Feline mitochondrial DNA sampling for forensic analysis: when enough is enough!

PubMed

Grahn, Robert A; Alhaddad, Hasan; Alves, Paulo C; Randi, Ettore; Waly, Nashwa E; Lyons, Leslie A

2015-05-01

Pet hair has a demonstrated value in resolving legal issues. Cat hair is chronically shed and it is difficult to leave a home with cats without some level of secondary transfer. The power of cat hair as an evidentiary resource may be underused because representative genetic databases are not available for exclusionary purposes. Mitochondrial control region databases are highly valuable for hair analyses and have been developed for the cat. In a representative worldwide data set, 83% of domestic cat mitotypes belong to one of twelve major types. Of the remaining 17%, 7.5% are unique within the published 1394 sample database. The current research evaluates the sample size necessary to establish a representative population for forensic comparison of the mitochondrial control region for the domestic cat. For most worldwide populations, randomly sampling 50 unrelated local individuals will achieve saturation at 95%. The 99% saturation is achieved by randomly sampling 60-170 cats, depending on the numbers of mitotypes available in the population at large. Likely due to the recent domestication of the cat and minimal localized population substructure, fewer cats are needed to meet mitochondria DNA control region database practical saturation than for humans or dogs. Coupled with the available worldwide feline control region database of nearly 1400 cats, minimal local sampling will be required to establish an appropriate comparative representative database and achieve significant exclusionary power. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Point-Sampling and Line-Sampling Probability Theory, Geometric Implications, Synthesis

Treesearch

L.R. Grosenbaugh

1958-01-01

Foresters concerned with measuring tree populations on definite areas have long employed two well-known methods of representative sampling. In list or enumerative sampling the entire tree population is tallied with a known proportion being randomly selected and measured for volume or other variables. In area sampling all trees on randomly located plots or strips...

Online Recruitment: Feasibility, Cost, and Representativeness in a Study of Postpartum Women.

PubMed

Leach, Liana S; Butterworth, Peter; Poyser, Carmel; Batterham, Philip J; Farrer, Louise M

2017-03-08

Online recruitment is feasible, low-cost, and can provide high-quality epidemiological data. However, little is known about the feasibility of recruiting postpartum women online, or sample representativeness. The current study investigates the feasibility of recruiting a population of postpartum women online for health research and examines sample representativeness. Two samples of postpartum women were compared: those recruited online as participants in a brief survey of new mothers (n=1083) and those recruited face-to-face as part of a nationally representative study (n=579). Sociodemographic, general health, and mental health characteristics were compared between the two samples. Obtaining a sample of postpartum women online for health research was highly efficient and low-cost. The online sample over-represented those who were younger (aged 25-29 years), were in a de facto relationship, had higher levels of education, spoke only English at home, and were first-time mothers. Members of the online sample were significantly more likely to have poor self-rated health and poor mental health than the nationally representative sample. Health differences remained after adjusting for sociodemographic differences. Potential exists for feasible and low-cost e-epidemiological research with postpartum populations; however, researchers should consider the potential influence of sample nonrepresentativeness. ©Liana S Leach, Peter Butterworth, Carmel Poyser, Philip J Batterham, Louise M Farrer. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 08.03.2017.

Sampling in epidemiological research: issues, hazards and pitfalls.

PubMed

Tyrer, Stephen; Heyman, Bob

2016-04-01

Surveys of people's opinions are fraught with difficulties. It is easier to obtain information from those who respond to text messages or to emails than to attempt to obtain a representative sample. Samples of the population that are selected non-randomly in this way are termed convenience samples as they are easy to recruit. This introduces a sampling bias. Such non-probability samples have merit in many situations, but an epidemiological enquiry is of little value unless a random sample is obtained. If a sufficient number of those selected actually complete a survey, the results are likely to be representative of the population. This editorial describes probability and non-probability sampling methods and illustrates the difficulties and suggested solutions in performing accurate epidemiological research.

Sampling in epidemiological research: issues, hazards and pitfalls

PubMed Central

Tyrer, Stephen; Heyman, Bob

2016-01-01

Surveys of people's opinions are fraught with difficulties. It is easier to obtain information from those who respond to text messages or to emails than to attempt to obtain a representative sample. Samples of the population that are selected non-randomly in this way are termed convenience samples as they are easy to recruit. This introduces a sampling bias. Such non-probability samples have merit in many situations, but an epidemiological enquiry is of little value unless a random sample is obtained. If a sufficient number of those selected actually complete a survey, the results are likely to be representative of the population. This editorial describes probability and non-probability sampling methods and illustrates the difficulties and suggested solutions in performing accurate epidemiological research. PMID:27087985

Analysis of genetic data on Jewish populations. I. Historical background, demographic features, and genetic markers.

PubMed Central

Bonné-Tamir, B; Karlin, S; Kenett, R

1979-01-01

Part I describes the data sets on which the analysis of Part II is based. This covers the nature of the populations sampled, the extent to which the samples are representative, and a brief review of historical and demographic facts on the populations involved. PMID:380329

Stratification of American hearing aid users by age and audiometric characteristics: a method for representative sampling.

PubMed

Aronoff, Justin M; Yoon, Yang-soo; Soli, Sigfrid D

2010-06-01

Stratified sampling plans can increase the accuracy and facilitate the interpretation of a dataset characterizing a large population. However, such sampling plans have found minimal use in hearing aid (HA) research, in part because of a paucity of quantitative data on the characteristics of HA users. The goal of this study was to devise a quantitatively derived stratified sampling plan for HA research, so that such studies will be more representative and generalizable, and the results obtained using this method are more easily reinterpreted as the population changes. Pure-tone average (PTA) and age information were collected for 84,200 HAs acquired in 2006 and 2007. The distribution of PTA and age was quantified for each HA type and for a composite of all HA users. Based on their respective distributions, PTA and age were each divided into three groups, the combination of which defined the stratification plan. The most populous PTA and age group was also subdivided, allowing greater homogeneity within strata. Finally, the percentage of users in each stratum was calculated. This article provides a stratified sampling plan for HA research, based on a quantitative analysis of the distribution of PTA and age for HA users. Adopting such a sampling plan will make HA research results more representative and generalizable. In addition, data acquired using such plans can be reinterpreted as the HA population changes.

Community BMI Surveillance Using an Existing Immunization Registry in San Diego, California.

PubMed

Ratigan, Amanda R; Lindsay, Suzanne; Lemus, Hector; Chambers, Christina D; Anderson, Cheryl A M; Cronan, Terry A; Browner, Deirdre K; Wooten, Wilma J

2017-06-01

This study examines the demographic representativeness of the County of San Diego Body Mass Index (BMI) Surveillance System to determine if the BMI estimates being obtained from this convenience sample of individuals who visited their healthcare provider for outpatient services can be generalized to the general population of San Diego. Height and weight were transmitted from electronic health records systems to the San Diego Immunization Registry (SDIR). Age, gender, and race/ethnicity of this sample are compared to general population estimates by sub-regional area (SRA) (n = 41) to account for regional demographic differences. A < 10% difference (calculated as the ratio of the differences between the frequencies of a sub-group in this sample and general population estimates obtained from the U.S. Census Bureau) was used to determine representativeness. In 2011, the sample consisted of 352,924 residents aged 2-100 years. The younger age groups (2-11, 12-17 years) and the oldest age group (≥65 years) were representative in 90, 75, and 85% of SRAs, respectively. Furthermore, at least one of the five racial/ethnic groups was represented in 71% of SRAs. This BMI Surveillance System was found to demographically represent some SRAs well, suggesting that this registry-based surveillance system may be useful in estimating and monitoring neighborhood-level BMI data.

Are we using the appropriate reference samples to develop juvenile age estimation methods based on bone size? An exploration of growth differences between average children and those who become victims of homicide.

PubMed

Spake, Laure; Cardoso, Hugo F V

2018-01-01

The population on which forensic juvenile skeletal age estimation methods are applied has not been critically considered. Previous research suggests that child victims of homicide tend to be from socioeconomically disadvantaged contexts, and that these contexts impair linear growth. This study investigates whether juvenile skeletal remains examined by forensic anthropologists are short for age compared to their normal healthy peers. Cadaver lengths were obtained from records of autopsies of 1256 individuals, aged birth to eighteen years at death, conducted between 2000 and 2015 in Australia, New Zealand, and the U.S. Growth status of the forensic population, represented by homicide victims, and general population, represented by accident victims, were compared using height for age Z-scores and independent sample t-tests. Cadaver lengths of the accident victims were compared to growth references using one sample t-tests to evaluate whether accident victims reflect the general population. Homicide victims are shorter for age than accident victims in samples from the U.S., but not in Australia and New Zealand. Accident victims are more representative of the general population in Australia and New Zealand. Different results in Australia and New Zealand as opposed to the U.S. may be linked to socioeconomic inequality. These results suggest that physical anthropologists should critically select reference samples when devising forensic juvenile skeletal age estimation methods. Children examined in forensic investigations may be short for age, and thus methods developed on normal healthy children may yield inaccurate results. A healthy reference population may not necessarily constitute an appropriate growth comparison for the forensic anthropology population. Copyright © 2017 Elsevier B.V. All rights reserved.

Genetic analysis of haplotype data for 23 Y-chromosome short tandem repeat loci in the Turkish population recently settled in Sarajevo, Bosnia and Herzegovina.

PubMed

Dogan, Serkan; Primorac, Dragan; Marjanović, Damir

2014-10-01

To explore the distribution and polymorphisms of 23 short tandem repeat (STR) loci on the Y chromosome in the Turkish population recently settled in Sarajevo, Bosnia and Herzegovina and to investigate its genetic relationships with the homeland Turkish population and neighboring populations. This study included 100 healthy unrelated male individuals from the Turkish population living in Sarajevo. Buccal swab samples were collected as a DNA source. Genomic DNA was extracted using the salting out method and amplification was performed using PowerPlex Y 23 amplification kit. The studied population was compared to other populations using pairwise genetic distances, which were represented with a multi-dimensional scaling plot. Haplotype and allele frequencies of the sample population were calculated and the results showed that all 100 samples had unique haplotypes. The most polymorphic locus was DYS458, and the least polymorphic DYS391. The observed haplotype diversity was 1.0000 ± 0.0014, with a discrimination capacity of 1.00 and the match probability of 0.01. Rst values showed that our sample population was closely related in both dimensions to the Lebanese and Iraqi populations, while it was more distant from Bosnian, Croatian, and Macedonian populations. Turkish population residing in Sarajevo could be observed as a representative Turkish population, since our results were consistent with those previously published for the homeland Turkish population. Also, this study once again proved that geographically close populations were genetically more related to each other.

Towards a system level understanding of non-model organisms sampled from the environment: a network biology approach.

PubMed

Williams, Tim D; Turan, Nil; Diab, Amer M; Wu, Huifeng; Mackenzie, Carolynn; Bartie, Katie L; Hrydziuszko, Olga; Lyons, Brett P; Stentiford, Grant D; Herbert, John M; Abraham, Joseph K; Katsiadaki, Ioanna; Leaver, Michael J; Taggart, John B; George, Stephen G; Viant, Mark R; Chipman, Kevin J; Falciani, Francesco

2011-08-01

The acquisition and analysis of datasets including multi-level omics and physiology from non-model species, sampled from field populations, is a formidable challenge, which so far has prevented the application of systems biology approaches. If successful, these could contribute enormously to improving our understanding of how populations of living organisms adapt to environmental stressors relating to, for example, pollution and climate. Here we describe the first application of a network inference approach integrating transcriptional, metabolic and phenotypic information representative of wild populations of the European flounder fish, sampled at seven estuarine locations in northern Europe with different degrees and profiles of chemical contaminants. We identified network modules, whose activity was predictive of environmental exposure and represented a link between molecular and morphometric indices. These sub-networks represented both known and candidate novel adverse outcome pathways representative of several aspects of human liver pathophysiology such as liver hyperplasia, fibrosis, and hepatocellular carcinoma. At the molecular level these pathways were linked to TNF alpha, TGF beta, PDGF, AGT and VEGF signalling. More generally, this pioneering study has important implications as it can be applied to model molecular mechanisms of compensatory adaptation to a wide range of scenarios in wild populations.

Towards a System Level Understanding of Non-Model Organisms Sampled from the Environment: A Network Biology Approach

PubMed Central

Williams, Tim D.; Turan, Nil; Diab, Amer M.; Wu, Huifeng; Mackenzie, Carolynn; Bartie, Katie L.; Hrydziuszko, Olga; Lyons, Brett P.; Stentiford, Grant D.; Herbert, John M.; Abraham, Joseph K.; Katsiadaki, Ioanna; Leaver, Michael J.; Taggart, John B.; George, Stephen G.; Viant, Mark R.; Chipman, Kevin J.; Falciani, Francesco

2011-01-01

The acquisition and analysis of datasets including multi-level omics and physiology from non-model species, sampled from field populations, is a formidable challenge, which so far has prevented the application of systems biology approaches. If successful, these could contribute enormously to improving our understanding of how populations of living organisms adapt to environmental stressors relating to, for example, pollution and climate. Here we describe the first application of a network inference approach integrating transcriptional, metabolic and phenotypic information representative of wild populations of the European flounder fish, sampled at seven estuarine locations in northern Europe with different degrees and profiles of chemical contaminants. We identified network modules, whose activity was predictive of environmental exposure and represented a link between molecular and morphometric indices. These sub-networks represented both known and candidate novel adverse outcome pathways representative of several aspects of human liver pathophysiology such as liver hyperplasia, fibrosis, and hepatocellular carcinoma. At the molecular level these pathways were linked to TNF alpha, TGF beta, PDGF, AGT and VEGF signalling. More generally, this pioneering study has important implications as it can be applied to model molecular mechanisms of compensatory adaptation to a wide range of scenarios in wild populations. PMID:21901081

Improvement of Predictive Ability by Uniform Coverage of the Target Genetic Space

PubMed Central

Bustos-Korts, Daniela; Malosetti, Marcos; Chapman, Scott; Biddulph, Ben; van Eeuwijk, Fred

2016-01-01

Genome-enabled prediction provides breeders with the means to increase the number of genotypes that can be evaluated for selection. One of the major challenges in genome-enabled prediction is how to construct a training set of genotypes from a calibration set that represents the target population of genotypes, where the calibration set is composed of a training and validation set. A random sampling protocol of genotypes from the calibration set will lead to low quality coverage of the total genetic space by the training set when the calibration set contains population structure. As a consequence, predictive ability will be affected negatively, because some parts of the genotypic diversity in the target population will be under-represented in the training set, whereas other parts will be over-represented. Therefore, we propose a training set construction method that uniformly samples the genetic space spanned by the target population of genotypes, thereby increasing predictive ability. To evaluate our method, we constructed training sets alongside with the identification of corresponding genomic prediction models for four genotype panels that differed in the amount of population structure they contained (maize Flint, maize Dent, wheat, and rice). Training sets were constructed using uniform sampling, stratified-uniform sampling, stratified sampling and random sampling. We compared these methods with a method that maximizes the generalized coefficient of determination (CD). Several training set sizes were considered. We investigated four genomic prediction models: multi-locus QTL models, GBLUP models, combinations of QTL and GBLUPs, and Reproducing Kernel Hilbert Space (RKHS) models. For the maize and wheat panels, construction of the training set under uniform sampling led to a larger predictive ability than under stratified and random sampling. The results of our methods were similar to those of the CD method. For the rice panel, all training set construction methods led to similar predictive ability, a reflection of the very strong population structure in this panel. PMID:27672112

Basin Visual Estimation Technique (BVET) and Representative Reach Approaches to Wadeable Stream Surveys: Methodological Limitations and Future Directions

Treesearch

Lance R. Williams; Melvin L. Warren; Susan B. Adams; Joseph L. Arvai; Christopher M. Taylor

2004-01-01

Basin Visual Estimation Techniques (BVET) are used to estimate abundance for fish populations in small streams. With BVET, independent samples are drawn from natural habitat units in the stream rather than sampling "representative reaches." This sampling protocol provides an alternative to traditional reach-level surveys, which are criticized for their lack...

Limits of Generalizing in Education Research: Why Criteria for Research Generalization Should Include Population Heterogeneity and Uses of Knowledge Claims

ERIC Educational Resources Information Center

Ercikan, Kadriye; Roth, Wolff-Michael

2014-01-01

Context: Generalization is a critical concept in all research designed to generate knowledge that applies to all elements of a unit (population) while studying only a subset of these elements (sample). Commonly applied criteria for generalizing focus on experimental design or representativeness of samples of the population of units. The criteria…

Effective School-Community Relations as a Key Performance Indicator for the Secondary School Administrator in Aba South District, Nigeria

ERIC Educational Resources Information Center

Abraham, Nath. M.; Ememe, Ogbonna N.

2012-01-01

This study investigates Effective School-Community Relations as a key Performance Indicator (KPI) of Secondary Schools Administrator in Aba South District, Nigeria. Descriptive survey method was adopted. All the 248 teachers made up the population and sample in a purposive sampling technique representing 100% of the entire population as sample. A…

Inheritance of Properties of Normal and Non-Normal Distributions after Transformation of Scores to Ranks

ERIC Educational Resources Information Center

Zimmerman, Donald W.

2011-01-01

This study investigated how population parameters representing heterogeneity of variance, skewness, kurtosis, bimodality, and outlier-proneness, drawn from normal and eleven non-normal distributions, also characterized the ranks corresponding to independent samples of scores. When the parameters of population distributions from which samples were…

Genetic analysis of haplotype data for 23 Y-chromosome short tandem repeat loci in the Turkish population recently settled in Sarajevo, Bosnia and Herzegovina

PubMed Central

Dogan, Serkan; Primorac, Dragan; Marjanović, Damir

2014-01-01

Aim To explore the distribution and polymorphisms of 23 short tandem repeat (STR) loci on the Y chromosome in the Turkish population recently settled in Sarajevo, Bosnia and Herzegovina and to investigate its genetic relationships with the homeland Turkish population and neighboring populations. Methods This study included 100 healthy unrelated male individuals from the Turkish population living in Sarajevo. Buccal swab samples were collected as a DNA source. Genomic DNA was extracted using the salting out method and amplification was performed using PowerPlex Y 23 amplification kit. The studied population was compared to other populations using pairwise genetic distances, which were represented with a multi-dimensional scaling plot. Results Haplotype and allele frequencies of the sample population were calculated and the results showed that all 100 samples had unique haplotypes. The most polymorphic locus was DYS458, and the least polymorphic DYS391. The observed haplotype diversity was 1.0000 ± 0.0014, with a discrimination capacity of 1.00 and the match probability of 0.01. Rst values showed that our sample population was closely related in both dimensions to the Lebanese and Iraqi populations, while it was more distant from Bosnian, Croatian, and Macedonian populations. Conclusion Turkish population residing in Sarajevo could be observed as a representative Turkish population, since our results were consistent with those previously published for the homeland Turkish population. Also, this study once again proved that geographically close populations were genetically more related to each other. PMID:25358886

Predicting Posttraumatic Stress Symptoms Longitudinally in a Representative Sample of Hospitalized Injured Adolescents

ERIC Educational Resources Information Center

Zatzick, Douglas F.; Grossman, David C.; Russo, Joan; Pynoos, Robert; Berliner, Lucy; Jurkovich, Gregory; Sabin, Janice A.; Katon, Wayne; Ghesquiere, Angela; McCauley, Elizabeth; Rivara, Frederick P.

2006-01-01

Objective: Adolescents constitute a high-risk population for traumatic physical injury, yet few longitudinal investigations have assessed the development of posttraumatic stress disorder (PTSD) symptoms over time in representative samples. Method: Between July 2002 and August 2003,108 randomly selected injured adolescent patients ages 12 to 18 and…

Sociodemographic Differences in Depressed Mood: Results from a Nationally Representative Sample of High School Adolescents

ERIC Educational Resources Information Center

Paxton, Raheem J.; Valois, Robert F.; Watkins, Ken W.; Huebner, E. Scott; Drane, J. Wanzer

2007-01-01

Background: Research on adolescent mental health suggests that prevalence rates for depressed mood are not uniformly distributed across all populations. This study examined demographic difference in depressed mood among a nationally representative sample of high school adolescents. Methods: The 2003 National Youth Risk Behavior Survey was utilized…

Recruiting and retaining youth and young adults: challenges and opportunities in survey research for tobacco control.

PubMed

Cantrell, Jennifer; Hair, Elizabeth C; Smith, Alexandria; Bennett, Morgane; Rath, Jessica Miller; Thomas, Randall K; Fahimi, Mansour; Dennis, J Michael; Vallone, Donna

2018-03-01

Evaluation studies of population-based tobacco control interventions often rely on large-scale survey data from numerous respondents across many geographic areas to provide evidence of their effectiveness. Significant challenges for survey research have emerged with the evolving communications landscape, particularly for surveying hard-to-reach populations such as youth and young adults. This study combines the comprehensive coverage of an address-based sampling (ABS) frame with the timeliness of online data collection to develop a nationally representative longitudinal cohort of young people aged 15-21. We constructed an ABS frame, partially supplemented with auxiliary data, to recruit this hard-to-reach sample. Branded and tested mail-based recruitment materials were designed to bring respondents online for screening, consent and surveying. Once enrolled, respondents completed online surveys every 6 months via computer, tablet or smartphone. Numerous strategies were utilized to enhance retention and representativeness RESULTS: Results detail sample performance, representativeness and retention rates as well as device utilization trends for survey completion among youth and young adult respondents. Panel development efforts resulted in a large, nationally representative sample with high retention rates. This study is among the first to employ this hybrid ABS-to-online methodology to recruit and retain youth and young adults in a probability-based online cohort panel. The approach is particularly valuable for conducting research among younger populations as it capitalizes on their increasing access to and comfort with digital communication. We discuss challenges and opportunities of panel recruitment and retention methods in an effort to provide valuable information for tobacco control researchers seeking to obtain representative, population-based samples of youth and young adults in the U.S. as well as across the globe. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

[Prevalence of Variants in the Apolipoprotein E (APOE) Gene in a General Population of Adults from an Urban Area of Medellin (Antioquia)].

PubMed

Arango Viana, Juan Carlos; Valencia, Ana Victoria; Páez, Ana Lucía; Montoya Gómez, Nilton; Palacio, Carlos; Arbeláez, María Patricia; Bedoya Berrío, Gabriel; García Valencia, Jenny

2014-01-01

To determine the allelic and genotype frequencies of apolipoproteine E (APOE) gene in a representative sample of the adult population of Medellin in 2010. A representative sample of the adult population of Medellin, was obtained by means of a multi-stage, stratified, conglomerate based sampling method. APOE genotyping was carried out on each of the participants. The sampling design was taken into consideration for the frequencies and association analysis. The frequencies of the APOE alleles E2, E3 and E4 were 3.9, 92.0 and 4.1%, respectively. The frequencies of the different APOE genotypes were as follows: 2/2, 0.2%; 2/3, 6.8%; 2/4, 0.6%; 3/3, 85.0%; 3/4, 7.2%, and 4/4, 0.3%. The allelic and genotype frequencies of APOE in an adult population of Medellin did not differ substantially from other series reported in South America. These data are important to determine the real impact of APOE on the population risk of several psychiatric diseases. Copyright © 2013 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Comparing adult cannabis treatment-seekers enrolled in a clinical trial with national samples of cannabis users in the United States

PubMed Central

McClure, Erin A.; King, Jacqueline S.; Wahle, Aimee; Matthews, Abigail G.; Sonne, Susan C.; Lofwall, Michelle R.; McRae-Clark, Aimee L.; Ghitza, Udi E.; Martinez, Melissa; Cloud, Kasie; Virk, Harvir S.; Gray, Kevin M.

2017-01-01

Background Cannabis use rates are increasing among adults in the United States (US) while the perception of harm is declining. This may result in an increased prevalence of cannabis use disorder and the need for more clinical trials to evaluate efficacious treatment strategies. Clinical trials are the gold standard for evaluating treatment, yet study samples are rarely representative of the target population. This finding has not yet been established for cannabis treatment trials. This study compared demographic and cannabis use characteristics of a cannabis cessation clinical trial sample (run through National Drug Abuse Treatment Clinical Trials Network) with three nationally representative datasets from the US; 1) National Survey on Drug Use and Health, 2) National Epidemiologic Survey on Alcohol and Related Conditions-III, and 3) Treatment Episodes Data Set – Admissions. Methods Comparisons were made between the clinical trial sample and appropriate cannabis using sub-samples from the national datasets, and propensity scores were calculated to determine the degree of similarity between samples. Results Results showed that the clinical trial sample was significantly different from all three national datasets, with the clinical trial sample having greater representation among older adults, African Americans, Hispanic/Latinos, adults with more education, non-tobacco users, and daily and almost daily cannabis users. Conclusions These results are consistent with previous studies of other substance use disorder populations and extend sample representation issues to a cannabis use disorder population. This illustrates the need to ensure representative samples within cannabis treatment clinical trials to improve the generalizability of promising findings. PMID:28511033

Comparing adult cannabis treatment-seekers enrolled in a clinical trial with national samples of cannabis users in the United States.

PubMed

McClure, Erin A; King, Jacqueline S; Wahle, Aimee; Matthews, Abigail G; Sonne, Susan C; Lofwall, Michelle R; McRae-Clark, Aimee L; Ghitza, Udi E; Martinez, Melissa; Cloud, Kasie; Virk, Harvir S; Gray, Kevin M

2017-07-01

Cannabis use rates are increasing among adults in the United States (US) while the perception of harm is declining. This may result in an increased prevalence of cannabis use disorder and the need for more clinical trials to evaluate efficacious treatment strategies. Clinical trials are the gold standard for evaluating treatment, yet study samples are rarely representative of the target population. This finding has not yet been established for cannabis treatment trials. This study compared demographic and cannabis use characteristics of a cannabis cessation clinical trial sample (run through National Drug Abuse Treatment Clinical Trials Network) with three nationally representative datasets from the US; 1) National Survey on Drug Use and Health, 2) National Epidemiologic Survey on Alcohol and Related Conditions-III, and 3) Treatment: Episodes Data Set - Admissions. Comparisons were made between the clinical trial sample and appropriate cannabis using sub-samples from the national datasets, and propensity scores were calculated to determine the degree of similarity between samples. showed that the clinical trial sample was significantly different from all three national datasets, with the clinical trial sample having greater representation among older adults, African Americans, Hispanic/Latinos, adults with more education, non-tobacco users, and daily and almost daily cannabis users. These results are consistent with previous studies of other substance use disorder populations and extend sample representation issues to a cannabis use disorder population. This illustrates the need to ensure representative samples within cannabis treatment clinical trials to improve the generalizability of promising findings. Copyright © 2017 Elsevier B.V. All rights reserved.

Design and Weighting Methods for a Nationally Representative Sample of HIV-infected Adults Receiving Medical Care in the United States-Medical Monitoring Project

PubMed Central

Iachan, Ronaldo; H. Johnson, Christopher; L. Harding, Richard; Kyle, Tonja; Saavedra, Pedro; L. Frazier, Emma; Beer, Linda; L. Mattson, Christine; Skarbinski, Jacek

2016-01-01

Background: Health surveys of the general US population are inadequate for monitoring human immunodeficiency virus (HIV) infection because the relatively low prevalence of the disease (<0.5%) leads to small subpopulation sample sizes. Objective: To collect a nationally and locally representative probability sample of HIV-infected adults receiving medical care to monitor clinical and behavioral outcomes, supplementing the data in the National HIV Surveillance System. This paper describes the sample design and weighting methods for the Medical Monitoring Project (MMP) and provides estimates of the size and characteristics of this population. Methods: To develop a method for obtaining valid, representative estimates of the in-care population, we implemented a cross-sectional, three-stage design that sampled 23 jurisdictions, then 691 facilities, then 9,344 HIV patients receiving medical care, using probability-proportional-to-size methods. The data weighting process followed standard methods, accounting for the probabilities of selection at each stage and adjusting for nonresponse and multiplicity. Nonresponse adjustments accounted for differing response at both facility and patient levels. Multiplicity adjustments accounted for visits to more than one HIV care facility. Results: MMP used a multistage stratified probability sampling design that was approximately self-weighting in each of the 23 project areas and nationally. The probability sample represents the estimated 421,186 HIV-infected adults receiving medical care during January through April 2009. Methods were efficient (i.e., induced small, unequal weighting effects and small standard errors for a range of weighted estimates). Conclusion: The information collected through MMP allows monitoring trends in clinical and behavioral outcomes and informs resource allocation for treatment and prevention activities. PMID:27651851

Stranded dolphin stomach contents represent the free-ranging population's diet

PubMed Central

Dunshea, Glenn; Barros, Nélio B.; Berens McCabe, Elizabeth J.; Gales, Nicholas J.; Hindell, Mark A.; Jarman, Simon N.; Wells, Randall S.

2013-01-01

Diet is a fundamental aspect of animal ecology. Cetacean prey species are generally identified by examining stomach contents of stranded individuals. Critical uncertainty in these studies is whether samples from stranded animals are representative of the diet of free-ranging animals. Over two summers, we collected faecal and gastric samples from healthy free-ranging individuals of an extensively studied bottlenose dolphin population. These samples were analysed by molecular prey detection and these data compared with stomach contents data derived from stranded dolphins from the same population collected over 22 years. There was a remarkable consistency in the prey species composition and relative amounts between the two datasets. The conclusions of past stomach contents studies regarding dolphin habitat associations, prey selection and proposed foraging mechanisms are supported by molecular data from live animals and the combined dataset. This is the first explicit test of the validity of stomach contents analysis for accurate population-scale diet determination of an inshore cetacean. PMID:23637389

A two-stage cluster sampling method using gridded population data, a GIS, and Google Earth(TM) imagery in a population-based mortality survey in Iraq.

PubMed

Galway, Lp; Bell, Nathaniel; Sae, Al Shatari; Hagopian, Amy; Burnham, Gilbert; Flaxman, Abraham; Weiss, Wiliam M; Rajaratnam, Julie; Takaro, Tim K

2012-04-27

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. 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. 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.

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

PubMed Central

2012-01-01

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. PMID:22540266

Population-specific FST values for forensic STR markers: A worldwide survey.

PubMed

Buckleton, John; Curran, James; Goudet, Jérôme; Taylor, Duncan; Thiery, Alexandre; Weir, B S

2016-07-01

The interpretation of matching between DNA profiles of a person of interest and an item of evidence is undertaken using population genetic models to predict the probability of matching by chance. Calculation of matching probabilities is straightforward if allelic probabilities are known, or can be estimated, in the relevant population. It is more often the case, however, that the relevant population has not been sampled and allele frequencies are available only from a broader collection of populations as might be represented in a national or regional database. Variation of allele probabilities among the relevant populations is quantified by the population structure quantity FST and this quantity affects matching proportions. Matching within a population can be interpreted only with respect to matching between populations and we show here that FST, can be estimated from sample allelic matching proportions within and between populations. We report such estimates from data we extracted from 250 papers in the forensic literature, representing STR profiles at up to 24 loci from nearly 500,000 people in 446 different populations. The results suggest that theta values in current forensic use do not have the buffer of conservatism often thought. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Population-specific FST values for forensic STR markers: A worldwide survey

PubMed Central

Buckleton, John; Curran, James; Goudet, Jérôme; Taylor, Duncan; Thiery, Alexandre; Weir, B.S.

2016-01-01

The interpretation of matching between DNA profiles of a person of interest and an item of evidence is undertaken using population genetic models to predict the probability of matching by chance. Calculation of matching probabilities is straightforward if allelic probabilities are known, or can be estimated, in the relevant population. It is more often the case, however, that the relevant population has not been sampled and allele frequencies are available only from a broader collection of populations as might be represented in a national or regional database. Variation of allele probabilities among the relevant populations is quantified by the population structure quantity FST and this quanity affects matching propoptions. Matching within a population can be interpreted only with respect to matching between populations and we show here that FST, can be estimated from sample allelic matching proportions within and between populations. We report such estimates from data we extracted from 250 papers in the forensic literature, representing STR profiles at up to 24 loci from nearly 500,000 people in 446 different populations. The results suggest that theta values in current forensic use do not have the buffer of conservativism often thought. PMID:27082756

Estimating the breeding population of long-billed curlew in the United States

USGS Publications Warehouse

Stanley, T.R.; Skagen, S.K.

2007-01-01

Determining population size and long-term trends in population size for species of high concern is a priority of international, national, and regional conservation plans. Long-billed curlews (Numenius americanus) are a species of special concern in North America due to apparent declines in their population. Because long-billed curlews are not adequately monitored by existing programs, we undertook a 2-year study with the goals of 1) determining present long-billed curlew distribution and breeding population size in the United States and 2) providing recommendations for a long-term long-billed curlew monitoring protocol. We selected a stratified random sample of survey routes in 16 western states for sampling in 2004 and 2005, and we analyzed count data from these routes to estimate detection probabilities and abundance. In addition, we evaluated habitat along roadsides to determine how well roadsides represented habitat throughout the sampling units. We estimated there were 164,515 (SE = 42,047) breeding long-billed curlews in 2004, and 109,533 (SE = 31,060) breeding individuals in 2005. These estimates far exceed currently accepted estimates based on expert opinion. We found that habitat along roadsides was representative of long-billed curlew habitat in general. We make recommendations for improving sampling methodology, and we present power curves to provide guidance on minimum sample sizes required to detect trends in abundance.

Analysis of four recruitment methods for obtaining normative data through a Web-based questionnaire: a pilot study.

PubMed

Nolte, Michael T; Shauver, Melissa J; Chung, Kevin C

2015-09-01

Quality normative data requires a diverse sample of participants and plays an important role in the appropriate use of health outcomes. Using social media and other online resources for survey recruitment is a tempting prospect, but the effectiveness of these methods in collecting a diverse sample is unknown. The purpose of this study is to pilot test four methods of recruitment to determine their ability to produce a sample representative of the general US population. This project is part of a larger study to gather normative data for the Michigan Hand Outcomes Questionnaire (MHQ). We used flyers, e-mail, Facebook, and an institution-specific clinical research recruitment Web site to direct participants to complete an online version of the MHQ. Participants also provided comorbidity and demographic information. The institution-specific recruitment Web site yielded the greatest number of respondents in an age distribution that mirrored the US population. Facebook was effective for recruiting young adults, and e-mail was successful for recruiting the older adults. None of the methods was successful in reaching an ethnically diverse sample. Obtaining normative data that is truly representative of the US population is a difficult task. The use of any one recruitment method is unlikely to result in a representative sample, but a greater understanding of these methods will empower researchers to use them to target specific populations. This pilot analysis provides support for the use of Facebook and clinical research sites in addition to traditional methods of e-mail and paper flyers.

Dental size and shape in the Roman imperial age: two examples from the area of Rome.

PubMed

Manzi, G; Santandrea, E; Passarello, P

1997-04-01

Different socioeconomic strata of Roman imperial age are represented by two large dental samples recovered from archaeological excavations near Rome, Italy. Teeth are investigated for crown dimensions and morphological variants. One sample, comprising 1,465 permanent teeth, represents the rural town of Lucus Feroniae (LFR) and is mainly composed of slaves and war veterans. The other, comprising 734 teeth from the Isola Sacra necropolis at Portus Romae (NIS), represents the "middle class" segment of an urban population. Both series show small dental dimensions and fit at the lower end of the trend toward dental reduction in Europe from the Upper Paleolithic to the historical times. The urban sample is less variable metrically and less sexually dimorphic than the rural one. The analysis of discrete crown traits shows absence of rare phenotypic variants in both series. The urban sample is also less variable in this last respect, suggesting that the gene pool of this particular "stratum" of the NIS population was more homogeneous than that of LFR. The occurrence of enamel hypoplasia indicates that metabolic stress during growth and development was similar in LFR and NIS. The overall set of available data is evaluated in the light of the history of the two Roman sites and the composition of each population.

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.

PubMed

Veugelers, Rebekka; Calis, Elsbeth A C; Penning, Corine; Verhagen, Arianne; Bernsen, Roos; Bouquet, Jan; Benninga, Marc A; Merkus, Peter J F M; Arets, Hubertus G M; Tibboel, Dick; Evenhuis, Heleen M

2005-07-19

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. 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. 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-site measurements are of first choice, but timely inclusion is jeopardized. The initiation of this first study among children with severe neurological impairment led to specific, unexpected problems. Despite small differences between participants and non-participating children, our sample is as representative as can be expected from any population-based study and will provide important, new information to bring us further towards effective interventions to prevent pneumonias in this population.

Sex Work Research: Methodological and Ethical Challenges

ERIC Educational Resources Information Center

Shaver, Frances M.

2005-01-01

The challenges involved in the design of ethical, nonexploitative research projects with sex workers or any other marginalized population are significant. First, the size and boundaries of the population are unknown, making it extremely difficult to get a representative sample. Second, because membership in hidden populations often involves…

Smaller than expected cognitive deficits in schizophrenia patients from the population-representative ABC catchment cohort.

PubMed

Lennertz, Leonhard; An der Heiden, Wolfram; Kronacher, Regina; Schulze-Rauschenbach, Svenja; Maier, Wolfgang; Häfner, Heinz; Wagner, Michael

2016-08-01

Most neuropsychological studies on schizophrenia suffer from sample selection bias, with male and chronic patients being overrepresented. This probably leads to an overestimation of cognitive impairments. The present study aimed to provide a less biased estimate of cognitive functions in schizophrenia using a population-representative catchment area sample. Schizophrenia patients (N = 89) from the prospective Mannheim ABC cohort were assessed 14 years after disease onset and first diagnosis, using a comprehensive neuropsychological test battery. A healthy control group (N = 90) was carefully matched according to age, gender, and geographic region (city, rural surrounds). The present sample was representative for the initial ABC cohort. In the comprehensive neuropsychological assessment, the schizophrenia patients were only moderately impaired as compared to the healthy control group (d = 0.56 for a general cognitive index, d = 0.42 for verbal memory, d = 0.61 for executive functions, d = 0.69 for attention). Only 33 % of the schizophrenia patients scored one standard deviation unit below the healthy control group in the general cognitive index. Neuropsychological performance did not correlate with measures of the clinical course including age at onset, number of hospital admissions, and time in paid work. Thus, in this population-representative sample of schizophrenia patients, neuropsychological deficits were less pronounced than expected from meta-analyses. In agreement with other epidemiological studies, this suggests a less devastating picture of cognition in schizophrenia.

Screening disordered eating in a representative sample of the German population: Usefulness and psychometric properties of the German SCOFF questionnaire.

PubMed

Richter, Felicitas; Strauss, Bernhard; Braehler, Elmar; Adametz, Luise; Berger, Uwe

2017-04-01

The prevention of eating disorders and the identification of high-risk individuals are essential for the public health sector. There is need for sensitive and specific screening instruments of disordered eating that can be applied in universal samples as an initial step into disease prevention. The SCOFF is a screening instrument for disordered eating, frequently used in international and cross-cultural contexts to detect individuals at risk. The objective of this research is to evaluate whether the SCOFF can be used as a screening tool for disordered eating in universal samples. This is the first study which examined the psychometric properties of the German version of the SCOFF in a general population sample. A representative sample (N=2527) of the German population, aged 14-95years, was recruited. Psychometric properties were determined including reliability, concurrent and construct validity, and factor structure. The prevalence of disordered eating was assessed. The prevalence of disordered eating in the general population was 10%. Using the established cutoff point of ≥2, values for diagnostic accuracy were 26% (sensitivity), 97% (specificity), 80% (positive predictive value), and 74% (negative predictive value). Factorial analyses revealed an excellent model fit of a unidimensional model. Due to its low sensitivity and a high percentage of false negatives, there are limitations in using the German version of the SCOFF in general population samples with wide age ranges. Copyright © 2016 Elsevier Ltd. All rights reserved.

Factors associated with positive attitudes toward organ donation in Arab Americans.

PubMed

Padela, Aasim I; Rasheed, Shoaib; Warren, Gareth J W; Choi, Hwajung; Mathur, Amit K

2011-01-01

The demand for transplantable organ continues to exceed supply, particularly in minority patient populations. We explored the factors influencing organ donation attitude within the Arab American community. Secondary data analysis from a face-to-face survey administered in late 2003 to 1016 adults from a representative population-based sample on Greater Detroit Arab Americans. Christian Arab Americans were more likely than Muslim Arab Americans, and women more than men, to believe organ donation after death was justifiable. Higher educational attainment and income, as well as greater acculturation into American society, were associated with greater odds of believing organ donation to be justified. Self-reported health status and level of psychological distress and health insurance status were not associated with beliefs about organ donation. A multifaceted approach toward increasing organ donation rates in this growing population requires targeted community-health care system collaborations involving religious and civic leaders using Arabic language and culturally sensitive media. Arab Americans represent a growing population about which little is known in regard to organ donation and transplantation. This population is not specifically captured within national and local transplantation databases, and little empiric work has assessed attitudes and barriers toward organ donation and transplantation within this community. Our work represents the first to use a representative population-based sample to explore the modifiable and non-modifiable characteristics of those who believe cadaveric organ donation to be justified. © 2010 John Wiley & Sons A/S.

Characterizing spatial structure of sediment E. coli populations to inform sampling design.

PubMed

Piorkowski, Gregory S; Jamieson, Rob C; Hansen, Lisbeth Truelstrup; Bezanson, Greg S; Yost, Chris K

2014-01-01

Escherichia coli can persist in streambed sediments and influence water quality monitoring programs through their resuspension into overlying waters. This study examined the spatial patterns in E. coli concentration and population structure within streambed morphological features during baseflow and following stormflow to inform sampling strategies for representative characterization of E. coli populations within a stream reach. E. coli concentrations in bed sediments were significantly different (p = 0.002) among monitoring sites during baseflow, and significant interactive effects (p = 0.002) occurred among monitoring sites and morphological features following stormflow. Least absolute shrinkage and selection operator (LASSO) regression revealed that water velocity and effective particle size (D 10) explained E. coli concentration during baseflow, whereas sediment organic carbon, water velocity and median particle diameter (D 50) were important explanatory variables following stormflow. Principle Coordinate Analysis illustrated the site-scale differences in sediment E. coli populations between disconnected stream segments. Also, E. coli populations were similar among depositional features within a reach, but differed in relation to high velocity features (e.g., riffles). Canonical correspondence analysis resolved that E. coli population structure was primarily explained by spatial (26.9–31.7 %) over environmental variables (9.2–13.1 %). Spatial autocorrelation existed among monitoring sites and morphological features for both sampling events, and gradients in mean particle diameter and water velocity influenced E. coli population structure for the baseflow and stormflow sampling events, respectively. Representative characterization of streambed E. coli requires sampling of depositional and high velocity environments to accommodate strain selectivity among these features owing to sediment and water velocity heterogeneity.

Quality of life of the Indonesian general population: Test-retest reliability and population norms of the EQ-5D-5L and WHOQOL-BREF.

PubMed

Purba, Fredrick Dermawan; Hunfeld, Joke A M; Iskandarsyah, Aulia; Fitriana, Titi Sahidah; Sadarjoen, Sawitri S; Passchier, Jan; Busschbach, Jan J V

2018-01-01

The objective of this study is to obtain population norms and to assess test-retest reliability of EQ-5D-5L and WHOQOL-BREF for the Indonesian population. A representative sample of 1056 people aged 17-75 years was recruited from the Indonesian general population. We used a multistage stratified quota sampling method with respect to residence, gender, age, education level, religion and ethnicity. Respondents completed EQ-5D-5L and WHOQOL-BREF with help from an interviewer. Norms data for both instruments were reported. For the test-retest evaluations, a sub-sample of 206 respondents completed both instruments twice. The total sample and test-retest sub-sample were representative of the Indonesian general population. The EQ-5D-5L shows almost perfect agreement between the two tests (Gwet's AC: 0.85-0.99 and percentage agreement: 90-99%) regarding the five dimensions. However, the agreement of EQ-VAS and index scores can be considered as poor (ICC: 0.45 and 0.37 respectively). For the WHOQOL-BREF, ICCs of the four domains were between 0.70 and 0.79, which indicates moderate to good agreement. For EQ-5D-5L, it was shown that female and older respondents had lower EQ-index scores, whilst rural, younger and higher-educated respondents had higher EQ-VAS scores. For WHOQOL-BREF: male, younger, higher-educated, high-income respondents had the highest scores in most of the domains, overall quality of life, and health satisfaction. This study provides representative estimates of self-reported health status and quality of life for the general Indonesian population as assessed by the EQ-5D-5L and WHOQOL-BREF instruments. The descriptive system of the EQ-5D-5L and the WHOQOL-BREF have high test-retest reliability while the EQ-VAS and the index score of EQ-5D-5L show poor agreement between the two tests. Our results can be useful to researchers and clinicians who can compare their findings with respect to these concepts with those of the Indonesian general population.

Eating Problems and Their Risk Factors: A 7-Year Longitudinal Study of a Population Sample of Norwegian Adolescent Girls

ERIC Educational Resources Information Center

Kansi, Juliska; Wichstrom, Lars; Bergman, Lars R.

2005-01-01

The longitudinal stability of eating problems and their relationships to risk factors were investigated in a representative population sample of 623 Norwegian girls aged 13-14 followed over 7 years (3 time points). Three eating problem symptoms were measured: Restriction, Bulimia-food preoccupation, and Diet, all taken from the 12-item Eating…

A Hands-On Exercise Improves Understanding of the Standard Error of the Mean

ERIC Educational Resources Information Center

Ryan, Robert S.

2006-01-01

One of the most difficult concepts for statistics students is the standard error of the mean. To improve understanding of this concept, 1 group of students used a hands-on procedure to sample from small populations representing either a true or false null hypothesis. The distribution of 120 sample means (n = 3) from each population had standard…

THE NORTH CAROLINA HERALD PILOT STUDY

EPA Science Inventory

The sampling design for the National Children's Study (NCS) calls for a population-based, multi-stage, clustered household sampling approach. The full sample is designed to be representative of both urban and rural births in the United States, 2007-2011. While other sur...

Design and Field Procedures in the US National Comorbidity Survey Replication Adolescent Supplement (NCS-A)

PubMed Central

Kessler, Ronald C.; Avenevoli, Shelli; Costello, E. Jane; Green, Jennifer Greif; Gruber, Michael J.; Heeringa, Steven; Merikangas, Kathleen R.; Pennell, Beth-Ellen; Sampson, Nancy A.; Zaslavsky, Alan M.

2009-01-01

An overview is presented of the design and field procedures of the US National Comorbidity Survey Replication Adolescent Supplement (NCS-A), a US face-to-face household survey of the prevalence and correlates of DSM-IV mental disorders. The survey was based on a dual-frame design that included 904 adolescent residents of the households that participated in the US National Comorbidity Survey Replication (85.9% response rate) and 9,244 adolescent students selected from a nationally representative sample of 320 schools (74.7% response rate). After expositing the logic of dual-frame designs, comparisons are presented of sample and population distributions on Census socio-demographic variables and, in the school sample, school characteristics. These document only minor differences between the samples and the population. The results of statistical analysis of the bias-efficiency trade-off in weight trimming are then presented. These show that modest trimming meaningfully reduces mean squared error. Analysis of comparative sample efficiency shows that the household sample is more efficient than the school sample, leading to the household sample getting a higher weight relative to its size in the consolidated sample relative to the school sample. Taken together, these results show that the NCS-A is an efficient sample of the target population with good representativeness on a range of socio-demographic and geographic variables. PMID:19507169

RECRUITING FOR A LONGITUDINAL STUDY OF CHILDREN'S HEALTH USING A HOUSEHOLD-BASED PROBABILITY SAMPLING APPROACH

EPA Science Inventory

The sampling design for the National Children¿s Study (NCS) calls for a population-based, multi-stage, clustered household sampling approach (visit our website for more information on the NCS : www.nationalchildrensstudy.gov). The full sample is designed to be representative of ...

Methodological Challenges in Collecting Social and Behavioural Data Regarding the HIV Epidemic among Gay and Other Men Who Have Sex with Men in Australia

PubMed Central

Holt, Martin; de Wit, John; Brown, Graham; Maycock, Bruce; Fairley, Christopher; Prestage, Garrett

2014-01-01

Background Behavioural surveillance and research among gay and other men who have sex with men (GMSM) commonly relies on non-random recruitment approaches. Methodological challenges limit their ability to accurately represent the population of adult GMSM. We compared the social and behavioural profiles of GMSM recruited via venue-based, online, and respondent-driven sampling (RDS) and discussed their utility for behavioural surveillance. Methods Data from four studies were selected to reflect each recruitment method. We compared demographic characteristics and the prevalence of key indicators including sexual and HIV testing practices obtained from samples recruited through different methods, and population estimates from respondent-driven sampling partition analysis. Results Overall, the socio-demographic profile of GMSM was similar across samples, with some differences observed in age and sexual identification. Men recruited through time-location sampling appeared more connected to the gay community, reported a greater number of sexual partners, but engaged in less unprotected anal intercourse with regular (UAIR) or casual partners (UAIC). The RDS sample overestimated the proportion of HIV-positive men and appeared to recruit men with an overall higher number of sexual partners. A single-website survey recruited a sample with characteristics which differed considerably from the population estimates with regards to age, ethnically diversity and behaviour. Data acquired through time-location sampling underestimated the rates of UAIR and UAIC, while RDS and online sampling both generated samples that underestimated UAIR. Simulated composite samples combining recruits from time-location and multi-website online sampling may produce characteristics more consistent with the population estimates, particularly with regards to sexual practices. Conclusion Respondent-driven sampling produced the sample that was most consistent to population estimates, but this methodology is complex and logistically demanding. Time-location and online recruitment are more cost-effective and easier to implement; using these approaches in combination may offer the potential to recruit a more representative sample of GMSM. PMID:25409440

Methodological challenges in collecting social and behavioural data regarding the HIV epidemic among gay and other men who have sex with men in Australia.

PubMed

Zablotska, Iryna B; Frankland, Andrew; Holt, Martin; de Wit, John; Brown, Graham; Maycock, Bruce; Fairley, Christopher; Prestage, Garrett

2014-01-01

Behavioural surveillance and research among gay and other men who have sex with men (GMSM) commonly relies on non-random recruitment approaches. Methodological challenges limit their ability to accurately represent the population of adult GMSM. We compared the social and behavioural profiles of GMSM recruited via venue-based, online, and respondent-driven sampling (RDS) and discussed their utility for behavioural surveillance. Data from four studies were selected to reflect each recruitment method. We compared demographic characteristics and the prevalence of key indicators including sexual and HIV testing practices obtained from samples recruited through different methods, and population estimates from respondent-driven sampling partition analysis. Overall, the socio-demographic profile of GMSM was similar across samples, with some differences observed in age and sexual identification. Men recruited through time-location sampling appeared more connected to the gay community, reported a greater number of sexual partners, but engaged in less unprotected anal intercourse with regular (UAIR) or casual partners (UAIC). The RDS sample overestimated the proportion of HIV-positive men and appeared to recruit men with an overall higher number of sexual partners. A single-website survey recruited a sample with characteristics which differed considerably from the population estimates with regards to age, ethnically diversity and behaviour. Data acquired through time-location sampling underestimated the rates of UAIR and UAIC, while RDS and online sampling both generated samples that underestimated UAIR. Simulated composite samples combining recruits from time-location and multi-website online sampling may produce characteristics more consistent with the population estimates, particularly with regards to sexual practices. Respondent-driven sampling produced the sample that was most consistent to population estimates, but this methodology is complex and logistically demanding. Time-location and online recruitment are more cost-effective and easier to implement; using these approaches in combination may offer the potential to recruit a more representative sample of GMSM.

Vision Research Literature May Not Represent the Full Intellectual Range of Autism Spectrum Disorder

PubMed Central

Brown, Alyse C.; Chouinard, Philippe A.; Crewther, Sheila G.

2017-01-01

Sensory, in particular visual processing is recognized as often perturbed in individuals with Autism Spectrum Disorder (ASD). However, in terms of the literature pertaining to visual processing, individuals in the normal intelligence range (IQ = 90–110) and above, are more frequently represented in study samples than individuals who score below normal in the borderline intellectual disability (ID) (IQ = 71–85) to ID (IQ < 70) ranges. This raises concerns as to whether or not current research is generalizable to a disorder that is often co-morbid with ID. Thus, the aim of this review is to better understand to what extent the current ASD visual processing literature is representative of the entire ASD population as either diagnosed or recognized under DSM-5. Our recalculation of ASD prevalence figures, using the criteria of DSM-5, indicates approximately 40% of the ASD population are likely to be ID although searching of the visual processing literature in ASD up to July 2016 showed that only 20% of papers included the ASD with-ID population. In the published literature, the mean IQ sampled was found to be 104, with about 80% of studies sampling from the 96–115 of the IQ range, highlighting the marked under-representation of the ID and borderline ID sections of the ASD population. We conclude that current understanding of visual processing and perception in ASD is not based on the mean IQ profile of the DSM-5 defined ASD population that now appears to lie within the borderline ID to ID range. Give the importance of the role of vision for the social and cognitive processing in ASD, we recommend accurately representing ASD via greater inclusion of individuals with IQ below 80, in future ASD research. PMID:28261072

Recruiting and enrolling pregnant adolescents for research.

PubMed

Kaiser, Margaret M; Hays, Bevely J

2006-01-01

Difficulty obtaining a sample is not justification for failure to study a hard-to-enroll population, particularly a vulnerable population such as pregnant adolescents. Recruitment of a representative, adequate sample of pregnant adolescents for a recent instrument development study provided multiple challenges. Although carefully developed, the sampling plan required several modifications to achieve the sample (n=145). Those challenges and the ensuing modifications to the sampling plan are discussed in relation to (a) access/institutional concerns, (b) the human subject's protection considerations, and (c) developmental/personal concerns of the pregnant adolescents. Recommendations for sampling strategies for future research are offered.

11,670 whole-genome sequences representative of the Han Chinese population from the CONVERGE project.

PubMed

Cai, Na; Bigdeli, Tim B; Kretzschmar, Warren W; Li, Yihan; Liang, Jieqin; Hu, Jingchu; Peterson, Roseann E; Bacanu, Silviu; Webb, Bradley Todd; Riley, Brien; Li, Qibin; Marchini, Jonathan; Mott, Richard; Kendler, Kenneth S; Flint, Jonathan

2017-02-14

The China, Oxford and Virginia Commonwealth University Experimental Research on Genetic Epidemiology (CONVERGE) project on Major Depressive Disorder (MDD) sequenced 11,670 female Han Chinese at low-coverage (1.7X), providing the first large-scale whole genome sequencing resource representative of the largest ethnic group in the world. Samples are collected from 58 hospitals from 23 provinces around China. We are able to call 22 million high quality single nucleotide polymorphisms (SNP) from the nuclear genome, representing the largest SNP call set from an East Asian population to date. We use these variants for imputation of genotypes across all samples, and this has allowed us to perform a successful genome wide association study (GWAS) on MDD. The utility of these data can be extended to studies of genetic ancestry in the Han Chinese and evolutionary genetics when integrated with data from other populations. Molecular phenotypes, such as copy number variations and structural variations can be detected, quantified and analysed in similar ways.

Sleepiness and Motor Vehicle Crashes in a Representative Sample of Portuguese Drivers: The Importance of Epidemiological Representative Surveys.

PubMed

Gonçalves, M; Peralta, A R; Monteiro Ferreira, J; Guilleminault, Christian

2015-01-01

Sleepiness is considered to be a leading cause of crashes. Despite the huge amount of information collected in questionnaire studies, only some are based on representative samples of the population. Specifics of the populations studied hinder the generalization of these previous findings. For the Portuguese population, data from sleep-related car crashes/near misses and sleepiness while driving are missing. The objective of this study is to determine the prevalence of near-miss and nonfatal motor vehicle crashes related to sleepiness in a representative sample of Portuguese drivers. Structured phone interviews regarding sleepiness and sleep-related crashes and near misses, driving habits, demographic data, and sleep quality were conducted using the Pittsburgh Sleep Quality Index and sleep apnea risk using the Berlin questionnaire. A multivariate regression analysis was used to determine the associations with sleepy driving (feeling sleepy or falling asleep while driving) and sleep-related near misses and crashes. Nine hundred subjects, representing the Portuguese population of drivers, were included; 3.1% acknowledged falling asleep while driving during the previous year and 0.67% recalled sleepiness-related crashes. Higher education, driving more than 15,000 km/year, driving more frequently between 12:00 a.m. and 6 a.m., fewer years of having a driver's license, less total sleep time per night, and higher scores on the Epworth Sleepiness Scale (ESS) were all independently associated with sleepy driving. Sleepiness-related crashes and near misses were associated only with falling asleep at the wheel in the previous year. Sleep-related crashes occurred more frequently in drivers who had also had sleep-related near misses. Portugal has lower self-reported sleepiness at the wheel and sleep-related near misses than most other countries where epidemiological data are available. Different population characteristics and cultural, social, and road safety specificities may be involved in these discrepancies. Despite this, Portuguese drivers report sleep-related crashes in frequencies similar to those of drivers in other countries.

Relationship between blood manganese and blood pressure in the Korean general population according to KNHANES 2008

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Byung-Kook; Kim, Yangho, E-mail: yanghokm@nuri.net

Introduction: We present data on the association of manganese (Mn) level with hypertension in a representative sample of the adult Korean population who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) 2008. Methods: This study was based on the data obtained by KNHANES 2008, which was conducted for three years (2007-2009) using a rolling sampling design involving a complex, stratified, multistage, probability-cluster survey of a representative sample of the noninstitutionalized civilian population of South Korea. Results: Multiple regression analysis after controlling for covariates, including gender, age, regional area, education level, smoking, drinking status, hemoglobin, and serum creatinine,more » showed that the beta coefficients of log blood Mn were 3.514, 1.878, and 2.517 for diastolic blood pressure, and 3.593, 2.449, and 2.440 for systolic blood pressure in female, male, and all participants, respectively. Multiple regression analysis including three other blood metals, lead, mercury, and cadmium, revealed no significant effects of the three metals on blood pressure and showed no effect on the association between blood Mn and blood pressure. In addition, doubling the blood Mn increased the risk of hypertension 1.828, 1.573, and 1.567 fold in women, men, and all participants, respectively, after adjustment for covariates. The addition of blood lead, mercury, and cadmium as covariates did not affect the association between blood Mn and the prevalence of hypertension. Conclusion: Blood Mn level was associated with an increased risk of hypertension in a representative sample of the Korean adult population. - Highlights: {yields} We showed the association of manganese with hypertension in Korean population. {yields} This study was based on the data obtained by KNHANES 2008. {yields} Blood manganese level was associated with an increased risk of hypertension.« less

Psychometric Validation of the Parental Bonding Instrument in a U.K. Population-Based Sample: Role of Gender and Association With Mental Health in Mid-Late Life.

PubMed

Xu, Man K; Morin, Alexandre J S; Marsh, Herbert W; Richards, Marcus; Jones, Peter B

2016-08-01

The factorial structure of the Parental Bonding Instrument (PBI) has been frequently studied in diverse samples but no study has examined its psychometric properties from large, population-based samples. In particular, important questions have not been addressed such as the measurement invariance properties across parental and offspring gender. We evaluated the PBI based on responses from a large, representative population-based sample, using an exploratory structural equation modeling method appropriate for categorical data. Analysis revealed a three-factor structure representing "care," "overprotection," and "autonomy" parenting styles. In terms of psychometric measurement validity, our results supported the complete invariance of the PBI ratings across sons and daughters for their mothers and fathers. The PBI ratings were also robust in relation to personality and mental health status. In terms of predictive value, paternal care showed a protective effect on mental health at age 43 in sons. The PBI is a sound instrument for capturing perceived parenting styles, and is predictive of mental health in middle adulthood. © The Author(s) 2016.

Sampling pig farms at the abattoir in a cross-sectional study - Evaluation of a sampling method.

PubMed

Birkegård, Anna Camilla; Halasa, Tariq; Toft, Nils

2017-09-15

A cross-sectional study design is relatively inexpensive, fast and easy to conduct when compared to other study designs. Careful planning is essential to obtaining a representative sample of the population, and the recommended approach is to use simple random sampling from an exhaustive list of units in the target population. This approach is rarely feasible in practice, and other sampling procedures must often be adopted. For example, when slaughter pigs are the target population, sampling the pigs on the slaughter line may be an alternative to on-site sampling at a list of farms. However, it is difficult to sample a large number of farms from an exact predefined list, due to the logistics and workflow of an abattoir. Therefore, it is necessary to have a systematic sampling procedure and to evaluate the obtained sample with respect to the study objective. We propose a method for 1) planning, 2) conducting, and 3) evaluating the representativeness and reproducibility of a cross-sectional study when simple random sampling is not possible. We used an example of a cross-sectional study with the aim of quantifying the association of antimicrobial resistance and antimicrobial consumption in Danish slaughter pigs. It was not possible to visit farms within the designated timeframe. Therefore, it was decided to use convenience sampling at the abattoir. Our approach was carried out in three steps: 1) planning: using data from meat inspection to plan at which abattoirs and how many farms to sample; 2) conducting: sampling was carried out at five abattoirs; 3) evaluation: representativeness was evaluated by comparing sampled and non-sampled farms, and the reproducibility of the study was assessed through simulated sampling based on meat inspection data from the period where the actual data collection was carried out. In the cross-sectional study samples were taken from 681 Danish pig farms, during five weeks from February to March 2015. The evaluation showed that the sampling procedure was reproducible with results comparable to the collected sample. However, the sampling procedure favoured sampling of large farms. Furthermore, both under-sampled and over-sampled areas were found using scan statistics. In conclusion, sampling conducted at abattoirs can provide a spatially representative sample. Hence it is a possible cost-effective alternative to simple random sampling. However, it is important to assess the properties of the resulting sample so that any potential selection bias can be addressed when reporting the findings. Copyright © 2017 Elsevier B.V. All rights reserved.

Representing genetic variation as continuous surfaces: An approach for identifying spatial dependency in landscape genetic studies

Treesearch

Melanie A. Murphy; Jeffrey S. Evans; Samuel A. Cushman; Andrew Storfer

2008-01-01

Landscape genetics, an emerging field integrating landscape ecology and population genetics, has great potential to influence our understanding of habitat connectivity and distribution of organisms. Whereas typical population genetics studies summarize gene flow as pairwise measures between sampling localities, landscape characteristics that influence population...

Creating a sampling frame for population-based veteran research: representativeness and overlap of VA and Department of Defense databases.

PubMed

Washington, Donna L; Sun, Su; Canning, Mark

2010-01-01

Most veteran research is conducted in Department of Veterans Affairs (VA) healthcare settings, although most veterans obtain healthcare outside the VA. Our objective was to determine the adequacy and relative contributions of Veterans Health Administration (VHA), Veterans Benefits Administration (VBA), and Department of Defense (DOD) administrative databases for representing the U.S. veteran population, using as an example the creation of a sampling frame for the National Survey of Women Veterans. In 2008, we merged the VHA, VBA, and DOD databases. We identified the number of unique records both overall and from each database. The combined databases yielded 925,946 unique records, representing 51% of the 1,802,000 U.S. women veteran population. The DOD database included 30% of the population (with 8% overlap with other databases). The VHA enrollment database contributed an additional 20% unique women veterans (with 6% overlap with VBA databases). VBA databases contributed an additional 2% unique women veterans (beyond 10% overlap with other databases). Use of VBA and DOD databases substantially expands access to the population of veterans beyond those in VHA databases, regardless of VA use. Adoption of these additional databases would enhance the value and generalizability of a wide range of studies of both male and female veterans.

Does sampling using random digit dialling really cost more than sampling from telephone directories: Debunking the myths

PubMed Central

Yang, Baohui; Eyeson-Annan, Margo

2006-01-01

Background Computer assisted telephone interviewing (CATI) is widely used for health surveys. The advantages of CATI over face-to-face interviewing are timeliness and cost reduction to achieve the same sample size and geographical coverage. Two major CATI sampling procedures are used: sampling directly from the electronic white pages (EWP) telephone directory and list assisted random digit dialling (LA-RDD) sampling. EWP sampling covers telephone numbers of households listed in the printed white pages. LA-RDD sampling has a better coverage of households than EWP sampling but is considered to be more expensive due to interviewers dialling more out-of-scope numbers. Methods This study compared an EWP sample and a LA-RDD sample from the New South Wales Population Health Survey in 2003 on demographic profiles, health estimates, coefficients of variation in weights, design effects on estimates, and cost effectiveness, on the basis of achieving the same level of precision of estimates. Results The LA-RDD sample better represented the population than the EWP sample, with a coefficient of variation of weights of 1.03 for LA-RDD compared with 1.21 for EWP, and average design effects of 2.00 for LA-RDD compared with 2.38 for EWP. Also, a LA-RDD sample can save up to 14.2% in cost compared to an EWP sample to achieve the same precision for health estimates. Conclusion A LA-RDD sample better represents the population, which potentially leads to reduced bias in health estimates, and rather than costing more than EWP actually costs less. PMID:16504117

Towards representative energy data: the Machiguenga study.

PubMed

Montgomery, E

1978-01-01

Representative energy data for a human population can be produced by combining randomly sampled time allocation observations with activity-specific energy expenditure measurements. Research to produce representative energy data for adults of a population of Machiguenga Indians has recently been conducted in lowland, southeastern Peru. Marked contrast was found between the sexes for average married adults in energy expended on an average day. Men spent about 3,200 kcals and women, about 1,925; ratio: 1.66 to 1. In general, men tended to work at somewhat more energetic activities and for longer periods than did women. In addition to sex-role-related task differences were contrasts in uses of technological items and in respective work settings. These representative behavior data permit direct estimates of population-level energy requirements for average days, seasons, or for 1 year.

Constraints on Generality (COG): A Proposed Addition to All Empirical Papers.

PubMed

Simons, Daniel J; Shoda, Yuichi; Lindsay, D Stephen

2017-11-01

Psychological scientists draw inferences about populations based on samples-of people, situations, and stimuli-from those populations. Yet, few papers identify their target populations, and even fewer justify how or why the tested samples are representative of broader populations. A cumulative science depends on accurately characterizing the generality of findings, but current publishing standards do not require authors to constrain their inferences, leaving readers to assume the broadest possible generalizations. We propose that the discussion section of all primary research articles specify Constraints on Generality (i.e., a "COG" statement) that identify and justify target populations for the reported findings. Explicitly defining the target populations will help other researchers to sample from the same populations when conducting a direct replication, and it could encourage follow-up studies that test the boundary conditions of the original finding. Universal adoption of COG statements would change publishing incentives to favor a more cumulative science.

Genetic diversity within and among populations of shortleaf pine (Pinus echinata Mill.) and loblolly pine (Pinus taeda L.)

Treesearch

Shiqin Xu; C.G. Tauer; C. Dana Nelson

2008-01-01

Shortleaf pine (n=93) and loblolly pine (n=112) trees representing 22 seed sources or 16 physiographic populations were sampled from Southwide Southern Pine Seed Source Study plantings located in Oklahoma, Arkansas and Mississippi. The sampled trees were grown from shortleaf pine and loblolly pine seeds formed in 1951 and 1952, prior to the start of intensive forest...

AN ARCGIS TOOL FOR CREATING POPULATIONS OF WATERSHEDS

EPA Science Inventory

For the Landscape Investigations for Pesticides Study in the Midwest, the goal is to sample a representative subset of watersheds selected statistically from a target population of watersheds within the glaciated corn belt. This area stretches from Ohio to Iowa and includes parts...

Occurrence of oral deformities in larval anurans

USGS Publications Warehouse

Drake, D.L.; Altig, R.; Grace, J.B.; Walls, S.C.

2007-01-01

We quantified deformities in the marginal papillae, tooth rows, and jaw sheaths of tadpoles from 13 population samples representing three families and 11 sites in the southeastern United States. Oral deformities were observed in all samples and in 13.5-98% of the specimens per sample. Batrachochytrium dendrobatidis (chytrid) infections were detected in three samples. There was high variability among samples in the pattern and number of discovered deformities. Pairwise associations between oral structures containing deformities were nonrandom for several populations, especially those with B. dendrobatidis infections or high total numbers of deformities. Comparisons of deformities among samples using multivariate analyses revealed that tadpole samples grouped together by family. Analyses of ordination indicated that three variables, the number of deformities, the number of significant associations among deformity types within populations, and whether populations were infected with B. dendrobatidis, were significantly correlated with the pattern of deformities. Our data indicate that the incidence of oral deformities can be high in natural populations and that phylogeny and B. dendrobatidis infection exert a strong influence on the occurrence and type of oral deformities in tadpoles. ?? by the American Society of Ichthyologists and Herperologists.

Population substructure in Cache County, Utah: the Cache County study

PubMed Central

2014-01-01

Background Population stratification is a key concern for genetic association analyses. In addition, extreme homogeneity of ethnic origins of a population can make it difficult to interpret how genetic associations in that population may translate into other populations. Here we have evaluated the genetic substructure of samples from the Cache County study relative to the HapMap Reference populations and data from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Results Our findings show that the Cache County study is similar in ethnic diversity to the self-reported "Whites" in the ADNI sample and less homogenous than the HapMap CEU population. Conclusions We conclude that the Cache County study is genetically representative of the general European American population in the USA and is an appropriate population for conducting broadly applicable genetic studies. PMID:25078123

Lutzomyia umbratilis, the Main Vector of Leishmania guyanensis, Represents a Novel Species Complex?

PubMed Central

Scarpassa, Vera Margarete; Alencar, Ronildo Baiatone

2012-01-01

Background Lutzomyia umbratilis is an important Leishmania guyanensis vector in South America. Previous studies have suggested differences in the vector competence between L. umbratilis populations situated on opposite banks of the Amazonas and Negro Rivers in the central Amazonian Brazil region, likely indicating a species complex. However, few studies have been performed on these populations and the taxonomic status of L. umbratilis remains unclear. Methodology/Principal Findings Phylogeographic structure was estimated for six L. umbratilis samples from the central Amazonian region in Brazil by analyzing mtDNA using 1181 bp of the COI gene to assess whether the populations on opposite banks of these rivers consist of incipient or distinct species. The genetic diversity was fairly high and the results revealed two distinct clades ( = lineages) with 1% sequence divergence. Clade I consisted of four samples from the left bank of the Amazonas and Negro Rivers, whereas clade II comprised two samples from the right bank of Negro River. No haplotypes were shared between samples of two clades. Samples within clades exhibited low to moderate genetic differentiation (F ST = −0.0390–0.1841), whereas samples between clades exhibited very high differentiation (F ST = 0.7100–0.8497) and fixed differences. These lineages have diverged approximately 0.22 Mya in the middle Pleistocene. Demographic expansion was detected for the lineages I and II approximately 30,448 and 15,859 years ago, respectively, in the late Pleistocene. Conclusions/Significance The two genetic lineages may represent an advanced speciation stage suggestive of incipient or distinct species within L. umbratilis. These findings suggest that the Amazonas and Negro Rivers may be acting as effective barriers, thus preventing gene flow between populations on opposite sides. Such findings have important implications for epidemiological studies, especially those related to vector competence and anthropophily, and for vector control strategies. In addition, L. umbratilis represents an interesting example in speciation studies. PMID:22662146

Culturally appropriate methodology in obtaining a representative sample of South Australian Aboriginal adults for a cross-sectional population health study: challenges and resolutions.

PubMed

Marin, Tania; Taylor, Anne Winifred; Grande, Eleonora Dal; Avery, Jodie; Tucker, Graeme; Morey, Kim

2015-05-19

The considerably lower average life expectancy of Aboriginal and Torres Strait Islander Australians, compared with non-Aboriginal and non-Torres Strait Islander Australians, has been widely reported. Prevalence data for chronic disease and health risk factors are needed to provide evidence based estimates for Australian Aboriginal and Torres Strait Islanders population health planning. Representative surveys for these populations are difficult due to complex methodology. The focus of this paper is to describe in detail the methodological challenges and resolutions of a representative South Australian Aboriginal population-based health survey. Using a stratified multi-stage sampling methodology based on the Australian Bureau of Statistics 2006 Census with culturally appropriate and epidemiological rigorous methods, 11,428 randomly selected dwellings were approached from a total of 209 census collection districts. All persons eligible for the survey identified as Aboriginal and/or Torres Strait Islander and were selected from dwellings identified as having one or more Aboriginal person(s) living there at the time of the survey. Overall, the 399 interviews from an eligible sample of 691 SA Aboriginal adults yielded a response rate of 57.7%. These face-to-face interviews were conducted by ten interviewers retained from a total of 27 trained Aboriginal interviewers. Challenges were found in three main areas: identification and recruitment of participants; interviewer recruitment and retainment; and using appropriate engagement with communities. These challenges were resolved, or at least mainly overcome, by following local protocols with communities and their representatives, and reaching agreement on the process of research for Aboriginal people. Obtaining a representative sample of Aboriginal participants in a culturally appropriate way was methodologically challenging and required high levels of commitment and resources. Adhering to these principles has resulted in a rich and unique data set that provides an overview of the self-reported health status for Aboriginal people living in South Australia. This process provides some important principles to be followed when engaging with Aboriginal people and their communities for the purpose of health research.

