Conclusion: PFHxA exposure may be associated with GS. Our findings do not support increased exposure in GS for other PFCs. - Highlights: • Most serum PFCs are not associated with clinically evident Gilbert syndrome. • However, serum perfluorohexanoic acid is positively associated. • The investigation addresses the clinical presentation, not the genetic mutation.

  6. Methods of evaluating the consequences of irradiation of populations. Final report 1976-1980

    International Nuclear Information System (INIS)

    1983-01-01

    The present state of scientific knowledge does not make it possible to set a threshold for the effects of ionizing radiation on the health of individuals or of populations. The pessimistic assumption whereby any exposure is liable to have a harmful effect therefore remains the basis for the evaluation of standards. The resulting recommendations formulated by the ICRP (Publication No. 26) consist in a system of dose limits, which constitute the new foundation of radiation protection, the aim being to ensure that: - no source of exposure is unjustified, with due regard to the benefits occurring therefrom, - all necessary exposure is kept as low as reasonable achievable, economic and social factors being taken into account, - the dose equivalents received do not exceed certain specified limits. In order to attain this objective, it appeared necessary to have at our disposal, in the context of any project for an installation that is liable to cause exposure to ionizing radiation, means of evaluating the following: 1. the levels of exposure to the individuals and population groups concerned, 2. the resulting radiological detriment to man, 3. the economic and social impacts thereof. In view of the foregoing, therefore, methods for making such evaluation had to be developed. The aim of the Contract of Association concluded in 1976 between the European Atomic Energy Community and the French Commissariat a l'Energie Atomique is to develop methodology for evaluating the consequence of the irradiation of populations. It appeared necessary to have such methods for the purpose of implementing the latest recommendations of the International Commission for Radiological Protection (ICRP) and the Community Directives, in particular as regards the justification of exposure levels and the optimization of protection measures

  7. Data-driven drug safety signal detection methods in pharmacovigilance using electronic primary care records: A population based study

    Directory of Open Access Journals (Sweden)

    Shang-Ming Zhou

    2017-04-01

    Data-driven analytic methods are a valuable aid to signal detection of ADEs from large electronic health records for drug safety monitoring. This study finds the methods can detect known ADE and so could potentially be used to detect unknown ADE.

  8. Medication use and kidney cancer risk: A population-based study.

    Science.gov (United States)

    Nayan, Madhur; Juurlink, David N; Austin, Peter C; Macdonald, Erin M; Finelli, Antonio; Kulkarni, Girish S; Hamilton, Robert J

    2017-09-01

    Exposure to commonly prescribed medications may be associated with cancer risk. However, there is limited data in kidney cancer. Furthermore, methods of classifying cumulative medication exposure in previous studies may be prone to bias. We conducted a population-based case-control study of 10,377 incident kidney cancer cases aged ≥66 years matched with 35,939 controls on age, sex, history of hypertension, comorbidity score, and geographic location. Cumulative exposure to commonly prescribed medications hypothesised to modulate cancer risk was obtained using prescription claims data. We modelled exposure in four different fashions: (1) as continuous exposures using (a) fractional polynomials (which allow for a non-linear relationship between an exposure and outcome) or (b) assuming linear relationships; and 2) as dichotomous exposures denoting (a) ≥3 years versus kidney cancer. The directions of association were relatively consistent across analyses; however, the magnitudes were sensitive to the method of analysis. When utilising fractional polynomials, increasing cumulative exposure to acetylsalicylic acid, selective serotonin reuptake inhibitors, and proton-pump inhibitors was associated with significantly reduced risk of kidney cancer, while increasing exposure to antihypertensive drugs was associated with significantly increased risk. Our study provides impetus to further explore the effect of commonly prescribed medications on carcinogenesis to identify modifiable pharmacological interventions to reduce the risk of kidney cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Retrospective Cohort Study of the Prevalence of Lumbosacral Transitional Vertebra in a Wide and Well-Represented Population

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    Demet Uçar

    2013-01-01

    Full Text Available Purpose. The aim of this study is to determine the prevalence of lumbosacral transitional vertebra (LSTV in a well-represented general population. Methods. For a retrospective cohort study, abdominal radiographs of adult subjects were queried with clear visibility of the vertebral body articulation of the last rib, all lumbar transverse processes, and complete sacral wings. Exclusion criteria included any radiologic evidence of previous lumbosacral surgery that would block our view. A total of 6200 abdominal films were reviewed, and 3607 were identified as being suitable for the measurement of the desired parameters. Results. A total of 3607 subjects were identified as eligible for the study, and 683 (18.9% were classified as positive for a lumbosacral transitional vertebra. The prevalence of sacralization and lumbarization was found as 17.2% and 1.7%, respectively. The average age at the time of the study was 39.5±15.2 years (18–86 years. Conclusions. As a result of different opinions, LSTV retains its controversial status. Our prevalence study of the general population will provide assistance for resolution of the controversy. Prevalence studies of the general population with a wide participation will shed light on comparative studies.

  10. A Simulation Study on the Urban Population of China Based on Nighttime Light Data Acquired from DMSP/OLS

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    Qingxu Huang

    2016-05-01

    Full Text Available The urban population (UP measure is one of the most direct indicators that reflect the urbanization process and the impacts of human activities. The dynamics of UP is of great importance to studying urban economic, social development, and resource utilization. Currently, China lacks long time series UP data with consistent standards and comparability over time. The nighttime light images from the Defense Meteorological Satellite Program’s (DMSP Operational Linescan System (OLS allow the acquisition of continuous and highly comparable long time series UP information. However, existing studies mainly focus on simulating the total population or population density level based on the nighttime light data. Few studies have focused on simulating the UP in China. Based on three regression models (i.e., linear, power function, and exponential, the present study discusses the relationship between DMSP/OLS nighttime light data and the UP and establishes optimal regression models for simulating the UPs of 339 major cities in China from 1990 to 2010. In addition, the present study evaluated the accuracy of UP and non-agricultural population (NAP simulations conducted using the same method. The simulation results show that, at the national level, the power function model is the optimal regression model between DMSP/OLS nighttime light data and UP data for 1990–2010. At the provincial scale, the optimal regression model varies among different provinces. The linear regression model is the optimal regression model for more than 60% of the provinces. In addition, the comparison results show that at the national, provincial, and city levels, the fitting results of the UP based on DMSP/OLS nighttime light data are better than those of the NAP. Therefore, DMSP/OLS nighttime light data can be used to effectively retrieve the UP of a large-scale region. In the context of frequent population flows between urban and rural areas in China and difficulty in obtaining

  11. Application of Network Scale Up Method in the Estimation of Population Size for Men Who Have Sex with Men in Shanghai, China.

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    Jun Wang

    Full Text Available Men who have sex with men (MSM are at high risk of HIV infection. For developing proper interventions, it is important to know the size of MSM population. However, size estimation of MSM populations is still a significant public health challenge due to high cost, hard to reach and stigma associated with the population.We aimed to estimate the social network size (c value in general population and the size of MSM population in Shanghai, China by using the net work scale-up method.A multistage random sampling was used to recruit participants aged from 18 to 60 years who had lived in Shanghai for at least 6 months. The "known population method" with adjustment of backward estimation and regression model was applied to estimate the c value. And the MSM population size was further estimated using an adjusted c value taking into account for the transmission effect through social respect level towards MSM.A total of 4017 participants were contacted for an interview, and 3907 participants met the inclusion criterion. The social network size (c value of participants was 236 after adjustment. The estimated size of MSM was 36354 (95% CI: 28489-44219 for the male Shanghaies aged 18 to 60 years, and the proportion of MSM among the total male population aged 18 to 60 years in Shanghai was 0.28%.We employed the network scale-up method and used a wide range of data sources to estimate the size of MSM population in Shanghai, which is useful for HIV prevention and intervention among the target population.

  12. Population study of Pyxis arachnoides brygooi (Vuillemin ...

    African Journals Online (AJOL)

    The Madagascar spider tortoise (Pyxis arachnoides spp.) is faced with the threat of habitat destruction as well as the international pet trade. Habitat requirements and population structure of this species are largely unknown. Detailed studies have so far concentrated on the subspecies Pyxis arachnoides arachnoides.

  13. Prenatal diagnosis of six major cardiac malformations in Europe - A population based study

    NARCIS (Netherlands)

    Garne, E

    Aim. To present data on prenatal diagnosis of six major cardiac malformations in low-risk European populations. Methods. Data from 12 Eurocat registries on congenital malformations. All registries have multiple sources of information and use the same methods of data collection and coding. The six

  14. Perceptions of Weight and Health Practices in Hispanic Children: A Mixed-Methods Study

    Directory of Open Access Journals (Sweden)

    Byron Alexander Foster

    2015-01-01

    Full Text Available Background. Perception of weight by parents of obese children may be associated with willingness to engage in behavior change. The relationship between parents’ perception of their child’s weight and their health beliefs and practices is poorly understood, especially among the Hispanic population which experiences disparities in childhood obesity. This study sought to explore the relationship between perceptions of weight and health beliefs and practices in a Hispanic population. Methods. A cross-sectional, mixed-methods approach was used with semistructured interviews conducted with parent-child (2–5 years old dyads in a primarily Hispanic, low-income population. Parents were queried on their perceptions of their child’s health, health practices, activities, behaviors, and beliefs. A grounded theory approach was used to analyze participants’ discussion of health practices and behaviors. Results. Forty parent-child dyads completed the interview. Most (58% of the parents of overweight and obese children misclassified their child’s weight status. The qualitative analysis showed that accurate perception of weight was associated with internal motivation and more concrete ideas of what healthy meant for their child. Conclusions. The qualitative data suggest there may be populations at different stages of readiness for change among parents of overweight and obese children, incorporating this understanding should be considered for interventions.

  15. Trend of Cardio-Metabolic Risk Factors in Polycystic Ovary Syndrome: A Population-Based Prospective Cohort Study

    OpenAIRE

    Ramezani Tehrani, Fahimeh; Montazeri, Seyed Ali; Hosseinpanah, Farhad; Cheraghi, Leila; Erfani, Hadi; Tohidi, Maryam; Azizi, Fereidoun

    2015-01-01

    Objective To see the changes of cardio-metabolic risk factors overtime in polycystic ovary syndrome vs. control women. Methods This study was conducted on 637 participants (85 PCOS and 552 control reproductive aged, 18–45 years) of Tehran Lipid and Glucose Study (TLGS), an ongoing population-based cohort study with 12 years of follow-up. The cardiovascular risk factors of these groups were assessed in three-year intervals using standard questionnaires, history taking, anthropometric measures,...

  16. Preschool Age Populations Research Needs - NCS Dietary Assessment Literature Review

    Science.gov (United States)

    Drawing conclusions from the validation studies on preschool populations discussed in this chapter is difficult because of the varied study designs, the relatively small study populations, and limited number of studies on each dietary assessment method.

  17. Human Population Problems

    Science.gov (United States)

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

    Asserts that overpopulation is the most pressing world problem. Topics discussed include population control in primitive societies, population growth and control in modern societies, methods of motivational population control, consequences of no population control, and mass famines during the 1970's in underdeveloped countries. Cities 33…

  18. Does adversity early in life affect general population suicide rates? a cross-national study

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    Ritesh Bhandarkar

    2011-01-01

    Full Text Available BACKGROUND: Adversity early in life has been suggested as a protective factor for elderly suicides. However, studies examining this relationship in general population suicide rates are scarce. METHODS: The relationship between general population suicide rates and four proxy measures of adversity earlier in life was examined using data from the World Health Organization and the United Nations data banks. RESULTS: General population suicide rates were negatively correlated with the percentage of children under the age of 5 years who were underweight, the percentage of children under the age of 5 years who were under height, the percentage of infants with low birth weight babies, and the percentage of the general population that was undernourished. The only independent predictor general population suicide rates in both sexes, on multiple regression analysis, was the Gini coefficient (a measure of income inequality. CONCLUSIONS: Income inequality may lead to low birth weight, undernourishment, underweight and under height because income inequality results in poor access to healthcare and nutrition. These adversities may increase child mortality rates and reduce life expectancy. Those surviving into adulthood in countries with greater adversity early in life may be at reduced risk of suicide because of selective survival of those at reduced risk of suicide due to constitutional or genetic factors and development of greater tolerance to hardship in adulthood.

  19. Falls among the elderly: risk factors in a population-based study

    Directory of Open Access Journals (Sweden)

    Iara Guimarães Rodrigues

    2014-09-01

    Full Text Available Purpose: The aim of the present study was to identify factors associated with the occurrence of falls among elderly adults in a population-based study (ISACamp 2008. Methods: A population-based cross-sectional study was carried out with two-stage cluster sampling. The sample was composed of 1,520 elderly adults living in the urban area of the city of Campinas, São Paulo, Brazil. The occurrence of falls was analyzed based on reports of the main accident occurred in the previous 12 months. Data on socioeconomic/demographic factors and adverse health conditions were tested for possible associations with the outcome. Prevalence ratios (PR were estimated and adjusted for gender and age using the Poisson multiple regression analysis. Results: Falls were more frequent, after adjustment for gender and age, among female elderly participants (PR = 2.39; 95% confidence interval (95%CI 1.47 - 3.87, elderly adults (80 years old and older (PR = 2.50; 95%CI 1.61 - 3.88, widowed (PR = 1.74; 95%CI 1.04 - 2.89 and among elderly adults who had rheumatism/arthritis/arthrosis (PR = 1.58; 95%CI 1.00 - 2.48, osteoporosis (PR = 1.71; 95%CI 1.18 - 2.49, asthma/bronchitis/emphysema (PR = 1,73; 95%CI 1.09 - 2.74, headache (PR = 1.59; 95%CI 1.07 - 2.38, mental common disorder (PR = 1.72; 95%CI 1.12 - 2.64, dizziness (PR = 2.82; 95%CI 1.98 - 4.02, insomnia (PR = 1.75; 95%CI 1.16 - 2.65, use of multiple medications (five or more (PR = 2.50; 95%CI 1.12 - 5.56 and use of cane/walker (PR = 2.16; 95%CI 1.19 - 3,93. Conclusion: The present study shows segments of the elderly population who are more prone to falls through the identification of factors associated with this outcome. The findings can contribute to the planning of public health policies and programs addressed to the prevention of falls.

  20. Optimal designs for population pharmacokinetic studies of oral artesunate in patients with uncomplicated falciparum malaria

    Directory of Open Access Journals (Sweden)

    Lindegardh Niklas

    2011-07-01

    Full Text Available Abstract Background Currently, population pharmacokinetic (PK studies of anti-malarial drugs are designed primarily by the logistical and ethical constraints of taking blood samples from patients, and the statistical models that are fitted to the data are not formally considered. This could lead to imprecise estimates of the target PK parameters, and/or designs insufficient to estimate all of the parameters. Optimal design methodology has been developed to determine blood sampling schedules that will yield precise parameter estimates within the practical constraints of sampling the study populations. In this work optimal design methods were used to determine sampling designs for typical future population PK studies of dihydroartemisinin, the principal biologically active metabolite of oral artesunate. Methods Optimal designs were derived using freely available software and were based on appropriate structural PK models from an analysis of data or the literature and key sampling constraints identified in a questionnaire sent to active malaria researchers (3-4 samples per patient, at least 15 minutes between samples. The derived optimal designs were then evaluated via simulation-estimation. Results The derived optimal sampling windows were 17 to 29 minutes, 30 to 57 minutes, 2.5 to 3.7 hours and 5.8 to 6.6 hours for non-pregnant adults; 16 to 29 minutes, 31 minutes to 1 hour, 2.0 to 3.4 hours and 5.5 to 6.6 hours for designs with non-pregnant adults and children and 35 to 59 minutes, 1.2 to 3.4 hours, 3.4 to 4.9 hours and 6.0 to 8.0 hours for pregnant women. The optimal designs resulted in acceptable precision of the PK parameters. Conclusions The proposed sampling designs in this paper are robust and efficient and should be considered in future PK studies of oral artesunate where only three or four blood samples can be collected.

  1. Longitudinal population-based studies of affective disorders: Where to from here?

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    Beard John R

    2008-09-01

    Full Text Available Abstract Background Longitudinal, population-based, research is important if we are to better characterize the lifetime patterns and determinants of affective disorders. While studies of this type are becoming increasingly prevalent, there has been little discussion about the limitations of the methods commonly used. Methods Discussion paper including a brief review of key prospective population-based studies as the basis for a critical appraisal of current approaches. Results We identified a number of common methodological weaknesses that restrict the potential of longitudinal research to characterize the diversity, prognosis, and determinants of affective disorders over time. Most studies using comprehensive diagnostic instruments have either been of relatively brief duration, or have suffered from long periods between waves. Most etiologic research has focused on first onset diagnoses, although these may be relatively uncommon after early adulthood and the burden of mental disorders falls more heavily on individuals with recurring disorders. Analysis has tended to be based on changes in diagnostic status rather than anges in symptom levels, limiting study power. Diagnoses have generally been treated as homogeneous entities and few studies have explored whether diagnostic subtypes such as atypical depression vary in their etiology or prognosis. Little research has considered whether there are distinct trajectories of symptoms over time and most has focused on individual disorders such as depression, rather than considering the relationship over time between symptoms of different affective disorders. There has also been limited longitudinal research on factors in the physical or social environment that may influence the onset, recurrence or chronicity of symptoms. Conclusion Many important, and in some respects quite basic, questions remain about the trajectory of depression and anxiety disorders over the life course and the factors that

  2. A retrospective population-based cohort study identifying target areas for prevention of acute lower respiratory infections in children

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    Richmond Peter

    2010-12-01

    Full Text Available Abstract Background Acute lower respiratory infections (ALRI are a major cause of hospitalisation in young children. Many factors can lead to increased risk of ALRI in children and predispose a child to hospitalisation, but population attributable fractions for different risk factors and how these fractions differ between Indigenous and non-Indigenous children is unknown. This study investigates population attributable fractions of known infant and maternal risk factors for ALRI to inform prevention strategies that target high-risk groups or particular risk factors. Methods A retrospective population-based data linkage study of 245,249 singleton births in Western Australia. Population attributable fractions of known maternal and infant risk factors for hospitalisation with ALRI between 1996 and 2005 were calculated using multiple logistic regression. Results The overall ALRI hospitalisation rate was 16.1/1,000 person-years for non-Aboriginal children and 93.0/1,000 for Aboriginal children. Male gender, being born in autumn, gestational age Conclusions The population attributable fractions estimated in this study should help in guiding public health interventions to prevent ALRI. A key risk factor for all children is maternal smoking during pregnancy, and multiple previous pregnancies and autumnal births are important high-risk groups. Specific key target areas are reducing elective caesareans in non-Aboriginal women and reducing teenage pregnancies and improving access to services and living conditions for the Aboriginal population.

  3. Wealth Inequality and Mental Disability Among the Chinese Population: A Population Based Study

    Science.gov (United States)

    Wang, Zhenjie; Du, Wei; Pang, Lihua; Zhang, Lei; Chen, Gong; Zheng, Xiaoying

    2015-01-01

    In the study described herein, we investigated and explored the association between wealth inequality and the risk of mental disability in the Chinese population. We used nationally represented, population-based data from the second China National Sample Survey on Disability, conducted in 2006. A total of 1,724,398 study subjects between the ages of 15 and 64, including 10,095 subjects with mental disability only, were used for the analysis. Wealth status was estimated by a wealth index that was derived from a principal component analysis of 10 household assets and four other variables related to wealth. Logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence interval (CI) for mental disability for each category, with the lowest quintile category as the referent. Confounding variables under consideration were age, gender, residence area, marital status, ethnicity, education, current employment status, household size, house type, homeownership and living arrangement. The distribution of various types and severities of mental disability differed significantly by wealth index category in the present population. Wealth index category had a positive association with mild mental disability (p for trend wealth index category had a significant, inverse association with mental disability when all severities of mental disability were taken into consideration. This study’s results suggest that wealth is a significant factor in the distribution of mental disability and it might have different influences on various types and severities of mental disability. PMID:26492258

  4. Unilateral Vocal Fold Paralysis and Risk of Pneumonia: A Nationwide Population-Based Cohort Study.

    Science.gov (United States)

    Tsai, Ming-Shao; Yang, Yao-Hsu; Liu, Chia-Yen; Lin, Meng-Hung; Chang, Geng-He; Tsai, Yao-Te; Li, Hsueh-Yu; Tsai, Ying-Huang; Hsu, Cheng-Ming

    2018-05-01

    Objective To investigate pneumonia risk among patients with unilateral vocal fold paralysis (UVFP). Study Design Retrospective population-based cohort study. Setting This study used data from the National Health Insurance Research Database of Taiwan, a nationwide population-based database. Subjects and Methods A total of 419 patients newly diagnosed with UVFP between January 1, 1997, and December 31, 2013, were identified from the Longitudinal Health Insurance Database 2000, a nationally representative database of 1 million randomly selected patients. Moreover, 1676 patients without UVFP were matched to patients with UVFP at a 1:4 ratio based on age, sex, socioeconomic status, urbanization level, and site-specific cancers. Patients were followed up until death or the end of the study period (December 31, 2013). The primary outcome was the occurrence of pneumonia. Results The cumulative incidence of pneumonia was significantly higher for patients with UVFP than those without UFVP ( P < .001). The adjusted Cox proportional hazard model showed that UVFP was significantly associated with a higher incidence of pneumonia (hazard ratio, 1.97; 95% CI, 1.35-2.86; P < .001). Subgroup analyses demonstrated that UVFP was an independent risk factor of pneumonia for 4 subgroups: young (18-50 years), older (≥51 years), male, and cancer. Conclusion This is the first nationwide population-based cohort study to investigate the association between UVFP and pneumonia. The findings indicate that UVFP is an independent risk factor of pneumonia. Given the study results, physicians should be aware of the potential for pneumonia occurrence following UVFP.

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

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    Wen-Hsien Lee

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

  6. Prevalence of Psychiatric Disorders among the Rural Geriatric Population: A Pilot Study in Karnataka, India

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    Sreejith S. Nair

    2015-03-01

    Full Text Available Background: Increasing life expectancy around the world, an outstanding achievement of our century, has brought with it new public health challenges. India is the second most populous country in the world, with over 72 million inhabitants above 60 years of age as of 2001. The life expectancy in India increased from 32 years in 1947 to over 66 years in 2010, with 8.0% of the population now reaching over 60 years of age. Few studies in India target the health, especially mental health, of this geriatric population. This study aims to estimate the current prevalence of psychiatric disorders in the geriatric population of the rural area of Singanodi,Karnataka, India.Methods: This cross sectional, epidemiological, community-based study was conducted in a rural health training area of Singanodi, Raichur District, Karnataka, India.The General Health Questionnaire-12, Mini Mental State Examination, and Geriatric Depression Scale were administered to 366 participants. Chi square tests with Yates correction were utilized for statistical analysis using SPSS 19.0 software.Results:We found that 33.9% of the geriatric population in the selected province were above the threshold for mental illness based on the GHQ-12 questionnaire. Females had a higher prevalence of mental disorder at 77.6% (152 out of 196 as compared to males who had a prevalence of 42.4% (72 out of 170. The most common psychiatric disorder was depression (21.9%, and generalized anxiety was present in 10.7% of the study population. Prevalence of cognitive impairment was 16.3%, with a significantly higher percentage of  affected individuals in 80+ age group.Conclusion: Mental disorders are common among elderly people, but they are not well documented in rural India. The assessment of psychiatric disorder prevalence will help strengthen psycho-geriatric services and thus improve the quality of life of the elderly.  A system that ensures comprehensive health care will have to be developed for

  7. THE STUDY OF CLINICO-AETIOLOGICAL PROFILE OF PANCYTOPENIA IN ELDERLY POPULATION

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    Vijayashree Thyagaraj

    2017-06-01

    Full Text Available BACKGROUND Pancytopenia is a common problem in clinical practice. Pancytopenia is defined as haemoglobin less than 9 gm/dL, total leucocyte count less than 4,000/dL and platelet count less than 1 lakhs/dL. Causes of pancytopenia vary from nutritional deficiencies, bone marrow failure status and malignancies. Pancytopenia is a common problem in geriatric population also. In this study, we try to find common causes of pancytopenia in geriatric population in a tertiary care hospital. MATERIALS AND METHODS 40 consecutive patients who are more than 60 years of age attending General Medicine Outpatient Department were included in the study. Pancytopenia due to acute infections like viral fever and sepsis were excluded. Patients suspected to be having malignancies like lymphadenopathy and hepatosplenomegaly were also excluded. These patients were subjected to detailed history taking and clinical examination. Routine investigations like complete blood count, peripheral smear, reticulocyte count, Coombs test, serum cobalamin levels, renal function tests and liver function tests were done. Bone marrow examination was done in cases where indicated. Upper gastrointestinal endoscopy and anti-intrinsic factor antibody and antiparietal cell antibody were done where indicated. RESULTS Out of 40 patients included in the study, 25 were males and 15 were females. 28 patients were aged between 60-70 years, 10 patients between 70-80 years and 2 were more than 80 years old. Mean age of the patients was 68 years. Fatigue was the most common symptom (70%, fever was seen in 15% cases, mild cognitive impairment was reported in 10% patients and bleeding manifestations were seen in 5% cases. Most common cause of pancytopenia was cobalamin deficiency (60%. Others causes were aplastic anaemia (7.5%, chronic liver disease (5%, myelodysplasia (5%, drug induced (2.5% and HIV associated (2.5% cases. In this study, we saw that most common of pancytopenia was cause of cobalamin

  8. Application of the backstepping method to the prediction of increase or decrease of infected population.

    Science.gov (United States)

    Kuniya, Toshikazu; Sano, Hideki

    2016-05-10

    In mathematical epidemiology, age-structured epidemic models have usually been formulated as the boundary-value problems of the partial differential equations. On the other hand, in engineering, the backstepping method has recently been developed and widely studied by many authors. Using the backstepping method, we obtained a boundary feedback control which plays the role of the threshold criteria for the prediction of increase or decrease of newly infected population. Under an assumption that the period of infectiousness is same for all infected individuals (that is, the recovery rate is given by the Dirac delta function multiplied by a sufficiently large positive constant), the prediction method is simplified to the comparison of the numbers of reported cases at the current and previous time steps. Our prediction method was applied to the reported cases per sentinel of influenza in Japan from 2006 to 2015 and its accuracy was 0.81 (404 correct predictions to the total 500 predictions). It was higher than that of the ARIMA models with different orders of the autoregressive part, differencing and moving-average process. In addition, a proposed method for the estimation of the number of reported cases, which is consistent with our prediction method, was better than that of the best-fitted ARIMA model ARIMA(1,1,0) in the sense of mean square error. Our prediction method based on the backstepping method can be simplified to the comparison of the numbers of reported cases of the current and previous time steps. In spite of its simplicity, it can provide a good prediction for the spread of influenza in Japan.

