Effect of population, collection year, after-ripening and incubation condition on seed germination of Stipa bungeana.

PubMed

Zhang, Rui; Baskin, J M; Baskin, C C; Mo, Qing; Chen, Lijun; Hu, Xiaowen; Wang, Yanrong

2017-10-24

Knowledge of the germination behavior of different populations of a species can be useful in the selection of appropriate seed sources for restoration. The aim of this study was to test the effect of seed population, collection year, after-ripening and incubation conditions on seed dormancy and germination of Stipa bungeana, a perennial grass used for revegetation of degraded grasslands on the Loess Plateau, China. Fresh S. bungeana seeds were collected from eight locally-adapted populations in 2015 and 2016. Dormancy and germination characteristics of fresh and 6-month-old dry-stored seeds were determined by incubating them over a range of alternating temperature regimes in light. Effect of water stress on germination was tested for fresh and 6-month-old dry-stored seeds. Seed dormancy and germination of S. bungeana differed with population and collection year. Six months of dry storage broke seed dormancy, broadened the temperature range for germination and increased among-population differences in germination percentage. The rank order of germination was not consistent in all germination tests, and it varied among populations. Thus, studies on comparing seed dormancy and germination among populations must consider year of collection, seed dormancy states and germination test conditions when selecting seeds for grassland restoration and management.

Effects of glyphosate formulations on the population dynamics of two freshwater cladoceran species.

PubMed

Reno, U; Doyle, S R; Momo, F R; Regaldo, L; Gagneten, A M

2018-02-05

The general objective of this work is to experimentally assess the effects of acute glyphosate pollution on two freshwater cladoceran species (Daphnia magna and Ceriodaphnia dubia) and to use this information to predict the population dynamics and the potential for recovery of exposed organisms. Five to six concentrations of four formulations of glyphosate (4-Gly) (Eskoba ® , Panzer Gold ® , Roundup Ultramax ® and Sulfosato Touchdown ® ) were evaluated in both cladoceran species through acute tests and 15-day recovery tests in order to estimate the population dynamics of microcrustaceans. The endpoints of the recovery test were: survival, growth (number of molts), fecundity, and the intrinsic population growth rate (r). A matrix population model (MPM) was applied to r of the survivor individuals of the acute tests, followed by a Monte Carlo simulation study. Among the 4-Gly tested, Sulfosato Touchdown ® was the one that showed higher toxicity, and C. dubia was the most sensitive species. The Monte Carlo simulation study showed an average value of λ always <1 for D. magna, indicating that its populations would not be able to survive under natural environmental conditions after an acute Gly exposure between 0.25 and 35 a.e. mg L -1 . The average value of λ for C. dubia was also <1 after exposure to Roundup Ultramax ® : 1.30 and 1.20 for 1.21 and 2.5 mg a.e. L -1 ,respectively. The combined methodology-recovery tests and the later analysis through MPM with a Monte Carlo simulation study-is proposed to integrate key demographic parameters and predict the possible fate of microcrustacean populations after being exposed to acute 4-Gly contamination events.

Investigating the Relationship between Test-Taker Background Characteristics and Test Performance in a Heterogeneous English-as-a-Second-Language (ESL) Test Population: A Factor Analytic Approach. Research Report. ETS RR-15-25

ERIC Educational Resources Information Center

Manna, Venessa F.; Yoo, Hanwook

2015-01-01

This study examined the heterogeneity in the English-as-a-second-language (ESL) test population by modeling the relationship between test-taker background characteristics and test performance as measured by the "TOEFL iBT"® using a confirmatory factor analysis (CFA) with covariate approach. The background characteristics studied…

Assessment of Geographic and Host-Associated Population Variations of the Carob Moth, Ectomyelois ceratoniae, on Pomegranate, Fig, Pistachio and Walnut, Using AFLP Markers

PubMed Central

Mozaffarian, Fariba; Mardi, Mohsen; Sarafrazi, Alimorad; Nouri Ganbalani, Gadir

2008-01-01

The carob moth, Ectomyelois ceratoniae (Zeller 1839) (Lepidoptera: Pyralidae) is the most important pest of pomegranate, Punica granatum L. (Myrtales: Ponicaceae), in Iran. In this study, 6 amplified fragment length polymorphism primer combinations were used to survey the genetic structure of the geographic and putative host-associated populations of this pest in Iran. An AMOVA was performed on test populations. Pairwise differences, Mantel test, multidimensional analysis, cluster analysis and migration rate were calculated for 5 geographic populations of E. ceratoniae sharing the same host, pomegranate. In another part of the study, 3 comparisons were performed on pairwise populations that were collected on different hosts (pomegranate, fig, pistachio and walnut) in same geographic regions. The results showed high within population variation (85.51% of total variation), however geographic populations differed significantly. The Mantel test did not show correlations between genetic and geographic distances. The probable factors that affect genetic distances are discussed. Multidimensional scaling analysis, migration rate and cluster analysis on geographic populations showed that the Arsanjan population was the most different from the others while the Saveh population was more similar to the Sabzevar population. The comparisons didn't show any host fidelity in test populations. It seems that the ability of E. ceratoniae to broaden its host range with no fidelity to hosts can decrease the efficiency of common control methods that are used on pomegranate. The results of this study suggest that in spite of the effects of geographic barriers, high within-population genetic variation, migration rate and gene flow can provide the opportunity for emerging new phenotypes or behaviors in pest populations, such as broadening host range, changing egg lying places, or changing over-wintering sites to adapt to difficult conditions such as those caused by intensive control methods. PMID:20345296

Summarising and validating test accuracy results across multiple studies for use in clinical practice.

PubMed

Riley, Richard D; Ahmed, Ikhlaaq; Debray, Thomas P A; Willis, Brian H; Noordzij, J Pieter; Higgins, Julian P T; Deeks, Jonathan J

2015-06-15

Following a meta-analysis of test accuracy studies, the translation of summary results into clinical practice is potentially problematic. The sensitivity, specificity and positive (PPV) and negative (NPV) predictive values of a test may differ substantially from the average meta-analysis findings, because of heterogeneity. Clinicians thus need more guidance: given the meta-analysis, is a test likely to be useful in new populations, and if so, how should test results inform the probability of existing disease (for a diagnostic test) or future adverse outcome (for a prognostic test)? We propose ways to address this. Firstly, following a meta-analysis, we suggest deriving prediction intervals and probability statements about the potential accuracy of a test in a new population. Secondly, we suggest strategies on how clinicians should derive post-test probabilities (PPV and NPV) in a new population based on existing meta-analysis results and propose a cross-validation approach for examining and comparing their calibration performance. Application is made to two clinical examples. In the first example, the joint probability that both sensitivity and specificity will be >80% in a new population is just 0.19, because of a low sensitivity. However, the summary PPV of 0.97 is high and calibrates well in new populations, with a probability of 0.78 that the true PPV will be at least 0.95. In the second example, post-test probabilities calibrate better when tailored to the prevalence in the new population, with cross-validation revealing a probability of 0.97 that the observed NPV will be within 10% of the predicted NPV. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Measurement properties of performance-based outcome measures to assess physical function in young and middle-aged people known to be at high risk of hip and/or knee osteoarthritis: a systematic review.

PubMed

Kroman, S L; Roos, E M; Bennell, K L; Hinman, R S; Dobson, F

2014-01-01

To systematically appraise the evidence on measurement properties of performance-based outcome measures to assess physical function in young and middle-aged people known to be at high risk of hip and/or knee osteoarthritis (OA). Electronic searches were performed in MEDLINE, CINAHL, Scopus and SPORTDiscus in May 2013. Two reviewers independently rated the measurement properties using the 4-point COSMIN checklist. Best evidence synthesis was made using COSMIN quality, consistency and direction of findings and sample size. Twenty of 2736 papers were eligible for inclusion and 24 different performance-based outcome measures knee or obese populations were evaluated. No tests related to hip populations were included. Twenty-five measurement properties including reliability (nine studies), construct validity (hypothesis testing) (nine studies), measurement error (three studies), structural validity (two studies), interpretability (one study) and responsiveness (one study) were evaluated. A positive rating was given to 12.5% (30/240) of all possible measurement ratings. Tests were grouped into two categories based on the population characteristics. The one-legged hop for distance, followed by the 6-m timed hop and cross over hop for distance were the best-rated tests for the knee-injured population. Whereas the 6-min walk test was the only included test for the obese population. This review highlights the many gaps in knowledge about the measurement properties of performance-based outcome measures for young and middle-aged people known to be at high risk of hip and/or knee OA. There is a need for consensus on which outcome measures should be used and/or combined when assessing physical function in this population. Further good quality research is required. Copyright © 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

The application of the haemagglutination test to a study of the immunity to malaria in protected and unprotected population groups in Australian New Guinea*

PubMed Central

Desowitz, R. S.; Saave, J. J.