A comparison of the prevalence and risk factors of suicidal ideation and suicide attempts in two American Indian and a general population sample

PubMed Central

Bolton, Shay-Lee; Elias, Brenda; Enns, Murray W.; Sareen, Jitender; Beals, Janette; Novins, Douglas K.

2015-01-01

The current study aimed to examine whether the prevalence and risk factors for suicidal ideation and attempts differ when comparing two American Indian reservation samples to the U.S. general population. Data were from the baseline nationally representative National Comorbidity Survey (N = 5,877) and the representative American Indian Service Utilization, Psychiatric Epidemiology, Risk and Protective Factors Project (AI-SUPERPFP; N = 3,084). Face-to-face interviews were conducted using the fully structured World Health Organization Composite International Diagnostic Interview. American Indians from these Northern Plains and Southwest tribes appeared significantly less likely to have suicidal thoughts in their lifetime when compared with the general population, odds ratio (OR) of 0.49 (99% CI [0.36, 0.66]) and 0.36 (99% CI [0.25, 0.51]), respectively. However, members of the Northern Plains tribe were more likely to have attempted suicide in their lifetime compared with the general population (OR=1.96, 99% CI [1.45, 2.65]). Suicide attempts without suicidal ideation were more common in the two American Indian samples than in the general population. In contrast, correlates of suicidal behavior appear quite similar when comparing the groups. Increased attention is needed to determine why rates of ideation and attempts may differ in American Indians when compared with the general population. PMID:24065607

Is Knowledge Random? Introducing Sampling and Bias through Outdoor Inquiry

ERIC Educational Resources Information Center

Stier, Sam

2010-01-01

Sampling, very generally, is the process of learning about something by selecting and assessing representative parts of that population or object. In the inquiry activity described here, students learned about sampling techniques as they estimated the number of trees greater than 12 cm dbh (diameter at breast height) in a wooded, discrete area…

The influence of polycyclic aromatic hydrocarbons on lung function in a representative sample of the Canadian population.

PubMed

Cakmak, Sabit; Hebbern, Chris; Cakmak, Jasmine D; Dales, Robert E

2017-09-01

We investigated the associations between exposure to polycyclic aromatic hydrocarbons (PAHs) and selected respiratory physiologic measures in cycles 2 and 3 of the Canadian Health Measures Survey, a nationally representative population sample. Using generalized linear mixed models, we tested the association between selected PAH metabolites and 1-second forced expiratory volume (FEV 1 ), forced vital capacity (FVC), and the ratio between the two (FEV 1 /FVC) in 3531 people from 6 to 79 years of age. An interquartile change in urinary PAH metabolite was associated with significant decrements in FEV 1 and FVC for eight PAHs, 2-hydroxynapthalene, 1-, and 2-hydroxyphenanthrene, 2-, 3-, and 9-hydroxyfluorene and 3- and 4-hydroxyphenanthrene. Exposure to PAH may negatively affect lung function in the Canadian population. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Forensic parameters of the X-STR Decaplex system in Mexican populations.

PubMed

Mariscal Ramos, C; Martínez-Cortes, G; Ramos-González, B; Rangel-Villalobos, H

2018-03-01

We studied the X-STR decaplex system in 529 DNA female samples of Mexican populations from five geographic regions. Allele frequencies and forensic parameters were estimated in each region and in the pooled Mexican population. Genotype distribution by locus was in agreement with Hardy-Weinberg expectations in each Mexican population sample. Similarly, linkage equilibrium was demonstrated between pair of loci. Pairwise comparisons and genetic distances between Mexican, Iberoamerican and one African populations were estimated and graphically represented. Interestingly, a non-significant interpopulation differentiation was detected (Fst = 0.0021; p = .74389), which allows using a global Mexican database for forensic interpretation of X-STR genotypes. Copyright © 2017 Elsevier B.V. All rights reserved.

An introduction to medical statistics for health care professionals: Hypothesis tests and estimation.

PubMed

Thomas, Elaine

2005-01-01

This article is the second in a series of three that will give health care professionals (HCPs) a sound introduction to medical statistics (Thomas, 2004). The objective of research is to find out about the population at large. However, it is generally not possible to study the whole of the population and research questions are addressed in an appropriate study sample. The next crucial step is then to use the information from the sample of individuals to make statements about the wider population of like individuals. This procedure of drawing conclusions about the population, based on study data, is known as inferential statistics. The findings from the study give us the best estimate of what is true for the relevant population, given the sample is representative of the population. It is important to consider how accurate this best estimate is, based on a single sample, when compared to the unknown population figure. Any difference between the observed sample result and the population characteristic is termed the sampling error. This article will cover the two main forms of statistical inference (hypothesis tests and estimation) along with issues that need to be addressed when considering the implications of the study results. Copyright (c) 2005 Whurr Publishers Ltd.

Independent Correlates of Reported Gambling Problems amongst Indigenous Australians

ERIC Educational Resources Information Center

Stevens, Matthew; Young, Martin

2010-01-01

To identify independent correlates of reported gambling problems amongst the Indigenous population of Australia. A cross-sectional design was applied to a nationally representative sample of the Indigenous population. Estimates of reported gambling problems are presented by remoteness and jurisdiction. Multivariable logistic regression was used to…

Actinomycetal complex of light sierozem on the Kopet-Dag piedmont plain

NASA Astrophysics Data System (ADS)

Zenova, G. M.; Zvyagintsev, D. G.; Manucharova, N. A.; Stepanova, O. A.; Chernov, I. Yu.

2016-10-01

The population density of actinomycetes in the samples of light sierozem from the Kopet Dag piedmont plain (75 km from Ashkhabad, Turkmenistan) reaches hundreds of thousand CFU/g soil. The actinomycetal complex is represented by two genera: Streptomyces and Micromonospora. Representatives of the Streptomyces genus predominate and comprise 73 to 87% of the actinomycetal complex. In one sample, representatives of the Micromonospora genus predominated in the complex (75%). The Streptomyces genus in the studied soil samples is represented by the species from several sections and series: the species of section Helvolo-Flavus series Helvolus represent the dominant component of the streptomycetal complex; their portion is up to 77% of all isolated actinomycetes. The species of other sections and series are much less abundant. Thus, the percentage of the Cinereus Achromogenes section in the actinomycetal complex does not exceed 28%; representatives of the Albus section Albus series, Roseus section Lavendulae-Roseus series, and Imperfectus section belong to rare species; they have been isolated not from all the studied samples of light sierozem, and their portion does not exceed 10% of the actinomycetal complex.

Are Apparent Sex Differences in Mean IQ Scores Created in Part by Sample Restriction and Increased Male Variance?

ERIC Educational Resources Information Center

Dykiert, Dominika; Gale, Catharine R.; Deary, Ian J.

2009-01-01

This study investigated the possibility that apparent sex differences in IQ are at least partly created by the degree of sample restriction from the baseline population. We used a nationally representative sample, the 1970 British Cohort Study. Sample sizes varied from 6518 to 11,389 between data-collection sweeps. Principal components analysis of…

Safe Schools? Transgender Youth's School Experiences and Perceptions of School Climate.

PubMed

Day, Jack K; Perez-Brumer, Amaya; Russell, Stephen T

2018-06-01

The magnitude of gender identity-related disparities in school-based outcomes is unknown because of a lack of representative studies that include measures of gender identity. By utilizing a representative sample generalizable to a broader population, this study elucidates the size of gender identity-related disparities, independent of sexual orientation, in school experiences associated with school connectedness and perceptions of school climate. Additionally, the inclusion of and comparison to results of a large non-representative sample allows for more direct comparisons to previous studies of the school experiences of transgender youth. The analyses in this study primarily draw on a sample of 31,896 youth representative of the middle and high school population in California who participated in the 2013-2015 California Student Survey (a subsample of the California Healthy Kids Survey, which includes the largest known sample of transgender youth). Over half the sample identified their sex as female (51.3%), and 398 identified as transgender (1.0%). The sample was racially and ethnically diverse: 30.7% identified as multiracial, 33.0% as White, 11.1% as Asian, 7.4% as Black, and 52.9% as Hispanic. Findings from multilevel analyses show that relative to non-transgender youth, transgender youth were more likely to be truant from school, to experience victimization and bias-based bullying, and to report more negative perceptions of school climate, though did not differ in self-reported grades. The findings have implications for improving school policies and practices to create safer and more supportive school climates for all youth.

Immunophenotype Discovery, Hierarchical Organization, and Template-Based Classification of Flow Cytometry Samples

DOE PAGES

Azad, Ariful; Rajwa, Bartek; Pothen, Alex

2016-08-31

We describe algorithms for discovering immunophenotypes from large collections of flow cytometry samples and using them to organize the samples into a hierarchy based on phenotypic similarity. The hierarchical organization is helpful for effective and robust cytometry data mining, including the creation of collections of cell populations’ characteristic of different classes of samples, robust classification, and anomaly detection. We summarize a set of samples belonging to a biological class or category with a statistically derived template for the class. Whereas individual samples are represented in terms of their cell populations (clusters), a template consists of generic meta-populations (a group ofmore » homogeneous cell populations obtained from the samples in a class) that describe key phenotypes shared among all those samples. We organize an FC data collection in a hierarchical data structure that supports the identification of immunophenotypes relevant to clinical diagnosis. A robust template-based classification scheme is also developed, but our primary focus is in the discovery of phenotypic signatures and inter-sample relationships in an FC data collection. This collective analysis approach is more efficient and robust since templates describe phenotypic signatures common to cell populations in several samples while ignoring noise and small sample-specific variations. We have applied the template-based scheme to analyze several datasets, including one representing a healthy immune system and one of acute myeloid leukemia (AML) samples. The last task is challenging due to the phenotypic heterogeneity of the several subtypes of AML. However, we identified thirteen immunophenotypes corresponding to subtypes of AML and were able to distinguish acute promyelocytic leukemia (APL) samples with the markers provided. Clinically, this is helpful since APL has a different treatment regimen from other subtypes of AML. Core algorithms used in our data analysis are available in the flowMatch package at www.bioconductor.org. It has been downloaded nearly 6,000 times since 2014.« less

Immunophenotype Discovery, Hierarchical Organization, and Template-Based Classification of Flow Cytometry Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azad, Ariful; Rajwa, Bartek; Pothen, Alex

We describe algorithms for discovering immunophenotypes from large collections of flow cytometry samples and using them to organize the samples into a hierarchy based on phenotypic similarity. The hierarchical organization is helpful for effective and robust cytometry data mining, including the creation of collections of cell populations’ characteristic of different classes of samples, robust classification, and anomaly detection. We summarize a set of samples belonging to a biological class or category with a statistically derived template for the class. Whereas individual samples are represented in terms of their cell populations (clusters), a template consists of generic meta-populations (a group ofmore » homogeneous cell populations obtained from the samples in a class) that describe key phenotypes shared among all those samples. We organize an FC data collection in a hierarchical data structure that supports the identification of immunophenotypes relevant to clinical diagnosis. A robust template-based classification scheme is also developed, but our primary focus is in the discovery of phenotypic signatures and inter-sample relationships in an FC data collection. This collective analysis approach is more efficient and robust since templates describe phenotypic signatures common to cell populations in several samples while ignoring noise and small sample-specific variations. We have applied the template-based scheme to analyze several datasets, including one representing a healthy immune system and one of acute myeloid leukemia (AML) samples. The last task is challenging due to the phenotypic heterogeneity of the several subtypes of AML. However, we identified thirteen immunophenotypes corresponding to subtypes of AML and were able to distinguish acute promyelocytic leukemia (APL) samples with the markers provided. Clinically, this is helpful since APL has a different treatment regimen from other subtypes of AML. Core algorithms used in our data analysis are available in the flowMatch package at www.bioconductor.org. It has been downloaded nearly 6,000 times since 2014.« less

Post-sampling mortality and non-response patterns in the English Cancer Patient Experience Survey: Implications for epidemiological studies based on surveys of cancer patients.

PubMed

Abel, Gary A; Saunders, Catherine L; Lyratzopoulos, Georgios

2016-04-01

Surveys of the experience of cancer patients are increasingly being introduced in different countries and used in cancer epidemiology research. Sampling processes, post-sampling mortality and survey non-response can influence the representativeness of cancer patient surveys. We examined predictors of post-sampling mortality and non-response among patients initially included in the sampling frame of the English Cancer Patient Experience Survey. We also compared the respondents' diagnostic case-mix to other relevant populations of cancer patients, including incident and prevalent cases. Of 109,477 initially sampled cancer patients, 6273 (5.7%) died between sampling and survey mail-out. Older age and diagnosis of brain, lung and pancreatic cancer were associated with higher risk of post-sampling mortality. The overall response rate was 67% (67,713 respondents), being >70% for the most affluent patients and those diagnosed with colon or breast cancer and <50% for Asian or Black patients, those under 35 and those diagnosed with brain cancer. The diagnostic case-mix of respondents varied substantially from incident or prevalent cancer cases. Respondents to the English Cancer Patient Experience Survey represent a population of recently treated cancer survivors. Although patient survey data can provide unique insights for improving cancer care quality, features of survey populations need to be acknowledged when analysing and interpreting findings from studies using such data. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Robust inference of population structure for ancestry prediction and correction of stratification in the presence of relatedness.

PubMed

Conomos, Matthew P; Miller, Michael B; Thornton, Timothy A

2015-05-01

Population structure inference with genetic data has been motivated by a variety of applications in population genetics and genetic association studies. Several approaches have been proposed for the identification of genetic ancestry differences in samples where study participants are assumed to be unrelated, including principal components analysis (PCA), multidimensional scaling (MDS), and model-based methods for proportional ancestry estimation. Many genetic studies, however, include individuals with some degree of relatedness, and existing methods for inferring genetic ancestry fail in related samples. We present a method, PC-AiR, for robust population structure inference in the presence of known or cryptic relatedness. PC-AiR utilizes genome-screen data and an efficient algorithm to identify a diverse subset of unrelated individuals that is representative of all ancestries in the sample. The PC-AiR method directly performs PCA on the identified ancestry representative subset and then predicts components of variation for all remaining individuals based on genetic similarities. In simulation studies and in applications to real data from Phase III of the HapMap Project, we demonstrate that PC-AiR provides a substantial improvement over existing approaches for population structure inference in related samples. We also demonstrate significant efficiency gains, where a single axis of variation from PC-AiR provides better prediction of ancestry in a variety of structure settings than using 10 (or more) components of variation from widely used PCA and MDS approaches. Finally, we illustrate that PC-AiR can provide improved population stratification correction over existing methods in genetic association studies with population structure and relatedness. © 2015 WILEY PERIODICALS, INC.

The population biology and genetics of the deep-sea spider crab, Encephaloides armstrongi Wood-Mason 1891 (Decapoda: Majidae)

PubMed Central

Creasey, S.; Rogers, A. D.; Tyler, P.; Young, C.; Gage, J.

1997-01-01

Numerous specimens of the majid spider crab, Encephaloides armstrongi, were sampled from six stations (populations) between 150 and 650 m depth, on the continental slope off the coast of Oman. This extended the known geographic and bathymetric range of E. armstrongi, which is now known to occur along the continental margins of the northern Indian Ocean from the western coast of Burma to the coast of Oman. This band-like distribution is contiguous to the oxygen minimum zone in this region. The biology and genetics of populations of Encephaloides armstrongi separated by depth were studied. The overall sex ratio of the E. armstrongi sampled was male-biased (p less than 0.01; 3.3 males: 1 female; So = 0.538). However, sex ratio varied both between populations (p less than 0.01) and between size classes of crabs. Size frequency analysis indicated that the male and female crabs consisted of at least two instars, one between 6 and 16mm carapace length and one between 16 and 29 mm carapace length, which probably represented the terminal (pubertal) moult for most individuals. Accumulation of female crabs in the terminal instar probably caused the variation of sex ratio with size classes. Some male crabs grew to a larger size (up to 38 mm carapace length), possibly as a result of maturity at later instars. Length frequency distribution was significantly different between sexes (one-way ANOVA p less than 0.001). Within sexes, length frequency distributions varied between different populations. In both male and female Encephaloides armstrongi the individuals from a single population located at 150 m depth were significantly smaller than individuals at all other stations and were considered to represent a juvenile cohort. For female crabs no other significant differences were detected in length frequency between populations from 300 m to 650 m depth. Significant differences in length frequency were detected between male crabs from populations between 300 and 650 m depth. Horizontal starch gel electrophoresis was used to detect six enzyme systems coding for eight loci for individuals sampled from each population of Encephaloides armstrongi. Genetic identity (I) values between populations of E. armstrongi (I = 0.98-1.00) were within the normal range for conspecific populations. Observed heterozygosity (Ho = 0.080-0.146) was lower than expected heterozygosity (He = 0.111-0.160), but in the normal range detected for eukaryotic organisms. F-statistics were used to analyse between population (FST) and within population (F ) genetic structure. For both male and female E. armstrongi significant genetic differentiation was detected between the population located at 150 m depth and all other populations. Analyses of FIS and FST, excluding the 150 m population indicated that for female E. armstrongi there was no significant structuring within or between populations. For male E. armstrongi significant heterozygote deficiencies were detected within populations and significant genetic differentiation between populations. The most likely explanations for the observations of the present study are: the population of Encephaloides armstrongi located at 150 m depth represented a juvenile cohort that is genetically distinct from deeper populations; female E. armstrongi formed a single population between 300 m and 650 m depth in the sampling area; male E. armstrongi were from two or more genetically distinct populations which are represented by different numbers of individuals at stations between 300 m and 650 m depth. This caused the observed significant differences in morphology (size distribition) and allele frequencies of male populations. It is likely that E. armstrongi exhibits gender-biased dispersal and that the crabs collected between 300 m and 650 m depth formed spawning aggressions. This also explains the bias in sex ratio of individuals sampled in the present study.

Recruitment Techniques among Understudied Populations and Their Implications for Physical Activity Promotion

ERIC Educational Resources Information Center

Kosma, Maria; Cardinal, Bradley; McCubbin, Jeffrey A.

2004-01-01

The inclusion of a representative sample of understudied populations (e.g., women, minorities, older adults, youth, and people with disabilities) in physical activity promotion studies is a public health priority. Given the limited empirical evidence of effective recruitment strategies and limitations in research methodology for both over…

Rural Values and Concensus(sic).

ERIC Educational Resources Information Center

England, J. Lynn; And Others

Sample populations from 15 Intermountain West communities (representative of population, ethnic, and employment variety) were surveyed to test the following hypotheses: (1) there is a greater degree of consensus in rural than in non-rural communities; (2) there are differences between values in rural and non-rural communities; (3) a model…

Obesity and Physical Inactivity in Rural America

ERIC Educational Resources Information Center

Patterson, Paul Daniel; Moore, Charity G.; Probst, Janice C.; Shinogle, Judith Ann

2004-01-01

Context and Purpose: Obesity and physical inactivity are common in the United States, but few studies examine this issue within rural populations. The present study uses nationally representative data to study obesity and physical inactivity in rural populations. Methods: Data came from the 1998 National Health Interview Survey Sample Adult and…

Thermal Inertia of Rocks and Rock Populations and Implications for Landing Hazards on Mars

NASA Technical Reports Server (NTRS)

Golombek, M. P.; Jakosky, B. M.; Mellon, M. T.

2001-01-01

Rocks represent an obvious potential hazard to a landing spacecraft. They also represent an impediment to rover travel and objects of prime scientific interest. Although Mars Orbiter Camera (MOC) images are of high enough resolution to distinguish the largest rocks (an extremely small population several meters diameter or larger), traditionally the abundance and distribution of rocks on Mars have been inferred from thermal inertia and radar measurements, our meager ground truth sampling of landing sites, and terrestrial rock populations. In this abstract, we explore the effective thermal inertia of rocks and rock populations, interpret the results in terms of abundances and populations of potentially hazardous rocks, and conclude with interpretations of rock hazards on the Martian surface and in extremely high thermal inertia areas.

Lipid Vesicle Shape Analysis from Populations Using Light Video Microscopy and Computer Vision

PubMed Central

Zupanc, Jernej; Drašler, Barbara; Boljte, Sabina; Kralj-Iglič, Veronika; Iglič, Aleš; Erdogmus, Deniz; Drobne, Damjana

2014-01-01

We present a method for giant lipid vesicle shape analysis that combines manually guided large-scale video microscopy and computer vision algorithms to enable analyzing vesicle populations. The method retains the benefits of light microscopy and enables non-destructive analysis of vesicles from suspensions containing up to several thousands of lipid vesicles (1–50 µm in diameter). For each sample, image analysis was employed to extract data on vesicle quantity and size distributions of their projected diameters and isoperimetric quotients (measure of contour roundness). This process enables a comparison of samples from the same population over time, or the comparison of a treated population to a control. Although vesicles in suspensions are heterogeneous in sizes and shapes and have distinctively non-homogeneous distribution throughout the suspension, this method allows for the capture and analysis of repeatable vesicle samples that are representative of the population inspected. PMID:25426933

Assessing the Relationship of Ancient and Modern Populations

PubMed Central

Schraiber, Joshua G.

2018-01-01

Genetic material sequenced from ancient samples is revolutionizing our understanding of the recent evolutionary past. However, ancient DNA is often degraded, resulting in low coverage, error-prone sequencing. Several solutions exist to this problem, ranging from simple approach, such as selecting a read at random for each site, to more complicated approaches involving genotype likelihoods. In this work, we present a novel method for assessing the relationship of an ancient sample with a modern population, while accounting for sequencing error and postmortem damage by analyzing raw reads from multiple ancient individuals simultaneously. We show that, when analyzing SNP data, it is better to sequence more ancient samples to low coverage: two samples sequenced to 0.5× coverage provide better resolution than a single sample sequenced to 2× coverage. We also examined the power to detect whether an ancient sample is directly ancestral to a modern population, finding that, with even a few high coverage individuals, even ancient samples that are very slightly diverged from the modern population can be detected with ease. When we applied our approach to European samples, we found that no ancient samples represent direct ancestors of modern Europeans. We also found that, as shown previously, the most ancient Europeans appear to have had the smallest effective population sizes, indicating a role for agriculture in modern population growth. PMID:29167200

Developing a synthetic national population to investigate the impact of different cardiovascular disease risk management strategies: A derivation and validation study

PubMed Central

Jackson, Rod

2017-01-01

Background Many national cardiovascular disease (CVD) risk factor management guidelines now recommend that drug treatment decisions should be informed primarily by patients’ multi-variable predicted risk of CVD, rather than on the basis of single risk factor thresholds. To investigate the potential impact of treatment guidelines based on CVD risk thresholds at a national level requires individual level data representing the multi-variable CVD risk factor profiles for a country’s total adult population. As these data are seldom, if ever, available, we aimed to create a synthetic population, representing the joint CVD risk factor distributions of the adult New Zealand population. Methods and results A synthetic population of 2,451,278 individuals, representing the actual age, gender, ethnicity and social deprivation composition of people aged 30–84 years who completed the 2013 New Zealand census was generated using Monte Carlo sampling. Each ‘synthetic’ person was then probabilistically assigned values of the remaining cardiovascular disease (CVD) risk factors required for predicting their CVD risk, based on data from the national census national hospitalisation and drug dispensing databases and a large regional cohort study, using Monte Carlo sampling and multiple imputation. Where possible, the synthetic population CVD risk distributions for each non-demographic risk factor were validated against independent New Zealand data sources. Conclusions We were able to develop a synthetic national population with realistic multi-variable CVD risk characteristics. The construction of this population is the first step in the development of a micro-simulation model intended to investigate the likely impact of a range of national CVD risk management strategies that will inform CVD risk management guideline updates in New Zealand and elsewhere. PMID:28384217

Developing a synthetic national population to investigate the impact of different cardiovascular disease risk management strategies: A derivation and validation study.

PubMed

Knight, Josh; Wells, Susan; Marshall, Roger; Exeter, Daniel; Jackson, Rod

2017-01-01

Many national cardiovascular disease (CVD) risk factor management guidelines now recommend that drug treatment decisions should be informed primarily by patients' multi-variable predicted risk of CVD, rather than on the basis of single risk factor thresholds. To investigate the potential impact of treatment guidelines based on CVD risk thresholds at a national level requires individual level data representing the multi-variable CVD risk factor profiles for a country's total adult population. As these data are seldom, if ever, available, we aimed to create a synthetic population, representing the joint CVD risk factor distributions of the adult New Zealand population. A synthetic population of 2,451,278 individuals, representing the actual age, gender, ethnicity and social deprivation composition of people aged 30-84 years who completed the 2013 New Zealand census was generated using Monte Carlo sampling. Each 'synthetic' person was then probabilistically assigned values of the remaining cardiovascular disease (CVD) risk factors required for predicting their CVD risk, based on data from the national census national hospitalisation and drug dispensing databases and a large regional cohort study, using Monte Carlo sampling and multiple imputation. Where possible, the synthetic population CVD risk distributions for each non-demographic risk factor were validated against independent New Zealand data sources. We were able to develop a synthetic national population with realistic multi-variable CVD risk characteristics. The construction of this population is the first step in the development of a micro-simulation model intended to investigate the likely impact of a range of national CVD risk management strategies that will inform CVD risk management guideline updates in New Zealand and elsewhere.

Insomnia Associated with Valerian and Melatonin Usage in the 2002 National Health Interview Survey

PubMed Central

Bliwise, Donald L.; Ansari, Farzaneh Pour

2007-01-01

Study Objective: Many people use dietary supplements or herbal products to help them sleep. We analyzed the associations between melatonin use and insomnia and between valerian use and insomnia in a representative sample of the United States population. Design and Participants: The data reported upon here were collected in the 2002 Alternative Health/Complementary and Alternative Medicine (CAM) Supplement to the National Health Interview Survey. This was a survey of 31,044 personal interviews that constituted an age-representative and socioeconomically representative sample of the civilian noninstitutionalized population of the United States. Results: Of the survey sample, 5.9% used valerian and 5.2% used melatonin. Of those using valerian, 29.9% endorsed insomnia as 1 reason for CAM use, and, of melatonin users, 27.5% endorsed insomnia as 1 reason for CAM use. Relatively greater use occurred in individuals under age 60 years. The decision to use such substances was made in consultation with a health care provider less than half of the time. Conclusions: Large segments of the United States population used valerian or melatonin for insomnia within the year preceding the survey, and usage typically fell outside the purview of the health care system. Citation: Bliwise DL; Ansari FP. Insomnia associated with valerian and melatonin usage in the 2002 National Health Interview Survey. SLEEP 2007;30(7):881-884. PMID:17682659

From K giants to G dwarfs: stellar lifetime effects on metallicity distributions derived from red giants

NASA Astrophysics Data System (ADS)

Manning, Ellen M.; Cole, Andrew A.

2017-11-01

We examine the biases inherent to chemical abundance distributions when targets are selected from the red giant branch (RGB), using simulated giant branches created from isochrones. We find that even when stars are chosen from the entire colour range of RGB stars and over a broad range of magnitudes, the relative numbers of stars of different ages and metallicities, integrated over all stellar types, are not accurately represented in the giant branch sample. The result is that metallicity distribution functions derived from RGB star samples require a correction before they can be fitted by chemical evolution models. We derive simple correction factors for over- and under-represented populations for the limiting cases of single-age populations with a broad range of metallicities and of continuous star formation at constant metallicity; an important general conclusion is that intermediate-age populations (≈1-4 Gyr) are over-represented in RGB samples. We apply our models to the case of the Large Magellanic Cloud bar and show that the observed metallicity distribution underestimates the true number of metal-poor stars by more than 25 per cent; as a result, the inferred importance of gas flows in chemical evolution models could potentially be overestimated. The age- and metallicity-dependences of RGB lifetimes require careful modelling if they are not to lead to spurious conclusions about the chemical enrichment history of galaxies.

Allele Frequencies for 15 Short Tandem Repeat Loci in Representative Sample of Croatian Population

PubMed Central

Projić, Petar; Škaro, Vedrana; Šamija, Ivana; Pojskić, Naris; Durmić-Pašić, Adaleta; Kovačević, Lejla; Bakal, Narcisa; Primorac, Dragan; Marjanović, Damir

2007-01-01

Aim To study the distribution of allele frequencies of 15 short tandem repeat (STR) loci in a representative sample of the Croatian population. Methods A total of 195 unrelated Caucasian individuals born in Croatia, from 14 counties and the City of Zagreb, were sampled for the analysis. All the tested individuals were voluntary donors. Buccal swab was used as the DNA source. AmpFlSTR® Identifiler® was applied to simultaneously amplify 15 STR loci. Total reaction volume was 12.5 μL. The polymerase chain reaction (PCR) amplification was carried out in PE Gene Amp PCR System Thermal Cycler. Electrophoresis of the amplification products was preformed on an ABI PRISM 3130 Genetic Analyzer. After PCR amplification and separation by electrophoresis, raw data were compiled, analyzed, and numerical allele designations of the profiles were obtained. Deviation from Hardy-Weinberg equilibrium, observed and expected heterozygosity, power of discrimination, and power of exclusion were calculated. Bonferroni’s correction was used before each comparative analysis. Results We compared Croatian data with those obtained from geographically neighboring European populations. The significant difference (at P<0.01) in allele frequencies was recorded only between the Croatian and Slovenian populations for vWA locus. There was no significant deviation from Hardy-Weinberg equilibrium for all the observed loci. Conclusion Obtained population data concurred with the expected “STR data frame” for this part of Europe. PMID:17696301

Y-chromosomal diversity of the Valachs from the Czech Republic: model for isolated population in Central Europe

PubMed Central

Ehler, Edvard; Vaněk, Daniel; Stenzl, Vlastimil; Vančata, Václav

2011-01-01

Aim To evaluate Y-chromosomal diversity of the Moravian Valachs of the Czech Republic and compare them with a Czech population sample and other samples from Central and South-Eastern Europe, and to evaluate the effects of genetic isolation and sampling. Methods The first sample set of the Valachs consisted of 94 unrelated male donors from the Valach region in northeastern Czech Republic border-area. The second sample set of the Valachs consisted of 79 men who originated from 7 paternal lineages defined by surname. No close relatives were sampled. The third sample set consisted of 273 unrelated men from the whole of the Czech Republic and was used for comparison, as well as published data for other 27 populations. The total number of samples was 3244. Y-short tandem repeat (STR) markers were typed by standard methods using PowerPlex® Y System (Promega) and Yfiler® Amplification Kit (Applied Biosystems) kits. Y-chromosomal haplogroups were estimated from the haplotype information. Haplotype diversity and other intra- and inter-population statistics were computed. Results The Moravian Valachs showed a lower genetic variability of Y-STR markers than other Central European populations, resembling more to the isolated Balkan populations (Aromuns, Csango, Bulgarian, and Macedonian Roma) than the surrounding populations (Czechs, Slovaks, Poles, Saxons). We illustrated the effect of sampling on Valach paternal lineages, which includes reduction of discrimination capacity and variability inside Y-chromosomal haplogroups. Valach modal haplotype belongs to R1a haplogroup and it was not detected in the Czech population. Conclusion The Moravian Valachs display strong substructure and isolation in their Y chromosomal markers. They represent a unique Central European population model for population genetics. PMID:21674832

Capturing goats: documenting two hundred years of mitochondrial DNA diversity among goat populations from Britain and Ireland.

PubMed

Cassidy, Lara M; Teasdale, Matthew D; Carolan, Seán; Enright, Ruth; Werner, Raymond; Bradley, Daniel G; Finlay, Emma K; Mattiangeli, Valeria

2017-03-01

The domestic goat ( Capra hircus ) plays a key role in global agriculture, being especially prized in regions of marginal pasture. However, the advent of industrialized breeding has seen a dramatic reduction in genetic diversity within commercial populations, while high extinction rates among feral herds have further depleted the reservoir of genetic variation available. Here, we present the first survey of whole mitochondrial genomic variation among the modern and historical goat populations of Britain and Ireland using a combination of mtDNA enrichment and high throughput sequencing. Fifteen historical taxidermy samples, representing the indigenous 'Old Goat' populations of the islands, were sequenced alongside five modern Irish dairy goats and four feral samples from endangered populations in western Ireland. Phylogenetic and network analyses of European mitochondrial variation revealed distinct groupings dominated by historical British and Irish samples, which demonstrate a degree of maternal genetic structure between the goats of insular and continental Europe. Several Irish modern feral samples also fall within these clusters, suggesting continuity between these dwindling populations and the ancestral 'Old Goats' of Ireland and Britain. © 2017 The Author(s).

Capturing goats: documenting two hundred years of mitochondrial DNA diversity among goat populations from Britain and Ireland

PubMed Central

Carolan, Seán; Enright, Ruth; Werner, Raymond; Bradley, Daniel G.; Finlay, Emma K.; Mattiangeli, Valeria

2017-01-01

The domestic goat (Capra hircus) plays a key role in global agriculture, being especially prized in regions of marginal pasture. However, the advent of industrialized breeding has seen a dramatic reduction in genetic diversity within commercial populations, while high extinction rates among feral herds have further depleted the reservoir of genetic variation available. Here, we present the first survey of whole mitochondrial genomic variation among the modern and historical goat populations of Britain and Ireland using a combination of mtDNA enrichment and high throughput sequencing. Fifteen historical taxidermy samples, representing the indigenous ‘Old Goat’ populations of the islands, were sequenced alongside five modern Irish dairy goats and four feral samples from endangered populations in western Ireland. Phylogenetic and network analyses of European mitochondrial variation revealed distinct groupings dominated by historical British and Irish samples, which demonstrate a degree of maternal genetic structure between the goats of insular and continental Europe. Several Irish modern feral samples also fall within these clusters, suggesting continuity between these dwindling populations and the ancestral ‘Old Goats’ of Ireland and Britain. PMID:28250207

Childhood adversity and personality disorders: results from a nationally representative population-based study.

PubMed

Afifi, Tracie O; Mather, Amber; Boman, Jonathon; Fleisher, William; Enns, Murray W; Macmillan, Harriet; Sareen, Jitender

2011-06-01

Although, a large population-based literature exists on the relationship between childhood adversity and Axis I mental disorders, research on the link between childhood adversity and Axis II personality disorders (PDs) relies mainly on clinical samples. The purpose of the current study was to examine the relationship between a range of childhood adversities and PDs in a nationally representative sample while adjusting for Axis I mental disorders. Data were from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC; n=34,653; data collection 2004-2005); a nationally representative sample of the United States population aged 20 years and older. The results indicated that many types of childhood adversity were highly prevalent among individuals with PDs in the general population and childhood adversity was most consistently associated with schizotypal, antisocial, borderline, and narcissistic PDs. The most robust childhood adversity findings were for child abuse and neglect with cluster A and cluster B PDs after adjusting for all other types of childhood adversity, mood disorders, anxiety disorders, substance use disorders, other PD clusters, and sociodemographic variables (Odd Ratios ranging from 1.22 to 1.63). In these models, mood disorders, anxiety disorders, and substance use disorders also remained significantly associated with PD clusters (Odds Ratios ranging from 1.26 to 2.38). Further research is necessary to understand whether such exposure has a causal role in the association with PDs. In addition to preventing child maltreatment, it is important to determine ways to prevent impairment among those exposed to adversity, as this may reduce the development of PDs. Copyright © 2010 Elsevier Ltd. All rights reserved.

Diversity of human small intestinal Streptococcus and Veillonella populations.

PubMed

van den Bogert, Bartholomeus; Erkus, Oylum; Boekhorst, Jos; de Goffau, Marcus; Smid, Eddy J; Zoetendal, Erwin G; Kleerebezem, Michiel

2013-08-01

Molecular and cultivation approaches were employed to study the phylogenetic richness and temporal dynamics of Streptococcus and Veillonella populations in the small intestine. Microbial profiling of human small intestinal samples collected from four ileostomy subjects at four time points displayed abundant populations of Streptococcus spp. most affiliated with S. salivarius, S. thermophilus, and S. parasanguinis, as well as Veillonella spp. affiliated with V. atypica, V. parvula, V. dispar, and V. rogosae. Relative abundances varied per subject and time of sampling. Streptococcus and Veillonella isolates were cultured using selective media from ileostoma effluent samples collected at two time points from a single subject. The richness of the Streptococcus and Veillonella isolates was assessed at species and strain level by 16S rRNA gene sequencing and genetic fingerprinting, respectively. A total of 160 Streptococcus and 37 Veillonella isolates were obtained. Genetic fingerprinting differentiated seven Streptococcus lineages from ileostoma effluent, illustrating the strain richness within this ecosystem. The Veillonella isolates were represented by a single phylotype. Our study demonstrated that the small intestinal Streptococcus populations displayed considerable changes over time at the genetic lineage level because only representative strains of a single Streptococcus lineage could be cultivated from ileostoma effluent at both time points. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Calculating Preference Weights for the Labor and Delivery Index: A Discrete Choice Experiment on Women's Birth Experiences.

PubMed

Gärtner, Fania R; de Bekker-Grob, Esther W; Stiggelbout, Anne M; Rijnders, Marlies E; Freeman, Liv M; Middeldorp, Johanna M; Bloemenkamp, Kitty W M; de Miranda, Esteriek; van den Akker-van Marle, M Elske

2015-09-01

The aim of this study was to calculate preference weights for the Labor and Delivery Index (LADY-X) to make it suitable as a utility measure for perinatal care studies. In an online discrete choice experiment, 18 pairs of hypothetical scenarios were presented to respondents, from which they had to choose a preferred option. The scenarios describe the birth experience in terms of the seven LADY-X attributes. A D-efficient discrete choice experiment design with priors based on a small sample (N = 110) was applied. Two samples were gathered, women who had recently given birth and subjects from the general population. Both samples were analyzed separately using a panel mixed logit (MMNL) model. Using the panel mixed multinomial logit (MMNL) model results and accounting for preference heterogeneity, we calculated the average preference weights for LADY-X attribute levels. These were transformed to represent a utility score between 0 and 1, with 0 representing the worst and 1 representing the best birth experience. In total, 1097 women who had recently given birth and 367 subjects from the general population participated. Greater value was placed on differences between bottom and middle attribute levels than on differences between middle and top levels. The attributes that resulted in larger utility increases than the other attributes were "feeling of safety" in the sample of women who had recently given birth and "feeling of safety" and "availability of professionals" in the general population sample. By using the derived preference weights, LADY-X has the potential to be used as a utility measure for perinatal (cost-) effectiveness studies. Copyright © 2015 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

77 FR 72205 - Testing and Labeling Pertaining to Product Certification Regarding Representative Samples for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-05

... testing periodically and when there has been a material change in the product's design or manufacturing... control data during product manufacture; and using manufacturing techniques with intrinsic manufacturing... sample in the production population an equal probability of being selected (75 FR at 28349 through 28350...

Epidemiology and genetic characterization of HIV-1 isolates in the general population of Djibouti (Horn of Africa).

PubMed

Maslin, Jérôme; Rogier, Christophe; Berger, Franck; Khamil, Mohamed Ali; Mattera, Didier; Grandadam, Marc; Caron, Mélanie; Nicand, Elizabeth

2005-06-01

During a national survey in 2002 in Djibouti, serum samples were collected using a valid sampling scheme from 2423 Djiboutians representing the general population of urban and rural districts. The HIV-1 seroprevalence was 2%. The HIV-1 polymerase gene from 53 untreated patients was amplified. Phylogenetic analysis of 34 isolates revealed a majority of subtype C (73%) as well as other subtypes, including CRF02_AG recombinants (18%), subtype D (6%), and subtype A (3%).

Questioning the stability of sense of coherence--the impact of socio-economic status and working conditions in the Canadian population.

PubMed

Smith, Peter M; Breslin, F Curtis; Beaton, Dorcas E

2003-09-01

Much debate exists about the stability of the sense of coherence measure. This study examined changes in sense of coherence (SOC), and the variables associated with these changes, over a 4-year period, in a representative sample of the Canadian labour force (n=6,790). Two methods were used to assess change in SOC: (1) Change outside of that which could be considered as indistinguishable from measurement error, and (2) Change of more than 10%, which was originally proposed by Antonovksy, the scales designer. Over the study period, 35.4% of the population reported changes in SOC outside the range we consider possible due to measurement error, with 58% reporting change greater than 10%. Unskilled occupations were associated with declines in SOC, with household income demonstrating a curvilinear relationship with decline in SOC in the female population only. None of the variables used predicted increases in SOC. Given the degree of change in SOC, and the representativeness of the study sample, we suggest that SOC has a large state component. Given this lack of stability, we recommend caution if using the SOC to represent a stable global orientation within a causal context.

Highly reported prevalence of drinking and driving in Brazil: data from the first representative household study.

PubMed

Pechansky, Flavio; De Boni, Raquel; Diemen, Lísia Von; Bumaguin, Daniela; Pinsky, Ilana; Zaleski, Marcos; Caetano, Raul; Laranjeira, Ronaldo

2009-06-01

Brazil lacks information about driving under the influence of alcohol (DUI) originated from representative samples obtained from the general population. 333 subjects with a valid driver's license and drinking in the last 12 months were drawn from a multistaged sample of 2,346 adults from the first Brazilian Household Survey of Patterns of Alcohol Use. A multivariate analysis was conducted to understand the associations between risk factors and driving after drinking three or more drinks. the overall DUI prevalence reported in the sample was 34.7% - 42.5% among males and 9.2% among females. Being male (OR = 6.0, 95% CI 2.9-12.6), having a previous DUI accident (OR = 7.9, 95% CI 2.5-24.9), binging in the last year (OR = 2.2, 95% CI 1.03-4.5) and having an unfavorable opinion towards policies (OR = 2.9, 95% CI 1.4-6.2) remained associated with heavy drinking and driving after model adjustments. This was the first study evaluating driving under the influence of alcohol in a representative sample of the Brazilian population. The prevalence of DUI found is alarming, and possibly underestimated in the sample. Results demonstrate the need for more studies on this association and show directions towards preventive strategies for the specific high-risk group of male drivers with previous problems with alcohol and unfavorable opinions about prevention policies.

12 CFR 715.8 - Requirements for verification of accounts and passbooks.

Code of Federal Regulations, 2010 CFR

2010-01-01

... selection: (ii) A sample which is representative of the population from which it was selected; (iii) An equal chance of selecting each dollar in the population; (iv) Sufficient accounts in both number and... consistent with GAAS if such methods provide for: (i) Sufficient accounts in both number and scope on which...

Differences between Adopted and Nonadopted Adolescents in Wilderness and Residential Treatment

ERIC Educational Resources Information Center

Bettmann, Joanna E.; Freeman, Pamela Clarkson; Parry, Kimber J.

2015-01-01

Adopted children are disproportionately represented in residential treatment programs in the United States. Adopted children in the United States constitute only 2% to 3% of the U.S population. Nevertheless, they comprise approximately 16.5% of the population in residential care. This descriptive study evaluated a sample of 473 psychological…

Statistical Modeling of the Individual: Rationale and Application of Multivariate Stationary Time Series Analysis

ERIC Educational Resources Information Center

Hamaker, Ellen L.; Dolan, Conor V.; Molenaar, Peter C. M.

2005-01-01

Results obtained with interindividual techniques in a representative sample of a population are not necessarily generalizable to the individual members of this population. In this article the specific condition is presented that must be satisfied to generalize from the interindividual level to the intraindividual level. A way to investigate…

The Study on Mental Health at Work: Design and sampling.

PubMed

Rose, Uwe; Schiel, Stefan; Schröder, Helmut; Kleudgen, Martin; Tophoven, Silke; Rauch, Angela; Freude, Gabriele; Müller, Grit

2017-08-01

The Study on Mental Health at Work (S-MGA) generates the first nationwide representative survey enabling the exploration of the relationship between working conditions, mental health and functioning. This paper describes the study design, sampling procedures and data collection, and presents a summary of the sample characteristics. S-MGA is a representative study of German employees aged 31-60 years subject to social security contributions. The sample was drawn from the employment register based on a two-stage cluster sampling procedure. Firstly, 206 municipalities were randomly selected from a pool of 12,227 municipalities in Germany. Secondly, 13,590 addresses were drawn from the selected municipalities for the purpose of conducting 4500 face-to-face interviews. The questionnaire covers psychosocial working and employment conditions, measures of mental health, work ability and functioning. Data from personal interviews were combined with employment histories from register data. Descriptive statistics of socio-demographic characteristics and logistic regressions analyses were used for comparing population, gross sample and respondents. In total, 4511 face-to-face interviews were conducted. A test for sampling bias revealed that individuals in older cohorts participated more often, while individuals with an unknown educational level, residing in major cities or with a non-German ethnic background were slightly underrepresented. There is no indication of major deviations in characteristics between the basic population and the sample of respondents. Hence, S-MGA provides representative data for research on work and health, designed as a cohort study with plans to rerun the survey 5 years after the first assessment.

Clinical and economic outcomes among hospitalized patients with acute coronary syndrome: an analysis of a national representative Medicare population.

PubMed

Chen, Shih-Yin; Crivera, Concetta; Stokes, Michael; Boulanger, Luke; Schein, Jeffrey

2013-01-01

To evaluate the clinical and economic burden of acute coronary syndrome (ACS), a common cardiovascular illness, in the Medicare population. Data from the Medicare Current Beneficiary Survey were analyzed. Patients with incident hospitalization for ACS without similar events during the 6 months prior were included. Outcomes evaluated included inpatient mortality, 30-day mortality and readmission, subsequent hospitalization events, and total direct health care costs. Sample population weights were applied, accounting for multistage sampling design to obtain nationally representative estimates for the US Medicare population. Between March 1, 2002 and December 31, 2006, we identified 795 incident ACS patients (mean age 76 years; 49% male) representing 2,542,211 Medicare beneficiaries. The inpatient mortality rate was 9.71% and the 30-day mortality ranged from 10.96% to 13.93%. The 30-day readmission rate for surviving patients was 18.56% for all causes and 17.90% for cardiovascular disease (CVD)-related diagnoses. The incidence of death since admission was 309 cases per 1000 person-years. Among patients discharged alive, the incidence was 197 for death, 847 for CVD-related admission, and 906 for all-cause admission. During the year when the ACS event occurred, mean annual total direct health care costs per person were US$50,458, with more than half attributable to inpatient hospitalization ($27,609). In this national representative Medicare population, we found a substantial clinical and economic burden for ACS. These findings suggest a continuing unmet medical need for more effective management of patients with ACS. The continuous burden underscores the importance of development of new interventions and/or strategies to improve long-term outcomes.

Maternal Responsiveness Predicts Child Language at Ages 3 and 4 in a Community-Based Sample of Slow-to-Talk Toddlers

ERIC Educational Resources Information Center

Hudson, Sophie; Levickis, Penny; Down, Kate; Nicholls, Ruth; Wake, Melissa

2015-01-01

Background: Maternal responsiveness has been shown to predict child language outcomes in clinical samples of children with language delay and non-representative samples of typically developing children. An effective and timely measure of maternal responsiveness for use at the population level has not yet been established. Aims: To determine…

Individualized head-related transfer functions based on population grouping.

PubMed

Xu, Song; Li, Zhizhong; Salvendy, Gavriel

2008-11-01

A method is proposed to divide a population into different groups for partial individualization of head-related transfer functions (HRTFs). Borrowing the basic idea in sizing system design, factor analysis is used to identify the most representative measurements which are then in a case study used to group the population. The comparison between the group mean HRTFs and the population mean HRTFs shows that the group mean HRTFs could greatly reduce spectral distortion at most sampled positions.

Determining the fraction of reddened quasars in COSMOS with multiple selection techniques from X-ray to radio wavelengths

NASA Astrophysics Data System (ADS)

Heintz, K. E.; Fynbo, J. P. U.; Møller, P.; Milvang-Jensen, B.; Zabl, J.; Maddox, N.; Krogager, J.-K.; Geier, S.; Vestergaard, M.; Noterdaeme, P.; Ledoux, C.

2016-10-01

The sub-population of quasars reddened by intrinsic or intervening clouds of dust are known to be underrepresented in optical quasar surveys. By defining a complete parent sample of the brightest and spatially unresolved quasars in the COSMOS field, we quantify to which extent this sub-population is fundamental to our understanding of the true population of quasars. By using the available multiwavelength data of various surveys in the COSMOS field, we built a parent sample of 33 quasars brighter than J = 20 mag, identified by reliable X-ray to radio wavelength selection techniques. Spectroscopic follow-up with the NOT/ALFOSC was carried out for four candidate quasars that had not been targeted previously to obtain a 100% redshift completeness of the sample. The population of high AV quasars (HAQs), a specific sub-population of quasars selected from optical/near-infrared photometry, some of which were shown to be missed in large optical surveys such as SDSS, is found to contribute 21%+9-5 of the parent sample. The full population of bright spatially unresolved quasars represented by our parent sample consists of 39%+9-8 reddened quasars defined by having AV > 0.1, and 21%+9-5 of the sample having E(B-V) > 0.1 assuming the extinction curve of the Small Magellanic Cloud. We show that the HAQ selection works well for selecting reddened quasars, but some are missed because their optical spectra are too blue to pass the g-r color cut in the HAQ selection. This is either due to a low degree of dust reddening or anomalous spectra. We find that the fraction of quasars with contributing light from the host galaxy, causing observed extended spatial morphology, is most dominant at z ≲ 1. At higher redshifts the population of spatially unresolved quasars selected by our parent sample is found to be representative of the full population of bright active galactic nuclei at J< 20 mag. This work quantifies the bias against reddened quasars in studies that are based solely on optical surveys. Partly based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias.

Generalizability of findings from randomized controlled trials: application to the National Institute of Drug Abuse Clinical Trials Network.

PubMed

Susukida, Ryoko; Crum, Rosa M; Ebnesajjad, Cyrus; Stuart, Elizabeth A; Mojtabai, Ramin

2017-07-01

To compare randomized controlled trial (RCT) sample treatment effects with the population effects of substance use disorder (SUD) treatment. Statistical weighting was used to re-compute the effects from 10 RCTs such that the participants in the trials had characteristics that resembled those of patients in the target populations. Multi-site RCTs and usual SUD treatment settings in the United States. A total of 3592 patients in 10 RCTs and 1 602 226 patients from usual SUD treatment settings between 2001 and 2009. Three outcomes of SUD treatment were examined: retention, urine toxicology and abstinence. We weighted the RCT sample treatment effects using propensity scores representing the conditional probability of participating in RCTs. Weighting the samples changed the significance of estimated sample treatment effects. Most commonly, positive effects of trials became statistically non-significant after weighting (three trials for retention and urine toxicology and one trial for abstinence); also, non-significant effects became significantly positive (one trial for abstinence) and significantly negative effects became non-significant (two trials for abstinence). There was suggestive evidence of treatment effect heterogeneity in subgroups that are under- or over-represented in the trials, some of which were consistent with the differences in average treatment effects between weighted and unweighted results. The findings of randomized controlled trials (RCTs) for substance use disorder treatment do not appear to be directly generalizable to target populations when the RCT samples do not reflect adequately the target populations and there is treatment effect heterogeneity across patient subgroups. © 2017 Society for the Study of Addiction.

Predictors of gender achievement in physical science at the secondary level

NASA Astrophysics Data System (ADS)

Kozlenko, Brittany Hunter

This study used the 2009 National Assessment of Educational Progress (NAEP) science restricted data-set for twelfth graders. The NAEP data used in this research study is derived from a sample group of 11,100 twelfth grade students that represented a national population of over 3,000,000 twelfth grade students enrolled in science in the United States in 2009. The researcher chose the NAEP data set because it provided a national sample using uniform questions. This study investigated how the factors of socioeconomic status (SES), parental education level, mode of instruction, and affective disposition affect twelfth grade students' physical science achievement levels in school for the sample population and subgroups for gender. The factors mode of instruction and affective disposition were built through factor analysis based on available questions from the student surveys. All four factors were found to be significant predictors of physical science achievement for the sample population. NAEP exams are administered to a national sample that represents the population of American students enrolled in public and private schools. This was a non-experimental study that adds to the literature on factors that impact physical science for both genders. A gender gap is essentially nonexistent at the fourth grade level but appears at the eighth grade level in science based on information from NAEP (NCES, 1997). The results of the study can be used to make recommendation for policy change to diminish this gender gap in the future. Educators need to be using research to make instructional decisions; research-based instruction helps all students.

Biomonitoring of urinary metals in a population living in the vicinity of industrial sources: a comparison with the general population of Andalusia, Spain.

PubMed

Aguilera, Inmaculada; Daponte, Antonio; Gil, Fernando; Hernández, Antonio F; Godoy, Patricia; Pla, Antonio; Ramos, Juan Luis

2008-12-15

The Ria of Huelva (south-west Spain) is one of the most polluted fluvial-estuarine systems in the world. Industrial activity delivers huge amounts of pollutants to the local environment, particularly heavy metals and arsenic. Here we aimed to determine urinary levels of As, Cd, Cr, Cu and Ni in a representative sample (n=857) of adults living in the Ria of Huelva. Levels were compared to those from a representative sample of 861 adults of the general urban population of Andalusia (southern Spain) and multiple regression models were developed to identify individual factors associated with urinary levels of these elements. Arsenic levels were significantly higher in the Ria of Huelva as compared to other Andalusian cities, whereas Cd and Ni levels were significantly lower. Despite these differences, levels in both groups were similar to the reference values reported in previous studies for general population. Age, gender, diet and lifestyle were the major factors contributing to the interindividual variation in urinary metals. In conclusion, despite living in a highly polluted area, the population of the Ria of Huelva failed to show higher urinary levels of the studied metals as compared to a reference urban population of the same region.

Measuring rural women's work and class position.

PubMed

Deere, C D; León de Leal, M

1979-01-01

On the basis of experience gained in researching the economic roles of rural women in a national level study in Colombia and in a regional level study in Peru, some of the methodological problems of measuring rural women's economic participation by sample survey are considered. The specific objective of the sample surveys was to quantify the existing sexual division of labor among the peasant population. The rural household was the unit of analysis, and the focus of measurement was the division of labor by sex in such activities as daily maintenance, household production, and income-generating activitives pursued outside the household. The focus of the survey questionnaire is on the sexual division of labor, but it necessarily must be related to another series of socioeconomic or cultural variables for analysis. The selection of these variables needs to be derived from the hypotheses guiding the study, yet much attention must be given to narrowing the range of inquiry. The time constraint on the length of the questionnaire requires that certain choices be made in terms of the complementary variables to be included. The most important problem in the design of a representative sample survey is the selection of the population to be sampled. The choice of population needs to be compatible with the theoretical framework. Since the interest was to measure the sexual division of labor in terms of class formation, the sample had to be representative of the different class strata in the rural areas. The measurement of access to means of production ideally should be quantitative and qualitative. The choice of the population to be sampled is also constrained by the available data base, a particular problem in rural areas.

Genotype diversity of Escherichia coli isolates in natural waters determined by PFGE and ERIC-PCR.

PubMed

Casarez, Elizabeth A; Pillai, Suresh D; Di Giovanni, George D

2007-08-01

Most library-dependent bacterial source tracking studies using Escherichia coli (E. coli) have focused on strain diversity of isolates obtained from known human and animal faecal sources for library development. In contrast, this study evaluated the genotype variation of E. coli isolated from natural surface water using pulsed field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus sequence polymerase chain reaction (ERIC-PCR) to better understand these naturally occurring populations. A total of 650 water samples were collected over a nine month period from eleven sampling stations from Lake Waco and Belton Lake in Central Texas. Of the 650 water samples collected, 412 were positive for E. coli, yielding a total of 631 E. coli isolates (1-12 isolates collected per sample). PFGE and ERIC-PCR patterns were successfully generated for 555 isolates and were compared using the curve-based Pearson's product-moment correlation coefficient. The 555 E. coli isolates represented 461 PFGE genotypes, with 84% (386/461) of the genotypes being represented by individual isolates. The remaining 75 genotypes were represented by 2-5 isolates each. Using ERIC-PCR, the 555 E. coli isolates represented 175 genotypes, with 63% (109/175) of the genotypes being represented by individual isolates. In contrast to the PFGE results, two ERIC-PCR genotypes represented 37% of the E. coli isolates, (83 and 124 isolates, respectively), and were found throughout the watersheds both spatially and temporally. Based on the PFGE genotype diversity of water isolates, there is little evidence that a small number of environmentally-adapted E. coli represent dominant populations in the studied waterbodies. However, with the lower discriminatory power technique ERIC-PCR, an opposing conclusion might have been drawn. These results emphasize the importance of considering the resolving power of the source tracking technique being used when assessing strain diversity and geographical stability.

Identifying the rooted species tree from the distribution of unrooted gene trees under the coalescent.

PubMed

Allman, Elizabeth S; Degnan, James H; Rhodes, John A

2011-06-01

Gene trees are evolutionary trees representing the ancestry of genes sampled from multiple populations. Species trees represent populations of individuals-each with many genes-splitting into new populations or species. The coalescent process, which models ancestry of gene copies within populations, is often used to model the probability distribution of gene trees given a fixed species tree. This multispecies coalescent model provides a framework for phylogeneticists to infer species trees from gene trees using maximum likelihood or Bayesian approaches. Because the coalescent models a branching process over time, all trees are typically assumed to be rooted in this setting. Often, however, gene trees inferred by traditional phylogenetic methods are unrooted. We investigate probabilities of unrooted gene trees under the multispecies coalescent model. We show that when there are four species with one gene sampled per species, the distribution of unrooted gene tree topologies identifies the unrooted species tree topology and some, but not all, information in the species tree edges (branch lengths). The location of the root on the species tree is not identifiable in this situation. However, for 5 or more species with one gene sampled per species, we show that the distribution of unrooted gene tree topologies identifies the rooted species tree topology and all its internal branch lengths. The length of any pendant branch leading to a leaf of the species tree is also identifiable for any species from which more than one gene is sampled.

Stellar Populations in Elliptical Galaxies

NASA Astrophysics Data System (ADS)

Angeletti, Lucio; Giannone, Pietro

The R1/n law for the radial surface brightness of elliptical galaxies and the "Best Accretion Model" together with the "Concentration Model" have been combined in order to determine the mass and dynamical structure of largely-populated star systems. Families of models depending on four parameters have been used to fit the observed surface radial profiles of some spectro-photometric indices of a sample of eleven galaxies. We present the best agreements of the spectral index Mg2 with observations for three selected galaxies representative of the full sample. For them we have also computed the spatial distributions of the metal abundances, which are essential to achieve a population synthesis.

Variance in binary stellar population synthesis

NASA Astrophysics Data System (ADS)

Breivik, Katelyn; Larson, Shane L.

2016-03-01

In the years preceding LISA, Milky Way compact binary population simulations can be used to inform the science capabilities of the mission. Galactic population simulation efforts generally focus on high fidelity models that require extensive computational power to produce a single simulated population for each model. Each simulated population represents an incomplete sample of the functions governing compact binary evolution, thus introducing variance from one simulation to another. We present a rapid Monte Carlo population simulation technique that can simulate thousands of populations in less than a week, thus allowing a full exploration of the variance associated with a binary stellar evolution model.

Studying Variance in the Galactic Ultra-compact Binary Population

NASA Astrophysics Data System (ADS)

Larson, Shane L.; Breivik, Katelyn

2017-01-01

In the years preceding LISA, Milky Way compact binary population simulations can be used to inform the science capabilities of the mission. Galactic population simulation efforts generally focus on high fidelity models that require extensive computational power to produce a single simulated population for each model. Each simulated population represents an incomplete sample of the functions governing compact binary evolution, thus introducing variance from one simulation to another. We present a rapid Monte Carlo population simulation technique that can simulate thousands of populations on week-long timescales, thus allowing a full exploration of the variance associated with a binary stellar evolution model.

Health Surveys Using Mobile Phones in Developing Countries: Automated Active Strata Monitoring and Other Statistical Considerations for Improving Precision and Reducing Biases

PubMed Central

Blynn, Emily; Ahmed, Saifuddin; Gibson, Dustin; Pariyo, George; Hyder, Adnan A

2017-01-01

In low- and middle-income countries (LMICs), historically, household surveys have been carried out by face-to-face interviews to collect survey data related to risk factors for noncommunicable diseases. The proliferation of mobile phone ownership and the access it provides in these countries offers a new opportunity to remotely conduct surveys with increased efficiency and reduced cost. However, the near-ubiquitous ownership of phones, high population mobility, and low cost require a re-examination of statistical recommendations for mobile phone surveys (MPS), especially when surveys are automated. As with landline surveys, random digit dialing remains the most appropriate approach to develop an ideal survey-sampling frame. Once the survey is complete, poststratification weights are generally applied to reduce estimate bias and to adjust for selectivity due to mobile ownership. Since weights increase design effects and reduce sampling efficiency, we introduce the concept of automated active strata monitoring to improve representativeness of the sample distribution to that of the source population. Although some statistical challenges remain, MPS represent a promising emerging means for population-level data collection in LMICs. PMID:28476726

Parental Opinion Concerning School Sexuality Education in a Culturally Diverse Population in the USA

ERIC Educational Resources Information Center

Heller, Janet R.; Johnson, Helen L.

2013-01-01

This study aimed to expand upon previous research related to parental opinion concerning school sexuality education by sampling a culturally diverse, low-income population that has been traditionally under-represented in the literature. A total of 191 parents attending an urban community college completed a written questionnaire about what topics…

Generalizability of causal inference in observational studies under retrospective convenience sampling.

PubMed

Hu, Zonghui; Qin, Jing

2018-05-20

Many observational studies adopt what we call retrospective convenience sampling (RCS). With the sample size in each arm prespecified, RCS randomly selects subjects from the treatment-inclined subpopulation into the treatment arm and those from the control-inclined into the control arm. Samples in each arm are representative of the respective subpopulation, but the proportion of the 2 subpopulations is usually not preserved in the sample data. We show in this work that, under RCS, existing causal effect estimators actually estimate the treatment effect over the sample population instead of the underlying study population. We investigate how to correct existing methods for consistent estimation of the treatment effect over the underlying population. Although RCS is adopted in medical studies for ethical and cost-effective purposes, it also has a big advantage for statistical inference: When the tendency to receive treatment is low in a study population, treatment effect estimators under RCS, with proper correction, are more efficient than their parallels under random sampling. These properties are investigated both theoretically and through numerical demonstration. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

Rapid estimation of microbial populations in fish samples by using terminal restriction fragment length polymorphism analysis of 16S rDNA.

PubMed

Tanaka, Yuichiro; Takahashi, Hajime; Kitazawa, Nao; Kimura, Bon

2010-01-01

A rapid system using terminal restriction fragment length polymorphism (T-RFLP) analysis targeting 16S rDNA is described for microbial population analysis in edible fish samples. The defined terminal restriction fragment database was constructed by collecting 102 strains of bacteria representing 53 genera that are associated with fish. Digestion of these 102 strains with two restriction enzymes, HhaI and MspI, formed 54 pattern groups with discrimination to the genus level. This T-RFLP system produced results comparable to those from a culture-based method in six natural fish samples with a qualitative correspondence of 71.4 to 92.3%. Using the T-RFLP system allowed an estimation of the microbial population within 7 h. Rapid assay of the microbial population is advantageous for food manufacturers and testing laboratories; moreover, the strategy presented here allows adaptation to specific testing applications.

Assessment of exposure to lead in humans and turtles living in an industrial site in Coatzacoalcos Veracruz, Mexico.

PubMed

Pelallo-Martínez, N A; Ilizaliturri-Hernández, C A; Espinosa-Reyes, G; Carrizales-Yáñez, L; González-Mille, D J

2011-06-01

The intake of lead from the environment may occur thru various receptors. In order to measure lead levels absorbed, samples were taken from Children who live in three localities surrounding an industrial complex in Coatzacoalcos, Veracruz. Samples were also taken from turtles. Samples were analyzed and results were compared against the general population. In children tested, over 75% of all values were determined to be above CDC's safety levels of (10 μg/dL). The geometric mean lead concentration was 11.4 μg/dL, which is clearly higher around the industrial complex than in the general population. In turtles, lead blood levels in the exposed population were 2-fold above (24.2 μg/dL) those of turtles in the reference population (10.1 μg/dL). Lead levels observed represent a risk for both human and fauna health.

Who Are the Turkers? A Characterization of MTurk Workers Using the Personality Assessment Inventory.

PubMed

McCredie, Morgan N; Morey, Leslie C

2018-02-01

As online data collection services such as Amazon's Mechanical Turk (MTurk) gain popularity, the quality and representativeness of such data sources have gained research attention. To date, the majority of existing studies have compared MTurk workers with undergraduate samples, localized community samples, or other Internet-based samples, and thus, there remains little known about the personality and mental health constructs of MTurk workers relative to a national representative sample. The present study addresses these limitations and broadens the scope of existing research through the use of the Personality Assessment Inventory, a multiscale, self-report questionnaire which provides information regarding data validity and personality and psychopathology features standardized against a national U.S. census-matched normative sample. Results indicate that MTurk workers generally provide high-quality data and are reasonably representative of the general population across most psychological dimensions assessed. However, several distinguishing features of MTurk workers emerged that were consistent with prior findings of such individuals, primarily involving somewhat higher negative affect and lower social engagement.

The Complex Demographic History and Evolutionary Origin of the Western Honey Bee, Apis Mellifera

PubMed Central

Tsutsui, Neil D.; Ramírez, Santiago R.

2017-01-01

The western honey bee, Apis mellifera, provides critical pollination services to agricultural crops worldwide. However, despite substantial interest and prior investigation, the early evolution and subsequent diversification of this important pollinator remain uncertain. The primary hypotheses place the origin of A. mellifera in either Asia or Africa, with subsequent radiations proceeding from one of these regions. Here, we use two publicly available whole-genome data sets plus newly sequenced genomes and apply multiple population genetic analysis methods to investigate the patterns of ancestry and admixture in native honey bee populations from Europe, Africa, and the Middle East. The combination of these data sets is critical to the analyses, as each contributes samples from geographic locations lacking in the other, thereby producing the most complete set of honey bee populations available to date. We find evidence supporting an origin of A. mellifera in the Middle East or North Eastern Africa, with the A and Y lineages representing the earliest branching lineages. This finding has similarities with multiple contradictory hypotheses and represents a disentangling of genetic relationships, geographic proximity, and secondary contact to produce a more accurate picture of the origins of A. mellifera. We also investigate how previous studies came to their various conclusions based on incomplete sampling of populations, and illustrate the importance of complete sampling in understanding evolutionary processes. These results provide fundamental knowledge about genetic diversity within Old World honey bee populations and offer insight into the complex history of an important pollinator. PMID:28164223

Tissues from population-based cancer registries: a novel approach to increasing research potential.

PubMed

Goodman, Marc T; Hernandez, Brenda Y; Hewitt, Stephen; Lynch, Charles F; Coté, Timothy R; Frierson, Henry F; Moskaluk, Christopher A; Killeen, Jeffrey L; Cozen, Wendy; Key, Charles R; Clegg, Limin; Reichman, Marsha; Hankey, Benjamin F; Edwards, Brenda

2005-07-01

Population-based cancer registries, such as those included in the Surveillance, Epidemiology, and End-Results (SEER) Program, offer tremendous research potential beyond traditional surveillance activities. We describe the expansion of SEER registries to gather formalin-fixed, paraffin-embedded tissue from cancer patients on a population basis. Population-based tissue banks have the advantage of providing an unbiased sampling frame for evaluating the public health impact of genes or protein targets that may be used for therapeutic or diagnostic purposes in defined communities. Such repositories provide a unique resource for testing new molecular classification schemes for cancer, validating new biologic markers of malignancy, prognosis and progression, assessing therapeutic targets, and measuring allele frequencies of cancer-associated genetic polymorphisms or germline mutations in representative samples. The assembly of tissue microarrays will allow for the use of rapid, large-scale protein-expression profiling of tumor samples while limiting depletion of this valuable resource. Access to biologic specimens through SEER registries will provide researchers with demographic, clinical, and risk factor information on cancer patients with assured data quality and completeness. Clinical outcome data, such as disease-free survival, can be correlated with previously validated prognostic markers. Furthermore, the anonymity of the study subject can be protected through rigorous standards of confidentiality. SEER-based tissue resources represent a step forward in true, population-based tissue repositories of tumors from US patients and may serve as a foundation for molecular epidemiology studies of cancer in this country.

Convenience Sampling of Children Presenting to Hospital-Based Outpatient Clinics to Estimate Childhood Obesity Levels in Local Surroundings.

PubMed

Gilliland, Jason; Clark, Andrew F; Kobrzynski, Marta; Filler, Guido

2015-07-01

Childhood obesity is a critical public health matter associated with numerous pediatric comorbidities. Local-level data are required to monitor obesity and to help administer prevention efforts when and where they are most needed. We hypothesized that samples of children visiting hospital clinics could provide representative local population estimates of childhood obesity using data from 2007 to 2013. Such data might provide more accurate, timely, and cost-effective obesity estimates than national surveys. Results revealed that our hospital-based sample could not serve as a population surrogate. Further research is needed to confirm this finding.

Molecular detection of hepatitis E virus in wild boar population in eastern Romania.

PubMed

Porea, D; Anita, A; Demange, A; Raileanu, C; Oslobanu Ludu, L; Anita, D; Savuta, G; Pavio, N

2018-04-01

In industrialized countries, Hepatitis E is a recognized zoonosis, with wild boar and swine representing the main reservoirs for zoonotic genotype HEV-3 in Europe. Data related to HEV infection in wild boar population in Romania are restricted to serological surveys. Therefore, our main goal was to determine the HEV prevalence in wild boar population and to characterize HEV strains circulating in Romania. Using TaqMan real-time RT-PCR assay, we analyzed the presence of RNA HEV in 45 liver samples and five spleen samples collected from 50 wild boars. Samples were collected during the 2013-2015 hunting seasons. Nine samples of 50 were tested positive for HEV RNA, resulting an overall prevalence of 18%. Phylogenetic analysis revealed that the isolates clustered in different HEV-3 monophyletic groups, depending on the sampling county. This is the first study signalling, based on molecular analysis, the presence of HEV in wild boar population from Romania. Also, in this study, we report the detection of HEV in splenic tissue from wild boar. © 2017 Blackwell Verlag GmbH.

Association of serum ferritin with metabolic syndrome and diabetes mellitus in the South Korean general population according to the Korean National Health and Nutrition Examination Survey 2008.

PubMed

Lee, Byung-Kook; Kim, Yangho; Kim, Young-Il

2011-10-01

We examined the association of serum ferritin levels with metabolic syndrome (MS) and diabetes mellitus in a representative sample of the adult South Korean population using data from the 2008 Korean National Health and Nutrition Examination Survey. We conducted a cross-sectional study of 6311 adults older than 20 years who participated in the 2008 Korean National Health and Nutrition Examination Survey. Metabolic syndrome was defined as the presence of at least 3 of the following: elevated blood pressure, low high-density lipoprotein cholesterol, elevated serum triglycerides, elevated plasma glucose, and abdominal obesity. Diabetes mellitus was defined as fasting glucose of at least 126 mg/dL. Insulin resistance was determined using the homeostasis model assessment estimate of insulin resistance. In a representative sample of the adult Korean population, MS was more prevalent in the highest quartile compared with the lowest quartile of serum ferritin concentrations in women following adjustments for age, education, smoking, alcohol intake, body mass index, aspartate aminotransferase, and alanine aminotransferase. Diabetes mellitus was more prevalent in the highest quartile compared with the lowest quartile of serum ferritin concentrations in premenopausal women and men. The geometric means of fasting insulin and insulin resistance determined using the homeostasis model assessment of insulin resistance in the fourth serum ferritin quartiles of postmenopausal women and men were significantly higher compared with those in the first quartile of the respective groups. The present study demonstrates that elevated serum ferritin concentrations are associated with an increased risk of MS and diabetes mellitus in a representative sample of the adult South Korean population. Copyright © 2011. Published by Elsevier Inc.