  9. A community based study of NCD risk factors among adult population in Dehradun, India

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    Himanshu Agarwal

    2016-06-01

    Full Text Available Background: A Non-Communicable disease (NCD is one which is non-infectious and non-transmissible among people. NCDs account for leading causes of death and disease burden worldwide. To decrease the burden of NCDs experts stress on the importance of prevention and control with respect to modifiable risk factors. The World Health Organization's World Health Report 2002 identified tobacco use, alcohol consumption, overweight, physical inactivity, high blood pressure and high cholesterol as the most important risk factors for NCDs.(1  Aims & Objectives: 1. To know the prevalence of risk factors leading to NCDs in the study population. 2. To know the socio-demographic correlates associated with risk factors of NCDs. 3. To suggest appropriate recommendations regarding modifiable risk factors of NCDs in study population. Material & Methods: A Cross-sectional study, Community-based study among 18+ population in field practice areas of Community Medicine Department, SGRRIM&HS, Dehradun. Sample Size: 300 each in urban and rural, total 60. Results: The prevalence of Smoking was 11.3%, Smokeless tobacco use 10.5%, Alcohol use 13.2%, Unhealthy diet 99.5%, Low physical activity 0.8%, High BMI (≥ 25 kg/m2 51.2%, above normal waist-hip ratio 57.0%, Raised blood pressure 58.5% and raised blood sugar 25.2%. Conclusion: Smoking is significantly associated with age, sex and occupation. Raised blood pressure is significantly associated with age, sex and social class.

  10. Population Neuroscience: Dementia Epidemiology Serving Precision Medicine and Population Health.

    Science.gov (United States)

    Ganguli, Mary; Albanese, Emiliano; Seshadri, Sudha; Bennett, David A; Lyketsos, Constantine; Kukull, Walter A; Skoog, Ingmar; Hendrie, Hugh C

    2018-01-01

    Over recent decades, epidemiology has made significant contributions to our understanding of dementia, translating scientific discoveries into population health. Here, we propose reframing dementia epidemiology as "population neuroscience," blending techniques and models from contemporary neuroscience with those of epidemiology and biostatistics. On the basis of emerging evidence and newer paradigms and methods, population neuroscience will minimize the bias typical of traditional clinical research, identify the relatively homogenous subgroups that comprise the general population, and investigate broader and denser phenotypes of dementia and cognitive impairment. Long-term follow-up of sufficiently large study cohorts will allow the identification of cohort effects and critical windows of exposure. Molecular epidemiology and omics will allow us to unravel the key distinctions within and among subgroups and better understand individuals' risk profiles. Interventional epidemiology will allow us to identify the different subgroups that respond to different treatment/prevention strategies. These strategies will inform precision medicine. In addition, insights into interactions between disease biology, personal and environmental factors, and social determinants of health will allow us to measure and track disease in communities and improve population health. By placing neuroscience within a real-world context, population neuroscience can fulfill its potential to serve both precision medicine and population health.

  11. Psychiatric morbidity, quality of life, and perceived social support among elderly population: a community-based study

    Directory of Open Access Journals (Sweden)

    Pallavi Kwan

    2016-01-01

    Full Text Available Background: The growth in the elderly population means an inevitable increase in general physical health, psychobiological and mental health-related problems. Aim of the study: The present study aims to examine psychiatric morbidity, quality of life, and perceived social support among elderly population. Research design: A cross-sectional community-based study was conducted. People in age group of 60 years and above, who were permanent members of their respective households of Ranga Pukri Para and Dekargaon village in Tezpur, Sonitpur district of Assam, were the sample for the present study. One thousand four hundred and ninety adult populations had been identified as sample frame from the electorate list. One hundred and four people of age 60 years and above had been identified from the list for the study purpose. Random sampling method was used for selection of the sample. Semi-structured socio-demographic datasheet, General Health Questionnaire-12 (GHQ-12, CAGE questionnaire, Multidimensional Scale of Perceived Social Support, and World Health Organization Quality of Life (WHOQOL-BREF scale were administered to the respondents. Results: Based on the GHQ-12 score, it was found that 24% of the respondents showed an indication of mental health problems and from the CAGE score, it indicated that 13% of the respondents were found to be misusing or was in dependence in alcohol. The result from the present study indicated that elderly population was getting more family social support, followed by friends and from significant others. The result indicated that the mean score was low in the domain of social relationships. Environment domain was high followed by physical health and psychological domains of WHOQOL-BREF. Conclusion: In the elderly population, overall health can be influenced by multiple factors, including a person’s physical, psychological, behavioural, and social factors. The mental health professionals can provide resources, services

  12. Association Between Zolpidem Use and Glaucoma Risk: A Taiwanese Population-Based Case-Control Study

    OpenAIRE

    Ho, Yi-Hao; Chang, Yue-Cune; Huang, Wei-Cheng; Chen, Hsin-Yi; Lin, Che-Chen; Sung, Fung-Chang

    2015-01-01

    Background To date, the relationship between zolpidem use and subsequent risk of glaucoma in a Taiwanese population has not been assessed. Methods We used data from the National Health Insurance system to investigate whether zolpidem use was related to glaucoma risk. A 1:4 matched case-control study was conducted. The cases were patients newly diagnosed with glaucoma from 2001 to 2010. The controls were randomly selected non-glaucoma subjects matched by sex and age (?5 years). Zolpidem exposu...

  13. Stochastic weighted particle methods for population balance equations

    International Nuclear Information System (INIS)

    Patterson, Robert I.A.; Wagner, Wolfgang; Kraft, Markus

    2011-01-01

    Highlights: → Weight transfer functions for Monte Carlo simulation of coagulation. → Efficient support for single-particle growth processes. → Comparisons to analytic solutions and soot formation problems. → Better numerical accuracy for less common particles. - Abstract: A class of coagulation weight transfer functions is constructed, each member of which leads to a stochastic particle algorithm for the numerical treatment of population balance equations. These algorithms are based on systems of weighted computational particles and the weight transfer functions are constructed such that the number of computational particles does not change during coagulation events. The algorithms also facilitate the simulation of physical processes that change single particles, such as growth, or other surface reactions. Four members of the algorithm family have been numerically validated by comparison to analytic solutions to simple problems. Numerical experiments have been performed for complex laminar premixed flame systems in which members of the class of stochastic weighted particle methods were compared to each other and to a direct simulation algorithm. Two of the weighted algorithms have been shown to offer performance advantages over the direct simulation algorithm in situations where interest is focused on the larger particles in a system. The extent of this advantage depends on the particular system and on the quantities of interest.

  14. Dietary pattern derived by reduced rank regression and depressive symptoms in a multi-ethnic population: the HELIUS study

    NARCIS (Netherlands)

    Vermeulen, E.; Stronks, K.; Visser, M.; Brouwer, I. A.; Snijder, M. B.; Mocking, R. J. T.; Derks, E. M.; Schene, A. H.; Nicolaou, M.

    2017-01-01

    BACKGROUND/OBJECTIVES: To investigate the association of dietary patterns derived by reduced rank regression (RRR) with depressive symptoms in a multi-ethnic population. SUBJECTS/METHODS: Cross-sectional data from the HELIUS study were used. In total, 4967 men and women (18-70 years) of Dutch,

  15. Dietary pattern derived by reduced rank regression and depressive symptoms in a multi-ethnic population: the HELIUS study

    NARCIS (Netherlands)

    Vermeulen, E.; Stronks, K.; Visser, M.; Brouwer, I. A.; Snijder, M. B.; Mocking, R. J.T.; Derks, E. M.; Schene, A. H.; Nicolaou, M.

    BACKGROUND/OBJECTIVES: To investigate the association of dietary patterns derived by reduced rank regression (RRR) with depressive symptoms in a multi-ethnic population. SUBJECTS/METHODS: Cross-sectional data from the HELIUS study were used. In total, 4967 men and women (18-70 years) of Dutch,

  16. Users’ dissatisfaction with dental care: a population-based household study

    Science.gov (United States)

    Martins, Andréa Maria Eleutério de Barros Lima; Ferreira, Raquel Conceição; dos Santos, Pedro Eleutério; Carreiro, Danilo Lima; Souza, João Gabriel Silva; Ferreira e Ferreira, Efigênia

    2015-01-01

    OBJECTIVE To examine whether demographic, socioeconomic conditions, oral health subjectivity and characterization of dental care are associated with users’ dissatisfaction with such are. METHODS Cross-sectional study of 781 people who required dental care in Montes Claros, MG, Southeastern Brazil, in 2012, a city with of medium-sized population situated in the North of Minas Gerais. Household interviews were conducted to assess the users’ dissatisfaction with dental care (dependent variable), demographic, socioeconomic conditions, oral health subjectivity and characterization of dental care (independent variables). Sample calculation was used for the finite population, with estimates made for proportions of dissatisfaction in 50.0% of the population, a 5.0% error margin, a non-response rate of 5.0% and a 2.0% design effect. Logistic regression was used, and the odds ratio was calculated with a 5% significance level and 95% confidence intervals. RESULTS Of the interviewed individuals, 9.0% (7.9%, with correction for design effect) were dissatisfied with the care provided. These were associated with lower educational level; negative self-assessment of oral health; perception that the care provider was unable to give dental care; negative evaluation of the way the patient was treated, the cleanliness of the rooms, based on the examination rooms and the toilets, and the size of the waiting and examination rooms. CONCLUSIONS The rate of dissatisfaction with dental care was low. This dissatisfaction was associated with socioeconomic conditions, subjectivity of oral health, skill of the health professionals relating to the professional-patient relationship and facility infrastructure. Educational interventions are suggested that aim at improving the quality of care among professionals by responsible agencies as is improving the infrastructure of the care units. PMID:26270017

  17. Respiratory symptoms and occupation: a cross-sectional study of the general population

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    Smit Henriëtte A

    2002-12-01

    Full Text Available Abstract Background This study focused on respiratory symptoms due to occupational exposures in a contemporary general population cohort. Subjects were from the Dutch Monitoring Project on Risk Factors for Chronic Diseases (MORGEN. The composition of this population enabled estimation of respiratory risks due to occupation from the recent past for both men and women. Methods The study subjects (aged 20–59 were all inhabitants of Doetinchem, a small industrial town, and came from a survey of a random sample of 1104 persons conducted in 1993. A total of 274 cases with respiratory symptoms (subdivided in asthma and bronchitis symptoms and 274 controls without symptoms were matched for age and sex. Relations between industry and occupation and respiratory symptoms were explored and adjusted for smoking habits and social economic status. Results Employment in the 'construction' (OR = 3.38; 95%CI 1.02 – 11.27, 'metal' (OR = 3.17; 95%CI 0. 98 – 10.28, 'rubber, plastics and synthetics' (OR = 6.52; 95%CI 1.26 – 53.80, and 'printing' industry (OR = 3.96; 95%CI 0.85 – 18.48 were positively associated with chronic bronchitis symptoms. In addition, the 'metal' industry was found to be weakly associated with asthma symptoms (OR = 2.59; 95%CI 0.87 – 7.69. Duration of employment within these industries was also positively associated with respiratory symptoms. Conclusion Respiratory symptoms in the general population are traceable to employment in particular industries even in a contemporary cohort with relatively young individuals.

  18. Use of HOMA-IR to diagnose non-alcoholic fatty liver disease: a population-based and inter-laboratory study

    OpenAIRE

    Isokuortti, Elina; Zhou, You; Peltonen, Markku; Bugianesi, Elisabetta; Clement, Karine; Bonnefont-Rousselot, Dominique; Lacorte, Jean-Marc; Gastaldelli, Amalia; Schuppan, Detlef; Schattenberg, Jörn M.; Hakkarainen, Antti; Lundbom, Nina; Jousilahti, Pekka; Männistö, Satu; Keinänen-Kiukaanniemi, Sirkka

    2017-01-01

    Aims/hypothesis\\ud \\ud Recent European guidelines for non-alcoholic fatty liver disease (NAFLD) call for reference values for HOMA-IR. In this study, we aimed to determine: (1) the upper limit of normal HOMA-IR in two population-based cohorts; (2) the HOMA-IR corresponding to NAFLD; (3) the effect of sex and PNPLA3 genotype at rs738409 on HOMA-IR; and (4) inter-laboratory variations in HOMA-IR.\\ud \\ud Methods\\ud \\ud We identified healthy individuals in two population-based cohorts (FINRISK 20...

  19. Headship Rate for Population Projection in Johor Bahru

    OpenAIRE

    Rawan Nurfilzah Mohamad; Zainun Noor Yasmin; Alias Ahmad Rizal; Ibrahim Izzah Sofea

    2017-01-01

    Headship rate method is used to forecast population for housing demand. This paper presents the application of the method for forecasting population in Johor Bahru metropolitan city in Malaysia. Data used in the projection was based on census data of Johor Bahru provided by Department of Statistic Malaysia for the period of three years. Headship rate can be determined based on the ratio of head of household in age group by its age group total population. Hence, the purpose for this study is t...

  20. Transfer of ERR for radiation-related leukemia from Japanese population to Chinese population

    International Nuclear Information System (INIS)

    Huang Liqiong; Sun Zhijuan; Zhao Yongcheng; Wang Jixian

    2011-01-01

    Objective: To establish a transfer model for excess relative risk (ERR) for radiation-related leukemia from Japanese population to Chinese population. Methods: Combined ERR of several subtypes of leukemia published in 1994, with the corresponding leukemia baseline incidence rates obtained from Cancer Incidence in Five Continents Vol. Ⅸ (CI5-Ⅸ) for Japanese population and Chinese population, a weighted risk transfer model was employed between an additive model and a multiplicative model, to execute ERR transfer. Results: A range of weighing factors was proposed for risk transfer models: weighing factor was 0.4 for male and 0.3 for female, acute lymphoblastic leukemia, acute myeloid leukemia and chronic myeloid leukemia. The uncertainty for ERR transfer was characterized by lognormal distribution. Conclusions: Based on the difference of baseline incidence rate for subtypes of leukemia between Japanese population and Chinese population, the transfer model and these weighing factors discussed in the present study could be applicable to transfer ERR for radiation-related leukemia from Japanese population to Chinese population. (authors)

  1. Somatic symptom profiles in the general population

    DEFF Research Database (Denmark)

    Eliasen, Marie; Jørgensen, Torben; Schröder, Andreas

    2017-01-01

    PURPOSE: The aim of this study was to identify and describe somatic symptom profiles in the general adult population in order to enable further epidemiological research within multiple somatic symptoms. METHODS: Information on 19 self-reported common somatic symptoms was achieved from a population...

  2. AMOVA-based clustering of population genetic data

    NARCIS (Netherlands)

    Meirmans, P.G.

    2012-01-01

    Determining the genetic structure of populations is becoming an increasingly important aspect of genetic studies. One of the most frequently used methods is the calculation of F-statistics using an Analysis of Molecular Variance (AMOVA). However, this has the drawback that the population hierarchy

  3. Pharmacologic studies in vulnerable populations: Using the pediatric experience.

    Science.gov (United States)

    Zimmerman, Kanecia; Gonzalez, Daniel; Swamy, Geeta K; Cohen-Wolkowiez, Michael

    2015-11-01

    Historically, few data exist to guide dosing in children and pregnant women. Multiple barriers to inclusion of these vulnerable populations in clinical trials have led to this paucity of data. However, federal legislation targeted at pediatric therapeutics, innovative clinical trial design, use of quantitative clinical pharmacology methods, pediatric thought leadership, and collaboration have successfully overcome many existing barriers. This success has resulted in improved knowledge on pharmacokinetics, safety, and efficacy of therapeutics in children. To date, research in pregnant women has not been characterized by similar success. Wide gaps in knowledge remain despite the common use of therapeutics in pregnancy. Given the similar barriers to drug research and development in pediatric and pregnant populations, the route toward success in children may serve as a model for the advancement of drug development and appropriate drug administration in pregnant women. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Febrile seizures: a population-based study

    Directory of Open Access Journals (Sweden)

    Juliane S. Dalbem

    2015-11-01

    Full Text Available Objectives: To determine the prevalence of benign febrile seizures of childhood and describe the clinical and epidemiological profile of this population. Methods: This was a population-based, cross-sectional study, carried out in the city of Barra do Bugres, MT, Brazil, from August 2012 to August 2013. Data were collected in two phases. In the first phase, a questionnaire that was previously validated in another Brazilian study was used to identify suspected cases of seizures. In the second phase, a neurological evaluation was performed to confirm diagnosis. Results: The prevalence was 6.4/1000 inhabitants (95% CI: 3.8–10.1. There was no difference between genders. Simple febrile seizures were found in 88.8% of cases. A family history of febrile seizures in first-degree relatives and history of epilepsy was present in 33.3% and 11.1% of patients, respectively. Conclusions: The prevalence of febrile seizures in Midwestern Brazil was lower than that found in other Brazilian regions, probably due to the inclusion only of febrile seizures with motor manifestations and differences in socioeconomic factors among the evaluated areas. Resumo: Objetivos: Estabelecer a prevalência das crises febris e descrever o perfil clínico e epidemiológico dessa população. Métodos: Estudo transversal de base populacional realizado na cidade de Barra do Bugres (MT, no período de agosto de 2012 a agosto de 2013. Os dados foram coletados em duas etapas. Na primeira fase utilizamos um questionário validado previamente em outro estudo brasileiro, para identificação de casos suspeitos de crises epilépticas. Na segunda etapa realizamos a avaliação neuroclínica para confirmação diagnóstica. Resultados: A prevalência de crise febril foi de 6,4/1000 habitantes (IC95% 3,8; 10,1. Não houve diferença entre os sexos. As crises febris simples foram encontradas em 88,8% dos casos. A história familiar de crise febril e epilepsia em parentes de 1° grau esteve

  5. People with dementia in nursing home research: a methodological review of the definition and identification of the study population.

    Science.gov (United States)

    Palm, Rebecca; Jünger, Saskia; Reuther, Sven; Schwab, Christian G G; Dichter, Martin N; Holle, Bernhard; Halek, Margareta

    2016-04-05

    There are various definitions and diagnostic criteria for dementia, leading to discrepancies in case ascertainment in both clinical practice and research. We reviewed the different definitions, approaches and measurements used to operationalize dementia in health care studies in German nursing homes with the aim of discussing the implications of different approaches. We conducted a systematic search of the MEDLINE and CINAHL databases to identify pre-2016 studies conducted in German nursing homes that focused on residents with dementia or cognitive impairment. In- or exclusion of studies were consented by all authors; data extraction was independently carried out by 2 authors (RP, SJ). The studies' sampling methods were compared with respect to their inclusion criteria, assessment tools and methods used to identify the study population. We summarized case ascertainment methods from 64 studies. Study participants were identified based on a diagnosis that was evaluated during the study, or a recorded medical dementia diagnosis, or a recorded medical diagnosis either with additional cognitive screenings or using screening tests exclusively. The descriptions of the diagnostics that were applied to assess a diagnosis of dementia were not fully transparent in most of the studies with respect to either a clear reference definition of dementia or applied diagnostic criteria. If reported, various neuropsychological tests were used, mostly without a clear rationale for their selection. Pragmatic considerations often determine the sampling strategy; they also may explain the variances we detected in the different studies. Variations in sampling methods impede the comparability of study results. There is a need to consent case ascertainment strategies in dementia studies in health service research in nursing homes. These strategies should consider resource constraints and ethical issues that are related to the vulnerable population of nursing home residents. Additionally

  6. Association of Blood Eosinophil and Blood Neutrophil Counts with Asthma Exacerbations in the Copenhagen General Population Study

    DEFF Research Database (Denmark)

    Vedel-Krogh, Signe; Nielsen, Sune Fallgaard; Lange, Peter

    2017-01-01

    BACKGROUND: Blood eosinophil count is a marker of eosinophilic airway inflammation and disease severity in asthma. However, blood neutrophil count might also be associated with disease severity. We tested the hypothesis that high blood eosinophil and neutrophil counts are both associated...... with the risk of asthma exacerbations among individuals with asthma from the general population. METHODS: From the Copenhagen General Population Study with 81351 participants, we included 4838 with self-reported asthma. We recorded baseline blood eosinophil and neutrophil counts, and asthma exacerbations during...... with blood eosinophil counts >0.29 × 10(9)/L (highest tertile) vs individuals with blood eosinophil counts

  7. Magnitude of depression and its correlates among elderly population in a rural area of Maharashtra: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Sourav Goswami

    2017-01-01

    Full Text Available Background: Depression is the most common psychiatric disorder among elderly population in India, yet, it is commonly misdiagnosed and undertreated. The exact burden of depression among the elderly population in rural India was not known. Objectives: To study the magnitude of depression among the elderly masses in rural Maharashtra and to find its correlates. Material and Methods: This is a cross sectional study, carried out among the elderly (≥60 years population of both sexes residing in the field practice area of the department of community medicine. Geriatric depression scale was used for screening depression among the study population. Data collection was completed within 2 months using convenience sampling. Ethical approval was taken before beginning the study. Magnitude was expressed in percentage along with its 95% confidence interval (CI. Univariate and multivariate logistic regression was carried out to study associated correlates. Odds ratio and 95% CI was used to express association. Results: The magnitude of depression among the elderly population was found to be 41.7% (95% CI 36.1–47.4. We got the significant positive association of female sex, living without spouse, lacking in decision making capability, a victim of abuse or neglect, or suffering from chronic illnesses with depression among elderly population in univariate analysis that did not hold good in the multivariate logistic regression. Our study showed the prevalence of mild depression among elderly to be 26.72% and that of severe depression to be 15.17%. Conclusion: To deal with this huge social problem of depression among the elderly population, more enthusiastic steps should be undertaken.

  8. [Food and population: study of three countries].

    Science.gov (United States)

    1988-12-01

    In 1985, despite a nearly 25% worldwide surplus of cereals, more than 700 million poor people had insufficient food and some 17 million children died of malnutrition or related causes. 16% of the developing world's population is undernourished. Rapid population growth is a major reason for the world's hunger. Large families exhaust the resources of many urban couples and rural couples with little land. Closely spaced pregnancies deplete the nutritional resources of the mother and lead to low birth weight babies and inadequate lactation. Population growth in already densely populated countries reduces the land available for each family, inevitably contributing to poverty and rural malnutrition. Unemployment and underemployment reach alarming proportions in the city, where the combination of high fertility rates and migration from the countryside have produced growth twice that of the world population as a whole. Few developing countries have been able to generate sufficient investment to create new jobs for all seeking them. Unstable governments attempt to pacify urban unrest by subsidizing food prices and concentrating social and economic investments in the cities, causing further deterioration in rural conditions. Today more than 60 countries have food deficits, although not all are suffering. India, Kenya, and Mexico are 3 countries that have had some success in balancing population growth and food production, but each still has undernourished population sectors because of economic policies that fail to provide sufficient help to their poor and because of implacable population growth. Ending malnutrition in the 3 countries will require reducing the cost of food for households and increasing their incomes, but both objectives are made more difficult by rapid population growth. As a result of the green revolution and other factors, food production in India has tripled since 1950, but population has almost doubled in the same years. With rapid population growth, per

  9. Correlates of kidney stone disease differ by race in a multi-ethnic middle-aged population: The ARIC study

    NARCIS (Netherlands)

    S. Akoudad (Saloua); M. Szklo (Moyses); M.A. McAdams (Mara); T. Fulop (Tibor); C.A.M. Anderson (Cheryl); J. Coresh (Josef); A. Köttgen (Anna)

    2010-01-01

    textabstractObjective: To identify correlates of kidney stone disease in white and African American men and women in a population-based longitudinal study starting in four US communities, and to assess differences in correlates across racial groups. Methods: Between 1993 and 1995, 12,161 middle-aged

  10. OCCUPATION AND EPICONDYLITIS: A POPULATION-BASED STUDY

    Science.gov (United States)

    Walker-Bone, Karen; Palmer, Keith T; Reading, Isabel C; Coggon, David; Cooper, Cyrus

    2012-01-01

    Objectives To explore the relationship between occupational exposures and lateral and medial epicondylitis and the effect of epicondylitis on sickness absence in a population sample of working aged adults. Methods This was a cross-sectional study of 9696 randomly selected adults aged 25-64 years involving a screening questionnaire and standardised physical examination. Age- and sex-specific prevalence rates of epicondylitis were estimated and associations with occupational risk factors explored. Results Among 6038 respondents, 636 (11%) reported elbow pain in the last week. 0.7% of those surveyed were diagnosed with lateral epicondylitis and 0.6% with medial epicondylitis. Lateral epicondylitis was associated with manual work (OR 4.0, 95% CI 1.9-8.4). In multivariate analyses, repetitive bending/straightening elbow > 1 hour day was independently associated with lateral (OR 2.5, 95% CI 1.2-5.5) and medial epicondylitis (OR 5.1, 95% CI 1.8-14.3). 5% of adults with epicondylitis took sickness absence because of their elbow symptoms in the past 12 months (median 29 days). Conclusions Repetitive exposure to bending/straightening the elbow was a significant risk factor for medial and lateral epicondylitis. Epicondylitis is associated with prolonged sickness absence in 5% of affected working-aged adults. PMID:22019808

  11. Study on Quality Improvement Effect and Separate Character of Soybean Male Sterile (MS1) Recurrent Selection Population

    Institute of Scientific and Technical Information of China (English)

    ZHAO Shuang-jin; ZHANG Meng-chen; JIANG Chun-zhi; YANG Chun-yan; LIU Bing-qiang; CUI Jue

    2007-01-01

    To solve the problem that soybean has narrow genetic base, we constructed a series of male sterile recurrent selection populations, and studied the effects of quality improvement and practical value. An LD-base population, which fits to our ecology type was constructed by 6 years' gene enrichment through the introduction of new genes from 23 local varieties and recurrent selection. The LD-base populations were then improved by making crosses with high protein and high oil genotypes. As a result we obtained a high protein sub-population (db) and a high oil sub-population (gy). For the db sub-population, the protein content is 1.18% higher than the base population, 22.38% of the individuals contain 45% or more of protein, which is 10.99% higher than the base population. For the gy sub-population, oil content is 0.24% higher than the base population. Individuals with oil content of 20% or more are 11.05% higher than the base population. The quantitative characters such as flowering date, mature date, pod habit, and hilum color, etc., all showed wide range of separation, and the segregation ratio approached balance. The c.v. of branch number of ms1 recurrent population (72.8%) is higher than general cross-population (57.3%), and the c.v. of 100 seed weight of ms1 (18.1%) is higher than general cross population (16.5%), the coefficient of variation of plant height, pods per plant, and seeds per pod were not significantly different. It was demonstrated in this paper that the quality character of ms1 male sterile recurrent selection population was improved by adding new genes. And the segregation of other characters widened, making the populations suitable for the objective of soybean breeding. In this paper, we also discussed the breeding method, key technology, and selection effect of soybean ms1 population.

  12. Estimating Population Turnover Rates by Relative Quantification Methods Reveals Microbial Dynamics in Marine Sediment.