1965-01-01

The formolized tanned sheep erythrocyte haemagglutination test has been applied to an immuno-malariometric study in Australian New Guinea to determine whether the haemagglutination titre reflects a subject's immune state and to measure the effect of malaria control operations on a population's immunity. Two population groups were studied—one (unprotected) living in holoendemic malaria conditions, the other (protected) living in an area subject to malaria control measures for four years. An increase in both serological positivity rates and geometric mean titres among the unprotected group with increasing age suggests that the test does serve to assess the state of immunity; the corresponding rates were much lower in the protected population, particularly among the children. The authors foresee the possible use of the haemagglutination test as a supplement to other procedures in assessing the progress of a malaria campaign. They, note, however, that more immuno-malariometric studies on populations subject to different degrees of malaria endemicity will need to be carried out before the relationship between the immune state and serological results can be clearly established. PMID:14310901

Estimate of population coverage with the prostate specific antigen (PSA) test to screen for prostate cancer in a metropolitan area of northern Italy.

PubMed

Russo, A; Autelitano, M; Bellini, A; Bisanti, L

2002-01-01

The use of the prostate specific antigen (PSA) test in the period 1999-2000 in a population of 311 822 men, aged 40 years or more, resident in Milan, Italy, was examined. Data were drawn from the outpatient database of the local health information system. A total of 139 350 PSA tests were used in 83 943 subjects. Overall, 26.9% of the male population aged 40 or older, with no history of prostate cancer, received a PSA test in the 2 year study period. For subjects older than 50 the rate rose to 34%. Results show a high coverage of the male population in northern Italy with screening using the PSA test for prostate cancer.

Refractive errors and binocular dysfunctions in a population of university students.

PubMed

Risovic, D J; Misailovic, K R; Eric-Marinkovic, J M; Kosanovic-Jakovic, N G; Milenkovic, S M; Petrovic, L Z

2008-01-01

This clinical study was performed to determine the presence of refractive errors and binocular dysfunctions in a population of university students. Refraction and binocular function were evaluated in a young patient population (230 students and 234 nonstudent subjects, aged 18-27 years). Distance visual acuity (DVA) and near visual acuity (NVA), refraction, cover test (CT), ocular motility, near-point of convergence, horizontal phoria measurement by Maddox wing, negative and positive vergence amplitude in prism diopters, fusion amplitude in synoptophore, as well as stereoacuity (Titmus test) were tested. Emmetropia was the most frequent refractive status in our student and nonstudent groups (78.7%). Myopia was the most frequent refractive disorder in the whole population (13.1%). Myopia and hypermetropia were significantly more frequent in the students than in nonstudents (chi-square emp 47.55). Exophoria is significantly more frequent in myopic subjects. Vergence amplitude (t test 0.000) and fusion amplitude (t test 0.005) show significantly lower values in student population. Results of Titmus test in the student group is significantly worse than in the nonstudent group (t test 0.000). Maddox wing resulted in significantly higher degree of heterophoria in the student population (t test 0.000). Myopic subjects, in the student group (t test 0.002) as well as in the nonstudent group (t test 0.001), show significantly better results in Titmus test. High near visual demand could be the most important factor for higher incidence of myopia, worse convergence and fusion amplitude, higher degree of exophoria, and worse results in Titmus test in the student population.

Changes in Student Populations and Average Test Scores of Dutch Primary Schools

ERIC Educational Resources Information Center

Luyten, Hans; de Wolf, Inge

2011-01-01

This article focuses on the relation between student population characteristics and average test scores per school in the final grade of primary education from a dynamic perspective. Aggregated data of over 5,000 Dutch primary schools covering a 6-year period were used to study the relation between changes in school populations and shifts in mean…

Tests for a disease-susceptibility locus allowing for an inbreeding coefficient (F).

PubMed

Song, Kijoung; Elston, Robert C

2003-11-01

We begin by discussing the false positive test results that arise because of cryptic relatedness and population substructure when testing a disease susceptibility locus. We extend and evaluate the Hardy-Weinberg disequilibrium (HWD) method, allowing for an inbreeding coefficient (F) in a similar way that Devlin and Roeder (1999) allowed for inbreeding in a case-control study. Then we compare the HWD measure and the common direct measure of linkage disequilibrium, both when there is no population substructure (F = 0) and when there is population substructure (F not = 0), for a single marker. The HWD test statistic gives rise to false positives caused by population stratification. These false positives can be controlled by adjusting the test statistic for the amount of variance inflation caused by the inbreeding coefficient (F). The power loss for the HWD test that arises when controlling for population structure is much less than that which arises for the common direct measure of linkage disequilibrium. However, in the multiplicative model, the HWD test has virtually no power even when allowing for non-zero F.

Diagnostic strategies using physical examination are minimally useful in defining carpal tunnel syndrome in population-based research studies.

PubMed

Descatha, A; Dale, A-M; Franzblau, A; Coomes, J; Evanoff, B

2010-02-01

We evaluated the utility of physical examination manoeuvres in the prediction of carpal tunnel syndrome (CTS) in a population-based research study. We studied a cohort of 1108 newly employed workers in several industries. Each worker completed a symptom questionnaire, a structured physical examination and nerve conduction study. For each hand, our CTS case definition required both median nerve conduction abnormality and symptoms classified as "classic" or "probable" on a hand diagram. We calculated the positive predictive values and likelihood ratios for physical examination manoeuvres in subjects with and without symptoms. The prevalence of CTS in our cohort was 1.2% for the right hand and 1.0% for the left hand. The likelihood ratios of a positive test for physical provocative tests ranged from 2.0 to 3.3, and those of a negative test from 0.3 to 0.9. The post-test probability of positive testing was <50% for all strategies tested. Our study found that physical examination, alone or in combination with symptoms, was not predictive of CTS in a working population. We suggest using specific symptoms as a first-level screening tool, and nerve conduction study as a confirmatory test, as a case definition strategy in research settings.

The projection of a test genome onto a reference population and applications to humans and archaic hominins.

PubMed

Yang, Melinda A; Harris, Kelley; Slatkin, Montgomery

2014-12-01

We introduce a method for comparing a test genome with numerous genomes from a reference population. Sites in the test genome are given a weight, w, that depends on the allele frequency, x, in the reference population. The projection of the test genome onto the reference population is the average weight for each x, [Formula: see text]. The weight is assigned in such a way that, if the test genome is a random sample from the reference population, then [Formula: see text]. Using analytic theory, numerical analysis, and simulations, we show how the projection depends on the time of population splitting, the history of admixture, and changes in past population size. The projection is sensitive to small amounts of past admixture, the direction of admixture, and admixture from a population not sampled (a ghost population). We compute the projections of several human and two archaic genomes onto three reference populations from the 1000 Genomes project-Europeans, Han Chinese, and Yoruba-and discuss the consistency of our analysis with previously published results for European and Yoruba demographic history. Including higher amounts of admixture between Europeans and Yoruba soon after their separation and low amounts of admixture more recently can resolve discrepancies between the projections and demographic inferences from some previous studies. Copyright © 2014 by the Genetics Society of America.

Status of the flora and fauna on the Nevada Test Site, 1992. Results of continuing basic environmental monitoring, January through December 1992

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

Hunter, R.B.

This report documents changes in the populations of plants and animals on the Nevada Test Site (NTS) for calendar year 1992. It is part of a Department of Energy (DOE) program (Basic Environmental Compliance and Monitoring Program -- BECAMP) that also includes monitoring DOE compliance with the Endangered Species Act, the Historic Preservation Act, and the American Indian Freedom of Religion Act. Ecological studies were to comply with the National Environmental Policy Act and DOE Order 5400.1, ``General Environmental Protection Program.`` These studies focused on the following: status of ephemeral plants on the Nevada Test Site, 1992; status of reptilemore » and amphibian populations on the Nevada Test Site, 1992; trends in small mammal populations on the Nevada Test Site, 1992; status of large mammals and birds at Nevada Test Site, 1992; and status of perennial plants on the Nevada Test Site, 1992.« less

Is there a risk of active sensitization to PPD by patch testing the general population?