Country Image and Ideal Destination Choice in Study Abroad: Evidence from the Republic of Korea

ERIC Educational Resources Information Center

Ghazarian, Peter Gregory; Keller, Daniel Ryan

2016-01-01

In a time of growing competition for tertiary education, international students represent an important resource. However, more work is required to detail the factors that influence destination choice in study abroad. Drawing from a representative sample (n = 620) of the adult population over 19 in the Republic of Korea, the present study examined…

Global Quality of Life (QOL), Health and Ability Are Primarily Determined by Our Consciousness: Research Findings from Denmark 1991-2004

ERIC Educational Resources Information Center

Ventegodt, Soren; Flensborg-Madsen, Trine; Andersen, Niels Jorgen; Nielsen, Michael; Mohammed, Morad; Merrick, Joav

2005-01-01

Objective: To explain the global quality of life (QOL) from 2000 indicators representing all aspects of life. Design and setting: Two cross sectional population studies, one prospective cohort study and one retrospective cohort study. Participants: (1) Representative sample of 2500 Danes (18-88 years), (2) 7222 members of the Copenhagen Perinatal…

Molecular and morphologic data reveal multiple species in Peromyscus pectoralis

PubMed Central

Bradley, Robert D.; Schmidly, David J.; Amman, Brian R.; Platt, Roy N.; Neumann, Kathy M.; Huynh, Howard M.; Muñiz-Martínez, Raúl; López-González, Celia; Ordóñez-Garza, Nicté

2015-01-01

DNA sequence and morphometric data were used to re-evaluate the taxonomy and systematics of Peromyscus pectoralis. Phylogenetic analyses (maximum likelihood and Bayesian inference) of DNA sequences from the mitochondrial cytochrome-b gene in 44 samples of P. pectoralis indicated 2 well-supported monophyletic clades. The 1st clade contained specimens from Texas historically assigned to P. p. laceianus; the 2nd was comprised of specimens previously referable to P. p. collinus, P. p. laceianus, and P. p. pectoralis obtained from northern and eastern Mexico. Levels of genetic variation (~7%) between these 2 clades indicated that the genetic divergence typically exceeded that reported for other species of Peromyscus. Samples of P. p. laceianus north and south of the Río Grande were not monophyletic. In addition, samples representing P. p. collinus and P. p. pectoralis formed 2 clades that differed genetically by 7.14%. Multivariate analyses of external and cranial measurements from 63 populations of P. pectoralis revealed 4 morpho-groups consistent with clades in the DNA sequence analysis: 1 from Texas and New Mexico assignable to P. p. laceianus; a 2nd from western and southern Mexico assignable to P. p. pectoralis; a 3rd from northern and central Mexico previously assigned to P. p. pectoralis but herein shown to represent an undescribed taxon; and a 4th from southeastern Mexico assignable to P. p. collinus. Based on the concordance of these results, populations from the United States are referred to as P. laceianus, whereas populations from Mexico are referred to as P. pectoralis (including some samples historically assigned to P. p. collinus, P. p. laceianus, and P. p. pectoralis). A new subspecies is described to represent populations south of the Río Grande in northern and central Mexico. Additional research is needed to discern if P. p. collinus warrants species recognition. PMID:26937045

Characterizing the context of sedentary lifestyles in a representative sample of adults: a cross-sectional study from the physical activity measurement study project.

PubMed

Kim, Youngwon; Welk, Gregory J

2015-12-09

Research has clearly demonstrated that excess time spent on sedentary behavior (SB) increases health risks in the population. However, the lack of information on the context of SB in the population prevents a detailed understanding of sedentary lifestyles. The purpose of this study was to characterize the context of SB in a representative sample of adults and to examine differences across various socio-demographic indicators. A diverse sample of 1442 adults (ages 20-71 year) completed an interviewer-administered 24-h activity recall to provide detailed information about the time, type and location of the previous day's activities. All reported activities were matched with MET scores from the Compendium of Physical Activity but only SB (i.e., METS < 1.5) were extracted for the present analyses. The reported SB were broadly distributed across 5 primary location categories (Work: 27.5%, Community: 24.8%, Home/Indoor: 20.5%, Home/Outdoor: 15.8%, and Transportation: 11.3%). Patterns of SB allocations varied considerably across different socio-demographic indicators indicating the extreme variability in SB in the population. The findings provide unique insights about the context of SB at the population level, and can serve as a guide for developing intervention/policy studies to reduce sedentary time and minimize disparities in SB.

Prevalence of Chronic Respiratory Disease in a Pulp Mill and a Paper Mill in the United States1

PubMed Central

Ferris, B. G.; Burgess, W. A.; Worcester, J.

1967-01-01

A sample of 147 men drawn from the workers in a pulp mill was compared with one of 124 men from a paper mill. The former included those exposed to chlorine and to sulphur dioxide. No significant differences were found in respiratory symptoms or in simple tests of ventilatory function in the two samples, but men working in chlorine had a somewhat poorer respiratory function and more shortness of breath than those working in sulphur dioxide. The working population of both mills together had a lower prevalence of respiratory disease than that of the male population of Berlin, N.H., previously studied, suggesting that working populations may not be representative of the general population. Further, a low prevalence of disease in a working population exposed to pollutants may not indicate their `safety' in general populations. PMID:6017136

Incidence and seroprevalence of tularaemia in Finland, 1995 to 2013: regional epidemics with cyclic pattern.

PubMed

Rossow, H; Ollgren, J; Hytonen, J; Rissanen, H; Huitu, O; Henttonen, H; Kuusi, M; Vapalahti, O

2015-08-20

We studied the incidence of reported tularaemia by year and region and the prevalence of antibodies against Francisella tularensis in the adult general population in Finland. Moreover, we assessed the correlation between vole population cycles and human tularaemia outbreaks. The seroprevalence study made use of serum samples from a nationwide population-based health survey (Health 2000). The samples of 1,045 randomly selected persons, representative for the Finnish population in each region, were screened with an enzyme-linked immunosorbent assay (ELISA) for the presence of IgG antibodies against F. tularensis, and positive results were further confirmed by immunoblotting. A serological response to F. tularensis was found in 2% (95% confidence interval: 1.1–3.5) of the population. Incidence and seroprevalence were highest in the same areas, and vole population peaks clearly preceded tularaemia outbreaks one year later.

Assessing genome-wide copy number variation in the Han Chinese population.

PubMed

Lu, Jianqi; Lou, Haiyi; Fu, Ruiqing; Lu, Dongsheng; Zhang, Feng; Wu, Zhendong; Zhang, Xi; Li, Changhua; Fang, Baijun; Pu, Fangfang; Wei, Jingning; Wei, Qian; Zhang, Chao; Wang, Xiaoji; Lu, Yan; Yan, Shi; Yang, Yajun; Jin, Li; Xu, Shuhua

2017-10-01

Copy number variation (CNV) is a valuable source of genetic diversity in the human genome and a well-recognised cause of various genetic diseases. However, CNVs have been considerably under-represented in population-based studies, particularly the Han Chinese which is the largest ethnic group in the world. To build a representative CNV map for the Han Chinese population. We conducted a genome-wide CNV study involving 451 male Han Chinese samples from 11 geographical regions encompassing 28 dialect groups, representing a less-biased panel compared with the currently available data. We detected CNVs by using 4.2M NimbleGen comparative genomic hybridisation array and whole-genome deep sequencing of 51 samples to optimise the filtering conditions in CNV discovery. A comprehensive Han Chinese CNV map was built based on a set of high-quality variants (positive predictive value >0.8, with sizes ranging from 369 bp to 4.16 Mb and a median of 5907 bp). The map consists of 4012 CNV regions (CNVRs), and more than half are novel to the 30 East Asian CNV Project and the 1000 Genomes Project Phase 3. We further identified 81 CNVRs specific to regional groups, which was indicative of the subpopulation structure within the Han Chinese population. Our data are complementary to public data sources, and the CNV map may facilitate in the identification of pathogenic CNVs and further biomedical research studies involving the Han Chinese population. © 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.

Navigating complex sample analysis using national survey data.

PubMed

Saylor, Jennifer; Friedmann, Erika; Lee, Hyeon Joo

2012-01-01

The National Center for Health Statistics conducts the National Health and Nutrition Examination Survey and other national surveys with probability-based complex sample designs. Goals of national surveys are to provide valid data for the population of the United States. Analyses of data from population surveys present unique challenges in the research process but are valuable avenues to study the health of the United States population. The aim of this study was to demonstrate the importance of using complex data analysis techniques for data obtained with complex multistage sampling design and provide an example of analysis using the SPSS Complex Samples procedure. Illustration of challenges and solutions specific to secondary data analysis of national databases are described using the National Health and Nutrition Examination Survey as the exemplar. Oversampling of small or sensitive groups provides necessary estimates of variability within small groups. Use of weights without complex samples accurately estimates population means and frequency from the sample after accounting for over- or undersampling of specific groups. Weighting alone leads to inappropriate population estimates of variability, because they are computed as if the measures were from the entire population rather than a sample in the data set. The SPSS Complex Samples procedure allows inclusion of all sampling design elements, stratification, clusters, and weights. Use of national data sets allows use of extensive, expensive, and well-documented survey data for exploratory questions but limits analysis to those variables included in the data set. The large sample permits examination of multiple predictors and interactive relationships. Merging data files, availability of data in several waves of surveys, and complex sampling are techniques used to provide a representative sample but present unique challenges. In sophisticated data analysis techniques, use of these data is optimized.

Representative Sampling: Follow-up of Spring 1972 and Spring 1973 Students. TEX-SIS FOLLOW-UP SC3.

ERIC Educational Resources Information Center

Wilkinson, Larry; And Others

This report presents the findings of a research study, conducted by the College of the Mainland (COM) as a subcontractor for Project FOLLOW-UP, designed to test the accuracy of random sampling and to measure non-response bias in mail surveys. In 1975, a computer-generated random sample of 500 students was drawn from a population of 1,256 students…

A Twin Study of ADHD Symptoms in Early Adolescence: Hyperactivity-Impulsivity and Inattentiveness Show Substantial Genetic Overlap but Also Genetic Specificity

ERIC Educational Resources Information Center

Greven, Corina U.; Rijsdijk, Fruhling V.; Plomin, Robert

2011-01-01

A previous paper in this journal revealed substantial genetic overlap between the ADHD dimensions of hyperactivity-impulsivity and inattentiveness in a sample of 8-year old twins drawn from a UK-representative population sample. Four years later, when the twins were 12 years old, more than 5,500 pairs drawn from the same sample were rated again on…

Palaeodemography of the Atapuerca-SH Middle Pleistocene hominid sample.

PubMed

Bermúdez de Castro, J M; Nicolás, M E

1997-01-01

We report here on the palaeodemographic analysis of the hominid sample recovered to date from the Sima de los Huesos (SH) Middle Pleistocene cave site in the Sierra de Atapuerca (Burgos, Spain). The analysis of the mandibular, maxillary, and dental remains has made it possible to estimate that a minimum of 32 individuals, who probably belonged to the same biological population, are represented in the current SH human hypodigm. The remains of nine-individuals are assigned to males, and nine to females, suggesting that a 1:1 sex ratio characterizes this hominid sample. The survivorship curve shows a low representation of infants and children, a high mortality among the adolescents and prime-age adults, and a low older adult mortality. Longevity was probably no greater than 40 years. This mortality pattern (adolescents and adults); which in some aspects resembles that observed in Neandertals, is quite different from those reported for recent foraging human groups. The adult age-at-death distribution of the SH hominid sample appears to be neither the consequence of underaging the older adults, nor of differential preservation or of the recognition of skeletal remains. Thus if we accept that they had a life history pattern similar to that of modern humans there would appear to be a clear contradiction between the demographic distribution and the demographic viability of the population represented by the SH hominid fossils. The possible representational bias of the SH hominid sample, as well as some aspects of the reproductive biology of the Pleistocene populations are also discussed.

Elder Abuse and Black Americans: Incidence, Correlates, Treatment and Prevention.

ERIC Educational Resources Information Center

Cazenave, Noel A.

Existing evidence on family violence rates by age and race as well as the available data on race and physical elder abuse incidence rates suggests that because such data are not based on random or representative samples and tend to reflect a "sampling artifact" of the particular client populations served by the professionals surveyed,…

An Inmate Classification System Based on PCL: SV Factor Scores in a Sample of Prison Inmates

ERIC Educational Resources Information Center

Wogan, Michael; Mackenzie, Marci

2007-01-01

Psychopaths represent a significant management challenge in a prison population. A sample of ninety-five male inmates from three medium security prisons was tested using the Hare Psychopathy Checklist: Screening Version (PCL:SV). Using traditional criteria, 22% of the inmates were classified as psychopaths. Scores on the two factor dimensions of…

Rurality and Ethnicity in Adolescent Physical Illness: Are Children of the Growing Rural Latino Population at Excess Health Risk?

ERIC Educational Resources Information Center

Wickrama, K. A. S.; Elder, Glen H.; Abraham, W. Todd

2007-01-01

Context and Purpose: This study's objectives are to: investigate potential additive and multiplicative influences of rurality and race/ethnicity on chronic physical illness in a nationally representative sample of youth; and examine intra-Latino processes using a Latino sub-sample. Specifically, we examine how rurality and individual psychosocial…

A Model for Predicting Behavioural Sleep Problems in a Random Sample of Australian Pre-Schoolers

ERIC Educational Resources Information Center

Hall, Wendy A.; Zubrick, Stephen R.; Silburn, Sven R.; Parsons, Deborah E.; Kurinczuk, Jennifer J.

2007-01-01

Behavioural sleep problems (childhood insomnias) can cause distress for both parents and children. This paper reports a model describing predictors of high sleep problem scores in a representative population-based random sample survey of non-Aboriginal singleton children born in 1995 and 1996 (1085 girls and 1129 boys) in Western Australia.…

Use of Nutritional Information in Canada: National Trends between 2004 and 2008

ERIC Educational Resources Information Center

Goodman, Samantha; Hammond, David; Pillo-Blocka, Francy; Glanville, Theresa; Jenkins, Richard

2011-01-01

Objective: To examine longitudinal trends in use of nutrition information among Canadians. Design: Population-based telephone and Internet surveys. Setting and Participants: Representative samples of Canadian adults recruited with random-digit dialing sampling in 2004 (n = 2,405) and 2006 (n = 2,014) and an online commercial panel in 2008 (n =…

Screening for Pragmatic Language Impairment: The Potential of the Children's Communication Checklist

ERIC Educational Resources Information Center

Ketelaars, Mieke P.; Cuperus, Juliane M.; van Daal, John; Jansonius, Kino; Verhoeven, Ludo

2009-01-01

The present study examines the validity of the Dutch Children's Communication Checklist (CCC) for children in kindergarten in a community sample, in order to assess the feasibility of using it as a screening instrument in the general population. Teachers completed the CCC for a representative sample of 1396 children at kindergarten level, taken…

Teacher Job Satisfaction for Secondary School Effectiveness in ABA Education Zone, South-East Nigeria

ERIC Educational Resources Information Center

Abraham, Nath. M.; Ememe, Ogbonna Nwuju; Egu, Rosemary Hannah N.

2012-01-01

This paper examines teacher job satisfaction for secondary school effectiveness. It was a descriptive survey. A sample of 512 teachers emerged from a population of 1280 representing 40% of the entire population. A 2-part, 15-item, 4-point scale instrument was used to generate data for answering 3 research questions. The instrument was validated by…

Adaptive differences between Phytophthora ramorum isolates from Europe and North America: evidence for separate subspecies?

Treesearch

Clive Brasier; Susan Kirk; Joan Rose

2006-01-01

The comparative risk to trees posed by European (E.U.) versus North American (U.S.) isolates of Phytophthora ramorum, the possible risk posed by genetic recombination between them, and whether European versus North American isolates represented discrete sub-populations was investigated. Population samples of E.U. and U.S. isolates were compared for...

A Profile of Selected Demographic and Socioeconomic Characteristics of Rural Georgia Counties.

ERIC Educational Resources Information Center

Pieper, Hanns; Miller, H. Max

Demographic and selected socioeconomic changes which have occurred during the past decade in rural Georgia are delineated in this paper. The sample consisted of 50 counties, none of which had any urban population in 1960 or 1970. These counties, which are representative of rural regions which are losing or gaining population, were divided into 2…

Socioeconomic Gradients and Child Development in a Very Low Income Population: Evidence from Madagascar

ERIC Educational Resources Information Center

Fernald, Lia C. H.; Weber, Ann; Galasso, Emanuela; Ratsifandrihamanana, Lisy

2011-01-01

Our objectives were to document and examine socioeconomic gradients across a comprehensive set of child development measures in a population living in extreme poverty, and to interpret these gradients in light of findings from the neuroscience literature. We assessed a nationally representative sample of 3-6-year-old children (n = 1332) from 150…

General Suppression of Escherichia coli O157:H7 in Sand-Based Dairy Livestock Bedding▿ †

PubMed Central

Westphal, Andreas; Williams, Michele L.; Baysal-Gurel, Fulya; LeJeune, Jeffrey T.; McSpadden Gardener, Brian B.

2011-01-01

Sand bedding material is frequently used in dairy operations to reduce the occurrence of mastitis and enhance cow comfort. One objective of this work was to determine if sand-based bedding also supported the microbiologically based suppression of an introduced bacterial pathogen. Bedding samples were collected in summer, fall, and winter from various locations within a dairy operation and tested for their ability to suppress introduced populations of Escherichia coli O157:H7. All sources of bedding displayed a heat-sensitive suppressiveness to the pathogen. Differences in suppressiveness were also noted between different samples at room temperature. At just 1 day postinoculation (dpi), the recycled sand bedding catalyzed up to a 1,000-fold reduction in E. coli counts, typically 10-fold greater than the reduction achieved with other substrates, depending on the sampling date. All bedding substrates were able to reduce E. coli populations by over 10,000-fold within 7 to 15 dpi, regardless of sampling date. Terminal restriction fragment length polymorphism (T-RFLP) analysis was used to identify bacterial populations potentially associated with the noted suppression of E. coli O157:H7 in sand bedding. Eleven terminal restriction fragments (TRFs) were overrepresented in paired comparisons of suppressive and nonsuppressive specimens at multiple sampling points, indicating that they may represent environmentally stable populations of pathogen-suppressing bacteria. Cloning and sequencing of these TRFs indicated that they represent a diverse subset of bacteria, belonging to the Cytophaga-Flexibacter-Bacteroidetes, Gammaproteobacteria, and Firmicutes, only a few of which have previously been identified in livestock manure. Such data indicate that microbial suppression may be harnessed to develop new options for mitigating the risk and dispersal of zoonotic bacterial pathogens on dairy farms. PMID:21257815

Simultaneous Multiparameter Cellular Energy Metabolism Profiling of Small Populations of Cells.

PubMed

Kelbauskas, Laimonas; Ashili, Shashaanka P; Lee, Kristen B; Zhu, Haixin; Tian, Yanqing; Meldrum, Deirdre R

2018-03-12

Functional and genomic heterogeneity of individual cells are central players in a broad spectrum of normal and disease states. Our knowledge about the role of cellular heterogeneity in tissue and organism function remains limited due to analytical challenges one encounters when performing single cell studies in the context of cell-cell interactions. Information based on bulk samples represents ensemble averages over populations of cells, while data generated from isolated single cells do not account for intercellular interactions. We describe a new technology and demonstrate two important advantages over existing technologies: first, it enables multiparameter energy metabolism profiling of small cell populations (<100 cells)-a sample size that is at least an order of magnitude smaller than other, commercially available technologies; second, it can perform simultaneous real-time measurements of oxygen consumption rate (OCR), extracellular acidification rate (ECAR), and mitochondrial membrane potential (MMP)-a capability not offered by any other commercially available technology. Our results revealed substantial diversity in response kinetics of the three analytes in dysplastic human epithelial esophageal cells and suggest the existence of varying cellular energy metabolism profiles and their kinetics among small populations of cells. The technology represents a powerful analytical tool for multiparameter studies of cellular function.

Challenges to Recruiting Population Representative Samples of Female Sex Workers in China Using Respondent Driven Sampling1

PubMed Central

Merli, M. Giovanna; Moody, James; Smith, Jeffrey; Li, Jing; Weir, Sharon; Chen, Xiangsheng

2014-01-01

We explore the network coverage of a sample of female sex workers (FSWs) in China recruited through Respondent Drive Sampling (RDS) as part of an effort to evaluate the claim of RDS of population representation with empirical data. We take advantage of unique information on the social networks of FSWs obtained from two overlapping studies --RDS and a venue-based sampling approach (PLACE) -- and use an exponential random graph modeling (ERGM) framework from local networks to construct a likely network from which our observed RDS sample is drawn. We then run recruitment chains over this simulated network to assess the assumption that the RDS chain referral process samples participants in proportion to their degree and the extent to which RDS satisfactorily covers certain parts of the network. We find evidence that, contrary to assumptions, RDS oversamples low degree nodes and geographically central areas of the network. Unlike previous evaluations of RDS which have explored the performance of RDS sampling chains on a non-hidden population, or the performance of simulated chains over previously mapped realistic social networks, our study provides a robust, empirically grounded evaluation of the performance of RDS chains on a real-world hidden population. PMID:24834869

Prevalence and sociodemographic associations of common mental disorders in a nationally representative sample of the general population of Greece

PubMed Central

2013-01-01

Background No study in Greece has assessed so far the full range of common mental disorders using a representative sample of the population from both mainland and insular regions of the country. The aim of the present paper was to present the results of the first such study. Methods The study was carried out between 2009–2010 in a nationally representative sample of 4894 individuals living in private households in Greece. Common mental disorders in the past week were assessed with the revised Clinical Interview Schedule (CIS-R). We also assessed alcohol use disorders (using AUDIT), smoking and cannabis use. Results 14% of the population (Male: 11%, Female: 17%) was found to have clinically significant psychiatric morbidity according to the scores on the CIS-R. The prevalence (past seven days) of specific common mental disorders was as follows: Generalized Anxiety Disorder: 4.10% (95% CI: 3.54, 4.65); Depression: 2.90% (2.43, 3.37); Panic Disorder: 1.88% (1.50, 2.26); Obsessive-Compulsive Disorder: 1.69% (1.33, 2.05); All Phobias: 2.79% (2.33, 3.26); Mixed anxiety-depression: 2.67% (2.22, 3.12). Harmful alcohol use was reported by 12.69% of the population (11.75, 13.62). Regular smoking was reported by 39.60% of the population (38.22, 40.97) while cannabis use (at least once during the past month) by 2.06% (1.66, 2.46). Clinically significant psychiatric morbidity was positively associated with the following variables: female gender, divorced or widowed family status, low educational status and unemployment. Use of all substances was more common in men compared to women. Common mental disorders were often comorbid, undertreated, and associated with a lower quality of life. Conclusions The findings of the present study can help in the better planning and development of mental health services in Greece, especially in a time of mental health budget restrictions. PMID:23734578

Prevalence and sociodemographic associations of common mental disorders in a nationally representative sample of the general population of Greece.

PubMed

Skapinakis, Petros; Bellos, Stefanos; Koupidis, Sotirios; Grammatikopoulos, Ilias; Theodorakis, Pavlos N; Mavreas, Venetsanos

2013-06-04

No study in Greece has assessed so far the full range of common mental disorders using a representative sample of the population from both mainland and insular regions of the country. The aim of the present paper was to present the results of the first such study. The study was carried out between 2009-2010 in a nationally representative sample of 4894 individuals living in private households in Greece. Common mental disorders in the past week were assessed with the revised Clinical Interview Schedule (CIS-R). We also assessed alcohol use disorders (using AUDIT), smoking and cannabis use. 14% of the population (Male: 11%, Female: 17%) was found to have clinically significant psychiatric morbidity according to the scores on the CIS-R. The prevalence (past seven days) of specific common mental disorders was as follows: Generalized Anxiety Disorder: 4.10% (95% CI: 3.54, 4.65); Depression: 2.90% (2.43, 3.37); Panic Disorder: 1.88% (1.50, 2.26); Obsessive-Compulsive Disorder: 1.69% (1.33, 2.05); All Phobias: 2.79% (2.33, 3.26); Mixed anxiety-depression: 2.67% (2.22, 3.12). Harmful alcohol use was reported by 12.69% of the population (11.75, 13.62). Regular smoking was reported by 39.60% of the population (38.22, 40.97) while cannabis use (at least once during the past month) by 2.06% (1.66, 2.46). Clinically significant psychiatric morbidity was positively associated with the following variables: female gender, divorced or widowed family status, low educational status and unemployment. Use of all substances was more common in men compared to women. Common mental disorders were often comorbid, undertreated, and associated with a lower quality of life. The findings of the present study can help in the better planning and development of mental health services in Greece, especially in a time of mental health budget restrictions.

Psychometric Properties of the Bermond-Vorst Alexithymia Questionnaire (BVAQ) in the General Population and a Clinical Population.

PubMed

de Vroege, Lars; Emons, Wilco H M; Sijtsma, Klaas; van der Feltz-Cornelis, Christina M

2018-01-01

The Bermond-Vorst Alexithymia Questionnaire (BVAQ) has been validated in student samples and small clinical samples, but not in the general population; thus, representative general-population norms are lacking. We examined the factor structure of the BVAQ in Longitudinal Internet Studies for the Social Sciences panel data from the Dutch general population ( N  = 974). Factor analyses revealed a first-order five-factor model and a second-order two-factor model. However, in the second-order model, the factor interpreted as analyzing ability loaded on both the affective factor and the cognitive factor. Further analyses showed that the first-order test scores are more reliable than the second-order test scores. External and construct validity were addressed by comparing BVAQ scores with a clinical sample of patients suffering from somatic symptom and related disorder (SSRD) ( N  = 235). BVAQ scores differed significantly between the general population and patients suffering from SSRD, suggesting acceptable construct validity. Age was positively associated with alexithymia. Males showed higher levels of alexithymia. The BVAQ is a reliable alternative measure for measuring alexithymia.

Prevalence of overweight and obesity in non-institutionalized people aged 65 or over from Spain: the elderly EXERNET multi-centre study.

PubMed

Gomez-Cabello, A; Pedrero-Chamizo, R; Olivares, P R; Luzardo, L; Juez-Bengoechea, A; Mata, E; Albers, U; Aznar, S; Villa, G; Espino, L; Gusi, N; Gonzalez-Gross, M; Casajus, J A; Ara, I

2011-08-01

Coupled with the growth of the older population, an increase in the prevalence of overweight and obesity in this age group has occurred in the last decades. The main aims of the present study were (i) to provide an updated prevalence of overweight and obesity in a representative sample of the Spanish elderly population; (ii) to calculate the prevalence of sarcopenic obesity (SO) and (iii) to analyse the relationships between adiposity measurements and lifestyle. A cross-sectional study was carried out in a sample of 3136 persons representative of the non-institutionalized population ≥65 years of age. Anthropometric measurements were obtained using standardized techniques and equipment. Overall, 84% of the population can be categorized as overweight and/or obese. The present study indicates that 67% of the Spanish elderly population has an increased percentage of fat mass and more than 56% suffer from central obesity. Moreover, SO is present in 15% of the Spanish elderly population. Finally, a strong relationship between both physically active and sedentary lifestyles and the level of adiposity was found. Prevalence of overweight and obesity among elderly people in Spain is very high and is still increasing. Lifestyle seems to be a determinant factor in the development of obesity among elderly people. © 2011 The Authors. obesity reviews © 2011 International Association for the Study of Obesity.

Impact of minimum catch size on the population viability of Strombus gigas (Mesogastropoda: Strombidae) in Quintana Roo, Mexico.

PubMed

Peel, Joanne R; Mandujano, María del Carmen

2014-12-01

The queen conch Strombus gigas represents one of the most important fishery resources of the Caribbean but heavy fishing pressure has led to the depletion of stocks throughout the region, causing the inclusion of this species into CITES Appendix II and IUCN's Red-List. In Mexico, the queen conch is managed through a minimum fishing size of 200 mm shell length and a fishing quota which usually represents 50% of the adult biomass. The objectives of this study were to determine the intrinsic population growth rate of the queen conch population of Xel-Ha, Quintana Roo, Mexico, and to assess the effects of a regulated fishing impact, simulating the extraction of 50% adult biomass on the population density. We used three different minimum size criteria to demonstrate the effects of minimum catch size on the population density and discuss biological implications. Demographic data was obtained through capture-mark-recapture sampling, collecting all animals encountered during three hours, by three divers, at four different sampling sites of the Xel-Ha inlet. The conch population was sampled each month between 2005 and 2006, and bimonthly between 2006 and 2011, tagging a total of 8,292 animals. Shell length and lip thickness were determined for each individual. The average shell length for conch with formed lip in Xel-Ha was 209.39 ± 14.18 mm and the median 210 mm. Half of the sampled conch with lip ranged between 200 mm and 219 mm shell length. Assuming that the presence of the lip is an indicator for sexual maturity, it can be concluded that many animals may form their lip at greater shell lengths than 200 mm and ought to be considered immature. Estimation of relative adult abundance and densities varied greatly depending on the criteria employed for adult classification. When using a minimum fishing size of 200 mm shell length, between 26.2% and up to 54.8% of the population qualified as adults, which represented a simulated fishing impact of almost one third of the population. When conch extraction was simulated using a classification criteria based on lip thickness, it had a much smaller impact on the population density. We concluded that the best management strategy for S. gigas is a minimum fishing size based on a lip thickness, since it has lower impact on the population density, and given that selective fishing pressure based on size may lead to the appearance of small adult individuals with reduced fecundity. Furthermore, based on the reproductive biology and the results of the simulated fishing, we suggest a minimum lip thickness of ≥ 15 mm, which ensures the protection of reproductive stages, reduces the risk of overfishing, leading to non-viable density reduction.

Attrition in a Large Scale Longitudinal Study of the Elderly: The Role of Health-Status Variables.

ERIC Educational Resources Information Center

Horgas, Ann L.; And Others

In a longitudinal study, subject attrition constitutes a potential threat to the usefulness of data collected from subjects remaining in later waves of the study. If attrition is selective, then the sample at later waves of the study may be representative of a different population than that represented at the outset of the study. This study…

Indicators Associated with Suicidal Ideation and Suicide Attempts among 16-35-Year-Old Danes: A National Representative Population Study

ERIC Educational Resources Information Center

Norlev, Jeanette; Davidsen, Michael; Sundaram, Vanita; Kjoller, Mette

2005-01-01

In this study indicators associated with suicidal ideation and suicide attempts in a nationwide representative sample (N = 3,184) of Danes aged 16-35 years were examined. The study was cross-sectional and had three aims: (1) to draw a profile of persons with and without suicidal tendency established on a combined quartered variable on current…

Presence and distribution of chlorinated organic compounds in streambed sediments, new jersey

USGS Publications Warehouse

Stackelberg, P.E.

1997-01-01

Concentrations of 18 hydrophobic chlorinated organic compounds in streambed sediments from 100 sites throughout New Jersey were examined to determine (1) which compounds were detected most frequently, (2) whether detection frequencies differed among selected drainage basins, and (3) whether concentrations differed significantly among selected drainage basins. Twelve drainage basins across New Jersey that contain a range of land-use patterns and population densities were selected to represent various types and degrees of development. To ensure an adequate number of samples for statistical comparison among drainage basins, the 12 selected basins were consolidated into seven drainage areas on the basis of similarities in land- use patterns and population densities. Additionally, data for three classes of chlorinated organic compounds in streambed sediments from 255 sites throughout New Jersey were examined to determine whether the presence of these compounds in streambed sediments is related to the type and degree of development within the drainage area of each sampling site. Chlorinated organic compounds detected most frequently within the seven representative drainage areas were DDT, DDE, DDD, chlordane, dieldrin, and PCBs. DDT, DDE, and DDD, which were the most widely distributed organic compounds, were detected in about 60 to 100 percent of the samples from all drainage areas hut one (where the detection rate for these compounds was about 20 to 40 percent). Chlordane and dieldrin were detected in about 80 to 100 percent of samples from highly urbanized and populated drainage areas; detection frequencies for these compounds tended to be smaller in less developed and populated areas. PCBs were detected in about 40 to 85 percent of samples from all drainage areas; detection frequencies were highest in the most heavily developed and populated areas. Analysis of variance on rank-transformed organic compound concentrations normalized to sediment organic carbon content was used to evaluate differences in concentrations among the seven representative drainage areas. Chlordane and PCBs were the chlorinated organic compounds with the most highly elevated concentrations in streambed sediments across the State. Median normalized COncentrations of all six of the most frequently detected chlorinated organic compounds were highest in the most heavily urbanized and populated drainage area and lowest in the less populated, predominantly agricultural or forested areas. Concentrations of DDT and DDE, however, did not differ significantly among most of the drainage areas. Concentrations of DDD, chlordane, dieldrin, and PCBs differed significantly among drainage areas. The highest median normalized concentrations were found in samples from the most heavily urbanized and populated areas, and the lowest were in samples from the least developed, most heavily forested area. Logistic regression was used to examine relations between the presence of hydrophobic chlorinated organic compounds in streambed sediments at specified concentrations and variables that characterize the type and degree of development within the drainage areas of 255 sites across New Jersey. The explanatory variables found most useful for predicting the presence of chlorinated organic compounds in streambed sediments include total population and amounts (in square kilometers) of various land-use categories. Logistic regression equations were developed to identify significant relations between population and amounts of specific land-use categories within drainage areas and the probability of detecting chlorinated organic contaminants in streambed sediments. These relations can be used to assist in the identification of geographic regions of primary concern for contamination of bed sediments by chlorinated organic compounds across the State.

A population-based study of associations between current posttraumatic stress symptoms and current fatigue.

PubMed

Lerdal, Anners; Lee, Kathryn A; Rokne, Berit; Knudsen, Øistein; Wahl, Astrid K; Dahl, Alv A

2010-10-01

This study explores current experience with posttraumatic stress disorder (PTSD) symptoms and other variables (sociodemographic, mental distress, somatic morbidity, self-rated health, and quality of life [QoL]) in relation to fatigue. A representative sample of the Norwegian population (N = 3,944) was invited to participate in a mailed survey, and 1,857 (47%) returned valid responses on the questionnaire that included the Fatigue Severity Scale and the Posttraumatic Symptom Scale-10. Posttraumatic stress disorder symptoms showed a strong association with fatigue in univariate (β = .41) and multivariate analyses (β = .33). Associations between psychosocial health variables, QoL, and fatigue were confirmed. However, PTSD symptoms showed the strongest association with fatigue in the analyses. Findings need to be replicated in other population samples and in clinical samples with PTSD and fatigue.

Mineral composition of Atriplex hymenelytra growing in the northern Mojave Desert

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallace, A.; Romney, E.M.; Hunter, R.B.

1980-01-01

Fifty samples of Atriplex hymenelytra (Torr.) S. Wats. were collected from several different locations in southern Nevada and California to test variability in mineral composition. Only Na, V, P, Ca, Mg, Mn, and Sr in the samples appeared to represent a uniform population resulting in normal curves for frequency distribution. Even so, about 40 percent of the variance for these elements was due to location. All elements differed enough with location so that no element really represented a uniform population. The coefficient of variation for most elements was over 40 percent and one was over 100 percent. The proportion ofmore » variance due to analytical variation averaged 16.2 +- 13.1 percent (standard deviation), that due to location was 43.0 +- 13.4 percent, and that due to variation of plants within location was 40.7 +- 13.0 percent.« less

The densest terrestrial vertebrate

USGS Publications Warehouse

Rodda, G.H.; Perry, G.; Rondeau, R.J.; Lazell, J.

2001-01-01

An understanding of the abundance of organisms is central to understanding ecology, but many population density estimates are unrepresentative because they were obtained from study areas chosen for the high abundance of the target species. For example, from a pool of 1072 lizard density estimates that we compiled from the literature, we sampled 303 estimates and scored each for its assessment of the degree to which the study site was representative. Less than half (45%) indicated that the study area was chosen to be representative of the population or habitat. An additional 15% reported that individual plots or transects were chosen randomly, but this often indicated only that the sample points were located randomly within a study area chosen for its high abundance of the target species. The remainder of the studies either gave no information or specified that the study area was chosen because the focal species was locally abundant.

Prevalence of Female Urinary Incontinence in the General Population According to Different Definitions and Study Designs.

PubMed

Bedretdinova, Dina; Fritel, Xavier; Panjo, Henri; Ringa, Virginie

2016-02-01

Estimates of the prevalence of female urinary incontinence (UI) vary widely. To estimate UI prevalence among women in France using data from five national surveys and analyse prevalence differences among the surveys according to their design (representative sample or not, survey focused on UI or not) and UI definition (based on symptoms or disease perception). Data came from two representative telephone surveys, Fecond (5017 women aged 15-49 yr) and Barometer (3089 women aged 40-85 yr), general and urinary postal surveys of the GAZEL cohort (3098 women aged 54-69 yr), and the web-based NutriNet survey (85,037 women aged 18-87 yr). Definitions of UI based on the International Conference on Incontinence Questionnaire UI short form (ICIQ-UI-SF) and on a list of health problems were considered. We compared age-adjusted prevalence rates among studies via logistic regression and generalised linear models. Overall, 13% of the women in Fecond, 24% in Barometer, 15% in the GAZEL general survey, 39% in the GAZEL urinary survey, and 1.5% in the NutriNet survey reported any UI. Prevalence rates in representative samples with the same UI definition (ICIQ-UI-SF) were concordant. UI prevalence in the representative samples was 17%. The estimated number of women in France with UI was 5.35 million (95% confidence interval [CI] 5.34-5.36 million) for any UI and 1.54 million (95% CI 1.53-1.55 million) for daily UI. For the GAZEL sample, UI prevalence was lower but UI severity was greater for responses to a questionnaire with the list-based UI definition rather than to a questionnaire with the ICIQ-UI-SF-based definition. In all surveys, information about UI was self-reported and was not validated by objective measurements. UI definitions and sampling strategies influence estimates of UI prevalence among women. Precise estimates of UI prevalence should be based on non-UI-focused surveys among representative samples and using a validated standardised symptom-based questionnaire. We looked at estimates of urinary incontinence (UI) prevalence in studies with different designs and different UI definitions in a large population of French women. We found that estimates varied with the definition and the design. We conclude that the most precise estimates of UI prevalence are obtained in studies of representative populations that are not focused on UI and use a validated international standard questionnaire with sufficient details to allow grading of UI severity. Most women reported rare urine leakages involving small amounts of urine with little impact on their quality of life. Copyright © 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Validation of two complementary oral-health related quality of life indicators (OIDP and OSS 0-10 ) in two qualitatively distinct samples of the Spanish population

PubMed Central

Montero, J; Bravo, M; Albaladejo, A

2008-01-01

Background Oral health-related quality of life can be assessed positively, by measuring satisfaction with mouth, or negatively, by measuring oral impact on the performance of daily activities. The study objective was to validate two complementary indicators, i.e., the OIDP (Oral Impacts on Daily Performances) and Oral Satisfaction 0–10 Scale (OSS), in two qualitatively different socio-demographic samples of the Spanish adult population, and to analyse the factors affecting both perspectives of well-being. Methods A cross-sectional study was performed, recruiting a Validation Sample from randomly selected Health Centres in Granada (Spain), representing the general population (n = 253), and a Working Sample (n = 561) randomly selected from active Regional Government staff, i.e., representing the more privileged end of the socio-demographic spectrum of this reference population. All participants were examined according to WHO methodology and completed an in-person interview on their oral impacts and oral satisfaction using the OIDP and OSS 0–10 respectively. The reliability and validity of the two indicators were assessed. An alternative method of describing the causes of oral impacts is presented. Results The reliability coefficient (Cronbach's alpha) of the OIDP was above the recommended 0.7 threshold in both Validation and Occupational samples (0.79 and 0.71 respectively). Test-retest analysis confirmed the external reliability of the OSS (Intraclass Correlation Coefficient, 0.89; p < 0.001) Some subjective factors (perceived need for dental treatment, complaints about mouth and intermediate impacts) were strongly associated with both indicators, supporting their construct and criterion validity. The main cause of oral impact was dental pain. Several socio-demographic, behavioural and clinical variables were identified as modulating factors. Conclusion OIDP and OSS are valid and reliable subjective measures of oral impacts and oral satisfaction, respectively, in an adult Spanish population. Exploring simultaneously these issues may provide useful insights into how satisfaction and impact on well-being are constructed. PMID:19019208

Cross-sectional study of height and weight in the population of Andalusia from age 3 to adulthood

PubMed Central

López-Siguero, Juan Pedro; García, Juan Manuel Fernández; Castillo, Juan de Dios Luna; Molina, Jose Antonio Moreno; Cosano, Carlos Ruiz; Ortiz, Antonio Jurado

2008-01-01

Background and objectives In Andalusia there were no studies including a representative sample of children and adolescent population assessing growth and weight increase. Our objectives were to develop reference standards for weight, height and BMI for the Andalusian pediatric population, from 3 to 18 years of age for both genders, and to identify the final adult height in Andalusia. Subjects and methods Two samples were collected. The first included individuals from 3 to 18 years of age (3592 girls and 3605 boys). They were stratified according type of study center, size of population of origin, age (32 categories of 0.5 years) and gender, using cluster sampling. Subjects from >18 to 23 years of age (947 women and 921 men) were sampled in 6 non-university educational centers and several university centers in Granada. Exclusion criteria included sons of non-Spanish mother or father, and individuals with chronic conditions and/or therapies affecting growth. Two trained fellows collected the data through February to December 2004, for the first sample, and through January to May 2005, for the second. Reference curves were adjusted using Cole's LMS method, and the quality of the adjustment was assessed using the tests proposed by Royston. In addition, a sensitivity analysis was applied to the final models obtained. Results Data for 9065 cases (4539 women and 4526 men) were obtained; 79.39% (n = 7197) in the up to 18 years of age group. In the first sampling only 0.07% (3 girls and 2 boys) refused to participate in the study. In addition, 327 students (4.5%) were absent when sampling was done. We present mean and standard deviation fort height, weight and BMI at 0.5 years intervals, from 3 to 23 years of age, for both genders. After adjustment with the different models, percentiles for height, weight (percentiles 3, 5, 10, 25, 50, 75, 90, 95, and 97) and BMI (percentiles 3, 5, 50, 85, 95, and 97) are presented for both genders. Conclusion This is the first study in Andalusia with a representative sample from the child-juvenile population to investigate weight, height and BMI in subjects from 3 to 23 years of age. The great variability observed in the values from sample of 18 to 23 years of age individuals, ensures the inclusion of extreme values, although random sampling was not used. There still is a lack of standard reference values for the Andalusian population younger done 3 years of age. PMID:18673524

Inclusion of mobile phone numbers into an ongoing population health survey in New South Wales, Australia: design, methods, call outcomes, costs and sample representativeness.

PubMed

Barr, Margo L; van Ritten, Jason J; Steel, David G; Thackway, Sarah V

2012-11-22

In Australia telephone surveys have been the method of choice for ongoing jurisdictional population health surveys. Although it was estimated in 2011 that nearly 20% of the Australian population were mobile-only phone users, the inclusion of mobile phone numbers into these existing landline population health surveys has not occurred. This paper describes the methods used for the inclusion of mobile phone numbers into an existing ongoing landline random digit dialling (RDD) health survey in an Australian state, the New South Wales Population Health Survey (NSWPHS). This paper also compares the call outcomes, costs and the representativeness of the resultant sample to that of the previous landline sample. After examining several mobile phone pilot studies conducted in Australia and possible sample designs (screening dual-frame and overlapping dual-frame), mobile phone numbers were included into the NSWPHS using an overlapping dual-frame design. Data collection was consistent, where possible, with the previous years' landline RDD phone surveys and between frames. Survey operational data for the frames were compared and combined. Demographic information from the interview data for mobile-only phone users, both, and total were compared to the landline frame using χ2 tests. Demographic information for each frame, landline and the mobile-only (equivalent to a screening dual frame design), and the frames combined (with appropriate overlap adjustment) were compared to the NSW demographic profile from the 2011 census using χ2 tests. In the first quarter of 2012, 3395 interviews were completed with 2171 respondents (63.9%) from the landline frame (17.6% landline only) and 1224 (36.1%) from the mobile frame (25.8% mobile only). Overall combined response, contact and cooperation rates were 33.1%, 65.1% and 72.2% respectively. As expected from previous research, the demographic profile of the mobile-only phone respondents differed most (more that were young, males, Aboriginal and Torres Strait Islanders, overseas born and single) compared to the landline frame responders. The profile of respondents from the two frames combined, with overlap adjustment, was most similar to the latest New South Wales (NSW) population profile. The inclusion of the mobile phone numbers, through an overlapping dual-frame design, did not impact negatively on response rates or data collection, and although costing more the design was still cost-effective because of the additional interviews that were conducted with young people, Aboriginal and Torres Strait Islanders and people who were born overseas resulting in a more representative overall sample.

Assessing representativeness of sampling methods for reaching men who have sex with men: a direct comparison of results obtained from convenience and probability samples.

PubMed

Schwarcz, Sandra; Spindler, Hilary; Scheer, Susan; Valleroy, Linda; Lansky, Amy

2007-07-01

Convenience samples are used to determine HIV-related behaviors among men who have sex with men (MSM) without measuring the extent to which the results are representative of the broader MSM population. We compared results from a cross-sectional survey of MSM recruited from gay bars between June and October 2001 to a random digit dial telephone survey conducted between June 2002 and January 2003. The men in the probability sample were older, better educated, and had higher incomes than men in the convenience sample, the convenience sample enrolled more employed men and men of color. Substance use around the time of sex was higher in the convenience sample but other sexual behaviors were similar. HIV testing was common among men in both samples. Periodic validation, through comparison of data collected by different sampling methods, may be useful when relying on survey data for program and policy development.

Is Toxoplasma Gondii Infection Related to Brain and Behavior Impairments in Humans? Evidence from a Population-Representative Birth Cohort.

PubMed

Sugden, Karen; Moffitt, Terrie E; Pinto, Lauriane; Poulton, Richie; Williams, Benjamin S; Caspi, Avshalom

2016-01-01

Toxoplasma gondii (T. gondii) is a protozoan parasite present in around a third of the human population. Infected individuals are commonly asymptomatic, though recent reports have suggested that infection might influence aspects of the host's behavior. In particular, Toxoplasma infection has been linked to schizophrenia, suicide attempt, differences in aspects of personality and poorer neurocognitive performance. However, these studies are often conducted in clinical samples or convenience samples. In a population-representative birth-cohort of individuals tested for presence of antibodies to T. gondii (N = 837) we investigated the association between infection and four facets of human behavior: neuropsychiatric disorder (schizophrenia and major depression), poor impulse control (suicidal behavior and criminality), personality, and neurocognitive performance. Suicide attempt was marginally more frequent among individuals with T. gondii seropositivity (p = .06). Seropositive individuals also performed worse on one out of 14 measures of neuropsychological function. On the whole, there was little evidence that T. gondii was related to increased risk of psychiatric disorder, poor impulse control, personality aberrations or neurocognitive impairment.

Is Toxoplasma Gondii Infection Related to Brain and Behavior Impairments in Humans? Evidence from a Population-Representative Birth Cohort

PubMed Central

Sugden, Karen; Moffitt, Terrie E.; Pinto, Lauriane; Poulton, Richie; Williams, Benjamin S.; Caspi, Avshalom

2016-01-01

Background Toxoplasma gondii (T. gondii) is a protozoan parasite present in around a third of the human population. Infected individuals are commonly asymptomatic, though recent reports have suggested that infection might influence aspects of the host’s behavior. In particular, Toxoplasma infection has been linked to schizophrenia, suicide attempt, differences in aspects of personality and poorer neurocognitive performance. However, these studies are often conducted in clinical samples or convenience samples. Methods/Results In a population-representative birth-cohort of individuals tested for presence of antibodies to T. gondii (N = 837) we investigated the association between infection and four facets of human behavior: neuropsychiatric disorder (schizophrenia and major depression), poor impulse control (suicidal behavior and criminality), personality, and neurocognitive performance. Suicide attempt was marginally more frequent among individuals with T. gondii seropositivity (p = .06). Seropositive individuals also performed worse on one out of 14 measures of neuropsychological function. Conclusion On the whole, there was little evidence that T. gondii was related to increased risk of psychiatric disorder, poor impulse control, personality aberrations or neurocognitive impairment. PMID:26886853

Population genomics of C. melanopterus using target gene capture data: demographic inferences and conservation perspectives

PubMed Central

Maisano Delser, Pierpaolo; Corrigan, Shannon; Hale, Matthew; Li, Chenhong; Veuille, Michel; Planes, Serge; Naylor, Gavin; Mona, Stefano

2016-01-01

Population genetics studies on non-model organisms typically involve sampling few markers from multiple individuals. Next-generation sequencing approaches open up the possibility of sampling many more markers from fewer individuals to address the same questions. Here, we applied a target gene capture method to deep sequence ~1000 independent autosomal regions of a non-model organism, the blacktip reef shark (Carcharhinus melanopterus). We devised a sampling scheme based on the predictions of theoretical studies of metapopulations to show that sampling few individuals, but many loci, can be extremely informative to reconstruct the evolutionary history of species. We collected data from a single deme (SID) from Northern Australia and from a scattered sampling representing various locations throughout the Indian Ocean (SCD). We explored the genealogical signature of population dynamics detected from both sampling schemes using an ABC algorithm. We then contrasted these results with those obtained by fitting the data to a non-equilibrium finite island model. Both approaches supported an Nm value ~40, consistent with philopatry in this species. Finally, we demonstrate through simulation that metapopulations exhibit greater resilience to recent changes in effective size compared to unstructured populations. We propose an empirical approach to detect recent bottlenecks based on our sampling scheme. PMID:27651217

Population genomics of C. melanopterus using target gene capture data: demographic inferences and conservation perspectives.

PubMed

Maisano Delser, Pierpaolo; Corrigan, Shannon; Hale, Matthew; Li, Chenhong; Veuille, Michel; Planes, Serge; Naylor, Gavin; Mona, Stefano

2016-09-21

Population genetics studies on non-model organisms typically involve sampling few markers from multiple individuals. Next-generation sequencing approaches open up the possibility of sampling many more markers from fewer individuals to address the same questions. Here, we applied a target gene capture method to deep sequence ~1000 independent autosomal regions of a non-model organism, the blacktip reef shark (Carcharhinus melanopterus). We devised a sampling scheme based on the predictions of theoretical studies of metapopulations to show that sampling few individuals, but many loci, can be extremely informative to reconstruct the evolutionary history of species. We collected data from a single deme (SID) from Northern Australia and from a scattered sampling representing various locations throughout the Indian Ocean (SCD). We explored the genealogical signature of population dynamics detected from both sampling schemes using an ABC algorithm. We then contrasted these results with those obtained by fitting the data to a non-equilibrium finite island model. Both approaches supported an Nm value ~40, consistent with philopatry in this species. Finally, we demonstrate through simulation that metapopulations exhibit greater resilience to recent changes in effective size compared to unstructured populations. We propose an empirical approach to detect recent bottlenecks based on our sampling scheme.

Health Surveys Using Mobile Phones in Developing Countries: Automated Active Strata Monitoring and Other Statistical Considerations for Improving Precision and Reducing Biases.

PubMed

Labrique, Alain; Blynn, Emily; Ahmed, Saifuddin; Gibson, Dustin; Pariyo, George; Hyder, Adnan A

2017-05-05

In low- and middle-income countries (LMICs), historically, household surveys have been carried out by face-to-face interviews to collect survey data related to risk factors for noncommunicable diseases. The proliferation of mobile phone ownership and the access it provides in these countries offers a new opportunity to remotely conduct surveys with increased efficiency and reduced cost. However, the near-ubiquitous ownership of phones, high population mobility, and low cost require a re-examination of statistical recommendations for mobile phone surveys (MPS), especially when surveys are automated. As with landline surveys, random digit dialing remains the most appropriate approach to develop an ideal survey-sampling frame. Once the survey is complete, poststratification weights are generally applied to reduce estimate bias and to adjust for selectivity due to mobile ownership. Since weights increase design effects and reduce sampling efficiency, we introduce the concept of automated active strata monitoring to improve representativeness of the sample distribution to that of the source population. Although some statistical challenges remain, MPS represent a promising emerging means for population-level data collection in LMICs. ©Alain Labrique, Emily Blynn, Saifuddin Ahmed, Dustin Gibson, George Pariyo, Adnan A Hyder. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 05.05.2017.

PCDD/F and PCB in human serum of differently exposed population groups of an Italian city.

PubMed

Turrio-Baldassarri, Luigi; Abate, Vittorio; Battistelli, Chiara Laura; Carasi, Sergio; Casella, Marialuisa; Iacovella, Nicola; Indelicato, Annamaria; La Rocca, Cinzia; Scarcella, Carmelo; Alivernini, Silvia

2008-08-01

A chemical plant located in Brescia, an industrial city in North-Western Italy, produced polychlorobiphenyls (PCBs) during a 30-50 year period, causing widespread pollution of the surrounding agricultural area. This area contains several small farms, which principally produce veal meat for private consumption of the farmers' families. The pollution went undiscovered for many years, during which period contaminated food was regularly consumed. This paper reports the polychlorodibenzodioxin (PCDD), polychlorodibenzofuran (PCDF) and PCB levels of a serum sample pooled from the consumers of contaminated food, compared to six population groups of the city of Brescia. Four of these groups were selected in order to represent, respectively, the local general population and the residents of three zones of the polluted area, while the last two groups represented, respectively, the present and the former workers of the plant. One human milk sample from one of the consumers of contaminated food was also analyzed. Results show that the consumers of the contaminated food and the former workers of the plant display considerably higher levels than all other groups. The levels of general population and of all other groups were generally similar both to each other and to the range of literature values for unexposed populations. The respective contribution of PCDDs, PCDFs, mono-ortho and non-ortho PCBs (dioxin-like PCBs) to (Toxicity Equivalents) TEQ of the population groups of this study were also compared to literature data: the two groups with a high contamination level, together with the human milk sample, displayed a higher incidence of mono-ortho PCBs and a lower contribution of PCDD, possibly correlated with the source of contamination.

Phylogeographic Structure in Penguin Ticks across an Ocean Basin Indicates Allopatric Divergence and Rare Trans-Oceanic Dispersal.

PubMed

Moon, Katherine L; Banks, Sam C; Fraser, Ceridwen I

2015-01-01

The association of ticks (Acarina) and seabirds provides an intriguing system for assessing the influence of long-distance dispersal on the evolution of parasitic species. Recent research has focused on host-parasite evolutionary relationships and dispersal capacity of ticks parasitising flighted seabirds. Evolutionary research on the ticks of non-flighted seabirds is, in contrast, scarce. We conducted the first phylogeographic investigation of a hard tick species (Ixodes eudyptidis) that parasitises the Little Blue Penguin (Eudyptula minor). Using one nuclear (28S) and two mitochondrial (COI and 16S) markers, we assessed genetic diversity among several populations in Australia and a single population on the South Island of New Zealand. Our results reveal two deeply divergent lineages, possibly representing different species: one comprising all New Zealand samples and some from Australia, and the other representing all other samples from Australian sites. No significant population differentiation was observed among any Australian sites from within each major clade, even those separated by hundreds of kilometres of coastline. In contrast, the New Zealand population was significantly different to all samples from Australia. Our phylogenetic results suggest that the New Zealand and Australian populations are effectively isolated from each other; although rare long-distance dispersal events must occur, these are insufficient to maintain trans-Tasman gene flow. Despite the evidence for limited dispersal of penguin ticks between Australia and New Zealand, we found no evidence to suggest that ticks are unable to disperse shorter distances at sea with their hosts, with no pattern of population differentiation found among Australian sites. Our results suggest that terrestrial seabird parasites may be quite capable of short-distance movements, but only sporadic longer-distance (trans-oceanic) dispersal.

Phylogeographic Structure in Penguin Ticks across an Ocean Basin Indicates Allopatric Divergence and Rare Trans-Oceanic Dispersal

PubMed Central

Moon, Katherine L.; Banks, Sam C.; Fraser, Ceridwen I.

2015-01-01

The association of ticks (Acarina) and seabirds provides an intriguing system for assessing the influence of long-distance dispersal on the evolution of parasitic species. Recent research has focused on host-parasite evolutionary relationships and dispersal capacity of ticks parasitising flighted seabirds. Evolutionary research on the ticks of non-flighted seabirds is, in contrast, scarce. We conducted the first phylogeographic investigation of a hard tick species (Ixodes eudyptidis) that parasitises the Little Blue Penguin (Eudyptula minor). Using one nuclear (28S) and two mitochondrial (COI and 16S) markers, we assessed genetic diversity among several populations in Australia and a single population on the South Island of New Zealand. Our results reveal two deeply divergent lineages, possibly representing different species: one comprising all New Zealand samples and some from Australia, and the other representing all other samples from Australian sites. No significant population differentiation was observed among any Australian sites from within each major clade, even those separated by hundreds of kilometres of coastline. In contrast, the New Zealand population was significantly different to all samples from Australia. Our phylogenetic results suggest that the New Zealand and Australian populations are effectively isolated from each other; although rare long-distance dispersal events must occur, these are insufficient to maintain trans-Tasman gene flow. Despite the evidence for limited dispersal of penguin ticks between Australia and New Zealand, we found no evidence to suggest that ticks are unable to disperse shorter distances at sea with their hosts, with no pattern of population differentiation found among Australian sites. Our results suggest that terrestrial seabird parasites may be quite capable of short-distance movements, but only sporadic longer-distance (trans-oceanic) dispersal. PMID:26083353

[Post-traumatic stress disorder (PTSD). Assessment of its rate of occurrence in the adult population of Portugal].

PubMed

De Albuquerque, Afonso; Soares, Catarina; De Jesus, Paula Martins; Alves, Catarina

2003-01-01

This is the first epidemiological study of posttraumatic stress disorder (PTSD) within the adult population (over 18 years of age) in Portugal. This study is particularly relevant given the proportion of the population exposed to trauma: 800,000 men participated in 14 years (from 1961 to 1975) of Portugal's colonial wars. A representative sample of the adult nation-wide population was defined using bi-phasic and stratified methodology. In accordance with study inclusion/exclusion criteria, subjects from all geographical regions were selected, either randomly from the community or via the protocol defined stratification. Subjects identified as having been exposed to one or more traumatic events were further interviewed and assessed with the Short Screening Scale (Breslau, 1999) to determine the presence/absence of DSM-IV defined PTSD. A representative sample of 2,606 subjects (53.3% men) was selected, aged 18 to 99 years old (mean = 43 years). Overall PTSD prevalence rate was 7.87% (205/2,606 subjects) with a statistically significative different distribution by gender: 4.8% for male and 11.4% for female subjects. Around 75% of the Portuguese adult population was exposed to at least one traumatic situation and 43.5% to more than one. We found that 11.6% of the sample were male exposed to combat/war and 9.9% of those developed PTSD. The most referred traumatic situation was Sudden violent death of family or friend, (29.3%), followed by Robed or assaulted, (22.7%) and Witnessing of serious accident or death, (22.2%). The prevalence of posttraumatic stress disorder (overall and by gender) was similar to that reported for other developed countries; lower than expected, given the extent of the population's exposure to combat.

Sex assessment using clavicle measurements: inter- and intra-population comparisons.

PubMed

Králík, Miroslav; Urbanová, Petra; Wagenknechtová, Martina

2014-01-01

We studied sexual dimorphism of the human clavicle in order to describe size variation and create population-specific discriminant tools for morphometric sex assessment. The studied sample consisted of 200 skeletons of adult individuals obtained from the University of Athens Human Skeletal Reference Collection, Athens, Greece. The specimens were well-documented and represented a modern population from cemeteries in the Athens area. Six dimensions typically used for clavicle measurements were recorded. For sexing clavicles, we used both traditional univariate (limiting, demarking and sectioning points) and multivariate discriminant function analysis. The accuracy of the best five classification equations/functions ranged from 91.62% to 92.55% of correctly assigned specimens. By testing new and previously published sexing functions (Greeks, Polynesians, Guatemalans) on four available population samples (English, Indians from Amritsar, Indians from Varanasi, and data from the present study) we found that, for some combinations of tested and reference samples, the accuracy of the sex assessment may decrease even below the probability given by random sex assignment. Therefore, measurements of the clavicle should not be used for sex assessment of individual cases (both forensic and archeological) whose population origin is unknown. However, significant metric differences were also recorded among three different Greek samples (i.e. within a population). As a consequence, application of a sexing method generated from one Greek sample and applied to another Greek sample led to negligible reduction in the success of sex assessment, despite general similarities in ethnic origin (Greeks), generation structure and presumed social background of the samples. Therefore, we believe that future studies should focus on understanding the nature of the differences among within-population reference samples. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The Complex Demographic History and Evolutionary Origin of the Western Honey Bee, Apis Mellifera.

PubMed

Cridland, Julie M; Tsutsui, Neil D; Ramírez, Santiago R

2017-02-01

The western honey bee, Apis mellifera, provides critical pollination services to agricultural crops worldwide. However, despite substantial interest and prior investigation, the early evolution and subsequent diversification of this important pollinator remain uncertain. The primary hypotheses place the origin of A. mellifera in either Asia or Africa, with subsequent radiations proceeding from one of these regions. Here, we use two publicly available whole-genome data sets plus newly sequenced genomes and apply multiple population genetic analysis methods to investigate the patterns of ancestry and admixture in native honey bee populations from Europe, Africa, and the Middle East. The combination of these data sets is critical to the analyses, as each contributes samples from geographic locations lacking in the other, thereby producing the most complete set of honey bee populations available to date. We find evidence supporting an origin of A. mellifera in the Middle East or North Eastern Africa, with the A and Y lineages representing the earliest branching lineages. This finding has similarities with multiple contradictory hypotheses and represents a disentangling of genetic relationships, geographic proximity, and secondary contact to produce a more accurate picture of the origins of A. mellifera. We also investigate how previous studies came to their various conclusions based on incomplete sampling of populations, and illustrate the importance of complete sampling in understanding evolutionary processes. These results provide fundamental knowledge about genetic diversity within Old World honey bee populations and offer insight into the complex history of an important pollinator. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

The comparison of automated clustering algorithms for resampling representative conformer ensembles with RMSD matrix.

PubMed

Kim, Hyoungrae; Jang, Cheongyun; Yadav, Dharmendra K; Kim, Mi-Hyun

2017-03-23

The accuracy of any 3D-QSAR, Pharmacophore and 3D-similarity based chemometric target fishing models are highly dependent on a reasonable sample of active conformations. Since a number of diverse conformational sampling algorithm exist, which exhaustively generate enough conformers, however model building methods relies on explicit number of common conformers. In this work, we have attempted to make clustering algorithms, which could find reasonable number of representative conformer ensembles automatically with asymmetric dissimilarity matrix generated from openeye tool kit. RMSD was the important descriptor (variable) of each column of the N × N matrix considered as N variables describing the relationship (network) between the conformer (in a row) and the other N conformers. This approach used to evaluate the performance of the well-known clustering algorithms by comparison in terms of generating representative conformer ensembles and test them over different matrix transformation functions considering the stability. In the network, the representative conformer group could be resampled for four kinds of algorithms with implicit parameters. The directed dissimilarity matrix becomes the only input to the clustering algorithms. Dunn index, Davies-Bouldin index, Eta-squared values and omega-squared values were used to evaluate the clustering algorithms with respect to the compactness and the explanatory power. The evaluation includes the reduction (abstraction) rate of the data, correlation between the sizes of the population and the samples, the computational complexity and the memory usage as well. Every algorithm could find representative conformers automatically without any user intervention, and they reduced the data to 14-19% of the original values within 1.13 s per sample at the most. The clustering methods are simple and practical as they are fast and do not ask for any explicit parameters. RCDTC presented the maximum Dunn and omega-squared values of the four algorithms in addition to consistent reduction rate between the population size and the sample size. The performance of the clustering algorithms was consistent over different transformation functions. Moreover, the clustering method can also be applied to molecular dynamics sampling simulation results.

Q-Sample Construction: A Critical Step for a Q-Methodological Study.

PubMed

Paige, Jane B; Morin, Karen H

2016-01-01

Q-sample construction is a critical step in Q-methodological studies. Prior to conducting Q-studies, researchers start with a population of opinion statements (concourse) on a particular topic of interest from which a sample is drawn. These sampled statements are known as the Q-sample. Although literature exists on methodological processes to conduct Q-methodological studies, limited guidance exists on the practical steps to reduce the population of statements to a Q-sample. A case exemplar illustrates the steps to construct a Q-sample in preparation for a study that explored perspectives nurse educators and nursing students hold about simulation design. Experts in simulation and Q-methodology evaluated the Q-sample for readability, clarity, and for representativeness of opinions contained within the concourse. The Q-sample was piloted and feedback resulted in statement refinement. Researchers especially those undertaking Q-method studies for the first time may benefit from the practical considerations to construct a Q-sample offered in this article. © The Author(s) 2014.

Surveying immigrants without sampling frames - evaluating the success of alternative field methods.

PubMed

Reichel, David; Morales, Laura

2017-01-01

This paper evaluates the sampling methods of an international survey, the Immigrant Citizens Survey, which aimed at surveying immigrants from outside the European Union (EU) in 15 cities in seven EU countries. In five countries, no sample frame was available for the target population. Consequently, alternative ways to obtain a representative sample had to be found. In three countries 'location sampling' was employed, while in two countries traditional methods were used with adaptations to reach the target population. The paper assesses the main methodological challenges of carrying out a survey among a group of immigrants for whom no sampling frame exists. The samples of the survey in these five countries are compared to results of official statistics in order to assess the accuracy of the samples obtained through the different sampling methods. It can be shown that alternative sampling methods can provide meaningful results in terms of core demographic characteristics although some estimates differ to some extent from the census results.

Patterns of drug use and HIV infection among adults in a nationally representative sample

PubMed Central

Shiau, Stephanie; Arpadi, Stephen M.; Yin, Michael T.; Martins, Silvia S.

2017-01-01

Background Little is known about drug use patterns among people living with HIV in comparison to an uninfected group in the general population. The aim of this study was to investigate the association between legal and illegal drug use and HIV infection in a nationally representative sample of adults in the United States. Methods Public use data files (2005–2014) from the National Survey on Drug Use and Health (NSDUH) were used. Respondents were asked whether a medical professional had ever told them that they had HIV/AIDS. Ever (lifetime), past-year, and past month use of cigarettes, alcohol, marijuana, cocaine, heroin, hallucinogens, inhalants, and nonmedical use of psychotherapeutics was assessed. Logistic regression was used to estimate adjusted odds ratios (aOR) of the relationship between drug use and HIV infection, adjusting for demographics. Results Of 377,787 respondents age 18 and older, 548 (0.19%) were categorized as HIV-infected. Ever use of cigarettes, tobacco, marijuana, cocaine, heroin, hallucinogens, inhalants, and psychotherapeutics was higher in HIV-infected individuals compared to HIV-uninfected individuals after adjustment for sex, age, race/ethnicity, education, total family income, and marital status. Past year and past month use was also higher for HIV-infected individuals for all substances aside from alcohol. Conclusions In a nationally representative sample, there are higher levels of drug use and DSM-IV dependence among the HIV-infected population compared to the HIV-uninfected population. This is of concern because drug use and dependence can impede engagement in HIV care and adherence to antiretroviral therapy. PMID:28088742

Moving on From Representativeness: Testing the Utility of the Global Drug Survey.

PubMed

Barratt, Monica J; Ferris, Jason A; Zahnow, Renee; Palamar, Joseph J; Maier, Larissa J; Winstock, Adam R

2017-01-01

A decline in response rates in traditional household surveys, combined with increased internet coverage and decreased research budgets, has resulted in increased attractiveness of web survey research designs based on purposive and voluntary opt-in sampling strategies. In the study of hidden or stigmatised behaviours, such as cannabis use, web survey methods are increasingly common. However, opt-in web surveys are often heavily criticised due to their lack of sampling frame and unknown representativeness. In this article, we outline the current state of the debate about the relevance of pursuing representativeness, the state of probability sampling methods, and the utility of non-probability, web survey methods especially for accessing hidden or minority populations. Our article has two aims: (1) to present a comprehensive description of the methodology we use at Global Drug Survey (GDS), an annual cross-sectional web survey and (2) to compare the age and sex distributions of cannabis users who voluntarily completed (a) a household survey or (b) a large web-based purposive survey (GDS), across three countries: Australia, the United States, and Switzerland. We find that within each set of country comparisons, the demographic distributions among recent cannabis users are broadly similar, demonstrating that the age and sex distributions of those who volunteer to be surveyed are not vastly different between these non-probability and probability methods. We conclude that opt-in web surveys of hard-to-reach populations are an efficient way of gaining in-depth understanding of stigmatised behaviours and are appropriate, as long as they are not used to estimate drug use prevalence of the general population.

Moving on From Representativeness: Testing the Utility of the Global Drug Survey

PubMed Central

Barratt, Monica J; Ferris, Jason A; Zahnow, Renee; Palamar, Joseph J; Maier, Larissa J; Winstock, Adam R

2017-01-01

A decline in response rates in traditional household surveys, combined with increased internet coverage and decreased research budgets, has resulted in increased attractiveness of web survey research designs based on purposive and voluntary opt-in sampling strategies. In the study of hidden or stigmatised behaviours, such as cannabis use, web survey methods are increasingly common. However, opt-in web surveys are often heavily criticised due to their lack of sampling frame and unknown representativeness. In this article, we outline the current state of the debate about the relevance of pursuing representativeness, the state of probability sampling methods, and the utility of non-probability, web survey methods especially for accessing hidden or minority populations. Our article has two aims: (1) to present a comprehensive description of the methodology we use at Global Drug Survey (GDS), an annual cross-sectional web survey and (2) to compare the age and sex distributions of cannabis users who voluntarily completed (a) a household survey or (b) a large web-based purposive survey (GDS), across three countries: Australia, the United States, and Switzerland. We find that within each set of country comparisons, the demographic distributions among recent cannabis users are broadly similar, demonstrating that the age and sex distributions of those who volunteer to be surveyed are not vastly different between these non-probability and probability methods. We conclude that opt-in web surveys of hard-to-reach populations are an efficient way of gaining in-depth understanding of stigmatised behaviours and are appropriate, as long as they are not used to estimate drug use prevalence of the general population. PMID:28924351

Building Models for the Relationship between Attitudes toward Suicide and Suicidal Behavior: Based on Data from General Population Surveys in Sweden, Norway, and Russia

ERIC Educational Resources Information Center

Renberg, Ellinor Salander; Hjelmeland, Heidi; Koposov, Roman

2008-01-01

Our aim was to build a model delineating the relationship between attitudes toward suicide and suicidal behavior and to assess equivalence by applying the model on data from different countries. Representative samples from the general population were approached in Sweden, Norway, and Russia with the Attitudes Toward Suicide (ATTS) questionnaire.…

A New Single Nucleotide Polymorphism Database for Rainbow Trout Generated Through Whole Genome Resequencing.

PubMed

Gao, Guangtu; Nome, Torfinn; Pearse, Devon E; Moen, Thomas; Naish, Kerry A; Thorgaard, Gary H; Lien, Sigbjørn; Palti, Yniv

2018-01-01

Single-nucleotide polymorphisms (SNPs) are highly abundant markers, which are broadly distributed in animal genomes. For rainbow trout ( Oncorhynchus mykiss ), SNP discovery has been previously done through sequencing of restriction-site associated DNA (RAD) libraries, reduced representation libraries (RRL) and RNA sequencing. Recently we have performed high coverage whole genome resequencing with 61 unrelated samples, representing a wide range of rainbow trout and steelhead populations, with 49 new samples added to 12 aquaculture samples from AquaGen (Norway) that we previously used for SNP discovery. Of the 49 new samples, 11 were double-haploid lines from Washington State University (WSU) and 38 represented wild and hatchery populations from a wide range of geographic distribution and with divergent migratory phenotypes. We then mapped the sequences to the new rainbow trout reference genome assembly (GCA_002163495.1) which is based on the Swanson YY doubled haploid line. Variant calling was conducted with FreeBayes and SAMtools mpileup , followed by filtering of SNPs based on quality score, sequence complexity, read depth on the locus, and number of genotyped samples. Results from the two variant calling programs were compared and genotypes of the double haploid samples were used for detecting and filtering putative paralogous sequence variants (PSVs) and multi-sequence variants (MSVs). Overall, 30,302,087 SNPs were identified on the rainbow trout genome 29 chromosomes and 1,139,018 on unplaced scaffolds, with 4,042,723 SNPs having high minor allele frequency (MAF > 0.25). The average SNP density on the chromosomes was one SNP per 64 bp, or 15.6 SNPs per 1 kb. Results from the phylogenetic analysis that we conducted indicate that the SNP markers contain enough population-specific polymorphisms for recovering population relationships despite the small sample size used. Intra-Population polymorphism assessment revealed high level of polymorphism and heterozygosity within each population. We also provide functional annotation based on the genome position of each SNP and evaluate the use of clonal lines for filtering of PSVs and MSVs. These SNPs form a new database, which provides an important resource for a new high density SNP array design and for other SNP genotyping platforms used for genetic and genomics studies of this iconic salmonid fish species.