    Science.gov (United States)

    Kevorkian, Richard; Bird, Jordan T; Shumaker, Alexander; Lloyd, Karen G

    2018-01-01

    The difficulty involved in quantifying biogeochemically significant microbes in marine sediments limits our ability to assess interspecific interactions, population turnover times, and niches of uncultured taxa. We incubated surface sediments from Cape Lookout Bight, North Carolina, USA, anoxically at 21°C for 122 days. Sulfate decreased until day 68, after which methane increased, with hydrogen concentrations consistent with the predicted values of an electron donor exerting thermodynamic control. We measured turnover times using two relative quantification methods, quantitative PCR (qPCR) and the product of 16S gene read abundance and total cell abundance (FRAxC, which stands for "fraction of read abundance times cells"), to estimate the population turnover rates of uncultured clades. Most 16S rRNA reads were from deeply branching uncultured groups, and ∼98% of 16S rRNA genes did not abruptly shift in relative abundance when sulfate reduction gave way to methanogenesis. Uncultured Methanomicrobiales and Methanosarcinales increased at the onset of methanogenesis with population turnover times estimated from qPCR at 9.7 ± 3.9 and 12.6 ± 4.1 days, respectively. These were consistent with FRAxC turnover times of 9.4 ± 5.8 and 9.2 ± 3.5 days, respectively. Uncultured Syntrophaceae , which are possibly fermentative syntrophs of methanogens, and uncultured Kazan-3A-21 archaea also increased at the onset of methanogenesis, with FRAxC turnover times of 14.7 ± 6.9 and 10.6 ± 3.6 days. Kazan-3A-21 may therefore either perform methanogenesis or form a fermentative syntrophy with methanogens. Three genera of sulfate-reducing bacteria, Desulfovibrio , Desulfobacter , and Desulfobacterium , increased in the first 19 days before declining rapidly during sulfate reduction. We conclude that population turnover times on the order of days can be measured robustly in organic-rich marine sediment, and the transition from sulfate-reducing to methanogenic conditions stimulates

  13. The epidemiology of neck pain: what we have learned from our population-based studies

    Science.gov (United States)

    Côté, Pierre; Cassidy, J. David; Carroll, Linda

    2003-01-01

    Background: There are few population-based studies on the epidemiology of neck pain in the general population. Purpose: To synthesize the findings of two large population-based studies of the epidemiology of neck pain and whiplash-associated disorders from the province of Saskatchewan, Canada. Study Design and Methods: We conducted two population-based cohort studies of neck pain and its related disability in Saskatchewan, Canada. First, the Saskatchewan Health and Back Pain Survey was designed to determine the prevalence and factors associated with neck pain in randomly selected adults. Second, we conducted a cohort study of the incidence and prognosis of whiplash and studied whether a change in the insurance system from tort to no-fault was related to a reduction in the number of whiplash claims and faster recovery. Results: In 1995, the six-month prevalence of neck pain was 54.2% and 4.6% of adults experienced disabling neck pain in the previous six-months. Neck pain was associated with education, comorbidities, smoking, self-reported general health and a history of neck injury in a motor vehicle collision. The incidence of treated and/or compensated whiplash injury was estimated at 834/100,000 adults in 1994, and dropped by 28% to 598/100,000 adults in 1995, after tort reform. Compared to tort, the median time-to-recovery was more than 230 days faster under no-fault. The strongest predictors of recovery were age, gender, education, injury severity, lawyer involvement and type of initial care provider. Conclusion: Neck pain is a public health problem. The incidence and prognosis of whiplash injuries are greatly influenced by compensation for pain and suffering, legal factors, injury severity and sociodemographic characteristics. Overall, neck pain is a multifaceted disabling problem that deserves more attention. When treating patients with neck pain, clinicians need to recognize that it is more than a physical problem and that its prognosis is influenced by

  14. Medical Genetics and the First Studies of the Genetics of Populations in Mexico.

    Science.gov (United States)

    Barahona, Ana

    2016-09-01

    Following World War II (WWII), there was a new emphasis within genetics on studying the genetic composition of populations. This probably had a dual source in the growing strength of evolutionary biology and the new international interest in understanding the effects of radiation on human populations, following the atomic bombings in Japan. These global concerns were shared by Mexican physicians. Indeed, Mexico was one of the leading centers of this trend in human genetics. Three leading players in this story were Mario Salazar Mallén, Adolfo Karl, and Rubén Lisker. Their trajectories and the international networks in human genetics that were established after WWII, paved the way for the establishment of medical and population genetics in Mexico. Salazar Mallén's studies on the distribution and characterization of ABO blood groups in indigenous populations were the starting point while Karl's studies on the distribution of abnormal hemoglobin in Mexican indigenous populations showed the relationships observed in other laboratories at the time. It was Lisker's studies, however, that were instrumental in the development of population genetics in the context of national public policies for extending health care services to the Mexican population. In particular, he conducted studies on Mexican indigenous groups contributing to the knowledge of the biological diversity of human populations according to international trends that focused on the variability of human populations in terms of genetic frequencies. From the start, however, Lisker was as committed to the reconstruction of shared languages and practices as he was to building networks of collaboration in order to guarantee the necessary groundwork for establishing the study of the genetics of human populations in Mexico. This study also allows us to place Mexican science within a global context in which connected narratives describe the interplay between global trends and national contexts. Copyright © 2016 by

  15. Evaluation of a digital method to assess evening meal intake in a free-living adult population

    Directory of Open Access Journals (Sweden)

    Anne Dahl Lassen

    2010-11-01

    Full Text Available Background: In recent years new applications of technologies, including digital images, to capture dietary behaviour in real time have been explored. Objectives: To validate a digital method for estimating evening meal intake in a free-living adult population, and to examine the feasibility of the method for recording evening meal intake over a prolonged period of time. Design: The digital method was compared against weighed records of 19 participants’ usual evening meals for five consecutive days. Two trained image analysts independently estimated the weight of individual foods within the meals into major food categories, and the nutrient content was calculated. A second study included interviews with 28 participants recording their evening meals on weekdays for three consecutive weeks to get their perspective on the feasibility of the method. Results: High correlation coefficients between the digital method and weighed records were found for all measured food categories and nutrients. Comparable means and acceptable limits of agreement (mean difference +/− 2 SD were found with regard to macronutrient distribution (e.g. fat content −5 to 6 E%, energy density (−75 to 91 kJ/100 g, and energy-adjusted foods (e.g. fruit and vegetable content −241 to 236 g/10 MJ. The majority of the participants expressed satisfaction with the method and were willing to record their evening meals for 1 month or more using the digital method. Conclusion: The digital method is valid and feasible for evening meal estimation in real-time where a prolonged recording period of participants’ meals is needed.

  16. Role of population genetics in the sterile insect technique

    International Nuclear Information System (INIS)

    Krafsur, E.S.

    2005-01-01

    The detection and analysis of genetic variation in natural and laboratory populations are reviewed. The application of population genetic methods and theory can help to plan and evaluate the implementation of area-wide integrated pest management (AW-IPM) programmes that use the sterile insect technique (SIT). Population genetic studies can play an important role in estimating dispersal rates and thus gene flow among target populations, determining if sibling species exist, establishing the origin of outbreaks or reintroductions, and supporting the quality control of mass-reared colonies. The target's population history may be examined, in terms of 'bottlenecks', range fragmentations, and expansions. Genetic methods can be helpful in distinguishing wild insects from released sterile or substerile ones, and in ascertaining, together with mating cross-compatibility studies, the compatibility of mass-reared colonies with target wild insects. (author)

  17. ANFIS Based Time Series Prediction Method of Bank Cash Flow Optimized by Adaptive Population Activity PSO Algorithm

    Directory of Open Access Journals (Sweden)

    Jie-Sheng Wang

    2015-06-01

    Full Text Available In order to improve the accuracy and real-time of all kinds of information in the cash business, and solve the problem which accuracy and stability is not high of the data linkage between cash inventory forecasting and cash management information in the commercial bank, a hybrid learning algorithm is proposed based on adaptive population activity particle swarm optimization (APAPSO algorithm combined with the least squares method (LMS to optimize the adaptive network-based fuzzy inference system (ANFIS model parameters. Through the introduction of metric function of population diversity to ensure the diversity of population and adaptive changes in inertia weight and learning factors, the optimization ability of the particle swarm optimization (PSO algorithm is improved, which avoids the premature convergence problem of the PSO algorithm. The simulation comparison experiments are carried out with BP-LMS algorithm and standard PSO-LMS by adopting real commercial banks’ cash flow data to verify the effectiveness of the proposed time series prediction of bank cash flow based on improved PSO-ANFIS optimization method. Simulation results show that the optimization speed is faster and the prediction accuracy is higher.

  18. Determining individual variation in growth and its implication for life-history and population processes using the empirical Bayes method.

    Directory of Open Access Journals (Sweden)

    Simone Vincenzi

    2014-09-01

    Full Text Available The differences in demographic and life-history processes between organisms living in the same population have important consequences for ecological and evolutionary dynamics. Modern statistical and computational methods allow the investigation of individual and shared (among homogeneous groups determinants of the observed variation in growth. We use an Empirical Bayes approach to estimate individual and shared variation in somatic growth using a von Bertalanffy growth model with random effects. To illustrate the power and generality of the method, we consider two populations of marble trout Salmo marmoratus living in Slovenian streams, where individually tagged fish have been sampled for more than 15 years. We use year-of-birth cohort, population density during the first year of life, and individual random effects as potential predictors of the von Bertalanffy growth function's parameters k (rate of growth and L∞ (asymptotic size. Our results showed that size ranks were largely maintained throughout marble trout lifetime in both populations. According to the Akaike Information Criterion (AIC, the best models showed different growth patterns for year-of-birth cohorts as well as the existence of substantial individual variation in growth trajectories after accounting for the cohort effect. For both populations, models including density during the first year of life showed that growth tended to decrease with increasing population density early in life. Model validation showed that predictions of individual growth trajectories using the random-effects model were more accurate than predictions based on mean size-at-age of fish.

  19. Determining individual variation in growth and its implication for life-history and population processes using the empirical Bayes method.

    Science.gov (United States)

    Vincenzi, Simone; Mangel, Marc; Crivelli, Alain J; Munch, Stephan; Skaug, Hans J

    2014-09-01

    The differences in demographic and life-history processes between organisms living in the same population have important consequences for ecological and evolutionary dynamics. Modern statistical and computational methods allow the investigation of individual and shared (among homogeneous groups) determinants of the observed variation in growth. We use an Empirical Bayes approach to estimate individual and shared variation in somatic growth using a von Bertalanffy growth model with random effects. To illustrate the power and generality of the method, we consider two populations of marble trout Salmo marmoratus living in Slovenian streams, where individually tagged fish have been sampled for more than 15 years. We use year-of-birth cohort, population density during the first year of life, and individual random effects as potential predictors of the von Bertalanffy growth function's parameters k (rate of growth) and L∞ (asymptotic size). Our results showed that size ranks were largely maintained throughout marble trout lifetime in both populations. According to the Akaike Information Criterion (AIC), the best models showed different growth patterns for year-of-birth cohorts as well as the existence of substantial individual variation in growth trajectories after accounting for the cohort effect. For both populations, models including density during the first year of life showed that growth tended to decrease with increasing population density early in life. Model validation showed that predictions of individual growth trajectories using the random-effects model were more accurate than predictions based on mean size-at-age of fish.

  20. THE STUDY OF CARDIAC ABNORMALITY IN GERIATRIC POPULATION OF RURAL CENTRAL INDIA

    Directory of Open Access Journals (Sweden)

    Aman Chaturvedi

    2017-09-01

    Full Text Available BACKGROUND Health care of elderly in the society has emerged as an increasingly important issue in the recent years. As the elderly proportion of our population expands, maintaining health and wellness of the aged will continue to be an important research priority in the near future. This study was undertaken to determine cardiac abnormalities in geriatric population by echocardiography in rural central India. The aim of this study is to map the spectrum of cardiac abnormality in geriatric population of rural central India. MATERIALS AND METHODS The study was carried out on subjects from September 2014 – August 2016. All geriatric subjects i.e. above the age of 60 years who were admitted in medicine ward or who attended medicine OPD were considered for the study. All the preliminary biodata was collected, history taking and physical examination were done, ECG was recorded and finally 2D echo was performed in MMode, 2D echo, Doppler (CW and PW and TDI. All observations were recorded on a standard proforma sheet, statistical analysis was performed and results and conclusions drawn. RESULTS In present study, there was higher prevalence of major diseases. On M-Mode echocardiography, left atrial enlargement, LV hypertrophy/dilatation was found in significant number of subjects. On 2D echo, Myocardial Scarring/Thinning, valvular Degeneration was found significantly higher in elderly males, mitral and aortic calcification was found most frequently with prevalence higher in males. On Doppler echocardiography, diastolic dysfunction was common in elderly with very few subjects having normal diastolic function, most of the subjects having grade II diastolic dysfunction. Aortic, mitral and tricuspid regurgitation was common in elderly, and stenotic lesions of aortic and mitral valve were common. CONCLUSION We recommend that echocardiography should become an investigative norm in the elderly, this will aid in early detection of cardiovascular abnormalities

  1. Large-scale Comparative Study of Hi-C-based Chromatin 3D Structure Modeling Methods

    KAUST Repository

    Wang, Cheng

    2018-05-17

    Chromatin is a complex polymer molecule in eukaryotic cells, primarily consisting of DNA and histones. Many works have shown that the 3D folding of chromatin structure plays an important role in DNA expression. The recently proposed Chro- mosome Conformation Capture technologies, especially the Hi-C assays, provide us an opportunity to study how the 3D structures of the chromatin are organized. Based on the data from Hi-C experiments, many chromatin 3D structure modeling methods have been proposed. However, there is limited ground truth to validate these methods and no robust chromatin structure alignment algorithms to evaluate the performance of these methods. In our work, we first made a thorough literature review of 25 publicly available population Hi-C-based chromatin 3D structure modeling methods. Furthermore, to evaluate and to compare the performance of these methods, we proposed a novel data simulation method, which combined the population Hi-C data and single-cell Hi-C data without ad hoc parameters. Also, we designed a global and a local alignment algorithms to measure the similarity between the templates and the chromatin struc- tures predicted by different modeling methods. Finally, the results from large-scale comparative tests indicated that our alignment algorithms significantly outperform the algorithms in literature.

  2. A population-based study of glioblastoma multiforme

    International Nuclear Information System (INIS)

    Paszat, Lawrence; Laperriere, Normand; Groome, Patti; Schulze, Karleen; Mackillop, William; Holowaty, Eric

    2001-01-01

    Purpose: To describe (1) the use of surgery and radiotherapy (RT) in the treatment of patients with glioblastoma (GBM) in Ontario, (2) survival, and (3) proportion of survival time spent in the hospital after diagnosis. Methods and Materials: We performed a population-based cohort study of all Ontario Cancer Registry (OCR) cases of GBM diagnosed between 1982 and 1994. We linked OCR records, hospital files containing surgical procedure codes from the Canadian Institute for Health Information, and province-wide RT records. We studied the odds of treatment using multivariate logistic regression. We expressed the time spent in the hospital as the mean number of days per case, and as a proportion of the interval between diagnosis and death, or 24 months following diagnosis, whichever came first. We used the life-table method and Cox proportional hazards regression to describe survival. Results: The proportion of patients with GBM undergoing any surgery directed at the tumor varied with age (p<0.0001) and region of residence (p<0.0001). The proportion undergoing RT varied with age (p<0.0001), region of residence (p<0.0001), and year of diagnosis (p=0.01). RT dose ≥53.5 Gy varied with age (p<0.0001), region of residence (p<0.0001), and year of diagnosis (p=0.0002). Median survival was 11 months among patients receiving RT and 3 months among those not receiving RT. The percentage of survival time spent in the hospital was similar among those who received from 49.5 to <53.5 Gy, compared to ≥53.5 Gy. Overall survival and the adjusted relative risk of death varied with age and region of residence. Conclusion: We observed practice variation in the treatment of patients with GBM according to age, region of residence, and year of diagnosis. Survival did not increase during the study period. The variation in RT dose between those receiving from 49.5 to <53.5 Gy compared to ≥53.5 Gy was not paralleled by variation in survival between regions where one or the other of the

  3. Breast feeding mediators among iranian women at premarital stage a population based study

    International Nuclear Information System (INIS)

    Hosseinzadeh, K.

    2017-01-01

    Objectives: To describe breastfeeding mediators among women at pre-marital stage in Iran. Methods: Using the simple randomized sampling method, 450 participants were enrolled in this population-based cross-sectional study. A structured questionnaire was used in order to collect data. Results: Eighty eight percent of the participants reported that had not met breastfeeding education previously. The available sources of information for 65% of respondents were radio and television. Seventy nine percent did not know any breastfeeding consultant. Mean score of participants' knowledge was lower than 50 score. Nearly 50% participants claimed the breastfeeding to be as a common barrier for their job and learning. Only 14% had intended to initiate breastfeeding immediately after childbearing. Mean score of perceived self efficacy about breastfeeding was less than 50 percent. Conclusion: Breastfeeding mediators among Iranian women at premarital stage are not in favorable situation. Findings of this study suggest a need for more breastfeeding education programs for Iranian women at premarital stage. (author)

  4. Prevalence and clinical symptoms of migrainous vertigo in Germany - a population based study

    OpenAIRE

    Feldmann, Maria

    2010-01-01

    Objective: To investigate the epidemiology of migrainous vertigo (MV) in the general population by assessing the prevalence, clinical features, co morbid conditions, quality of life, and health care utilization. Methods: We screened a representative sample of the adult population in Germany (n=4,869) for moderate or severe dizziness/vertigo and followed up with validated neurotologic telephone interviews (n=1003). Diagnostic criteria for MV were as follows: 1. recurrent vestibular vertigo, 2....

  5. Parallel grid population

    Science.gov (United States)

    Wald, Ingo; Ize, Santiago

    2015-07-28

    Parallel population of a grid with a plurality of objects using a plurality of processors. One example embodiment is a method for parallel population of a grid with a plurality of objects using a plurality of processors. The method includes a first act of dividing a grid into n distinct grid portions, where n is the number of processors available for populating the grid. The method also includes acts of dividing a plurality of objects into n distinct sets of objects, assigning a distinct set of objects to each processor such that each processor determines by which distinct grid portion(s) each object in its distinct set of objects is at least partially bounded, and assigning a distinct grid portion to each processor such that each processor populates its distinct grid portion with any objects that were previously determined to be at least partially bounded by its distinct grid portion.

  6. Whole-body magnetic resonance imaging of healthy volunteers. Pilot study results from the population-based SHIP study

    Energy Technology Data Exchange (ETDEWEB)

    Hegenscheid, K.; Kuehn, J.P.; Hosten, N.; Puls, R. [Inst. fuer Diagnostische Radiologie und Neuroradiologie, Universitaetsklinikum der Ernst-Moritz-Arndt-Univ. Greifswald (Germany); Voelzke, H. [Inst. fuer Community Medicine, Universitaetsklinikum der Ernst-Moritz-Arndt-Univ. Greifswald (Germany); Biffar, R. [Zentrum fuer Zahn-, Mund- und Kieferheilkunde, Universitaetsklinikum der Ernst-Moritz-Arndt-Univ. Greifswald (Germany)

    2009-08-15

    Purpose: Approximately 4000 volunteers will undergo whole-body magnetic resonance imaging (WB-MRI) within the next 3 years in the population-based Study of Health in Pomerania (SHIP). Here we present a pilot study conducted (a) to determine the feasibility of adding a WB-MRI protocol to a large-scale population-based study, (b) to evaluate the reliability of standardized MRI interpretation, and (c) to establish an approach for handling pathological findings. Materials and Methods: The institutional review board approved the study, and oral and written informed consent was obtained from each participant. Two hundred healthy volunteers (99 women, 101 men; mean age 48.3 years) underwent a standardized WB-MRI protocol. The protocol was supplemented by contrast-enhanced cardiac MR1 and magnetic resonance (MR) angiography in 61 men (60.4%) and cardiac MRI and MR mammography in 44 women (44.4%). MR scans were evaluated independently by two readers. Abnormalities were discussed by an advisory board and classified according to the need for further clinical work-up. Results: One hundred ninety-four (97.0%) WB-MRI examinations were successfully completed in a mean scan time per subject of 90 minutes. There were 431 pathological findings in 176 (88%) of the participants. Of those 45 (10.4%) required further clinical work-up and 386 (89.6%) characterized as benign lesions did not. The interobserver agreement for the detection of pathological findings was excellent (K = 0.799) (orig.)

  7. Whole-body magnetic resonance imaging of healthy volunteers. Pilot study results from the population-based SHIP study

    International Nuclear Information System (INIS)

    Hegenscheid, K.; Kuehn, J.P.; Hosten, N.; Puls, R.; Voelzke, H.; Biffar, R.

    2009-01-01

    Purpose: Approximately 4000 volunteers will undergo whole-body magnetic resonance imaging (WB-MRI) within the next 3 years in the population-based Study of Health in Pomerania (SHIP). Here we present a pilot study conducted (a) to determine the feasibility of adding a WB-MRI protocol to a large-scale population-based study, (b) to evaluate the reliability of standardized MRI interpretation, and (c) to establish an approach for handling pathological findings. Materials and Methods: The institutional review board approved the study, and oral and written informed consent was obtained from each participant. Two hundred healthy volunteers (99 women, 101 men; mean age 48.3 years) underwent a standardized WB-MRI protocol. The protocol was supplemented by contrast-enhanced cardiac MR1 and magnetic resonance (MR) angiography in 61 men (60.4%) and cardiac MRI and MR mammography in 44 women (44.4%). MR scans were evaluated independently by two readers. Abnormalities were discussed by an advisory board and classified according to the need for further clinical work-up. Results: One hundred ninety-four (97.0%) WB-MRI examinations were successfully completed in a mean scan time per subject of 90 minutes. There were 431 pathological findings in 176 (88%) of the participants. Of those 45 (10.4%) required further clinical work-up and 386 (89.6%) characterized as benign lesions did not. The interobserver agreement for the detection of pathological findings was excellent (K = 0.799) (orig.)

  8. Probability Sampling Method for a Hidden Population Using Respondent-Driven Sampling: Simulation for Cancer Survivors.

    Science.gov (United States)

    Jung, Minsoo

    2015-01-01

    When there is no sampling frame within a certain group or the group is concerned that making its population public would bring social stigma, we say the population is hidden. It is difficult to approach this kind of population survey-methodologically because the response rate is low and its members are not quite honest with their responses when probability sampling is used. The only alternative known to address the problems caused by previous methods such as snowball sampling is respondent-driven sampling (RDS), which was developed by Heckathorn and his colleagues. RDS is based on a Markov chain, and uses the social network information of the respondent. This characteristic allows for probability sampling when we survey a hidden population. We verified through computer simulation whether RDS can be used on a hidden population of cancer survivors. According to the simulation results of this thesis, the chain-referral sampling of RDS tends to minimize as the sample gets bigger, and it becomes stabilized as the wave progresses. Therefore, it shows that the final sample information can be completely independent from the initial seeds if a certain level of sample size is secured even if the initial seeds were selected through convenient sampling. Thus, RDS can be considered as an alternative which can improve upon both key informant sampling and ethnographic surveys, and it needs to be utilized for various cases domestically as well.

  9. populations de Cobe defassa (kobus ellypsiprimnus defassa ...

    African Journals Online (AJOL)

    PR BOKO

    defassa (kobus ellypsiprimnus defassa, Ruppell) population in Pendjari's biosphere park in. Benin. Among the demographic factors that characterize a given population figure priority knowledge of its workforce over time and its distribution in space. This study is conducted in order to assess the relevance of two methods of ...

  10. Estimation of effectiveness of three methods of feral cat population control by use of a simulation model.

    Science.gov (United States)

    McCarthy, Robert J; Levine, Stephen H; Reed, J Michael

    2013-08-15

    To predict effectiveness of 3 interventional methods of population control for feral cat colonies. Population model. Estimates of vital data for feral cats. Data were gathered from the literature regarding the demography and mating behavior of feral cats. An individual-based stochastic simulation model was developed to evaluate the effectiveness of trap-neuter-release (TNR), lethal control, and trap-vasectomy-hysterectomy-release (TVHR) in decreasing the size of feral cat populations. TVHR outperformed both TNR and lethal control at all annual capture probabilities between 10% and 90%. Unless > 57% of cats were captured and neutered annually by TNR or removed by lethal control, there was minimal effect on population size. In contrast, with an annual capture rate of ≥ 35%, TVHR caused population size to decrease. An annual capture rate of 57% eliminated the modeled population in 4,000 days by use of TVHR, whereas > 82% was required for both TNR and lethal control. When the effect of fraction of adult cats neutered on kitten and young juvenile survival rate was included in the analysis, TNR performed progressively worse and could be counterproductive, such that population size increased, compared with no intervention at all. TVHR should be preferred over TNR for management of feral cats if decrease in population size is the goal. This model allowed for many factors related to the trapping program and cats to be varied and should be useful for determining the financial and person-effort commitments required to have a desired effect on a given feral cat population.

  11. Improved method for calculation of population doses from nuclear complexes over large geographical areas

    International Nuclear Information System (INIS)

    Corley, J.P.; Baker, D.A.; Hill, E.R.; Wendell, L.L.

    1977-09-01

    To simplify the calculation of potential long-distance environmental impacts, an overall average population exposure coefficient (P.E.C.) for the entire contiguous United States was calculated for releases to the atmosphere from Hanford facilities. The method, requiring machine computation, combines Bureau of Census population data by census enumeration district and an annual average atmospheric dilution factor (anti chi/Q') derived from 12-hourly gridded wind analyses provided by the NOAA's National Meteorological Center. A variable-trajectory puff-advection model was used to calculate an hourly anti chi/Q' for each grid square, assuming uniform hourly releases; seasonal and annual averages were then calculated. For Hanford, using 1970 census data, a P.E.C. of 2 x 10 -3 man-seconds per cubic meter was calculated. The P.E.C. is useful for both radioactive and nonradioactive releases. To calculate population doses for the entire contiguous United States, the P.E.C. is multiplied by the annual average release rate and then by the dose factor (rem/yr per Ci/m 3 ) for each radionuclide, and the dose contribution in man-rem is summed for all radionuclides. For multiple pathways, the P.E.C. is still useful, provided that doses from a unit release can be obtained from a set of atmospheric dose factors. The methodology is applicable to any point source, any set of population data by map grid coordinates, and any geographical area covered by equivalent meteorological data

  12. Seasonal Differences in Determinants of Time Location Patterns in an Urban Population: A Large Population-Based Study in Korea.

    Science.gov (United States)

    Lee, Sewon; Lee, Kiyoung

    2017-06-22

    Time location patterns are a significant factor for exposure assessment models of air pollutants. Factors associated with time location patterns in urban populations are typically due to high air pollution levels in urban areas. The objective of this study was to determine the seasonal differences in time location patterns in two urban cities. A Time Use Survey of Korean Statistics (KOSTAT) was conducted in the summer, fall, and winter of 2014. Time location data from Seoul and Busan were collected, together with demographic information obtained by diaries and questionnaires. Determinants of the time spent at each location were analyzed by multiple linear regression and the stepwise method. Seoul and Busan participants had similar time location profiles over the three seasons. The time spent at own home, other locations, workplace/school and during walk were similar over the three seasons in both the Seoul and Busan participants. The most significant time location pattern factors were employment status, age, gender, monthly income, and spouse. Season affected the time spent at the workplace/school and other locations in the Seoul participants, but not in the Busan participants. The seasons affected each time location pattern of the urban population slightly differently, but overall there were few differences.