PubMed

Thyssen, Jacob Pontoppidan; Menné, Torkil; Nielsen, Niels Henrik; Linneberg, Allan

2007-08-01

Para-phenylenediamine (PPD), a constituent of permanent hair dyes, may cause contact allergy in exposed individuals. It has previously been questioned whether a patch testing with PPD in population-based epidemiological studies is entirely safe. The Glostrup allergy studies patch tested the same cohort twice. In 1990, 567 persons were patch-tested and only one person had a (+) positive reaction to PPD. In 1998, 540 persons were re-invited to a new patch test and 365 (participation rate 68%) were re-tested. There were no positive reactions to PPD. These studies indicate that patch testing with PPD in individuals with no previous positive reactions to PPD or with only one previous positive reaction does not cause active sensitization and can be performed with minimal risk.

Investigation of blood lead concentrations in dogs living in Flint, Michigan.

PubMed

Langlois, Daniel K; Kaneene, John B; Yuzbasiyan-Gurkan, Vilma; Daniels, Barbara L; Mejia-Abreu, Hilda; Frank, Nancy A; Buchweitz, John P

2017-10-15

OBJECTIVE To measure blood lead concentrations (BLCs) in dogs living in Flint, Mich, following a declared water crisis and to assess potential associations of BLCs with demographic data, water sources, and clinical signs in these dogs. DESIGN Cross-sectional study. ANIMALS 284 dogs residing in Flint, Mich (test population), and 47 dogs residing in East Lansing, Mich (control population), and immediately adjacent areas. PROCEDURES Blood samples were collected at free screening clinics in Flint (test population) and at the Michigan State University College of Veterinary Medicine Veterinary Medical Center (control population). Owners of test population dogs completed questionnaires providing demographic and clinical information. Hematologic evaluations were performed; BLCs were measured by inductively coupled plasma-mass spectrometry. RESULTS 4 of 284 test population dogs had BLCs > 50 ppb; an additional 20 had BLCs > 20 ppb. Overall, BLCs of test population dogs were higher than those of control dogs. Within the test population, young dogs (≤ 2 years of age) had higher BLCs than old dogs (≥ 6 years of age). Only 7.2% of test population dogs were drinking unfiltered tap water at the time of screening; however, dogs that had been receiving filtered or bottled water for ≤ 3 months before screening had higher BLCs than did those that received such water for > 3 months. CONCLUSIONS AND CLINICAL RELEVANCE Taken together, findings suggested that the impact of the Flint water crisis extended to companion animals. Results highlighted the importance of maintaining awareness of lead exposure and considering both human and animal well-being in cases of environmental toxicant exposures.

Unresolved versus resolved: testing the validity of young simple stellar population models with VLT/MUSE observations of NGC 3603

NASA Astrophysics Data System (ADS)

Kuncarayakti, H.; Galbany, L.; Anderson, J. P.; Krühler, T.; Hamuy, M.

2016-09-01

Context. Stellar populations are the building blocks of galaxies, including the Milky Way. The majority, if not all, extragalactic studies are entangled with the use of stellar population models given the unresolved nature of their observation. Extragalactic systems contain multiple stellar populations with complex star formation histories. However, studies of these systems are mainly based upon the principles of simple stellar populations (SSP). Hence, it is critical to examine the validity of SSP models. Aims: This work aims to empirically test the validity of SSP models. This is done by comparing SSP models against observations of spatially resolved young stellar population in the determination of its physical properties, that is, age and metallicity. Methods: Integral field spectroscopy of a young stellar cluster in the Milky Way, NGC 3603, was used to study the properties of the cluster as both a resolved and unresolved stellar population. The unresolved stellar population was analysed using the Hα equivalent width as an age indicator and the ratio of strong emission lines to infer metallicity. In addition, spectral energy distribution (SED) fitting using STARLIGHT was used to infer these properties from the integrated spectrum. Independently, the resolved stellar population was analysed using the colour-magnitude diagram (CMD) to determine age and metallicity. As the SSP model represents the unresolved stellar population, the derived age and metallicity were tested to determine whether they agree with those derived from resolved stars. Results: The age and metallicity estimate of NGC 3603 derived from integrated spectroscopy are confirmed to be within the range of those derived from the CMD of the resolved stellar population, including other estimates found in the literature. The result from this pilot study supports the reliability of SSP models for studying unresolved young stellar populations. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 60.A-9344.

Variation in healthcare services for specialist genetic testing and implications for planning genetic services: the example of inherited retinal dystrophy in the English NHS.

PubMed

Harrison, Mark; Birch, Stephen; Eden, Martin; Ramsden, Simon; Farragher, Tracey; Payne, Katherine; Hall, Georgina; Black, Graeme Cm

2015-04-01

This study aims to identify and quantify the extent of current variation in service provision of a genetic testing service for dominant and X-linked retinal dystrophies in the English National Health Service (NHS). National audit data (all test requests and results (n = 1839) issued between 2003 and 2011) and survey of English regional genetic testing services were used. Age- and gender-adjusted standardised testing rates were calculated using indirect standardisation, and survey responses were transcribed verbatim and data collated and summarised. The cumulative incidence rate of testing in England was 4.5 per 100,000 population for males and 2.6 per 100,000 population for females. The standardised testing rate (STR) varied widely between regions of England, being particularly low in the North-east (STR 0.485), with half as many tests as expected based on the size and demographic distribution of the population and high in the South-east (STR 1.355), with 36 % more tests than expected. Substantial and significantly different rates of testing were found between regional populations. Specific policy mechanisms to promote, monitor and evaluate the regional distribution of access to genetic and genomic testing are required. However, commissioners will require information on the scope and role of genetic services and the population at risk of the conditions for which patients are tested.

Use of laboratory testing for genital chlamydial infection in Norway.

PubMed Central

Aavitsland, P

1993-01-01

OBJECTIVE--To assess the use of laboratory tests for genital chlamydial infection in Norway. DESIGN--Questionnaire survey of general practitioners' practice in chlamydial testing, retrospective survey of laboratory records, 1986-91, and prospective study of testing in one laboratory during four weeks. SETTING--All 18 microbiological laboratories in Norway (4.2 million population), including one serving all doctors in Vestfold county (0.2 million population). SUBJECTS--302 general practitioners. MAIN MEASURES--GPs' routine practice, methods used for testing, 1986-91, and sex specific and age group specific testing in 1991. RESULTS--201(69%) GPs replied to the questionnaire: 101(51%) would test all women younger than 25 years at routine pelvic examination, 107(54%) all girls at first pelvic examination, 131(66%) all pregnant women, and 106(54%) all men whose female partner had urogenital complaints. Nationwide in 1986, 122,000 tests were performed (2.9 per 100 population); 10% were positive and 51% were cell culture tests. In 1991, 341,000 tests were performed (8.0 per 100 population); 4.5% were positive and 15% were cell culture tests. 13,184 tests were performed in Vestfold in 1991 (6.6 per 100 population). The age group specific rates (per 100 population) among women were: age 15-19 years, 22.0(95% confidence interval 18.2 to 25.8); 20-24 years, 47.2(42.1 to 52.3); 25-29 years, 42.3(37.1 to 47.5); 30-34 years, 29.8(25.4 to 34.2); and 35-39 years, 12.5(9.5 to 15.5). CONCLUSIONS--GPs use liberal indications for testing. The dramatic increase in testing, especially by enzyme immunoassays, in populations with a low prevalence of infection results in low cost effectiveness and low predictive value of positive tests, which in women over 29 years is estimated as 17-36%. IMPLICATIONS--Doctors should be educated about the limitations of enzyme immunoassays in screening low prevalence populations, and laboratories should apply a confirmatory test to specimens testing positive with such assays. PMID:10131639

Multivariate Qst–Fst Comparisons: A Neutrality Test for the Evolution of the G Matrix in Structured Populations