Comparison of Sociodemographic and Health-Related Characteristics of UK Biobank Participants With Those of the General Population

PubMed Central

Fry, Anna; Littlejohns, Thomas J; Sudlow, Cathie; Doherty, Nicola; Adamska, Ligia; Sprosen, Tim; Collins, Rory; Allen, Naomi E

2017-01-01

Abstract The UK Biobank cohort is a population-based cohort of 500,000 participants recruited in the United Kingdom (UK) between 2006 and 2010. Approximately 9.2 million individuals aged 40–69 years who lived within 25 miles (40 km) of one of 22 assessment centers in England, Wales, and Scotland were invited to enter the cohort, and 5.5% participated in the baseline assessment. The representativeness of the UK Biobank cohort was investigated by comparing demographic characteristics between nonresponders and responders. Sociodemographic, physical, lifestyle, and health-related characteristics of the cohort were compared with nationally representative data sources. UK Biobank participants were more likely to be older, to be female, and to live in less socioeconomically deprived areas than nonparticipants. Compared with the general population, participants were less likely to be obese, to smoke, and to drink alcohol on a daily basis and had fewer self-reported health conditions. At age 70–74 years, rates of all-cause mortality and total cancer incidence were 46.2% and 11.8% lower, respectively, in men and 55.5% and 18.1% lower, respectively, in women than in the general population of the same age. UK Biobank is not representative of the sampling population; there is evidence of a “healthy volunteer” selection bias. Nonetheless, valid assessment of exposure-disease relationships may be widely generalizable and does not require participants to be representative of the population at large. PMID:28641372

CLImAT-HET: detecting subclonal copy number alterations and loss of heterozygosity in heterogeneous tumor samples from whole-genome sequencing data.

PubMed

Yu, Zhenhua; Li, Ao; Wang, Minghui

2017-03-15

Copy number alterations (CNA) and loss of heterozygosity (LOH) represent a large proportion of genetic structural variations of cancer genomes. These aberrations are continuously accumulated during the procedure of clonal evolution and patterned by phylogenetic branching. This invariably results in the emergence of multiple cell populations with distinct complement of mutational landscapes in tumor sample. With the advent of next-generation sequencing technology, inference of subclonal populations has become one of the focused interests in cancer-associated studies, and is usually based on the assessment of combinations of somatic single-nucleotide variations (SNV), CNA and LOH. However, cancer samples often have several inherent issues, such as contamination of normal stroma, tumor aneuploidy and intra-tumor heterogeneity. Addressing these critical issues is imperative for accurate profiling of clonal architecture. We present CLImAT-HET, a computational method designed for capturing clonal diversity in the CNA/LOH dimensions by taking into account the intra-tumor heterogeneity issue, in the case where a reference or matched normal sample is absent. The algorithm quantitatively represents the clonal identification problem using a factorial hidden Markov model, and takes an integrated analysis of read counts and allele frequency data. It is able to infer subclonal CNA and LOH events as well as the fraction of cells harboring each event. The results on simulated datasets indicate that CLImAT-HET has high power to identify CNA/LOH segments, it achieves an average accuracy of 0.87. It can also accurately infer proportion of each clonal population with an overall Pearson correlation coefficient of 0.99 and a mean absolute error of 0.02. CLImAT-HET shows significant advantages when compared with other existing methods. Application of CLImAT-HET to 5 primary triple negative breast cancer samples demonstrates its ability to capture clonal diversity in the CAN/LOH dimensions. It detects two clonal populations in one sample, and three clonal populations in one other sample. CLImAT-HET, a novel algorithm is introduced to infer CNA/LOH segments from heterogeneous tumor samples. We demonstrate CLImAT-HET's ability to accurately recover clonal compositions using tumor WGS data without a match normal sample.

Photographic Identification of Humpback and Blue Whales off the US West Coast: Results and Updated Abundance Estimates from 2008 Field Season

DTIC Science & Technology

2009-12-01

1990s and only being present part of the time off the US West Coast lowering the average density present (but not reflecting an actual population ...the average density present (but not reflecting an actual population decline). 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...due to our sample representing a decreasing proportion of this growing population leading to greater variation and possibly greater susceptibility to

Low levels of genetic divergence across geographically and linguistically diverse populations from India.

PubMed

Rosenberg, Noah A; Mahajan, Saurabh; Gonzalez-Quevedo, Catalina; Blum, Michael G B; Nino-Rosales, Laura; Ninis, Vasiliki; Das, Parimal; Hegde, Madhuri; Molinari, Laura; Zapata, Gladys; Weber, James L; Belmont, John W; Patel, Pragna I

2006-12-01

Ongoing modernization in India has elevated the prevalence of many complex genetic diseases associated with a western lifestyle and diet to near-epidemic proportions. However, although India comprises more than one sixth of the world's human population, it has largely been omitted from genomic surveys that provide the backdrop for association studies of genetic disease. Here, by genotyping India-born individuals sampled in the United States, we carry out an extensive study of Indian genetic variation. We analyze 1,200 genome-wide polymorphisms in 432 individuals from 15 Indian populations. We find that populations from India, and populations from South Asia more generally, constitute one of the major human subgroups with increased similarity of genetic ancestry. However, only a relatively small amount of genetic differentiation exists among the Indian populations. Although caution is warranted due to the fact that United States-sampled Indian populations do not represent a random sample from India, these results suggest that the frequencies of many genetic variants are distinctive in India compared to other parts of the world and that the effects of population heterogeneity on the production of false positives in association studies may be smaller in Indians (and particularly in Indian-Americans) than might be expected for such a geographically and linguistically diverse subset of the human population.

Population Structure of Barley Landrace Populations and Gene-Flow with Modern Varieties

PubMed Central

Bellucci, Elisa; Bitocchi, Elena; Rau, Domenico; Nanni, Laura; Ferradini, Nicoletta; Giardini, Alessandro; Rodriguez, Monica; Attene, Giovanna; Papa, Roberto

2013-01-01

Landraces are heterogeneous plant varieties that are reproduced by farmers as populations that are subject to both artificial and natural selection. Landraces are distinguished by farmers due to their specific traits, and different farmers often grow different populations of the same landrace. We used simple sequence repeats (SSRs) to analyse 12 barley landrace populations from Sardinia from two collections spanning 10 years. We analysed the population structure, and compared the population diversity of the landraces that were collected at field level (population). We used a representative pool of barley varieties for diversity comparisons and to analyse the effects of gene flow from modern varieties. We found that the Sardinian landraces are a distinct gene pool from those of both two-row and six-row barley varieties. There is also a low, but significant, mean level and population-dependent level of introgression from the modern varieties into the Sardinian landraces. Moreover, we show that the Sardinian landraces have the same level of gene diversity as the representative sample of modern commercial varieties grown in Italy in the last decades, even within population level. Thus, these populations represent crucial sources of germplasm that will be useful for crop improvement and for population genomics studies and association mapping, to identify genes, loci and genome regions responsible for adaptive variations. Our data also suggest that landraces are a source of valuable germplasm for sustainable agriculture in the context of future climate change, and that in-situ conservation strategies based on farmer use can preserve the genetic identity of landraces while allowing adaptation to local environments. PMID:24386303

Whither RDS? An investigation of Respondent Driven Sampling as a method of recruiting mainstream marijuana users

PubMed Central

2010-01-01

Background An important challenge in conducting social research of specific relevance to harm reduction programs is locating hidden populations of consumers of substances like cannabis who typically report few adverse or unwanted consequences of their use. Much of the deviant, pathologized perception of drug users is historically derived from, and empirically supported, by a research emphasis on gaining ready access to users in drug treatment or in prison populations with higher incidence of problems of dependence and misuse. Because they are less visible, responsible recreational users of illicit drugs have been more difficult to study. Methods This article investigates Respondent Driven Sampling (RDS) as a method of recruiting experienced marijuana users representative of users in the general population. Based on sampling conducted in a multi-city study (Halifax, Montreal, Toronto, and Vancouver), and compared to samples gathered using other research methods, we assess the strengths and weaknesses of RDS recruitment as a means of gaining access to illicit substance users who experience few harmful consequences of their use. Demographic characteristics of the sample in Toronto are compared with those of users in a recent household survey and a pilot study of Toronto where the latter utilized nonrandom self-selection of respondents. Results A modified approach to RDS was necessary to attain the target sample size in all four cities (i.e., 40 'users' from each site). The final sample in Toronto was largely similar, however, to marijuana users in a random household survey that was carried out in the same city. Whereas well-educated, married, whites and females in the survey were all somewhat overrepresented, the two samples, overall, were more alike than different with respect to economic status and employment. Furthermore, comparison with a self-selected sample suggests that (even modified) RDS recruitment is a cost-effective way of gathering respondents who are more representative of users in the general population than nonrandom methods of recruitment ordinarily produce. Conclusions Research on marijuana use, and other forms of drug use hidden in the general population of adults, is important for informing and extending harm reduction beyond its current emphasis on 'at-risk' populations. Expanding harm reduction in a normalizing context, through innovative research on users often overlooked, further challenges assumptions about reducing harm through prohibition of drug use and urges consideration of alternative policies such as decriminalization and legal regulation. PMID:20618944

Recruitment of representative samples for low incidence cancer populations: Do registries deliver?

PubMed Central

2011-01-01

Background Recruiting large and representative samples of adolescent and young adult (AYA) cancer survivors is important for gaining accurate data regarding the prevalence of unmet needs in this population. This study aimed to describe recruitment rates for AYAs recruited through a cancer registry with particular focus on: active clinician consent protocols, reasons for clinicians not providing consent and the representativeness of the final sample. Methods Adolescents and young adults aged 14 to19 years inclusive and listed on the cancer registry from January 1 2002 to December 31 2007 were identified. An active clinician consent protocol was used whereby the registry sent a letter to AYAs primary treating clinicians requesting permission to contact the survivors. The registry then sent survivors who received their clinician's consent a letter seeking permission to forward their contact details to the research team. Consenting AYAs were sent a questionnaire which assessed their unmet needs. Results The overall consent rate for AYAs identified as eligible by the registry was 7.8%. Of the 411 potentially eligible survivors identified, just over half (n = 232, 56%) received their clinician's consent to be contacted. Of those 232 AYAs, 65% were unable to be contacted. Only 18 AYAs (7.8%) refused permission for their contact details to be passed on to the research team. Of the 64 young people who agreed to be contacted, 50% (n = 32) completed the questionnaire. Conclusions Cancer registries which employ active clinician consent protocols may not be appropriate for recruiting large, representative samples of AYAs diagnosed with cancer. Given that AYA cancer survivors are highly mobile, alternative methods such as treatment centre and clinic based recruitment may need to be considered. PMID:21235819

Dengue Virus Exposures Among Deployed U.S. Military Personnel

PubMed Central

Hesse, Elisabeth M.; Martinez, Luis J.; Jarman, Richard G.; Lyons, Arthur G.; Eckels, Kenneth H.; De La Barrera, Rafael A.; Thomas, Stephen J.

2017-01-01

Dengue virus infections have adversely impacted U.S. military operations since the Spanish–American War. The erosion of mission capabilities and lost duty days are underestimated. Appreciating the incidence and prevalence of dengue infections in U.S. military personnel is important to inform disease prevention strategies. Banked pre- and post-deployment serum samples from 1,000 U.S. military personnel with a single deployment to a dengue-endemic region were tested using a screening microneutralization assay to detect anti-dengue-virus-neutralizing antibodies. A total of 76 (7.6%) post-deployment samples were positive and 15 of the pre-deployment samples were negative. These figures represent an infection incidence of 1.5% and total of 17.6 seroconversions per 10,000 deployment months. These data represent a deploying military population with a relatively high background rate of dengue seropositivity, a low level of infection during deployment compared with background infection rates in the local populations, and the potential for worsening clinical attack rates with increased frequency of deployment. Additional studies are required to more clearly elucidate the dengue infection and disease risk in U.S. military personnel. PMID:28193746

Dengue Virus Exposures Among Deployed U.S. Military Personnel.

PubMed

Hesse, Elisabeth M; Martinez, Luis J; Jarman, Richard G; Lyons, Arthur G; Eckels, Kenneth H; De La Barrera, Rafael A; Thomas, Stephen J

2017-05-01

AbstractDengue virus infections have adversely impacted U.S. military operations since the Spanish-American War. The erosion of mission capabilities and lost duty days are underestimated. Appreciating the incidence and prevalence of dengue infections in U.S. military personnel is important to inform disease prevention strategies. Banked pre- and post-deployment serum samples from 1,000 U.S. military personnel with a single deployment to a dengue-endemic region were tested using a screening microneutralization assay to detect anti-dengue-virus-neutralizing antibodies. A total of 76 (7.6%) post-deployment samples were positive and 15 of the pre-deployment samples were negative. These figures represent an infection incidence of 1.5% and total of 17.6 seroconversions per 10,000 deployment months. These data represent a deploying military population with a relatively high background rate of dengue seropositivity, a low level of infection during deployment compared with background infection rates in the local populations, and the potential for worsening clinical attack rates with increased frequency of deployment. Additional studies are required to more clearly elucidate the dengue infection and disease risk in U.S. military personnel.

Adding Postal Follow-Up to a Web-Based Survey of Primary Care and Gastroenterology Clinic Physician Chiefs Improved Response Rates but not Response Quality or Representativeness.

PubMed

Partin, Melissa R; Powell, Adam A; Burgess, Diana J; Haggstrom, David A; Gravely, Amy A; Halek, Krysten; Bangerter, Ann; Shaukat, Aasma; Nelson, David B

2015-09-01

This study assessed whether postal follow-up to a web-based physician survey improves response rates, response quality, and representativeness. We recruited primary care and gastroenterology chiefs at 125 Veterans Affairs medical facilities to complete a 10-min web-based survey on colorectal cancer screening and diagnostic practices in 2010. We compared response rates, response errors, and representativeness in the primary care and gastroenterology samples before and after adding postal follow-up. Adding postal follow-up increased response rates by 20-25 percentage points; markedly greater increases than predicted from a third e-mail reminder. In the gastroenterology sample, the mean number of response errors made by web responders (0.25) was significantly smaller than the mean number made by postal responders (2.18), and web responders provided significantly longer responses to open-ended questions. There were no significant differences in these outcomes in the primary care sample. Adequate representativeness was achieved before postal follow-up in both samples, as indicated by the lack of significant differences between web responders and the recruitment population on facility characteristics. We conclude adding postal follow-up to this web-based physician leader survey improved response rates but not response quality or representativeness. © The Author(s) 2013.

Examination of anonymous canine faecal samples provides data on endoparasite prevalence rates in dogs for comparative studies.

PubMed

Hinney, Barbara; Gottwald, Michaela; Moser, Jasmine; Reicher, Bianca; Schäfer, Bhavapriya Jasmin; Schaper, Roland; Joachim, Anja; Künzel, Frank

2017-10-15

Several endoparasites of dogs cannot only be detrimental to their primary host but might also represent a threat to human health because of their zoonotic potential. Due to their high dog population densities, metropolitan areas can be highly endemic for such parasites. We aimed to estimate the prevalence of endoparasites in dogs in the Austrian capital of Vienna by examining a representative number of canine faecal samples and to compare the prevalences with two neighbouring peri-urban and rural regions. In addition we analysed whether the density of dog populations and cleanliness of dog zones correlated with parasite occurrence. We collected 1001 anonymous faecal samples from 55 dog zones from all 23 districts of the federal state of Vienna, as well as 480 faecal samples from the Mödling district and Wolkersdorf with a peri-urban and rural character, respectively. Faeces were examined by flotation and by Baermann technique. Additionally we evaluated 292 Viennese, 102 peri-urban and 50 rural samples for Giardia and Cryptosporidium by GiardiaFASTest ® and CryptoFASTest ® . Samples from "clean" dog zones were compared to samples from "dirty" zones. The infection rate of Toxocara was surprisingly low, ranging from 0.6% to 1.9%. Trichuris was the most frequent helminth (1.8-7.5%) and Giardia the most frequent protozoan (4.0-10.8%). Ancylostomatidae, Crenosoma, Capillaria, Taeniidae, Cystoisospora and Sarcocystis were found in 1.8-2.2%, 0-0.9%, 0-0.9%, 0-0.6%, 0.3-3.1% and 0-0.6% of the samples, respectively. Samples from "dirty" dog zones in Vienna showed a significantly higher rate of parasites overall (p=0.003) and of Trichuris (p=0.048) compared to samples from "clean" dog zones. There were no statistically significant differences in densely vs. less densely populated areas of Vienna. Samples from the rural region of Wolkersdorf had significantly higher overall parasite, Trichuris and Cystoisospora prevalences than the peri-urban Mödling district and Vienna (p=0.000-0.039), while samples from the Mödling district had a significantly higher Giardia, Crenosoma and Capillaria prevalence than those from Vienna (p=0.002-0.047). Parasite excretion is dynamic and representative sampling and monitoring are necessary for parasite surveillance. Dog owners should be informed about the zoonotic risk and encouraged to remove dog faeces and dispose of them properly to reduce the infection risk for both other dogs and humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Pollution gets personal! A first population-based human biomonitoring study in Austria.

PubMed

Hohenblum, Philipp; Steinbichl, Philipp; Raffesberg, Wolfgang; Weiss, Stefan; Moche, Wolfgang; Vallant, Birgit; Scharf, Sigrid; Haluza, Daniela; Moshammer, Hanns; Kundi, Michael; Piegler, Brigitte; Wallner, Peter; Hutter, Hans-Peter

2012-02-01

Humans are exposed to a broad variety of man-made chemicals. Human biomonitoring (HBM) data reveal the individual body burden irrespective of sources and routes of uptake. A first population-based study was started in Austria in 2008 and was finished at the end of May 2011. This cross sectional study aims at documenting the extent, the distribution and the determinants of human exposure to industrial chemicals as well as proving the feasibility of a representative HBM study. Overall, 150 volunteers (50 families) were selected by stratified random sampling. Exposure to phthalates, trisphosphates, polybrominated diphenyl ethers (PBDE), bisphenol A (along with nonyl- and octyl phenol) and methyl mercury was assessed. Sixteen of 18 PBDE determined were detected above the limit of quantification (LOQ) in blood samples with #153 and #197 the most abundant species. Bisphenol A in urine was measured in a subsample of 25 with only 4 samples found above the LOQ. In 3 of 100 urine samples at least one of 8 trisphosphate compounds assessed was above the LOQ. These first analytical results of the human biomonitoring data show that the body burden of the Austrian population with respect to the assessed compounds is comparable to or even lower than in other European countries. Overall, the study revealed that in order to develop a feasible protocol for representative human biomonitoring studies procedures have to be optimized to allow for non-invasive sampling of body tissues in accordance with the main metabolic pathways. Procedures of participants' recruitment were, however, labor intensive and have to be improved. Copyright © 2011 Elsevier GmbH. All rights reserved.

Population Genetic Analysis of Theileria annulata from Six Geographical Regions in China, Determined on the Basis of Micro- and Mini-satellite Markers

PubMed Central

Yin, Fangyuan; Liu, Zhijie; Liu, Junlong; Liu, Aihong; Salih, Diaeldin A.; Li, Youquan; Liu, Guangyuan; Luo, Jianxun; Guan, Guiquan; Yin, Hong

2018-01-01

Theileria annulata, a tick-borne apicomplexan protozoan, causes a lymphoproliferative disease of cattle with high prevalence in tropical and sub-tropical regions. Understanding the genetic diversity and structure of local populations will provide more fundamental knowledge for the population genetics and epidemics of protozoa. In this study, 78 samples of T. annulata collected from cattle/yaks representing 6 different geographic populations in China were genotyped using eight micro- and mini-satellite markers. High genetic variation within population, moderate genetic differentiation, and high level of diversity co-occurring with significant linkage disequilibrium were observed, which indicates there is gene flow between these populations in spite of the existence of reproductive and geographical barriers among populations. Furthermore, some degree of genetic differentiation was also found between samples from China and Oman. These findings provide a first glimpse of the genetic diversity of the T. annulata populations in China, and might contribute to the knowledge of distribution, dynamics, and epidemiology of T. annulata populations and optimize the management strategies for control. PMID:29515624

Mitochondrial DNA diversity of orchid bee Euglossa fimbriata (Hymenoptera: Apidae) populations assessed by PCR-RFLP.

PubMed

Suzuki, Karen M; Arias, Maria C; Giangarelli, Douglas C; Freiria, Gabriele A; Sofia, Silvia H

2010-04-01

Euglossa fimbriata is a euglossine species widely distributed in Brazil and occurring primarily in Atlantic Forest remnants. In this study, the genetic mitochondrial structure of E. fimbriata from six Atlantic Forest fragments was studied by RFLP analysis of three PCR-amplified mtDNA gene segments (16S, COI-COII, and cyt b). Ten composite haplotypes were identified, six of which were exclusive and represented singleton mitotypes. Low haplotype diversity (0.085-0.289) and nucleotide diversity (0.000-0.002) were detected within samples. AMOVA partitioned 91.13% of the overall genetic variation within samples and 8.87% (phi(st) = 0.089; P < 0.05) among samples. Pairwise comparisons indicated high levels of differentiation among some pairs of samples (phi(st) = 0.161-0.218; P < 0.05). These high levels indicate that these populations of E. fimbriata, despite their highly fragmented landscape, apparently have not suffered loss of genetic variation, suggesting that this particular population is not currently endangered.

Genomic reconstruction of the history of extant populations of India reveals five distinct ancestral components and a complex structure

PubMed Central

Basu, Analabha; Sarkar-Roy, Neeta; Majumder, Partha P.

2016-01-01

India, occupying the center stage of Paleolithic and Neolithic migrations, has been underrepresented in genome-wide studies of variation. Systematic analysis of genome-wide data, using multiple robust statistical methods, on (i) 367 unrelated individuals drawn from 18 mainland and 2 island (Andaman and Nicobar Islands) populations selected to represent geographic, linguistic, and ethnic diversities, and (ii) individuals from populations represented in the Human Genome Diversity Panel (HGDP), reveal four major ancestries in mainland India. This contrasts with an earlier inference of two ancestries based on limited population sampling. A distinct ancestry of the populations of Andaman archipelago was identified and found to be coancestral to Oceanic populations. Analysis of ancestral haplotype blocks revealed that extant mainland populations (i) admixed widely irrespective of ancestry, although admixtures between populations was not always symmetric, and (ii) this practice was rapidly replaced by endogamy about 70 generations ago, among upper castes and Indo-European speakers predominantly. This estimated time coincides with the historical period of formulation and adoption of sociocultural norms restricting intermarriage in large social strata. A similar replacement observed among tribal populations was temporally less uniform. PMID:26811443

Genome-Wide Association Study of a Validated Case Definition of Gulf War Illness in a Population-Representative Sample

DTIC Science & Technology

2013-09-01

sequence dataset. All procedures were performed by personnel in the IIMT UT Southwestern Genomics and Microarray Core using standard protocols. More... sequencing run, samples were demultiplexed using standard algorithms in the Genomics and Microarray Core and processed into individual sample Illumina single... Sequencing (RNA-Seq), using Illumina’s multiplexing mRNA-Seq to generate full sequence libraries from the poly-A tailed RNA to a read depth of 30

Accounting for selection bias in association studies with complex survey data.

PubMed

Wirth, Kathleen E; Tchetgen Tchetgen, Eric J

2014-05-01

Obtaining representative information from hidden and hard-to-reach populations is fundamental to describe the epidemiology of many sexually transmitted diseases, including HIV. Unfortunately, simple random sampling is impractical in these settings, as no registry of names exists from which to sample the population at random. However, complex sampling designs can be used, as members of these populations tend to congregate at known locations, which can be enumerated and sampled at random. For example, female sex workers may be found at brothels and street corners, whereas injection drug users often come together at shooting galleries. Despite the logistical appeal, complex sampling schemes lead to unequal probabilities of selection, and failure to account for this differential selection can result in biased estimates of population averages and relative risks. However, standard techniques to account for selection can lead to substantial losses in efficiency. Consequently, researchers implement a variety of strategies in an effort to balance validity and efficiency. Some researchers fully or partially account for the survey design, whereas others do nothing and treat the sample as a realization of the population of interest. We use directed acyclic graphs to show how certain survey sampling designs, combined with subject-matter considerations unique to individual exposure-outcome associations, can induce selection bias. Finally, we present a novel yet simple maximum likelihood approach for analyzing complex survey data; this approach optimizes statistical efficiency at no cost to validity. We use simulated data to illustrate this method and compare it with other analytic techniques.

Genetic Diversity and Population Structure of Theileria annulata in Oman

PubMed Central

Al-Hamidhi, Salama; H. Tageldin, Mohammed.; Weir, William; Al-Fahdi, Amira; Johnson, Eugene H.; Bobade, Patrick; Alqamashoui, Badar; Beja-Pereira, Albano; Thompson, Joanne; Kinnaird, Jane; Shiels, Brian; Tait, Andy; Babiker, Hamza

2015-01-01

Background Theileriosis, caused by a number of species within the genus Theileria, is a common disease of livestock in Oman. It is a major constraint to the development of the livestock industry due to a high rate of morbidity and mortality in both cattle and sheep. Since little is currently known about the genetic diversity of the parasites causing theileriosis in Oman, the present study was designed to address this issue with specific regard to T. annulata in cattle. Methods Blood samples were collected from cattle from four geographically distinct regions in Oman for genetic analysis of the Theileria annulata population. Ten genetic markers (micro- and mini-satellites) representing all four chromosomes of T. annulata were applied to these samples using a combination of PCR amplification and fragment analysis. The resultant genetic data was analysed to provide a first insight into the structure of the T. annulata population in Oman. Results We applied ten micro- and mini-satellite markers to a total of 310 samples obtained from different regions (174 [56%] from Dhofar, 68 [22%] from Dhira, 44 [14.5%] from Batinah and 24 [8%] from Sharqia). A high degree of allelic diversity was observed among the four parasite populations. Expected heterozygosity for each site ranged from 0.816 to 0.854. A high multiplicity of infection was observed in individual hosts, with an average of 3.3 to 3.4 alleles per locus, in samples derived from Batinah, Dhofar and Sharqia regions. In samples from Dhira region, an average of 2.9 alleles per locus was observed. Mild but statistically significant linkage disequilibrium between pairs of markers was observed in populations from three of the four regions. In contrast, when the analysis was performed at farm level, no significant linkage disequilibrium was observed. Finally, no significant genetic differentiation was seen between the four populations, with most pair-wise FST values being less than 0.03. Slightly higher FST values (GST’ = 0.075, θ = 0.07) were detected when the data for T. annulata parasites in Oman was compared with that previously generated for Turkey and Tunisia. Conclusion Genetic analyses of T. annulata samples representing four geographical regions in Oman revealed a high level of genetic diversity in the parasite population. There was little evidence of genetic differentiation between parasites from different regions, and a high level of genetic diversity was maintained within each sub-population. These findings are consistent with a high parasite transmission rate and frequent movement of animals between different regions in Oman. PMID:26469349

Genetic Diversity and Population Structure of Theileria annulata in Oman.

PubMed

Al-Hamidhi, Salama; H Tageldin, Mohammed; Weir, William; Al-Fahdi, Amira; Johnson, Eugene H; Bobade, Patrick; Alqamashoui, Badar; Beja-Pereira, Albano; Thompson, Joanne; Kinnaird, Jane; Shiels, Brian; Tait, Andy; Babiker, Hamza

2015-01-01

Theileriosis, caused by a number of species within the genus Theileria, is a common disease of livestock in Oman. It is a major constraint to the development of the livestock industry due to a high rate of morbidity and mortality in both cattle and sheep. Since little is currently known about the genetic diversity of the parasites causing theileriosis in Oman, the present study was designed to address this issue with specific regard to T. annulata in cattle. Blood samples were collected from cattle from four geographically distinct regions in Oman for genetic analysis of the Theileria annulata population. Ten genetic markers (micro- and mini-satellites) representing all four chromosomes of T. annulata were applied to these samples using a combination of PCR amplification and fragment analysis. The resultant genetic data was analysed to provide a first insight into the structure of the T. annulata population in Oman. We applied ten micro- and mini-satellite markers to a total of 310 samples obtained from different regions (174 [56%] from Dhofar, 68 [22%] from Dhira, 44 [14.5%] from Batinah and 24 [8%] from Sharqia). A high degree of allelic diversity was observed among the four parasite populations. Expected heterozygosity for each site ranged from 0.816 to 0.854. A high multiplicity of infection was observed in individual hosts, with an average of 3.3 to 3.4 alleles per locus, in samples derived from Batinah, Dhofar and Sharqia regions. In samples from Dhira region, an average of 2.9 alleles per locus was observed. Mild but statistically significant linkage disequilibrium between pairs of markers was observed in populations from three of the four regions. In contrast, when the analysis was performed at farm level, no significant linkage disequilibrium was observed. Finally, no significant genetic differentiation was seen between the four populations, with most pair-wise FST values being less than 0.03. Slightly higher FST values (GST' = 0.075, θ = 0.07) were detected when the data for T. annulata parasites in Oman was compared with that previously generated for Turkey and Tunisia. Genetic analyses of T. annulata samples representing four geographical regions in Oman revealed a high level of genetic diversity in the parasite population. There was little evidence of genetic differentiation between parasites from different regions, and a high level of genetic diversity was maintained within each sub-population. These findings are consistent with a high parasite transmission rate and frequent movement of animals between different regions in Oman.

Impact of forced displacement during World War II on the present-day mental health of the elderly: a population-based study.

PubMed

Kuwert, Philipp; Brähler, Elmar; Glaesmer, Heide; Freyberger, Harald Jürgen; Decker, Oliver

2009-08-01

The effects of traumatization among the elderly is a neglected topic in research and clinical settings. Forced displacement of civilians is one of the main traumatic features of modern armed conflict. Roughly 12 million German people were displaced in World War II (WWII) and to our knowledge there has been no representative study investigating the mental health outcomes of such trauma in the elderly population. The survey assessed whether current depression, anxiety, resilience and life satisfaction were significantly associated with forced displacement in WWII. A nationwide representative face-to-face household survey was conducted in Germany. A representative sample of the German population aged 61 years or older (N = 1513 participants, N = 239 displaced in WWII) was approached using 258 sample points. Measurements included depressive symptoms (PHQ-2), anxiety (GAD-7), resilience (RS-11), general and domain-specific life satisfaction (FLZ(M)) and sociodemographic variables. Forced displacement in WWII is significantly associated with higher levels of anxiety and lower levels of resilience and life satisfaction 60 years later. In regression analyses, forced displacement in WWII significantly predicted current anxiety (beta 0.07; p < 0.01), life satisfaction (beta -0.06; p < 0.05) and resilience (beta -0.07; p < 0.01). To our knowledge this is the first nationwide representative survey to examine the late-life effects of forced displacement, particularly of persons displaced during WWII in Germany. Further research is needed to identify mediating variables and to evaluate psychotherapeutic interventions in elderly trauma survivors.

TNO/Centaurs grouping tested with asteroid data sets

NASA Astrophysics Data System (ADS)

Fulchignoni, M.; Birlan, M.; Barucci, M. A.

2001-11-01

Recently, we have discussed the possible subdivision in few groups of a sample of 22 TNO and Centaurs for which the BVRIJ photometry were available (Barucci et al., 2001, A&A, 371,1150). We obtained this results using the multivariate statistics adopted to define the current asteroid taxonomy, namely the Principal Components Analysis and the G-mode method (Tholen & Barucci, 1989, in ASTEROIDS II). How these methods work with a very small statistical sample as the TNO/Centaurs one? Theoretically, the number of degrees of freedom of the sample is correct. In fact it is 88 in our case and have to be larger then 50 to cope with the requirements of the G-mode. Does the random sampling of the small number of members of a large population contain enough information to reveal some structure in the population? We extracted several samples of 22 asteroids out of a data-base of 86 objects of known taxonomic type for which BVRIJ photometry is available from ECAS (Zellner et al. 1985, ICARUS 61, 355), SMASS II (S.W. Bus, 1999, PhD Thesis, MIT), and the Bell et al. Atlas of the asteroid infrared spectra. The objects constituting the first sample were selected in order to give a good representation of the major asteroid taxonomic classes (at least three samples each class): C,S,D,A, and G. Both methods were able to distinguish all these groups confirming the validity of the adopted methods. The S class is hard to individuate as a consequence of the choice of I and J variables, which imply a lack of information on the absorption band at 1 micron. The other samples were obtained by random choice of the objects. Not all the major groups were well represented (less than three samples per groups), but the general trend of the asteroid taxonomy has been always obtained. We conclude that the quoted grouping of TNO/Centaurs is representative of some physico-chemical structure of the outer solar system small body population.

Productivity and population density estimates of the dengue vector mosquito Aedes aegypti (Stegomyia aegypti) in Australia.

PubMed

Williams, C R; Johnson, P H; Ball, T S; Ritchie, S A

2013-09-01

New mosquito control strategies centred on the modifying of populations require knowledge of existing population densities at release sites and an understanding of breeding site ecology. Using a quantitative pupal survey method, we investigated production of the dengue vector Aedes aegypti (L.) (Stegomyia aegypti) (Diptera: Culicidae) in Cairns, Queensland, Australia, and found that garden accoutrements represented the most common container type. Deliberately placed 'sentinel' containers were set at seven houses and sampled for pupae over 10 weeks during the wet season. Pupal production was approximately constant; tyres and buckets represented the most productive container types. Sentinel tyres produced the largest female mosquitoes, but were relatively rare in the field survey. We then used field-collected data to make estimates of per premises population density using three different approaches. Estimates of female Ae. aegypti abundance per premises made using the container-inhabiting mosquito simulation (CIMSiM) model [95% confidence interval (CI) 18.5-29.1 females] concorded reasonably well with estimates obtained using a standing crop calculation based on pupal collections (95% CI 8.8-22.5) and using BG-Sentinel traps and a sampling rate correction factor (95% CI 6.2-35.2). By first describing local Ae. aegypti productivity, we were able to compare three separate population density estimates which provided similar results. We anticipate that this will provide researchers and health officials with several tools with which to make estimates of population densities. © 2012 The Royal Entomological Society.

Comparing Ex Servicemember And Civilian Use of Employment Insurance

DTIC Science & Technology

2018-01-01

of the government under an early release program; a medical disqualification, pregnancy , parenthood, or any service-incurred injury or disability...veteran population.1 The U.S. Census Bureau’s American Community Survey is a representative sample of the U.S. population and includes... early because of a qualifying “acceptable narrative reason,” then he or she will be eligible for benefits.5 UCX provides income while former active

A Cluster of Legionella-Associated Pneumonia Cases in a Population of Military Recruits

DTIC Science & Technology

2007-06-01

this cluster may suggest a previously unrecognized suscep- FIG. 1. Phylogenic analysis of the training center strain (represented by the MCRD consensus...military recruits during population- based surveillance for pneumonia pathogens. Results were confirmed by sequence analysis . Cases cluster tightly...17 April 2007 A Legionella cluster was identified through retrospective PCR analysis of 240 throat swab samples from X-ray-confirmed pneumonia cases

CHARACTERISTICS OF PERSONS WITH IMPAIRED HEARING. UNITED STATES--JULY 1962-JUNE 1963. VITAL AND HEALTH STATISTICS--DATA FROM THE NATIONAL HEALTH SURVEY, NATIONAL CENTER FOR HEALTH STATISTICS.

ERIC Educational Resources Information Center

LINDER, FORREST E.; AND OTHERS

COLLECTED BY INTERVIEWERS FROM A REPRESENTATIVE SAMPLE OF 42,000 HOUSEHOLDS CONTAINING 134,000 PERSONS, THIS DATA PERTAINS TO THE HEARING-IMPAIRED POPULATION IN 1962-1963. THE REPORT PRESENTS THE SOCIAL, ECONOMIC, AND DEMOGRAPHIC CHARACTERISTICS OF THE POPULATION WITH IMPAIRED HEARING, AND ALSO GIVES DATA ON THE UTILIZATION OF AND SATISFACTION…

Comparison of Smoking, Drinking, and Marijuana Use between Students Present or Absent on the Day of a School-Based Survey

ERIC Educational Resources Information Center

Bovet, Pascal; Viswanathan, Bharathi; Faeh, David; Warren, Wick

2006-01-01

The aim of this population-based survey was to compare the prevalence of selected risk behaviors between students present or absent on the day of a school-based survey. The study population was a representative sample of all students of secondary schools in the Seychelles (Indian Ocean). Students absent on the day of the survey were traced and…

Pedometer-Determined Physical Activity and Its Comparison with the International Physical Activity Questionnaire in a Sample of Belgian Adults

ERIC Educational Resources Information Center

De Cocker, Katrien; Cardon, Greet; De Bourdeaudhuij, Ilse

2007-01-01

Pedometer-determined physical activity (PA) levels in Belgian adults were provided and compared to PA scores reported in the International Physical Activity Questionnaire (IPAQ). The representative sample (N = 1,239) of the Belgian population took on average 9,655 (4,526) steps/day. According to pedometer indices 58.4% were insufficiently active.…

Gender Ratio in a Clinical Population Sample, Age of Diagnosis and Duration of Assessment in Children and Adults with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Rutherford, Marion; McKenzie, Karen; Johnson, Tess; Catchpole, Ciara; O'Hare, Anne; McClure, Iain; Forsyth, Kirsty; McCartney, Deborah; Murray, Aja

2016-01-01

This article reports on gender ratio, age of diagnosis and the duration of assessment procedures in autism spectrum disorder diagnosis in a national study which included all types of clinical services for children and adults. Findings are reported from a retrospective case note analysis undertaken with a representative sample of 150 Scottish…

Structure and genetic diversity of natural populations of Morus alba in the trans-Himalayan Ladakh region.

PubMed

Bajpai, Prabodh K; Warghat, Ashish R; Sharma, Ram Kumar; Yadav, Ashish; Thakur, Anil K; Srivastava, Ravi B; Stobdan, Tsering

2014-04-01

Sequence-related amplified polymorphism markers were used to assess the genetic structure in three natural populations of Morus alba from trans-Himalaya. Multilocation sampling was conducted across 14 collection sites. The overall genetic diversity estimates were high: percentage polymorphic loci 89.66%, Nei's gene diversity 0.2286, and Shannon's information index 0.2175. At a regional level, partitioning of variability assessed using analysis of molecular variance (AMOVA), revealed 80% variation within and 20% among collection sites. Pattern appeared in STRUCTURE, BARRIER, and AMOVA, clearly demonstrating gene flow between the Indus and Suru populations and a geographic barrier between the Indus-Suru and Nubra populations, which effectively hinders gene flow. The results showed significant genetic differentiation, population structure, high to restricted gene flow, and high genetic diversity. The assumption that samples collected from the three valleys represent three different populations does not hold true. The fragmentation present in trans-Himalaya was more natural and less anthropogenic.

Population Genetics of the Aquatic Fungus Tetracladium marchalianum over Space and Time

PubMed Central

Anderson, Jennifer L.; Shearer, Carol A.

2011-01-01

Aquatic hyphomycete fungi are fundamental mediators of energy flow and nutrient spiraling in rivers. These microscopic fungi are primarily dispersed in river currents, undergo substantial annual fluctuations in abundance, and reproduce either predominantly or exclusively asexually. These aspects of aquatic hyphomycete biology are expected to influence levels and distributions of genetic diversity over both spatial and temporal scales. In this study, we investigated the spatiotemporal distribution of genotypic diversity in the representative aquatic hyphomycete Tetracladium marchalianum. We sampled populations of this fungus from seven sites, three sites each in two rivers in Illinois, USA, and one site in a Wisconsin river, USA, and repeatedly sampled one population over two years to track population genetic parameters through two seasonal cycles. The resulting fungal isolates (N = 391) were genotyped at eight polymorphic microsatellite loci. In spite of seasonal reductions in the abundance of this species, genotypic diversity was consistently very high and allele frequencies remarkably stable over time. Likewise, genotypic diversity was very high at all sites. Genetic differentiation was only observed between the most distant rivers (∼450 km). Clear evidence that T. marchalianum reproduces sexually in nature was not observed. Additionally, we used phylogenetic analysis of partial β-tubulin gene sequences to confirm that the fungal isolates studied here represent a single species. These results suggest that populations of T. marchalianum may be very large and highly connected at local scales. We speculate that large population sizes and colonization of alternate substrates in both terrestrial and aquatic environments may effectively buffer the aquatic populations from in-stream population fluctuations and facilitate stability in allele frequencies over time. These data also suggest that overland dispersal is more important for structuring populations of T. marchalianum over geographic scales than expected. PMID:21264239

[Representations of insanity, mental illness and depression in general population in France].

PubMed

Roelandt, J-L; Caria, A; Defromont, L; Vandeborre, A; Daumerie, N

2010-01-01

The aim of this study was to describe the representations of insane, mentally ill and depressive persons, in a representative sample from the French General Population. Data were derived from the multicentric survey "Mental Health in the General Population: images and realities", carried out in 47 French public sites between 1999 and 2003. A face-to-face questionnaire was used to interview a representative sample of French metropolitan subjects, aged 18 and over, non-institutionalized and homeless. These subjects were recruited using quota sampling for age, sex, socioprofessional and education levels, according to data from the 1999 national French population census. Representations of insane, mentally ill and depressive persons were explored by a specific questionnaire with open and semi-open questions. Psychiatric diagnoses were identified using the Mini International Neuropsychiatric Interview (MINI). A national database was then constituted by pooling data from all sites, weighted for age, sex, level of education, socioprofessional level and work status to be representative of the French general population. Of the 36,000 individuals included in this study, over 75% associated the words "insane" and "mentally ill" with violent and dangerous behaviours and the term "depressive" with sadness, isolation and suicide. Young people, those with higher education and higher income level more frequently associated dangerous behaviours with mental illness rather than with insanity. The study shows that the general population draws a clear line between the representation of insane and mentally ill on one hand, and depressive on the other hand. Insane and mentally people are described as abnormal, irresponsible, unconscious, socially excluded, far from being curable, and to be cured against their will by psychotropic drugs and psychiatric hospitalisation. Whereas the depressive is perceived as a more familiar character, suffering, curable, who can be cured with psychotropic drugs and social support, but not to be hospitalized. This study highlights the overwhelming representations of insanity and mental illness in the French general population. As those stereotypes strongly affect access to care and behaviours toward psychiatric patients, the results show the need to think over the best way to fight against stigma and discrimination, in order to reduce psychiatric patients' social exclusion. Copyright 2010 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

Correction of bias in belt transect studies of immotile objects

USGS Publications Warehouse

Anderson, D.R.; Pospahala, R.S.

1970-01-01

Unless a correction is made, population estimates derived from a sample of belt transects will be biased if a fraction of, the individuals on the sample transects are not counted. An approach, useful for correcting this bias when sampling immotile populations using transects of a fixed width, is presented. The method assumes that a searcher's ability to find objects near the center of the transect is nearly perfect. The method utilizes a mathematical equation, estimated from the data, to represent the searcher's inability to find all objects at increasing distances from the center of the transect. An example of the analysis of data, formation of the equation, and application is presented using waterfowl nesting data collected in Colorado.

Lead burdens and behavioral impairments of the lined shore crab Pachygrapsus crassipes

USGS Publications Warehouse

Hui, Clifford A.

2002-01-01

Unless a correction is made, population estimates derived from a sample of belt transects will be biased if a fraction of, the individuals on the sample transects are not counted. An approach, useful for correcting this bias when sampling immotile populations using transects of a fixed width, is presented. The method assumes that a searcher's ability to find objects near the center of the transect is nearly perfect. The method utilizes a mathematical equation, estimated from the data, to represent the searcher's inability to find all objects at increasing distances from the center of the transect. An example of the analysis of data, formation of the equation, and application is presented using waterfowl nesting data collected in Colorado.

Who are your public? A survey comparing the views of a population-based sample with those of a community-based public forum in Scotland.

PubMed

Emslie, Margaret J; Andrew, Jane; Angus, Val; Entwistle, Vikki; Walker, Kim

2005-03-01

This paper describes a questionnaire survey, carried out in the NHS Grampian area of NE Scotland. It compares responses from 84 members of a community-based public forum (39 of whom were sent questionnaires) and a random sample of 10,000 adults registered with general practices in Grampian (2,449 of whom were sent questionnaires). differences in demographic profiles and opinions about different feedback mechanisms (patient representative, telephone helpline and NHS feedback website) and their likely effectiveness in three different scenarios. 46% of community forum members consented to take part compared to 24% of the population sample. Younger people and residents in more deprived areas were under-represented in both groups. Community forum members were older (only one under 40 years of age), more likely to be retired and not in employment. Internet access was similar in both groups. Opinions about different systems of feeding back views to the NHS varied but community forum members were more likely to be positive in their opinions about the value of different feedback mechanisms and less likely to think they were 'a waste of NHS money'. Responses to three scenarios revealed similar opinions, but on some issues, there were key differences in the responses from the two groups. Community forum members were more likely to consider writing a letter as a means of getting something done about a problem and were more likely to talk to their GP if experiencing a problem than respondents in the main group. In general their responses were more positive towards the NHS. There is a need to ensure a broad basis for membership of public forums and/or proactively seek the views of groups that are under-represented if public forums are to be used to represent the views of the wider population and inform decision making in the NHS.

An investigation of the representativity of neuropsychiatrists and their patients in a drug utilization observation study on fluoxetine.

PubMed

Schaaf, B; Linden, M; Weber, H J

1997-01-01

This study presents a methodological approach to an expost facto investigation of sample bias in drug utilization observation (DUO) studies using the example of a DUO with the nontricyclic antidepressant fluoxetine. A total of 479 psychiatrists and neurologists and 2,401 patients were investigated. The purpose of the study was to judge the representativeness of our DUO sample for two populations: first, for all psychiatrics and neurologists prescribing fluoxetine or all patients being treated with fluoxetine in Germany and, second, for all psychiatrists and neurologists prescribing antidepressants or all patients being treated with antidepressants in Germany. Criteria for the representativeness test were physician variables (gender, size of community where practicing, federal state, age, volume of prescriptions) and patient variables (gender, age, prescription-related diagnosis, concurrent illnesses, concomitant medications). The study shows that the DUO sample can rightfully claim representativeness in the majority of parameters for the psychiatrists and neurologists prescribing fluoxetine and for the patients being treated with fluoxetine. There are more noticeable discrepancies with regard to the psychiatrists and neurologists in general and to the patients being treated with antidepressants in general. The methodological problems of pharmacoepidemiological investigation of representativeness are discussed.

Population Genomics of Sub-Saharan Drosophila melanogaster: African Diversity and Non-African Admixture

PubMed Central

Pool, John E.; Corbett-Detig, Russell B.; Sugino, Ryuichi P.; Stevens, Kristian A.; Cardeno, Charis M.; Crepeau, Marc W.; Duchen, Pablo; Emerson, J. J.; Saelao, Perot; Begun, David J.; Langley, Charles H.

2012-01-01

Drosophila melanogaster has played a pivotal role in the development of modern population genetics. However, many basic questions regarding the demographic and adaptive history of this species remain unresolved. We report the genome sequencing of 139 wild-derived strains of D. melanogaster, representing 22 population samples from the sub-Saharan ancestral range of this species, along with one European population. Most genomes were sequenced above 25X depth from haploid embryos. Results indicated a pervasive influence of non-African admixture in many African populations, motivating the development and application of a novel admixture detection method. Admixture proportions varied among populations, with greater admixture in urban locations. Admixture levels also varied across the genome, with localized peaks and valleys suggestive of a non-neutral introgression process. Genomes from the same location differed starkly in ancestry, suggesting that isolation mechanisms may exist within African populations. After removing putatively admixed genomic segments, the greatest genetic diversity was observed in southern Africa (e.g. Zambia), while diversity in other populations was largely consistent with a geographic expansion from this potentially ancestral region. The European population showed different levels of diversity reduction on each chromosome arm, and some African populations displayed chromosome arm-specific diversity reductions. Inversions in the European sample were associated with strong elevations in diversity across chromosome arms. Genomic scans were conducted to identify loci that may represent targets of positive selection within an African population, between African populations, and between European and African populations. A disproportionate number of candidate selective sweep regions were located near genes with varied roles in gene regulation. Outliers for Europe-Africa FST were found to be enriched in genomic regions of locally elevated cosmopolitan admixture, possibly reflecting a role for some of these loci in driving the introgression of non-African alleles into African populations. PMID:23284287

The Use of Carcasses for the Analysis of Cetacean Population Genetic Structure: A Comparative Study in Two Dolphin Species

PubMed Central

Bilgmann, Kerstin; Möller, Luciana M.; Harcourt, Robert G.; Kemper, Catherine M.; Beheregaray, Luciano B.

2011-01-01

Advances in molecular techniques have enabled the study of genetic diversity and population structure in many different contexts. Studies that assess the genetic structure of cetacean populations often use biopsy samples from free-ranging individuals and tissue samples from stranded animals or individuals that became entangled in fishery or aquaculture equipment. This leads to the question of how representative the location of a stranded or entangled animal is with respect to its natural range, and whether similar results would be obtained when comparing carcass samples with samples from free-ranging individuals in studies of population structure. Here we use tissue samples from carcasses of dolphins that stranded or died as a result of bycatch in South Australia to investigate spatial population structure in two species: coastal bottlenose (Tursiops sp.) and short-beaked common dolphins (Delphinus delphis). We compare these results with those previously obtained from biopsy sampled free-ranging dolphins in the same area to test whether carcass samples yield similar patterns of genetic variability and population structure. Data from dolphin carcasses were gathered using seven microsatellite markers and a fragment of the mitochondrial DNA control region. Analyses based on carcass samples alone failed to detect genetic structure in Tursiops sp., a species previously shown to exhibit restricted dispersal and moderate genetic differentiation across a small spatial scale in this region. However, genetic structure was correctly inferred in D. delphis, a species previously shown to have reduced genetic structure over a similar geographic area. We propose that in the absence of corroborating data, and when population structure is assessed over relatively small spatial scales, the sole use of carcasses may lead to an underestimate of genetic differentiation. This can lead to a failure in identifying management units for conservation. Therefore, this risk should be carefully assessed when planning population genetic studies of cetaceans. PMID:21655285

A comparison of four sampling methods among men having sex with men in China: implications for HIV/STD surveillance and prevention

PubMed Central

Guo, Yan; Li, Xiaoming; Fang, Xiaoyi; Lin, Xiuyun; Song, Yan; Jiang, Shuling; Stanton, Bonita

2011-01-01

Sample representativeness remains one of the challenges in effective HIV/STD surveillance and prevention targeting MSM worldwide. Although convenience samples are widely used in studies of MSM, previous studies suggested that these samples might not be representative of the broader MSM population. This issue becomes even more critical in many developing countries where needed resources for conducting probability sampling are limited. We examined variations in HIV and Syphilis infections and sociodemographic and behavioral factors among 307 young migrant MSM recruited using four different convenience sampling methods (peer outreach, informal social network, Internet, and venue-based) in Beijing, China in 2009. The participants completed a self-administered survey and provided blood specimens for HIV/STD testing. Among the four MSM samples using different recruitment methods, rates of HIV infections were 5.1%, 5.8%, 7.8%, and 3.4%; rates of Syphilis infection were 21.8%, 36.2%, 11.8%, and 13.8%; rates of inconsistent condom use were 57%, 52%, 58%, and 38%. Significant differences were found in various sociodemographic characteristics (e.g., age, migration history, education, income, places of employment) and risk behaviors (e.g., age at first sex, number of sex partners, involvement in commercial sex, and substance use) among samples recruited by different sampling methods. The results confirmed the challenges of obtaining representative MSM samples and underscored the importance of using multiple sampling methods to reach MSM from diverse backgrounds and in different social segments and to improve the representativeness of the MSM samples when the use of probability sampling approach is not feasible. PMID:21711162

A comparison of four sampling methods among men having sex with men in China: implications for HIV/STD surveillance and prevention.

PubMed

Guo, Yan; Li, Xiaoming; Fang, Xiaoyi; Lin, Xiuyun; Song, Yan; Jiang, Shuling; Stanton, Bonita

2011-11-01

Sample representativeness remains one of the challenges in effective HIV/STD surveillance and prevention targeting men who have sex with men (MSM) worldwide. Although convenience samples are widely used in studies of MSM, previous studies suggested that these samples might not be representative of the broader MSM population. This issue becomes even more critical in many developing countries where needed resources for conducting probability sampling are limited. We examined variations in HIV and Syphilis infections and sociodemographic and behavioral factors among 307 young migrant MSM recruited using four different convenience sampling methods (peer outreach, informal social network, Internet, and venue-based) in Beijing, China in 2009. The participants completed a self-administered survey and provided blood specimens for HIV/STD testing. Among the four MSM samples using different recruitment methods, rates of HIV infections were 5.1%, 5.8%, 7.8%, and 3.4%; rates of Syphilis infection were 21.8%, 36.2%, 11.8%, and 13.8%; and rates of inconsistent condom use were 57%, 52%, 58%, and 38%. Significant differences were found in various sociodemographic characteristics (e.g., age, migration history, education, income, and places of employment) and risk behaviors (e.g., age at first sex, number of sex partners, involvement in commercial sex, and substance use) among samples recruited by different sampling methods. The results confirmed the challenges of obtaining representative MSM samples and underscored the importance of using multiple sampling methods to reach MSM from diverse backgrounds and in different social segments and to improve the representativeness of the MSM samples when the use of probability sampling approach is not feasible.

Violence reported by the immigrant population is high as compared with the native population in southeast Spain.

PubMed

Colorado-Yohar, S; Tormo, M J; Salmerón, D; Dios, S; Ballesta, M; Navarro, C

2012-11-01

Immigrants constitute a population vulnerable to the problem of violence. This study sought to ascertain the prevalence of violence reported by the immigrant population in the Murcian Region of Spain and characterize the related factors, taking the country population as reference. A cross-sectional study was carried out based on a representative population sample of Latin American (n = 672; 48% women), Moroccan (n = 361; 25% women), and Spanish origin (n = 1,303; 66% women), aged 16 to 64 years. Using a specific questionnaire, the prevalence of violence in the preceding year was assessed. The results were compared with the Spaniards using the 2006 National Health Survey (NHS). Multivariate logistic regression models were used to study the factors associated with violence having been reported in each group, both separately and in immigrants versus Spaniards. Finally, the cause and place of last aggression were studied. The prevalence of violence was 6.5% in Latin Americans, 12.0% in Moroccans, and 2.7% in Spaniards. Discrimination was the principal violence-related factor in all three groups. Among Latin Americans, low educational level was also associated with violence. Among Moroccans, those who had perceived discrimination showed the greatest differences in prevalence of violence compared with natives. Intimate partner violence (IPV) registered a prevalence of below 2%. As a conclusion, in this study, violence was little reported and higher among immigrants. The principal violence-related factor was discrimination. More studies of this type are called for to characterize the problem in other population-representative samples.

Population Genetic Structure of the People of Qatar

PubMed Central

Hunter-Zinck, Haley; Musharoff, Shaila; Salit, Jacqueline; Al-Ali, Khalid A.; Chouchane, Lotfi; Gohar, Abeer; Matthews, Rebecca; Butler, Marcus W.; Fuller, Jennifer; Hackett, Neil R.; Crystal, Ronald G.; Clark, Andrew G.

2010-01-01

People of the Qatar peninsula represent a relatively recent founding by a small number of families from three tribes of the Arabian Peninsula, Persia, and Oman, with indications of African admixture. To assess the roles of both this founding effect and the customary first-cousin marriages among the ancestral Islamic populations in Qatar's population genetic structure, we obtained and genotyped with Affymetrix 500k SNP arrays DNA samples from 168 self-reported Qatari nationals sampled from Doha, Qatar. Principal components analysis was performed along with samples from the Human Genetic Diversity Project data set, revealing three clear clusters of genotypes whose proximity to other human population samples is consistent with Arabian origin, a more eastern or Persian origin, and individuals with African admixture. The extent of linkage disequilibrium (LD) is greater than that of African populations, and runs of homozygosity in some individuals reflect substantial consanguinity. However, the variance in runs of homozygosity is exceptionally high, and the degree of identity-by-descent sharing generally appears to be lower than expected for a population in which nearly half of marriages are between first cousins. Despite the fact that the SNPs of the Affymetrix 500k chip were ascertained with a bias toward SNPs common in Europeans, the data strongly support the notion that the Qatari population could provide a valuable resource for the mapping of genes associated with complex disorders and that tests of pairwise interactions are particularly empowered by populations with elevated LD like the Qatari. PMID:20579625

Phylogeography of a vanishing North American songbird: The Painted Bunting (Passerina ciris)

USGS Publications Warehouse

Herr, C.A.; Sykes, P.W.; Klicka, J.

2011-01-01

The breeding distribution of Painted Buntings (Passerina ciris) is comprised of two allopatric populations separated by a 550-km distributional gap in the southeastern United States. Curiously, the boundary between the two recognized P. ciris subspecies does not separate the two allopatric breeding populations but instead runs roughly through the center of the interior population. Genetic relationships among these subspecies, and the allopatric breeding populations of Painted Bunting, have not been assessed. Given the recent decline in overall abundance of this species, such an assessment is warranted. We sampled birds from 15 localities (138 individuals) and identified 35 distinct haplotypes, six belonging to the Atlantic Coast population and 26 to the interior population, with three shared by both populations. AMOVA results showed that a significantly greater portion of the total genetic variance is explained when grouping birds by the interior and Atlantic Coast populations rather than by subspecies. Furthermore, our data indicate that the Atlantic Coast and interior populations represent independently evolving taxa, with no measureable gene flow between them. Although recently diverged (26,000-115,000 years ago), these isolated bunting populations represent incipient species. For development of conservation strategies, we suggest that the Atlantic Coast and interior populations be recognized as separate management units. ?? 2011 Springer Science+Business Media B.V.

Genetic Population Structure of Local Populations of the Endangered Saltmarsh Sesarmid Crab Clistocoeloma sinense in Japan

PubMed Central

Yuhara, Takeshi; Kawane, Masako; Furota, Toshio

2014-01-01

During recent decades, over 40% of Japanese estuarine tidal flats have been lost due to coastal developments. Local populations of the saltmarsh sesarmid crab Clistocoeloma sinense, designated as an endangered species due to the limited suitable saltmarsh habitat available, have decreased accordingly, being now represented as small remnant populations. Several such populations in Tokyo Bay, have been recognised as representing distributional limits of the species. To clarify the genetic diversity and connectivity among local coastal populations of Japanese Clistocoeloma sinense, including those in Tokyo Bay, mitochondrial DNA analyses were conducted in the hope of providing fundamental information for future conservation studies and an understanding of metapopulation dynamics through larval dispersal among local populations. All of the populations sampled indicated low levels of genetic diversity, which may have resulted from recent population bottlenecks or founder events. However, the results also revealed clear genetic differentiation between two enclosed-water populations in Tokyo Bay and Ise-Mikawa Bay, suggesting the existence of a barrier to larval transport between these two water bodies. Since the maintenance of genetic connectivity is a requirement of local population stability, the preservation of extant habitats and restoration of saltmarshes along the coast of Japan may be the most effective measures for conservation of this endangered species. PMID:24400112

PRELIMINARY REPORT ON NATIONWIDE STUDY OF DRINKING WATER AND CARDIOVASCULAR DISEASES

EPA Science Inventory

This study was designed to further investigate the association(s) of cardiovascular diseases and drinking water constituents. A sample of 4200 adults were randomly selected from 35 geographic areas to represent the civilian noninstitutionalized population of the contiguous United...

Validity of the EQ-5D-5L and reference norms for the Spanish population.

PubMed

Hernandez, Gimena; Garin, Olatz; Pardo, Yolanda; Vilagut, Gemma; Pont, Àngels; Suárez, Mónica; Neira, Montse; Rajmil, Luís; Gorostiza, Inigo; Ramallo-Fariña, Yolanda; Cabases, Juan; Alonso, Jordi; Ferrer, Montse

2018-05-16

The EuroQol 5 dimensions 5 levels (EQ-5D-5L) is the new version of EQ-5D, developed to improve its discriminatory capacity. This study aims to evaluate the construct validity of the Spanish version and provide index and dimension population-based reference norms for the new EQ-5D-5L. Data were obtained from the 2011/2012 Spanish National Health Survey, with a representative sample (n = 20,587) of non-institutionalized Spanish adults (≥ 18 years). The EQ-5D-5L index was calculated by using the Spanish value set. Construct validity was evaluated by comparing known groups with estimators obtained through regression models, adjusted by age and gender. Sampling weights were applied to restore the representativeness of the sample and to calculate the norms stratified by gender and age groups. We calculated the percentages and standard errors of dimensions, and the deciles, percentiles 5 and 95, means, and 95% confidence intervals of the health index. All the hypotheses established a priori for known groups were confirmed (P < 0.001). The EQ-5D-5L index indicated worse health in groups with lower education level (from 0.94 to 0.87), higher number of chronic conditions (0.96-0.79), probable psychiatric disorder (0.94 vs 0.80), strong limitations (0.96-0.46), higher number of days of restriction (0.93-0.64) or confinement to bed (0.92-0.49), and hospitalized in the previous 12 months (0.92 vs 0.81). The EQ-5D-5L is a valid instrument to measure perceived health in the Spanish-speaking population. The representative population-based norms provided here will help improve the interpretation of results obtained with the new EQ-5D-5L.

A Seroprevalence Study of Hepatitis B and C Virus Infections in a Hospitalized Population in Romania, an Opportunity for a Better National Prevention and Control Strategy.

PubMed

Popovici, Odette; Molnar, Geza B; Popovici, Florin; Janţă, Denisa; Pistol, Adriana; Azoicăi, Doina

2016-03-01

The most recent prevalence data for hepatitis B virus (HBV) infection in Romania came from an ESEN 2 study (2002), and from a Romanian population-based study performed in 2008. Most of the previous studies were regional and performed in specific groups (blood donors, pregnant women, institutionalized people, etc) and had limited representativeness at the national level, both for HBV and hepatitis C virus (HCV) infection. The scarcity of prevalence data for HBV and HCV infection coming from the routine surveillance was also considered. The aim of our study was to obtain overall and age group specific estimates of the prevalence of HBV and HCV infections markers in Romania, in order to recommend evidence-based public health interventions. The main outcome was the proportion of persons with HBV, HCV and HBV+HCV infection markers, overall and by age group and gender. Our seroprevalence study ensured national representativeness for the targeted hospitalized population. A prospective collection of serum samples in hospital laboratories was completed between September and November 2013, using a systematic sampling. The study respected the confidentiality of personal data. We calculated the sample size using EpiInfo7 and used Z test - Two-tailed probability for statistical significance. The overall prevalence data estimated in our study were HBc Ab 28%, HBs Ag 4.2%, HBs Ab regardless of titer 64.1%, HBs Ab in titer of at least 10 mUI/ml and negative HBc Ab 17.5%; HCV Ab 5.6%; HBc Ab and HCV Ab 2.8%, as markers of double infection. The overall prevalence data estimated in our study for HBs Ag (4.2%) and HCV Ab (5.6%) correspond to a medium endemicity based on the WHO criteria. The estimated prevalence of HBV and HCV infection markers in the study population should represent an opportunity for a better national prevention and control strategy.

The Alcohol Use Disorders Identification Test (AUDIT): Exploring the Factor Structure and Cutoff Thresholds in a Representative Post-Conflict Population in Northern Uganda.

PubMed

Blair, Alden Hooper; Pearce, Margo Ellen; Katamba, Achilles; Malamba, Samuel S; Muyinda, Herbert; Schechter, Martin T; Spittal, Patricia M

2017-05-01

Despite increased use of the Alcohol Use Disorders Identification Test (AUDIT) in sub-Saharan Africa, few studies have assessed its underlying conceptual framework, and none have done so in post-conflict settings. Further, significant inconsistencies exist between definitions used for problematic consumption. Such is the case in Uganda, facing one of the highest per-capita alcohol consumption levels regionally, which is thought to be hindering rebuilding in the North after two decades of civil war. This study explores the impact of varying designation cutoff thresholds in the AUDIT as well as its conceptual factor structure in a representative sample of the population. In all, 1720 Cango Lyec Project participants completed socio-economic and mental health questionnaires, provided blood samples and took the AUDIT. Participant characteristics and consumption designations were compared at AUDIT summary score thresholds of ≥3, ≥5 and ≥8. Confirmatory factor analyses (CFA) explored one-, two- and three-factor level models overall and by sex with relative and absolute fit indicators. There were no significant differences in participant demographic characteristics between thresholds. At higher cutoffs, the test increased in specificity to identify those with hazardous drinking, disordered drinking and suffering from alcohol-related harms. All conceptual models indicated good fit, with three-factor models superior overall and within both sexes. In Northern Uganda, a three-factor AUDIT model best explores alcohol use in the population and is appropriate for use in both sexes. Lower cutoff thresholds are recommended to identify those with potentially disordered drinking to best plan effective interventions and treatments. A CFA of the AUDIT showed good fit for one-, two, and three-factor models overall and by sex in a representative sample in post-conflict Northern Uganda. A three-plus total AUDIT cutoff score is suggested to screen for hazardous drinking in this or similar populations. © The Author 2016. Medical Council on Alcohol and Oxford University Press. All rights reserved.

Organochlorinated pesticides levels in a representative sample of the Spanish adult population: The Bioambient.es project.

PubMed

Ramos, Juan José; Huetos, Olga; González, Sara; Esteban, Marta; Calvo, Eva; Pérez-Gómez, Beatriz; Castaño, Argelia

2017-03-01

Organochlorinated pesticides (OCPs) were measured in a representative sample of Spanish adults within the Bioambient.es project, a nationwide human biomonitoring program promoted by Spanish Ministry of Agriculture, Food and Environment. The objective of Bioambient.es is to establish reference levels of environmental pollutants in the general population. Participants were recruited in 2009-2010 during their annual medical examination at work. Serum levels of thirteen OCPs were investigated: Aldrin, endrin, dieldrin, heptachlor, heptachlor-epoxide, dichlorodiphenyldichloroethylenes (DDEs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) The highest concentrations were observed for DDE, HCB and β-HCH. The 95th percentile, in ng/g lipids, were: 717.7 for 4,4-DDE, 160.4 for HCB and 107.2 for β-HCH, while concentrations of aldrin, endrin, heptachlor, α-HCH, 2,4-DDT, 4,4-DDT and 2,4-DDE were markedly lower and detected in less than 10% of the samples. Significant differences (p<0.05) were found for DDE and HCB and seasonality, gender and age. Analyzing the geographical distribution, participants from the north of Spain had highest levels of HCB while those from the center of Spain had highest levels of 4,4-DDE. Comparing to earlier studies, the results indicated a sharp decline in the OCP concentrations in the Spanish population over time, and today values are in the same range or lower than those reported in similar studies worldwide, except for HCHs and HCB that presented higher levels than in other European countries and much higher than those observed in US and Canada. This study represents the first nationwide survey of exposure to OCPs in Spain and provides a background reference range for exposure to OCPs in the Spanish adult occupied population. These results will allow establishing reference values, observing temporal trends and identifying high exposure groups. Copyright © 2016 Elsevier GmbH. All rights reserved.

Contaminants in fish tissue from US lakes and reservoirs: A ...

EPA Pesticide Factsheets

An unequal probability design was used to develop national estimates for 268 persistent, bioaccumulative, and toxic chemicals in fish tissue from lakes and reservoirs of the conterminous United States (excluding the Laurentian Great Lakes and Great Salt Lake). Predator (fillet) and bottom-dweller (whole-body) composites were collected from 500 lakes selected randomly from the target population of 147,343 lakes in the lower 48 states. Each of these composite types comprised nationally representative samples whose results were extrapolated to the sampled population of an estimated 76,559 lakes for predators and 46,190 lakes for bottom dwellers. Mercury and PCBs were detected in all fish samples. Dioxins and furans were detected in 81% and 99% of predator and bottom-dweller samples, respectively. Cumulative frequency distributions showed that mercury concentrations exceeded the EPA 300 ppb mercury fish tissue criterion at nearly half of the lakes in the sampled population. Total PCB concentrations exceeded a 12 ppb human health risk-based consumption limit at nearly 17% of lakes, and dioxins and furans exceeded a 0.15 ppt (toxic equivalent or TEQ) risk-based threshold at nearly 8% of lakes in the sampled population. In contrast, 43 target chemicals were not detected in any samples. No detections were reported for nine organophosphate pesticides, one PCB congener, 16 polycyclic aromatic hydrocarbons, or 17 other semivolatile organic chemicals. An unequal prob

Contaminants in fish tissue from US lakes and reservoirs: a national probabilistic study.

PubMed

Stahl, Leanne L; Snyder, Blaine D; Olsen, Anthony R; Pitt, Jennifer L

2009-03-01

An unequal probability design was used to develop national estimates for 268 persistent, bioaccumulative, and toxic chemicals in fish tissue from lakes and reservoirs of the conterminous United States (excluding the Laurentian Great Lakes and Great Salt Lake). Predator (fillet) and bottom-dweller (whole body) composites were collected from 500 lakes selected randomly from the target population of 147,343 lakes in the lower 48 states. Each of these composite types comprised nationally representative samples whose results were extrapolated to the sampled population of an estimated 76,559 lakes for predators and 46,190 lakes for bottom dwellers. Mercury and PCBs were detected in all fish samples. Dioxins and furans were detected in 81% and 99% of predator and bottom-dweller samples, respectively. Cumulative frequency distributions showed that mercury concentrations exceeded the EPA 300 ppb mercury fish tissue criterion at nearly half of the lakes in the sampled population. Total PCB concentrations exceeded a 12 ppb human health risk-based consumption limit at nearly 17% of lakes, and dioxins and furans exceeded a 0.15 ppt (toxic equivalent or TEQ) risk-based threshold at nearly 8% of lakes in the sampled population. In contrast, 43 target chemicals were not detected in any samples. No detections were reported for nine organophosphate pesticides, one PCB congener, 16 polycyclic aromatic hydrocarbons, or 17 other semivolatile organic chemicals.

How Representative Are Research Tissue Biobanks of the Local Populations? Experience of the Infectious Diseases Biobank at King's College, London, UK.

PubMed

Kozlakidis, Zisis; Mant, Christine; Peters, Barry; Post, Frank; Fox, Julie; Philpott-Howard, John; Tong, William C-Y; Edgeworth, Jonathan; Peakman, Mark; Malim, Michael; Cason, John

2011-09-01

Biobanks have a primary responsibility to collect tissues that are a true reflection of their local population and thereby promote translational research, which is applicable to the community. The Infectious Diseases BioBank (IDB) at King's College London is located in the southeast of the city, an area that is ethnically diverse. Transplantation programs have frequently reported a low rate of donation among some ethnic minorities. To determine whether patients who volunteered peripheral venous blood samples to the IDB were representative of the local community, we compared local government demographic data to characteristics of patients who have donated to the IDB. There was a good match between these statistics, indicating that the IDB's volunteer population of human immunodeficiency virus patients was similar to local demographics.

How Representative Are Research Tissue Biobanks of the Local Populations? Experience of the Infectious Diseases Biobank at King's College, London, UK

PubMed Central

Kozlakidis, Zisis; Mant, Christine; Peters, Barry; Post, Frank; Fox, Julie; Philpott-Howard, John; Tong, William C.-Y.; Edgeworth, Jonathan; Peakman, Mark; Malim, Michael

2011-01-01

Biobanks have a primary responsibility to collect tissues that are a true reflection of their local population and thereby promote translational research, which is applicable to the community. The Infectious Diseases BioBank (IDB) at King's College London is located in the southeast of the city, an area that is ethnically diverse. Transplantation programs have frequently reported a low rate of donation among some ethnic minorities. To determine whether patients who volunteered peripheral venous blood samples to the IDB were representative of the local community, we compared local government demographic data to characteristics of patients who have donated to the IDB. There was a good match between these statistics, indicating that the IDB's volunteer population of human immunodeficiency virus patients was similar to local demographics. PMID:21977243

Geospatial techniques for developing a sampling frame of watersheds across a region

USGS Publications Warehouse

Gresswell, Robert E.; Bateman, Douglas S.; Lienkaemper, George; Guy, T.J.

2004-01-01

Current land-management decisions that affect the persistence of native salmonids are often influenced by studies of individual sites that are selected based on judgment and convenience. Although this approach is useful for some purposes, extrapolating results to areas that were not sampled is statistically inappropriate because the sampling design is usually biased. Therefore, in recent investigations of coastal cutthroat trout (Oncorhynchus clarki clarki) located above natural barriers to anadromous salmonids, we used a methodology for extending the statistical scope of inference. The purpose of this paper is to apply geospatial tools to identify a population of watersheds and develop a probability-based sampling design for coastal cutthroat trout in western Oregon, USA. The population of mid-size watersheds (500-5800 ha) west of the Cascade Range divide was derived from watershed delineations based on digital elevation models. Because a database with locations of isolated populations of coastal cutthroat trout did not exist, a sampling frame of isolated watersheds containing cutthroat trout had to be developed. After the sampling frame of watersheds was established, isolated watersheds with coastal cutthroat trout were stratified by ecoregion and erosion potential based on dominant bedrock lithology (i.e., sedimentary and igneous). A stratified random sample of 60 watersheds was selected with proportional allocation in each stratum. By comparing watershed drainage areas of streams in the general population to those in the sampling frame and the resulting sample (n = 60), we were able to evaluate the how representative the subset of watersheds was in relation to the population of watersheds. Geospatial tools provided a relatively inexpensive means to generate the information necessary to develop a statistically robust, probability-based sampling design.