  13. Seasonal Differences in Determinants of Time Location Patterns in an Urban Population: A Large Population-Based Study in Korea

    Directory of Open Access Journals (Sweden)

    Sewon Lee

    2017-06-01

    Full Text Available Time location patterns are a significant factor for exposure assessment models of air pollutants. Factors associated with time location patterns in urban populations are typically due to high air pollution levels in urban areas. The objective of this study was to determine the seasonal differences in time location patterns in two urban cities. A Time Use Survey of Korean Statistics (KOSTAT was conducted in the summer, fall, and winter of 2014. Time location data from Seoul and Busan were collected, together with demographic information obtained by diaries and questionnaires. Determinants of the time spent at each location were analyzed by multiple linear regression and the stepwise method. Seoul and Busan participants had similar time location profiles over the three seasons. The time spent at own home, other locations, workplace/school and during walk were similar over the three seasons in both the Seoul and Busan participants. The most significant time location pattern factors were employment status, age, gender, monthly income, and spouse. Season affected the time spent at the workplace/school and other locations in the Seoul participants, but not in the Busan participants. The seasons affected each time location pattern of the urban population slightly differently, but overall there were few differences.

  14. A glossary for big data in population and public health: discussion and commentary on terminology and research methods.

    Science.gov (United States)

    Fuller, Daniel; Buote, Richard; Stanley, Kevin

    2017-11-01

    The volume and velocity of data are growing rapidly and big data analytics are being applied to these data in many fields. Population and public health researchers may be unfamiliar with the terminology and statistical methods used in big data. This creates a barrier to the application of big data analytics. The purpose of this glossary is to define terms used in big data and big data analytics and to contextualise these terms. We define the five Vs of big data and provide definitions and distinctions for data mining, machine learning and deep learning, among other terms. We provide key distinctions between big data and statistical analysis methods applied to big data. We contextualise the glossary by providing examples where big data analysis methods have been applied to population and public health research problems and provide brief guidance on how to learn big data analysis methods. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  15. On the methodological approaches to the study of saving behavior of the population

    Directory of Open Access Journals (Sweden)

    Galina Vadimovna Belekhova

    2015-03-01

    Full Text Available The task to ensure effective functioning of all systems in the society and sustainable economic growth requires significant amounts of investment resources, which include savings of the population. This involves identification of the amount of funds accumulated by the population and studies of the characteristics of its saving behavior. The article reveals advantages and disadvantages of the main methodological approaches to the research in saving behavior and gives a comparative analysis of methods on the basis of official statistical information. As for Russia income is a key factor in saving behavior, the article also addresses the problem of assessing the degree of income differentiation of saving behavior. For this purpose we have used a method of household budgets sample surveys on the basis of which we have calculated and analyzed key performance indicators of savings behavior of households, including in the context of groups with different income levels. Unlike previous works on the topic, our study uses available resources (not money income as a basis for the calculation of saving behavior indicators, as they more fully characterize funds of low-income households, which are mostly represented in the budget surveys sample. The performed analysis has helped identify that the degree of the population’s savings differentiation does not yield to the incomes differentiation, and the highest levels of savings and used financial assets belong to the well-to-do group. What is more, the growth in per capita income has not encouraged the poor to save. Thus, in contrast to the well-to-do, increasing the volume of savings in the cost structure, poorer groups direct the major part of funds for consumer needs and different payments. Thus, the share of savings in the overall structure of their income remains practically unchanged. The conclusion emphasizes that sociological methods can be used to study qualitative changes in saving behavior and

  16. Cynical hostility, socioeconomic position, health behaviors, and symptom load: a cross-sectional analysis in a Danish population-based study

    DEFF Research Database (Denmark)

    Christensen, Ulla; Lund, Rikke; Damsgaard, Mogens Trab

    2004-01-01

    OBJECTIVE: To analyze the cross-sectional association between cynical hostility and high symptom load in a Danish population-based study. Furthermore, the aim was to investigate to what extent health risk behaviors mediated this association. METHODS: Data were based on a postal questionnaire...

  17. Provincial prenatal record revision: a multiple case study of evidence-based decision-making at the population-policy level

    Directory of Open Access Journals (Sweden)

    Olson Joanne

    2008-12-01

    Full Text Available Abstract Background There is a significant gap in the knowledge translation literature related to how research evidence actually contributes to health care decision-making. Decisions around what care to provide at the population (rather than individual level are particularly complex, involving considerations such as feasibility, cost, and population needs in addition to scientific evidence. One example of decision-making at this "population-policy" level involves what screening questions and intervention guides to include on standardized provincial prenatal records. As mandatory medical reporting forms, prenatal records are potentially powerful vehicles for promoting population-wide evidence-based care. However, the extent to which Canadian prenatal records reflect best-practice recommendations for the assessment of well-known risk factors such as maternal smoking and alcohol consumption varies markedly across Canadian provinces and territories. The goal of this study is to better understand the interaction of contextual factors and research evidence on decision-making at the population-policy level, by examining the processes by which provincial prenatal records are reviewed and revised. Methods Guided by Dobrow et al.'s (2004 conceptual model for context-based evidence-based decision-making, this study will use a multiple case study design with embedded units of analysis to examine contextual factors influencing the prenatal record revision process in different Canadian provinces and territories. Data will be collected using multiple methods to construct detailed case descriptions for each province/territory. Using qualitative data analysis techniques, decision-making processes involving prenatal record content specifically related to maternal smoking and alcohol use will be compared both within and across each case, to identify key contextual factors influencing the uptake and application of research evidence by prenatal record review

  18. The population of Indonesia : regional demographic scenarios using a multiregional method and multiple data sources

    NARCIS (Netherlands)

    Muhidin, Salahudin

    2002-01-01

    This study attempts to contribute on the understanding of regional population dynamics in Indonesia. It outlines a detailed analysis of the changes in regional demographic variables during the last three decades. It provides an assessment of the past population projections, as well as the advantages

  19. A population-based prescription study of asthma drugs during pregnancy

    DEFF Research Database (Denmark)

    Olesen, Charlotte; Thrane, Nana; Nielsen, G.L.

    2001-01-01

    Background: Among the goals of gestational asthma, therapy is optimisation of pulmonary function. According to the US Food and Drug Administration, no asthma drugs can be considered ‘safe’ during pregnancy. Fear of adverse fetal effects may thus lead to restrictive use of asthma drugs during...... pregnancy, and no population-based studies concerning gestational asthma therapy exist. Objectives: To examine whether asthma drugs or changing intensity of asthma therapy during pregnancy was associated with deviations from expected values of gestational age, birth weight, length at birth, or malformations....... Methods: The Birth Registry was used to identify all 15,756 primiparous women who gave birth in the County of North Jutland between 1991 and 1996. According to the North Jutland Prescription Database, 303 of these women received prescriptions for asthma drugs during pregnancy. Women who did not purchase...

  20. Environment And Genetics in Lung cancer Etiology (EAGLE study: An integrative population-based case-control study of lung cancer

    Directory of Open Access Journals (Sweden)

    Colombi Antonio

    2008-06-01

    Full Text Available Abstract Background Lung cancer is the leading cause of cancer mortality worldwide. Tobacco smoking is its primary cause, and yet the precise molecular alterations induced by smoking in lung tissue that lead to lung cancer and impact survival have remained obscure. A new framework of research is needed to address the challenges offered by this complex disease. Methods/Design We designed a large population-based case-control study that combines a traditional molecular epidemiology design with a more integrative approach to investigate the dynamic process that begins with smoking initiation, proceeds through dependency/smoking persistence, continues with lung cancer development and ends with progression to disseminated disease or response to therapy and survival. The study allows the integration of data from multiple sources in the same subjects (risk factors, germline variation, genomic alterations in tumors, and clinical endpoints to tackle the disease etiology from different angles. Before beginning the study, we conducted a phone survey and pilot investigations to identify the best approach to ensure an acceptable participation in the study from cases and controls. Between 2002 and 2005, we enrolled 2101 incident primary lung cancer cases and 2120 population controls, with 86.6% and 72.4% participation rate, respectively, from a catchment area including 216 municipalities in the Lombardy region of Italy. Lung cancer cases were enrolled in 13 hospitals and population controls were randomly sampled from the area to match the cases by age, gender and residence. Detailed epidemiological information and biospecimens were collected from each participant, and clinical data and tissue specimens from the cases. Collection of follow-up data on treatment and survival is ongoing. Discussion EAGLE is a new population-based case-control study that explores the full spectrum of lung cancer etiology, from smoking addiction to lung cancer outcome, through

  1. Spatially explicit inference for open populations: estimating demographic parameters from camera-trap studies.

    Science.gov (United States)

    Gardner, Beth; Reppucci, Juan; Lucherini, Mauro; Royle, J Andrew

    2010-11-01

    We develop a hierarchical capture-recapture model for demographically open populations when auxiliary spatial information about location of capture is obtained. Such spatial capture-recapture data arise from studies based on camera trapping, DNA sampling, and other situations in which a spatial array of devices records encounters of unique individuals. We integrate an individual-based formulation of a Jolly-Seber type model with recently developed spatially explicit capture-recapture models to estimate density and demographic parameters for survival and recruitment. We adopt a Bayesian framework for inference under this model using the method of data augmentation which is implemented in the software program WinBUGS. The model was motivated by a camera trapping study of Pampas cats Leopardus colocolo from Argentina, which we present as an illustration of the model in this paper. We provide estimates of density and the first quantitative assessment of vital rates for the Pampas cat in the High Andes. The precision of these estimates is poor due likely to the sparse data set. Unlike conventional inference methods which usually rely on asymptotic arguments, Bayesian inferences are valid in arbitrary sample sizes, and thus the method is ideal for the study of rare or endangered species for which small data sets are typical.

  2. Psychological distress among Bam earthquake survivors in Iran: a population-based study

    Directory of Open Access Journals (Sweden)

    Garmaroudi Gholamreza

    2005-01-01

    Full Text Available Abstract Background An earthquake measuring 6.3 on the Richter scale struck the city of Bam in Iran on the 26th of December 2003 at 5.26 A.M. It was devastating, and left over 40,000 dead and around 30,000 injured. The profound tragedy of thousands killed has caused emotional and psychological trauma for tens of thousands of people who have survived. A study was carried out to assess psychological distress among Bam earthquake survivors and factors associated with severe mental health in those who survived the tragedy. Methods This was a population-based study measuring psychological distress among the survivors of Bam earthquake in Iran. Using a multi-stage stratified sampling method a random sample of individuals aged 15 years and over living in Bam were interviewed. Psychological distress was measured using the 12-item General Health Questionnaire (GHQ-12. Results In all 916 survivors were interviewed. The mean age of the respondents was 32.9 years (SD = 12.4, mostly were males (53%, married (66% and had secondary school education (50%. Forty-one percent reported they lost 3 to 5 members of their family in the earthquake. In addition the findings showed that 58% of the respondents suffered from severe mental health as measured by the GHQ-12 and this was three times higher than reported psychological distress among the general population. There were significant differences between sub-groups of the study sample with regard to their psychological distress. The results of the logistic regression analysis also indicated that female gender; lower education, unemployment, and loss of family members were associated with severe psychological distress among earthquake victims. Conclusion The study findings indicated that the amount of psychological distress among earthquake survivors was high and there is an urgent need to deliver mental health care to disaster victims in local medical settings and to reduce negative health impacts of the earthquake

  3. Psychiatric morbidity in the community: A population based-study from Kerala

    Science.gov (United States)

    Shaji, K. S.; Raju, D.; Sathesh, V; Krishnakumar, P.; Punnoose, Varghese P.; Kiran, P. S; Mini, B. S.; Kumar, Shibu; Anish, P. K; Kaimal, Ganga G.; Gupthan, Lekshmy; Sumesh, T. P.; Nikhil, U. G; Cyriac, Nisha; Vinod, M. D.; Kumar, R. Prasad; Chandran, Ramesh; Rejani, P. P; Amrutha, R; Mahesh; Anand, TN

    2017-01-01

    Background: Estimates of psychiatric morbidity in the community will help service development. Participation of trained nonspecialist health-care providers will facilitate scaling up of services in resource-limited settings. Aims: This study aimed to estimate the prevalence of priority mental health problems in populations served by the District Mental Health Program (DMHP). Settings and Design: This is a population-based cross-sectional survey. Materials and Methods: We did stratified cluster sampling of households in five districts of Kerala. Trained Accredited Social Health Activists (ASHAs) identified people who had symptoms suggestive of schizophrenia or bipolar disorder. Clinicians evaluated the information collected by the ASHAs and designated individuals as probable cases of psychosis or noncases. Screening instruments such as General Health Questionnaire-12, CAGE questionnaire, and Everyday Abilities Scale for India were used for identifying common mental disorders (CMDs), clinically significant alcohol-related problems, and functional impairment. Results: We found 12.43% of the adult population affected by mental health conditions. We found CMD as most common with a prevalence of 9%. The prevalence of psychosis was 0.71%, clinically significant alcohol-related problems was 1.46%, and dementia and other cognitive impairments was 1.26%. We found informant-based case finding to be useful in the identification of psychosis. Conclusions: Mental health problems are common. Nonspecialist health-care providers can be trained to identify psychiatric morbidity in the community. Their participation will help in narrowing the treatment gap. Embedding operational research to DMHP will make scaling up more efficient. PMID:28827860

  4. Use of models in small mammal population studies

    International Nuclear Information System (INIS)

    Conley, W.; Nichols, J.D.

    1978-01-01

    The role of models as contributors to the understanding of natural populations of small mammals is reviewed. A philosophy of model use and projections for future work are also included. Categories of biological phenomena reviewed include models on population dynamics (demographic variables and population regulation, dispersal, sex-ratios, predation, population cycles), population responses to environmental conditions, genetics of small mammal populations, competitive interactions, ecosystems and small mammal functions, and control and management of small mammal populations

  5. Selection signatures in worldwide sheep populations.

    OpenAIRE

    Fariello, Maria-Ines; Servin, Bertrand; Tosser-Klopp, Gwenola; Rupp, Rachel; Moreno, Carole; San Cristobal, Magali; Boitard, Simon; Drögemüller, Cord; The International Sheep Genomics Consortium, ISGC

    2014-01-01

    The diversity of populations in domestic species offers great opportunities to study genome response to selection. The recently published Sheep HapMap dataset is a great example of characterization of the world wide genetic diversity in sheep. In this study, we re-analyzed the Sheep HapMap dataset to identify selection signatures in worldwide sheep populations. Compared to previous analyses, we made use of statistical methods that (i) take account of the hierarchical structure of sheep popula...

  6. Selection Signatures in Worldwide Sheep Populations

    OpenAIRE

    Fariello, Maria-Ines; Servin, Bertrand; Tosser-Klopp, Gwenola; Rupp, Rachel; Moreno, Carole; Cristobal, Magali San; Boitard, Simon

    2014-01-01

    The diversity of populations in domestic species offers great opportunities to study genome response to selection. The recently published Sheep HapMap dataset is a great example of characterization of the world wide genetic diversity in sheep. In this study, we re-analyzed the Sheep HapMap dataset to identify selection signatures in worldwide sheep populations. Compared to previous analyses, we made use of statistical methods that (i) take account of the hierarchical structure of sheep popula...

  7. Chemical control of different Digitaria insularis populations and management of a glyphosate-resistant population

    OpenAIRE

    CORREIA,N.M.; ACRA,L.T.; BALIEIRO,G.

    2015-01-01

    This study aimed to control different populations of Digitaria insularisby glyphosate herbicide, isolated and mixed, besides the combination of methods (chemical and mechanical) to manage resistant adult plants. Three experiments were conducted, one in pots which were maintained under non-controlled conditions and two under field conditions. In the experiment in pots, twelve populations of D. insularis were sprayed with isolated glyphosate (1.44 and 2.16 kg a.e. ha-1) and mixed (1.44 and 2.16...

  8. A dynamic activity-based population modelling approach to evaluate exposure to air pollution: Methods and application to a Dutch urban area

    International Nuclear Information System (INIS)

    Beckx, Carolien; Int Panis, Luc; Arentze, Theo; Janssens, Davy; Torfs, Rudi; Broekx, Steven; Wets, Geert

    2009-01-01

    Recent air quality studies have highlighted that important differences in pollutant concentrations can occur over the day and between different locations. Traditional exposure analyses, however, assume that people are only exposed to pollution at their place of residence. Activity-based models, which recently have emerged from the field of transportation research, offer a technique to micro-simulate activity patterns of a population with a high resolution in space and time. Due to their characteristics, this model can be applied to establish a dynamic exposure assessment to air pollution. This paper presents a new exposure methodology, using a micro-simulator of activity-travel behaviour, to develop a dynamic exposure assessment. The methodology is applied to a Dutch urban area to demonstrate the advantages of the approach for exposure analysis. The results for the exposure to PM 10 and PM 2.5 , air pollutants considered as hazardous for human health, reveal large differences between the static and the dynamic approach, mainly due to an underestimation of the number of hours spent in the urban region by the static method. We can conclude that this dynamic population modelling approach is an important improvement over traditional methods and offers a new and more sensitive way for estimating population exposure to air pollution. In the light of the new European directive, aimed at reducing the exposure of the population to PM 2.5 , this new approach contributes to a much more accurate exposure assessment that helps evaluate policies to reduce public exposure to air pollution

  9. Small mammal populations in zoonotic disease and toxicological studies

    International Nuclear Information System (INIS)

    Muul, I.

    1978-01-01

    Examples of zoonotic diseases are discussed in relation to their distribution in mammalian hosts. Various ecological factors influence disease distribution patterns so that only a certain portion of the mammalian populations are subject to infections. Emphasis was placed on some of these ecological factors in studying the mainstream of infections in endemic hosts and vectors. This approach might be called medical ecology and would be supplemental to epidemiological studies which characteristically emphasize human involvement in zoonotic disease transmission. For example, occurrence in certain habitats and vertical distribution within forest habitats predisposed various mammalian species to infections. Arboreal species did not have scrub typhus infections while terrestrial species had high infection rates. Malaria parasites were common in arboreal mammals but uncommon in terrestrial species. Additionally, disease surveys in the absence of population data pertaining to potential host species sometimes yield misleading results, especially if age structure within populations changes through time. In field studies use of sentinel animals of known immunological history provide valuable supplemental information to surveys of free living animals which may have been infected at some unknown time in the past. As many different species should be studied as is practical since some species may not be susceptible to certain diseases under study. In laboratory studies, inclusion of non-standard mammals may provide opportunities to culture disease organisms which do not proliferate in standard laboratory species, or to replace diminishing resources of such species as primates

  10. The study to estimate the floating population in Seoul, Korea.

    Science.gov (United States)

    Lee, Geon Woo; Lee, Yong Jin; Kim, Youngeun; Hong, Seung-Han; Kim, Soohwaun; Kim, Jeong Soo; Lee, Jong Tae; Shin, Dong Chun; Lim, Youngwook

    2017-01-01

    Traffic-related pollutants have been reported to increase the morbidity of respiratory diseases. In order to apply management policies related to motor vehicles, studies of the floating population living in cities are important. The rate of metro rail transit system use by passengers residing in Seoul is about 54% of total public transportation use. Through the rate of metro use, the people-flow ratios in each administrative area were calculated. By applying a people-flow ratio based on the official census count, the floating population in 25 regions was calculated. The reduced level of deaths among the floating population in 14 regions having the roadside monitoring station was calculated as assuming a 20% reduction of mobile emission based on the policy. The hourly floating population size was calculated by applying the hourly population ratio to the regional population size as specified in the official census count. The number of people moving from 5 a.m. to next day 1 a.m. could not be precisely calculated when the population size was applied, but no issue was observed that would trigger a sizable shift in the rate of population change. The three patterns of increase, decrease, and no change of population in work hours were analyzed. When the concentration of particulate matter less than 10 μm in aerodynamic diameter was reduced by 20%, the number of excess deaths varied according to the difference of the floating population. The effective establishment of directions to manage the pollutants in cities should be carried out by considering the floating population. Although the number of people using the metro system is only an estimate, this disadvantage was supplemented by calculating inflow and outflow ratio of metro users per time in the total floating population in each region. Especially, 54% of metro usage in public transport causes high reliability in application.

  11. The study to estimate the floating population in Seoul, Korea

    Directory of Open Access Journals (Sweden)

    Geon Woo Lee

    2017-05-01

    Full Text Available Traffic-related pollutants have been reported to increase the morbidity of respiratory diseases. In order to apply management policies related to motor vehicles, studies of the floating population living in cities are important. The rate of metro rail transit system use by passengers residing in Seoul is about 54% of total public transportation use. Through the rate of metro use, the people-flow ratios in each administrative area were calculated. By applying a people-flow ratio based on the official census count, the floating population in 25 regions was calculated. The reduced level of deaths among the floating population in 14 regions having the roadside monitoring station was calculated as assuming a 20% reduction of mobile emission based on the policy. The hourly floating population size was calculated by applying the hourly population ratio to the regional population size as specified in the official census count. The number of people moving from 5 a.m. to next day 1 a.m. could not be precisely calculated when the population size was applied, but no issue was observed that would trigger a sizable shift in the rate of population change. The three patterns of increase, decrease, and no change of population in work hours were analyzed. When the concentration of particulate matter less than 10 μm in aerodynamic diameter was reduced by 20%, the number of excess deaths varied according to the difference of the floating population. The effective establishment of directions to manage the pollutants in cities should be carried out by considering the floating population. Although the number of people using the metro system is only an estimate, this disadvantage was supplemented by calculating inflow and outflow ratio of metro users per time in the total floating population in each region. Especially, 54% of metro usage in public transport causes high reliability in application.

  12. [Nutrition and population: study of three countries].

    Science.gov (United States)

    1988-12-01

    The cases of Mexico, Kenya, and India are described to illustrate the difficulty of assuring national food supplies in the face of rapid population growth. In 1985, despite a world cereal surplus, some 700 million of the earth's poorest inhabitants lacked sufficient food to support a normal life, and some 17 million children died of malnutrition or diseases aggravated by malnutrition. 16% of today's Third World population lacks sufficient food to maintain health. Rapid population growth is a cause of hunger in both countries and households. In already densely populated countries such as Bangladesh, population growth reduces the availability of agricultural land for each rural family, causing rural incomes to decrease and worsening rural unemployment. Few developing countries have been able to avoid serious urban unemployment and underemployment. Unstable governments try to calm urban unrest by concentrating all social and economic investment in the cities, causing suffering and diminished production in the countryside. Today more than 60 countries have food deficits. The majority of them are poor and becoming poorer. India, Kenya, and Mexico have had relative success in balancing food production and population growth, but each still has malnutrition due to inadequate economic policies for most of the poor and to implacable population growth. India's population of 785 million is growing at a rate of 2.3%/year. 1984 per capita calorie consumption was 92% of the required minimum. The poorest 20% of the population shared 7% of total household income. Since 1950 food production in India has almost tripled, but population nearly doubled in the same years. Poor food distribution and unequal agricultural progress have meant that malnutrition continues to plague India. Approximately 45% of the population suffered some degree of malnutrition in 1986. It is unlikely that India's future agricultural progress will be as rapid as that of the past 3 decades. Erosion

  13. Users’ dissatisfaction with dental care: a population-based household study

    Directory of Open Access Journals (Sweden)

    Andréa Maria Eleutério de Barros Lima Martins

    2015-01-01

    Full Text Available OBJECTIVE To examine whether demographic, socioeconomic conditions, oral health subjectivity and characterization of dental care are associated with users’ dissatisfaction with such are.METHODS Cross-sectional study of 781 people who required dental care in Montes Claros, MG, Southeastern Brazil, in 2012, a city with of medium-sized population situated in the North of Minas Gerais. Household interviews were conducted to assess the users’ dissatisfaction with dental care (dependent variable, demographic, socioeconomic conditions, oral health subjectivity and characterization of dental care (independent variables. Sample calculation was used for the finite population, with estimates made for proportions of dissatisfaction in 50.0% of the population, a 5.0% error margin, a non-response rate of 5.0% and a 2.0% design effect. Logistic regression was used, and the odds ratio was calculated with a 5% significance level and 95% confidence intervals.RESULTS Of the interviewed individuals, 9.0% (7.9%, with correction for design effect were dissatisfied with the care provided. These were associated with lower educational level; negative self-assessment of oral health; perception that the care provider was unable to give dental care; negative evaluation of the way the patient was treated, the cleanliness of the rooms, based on the examination rooms and the toilets, and the size of the waiting and examination rooms.CONCLUSIONS The rate of dissatisfaction with dental care was low. This dissatisfaction was associated with socioeconomic conditions, subjectivity of oral health, skill of the health professionals relating to the professional-patient relationship and facility infrastructure. Educational interventions are suggested that aim at improving the quality of care among professionals by responsible agencies as is improving the infrastructure of the care units.

  14. Method of capture and population structure of Aegla georginae Santos and Jara, 2013 (Decapoda: Anomura: Aeglidae in a tributary of the Ibicuí River in southern Brazil

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    C. E. Copatti

    Full Text Available Abstract In the current study, we investigated population aspects of Aegla georginae in the Ibicuí River Basin by considering different capture methods and the implication of these data in the analysis of population dynamics. We sampled 1774 individuals: 1259 males (21 and 97 juveniles and 1029 and 113 adults in trap and handnet, respectively, 512 females (05 and 140 juveniles, 184 and 64 adults, and 81 and 38 ovigerous in trap and handnet, respectively and 03 unsexed individuals (02 and 01 in trap and handnet, respectively. The frequency distribution in size classes shows a bimodal model for both sexes. The carapace length (CL in males and females varied from 3.11 to 26.00 and 3.73 to 22.36 mm, respectively. Males presented significantly larger sizes than females. The relative abundance between males and females was significantly different from 1:1 with more males than females in most sampling periods (p 0.05. Juveniles were recorded in all seasons, and reproduction occurs throughout the year. The population structure is similar to the model known for aeglids, and the capture methods affected the analysis of A. georginae, where the grouped data and trap captures presented greater abundance of individuals than handnet and males predominate in the larger size classes, and females in the intermediary size classes. Therefore, an integrated view of the capture methods is the best model for studying the population dynamics of aeglids.

  15. Survey of studies of occupational populations exposed to low-level radiation

    International Nuclear Information System (INIS)

    Marks, S.

    1980-04-01

    Studies of occupational populations exposed to large doses of radiation, principally from the ingestion of radium by dial painters and inhalation of radon and its daughters by miners, have provided important information on the health effects of those radioisotopes. Studies of medical radiologists, military personnel exposed to nuclear tests, and factory workers exposed to thorium are in progress. Employees of DOE-contractor facilities and of naval shipyards are also under study. Personnel dosimetry data are generally available for the latter category of occupational populations. Reasons for conducting the studies include interest in exploring the verification at low exposure levels of results of studies of heavily exposed populations and the responsibility of the employer to maintain adequate surveillance of the health of his workers by conducting appropriate epidemiologic studies. The low level of exposure of workers in facilities where adequate personnel dosimetry records are available make it unlikely that the results of such studies can be used to provide health risk estimates in the near future

  16. Heterogeneity in risk of prostate cancer: A Swedish population-based cohort study of competing risks and type 2 diabetes mellitus.