PubMed Central

Martin, Guillaume; Chapuis, Elodie; Goudet, Jérôme

2008-01-01

Neutrality tests in quantitative genetics provide a statistical framework for the detection of selection on polygenic traits in wild populations. However, the existing method based on comparisons of divergence at neutral markers and quantitative traits (Qst–Fst) suffers from several limitations that hinder a clear interpretation of the results with typical empirical designs. In this article, we propose a multivariate extension of this neutrality test based on empirical estimates of the among-populations (D) and within-populations (G) covariance matrices by MANOVA. A simple pattern is expected under neutrality: D = 2Fst/(1 − Fst)G, so that neutrality implies both proportionality of the two matrices and a specific value of the proportionality coefficient. This pattern is tested using Flury's framework for matrix comparison [common principal-component (CPC) analysis], a well-known tool in G matrix evolution studies. We show the importance of using a Bartlett adjustment of the test for the small sample sizes typically found in empirical studies. We propose a dual test: (i) that the proportionality coefficient is not different from its neutral expectation [2Fst/(1 − Fst)] and (ii) that the MANOVA estimates of mean square matrices between and among populations are proportional. These two tests combined provide a more stringent test for neutrality than the classic Qst–Fst comparison and avoid several statistical problems. Extensive simulations of realistic empirical designs suggest that these tests correctly detect the expected pattern under neutrality and have enough power to efficiently detect mild to strong selection (homogeneous, heterogeneous, or mixed) when it is occurring on a set of traits. This method also provides a rigorous and quantitative framework for disentangling the effects of different selection regimes and of drift on the evolution of the G matrix. We discuss practical requirements for the proper application of our test in empirical studies and potential extensions. PMID:18245845

Use of Pearson's Chi-Square for Testing Equality of Percentile Profiles across Multiple Populations.

PubMed

Johnson, William D; Beyl, Robbie A; Burton, Jeffrey H; Johnson, Callie M; Romer, Jacob E; Zhang, Lei

2015-08-01

In large sample studies where distributions may be skewed and not readily transformed to symmetry, it may be of greater interest to compare different distributions in terms of percentiles rather than means. For example, it may be more informative to compare two or more populations with respect to their within population distributions by testing the hypothesis that their corresponding respective 10 th , 50 th , and 90 th percentiles are equal. As a generalization of the median test, the proposed test statistic is asymptotically distributed as Chi-square with degrees of freedom dependent upon the number of percentiles tested and constraints of the null hypothesis. Results from simulation studies are used to validate the nominal 0.05 significance level under the null hypothesis, and asymptotic power properties that are suitable for testing equality of percentile profiles against selected profile discrepancies for a variety of underlying distributions. A pragmatic example is provided to illustrate the comparison of the percentile profiles for four body mass index distributions.

Sensitivity and specificity of normality tests and consequences on reference interval accuracy at small sample size: a computer-simulation study.

PubMed

Le Boedec, Kevin

2016-12-01

According to international guidelines, parametric methods must be chosen for RI construction when the sample size is small and the distribution is Gaussian. However, normality tests may not be accurate at small sample size. The purpose of the study was to evaluate normality test performance to properly identify samples extracted from a Gaussian population at small sample sizes, and assess the consequences on RI accuracy of applying parametric methods to samples that falsely identified the parent population as Gaussian. Samples of n = 60 and n = 30 values were randomly selected 100 times from simulated Gaussian, lognormal, and asymmetric populations of 10,000 values. The sensitivity and specificity of 4 normality tests were compared. Reference intervals were calculated using 6 different statistical methods from samples that falsely identified the parent population as Gaussian, and their accuracy was compared. Shapiro-Wilk and D'Agostino-Pearson tests were the best performing normality tests. However, their specificity was poor at sample size n = 30 (specificity for P < .05: .51 and .50, respectively). The best significance levels identified when n = 30 were 0.19 for Shapiro-Wilk test and 0.18 for D'Agostino-Pearson test. Using parametric methods on samples extracted from a lognormal population but falsely identified as Gaussian led to clinically relevant inaccuracies. At small sample size, normality tests may lead to erroneous use of parametric methods to build RI. Using nonparametric methods (or alternatively Box-Cox transformation) on all samples regardless of their distribution or adjusting, the significance level of normality tests depending on sample size would limit the risk of constructing inaccurate RI. © 2016 American Society for Veterinary Clinical Pathology.

Social Media Interventions to Promote HIV Testing, Linkage, Adherence, and Retention: Systematic Review and Meta-Analysis

PubMed Central

Gupta, Somya; Wang, Jiangtao; Hightow-Weidman, Lisa B; Muessig, Kathryn E; Tang, Weiming; Pan, Stephen; Pendse, Razia; Tucker, Joseph D

2017-01-01

Background Social media is increasingly used to deliver HIV interventions for key populations worldwide. However, little is known about the specific uses and effects of social media on human immunodeficiency virus (HIV) interventions. Objective This systematic review examines the effectiveness of social media interventions to promote HIV testing, linkage, adherence, and retention among key populations. Methods We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist and Cochrane guidelines for this review and registered it on the International Prospective Register of Systematic Reviews, PROSPERO. We systematically searched six databases and three conference websites using search terms related to HIV, social media, and key populations. We included studies where (1) the intervention was created or implemented on social media platforms, (2) study population included men who have sex with men (MSM), transgender individuals, people who inject drugs (PWID), and/or sex workers, and (3) outcomes included promoting HIV testing, linkage, adherence, and/or retention. Meta-analyses were conducted by Review Manager, version 5.3. Pooled relative risk (RR) and 95% confidence intervals were calculated by random-effects models. Results Among 981 manuscripts identified, 26 studies met the inclusion criteria. We found 18 studies from high-income countries, 8 in middle-income countries, and 0 in low-income countries. Eight were randomized controlled trials, and 18 were observational studies. All studies (n=26) included MSM; five studies also included transgender individuals. The focus of 21 studies was HIV testing, four on HIV testing and linkage to care, and one on antiretroviral therapy adherence. Social media interventions were used to do the following: build online interactive communities to encourage HIV testing/adherence (10 studies), provide HIV testing services (9 studies), disseminate HIV information (9 studies), and develop intervention materials (1 study). Of the studies providing HIV self-testing, 16% of participants requested HIV testing kits from social media platforms. Existing social media platforms such as Facebook (n=15) and the gay dating app Grindr (n=10) were used most frequently. Data from four studies show that HIV testing uptake increased after social media interventions (n=1283, RR 1.50, 95% CI 1.28-1.76). In the studies where social media interventions were participatory, HIV testing uptake was higher in the intervention arm than the comparison arm (n=1023, RR 1.64, 95% CI 1.19-2.26). Conclusions Social media interventions are effective in promoting HIV testing among MSM in many settings. Social media interventions to improve HIV services beyond HIV testing in low- and middle-income countries and among other key populations need to be considered. Trial Registration International Prospective Register of Systematic Reviews (PROSPERO): CRD42016048073; http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42016048073 (Archived by WebCite at http://www. webcitation.org/6usLCJK3v) PMID:29175811

A Venue-Based Approach to Reaching MSM, IDUs and the General Population with VCT: A Three Study Site in Kenya

PubMed Central

Singh, Kavita; Brodish, Paul; Mbai, Fiona; Kingola, Nzioki; Rinyuri, Agnes; Njeru, Carol; Mureithi, Patrick; Sambisa, William; Weir, Sharon

2014-01-01

A venue-based HIV prevention study which included Voluntary Counseling and Testing (VCT) was conducted in three diverse areas of Kenya— Malindi, Nanyuki and Rachounyo. Aims of the study were to: 1) assess the acceptability of VCT for the general population, men who have sex with men (MSM), and injecting drug users (IDUs) within the context of a venue-based approach; 2) determine if there were differences between those agreeing and not agreeing to testing; and 3) study factors associated with being HIV positive. Approximately 98% of IDUs and 97% of MSM agreed to VCT, providing evidence that populations with little access to services and whose behaviors are stigmatized and often considered illegal in their countries can be reached with needed HIV prevention services. Acceptability of VCT in the general population ranged from 60% in Malindi to 48% in Nanyuki. There were a few significant differences between those accepting and declining testing. Notably in Rachuonyo and Malindi those reporting multiple partners were more likely to accept testing. There was also evidence that riskier sexual behavior was associated with being HIV positive for both men in Rachounyo and women in Malindi. Overall HIV prevalence was higher among the individuals in this study compared to individuals sampled in the 2008–2009 Kenya Demographic and Health Survey, indicating the method is an appropriate means to reach the highest risk individuals including stigmatized populations. PMID:22198312

Genetic variation of Lymnaea stagnalis tolerance to copper: A test of selection hypotheses and its relevance for ecological risk assessment.