Pediatric sample inclusion in an opt-out biorepository linking DNA to de-identified medical records: Pediatric BioVU

PubMed Central

McGregor, Tracy L.; Van Driest, Sara L.; Brothers, Kyle B.; Bowton, Erica A.; Muglia, Louis J.; Roden, Dan M.

2013-01-01

The Vanderbilt DNA repository, BioVU, links DNA from leftover clinical blood samples to de-identified electronic medical records. After initiating adult sample collection, pediatric extension required consideration of ethical concerns specific to pediatrics and implementation of specialized DNA extraction methods. In the first year of pediatric sample collection, over 11,000 samples were included from individuals younger than 18 years. We compared the pediatric BioVU cohort to the overall Vanderbilt University Medical Center pediatric population and found similar demographic characteristics; however, the BioVU cohort has higher rates of select diseases, medication exposures, and laboratory testing, demonstrating enriched representation of severe or chronic disease. This unbalanced sample accumulation may accelerate research of some cohorts, but also may limit study of relatively benign conditions and the accrual of unaffected and unbiased control samples. BioVU represents a feasible model for pediatric DNA biobanking but involves both ethical and practical considerations specific to the pediatric population. PMID:23281421

Normative values of cognitive and physical function in older adults: findings from the Irish Longitudinal Study on Ageing.

PubMed

Kenny, Rose Anne; Coen, Robert F; Frewen, John; Donoghue, Orna A; Cronin, Hilary; Savva, George M

2013-05-01

To provide normative values of tests of cognitive and physical function based on a large sample representative of the population of Ireland aged 50 and older. Data were used from the first wave of The Irish Longitudinal Study on Ageing (TILDA), a prospective cohort study that includes a comprehensive health assessment. Health assessment was undertaken at one of two dedicated health assessment centers or in the study participant's home if travel was not practicable. Five thousand eight hundred ninety-seven members of a nationally representative sample of the community-living population of Ireland aged 50 and older. Those with severe cognitive impairment, dementia, or Parkinson's disease were excluded. Measurements included height and weight, normal walking speed, Timed Up-and-Go, handgrip strength, Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Color Trails Test, and bone mineral density. Normative values were estimated using generalized additive models for location shape and scale (GAMLSS) and are presented as percentiles, means, and standard deviations. Generalized additive models for location shape and scale fit the observed data well for each measure, leading to reliable estimates of normative values. Performance on all tasks decreased with age. Educational attainment was a strong determinant of performance on all cognitive tests. Tests of walking speed were dependent on height. Distribution of body mass index did not change with age, owing to simultaneous declines in weight and height. Normative values were found for tests of many aspects of cognitive and physical function based on a representative sample of the general older Irish population. © 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society.

Sampling Methods in Cardiovascular Nursing Research: An Overview.

PubMed

Kandola, Damanpreet; Banner, Davina; O'Keefe-McCarthy, Sheila; Jassal, Debbie

2014-01-01

Cardiovascular nursing research covers a wide array of topics from health services to psychosocial patient experiences. The selection of specific participant samples is an important part of the research design and process. The sampling strategy employed is of utmost importance to ensure that a representative sample of participants is chosen. There are two main categories of sampling methods: probability and non-probability. Probability sampling is the random selection of elements from the population, where each element of the population has an equal and independent chance of being included in the sample. There are five main types of probability sampling including simple random sampling, systematic sampling, stratified sampling, cluster sampling, and multi-stage sampling. Non-probability sampling methods are those in which elements are chosen through non-random methods for inclusion into the research study and include convenience sampling, purposive sampling, and snowball sampling. Each approach offers distinct advantages and disadvantages and must be considered critically. In this research column, we provide an introduction to these key sampling techniques and draw on examples from the cardiovascular research. Understanding the differences in sampling techniques may aid nurses in effective appraisal of research literature and provide a reference pointfor nurses who engage in cardiovascular research.

Associations between behavioural risk factors and overweight and obesity among adults in population-based samples from 31 countries.

PubMed

Pengpid, Supa; Peltzer, Karl

Concern about overweight and obesity is growing worldwide, and more research to examine behaviours associated with the risk for increased weight in adult populations is needed. The aim of this study was to estimate associations between behavioural risk factors and overweight and obesity among adults in nationally representative population samples from 20 countries in Europe, 8 countries in Asia, Australia, Chile and USA. This secondary analysis is based on the International Social Survey Program (ISSP), 2011-2013, Health and Health Care Module. In a cross-sectional population-based survey (N=48,741) (mean age 46.6 years, SD=17.4, age range 15-102 years) simple or multi-stage stratified random sampling was used, yielding representative samples of the adult population of respective countries. Body Mass Index was assessed by self-reported height and weight. Correlates were risk behaviours for chronic disease (smoking status, alcohol intake, consumption of fruits and vegetable (=FV), and physical activity). Overall, for all 31 countries the prevalence of overweight or obesity was 44.1%, 31.7% overweight and 12.4% obese. In adjusted logistic regression models, among men and among women ex-smoking was positively associated with both overweight and obesity, while light or moderate smoking overall and among men were inversely related with obesity. Moderate alcohol use was positively associated with both overweight and obesity, while heavy alcohol use was negatively associated with overweight. The daily consumption of FV was found to be protective from both overweight and obesity, overall and for men but not for women. Physical activity was positively associated with overweight but not obesity. Some risk behaviours for chronic disease appear to be associated with overweight and obesity among adults. Interventions targeting these risk behaviours may have the potential to reduce weight. Copyright © 2016 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

EurEAs_Gplex--A new SNaPshot assay for continental population discrimination and gender identification.

PubMed

Daca-Roszak, P; Pfeifer, A; Żebracka-Gala, J; Jarząb, B; Witt, M; Ziętkiewicz, E

2016-01-01

Assays that allow analysis of the biogeographic origin of biological samples in a standard forensic laboratory have to target a small number of highly differentiating markers. Such markers should be easy to multiplex and the assay must perform well in the degraded and scarce biological material. SNPs localized in the genome regions, which in the past were subjected to differential selective pressure in various populations, are the most widely used markers in the studies of biogeographic affiliation. SNPs reflecting biogeographic differences not related to any phenotypic traits are not sufficiently explored. The goal of our study was to identify a small set of SNPs not related to any known pigmentation/phenotype-specific genes, which would allow efficient discrimination between populations of Europe and East Asia. The selection of SNPs was based on the comparative analysis of representative European and Chinese/Japanese samples (B-lymphocyte cell lines), genotyped using the Infinium HumanOmniExpressExome microarray (Illumina). The classifier, consisting of 24 unlinked SNPs (24-SNP classifier), was selected. The performance of a 14-SNP subset of this classifier (14-SNP subclassifier) was tested using genotype data from several populations. The 14-SNP subclassifier differentiated East Asians, Europeans and Africans with ∼100% accuracy; Palestinians, representative of the Middle East, clustered with Europeans, while Amerindians and Pakistani were placed between East Asian and European populations. Based on these results, we have developed a SNaPshot assay (EurEAs_Gplex) for genotyping SNPs from the 14-SNP subclassifier, combined with an additional marker for gender identification. Forensic utility of the EurEAs_Gplex was verified using degraded and low quantity DNA samples. The performance of the EurEAs_Gplex was satisfactory when using degraded DNA; tests using low quantity DNA samples revealed a previously not described source of genotyping errors, potentially important for any SNaPshot-based assays. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Surface degassing and modifications to vesicle size distributions in active basalt flows

USGS Publications Warehouse

Cashman, K.V.; Mangan, M.T.; Newman, S.

1994-01-01

The character of the vesicle population in lava flows includes several measurable parameters that may provide important constraints on lava flow dynamics and rheology. Interpretation of vesicle size distributions (VSDs), however, requires an understanding of vesiculation processes in feeder conduits, and of post-eruption modifications to VSDs during transport and emplacement. To this end we collected samples from active basalt flows at Kilauea Volcano: (1) near the effusive Kupaianaha vent; (2) through skylights in the approximately isothermal Wahaula and Kamoamoa tube systems transporting lava to the coast; (3) from surface breakouts at different locations along the lava tubes; and (4) from different locations in a single breakout from a lava tube 1 km from the 51 vent at Pu'u 'O'o. Near-vent samples are characterized by VSDs that show exponentially decreasing numbers of vesicles with increasing vesicle size. These size distributions suggest that nucleation and growth of bubbles were continuous during ascent in the conduit, with minor associated bubble coalescence resulting from differential bubble rise. The entire vesicle population can be attributed to shallow exsolution of H2O-dominated gases at rates consistent with those predicted by simple diffusion models. Measurements of H2O, CO2 and S in the matrix glass show that the melt equilibrated rapidly at atmospheric pressure. Down-tube samples maintain similar VSD forms but show a progressive decrease in both overall vesicularity and mean vesicle size. We attribute this change to open system, "passive" rise and escape of larger bubbles to the surface. Such gas loss from the tube system results in the output of 1.2 ?? 106 g/day SO2, an output representing an addition of approximately 1% to overall volatile budget calculations. A steady increase in bubble number density with downstream distance is best explained by continued bubble nucleation at rates of 7-8/cm3s. Rates are ???25% of those estimated from the vent samples, and thus represent volatile supersaturations considerably less than those of the conduit. We note also that the small total volume represented by this new bubble population does not: (1) measurably deplete the melt in volatiles; or (2) make up for the overall vesicularity decrease resulting from the loss of larger bubbles. Surface breakout samples have distinctive VSDs characterized by an extreme depletion in the small vesicle population. This results in samples with much lower number densities and larger mean vesicle sizes than corresponding tube samples. Similar VSD patterns have been observed in solidified lava flows and are interpreted to result from either static (wall rupture) or dynamic (bubble rise and capture) coalescence. Through comparison with vent and tube vesicle populations, we suggest that, in addition to coalescence, the observed vesicle populations in the breakout samples have experienced a rapid loss of small vesicles consistent with 'ripening' of the VSD resulting from interbubble diffusion of volatiles. Confinement of ripening features to surface flows suggests that the thin skin that forms on surface breakouts may play a role in the observed VSD modification. ?? 1994.

The prevalence of crash risk factors in a population-based study of motorcycle riders.

PubMed

de Rome, Liz; Fitzharris, Michael; Baldock, Matthew; Fernandes, Ralston; Ma, Alice; Brown, Julie

2016-09-01

Motorcyclists represent an increasing proportion of road traffic casualties but, while factors associated with crashes are readily identifiable, little is known about the prevalence of those risk factors in the motorcycling population. A stratified random-sampling frame was used to survey the population of registered motorcycles owners in New South Wales (NSW) when they attended motor registry offices. The postal codes in the State database of registered motorcycle were used to stratify the population into quartiles based on socioeconomic characteristics and to determine sample weights. Participants (n=506) represented 47% of eligible riders approached. On average participants were aged 43, rode 7h/week and had 17 years of riding experience. Estimates based on multiple ownership rates suggest motorcycle registration numbers exceed the active riding population by approximately 15%. Less than half rode under 101km/week, 25% rode over 300km/week and just 42% rode every day. More rode frequently for leisure (70%) than for commuting (53%) and over half rarely rode in dark (52%) or wet (67%) conditions. Most wore protective clothing - helmets (100%), jackets (82%), pants (56%), boots (57%) and gloves (73%). Those with traffic infringements (32%) were mostly for driving (25%), not riding (10%) offences. In the past year, 13% had one or more motorcycle crashes including minor spills and 76% one or more near-crash experiences. The youngest riders (15-19) reported the highest rates of exposure in kilometres, hours, frequency of riding and commuting. They also reported lower crash involvement (3%) but more near-crashes (80%). This study provides an account of the prevalence of key risk factors across age groups in a population of active motorcycle riders in NSW. Novice riders were represented in all age groups although most novices were under 40 years. These data can be used to guide the development of targeted countermeasures aimed at improving motorcycling safety for riders of different age groups. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Living on the edge: reconstructing the genetic history of the Finnish wolf population

PubMed Central

2014-01-01

Background Many western European carnivore populations became almost or completely eradicated during the last ~200 years, but are now recovering. Extirpation of wolves started in Finland in the 19th century, and for more than 150 years the population size of wolves has remained small. To investigate historical patterns of genetic variation, we extracted DNA from 114 wolf samples collected in zoological museums over the last ~150 years. Fifteen microsatellite loci were used to look at genotypic variation in this historical sample. Additionally, we amplified a 430 bp sequence of mtDNA control region from the same samples. Contemporary wolf samples (N = 298) obtained after the population recovery in the mid-1990s, were used as a reference. Results Our analyses of mtDNA revealed reduced variation in the mtDNA control region through the loss of historical haplotypes observed prior to wolf declines. Heterozygosity at autosomal microsatellite loci did not decrease significantly. However, almost 20% of microsatellite alleles were unique to wolves collected before the 1960s. The genetic composition of the population changed gradually with the largest changes occurring prior to 1920. Half of the oldest historical samples formed a distinguishable genetic cluster not detected in the modern-day Finnish or Russian samples, and might therefore represent northern genetic variation lost from today’s gene pool. Point estimates of Ne were small (13.2 and 20.5) suggesting population fragmentation. Evidence of a genetic population bottleneck was also detected. Conclusions Our genetic analyses confirm changes in the genetic composition of the Finnish wolf population through time, despite the geographic interconnectivity to a much larger population in Russia. Our results emphasize the need for restoration of the historical connectivity between the present wolf populations to secure long-term viability. This might be challenging, however, because the management policies between Western and Eastern Europe often differ greatly. Additionally, wolf conservation is still a rather controversial issue, and anthropogenic pressure towards wolves remains strong. PMID:24678616

[Study of access to health care and drugs in Cameroon: 1. Methods and validation].

PubMed

Commeyras, Christophe; Ndo, Jean Rolin; Merabet, Omar; Koné, Hamidou; Rakotondrabé, Faraniaina Patricia

2005-01-01

During the 1980s, an economic depression and the concomitant decrease in the national health budget modified the population's health behavior. Improvement of the economy since the late 1990s makes it possible to renew the national health policy. To prepare the highly indebted and poor countries' program (HIPC), the Minister of Health and its partners commissioned a survey to measure the population's real access to health care and the factors that determine this accessibility and to propose concrete corrective actions. To fulfill these objectives, the steering committee decided to analyze health care demand, through a national population survey, and supply capacity, through a national survey of pharmacies and other drug dispensers. A survey of persons using medications will also be conducted (Fig.1). Focusing on this component of health care is justified by these findings: 95% of persons feeling ill buy drugs, whereas only 31% consult a physician or other healthcare provider, and half of the average household's health expenditures are for drugs. Financial, geographic, social and quality indicators were defined to measure accessibility and its determining factors (Table 1). The smallest administrative unit, the health area (HA), was chosen as the sampling unit, to enable us to survey together healthcare demand, supply and consumption according to different concentrations of supply and demand . It behaves as a cluster of sampling units of different populations: drug retailers of all sectors, drug users, households, and ill persons within the households. The HA samples include Yaounde and Douala, with urban and rural sub-samples, for which sampling ratios increase with the diversity of supply and demand, according to several pre-defined factors. The study includes 400 HAs, covering more than one third of the population (Table 2). Within these HAs, 900 pharmacies and other formal drug retailers, 709 street vendors, 4,505 households, 2,532 ill persons in these households, 4,121 pharmacy customers and 850 customers of street vendors were surveyed, i.e., more than 13,600 questionnaires. Assessment of data quality shows that the sample is representative of the national population for its socioeconomic characteristics. Its geographic distribution, even after correction, nonetheless favors urban areas, where both supply and demand are high. Generalizing the 3 sub-samples to the national level thus requires caution, especially for the geographic distribution. Other limitations and possible biases are described and evaluated. However, the retrospective demographic and statistic evaluation shows that the samples are representative of their population and that the data quality can be considered good. This article describes the background of this study and justifies its methodological choices. Future publications will analyze the data collected.

Detecting the influence of ornamental Berberis thunbergii var. atropurpurea in invasive populations of Berberis thunbergii (Berberidaceae) using AFLP1.

PubMed

Lubell, Jessica D; Brand, Mark H; Lehrer, Jonathan M; Holsinger, Kent E

2008-06-01

Japanese barberry (Berberis thunbergii DC.) is a widespread invasive plant that remains an important landscape shrub represented by ornamental, purple-leaved forms of the botanical variety atropurpurea. These forms differ greatly in appearance from feral plants, bringing into question whether they contribute to invasive populations or whether the invasions represent self-sustaining populations derived from the initial introduction of the species in the late 19th century. In this study we used amplified fragment length polymorphism (AFLP) markers to determine whether genetic contributions from B. t. var. atropurpurea are found within naturalized Japanese barberry populations in southern New England. Bayesian clustering of AFLP genotypes and principal coordinate analysis distinguished B. t. var. atropurpurea genotypes from 85 plants representing five invasive populations. While a single feral plant resembled B. t. var. atropurpurea phenotypically and fell within the same genetic cluster, all other naturalized plants sampled were genetically distinct from the purple-leaved genotypes. Seven plants from two different sites possessed morphology consistent with Berberis vulgaris (common barberry) or B. ×ottawensis (B. thunbergii × B. vulgaris). Genetic analysis placed these plants in two clusters separate from B. thunbergii. Although the Bayesian analysis indicated some introgression of B. t. var. atropurpurea and B. vulgaris, these genotypes have had limited influence on extant feral populations of B. thunbergii.

How Is Emotional Awareness Related to Emotion Regulation Strategies and Self-Reported Negative Affect in the General Population?

PubMed Central

Subic-Wrana, Claudia; Beutel, Manfred E.; Brähler, Elmar; Stöbel-Richter, Yve; Knebel, Achim; Lane, Richard D.; Wiltink, Jörg

2014-01-01

Objective The Levels of Emotional Awareness Scale (LEAS) as a performance task discriminates between implicit or subconscious and explicit or conscious levels of emotional awareness. An impaired awareness of one's feeling states may influence emotion regulation strategies and self-reports of negative emotions. To determine this influence, we applied the LEAS and self-report measures for emotion regulation strategies and negative affect in a representative sample of the German general population. Sample and Methods A short version of the LEAS, the Hospital Anxiety and Depression Scale (HADS) and the Emotion Regulation Questionnaire (ERQ), assessing reappraisal and suppression as emotion regulation strategies, were presented to N = 2524 participants of a representative German community study. The questionnaire data were analyzed with regard to the level of emotional awareness. Results LEAS scores were independent from depression, but related to self-reported anxiety. Although of small or medium effect size, different correlational patters between emotion regulation strategies and negative affectivity were related to implict and explict levels of emotional awareness. In participants with implicit emotional awareness, suppression was related to higher anxiety and depression, whereas in participants with explicit emotional awareness, in addition to a positive relationship of suppression and depression, we found a negative relationship of reappraisal to depression. These findings were independent of age. In women high use of suppression and little use of reappraisal were more strongly related to negative affect than in men. Discussion Our first findings suggest that conscious awareness of emotions may be a precondition for the use of reappraisal as an adaptive emotion regulation strategy. They encourage further research in the relation between subconsious and conscious emotional awareness and the prefarance of adaptive or maladaptive emotion regulation strategies The correlational trends found in a representative sample of the general population may become more pronounced in clinical samples. PMID:24637792

Malaria vector populations across ecological zones in Guinea Conakry and Mali, West Africa.

PubMed

Coulibaly, Boubacar; Kone, Raymond; Barry, Mamadou S; Emerson, Becky; Coulibaly, Mamadou B; Niare, Oumou; Beavogui, Abdoul H; Traore, Sekou F; Vernick, Kenneth D; Riehle, Michelle M

2016-04-08

Malaria remains a pervasive public health problem in sub-Saharan West Africa. Here mosquito vector populations were explored across four sites in Mali and the Republic of Guinea (Guinea Conakry). The study samples the major ecological zones of malaria-endemic regions in West Africa within a relatively small distance. Mosquito vectors were sampled from larval pools, adult indoor resting sites, and indoor and outdoor human-host seeking adults. Mosquitoes were collected at sites spanning 350 km that represented arid savannah, humid savannah, semi-forest and deep forest ecological zones, in areas where little was previously known about malaria vector populations. 1425 mosquito samples were analysed by molecular assays to determine species, genetic attributes, blood meal sources and Plasmodium infection status. Anopheles gambiae and Anopheles coluzzii were the major anophelines represented in all collections across the ecological zones, with A. coluzzii predominant in the arid savannah and A. gambiae in the more humid sites. The use of multiple collection methodologies across the sampling sites allows assessment of potential collection bias of the different methods. The L1014F kdr insecticide resistance mutation (kdr-w) is found at high frequency across all study sites. This mutation appears to have swept almost to fixation, from low frequencies 6 years earlier, despite the absence of widespread insecticide use for vector control. Rates of human feeding are very high across ecological zones, with only small fractions of animal derived blood meals in the arid and humid savannah. About 30 % of freshly blood-fed mosquitoes were positive for Plasmodium falciparum presence, while the rate of mosquitoes with established infections was an order of magnitude lower. The study represents detailed vector characterization from an understudied area in West Africa with endemic malaria transmission. The deep forest study site includes the epicenter of the 2014 Ebola virus epidemic. With new malaria control interventions planned in Guinea, these data provide a baseline measure and an opportunity to assess the outcome of future interventions.

An Epidemiological Model for Examining Marijuana Use over the Life Course

PubMed Central

Paddock, Susan M.; Kilmer, Beau; Caulkins, Jonathan P.; Booth, Marika J.; Pacula, Rosalie L.

2012-01-01

Trajectories of drug use are usually studied empirically by following over time persons sampled from either the general population (most often youth and young adults) or from heavy or problematic users (e.g., arrestees or those in treatment). The former, population-based samples, describe early career development, but miss the years of use that generate the greatest social costs. The latter, selected populations, help to summarize the most problematic use, but cannot easily explain how people become problem users nor are they representative of the population as a whole. This paper shows how microsimulation can synthesize both sorts of data within a single analytical framework, while retaining heterogeneous influences that can impact drug use decisions over the life course. The RAND Marijuana Microsimulation Model is constructed for marijuana use, validated, and then used to demonstrate how such models can be used to evaluate alternative policy options aimed at reducing use over the life course. PMID:23236590

Harnessing Social Networks along with Consumer-Driven Electronic Communication Technologies to Identify and Engage Members of 'Hard-to-Reach' Populations: A Methodological Case Report

PubMed Central

2010-01-01

Background Sampling in the absence of accurate or comprehensive information routinely poses logistical, ethical, and resource allocation challenges in social science, clinical, epidemiological, health service and population health research. These challenges are compounded if few members of a target population know each other or regularly interact. This paper reports on the sampling methods adopted in ethnographic case study research with a 'hard-to-reach' population. Methods To identify and engage a small yet diverse sample of people who met an unusual set of criteria (i.e., pet owners who had been treating cats or dogs for diabetes), four sampling strategies were used. First, copies of a recruitment letter were posted in pet-friendly places. Second, information about the study was diffused throughout the study period via word of mouth. Third, the lead investigator personally sent the recruitment letter via email to a pet owner, who then circulated the information to others, and so on. Fourth, veterinarians were enlisted to refer people who had diabetic pets. The second, third and fourth strategies rely on social networks and represent forms of chain referral sampling. Results Chain referral sampling via email proved to be the most efficient and effective, yielding a small yet diverse group of respondents within one month, and at negligible cost. Conclusions The widespread popularity of electronic communication technologies offers new methodological opportunities for researchers seeking to recruit from hard-to-reach populations. PMID:20089187

Harnessing social networks along with consumer-driven electronic communication technologies to identify and engage members of 'hard-to-reach' populations: a methodological case report.

PubMed

Rock, Melanie J

2010-01-20

Sampling in the absence of accurate or comprehensive information routinely poses logistical, ethical, and resource allocation challenges in social science, clinical, epidemiological, health service and population health research. These challenges are compounded if few members of a target population know each other or regularly interact. This paper reports on the sampling methods adopted in ethnographic case study research with a 'hard-to-reach' population. To identify and engage a small yet diverse sample of people who met an unusual set of criteria (i.e., pet owners who had been treating cats or dogs for diabetes), four sampling strategies were used. First, copies of a recruitment letter were posted in pet-friendly places. Second, information about the study was diffused throughout the study period via word of mouth. Third, the lead investigator personally sent the recruitment letter via email to a pet owner, who then circulated the information to others, and so on. Fourth, veterinarians were enlisted to refer people who had diabetic pets. The second, third and fourth strategies rely on social networks and represent forms of chain referral sampling. Chain referral sampling via email proved to be the most efficient and effective, yielding a small yet diverse group of respondents within one month, and at negligible cost. The widespread popularity of electronic communication technologies offers new methodological opportunities for researchers seeking to recruit from hard-to-reach populations.

Bias of health estimates obtained from chronic disease and risk factor surveillance systems using telephone population surveys in Australia: results from a representative face-to-face survey in Australia from 2010 to 2013.

PubMed

Dal Grande, Eleonora; Chittleborough, Catherine R; Campostrini, Stefano; Taylor, Anne W

2016-04-18

Emerging communication technologies have had an impact on population-based telephone surveys worldwide. Our objective was to examine the potential biases of health estimates in South Australia, a state of Australia, obtained via current landline telephone survey methodologies and to report on the impact of mobile-only household on household surveys. Data from an annual multi-stage, systematic, clustered area, face-to-face population survey, Health Omnibus Survey (approximately 3000 interviews annually), included questions about telephone ownership to assess the population that were non-contactable by current telephone sampling methods (2006 to 2013). Univariable analyses (2010 to 2013) and trend analyses were conducted for sociodemographic and health indicator variables in relation to telephone status. Relative coverage biases (RCB) of two hypothetical telephone samples was undertaken by examining the prevalence estimates of health status and health risk behaviours (2010 to 2013): directory-listed numbers, consisting mainly of landline telephone numbers and a small proportion of mobile telephone numbers; and a random digit dialling (RDD) sample of landline telephone numbers which excludes mobile-only households. Telephone (landline and mobile) coverage in South Australia is very high (97%). Mobile telephone ownership increased slightly (7.4%), rising from 89.7% in 2006 to 96.3% in 2013; mobile-only households increased by 431% over the eight year period from 5.2% in 2006 to 27.6% in 2013. Only half of the households have either a mobile or landline number listed in the telephone directory. There were small differences in the prevalence estimates for current asthma, arthritis, diabetes and obesity between the hypothetical telephone samples and the overall sample. However, prevalence estimate for diabetes was slightly underestimated (RCB value of -0.077) in 2013. Mixed RCB results were found for having a mental health condition for both telephone samples. Current smoking prevalence was lower for both hypothetical telephone samples in absolute differences and RCB values: -0.136 to -0.191 for RDD landline samples and -0.129 to -0.313 for directory-listed samples. These findings suggest landline-based sampling frames used in Australia, when appropriately weighted, produce reliable representative estimates for some health indicators but not for all. Researchers need to be aware of their limitations and potential biased estimates.

Baird's tapir density in high elevation forests of the Talamanca region of Costa Rica.

PubMed

González-Maya, José F; Schipper, Jan; Polidoro, Beth; Hoepker, Annelie; Zárrate-Charry, Diego; Belant, Jerrold L

2012-12-01

Baird's tapir (Tapirus bairdii) is currently endangered throughout its neotropical range with an expected population decline >50% in the next 30 years. We present the first density estimation of Baird's tapir for the Talamanca mountains of Costa Rica, and one of the first for the country. Ten stations with paired cameras were established in Valle del Silencio within Parque Internacional La Amistad (PILA). Seventy-seven tapir pictures of 15 individuals comprising 25 capture-recapture events were analyzed using mark-recapture techniques. The 100% minimum convex polygon of the sampled area was 5.7 km(2) and the effective sampled area using half mean maximum distances moved by tapirs was 7.16 km(2) . We estimated a tapir density of 2.93 individuals/km(2) which represents the highest density reported for this species. Intermountain valleys can represent unique and important habitats for large mammal species. However, the extent of isolation of this population, potentially constrained by steep slopes of the cordillera, remains unknown. Further genetic and movement studies are required to understand meta-population dynamics and connectivity between lowland and highland areas for Baird's tapir conservation in Costa Rica. © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.

Shoulder strength value differences between genders and age groups.

PubMed

Balcells-Diaz, Eudald; Daunis-I-Estadella, Pepus

2018-03-01

The strength of a normal shoulder differs according to gender and decreases with age. Therefore, the Constant score, which is a shoulder function measurement tool that allocates 25% of the final score to strength, differs from the absolute values but likely reflects a normal shoulder. To compare group results, a normalized Constant score is needed, and the first step to achieving normalization involves statistically establishing the gender differences and age-related decline. In this investigation, we sought to verify the gender difference and age-related decline in strength. We obtained a randomized representative sample of the general population in a small to medium-sized Spanish city. We then invited this population to participate in our study, and we measured their shoulder strength. We performed a statistical analysis with a power of 80% and a P value < .05. We observed a statistically significant difference between the genders and a statistically significant decline with age. To the best of our knowledge, this is the first investigation to study a representative sample of the general population from which conclusions can be drawn regarding Constant score normalization. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Measuring selected PPCPs in wastewater to estimate the population in different cities in China.

PubMed

Gao, Jianfa; O'Brien, Jake; Du, Peng; Li, Xiqing; Ort, Christoph; Mueller, Jochen F; Thai, Phong K

2016-10-15

Sampling and analysis of wastewater from municipal wastewater treatment plants (WWTPs) has become a useful tool for understanding exposure to chemicals. Both wastewater based studies and management and planning of the catchment require information on catchment population in the time of monitoring. Recently, a model has been developed and calibrated using selected pharmaceutical and personal care products (PPCPs) measured in influent wastewater for estimating population in different catchments in Australia. The present study aimed at evaluating the feasibility of utilizing this population estimation approach in China. Twenty-four hour composite influent samples were collected from 31 WWTPs in 17 cities with catchment sizes from 200,000-3,450,000 people representing all seven regions of China. The samples were analyzed for 19 PPCPs using liquid chromatography coupled to tandem mass spectrometry in direct injection mode. Eight chemicals were detected in more than 50% of the samples. Significant positive correlations were found between individual PPCP mass loads and population estimates provided by WWTP operators. Using the PPCP mass load modeling approach calibrated with WWTP operator data, we estimated the population size of each catchment with good agreement with WWTP operator values (between 50-200% for all sites and 75-125% for 23 of the 31 sites). Overall, despite much lower detection and relatively high heterogeneity in PPCP consumption across China the model provided a good estimate of the population contributing to a given wastewater sample. Wastewater analysis could also provide objective PPCP consumption status in China. Copyright © 2016 Elsevier B.V. All rights reserved.

Protection motivation theory and physical activity: a longitudinal test among a representative population sample of Canadian adults.

PubMed

Plotnikoff, Ronald C; Rhodes, Ryan E; Trinh, Linda

2009-11-01

The purpose of this study was to examine the Protection Motivation Theory (PMT) to predict physical activity (PA) behaviour in a large, population-based sample of adults. One thousand six hundred and two randomly selected individuals completed two telephone interviews over two consecutive six-month periods assessing PMT constructs. PMT explained 35 per cent and 20 per cent of the variance in intention and behaviour respectively. Coping cognitions as moderators of threat explained 1 per cent of the variance in intention and behaviour. Age and gender as moderators of threat did not provide additional variance in the models. We conclude that salient PMT predictors (e.g. self-efficacy) may guide the development of effective PA interventions in the general population.

Afghan Hindu Kush: Where Eurasian Sub-Continent Gene Flows Converge

PubMed Central

Mazières, Stéphane; Myres, Natalie M.; Lin, Alice A.; Temori, Shah Aga; Metspalu, Mait; Metspalu, Ene; Witzel, Michael; King, Roy J.; Underhill, Peter A.; Villems, Richard; Chiaroni, Jacques

2013-01-01

Despite being located at the crossroads of Asia, genetics of the Afghanistan populations have been largely overlooked. It is currently inhabited by five major ethnic populations: Pashtun, Tajik, Hazara, Uzbek and Turkmen. Here we present autosomal from a subset of our samples, mitochondrial and Y- chromosome data from over 500 Afghan samples among these 5 ethnic groups. This Afghan data was supplemented with the same Y-chromosome analyses of samples from Iran, Kyrgyzstan, Mongolia and updated Pakistani samples (HGDP-CEPH). The data presented here was integrated into existing knowledge of pan-Eurasian genetic diversity. The pattern of genetic variation, revealed by structure-like and Principal Component analyses and Analysis of Molecular Variance indicates that the people of Afghanistan are made up of a mosaic of components representing various geographic regions of Eurasian ancestry. The absence of a major Central Asian-specific component indicates that the Hindu Kush, like the gene pool of Central Asian populations in general, is a confluence of gene flows rather than a source of distinctly autochthonous populations that have arisen in situ: a conclusion that is reinforced by the phylogeography of both haploid loci. PMID:24204668

Human gut microbiome viewed across age and geography

USDA-ARS?s Scientific Manuscript database

Gut microbial communities represent one source of human genetic and metabolic diversity. To examine how gut microbiomes differ among human populations, we characterized bacterial species in fecal samples from 531 individuals, plus the gene content of 110 of them. The cohort encompassed healthy child...

A National Study of Autistic Symptoms in the General Population of School-Age Children and Those Diagnosed with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Goldstein, Sam; Naglieri, Jack A.; Rzepa, Sara; Williams, Kevin M.

2012-01-01

We examined the interrelationships among symptoms related to autism spectrum disorders (ASD) using a large representative sample and clinical groups of children aged 6 to 11 and youth aged 12 to 18 years rated by parents (N = 1,881) or teachers (N = 2,171). The samples included individuals from the United States and Canada from the standardization…

[A short version of the Narcissistic Personality Inventory (NPI-15): dimensionality and psychometric properties in a representative sample of the German population].

PubMed

Spangenberg, Lena; Romppel, Matthias; Bormann, Bianca; Hofmeister, Dirk; Brähler, Elmar; Strauß, Bernhard

2013-08-01

The Narcissistic Personality Inventory (NPI) is a commonly used measure of narcissism. This study administered a 15 item short version of the NPI (NPI-15). Central aims of the present study were to examine its dimensionality, and to provide data on its psychometric properties. NPI-15 and Hospital Anxiety and Depression Scale (HADS-D) were assessed in a representative sample of the German population (N=2,512). According to Scree-plot and model fit, a solution with 2 or 3 factors seemed feasible. Because of factor loadings and item-level associations to depression/anxiety we decided to favour a 2-factor-solution. 2 subscales reflecting different facets of narcissism were compiled (leadership ability/personality [LA/LP], grandiosity [G]). The psychometric properties of these scales were good (LA/LP) respectively unsatisfactory (G). The validity of the NPI-15 needs to be further studied. © Georg Thieme Verlag KG Stuttgart · New York.

[The practical measurement of health literacy in Hungary and in international comparison].

PubMed

Koltai, Júlia; Kun, Eszter

2016-12-01

The study presents results of an innovative measurement of practical health literacy in international context. To show the level of practical health literacy in the Hungarian society and in international comparison. We measured practical health literacy with Newest Vital Sign test on a Hungarian national representative sample, asked from 1008 persons, between May and June, 2015 from population 16 years or older, using methodological standards of Eurobarometer. The sample is representative to the above mentioned population by gender, age, region and settlement-size. Based on Newest Vital Sign test, members of the Hungarian society have good practical health literacy. The accomplishment is inconsistent with self-reported health literacy, since it shows weak results. As low level of self-reported health literacy implies that respondents don't have daily routine in practicing their skills, we could draw people's attention to food-information, that are important and show, how to utilize them. Orv. Hetil., 2016, 157(50), 2002-2006.

The functional spectrum of low-frequency coding variation.

PubMed

Marth, Gabor T; Yu, Fuli; Indap, Amit R; Garimella, Kiran; Gravel, Simon; Leong, Wen Fung; Tyler-Smith, Chris; Bainbridge, Matthew; Blackwell, Tom; Zheng-Bradley, Xiangqun; Chen, Yuan; Challis, Danny; Clarke, Laura; Ball, Edward V; Cibulskis, Kristian; Cooper, David N; Fulton, Bob; Hartl, Chris; Koboldt, Dan; Muzny, Donna; Smith, Richard; Sougnez, Carrie; Stewart, Chip; Ward, Alistair; Yu, Jin; Xue, Yali; Altshuler, David; Bustamante, Carlos D; Clark, Andrew G; Daly, Mark; DePristo, Mark; Flicek, Paul; Gabriel, Stacey; Mardis, Elaine; Palotie, Aarno; Gibbs, Richard

2011-09-14

Rare coding variants constitute an important class of human genetic variation, but are underrepresented in current databases that are based on small population samples. Recent studies show that variants altering amino acid sequence and protein function are enriched at low variant allele frequency, 2 to 5%, but because of insufficient sample size it is not clear if the same trend holds for rare variants below 1% allele frequency. The 1000 Genomes Exon Pilot Project has collected deep-coverage exon-capture data in roughly 1,000 human genes, for nearly 700 samples. Although medical whole-exome projects are currently afoot, this is still the deepest reported sampling of a large number of human genes with next-generation technologies. According to the goals of the 1000 Genomes Project, we created effective informatics pipelines to process and analyze the data, and discovered 12,758 exonic SNPs, 70% of them novel, and 74% below 1% allele frequency in the seven population samples we examined. Our analysis confirms that coding variants below 1% allele frequency show increased population-specificity and are enriched for functional variants. This study represents a large step toward detecting and interpreting low frequency coding variation, clearly lays out technical steps for effective analysis of DNA capture data, and articulates functional and population properties of this important class of genetic variation.

Gambling Type, Substance Abuse, Health and Psychosocial Correlates of Male and Female Problem Gamblers in a Nationally Representative French Sample.

PubMed

Bonnaire, C; Kovess-Masfety, V; Guignard, R; Richard, J B; du Roscoät, E; Beck, F

2017-06-01

Many studies carried out on treatment-seeking problem gamblers (PG) have reported high levels of comorbid substance use disorders, and mental and physical health problems. Nevertheless, general population studies are still sparse, most of them have been carried out in the United States or Canada, and gender differences have not always been considered. Thus, the aim of this study was to describe the type of games, and psychological and physical correlates in male and female PG in a nationally representative French sample. The total sample studied involved 25,647 subjects aged 15-85 years, including 333 PG and 25,314 non-problem gamblers (NPG). Data were extracted from a large survey of a representative sample of the French general population. They were evaluated for sociodemographic variables, gambling behavior, type of gambling activity, substance use, psychological distress, body mass index, chronic disease, and lack of sleep. Overall, there were significant differences between PG and NPG in gender, age, education, employment and marital status, substance use disorders (alcohol, tobacco, cannabis, cocaine and heroin), psychological distress, obesity, lack of sleep and type of gambling activity. Although male and female PG had different profiles, the gambling type, especially strategic games, appeared as an important variable in the relationship between gender and problem gambling. This research underlines the importance of considering gender differences and gambling type in the study of gambling disorders. Identifying specific factors in the relationship between gender, gambling type and gambling problems may help improve clinical interventions and health promotion strategies.

Malaria prevalence metrics in low- and middle-income countries: an assessment of precision in nationally-representative surveys.

PubMed

Alegana, Victor A; Wright, Jim; Bosco, Claudio; Okiro, Emelda A; Atkinson, Peter M; Snow, Robert W; Tatem, Andrew J; Noor, Abdisalan M

2017-11-21

One pillar to monitoring progress towards the Sustainable Development Goals is the investment in high quality data to strengthen the scientific basis for decision-making. At present, nationally-representative surveys are the main source of data for establishing a scientific evidence base, monitoring, and evaluation of health metrics. However, little is known about the optimal precisions of various population-level health and development indicators that remains unquantified in nationally-representative household surveys. Here, a retrospective analysis of the precision of prevalence from these surveys was conducted. Using malaria indicators, data were assembled in nine sub-Saharan African countries with at least two nationally-representative surveys. A Bayesian statistical model was used to estimate between- and within-cluster variability for fever and malaria prevalence, and insecticide-treated bed nets (ITNs) use in children under the age of 5 years. The intra-class correlation coefficient was estimated along with the optimal sample size for each indicator with associated uncertainty. Results suggest that the estimated sample sizes for the current nationally-representative surveys increases with declining malaria prevalence. Comparison between the actual sample size and the modelled estimate showed a requirement to increase the sample size for parasite prevalence by up to 77.7% (95% Bayesian credible intervals 74.7-79.4) for the 2015 Kenya MIS (estimated sample size of children 0-4 years 7218 [7099-7288]), and 54.1% [50.1-56.5] for the 2014-2015 Rwanda DHS (12,220 [11,950-12,410]). This study highlights the importance of defining indicator-relevant sample sizes to achieve the required precision in the current national surveys. While expanding the current surveys would need additional investment, the study highlights the need for improved approaches to cost effective sampling.

Reaching Asian Americans: sampling strategies and incentives.

PubMed

Lee, Soo-Kyung; Cheng, Yu-Yao

2006-07-01

Reaching and recruiting representative samples of minority populations is often challenging. This study examined in Chinese and Korean Americans: 1) whether using two different sampling strategies (random sampling vs. convenience sampling) significantly affected characteristics of recruited participants and 2) whether providing different incentives in the mail survey produced different response rates. We found statistically significant, however mostly not remarkable, differences between random and convenience samples. Offering monetary incentives in the mail survey improved response rates among Chinese Americans, while offering a small gift did not improve response rates among either Chinese or Korean Americans. This information will be useful for researchers and practitioners working with Asian Americans.

A Genome-Wide Analysis of Populations from European Russia Reveals a New Pole of Genetic Diversity in Northern Europe

PubMed Central

Khrunin, Andrey V.; Khokhrin, Denis V.; Filippova, Irina N.; Esko, Tõnu; Nelis, Mari; Bebyakova, Natalia A.; Bolotova, Natalia L.; Klovins, Janis; Nikitina-Zake, Liene; Rehnström, Karola; Ripatti, Samuli; Schreiber, Stefan; Franke, Andre; Macek, Milan; Krulišová, Veronika; Lubinski, Jan; Metspalu, Andres; Limborska, Svetlana A.

2013-01-01

Several studies examined the fine-scale structure of human genetic variation in Europe. However, the European sets analyzed represent mainly northern, western, central, and southern Europe. Here, we report an analysis of approximately 166,000 single nucleotide polymorphisms in populations from eastern (northeastern) Europe: four Russian populations from European Russia, and three populations from the northernmost Finno-Ugric ethnicities (Veps and two contrast groups of Komi people). These were compared with several reference European samples, including Finns, Estonians, Latvians, Poles, Czechs, Germans, and Italians. The results obtained demonstrated genetic heterogeneity of populations living in the region studied. Russians from the central part of European Russia (Tver, Murom, and Kursk) exhibited similarities with populations from central–eastern Europe, and were distant from Russian sample from the northern Russia (Mezen district, Archangelsk region). Komi samples, especially Izhemski Komi, were significantly different from all other populations studied. These can be considered as a second pole of genetic diversity in northern Europe (in addition to the pole, occupied by Finns), as they had a distinct ancestry component. Russians from Mezen and the Finnic-speaking Veps were positioned between the two poles, but differed from each other in the proportions of Komi and Finnic ancestries. In general, our data provides a more complete genetic map of Europe accounting for the diversity in its most eastern (northeastern) populations. PMID:23505534

Genetic portrait of Tamil non-tribal and Irula tribal population using Y chromosome STR markers.

PubMed

Raghunath, Rajshree; Krishnamoorthy, Kamalakshi; Balasubramanian, Lakshmi; Kunka Mohanram, Ramkumar

2016-03-01

The 17 Y chromosomal short tandem repeat loci included in the AmpFlSTR® Yfiler™ PCR Amplification Kit were used to analyse the genetic diversity of 517 unrelated males representing the non-tribal and Irula tribal population of Tamil Nadu. A total of 392 unique haplotypes were identified among the 400 non-tribal samples whereas 111 were observed among the 117 Irula tribal samples. Rare alleles for the loci DYS458, DYS635 and YGATAH4.1 were also observed in both population. The haplotype diversity for the non-tribal and Irula tribal population were found to be 0.9999, and the gene diversity ranged from 0.2041 (DYS391) to 0.9612 (DYS385). Comparison of the test population with 26 national and global population using principal coordinate analysis (PCoA) and determination of the genetic distance matrix using phylogenetic molecular analysis indicate a clustering of the Tamil Nadu non-tribal and Irula tribal population away from other unrelated population and proximity towards some Indo-European (IE) and Asian population. Data are available in the Y chromosome haplotype reference database (YHRD) under accession number YA004055 for Tamil non-tribal and YA004056 for the Irula tribal group.

Social surveys in HIV/AIDS: telling or writing? A comparison of interview and postal methods.

PubMed

McEwan, R T; Harrington, B E; Bhopal, R S; Madhok, R; McCallum, A

1992-06-01

We compare a probability sample postal questionnaire survey and a quota controlled interview survey, and review the literature on these subjects. In contrast to other studies, where quota samples were not representative because of biased selection of respondents by interviewers, our quota sample was representative. Response rates were similar in our postal and interview surveys (74 and 77%, respectively), although many previous similar postal surveys had poor response rates. As in other comparison studies, costs were higher in our interview survey, substantive responses and the quality of responses to closed-ended questions were similar, and responses to open-ended questions were better in the interview survey. 'Socially unacceptable' responses on sexual behaviour were less likely in interviews. Quota controlled surveys are appropriate in surveys on HIV/AIDS under certain circumstances, e.g. where the population parameters are well known, and where interviewers can gain access to the entire population. Postal questionnaires are better for obtaining information on sexual behaviour, if adequate steps are taken to improve response rates, and when in-depth answers are not needed. For most surveys in the HIV/AIDS field we recommend the postal method.

Sexual health risk among dance drug users: cross-sectional comparisons with nationally representative data.

PubMed

Mitcheson, Luke; McCambridge, Jim; Byrne, Angela; Hunt, Neil; Winstock, Adam

2008-08-01

To describe the sexual behaviour and related risk of a sample of dance drug users and compare this with data from the UK National Survey of Sexual Attitudes and Lifestyles 2000 survey. Cross-sectional purposive sampling using both self-completion postal and web-based questionnaires. This sample of dance drug users are more sexually active and have more concurrent partners than the general population. Rates of anal or vaginal sex within the last year without condom use are high and of concern (men 80 per cent; women 90 per cent). These dance drug users appear also to have higher lifetime prevalence of sexually transmitted infections than the general population and are also more likely to have ever attended a sexual health clinic. Clubbing and dance drug use, as part of a socially active lifestyle, is associated with elevated and pronounced sexual health risk. Future epidemiological studies of sexual health risk should incorporate investigation of both clubbing and recreational drug use in order to confirm the representativeness of these observations. Clubbers should be considered a target for dedicated sexual health promotion interventions, which may also be combined with interventions targeting drug and alcohol use.

The prevalence of compulsive hoarding and its association with compulsive buying in a German population-based sample.

PubMed

Mueller, Astrid; Mitchell, James E; Crosby, Ross D; Glaesmer, Heide; de Zwaan, Martina

2009-08-01

The aims of the study were to estimate the prevalence rate of compulsive hoarding, and to determine the association between compulsive hoarding and compulsive buying in a nationally representative sample of the German population (N = 2307). Compulsive hoarding was assessed with the German version of the Saving Inventory-Revised (SI-R; Frost, R.O., Steketee, G., & Grisham, J. (2004). Measurement of compulsive hoarding: saving inventory-revised. Behaviour Research and Therapy, 42, 1163-1182.). The point prevalence of compulsive hoarding was estimated to be 4.6%. Individuals with compulsive hoarding did not differ significantly from those without compulsive hoarding regarding age, gender, and other sociodemographic characteristics. Significant correlations were found between the compulsive hoarding and the compulsive buying measures. Participants with compulsive hoarding reported a higher propensity to compulsive buying than respondents without hoarding. About two thirds of participants classified as having compulsive hoarding were also defined as suffering from compulsive buying. In summary, these results suggest that compulsive hoarding may be relatively prevalent in Germany and they confirm the close association between compulsive hoarding and compulsive buying through the investigation of a large scale representative sample.

The validity of military screening for mental health problems: diagnostic accuracy of the PCL, K10 and AUDIT scales in an entire military population.

PubMed

Searle, Amelia K; Van Hooff, Miranda; McFarlane, Alexander C; Davies, Christopher E; Fairweather-Schmidt, A Kate; Hodson, Stephanie E; Benassi, Helen; Steele, Nicole

2015-03-01

Depression, alcohol use disorders and post-traumatic stress disorder (PTSD) are serious issues among military personnel due to their impact on operational capability and individual well-being. Several military forces screen for these disorders using scales including the Kessler Psychological Distress Scale (K10), Alcohol Use Disorders Identification Test (AUDIT), and Post-traumatic Stress Disorder Checklist (PCL). However, it is unknown whether established cutoffs apply to military populations. This study is the first to test the diagnostic accuracy of these three scales in a population-based military cohort. A large sample of currently-serving Australian Defence Force (ADF) Navy, Army and Air Force personnel (n = 24,481) completed the K10, AUDIT and PCL-C (civilian version). Then, a stratified sub-sample (n = 1798) completed a structured diagnostic interview detecting 30-day disorder. Data were weighted to represent the ADF population (n = 50,049). Receiver operating characteristic (ROC) analyses suggested all three scales had acceptable sensitivity and specificity, with areas under the curve from 0.75 to 0.93. AUDIT and K10 screening cutoffs closely paralleled established cutoffs, whereas the PCL-C screening cutoff resembled that recommended for US military personnel. These self-report scales represent a cost-effective and clinically-useful means of screening personnel for disorder. Military populations may need lower cutoffs than civilians to screen for PTSD. Copyright © 2014 John Wiley & Sons, Ltd.

The California School Psychologist, 1999.

ERIC Educational Resources Information Center

Wilson, Marilyn, Ed.

1999-01-01

This publication of the California Association of School Psychologists includes articles written by practitioners, trainers, and students. The topics represent a sampling of the broad range of students that school psychologists are asked to serve today. Two articles discuss current findings relevant to working with the populations of students who…

The Test Validation Summary

ERIC Educational Resources Information Center

Frederick, Richard I.; Bowden, Stephen C.

2009-01-01

Common rates employed in classificatory testing are the true positive rate (TPR), false positive rate (FPR), positive predictive power (PPP), and negative predictive power (NPP). FPR and TPR are estimated from research samples representing populations to be distinguished by classificatory testing. PPP and NPP are used by clinicians to classify…

Evidence-Based Psychosocial Treatments for Eating Problems and Eating Disorders

ERIC Educational Resources Information Center

Keel, Pamela K.; Haedt, Alissa

2008-01-01

Eating disorders represent a significant source of psychological impairment among adolescents. However, most controlled treatment studies have focused on adult populations. This review provides a synthesis of existing data concerning the efficacy of various psychosocial interventions for eating disorders in adolescent samples. Modes of therapy…

Disentangling the complex evolutionary history of the Western Palearctic blue tits (Cyanistes spp.) - phylogenomic analyses suggest radiation by multiple colonization events and subsequent isolation.

PubMed

Stervander, Martin; Illera, Juan Carlos; Kvist, Laura; Barbosa, Pedro; Keehnen, Naomi P; Pruisscher, Peter; Bensch, Staffan; Hansson, Bengt

2015-05-01

Isolated islands and their often unique biota continue to play key roles for understanding the importance of drift, genetic variation and adaptation in the process of population differentiation and speciation. One island system that has inspired and intrigued evolutionary biologists is the blue tit complex (Cyanistes spp.) in Europe and Africa, in particular the complex evolutionary history of the multiple genetically distinct taxa of the Canary Islands. Understanding Afrocanarian colonization events is of particular importance because of recent unconventional suggestions that these island populations acted as source of the widespread population in mainland Africa. We investigated the relationship between mainland and island blue tits using a combination of Sanger sequencing at a population level (20 loci; 12 500 nucleotides) and next-generation sequencing of single population representatives (>3 200 000 nucleotides), analysed in coalescence and phylogenetic frameworks. We found (i) that Afrocanarian blue tits are monophyletic and represent four major clades, (ii) that the blue tit complex has a continental origin and that the Canary Islands were colonized three times, (iii) that all island populations have low genetic variation, indicating low long-term effective population sizes and (iv) that populations on La Palma and in Libya represent relicts of an ancestral North African population. Further, demographic reconstructions revealed (v) that the Canary Islands, conforming to traditional views, hold sink populations, which have not served as source for back colonization of the African mainland. Our study demonstrates the importance of complete taxon sampling and an extensive multimarker study design to obtain robust phylogeographical inferences. © 2015 John Wiley & Sons Ltd.

Identification of population substructure among Jews using STR markers and dependence on reference populations included.

PubMed

Listman, Jennifer B; Hasin, Deborah; Kranzler, Henry R; Malison, Robert T; Mutirangura, Apiwat; Sughondhabirom, Atapol; Aharonovich, Efrat; Spivak, Baruch; Gelernter, Joel

2010-06-14

Detecting population substructure is a critical issue for association studies of health behaviors and other traits. Whether inherent in the population or an artifact of marker choice, determining aspects of a population's genetic history as potential sources of substructure can aid in design of future genetic studies. Jewish populations, among which association studies are often conducted, have a known history of migrations. As a necessary step in understanding population structure to conduct valid association studies of health behaviors among Israeli Jews, we investigated genetic signatures of this history and quantified substructure to facilitate future investigations of these phenotypes in this population. Using 32 autosomal STR markers and the program STRUCTURE, we differentiated between Ashkenazi (AJ, N = 135) and non-Ashkenazi (NAJ, N = 226) Jewish populations in the form of Northern and Southern geographic genetic components (AJ north 73%, south 23%, NAJ north 33%, south 60%). The ability to detect substructure within these closely related populations using a small STR panel was contingent on including additional samples representing major continental populations in the analyses. Although clustering programs such as STRUCTURE are designed to assign proportions of ancestry to individuals without reference population information, when Jewish samples were analyzed in the absence of proxy parental populations, substructure within Jews was not detected. Generally, for samples with a given grandparental country of birth, STRUCTURE assignment values to Northern, Southern, African and Asian clusters agreed with mitochondrial DNA and Y-chromosomal data from previous studies as well as historical records of migration and intermarriage.

Identification of population substructure among Jews using STR markers and dependence on reference populations included

PubMed Central

2010-01-01

Background Detecting population substructure is a critical issue for association studies of health behaviors and other traits. Whether inherent in the population or an artifact of marker choice, determining aspects of a population's genetic history as potential sources of substructure can aid in design of future genetic studies. Jewish populations, among which association studies are often conducted, have a known history of migrations. As a necessary step in understanding population structure to conduct valid association studies of health behaviors among Israeli Jews, we investigated genetic signatures of this history and quantified substructure to facilitate future investigations of these phenotypes in this population. Results Using 32 autosomal STR markers and the program STRUCTURE, we differentiated between Ashkenazi (AJ, N = 135) and non-Ashkenazi (NAJ, N = 226) Jewish populations in the form of Northern and Southern geographic genetic components (AJ north 73%, south 23%, NAJ north 33%, south 60%). The ability to detect substructure within these closely related populations using a small STR panel was contingent on including additional samples representing major continental populations in the analyses. Conclusions Although clustering programs such as STRUCTURE are designed to assign proportions of ancestry to individuals without reference population information, when Jewish samples were analyzed in the absence of proxy parental populations, substructure within Jews was not detected. Generally, for samples with a given grandparental country of birth, STRUCTURE assignment values to Northern, Southern, African and Asian clusters agreed with mitochondrial DNA and Y-chromosomal data from previous studies as well as historical records of migration and intermarriage. PMID:20546593

The neglected 95%: why American psychology needs to become less American.

PubMed

Arnett, Jeffrey J

2008-10-01

This article proposes that psychological research published in APA journals focuses too narrowly on Americans, who comprise less than 5% of the world's population. The result is an understanding of psychology that is incomplete and does not adequately represent humanity. First, an analysis of articles published in six premier APA journals is presented, showing that the contributors, samples, and editorial leadership of the journals are predominantly American. Then, a demographic profile of the human population is presented to show that the majority of the world's population lives in conditions vastly different from the conditions of Americans, underlining doubts of how well American psychological research can be said to represent humanity. The reasons for the narrowness of American psychological research are examined, with a focus on a philosophy of science that emphasizes fundamental processes and ignores or strips away cultural context. Finally, several suggestions for broadening the scope of American psychology are offered.

Chronic Rhinosinusitis: Potential Role of Microbial Dysbiosis and Recommendations for Sampling Sites

PubMed Central

Copeland, Elizabeth; Leonard, Katherine; Carney, Richard; Kong, Justin; Forer, Martin; Naidoo, Yuresh; Oliver, Brian G. G.; Seymour, Justin R.; Woodcock, Stephen; Burke, Catherine M.; Stow, Nicholas W.

2018-01-01

Chronic rhinosinusitis (CRS) is an inflammatory condition that affects up to 12% of the human population in developed countries. Previous studies examining the potential role of the sinus bacterial microbiota within CRS infections have found inconsistent results, possibly because of inconsistencies in sampling strategies. The aim of this study was to determine whether the sinus microbiome is altered in CRS and additionally if the middle meatus is a suitable representative site for sampling the sinus microbiome. Swab samples were collected from 12 healthy controls and 21 CRS patients, including all eight sinuses for CRS patients and between one and five sinuses for control subjects. The left and right middle meatus and nostril swabs were also collected. Significant differences in the sinus microbiomes between CRS and control samples were revealed using high-throughput 16S rRNA gene sequencing. The genus Escherichia was over-represented in CRS sinuses, and associations between control patients and Corynebacterium and Dolosigranulum were also identified. Comparisons of the middle meatuses between groups did not reflect these differences, and the abundance of the genus Escherichia was significantly lower at this location. Additionally, intra-patient variation was lower between sinuses than between sinus and middle meatus, which together with the above results suggests that the middle meatus is not an effective representative sampling site. PMID:29541629

The correlation between temperature and humidity with the population density of Aedes aegypti as dengue fever’s vector

NASA Astrophysics Data System (ADS)

Sintorini, M. M.

2018-01-01

The weather change in South East Asia have triggered the increase of dengue fever illness in Indonesia. Jakarta has been declared as one of dengue fever endemic region. This research aim to gain the dynamic of dengue fever incidents related to temperature, humidity and the population density of Aedes aegypti. This research implementated Design of Ecology Study. The samples were collected from April 2015 to March 2016, from houses located in the suburbs i.e. Pasar Minggu, Ciracas, Sunter Agung, Palmerah and Bendungan Hilir. The sampling based on Sampling Design Cluster and each suburb represents 153 samples. The research shows correlation between temperature (p value 0.000) and humidity (p value 0,000) with Aedes aegypti as dengue fever’s Vector. Therefore, an early warning system should be developed based on environmental factors to anticipate the spread of dengue fever.

Experience of elder abuse among older Korean immigrants.

PubMed

Chang, Miya

2016-01-01

Studies on the scope and nature of Asian American elder abuse conducted with older immigrants are extremely limited. The overall purpose of this study was to examine the extent and type of elder abuse among older Korean immigrants, and to investigate critical predictors of elder abuse in this population. The sample consisted of 200 older Korean immigrants aged 60 to 90 years who resided in Los Angeles County in 2008. One of the key findings indicated that 58.3% of respondents experienced one or more types of elder abuse. Logistic regression indicated that the victims' health status and educational level were statistically significant predictors of the likelihood of experiencing abuse. The present study, although limited in sample size, measures, sampling methods, and population representation, has contributed to this important area of knowledge. It is recommended that future studies conduct research on elder abuse with more representative national samples that can measure the extent of abuse and neglect more accurately.

Comparing Study Populations of Men Who Have Sex with Men: Evaluating Consistency Within Repeat Studies and Across Studies in the Seattle Area Using Different Recruitment Methodologies

PubMed Central

Burt, Richard D.; Oster, Alexandra M.; Golden, Mathew R.; Thiede, Hanne

2013-01-01

There is no gold standard for recruiting unbiased samples of men who have sex with men (MSM). To assess differing recruitment methods, we compared Seattle-area MSM samples from: venue-day-time sampling-based National HIV Behavioral Surveillance (NHBS) surveys in 2008 and 2011, random-digit-dialed (RDD) surveys in 2003 and 2006, and STD clinic patient data 2001–2011. We compared sociodemographics, sexual and drug-associated behavior, and HIV status and testing. There was generally good consistency between the two NHBS surveys and within STD clinic data across time. NHBS participants reported higher levels of drug-associated and lower levels of sexual risk than STD clinic patients. RDD participants differed from the other study populations in sociodemographics and some risk behaviors. While neither NHBS nor the STD clinic study populations may be representative of all MSM, both appear to provide consistent samples of MSM subpopulations across time that can provide useful information to guide HIV prevention. PMID:23900958

Control of diabetes and fibrinogen levels as well as improvement in health care might delay low cognitive performance in societies aging progressively.

PubMed

Lopes, Daniele Almeida; Moraes, Suzana Alves de; Freitas, Isabel Cristina Martins de

2015-01-01

To know the prevalence and factors associated to low cognitive performance in a representative sample of the adult population in a society aging progressively. Cross-sectional population-based study carried out in a three-stage sampling: 81 census tracts (primary sampling unity) were randomly selected, followed by 1,672 households and 2,471 participants (weighted sample) corresponding to the second and third stages, respectively. The outcome prevalence was calculated according sociodemographic, behavioral and health related variables. Crude and adjusted prevalence ratios were estimated using Poisson regression. The prevalence of low cognitive performance was high, mainly among females, and indicated linear trends into categories of age, schooling, income, plasma fibrinogen and self-reported health status. In multivariate models, gender, diabetes, fibrinogen and self-reported health status presented positive associations, while schooling, employment and sitting time presented negative associations with the outcome. Interventions related to diabetes and fibrinogen levels control as well as improvement in health care might delay low cognitive performance in societies aging progressively as such the study population.

The National Comorbidity Survey Adolescent Supplement (NCS-A): II. Overview and Design

PubMed Central

Kessler, Ronald C.; Avenevoli, Shelli; Costello, E. Jane; Green, Jennifer Greif; Gruber, Michael J.; Heeringa, Steven; Merikangas, Kathleen R.; Pennell, Beth-Ellen; Sampson, Nancy A.; Zaslavsky, Alan M.

2009-01-01

OBJECTIVE To present an overview of the design and field procedures of the National Comorbidity Survey Replication Adolescent Supplement (NCS-A) METHOD The NCS-A is a nationally representative face-to-face household survey of the prevalence and correlates of DSM-IV mental disorders among US adolescents (ages 13–17) that was carried out between February 2001 and January 2004 by the Survey Research Center of the Institute for Social Research at the University of Michigan. The sample was based on a dual-frame design that included 904 adolescent residents of the households that participated in the National Comorbidity Survey Replication (85.9% response rate) and 9244 adolescent students selected from a representative sample of 320 schools in the same nationally representative sample of counties as the NCS-R (74.7% response rate). RESULTS Comparisons of sample and population distributions on Census socio-demographic variables and, in the school sample, school characteristics documented only minor differences that were corrected with post-stratification weighting. Comparisons of DSM-IV disorder prevalence estimates among household vs. school sample respondents in counties that differed in the use of replacement schools for originally selected schools that refused to participate showed that the use of replacement schools did not introduce bias into prevalence estimates. CONCLUSIONS The NCS-A is a rich nationally representative dataset that will substantially increase understanding of the mental health and well-being of adolescents in the United States. PMID:19242381

Population genetic structure of the people of Qatar.

PubMed

Hunter-Zinck, Haley; Musharoff, Shaila; Salit, Jacqueline; Al-Ali, Khalid A; Chouchane, Lotfi; Gohar, Abeer; Matthews, Rebecca; Butler, Marcus W; Fuller, Jennifer; Hackett, Neil R; Crystal, Ronald G; Clark, Andrew G

2010-07-09

People of the Qatar peninsula represent a relatively recent founding by a small number of families from three tribes of the Arabian Peninsula, Persia, and Oman, with indications of African admixture. To assess the roles of both this founding effect and the customary first-cousin marriages among the ancestral Islamic populations in Qatar's population genetic structure, we obtained and genotyped with Affymetrix 500k SNP arrays DNA samples from 168 self-reported Qatari nationals sampled from Doha, Qatar. Principal components analysis was performed along with samples from the Human Genetic Diversity Project data set, revealing three clear clusters of genotypes whose proximity to other human population samples is consistent with Arabian origin, a more eastern or Persian origin, and individuals with African admixture. The extent of linkage disequilibrium (LD) is greater than that of African populations, and runs of homozygosity in some individuals reflect substantial consanguinity. However, the variance in runs of homozygosity is exceptionally high, and the degree of identity-by-descent sharing generally appears to be lower than expected for a population in which nearly half of marriages are between first cousins. Despite the fact that the SNPs of the Affymetrix 500k chip were ascertained with a bias toward SNPs common in Europeans, the data strongly support the notion that the Qatari population could provide a valuable resource for the mapping of genes associated with complex disorders and that tests of pairwise interactions are particularly empowered by populations with elevated LD like the Qatari. Copyright 2010 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Strong population structure in the marine sponge Crambe crambe (Poecilosclerida) as revealed by microsatellite markers.

PubMed

Duran, S; Pascual, M; Estoup, A; Turon, X

2004-03-01

Different categories of molecular markers have been used so far to study the population structure of sponges. However, these markers often did not have the resolution power to address precisely questions on structuring processes, especially at the intrapopulational level. In this study we show that microsatellites fulfil these expectations, allowing a fine description of population structure at different geographical scales in the marine sponge Crambe crambe. Specimens were collected in 11 locations, representing most of the Atlanto-Mediterranean range of the species, and were analysed at six loci. As expected for a sessile invertebrate with lecitotrophic larvae, high levels of between-population structure were found (FST = 0.18) and a significant isolation-by-distance pattern was observed. A strong genetic structure was also found within sampled sites (FIS = 0.21) that may be explained by several factors including inbreeding, selfing and the Wahlund effect. In spite of a sampling design planned to avoid the sampling of clones, genotypically identical individuals for the six loci were found in some locations. The significance of these potential clones is discussed and their effect on the observed pattern of population structure assessed. Patterns of allelic distribution within populations suggest the possibility of a recent colonization of the Atlantic range from the Mediterranean Sea.

Population genetic structure analysis and forensic evaluation of Xinjiang Uigur ethnic group on genomic deletion and insertion polymorphisms.

PubMed

Mei, Ting; Shen, Chun-Mei; Liu, Yao-Shun; Meng, Hao-Tian; Zhang, Yu-Dang; Guo, Yu-Xin; Dong, Qian; Wang, Xin-Xin; Yan, Jiang-Wei; Zhu, Bo-Feng; Zhang, Li-Ping

2016-01-01

The Uigur ethnic minority is the largest ethnic group in the Xinjiang Uygur Autonomous Region of China, and valuable resource for the study of ethnogeny. The objective of this study was to estimate the genetic diversities and forensic parameters of 30 insertion-deletion loci in Uigur ethnic group from Xinjiang Uigur Autonomous Region of China and to analyze the genetic relationships between Xinjiang Uigur group and other previously published groups based on population data of these loci. All the tested loci were conformed to Hardy-Weinberg equilibrium after Bonferroni correction. The observed and expected heterozygosity ranged from 0.3750 to 0.5515; and 0.4057 to 0.5037, respectively. The combined power of discrimination and probability of exclusion in the group were 0.99999999999940 and 0.9963, respectively. We analyzed the D A distance, interpopulation differentiations and population structure, conducted principal component analysis and neighbor-joining tree based on our studied group and 21 reference groups. The present results indicated that the studied Xinjiang Uigur group (represented our samples from the whole territory of Xinjiang Uigur Autonomous Region) had a close relationships with Urumchi Uigur (represented previously reported samples from Urumchi of Xinjiang) and Kazak groups. The present study may provide novel biological information for the study of population genetics, and can also increase our understanding of the genetic relationships between Xinjiang Uigur group and other groups.

An integrated national mortality surveillance system for death registration and mortality surveillance, China.

PubMed

Liu, Shiwei; Wu, Xiaoling; Lopez, Alan D; Wang, Lijun; Cai, Yue; Page, Andrew; Yin, Peng; Liu, Yunning; Li, Yichong; Liu, Jiangmei; You, Jinling; Zhou, Maigeng

2016-01-01

In China, sample-based mortality surveillance systems, such as the Chinese Center for Disease Control and Prevention's disease surveillance points system and the Ministry of Health's vital registration system, have been used for decades to provide nationally representative data on health status for health-care decision-making and performance evaluation. However, neither system provided representative mortality and cause-of-death data at the provincial level to inform regional health service needs and policy priorities. Moreover, the systems overlapped to a considerable extent, thereby entailing a duplication of effort. In 2013, the Chinese Government combined these two systems into an integrated national mortality surveillance system to provide a provincially representative picture of total and cause-specific mortality and to accelerate the development of a comprehensive vital registration and mortality surveillance system for the whole country. This new system increased the surveillance population from 6 to 24% of the Chinese population. The number of surveillance points, each of which covered a district or county, increased from 161 to 605. To ensure representativeness at the provincial level, the 605 surveillance points were selected to cover China's 31 provinces using an iterative method involving multistage stratification that took into account the sociodemographic characteristics of the population. This paper describes the development and operation of the new national mortality surveillance system, which is expected to yield representative provincial estimates of mortality in China for the first time.

Urinary Concentrations of Bisphenol A and 4-Nonylphenol in a Human Reference Population

PubMed Central

Calafat, Antonia M.; Kuklenyik, Zsuzsanna; Reidy, John A.; Caudill, Samuel P.; Ekong, John; Needham, Larry L.

2005-01-01

Bisphenol A (BPA) is used to manufacture polycarbonate plastic and epoxy resins, which are used in baby bottles, as protective coatings on food containers, and for composites and sealants in dentistry. 4-Nonylphenol (NP) is used to make nonylphenol ethoxylates, nonionic surfactants applied as emulsifying, wetting, dispersing, or stabilizing agents in industrial, agricultural, and domestic consumer products. The potential for human exposure to BPA and NP is high because of their widespread use. We measured BPA and NP in archived urine samples from a reference population of 394 adults in the United States using isotope-dilution gas chromatography/mass spectrometry. The concentration ranges of BPA and NP were similar to those observed in other human populations. BPA was detected in 95% of the samples examined at concentrations ≥0.1 μg/L urine; the geometric mean and median concentrations were 1.33 μg/L (1.36 μg/g creatinine) and 1.28 μg/L (1.32 μg/g creatinine), respectively; the 95th percentile concentration was 5.18 μg/L (7.95 μg/g creatinine). NP was detected in 51% of the samples examined ≥0.1 μg/L. The median and 95th percentile concentrations were < 0.1 μg/L and 1.57 μg/L (1.39 μg/g creatinine), respectively. The frequent detection of BPA suggests widespread exposure to this compound in residents of the United States. The lower frequency of detection of NP than of BPA could be explained by a lower exposure of humans to NP, by different pharmacokinetic factors (i.e., absorption, distribution, metabolism, elimination), by the fact that 4-n-nonylphenol—the measured NP isomer—represents a small percentage of the NP used in commercial mixtures, or a combination of all of the above. Additional research is needed to determine the best urinary biomarker(s) to assess exposure to NP. Despite the sample population’s nonrepresentativeness of the U.S. population (although sample weights were used to improve the extent to which the results represent the U.S. population) and relatively small size, this study provides the first reference range of human internal dose levels of BPA and NP in a demographically diverse human population. PMID:15811827

Intelligence in Bali--A Case Study on Estimating Mean IQ for a Population Using Various Corrections Based on Theory and Empirical Findings

ERIC Educational Resources Information Center

Rindermann, Heiner; te Nijenhuis, Jan

2012-01-01

A high-quality estimate of the mean IQ of a country requires giving a well-validated test to a nationally representative sample, which usually is not feasible in developing countries. So, we used a convenience sample and four corrections based on theory and empirical findings to arrive at a good-quality estimate of the mean IQ in Bali. Our study…

An empirical literature review of definitions of severe and persistent mental illness.