    Science.gov (United States)

    Häggström, Christel; Van Hemelrijck, Mieke; Garmo, Hans; Robinson, David; Stattin, Pär; Rowley, Mark; Coolen, Anthony C C; Holmberg, Lars

    2018-05-09

    Most previous studies of prostate cancer have not taken into account that men in the studied populations are also at risk of competing event, and that these men may have different susceptibility to prostate cancer risk. The aim of this study was to investigate heterogeneity in risk of prostate cancer, using a recently developed latent class regression method for competing risks. We further aimed to elucidate the association between type 2 diabetes mellitus (T2DM) and prostate cancer risk, and to compare the results with conventional methods for survival analysis. We analysed the risk of prostate cancer in 126,482 men from the comparison cohort of the Prostate Cancer Data base Sweden (PCBaSe) 3.0. During a mean follow-up of 6 years 6,036 men were diagnosed with prostate cancer and 22,393 men died. We detected heterogeneity in risk of prostate cancer with two distinct latent classes in the study population. The smaller class included 9% of the study population in which men had a higher risk of prostate cancer and the risk was stronger associated with class membership than any of the covariates included in the study. Moreover, we found no association between T2DM and risk of prostate cancer after removal of the effect of informative censoring due to competing risks. The recently developed latent class for competing risks method could be used to provide new insights in precision medicine with the target to classify individuals regarding different susceptibility to a particular disease, reaction to a risk factor or response to treatment. This article is protected by copyright. All rights reserved. © 2018 UICC.

  17. [Static Retinal Vessel Analysis in Population-based Study SHIP-Trend].

    Science.gov (United States)

    Theophil, Constanze; Jürgens, Clemens; Großjohann, Rico; Kempin, Robert; Ittermann, Till; Nauck, Matthias; Völzke, Henry; Tost, Frank H W

    2017-08-24

    Background Interdisciplinary investigations of possible connections between general diseases and ophthalmological changes are difficult to perform in the clinical environment. But they are gaining in importance as a result of the age-related increase in chronic diseases. The collection of health-related parameters in the Study of Health in Pomerania (SHIP) project allows to derive conclusions for the general population. Methods The population-based SHIP trend study was conducted between 2008 and 2012 in Greifswald. The baseline cohort included 4420 subjects (response 50.1%) at the age of 20 to 84 years. The pre-existence of arterial hypertension, diabetes mellitus and smoking status were questioned in a standardized questionnaire, the blood pressure and the HbA 1c were determined by the laboratory. The vascular diameter of retinal arterioles and venules were determined by means of non-mydriatic fundus images and the retinal arterial (CRAE) and venous equivalent (CRVE) were calculated therefrom. The association of diabetes mellitus, HbA 1c , smoking status and blood pressure with the retinal vascular parameters was tested for age and sex with linear regression models. Results In 3218 subjects with evaluable standardized fundus photographs, significant associations of elevated HbA 1c (> 6.5%), smoking status and systolic and diastolic blood pressure were found with the retinal vessel widths CRAE and CRVE. Anamnestic diabetes mellitus, on the other hand, was not associated with any of the vascular parameters. Conclusion This research study reveals a relevant correlation between general diseases and the retinal blood flow in the eye. Therefore, general diseases can induce ophthalmological changes and eye examination can provide information for the assessment of general diseases. Georg Thieme Verlag KG Stuttgart · New York.

  18. The incidence of inflammatory bowel disease in Northern China: a prospective population-based study.

    Directory of Open Access Journals (Sweden)

    Hong Yang

    Full Text Available AIMS & BACKGROUNDS: Although inflammatory bowel diseases (IBD are emerging and increasing in China, epidemiologic data are rarely available. This study was to investigate the epidemiological and clinical characteristics of IBD in Northern China. METHODS: This is a prospective, population-based study of incidence of IBD in Daqing, Heilongjiang province of Northern China from March 1, 2012 to February 28, 2013. All incident patients with IBD were clinically identified by IBD specialist group from five main General Hospitals covering the healthcare service for 1,343,364 residents in the urban areas of Daqing. IBD cases included in this study were followed-up for three months for diagnosis confirmation. RESULTS: A total of 27 new IBD cases including 25 cases of ulcerative colitis (UC and 2 cases of Crohn's disease (CD were identified. The population at risk was 1,343,364 person years. Age-adjusted incidence for total IBD, CD and UC were 1.77, 0.13, and 1.64 per 100,000 population, respectively. A male predominance was found in CD patients (male to female ratio was 2 ∶ 0. In contrast, no obvious gender predominance was found in UC patients (male to female ratio was 1 ∶ 1.1. CD patients were diagnosed at an average age of 39.5 years. The main disease phenotypes of UC were distal colitis with a 24% of proctitis and 56% of left-sided colitis. The mean diagnostic age of UC patients was 48.9 years. CONCLUSIONS: This is the first report on the incidence of IBD in the Northern Chinese population. A lower incidence of IBD, similar male predominance for CD, similar disease phenotype of UC, and lower disease activity was observed in Daqing compared to that in Southern China.

  19. Association between Kawasaki Disease and Autism: A Population-Based Study in Taiwan

    Directory of Open Access Journals (Sweden)

    Ho-Chang Kuo

    2014-04-01

    Full Text Available Objective: The association between Kawasaki disease and autism has rarely been studied in Asian populations. By using a nationwide Taiwanese population-based claims database, we tested the hypothesis that Kawasaki disease may increase the risk of autism in Taiwan. Materials and Methods: Our study cohort consisted of patients who had received the diagnosis of Kawasaki disease (ICD-9-CM: 446.1 between 1997 and 2005 (N = 563. For a comparison cohort, five age- and gender-matched control patients for every patient in the study cohort were selected using random sampling (N = 2,815. All subjects were tracked for 5 years from the date of cohort entry to identify whether they had developed autism (ICD-9-CM code 299.0 or not. Cox proportional hazard regressions were then performed to evaluate 5-year autism-free survival rates. Results: The main finding of this study was that patients with Kawasaki disease seem to not be at increased risk of developing autism. Of the total patients, four patients developed autism during the 5-year follow-up period, among whom two were Kawasaki disease patients and two were in the comparison cohort. Further, the adjusted hazard ratios (AHR (AHR: 4.81; 95% confidence interval: 0.68–34.35; P = 0.117 did not show any statistical significance between the Kawasaki disease group and the control group during the 5-year follow-up. Conclusion: Our study indicated that patients with Kawasaki disease are not at increased risk of autism.

  20. Radiation dozes reconstruction of Semipalatinsk region Beskaragai area's population by the method of biological measure

    International Nuclear Information System (INIS)

    Bigaliev, A.; Kundakbaeva, G.; Bigalieva, R.

    2001-01-01

    Full text: The study of radiation situation (on the position of May 1989) in Beskaragai area of Semipalatinsk region showed that the level of γ-radiation on it's territory reached 13-20 μR/hour, which was determined by the traces of long living radionuclides. In the inhabited regions of Dolon, Kanonerka, Buras, Ramadan villages the effect of deepening was noticed, α-particle's density level has reached maximum on the depth of approximately 10 cm, and further it decreases up to the 30 cm depth, This circumstance witnesses about the fact that we are talking about radioactive traces of many years ago happening with a time going to the depth from the upper coverage of soil. We've made the evaluation of radiation influence's genetic effects on the man's population. Cytogenetic analysis (with the use of G-method of chromosome's coloring) at whole in Beskaragai region shows that the frequency of aberrations for the cell among the inhabitants of the region is obviously higher 3.3 times at average in the region than among the population of the controlled area. During the study of the cytogenetic effects of increased radiation level's influence it is important first of all to determine the frequency of chromosome type aberrations - dicentric chromosomes, centric circles, acentric pair fragments. As it is known, the level of chromosome type aberrations is sufficiently well correlated with the doze, We have determined accumulative doze of radiation using the formula (D.C. Lloyd at all. 1992) for the calculation of dicentrics under the chronical influence of the small dozes of ionized radiation. According to the made calculations the oriented reconstruction of radiation dozes in Beskaragai region made 11 ber = 0.11 Sv, for the Dolon village - 14 ber, Kanonerka village - 13 ber, Buras village - 6 ber, Ramadan - 9.5 ber. Presented data allows to ask the question about the more spread use of cytogenetic method of research among the different population's categories living at

  1. Replication of genome wide association studies on hepatocellular carcinoma susceptibility loci in a Chinese population.

    Science.gov (United States)

    Chen, Kangmei; Shi, Weimei; Xin, Zhenhui; Wang, Huifen; Zhu, Xilin; Wu, Xiaopan; Li, Zhuo; Li, Hui; Liu, Ying

    2013-01-01

    Genome-wide association studies (GWAS) have identified three loci (rs17401966 in KIF1B, rs7574865 in STAT4, rs9275319 in HLA-DQ) as being associated with hepatitis B virus-related hepatocellular carcinoma (HBV-related HCC) in a Chinese population, two loci (rs2596542 in MICA, rs9275572 located between HLA-DQA and HLA-DQB) with hepatitis C virus-related HCC (HCV-related HCC) in a Japanese population. In the present study, we sought to determine whether these SNPs are predictive for HBV-related HCC development in other Chinese population as well. We genotyped 4 SNPs, rs2596542, rs9275572, rs17401966, rs7574865, in 506 HBV-related HCC patients and 772 chronic hepatitis B (CHB) patients in Han Chinese by TaqMan methods. Odds ratio(OR)and 95% confidence interval (CI) were calculated by logistic regression. In our case-control study, significant association between rs9275572 and HCC were observed (P = 0.02, OR = 0.73, 95% CI = 0.56-0.95). In the further haplotype analysis between rs2596542 at 6p21.33 and rs9275572 at 6p21.3, G-A showed a protective effect on HBV-related HCC occurrence (P<0.001, OR = 0.66, 95% CI = 0.52-0.84). These findings provided convincing evidence that rs9275572 significantly associated with HBV-related HCC.

  2. Usual Intake Distribution of Vitamins and Prevalence of Inadequacy in a Large Sample of Iranian At-Risk Population: Application of NCI Method.

    Science.gov (United States)

    Heidari, Zahra; Feizi, Awat; Azadbakht, Leila; Sarrafzadegan, Nizal

    2016-01-01

    This study provides an assessment of usual intake distribution of vitamins and estimating prevalence of inadequacy and excess among a large representative sample of middle-aged and elderly people in central regions of Iran. A cross-sectional study that is a second follow-up to the Isfahan Cohort Study (ICS). The study setting included urban and rural areas from 3 cities (Isfahan, Najafabad, and Arak) in central regions of Iran. Subjects included 1922 people aged 40 years and older, with a mean age of 55.9 ± 10.6; 50.4% were male and the majority (79.3%) were urban. Dietary intakes were collected using a 24-hour recall and 2 food records. Distribution of vitamins intake was estimated using traditional and national cancer institute (NCI) methods. The proportion of subjects at risk of vitamin intake inadequacy or excess was estimated using the estimated average requirement (EAR) cut-point method and the tolerable upper intake levels (UL) index. There were differences between values obtained from traditional and NCI methods, particularly in the lower and upper percentiles of the intake distribution. High prevalence of inadequacies for vitamins A, D, E, B2, B3 (especially among females), and B9 was observed. Significant gender differences were found in terms of inadequate intakes for vitamins A, B1, B2, B3, B6, B9, B12, and C (p vitamin intake was observed in the middle-aged and elderly Iranian population. Nutritional interventions particularly through population-based educational programs in order to improve diet variety and consume nutrient supplements may be necessary.

  3. A dynamic urban air pollution population exposure assessment study using model and population density data derived by mobile phone traffic

    Science.gov (United States)

    Gariazzo, Claudio; Pelliccioni, Armando; Bolignano, Andrea

    2016-04-01

    A dynamic city-wide air pollution exposure assessment study has been carried out for the urban population of Rome, Italy, by using time resolved population distribution maps, derived by mobile phone traffic data, and modelled air pollutants (NO2, O3 and PM2.5) concentrations obtained by an integrated air dispersion modelling system. More than a million of persons were tracked during two months (March and April 2015) for their position within the city and its surroundings areas, with a time resolution of 15 min and mapped over an irregular grid system with a minimum resolution of 0.26 × 0.34 Km2. In addition, demographics information (as gender and age ranges) were available in a separated dataset not connected with the total population one. Such BigData were matched in time and space with air pollution model results and then used to produce hourly and daily resolved cumulative population exposures during the studied period. A significant mobility of population was identified with higher population densities in downtown areas during daytime increasing of up to 1000 people/Km2 with respect to nigh-time one, likely produced by commuters, tourists and working age population. Strong variability (up to ±50% for NO2) of population exposures were detected as an effect of both mobility and time/spatial changing in pollutants concentrations. A comparison with the correspondent stationary approach based on National Census data, allows detecting the inability of latter in estimating the actual variability of population exposure. Significant underestimations of the amount of population exposed to daily PM2.5 WHO guideline was identified for the Census approach. Very small differences (up to a few μg/m3) on exposure were detected for gender and age ranges population classes.

  4. Communicating the risks of bioterrorism and other emergencies in a diverse society: a case study of special populations in North Dakota.

    Science.gov (United States)

    McGough, Marty; Frank, Loreeta Leer; Tipton, Stacia; Tinker, Tim L; Vaughan, Elaine

    2005-01-01

    In the event that terrorists use air, water, or food to deliver destructive agents to civilian populations, some groups and populations may be disproportionately at risk and have unique communications needs. Bioterrorism represents an even greater national public health threat if the nation's preparedness and readiness plans do not address the needs and perspectives of, for example, low-income residents, racially and ethnically diverse communities, and other "special populations". The objective of this study was to develop communications strategies to reach special populations in North Dakota before, during, and after a bioterrorism attack or other crisis. To achieve the study objectives, the investigators used telephone interviews and telephone focus groups with organizations that represented special populations. Areas of inquiry included attitudes and concerns about crises, sources of information used and those identified as most credible, methods to reach people during a crisis event, and awareness of and attitudes about the agencies and organizations that affect risk communications.

  5. Population-based study on the seroprevalence of parvovirus B19 in Amsterdam

    NARCIS (Netherlands)

    van Rijckevorsel, G. G. C.; Sonder, G. J. B.; Schim van der Loeff, M. F.; van den Hoek, J. A. R.

    2009-01-01

    A study was undertaken to estimate the seroprevalence of parvovirus B19 infection in the general adult population of Amsterdam, The Netherlands. To our knowledge this is the first study testing parvovirus B19 in a random sample of the Dutch adult population. The study was a cross-sectional survey,

  6. A POPULATION-BASED STUDY ON CHRONIC KIDNEY DISEASE IN KANYAKUMARI GOVERNMENT MEDICAL COLLEGE

    Directory of Open Access Journals (Sweden)

    Ponnaian John Christopher

    2016-12-01

    Full Text Available BACKGROUND Chronic kidney disease encompasses a spectrum of different pathophysiologic processes associated with abnormal kidney function and a progressive decline in glomerular filtration rate. Our study deals with the risk factors, stages and the management among the general population of Kanyakumari district who came to Kanyakumari Government Medical College during the period of 2014-2015. MATERIALS AND METHODS The newly-diagnosed CKD patients who were admitted as inpatients in the Department of General Medicine in the period of 2014-2015 were studied retrospectively. Those who came as outpatients as well as previously diagnosed ESRD patients who had repeated admissions for maintenance haemodialysis were excluded from our study. We documented the age, sex, previous history of diabetes, hypertension, the mean duration of diabetes or hypertension, eGFR of the patient, stage of CKD and the treatment given. RESULTS The number of CKD patients admitted in our hospital during 2014-2015 were 314 of which newly detected CKD cases were 212. The most frequent cause of CKD in this population is diabetic nephropathy secondary to type 2 diabetes mellitus (90%. CKD is most common among males in this population. The mean age of association of diabetes in this population is 9-12 years. Patients with newly-diagnosed CKD often present with hypertension. eGFR was calculated for all CKD patients by CockgraftGault Equation. 18 out of 212 newly-diagnosed CKD patients (8.5% presented with ESRD (eGFR <15 mL/min./1.73 m2 and haemodialysis was initiated. Most evident complications among this patients were anaemia, easy fatigability, decreased appetite, progressive malnutrition and electrolyte abnormalities. CONCLUSION Diabetes, glomerulonephritis and hypertension associated CKD are the leading categories of aetiologies of CKD. When no overt evidence for a primary glomerular disease or tubulointerstitial disease process is present, CKD is often attributed to

  7. Hospitalization for Pneumonia among Individuals With and Without HIV Infection, 1995-2007: A Danish Population-Based, Nationwide Cohort Study

    DEFF Research Database (Denmark)

    Sogaard, Ole S; Lohse, Nicolai; Gerstoft, Jan

    2008-01-01

    ). Risk factors were assessed by Poisson regression. Results. @nbsp; The study included 3516 persons with HIV infection and 328,738 persons without HIV infection, which provided 23,677 person-years and 2,944,760 person-years of observation, respectively. Incidence rates of pneumonia in HIV......-infected individuals decreased from 50.6 hospitalizations per 1000 person-years (95% confidence interval [CI], 42.9-59.7 hospitalizations per 1000 person-years) during 1995-1996 to 19.7 hospitalizations per 1000 person-years (95% CI, 16.2-23.8 hospitalizations per 1000 person-years) during 2005-2007. Compared......-infected population. Methods. @nbsp; This was an observational cohort study conducted during 1995-2007. Each member of a Danish population-based nationwide cohort of HIV-infected individuals was matched with up to 99 control individuals from the general population. Data on age, mortality, emigration, and hospital...

  8. Tooth replacement related to number of natural teeth in a dentate adult population in Bulgaria: a cross-sectional study

    NARCIS (Netherlands)

    Damyanov, N.D.; Witter, D.J.; Bronkhorst, E.M.; Creugers, N.H.J.

    2013-01-01

    PURPOSE: This study aimed to explore the relationships among tooth replacement, number of present natural teeth, and sociodemographic and behavioral factors in an adult population in Bulgaria. MATERIALS AND METHODS: Quota sampling was used to recruit 2,531 dentate subjects aged 20 years and over

  9. Predicting Risk of Type 2 Diabetes Mellitus: A Population-Based Study

    Directory of Open Access Journals (Sweden)

    Mahmut Kilic

    2016-04-01

    Full Text Available Aim: One of the major risk factors that can cause death in the world is also type-2 diabetes mellitus (DM. Turkey does not have a vehicle in the society has been formulate predicting the risk of developing DM. The purpose of this study is to determine the level of DM risk in Turkish society using the Finnish Diabetes Risk Score (FINDRISC tool. Material and Method: This is a cross-sectional study. The data has been obtained from %u201Cbehavioral risk factors for chronic diseases study%u201D that was made in the province of Yozgat, in 2011. The study population included 825 subjects between 25 to 79 years old who had measured their blood sugar before, but who were not diagnosed DM. DM risk level was calculated using FINDRISC tool. The scale score is between 0-26, %u226515 points are considered high risk (risk ratio 1/3. In analyzing the data, t-test, ANOVA and chi-square test and binary logistic regression were used. Results: Of the subjects 10 years of DM risk score%u2019s mean was 8.8 ± 4.6. When FINDRISC score low / medium and high divided into 2 groups, the proportion of those in the high risk group is 11.5%. This rate is similar to the 10-year incidence of DM calculated (11-12.4% for Turkey. In this study, all of the factors taken into FINDRISC calculations were statistically significant (p 0.05. Discussion: FINDRISC used to be in the DM risk calculations of Turkish population. One out of every ten adults are at high risk of developing DM in 10 years. To avoid this problem urgently needs to be implemented by the various programs on an individual and societal level.

  10. Quantifying introgression risk with realistic population genetics.

    Science.gov (United States)

    Ghosh, Atiyo; Meirmans, Patrick G; Haccou, Patsy

    2012-12-07

    Introgression is the permanent incorporation of genes from the genome of one population into another. This can have severe consequences, such as extinction of endemic species, or the spread of transgenes. Quantification of the risk of introgression is an important component of genetically modified crop regulation. Most theoretical introgression studies aimed at such quantification disregard one or more of the most important factors concerning introgression: realistic genetical mechanisms, repeated invasions and stochasticity. In addition, the use of linkage as a risk mitigation strategy has not been studied properly yet with genetic introgression models. Current genetic introgression studies fail to take repeated invasions and demographic stochasticity into account properly, and use incorrect measures of introgression risk that can be manipulated by arbitrary choices. In this study, we present proper methods for risk quantification that overcome these difficulties. We generalize a probabilistic risk measure, the so-called hazard rate of introgression, for application to introgression models with complex genetics and small natural population sizes. We illustrate the method by studying the effects of linkage and recombination on transgene introgression risk at different population sizes.

  11. Our World of 7 Billion: Population Studies in Today's Social Studies Classroom

    Science.gov (United States)

    Wasserman, Pamela

    2011-01-01

    The study of world population integrates so many themes and disciplines in the social studies because it encompasses all of human history--the rise of agriculture and civilizations, scientific progress, territorial conflicts, changing gender roles and more. It is also at the heart of human geography and how people came to dominate and alter the…

  12. Congenital anomalies in children with cerebral palsy: a population-based record linkage study

    DEFF Research Database (Denmark)

    Rankin, Judith; Cans, Christine; Garne, Ester

    2009-01-01

    Aim Our aim was to determine the proportion of children with cerebral palsy (CP) who have a congenital anomaly (CA) in three regions (Isère Region, French Alps; Funen County, Denmark; Northern Region, England) where population-based CP and CA registries exist, and to classify the children according...... to CA subtype. Method Data for children born between 1991 and 1999 were linked using electronic matching of cases. All potential matches were checked manually by each centre and verified as true matches. Results A total of 1104 children with CP were born during the study period (663 males, 441 females...

  13. Using spatial capture–recapture to elucidate population processes and space-use in herpetological studies

    Science.gov (United States)

    Muñoz, David J.; Miller, David A.W.; Sutherland, Chris; Grant, Evan H. Campbell

    2016-01-01

    The cryptic behavior and ecology of herpetofauna make estimating the impacts of environmental change on demography difficult; yet, the ability to measure demographic relationships is essential for elucidating mechanisms leading to the population declines reported for herpetofauna worldwide. Recently developed spatial capture–recapture (SCR) methods are well suited to standard herpetofauna monitoring approaches. Individually identifying animals and their locations allows accurate estimates of population densities and survival. Spatial capture–recapture methods also allow estimation of parameters describing space-use and movement, which generally are expensive or difficult to obtain using other methods. In this paper, we discuss the basic components of SCR models, the available software for conducting analyses, and the experimental designs based on common herpetological survey methods. We then apply SCR models to Red-backed Salamander (Plethodon cinereus), to determine differences in density, survival, dispersal, and space-use between adult male and female salamanders. By highlighting the capabilities of SCR, and its advantages compared to traditional methods, we hope to give herpetologists the resource they need to apply SCR in their own systems.

  14. Critical mutation rate has an exponential dependence on population size in haploid and diploid populations.

    Directory of Open Access Journals (Sweden)

    Elizabeth Aston

    Full Text Available Understanding the effect of population size on the key parameters of evolution is particularly important for populations nearing extinction. There are evolutionary pressures to evolve sequences that are both fit and robust. At high mutation rates, individuals with greater mutational robustness can outcompete those with higher fitness. This is survival-of-the-flattest, and has been observed in digital organisms, theoretically, in simulated RNA evolution, and in RNA viruses. We introduce an algorithmic method capable of determining the relationship between population size, the critical mutation rate at which individuals with greater robustness to mutation are favoured over individuals with greater fitness, and the error threshold. Verification for this method is provided against analytical models for the error threshold. We show that the critical mutation rate for increasing haploid population sizes can be approximated by an exponential function, with much lower mutation rates tolerated by small populations. This is in contrast to previous studies which identified that critical mutation rate was independent of population size. The algorithm is extended to diploid populations in a system modelled on the biological process of meiosis. The results confirm that the relationship remains exponential, but show that both the critical mutation rate and error threshold are lower for diploids, rather than higher as might have been expected. Analyzing the transition from critical mutation rate to error threshold provides an improved definition of critical mutation rate. Natural populations with their numbers in decline can be expected to lose genetic material in line with the exponential model, accelerating and potentially irreversibly advancing their decline, and this could potentially affect extinction, recovery and population management strategy. The effect of population size is particularly strong in small populations with 100 individuals or less; the

  15. Developing a dashboard to help measure and achieve the triple aim: a population-based cohort study.

    Science.gov (United States)

    Seow, Hsien-Yeang; Sibley, Lyn M

    2014-08-30

    Health system planners aim to pursue the three goals of Triple Aim: 1) reduce health care costs; 2) improve population health; and 3) improve the care experience. Moreover, they also need measures that can reliably predict future health care needs in order to manage effectively the health system performance. Yet few measures exist to assess Triple Aim and predict future needs at a health system level. The purpose of this study is to explore the novel application of a case-mix adjustment method in order to measure and help improve the Triple Aim of health system performance. We applied a case-mix adjustment method to a population-based analysis to assess its usefulness as a measure of health system performance and Triple Aim. The study design was a retrospective, cohort study of adults from Ontario, Canada using administrative databases: individuals were assigned a predicted illness burden score using a case-mix adjustment system from diagnoses and health utilization data in 2008, and then followed forward to assess the actual health care utilization and costs in the following year (2009). We applied the Johns Hopkins Adjusted Clinical Group (ACG) Case-Mix System to categorize individuals into 60 levels of healthcare need, called ACGs. The outcomes were: 1) Number of individuals per ACG; 2) Total system costs per ACG; and 3) Mean cost per person per ACG, which together formed a health system "dashboard". We identified 11.4 million adults. 16.1% were aged 65 or older, 3.2 million (28%) did not use health care services that year, and 45,000 (0.4%) were in the highest acuity ACG category using 12 times more than an average adult. The sickest 1%, 5% and 15% of the population use about 10%, 30% and 50% of total health system costs respectively. The dashboard measures 2 dimensions of Triple Aim: 1) reduced costs: when total system costs per ACG or when average costs per person is reduced; and 2) improved population health: when more people move into healthier rather than

  16. Isoniazid Toxicity among an Older Veteran Population: A Retrospective Cohort Study

    Directory of Open Access Journals (Sweden)

    Christopher Vinnard

    2013-01-01

    Full Text Available Background: our objective was to determine the incidence of toxicity among veterans initiating isoniazid therapy for latent tuberculosis infection (LTBI and determine whether advancing age was a risk factor for toxicity. Methods: we performed a retrospective cohort study among all adults initiating isoniazid treatment for LTBI at a Veterans Medical Center from 1999 to 2005. We collected data on patient demographics, co-morbidities, site of initiation, and treatment outcome. Results: 219 patients initiated isoniazid therapy for LTBI during the period of observation, and the completion of therapy was confirmed in 100 patients (46%. Among 18/219 patients (8% that discontinued therapy due to a documented suspected toxicity, the median time to onset was 3 months (IQR 1–5 months. In an adjusted Cox regression model, there was no association between discontinuation due to suspected toxicity and advancing age (HR 1.03, 95% CI 0.99, 1.07. In contrast, hepatitis C infection was a significant predictor of cessation due to toxicity in the adjusted analysis (HR 3.03, 95% CI 1.08, 8.52. Conclusions: cessation of isoniazid therapy due to suspected toxicity was infrequently observed among a veteran population and was not associated with advancing age. Alternative LTBI treatment approaches should be further examined in the veteran population.