PubMed

Côte, Jessica; Bouétard, Anthony; Pronost, Yannick; Besnard, Anne-Laure; Coke, Maïra; Piquet, Fabien; Caquet, Thierry; Coutellec, Marie-Agnès

2015-10-01

The use of standardized monospecific testing to assess the ecological risk of chemicals implicitly relies on the strong assumption that intraspecific variation in sensitivity is negligible or irrelevant in this context. In this study, we investigated genetic variation in copper sensitivity of the freshwater snail Lymnaea stagnalis, using lineages stemming from eight natural populations or strains found to be genetically differentiated at neutral markers. Copper-induced mortality varied widely among populations, as did the estimated daily death rate and time to 50% mortality (LT50). Population genetic divergence in copper sensitivity was compared to neutral differentiation using the QST-FST approach. No evidence for homogenizing selection could be detected. This result demonstrates that species-level extrapolations from single population studies are highly unreliable. The study provides a simple example of how evolutionary principles could be incorporated into ecotoxicity testing in order to refine ecological risk assessment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of the clock test and a questionnaire-based test for screening for cognitive impairment in Nigerians.

PubMed

VanderJagt, D J; Ganga, S; Obadofin, M O; Stanley, P; Zimmerman, M; Skipper, B J; Glew, R H

2006-01-01

Since it is projected that by 2020 seventy percent of the elderly will reside in developing countries, a reliable screening method for dementia and cognitive impairment in general in populations with diverse languages, culture, education and literacy will be needed. We sought to determine if the Clock Test, a screening test for dementia, was suitable for use in a Nigerian population. Cross-sectional survey of 54 men and 12 women from Northern Nigeria. Researchers administered two dementia screening tools: a questionnaire-based test adapted for use in a Nigerian population and the Clock Test. Overall, 53.0% of the subjects had an abnormal Clock Test whereas 10.6% of the subjects had an abnormal questionnaire score. Only 9.1% of the subjects had abnormal scores on both tests. Subjects with more schooling had a greater probability of having a positive clock concept (understanding that a circle represented a clock). Of those with more than 6 years of schooling, 91.0% had a positive clock concept. Subjects with a negative clock concept were more likely to have an abnormal Clock Test (93.3%) than a questionnaire (26.6%). The main finding of our study was the discrepancy between the results of the Clock Test and the questionnaire. Performance on the Clock Test appeared to have been heavily influenced by education level, indicating the test is not universally applicable across cultures. The questionnaire-based test appears to reduce the effects of illiteracy on assessing dementia in a Nigerian population. Larger studies should be done to control for how education affects the assessment of dementia.

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.

Diagnosis of aphasia in stroke populations: A systematic review of language tests

PubMed Central

2018-01-01

Background and purpose Accurate aphasia diagnosis is important in stroke care. A wide range of language tests are available and include informal assessments, tests developed by healthcare institutions and commercially published tests available for purchase in pre-packaged kits. The psychometrics of these tests are often reported online or within the purchased test manuals, not the peer-reviewed literature, therefore the diagnostic capabilities of these measures have not been systematically evaluated. This review aimed to identify both commercial and non-commercial language tests and tests used in stroke care and to examine the diagnostic capabilities of all identified measures in diagnosing aphasia in stroke populations. Methods Language tests were identified through a systematic search of 161 publisher databases, professional and resource websites and language tests reported to be used in stroke care. Two independent reviewers evaluated test manuals or associated resources for cohort or cross-sectional studies reporting the tests’ diagnostic capabilities (sensitivity, specificity, likelihood ratios or diagnostic odds ratios) in differentiating aphasic and non-aphasic stroke populations. Results Fifty-six tests met the study eligibility criteria. Six “non-specialist” brief screening tests reported sensitivity and specificity information, however none of these measures reported to meet the specific diagnostic needs of speech pathologists. The 50 remaining measures either did not report validity data (n = 7); did not compare patient test performance with a comparison group (n = 17); included non-stroke participants within their samples (n = 23) or did not compare stroke patient performance against a language reference standard (n = 3). Diagnostic sensitivity analysis was completed for six speech pathology measures (WAB, PICA, CADL-2, ASHA-FACS, Adult FAVRES and EFA-4), however all studies compared aphasic performance with that of non-stroke healthy controls and were consequently excluded from the review. Conclusions No speech pathology test was found which reported diagnostic data for identifying aphasia in stroke populations. A diagnostically validated post-stroke aphasia test is needed. PMID:29566043

Population structure and genetic diversity of black redhorse (Moxostoma duquesnei) in a highly fragmented watershed

USGS Publications Warehouse

Reid, S.M.; Wilson, C.C.; Mandrak, N.E.; Carl, L.M.

2008-01-01

Dams have the potential to affect population size and connectivity, reduce genetic diversity, and increase genetic differences among isolated riverine fish populations. Previous research has reported adverse effects on the distribution and demographics of black redhorse (Moxostoma duquesnei), a threatened fish species in Canada. However, effects on genetic diversity and population structure are unknown. We used microsatellite DNA markers to assess the number of genetic populations in the Grand River (Ontario) and to test whether dams have resulted in a loss of genetic diversity and increased genetic differentiation among populations. Three hundred and seventy-seven individuals from eight Grand River sites were genotyped at eight microsatellite loci. Measures of genetic diversity were moderately high and not significantly different among populations; strong evidence of recent population bottlenecks was not detected. Pairwise FST and exact tests identified weak (global FST = 0.011) but statistically significant population structure, although little population structuring was detected using either genetic distances or an individual-based clustering method. Neither geographic distance nor the number of intervening dams were correlated with pairwise differences among populations. Tests for regional equilibrium indicate that Grand River populations were either in equilibrium between gene flow and genetic drift or that gene flow is more influential than drift. While studies on other species have identified strong dam-related effects on genetic diversity and population structure, this study suggests that barrier permeability, river fragment length and the ecological characteristics of affected species can counterbalance dam-related effects. ?? 2007 Springer Science+Business Media B.V.

A comparison of the millon behavioral medical diagnostic and millon behavioral health inventory with medical populations.

PubMed

Wise, Edward A; Streiner, David L

2010-12-01

There is a lack of normative data on broadband omnibus types of personality tests with medical populations. In fact, the only two tests normed on medical populations are the Millon Behavioral Medicine Diagnostic (MBMD) and the Millon Behavioral Health Inventory (MBHI). The internal consistency, test-retest reliabilities, and validity studies of these instruments are reviewed and compared in an effort to aid clinicians in discerning their relative psychometric strengths and weaknesses. Due to the lack of validity studies with the MBMD and the fact that reliability limits the ceiling of validity coefficients, the MBMD has yet to meet the challenges it was designed to meet. Implications for practice are addressed. © 2010 Wiley Periodicals, Inc.

HIV Testing Beliefs in a Predominantly Hispanic Community Health Center During the Routine HIV Testing Era: Does English Language Ability Matter?

PubMed Central

Amspoker, Amber B.; Lalani, Naina; Patuwo, Beverly; Kallen, Michael; Street, Richard; Viswanath, Kasisomayajula; Giordano, Thomas P.

2013-01-01

Abstract The Hispanic population in the U.S. carries a disproportionate burden of HIV. Despite the high prevalence of HIV, many Hispanics remain untested for HIV. The purpose of this study conducted in a predominantly Hispanic-serving community health center in a high HIV prevalence area was to understand patient beliefs of who should be tested for HIV in the routine HIV testing era. Survey participants were presented with nine populations of people that should be tested for HIV based on CDC HIV testing recommendations. Of the 90 participants (67.1% Hispanic) who answered the HIV testing beliefs question, only approximately 45% were aware that all adults and teenagers should be HIV tested. Only 30% correctly identified all nine populations of people that should be tested for HIV based on CDC HIV testing recommendations. Our study suggests that Hispanics are either unaware of or disagree with the latest CDC recommendations for routine HIV testing of all persons ages 13–64 in high HIV prevalence areas. Improving knowledge of the current HIV epidemiologic profile in the U.S. and the most recent routine HIV testing recommendations may improve HIV testing rates in Hispanic communities. PMID:23305261

Psychological strains and depression in Chinese rural populations.