PubMed

Schinnar, A P; Rothbard, A B; Kanter, R; Jung, Y S

1990-12-01

Seventeen definitions of the severely and persistently mentally ill have appeared in the literature over the past decade. These definitions have been used by 13 authors to formulate service programs and to estimate the prevalence of serious mental illness in the population. To test the applicability of these definitions, the authors operationalized each definition and applied it to a representative sample of 222 patients receiving services in one of Philadelphia's inner-city neighborhoods. The analysis showed estimates of prevalence of serious mental illness ranging from 4% to 88% of the treated population, depending on the definition applied. The NIMH (1987) definition was representative of the middle-range estimates of 45% to 55% arrived at by eight authors.

Colonoscopy screening for colorectal cancer: the outcomes of two recruitment methods.

PubMed

Corbett, Mike; Chambers, Sharon L; Shadbolt, Bruce; Hillman, Lybus C; Taupin, Doug

2004-10-18

To determine the response to colorectal cancer (CRC) screening by colonoscopy, through direct invitation or through invitation by general practitioners. Two-way comparison of randomised population sampling versus cluster sampling of a representative general practice population in the Australian Capital Territory, May 2002 to January 2004. Invitation to screen, assessment for eligibility, interview, and colonoscopy. 881 subjects aged 55-74 years were invited to screen: 520 from the electoral roll (ER) sample and 361 from the general practice (GP) cluster sample. Response rate, participation rate, and rate of adenomatous polyps in the screened group. Participation was similar in the ER arm (35.1%; 95% CI, 30.2%-40.3%) and the GP arm (40.1%; 95% CI, 29.2%-51.0%) after correcting for ineligibility, which was higher in the ER arm. Superior eligibility in the GP arm was offset by the labour of manual record review. Response rates after two invitations were similar for the two groups (ER arm: 78.8%; 95% CI, 75.1%-82.1%; GP arm: 81.7%; 95% CI, 73.8%-89.6%). Overall, 53.4% ineligibility arose from having a colonoscopy in the past 10 years (ER arm, 98/178; GP arm, 42/84). Of 231 colonoscopies performed, 229 were complete, with 32% of subjects screened having adenomatous polyps. Colonoscopy-based CRC screening yields similar response and participation rates with either random population sampling or general practice cluster sampling, with population sampling through the electoral roll providing greater ease of recruitment.

Assessing the fit of the Dysphoric Arousal model across two nationally representative epidemiological surveys: The Australian NSMHWB and the United States NESARC.

PubMed

Armour, Cherie; Carragher, Natacha; Elhai, Jon D

2013-01-01

Since the initial inclusion of PTSD in the DSM nomenclature, PTSD symptomatology has been distributed across three symptom clusters. However, a wealth of empirical research has concluded that PTSD's latent structure is best represented by one of two four-factor models: Numbing or Dysphoria. Recently, a newly proposed five-factor Dysphoric Arousal model, which separates the DSM-IV's Arousal cluster into two factors of Anxious Arousal and Dysphoric Arousal, has gathered support across a variety of trauma samples. To date, the Dysphoric Arousal model has not been assessed using nationally representative epidemiological data. We employed confirmatory factor analysis to examine PTSD's latent structure in two independent population based surveys from American (NESARC) and Australia (NSWHWB). We specified and estimated the Numbing model, the Dysphoria model, and the Dysphoric Arousal model in both samples. Results revealed that the Dysphoric Arousal model provided superior fit to the data compared to the alternative models. In conclusion, these findings suggest that items D1-D3 (sleeping difficulties; irritability; concentration difficulties) represent a separate, fifth factor within PTSD's latent structure using nationally representative epidemiological data in addition to single trauma specific samples. Copyright © 2012 Elsevier Ltd. All rights reserved.

A systematic review of childhood maltreatment assessments in population-representative surveys since 1990.

PubMed

Hovdestad, Wendy; Campeau, Aimée; Potter, Dawn; Tonmyr, Lil

2015-01-01

Population-representative surveys that assess childhood maltreatment and health are a valuable resource to explore the implications of child maltreatment for population health. Systematic identification and evaluation of such surveys is needed to facilitate optimal use of their data and to inform future research. To inform researchers of the existence and nature of population-representative surveys relevant to understanding links between childhood maltreatment and health; to evaluate the assessment of childhood maltreatment in this body of work. We included surveys that: 1) were representative of the non-institutionalized population of any size nation or of any geopolitical region ≥ 10 million people; 2) included a broad age range (≥ 40 years); 3) measured health; 4) assessed childhood maltreatment retrospectively; and 5) were conducted since 1990. We used Internet and database searching (including CINAHL, Embase, ERIC, Global Health, MEDLINE, PsycINFO, Scopus, Social Policy and Practice: January 1990 to March 2014), expert consultation, and other means to identify surveys and associated documentation. Translations of non-English survey content were verified by fluent readers of survey languages. We developed checklists to abstract and evaluate childhood maltreatment content. Fifty-four surveys from 39 countries met inclusion criteria. Sample sizes ranged from 1,287-51,945 and response rates from 15%-96%. Thirteen surveys assessed neglect, 15 emotional abuse; 18 exposure to family violence; 26 physical abuse; 48 sexual abuse. Fourteen surveys assessed more than three types; six of these were conducted since 2010. In nine surveys childhood maltreatment assessments were detailed (+10 items for at least one type of maltreatment). Seven surveys' assessments had known reliability and/or validity. Data from 54 surveys can be used to explore the population health relevance of child maltreatment. Assessment of childhood maltreatment is not comprehensive but there is evidence of recent improvement.

Guidelines for Measuring Disease Episodes: An Analysis of the Effects on the Components of Expenditure Growth.

PubMed

Dunn, Abe; Liebman, Eli; Rittmueller, Lindsey; Shapiro, Adam Hale

2017-04-01

To provide guidelines to researchers measuring health expenditures by disease and compare these methodologies' implied inflation estimates. A convenience sample of commercially insured individuals over the 2003 to 2007 period from Truven Health. Population weights are applied, based on age, sex, and region, to make the sample of over 4 million enrollees representative of the entire commercially insured population. Different methods are used to allocate medical-care expenditures to distinct condition categories. We compare the estimates of disease-price inflation by method. Across a variety of methods, the compound annual growth rate stays within the range 3.1 to 3.9 percentage points. Disease-specific inflation measures are more sensitive to the selected methodology. The selected allocation method impacts aggregate inflation rates, but considering the variety of methods applied, the differences appear small. Future research is necessary to better understand these differences in other population samples and to connect disease expenditures to measures of quality. © Health Research and Educational Trust.

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

PubMed

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.

[Participation and representation of the immigrant population in the Spanish National Health Survey 2011-2012].

PubMed

González-Rábago, Yolanda; La Parra, Daniel; Martín, Unai; Malmusi, Davide

2014-01-01

Population health surveys have been the main data source for analysis of immigrants' health status in Spain. The aim of this study was to analyze the representation of this population in the Spanish National Health Survey (SNHS) 2011-2012. We analyzed methodological publications and data from the SNHS 2011-2012 and the population registry. Differences in the participation rate between the national and foreign populations and the causes for these differences were analyzed, as well as the representation of 11 countries of birth in the survey with respect to the general population, with and without weighting. Households with any foreign person had a lower participation rate, either due to a higher error in the sampling frame or to a higher non-response rate. In each country of birth, the sample was smaller than would be expected according to the population registry, especially among the Chinese population. When we applied the sample weights to the 11 countries of birth, the estimated population volume was closer to the estimated volume of the population registry for all the countries considered, although globally both the underrepresentation and the intranational bias remained. The lower participation of the immigrant population and differences in participation depending on the country of origin suggest the existence of a potential bias in the SNHS, which should be taken into account in studies analyzing the health of this population. The lower participation rate should be studied in greater depth in order to take appropriate measures to increase the representativeness of health surveys. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

A tale of two seas: contrasting patterns of population structure in the small-spotted catshark across Europe

PubMed Central

Gubili, Chrysoula; Sims, David W.; Veríssimo, Ana; Domenici, Paolo; Ellis, Jim; Grigoriou, Panagiotis; Johnson, Andrew F.; McHugh, Matthew; Neat, Francis; Satta, Andrea; Scarcella, Giuseppe; Serra-Pereira, Bárbara; Soldo, Alen; Genner, Martin J.; Griffiths, Andrew M.

2014-01-01

Elasmobranchs represent important components of marine ecosystems, but they can be vulnerable to overexploitation. This has driven investigations into the population genetic structure of large-bodied pelagic sharks, but relatively little is known of population structure in smaller demersal taxa, which are perhaps more representative of the biodiversity of the group. This study explores spatial population genetic structure of the small-spotted catshark (Scyliorhinus canicula), across European seas. The results show significant genetic differences among most of the Mediterranean sample collections, but no significant structure among Atlantic shelf areas. The data suggest the Mediterranean populations are likely to have persisted in a stable and structured environment during Pleistocene sea-level changes. Conversely, the Northeast Atlantic populations would have experienced major changes in habitat availability during glacial cycles, driving patterns of population reduction and expansion. The data also provide evidence of male-biased dispersal and female philopatry over large spatial scales, implying complex sex-determined differences in the behaviour of elasmobranchs. On the basis of this evidence, we suggest that patterns of connectivity are determined by trends of past habitat stability that provides opportunity for local adaptation in species exhibiting philopatric behaviour, implying that resilience of populations to fisheries and other stressors may differ across the range of species. PMID:26064555

The mass distribution of Population III stars

NASA Astrophysics Data System (ADS)

Fraser, M.; Casey, A. R.; Gilmore, G.; Heger, A.; Chan, C.

2017-06-01

Extremely metal-poor (EMP) stars are uniquely informative on the nature of massive Population III stars. Modulo a few elements that vary with stellar evolution, the present-day photospheric abundances observed in EMP stars are representative of their natal gas cloud composition. For this reason, the chemistry of EMP stars closely reflects the nucleosynthetic yields of supernovae from massive Population III stars. Here we collate detailed abundances of 53 EMP stars from the literature and infer the masses of their Population III progenitors. We fit a simple initial mass function (IMF) to a subset of 29 of the inferred Population III star masses, and find that the mass distribution is well represented by a power-law IMF with exponent α = 2.35^{+0.29}_{-0.24}. The inferred maximum progenitor mass for supernovae from massive Population III stars is M_{max} = 87^{+13}_{-33} M⊙, and we find no evidence in our sample for a contribution from stars with masses above ˜120 M⊙. The minimum mass is strongly consistent with the theoretical lower mass limit for Population III supernovae. We conclude that the IMF for massive Population III stars is consistent with the IMF of present-day massive stars and there may well have formed stars much below the supernova mass limit that could have survived to the present day.

Learning Profiles: The Learning Crisis Is Not (Mostly) about Enrollment

ERIC Educational Resources Information Center

Sandefur, Justin; Pritchett, Lant; Beatty, Amanda

2016-01-01

The differential patterns of grade progression have direct implications for the calculation of learning profiles. Researchers measure learning in primary school using survey data on reading and math skills of a nationally representative, population-based sample of children in India, Pakistan, Kenya, Tanzania, and Uganda. Research demonstrates that…

Prevalence and Costs of Five Chronic Conditions in Children

ERIC Educational Resources Information Center

Miller, Gabrielle F.; Coffield, Edward; Leroy, Zanie; Wallin, Robin

2016-01-01

The objective is to examine the prevalence and health-care costs associated with asthma, epilepsy, hypertension, food allergies, and diabetes in children aged 0-18 years. Prevalence was calculated using 2005-2012 Medical Expenditure Panel Survey (MEPS) data, a population-based, nationally representative sample. Using MEPS, two-part models…

A Year in Head Start: Children, Families and Programs. ACF-ORPRE Report

ERIC Educational Resources Information Center

Aikens, Nikki; Tarullo, Louisa; Hulsey, Lara; Ross, Christine; West, Jerry; Xue, Yange

2010-01-01

The Head Start Family and Child Experiences Survey (FACES) was first launched in 1997 as a periodic longitudinal study of program performance. Successive nationally representative samples of Head Start children, their families, classrooms, and programs provide descriptive information on the population served; staff qualifications, credentials,…

RELATIONSHIPS OF INDOOR, OUTDOOR, AND PERSONAL AIR (RIOPA). PART I. COLLECTION METHODS AND DESCRIPTIVE ANALYSES

EPA Science Inventory

The homes and subjects selected did not proportionally represent the greater population. Rather, homes close to sources were preferentially sampled in order to examine the impact of possibly high exposures. In addition, the characteristics of the subjects and the homes diff...

Configurations of Common Childhood Psychosocial Risk Factors

ERIC Educational Resources Information Center

Copeland, William; Shanahan, Lilly; Costello, E. Jane; Angold, Adrian

2009-01-01

Background: Co-occurrence of psychosocial risk factors is commonplace, but little is known about psychiatrically-predictive configurations of psychosocial risk factors. Methods: Latent class analysis (LCA) was applied to 17 putative psychosocial risk factors in a representative population sample of 920 children ages 9 to 17. The resultant class…

Development of the Wechsler Memory Scale--Revised.

ERIC Educational Resources Information Center

Herman, David O.; Young, Laura

A study involving a sample of people selected to represent the nonimpaired American population, aged 16 to 74 years, was undertaken to determine the effectiveness of the Wechsler Memory Scale--Revised. The scale's subtests were designed to assess memory of personal and general knowledge, logical memory, verbal paired association, figural memory,…

ESTIMATING PERENNIAL AND NON-PERENNIAL STREAM AND RIVER LENGTH IN 12 WESTERN STATES

EPA Science Inventory

The accuracy of a sampling frame in representing the resource population of interest is a potentially important source of uncertainty in the design and interpretation of environmental monitoring surveys. As part of the EMAP Western Pilot study (EMAP-WP), two surveys of the EPA R...

An Integrated Performance-Based Budgeting Model for Thai Higher Education

ERIC Educational Resources Information Center

Charoenkul, Nantarat; Siribanpitak, Pruet

2012-01-01

This research mainly aims to develop an administrative model of performance-based budgeting for autonomous state universities. The sample population in this study covers 4 representatives of autonomous state universities from 4 regions of Thailand, where the performance-based budgeting system has been fully practiced. The research informants…

Beta vulgaris crop types: Genomic signatures of selection (GSS) using next generation sequencing of pooled samples

USDA-ARS?s Scientific Manuscript database

Beta vulgaris crop types represent highly diverged populations with distinct phenotypes resulting from long-term selection. Differential end use in the crop types includes: leaf quality (chard/leaf beet), root enlargement and biomass, (table beet, fodder beet, sugar beet), and secondary metabolite a...

Haplotype diversity in 11 candidate genes across four populations.

PubMed

Beaty, T H; Fallin, M D; Hetmanski, J B; McIntosh, I; Chong, S S; Ingersoll, R; Sheng, X; Chakraborty, R; Scott, A F

2005-09-01

Analysis of haplotypes based on multiple single-nucleotide polymorphisms (SNP) is becoming common for both candidate gene and fine-mapping studies. Before embarking on studies of haplotypes from genetically distinct populations, however, it is important to consider variation both in linkage disequilibrium (LD) and in haplotype frequencies within and across populations, as both vary. Such diversity will influence the choice of "tagging" SNPs for candidate gene or whole-genome association studies because some markers will not be polymorphic in all samples and some haplotypes will be poorly represented or completely absent. Here we analyze 11 genes, originally chosen as candidate genes for oral clefts, where multiple markers were genotyped on individuals from four populations. Estimated haplotype frequencies, measures of pairwise LD, and genetic diversity were computed for 135 European-Americans, 57 Chinese-Singaporeans, 45 Malay-Singaporeans, and 46 Indian-Singaporeans. Patterns of pairwise LD were compared across these four populations and haplotype frequencies were used to assess genetic variation. Although these populations are fairly similar in allele frequencies and overall patterns of LD, both haplotype frequencies and genetic diversity varied significantly across populations. Such haplotype diversity has implications for designing studies of association involving samples from genetically distinct populations.

Context of Physical Activity in a Representative Sample of Adults.

PubMed

Welk, Gregory J; Kim, Youngwon

2015-10-01

The establishment of formal physical activity (PA) guidelines has led to considerable interest in quantifying participation in moderate to vigorous PA (MVPA). However, evidence on the context of MVPA at the population level is scarce. The aim of this study was to provide information on the type, location, and purpose of MVPA in a representative sample of adults. Data from a representative sample of 1234 Iowa adults were included in this study. Each participant performed a telephone-administered 24-h PA recall method to recall PA in the previous 24 h. Self-reported data from the recall instrument included time and types of reported activities across five distinct location and purpose codes. Reported activities were matched with corresponding metabolic equivalent (MET) scores from a reduced list of compendium of physical activities. MVPA was defined as any activity with assigned MET ≥ 3.0. Of the top 30 most frequently reported MVPA, 16 were lifestyle activities involving walking, and only 4 can be regarded as traditional "exercises." Occupational activities (41% for purpose and 40% for location) and household activities (37% for purpose and 39% for location) accounted for nearly 80% of total reported MVPA time. Time allocations across purpose and location codes considerably differed by sociodemographic indicators. Lifestyle activities are more frequently reported than sports and/or recreational activities. Individuals with varying levels of sociodemographic indicators exhibit different patterns of use of time within a given day. A multidomain approach is needed to better understand and increase MVPA in diverse populations of US adults.

Representativeness of two sampling procedures for an internet intervention targeting cancer-related distress: a comparison of convenience and registry samples.

PubMed

Owen, Jason E; Bantum, Erin O'Carroll; Criswell, Kevin; Bazzo, Julie; Gorlick, Amanda; Stanton, Annette L

2014-08-01

Internet interventions often rely on convenience sampling, yet convenience samples may differ in important ways from systematic recruitment approaches. The purpose of this study was to evaluate potential demographic, medical, and psychosocial differences between Internet-recruited and registry-recruited cancer survivors in an Internet-based intervention. Participants were recruited from a cancer registry (n = 80) and via broad Internet outreach efforts (n = 160). Participants completed a set of self-report questionnaires, and both samples were compared to a population-based sample of cancer survivors (n = 5,150). The Internet sample was younger, better educated, more likely to be female, had longer time since diagnosis, and had more advanced stage of disease (p's < .001), and the registry-sample was over-represented by men and those with prostate or other cancer types (p's < .001). The Internet sample also exhibited lower quality of life and social support and greater mood disturbance (p's < .001). Understanding how convenience and systematic samples differ has important implications for external validity and potential for dissemination of Internet-based interventions.

Hiding in Plain Sight: A Case for Cryptic Metapopulations in Brook Trout (Salvelinus fontinalis)

PubMed Central

Kazyak, David C.; Hilderbrand, Robert H.; King, Tim L.; Keller, Stephen R.; Chhatre, Vikram E.

2016-01-01

A fundamental issue in the management and conservation of biodiversity is how to define a population. Spatially contiguous fish occupying a stream network have often been considered to represent a single, homogenous population. However, they may also represent multiple discrete populations, a single population with genetic isolation-by-distance, or a metapopulation. We used microsatellite DNA and a large-scale mark-recapture study to assess population structure in a spatially contiguous sample of Brook Trout (Salvelinus fontinalis), a species of conservation concern. We found evidence for limited genetic exchange across small spatial scales and in the absence of barriers to physical movement. Mark-recapture and stationary passive integrated transponder antenna records demonstrated that fish from two tributaries very seldom moved into the opposite tributary, but movements between the tributaries and mainstem were more common. Using Bayesian genetic clustering, we identified two genetic groups that exhibited significantly different growth rates over three years of study, yet survival rates were very similar. Our study highlights the importance of considering the possibility of multiple genetically distinct populations occurring within spatially contiguous habitats, and suggests the existence of a cryptic metapopulation: a spatially continuous distribution of organisms exhibiting metapopulation-like behaviors. PMID:26730588

Hiding in Plain Sight: A Case for Cryptic Metapopulations in Brook Trout (Salvelinus fontinalis).

PubMed

Kazyak, David C; Hilderbrand, Robert H; King, Tim L; Keller, Stephen R; Chhatre, Vikram E

2016-01-01

A fundamental issue in the management and conservation of biodiversity is how to define a population. Spatially contiguous fish occupying a stream network have often been considered to represent a single, homogenous population. However, they may also represent multiple discrete populations, a single population with genetic isolation-by-distance, or a metapopulation. We used microsatellite DNA and a large-scale mark-recapture study to assess population structure in a spatially contiguous sample of Brook Trout (Salvelinus fontinalis), a species of conservation concern. We found evidence for limited genetic exchange across small spatial scales and in the absence of barriers to physical movement. Mark-recapture and stationary passive integrated transponder antenna records demonstrated that fish from two tributaries very seldom moved into the opposite tributary, but movements between the tributaries and mainstem were more common. Using Bayesian genetic clustering, we identified two genetic groups that exhibited significantly different growth rates over three years of study, yet survival rates were very similar. Our study highlights the importance of considering the possibility of multiple genetically distinct populations occurring within spatially contiguous habitats, and suggests the existence of a cryptic metapopulation: a spatially continuous distribution of organisms exhibiting metapopulation-like behaviors.

Highly Diverse Endophytic and Soil Fusarium oxysporum Populations Associated with Field-Grown Tomato Plants

PubMed Central

Demers, Jill E.; Gugino, Beth K.

2014-01-01

The diversity and genetic differentiation of populations of Fusarium oxysporum associated with tomato fields, both endophytes obtained from tomato plants and isolates obtained from soil surrounding the sampled plants, were investigated. A total of 609 isolates of F. oxysporum were obtained, 295 isolates from a total of 32 asymptomatic tomato plants in two fields and 314 isolates from eight soil cores sampled from the area surrounding the plants. Included in this total were 112 isolates from the stems of all 32 plants, a niche that has not been previously included in F. oxysporum population genetics studies. Isolates were characterized using the DNA sequence of the translation elongation factor 1α gene. A diverse population of 26 sequence types was found, although two sequence types represented nearly two-thirds of the isolates studied. The sequence types were placed in different phylogenetic clades within F. oxysporum, and endophytic isolates were not monophyletic. Multiple sequence types were found in all plants, with an average of 4.2 per plant. The population compositions differed between the two fields but not between soil samples within each field. A certain degree of differentiation was observed between populations associated with different tomato cultivars, suggesting that the host genotype may affect the composition of plant-associated F. oxysporum populations. No clear patterns of genetic differentiation were observed between endophyte populations and soil populations, suggesting a lack of specialization of endophytic isolates. PMID:25304514

The Kalash Genetic Isolate: Ancient Divergence, Drift, and Selection

PubMed Central

Ayub, Qasim; Mezzavilla, Massimo; Pagani, Luca; Haber, Marc; Mohyuddin, Aisha; Khaliq, Shagufta; Mehdi, Syed Qasim; Tyler-Smith, Chris

2015-01-01

The Kalash represent an enigmatic isolated population of Indo-European speakers who have been living for centuries in the Hindu Kush mountain ranges of present-day Pakistan. Previous Y chromosome and mitochondrial DNA markers provided no support for their claimed Greek descent following Alexander III of Macedon's invasion of this region, and analysis of autosomal loci provided evidence of a strong genetic bottleneck. To understand their origins and demography further, we genotyped 23 unrelated Kalash samples on the Illumina HumanOmni2.5M-8 BeadChip and sequenced one male individual at high coverage on an Illumina HiSeq 2000. Comparison with published data from ancient hunter-gatherers and European farmers showed that the Kalash share genetic drift with the Paleolithic Siberian hunter-gatherers and might represent an extremely drifted ancient northern Eurasian population that also contributed to European and Near Eastern ancestry. Since the split from other South Asian populations, the Kalash have maintained a low long-term effective population size (2,319–2,603) and experienced no detectable gene flow from their geographic neighbors in Pakistan or from other extant Eurasian populations. The mean time of divergence between the Kalash and other populations currently residing in this region was estimated to be 11,800 (95% confidence interval = 10,600−12,600) years ago, and thus they represent present-day descendants of some of the earliest migrants into the Indian sub-continent from West Asia. PMID:25937445

The Kalash genetic isolate: ancient divergence, drift, and selection.

PubMed

Ayub, Qasim; Mezzavilla, Massimo; Pagani, Luca; Haber, Marc; Mohyuddin, Aisha; Khaliq, Shagufta; Mehdi, Syed Qasim; Tyler-Smith, Chris

2015-05-07

The Kalash represent an enigmatic isolated population of Indo-European speakers who have been living for centuries in the Hindu Kush mountain ranges of present-day Pakistan. Previous Y chromosome and mitochondrial DNA markers provided no support for their claimed Greek descent following Alexander III of Macedon's invasion of this region, and analysis of autosomal loci provided evidence of a strong genetic bottleneck. To understand their origins and demography further, we genotyped 23 unrelated Kalash samples on the Illumina HumanOmni2.5M-8 BeadChip and sequenced one male individual at high coverage on an Illumina HiSeq 2000. Comparison with published data from ancient hunter-gatherers and European farmers showed that the Kalash share genetic drift with the Paleolithic Siberian hunter-gatherers and might represent an extremely drifted ancient northern Eurasian population that also contributed to European and Near Eastern ancestry. Since the split from other South Asian populations, the Kalash have maintained a low long-term effective population size (2,319-2,603) and experienced no detectable gene flow from their geographic neighbors in Pakistan or from other extant Eurasian populations. The mean time of divergence between the Kalash and other populations currently residing in this region was estimated to be 11,800 (95% confidence interval = 10,600-12,600) years ago, and thus they represent present-day descendants of some of the earliest migrants into the Indian sub-continent from West Asia. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

The HealthNuts population-based study of paediatric food allergy: validity, safety and acceptability.

PubMed

Osborne, N J; Koplin, J J; Martin, P E; Gurrin, L C; Thiele, L; Tang, M L; Ponsonby, A-L; Dharmage, S C; Allen, K J

2010-10-01

The incidence of hospital admissions for food allergy-related anaphylaxis in Australia has increased, in line with world-wide trends. However, a valid measure of food allergy prevalence and risk factor data from a population-based study is still lacking. To describe the study design and methods used to recruit infants from a population for skin prick testing and oral food challenges, and the use of preliminary data to investigate the extent to which the study sample is representative of the target population. The study sampling frame design comprises 12-month-old infants presenting for routine scheduled vaccination at immunization clinics in Melbourne, Australia. We compared demographic features of participating families to population summary statistics from the Victorian Perinatal census database, and administered a survey to those non-responders who chose not to participate in the study. Study design proved acceptable to the community with good uptake (response rate 73.4%), with 2171 participants recruited. Demographic information on the study population mirrored the Victorian population with most the population parameters measured falling within our confidence intervals (CI). Use of a non-responder questionnaire revealed that a higher proportion of infants who declined to participate (non-responders) were already eating and tolerating peanuts, than those agreeing to participate (54.4%; 95% CI 50.8, 58.0 vs. 27.4%; 95% CI 25.5, 29.3 among participants). A high proportion of individuals approached in a community setting participated in a food allergy study. The study population differed from the eligible sample in relation to family history of allergy and prior consumption and peanut tolerance, providing some insights into the internal validity of the sample. The study exhibited external validity on general demographics to all births in Victoria. © 2010 Blackwell Publishing Ltd.

Turkish Population Structure and Genetic Ancestry Reveal Relatedness among Eurasian Populations

PubMed Central

Hodoğlugil, Uğur; Mahley, Robert W.

2013-01-01

Summary Turkey connects the Middle East, Europe, and Asia and has experienced major population movements. We examined the population structure and genetic relatedness of samples from three regions of Turkey using over 500,000 SNP genotypes. The data were analyzed together with Human Genome Diversity Panel data. To obtain a more representative sampling from Central Asia, Kyrgyz samples (Bishkek, Kyrgyzstan) were genotyped and analyzed. Principal component (PC) analysis reveals a significant overlap between Turks and Middle Easterners and a relationship with Europeans and South and Central Asians; however, the Turkish genetic structure is unique. FRAPPE, STRUCTURE, and phylogenetic analyses support the PC analysis depending upon the number of parental ancestry components chosen. For example, supervised STRUCTURE (K = 3) illustrates a genetic ancestry for the Turks of 45% Middle Eastern (95% CI, 42–49), 40% European (95% CI, 36–44), and 15% Central Asian (95% CI, 13–16), whereas at K = 4 the genetic ancestry of the Turks was 38% European (95% CI, 35–42), 35% Middle Eastern (95% CI, 33–38), 18% South Asian (95% CI, 16–19), and 9% Central Asian (95% CI, 7–11). PC analysis and FRAPPE/STRUCTURE results from three regions in Turkey (Aydin, Istanbul, and Kayseri) were superimposed, without clear subpopulation structure, suggesting the selected samples were rather homogeneous. Thus, this study demonstrates admixture of Turkish people reflecting the population migration patterns. PMID:22332727

Methodology of the 2009 Survey on Living with Chronic Diseases in Canada--hypertension component.

PubMed

Bienek, A S; Gee, M E; Nolan, R P; Kaczorowski, J; Campbell, N R; Bancej, C; Gwadry-Sridhar, F; Robitaille, C; Walker, R L; Dai, S

2013-09-01

The Survey on Living with Chronic Diseases in Canada--hypertension component (SLCDC-H) is a 20-minute cross-sectional telephone survey on hypertension diagnosis and management. Sampled from the 2008 Canadian Community Health Survey (CCHS), the SLCDC-H includes Canadians (aged ≥ 20 years) with self-reported hypertension from the ten provinces. The questionnaire was developed by Delphi technique, externally reviewed and qualitatively tested. Statistics Canada performed sampling strategies, recruitment, data collection and processing. Proportions were weighted to represent the Canadian population, and 95% confidence intervals (CIs) were derived by bootstrap method. Compared with the CCHS population reporting hypertension, the SLCDC-H sample (n = 6142) is slightly younger (SLCDC-H mean age: 61.2 years, 95% CI: 60.8-61.6; CCHS mean age: 62.2 years, 95% CI: 61.8-62.5), has more post-secondary school graduates (SLCDC-H: 52.0%, 95% CI: 49.7%-54.2%; CCHS: 47.5%, 95% CI: 46.1%-48.9%) and has fewer respondents on hypertension medication (SLCDC-H: 82.5%, 95% CI: 80.9%-84.1%; CCHS: 88.6%, 95% CI: 87.7%-89.6%). Overall, the 2009 SLCDC-H represents its source population and provides novel, comprehensive data on the diagnosis and management of hypertension. The survey has been adapted to other chronic conditions--diabetes, asthma/chronic obstructive pulmonary disease and neurological conditions. The questionnaire is available on the Statistics Canada website; descriptive results have been disseminated by the Public Health Agency of Canada.

Comparing the MMPI-2 scale scores of parents involved in parental competency and child custody assessments.

PubMed

Resendes, John; Lecci, Len

2012-12-01

MMPI-2 scores from a parent competency sample (N = 136 parents) are compared with a previously published data set of MMPI-2 scores for child custody litigants (N = 508 parents; Bathurst et al., 1997). Independent samples t tests yielded significant and in some cases substantial differences on the standard MMPI-2 clinical scales (especially Scales 4, 8, 2, and 0), with the competency sample obtaining higher clinical scores as well as higher scores on F, FB, VRIN, TRIN, and L, but lower scores on K, relative to the custody sample. Despite the higher scores in the competency sample, MMPI-2 mean scores did not exceed the clinical cutoff (T > 65). Moreover, the present competency sample essentially replicates the MMPI-2 scores of a previously published competency sample, suggesting that the present findings are representative of that population. The present findings suggest that separate reference groups be used when conducting child custody vs. parental competency evaluations, as these appear to be distinct populations despite there being similarities in the testing circumstances.

Spatio-temporal population structuring and genetic diversity retention in depleted Atlantic Bluefin tuna of the Mediterranean Sea

PubMed Central

Riccioni, Giulia; Landi, Monica; Ferrara, Giorgia; Milano, Ilaria; Cariani, Alessia; Zane, Lorenzo; Sella, Massimo; Barbujani, Guido; Tinti, Fausto

2010-01-01

Fishery genetics have greatly changed our understanding of population dynamics and structuring in marine fish. In this study, we show that the Atlantic Bluefin tuna (ABFT, Thunnus thynnus), an oceanic predatory species exhibiting highly migratory behavior, large population size, and high potential for dispersal during early life stages, displays significant genetic differences over space and time, both at the fine and large scales of variation. We compared microsatellite variation of contemporary (n = 256) and historical (n = 99) biological samples of ABFTs of the central-western Mediterranean Sea, the latter dating back to the early 20th century. Measures of genetic differentiation and a general heterozygote deficit suggest that differences exist among population samples, both now and 96–80 years ago. Thus, ABFTs do not represent a single panmictic population in the Mediterranean Sea. Statistics designed to infer changes in population size, both from current and past genetic variation, suggest that some Mediterranean ABFT populations, although still not severely reduced in their genetic potential, might have suffered from demographic declines. The short-term estimates of effective population size are straddled on the minimum threshold (effective population size = 500) indicated to maintain genetic diversity and evolutionary potential across several generations in natural populations. PMID:20080643

Frequent Users of Hospital Emergency Departments in Korea Characterized by Claims Data from the National Health Insurance: A Cross Sectional Study

PubMed Central

Woo, Jung Hoon; Grinspan, Zachary; Shapiro, Jason; Rhee, Sang Youl

2016-01-01

The Korean National Health Insurance, which provides universal coverage for the entire Korean population, is now facing financial instability. Frequent emergency department (ED) users may represent a medically vulnerable population who could benefit from interventions that both improve care and lower costs. To understand the nature of frequent ED users in Korea, we analyzed claims data from a population-based national representative sample. We performed both bivariate and multivariable analyses to investigate the association between patient characteristics and frequent ED use (4+ ED visits in a year) using claims data of a 1% random sample of the Korean population, collected in 2009. Among 156,246 total ED users, 4,835 (3.1%) were frequent ED users. These patients accounted for 14% of 209,326 total ED visits and 17.2% of $76,253,784 total medical expenses generated from all ED visits in the 1% data sample. Frequent ED users tended to be older, male, and of lower socio-economic status compared with occasional ED users (p < 0.001 for each). Moreover, frequent ED users had longer stays in the hospital when admitted, higher probability of undergoing an operative procedure, and increased mortality. Among 8,425 primary diagnoses, alcohol-related complaints and schizophrenia showed the strongest positive correlation with the number of ED visits. Among the frequent ED users, mortality and annual outpatient department visits were significantly lower in the alcohol-related patient subgroup compared with other frequent ED users; furthermore, the rate was even lower than that for non-frequent ED users. Our findings suggest that expanding mental health and alcohol treatment programs may be a reasonable strategy to decrease the dependence of these patients on the ED. PMID:26809051

Occurence of internet addiction in a general population sample: a latent class analysis.

PubMed

Rumpf, Hans-Jürgen; Vermulst, Ad A; Bischof, Anja; Kastirke, Nadin; Gürtler, Diana; Bischof, Gallus; Meerkerk, Gert-Jan; John, Ulrich; Meyer, Christian

2014-01-01

Prevalence studies of Internet addiction in the general population are rare. In addition, a lack of approved criteria hampers estimation of its occurrence. This study conducted a latent class analysis (LCA) in a large general population sample to estimate prevalence. A telephone survey was conducted based on a random digit dialling procedure including landline telephone (n=14,022) and cell phone numbers (n=1,001) in participants aged 14-64. The Compulsive Internet Use Scale (CIUS) served as the basis for a LCA used to look for subgroups representing participants with Internet addiction or at-risk use. CIUS was given to participants reporting to use the Internet for private purposes at least 1 h on a typical weekday or at least 1 h on a day at the weekend (n=8,130). A 6-class model showed best model fit and included two groups likely to represent Internet addiction and at-risk Internet use. Both groups showed less social participation and the Internet addiction group less general trust in other people. Proportions of probable Internet addiction were 1.0% (CI 0.9-1.2) among the entire sample, 2.4% (CI 1.9-3.1) in the age group 14-24, and 4.0% (CI 2.7-5.7) in the age group 14-16. No difference in estimated proportions between males and females was found. Unemployment (OR 3.13; CI 1.74-5.65) and migration background (OR 3.04; CI 2.12-4.36) were related to Internet addiction. This LCA-based study differentiated groups likely to have Internet addiction and at-risk use in the general population and provides characteristics to further define this rather new disorder. © 2013 S. Karger AG, Basel.

Sampling intraspecific variability in leaf functional traits: Practical suggestions to maximize collected information.

PubMed

Petruzzellis, Francesco; Palandrani, Chiara; Savi, Tadeja; Alberti, Roberto; Nardini, Andrea; Bacaro, Giovanni

2017-12-01

The choice of the best sampling strategy to capture mean values of functional traits for a species/population, while maintaining information about traits' variability and minimizing the sampling size and effort, is an open issue in functional trait ecology. Intraspecific variability (ITV) of functional traits strongly influences sampling size and effort. However, while adequate information is available about intraspecific variability between individuals (ITV BI ) and among populations (ITV POP ), relatively few studies have analyzed intraspecific variability within individuals (ITV WI ). Here, we provide an analysis of ITV WI of two foliar traits, namely specific leaf area (SLA) and osmotic potential (π), in a population of Quercus ilex L. We assessed the baseline ITV WI level of variation between the two traits and provided the minimum and optimal sampling size in order to take into account ITV WI , comparing sampling optimization outputs with those previously proposed in the literature. Different factors accounted for different amount of variance of the two traits. SLA variance was mostly spread within individuals (43.4% of the total variance), while π variance was mainly spread between individuals (43.2%). Strategies that did not account for all the canopy strata produced mean values not representative of the sampled population. The minimum size to adequately capture the studied functional traits corresponded to 5 leaves taken randomly from 5 individuals, while the most accurate and feasible sampling size was 4 leaves taken randomly from 10 individuals. We demonstrate that the spatial structure of the canopy could significantly affect traits variability. Moreover, different strategies for different traits could be implemented during sampling surveys. We partially confirm sampling sizes previously proposed in the recent literature and encourage future analysis involving different traits.

SHEEP: The Search for the High Energy Extragalactic Population

NASA Technical Reports Server (NTRS)

Nandra, K.; Georgantopoulos, I.; Ptak, A.; Turner, T. J.; White, Nicholas E. (Technical Monitor)

2002-01-01

We present the SHEEP survey for serendipitously-detected hard X-ray sources in ASCA GIS images. In a survey area of approx. 40 sq deg, 69 sources were detected in the 5-10 keV band to a limiting flux of approx. 10(exp -13) erg/sq cm/s. The number counts agree with those obtained by the similar BeppoSAX HELLAS survey, and both are in close agreement with ASCA and BeppoSAX 2-10 keV surveys. Spectral analysis of the SHEEP sample reveals that the 2-10 and 5-10 keV surveys do not sample the same populations, however, as we find considerably harder spectra, with an average Gamma approx. 1.0 assuming no absorption. The implication is that the agreement in the number counts is coincidental, with the 5-10 keV surveys gaining approximately as many hard sources as they lose soft ones, when compared to the 2-10 keV surveys. This is hard to reconcile with standard AGN "population synthesis" models for the X-ray background, which posit the existence of a large population of absorbed sources. We find no evidence of the population hardening at faint fluxes, with the exception that the few very brightest objects are anomalously soft. 53 of the SHEEP sources have been covered by ROSAT in the pointed phase. Of these 32 were detected. An additional 3 were detected in the RASS. As expected the sources detected with ROSAT are systematically softer than those detected with ASCA alone, and of the sample as a whole. Although they represent a biased subsample, the ROSAT positions allow relatively secure catalog identifications to be made. We find associations with a wide variety of AGN and a few clusters and groups. At least two X-ray sources identified with high-z QSOs present very hard X-ray spectra indicative of absorption, despite the presence of broad optical lines. A possible explanation for this is that we are seeing relatively dust-free "warm absorbers" in high luminosity/redshift objects. Our analysis defines a new, hard X-ray selected sample of objects - mostly active galactic nuclei - which is less prone to bias due to obscuration than previous optical or soft X-ray samples. They are therefore more representative of the population of AGN in the universe in general, and the SHEEP survey should produce bright examples of the sources that make up the hard X-ray background, the majority of which has recently been resolved by Chandra. This should help elucidate the nature of the new populations.

Forensic parameters and admixture in Mestizos from five geographic regions of Mexico based on 20 autosomal STRs (Powerplex 21 system).

PubMed

Aguilar-Velázquez, J A; Martínez-Cortés, G; Inclán-Sánchez, A; Favela-Mendoza, A F; Velarde-Félix, J S; Rangel-Villalobos, H

2018-03-01

We analyzed Mestizo (admixed) population samples from different geographic regions of Mexico (n = 1283) with 20 autosomal STRs (PowerPlex® 21, Promega Corp.). Allele frequencies and forensic parameters from the Northwest, Northeast, West, Center, and Southeast regions are reported, as well as from the pooled Mexican population sample. The combined PD and PE for this 20 STR system were > 0.9999999999 and > 0.99999996593% in all five population samples, respectively. Analysis of molecular variance (AMOVA) of these Mexican population samples, plus Monterrey (Northeast) and Mexico (Center) Cities, showed low but significant differences among Mexican-Mestizos from the seven populations (Fst = 0.20%; p = 0.0000). Structure analysis showed the highest proportion of Native American ancestry in Mexico City, Center, and Southeast regions, respectively, which was in agreement with the estimated genetic distances represented in a MDS plot and a NJ tree. The best fit of population clusters (K = 4) obtained with the Structure software indicates that Mexican-Mestizos are mainly composed by European, African, and two Native American ancestries. The European and Native American ancestries displayed a contrary gradient, increasing toward the North-West and South-Southeast, respectively. These 20 autosomal STR loci improved the admixture estimation regarding previous studies with the 13 CODIS-STRs, as supported by the higher similarity with previous estimates based on genome-wide SNP. In brief, this study validates the confident use of the PowerPlex® 21 system for human identification purposes in Mestizo populations throughout the Mexican territory.

Recruitment and Participation of Recreational Runners in a Large Epidemiological and Genetic Research Study: Retrospective Data Analysis

PubMed Central

Manzanero, Silvia; Kozlovskaia, Maria; Vlahovich, Nicole

2018-01-01

Background With the increasing capacity for remote collection of both data and samples for medical research, a thorough assessment is needed to determine the association of population characteristics and recruitment methodologies with response rates. Objective The aim of this research was to assess population representativeness in a two-stage study of health and injury in recreational runners, which consisted of an epidemiological arm and genetic analysis. Methods The cost and success of various classical and internet-based methods were analyzed, and demographic representativeness was assessed for recruitment to the epidemiological survey, reported willingness to participate in the genetic arm of the study, actual participation, sample return, and approval for biobank storage. Results A total of 4965 valid responses were received, of which 1664 were deemed eligible for genetic analysis. Younger age showed a negative association with initial recruitment rate, expressed willingness to participate in genetic analysis, and actual participation. Additionally, female sex was associated with higher initial recruitment rates, and ethnic origin impacted willingness to participate in the genetic analysis (all P<.001). Conclusions The sharp decline in retention through the different stages of the study in young respondents suggests the necessity to develop specific recruitment and retention strategies when investigating a young, physically active population. PMID:29792293

Effects of aging on sleep structure throughout adulthood: a population-based study.

PubMed

Moraes, Walter; Piovezan, Ronaldo; Poyares, Dalva; Bittencourt, Lia Rita; Santos-Silva, Rogerio; Tufik, Sergio

2014-04-01

Although many studies have shown the evolution of sleep parameters across the lifespan, not many have included a representative sample of the general population. The objective of this study was to describe age-related changes in sleep structure, sleep respiratory parameters and periodic limb movements of the adult population of São Paulo. We selected a representative sample of the city of São Paulo, Brazil that included both genders and an age range of 20-80 years. Pregnant and lactating women, people with physical or mental impairments that prevent self-care and people who work every night were not included. This sample included 1024 individuals who were submitted to polysomnography and structured interviews. We subdivided our sample into five-year age groups. One-way analysis of variance was used to compare age groups. Pearson product-moment was used to evaluate correlation between age and sleep parameters. Total sleep time, sleep efficiency, percentage of rapid eye movement (REM) sleep and slow wave sleep showed a significant age-related decrease (P<0.05). WASO (night-time spent awake after sleep onset), arousal index, sleep latency, REM sleep latency, and the percentage of stages 1 and 2 showed a significant increase (P<0.05). Furthermore, apnea-hypopnea index increased and oxygen saturation decreased with age. The reduction in the percentage of REM sleep significantly correlated with age in women, whereas the reduction in the percentage of slow wave sleep correlated with age in men. The periodic limb movement (PLM) index increased with age in men and women. Sleep structure and duration underwent significant alterations throughout the aging process in the general population. There was an important correlation between age, sleep respiratory parameters and PLM index. In addition, men and women showed similar trends but with different effect sizes. Copyright © 2014 Elsevier B.V. All rights reserved.

Ecogenomics and potential biogeochemical impacts of globally abundant ocean viruses.

PubMed

Roux, Simon; Brum, Jennifer R; Dutilh, Bas E; Sunagawa, Shinichi; Duhaime, Melissa B; Loy, Alexander; Poulos, Bonnie T; Solonenko, Natalie; Lara, Elena; Poulain, Julie; Pesant, Stéphane; Kandels-Lewis, Stefanie; Dimier, Céline; Picheral, Marc; Searson, Sarah; Cruaud, Corinne; Alberti, Adriana; Duarte, Carlos M; Gasol, Josep M; Vaqué, Dolors; Bork, Peer; Acinas, Silvia G; Wincker, Patrick; Sullivan, Matthew B

2016-09-29

Ocean microbes drive biogeochemical cycling on a global scale. However, this cycling is constrained by viruses that affect community composition, metabolic activity, and evolutionary trajectories. Owing to challenges with the sampling and cultivation of viruses, genome-level viral diversity remains poorly described and grossly understudied, with less than 1% of observed surface-ocean viruses known. Here we assemble complete genomes and large genomic fragments from both surface- and deep-ocean viruses sampled during the Tara Oceans and Malaspina research expeditions, and analyse the resulting 'global ocean virome' dataset to present a global map of abundant, double-stranded DNA viruses complete with genomic and ecological contexts. A total of 15,222 epipelagic and mesopelagic viral populations were identified, comprising 867 viral clusters (defined as approximately genus-level groups). This roughly triples the number of known ocean viral populations and doubles the number of candidate bacterial and archaeal virus genera, providing a near-complete sampling of epipelagic communities at both the population and viral-cluster level. We found that 38 of the 867 viral clusters were locally or globally abundant, together accounting for nearly half of the viral populations in any global ocean virome sample. While two-thirds of these clusters represent newly described viruses lacking any cultivated representative, most could be computationally linked to dominant, ecologically relevant microbial hosts. Moreover, we identified 243 viral-encoded auxiliary metabolic genes, of which only 95 were previously known. Deeper analyses of four of these auxiliary metabolic genes (dsrC, soxYZ, P-II (also known as glnB) and amoC) revealed that abundant viruses may directly manipulate sulfur and nitrogen cycling throughout the epipelagic ocean. This viral catalog and functional analyses provide a necessary foundation for the meaningful integration of viruses into ecosystem models where they act as key players in nutrient cycling and trophic networks.

Psychometric properties and measurement invariance of the Beck hopelessness scale (BHS): results from a German representative population sample.

PubMed

Kliem, Sören; Lohmann, Anna; Mößle, Thomas; Brähler, Elmar

2018-04-25

The Beck Hopelessness Scale (BHS) has been the most frequently used instrument for the measurement of hopelessness in the past 40 years. Only recently has it officially been translated into German. The psychometric properties and factor structure of the BHS have been cause for intensive debate in the past. Based on a representative sample of the German population (N = 2450) item analysis including item sensitivity, item-total correlation and item difficulty was performed. Confirmatory factor analyses (CFA) for several factor solutions from the literature were performed. Multiple group factor analysis was performed to assess measurement invariance. Construct validity was assessed via the replication of well-established correlations with concurrently assessed measures. Most items exhibited adequate properties. Items #4, #8 and #13 exhibited poor item characteristics- each of these items had previously received negative evaluations in international studies. A one-dimensional factor solution, favorable for the calculation and interpretation of a sum score, was regarded as adequate. A bi-factor model with one content factor and two method factors (defined by positive/negative item coding) resulted in an excellent model fit. Cronbach's alpha in the current sample was .87. Hopelessness, as measured by the BHS, significantly correlated in the expected direction with suicidal ideation (r = .36), depression (r = .53) and life satisfaction (r = -.53). Strict measurement invariance could be established regarding gender and depression status. Due to limited research regarding the interpretation of fit indices with dichotomous data, interpretation of CFA results needs to remain tentative. The BHS is a valid measure of hopelessness in various subgroups of the general population. Future research could aim at replicating these findings using item response theory and cross-cultural samples. A one-dimensional bi-factor model seems appropriate even in a non-clinical population.

Ecogenomics and potential biogeochemical impacts of globally abundant ocean viruses

NASA Astrophysics Data System (ADS)

2016-09-01

Ocean microbes drive biogeochemical cycling on a global scale. However, this cycling is constrained by viruses that affect community composition, metabolic activity, and evolutionary trajectories. Owing to challenges with the sampling and cultivation of viruses, genome-level viral diversity remains poorly described and grossly understudied, with less than 1% of observed surface-ocean viruses known. Here we assemble complete genomes and large genomic fragments from both surface- and deep-ocean viruses sampled during the Tara Oceans and Malaspina research expeditions, and analyse the resulting ‘global ocean virome’ dataset to present a global map of abundant, double-stranded DNA viruses complete with genomic and ecological contexts. A total of 15,222 epipelagic and mesopelagic viral populations were identified, comprising 867 viral clusters (defined as approximately genus-level groups). This roughly triples the number of known ocean viral populations and doubles the number of candidate bacterial and archaeal virus genera, providing a near-complete sampling of epipelagic communities at both the population and viral-cluster level. We found that 38 of the 867 viral clusters were locally or globally abundant, together accounting for nearly half of the viral populations in any global ocean virome sample. While two-thirds of these clusters represent newly described viruses lacking any cultivated representative, most could be computationally linked to dominant, ecologically relevant microbial hosts. Moreover, we identified 243 viral-encoded auxiliary metabolic genes, of which only 95 were previously known. Deeper analyses of four of these auxiliary metabolic genes (dsrC, soxYZ, P-II (also known as glnB) and amoC) revealed that abundant viruses may directly manipulate sulfur and nitrogen cycling throughout the epipelagic ocean. This viral catalog and functional analyses provide a necessary foundation for the meaningful integration of viruses into ecosystem models where they act as key players in nutrient cycling and trophic networks.

The effects of land use on fluvial sediment chemistry for the conterminous U.S. - Results from the first cycle of the NAWQA Program: Trace and major elements, phosphorus, carbon, and sulfur

USGS Publications Warehouse

Horowitz, A.J.; Stephens, V.C.

2008-01-01

In 1991, the U.S. Geological Survey (USGS) began the first cycle of its National Water Quality Assessment (NAWQA) Program. The Program encompassed 51 river basins that collectively accounted for more than 70% of the total water use (excluding power generation), and 50% of the drinking water supply in the U.S. The basins represented a variety of hydrologic settings, rock types (geology), land-use categories, and population densities. One aspect of the first cycle included bed sediment sampling; sites were chosen to represent baseline and important land-use categories (e.g., agriculture, urban) in each basin. In total, over 1200 bed sediment samples were collected. All samples were size-limited (< 63????m) to facilitate spatial and/or temporal comparisons, and subsequently analyzed for a variety of chemical constituents including major (e.g., Fe, Al,) and trace elements (e.g., Cu, Zn, Cd), nutrients (e.g., P), and carbon. The analyses yielded total (??? 95% of the concentrations present), rather than total-recoverable chemical data. Land-use percentages, upstream underlying geology, and population density were determined for each site and evaluated to asses their relative influence on sediment chemistry. Baseline concentrations for the entire U.S. also were generated from a subset of all the samples, and are based on material collected from low population (??? 27??p km- 2) density, low percent urban (??? 5%), agricultural or undeveloped areas. The NAWQA baseline values are similar to those found in other national and global datasets. Further, it appears that upstream/underlying rock type has only a limited effect (mostly major elements) on sediment chemistry. The only land-use category that appears to substantially affect sediment chemistry is percent urban, and this result is mirrored by population density; in fact, the latter appears more consistent than the former.

Value of information methods to design a clinical trial in a small population to optimise a health economic utility function.

PubMed

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 whom the treatment under investigation is intended. This might be particularly suitable for small populations when there is considerable information about the patient population.

The red and blue galaxy populations in the GOODS field: evidence for an excess of red dwarfs

NASA Astrophysics Data System (ADS)

Salimbeni, S.; Giallongo, E.; Menci, N.; Castellano, M.; Fontana, A.; Grazian, A.; Pentericci, L.; Trevese, D.; Cristiani, S.; Nonino, M.; Vanzella, E.

2008-01-01

Aims: We study the evolution of the galaxy population up to z˜ 3 as a function of its colour properties. In particular, luminosity functions and luminosity densities were derived as a function of redshift for the blue/late and red/early populations. Methods: We use data from the GOODS-MUSIC catalogue, which have typical magnitude limits z850≤ 26 and K_s≤ 23.5 for most of the sample. About 8% of the galaxies have spectroscopic redshifts; the remaining have well calibrated photometric redshifts derived from the extremely wide multi-wavelength coverage in 14 bands (from the U band to the Spitzer 8~ μm band). We have derived a catalogue of galaxies complete in the rest-frame B-band, which has been divided into two subsamples according to their rest-frame U-V colour (or derived specific star formation rate) properties. Results: We confirm a bimodality in the U-V colour and specific star formation rate of the galaxy sample up to z˜ 3. This bimodality is used to compute the luminosity functions of the blue/late and red/early subsamples. The luminosity functions of the blue/late and total samples are well represented by steep Schechter functions evolving in luminosity with increasing redshifts. The volume density of the luminosity functions of the red/early populations decreases with increasing redshift. The shape of the red/early luminosity functions shows an excess of faint red dwarfs with respect to the extrapolation of a flat Schechter function and can be represented by the sum of two Schechter functions. Our model for galaxy formation in the hierarchical clustering scenario, which also includes external feedback due to a diffuse UV background, shows a general broad agreement with the luminosity functions of both populations, the larger discrepancies being present at the faint end for the red population. Hints on the nature of the red dwarf population are given on the basis of their stellar mass and spatial distributions.

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

PubMed

Kotěrová, Anežka; Velemínská, Jana; Dupej, Ján; Brzobohatá, Hana; Pilný, Aleš; Brůžek, Jaroslav

2017-01-01

Forensic anthropology has developed classification techniques for sex estimation of unknown skeletal remains, for example population-specific discriminant function analyses. These methods were designed for populations that lived mostly in the late nineteenth and twentieth centuries. Their level of reliability or misclassification is important for practical use in today's forensic practice; it is, however, unknown. We addressed the question of what the likelihood of errors would be if population specificity of discriminant functions of the tibia were disregarded. Moreover, five classification functions in a Czech sample were proposed (accuracies 82.1-87.5 %, sex bias ranged from -1.3 to -5.4 %). We measured ten variables traditionally used for sex assessment of the tibia on a sample of 30 male and 26 female models from recent Czech population. To estimate the classification accuracy and error (misclassification) rates ignoring population specificity, we selected published classification functions of tibia for the Portuguese, south European, and the North American populations. These functions were applied on the dimensions of the Czech population. Comparing the classification success of the reference and the tested Czech sample showed that females from Czech population were significantly overestimated and mostly misclassified as males. Overall accuracy of sex assessment significantly decreased (53.6-69.7 %), sex bias -29.4-100 %, which is most probably caused by secular trend and the generally high variability of body size. Results indicate that the discriminant functions, developed for skeletal series representing geographically and chronologically diverse populations, are not applicable in current forensic investigations. Finally, implications and recommendations for future research are discussed.

Association between edentulism and angina pectoris in Mexican adults aged 35 years and older: a multivariate analysis of a population-based survey.

PubMed

Medina-Solís, Carlo Eduardo; Pontigo-Loyola, América Patricia; Pérez-Campos, Eduardo; Hernández-Cruz, Pedro; Ávila-Burgos, Leticia; Kowolik, Michael J; Maupomé, Gerardo

2014-03-01

The possible association between oral infection and chronic inflammation and cardiovascular disease risk has been studied intensively. The present study is designed to determine the strength of association between edentulism and angina pectoris in Mexican adults aged 35 years and older. Using the tools and sampling strategies of the World Health Survey of the World Health Organization, cross-sectional data were collected in Mexico in the National Performance Assessment Survey (probabilistic, multistage, and cluster sampling). Dental information was available for 20 of the 32 states of Mexico. Angina and edentulism are self-reported in this study. Statistical analysis was performed using binary logistic regression adjusting for complex samples. A total of 13,966 participants, representing a population of 29,853,607 individuals, were included. Of the complete study population, 3,052,263 (10.2%) were completely toothless, and 673,810 (2.3%) were diagnosed with angina pectoris. After adjusting for smoking, alcohol consumption, diabetes, body mass index, and sex, the effect of edentulism on angina was modified by age (interaction), being more marked in the younger age group (odds ratio [OR] = exp(2.5597) =12.93) than in the older individuals surveyed (OR = exp(2.5597 + (-0.0334)) =12.51). Additionally, low physical activity (OR = 1.51; 95% confidence interval [CI] = 1.03 to 2.22) and higher socioeconomic status (OR = 1.37; 95% CI = 1.00 to 1.90) were more likely to be associated with angina pectoris. Overall, the results of this study, conducted in a representative sample of Mexican adults, suggest that an association exists between edentulism and angina pectoris. Additional studies are necessary to elucidate the underlying mechanism for this association.

Attitudes toward Bisexual Men and Women among a Nationally Representative Probability Sample of Adults in the United States

PubMed Central

Herbenick, Debby; Friedman, M. Reuel; Schick, Vanessa; Fu, Tsung-Chieh (Jane); Bostwick, Wendy; Bartelt, Elizabeth; Muñoz-Laboy, Miguel; Pletta, David; Reece, Michael; Sandfort, Theo G. M.

2016-01-01

As bisexual individuals in the United States (U.S.) face significant health disparities, researchers have posited that these differences may be fueled, at least in part, by negative attitudes, prejudice, stigma, and discrimination toward bisexual individuals from heterosexual and gay/lesbian individuals. Previous studies of individual and social attitudes toward bisexual men and women have been conducted almost exclusively with convenience samples, with limited generalizability to the broader U.S. population. Our study provides an assessment of attitudes toward bisexual men and women among a nationally representative probability sample of heterosexual, gay, lesbian, and other-identified adults in the U.S. Data were collected from the 2015 National Survey of Sexual Health and Behavior (NSSHB), via an online questionnaire with a probability sample of adults (18 years and over) from throughout the U.S. We included two modified 5-item versions of the Bisexualities: Indiana Attitudes Scale (BIAS), validated sub-scales that were developed to measure attitudes toward bisexual men and women. Data were analyzed using descriptive statistics, gamma regression, and paired t-tests. Gender, sexual identity, age, race/ethnicity, income, and educational attainment were all significantly associated with participants' attitudes toward bisexual individuals. In terms of responses to individual scale items, participants were most likely to “neither agree nor disagree” with all attitudinal statements. Across sexual identities, self-identified other participants reported the most positive attitudes, while heterosexual male participants reported the least positive attitudes. As in previous research on convenience samples, we found a wide range of demographic characteristics were related with attitudes toward bisexual individuals in our nationally-representative study of heterosexual, gay/lesbian, and other-identified adults in the U.S. In particular, gender emerged as a significant characteristic; female participants’ attitudes were more positive than male participants’ attitudes, and all participants’ attitudes were generally more positive toward bisexual women than bisexual men. While recent population data suggest a marked shift in more positive attitudes toward gay men and lesbian women in the general population of the U.S., the largest proportions of participants in our study reported a relative lack of agreement or disagreement with all affective-evaluative statements in the BIAS scales. Findings document the relative lack of positive attitudes toward bisexual individuals among the general population of adults in the U.S. and highlight the need for developing intervention approaches to promote more positive attitudes toward bisexual individuals, targeted toward not only heterosexual but also gay/lesbian individuals and communities. PMID:27783644

Impact of Bioreactor Environment and Recovery Method on the Profile of Bacterial Populations from Water Distribution Systems.

PubMed

Luo, Xia; Jellison, Kristen L; Huynh, Kevin; Widmer, Giovanni

2015-01-01

Multiple rotating annular reactors were seeded with biofilms flushed from water distribution systems to assess (1) whether biofilms grown in bioreactors are representative of biofilms flushed from the water distribution system in terms of bacterial composition and diversity, and (2) whether the biofilm sampling method affects the population profile of the attached bacterial community. Biofilms were grown in bioreactors until thickness stabilized (9 to 11 weeks) and harvested from reactor coupons by sonication, stomaching, bead-beating, and manual scraping. High-throughput sequencing of 16S rRNA amplicons was used to profile bacterial populations from flushed biofilms seeded into bioreactors as well as biofilms recovered from bioreactor coupons by different methods. β diversity between flushed and reactor biofilms was compared to β diversity between (i) biofilms harvested from different reactors and (ii) biofilms harvested by different methods from the same reactor. These analyses showed that average diversity between flushed and bioreactor biofilms was double the diversity between biofilms from different reactors operated in parallel. The diversity between bioreactors was larger than the diversity associated with different biofilm recovery methods. Compared to other experimental variables, the method used to recover biofilms had a negligible impact on the outcome of water biofilm analyses based on 16S amplicon sequencing. Results from this study show that biofilms grown in reactors over 9 to 11 weeks are not representative models of the microbial populations flushed from a distribution system. Furthermore, the bacterial population profile of biofilms grown in replicate reactors from the same flushed water are likely to diverge. However, four common sampling protocols, which differ with respect to disruption of bacterial cells, provide similar information with respect to the 16S rRNA population profile of the biofilm community.

The German Version of the Dutch Eating Behavior Questionnaire: Psychometric Properties, Measurement Invariance, and Population-Based Norms

PubMed Central

Hilbert, Anja; de Zwaan, Martina; Braehler, Elmar; Kersting, Anette

2016-01-01

The Dutch Eating Behavior Questionnaire is an internationally widely used instrument assessing different eating styles that may contribute to weight gain and overweight: emotional eating, external eating, and restraint. This study aimed to evaluate the psychometric properties of the 30-item German version of the DEBQ including its measurement invariance across gender, age, and BMI-status in a representative German population sample. Furthermore, we examined the distribution of eating styles in the general population and provide population-based norms for DEBQ scales. A representative sample of the German general population (N = 2513, age ≥ 14 years) was assessed with the German version of the DEBQ along with information on sociodemographic characteristics and body weight and height. The German version of the DEQB demonstrates good item characteristics and reliability (restraint: α = .92, emotional eating: α = .94, external eating: α = .89). The 3-factor structure of the DEBQ could be replicated in exploratory and confirmatory factor analyses and results of multi-group confirmatory factor analyses supported its metric and scalar measurement invariance across gender, age, and BMI-status. External eating was the most prevalent eating style in the German general population. Women scored higher on emotional and restrained eating scales than men, and overweight individuals scored higher in all three eating styles compared to normal weight individuals. Small differences across age were found for external eating. Norms were provided according to gender, age, and BMI-status. Our findings suggest that the German version of the DEBQ has good reliability and construct validity, and is suitable to reliably measure eating styles across age, gender, and BMI-status. Furthermore, the results demonstrate a considerable variation of eating styles across gender and BMI-status. PMID:27656879

Social acceptance and population confidence in telehealth in Quebec.

PubMed

Poder, Thomas G; Bellemare, Christian A; Bédard, Suzanne K; Lemieux, Renald

2015-02-21

Access to healthcare in remote areas is difficult and telehealth could be a promising avenue if accepted by the population. The aim of this study is to assess social acceptance and population confidence in telehealth in the Province of Quebec. We conducted a survey using a questionnaire assessing the social acceptance of and confidence level in telehealth. Two strategies were used: 1) paper questionnaires were sent to two hospitals in Quebec; and 2) online questionnaires were randomly sent by a firm specialized in online survey to a representative sample of the population of the Province of Quebec. Respondents were all residents of the Province of Quebec and 18 years and older. Questions were scored with a four-level Likert scale. A total of 1816 questionnaires were analyzed (229 written and 1,587 online questionnaires). The socio-demographic variables in our samples, especially the online questionnaires, were fairly representative of Quebec's population. Overall, social acceptance scored at 77.71% and confidence level at 65.76%. Both scores were higher in the case of treatment (3 scenarios were proposed) vs. diagnosis (p < 0.05). No difference was found when respondents were asked to respond for themselves and for a member of their family, which demonstrates a true interest in telehealth in Quebec. In addition, we found a significant difference (p < 0.05) between written and online questionnaires regarding social acceptance (80.75% vs. 77.33%) and confidence level (74.84% vs. 64.55%). These differences may be due to social desirability or avidity bias in the written questionnaires. Our results suggest that the population in Quebec encourages the development of telehealth for real time diagnosis and long distance treatment for regions deprived of healthcare professionals.

The German Version of the Dutch Eating Behavior Questionnaire: Psychometric Properties, Measurement Invariance, and Population-Based Norms.

PubMed

Nagl, Michaela; Hilbert, Anja; de Zwaan, Martina; Braehler, Elmar; Kersting, Anette

The Dutch Eating Behavior Questionnaire is an internationally widely used instrument assessing different eating styles that may contribute to weight gain and overweight: emotional eating, external eating, and restraint. This study aimed to evaluate the psychometric properties of the 30-item German version of the DEBQ including its measurement invariance across gender, age, and BMI-status in a representative German population sample. Furthermore, we examined the distribution of eating styles in the general population and provide population-based norms for DEBQ scales. A representative sample of the German general population (N = 2513, age ≥ 14 years) was assessed with the German version of the DEBQ along with information on sociodemographic characteristics and body weight and height. The German version of the DEQB demonstrates good item characteristics and reliability (restraint: α = .92, emotional eating: α = .94, external eating: α = .89). The 3-factor structure of the DEBQ could be replicated in exploratory and confirmatory factor analyses and results of multi-group confirmatory factor analyses supported its metric and scalar measurement invariance across gender, age, and BMI-status. External eating was the most prevalent eating style in the German general population. Women scored higher on emotional and restrained eating scales than men, and overweight individuals scored higher in all three eating styles compared to normal weight individuals. Small differences across age were found for external eating. Norms were provided according to gender, age, and BMI-status. Our findings suggest that the German version of the DEBQ has good reliability and construct validity, and is suitable to reliably measure eating styles across age, gender, and BMI-status. Furthermore, the results demonstrate a considerable variation of eating styles across gender and BMI-status.

Gastrointestinal symptoms are still common in a general Western population.

PubMed

van Kerkhoven, L A S; Eikendal, T; Laheij, R J F; van Oijen, M G H; Jansen, J B M J

2008-01-01

Results from studies conducted in the late 1980s and early 1990 s showed that gastrointestinal symptoms were common among the general population. Meanwhile, lifestyle habits have changed and important treatment options have been introduced. This might have influenced symptom prevalence. This study aimed to describe the current prevalence of upper and lower gastrointestinal symptoms within the general population. For this purpose, a demographically representative sample of the Dutch population within the city of Nijmegen and surrounding areas was selected after careful comparison with demographic figures from a government demographic database. Participants were invited to fill in a valid self-report questionnaire about gastrointestinal symptoms and prevalence figures were calculated. A total of 5000 questionnaires was sent and 1616 (32%) were returned. Of these, 839 (52%) subjects reported having had upper (43%) or lower (38%) gastrointestinal symptoms in the past four weeks. The most prevalent individual symptoms reported were flatulence (47%), abdominal rumbling (40%), bloating (37%), alternating solid and loose stools (31%), belching (25%) and postprandial fullness (25%). People who smoked or used a proton pump inhibitor had an increased risk for reporting upper as well as lower gastrointestinal symptoms (OR 1.99; 95% CI 1.56 to 2.55, and OR 1.37; 95% CI 1.01 to 1.75, respectively for smoking; and OR 3.17; 95% CI 2.17 to 4.72, and OR 2.14; 95% CI 1.49 to 3.08, respectively for PPIs). Both upper and lower gastrointestinal symptoms are very common in a representative sample of a general Western population.

One-step estimation of networked population size: Respondent-driven capture-recapture with anonymity.

PubMed

Khan, Bilal; Lee, Hsuan-Wei; Fellows, Ian; Dombrowski, Kirk

2018-01-01

Size estimation is particularly important for populations whose members experience disproportionate health issues or pose elevated health risks to the ambient social structures in which they are embedded. Efforts to derive size estimates are often frustrated when the population is hidden or hard-to-reach in ways that preclude conventional survey strategies, as is the case when social stigma is associated with group membership or when group members are involved in illegal activities. This paper extends prior research on the problem of network population size estimation, building on established survey/sampling methodologies commonly used with hard-to-reach groups. Three novel one-step, network-based population size estimators are presented, for use in the context of uniform random sampling, respondent-driven sampling, and when networks exhibit significant clustering effects. We give provably sufficient conditions for the consistency of these estimators in large configuration networks. Simulation experiments across a wide range of synthetic network topologies validate the performance of the estimators, which also perform well on a real-world location-based social networking data set with significant clustering. Finally, the proposed schemes are extended to allow them to be used in settings where participant anonymity is required. Systematic experiments show favorable tradeoffs between anonymity guarantees and estimator performance. Taken together, we demonstrate that reasonable population size estimates are derived from anonymous respondent driven samples of 250-750 individuals, within ambient populations of 5,000-40,000. The method thus represents a novel and cost-effective means for health planners and those agencies concerned with health and disease surveillance to estimate the size of hidden populations. We discuss limitations and future work in the concluding section.

Dengue seroprevalence and force of primary infection in a representative population of urban dwelling Indonesian children.

PubMed

Prayitno, Ari; Taurel, Anne-Frieda; Nealon, Joshua; Satari, Hindra Irawan; Karyanti, Mulya Rahma; Sekartini, Rini; Soedjatmiko, Soedjatmiko; Gunardi, Hartono; Medise, Bernie Endyarni; Sasmono, R Tedjo; Simmerman, James Mark; Bouckenooghe, Alain; Hadinegoro, Sri Rezeki

2017-06-01

Indonesia reports the second highest dengue disease burden in the world; these data are from passive surveillance reports and are likely to be significant underestimates. Age-stratified seroprevalence data are relatively unbiased indicators of past exposure and allow understanding of transmission dynamics. To better understand dengue infection history and associated risk factors in Indonesia, a representative population-based cross-sectional dengue seroprevalence study was conducted in 1-18-year-old urban children. From October to November 2014, 3,210 children were enrolled from 30 geographically dispersed clusters. Serum samples were tested for anti-dengue IgG antibodies by indirect ELISA. A questionnaire investigated associations between dengue serologic status and household socio-demographic and behavioural factors. Overall, 3,194 samples were tested, giving an adjusted national seroprevalence in this urban population of 69.4% [95% CI: 64.4-74.3] (33.8% [95% CI: 26.4-41.2] in the 1-4-year-olds, 65.4% [95% CI: 69.1-71.7] in the 5-9-year-olds, 83.1% [95% CI: 77.1-89.0] in the 10-14-year-olds, and 89.0% [95% CI: 83.9-94.1] in the 15-18-year-olds). The median age of seroconversion estimated through a linear model was 4.8 years. Using a catalytic model and considering a constant force of infection we estimated 13.1% of children experience a primary infection per year. Through a hierarchical logistic multivariate model, the subject's age group (1-4 vs 5-9 OR = 4.25; 1-4 vs. 10-14 OR = 12.60; and 1-4 vs 15-18 OR = 21.87; p<0.0001) and the number of cases diagnosed in the household since the subject was born (p = 0.0004) remained associated with dengue serological status. This is the first dengue seroprevalence study in Indonesia that is targeting a representative sample of the urban paediatric population. This study revealed that more than 80% of children aged 10 years or over have experienced dengue infection at least once. Prospective incidence studies would likely reveal dengue burdens far in excess of reported incidence rates.