  17. Radiation belt seed population and its association with the relativistic electron dynamics: A statistical study: Radiation Belt Seed Population

    International Nuclear Information System (INIS)

    Tang, C. L.; Wang, Y. X.; Ni, B.; Zhang, J.-C.

    2017-01-01

    Using the Van Allen Probes data, we study the radiation belt seed population and it associated with the relativistic electron dynamics during 74 geomagnetic storm events. Based on the flux changes of 1 MeV electrons before and after the storm peak, these storm events are divided into two groups of “non-preconditioned” and “preconditioned”. The statistical study shows that the storm intensity is of significant importance for the distribution of the seed population (336 keV electrons) in the outer radiation belt. However, substorm intensity can also be important to the evolution of the seed population for some geomagnetic storm events. For non-preconditioned storm events, the correlation between the peak fluxes and their L-shell locations of the seed population and relativistic electrons (592 keV, 1.0 MeV, 1.8 MeV, and 2.1 MeV) is consistent with the energy-dependent dynamic processes in the outer radiation belt. For preconditioned storm events, the correlation between the features of the seed population and relativistic electrons is not fully consistent with the energy-dependent processes. It is suggested that the good correlation between the radiation belt seed population and ≤1.0 MeV electrons contributes to the prediction of the evolution of ≤1.0 MeV electrons in the Earth’s outer radiation belt during periods of geomagnetic storms.

  18. Study of Y Chromosome Microdeletion in AZF Region in Infertile Males of Isfahan Population

    Directory of Open Access Journals (Sweden)

    M Motovali-Bashi

    2013-02-01

    Full Text Available Abstract Background & aim: One of the main genetic factors of infertility is the deletions in the chromosome Y. Accordingly this study was conducted to determine the frequency of microdeletion of AZF region in infertile men of Isfahan, Iran. Methods: In this case-control study, 100 infertile men referred to the Infertility Center of Isfahan and 100 fertile men as controls were randomly selected. Genomic DNA was extracted from their blood and amplified by sequence tagged sites-polymerase chain reaction (STS-PCR method. The presence of microdeletion in AZF locus was diagnosed. Results: No AZFa, AZFb or AZFc deletions were found in the control group. Microdeletions were observed in one patient in AZFb region, eight patients in AZFc region and two patients in AZFa region. Conclusion: The incidence of Yq microdeletions in Iranian population is similar to the international frequency. Our data agree with other studies regarding microdeletions of AZFc, but for microdeletions of AZFa (2% our results show smaller frequency and differ significantly with many studies. Key words: Infertility, Y chromosome, Microdeletion

  19. Nationwide Genomic Study in Denmark Reveals Remarkable Population Homogeneity.

    Science.gov (United States)

    Athanasiadis, Georgios; Cheng, Jade Y; Vilhjálmsson, Bjarni J; Jørgensen, Frank G; Als, Thomas D; Le Hellard, Stephanie; Espeseth, Thomas; Sullivan, Patrick F; Hultman, Christina M; Kjærgaard, Peter C; Schierup, Mikkel H; Mailund, Thomas

    2016-10-01

    Denmark has played a substantial role in the history of Northern Europe. Through a nationwide scientific outreach initiative, we collected genetic and anthropometrical data from ∼800 high school students and used them to elucidate the genetic makeup of the Danish population, as well as to assess polygenic predictions of phenotypic traits in adolescents. We observed remarkable homogeneity across different geographic regions, although we could still detect weak signals of genetic structure reflecting the history of the country. Denmark presented genomic affinity with primarily neighboring countries with overall resemblance of decreasing weight from Britain, Sweden, Norway, Germany, and France. A Polish admixture signal was detected in Zealand and Funen, and our date estimates coincided with historical evidence of Wend settlements in the south of Denmark. We also observed considerably diverse demographic histories among Scandinavian countries, with Denmark having the smallest current effective population size compared to Norway and Sweden. Finally, we found that polygenic prediction of self-reported adolescent height in the population was remarkably accurate (R 2 = 0.639 ± 0.015). The high homogeneity of the Danish population could render population structure a lesser concern for the upcoming large-scale gene-mapping studies in the country. Copyright © 2016 by the Genetics Society of America.

  20. Population Projection. Applications of Linear Algebra to Population Studies. Modules and Monographs in Undergraduate Mathematics and Its Applications. UMAP Module 345.

    Science.gov (United States)

    Keller, Edward L.

    This unit, which looks at applications of linear algebra to population studies, is designed to help pupils: (1) understand an application of matrix algebra to the study of populations; (2) see how knowledge of eigen values and eigen vectors is useful in studying powers of matrices; and (3) be briefly exposed to some difficult but interesting…

  1. Population blood pressure and low to moderate alcohol intake in an untreated population followed over 20years. Copenhagen City heart study

    DEFF Research Database (Denmark)

    Andersen, Ulla Overgaard; Jensen, Gorm Boje

    2011-01-01

    The aim of this study is to evaluate whether a changing population alcohol intake is capable of setting off a shift in the blood pressure distribution in the untreated part of a population. The focus is on subjects with an alcohol intake well below the limits of alcoholism because these subjects...... and an increasing self-reported alcohol intake. The population increase was based on an increasing proportion of light to moderate drinkers. There was no effect of a moderately increasing alcohol intake as a covariate in a multivariate analysis of population systolic BP. Conclusion: A moderately increasing...... population alcohol intake cannot explain the observed changes in population systolic blood pressure....

  2. Occupational risk and chronic kidney disease: a population-based study in the United States adult population.

    Science.gov (United States)

    Rubinstein, Sofia; Wang, Chengwei; Qu, Wenchun

    2013-01-01

    Previous studies on occupational risk for chronic kidney disease (CKD) have analyzed a limited range of occupations and focused on nephrotoxins. The primary purpose of this study was to examine the relative risk for the occurrence of CKD between different occupations in the US adult population. This was a population-based survey study of 91,340 participants in the US, who completed the National Health Interview Survey, 2004 through 2008. The outcome variable, CKD, was defined as having weakening/failing kidneys in the past 12 months, as diagnosed by a physician. The predictor variable, occupation, was obtained using the census occupational codes, regrouped according to North American Industrial Classification System. After controlling for age, gender, hypertension, and education, and with the category Life, Physical, and Social Science Occupations as a reference group, the likelihood of developing CKD was 4.3 times higher in respondents working in Building, Grounds Cleaning and Maintenance Occupations, 4.4 times higher in Healthcare Practitioners and Technical Occupations, 4.7 times higher in Transportation and Material Moving Occupations and in Computer and Mathematical Occupations, 4.8 times higher in Production Occupations, 5.3 times higher in Food Preparation and Serving Related Occupations, and 6.1 times higher in Healthcare Support Occupations and in Legal Occupations. This study identified occupation groups in US adult population with increased risk for CKD. Alleviation of workplace stress is suggested as a goal for behavioral intervention in high-risk occupations.

  3. Sanitary study of the population living in the Chernobyl region

    International Nuclear Information System (INIS)

    Mettler, F.A. Jr.; Briggs, J.E.

    1991-01-01

    The populations of Ukraine, Belarus and Russian Federation affected by Chernobyl accident are anxious about the radiation effects on their healthy. The International Chernobyl Project has, in a great part, looked for the pathology increase and to assess its incidence on their healthy. This study does not prove that the Chernobyl accident would have important effects on population healthy of contaminated areas

  4. Evaluation of microsatellite markers for populations studies and forensic identification of African lions (Panthera leo).

    Science.gov (United States)

    Miller, Susan M; Harper, Cindy K; Bloomer, Paulette; Hofmeyr, Jennifer; Funston, Paul J

    2014-01-01

    The South African lion (Panthera leo) population is highly fragmented. One-third of its wild lions occur in small (lions were reintroduced from other areas of the species' historical range. Management practices on these reserves have not prioritized genetic provenance or heterozygosity. These trends potentially constrain the conservation value of these lions. To ensure the best management and long-term survival of these subpopulations as a viable collective population, the provenance and current genetic diversity must be described. Concurrently, poaching of lions to supply a growing market for lion bones in Asia may become a serious conservation challenge in the future. Having a standardized, validated method for matching confiscated lion parts with carcasses will be a key tool in investigating these crimes. We evaluated 28 microsatellites in the African lion using samples from 18 small reserves and 1 captive facility in South Africa, two conservancies in Zimbabwe, and Kruger National and Kgalagadi Transfrontier Parks to determine the loci most suited for population management and forensic genetic applications. Twelve microsatellite loci with a match probability of 1.1×10(-5) between siblings were identified for forensics. A further 10 could be added for population genetics studies. © The American Genetic Association 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Prevalence and risk factors for refractive errors in the South Indian adult population: The Andhra Pradesh Eye disease study

    Directory of Open Access Journals (Sweden)

    Sannapaneni Krishnaiah

    2008-12-01

    Full Text Available Sannapaneni Krishnaiah1,2,3, Marmamula Srinivas1,2,3, Rohit C Khanna1,2, Gullapalli N Rao1,2,31L V Prasad Eye Institute, Banjara Hills, Hyderabad, India; 2International Center for Advancement of Rural Eye Care, L V Prasad Eye Institute, Banjara Hills, Hyderabad, India; 3Vision CRC, University of New South Wales, Sydney, NSW, AustraliaAim: To report the prevalence, risk factors and associated population attributable risk percentage (PAR for refractive errors in the South Indian adult population.Methods: A population-based cross-sectional epidemiologic study was conducted in the Indian state of Andhra Pradesh. A multistage cluster, systematic, stratified random sampling method was used to obtain participants (n = 10293 for this study.Results: The age-gender-area-adjusted prevalence rates in those ≥40 years of age were determined for myopia (spherical equivalent [SE] < −0.5 D 34.6% (95% confidence interval [CI]: 33.1–36.1, high-myopia (SE < −5.0 D 4.5% (95% CI: 3.8–5.2, hyperopia (SE > +0.5 D 18.4% (95% CI: 17.1–19.7, astigmatism (cylinder < −0.5 D 37.6% (95% CI: 36–39.2, and anisometropia (SE difference between right and left eyes >0.5 D 13.0% (95% CI: 11.9–14.1. The prevalence of myopia, astigmatism, high-myopia, and anisometropia significantly increased with increasing age (all p < 0.0001. There was no gender difference in prevalence rates in any type of refractive error, though women had a significantly higher rate of hyperopia than men (p < 0.0001. Hyperopia was significantly higher among those with a higher educational level (odds ratio [OR] 2.49; 95% CI: 1.51–3.95 and significantly higher among the hypertensive group (OR 1.24; 95% CI: 1.03–1.49. The severity of lens nuclear opacity was positively associated with myopia and negatively associated with hyperopia.Conclusions: The prevalence of myopia in this adult Indian population is much higher than in similarly aged white populations. These results confirm the previously

  6. The effects of spatial population dataset choice on estimates of population at risk of disease

    Directory of Open Access Journals (Sweden)

    Gething Peter W

    2011-02-01

    consistently more accurate than the others in estimating PAR. The sizes of such differences among modeled human populations were related to variations in the methods, input resolution, and date of the census data underlying each dataset. Data quality varied from country to country within the spatial population datasets. Conclusions Detailed, highly spatially resolved human population data are an essential resource for planning health service delivery for disease control, for the spatial modeling of epidemics, and for decision-making processes related to public health. However, our results highlight that for the low-income regions of the world where disease burden is greatest, existing datasets display substantial variations in estimated population distributions, resulting in uncertainty in disease assessments that utilize them. Increased efforts are required to gather contemporary and spatially detailed demographic data to reduce this uncertainty, particularly in Africa, and to develop population distribution modeling methods that match the rigor, sophistication, and ability to handle uncertainty of contemporary disease mapping and spread modeling. In the meantime, studies that utilize a particular spatial population dataset need to acknowledge the uncertainties inherent within them and consider how the methods and data that comprise each will affect conclusions.

  7. DIETARY HABITS OF A MEDITERRANEAN POPULATION OF ...

    African Journals Online (AJOL)

    SWEET

    The nutrient intake of the studied population is not in line with that ... habitual cooking methods, to estimate the usual diet of individuals during the previous year. ... However, the mean intakes were below the RDA for dietary calcium, ... As shown in table 6, the population was also stratified by education level, and the intakes.

  8. Genetic affinities of north and northeastern populations of India: inference from HLA-based study.

    Science.gov (United States)

    Agrawal, S; Srivastava, S K; Borkar, M; Chaudhuri, T K

    2008-08-01

    India is like a microcosm of the world in terms of its diversity; religion, climate and ethnicity which leads to genetic variations in the populations. As a highly polymorphic marker, the human leukocyte antigen (HLA) system plays an important role in the genetic differentiation studies. To assess the genetic diversity of HLA class II loci, we studied a total of 1336 individuals from north India using DNA-based techniques. The study included four endogamous castes (Kayastha, Mathurs, Rastogies and Vaishyas), two inbreeding Muslim populations (Shias and Sunnis) from north India and three northeast Indian populations (Lachung, Mech and Rajbanshi). A total of 36 alleles were observed at DRB1 locus in both Hindu castes and Muslims from north, while 21 alleles were seen in northeast Indians. At the DQA1 locus, the number of alleles ranged from 11 to 17 in the studied populations. The total number of alleles at DQB1 was 19, 12 and 20 in the studied castes, Muslims and northeastern populations, respectively. The most frequent haplotypes observed in all the studied populations were DRB1*0701-DQA1*0201-DQB1*0201 and DRB1*1501-DQA1*0103-DQB1*0601. Upon comparing our results with other world populations, we observed the presence of Caucasoid element in north Indian population. However, differential admixturing among Sunnis and Shias with the other north Indians was evident. Northeastern populations showed genetic affinity with Mongoloids from southeast Asia. When genetic distances were calculated, we found the north Indians and northeastern populations to be markedly unrelated.

  9. Early eczema and the risk of childhood asthma: a prospective, population-based study

    Directory of Open Access Journals (Sweden)

    Saunes Marit

    2012-10-01

    Full Text Available Abstract Background Severe eczema in young children is associated with an increased risk of developing asthma and rhino-conjunctivitis. In the general population, however, most cases of eczema are mild to moderate. In an unselected cohort, we studied the risk of current asthma and the co-existence of allergy-related diseases at 6 years of age among children with and without eczema at 2 years of age. Methods Questionnaires assessing various environmental exposures and health variables were administered at 2 years of age. An identical health questionnaire was completed at 6 years of age. The clinical investigation of a random subsample ascertained eczema diagnoses, and missing data were handled by multiple imputation analyses. Results The estimate for the association between eczema at 2 years and current asthma at 6 years was OR=1.80 (95% CI 1.10-2.96. Four of ten children with eczema at 6 years had the onset of eczema after the age of 2 years, but the co-existence of different allergy-related diseases at 6 years was higher among those with the onset of eczema before 2 years of age. Conclusions Although most cases of eczema in the general population were mild to moderate, early eczema was associated with an increased risk of developing childhood asthma. These findings support the hypothesis of an atopic march in the general population. Trial registration The Prevention of Allergy among Children in Trondheim study has been identified as ISRCTN28090297 in the international Current Controlled Trials database

  10. Noise nuisance and health inequalities in Belgium: a population study

    OpenAIRE

    Schmit, C; Lorant, V

    2009-01-01

    Context Lower socioeconomic groups are more likely to live in contaminated environments. This may partly explain socioeconomic health inequalities. Aims Does noise nuisance contribute to socio-economic inequalities in subjective health? Method This research is based on the last Belgian census data carried out in 2001. We work on a 10% sample of the Belgian population. The data are processed through bivariate and multivariate analyses. We model poor subjective health in relation to exposure to...

  11. Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1981-01-01

    The present review provides an understanding of our current knowledge of the carcinogenic effect of low-dose radiation in man, and surveys the epidemiological studies of human populations exposed to nuclear explosions and medical radiation. Discussion centers on the contributions of quantitative epidemiology to present knowledge, the reliability of the dose-incidence data, and those relevant epidemiological studies that provide the most useful information for risk estimation of cancer induction in man. Reference is made to dose-incidence relationships from laboratory animal experiments where they may obtain, for problems and difficulties in extrapolation from data obtained at high doses to low doses, and from animal data to the human situation. The paper describes the methods of application of such epidemiological data for estimation of excess risk of radiation-induced cancer in exposed human populations and discusses the strengths and limitations of epidemiology in guiding radiation protection philosophy and public health policy

  12. A study of distribution, sex differences and stability of lip print patterns in an Indian population.

    Science.gov (United States)

    Kapoor, Neeti; Badiye, Ashish

    2017-09-01

    Lip prints are very useful in forensic investigations. The objective of this study is to determine predominant lip print pattern found among a central Indian population, to evaluate whether any sex difference exists and to study the permanence of the pattern over a 6 month duration. This study included 200 healthy adult subjects comprising of 100 males and 100 females in the age group of 18-25 years. A convenient and easier method of data collection i.e., digital photography was used instead of the traditional lipstick methods. Lip prints were then divided into four quadrants and recognized as per Suzuki and Tsuchihashi's classification. Type I (30.63%) was found to be most predominant overall in the Marathi population. Type I (29.75%) and Type III (35.75%) were found most prevalent in males and females respectively. Applying the Chi-Square test, statistically significant differences ( p  < 0.05) were observed between male and female lip print patterns in each of the quadrants individually and all quadrants taken together. The lip print patterns remained stable over a period of six-months. Being stable and with significant sex differences, lip prints can be effectively used as an important tool in forensic investigations for individualization as well as identification of sex of the donor, thus, narrowing down the scope of investigation to almost half.

  13. POPULATION SYNTHESIS OF HOT SUBDWARFS: A PARAMETER STUDY

    International Nuclear Information System (INIS)

    Clausen, Drew; Wade, Richard A.; Kopparapu, Ravi Kumar; O'Shaughnessy, Richard

    2012-01-01

    Binaries that contain a hot subdwarf (sdB) star and a main-sequence companion may have interacted in the past. This binary population has historically helped determine our understanding of binary stellar evolution. We have computed a grid of binary population synthesis models using different assumptions about the minimum core mass for helium ignition, the envelope binding energy, the common-envelope ejection efficiency, the amount of mass and angular momentum lost during stable mass transfer, and the criteria for stable mass transfer on the red giant branch and in the Hertzsprung gap. These parameters separately and together can significantly change the entire predicted population of sdBs. Nonetheless, several different parameter sets can reproduce the observed subpopulation of sdB + white dwarf and sdB + M dwarf binaries, which has been used to constrain these parameters in previous studies. The period distribution of sdB + early F dwarf binaries offers a better test of different mass transfer scenarios for stars that fill their Roche lobes on the red giant branch.

  14. Development of a Population Balance Model of a pharmaceutical drying process and testing of solution methods

    DEFF Research Database (Denmark)

    Mortier, Séverine Thérèse F.C.; Gernaey, Krist; De Beer, Thomas

    2013-01-01

    Drying is frequently used in the production of pharmaceutical tablets. Simulation-based control strategy development for such a drying process requires a detailed model. First, the drying of wet granules is modelled using a Population Balance Model. A growth term based on a reduced model was used......, which describes the decrease of the moisture content, to follow the moisture content distribution for a batch of granules. Secondly, different solution methods for solving the PBM are compared. The effect of grid size (discretization methods) is analyzed in terms of accuracy and calculation time. All...

  15. Are invasive populations characterized by a broader diet than native populations?

    Directory of Open Access Journals (Sweden)

    Julien Courant

    2017-05-01

    Full Text Available Background Invasive species are among the most significant threats to biodiversity. The diet of invasive animal populations is a crucial factor that must be considered in the context of biological invasions. A broad dietary spectrum is a frequently cited characteristic of invasive species, allowing them to thrive in a wide range of environments. Therefore, empirical studies comparing diet in invasive and native populations are necessary to understand dietary requirements, dietary flexibility, and the associated impacts of invasive species. Methods In this study, we compared the diet of populations of the African clawed frog, Xenopus laevis in its native range, with several areas where it has become invasive. Each prey category detected in stomach contents was assigned to an ecological category, allowing a comparison of the diversity of ecological traits among the prey items in the diet of native and introduced populations. The comparison of diets was also performed using evenness as a niche breadth index on all sampled populations, and electivity as a prey selection index for three out of the six sampled populations. Results Our results showed that diet breadth could be either narrow or broad in invasive populations. According to diet and prey availability, zooplankton was strongly preferred in most cases. In lotic environments, zooplankton was replaced by benthic preys, such as ephemeropteran larvae. Discussion The relative proportions of prey with different ecological traits, and dietary variability within and between areas of occurrence, suggest that X. laevis is a generalist predator in both native and invasive populations. Shifts in the realized trophic niche are observed, and appear related to resource availability. Xenopus laevis may strongly impact aquatic ecosystems because of its near complete aquatic lifestyle and its significant consumption of key taxa for the trophic relationships in ponds.

  16. Value of information methods to design a clinical trial in a small population to optimise a health economic utility function

    Directory of Open Access Journals (Sweden)

    Michael Pearce

    2018-02-01

    Full Text Available Abstract Background Most confirmatory randomised controlled clinical trials (RCTs are designed with specified power, usually 80% or 90%, for a hypothesis test conducted at a given significance level, usually 2.5% for a one-sided test. Approval of the experimental treatment by regulatory agencies is then based on the result of such a significance test with other information to balance the risk of adverse events against the benefit of the treatment to future patients. In the setting of a rare disease, recruiting sufficient patients to achieve conventional error rates for clinically reasonable effect sizes may be infeasible, suggesting that the decision-making process should reflect the size of the target population. Methods We considered the use of a decision-theoretic value of information (VOI method to obtain the optimal sample size and significance level for confirmatory RCTs in a range of settings. We assume the decision maker represents society. For simplicity we assume the primary endpoint to be normally distributed with unknown mean following some normal prior distribution representing information on the anticipated effectiveness of the therapy available before the trial. The method is illustrated by an application in an RCT in haemophilia A. We explicitly specify the utility in terms of improvement in primary outcome and compare this with the costs of treating patients, both financial and in terms of potential harm, during the trial and in the future. Results The optimal sample size for the clinical trial decreases as the size of the population decreases. For non-zero cost of treating future patients, either monetary or in terms of potential harmful effects, stronger evidence is required for approval as the population size increases, though this is not the case if the costs of treating future patients are ignored. Conclusions Decision-theoretic VOI methods offer a flexible approach with both type I error rate and power (or equivalently

  17. Specialist Cohort Event Monitoring studies: a new study method for risk management in pharmacovigilance.

    Science.gov (United States)

    Layton, Deborah; Shakir, Saad A W

    2015-02-01

    The evolving regulatory landscape has heightened the need for innovative, proactive, efficient and more meaningful solutions for 'real-world' post-authorization safety studies (PASS) that not only align with risk management objectives to gather additional safety monitoring information or assess a pattern of drug utilization, but also satisfy key regulatory requirements for marketing authorization holder risk management planning and execution needs. There is a need for data capture across the primary care and secondary care interface, or for exploring use of new medicines in secondary care to support conducting PASS. To fulfil this need, event monitoring has evolved. The Specialist Cohort Event Monitoring (SCEM) study is a new application that enables a cohort of patients prescribed a medicine in the hospital and secondary care settings to be monitored. The method also permits the inclusion of a comparator cohort of patients receiving standard care, or another counterfactual comparator group, to be monitored concurrently, depending on the study question. The approach has been developed in parallel with the new legislative requirement for pharmaceutical companies to undertake a risk management plan as part of post-authorization safety monitoring. SCEM studies recognize that the study population comprises those patients who may have treatment initiated under the care of specialist health care professionals and who are more complex in terms of underlying disease, co-morbidities and concomitant medications than the general disease population treated in primary care. The aims of this paper are to discuss the SCEM new-user study design, rationale and features that aim to address possible bias (such as selection bias) and current applications.

  18. Bowel, Urinary, and Sexual Problems Among Long-Term Prostate Cancer Survivors: A Population-Based Study

    International Nuclear Information System (INIS)

    Mols, Floortje; Korfage, Ida J.; Vingerhoets, Ad J.J.M.; Kil, Paul J.M.; Coebergh, Jan Willem W.; Essink-Bot, Marie-Louise; Poll-Franse, Lonneke V. van de

    2009-01-01

    Purpose: To obtain insight into the long-term (5- to 10-year) effects of prostate cancer and treatment on bowel, urinary, and sexual function, we performed a population-based study. Prostate-specific function was compared with an age-matched normative population without prostate cancer. Methods and Materials: Through the population-based Eindhoven Cancer Registry, we selected all men diagnosed with prostate cancer between 1994 and 1998 in the southern Netherlands. In total, 964 patients, alive in November 2004, received questionnaire; 780 (81%) responded. Results: Urinary problems were most common after a prostatectomy; bowel problems were most common after radiotherapy. Compared with an age-matched normative population both urinary and bowel functioning and bother were significantly worse among survivors. Urinary incontinence was reported by 23-48% of survivors compared with 4% of the normative population. Bowel leakage occurred in 5-14% of patients compared with 2% of norms. Erection problems occurred in 40-74% of patients compared with 18% of norms. Conclusions: These results form an important contribution to the limited information available on prostate-specific problems in the growing group of long-term prostate cancer survivors. Bowel, urinary, and sexual problems occur more often among long-term survivors compared with a reference group and cannot be explained merely by age. Because these problems persist for many years, urologists should provide patients with adequate information before treatment. After treatment, there should be an appropriate focus on these problems

  19. “Health divide” between indigenous and non-indigenous populations in Kerala, India: Population based study

    Directory of Open Access Journals (Sweden)

    Haddad Slim

    2012-05-01

    Full Text Available Abstract Background The objective of this study is to investigate the magnitude and nature of health inequalities between indigenous (Scheduled Tribes and non-indigenous populations, as well as between different indigenous groups, in a rural district of Kerala State, India. Methods A health survey was carried out in a rural community (N = 1660 men and women, 18–96 years. Age- and sex-standardised prevalence of underweight (BMI 2, anaemia, goitre, suspected tuberculosis and hypertension was compared across forward castes, other backward classes and tribal populations. Multi-level weighted logistic regression models were used to estimate the predicted prevalence of morbidity for each age and social group. A Blinder-Oaxaca decomposition was used to further explore the health gap between tribes and non-tribes, and between subgroups of tribes. Results Social stratification remains a strong determinant of health in the progressive social policy environment of Kerala. The tribal groups are bearing a higher burden of underweight (46.1 vs. 24.3%, anaemia (9.9 vs. 3.5% and goitre (8.5 vs. 3.6% compared to non-tribes, but have similar levels of tuberculosis (21.4 vs. 20.4% and hypertension (23.5 vs. 20.1%. Significant health inequalities also exist within tribal populations; the Paniya have higher levels of underweight (54.8 vs. 40.7% and anaemia (17.2 vs. 5.7% than other Scheduled Tribes. The social gradient in health is evident in each age group, with the exception of hypertension. The predicted prevalence of underweight is 31 and 13 percentage points higher for Paniya and other Scheduled Tribe members, respectively, compared to Forward Caste members 18–30 y (27.1%. Higher hypertension is only evident among Paniya adults 18–30 y (10 percentage points higher than Forward Caste adults of the same age group (5.4%. The decomposition analysis shows that poverty and other determinants of health only explain 51% and 42% of the health gap

  20. Managing Ethical Problems in Qualitative Research Involving Vulnerable Populations, Using a Pilot Study

    Directory of Open Access Journals (Sweden)

    Evalina van Wijk RN, PhD

    2013-02-01

    Full Text Available The purpose of the researcher's study was to examine the meaning that intimate partners of female rape victims attached to their lived experiences after the rape. The conduct of qualitative research concerning non-offending partners of female rape victims, however, often involves multifaceted ethical and practical challenges, which can be managed through the use of pilot studies. The pilot study described in this report had three objectives. The first was to pretest and refine the proposed method for locating, accessing, and recruiting intimate partners of female rape victims, within the first two weeks after the rape, for participation in a six-month longitudinal study. The second objective was to identify and prevent all possible risk factors in the proposed recruitment and data collection methods that could harm the participants' safety during the main study. The third objective was to determine the feasibility of the main study, in terms of the limited financial and human resources available. The pilot phase was valuable in identifying ethical and methodological problems during the recruitment of participants and collection of data. It allowed for methodological adjustments prior to the main study and confirmed the feasibility of the overall research design. A pilot, pretesting phase is therefore seen as an essential component of a qualitative study involving a vulnerable population.