PubMed

Zhang, Jie; Lv, Juncheng

2014-01-01

The aim of this study is to explore the relationship between psychological strains and depression and to further test the Strain Theory of Suicide and Mental Disorders. Data for the current study were from a large psychological autopsy (PA) study in Chinese rural populations with a case-control design to investigate the environmental and other characteristics of rural young suicides and controls. Subjects (N = 1618) for the current study were the informants in the PA interviews. The center for epidemiologic studies depression scale was used to assess the respondents' depression level. Chi-square x², t test, t' test, and general linear regression model were used to analyse the data by SPSS software. Value strain and deprivation strain are positively correlated with the depression level for both men and women of the Chinese rural population. Religion is another strong risk factor for depression and marriage is not a protective factor for depression in this sample. The study verifies that there is strong correlation between the psychological strains and depression in Chinese rural populations. It is suggested that reducing psychological strains may be a possible approach to reduce the prevalence of depression so as to help bring down the suicide risk in rural China.

Carotid atherosclerosis predicts lower cognitive test results: a 7-year follow-up study of 4,371 stroke-free subjects - the Tromsø study.

PubMed

Arntzen, Kjell Arne; Schirmer, Henrik; Johnsen, Stein Harald; Wilsgaard, Tom; Mathiesen, Ellisiv B

2012-01-01

Carotid artery atherosclerosis is a major risk factor for stroke and subsequent cognitive impairment. Prospective population studies have shown associations between carotid intima-media thickness (IMT) and stenosis and cognitive decline and dementia in elderly stroke-free persons, whereas results in the middle-aged are conflicting. In this prospective population-based study, 4,371 stroke-free middle-aged participants underwent carotid ultrasound examination and assessment of vascular risk factors at baseline and were tested for cognitive function 7 years later. Associations between IMT, number of plaques and total plaque area and cognitive test scores on verbal memory test, digit symbol-coding test and tapping test were assessed in linear regression models. In the multivariable analyses adjusted for sex, age, education, depression and vascular risk factors, the presence of plaques was significantly associated with lower test scores on the verbal memory test (p = 0.01) and on the digit symbol-coding test (p = 0.03). The number of plaques (p = 0.01) and the total plaque area (p = 0.02) were associated with lower scores on the verbal memory test. No significant association was seen between common carotid artery IMT and cognitive test scores. The tapping test was not associated with the carotid ultrasound variables. In this middle-aged general population, subclinical carotid atherosclerosis measured as the presence of plaques, number of plaques and total plaque area were independent long-term predictors of lower cognitive test scores. Copyright © 2012 S. Karger AG, Basel.

Genetic Misdiagnoses and the Potential for Health Disparities.

PubMed

Manrai, Arjun K; Funke, Birgit H; Rehm, Heidi L; Olesen, Morten S; Maron, Bradley A; Szolovits, Peter; Margulies, David M; Loscalzo, Joseph; Kohane, Isaac S

2016-08-18

For more than a decade, risk stratification for hypertrophic cardiomyopathy has been enhanced by targeted genetic testing. Using sequencing results, clinicians routinely assess the risk of hypertrophic cardiomyopathy in a patient's relatives and diagnose the condition in patients who have ambiguous clinical presentations. However, the benefits of genetic testing come with the risk that variants may be misclassified. Using publicly accessible exome data, we identified variants that have previously been considered causal in hypertrophic cardiomyopathy and that are overrepresented in the general population. We studied these variants in diverse populations and reevaluated their initial ascertainments in the medical literature. We reviewed patient records at a leading genetic-testing laboratory for occurrences of these variants during the near-decade-long history of the laboratory. Multiple patients, all of whom were of African or unspecified ancestry, received positive reports, with variants misclassified as pathogenic on the basis of the understanding at the time of testing. Subsequently, all reported variants were recategorized as benign. The mutations that were most common in the general population were significantly more common among black Americans than among white Americans (P<0.001). Simulations showed that the inclusion of even small numbers of black Americans in control cohorts probably would have prevented these misclassifications. We identified methodologic shortcomings that contributed to these errors in the medical literature. The misclassification of benign variants as pathogenic that we found in our study shows the need for sequencing the genomes of diverse populations, both in asymptomatic controls and the tested patient population. These results expand on current guidelines, which recommend the use of ancestry-matched controls to interpret variants. As additional populations of different ancestry backgrounds are sequenced, we expect variant reclassifications to increase, particularly for ancestry groups that have historically been less well studied. (Funded by the National Institutes of Health.).

Assessing Genetic Literacy Awareness and Knowledge Gaps in the US Population: Results from the Health Information National Trends Survey.

PubMed

Krakow, Melinda; Ratcliff, Chelsea L; Hesse, Bradford W; Greenberg-Worisek, Alexandra J

2018-05-31

Public understanding of the role of genetics in disease risk is key to appropriate disease prevention and detection. This study assessed the current extent of awareness and use of genetic testing in the US population. Additionally, the study identified characteristics of subgroups more likely to be at risk for low genetic literacy. The study used data from the National Cancer Institute's 2017 Health Information National Trends Survey, including measures of genetic testing awareness, genetic testing applications and genetic testing usage. Multivariable logistic regression models estimated associations between sociodemographics, genetic testing awareness, and genetic testing use. Fifty-seven percent of respondents were aware of genetic tests. Testing awareness differed by age, household income, and race/ethnicity. Most participants had heard of using tests to determine personal disease risk (82.58%) or inherited disease risk in children (81.41%), but less were familiar with determining treatment (38.29%) or drug efficacy (40.76%). Among those with genetic testing awareness, actual testing uptake was low. A large portion of the general public lacks genetic testing awareness and may benefit from educational campaigns. As precision medicine expands, increasing public awareness about genetic testing applications for disease prevention and treatment will be important to support population health. This is a work of the US Government and is not subject to copyright protection in the United States. Foreign copyrights may apply. Published by S. Karger AG, Basel.

Applying the multivariate time-rescaling theorem to neural population models

PubMed Central

Gerhard, Felipe; Haslinger, Robert; Pipa, Gordon

2011-01-01

Statistical models of neural activity are integral to modern neuroscience. Recently, interest has grown in modeling the spiking activity of populations of simultaneously recorded neurons to study the effects of correlations and functional connectivity on neural information processing. However any statistical model must be validated by an appropriate goodness-of-fit test. Kolmogorov-Smirnov tests based upon the time-rescaling theorem have proven to be useful for evaluating point-process-based statistical models of single-neuron spike trains. Here we discuss the extension of the time-rescaling theorem to the multivariate (neural population) case. We show that even in the presence of strong correlations between spike trains, models which neglect couplings between neurons can be erroneously passed by the univariate time-rescaling test. We present the multivariate version of the time-rescaling theorem, and provide a practical step-by-step procedure for applying it towards testing the sufficiency of neural population models. Using several simple analytically tractable models and also more complex simulated and real data sets, we demonstrate that important features of the population activity can only be detected using the multivariate extension of the test. PMID:21395436

Type 2 Diabetes Susceptibility in the Greek-Cypriot Population: Replication of Associations with TCF7L2, FTO, HHEX, SLC30A8 and IGF2BP2 Polymorphisms

PubMed Central

Votsi, Christina; Toufexis, Costas; Michailidou, Kyriaki; Antoniades, Athos; Skordis, Nicos; Karaolis, Minas; Pattichis, Constantinos S.; Christodoulou, Kyproula

2017-01-01

Type 2 diabetes (T2D) has been the subject of numerous genetic studies in recent years which revealed associations of the disease with a large number of susceptibility loci. We hereby initiate the evaluation of T2D susceptibility loci in the Greek-Cypriot population by performing a replication case-control study. One thousand and eighteen individuals (528 T2D patients, 490 controls) were genotyped at 21 T2D susceptibility loci, using the allelic discrimination method. Statistically significant associations of T2D with five of the tested single nucleotide polymorphisms (SNPs) (TCF7L2 rs7901695, FTO rs8050136, HHEX rs5015480, SLC30A8 rs13266634 and IGF2BP2 rs4402960) were observed in this study population. Furthermore, 14 of the tested SNPs had odds ratios (ORs) in the same direction as the previously published studies, suggesting that these variants can potentially be used in the Greek-Cypriot population for predictive testing of T2D. In conclusion, our findings expand the genetic assessment of T2D susceptibility loci and reconfirm five of the worldwide established loci in a distinct, relatively small, newly investigated population. PMID:28067832

Can the experimental evolution programme help us elucidate the genetic basis of adaptation in nature?