The effects of economic deprivation on psychological well-being among the working population of Switzerland

PubMed Central

Vetter, Stefan; Endrass, Jerome; Schweizer, Ivo; Teng, Hsun-Mei; Rossler, Wulf; Gallo, William T

2006-01-01

Background The association between poverty and mental health has been widely investigated. There is, however, limited evidence of mental health implications of working poverty, despite its representing a rapidly expanding segment of impoverished populations in many developed nations. In this study, we examined whether working poverty in Switzerland, a country with substantial recent growth among the working poor, was correlated with two dependent variables of interest: psychological health and unmet mental health need. Methods This cross-sectional study used data drawn from the first 3 waves (1999–2001) of the Swiss Household Panel, a nationally representative sample of the permanent resident population of Switzerland. The study sample comprised 5453 subjects aged 20–59 years. We used Generalized Estimating Equation models to investigate the association between working poverty and psychological well-being; we applied logistic regression models to analyze the link between working poverty and unmet mental health need. Working poverty was represented by dummy variables indicating financial deficiency, restricted standard of living, or both conditions. Results After controlling other factors, restricted standard of living was significantly (p < .001) negatively correlated with psychological well-being; it was also associated with approximately 50% increased risk of unmet mental health need (OR = 1.55; 95% CI 1.17 – 2.06). Conclusion The findings of this study contribute to our understanding of the potential psychological impact of material deprivation on working Swiss citizens. Such knowledge may aid in the design of community intervention programs to help reduce the individual and societal burdens of poverty in Switzerland. PMID:16952322

Insight into the bacterial gut microbiome of the North American moose (Alces alces)

PubMed Central

2012-01-01

Background The work presented here provides the first intensive insight into the bacterial populations in the digestive tract of the North American moose (Alces alces). Eight free-range moose on natural pasture were sampled, producing eight rumen samples and six colon samples. Second generation (G2) PhyloChips were used to determine the presence of hundreds of operational taxonomic units (OTUs), representing multiple closely related species/strains (>97% identity), found in the rumen and colon of the moose. Results A total of 789 unique OTUs were used for analysis, which passed the fluorescence and the positive fraction thresholds. There were 73 OTUs, representing 21 bacterial families, which were found exclusively in the rumen samples: Lachnospiraceae, Prevotellaceae and several unclassified families, whereas there were 71 OTUs, representing 22 bacterial families, which were found exclusively in the colon samples: Clostridiaceae, Enterobacteriaceae and several unclassified families. Overall, there were 164 OTUs that were found in 100% of the samples. The Firmicutes were the most dominant bacteria phylum in both the rumen and the colon. Microarray data available at ArrayExpress, accession number E-MEXP-3721. Conclusions Using PhyloTrac and UniFrac computer software, samples clustered into two distinct groups: rumen and colon, confirming that the rumen and colon are distinct environments. There was an apparent correlation of age to cluster, which will be validated by a larger sample size in future studies, but there were no detectable trends based upon gender. PMID:22992344

Carabelli's trait in contemporary Slovenes and inhabitants of a medieval settlement (Sredisce by the Drava River).

PubMed

Stamfelj, Iztok; Stefancić, Marija; Gaspersic, Dominik; Cvetko, Erika

2006-06-01

The objectives of this study were to determine the total frequency, expression and asymmetry of Carabelli's trait in permanent dentitions of contemporary Slovenes and a medieval skeletal population from northeastern Slovenia. A total of 254 dental casts from contemporary Slovene children were examined. The population of a medieval settlement (10th-15th centuries), was represented by 94 skeletons. A modification of the method of Alvesalo and associates was used to classify Carabelli's trait on a five-grade scale. The trait was expressed on the upper first molars of 79.7% of the contemporary subjects and 75.8% of the medieval sample. Positive expressions of the trait were found in 10.1% of the contemporary subjects and 15.2% of the medieval sample. While the observed total frequency of the trait in both samples is characteristic of Europeans, the rates of positive expressions are surprisingly low but consistent with data from a recently published worldwide literature survey. Both populations showed a low rate of left-right fluctuating asymmetry of the trait. This finding might reflect a pronounced ability of individuals in the medieval population to buffer unfavourable influences from the environment and a relatively low level of environmental stress in the contemporary population.

Estimating population size for Capercaillie (Tetrao urogallus L.) with spatial capture-recapture models based on genotypes from one field sample

USGS Publications Warehouse

Mollet, Pierre; Kery, Marc; Gardner, Beth; Pasinelli, Gilberto; Royle, Andy

2015-01-01

We conducted a survey of an endangered and cryptic forest grouse, the capercaillie Tetrao urogallus, based on droppings collected on two sampling occasions in eight forest fragments in central Switzerland in early spring 2009. We used genetic analyses to sex and individually identify birds. We estimated sex-dependent detection probabilities and population size using a modern spatial capture-recapture (SCR) model for the data from pooled surveys. A total of 127 capercaillie genotypes were identified (77 males, 46 females, and 4 of unknown sex). The SCR model yielded atotal population size estimate (posterior mean) of 137.3 capercaillies (posterior sd 4.2, 95% CRI 130–147). The observed sex ratio was skewed towards males (0.63). The posterior mean of the sex ratio under the SCR model was 0.58 (posterior sd 0.02, 95% CRI 0.54–0.61), suggesting a male-biased sex ratio in our study area. A subsampling simulation study indicated that a reduced sampling effort representing 75% of the actual detections would still yield practically acceptable estimates of total size and sex ratio in our population. Hence, field work and financial effort could be reduced without compromising accuracy when the SCR model is used to estimate key population parameters of cryptic species.

Caste- and ethnicity-based inequalities in HIV/AIDS-related knowledge gap: a case of Nepal.

PubMed

Atteraya, Madhu; Kimm, HeeJin; Song, In Han

2015-05-01

Caste- and ethnicity-based inequalities are major obstacles to achieving health equity. The authors investigated whether there is any association between caste- and ethnicity-based inequalities and HIV-related knowledge within caste and ethnic populations. They used the 2011 Nepal Demographic and Health Survey, a nationally represented cross-sectional study data set. The study sample consisted of 11,273 women between 15 and 49 years of age. Univariate and logistic regression models were used to examine the relationship between caste- and ethnicity-based inequalities and HIV-related knowledge. The study sample was divided into high Hindu caste (47.9 percent), "untouchable" caste (18.4 percent), and indigenous populations (33.7 percent). Within the study sample, the high-caste population was found to have the greatest knowledge of the means by which HIV is prevented and transmitted. After controlling for socioeconomic and demographic characteristics, untouchables were the least knowledgeable. The odds ratio for incomplete knowledge about transmission among indigenous populations was 1.27 times higher than that for high Hindu castes, but there was no significant difference in knowledge of preventive measures. The findings suggest the existence of a prevailing HIV knowledge gap. This in turn suggests that appropriate steps need to be implemented to convey complete knowledge to underprivileged populations.

Science, Technology, Engineering, and Mathematics (STEM) Participation among College Students with an Autism Spectrum Disorder

ERIC Educational Resources Information Center

Wei, Xin; Yu, Jennifer W.; Shattuck, Paul; McCracken, Mary; Blackorby, Jose

2013-01-01

Little research has examined the popular belief that individuals with an autism spectrum disorder (ASD) are more likely than the general population to gravitate toward science, technology, engineering, and mathematics (STEM) fields. This study analyzed data from the National Longitudinal Transition Study-2, a nationally representative sample of…

Greenness and Self-Reported Well-Being in a Representative Sample of the US Population (US-IALE 2018)

EPA Science Inventory

There is growing recognition that the natural environment has a critical role in promoting human health and well-being. However, we need to better characterize the magnitude of potential beneficial effects, at the individual level, and the factors that influence the association b...

Assessing Literacy: The Framework for the National Adult Literacy Survey.

ERIC Educational Resources Information Center

Campbell, Anne; And Others

To satisfy federal requirements, the National Center for Education Statistics and the Division of Adult Education and Literacy planned a nationally representative household sample survey to assess the literacy skills of the adult population of the United States, to be conducted by the Educational Testing Service with the assistance of Westat, Inc.…

Meaningful Commitment: Finding Meaning in Volunteer Work

ERIC Educational Resources Information Center

Schnell, Tatjana; Hoof, Matthias

2012-01-01

This study tests the hypothesis that volunteer work is associated with various aspects of meaning making by employing a multi-dimensional model of meaning operationalized by the "Sources of Meaning and Meaning in Life Questionnaire" ("SoMe"). An empirical study comparing 168 volunteers with a representative sample of the general population (N =…

Student Needs and Priorities Survey, California State University, Fresno, Spring 1989.

ERIC Educational Resources Information Center

Daigle, Stephen L.; Stock, William P.

The 1989 Student Needs and Priorities Survey (SNAPS) was administered on 18 of the 19 California State University (CSU) campuses to obtain a representative sample of student opinions and perceptions regarding important educational factors. This report supplements the systemwide report with a focus on the Fresno campus student population.…

Brief Report: Sexual Attraction and Relationships in Adolescents with Autism

ERIC Educational Resources Information Center

May, Tamara; Pang, Ken C.; Williams, Katrina

2017-01-01

Past research suggests more variation in sexual attraction in Autism Spectrum Disorder (ASD) using clinical samples. This study utilised a population representative group of 14/15 year olds from the Longitudinal Study of Australian Children. Ninety-four adolescents (73 males, 21 females) with ASD and 3454 (1685 males, 1675 females) without…

Dual Use of Cigarettes and Smokeless Tobacco among South African Adolescents

ERIC Educational Resources Information Center

Rantao, Masego; Ayo-Yusuf, Olalekan A.

2012-01-01

Objectives: To determine factors associated with dual use of tobacco products in a population of black South African adolescents. Methods: Data were obtained from a self-administered questionnaire completed by a representative sample of grade 8 students from 21 randomly selected secondary state schools in the Limpopo Province, South Africa (n =…

Correlates of Sexual Abuse and Smoking among French Adults

ERIC Educational Resources Information Center

King, Gary; Guilbert, Philippe; Ward, D. Gant; Arwidson, Pierre; Noubary, Farzad

2006-01-01

Objective: The goal of this study was to examine the association between sexual abuse (SA) and initiation, cessation, and current cigarette smoking among a large representative adult population in France. Method: A random sample size of 12,256 adults (18-75 years of age) was interviewed by telephone concerning demographic variables, health…

The Measurement and Evaluation of Social Attitudes in Two British Cohort Studies

ERIC Educational Resources Information Center

Cheng, Helen; Bynner, John; Wiggins, Richard; Schoon, Ingrid

2012-01-01

This paper presents an empirical evaluation of the internal consistency and validity of six attitudes scales assessing left-right beliefs, political cynicism, antiracism, libertarian-authoritarian views, and gender equality (two versions) in two large nationally representative samples of the British population born in 1958 and 1970. In the 1958…

Adult Literacy: An International Perspective. Working Paper Series.

ERIC Educational Resources Information Center

Binkley, Marilyn; Matheson, Nancy; Williams, Trevor

The comparison of adult literacy in the United States and in other countries is based on data gathered in interviews with a sample of individuals representative of the population aged 16-65 in twelve countries: Sweden, the Netherlands, Canada, Germany, New Zealand, Australia, the United States, Belgium, the United Kingdom, Ireland, Switzerland,…

Smoking Habits among Teachers in Primary Schools in Norway 1977.

ERIC Educational Resources Information Center

Seip, Anne Karen

1982-01-01

A representative sample (N=1988) of members of the two main teachers' organizations in Norway were mailed questionnaires in the spring of 1977 regarding their past and present smoking habits, and 92 percent responded. The percentage of daily smokers among the teachers was approximately half of that found in the general population. (BRR)

English Learners with Disabilities in High School: Population Characteristics, Transition Programs, and Postschool Outcomes

ERIC Educational Resources Information Center

Trainor, Audrey; Murray, Angela; Kim, Hye-Jung

2016-01-01

Little is known about the characteristics, transition education, and postschool outcomes of English learners with disabilities (ELSWDs), despite that English learners are a rapidly growing group of U.S. students with consistently poor outcomes. This study examines a nationally representative sample of ELSWDs through a secondary analysis of the…

Impact of a spring defoliator on common oak

Treesearch

Victor V. Rubtsov; Irina A. Utkina

1991-01-01

We have investigated the population dynamics of some common phyllophagous insects in oak stands of the forest-steppe zone and their impact on common oak (Quercus robur L). Considerable attention has also been paid to mathematical modeling of the studied processes. All field data represent samples taken from the Tellerman oak grove in the Voronezh...

Data Tables for FACES 2006: A Year in Head Start Report. ACF-ORPRE Report

ERIC Educational Resources Information Center

Hulsey, Lara; Aikens, Nikki; Xue, Yange; Tarullo, Louisa; West, Jerry

2010-01-01

The Head Start Family and Child Experiences Survey (FACES) was first launched in 1997 as a periodic longitudinal study of program performance. Successive nationally representative samples of Head Start children, their families, classrooms, and programs provide descriptive information on the population served; staff qualifications, credentials,…

Sampling methods for bats.

Treesearch

D.W. Thomas; S.D. West

1989-01-01

Bats represent the second most diverse group of mammals inhabiting the western slopes of the Cascade Range in southern Washington and the Oregon Coast Range. Bat populations may well be sensitive to changes in forest age, structure, or distribution, but their nocturnal habits and high mobility render the study of the habitat requirements of bats problematical. Unlike...

Is Childhood Physical Abuse Associated with Peptic Ulcer Disease? Findings from a Population-Based Study

ERIC Educational Resources Information Center

Fuller-Thomson, Esme; Bottoms, Jennifer; Brennenstuhl, Sarah; Hurd, Marion

2011-01-01

This study investigated childhood physical abuse and ulcers in a regionally representative community sample. Age, race and sex were controlled for in addition to five clusters of potentially confounding factors: adverse childhood conditions, adult socioeconomic status, current health behaviors, current stress and marital status, and history of…

Science, Technology, Engineering, and Mathematics (STEM) Participation among College Students with an Autism Spectrum Disorder

ERIC Educational Resources Information Center

Wei, Xin; Christiano, Elizabeth R.; Yu, Jennifer W.; Blackorby, Jose; Shattuck, Paul; Newman, Lynn A.

2014-01-01

Little research has examined the popular belief that individuals with an autism spectrum disorder (ASD) are more likely than the general population to gravitate toward science, technology, engineering, and mathematics (STEM) fields. This study analyzed data from the National Longitudinal Transition Study-2, a nationally representative sample of…

[Personal satisfaction as a component of adult's quality of life in Medellin].

PubMed

Cardona, Doris; Agudelo, Héctor B

2007-01-01

Determining personal satisfaction as the main component of the quality of life of men and women aged 20 to 64 in Medellin during 2005. This was a cross/sectional descriptive population study. Its primary source of information consisted of two samples (659 men and 683 women) representing 523,705 and 651,704 people respectively, according to population expansion factors, selected via probabilistic complex sampling, stratified by socioeconomic level, clustering, city blocks, houses and people. The quality of life for adults in Medellin is mainly represented by personal and economic aspects, their housing's physical environment and social security. The aspects analysed in this study were evaluated above 75%; personal abilities and capability produced the greatest satisfaction, whilst the economic situation and social security produced least satisfaction. There were no significant differences according to gender regarding personal satisfaction concerning various aspects of life. This study's contribution to knowledge lies in making evident the need to integrate each person's subjectivity, opinions and individual perception of his/her own life, since these are the main components in evaluating an individual's quality of life.

Temperamental factors in remitted depression: The role of effortful control and attentional mechanisms.

PubMed

Marchetti, Igor; Shumake, Jason; Grahek, Ivan; Koster, Ernst H W

2018-08-01

Temperamental effortful control and attentional networks are increasingly viewed as important underlying processes in depression and anxiety. However, it is still unknown whether these factors facilitate depressive and anxiety symptoms in the general population and, more specifically, in remitted depressed individuals. We investigated to what extent effortful control and attentional networks (i.e., Attention Network Task) explain concurrent depressive and anxious symptoms in healthy individuals (n = 270) and remitted depressed individuals (n = 90). Both samples were highly representative of the US population. Increased effortful control predicted a substantial decrease in symptoms of both depression and anxiety in the whole sample, whereas decreased efficiency of executive attention predicted a modest increase in depressive symptoms. Remitted depressed individuals did not show less effortful control nor less efficient attentional networks than healthy individuals. Moreover, clinical status did not moderate the relationship between temperamental factors and either depressive or anxiety symptoms. Limitations include the cross-sectional nature of the study. Our study shows that temperamental effortful control represents an important transdiagnostic process for depressive and anxiety symptoms in adults. Copyright © 2018 Elsevier B.V. All rights reserved.

Uncertainty, learning, and the optimal management of wildlife

USGS Publications Warehouse

Williams, B.K.

2001-01-01

Wildlife management is limited by uncontrolled and often unrecognized environmental variation, by limited capabilities to observe and control animal populations, and by a lack of understanding about the biological processes driving population dynamics. In this paper I describe a comprehensive framework for management that includes multiple models and likelihood values to account for structural uncertainty, along with stochastic factors to account for environmental variation, random sampling, and partial controllability. Adaptive optimization is developed in terms of the optimal control of incompletely understood populations, with the expected value of perfect information measuring the potential for improving control through learning. The framework for optimal adaptive control is generalized by including partial observability and non-adaptive, sample-based updating of model likelihoods. Passive adaptive management is derived as a special case of constrained adaptive optimization, representing a potentially efficient suboptimal alternative that nonetheless accounts for structural uncertainty.

[Validation of the Eating Attitudes Test as a screening instrument for eating disorders in general population].

PubMed

Peláez-Fernández, María Angeles; Ruiz-Lázaro, Pedro Manuel; Labrador, Francisco Javier; Raich, Rosa María

2014-02-20

To validate the best cut-off point of the Eating Attitudes Test (EAT-40), Spanish version, for the screening of eating disorders (ED) in the general population. This was a transversal cross-sectional study. The EAT-40 Spanish version was administered to a representative sample of 1.543 students, age range 12 to 21 years, in the Region of Madrid. Six hundred and two participants (probable cases and a random sample of controls) were interviewed. The best diagnostic prediction was obtained with a cut-off point of 21, with sensitivity: 88.2%; specificity: 62.1%; positive predictive value: 17.7%; negative predictive value: 62.1%. Use of a cut-off point of 21 is recommended in epidemiological studies of eating disorders in the Spanish general population. Copyright © 2012 Elsevier España, S.L. All rights reserved.

HIV Research with Men who Have Sex with Men (MSM): Advantages and Challenges of Different Methods for Most Appropriately Targeting a Key Population.

PubMed

Gama, Ana; Martins, Maria O; Dias, Sónia

2017-01-01

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.

Physician-industry conflict of interest: public opinion regarding industry-sponsored research.

PubMed

Fisher, Charles G; DiPaola, Christian P; Noonan, Vanessa K; Bailey, Christopher; Dvorak, Marcel F S

2012-07-01

The nature of physician-industry conflict of interest (COI) has become a source of considerable concern, but is often not discussed in the research setting. With reduced funding available from government and nonprofit sources, industry support has enthusiastically grown, but along with this comes the potential for COI that must be regulated. In this era of shared decision making in health care, society must have input into this regulation. The purpose of this study was to assess the opinions of a North American population sample on COI regarding industry-funded research and to analyze population subgroups for trends. A survey was developed for face and content validity, underwent focus group evaluation for clarity and bias reduction, and was administered via the World Wide Web. Demographic and general survey results were summarized as a percentage for each answer, and subgroup analysis was done using logistic regression. Generalizability of the sample to the US population was also assessed. Of 541 surveys, 40 were excluded due to missing information, leaving 501 surveys for analysis. The sample population was composed of more females, was older, and was more educated than a representative cross-section of the American population. Respondents support multidisciplinary surgeon-industry COI regulation and trust doctors and their professional societies the most to head this effort. Respondents trust government officials and company representatives the least with respect to regulation of COI. Most respondents feel that industry-sponsored research can involve physicians and be both objective and beneficial to patients. Most respondents in this study felt that surgeons should be involved in industry-sponsored research and that more research, regardless of funding source, will ultimately benefit patients. The majority of respondents distrust government or industry to regulate COI. The development of evidence-based treatment recommendations requires the inclusion of patient preference. The authors encourage regulatory bodies to follow suit and include society's perspective on regulation of COI in research.

Cardiovascular risk factors in a Mexican middle-class urban population. The Lindavista Study. Baseline data.

PubMed

Meaney, Alejandra; Ceballos-Reyes, Guillermo; Gutiérrez-Salmean, Gabriela; Samaniego-Méndez, Virginia; Vela-Huerta, Agustín; Alcocer, Luis; Zárate-Chavarría, Elisa; Mendoza-Castelán, Emma; Olivares-Corichi, Ivonne; García-Sánchez, Rubén; Martínez-Marroquín, Yolanda; Ramírez-Sánchez, Israel; Meaney, Eduardo

2013-01-01

The aim of this communication is to describe the cardiovascular risk factors affecting a Mexican urban middle-class population. A convenience sample of 2602 middle class urban subjects composed the cohort of the Lindavista Study, a prospective study aimed to determine if conventional cardiovascular risks factors have the same prognosis impact as in other populations. For the baseline data, several measurements were done: obesity indexes, smoking, blood pressure, fasting serum glucose, total cholesterol, HDL-c, LDL-c and triglycerides. This paper presents the basal values of this population, which represents a sample of the Mexican growing urban middle-class. The mean age in the sample was 50 years; 59% were females. Around 50% of the entire group were overweighed, while around 24% were obese. 32% smoked; 32% were hypertensive with a 20% rate of controlled pressure. 6% had diabetes, and 14% had impaired fasting glucose; 66% had total cholesterol ≥ 200 mg/dL; 62% showed HDL-c levels<40 mg/dL; 52% triglycerides>150 mg/dL, and 34% levels of LDL-c ≥ 160 mg/dL. Half of the population studied had the metabolic syndrome. These data show a population with a high-risk profile, secondary to the agglomeration of several cardiovascular risk factors. Copyright © 2012 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

Epidemiology of tinea pedis in marathon runners: prevalence of occult athlete's foot.

PubMed

Auger, P; Marquis, G; Joly, J; Attye, A

1993-01-01

Studies on the prevalence of tinea pedis, a frequently encountered dermatophytic infection, have been conducted mostly in swimmers although people who regularly practise other types of physical activities may also have a high rate of clinical or subclinical infection. This investigation was undertaken to establish the rate of infection in marathon runners, and to determine the incidence of occult athlete's foot disease in this population. Among samples obtained from 405 individuals, 22% were positive. The rate of infection was highest in the older age groups. The prevalence of infection was 24.2% in men and 6.1% in women. Trichophyton rubrum and Trichophyton mentagrophytes were the two species of dermatophytes most commonly isolated on culture. Occult athlete's foot disease represented 48% of cases with a positive culture. Finally, routine sampling of both feet was confirmed necessary to adequately establish the rate of infection: 26.9% of cases with a positive culture would have been missed by unilateral sampling. Other epidemiological factors were not clearly linked to the prevalence of disease in marathon runners: weight; presence of pet animals; practice of other sports; race and country of origin. In conclusion, we establish that marathon runners represent a population at risk for the occurrence of both clinical and subclinical tinea pedis infection.

Phylogenetic assessment of heterotrophic bacteria from a water distribution system using 16S rDNA sequencing.

PubMed

Tokajian, Sima T; Hashwa, Fuad A; Hancock, Ian C; Zalloua, Pierre A

2005-04-01

Determination of a heterotrophic plate count (HPC) for drinking-water samples alone is not enough to assess possible health hazards associated with sudden changes in the bacterial count. Speciation is very crucial to determine whether the population includes pathogens and (or) opportunistic pathogens. Most of the isolates recovered from drinking water samples could not be allocated to a specific phylogenetic branch based on the use of conventional diagnostic methods. The present study had to use phylogenetic analysis, which was simplified by determining and using the first 500-bp sequence of the 16S rDNA, to successfully identify the type and species of bacteria found in the samples. Gram-positive bacteria alpha-, beta-, and gamma-Proteobacteria were found to be the major groups representing the heterotrophic bacteria in drinking water. The study also revealed that the presence of sphingomonads in drinking water supplies may be much more common than has been reported so far and thus further studies are merited. The intermittent mode of supply, mainly characterized by water stagnation and flow interruption associated possibly with biofilm detachment, raised the possibility that the studied bacterial populations in such systems represented organisms coming from 2 different niches, the biofilm and the water column.

The short-form version of the Depression Anxiety Stress Scales (DASS-21): construct validity and normative data in a large non-clinical sample.

PubMed

Henry, Julie D; Crawford, John R

2005-06-01

To test the construct validity of the short-form version of the Depression anxiety and stress scale (DASS-21), and in particular, to assess whether stress as indexed by this measure is synonymous with negative affectivity (NA) or whether it represents a related, but distinct, construct. To provide normative data for the general adult population. Cross-sectional, correlational and confirmatory factor analysis (CFA). The DASS-21 was administered to a non-clinical sample, broadly representative of the general adult UK population (N = 1,794). Competing models of the latent structure of the DASS-21 were evaluated using CFA. The model with optimal fit (RCFI = 0.94) had a quadripartite structure, and consisted of a general factor of psychological distress plus orthogonal specific factors of depression, anxiety, and stress. This model was a significantly better fit than a competing model that tested the possibility that the Stress scale simply measures NA. The DASS-21 subscales can validly be used to measure the dimensions of depression, anxiety, and stress. However, each of these subscales also taps a more general dimension of psychological distress or NA. The utility of the measure is enhanced by the provision of normative data based on a large sample.

Retail food safety risks for populations of different races, ethnicities, and income levels.

PubMed

Signs, Renata J; Darcey, Valerie L; Carney, Trish A; Evans, Alison A; Quinlan, Jennifer J

2011-10-01

Research has found that populations with low socioeconomic status (SES) and minority populations have greater access to small corner markets and less access to supermarkets than high-SES and Caucasian populations. This represents a significant difference in the farm-to-fork continuum that these populations experience. This research examined whether differential retail access to foods results in different food safety risks at the retail level for consumers with different demographics. U.S. Census Bureau census tracts with high African American, Asian, Hispanic, Caucasian, low-SES, and high-SES populations were identified in Philadelphia, PA. Approximately 60 retail food establishments were sampled in each census tract category from June 2008 to June 2010. Food samples collected at stores included milk, eggs, lunchmeat, sandwiches, and ready-to-eat (RTE) fresh fruit, greens, and herbs, when available. With the exception of milk and eggs, only food that had been handled and/or prepared at the retail level was sampled. Food samples were tested for temperature, aerobic plate count, coliforms, fecal coliforms, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes. The results indicated that internal egg temperatures were higher in samples from low-SES census tracts than in eggs from Caucasian census tracts, and eggs were more often found unrefrigerated in markets in low-SES and Asian census tracts. Milk samples from markets in Hispanic and low-SES census tracts had higher aerobic plate counts than high-SES census tract samples. Sandwiches from markets in high-SES census tracts had higher coliform counts than sandwiches from markets in all other census tract categories. Markets in Asian census tracts had a higher incidence of fecal coliform contamination on sandwiches than markets in Caucasian census tracts. Fecal coliforms were present in a percentage of RTE greens from markets in all census tracts except African American, with the highest percentages of RTE greens positive for fecal coliforms in low-SES (100%), Asian (71.4%), and Caucasian (45.5%) markets.

Cancerous epithelial cell lines shed extracellular vesicles with a bimodal size distribution that is sensitive to glutamine inhibition

NASA Astrophysics Data System (ADS)

Santana, Steven Michael; Antonyak, Marc A.; Cerione, Richard A.; Kirby, Brian J.

2014-12-01

Extracellular shed vesicles (ESVs) facilitate a unique mode of cell-cell communication wherein vesicle uptake can induce a change in the recipient cell's state. Despite the intensity of ESV research, currently reported data represent the bulk characterization of concentrated vesicle samples with little attention paid to heterogeneity. ESV populations likely represent diversity in mechanisms of formation, cargo and size. To better understand ESV subpopulations and the signaling cascades implicated in their formation, we characterize ESV size distributions to identify subpopulations in normal and cancerous epithelial cells. We have discovered that cancer cells exhibit bimodal ESV distributions, one small-diameter and another large-diameter population, suggesting that two mechanisms may govern ESV formation, an exosome population and a cancer-specific microvesicle population. Altered glutamine metabolism in cancer is thought to fuel cancer growth but may also support metastatic niche formation through microvesicle production. We describe the role of a glutaminase inhibitor, compound 968, in ESV production. We have discovered that inhibiting glutamine metabolism significantly impairs large-diameter microvesicle production in cancer cells.

Cross-cultural measurement invariance of the General Health Questionnaire-12 in a German and a Colombian population sample.

PubMed

Romppel, Matthias; Hinz, Andreas; Finck, Carolyn; Young, Jeremy; Brähler, Elmar; Glaesmer, Heide

2017-12-01

While the General Health Questionnaire, 12-item version (GHQ-12) has been widely used in cross-cultural comparisons, rigorous tests of the measurement equivalence of different language versions are still lacking. Thus, our study aims at investigating configural, metric and scalar invariance across the German and the Spanish version of the GHQ-12 in two population samples. The GHQ-12 was applied in two large-scale population-based samples in Germany (N = 1,977) and Colombia (N = 1,500). To investigate measurement equivalence, confirmatory factor analyses were conducted in both samples. In the German sample mean GHQ-12 total scores were higher than in the Colombian sample. A one-factor model including response bias on the negatively worded items showed superior fit in the German and the Colombian sample; thus both versions of the GHQ-12 showed configural invariance. Factor loadings and intercepts were not equal across both samples; thus GHQ-12 showed no metric and scalar invariance. As both versions of the GHQ-12 did not show measurement equivalence, it is not recommendable to compare both measures and to conclude that mental distress is higher in the German sample, although we do not know if the differences are attributable to measurement problems or represent a real difference in mental distress. The study underlines the importance of measurement equivalence in cross-cultural comparisons. Copyright © 2017 John Wiley & Sons, Ltd.

Modeling and Forecasting Mortality With Economic Growth: A Multipopulation Approach.

PubMed

Boonen, Tim J; Li, Hong

2017-10-01

Research on mortality modeling of multiple populations focuses mainly on extrapolating past mortality trends and summarizing these trends by one or more common latent factors. This article proposes a multipopulation stochastic mortality model that uses the explanatory power of economic growth. In particular, we extend the Li and Lee model (Li and Lee 2005) by including economic growth, represented by the real gross domestic product (GDP) per capita, to capture the common mortality trend for a group of populations with similar socioeconomic conditions. We find that our proposed model provides a better in-sample fit and an out-of-sample forecast performance. Moreover, it generates lower (higher) forecasted period life expectancy for countries with high (low) GDP per capita than the Li and Lee model.

Genetic and educational assortative mating among US adults.

PubMed

Domingue, Benjamin W; Fletcher, Jason; Conley, Dalton; Boardman, Jason D

2014-06-03

Understanding the social and biological mechanisms that lead to homogamy (similar individuals marrying one another) has been a long-standing issue across many fields of scientific inquiry. Using a nationally representative sample of non-Hispanic white US adults from the Health and Retirement Study and information from 1.7 million single-nucleotide polymorphisms, we compare genetic similarity among married couples to noncoupled pairs in the population. We provide evidence for genetic assortative mating in this population but the strength of this association is substantially smaller than the strength of educational assortative mating in the same sample. Furthermore, genetic similarity explains at most 10% of the assortative mating by education levels. Results are replicated using comparable data from the Framingham Heart Study.

How is emotional awareness related to emotion regulation strategies and self-reported negative affect in the general population?

PubMed

Subic-Wrana, Claudia; Beutel, Manfred E; Brähler, Elmar; Stöbel-Richter, Yve; Knebel, Achim; Lane, Richard D; Wiltink, Jörg

2014-01-01

The Levels of Emotional Awareness Scale (LEAS) as a performance task discriminates between implicit or subconscious and explicit or conscious levels of emotional awareness. An impaired awareness of one's feeling states may influence emotion regulation strategies and self-reports of negative emotions. To determine this influence, we applied the LEAS and self-report measures for emotion regulation strategies and negative affect in a representative sample of the German general population. A short version of the LEAS, the Hospital Anxiety and Depression Scale (HADS) and the Emotion Regulation Questionnaire (ERQ), assessing reappraisal and suppression as emotion regulation strategies, were presented to N = 2524 participants of a representative German community study. The questionnaire data were analyzed with regard to the level of emotional awareness. LEAS scores were independent from depression, but related to self-reported anxiety. Although of small or medium effect size, different correlational patters between emotion regulation strategies and negative affectivity were related to implict and explict levels of emotional awareness. In participants with implicit emotional awareness, suppression was related to higher anxiety and depression, whereas in participants with explicit emotional awareness, in addition to a positive relationship of suppression and depression, we found a negative relationship of reappraisal to depression. These findings were independent of age. In women high use of suppression and little use of reappraisal were more strongly related to negative affect than in men. Our first findings suggest that conscious awareness of emotions may be a precondition for the use of reappraisal as an adaptive emotion regulation strategy. They encourage further research in the relation between subconsious and conscious emotional awareness and the prefarance of adaptive or maladaptive emotion regulation strategies The correlational trends found in a representative sample of the general population may become more pronounced in clinical samples.

Population-wide weight loss and regain in relation to diabetes burden and cardiovascular mortality in Cuba 1980-2010: repeated cross sectional surveys and ecological comparison of secular trends.

PubMed

Franco, Manuel; Bilal, Usama; Orduñez, Pedro; Benet, Mikhail; Morejón, Alain; Caballero, Benjamín; Kennelly, Joan F; Cooper, Richard S

2013-04-09

To evaluate the associations between population-wide loss and gain in weight with diabetes prevalence, incidence, and mortality, as well as cardiovascular and cancer mortality trends, in Cuba over a 30 year interval. Repeated cross sectional surveys and ecological comparison of secular trends. Cuba and the province of Cienfuegos, from 1980 to 2010. Measurements in Cienfuegos included a representative sample of 1657, 1351, 1667, and 1492 adults in 1991, 1995, 2001, and 2010, respectively. National surveys included a representative sample of 14 304, 22 851, and 8031 participants in 1995, 2001, and 2010, respectively. Changes in smoking, daily energy intake, physical activity, and body weight were tracked from 1980 to 2010 using national and regional surveys. Data for diabetes prevalence and incidence were obtained from national population based registries. Mortality trends were modelled using national vital statistics. Rapid declines in diabetes and heart disease accompanied an average population-wide loss of 5.5 kg in weight, driven by an economic crisis in the mid-1990s. A rebound in population weight followed in 1995 (33.5% prevalence of overweight and obesity) and exceeded pre-crisis levels by 2010 (52.9% prevalence). The population-wide increase in weight was immediately followed by a 116% increase in diabetes prevalence and 140% increase in diabetes incidence. Six years into the weight rebound phase, diabetes mortality increased by 49% (from 9.3 deaths per 10 000 people in 2002 to 13.9 deaths per 10 000 people in 2010). A deceleration in the rate of decline in mortality from coronary heart disease was also observed. In relation to the Cuban experience in 1980-2010, there is an association at the population level between weight reduction and death from diabetes and cardiovascular disease; the opposite effect on the diabetes and cardiovascular burden was seen on population-wide weight gain.

Body size of young Australians aged five to 16 years.

PubMed

Hitchcock, N E; Maller, R A; Gilmour, A I

1986-10-20

In 1983-1984, 4578 Perth primary and secondary schoolchildren were studied. The selected sample was broadly representative of the ethnic groups that make up the Perth population and of the different social ranks within that population. The age, sex, weight, height, country of birth of the child and the parents, and occupation of the father were recorded for each subject. Weight, height and body mass index (BMI) increased with age. Age and sex were the most important determinants of body size. However, children of lower social rank and those with a southern European background were over-represented among the overweight children (greater than the 90th centile for BMI), particularly in adolescence. Children with an Asian background who were 11 years of age and younger were over-represented among the underweight children (less than or equal to the 10th centile for BMI). Results from this study indicate a continuing, though small (1.5 cm to 1.6 cm), secular increase in height over the past 13 to 14 years.

Statistical design and analysis plan for an impact evaluation of an HIV treatment and prevention intervention for female sex workers in Zimbabwe: a study protocol for a cluster randomised controlled trial.

PubMed

Hargreaves, James R; Fearon, Elizabeth; Davey, Calum; Phillips, Andrew; Cambiano, Valentina; Cowan, Frances M

2016-01-05

Pragmatic cluster-randomised trials should seek to make unbiased estimates of effect and be reported according to CONSORT principles, and the study population should be representative of the target population. This is challenging when conducting trials amongst 'hidden' populations without a sample frame. We describe a pair-matched cluster-randomised trial of a combination HIV-prevention intervention to reduce the proportion of female sex workers (FSW) with a detectable HIV viral load in Zimbabwe, recruiting via respondent driven sampling (RDS). We will cross-sectionally survey approximately 200 FSW at baseline and at endline to characterise each of 14 sites. RDS is a variant of chain referral sampling and has been adapted to approximate random sampling. Primary analysis will use the 'RDS-2' method to estimate cluster summaries and will adapt Hayes and Moulton's '2-step' method to adjust effect estimates for individual-level confounders and further adjust for cluster baseline prevalence. We will adapt CONSORT to accommodate RDS. In the absence of observable refusal rates, we will compare the recruitment process between matched pairs. We will need to investigate whether cluster-specific recruitment or the intervention itself affects the accuracy of the RDS estimation process, potentially causing differential biases. To do this, we will calculate RDS-diagnostic statistics for each cluster at each time point and compare these statistics within matched pairs and time points. Sensitivity analyses will assess the impact of potential biases arising from assumptions made by the RDS-2 estimation. We are not aware of any other completed pragmatic cluster RCTs that are recruiting participants using RDS. Our statistical design and analysis approach seeks to transparently document participant recruitment and allow an assessment of the representativeness of the study to the target population, a key aspect of pragmatic trials. The challenges we have faced in the design of this trial are likely to be shared in other contexts aiming to serve the needs of legally and/or socially marginalised populations for which no sampling frame exists and especially when the social networks of participants are both the target of intervention and the means of recruitment. The trial was registered at Pan African Clinical Trials Registry (PACTR201312000722390) on 9 December 2013.

The international Genome sample resource (IGSR): A worldwide collection of genome variation incorporating the 1000 Genomes Project data

PubMed Central

Clarke, Laura; Fairley, Susan; Zheng-Bradley, Xiangqun; Streeter, Ian; Perry, Emily; Lowy, Ernesto; Tassé, Anne-Marie; Flicek, Paul

2017-01-01

The International Genome Sample Resource (IGSR; http://www.internationalgenome.org) expands in data type and population diversity the resources from the 1000 Genomes Project. IGSR represents the largest open collection of human variation data and provides easy access to these resources. IGSR was established in 2015 to maintain and extend the 1000 Genomes Project data, which has been widely used as a reference set of human variation and by researchers developing analysis methods. IGSR has mapped all of the 1000 Genomes sequence to the newest human reference (GRCh38), and will release updated variant calls to ensure maximal usefulness of the existing data. IGSR is collecting new structural variation data on the 1000 Genomes samples from long read sequencing and other technologies, and will collect relevant functional data into a single comprehensive resource. IGSR is extending coverage with new populations sequenced by collaborating groups. Here, we present the new data and analysis that IGSR has made available. We have also introduced a new data portal that increases discoverability of our data—previously only browseable through our FTP site—by focusing on particular samples, populations or data sets of interest. PMID:27638885

Evidence for population bottlenecks and subtle genetic structure in the yellow rail

USGS Publications Warehouse

Popper, Kenneth J.; Miller, Leonard F.; Green, Michael; Haig, Susan M.; Mullins, Thomas D.

2012-01-01

The Yellow Rail (Coturnicops noveboracencis) is among the most enigmatic and least studied North American birds. Nesting exclusively in marshes and wetlands, it breeds largely east of the Rocky Mountains in the northern United States and Canada, but there is an isolated population in southern Oregon once believed extirpated. The degree of connectivity of the Oregon population with the main population is unknown. We used mitochondrial DNA sequences (mtDNA) and six microsatellite loci to characterize the Yellow Rail's genetic structure and diversity patterns in six areas. Our mtDNA-based analyses of genetic structure identified significant population differentiation, but pairwise comparison of regions identified no clear geographic trends. In contrast, microsatellites suggested subtle genetic structure differentiating the Oregon population from those in the five regions sampled in the Yellow Rail's main breeding range. The genetic diversity of the Oregon population was also the lowest of the six regions sampled, and Oregon was one of three regions that demonstrated evidence of recent population bottlenecks. Factors that produced population reductions may include loss of wetlands to development and agricultural conversion, drought, and wildfire. At this time, we are unable to determine if the high percentage (50%) of populations having experienced bottlenecks is representative of the Yellow Rail's entire range. Further genetic data from additional breeding populations will be required for this issue to be addressed.

Methodological assessment of 2b-RAD genotyping technique for population structure inferences in yellowfin tuna (Thunnus albacares).

PubMed

Pecoraro, Carlo; Babbucci, Massimiliano; Villamor, Adriana; Franch, Rafaella; Papetti, Chiara; Leroy, Bruno; Ortega-Garcia, Sofia; Muir, Jeff; Rooker, Jay; Arocha, Freddy; Murua, Hilario; Zudaire, Iker; Chassot, Emmanuel; Bodin, Nathalie; Tinti, Fausto; Bargelloni, Luca; Cariani, Alessia

2016-02-01

Global population genetic structure of yellowfin tuna (Thunnus albacares) is still poorly understood despite its relevance for the tuna fishery industry. Low levels of genetic differentiation among oceans speak in favour of the existence of a single panmictic population worldwide of this highly migratory fish. However, recent studies indicated genetic structuring at a much smaller geographic scales than previously considered, pointing out that YFT population genetic structure has not been properly assessed so far. In this study, we demonstrated for the first time, the utility of 2b-RAD genotyping technique for investigating population genetic diversity and differentiation in high gene-flow species. Running de novo pipeline in Stacks, a total of 6772 high-quality genome-wide SNPs were identified across Atlantic, Indian and Pacific population samples representing all major distribution areas. Preliminary analyses showed shallow but significant population structure among oceans (FST=0.0273; P-value<0.01). Discriminant Analysis of Principal Components endorsed the presence of genetically discrete yellowfin tuna populations among three oceanic pools. Although such evidence needs to be corroborated by increasing sample size, these results showed the efficiency of this genotyping technique in assessing genetic divergence in a marine fish with high dispersal potential. Copyright © 2015 Elsevier B.V. All rights reserved.

History and structure of sub-Saharan populations of Drosophila melanogaster.

PubMed

Pool, John E; Aquadro, Charles F

2006-10-01

Drosophila melanogaster is an important model organism in evolutionary genetics, yet little is known about the population structure and the demographic history of this species within sub-Saharan Africa, which is thought to contain its ancestral range. We surveyed nucleotide variation at four 1-kb fragments in 240 individual lines representing 21 sub-Saharan and 4 Palearctic population samples of D. melanogaster. In agreement with recent studies, we find a small but significant level of genetic differentiation within sub-Saharan Africa. A clear geographic pattern is observed, with eastern and western African populations composing two genetically distinct groups. This pattern may have resulted from a relatively recent establishment of D. melanogaster in western Africa. Eastern populations show greater evidence for long-term stability, consistent with the hypothesis that eastern Africa contains the ancestral range of the species. Three sub-Saharan populations show evidence for cosmopolitan introgression. Apart from those cases, the closest relationships between Palearctic and sub-Saharan populations involve a sample from the rift zone (Uganda), suggesting that the progenitors of Palearctic D. melanogaster might have come from this region. Finally, we find a large excess of singleton polymorphisms in the full data set, which is best explained by a combination of population growth and purifying selection.

Population data of 16 autosomal STR loci of the Powerplex ESX 17 System in a Brazilian Population from the State of São Paulo.

PubMed

Almeida Prado Oliveira e Sousa, Maria Luiza; de Oliveira, Marco Aurelio Tuena; Auler-Bittencout, Eloisa A; Soares-Vieira, Jose Arnaldo; Munoz, Daniel Romero; Iwamura, Edna Sadayo Miazato

2014-07-01

The State of São Paulo is the most populous state in Brazil, including approximately one fifth of the population of the country. In addition to a strong economy, the state has relatively good social indicators when compared with the rest of the country. The capital city, also called São Paulo, is the sixth largest city in the world. Its population is considered the most multicultural and racially mixed in Brazil. Currently, the largest populations in São Paulo are of Italian, Lebanese, Spanish and Japanese origin, and the state has the largest number of Northeasterners outside of the Northeast region. This population structure may lead to a particular genotype frequency. In this context, the formation of a new database containing the allele frequencies of five new genetic markers (D2S441, D10S1248, D22S1045, D1S1656 and D12S391) in a sample population is relevant. The allele frequencies of 16 STR loci, including the five new European Standard Set (ESS) loci, were calculated in a sample of 1088-1098 unrelated individuals, who geographically represent the Capital city. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Multi-Genetic Marker Approach and Spatio-Temporal Analysis Suggest There Is a Single Panmictic Population of Swordfish Xiphias gladius in the Indian Ocean

PubMed Central

Muths, Delphine; Le Couls, Sarah; Evano, Hugues; Grewe, Peter; Bourjea, Jerome

2013-01-01

Genetic population structure of swordfish Xiphias gladius was examined based on 2231 individual samples, collected mainly between 2009 and 2010, among three major sampling areas within the Indian Ocean (IO; twelve distinct sites), Atlantic (two sites) and Pacific (one site) Oceans using analysis of nineteen microsatellite loci (n = 2146) and mitochondrial ND2 sequences (n = 2001) data. Sample collection was stratified in time and space in order to investigate the stability of the genetic structure observed with a special focus on the South West Indian Ocean. Significant AMOVA variance was observed for both markers indicating genetic population subdivision was present between oceans. Overall value of F-statistics for ND2 sequences confirmed that Atlantic and Indian Oceans swordfish represent two distinct genetic stocks. Indo-Pacific differentiation was also significant but lower than that observed between Atlantic and Indian Oceans. However, microsatellite F-statistics failed to reveal structure even at the inter-oceanic scale, indicating that resolving power of our microsatellite loci was insufficient for detecting population subdivision. At the scale of the Indian Ocean, results obtained from both markers are consistent with swordfish belonging to a single unique panmictic population. Analyses partitioned by sampling area, season, or sex also failed to identify any clear structure within this ocean. Such large spatial and temporal homogeneity of genetic structure, observed for such a large highly mobile pelagic species, suggests as satisfactory to consider swordfish as a single panmictic population in the Indian Ocean. PMID:23717447

Effect of selective logging on genetic diversity and gene flow in Cariniana legalis sampled from a cacao agroforestry system.

PubMed

Leal, J B; Santos, R P; Gaiotto, F A

2014-01-28

The fragments of the Atlantic Forest of southern Bahia have a long history of intense logging and selective cutting. Some tree species, such as jequitibá rosa (Cariniana legalis), have experienced a reduction in their populations with respect to both area and density. To evaluate the possible effects of selective logging on genetic diversity, gene flow, and spatial genetic structure, 51 C. legalis individuals were sampled, representing the total remaining population from the cacao agroforestry system. A total of 120 alleles were observed from the 11 microsatellite loci analyzed. The average observed heterozygosity (0.486) was less than the expected heterozygosity (0.721), indicating a loss of genetic diversity in this population. A high fixation index (FIS = 0.325) was found, which is possibly due to a reduction in population size, resulting in increased mating among relatives. The maximum (1055 m) and minimum (0.095 m) distances traveled by pollen or seeds were inferred based on paternity tests. We found 36.84% of unique parents among all sampled seedlings. The progenitors of the remaining seedlings (63.16%) were most likely out of the sampled area. Positive and significant spatial genetic structure was identified in this population among classes 10 to 30 m away with an average coancestry coefficient between pairs of individuals of 0.12. These results suggest that the agroforestry system of cacao cultivation is contributing to maintaining levels of diversity and gene flow in the studied population, thus minimizing the effects of selective logging.

What is a representative brain? Neuroscience meets population science.

PubMed

Falk, Emily B; Hyde, Luke W; Mitchell, Colter; Faul, Jessica; Gonzalez, Richard; Heitzeg, Mary M; Keating, Daniel P; Langa, Kenneth M; Martz, Meghan E; Maslowsky, Julie; Morrison, Frederick J; Noll, Douglas C; Patrick, Megan E; Pfeffer, Fabian T; Reuter-Lorenz, Patricia A; Thomason, Moriah E; Davis-Kean, Pamela; Monk, Christopher S; Schulenberg, John

2013-10-29

The last decades of neuroscience research have produced immense progress in the methods available to understand brain structure and function. Social, cognitive, clinical, affective, economic, communication, and developmental neurosciences have begun to map the relationships between neuro-psychological processes and behavioral outcomes, yielding a new understanding of human behavior and promising interventions. However, a limitation of this fast moving research is that most findings are based on small samples of convenience. Furthermore, our understanding of individual differences may be distorted by unrepresentative samples, undermining findings regarding brain-behavior mechanisms. These limitations are issues that social demographers, epidemiologists, and other population scientists have tackled, with solutions that can be applied to neuroscience. By contrast, nearly all social science disciplines, including social demography, sociology, political science, economics, communication science, and psychology, make assumptions about processes that involve the brain, but have incorporated neural measures to differing, and often limited, degrees; many still treat the brain as a black box. In this article, we describe and promote a perspective--population neuroscience--that leverages interdisciplinary expertise to (i) emphasize the importance of sampling to more clearly define the relevant populations and sampling strategies needed when using neuroscience methods to address such questions; and (ii) deepen understanding of mechanisms within population science by providing insight regarding underlying neural mechanisms. Doing so will increase our confidence in the generalizability of the findings. We provide examples to illustrate the population neuroscience approach for specific types of research questions and discuss the potential for theoretical and applied advances from this approach across areas.

What is a representative brain? Neuroscience meets population science

PubMed Central

Falk, Emily B.; Hyde, Luke W.; Mitchell, Colter; Faul, Jessica; Gonzalez, Richard; Heitzeg, Mary M.; Keating, Daniel P.; Langa, Kenneth M.; Martz, Meghan E.; Maslowsky, Julie; Morrison, Frederick J.; Noll, Douglas C.; Patrick, Megan E.; Pfeffer, Fabian T.; Reuter-Lorenz, Patricia A.; Thomason, Moriah E.; Davis-Kean, Pamela; Monk, Christopher S.; Schulenberg, John

2013-01-01

The last decades of neuroscience research have produced immense progress in the methods available to understand brain structure and function. Social, cognitive, clinical, affective, economic, communication, and developmental neurosciences have begun to map the relationships between neuro-psychological processes and behavioral outcomes, yielding a new understanding of human behavior and promising interventions. However, a limitation of this fast moving research is that most findings are based on small samples of convenience. Furthermore, our understanding of individual differences may be distorted by unrepresentative samples, undermining findings regarding brain–behavior mechanisms. These limitations are issues that social demographers, epidemiologists, and other population scientists have tackled, with solutions that can be applied to neuroscience. By contrast, nearly all social science disciplines, including social demography, sociology, political science, economics, communication science, and psychology, make assumptions about processes that involve the brain, but have incorporated neural measures to differing, and often limited, degrees; many still treat the brain as a black box. In this article, we describe and promote a perspective—population neuroscience—that leverages interdisciplinary expertise to (i) emphasize the importance of sampling to more clearly define the relevant populations and sampling strategies needed when using neuroscience methods to address such questions; and (ii) deepen understanding of mechanisms within population science by providing insight regarding underlying neural mechanisms. Doing so will increase our confidence in the generalizability of the findings. We provide examples to illustrate the population neuroscience approach for specific types of research questions and discuss the potential for theoretical and applied advances from this approach across areas. PMID:24151336

First HIV prevalence estimates of a representative sample of adult sub-Saharan African migrants in a European city. Results of a community-based, cross-sectional study in Antwerp, Belgium.

PubMed

Loos, Jasna; Nöstlinger, Christiana; Vuylsteke, Bea; Deblonde, Jessika; Ndungu, Morgan; Kint, Ilse; Manirankunda, Lazare; Reyniers, Thijs; Adobea, Dorothy; Laga, Marie; Colebunders, Robert

2017-01-01

While sub-Saharan African migrants are the second largest group affected by HIV in Europe, sound HIV prevalence estimates based on representative samples of these heterogeneous communities are lacking. Such data are needed to inform prevention and public health policy. This community-based, cross-sectional study combined oral fluid HIV testing with an electronic behavioral survey. Adopting a two-stage time location sampling HIV prevalence estimates for a representative sample of adult sub-Saharan African migrants in Antwerp, Belgium were obtained. Sample proportions and estimated adjusted population proportions were calculated for all variables. Univariable and multivariable logistic regression analysis explored factors independently associated with HIV infection. Between December 2013 and October 2014, 744 sub-Saharan African migrants were included (37% women). A substantial proportion was socially, legally and economically vulnerable: 21% were probably of undocumented status, 63% had financial problems in the last year and 9% lacked stable housing. Sexual networks were mostly African and crossed national borders, i.e. sexual encounters during travels within Europa and Africa. Concurrency is common, 34% of those in a stable relationship had a partner on the side in the last year. HIV prevalence was 5.9%(95%CI:3.4%-10.1%) among women and 4.2% (95%CI:1.6%-10.6%) among men. Although high lifetime HIV testing was reported at community level (73%), 65.2% (CI95%:32.4%-88.0%) of sub-Saharan African migrants were possibly undiagnosed. Being 45 years or older, unprotected sex when travelling within Europe in the last year, high intentions to use condoms, being unaware of their last sexual partners' HIV status, recent HIV testing and not having encountered partner violence in the last year were independently associated with HIV infection in multivariable logical regression. In univariable analysis, HIV infection was additionally associated to unemployment. This is the first HIV prevalence study among adult sub-Saharan African migrants resettling in a European city based on a representative sample. HIV prevalence was high and could potentially increase further due to the high number of people with an undiagnosed HIV infection, social vulnerability, high levels of concurrency and mainly African sexual networks. Given this population's mobility, an aligned European combination prevention approach addressing these determinants is urgently needed.

A population-based prevalence study of hepatitis A, B and C virus using oral fluid in Flanders, Belgium.

PubMed

Quoilin, Sophie; Hutse, Veronik; Vandenberghe, Hans; Claeys, Françoise; Verhaegen, Els; De Cock, Liesbet; Van Loock, Frank; Top, Geert; Van Damme, Pierre; Vranckx, Robert; Van Oyen, Herman

2007-01-01

Ten years after the first seroprevalence study performed in Flanders, the aim of this cross sectional study was to follow the evolution of hepatitis A, B and C prevalence. The prevalence of hepatitis A antibodies, hepatitis B surface antigen and hepatitis C antibodies was measured in oral fluid samples collected by postal survey. Using the National Population Register, an incremental sampling plan was developed to obtain a representative sampling of the general population. A total of 24,000 persons were selected and 6,000 persons among them contacted in a first wave. With 1834 participants a response rate of 30.6% was achieved. The prevalence was weighted for age and was 20.2% (95% CI 19.43-21.08) for hepatitis A, 0.66% (95% CI 0.51-0.84) for hepatitis B surface antigen and 0.12% (95% CI 0.09-0.39) for hepatitis C. The prevalence of hepatitis A and C in the Flemish population is lower in 2003 compared with the results of the study performed in 1993. The difference may be due to a real decrease of the diseases but also to differences in the methodology. The prevalence of hepatitis B surface antigen remains stable. Considering the 30% response rate and the high quality of the self-collected samples as reflect of a good participation of the general population, saliva test for prevalence study is a good epidemiological monitoring tool.

Population size and stopover duration estimation using mark–resight data and Bayesian analysis of a superpopulation model

USGS Publications Warehouse

Lyons, James E.; Kendall, William L.; Royle, J. Andrew; Converse, Sarah J.; Andres, Brad A.; Buchanan, Joseph B.

2016-01-01

We present a novel formulation of a mark–recapture–resight model that allows estimation of population size, stopover duration, and arrival and departure schedules at migration areas. Estimation is based on encounter histories of uniquely marked individuals and relative counts of marked and unmarked animals. We use a Bayesian analysis of a state–space formulation of the Jolly–Seber mark–recapture model, integrated with a binomial model for counts of unmarked animals, to derive estimates of population size and arrival and departure probabilities. We also provide a novel estimator for stopover duration that is derived from the latent state variable representing the interim between arrival and departure in the state–space model. We conduct a simulation study of field sampling protocols to understand the impact of superpopulation size, proportion marked, and number of animals sampled on bias and precision of estimates. Simulation results indicate that relative bias of estimates of the proportion of the population with marks was low for all sampling scenarios and never exceeded 2%. Our approach does not require enumeration of all unmarked animals detected or direct knowledge of the number of marked animals in the population at the time of the study. This provides flexibility and potential application in a variety of sampling situations (e.g., migratory birds, breeding seabirds, sea turtles, fish, pinnipeds, etc.). Application of the methods is demonstrated with data from a study of migratory sandpipers.

Correction of Population Stratification in Large Multi-Ethnic Association Studies

PubMed Central

Serre, David; Montpetit, Alexandre; Paré, Guillaume; Engert, James C.; Yusuf, Salim; Keavney, Bernard; Hudson, Thomas J.; Anand, Sonia

2008-01-01

Background 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. Methodology/Principal Findings 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. Conclusions/Significance 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. PMID:18196181

Population structure and history of a phenotypically variable teiid lizard (Ameiva chrysolaema) from Hispaniola: the influence of a geologically complex island.

PubMed

Gifford, Matthew E; Powell, Robert; Larson, Allan; Gutberlet, Ronald L

2004-09-01

Ameiva chrysolaema is distributed across the island of Hispaniola in the West Indies. The species is restricted to dry lowlands between major mountain ranges and along the southern and eastern coasts. Phylogenetic and phylogeographic analyses of mtDNA sequence variation from 14 sampling localities identify at least three independent evolutionary lineages, separated from one another by major mountain ranges. Nested clade phylogeographic analysis (NCPA) suggests a complex history of population fragmentation, consistent with geological evidence of seawater incursions into the Azua and Enriquillo basins during the Pliocene/Pleistocene (approximately 1.6 mya). Significantly negative Fu's F(S) values and parameters of mismatch distributions suggest that formerly fragmented populations have recently expanded their ranges. Significantly large average population clade distances (APCD) for two sampling localities in the Azua basin suggest secondary contact at these localities of previously separated populations. The distribution of haplotypes among polymorphic populations of A. chrysolaema suggests that variation in dorsal pattern represents a polymorphism within evolutionary lineages. Ameiva leberi is ecologically indistinguishable from and syntopic with A. chrysolaema. Genetic data suggest that A. leberi is a junior synonym of A. chrysolaema.

Genetic Structure of Anopheles (Nyssorhynchus) marajoara (Diptera: Culicidae) in Colombia

PubMed Central

Brochero, Helena; Li, Cong; Wilkerson, Richard; Conn, Jan E.; Ruiz-García, Manuel

2010-01-01

Five Anopheles marajoara Galvão and Damasceno populations, representing diverse ecological conditions, were sampled throughout Colombia and analyzed using nine hypervariable DNA microsatellite loci. The overall genetic diversity (H = 0.58) was lower than that determined for some Brazilian populations using the same markers. The Caquetá population (Colombia) had the lowest gene diversity (H = 0.48), and it was the only population at Hardy–Weinberg equilibrium. Hardy–Weinberg disequilibrium in the remaining four populations was probably caused by the Wahlund effect. The assignment analyses showed two incompletely isolated gene pools separated by the Eastern Andean cordillera. However, other possible geographical barriers (rivers and other mountains) did not play any role in the moderate genetic heterogeneity found among these populations (FST = 0.069). These results are noteworthy, because this species is a putative malaria vector in Colombia. PMID:20810825

Determination of Coreceptor Usage of Human Immunodeficiency Virus Type 1 from Patient Plasma Samples by Using a Recombinant Phenotypic Assay

PubMed Central

Trouplin, Virginie; Salvatori, Francesca; Cappello, Fanny; Obry, Veronique; Brelot, Anne; Heveker, Nikolaus; Alizon, Marc; Scarlatti, Gabriella; Clavel, François; Mammano, Fabrizio

2001-01-01

We developed a recombinant virus technique to determine the coreceptor usage of human immunodeficiency virus type 1 (HIV-1) from plasma samples, the source expected to represent the most actively replicating virus population in infected subjects. This method is not subject to selective bias associated with virus isolation in culture, a step required for conventional tropism determination procedures. The addition of a simple subcloning step allowed semiquantitative evaluation of virus populations with a different coreceptor (CCR5 or CXCR4) usage specificity present in each plasma sample. This procedure detected mixtures of CCR5- and CXCR4-exclusive virus populations as well as dualtropic viral variants, in variable proportions. Sequence analysis of dualtropic clones indicated that changes in the V3 loop are necessary for the use of CXCR4 as a coreceptor, but the overall context of the V1-V3 region is important to preserve the capacity to use CCR5. This convenient technique can greatly assist the study of virus evolution and compartmentalization in infected individuals. PMID:11119595

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

PubMed

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.

Impact of allergy treatment on the association between allergies and mood and anxiety in a population sample

PubMed Central

Goodwin, Renee D; Galea, Sandro; Perzanowski, Matthew; Jacobi, Frank

2013-01-01

Background Previous studies have suggested an association between allergy and mood and anxiety disorders. Yet, extant work suffers from methodologic limitations. Objective To investigate the association between physician diagnosed allergy and DSM-IV mood and anxiety disorders in the general population, and to examine the role of allergy treatment in this relationship. Methods Data were drawn from the German National Health Interview and Examination Survey, a population-based, representative sample of 4,181 adults aged 18-65 in Germany. Allergy was diagnosed by physicians during medical examination and mental disorders were diagnosed using the CIDI. Results Allergy was associated with an increased prevalence of any anxiety disorder (OR=1.3 (1.1, 1.6)), panic attacks (OR=1.6 (1.1, 2.1)), panic disorder (OR=1.6 (1.01, 2.3)), GAD (OR=1.8 (1.1, 3.0)), any mood disorder (OR= 1.4 (1.1, 1.7)), depression (OR=1.4 (1.1, 1.7)), and bipolar disorder (OR=2.0, (1.0, 3.8)). After adjusting for desensitization treatment status, these relationships were no longer significant. Those treated for allergy were significantly less likely to have any mood or anxiety disorder (OR=0.65 (0.4, 0.96)), compared to those untreated. All relationships were adjusted for age, sex and socioeconomic status (SES). Conclusions & Clinical Relevance These findings provide the first evidence of a link between physician diagnosed allergy and DSM-IV mood and anxiety disorders in a representative sample. Treatment for allergy may mitigate much of this relationship. PMID:23181792

Mitigating aggressiveness through education? The monoamine oxidase A genotype and mental health in general population.

PubMed

Kiive, Evelyn; Laas, Kariina; Akkermann, Kirsti; Comasco, Erika; Oreland, Lars; Veidebaum, Toomas; Harro, Jaanus

2014-02-01

Monoamine oxidase A (MAOA) gene promoter region includes a variable number of tandem repeat (VNTR) associated with antisocial behaviour in adverse environment. We have examined the effect of the MAOA-uVNTR on mental health and academic success by using a population representative sample and a longitudinal design. The data of the older cohort (n = 593, aged 15 years at the original sampling) of the longitudinal Estonian Children Personality, Behaviour and Health Study (ECPBHS) were used. Follow-ups were conducted at ages 18 and 25 years. Aggressiveness, inattention and hyperactivity were reported by class teachers or, at older age, self-reported. Stressful life events, psychological environment in the family and interactions between family members were self-reported. Data of general mental abilities and education were obtained at the age of 25, and lifetime psychiatric disorder assessment was carried out with the Mini-International Neuropsychiatric Interview (MINI) interview. MAOA-uVNTR genotype had no independent effect on aggressiveness, hyperactive and inattentive symptoms, and neither was there a genotype interaction with adverse life events. Interestingly, the proportion of male subjects with higher education by the age of 25 was significantly larger among those with MAOA low-activity alleles (χ² = 7.13; p = 0.008). Logistic regression revealed that MAOA low-activity alleles, higher mental abilities, occurrence of anxiety disorders and absence of substance-use disorder were significant independent predictors for higher education in male subjects. In a population representative sample of young subjects, the MAOA-uVNTR 'risk genotype' predicted better life outcomes as expressed in higher level of education.

Population density and youth antisocial behavior.

PubMed

Harden, K Paige; D'Onofrio, Brian M; Van Hulle, Carol; Turkheimer, Eric; Rodgers, Joseph L; Waldman, Irwin D; Lahey, Benjamin B

2009-08-01

Theoretical models concerning how neighborhood contexts adversely influence juvenile antisocial behavior frequently focus on urban neighborhoods; however, previous studies comparing urban and rural areas on the prevalence of youth antisocial behavior have yielded mixed results. The current study uses longitudinal data on the offspring of a nationally representative sample of mothers (N = 4,886) in the US. There was no relation between density and mother-reported child conduct problems across ages 4-13 years, but youth living in areas of greater population density exhibited more youth self-reported delinquency across 10-17 years. Families often moved to counties with greater or lesser population density, but longitudinal analyses treating population density as a time-varying covariate did not support the hypothesis that living in densely populated counties influenced youth delinquency. Rather, the association between population density and delinquency appears to be due to unmeasured selection variables that differ between families who live in more or less densely populated counties.

Urbanization shapes the demographic history of a native rodent (the white-footed mouse, Peromyscus leucopus) in New York City.

PubMed

Harris, Stephen E; Xue, Alexander T; Alvarado-Serrano, Diego; Boehm, Joel T; Joseph, Tyler; Hickerson, Michael J; Munshi-South, Jason

2016-04-01

How urbanization shapes population genomic diversity and evolution of urban wildlife is largely unexplored. We investigated the impact of urbanization on white-footed mice,Peromyscus leucopus,in the New York City (NYC) metropolitan area using coalescent-based simulations to infer demographic history from the site-frequency spectrum. We assigned individuals to evolutionary clusters and then inferred recent divergence times, population size changes and migration using genome-wide single nucleotide polymorphisms genotyped in 23 populations sampled along an urban-to-rural gradient. Both prehistoric climatic events and recent urbanization impacted these populations. Our modelling indicates that post-glacial sea-level rise led to isolation of mainland and Long Island populations. These models also indicate that several urban parks represent recently isolated P. leucopus populations, and the estimated divergence times for these populations are consistent with the history of urbanization in NYC. © 2016 The Author(s).

No Parent Left Behind: Predicting Parental Involvement in Adolescents' Education within a Sociodemographically Diverse Population

ERIC Educational Resources Information Center

Park, Sira; Holloway, Susan D.

2013-01-01

Numerous studies have investigated the utility of the Hoover-Dempsey and Sandler (HDS) model for predicting parents' involvement in students' education. Yet, the model has yet to be thoroughly evaluated with respect to youth who are (a) in high school and (b) from sociodemographically diverse families. Using a nationally representative sample of…

The Implications of Symptom Validity Test Failure for Ability-Based Test Performance in a Pediatric Sample

ERIC Educational Resources Information Center

Kirkwood, Michael W.; Yeates, Keith Owen; Randolph, Christopher; Kirk, John W.

2012-01-01

If an examinee exerts inadequate effort to perform well during a psychological or neuropsychological exam, the resulting data will represent an inaccurate representation of the individual's true abilities and difficulties. In adult populations, methodologies to identify noncredible effort have grown exponentially in the last 2 decades. Though a…

Awareness and Use of Folic Acid among Women in the Lower Mississippi Delta

ERIC Educational Resources Information Center

Robbins, James M.; Hopkins, Sarah E.; Mosley, Bridget S.; Casey, Patrick H.; Cleves, Mario A.; Hobbs, Charlotte A.

2006-01-01

Context: National and state efforts to increase folic acid awareness and use may not be reaching large segments of the population. Purpose: This study examines folic acid awareness and use among women of childbearing age in a representative, economically at-risk rural sample and identifies factors that influence awareness and use. Methods: A…

Institutional Uses of Twitter in U.S. Higher Education

ERIC Educational Resources Information Center

Kimmons, Royce; Veletsianos, George; Woodward, Scott

2017-01-01

This study employed data mining and quantitative methods to collect and analyze the available histories of primary Twitter accounts of institutions of higher education in the U.S. (n = 2411). The study comprises a sample of 5.7 million tweets, representing 62% of all tweets created by these accounts and the entire population of U.S. colleges and…

Physical Activity Levels in Older Adults with Intellectual Disabilities Are Extremely Low

ERIC Educational Resources Information Center

Hilgenkamp, Thessa I. M.; Reis, Debora; van Wijck, Ruud; Evenhuis, Heleen M.

2012-01-01

This study measures physical activity levels in a representative population-based sample of older adults (aged [greater than or equal to]50 years) with intellectual disabilities. For this, the steps/day of all 1050 participants of the Healthy Ageing and Intellectual Disabilities study (HA-ID; a study conducted among three Dutch healthcare…

Behavior Problems at 5 Years of Age and Maternal Mental Health in Autism and Intellectual Disability

ERIC Educational Resources Information Center

Totsika, Vasiliki; Hastings, Richard P.; Emerson, Eric; Berridge, Damon M.; Lancaster, Gillian A.

2011-01-01

We examined child behavior problems and maternal mental health in a British population-representative sample of 5 year-old children with an autism spectrum disorder (ASD), controlling for the presence of an intellectual disability (ID). Behavior problems were significantly higher in children with ASD with/out ID compared to typically developing…

The Politics of the Gene: Social Status and Beliefs about Genetics for Individual Outcomes

ERIC Educational Resources Information Center

Shostak, Sara; Freese, Jeremy; Link, Bruce G.; Phelan, Jo C.

2009-01-01

Social scientists have predicted that individuals who occupy socially privileged positions or who have conservative political orientations are most likely to endorse the idea that genes are the root cause of differences among individuals. Drawing on a nationally representative sample of the US population, this study examines belief in the…

Adolescent Gambling Behaviour and Attitudes: A Prevalence Study and Correlates in an Australian Population

ERIC Educational Resources Information Center

Jackson, Alun C.; Dowling, Nicki; Thomas, Shane A.; Bond, Lyndal; Patton, George

2008-01-01

There is considerable evidence that a range of risk factors are associated with adolescent problem gambling. Using a representative sample of 2,788 eighth grade students in Victoria, Australia, the primary aim of this study was to examine the degree to which these risk factors are associated with different levels of adolescent gambling…

Sources of Score Scale Inconsistency. Research Report. ETS RR-11-10

ERIC Educational Resources Information Center

Haberman, Shelby J.; Dorans, Neil J.

2011-01-01

For testing programs that administer multiple forms within a year and across years, score equating is used to ensure that scores can be used interchangeably. In an ideal world, samples sizes are large and representative of populations that hardly change over time, and very reliable alternate test forms are built with nearly identical psychometric…

Topiramate in Long-Term Treatment of Epilepsy in the Intellectually Disabled

ERIC Educational Resources Information Center

Arvio, M.; Sillanpaa, M.

2005-01-01

To study the effectiveness of topiramate (TPM) in refractory epilepsy in patients who have intellectual disability (ID). A representative population sample of 57 patients with ID (age range 261, mean 32.8) was administered add-on TPM for drug-refractory epilepsy. Results Seizure freedom for at least for 6months was attained by 10 (17%), and…

Health Behaviors in a Representative Sample of Older Canadians: Prevalences, Reported Change, Motivation to Change, and Perceived Barriers

ERIC Educational Resources Information Center

Newsom, Jason T.; Kaplan, Mark S.; Huguet, Nathalie; McFarland, Bentson H.

2004-01-01

Purpose: Prevalence estimates of healthy behaviors and preventive care among older adults have not received sufficient attention, despite important health benefits such as longevity and better quality of life. Moreover, little is known about general population prevalences of older adults' efforts to change behavior, motivations to improve health…

Diversity of Participation in Children with Cerebral Palsy

ERIC Educational Resources Information Center

Imms, Christine; Reilly, Sheena; Carlin, John; Dodd, Karen

2008-01-01

The aim of this study was to investigate the participation of children with cerebral palsy (CP) in activities outside school and to compare their participation with a large representative sample of children. A population-based survey was conducted of children with CP born in Victoria, Australia in 1994 and 1995. Of 219 living children identified,…

Mothers' Antenatal Depression and Their Children's Antisocial Outcomes

ERIC Educational Resources Information Center

Hay, Dale F.; Pawlby, Susan; Waters, Cerith S.; Perra, Oliver; Sharp, Deborah

2010-01-01

Interviews of 120 British adolescents and their parents (80% of a random sample of antenatal patients drawn from a representative urban population and followed longitudinally) revealed that 40 (33%) had been arrested and/or had a diagnosis of "DSM-IV" conduct disorder by 16 years of age; of those, 18 (45%) had committed violent acts.…

Social Status, Cognitive Ability, and Educational Attainment as Predictors of Liberal Social Attitudes and Political Trust

ERIC Educational Resources Information Center

Schoon, Ingrid; Cheng, Helen; Gale, Catharine R.; Batty, G. David; Deary, Ian J.