  1. Crossing Methods and Cultivation Conditions for Rapid Production of Segregating Populations in Three Grain Amaranth Species.

    Science.gov (United States)

    Stetter, Markus G; Zeitler, Leo; Steinhaus, Adrian; Kroener, Karoline; Biljecki, Michelle; Schmid, Karl J

    2016-01-01

    Grain amaranths (Amaranthus spp.) have been cultivated for thousands of years in Central and South America. Their grains are of high nutritional value, but the low yield needs to be increased by selection of superior genotypes from genetically diverse breeding populations. Amaranths are adapted to harsh conditions and can be cultivated on marginal lands although little is known about their physiology. The development of controlled growing conditions and efficient crossing methods is important for research on and improvement of this ancient crop. Grain amaranth was domesticated in the Americas and is highly self-fertilizing with a large inflorescence consisting of thousands of very small flowers. We evaluated three different crossing methods (open pollination, hot water emasculation and hand emasculation) for their efficiency in amaranth and validated them with genetic markers. We identified cultivation conditions that allow an easy control of flowering time by day length manipulation and achieved flowering times of 4 weeks and generation times of 2 months. All three different crossing methods successfully produced hybrid F1 offspring, but with different success rates. Open pollination had the lowest (10%) and hand emasculation the highest success rate (74%). Hot water emasculation showed an intermediate success rate (26%) with a maximum of 94% success. It is simple to perform and suitable for a more large-scale production of hybrids. We further evaluated 11 single nucleotide polymorphism (SNP) markers and found that they were sufficient to validate all crosses of the genotypes used in this study for intra- and interspecific hybridizations. Despite its very small flowers, crosses in amaranth can be carried out efficiently and evaluated with inexpensive SNP markers. Suitable growth conditions strongly reduce the generation time and allow the control of plant height, flowering time, and seed production. In combination, this enables the rapid production of segregating

  2. The present-day galaxy population in spiral galaxies

    NARCIS (Netherlands)

    Peletier, Reynier; Antonelli, LA; Limongi, M; Menci, N; Tornambe, A; Brocato, E; Raimondo, G

    2009-01-01

    Although there are many more stellar population studies of elliptical and lenticular galaxies, studies of spiral galaxies are catching up, due to higher signal to noise data on one hand, and better analysis methods on the other. Here I start by discussing some modern methods of analyzing integrated

  3. Risk of myocardial infarction in parents of HIV-infected individuals: a population-based cohort study

    DEFF Research Database (Denmark)

    Rasmussen, Line D; Omland, Lars H; Pedersen, Court

    2010-01-01

    associated with the HIV disease and HAART or whether life-style related or genetic factors also increase the risk in this population. To establish whether the increased risk of myocardial infarction in HIV patients partly reflects an increased risk of MI in their families, we estimated the relative risk...... of MI in parents of HIV-infected individuals METHODS: From the Danish HIV Cohort Study and the Danish Civil Registration System we identified the parents of all HIV-infected patients born in Denmark after 1952 in whom a Danish born mother was identifiable. For each HIV patient, 4 matched population...... controls and their parents were identified. Cumulative incidence functions were constructed to illustrate time to first MI of the parents as registered in the Danish National Hospital Registry. Incidence rate ratios (IRR) were estimated by Cox's regression analyses. Due to the confidential type...

  4. The population abundance, distribution pattern and culture studies ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-18

    Aug 18, 2009 ... The population abundance, distribution pattern and culture studies of ... plankton species belong mainly to the nanoplankton and microplankton ... Algal samples were collected from the shore using microalgal net cone shaped of .... species diversity of Porto Novo, Tamil Nadu and De et al. (1994) in the ...

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  6. Population health state

    International Nuclear Information System (INIS)

    1993-01-01

    General conception on the Chernobyl accident effect on the human health (persons took part in the emergency response, children and adults in the Chernobyl region as a whole) is given. Pattern of population disease incidence in the whole region was compared with that of contaminated regions in Russia. New method for assessment of population disease incidence in the contaminated zones due to the Chernobyl accident is proposed taking into account low dose radiation effects, territory ecological difference, medical-demographic unhomogeneity of the population and personal instability. Methods of complex mathematical analysis were used. Data on the Tula region are presented as an example. 17 figs.; 6 tabs

  7. Tinnitus: an epidemiologic study in Iranian population.

    Directory of Open Access Journals (Sweden)

    Maryam Jalessi

    2013-12-01

    Full Text Available A wide range of population, 4% to 30%, suffers from tinnitus that is defined as perception of sound without apparent acoustic stimulus. We conducted the present study to determine the prevalence of tinnitus in Iranian population; Tehran province. This cross-sectional study was conducted from January 2009 to December 2009, recruiting 3207 individuals (age range, 7-98 who were residing in Tehran province, Iran. Participants were asked to fill two questionnaires; the validated Persian version of Tinnitus Questionnaire (TQ and another one that was specifically designed for this study. Prevalence of tinnitus and its association factors were evaluated. 3207 participants enrolled into our study comprising 1429 (44.7% male and 1765 (55.3% female with mean age of 55.01±17.85. Of total of 3207 participants, 146 (4.6% had tinnitus consisting of 80 male (54.8% and 66 (45.2% female participants. It showed a rising trend with increasing age that was especially significant after the sixth decade of life (P=0.001. The analysis showed mean TQ global score of 35.96±25.52 that was significantly different between male and female participants (P=0.051 and had no significant correlation with increasing age (Spearman's r=0.1, P=0.10. The tinnitus intensity was moderate to very severe in 95 (56.1% of the participants. Its severity level was not significantly different between men and women (P=0.09. Tinnitus intensity had no significant association with increasing age (Spearman's r=0.1, P=0.31. Patients with higher TQ global score had higher tinnitus intensities (P=0.001. The annoyance level was significantly different between men and women (P=0.04 and its impact on the participants daily routine functions were significantly higher in men (P=0.003. Given the results of the study, demonstrating that prevalence of tinnitus in Iranian population (Tehran province was lower than the other countries and had a direct correlation with increasing age only after the sixth

  8. Modelling population dynamics model formulation, fitting and assessment using state-space methods

    CERN Document Server

    Newman, K B; Morgan, B J T; King, R; Borchers, D L; Cole, D J; Besbeas, P; Gimenez, O; Thomas, L

    2014-01-01

    This book gives a unifying framework for estimating the abundance of open populations: populations subject to births, deaths and movement, given imperfect measurements or samples of the populations.  The focus is primarily on populations of vertebrates for which dynamics are typically modelled within the framework of an annual cycle, and for which stochastic variability in the demographic processes is usually modest. Discrete-time models are developed in which animals can be assigned to discrete states such as age class, gender, maturity,  population (within a metapopulation), or species (for multi-species models). The book goes well beyond estimation of abundance, allowing inference on underlying population processes such as birth or recruitment, survival and movement. This requires the formulation and fitting of population dynamics models.  The resulting fitted models yield both estimates of abundance and estimates of parameters characterizing the underlying processes.  

  9. Age estimation using development of third molars in South Indian population: A radiological study.

    Science.gov (United States)

    Priyadharshini, K Indra; Idiculla, Jose Joy; Sivapathasundaram, B; Mohanbabu, V; Augustine, Dominic; Patil, Shankargouda

    2015-05-01

    To assess the estimation of chronological age based on the stages of third molar development following the eight stages (A-H) method of Demirjian et al. in Chennai population of South India. A sample consisting of 848 individuals (471 males and 377 females) aged between 14 and 30 years was randomly selected for the clinical evaluation and 323 orthopantomograms with clinically missing third molars were taken for radiological evaluation using Demirjian's method from a Chennai population of known chronological age and sex. Statistical analysis was performed using Pearson's Chi-square test and mean values were compared between the study groups using t-test or analysis of variance (ANOVA) followed by Tukey's highly significant difference (HSD). In the present study, P age of having clinically completely erupted maxillary third molars was 22.41 years in male subjects and 23.81 years in female subjects and that of mandibular third molars was 21.49 years in male subjects and 23.34 years in female subjects. Mandibular third molars were clinically missing more often in females than in males. Eruption of mandibular third molars was generally ahead of the emergence of maxillary third molars into the oral cavity. Third molar development between male and female subjects showed statistically significant differences at calcification stage F and stage G in maxillary third molars and stage F in mandibular third molars (P third molar eruption reached Demirjian's formation stages earlier in males than in females. It is suggested that in future studies, to increase the accuracy of age determination, indications of sexual maturity and ossification should also be evaluated in addition to third molar mineralization.

  10. A review of population data utilization in beef cattle research.

    Science.gov (United States)

    Jones, R; Langemeier, M

    2010-04-01

    Controlled experimentation has been the most common source of research data in most biological sciences. However, many research questions lend themselves to the use of population data, or combinations of population data and data resulting from controlled experimentation. Studies of important economic outcomes, such as efficiency, profits, and costs, lend themselves particularly well to this type of analysis. Analytical methods that have been most commonly applied to population data in studies related to livestock production and management include statistical regression and mathematical programming. In social sciences, such as applied economics, it has become common to utilize more than one method in the same study to provide answers to the various questions at hand. Of course, care must be taken to ensure that the methods of analysis are appropriately applied; however, a wide variety of beef industry research questions are being addressed using population data. Issues related to data sources, aggregation levels, and consistency of collection often surface when using population data. These issues are addressed by careful consideration of the questions being addressed and the costs of data collection. Previous research across a variety of cattle production and marketing issues provides a broad foundation upon which to build future research. There is tremendous opportunity for increased use of population data and increased collaboration across disciplines to address issues of importance to the cattle industry.

  11. Associations among binge eating behavior patterns and gastrointestinal symptoms: a population-based study

    Science.gov (United States)

    Cremonini, F; Camilleri, M; Clark, MM; Beebe, TJ; Locke, GR; Zinsmeister, AR; Herrick, LM; Talley, NJ

    2009-01-01

    Background The psychological symptoms associated with binge eating disorder (BED) have been well documented. However, the physical symptoms associated with BED have not been explored. Gastrointestinal (GI) symptoms such as heartburn and diarrhea are more prevalent in obese adults, but the associations remain unexplained. Patients with bulimia have increased gastric capacity. The objective of the study was to examine if the severity of binge eating episodes would be associated with upper and lower GI symptoms. Methods Population-based survey of community residents through a mailed questionnaire measuring GI symptoms, frequency of binge eating episodes and physical activity level. The association of GI symptoms with frequency of binge eating episodes was assessed using logistic regression models adjusting for age, gender, body mass index (BMI) and physical activity level. Results In 4096 subjects, BED was present in 6.1%. After adjusting for BMI, age, gender, race, diabetes mellitus, socioeconomic status and physical activity level, BED was independently associated with the following upper GI symptoms: acid regurgitation (P symptoms: diarrhea (P symptoms in the general population, independent of the level of obesity. The relationship between increased GI symptoms and physiological responses to increased volume and calorie loads, nutritional selections and rapidity of food ingestion in individuals with BED deserves further study. PMID:19139750

  12. Elevated incidence rates of diabetes in Peru: report from PERUDIAB, a national urban population-based longitudinal study

    OpenAIRE

    Seclen, Segundo Nicolas; Rosas, Moises Ernesto; Arias, Arturo Jaime; Medina, Cecilia Alexandra

    2017-01-01

    Objective A recent report from a non-nationally representative, geographically diverse sample in four separate communities in Peru suggests an unusually high diabetes incidence. We aimed to estimate the national diabetes incidence rate using PERUDIAB, a probabilistic, national urban population-based longitudinal study. Research design and methods 662 subjects without diabetes, selected by multistage, cluster, random sampling of households, representing the 24 administrative and the 3 (coast, ...

  13. Developing population models with data from marked individuals

    Science.gov (United States)

    Hae Yeong Ryu,; Kevin T. Shoemaker,; Eva Kneip,; Anna Pidgeon,; Patricia Heglund,; Brooke Bateman,; Thogmartin, Wayne E.; Reşit Akçakaya,

    2016-01-01

    Population viability analysis (PVA) is a powerful tool for biodiversity assessments, but its use has been limited because of the requirements for fully specified population models such as demographic structure, density-dependence, environmental stochasticity, and specification of uncertainties. Developing a fully specified population model from commonly available data sources – notably, mark–recapture studies – remains complicated due to lack of practical methods for estimating fecundity, true survival (as opposed to apparent survival), natural temporal variability in both survival and fecundity, density-dependence in the demographic parameters, and uncertainty in model parameters. We present a general method that estimates all the key parameters required to specify a stochastic, matrix-based population model, constructed using a long-term mark–recapture dataset. Unlike standard mark–recapture analyses, our approach provides estimates of true survival rates and fecundities, their respective natural temporal variabilities, and density-dependence functions, making it possible to construct a population model for long-term projection of population dynamics. Furthermore, our method includes a formal quantification of parameter uncertainty for global (multivariate) sensitivity analysis. We apply this approach to 9 bird species and demonstrate the feasibility of using data from the Monitoring Avian Productivity and Survivorship (MAPS) program. Bias-correction factors for raw estimates of survival and fecundity derived from mark–recapture data (apparent survival and juvenile:adult ratio, respectively) were non-negligible, and corrected parameters were generally more biologically reasonable than their uncorrected counterparts. Our method allows the development of fully specified stochastic population models using a single, widely available data source, substantially reducing the barriers that have until now limited the widespread application of PVA. This method

  14. Population structure of Vibrio fischeri within the light organs of Euprymna scolopes squid from Two Oahu (Hawaii) populations.

    Science.gov (United States)

    Wollenberg, M S; Ruby, E G

    2009-01-01

    We resolved the intraspecific diversity of Vibrio fischeri, the bioluminescent symbiont of the Hawaiian sepiolid squid Euprymna scolopes, at two previously unexplored morphological and geographical scales. These scales ranged from submillimeter regions within the host light organ to the several kilometers encompassing two host populations around Oahu. To facilitate this effort, we employed both novel and standard genetic and phenotypic assays of light-organ symbiont populations. A V. fischeri-specific fingerprinting method and five phenotypic assays were used to gauge the genetic richness of V. fischeri populations; these methods confirmed that the symbiont population present in each adult host's light organ is polyclonal. Upon statistical analysis of these genetic and phenotypic population data, we concluded that the characteristics of symbiotic populations were more similar within individual host populations than between the two distinct Oahu populations of E. scolopes, providing evidence that local geographic symbiont population structure exists. Finally, to better understand the genesis of symbiont diversity within host light organs, the process of symbiosis initiation in newly hatched juvenile squid was examined both experimentally and by mathematical modeling. We concluded that, after the juvenile hatches, only one or two cells of V. fischeri enter each of six internal epithelium-lined crypts present in the developing light organ. We hypothesize that the expansion of different, crypt-segregated, clonal populations creates the polyclonal adult light-organ population structure observed in this study. The stability of the luminous-bacterium-sepiolid squid mutualism in the presence of a polyclonal symbiont population structure is discussed in the context of contemporary evolutionary theory.

  15. Estimation of effective population size in continuously distributed populations: There goes the neighborhood

    Science.gov (United States)

    M. C. Neel; K. McKelvey; N. Ryman; M. W. Lloyd; R. Short Bull; F. W. Allendorf; M. K. Schwartz; R. S. Waples

    2013-01-01

    Use of genetic methods to estimate effective population size (Ne) is rapidly increasing, but all approaches make simplifying assumptions unlikely to be met in real populations. In particular, all assume a single, unstructured population, and none has been evaluated for use with continuously distributed species. We simulated continuous populations with local mating...

  16. Are PCI Service Volumes Associated with 30-Day Mortality? A Population-Based Study from Taiwan.

    Science.gov (United States)

    Yu, Tsung-Hsien; Chou, Ying-Yi; Wei, Chung-Jen; Tung, Yu-Chi

    2017-11-09

    The volume-outcome relationship has been discussed for over 30 years; however, the findings are inconsistent. This might be due to the heterogeneity of service volume definitions and categorization methods. This study takes percutaneous coronary intervention (PCI) as an example to examine whether the service volume was associated with PCI 30-day mortality, given different service volume definitions and categorization methods. A population-based, cross-sectional multilevel study was conducted. Two definitions of physician and hospital volume were used: (1) the cumulative PCI volume in a previous year before each PCI; (2) the cumulative PCI volume within the study period. The volume was further treated in three ways: (1) a categorical variable based on the American Heart Association's recommendation; (2) a semi-data-driven categorical variable based on k-means clustering algorithm; and (3) a data-driven categorical variable based on the Generalized Additive Model. The results showed that, after adjusting the patient-, physician-, and hospital-level covariates, physician volume was associated inversely with PCI 30-day mortality, but hospital volume was not, no matter which definitions and categorization methods of service volume were applied. Physician volume is negatively associated with PCI 30-day mortality, but the results might vary because of definition and categorization method.

  17. Contribution of type 2 diabetes associated loci in the Arabic population from Tunisia: a case-control study

    Directory of Open Access Journals (Sweden)

    Almawi Wassim Y

    2009-04-01

    Full Text Available Abstract Background Candidate gene and genome-wide association studies have both reproducibly identified several common Single Nucleotide Polymorphisms (SNPs that confer type 2 diabetes (T2D risk in European populations. Our aim was to evaluate the contribution to T2D of five of these established T2D-associated loci in the Arabic population from Tunisia. Methods A case-control design comprising 884 type 2 diabetic patients and 513 control subjects living in the East-Center of Tunisia was used to analyze the contribution to T2D of the following SNPs: E23K in KCNJ11/Kir6.2, K121Q in ENPP1, the -30G/A variant in the pancreatic β-cell specific promoter of Glucokinase, rs7903146 in TCF7L2 encoding transcription factor 7-like2, and rs7923837 in HHEX encoding the homeobox, hematopoietically expressed transcription factor. Results TCF7L2-rs7903146 T allele increased susceptibility to T2D (OR = 1.25 [1.06–1.47], P = 0.006 in our study population. This risk was 56% higher among subjects carrying the TT genotype in comparison to those carrying the CC genotype (OR = 1.56 [1.13–2.16], P = 0.002. No allelic or genotypic association with T2D was detected for the other studied polymorphisms. Conclusion In the Tunisian population, TCF7L2-rs7903146 T allele confers an increased risk of developing T2D as previously reported in the European population and many other ethnic groups. In contrast, none of the other tested SNPs that influence T2D risk in the European population was associated with T2D in the Tunisian Arabic population. An insufficient power to detect minor allelic contributions or genetic heterogeneity of T2D between different ethnic groups can explain these findings.

  18. [A sero-epidemiological study of hepatitis E among general population in Shandong Province of China in 2014].

    Science.gov (United States)

    Yan, B Y; Zhang, L; Lyu, J J; Feng, Y; Liu, J Y; Wu, W L; Song, L Z; Xu, A Q

    2017-07-06

    Objective: To analyze the sero-epidemiological characteristics of hepatitis E virus (HEV) in Shandong province, and thereby to provide evidence for the policy-making of hepatitis E prevention and control. Methods: The inhabitants aged between 1-59 years old were randomly selected to participate in the study by two-stage stratified random sampling method from 12 counties in Shandong province in October, 2014. Firstly two townships were selected from each county by probability proportional to size sampling (PPS) method. A total of 5 229 participants aged 1-59 years old were selected by stratified random sampling method. All the participants finished a questionnaire survey and a venous blood sample (3-5 ml) was collected from each to test anti-HEV IgG by enzyme-linked assay (ELISA). The weighted prevalence of anti-HEV IgG with different demographic characteristics was estimated. The variance of the positive rate of anti-HEV IgG was calculated by Taylor series linearization method, as well as its 95 %CI . A statistical test was conducted to compare the rate of its 95 %CI , and the results in the present study were compared with those in sero-survey in 2006. Results: A total of 5 229 subjects entered the final analysis in 2014. The overall weighed prevalence of anti-HEV IgG was 9.19% (95 %CI: 6.18%-12.20%) among natural population in Shandong province, decreased by 19.88% in comparison with that in 2006 sero-survey (11.47%, 95 %CI: 8.92%-14.02%). The prevalence increased with age increasing (χ(2trend)=288.11, Ppopulations (13.76%, 95 %CI: 10.15%-17.38%; 21.11%, 95 %CI: 12.67%-29.55%; 17.81%, 95 %CI: 7.63%-28.00%; 21.08%, 95 %CI: 0.03%-42.12%) in 2006 survey. Conclusion: The prevalence of anti-HEV IgG has decreased in Shandong province in the recent years, but the epidemiological characteristics found no obvious changes. HEV susceptibility in natural population was generally high. Hepatitis E vaccines were recommended to be used in HEV high-risk population in the

  19. The Association between Bone Quality and Atherosclerosis: Results from Two Large Population-Based Studies

    Directory of Open Access Journals (Sweden)

    V. Lange

    2017-01-01

    Full Text Available Objective. It is highly debated whether associations between osteoporosis and atherosclerosis are independent of cardiovascular risk factors. We aimed to explore the associations between quantitative ultrasound (QUS parameters at the heel with the carotid artery intima-media thickness (IMT, the presence of carotid artery plaques, and the ankle-brachial index (ABI. Methods. The study population comprised 5680 men and women aged 20–93 years from two population-based cohort studies: Study of Health in Pomerania (SHIP and SHIP-Trend. QUS measurements were performed at the heel. The extracranial carotid arteries were examined with B-mode ultrasonography. ABI was measured in a subgroup of 3853 participants. Analyses of variance and linear and logistic regression models were calculated and adjusted for major cardiovascular risk factors. Results. Men but not women had significantly increased odds for carotid artery plaques with decreasing QUS parameters independent of diabetes mellitus, dyslipidemia, and hypertension. Beyond this, the QUS parameters were not significantly associated with IMT or ABI in fully adjusted models. Conclusions. Our data argue against an independent role of bone metabolism in atherosclerotic changes in women. Yet, in men, associations with advanced atherosclerosis, exist. Thus, men presenting with clinical signs of osteoporosis may be at increased risk for atherosclerotic disease.

  20. CardioBengo study protocol: a population based cardiovascular longitudinal study in Bengo Province, Angola

    Directory of Open Access Journals (Sweden)

    João M. Pedro

    2016-03-01

    Full Text Available Abstract Background Cardiovascular diseases and other non-communicable diseases are major causes of morbidity and mortality, responsible for 38 million deaths in 2012, 75 % occurring in low- and middle-income countries. Most of these countries are facing a period of epidemiological transition, being confronted with an increased burden of non-communicable diseases, which challenge health systems mainly designed to deal with infectious diseases. With the adoption of the World Health Organization “Global Action Plan for the Prevention and Control of non-communicable diseases, 2013–2020”, the national dimension of risk factors for non-communicable diseases must be reported on a regular basis. Angola has no national surveillance system for non-communicable diseases, and periodic population-based studies can help to overcome this lack of information. CardioBengo will collect information on risk factors, awareness rates and prevalence of symptoms relevant to cardiovascular diseases, to assist decision makers in the implementation of prevention and treatment policies and programs. Methods CardioBengo is designed as a research structure that comprises a cross-sectional component, providing baseline information and the assembling of a cohort to follow-up the dynamics of cardiovascular diseases risk factors in the catchment area of the Dande Health and Demographic Surveillance System of the Health Research Centre of Angola, in Bengo Province, Angola. The World Health Organization STEPwise approach to surveillance questionnaires and procedures will be used to collect information on a representative sex-age stratified sample, aged between 15 and 64 years old. Discussion CardioBengo will recruit the first population cohort in Angola designed to evaluate cardiovascular diseases risk factors. Using the structures in place of the Dande Health and Demographic Surveillance System and a reliable methodology that generates comparable results with other

  1. HIV Research with Men who Have Sex with Men (MSM: Advantages and Challenges of Different Methods for Most Appropriately Targeting a Key Population

    Directory of Open Access Journals (Sweden)

    Ana Gama

    2017-05-01

    Full Text Available The difficulty in accessing hard-to-reach populations as men who have sex with men presents a dilemma for HIV surveillance as their omission from surveillance systems leaves significant gaps in our understanding of HIV/AIDS epidemics. Several methods for recruiting difficult-to-access populations and collecting data on trends of HIV prevalence and behavioural factors for surveillance and research purposes have emerged. This paper aims to critically review different sampling approaches, from chain-referral and venue-based to respondent-driven, time-location and internet sampling methods, focusing on its main advantages and challenges for conducting HIV research among key populations, such as men who have sex with men. The benefits of using these approaches to recruit participants must be weighed against privacy concerns inherent in any social situation or health condition. Nevertheless, the methods discussed in this paper represent some of the best efforts to effectively reach most-at-risk subgroups of men who have sex with men, contributing to obtain unbiased trends of HIV prevalence and HIV-related risk behaviours among this population group.

  2. The Growth of Older Inmate Populations: How Population Aging Explains Rising Age at Admission.

    Science.gov (United States)

    Luallen, Jeremy; Cutler, Christopher

    2017-09-01

    Older inmates are the fastest growing segment of the prison population; however, the reasons for this are not well understood. One explanation is that the general population is aging, driving prison age distributions to change. For this article, we study the role of population aging in prison growth by investigating how the baby boom phenomenon of post-World War II has contributed to the growth of older inmate populations. We identify the impact of population aging using simulation methods that explain prison growth as the combination of criminal justice processes. Overall, we find evidence that population aging has played a significant role in explaining the growth of older inmate populations, in particular among inmates aged between 50 and 64 years, contributing to as much as half of the observed increase in these groups since 2000. This finding stands in contrast to the notion that population aging has little explanatory power in describing the growth of prison populations and implies that older inmate groups are more sensitive to compositional changes in the general population. We argue that prediction-based modeling of prison growth should more seriously consider the impacts and consequences of demographic shifts among older prisoner populations. © The Author 2015. 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.