PubMed

Bailey, Susan F; Bataillon, Thomas

2016-01-01

There have been a variety of approaches taken to try to characterize and identify the genetic basis of adaptation in nature, spanning theoretical models, experimental evolution studies and direct tests of natural populations. Theoretical models can provide formalized and detailed hypotheses regarding evolutionary processes and patterns, from which experimental evolution studies can then provide important proofs of concepts and characterize what is biologically reasonable. Genetic and genomic data from natural populations then allow for the identification of the particular factors that have and continue to play an important role in shaping adaptive evolution in the natural world. Further to this, experimental evolution studies allow for tests of theories that may be difficult or impossible to test in natural populations for logistical and methodological reasons and can even generate new insights, suggesting further refinement of existing theories. However, as experimental evolution studies often take place in a very particular set of controlled conditions--that is simple environments, a small range of usually asexual species, relatively short timescales--the question remains as to how applicable these experimental results are to natural populations. In this review, we discuss important insights coming from experimental evolution, focusing on four key topics tied to the evolutionary genetics of adaptation, and within those topics, we discuss the extent to which the experimental work compliments and informs natural population studies. We finish by making suggestions for future work in particular a need for natural population genomic time series data, as well as the necessity for studies that combine both experimental evolution and natural population approaches. © 2015 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

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.

Social Media Interventions to Promote HIV Testing, Linkage, Adherence, and Retention: Systematic Review and Meta-Analysis.

PubMed

Cao, Bolin; Gupta, Somya; Wang, Jiangtao; Hightow-Weidman, Lisa B; Muessig, Kathryn E; Tang, Weiming; Pan, Stephen; Pendse, Razia; Tucker, Joseph D

2017-11-24

Social media is increasingly used to deliver HIV interventions for key populations worldwide. However, little is known about the specific uses and effects of social media on human immunodeficiency virus (HIV) interventions. This systematic review examines the effectiveness of social media interventions to promote HIV testing, linkage, adherence, and retention among key populations. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist and Cochrane guidelines for this review and registered it on the International Prospective Register of Systematic Reviews, PROSPERO. We systematically searched six databases and three conference websites using search terms related to HIV, social media, and key populations. We included studies where (1) the intervention was created or implemented on social media platforms, (2) study population included men who have sex with men (MSM), transgender individuals, people who inject drugs (PWID), and/or sex workers, and (3) outcomes included promoting HIV testing, linkage, adherence, and/or retention. Meta-analyses were conducted by Review Manager, version 5.3. Pooled relative risk (RR) and 95% confidence intervals were calculated by random-effects models. Among 981 manuscripts identified, 26 studies met the inclusion criteria. We found 18 studies from high-income countries, 8 in middle-income countries, and 0 in low-income countries. Eight were randomized controlled trials, and 18 were observational studies. All studies (n=26) included MSM; five studies also included transgender individuals. The focus of 21 studies was HIV testing, four on HIV testing and linkage to care, and one on antiretroviral therapy adherence. Social media interventions were used to do the following: build online interactive communities to encourage HIV testing/adherence (10 studies), provide HIV testing services (9 studies), disseminate HIV information (9 studies), and develop intervention materials (1 study). Of the studies providing HIV self-testing, 16% of participants requested HIV testing kits from social media platforms. Existing social media platforms such as Facebook (n=15) and the gay dating app Grindr (n=10) were used most frequently. Data from four studies show that HIV testing uptake increased after social media interventions (n=1283, RR 1.50, 95% CI 1.28-1.76). In the studies where social media interventions were participatory, HIV testing uptake was higher in the intervention arm than the comparison arm (n=1023, RR 1.64, 95% CI 1.19-2.26). Social media interventions are effective in promoting HIV testing among MSM in many settings. Social media interventions to improve HIV services beyond HIV testing in low- and middle-income countries and among other key populations need to be considered. International Prospective Register of Systematic Reviews (PROSPERO): CRD42016048073; http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42016048073 (Archived by WebCite at http://www. webcitation.org/6usLCJK3v). ©Bolin Cao, Somya Gupta, Jiangtao Wang, Lisa B Hightow-Weidman, Kathryn E Muessig, Weiming Tang, Stephen Pan, Razia Pendse, Joseph D. Tucker. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 24.11.2017.

Audiometric Testing Guideline Adherence in Children Undergoing Tympanostomy Tubes: A Population-Based Study.

PubMed

Beyea, Jason A; Rosen, Emily; Stephens, Trina; Nguyen, Paul; Hall, Stephen F

2018-02-01

Objective Tympanostomy tube (TT) insertion is the most common ambulatory surgery performed on children. American Academy of Otolaryngology-Head and Neck Surgery Founda-tion (AAO-HNSF) Clinical Practice Guidelines (CPGs) recommend hearing testing for all pediatric TT candidates. The aim of this study was to assess audiometric testing in this population. Study Design Retrospective population-based cohort study. Setting All hospitals in the Canadian province of Ontario. Subjects and Methods All patients 12 years of age and younger who underwent at least 1 TT procedure between January 1993 and June 2016. The primary outcomes were the percentage of patients who underwent a hearing test within 1 year before and/or 1 year after surgery. Results A total of 316,599 bilateral TT procedures were performed during the study period (1993 to 2016). Presurgical hearing tests increased from 55.7% to 74.9%, and postsurgical hearing tests increased from 42.2% to 68.9%. Younger surgeons demonstrated a greater adherence to the CPGs (relative risk [RR], 1.22; 95% CI, 1.08-1.38; P = .001). Remarkably, there was not a spike in preoperative hearing tests following the introduction of the CPGs in 2013 (RR, 1.12; 95% CI, 0.85-1.47; P = .432). Presurgical hearing testing ranged from 26.1% to 83.5% across health regions. Conclusion In this cohort of children who underwent TT placement, the trends of preoperative and postoperative audiometric testing are increasing but are still lower than recommended by the CPGs, despite a tripling of practicing audiologists. This study describes the current state of testing in Ontario and highlights issues of access to audiology services, possible parent preferences, and the importance of ongoing continuing medical education for all health care practitioners.

Performance of middle-aged and elderly European minority and majority populations on a Cross-Cultural Neuropsychological Test Battery (CNTB).

PubMed

Nielsen, T Rune; Segers, Kurt; Vanderaspoilden, Valérie; Bekkhus-Wetterberg, Peter; Minthon, Lennart; Pissiota, Anna; Bjørkløf, Guro Hanevold; Beinhoff, Ulrike; Tsolaki, Magda; Gkioka, Mara; Waldemar, Gunhild

2018-01-24

The aim of this study was to examine test performance on a cross-cultural neuropsychological test battery for assessment of middle-aged and elderly ethnic minority and majority populations in western Europe, and to present preliminary normative data. The study was a cross-sectional multi-center study. Tests in the European Cross-Cultural Neuropsychological Test Battery (CNTB) cover several cognitive domains, including global cognitive function, memory, executive functions, and visuospatial functions. A total of 330 participants were included: 14 Moroccan, 45 Pakistani/Indian Punjabi, 41 Polish, 66 Turkish, and 19 former Yugoslavian minority participants, and 145 western European majority participants. Significant differences between ethnic groups were found on most CNTB measures. However, ethnic groups differed greatly in demographic characteristics and differences in test scores were mainly related to educational differences, explaining an average of 15% of the variance. Preliminary multicultural CNTB normative data dichotomized by education and age were constructed using overlapping cells. Applying this normative data across the whole sample resulted in an acceptable number of participants scoring in the impaired range across all ethnic groups. Factor analyses found the CNTB to have a stable and clinically meaningful factor structure. The CNTB represents the first European joint effort to establish neuropsychological measures appropriate for ethnic minority populations in western Europe. The CNTB can be applied in approximately 60 min, covers several cognitive domains, and appears appropriate for assessment of the targeted populations. However, due to the small sample size in some ethnic groups further studies are needed replicate and support this.

Cross-validation of a dementia screening test in a heterogeneous population.

PubMed

Ritchie, K A; Hallerman, E F

1989-09-01

Recognition of the increasing importance of early dementia screening for both research and clinical purposes has led to the development of numerous screening instruments. The most promising of these are based on neuropsychological measures which are able to focus on very specific cognitive functions. Of these tests the Iowa screening test is of particular interest to researchers and clinicians working with heterogenous populations or wishing to make cross-cultural comparisons as it is relatively culture-fair and does not assume literacy. A preliminary study of the performance of the Iowa in an Israeli sample of diverse ethnic origins and low education level suggests it to be a very sensitive measure even in such groups. The study also demonstrates the inadvisability of adopting item weights derived by multivariate statistical techniques from another population.