2010-01-01

We examined the prospective associations between family socio-economic background, childhood intelligence ("g") at age 11, educational and occupational attainment, and social attitudes at age 33 in a large (N = 8804), representative sample of the British population born in 1958. Structural equation Modeling identified a latent trait of…

Reporting Rape in a National Sample of College Women

ERIC Educational Resources Information Center

Wolitzky-Taylor, Kate B.; Resnick, Heidi S.; Amstadter, Ananda B.; McCauley, Jenna L.; Ruggiero, Kenneth J.; Kilpatrick, Dean G.

2011-01-01

Background: Studies indicate that a small percentage of rapes are reported to law enforcement officials. Research also suggests that rapes perpetrated by a stranger are more likely to be reported and that rapes involving drugs and/or alcohol are less likely to be reported. College women represent a unique and understudied population with regard to…

Sexism, Homophobia and Transphobia in a Sample of Italian Pre-Service Teachers: The Role of Socio-Demographic Features

ERIC Educational Resources Information Center

Scandurra, Cristiano; Picariello, Simona; Valerio, Paolo; Amodeo, Anna Lisa

2017-01-01

Although recent research has highlighted that lesbian, gay, bisexual and transgender (LGBT) youths represent a resilient population, they still suffer from social stigma and oppression, being potentially at additional risk of developing negative mental health outcomes. One of the main environments where violence and harassment against this…

Perceived Community Disorder Moderates the Relation between Victimization and Fear of Crime

ERIC Educational Resources Information Center

Roccato, Michele; Russo, Silvia; Vieno, Alessio

2011-01-01

In a representative sample of the Italian population (N=2,002), surveyed in January 2008, we studied the direct and interactive effects exerted on fear of crime by direct and indirect victimization, on the one hand, and perceived level of disorder of participants' community, on the other hand. Indirect victimization fostered fear of crime among…

Grandparents Providing Care to Grandchildren: A Population-Based Study of Continuity and Change

ERIC Educational Resources Information Center

Luo, Ye; LaPierre, Tracey A.; Hughes, Mary Elizabeth; Waite, Linda J.

2012-01-01

This study examines transitions in grandchild care and the characteristics of grandparents making these transitions, using longitudinal data from a nationally representative sample of 13,626 grandparents in the 1998-2008 Health and Retirement Study. More than 60% of grandparents provided grandchild care over the 10-year period; more than 70% of…

Anthropometry of Infants, Children, and Youths to Age 18 for Product Safety Design. Final Report.

ERIC Educational Resources Information Center

Snyder, Richard G.; And Others

A total of 87 traditional and functional body measurements were taken on a sample of 4,127 infants, children, and youths representing the U.S. population aged two weeks through 18 years. Measurements were taken throughout the United States by two teams of anthropometrists using an automated anthropometric data acquisition system. Standard…

From Pump to Plug: Measuring the Public's Attitude about Plug-In Electric

Science.gov Websites

-National Benchmark Report, presents the findings of a study on the public's sentiments regarding PEVs, with February 2015, the study covered a 1,015-household sample designed to be representative of the U.S . population. NREL plans to repeat the study annually to track changing consumer perceptions. Consumer Views

The Association of Divorce and Extramarital Sex in a Representative U.S. Sample

ERIC Educational Resources Information Center

Allen, Elizabeth S.; Atkins, David C.

2012-01-01

Few studies provide specific rates of marital divorce or separation in association with a history of infidelity. Research based primarily from clinical or help-seeking populations suggests that most couples who have experienced infidelity do not divorce within the time frames assessed. Using self-reported history of extramarital sex (EMS),…

Delimitacion de las Zonas Dialectales de Mexico: Objetivos y Problemas (Delimitation of Dialect Zones in Mexico: Objectives and Problems)

ERIC Educational Resources Information Center

Blanch, Juan M. Lope

1975-01-01

Before creating a linguistic map of Mexican dialects, it is necessary to determine the dialect regions of the country. An extensive questionnaire must be written and distributed to collect data from a representative sample of the population for an accurate picture of the language. (CK) (Text in Spanish.)

Modeling the sssociation between 25[OH]D and all-cause mortality in a representative US population sample

USDA-ARS?s Scientific Manuscript database

Vitamin D has been identified as a potential key risk factor for several chronic diseases and mortality. The association between all-cause mortality and circulating levels of 25-ydroxyvitamin D (25[OH]D) has been described as non-monotonic with excess mortality at both low and high levels (1). Howev...

Observation procedure, observer gender, and behavior valence as determinants of sampling error in a behavior assessment analogue

PubMed Central

Farkas, Gary M.; Tharp, Roland G.

1980-01-01

Several factors thought to influence the representativeness of behavioral assessment data were examined in an analogue study using a multifactorial design. Systematic and unsystematic methods of observing group behavior were investigated using 18 male and 18 female observers. Additionally, valence properties of the observed behaviors were inspected. Observers' assessments of a videotape were compared to a criterion code that defined the population of behaviors. Results indicated that systematic observation procedures were more accurate than unsystematic procedures, though this factor interacted with gender of observer and valence of behavior. Additionally, males tended to sample more representatively than females. A third finding indicated that the negatively valenced behavior was overestimated, whereas the neutral and positively valenced behaviors were accurately assessed. PMID:16795631

Peer-relationship-problems account for quality of life impairments in pediatric psoriasis.

PubMed

Matterne, Uwe; Apfelbacher, Christian

2016-05-01

Most research on HRQoL-impairments in psoriasis has been conducted in adult patients, small pediatric patient samples or samples not representative of the pediatric population at large. We thus aimed to comprehensively describe HRQoL in pediatric psoriasis compared to psoriasis-free children and adolescents, identify domains most commonly affected and analyze its impact on HRQoL while controlling for important other predictors of HRQoL in a representative pediatric sample. The impact of lifetime-prevalence of psoriasis on total and subscale HRQoL was analyzed by complex sample general linear models alone and adjusted for sociodemographic and clinical variables in a population-based sample (n=6518) of children and adolescents aged 11-17. Total HRQoL and the physical domain were significantly affected by lifetime-psoriasis in univariate analysis. In multivariate analyses, lifetime-psoriasis significantly impacted on total HRQoL and the subscale 'quality of relationships with friends/peers'. Although substantial amounts of variance in HRQoL were explained by mental health, independent effects of lifetime-psoriasis remained after adjustment for this covariate. Total explained variance in total HRQoL was 20%. Our findings suggest psoriasis to be a significant burden as it affects HRQoL even when controlling for mental health. Most of this effect appears to be driven by perceived impairments in the quality of relationship with friends/peers. How this exactly occurs needs to be explored in future research. Meanwhile clinicians need to be more attentive to this effect of psoriasis. Copyright © 2016 Elsevier Inc. All rights reserved.

Recruitment via the Internet and social networking sites: the 1989-1995 cohort of the Australian Longitudinal Study on Women's Health.

PubMed

Mishra, Gita Devi; Hockey, Richard; Powers, Jennifer; Loxton, Deborah; Tooth, Leigh; Rowlands, Ingrid; Byles, Julie; Dobson, Annette

2014-12-15

Faced with the challenge of recruiting young adults for health studies, researchers have increasingly turned to the Internet and social networking sites, such as Facebook, as part of their recruitment strategy. As yet, few large-scale studies are available that report on the characteristics and representativeness of the sample obtained from such recruitment methods. The intent of the study was to describe the sociodemographic and health characteristics of a national sample of young Australian women recruited mainly through the Internet and social networking sites and to discuss the representativeness of their sociodemographic, health, and lifestyle characteristics relative to the population. A cohort of 17,069 women (born between 1989 and 1995) was recruited in 2012-13 for the Australian Longitudinal Study on Women's Health. Sociodemographic characteristics (percentages, means, and 95% confidence intervals) from the online survey data were compared with women aged 18-23 years from the 2011 Australian Census. Sample data were compared by age and education level with data from the 2011-13 Australian Health Survey (AHS). Compared to the Australian Census data, study participants were broadly representative in terms of geographical distribution across Australia, marital status (95.62%, 16,321/17,069) were never married), and age distribution. A higher percentage had attained university (22.52%, 3844/17,069) and trade/certificate/diploma qualifications (25.94%, 4428/17,069) compared with this age group of women in the national population (9.4% and 21.7% respectively). Among study participants, 22.05% (3721/16,877) were not in paid employment with 35.18% (5931/16,857) studying 16 or more hours a week. A higher percentage of study participants rated their health in the online survey as fair or poor (rather than good, very good, or excellent) compared with those participating in face-to-face interviews in the AHS (18.77%, 3203/17,069 vs 10.1%). A higher percentage of study participants were current smokers (21.78%, 3718/17,069 vs 16.4%) and physically active (59.30%, 10,089/17,014 were classified as sufficiently active vs 48.3%) but alcohol consumption was lower (59.58%, 9865/16,558 reported drinking alcohol at least once per month vs 65.9% in the AHS). Using self-reported height and weight to determine body mass index (BMI, kg/m(2)), 34.80% (5901/16,956) of the cohort were classified as overweight or obese (BMI of 25 or more), compared with 33.6% respectively using measured height and weight in the AHS. Findings indicated that using the Internet and social networking sites for an online survey represent a feasible recruitment strategy for a national cohort of young women and result in a broadly representative sample of the Australian population.

Assessment of rarity of the blackmouth shiner Notropis melanostomus (Cyprinidae) based on museum and recent survey data

USGS Publications Warehouse

O'Connell, M. T.; Uzee O'Connell, A.M.; Williams, J.D.

2005-01-01

Accurate knowledge of an organism's distribution is necessary for conserving species with small or isolated populations. A perceived rarity may only reflect inadequate sampling effort and suggest the need for more research. We used a recently developed method to evaluate the distribution of a rare fish species, the blackmouth shiner Notropis melanostomus Bortone 1989 (Cyprinidae), which occurs in disjunct populations in Mississippi and Florida. Until 1995, N. melanostomus had been collected from only three localities in Mississippi, but in 1995, eight new localities were discovered. We analyzed museum records of fish collections from Mississippi, Florida, and Alabama to compare sampling effort before and after 1995. Results supported our predictions that 1) pre-1995 data would indicate inadequate sampling effort in Mississippi, 2) additional post-1995 sampling improved confidence in the currently known Mississippi distribution, and 3) there has not been enough sampling to accurately represent the actual distribution of N. melanostomus in Florida and across its entire known range. This last prediction was confirmed with the recent (2003) discovery of the first N. melanostomus in Alabama.

GenoCore: A simple and fast algorithm for core subset selection from large genotype datasets.

PubMed

Jeong, Seongmun; Kim, Jae-Yoon; Jeong, Soon-Chun; Kang, Sung-Taeg; Moon, Jung-Kyung; Kim, Namshin

2017-01-01

Selecting core subsets from plant genotype datasets is important for enhancing cost-effectiveness and to shorten the time required for analyses of genome-wide association studies (GWAS), and genomics-assisted breeding of crop species, etc. Recently, a large number of genetic markers (>100,000 single nucleotide polymorphisms) have been identified from high-density single nucleotide polymorphism (SNP) arrays and next-generation sequencing (NGS) data. However, there is no software available for picking out the efficient and consistent core subset from such a huge dataset. It is necessary to develop software that can extract genetically important samples in a population with coherence. We here present a new program, GenoCore, which can find quickly and efficiently the core subset representing the entire population. We introduce simple measures of coverage and diversity scores, which reflect genotype errors and genetic variations, and can help to select a sample rapidly and accurately for crop genotype dataset. Comparison of our method to other core collection software using example datasets are performed to validate the performance according to genetic distance, diversity, coverage, required system resources, and the number of selected samples. GenoCore selects the smallest, most consistent, and most representative core collection from all samples, using less memory with more efficient scores, and shows greater genetic coverage compared to the other software tested. GenoCore was written in R language, and can be accessed online with an example dataset and test results at https://github.com/lovemun/Genocore.

Viewing child pornography: prevalence and correlates in a representative community sample of young Swedish men.

PubMed

Seto, Michael C; Hermann, Chantal A; Kjellgren, Cecilia; Priebe, Gisela; Svedin, Carl Göran; Långström, Niklas

2015-01-01

Most research on child pornography use has been based on selected clinical or criminal justice samples; risk factors for child pornography use in the general population remain largely unexplored. In this study, we examined prevalence, risk factors, and correlates of viewing depictions of adult-child sex in a population-representative sample of 1,978 young Swedish men (17-20 years, Mdn = 18 years, overall response rate, 77 %). In an anonymous, school-based survey, participants self-reported sexual coercion experiences, attitudes and beliefs about sex, perceived peer attitudes, and sexual interests and behaviors; including pornography use, sexual interest in children, and sexually coercive behavior. A total of 84 (4.2 %) young men reported they had ever viewed child pornography. Most theory-based variables were moderately and significantly associated with child pornography viewing and were consistent with models of sexual offending implicating both antisociality and sexual deviance. In multivariate logistic regression analysis, 7 of 15 tested factors independently predicted child pornography viewing and explained 42 % of the variance: ever had sex with a male, likely to have sex with a child aged 12-14, likely to have sex with a child 12 or less, perception of children as seductive, having friends who have watched child pornography, frequent pornography use, and ever viewed violent pornography. From these, a 6-item Child Pornography Correlates Scale was constructed and then cross-validated in a similar but independent Norwegian sample.

A Systematic Review of Childhood Maltreatment Assessments in Population-Representative Surveys Since 1990

PubMed Central

Hovdestad, Wendy; Campeau, Aimée; Potter, Dawn; Tonmyr, Lil

2015-01-01

Background Population-representative surveys that assess childhood maltreatment and health are a valuable resource to explore the implications of child maltreatment for population health. Systematic identification and evaluation of such surveys is needed to facilitate optimal use of their data and to inform future research. Objectives To inform researchers of the existence and nature of population-representative surveys relevant to understanding links between childhood maltreatment and health; to evaluate the assessment of childhood maltreatment in this body of work. Methods We included surveys that: 1) were representative of the non-institutionalized population of any size nation or of any geopolitical region ≥ 10 million people; 2) included a broad age range (≥ 40 years); 3) measured health; 4) assessed childhood maltreatment retrospectively; and 5) were conducted since 1990. We used Internet and database searching (including CINAHL, Embase, ERIC, Global Health, MEDLINE, PsycINFO, Scopus, Social Policy and Practice: January 1990 to March 2014), expert consultation, and other means to identify surveys and associated documentation. Translations of non-English survey content were verified by fluent readers of survey languages. We developed checklists to abstract and evaluate childhood maltreatment content. Results Fifty-four surveys from 39 countries met inclusion criteria. Sample sizes ranged from 1,287-51,945 and response rates from 15%-96%. Thirteen surveys assessed neglect, 15 emotional abuse; 18 exposure to family violence; 26 physical abuse; 48 sexual abuse. Fourteen surveys assessed more than three types; six of these were conducted since 2010. In nine surveys childhood maltreatment assessments were detailed (+10 items for at least one type of maltreatment). Seven surveys’ assessments had known reliability and/or validity. Conclusions and Implications Data from 54 surveys can be used to explore the population health relevance of child maltreatment. Assessment of childhood maltreatment is not comprehensive but there is evidence of recent improvement. PMID:25993481

Genome-wide genetic diversity, population structure and admixture analysis in African and Asian cattle breeds.

PubMed

Edea, Z; Bhuiyan, M S A; Dessie, T; Rothschild, M F; Dadi, H; Kim, K S

2015-02-01

Knowledge about genetic diversity and population structure is useful for designing effective strategies to improve the production, management and conservation of farm animal genetic resources. Here, we present a comprehensive genome-wide analysis of genetic diversity, population structure and admixture based on 244 animals sampled from 10 cattle populations in Asia and Africa and genotyped for 69,903 autosomal single-nucleotide polymorphisms (SNPs) mainly derived from the indicine breed. Principal component analysis, STRUCTURE and distance analysis from high-density SNP data clearly revealed that the largest genetic difference occurred between the two domestic lineages (taurine and indicine), whereas Ethiopian cattle populations represent a mosaic of the humped zebu and taurine. Estimation of the genetic influence of zebu and taurine revealed that Ethiopian cattle were characterized by considerable levels of introgression from South Asian zebu, whereas Bangladeshi populations shared very low taurine ancestry. The relationships among Ethiopian cattle populations reflect their history of origin and admixture rather than phenotype-based distinctions. The high within-individual genetic variability observed in Ethiopian cattle represents an untapped opportunity for adaptation to changing environments and for implementation of within-breed genetic improvement schemes. Our results provide a basis for future applications of genome-wide SNP data to exploit the unique genetic makeup of indigenous cattle breeds and to facilitate their improvement and conservation.

The impact of comorbidity of mental and physical conditions on role disability in the US adult household population.

PubMed

Merikangas, Kathleen R; Ames, Minnie; Cui, Lihong; Stang, Paul E; Ustun, T Bedirhan; Von Korff, Michael; Kessler, Ronald C

2007-10-01

There is limited information that accounts for comorbidity on the impact of role disability associated with a wide range of mental and physical disorders in population-based samples. To estimate the comparative effects of common mental and physical conditions on role disability in the general population using a novel method that accounts for comorbidity. Direct interviews about physical and mental conditions during the past year. The National Comorbidity Survey Replication, a nationally representative series of face-to-face interviews. A nationally representative sample of adults living in households (N = 5962 respondents, 18 years and older). Disability in major life roles was assessed with the World Health Organization Disability Assessment Schedule. Simulations that allow for complex interactions among conditions were used to estimate the conditions' effects on disability days, when respondents were completely unable to carry out their usual daily activities because of problems with mental or physical health, in the past 12 months. An estimated 53.4% of US adults have 1 or more of the mental or physical conditions assessed in the survey. These respondents report an average 32.1 more role-disability days in the past year than demographically matched controls, equivalent to nearly 3.6 billion days of role disability in the population. Musculoskeletal disorders and major depression had the greatest effects on disability days. Mental conditions accounted for more than half as many disability days as all physical conditions at the population level. Associations of specific conditions with disability decreased substantially after controlling for comorbidity, suggesting that prior studies, which generally did not control for comorbidity, overestimated disease-specific effects. The staggering amount of health-related disability associated with mental and physical conditions should be considered in establishing priorities for the allocation of health care and research resources.

Allele Frequencies Net Database: Improvements for storage of individual genotypes and analysis of existing data.

PubMed

Santos, Eduardo Jose Melos Dos; McCabe, Antony; Gonzalez-Galarza, Faviel F; Jones, Andrew R; Middleton, Derek

2016-03-01

The Allele Frequencies Net Database (AFND) is a freely accessible database which stores population frequencies for alleles or genes of the immune system in worldwide populations. Herein we introduce two new tools. We have defined new classifications of data (gold, silver and bronze) to assist users in identifying the most suitable populations for their tasks. The gold standard datasets are defined by allele frequencies summing to 1, sample sizes >50 and high resolution genotyping, while silver standard datasets do not meet gold standard genotyping resolution and/or sample size criteria. The bronze standard datasets are those that could not be classified under the silver or gold standards. The gold standard includes >500 datasets covering over 3 million individuals from >100 countries at one or more of the following loci: HLA-A, -B, -C, -DPA1, -DPB1, -DQA1, -DQB1 and -DRB1 - with all loci except DPA1 present in more than 220 datasets. Three out of 12 geographic regions have low representation (the majority of their countries having less than five datasets) and the Central Asia region has no representation. There are 18 countries that are not represented by any gold standard datasets but are represented by at least one dataset that is either silver or bronze standard. We also briefly summarize the data held by AFND for KIR genes, alleles and their ligands. Our second new component is a data submission tool to assist users in the collection of the genotypes of the individuals (raw data), facilitating submission of short population reports to Human Immunology, as well as simplifying the submission of population demographics and frequency data. Copyright © 2015 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

The South African Food Sensitisation and Food Allergy population-based study of IgE-mediated food allergy: validity, safety, and acceptability.

PubMed

Basera, Wisdom; Botha, Maresa; Gray, Claudia L; Lunjani, Nonhlanhla; Watkins, Alexandra S M; Venter, Carina; Allen, Katrina J; Hlela, Carol; Zar, Heather J; Levin, Michael E

2015-08-01

Few studies exist on food sensitization and challenge-proven food allergy in low- and middle-income countries. To describe the study design and methodology to recruit infants from an African population for skin prick testing and oral food challenges and the use of preliminary data to investigate the extent to which the study sample is representative of the target population. Children 12 to 36 months old were recruited from childcare education facilities in Cape Town. Children underwent skin prick testing to foods. Those with a reactive wheal of at least 1 mm larger than the negative control and not clearly tolerant according to history to a full age-appropriate portion to at least 1 food underwent oral food challenges. Parents who chose not to participate completed a nonparticipant questionnaire. Interim analysis of at least 500 respondents was performed. Demographic features of participating children were compared with those of nonparticipants and the population demographics of the most recent Cape Town census data. The response rate was 60.1%, with high participation and completion rates of 96.5% and 97.5%, respectively. Demographics of the completed participant sample were similar to those of the Cape Town census. Use of a nonrespondent questionnaire indicated no selection bias in favor of increased participation of participants with allergy. No ethnic differences in sensitization or food allergy were evident. The study was safe and feasible and the recruitment was effective and representative of the target population. Future studies will aim to increase the precision of the prevalence of food sensitization and allergy, describe environmental risk factors, and include a rural black African cohort. Copyright © 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

The mitochondrial phylogeography and intraspecific taxonomy of the Steppe Racerunner, Eremias arguta (Pallas) (Lacertidae: Sauria, Reptilia), reflects biogeographic patterns in Middle Asia.

PubMed

Poyarkov, Nikolay A; Orlova, Valentina F; Chirikova, Marina A

2014-12-15

Steppe racerunner, Eremias (Eremias) arguta, is one of the most widespread species of the Asian racerunners (genus Eremias). Several subspecies were traditionally recognized however, morphological variability is so high that delimitation of these subspecies was always problematic. Here we present a phylogenetic hypothesis for this species based on cytochrome b sequences (55 samples from 35 populations, 900 bp partial sequences), infer it biogeography and the revise its subspecific structure. Six major phylogenetic lineages were revealed. The southernmost populations (E. a. uzbekistanica) from Uzbekistan form a clade together with the Issyk-Kul Lake subspecies (E. a. darevskii) based on both molecular and morphological evidence. Within more northern populations, there is a split between populations from Northern Caucasus, Europe and Western Kazakhstan (E. a. deserti) and Central and Eastern Kazakhstan populations (E. a. arguta). Transcaucasian (E. a. transcaucasica) steppe racerunners are grouped with Middle Asian populations. Finally, the easternmost samples, assigned to "E. a. potanini" are nested within the E. a. arguta clade. Populations from the Ili River Valley form a separate lineage sister to the clade joining all other E. arguta lineages and might represent a yet undescribed taxon. Species distribution in relation to historical biogeography of Middle Asia is discussed. 

The prevalence of physical activity and its associated factors among Malaysian adults: findings from the National Health and Morbidity Survey 2011.

PubMed

Teh, C H; Lim, K K; Chan, Y Y; Lim, K H; Azahadi, O; Hamizatul Akmar, A H; Ummi Nadiah, Y; Syafinaz, M S; Kee, C C; Yeo, P S; Fadhli, Y

2014-05-01

Despite the health-enhancing benefits of physical activity, a large segment of the Malaysian population does not engage in regular physical activity at the recommended level. This study aimed to determine physical activity patterns and the associated sociodemographic correlates of physical activity. Data on physical activity were obtained from the National Health and Morbidity Survey (NHMS) 2011, a nationally representative, population-based cross-sectional study. A two-stage stratified sampling method was used to select a representative sample of Malaysian adults aged 16 years and above. A total of 19,145 adults aged 16 years and above were recruited, and face-to-face interviews were conducted using the International Physical Activity Questionnaire (IPAQ), short version. The correlates for physical activity were identified using multivariate analysis. In this study, 64.3% (95%CI: 63.1-65.5) of Malaysian adults aged 16 and above were physically active, but overall physical activity levels decreased with advancing age. Men, rural residents, 'other' ethnic groups, and married women were more likely to demonstrate higher levels of physical activity. Approximately 65% of Malaysian adults were physically active. However, it is recommended that health promotions for active lifestyles should be targeted to the least active segments, which constitute more than a quarter of the Malaysian population. Copyright © 2013 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

A representative survey of the dynamics and energetics of FR II radio galaxies

NASA Astrophysics Data System (ADS)

Ineson, J.; Croston, J. H.; Hardcastle, M. J.; Mingo, B.

2017-05-01

We report the first large, systematic study of the dynamics and energetics of a representative sample of Fanaroff-Riley type II (FR II) radio galaxies with well-characterized group/cluster environments. We used X-ray inverse-Compton and radio synchrotron measurements to determine the internal radio-lobe conditions, and these were compared with external pressures acting on the lobes, determined from measurements of the thermal X-ray emission of the group/cluster. Consistent with previous work, we found that FR II radio lobes are typically electron dominated by a small factor relative to equipartition, and are overpressured relative to the external medium in their outer parts. These results suggest that there is typically no energetically significant proton population in the lobes of FR II radio galaxies (unlike for FR Is), and so for this population, inverse-Compton modelling provides an accurate way of measuring total energy content and estimating jet power. We estimated the distribution of Mach numbers for the population of expanding radio lobes, finding that at least half of the radio galaxies are currently driving strong shocks into their group/cluster environments. Finally, we determined a jet power-radio luminosity relation for FR II radio galaxies based on our estimates of lobe internal energy and Mach number. The slope and normalization of this relation are consistent with theoretical expectations, given the departure from equipartition and environmental distribution for our sample.

Stalking and health – an Austrian prevalence study.

PubMed

Freidl, W; Neuberger, I; Schönberger, S; Raml, R

2011-04-01

The aim of this study was to estimate the prevalence of stalking and related subjective health impairment, based on concrete definitions of stalking, for a representative random sample of the female population in the Austrian Federal State of Styria. A representative random sample (randomised last digits procedure) of 2000 women selected from the female population of Styria aged 18 years or older underwent a computer-aided phone interview survey (CATI). Questions centred on the occurrence of stalking, the exact period of stalking, the gender of the stalker, the subjective impairment through stalking, addressing the aspects of life-style and the subjectively perceived state of health, and socio-demographic variables. For data analyses descriptive statistics, and chi(2)-tests and t-tests were applied. Lifetime prevalence varies between ca. 6% and 18%, depending on definition levels. The annual prevalences reveal a range of 1-4%. 39-43% of the stalked women feel they are impaired in their life-style, and 32-40% feel impaired in their health. Higher age and living in a partnership reduce the likelihood of being stalked. 81% of the stalked women are stalked by a male person. The prevalences found in this study are in line with other international studies, although, in a direct comparison, they are in the lower range. However, these data document the relevance of the phenomenon of stalking for the female Austrian population. © Georg Thieme Verlag KG Stuttgart · New York.

Monitoring Puerto Rican avifauna using roadside surveys

USGS Publications Warehouse

Pardieck, K.L.; Peterjohn, B.G.; Ralph, C. John; Rich, Terrell D.

2005-01-01

In 1997 we began investigating the use of roadside point counts to monitor the long-term status and trends of Puerto Rican bird populations. If such a methodology proves feasible it may provide the empirical data needed for the development of sound conservation plans for the island's avifauna in much the same way that North American Breeding Bird Survey data are used by the avian conservation prioritization process of Partners in Flight, the U.S. Fish and Wildlife Service, and the Canadian Wildlife Service. By the end of the 2003 field season, we will have the data needed to quantitatively evaluate the utility of the program for tracking the population trends of Puerto Rican avifauna. Here we present data from the 2001 and 2002 field seasons to demonstrate the potential utility of these data for quantifying and portraying avian distributions, abundances, and population trend estimates. In 2001, 27 of the 44 available 5-mile roadside routes (11 stops/route) were sampled between 15 April and 15 May. At each stop a 5-minute point count was conducted. The surveys detected 5,471 individuals representing 70 species. Distribution and abundance maps are depicted for seven endemic species. In 2002, 29 routes were sampled. A total of 6,252 individuals was detected representing 79 species. Significantly fewer species and individuals were detected on wet zone routes as compared to moist and dry zone routes.

Recruitment and Participation of Recreational Runners in a Large Epidemiological and Genetic Research Study: Retrospective Data Analysis.

PubMed

Manzanero, Silvia; Kozlovskaia, Maria; Vlahovich, Nicole; Hughes, David C

2018-05-23

With the increasing capacity for remote collection of both data and samples for medical research, a thorough assessment is needed to determine the association of population characteristics and recruitment methodologies with response rates. The aim of this research was to assess population representativeness in a two-stage study of health and injury in recreational runners, which consisted of an epidemiological arm and genetic analysis. The cost and success of various classical and internet-based methods were analyzed, and demographic representativeness was assessed for recruitment to the epidemiological survey, reported willingness to participate in the genetic arm of the study, actual participation, sample return, and approval for biobank storage. A total of 4965 valid responses were received, of which 1664 were deemed eligible for genetic analysis. Younger age showed a negative association with initial recruitment rate, expressed willingness to participate in genetic analysis, and actual participation. Additionally, female sex was associated with higher initial recruitment rates, and ethnic origin impacted willingness to participate in the genetic analysis (all P<.001). The sharp decline in retention through the different stages of the study in young respondents suggests the necessity to develop specific recruitment and retention strategies when investigating a young, physically active population. ©Silvia Manzanero, Maria Kozlovskaia, Nicole Vlahovich, David C Hughes. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 23.05.2018.

Relative survival: a useful tool to assess generalisability in longitudinal studies of health in older persons

PubMed Central

2011-01-01

Background Generalisability of longitudinal studies is threatened by issues such as choice of sampling frame, representativeness of the initial sample, and attrition. To determine representativeness, cohorts are often compared with the population of interest at baseline on demographic and health characteristics. This study illustrates the use of relative survival as a tool for assessing generalisability of results from a cohort of older people among whom death is a potential threat to generalisability. Methods The authors used data from the 1921-26 cohort (n = 12,416, aged 70-75 in 1996) of the Australian Longitudinal Study on Women's Health (ALSWH). Vital status was determined by linkage to the National Death Index, and expected deaths were derived using Australian life tables. Relative survival was estimated using observed survival in the cohort divided by expected survival among women of the same age and State or Territory. Results Overall, the ALSWH women showed relative survival 9.5% above the general population. Within States and Territories, the relative survival advantage varied from 6% to 23%. The interval-specific relative survival remained relatively constant over the 12 years (1996-2008) under review, indicating that the survival advantage of the cohort has not diminished over time. Conclusion This study demonstrates that relative survival can be a useful measure of generalisability in a longitudinal study of the health of the general population, particularly when participants are older. PMID:21294918

Molecular identification of bacteria on the tongue dorsum of subjects with and without halitosis.

PubMed

Riggio, M P; Lennon, A; Rolph, H J; Hodge, P J; Donaldson, A; Maxwell, A J; Bagg, J

2008-04-01

Compare the microbial profiles on the tongue dorsum in patients with halitosis and control subjects in a UK population using culture-independent techniques. Halitosis patients were screened according to our recently developed recruitment protocol. Scrapings from the tongue dorsum were obtained for 12 control subjects and 20 halitosis patients. Bacteria were identified by PCR amplification, cloning and sequencing of 16S rRNA genes. The predominant species found in the control samples were Lysobacter-type species, Streptococcus salivarius, Veillonella dispar, unidentified oral bacterium, Actinomyces odontolyticus, Atopobium parvulum and Veillonella atypica. In the halitosis samples, Lysobacter-type species, S. salivarius, Prevotella melaninogenica, unidentified oral bacterium, Prevotella veroralis and Prevotella pallens were the most commonly found species. For the control samples, 13-16 (4.7-5.8%) of 276 clones represented uncultured species, whereas in the halitosis samples, this proportion increased to 6.5-9.6% (36-53 of 553 clones). In the control samples, 22 (8.0%) of 276 clones represented potentially novel phylotypes, and in the halitosis samples, this figure was 39 (7.1%) of 553 clones. The microflora associated with the tongue dorsum is complex in both the control and halitosis groups, but several key species predominate in both groups.

[Genetic Differentiation of Sockeye Salmon Oncorhynchus nerka from Kamchatka River Basin and the Lake-River Systems of the West Coast of the Bering Sea as Inferred from Data on Single Nucleotide Polymorphism].

PubMed

Khrustaleva, A M; Klovach, N V; Vedischeva, E V; Seeb, J E

2015-10-01

The variability of 45 single nucleotide polymorphism loci (SNP) was studied in sockeye salmon from the Kamchatka River basin and four lake-river systems of the west coast of the Bering Sea. Based on the genetic differentiation estimates for the largest sockeye salmon populations of Eastern Kamchatka and Chukotka, the examined samples were combined into two regional groups represented by the population of the Kamchatka River drainage, which included numerous local subpopulations and seasonal races, and the northern population grouping from the rivers of Olutorsko-Navarinsky raion, wherein the sockeye salmon from Maynypilginskaya Lake-River system was relatively isolated. Considerable divergence was observed between the island (Sarannoe Lake, Bering Island) and continental populations. Genetic heterogeneity was revealed and groups of early- and late-maturing individuals were isolated in the sample of late-run sockeye salmon from Kamchatka River. In Apuka River, subdivision of the spawning run into two genetically distinct spatial and temporal groupings was also observed. The results suggest that the differentiation of sockeye salmon samples by single nucleotide substitution frequencies was largely due to differences in the direction and strength of local selection at some loci in the population complexes and intrapopulation groupings from the examined river basins of Eastern Kamchatka, Chukotka, and Commander Islands.

World without borders-genetic population structure of a highly migratory marine predator, the blue shark (Prionace glauca).

PubMed

Veríssimo, Ana; Sampaio, Íris; McDowell, Jan R; Alexandrino, Paulo; Mucientes, Gonzalo; Queiroz, Nuno; da Silva, Charlene; Jones, Catherine S; Noble, Leslie R

2017-07-01

Highly migratory, cosmopolitan oceanic sharks often exhibit complex movement patterns influenced by ontogeny, reproduction, and feeding. These elusive species are particularly challenging to population genetic studies, as representative samples suitable for inferring genetic structure are difficult to obtain. Our study provides insights into the genetic population structure one of the most abundant and wide-ranging oceanic shark species, the blue shark Prionace glauca, by sampling the least mobile component of the populations, i.e., young-of-year and small juveniles (<2 year; N  = 348 individuals), at three reported nursery areas, namely, western Iberia, Azores, and South Africa. Samples were collected in two different time periods (2002-2008 and 2012-2015) and were screened at 12 nuclear microsatellites and at a 899-bp fragment of the mitochondrial control region. Our results show temporally stable genetic homogeneity among the three Atlantic nurseries at both nuclear and mitochondrial markers, suggesting basin-wide panmixia. In addition, comparison of mtDNA CR sequences from Atlantic and Indo-Pacific locations also indicated genetic homogeneity and unrestricted female-mediated gene flow between ocean basins. These results are discussed in light of the species' life history and ecology, but suggest that blue shark populations may be connected by gene flow at the global scale. The implications of the present findings to the management of this important fisheries resource are also discussed.

The Complete Local-Volume Groups Sample (CLoGS): Early results from X-ray and radio observations

NASA Astrophysics Data System (ADS)

Vrtilek, Jan M.; O'Sullivan, Ewan; David, Laurence P.; Giacintucci, Simona; Kolokythas, Konstantinos

2017-08-01

Although the group environment is the dominant locus of galaxy evolution (in contrast to rich clusters, which contain only a few percent of galaxies), there has been a lack of reliable, representative group samples in the local Universe. In particular, X-ray selected samples are strongly biased in favor of the X-ray bright, centrally-concentrated cool-core systems. In response, we have designed the Complete Local-Volume Groups Sample (CLoGS), an optically-selected statistically-complete sample of 53 groups within 80 Mpc which is intended to overcome the limitations of X-ray selected samples and serve as a representative survey of groups in the local Universe. We have supplemented X-ray data from Chandra and XMM (70% complete to date, using both archival and new observations, with a 26-group high richness subsample 100% complete) with GMRT radio continuum observations (at 235 and 610 MHz, complete for the entire sample). CLoGS includes groups with a wide variety of properties in terms of galaxy population, hot gas content, and AGN power. We here describe early results from the survey, including the range of AGN activity observed in the dominant galaxies, the relative fraction of cool-core and non-cool-core groups in our sample, and the degree of disturbance observed in the IGM.

The contributions of admixture and genetic drift to diversity among post-contact populations in the Americas.

PubMed

Koehl, Anthony J; Long, Jeffrey C

2018-02-01

We present a model that partitions Nei's minimum genetic distance between admixed populations into components of admixture and genetic drift. We applied this model to 17 admixed populations in the Americas to examine how admixture and drift have contributed to the patterns of genetic diversity. We analyzed 618 short tandem repeat loci in 949 individuals from 49 population samples. Thirty-two samples serve as proxies for continental ancestors. Seventeen samples represent admixed populations: (4) African-American and (13) Latin American. We partition genetic distance, and then calculate fixation indices and principal coordinates to interpret our results. A computer simulation confirms that our method correctly estimates drift and admixture components of genetic distance when the assumptions of the model are met. The partition of genetic distance shows that both admixture and genetic drift contribute to patterns of genetic diversity. The admixture component of genetic distance provides evidence for two distinct axes of continental ancestry. However, the genetic distances show that ancestry contributes to only one axis of genetic differentiation. The genetic distances among the 13 Latin American populations in this analysis show contributions from both differences in ancestry and differences in genetic drift. By contrast, the genetic distances among the four African American populations in this analysis owe mostly to genetic drift because these groups have similar fractions of European and African ancestry. The genetic structure of admixed populations in the Americas reflects more than admixture. We show that the history of serial founder effects constrains the impact of admixture on allele frequencies to a single dimension. Genetic drift in the admixed populations imposed a new level of genetic structure onto that created by admixture. © 2017 Wiley Periodicals, Inc.

Development of a scale to assess cancer stigma in the non-patient population.

PubMed

Marlow, Laura A V; Wardle, Jane

2014-04-23

Illness-related stigma has attracted considerable research interest, but few studies have specifically examined stigmatisation of cancer in the non-patient population. The present study developed and validated a Cancer Stigma Scale (CASS) for use in the general population. An item pool was developed on the basis of previous research into illness-related stigma in the general population and patients with cancer. Two studies were carried out. The first study used Exploratory factor analysis to explore the structure of items in a sample of 462 postgraduate students recruited through a London university. The second study used Confirmatory factor analysis to confirm the structure among 238 adults recruited through an online market research panel. Internal reliability, test-retest reliability and construct validity were also assessed. Exploratory factor analysis suggested six subscales, representing: Awkwardness, Severity, Avoidance, Policy Opposition, Personal Responsibility and Financial Discrimination. Confirmatory factor analysis confirmed this structure with a 25-item scale. All subscales showed adequate to good internal and test-retest reliability in both samples. Construct validity was also good, with mean scores for each subscale varying in the expected directions by age, gender, experience of cancer, awareness of lifestyle risk factors for cancer, and social desirability. Means for the subscales were consistent across the two samples. These findings highlight the complexity of cancer stigma and provide the Cancer Stigma Scale (CASS) which can be used to compare populations, types of cancer and evaluate the effects of interventions designed to reduce cancer stigma in non-patient populations.

Statistical and population genetics issues of two Hungarian datasets from the aspect of DNA evidence interpretation.

PubMed

Szabolcsi, Zoltán; Farkas, Zsuzsa; Borbély, Andrea; Bárány, Gusztáv; Varga, Dániel; Heinrich, Attila; Völgyi, Antónia; Pamjav, Horolma

2015-11-01

When the DNA profile from a crime-scene matches that of a suspect, the weight of DNA evidence depends on the unbiased estimation of the match probability of the profiles. For this reason, it is required to establish and expand the databases that reflect the actual allele frequencies in the population applied. 21,473 complete DNA profiles from Databank samples were used to establish the allele frequency database to represent the population of Hungarian suspects. We used fifteen STR loci (PowerPlex ESI16) including five, new ESS loci. The aim was to calculate the statistical, forensic efficiency parameters for the Databank samples and compare the newly detected data to the earlier report. The population substructure caused by relatedness may influence the frequency of profiles estimated. As our Databank profiles were considered non-random samples, possible relationships between the suspects can be assumed. Therefore, population inbreeding effect was estimated using the FIS calculation. The overall inbreeding parameter was found to be 0.0106. Furthermore, we tested the impact of the two allele frequency datasets on 101 randomly chosen STR profiles, including full and partial profiles. The 95% confidence interval estimates for the profile frequencies (pM) resulted in a tighter range when we used the new dataset compared to the previously published ones. We found that the FIS had less effect on frequency values in the 21,473 samples than the application of minimum allele frequency. No genetic substructure was detected by STRUCTURE analysis. Due to the low level of inbreeding effect and the high number of samples, the new dataset provides unbiased and precise estimates of LR for statistical interpretation of forensic casework and allows us to use lower allele frequencies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The genetic architecture of sexually selected traits in two natural populations of Drosophila montana

PubMed Central

Veltsos, P; Gregson, E; Morrissey, B; Slate, J; Hoikkala, A; Butlin, R K; Ritchie, M G

2015-01-01

We investigated the genetic architecture of courtship song and cuticular hydrocarbon traits in two phygenetically distinct populations of Drosophila montana. To study natural variation in these two important traits, we analysed within-population crosses among individuals sampled from the wild. Hence, the genetic variation analysed should represent that available for natural and sexual selection to act upon. In contrast to previous between-population crosses in this species, no major quantitative trait loci (QTLs) were detected, perhaps because the between-population QTLs were due to fixed differences between the populations. Partitioning the trait variation to chromosomes suggested a broadly polygenic genetic architecture of within-population variation, although some chromosomes explained more variation in one population compared with the other. Studies of natural variation provide an important contrast to crosses between species or divergent lines, but our analysis highlights recent concerns that segregating variation within populations for important quantitative ecological traits may largely consist of small effect alleles, difficult to detect with studies of moderate power. PMID:26198076

The psychometric properties of the German version of the WHOQOL-OLD in the German population aged 60 and older.

PubMed

Conrad, Ines; Matschinger, Herbert; Riedel-Heller, Steffi; von Gottberg, Carolin; Kilian, Reinhold

2014-09-05

The WHOQOL-OLD is an instrument for the assessment of subjective quality of life in elderly people. It is based on the WHO definition of quality of life and is available in more than 20 languages. However, in most countries, the psychometric properties of the WHOQOL-OLD have been assessed only on the basis of small local samples and not in representative studies. In this study, the psychometric properties of the WHOQOL-OLD are evaluated based on a representative sample of Germany's elderly population. Face-to-face interviews with 1133 respondents from the German population aged 60 years and older were conducted. Quality of life was assessed by means of the WHOQOL-BREF, the WHOQOL-OLD and the SF12. Moreover, the GDS, the DemTect and the IADL were applied for the assessment of depressive symptoms, cognitive capacities and capacity for carrying out daily activities. Psychometric properties of the WHOQOL-OLD were evaluated by means of classical and probabilistic test theory, confirmatory factor analysis and multivariate regression model. Cronbach's alpha was found to be above 0.85 for four and above .75 for two of the six facets of the WHOQOL-OLD. IRT analyses indicated that all items of the WHOQOL-OLD contribute considerably to the measurement of the associated facets. While the six-facet structure of the WHOQOL-OLD was well supported by the results of the confirmatory factor analysis, a common latent factor for the WHOQOL-OLD total scale could not be identified. Correlations with other quality of life measures and multivariate regression models with GDS, IADL and the DemTect indicate a good criterion validity of all six WHOQOL-OLD facets. Study results confirm that the good psychometric properties of the WHOQOL-OLD that have been found in international studies could be replicated in a representative study of the German population. These results suggest that the WHOQOL-OLD is an instrument that is well suited to identify the needs and the wishes of an aging population.

Geographic Patterns of Genetic Variation in a Broadly Distributed Marine Vertebrate: New Insights into Loggerhead Turtle Stock Structure from Expanded Mitochondrial DNA Sequences

PubMed Central

Shamblin, Brian M.; Bolten, Alan B.; Abreu-Grobois, F. Alberto; Bjorndal, Karen A.; Cardona, Luis; Carreras, Carlos; Clusa, Marcel; Monzón-Argüello, Catalina; Nairn, Campbell J.; Nielsen, Janne T.; Nel, Ronel; Soares, Luciano S.; Stewart, Kelly R.; Vilaça, Sibelle T.; Türkozan, Oguz; Yilmaz, Can; Dutton, Peter H.

2014-01-01

Previous genetic studies have demonstrated that natal homing shapes the stock structure of marine turtle nesting populations. However, widespread sharing of common haplotypes based on short segments of the mitochondrial control region often limits resolution of the demographic connectivity of populations. Recent studies employing longer control region sequences to resolve haplotype sharing have focused on regional assessments of genetic structure and phylogeography. Here we synthesize available control region sequences for loggerhead turtles from the Mediterranean Sea, Atlantic, and western Indian Ocean basins. These data represent six of the nine globally significant regional management units (RMUs) for the species and include novel sequence data from Brazil, Cape Verde, South Africa and Oman. Genetic tests of differentiation among 42 rookeries represented by short sequences (380 bp haplotypes from 3,486 samples) and 40 rookeries represented by long sequences (∼800 bp haplotypes from 3,434 samples) supported the distinction of the six RMUs analyzed as well as recognition of at least 18 demographically independent management units (MUs) with respect to female natal homing. A total of 59 haplotypes were resolved. These haplotypes belonged to two highly divergent global lineages, with haplogroup I represented primarily by CC-A1, CC-A4, and CC-A11 variants and haplogroup II represented by CC-A2 and derived variants. Geographic distribution patterns of haplogroup II haplotypes and the nested position of CC-A11.6 from Oman among the Atlantic haplotypes invoke recent colonization of the Indian Ocean from the Atlantic for both global lineages. The haplotypes we confirmed for western Indian Ocean RMUs allow reinterpretation of previous mixed stock analysis and further suggest that contemporary migratory connectivity between the Indian and Atlantic Oceans occurs on a broader scale than previously hypothesized. This study represents a valuable model for conducting comprehensive international cooperative data management and research in marine ecology. PMID:24465810

Optimism is universal: exploring the presence and benefits of optimism in a representative sample of the world.

PubMed

Gallagher, Matthew W; Lopez, Shane J; Pressman, Sarah D

2013-10-01

Current theories of optimism suggest that the tendency to maintain positive expectations for the future is an adaptive psychological resource associated with improved well-being and physical health, but the majority of previous optimism research has been conducted in industrialized nations. The present study examined (a) whether optimism is universal, (b) what demographic factors predict optimism, and (c) whether optimism is consistently associated with improved subjective well-being and perceived health worldwide. The present study used representative samples of 142 countries that together represent 95% of the world's population. The total sample of 150,048 individuals had a mean age of 38.28 (SD = 16.85) and approximately equal sex distribution (51.2% female). The relationships between optimism, subjective well-being, and perceived health were examined using hierarchical linear modeling. Results indicated that most individuals and most countries worldwide are optimistic and that higher levels of optimism are associated with improved subjective well-being and perceived health worldwide. The present study provides compelling evidence that optimism is a universal phenomenon and that the associations between optimism and improved psychological functioning are not limited to industrialized nations. © 2012 Wiley Periodicals, Inc.

Residential scene classification for gridded population sampling in developing countries using deep convolutional neural networks on satellite imagery.

PubMed

Chew, Robert F; Amer, Safaa; Jones, Kasey; Unangst, Jennifer; Cajka, James; Allpress, Justine; Bruhn, Mark

2018-05-09

Conducting surveys in low- and middle-income countries is often challenging because many areas lack a complete sampling frame, have outdated census information, or have limited data available for designing and selecting a representative sample. Geosampling is a probability-based, gridded population sampling method that addresses some of these issues by using geographic information system (GIS) tools to create logistically manageable area units for sampling. GIS grid cells are overlaid to partition a country's existing administrative boundaries into area units that vary in size from 50 m × 50 m to 150 m × 150 m. To avoid sending interviewers to unoccupied areas, researchers manually classify grid cells as "residential" or "nonresidential" through visual inspection of aerial images. "Nonresidential" units are then excluded from sampling and data collection. This process of manually classifying sampling units has drawbacks since it is labor intensive, prone to human error, and creates the need for simplifying assumptions during calculation of design-based sampling weights. In this paper, we discuss the development of a deep learning classification model to predict whether aerial images are residential or nonresidential, thus reducing manual labor and eliminating the need for simplifying assumptions. On our test sets, the model performs comparable to a human-level baseline in both Nigeria (94.5% accuracy) and Guatemala (96.4% accuracy), and outperforms baseline machine learning models trained on crowdsourced or remote-sensed geospatial features. Additionally, our findings suggest that this approach can work well in new areas with relatively modest amounts of training data. Gridded population sampling methods like geosampling are becoming increasingly popular in countries with outdated or inaccurate census data because of their timeliness, flexibility, and cost. Using deep learning models directly on satellite images, we provide a novel method for sample frame construction that identifies residential gridded aerial units. In cases where manual classification of satellite images is used to (1) correct for errors in gridded population data sets or (2) classify grids where population estimates are unavailable, this methodology can help reduce annotation burden with comparable quality to human analysts.

Genome-Wide Analysis in Brazilian Xavante Indians Reveals Low Degree of Admixture

PubMed Central

Kuhn, Patricia C.; Horimoto, Andréa R. V. Russo.; Sanches, José Maurício; Vieira Filho, João Paulo B.; Franco, Luciana; Fabbro, Amaury Dal; Franco, Laercio Joel; Pereira, Alexandre C.; Moises, Regina S

2012-01-01

Characterization of population genetic variation and structure can be used as tools for research in human genetics and population isolates are of great interest. The aim of the present study was to characterize the genetic structure of Xavante Indians and compare it with other populations. The Xavante, an indigenous population living in Brazilian Central Plateau, is one of the largest native groups in Brazil. A subset of 53 unrelated subjects was selected from the initial sample of 300 Xavante Indians. Using 86,197 markers, Xavante were compared with all populations of HapMap Phase III and HGDP-CEPH projects and with a Southeast Brazilian population sample to establish its population structure. Principal Components Analysis showed that the Xavante Indians are concentrated in the Amerindian axis near other populations of known Amerindian ancestry such as Karitiana, Pima, Surui and Maya and a low degree of genetic admixture was observed. This is consistent with the historical records of bottlenecks experience and cultural isolation. By calculating pair-wise Fst statistics we characterized the genetic differentiation between Xavante Indians and representative populations of the HapMap and from HGDP-CEPH project. We found that the genetic differentiation between Xavante Indians and populations of Ameridian, Asian, European, and African ancestry increased progressively. Our results indicate that the Xavante is a population that remained genetically isolated over the past decades and can offer advantages for genome-wide mapping studies of inherited disorders. PMID:22900041

Genome-wide analysis in Brazilian Xavante Indians reveals low degree of admixture.

PubMed

Kuhn, Patricia C; Horimoto, Andréa R V Russo; Sanches, José Maurício; Vieira Filho, João Paulo B; Franco, Luciana; Fabbro, Amaury Dal; Franco, Laercio Joel; Pereira, Alexandre C; Moises, Regina S

2012-01-01

Characterization of population genetic variation and structure can be used as tools for research in human genetics and population isolates are of great interest. The aim of the present study was to characterize the genetic structure of Xavante Indians and compare it with other populations. The Xavante, an indigenous population living in Brazilian Central Plateau, is one of the largest native groups in Brazil. A subset of 53 unrelated subjects was selected from the initial sample of 300 Xavante Indians. Using 86,197 markers, Xavante were compared with all populations of HapMap Phase III and HGDP-CEPH projects and with a Southeast Brazilian population sample to establish its population structure. Principal Components Analysis showed that the Xavante Indians are concentrated in the Amerindian axis near other populations of known Amerindian ancestry such as Karitiana, Pima, Surui and Maya and a low degree of genetic admixture was observed. This is consistent with the historical records of bottlenecks experience and cultural isolation. By calculating pair-wise F(st) statistics we characterized the genetic differentiation between Xavante Indians and representative populations of the HapMap and from HGDP-CEPH project. We found that the genetic differentiation between Xavante Indians and populations of Ameridian, Asian, European, and African ancestry increased progressively. Our results indicate that the Xavante is a population that remained genetically isolated over the past decades and can offer advantages for genome-wide mapping studies of inherited disorders.

S-phenylmercapturic acid (S-PMA) levels in urine as an indicator of exposure to benzene in the Kinshasa population.

PubMed

Tuakuila, J

2013-07-01

Data on human exposure to chemicals in Africa are scarce. A biomonitoring study was conducted in a representative sample of the population in Kinshasa (Democratic Republic of Congo) to document exposure to benzene. S-phenylmercapturic acid (S-PMA) was measured by LC-MS/MS in spot urine samples from 220 individuals (50.5% women), aged 6-70 years living in the urban area and from 50 additional subjects from the sub-rural area of Kinshasa. Data were compiled as arithmetic means, geometric means, percentile 95th and range expressed in μg/L. Overall, living in urban Kinshasa was associated with increased levels of S-PMA in urine as compared to a population living in the sub-rural area. Increased levels were also found by comparison with some date from literature. This study reveals the high benzene exposure of the Kinshasa population requiring the determination of benzene concentrations in ambient air of Kinshasa and limit values for the protection of human health. Copyright © 2013 Elsevier GmbH. All rights reserved.

[Food consumption and the nutritional status of schoolchildren of the Community of Madrid (CAENPE): general methodology and overall food consumption. Consumo de alimentos y estado nutricional de la población escolar].

PubMed

Vázquez, C; de Cos, A I; Martínez, P; Jaunsolo, M A; Román, E; Gómez, C; López, T; Hernáez, I; Seijas, V; Ramos, V

1995-01-01

The CAENPE study (Food Consumption and Nutritional State of the School Population) was a transversal observational study funded and promoted by the Directorate-General of Food Hygiene in the Ministry of Health, implemented in 1991-93, with the main aim of quantifying food consumption in the school population (6-14 years of age) in the Regional Community of Madrid, together with an anthropometric study and nutritional analysis of that population. This project sets our the General Methodology for the study, paying particular attention to the sampling design, to ensure that the sample is representative of the community, and the results of the overall consumption of food and its comparison with recommended diet and other population studies. Quantification shows a high and rising consumption of meat, meat products, sweets, snacks and prepared dishes, suitable consumption of eggs, legumes and fruit and a notable lack of greens, vegetables and potatoes. The basic results underline the need to introduce educational measures with practical effect on home and school menus.

HS-SPME/GC analysis reveals the population variability of terpene contents in Juniperus communis needles.

PubMed

Filipowicz, Natalia; Madanecki, Piotr; Gołebiowski, Marek; Stepnowski, Piotr; Ochocka, J Renata

2009-12-01

Juniperus communis var. communis L. is an aromatic plant - typical boreal element of flora. In the extensive literature concerning J. communis, there is much data on the composition and the content of essential oil of needles and coneberries, but a detailed analysis of terpene distribution within and between populations is missing. A representative pool of 74 J. communis individuals originating from ten populations of Northern Poland was investigated in order to evaluate the intra- and interpopulational variability of the terpene pattern. Headspace solid-phase microextraction (HS-SPME) coupled with GC/MS and GC/FID was applied in achiral and enantioselective analysis. The majority of the samples (85%), despite different origin, were similar in the terpene pattern. High diversity of terpenes was observed within the populations and low diversity between them. High variation of enantiomeric composition was in accordance with large variation of individual compounds in general (achiral analysis). J. communis samples from Northern Poland could be distinguished by the alpha-pinene/sabinene ratio, and they were divided into three chemical races.

The First National Study of Neighborhood Parks

PubMed Central

Cohen, Deborah A.; Han, Bing; Nagel, Catherine; Harnik, Peter; McKenzie, Thomas L.; Evenson, Kelly R.; Marsh, Terry; Williamson, Stephanie; Vaughan, Christine; Katta, Sweatha

2016-01-01

Introduction An extensive infrastructure of neighborhood parks supports leisure time physical activity in most U.S. cities; yet, most Americans do not meet national guidelines for physical activity. Neighborhood parks have never been assessed nationally to identify their role in physical activity. Methods Using a stratified multistage sampling strategy, a representative sample of 174 neighborhood parks in 25 major cities (population >100,000) across the U.S. was selected. Park use, park-based physical activity, and park conditions were observed during a typical week using systematic direct observation during spring/summer of 2014. Park administrators were interviewed to assess policies and practices. Data were analyzed in 2014–2015 using repeated-measure negative binomial regressions to estimate weekly park use and park-based physical activity. Results Nationwide, the average neighborhood park of 8.8 acres averaged 23 users/hour or an estimated 1,533 person hours of weekly use. Walking loops and gymnasia each generated 221 hours/week of moderate to vigorous physical activity. Seniors represented 4% of park users, but 20% of the general population. Parks were used less in low-income than in high-income neighborhoods, largely explained by fewer supervised activities and marketing/outreach efforts. Programming and marketing were associated with 37% and 63% more hours of moderate to vigorous physical activity/week in parks, respectively. Conclusions The findings establish national benchmarks for park use, which can guide future park investments and management practices to improve population health. Offering more programming, using marketing tools like banners and posters, and installing facilities like walking loops may help currently underutilized parks increase population physical activity. PMID:27209496

Changes in attitudes, intended behaviour, and mental health literacy in the Swedish population 2009-2014: an evaluation of a national antistigma programme.

PubMed

Hansson, L; Stjernswärd, S; Svensson, B

2016-08-01

Public stigma of mental illness is still a major problem where numerous population studies during the last decade have mainly shown no improvements. A Swedish national antistigma campaign has been running 2010-2014. The aim of this study was to investigate changes in public stigma during this period as compared to baseline in 2009. Yearly population surveys were made between 2009 and 2014 including assessments of mental health literacy, attitudes, and intended future behaviour. Two surveys were made, one including a nationally representative sample and one including a representative sample from three original campaign regions. Multiple regression analyses, also including age, gender, education, and familiarity with mental illness were made to investigate yearly changes in public stigma compared to baseline. Mental health literacy improved significantly in the campaign regions between 2009 and 2014, as did intended future behaviour. Attitudes toward mental illness also improved significantly. Improvements were also shown in the national population surveys, but the time pattern of these compared to that of the original campaign regions indicated that these changes took place mainly after the campaign had been extended to a further five Swedish regions. The results of our surveys suggest that a campaign primarily based on social contact theory and involving people with lived experience of mental illness may, even in a rather short-term perspective, have a significant positive impact on mental health literacy, attitudes, and intentions of social contact with people with mental illness. © 2016 The Authors. Acta Psychiatrica Scandinavica Published by John Wiley & Sons Ltd.

Alexithymia in the German general population.

PubMed

Franz, Matthias; Popp, Kerstin; Schaefer, Ralf; Sitte, Wolfgang; Schneider, Christine; Hardt, Jochen; Decker, Oliver; Braehler, Elmar

2008-01-01

The Toronto-Alexithymia-Scale (TAS-20) is used worldwide as a valid measurement of alexithymia. Until now, population-based standardization and cut-off values of the German TAS-20 version have not been available. This study provides these by means of a representative German sample and by investigating the factorial structure of the TAS-20. Data were generated from a representative random sample of the German general population (1,859 subjects aged between 20 and 69). The TAS-20 sum score was normally distributed. The mean value was 49.5 (SD=9.3) in men and 48.2 (SD=9.2) in women. Divorce, single and low social status were associated with enhanced sum scores. Ten percent of the population exceeded the TAS-20 sum score threshold of >or=61. The 66th percentile reached 53 for men and 52 for women. Factor analysis identified three factors that match the scales of the English original version. An additional fourth factor ("importance of emotional introspection") was extracted. Total explanation of variance by these four factors was 52.27%. The sum score of the German TAS-20 version is suited for the standardized measure of alexithymia. For selecting alexithymic individuals in experimental studies, the cut-off >or=61 is possibly too restrictive. Therefore, we propose the 66th percentile for the identification of high alexithymics. The TAS-20 sum score is associated with important socio-demographic variables. The factorial structure is reliable; the fourth factor ("importance of emotional introspection") provides differentiation of content and allows for enhanced explanation of variance.

Workplace stress, lifestyle and social factors as correlates of back pain: a representative study of the German working population.

PubMed

Schneider, Sven; Schmitt, Holger; Zoller, Silke; Schiltenwolf, Marcus

2005-05-01

To investigate the prevalence of back pain in the German working population and the relationship between back pain and workplace stresses, lifestyle and social factors. The first National Health Survey of the Federal Republic of Germany was carried out between October 1997 and March 1999. It comprised a representative epidemiological cross-sectional study of the working population, with a total sample of 3,488 persons between the ages of 18 and 69 years. The participants took part in a medical examination and answered a self-rating questionnaire. The relationship between subjective back pain and workplace stresses and social and lifestyle factors was investigated with bivariate tests and multiple logistical regression analyses. The 7-day prevalence for back pain in the German working population was found to be 34%, and the 1-year prevalence was 60%. The odds ratios were significantly higher in women, persons of lower socioeconomic status, married and depressed persons and non-athletes. Carrying heavy loads or maintaining a single working posture were the most significant work-related correlates of back pain, for members of both the female and male working population, while environmental stress and psychological stress correlated significantly with back pain in men only. This study reports the first representative epidemiological prevalence data for back pain, and its correlates and potential risk factors, for the German working population. To reduce the negative impact of back pain the most promising behavioural and conditional prevention measures in the workplace would be to reduce carrying stress and to vary working posture. In addition, a more active, athletic lifestyle, plus the avoidance of being overweight, should provide an additional protective or preventive effect.

Dutch population specific sex estimation formulae using the proximal femur.

PubMed

Colman, K L; Janssen, M C L; Stull, K E; van Rijn, R R; Oostra, R J; de Boer, H H; van der Merwe, A E

2018-05-01

Sex estimation techniques are frequently applied in forensic anthropological analyses of unidentified human skeletal remains. While morphological sex estimation methods are able to endure population differences, the classification accuracy of metric sex estimation methods are population-specific. No metric sex estimation method currently exists for the Dutch population. The purpose of this study is to create Dutch population specific sex estimation formulae by means of osteometric analyses of the proximal femur. Since the Netherlands lacks a representative contemporary skeletal reference population, 2D plane reconstructions, derived from clinical computed tomography (CT) data, were used as an alternative source for a representative reference sample. The first part of this study assesses the intra- and inter-observer error, or reliability, of twelve measurements of the proximal femur. The technical error of measurement (TEM) and relative TEM (%TEM) were calculated using 26 dry adult femora. In addition, the agreement, or accuracy, between the dry bone and CT-based measurements was determined by percent agreement. Only reliable and accurate measurements were retained for the logistic regression sex estimation formulae; a training set (n=86) was used to create the models while an independent testing set (n=28) was used to validate the models. Due to high levels of multicollinearity, only single variable models were created. Cross-validated classification accuracies ranged from 86% to 92%. The high cross-validated classification accuracies indicate that the developed formulae can contribute to the biological profile and specifically in sex estimation of unidentified human skeletal remains in the Netherlands. Furthermore, the results indicate that clinical CT data can be a valuable alternative source of data when representative skeletal collections are unavailable. Copyright © 2017 Elsevier B.V. All rights reserved.

Return of a giant: DNA from archival museum samples helps to identify a unique cutthroat trout lineage formerly thought to be extinct.

PubMed

Peacock, Mary M; Hekkala, Evon R; Kirchoff, Veronica S; Heki, Lisa G

2017-11-01

Currently one small, native population of the culturally and ecologically important Lahontan cutthroat trout ( Oncorhynchus clarkii henshawi , LCT, Federally listed) remains in the Truckee River watershed of northwestern Nevada and northeastern California. The majority of populations in this watershed were extirpated in the 1940s due to invasive species, overharvest, anthropogenic water consumption and changing precipitation regimes. In 1977, a population of cutthroat trout discovered in the Pilot Peak Mountains in the Bonneville basin of Utah, was putatively identified as the extirpated LCT lacustrine lineage native to Pyramid Lake in the Truckee River basin based on morphological and meristic characters. Our phylogenetic and Bayesian genotype clustering analyses of museum specimens collected from the large lakes (1872-1913) and contemporary samples collected from populations throughout the extant range provide evidence in support of a genetically distinct Truckee River basin origin for this population. Analysis of museum samples alone identified three distinct genotype clusters and historical connectivity among water bodies within the Truckee River basin. Baseline data from museum collections indicate that the extant Pilot Peak strain represents a remnant of the extirpated lacustrine lineage. Given the limitations on high-quality data when working with a sparse number of preserved museum samples, we acknowledge that, in the end, this may be a more complicated story. However, the paucity of remnant populations in the Truckee River watershed, in combination with data on the distribution of morphological, meristic and genetic data for Lahontan cutthroat trout, suggests that recovery strategies, particularly in the large lacustrine habitats should consider this lineage as an important part of the genetic legacy of this species.

Return of a giant: DNA from archival museum samples helps to identify a unique cutthroat trout lineage formerly thought to be extinct

PubMed Central

Hekkala, Evon R.; Kirchoff, Veronica S.; Heki, Lisa G.

2017-01-01

Currently one small, native population of the culturally and ecologically important Lahontan cutthroat trout (Oncorhynchus clarkii henshawi, LCT, Federally listed) remains in the Truckee River watershed of northwestern Nevada and northeastern California. The majority of populations in this watershed were extirpated in the 1940s due to invasive species, overharvest, anthropogenic water consumption and changing precipitation regimes. In 1977, a population of cutthroat trout discovered in the Pilot Peak Mountains in the Bonneville basin of Utah, was putatively identified as the extirpated LCT lacustrine lineage native to Pyramid Lake in the Truckee River basin based on morphological and meristic characters. Our phylogenetic and Bayesian genotype clustering analyses of museum specimens collected from the large lakes (1872–1913) and contemporary samples collected from populations throughout the extant range provide evidence in support of a genetically distinct Truckee River basin origin for this population. Analysis of museum samples alone identified three distinct genotype clusters and historical connectivity among water bodies within the Truckee River basin. Baseline data from museum collections indicate that the extant Pilot Peak strain represents a remnant of the extirpated lacustrine lineage. Given the limitations on high-quality data when working with a sparse number of preserved museum samples, we acknowledge that, in the end, this may be a more complicated story. However, the paucity of remnant populations in the Truckee River watershed, in combination with data on the distribution of morphological, meristic and genetic data for Lahontan cutthroat trout, suggests that recovery strategies, particularly in the large lacustrine habitats should consider this lineage as an important part of the genetic legacy of this species. PMID:29291110

Australian health-related quality of life population norms derived from the SF-6D.

PubMed

Norman, Richard; Church, Jody; van den Berg, Bernard; Goodall, Stephen

2013-02-01

To investigate population health-related quality of life norms in an Australian general sample by age, gender, BMI, education and socioeconomic status. The SF-36 was included in the 2009/10 wave of the Household, Income and Labour Dynamics in Australia (HILDA) survey (n=17,630 individuals across 7,234 households), and converted into SF-6D utility scores. Trends across the various population subgroups were investigated employing population weights to ensure a balanced panel, and were all sub-stratified by gender. SF-6D scores decline with age beyond 40 years, with decreasing education and by higher levels of socioeconomic disadvantage. Scores were also lower at very low and very high BMI levels. Males reported higher SF-6D scores than females across most analyses. This study reports Australian population utility data measured using the SF-6D, based on a national representative sample. These results can be used in a range of policy settings such as cost-utility analysis or exploration of health-related inequality. In general, the patterns are similar to those reported using other multi-attribute utility instruments and in different countries. © 2013 The Authors. ANZJPH © 2013 Public Health Association of Australia.

Clonal populations of amniotic cells by dilution and direct plating: evidence for hidden diversity.

PubMed

Wilson, Patricia G; Devkota, Lorna; Payne, Tiffany; Crisp, Laddie; Winter, Allison; Wang, Zhan

2012-01-01

Fetal cells are widely considered a superior cell source for regenerative medicine; fetal cells show higher proliferative capacity and have undergone fewer replicative cycles that could generate spontaneous mutations. Fetal cells in amniotic fluid were among the first normal primary cells to be cultured ex vivo, but the undefined composition of amniotic fluid has hindered advance for regenerative applications. We first developed a highly efficient method to generate clonal populations by dilution of amniocentesis samples in media and direct plating without intervening refrigeration, centrifugation, or exposure of cells to the paracrine effects in mixed cell cultures. More than 40 clonal populations were recovered from 4 amniocentesis samples and representative clones were characterized by flow cytometry, conventional assays for differentiation potential, immunofluorescence imaging, and transcript analysis. The results revealed previously unreported diversity among stromal and epithelial cell types and identified unique cell types that could be lost or undetected in mixed cell populations. The differentiation potential of amniotic cells proved to be uncoupled from expression of definitive cell surface or cytoplasmic markers for stromal and epithelial cells. Evidence for diversity among stromal and epithelial cells in amniotic fluid bears on interpretations applied to molecular and functional tests of amniotic cell populations.

HIV Research with Men who Have Sex with Men (MSM): Advantages and Challenges of Different Methods for Most Appropriately Targeting a Key Population

PubMed Central

Gama, Ana; Martins, Maria O.; Dias, Sónia

2017-01-01

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. PMID:29546214

Adenovirus and Herpesvirus Diversity in Free-Ranging Great Apes in the Sangha Region of the Republic of Congo

PubMed Central

Seimon, Tracie A.; Olson, Sarah H.; Lee, Kerry Jo; Rosen, Gail; Ondzie, Alain; Cameron, Kenneth; Reed, Patricia; Anthony, Simon J.; Joly, Damien O.; McAloose, Denise; Lipkin, W. Ian

2015-01-01

Infectious diseases have caused die-offs in both free-ranging gorillas and chimpanzees. Understanding pathogen diversity and disease ecology is therefore critical for conserving these endangered animals. To determine viral diversity in free-ranging, non-habituated gorillas and chimpanzees in the Republic of Congo, genetic testing was performed on great-ape fecal samples collected near Odzala-Kokoua National Park. Samples were analyzed to determine ape species, identify individuals in the population, and to test for the presence of herpesviruses, adenoviruses, poxviruses, bocaviruses, flaviviruses, paramyxoviruses, coronaviruses, filoviruses, and simian immunodeficiency virus (SIV). We identified 19 DNA viruses representing two viral families, Herpesviridae and Adenoviridae, of which three herpesviruses had not been previously described. Co-detections of multiple herpesviruses and/or adenoviruses were present in both gorillas and chimpanzees. Cytomegalovirus (CMV) and lymphocryptovirus (LCV) were found primarily in the context of co-association with each other and adenoviruses. Using viral discovery curves for herpesviruses and adenoviruses, the total viral richness in the sample population of gorillas and chimpanzees was estimated to be a minimum of 23 viruses, corresponding to a detection rate of 83%. These findings represent the first description of DNA viral diversity in feces from free-ranging gorillas and chimpanzees in or near the Odzala-Kokoua National Park and form a basis for understanding the types of viruses circulating among great apes in this region. PMID:25781992

Adenovirus and herpesvirus diversity in free-ranging great apes in the Sangha region of the Republic Of Congo.

PubMed

Seimon, Tracie A; Olson, Sarah H; Lee, Kerry Jo; Rosen, Gail; Ondzie, Alain; Cameron, Kenneth; Reed, Patricia; Anthony, Simon J; Joly, Damien O; Karesh, William B; McAloose, Denise; Lipkin, W Ian

2015-01-01

Infectious diseases have caused die-offs in both free-ranging gorillas and chimpanzees. Understanding pathogen diversity and disease ecology is therefore critical for conserving these endangered animals. To determine viral diversity in free-ranging, non-habituated gorillas and chimpanzees in the Republic of Congo, genetic testing was performed on great-ape fecal samples collected near Odzala-Kokoua National Park. Samples were analyzed to determine ape species, identify individuals in the population, and to test for the presence of herpesviruses, adenoviruses, poxviruses, bocaviruses, flaviviruses, paramyxoviruses, coronaviruses, filoviruses, and simian immunodeficiency virus (SIV). We identified 19 DNA viruses representing two viral families, Herpesviridae and Adenoviridae, of which three herpesviruses had not been previously described. Co-detections of multiple herpesviruses and/or adenoviruses were present in both gorillas and chimpanzees. Cytomegalovirus (CMV) and lymphocryptovirus (LCV) were found primarily in the context of co-association with each other and adenoviruses. Using viral discovery curves for herpesviruses and adenoviruses, the total viral richness in the sample population of gorillas and chimpanzees was estimated to be a minimum of 23 viruses, corresponding to a detection rate of 83%. These findings represent the first description of DNA viral diversity in feces from free-ranging gorillas and chimpanzees in or near the Odzala-Kokoua National Park and form a basis for understanding the types of viruses circulating among great apes in this region.