  3. How healthy are the rhinoceros populations in the Hluhluwe-iMfolosi Park?

    Directory of Open Access Journals (Sweden)

    LP Fatti

    2013-06-01

    Full Text Available Arising from a study conducted in the Hluhluwe-iMfolosi Park by the author in the late nineties, a method is proposed for improving the estimate of the size of a wildlife population by combining data from current and past surveys. The method is based on a simple state space model which takes into account the (unknown birth rate in the population and all known losses (mortalities and relocations and gains (introductions in the population between successive surveys, as well as the errors in the survey estimates. The method is applied to the White- and Black Rhinoceros populations in the Hluhluwe-iMfolosi Park and tentative conclusions are drawn on the health of these two populations.

  4. A UK population-based study of the relationship between mental disorder and victimisation

    NARCIS (Netherlands)

    Hart, C.; Vet, R. de; Moran, P.; Hatch, S.L.; Dean, K.

    2012-01-01

    PURPOSE: To establish the prevalence of victimisation in a UK population-based sample and to investigate the association between mental disorder and victimisation in both cross-sectional and prospective manner, whilst adjusting for potential confounds. METHODS: Data from the National Child

  5. Transgender-inclusive measures of sex/gender for population surveys: Mixed-methods evaluation and recommendations.

    Science.gov (United States)

    Bauer, Greta R; Braimoh, Jessica; Scheim, Ayden I; Dharma, Christoffer

    2017-01-01

    Given that an estimated 0.6% of the U.S. population is transgender (trans) and that large health disparities for this population have been documented, government and research organizations are increasingly expanding measures of sex/gender to be trans inclusive. Options suggested for trans community surveys, such as expansive check-all-that-apply gender identity lists and write-in options that offer maximum flexibility, are generally not appropriate for broad population surveys. These require limited questions and a small number of categories for analysis. Limited evaluation has been undertaken of trans-inclusive population survey measures for sex/gender, including those currently in use. Using an internet survey and follow-up of 311 participants, and cognitive interviews from a maximum-diversity sub-sample (n = 79), we conducted a mixed-methods evaluation of two existing measures: a two-step question developed in the United States and a multidimensional measure developed in Canada. We found very low levels of item missingness, and no indicators of confusion on the part of cisgender (non-trans) participants for both measures. However, a majority of interview participants indicated problems with each question item set. Agreement between the two measures in assessment of gender identity was very high (K = 0.9081), but gender identity was a poor proxy for other dimensions of sex or gender among trans participants. Issues to inform measure development or adaptation that emerged from analysis included dimensions of sex/gender measured, whether non-binary identities were trans, Indigenous and cultural identities, proxy reporting, temporality concerns, and the inability of a single item to provide a valid measure of sex/gender. Based on this evaluation, we recommend that population surveys meant for multi-purpose analysis consider a new Multidimensional Sex/Gender Measure for testing that includes three simple items (one asked only of a small sub-group) to assess gender

  6. Transgender-inclusive measures of sex/gender for population surveys: Mixed-methods evaluation and recommendations.

    Directory of Open Access Journals (Sweden)

    Greta R Bauer

    Full Text Available Given that an estimated 0.6% of the U.S. population is transgender (trans and that large health disparities for this population have been documented, government and research organizations are increasingly expanding measures of sex/gender to be trans inclusive. Options suggested for trans community surveys, such as expansive check-all-that-apply gender identity lists and write-in options that offer maximum flexibility, are generally not appropriate for broad population surveys. These require limited questions and a small number of categories for analysis. Limited evaluation has been undertaken of trans-inclusive population survey measures for sex/gender, including those currently in use. Using an internet survey and follow-up of 311 participants, and cognitive interviews from a maximum-diversity sub-sample (n = 79, we conducted a mixed-methods evaluation of two existing measures: a two-step question developed in the United States and a multidimensional measure developed in Canada. We found very low levels of item missingness, and no indicators of confusion on the part of cisgender (non-trans participants for both measures. However, a majority of interview participants indicated problems with each question item set. Agreement between the two measures in assessment of gender identity was very high (K = 0.9081, but gender identity was a poor proxy for other dimensions of sex or gender among trans participants. Issues to inform measure development or adaptation that emerged from analysis included dimensions of sex/gender measured, whether non-binary identities were trans, Indigenous and cultural identities, proxy reporting, temporality concerns, and the inability of a single item to provide a valid measure of sex/gender. Based on this evaluation, we recommend that population surveys meant for multi-purpose analysis consider a new Multidimensional Sex/Gender Measure for testing that includes three simple items (one asked only of a small sub-group to

  7. Transgender-inclusive measures of sex/gender for population surveys: Mixed-methods evaluation and recommendations

    Science.gov (United States)

    Bauer, Greta R.; Braimoh, Jessica; Scheim, Ayden I.; Dharma, Christoffer

    2017-01-01

    Given that an estimated 0.6% of the U.S. population is transgender (trans) and that large health disparities for this population have been documented, government and research organizations are increasingly expanding measures of sex/gender to be trans inclusive. Options suggested for trans community surveys, such as expansive check-all-that-apply gender identity lists and write-in options that offer maximum flexibility, are generally not appropriate for broad population surveys. These require limited questions and a small number of categories for analysis. Limited evaluation has been undertaken of trans-inclusive population survey measures for sex/gender, including those currently in use. Using an internet survey and follow-up of 311 participants, and cognitive interviews from a maximum-diversity sub-sample (n = 79), we conducted a mixed-methods evaluation of two existing measures: a two-step question developed in the United States and a multidimensional measure developed in Canada. We found very low levels of item missingness, and no indicators of confusion on the part of cisgender (non-trans) participants for both measures. However, a majority of interview participants indicated problems with each question item set. Agreement between the two measures in assessment of gender identity was very high (K = 0.9081), but gender identity was a poor proxy for other dimensions of sex or gender among trans participants. Issues to inform measure development or adaptation that emerged from analysis included dimensions of sex/gender measured, whether non-binary identities were trans, Indigenous and cultural identities, proxy reporting, temporality concerns, and the inability of a single item to provide a valid measure of sex/gender. Based on this evaluation, we recommend that population surveys meant for multi-purpose analysis consider a new Multidimensional Sex/Gender Measure for testing that includes three simple items (one asked only of a small sub-group) to assess gender

  8. The Clinical Assessment Study of the Hand (CAS-HA: a prospective study of musculoskeletal hand problems in the general population

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    Marshall Michelle

    2007-08-01

    Full Text Available Abstract Background Pain in the hand affects an estimated 12–21% of the population, and at older ages the hand is one of the most common sites of pain and osteoarthritis. The association between symptomatic hand osteoarthritis and disability in everyday life has not been studied in detail, although there is evidence that older people with hand problems suffer significant pain and disability. Despite the high prevalence of hand problems and the limitations they cause in older adults, little attention has been paid to the hand by health planners and policy makers. We plan to conduct a prospective, population-based, observational cohort study designed in parallel with our previously reported cohort study of knee pain, to describe the course of musculoskeletal hand problems in older adults and investigate the relative merits of different approaches to classification and defining prognosis. Methods/Design All adults aged 50 years and over registered with two general practices in North Staffordshire will be invited to take part in a two-stage postal survey. Respondents to the survey who indicate that they have experienced hand pain or problems within the previous 12 months will be invited to attend a research clinic for a detailed assessment. This will consist of clinical interview, hand assessment, screening test of lower limb function, digital photography, plain x-rays, anthropometric measurement and brief self-complete questionnaire. All consenting clinic attenders will be followed up by (i general practice medical record review, (ii repeat postal questionnaire at 18-months, and (iii repeat postal questionnaire at 3 years. Discussion This paper describes the protocol for the Clinical Assessment Study of the Hand (CAS-HA, a prospective, population-based, observational cohort study of community-dwelling older adults with hand pain and hand problems based in North Staffordshire.

  9. The association between serum 25-hydroxyvitamin D level and recurrent falls in the elderly population: a cohort study

    OpenAIRE

    Ghafouri, Hamed Basir; Zare, Morteza; Bazrafshan, Azam; Modirian, Ehsan; Mousavi, Afkham; Abazarian, Niloofar

    2016-01-01

    Introduction Serum vitamin D concentration is a major contributing factor for increasing the risk of fall and fall-related injuries in older adults. However, when prescribed and supplemented for these populations, the outcomes are controversial, and in several cases no improvement has been reported in reducing the risk of recurrent falls. This study aimed to examine the association between serum vitamin D concentration and recurrent falls in Iranian older adults. Methods This cohort study was...

  10. Trends in use of neonatal CPAP: a population-based study

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    Bowen Jennifer R

    2011-10-01

    Full Text Available Abstract Background Continuous positive airway pressure (CPAP is used widely to provide respiratory support for neonates, and is often the first treatment choice in tertiary centres. Recent trials have demonstrated that CPAP reduces need for intubation and ventilation for infants born at 25-28 weeks gestation, and at > 32weeks, in non-tertiary hospitals, CPAP reduces need for transfer to NICU. The aim of this study was to examine recent population trends in the use of neonatal continuous positive airway pressure. Methods We undertook a population-based cohort study of all 696,816 liveborn neonates ≥24 weeks gestation in New South Wales (NSW Australia, 2001-2008. Data were obtained from linked birth and hospitalizations records, including neonatal transfers. The primary outcome was CPAP without mechanical ventilation (via endotracheal intubation between birth and discharge from the hospital system. Analyses were stratified by age ≤32 and > 32 weeks gestation. Results Neonates receiving any ventilatory support increased from 1,480 (17.9/1000 in 2001 to 2,486 (26.9/1000 in 2008, including 461 (5.6/1000 to 1,465 (15.8/1000 neonates who received CPAP alone. There was a concurrent decrease in mechanical ventilation use from 12.3 to 11.0/1000. The increase in CPAP use was greater among neonates > 32 weeks (from 3.2 to 11.8/1000 compared with neonates ≤32 weeks (from 18.1 to 32.7/1000. The proportion of CPAP > 32 weeks initiated in non-tertiary hospitals increased from 6% to 30%. Conclusions The use of neonatal CPAP is increasing, especially > 32 weeks gestation and among non-tertiary hospitals. Recommendations are required regarding which infants should be considered for CPAP, resources necessary for a unit to offer CPAP and monitoring of longer term outcomes.

  11. Study of the uranium effects on energy budget and population dynamics in Daphnia magna

    International Nuclear Information System (INIS)

    Massarin, S.

    2010-01-01

    This work aimed to study effects of uranium on energy budget and population dynamics in Daphnia magna a representative micro-crustacean of freshwater ecosystems. An experimental study of uranium toxicity on physiology (nutrition, respiration) and life history (survival, growth and reproduction) of D. magna was carried out, based on exposures over one, two or three successive generations (F0, F1 and F2) started with neonates from 1. or 5. brood, at 0, 10, 25 and 75 μg U.L -1 . Results showed that toxic effects increased across generations (partially due to daphnid exposure during embryogenesis) and that individuals from 1. brood were more sensitive than individuals from 5. brood. Significant reductions in assimilation rates, measured using a radio-tracing method with 14 C-labelled food, allowed us to identify an effect on assimilation as the mode of action for uranium, in agreement with important damages in the integrity of intestinal epithelium observed by optic microscopy. Integrating results in a dynamic energy budget model (DEBtox) yielded estimated no effect concentrations (NEC) of 9.37, 8.21 and 2.31 μg U.L -1 above which organism functions were altered in generations F0, F1 and F2, respectively. Combining DEBtox with matrix models allowed us to extrapolate consequences on asymptotic population growth rate (λ), a relevant endpoint in an ecological context. Simulations predicted an increase in uranium impact across generations with reduction of λ in F0 and population extinctions at 51-59 μg U.L -1 in F1 and 39-41 μg U.L -1 in F2. Simulations emphasized the importance of considering the most sensitive individuals while determining population response. (author)

  12. Value of information methods to design a clinical trial in a small population to optimise a health economic utility function.

    Science.gov (United States)

    Pearce, Michael; Hee, Siew Wan; Madan, Jason; Posch, Martin; Day, Simon; Miller, Frank; Zohar, Sarah; Stallard, Nigel

    2018-02-08

    Most confirmatory randomised controlled clinical trials (RCTs) are designed with specified power, usually 80% or 90%, for a hypothesis test conducted at a given significance level, usually 2.5% for a one-sided test. Approval of the experimental treatment by regulatory agencies is then based on the result of such a significance test with other information to balance the risk of adverse events against the benefit of the treatment to future patients. In the setting of a rare disease, recruiting sufficient patients to achieve conventional error rates for clinically reasonable effect sizes may be infeasible, suggesting that the decision-making process should reflect the size of the target population. We considered the use of a decision-theoretic value of information (VOI) method to obtain the optimal sample size and significance level for confirmatory RCTs in a range of settings. We assume the decision maker represents society. For simplicity we assume the primary endpoint to be normally distributed with unknown mean following some normal prior distribution representing information on the anticipated effectiveness of the therapy available before the trial. The method is illustrated by an application in an RCT in haemophilia A. We explicitly specify the utility in terms of improvement in primary outcome and compare this with the costs of treating patients, both financial and in terms of potential harm, during the trial and in the future. The optimal sample size for the clinical trial decreases as the size of the population decreases. For non-zero cost of treating future patients, either monetary or in terms of potential harmful effects, stronger evidence is required for approval as the population size increases, though this is not the case if the costs of treating future patients are ignored. Decision-theoretic VOI methods offer a flexible approach with both type I error rate and power (or equivalently trial sample size) depending on the size of the future population for

  13. A STUDY ON FEMORAL ANTEVERSION IN ADULT DRY FEMORA OF SOUTH INDIAN POPULATION

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    Sushma Korukonda

    2017-01-01

    Full Text Available BACKGROUND Femoral Neck Anteversion (FNA is an important parameter for diagnosis of gait abnormality in children, risk of various congenital and acquired orthopaedic disorders as well as corrective osteotomy and hip arthroplasty. Femoral anteversion is the lateral rotation of the neck of the femur to the long axis of its shaft. Variability in FNA has been reported and is due to torsional forces applied on femur during development. The aim of this study was to estimate the angle of anteversion of femur in both genders on both sides. The present study was an attempt to provide baseline data of FNA in South Indian population, in particular, Andhra Pradesh. MATERIALS AND METHODS The study was conducted mechanically on 70 dried adult unpaired human femora, i.e. 48 male and 22 female bones. The Kingsley Olmsted 1 method was used for the study and the data was analysed. Statistical analysis - Statistical analysis was done using student unpaired ‘t’ test. The data was analysed using GraphPad Prism 5.0 (Free Trial Version. RESULTS Out of the 70 femora undertaken, mean value of FNA obtained in male is 15.95, 14.1 on right and 17.8 on left sides and in female it is 19.2, 21.8 on right and 16.6 on left side. Statistical analysis revealed significant (p < 0.05 greater average anteversion in female bones and right-left variations being greater on the left side. CONCLUSION In the present study, the mean FNA was 17.8 deg. There was a gender variation for the FNA values in the population studied with females showing higher value than the male with a statistically significant difference. The reason for the difference obtained could be the small sample size of female femora due to the rarity of the donated female bodies. The value was higher on the left side than the right; 50% of the femora had the range of 16 - 25 deg of FNA. The overall mean of femoral anteversion determined is very much different from the studies in various regions in India.

  14. International Collaboration for the Epidemiology of eGFR in Low and Middle Income Populations - Rationale and core protocol for the Disadvantaged Populations eGFR Epidemiology Study (DEGREE).

    Science.gov (United States)

    Caplin, Ben; Jakobsson, Kristina; Glaser, Jason; Nitsch, Dorothea; Jha, Vivekanand; Singh, Ajay; Correa-Rotter, Ricardo; Pearce, Neil

    2017-01-03

    There is an increasing recognition of epidemics of primarily tubular-interstitial chronic kidney disease (CKD) clustering in agricultural communities in low- and middle-income countries (LMICs). Although it is currently unclear whether there is a unified underlying aetiology, these conditions have been collectively termed CKD of undetermined cause (CKDu). CKDu is estimated to have led to the premature deaths of tens to hundreds of thousands of young men and women over the last 2 decades. Thus, there is an urgent need to understand the aetiology and pathophysiology of these condition (s). International comparisons have provided the first steps in understanding many chronic diseases, but such comparisons rely on the availability of standardised tools to estimate disease prevalence. This is a particular problem with CKD, since the disease is asymptomatic until the late stages, and the biases inherent in the methods used to estimate the glomerular filtration rate (GFR) in population studies are highly variable across populations. We therefore propose a simple standardised protocol to estimate the distribution of GFR in LMIC populations - The Disadvantaged Populations eGFR Epidemiology (DEGREE) Study. This involves the quantification of renal function in a representative adult population-based sample and a requirement for standardisation of serum creatinine measurements, along with storage of samples for future measurements of cystatin C and ascertainment of estimates of body composition, in order to obtain valid comparisons of estimated GFR (eGFR) within and between populations. The methodology we present is potentially applicable anywhere, but our particular focus is on disadvantaged populations in LMICs, since these appear to be most susceptible to CKDu. Although the protocol could also be used in specific groups (e.g. occupational groups, thought to be at excess risk of CKDu) the primary aim of the DEGREE project is characterise the population distribution of e

  15. Population specific biomarkers of human aging: a big data study using South Korean, Canadian and Eastern European patient populations.

    Science.gov (United States)

    Mamoshina, Polina; Kochetov, Kirill; Putin, Evgeny; Cortese, Franco; Aliper, Alexander; Lee, Won-Suk; Ahn, Sung-Min; Uhn, Lee; Skjodt, Neil; Kovalchuk, Olga; Scheibye-Knudsen, Morten; Zhavoronkov, Alex

    2018-01-11

    Accurate and physiologically meaningful biomarkers for human aging are key to assessing anti-aging therapies. Given ethnic differences in health, diet, lifestyle, behaviour, environmental exposures and even average rate of biological aging, it stands to reason that aging clocks trained on datasets obtained from specific ethnic populations are more likely to account for these potential confounding factors, resulting in an enhanced capacity to predict chronological age and quantify biological age. Here we present a deep learning-based hematological aging clock modeled using the large combined dataset of Canadian, South Korean and Eastern European population blood samples that show increased predictive accuracy in individual populations compared to population-specific hematologic aging clocks. The performance of models was also evaluated on publicly-available samples of the American population from the National Health and Nutrition Examination Survey (NHANES). In addition, we explored the association between age predicted by both population-specific and combined hematological clocks and all-cause mortality. Overall, this study suggests a) the population-specificity of aging patterns and b) hematologic clocks predicts all-cause mortality. Proposed models added to the freely available Aging.AI system allowing improved ability to assess human aging. © The Author(s) 2018. Published by Oxford University Press on behalf of The Gerontological Society of America.

  16. Impaired Fertility Associated with Subclinical Hypothyroidism and Thyroid Autoimmunity: The Danish General Suburban Population Study

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    Anne-Dorthe Feldthusen

    2015-01-01

    Full Text Available Introduction. The aim of this study was to estimate the significance of TSH, thyroid peroxidase antibody (TPOAb, and mild (subclinical hypothyroidism in women from The Danish General Suburban Population Study (GESUS on the number of children born, the number of pregnancies, and the number of spontaneous abortions. Methods. Retrospective cross sectional study of 11254 women participating in GESUS. Data included biochemical measurements and a self-administrated questionnaire. Results. 6.7% had mild (subclinical hypothyroidism and 9.4% prevalent hypothyroidism. In women with mild hypothyroidism TPOAb was significantly elevated and age at first child was older compared to controls. TSH and TPOAb were negatively linearly associated with the number of children born and the number of pregnancies in the full cohort in age-adjusted and multiadjusted models. TSH or TPOAb was not associated with spontaneous abortions. Mild (subclinical hypothyroidism was associated with a risk of not having children and a risk of not getting pregnant in age-adjusted and multiadjusted models. Prevalent hypothyroidism was not associated with the number of children born, the number of pregnancies, or spontaneous abortions. Conclusion. Impaired fertility is associated with TSH, TPOAb, and mild (subclinical hypothyroidism in a Danish population of women.

  17. Studies on population dynamic of diamondback moth in the field

    International Nuclear Information System (INIS)

    Malakrong, A.; Limohpasmanee, W.; Keawchoung, P.; Kodcharint, P.

    1994-01-01

    The population dynamic of diamondback moth larva in the field was studied at Khao Khor High-land Agricultural Research Station during August-October 1993 and February-April 1994. The distribution patterns of diamondback moth larva was clumped when population was low and would change to be random when population was high. The maximun and minimum number of diamondback moth in the field were 71,203 and 2,732 larva/rai during March and September. Temperature, rainfall and age of cabbage were slightly relative with number of larva (r=-0.2891, p=0.30; r=-0.2816, p=0.31 and r=0.2931, p=0.29 respectively) but relative humidity has no effect on number of larva

  18. Genetic determinants of lipid traits in diverse populations from the population architecture using genomics and epidemiology (PAGE study.

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    Logan Dumitrescu

    2011-06-01

    Full Text Available For the past five years, genome-wide association studies (GWAS have identified hundreds of common variants associated with human diseases and traits, including high-density lipoprotein cholesterol (HDL-C, low-density lipoprotein cholesterol (LDL-C, and triglyceride (TG levels. Approximately 95 loci associated with lipid levels have been identified primarily among populations of European ancestry. The Population Architecture using Genomics and Epidemiology (PAGE study was established in 2008 to characterize GWAS-identified variants in diverse population-based studies. We genotyped 49 GWAS-identified SNPs associated with one or more lipid traits in at least two PAGE studies and across six racial/ethnic groups. We performed a meta-analysis testing for SNP associations with fasting HDL-C, LDL-C, and ln(TG levels in self-identified European American (~20,000, African American (~9,000, American Indian (~6,000, Mexican American/Hispanic (~2,500, Japanese/East Asian (~690, and Pacific Islander/Native Hawaiian (~175 adults, regardless of lipid-lowering medication use. We replicated 55 of 60 (92% SNP associations tested in European Americans at p<0.05. Despite sufficient power, we were unable to replicate ABCA1 rs4149268 and rs1883025, CETP rs1864163, and TTC39B rs471364 previously associated with HDL-C and MAFB rs6102059 previously associated with LDL-C. Based on significance (p<0.05 and consistent direction of effect, a majority of replicated genotype-phentoype associations for HDL-C, LDL-C, and ln(TG in European Americans generalized to African Americans (48%, 61%, and 57%, American Indians (45%, 64%, and 77%, and Mexican Americans/Hispanics (57%, 56%, and 86%. Overall, 16 associations generalized across all three populations. For the associations that did not generalize, differences in effect sizes, allele frequencies, and linkage disequilibrium offer clues to the next generation of association studies for these traits.

  19. Genetic Determinants of Lipid Traits in Diverse Populations from the Population Architecture using Genomics and Epidemiology (PAGE) Study

    Science.gov (United States)

    Dumitrescu, Logan; Carty, Cara L.; Taylor, Kira; Schumacher, Fredrick R.; Hindorff, Lucia A.; Ambite, José L.; Anderson, Garnet; Best, Lyle G.; Brown-Gentry, Kristin; Bůžková, Petra; Carlson, Christopher S.; Cochran, Barbara; Cole, Shelley A.; Devereux, Richard B.; Duggan, Dave; Eaton, Charles B.; Fornage, Myriam; Franceschini, Nora; Haessler, Jeff; Howard, Barbara V.; Johnson, Karen C.; Laston, Sandra; Kolonel, Laurence N.; Lee, Elisa T.; MacCluer, Jean W.; Manolio, Teri A.; Pendergrass, Sarah A.; Quibrera, Miguel; Shohet, Ralph V.; Wilkens, Lynne R.; Haiman, Christopher A.; Le Marchand, Loïc; Buyske, Steven; Kooperberg, Charles; North, Kari E.; Crawford, Dana C.

    2011-01-01

    For the past five years, genome-wide association studies (GWAS) have identified hundreds of common variants associated with human diseases and traits, including high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) levels. Approximately 95 loci associated with lipid levels have been identified primarily among populations of European ancestry. The Population Architecture using Genomics and Epidemiology (PAGE) study was established in 2008 to characterize GWAS–identified variants in diverse population-based studies. We genotyped 49 GWAS–identified SNPs associated with one or more lipid traits in at least two PAGE studies and across six racial/ethnic groups. We performed a meta-analysis testing for SNP associations with fasting HDL-C, LDL-C, and ln(TG) levels in self-identified European American (∼20,000), African American (∼9,000), American Indian (∼6,000), Mexican American/Hispanic (∼2,500), Japanese/East Asian (∼690), and Pacific Islander/Native Hawaiian (∼175) adults, regardless of lipid-lowering medication use. We replicated 55 of 60 (92%) SNP associations tested in European Americans at p<0.05. Despite sufficient power, we were unable to replicate ABCA1 rs4149268 and rs1883025, CETP rs1864163, and TTC39B rs471364 previously associated with HDL-C and MAFB rs6102059 previously associated with LDL-C. Based on significance (p<0.05) and consistent direction of effect, a majority of replicated genotype-phentoype associations for HDL-C, LDL-C, and ln(TG) in European Americans generalized to African Americans (48%, 61%, and 57%), American Indians (45%, 64%, and 77%), and Mexican Americans/Hispanics (57%, 56%, and 86%). Overall, 16 associations generalized across all three populations. For the associations that did not generalize, differences in effect sizes, allele frequencies, and linkage disequilibrium offer clues to the next generation of association studies for these traits. PMID:21738485

  20. [Epidemiological study of hypertension in Dongxiang population of Dongxiang county in Gansu province].

    Science.gov (United States)

    Li, X H; Qiao, Y; Xie, P; Ma, H Z; Ma, Y A

    2016-09-24

    Objective: To investigate the prevalence, awareness, treatment and control rate of hypertension among Dongxiang population of Dongxiang county in Gansu province, and analyze risk factors of hypertension in this population. Methods: A total of 1 879 Dongxiang residents of Dongxiang county in Gansu province aged 18 years and over were selected in one town and eight villages by random cluster method from April to June in 2014. All subjects were interviewed and physical examination including blood pressure measurement was performed. Multivariate logistic regression analysis was used to analyze the risk factors of hypertension. Results: Prevalence of hypertension in this population was 21.4%(402/1 879). Prevalence of hypertension increased with aging and was 7.9%(35/441) in 18-39 years old people, and 20.2%(151/749)in 40-59 years old people, and 31.3%(216/689)in ≥60 years old people ( P old group (8.0%(20/249)vs. 7.8%(15/192), P >0.05) and 40-59 years old group (19.8%(78/393) vs. 20.5%(73/356), P >0.05), while the prevalence of hypertension was significantly higher in male than in female(34.2%(123/360) vs. 28.3%(93/329), P old group. Prevalence of hypertension was also significantly higher in rural area residents than in county town residents (23.4%(255/1 090) vs.18.6%(147/789), P county residents. Multivariate logistic regression analysis showed that age, family history of hypertension, high body mass index, less physical activity and more static state were risk factors of hypertension in this population( P county in Gansu province. Hypertension prevention focusing on risk factors control and treatment strategies should be enhanced in this population.