Color vision impairment with low-level methylmercury exposure of an Amazonian population - Brazil.

PubMed

Feitosa-Santana, Claudia; Souza, Givago da Silva; Sirius, Esaú Ventura Pupo; Rodrigues, Anderson Raiol; Cortes, Maria Izabel Tentes; Silveira, Luiz Carlos de Lima; Ventura, Dora Fix

2018-05-01

Land exploitation that follows deforestation and mining can result in soil erosion and the release of mercury to the waters of rivers in the Amazon Basin. Inorganic mercury is methylated by bacteria that are present in the environment and it serves as a source of human contamination through fish consumption in the form of methylmercury. Long-term exposure to low-level methylmercury in the riverside populations can lead to nervous system alterations, some of which are visual impairments such as loss of luminance contrast sensitivity, restricted visual fields and color vision defects. The present study sought to examine color vision in a group of adults living in the central Brazilian Amazon who were exposed to low-levels of methylmercury. Total Hg concentrations were measured from hair collected at the time of the testing. The D15d and FM100 color vision arrangement tests were applied in a population of 36 (22 males) and 42 (25 males), respectively. Controls were healthy volunteers from the cities of São Paulo for the D15d and Belém for the FM100. There was a statistically significant difference in performance between those who were exposed and controls for both tests (p < 0.01 and p < 0.0001, respectively, Mann-Whitney U test), meaning that adults living in this region of the Amazon made more mistakes on both tests when compared to controls. A linear regression was performed using Hg concentrations and test scores. Hg concentrations accounted for 7% and 2% of color D15d and FM100 arrangement test errors, respectively. Although other studies have previously found color vision impairment in the Amazon, they tested inhabitants on the east side of the Amazon, while this study was conducted in the central Amazon region and it is the first study in a population with no direct contact with the Hg source of contamination. These results suggest that long-term exposure to low-level methylmercury in riverside populations is more widely spread in the Amazon Basin than previously reported. This information is needed to implement public health policies that will ensure a safer environment for the Amazonian population. Copyright © 2018 Elsevier B.V. All rights reserved.

Predictors of Inappropriate Use of Diagnostic Tests and Management of Bronchiolitis

PubMed Central

Sarmiento, Lorena; Rojas-Soto, Gladys E.

2017-01-01

Background The aim of the present study was to determine predictors of inappropriate use of diagnostic tests and management of bronchiolitis in a population of hospitalized infants. Methods In an analytical cross-sectional study, we determined independent predictors of the inappropriate use of diagnostic tests and management of bronchiolitis in a population of hospitalized infants. We defined a composite outcome score as the main outcome variable. Results Of the 303 included patients, 216 (71.3%) experienced an inappropriate use of diagnostic tests and treatment of bronchiolitis. After controlling for potential confounders, it was found that atopic dermatitis (OR 5.30; CI 95% 1.14–24.79; p = 0.034), length of hospital stay (OR 1.48; CI 95% 1.08–2.03; p = 0.015), and the number of siblings (OR 1.92; CI 95% 1.13–3.26; p = 0.015) were independent predictors of an inappropriate use of diagnostic tests and treatment of the disease. Conclusions Inappropriate use of diagnostic tests and treatment of bronchiolitis was a highly prevalent outcome in our population of study. Participants with atopic dermatitis, a longer hospital stay, and a greater number of siblings were at increased risk for inappropriate use of diagnostic tests and management of the disease. PMID:28758127

[The Study of Health in Pomerania (SHIP) reference values for cardiopulmonary exercise testing].

PubMed

Gläser, S; Ittermann, T; Schäper, C; Obst, A; Dörr, M; Spielhagen, T; Felix, S B; Völzke, H; Bollmann, T; Opitz, C F; Warnke, C; Koch, B; Ewert, R

2013-01-01

The interpretation of gas exchange measured by cardiopulmonary exercise testing (CPET) depends on reliable reference values. Within the population based Study of Health in Pomerania (SHIP) CPET was assessed in 1706 volunteers. The assessment based on symptom limited exercise tests on a bicycle in a sitting position according to a modified Jones protocol. CPET was embedded in an extensive examination program. After the exclusion of active smokers and volunteers with evidence of cardiopulmonary and musculoskeletal disorders the reference population comprised 616 healthy subjects (333 women) aged 25 to 85 years. Reference equations including upper and/or lower limits based on quantile regression were assessed. All values were corrected for the most important influencing factors.This study provides reference equations for gas exchange and exercise capacity assessed within a population in Germany. © Georg Thieme Verlag KG Stuttgart · New York.

Predicting tuberculosis risk in the foreign-born population of British Columbia, Canada: study protocol for a retrospective population-based cohort study

PubMed Central

Ronald, Lisa A; Campbell, Jonathon R; Balshaw, Robert F; Roth, David Z; Romanowski, Kamila; Marra, Fawziah; Cook, Victoria J; Johnston, James C

2016-01-01

Introduction Improved understanding of risk factors for developing active tuberculosis (TB) will better inform decisions about diagnostic testing and treatment for latent TB infection (LTBI) in migrant populations in low-incidence regions. We aim to examine TB risk factors among the foreign-born population in British Columbia (BC), Canada, and to create and validate a clinically relevant multivariate risk score to predict active TB. Methods and analysis This retrospective population-based cohort study will include all foreign-born individuals who acquired permanent resident status in Canada between 1 January 1985 and 31 December 2013 and acquired healthcare coverage in BC at any point during this period. Multiple administrative databases and disease registries will be linked, including a National Immigration Database, BC Provincial Health Insurance Registration, physician billings, hospitalisations, drugs dispensed from community pharmacies, vital statistics, HIV testing and notifications, cancer, chronic kidney disease and dialysis treatment, and all TB and LTBI testing and treatment data in BC. Extended proportional hazards regression will be used to estimate risk factors for TB and to create a prognostic TB risk score. Ethics and dissemination Ethical approval for this study has been obtained from the University of British Columbia Clinical Ethics Review Board. Once completed, study findings will be presented at conferences and published in peer-reviewed journals. An online TB risk score calculator will also be created. PMID:27888179

Conducting Internet Research With the Transgender Population: Reaching Broad Samples and Collecting Valid Data

PubMed Central

Miner, Michael H.; Bockting, Walter O.; Romine, Rebecca Swinburne; Raman, Sivakumaran

2013-01-01

Health research on transgender people has been hampered by the challenges inherent in studying a hard-to-reach, relatively small, and geographically dispersed population. The Internet has the potential to facilitate access to transgender samples large enough to permit examination of the diversity and syndemic health disparities found among this population. In this article, we describe the experiences of a team of investigators using the Internet to study HIV risk behaviors of transgender people in the United States. We developed an online instrument, recruited participants exclusively via websites frequented by members of the target population, and collected data using online quantitative survey and qualitative synchronous and asynchronous interview methods. Our experiences indicate that the Internet environment presents the investigator with some unique challenges and that commonly expressed criticisms about Internet research (e.g., lack of generalizable samples, invalid study participants, and multiple participation by the same subject) can be overcome with careful method design, usability testing, and pilot testing. The importance of both usability and pilot testing are described with respect to participant engagement and retention and the quality of data obtained online. PMID:24031157

Conducting Internet Research With the Transgender Population: Reaching Broad Samples and Collecting Valid Data.

PubMed

Miner, Michael H; Bockting, Walter O; Romine, Rebecca Swinburne; Raman, Sivakumaran

2012-05-01

Health research on transgender people has been hampered by the challenges inherent in studying a hard-to-reach, relatively small, and geographically dispersed population. The Internet has the potential to facilitate access to transgender samples large enough to permit examination of the diversity and syndemic health disparities found among this population. In this article, we describe the experiences of a team of investigators using the Internet to study HIV risk behaviors of transgender people in the United States. We developed an online instrument, recruited participants exclusively via websites frequented by members of the target population, and collected data using online quantitative survey and qualitative synchronous and asynchronous interview methods. Our experiences indicate that the Internet environment presents the investigator with some unique challenges and that commonly expressed criticisms about Internet research (e.g., lack of generalizable samples, invalid study participants, and multiple participation by the same subject) can be overcome with careful method design, usability testing, and pilot testing. The importance of both usability and pilot testing are described with respect to participant engagement and retention and the quality of data obtained online.

From individual to population level effects of toxicants in the tubicifid Branchiura sowerbyi using threshold effect models in a Bayesian framework.

PubMed

Ducrot, Virginie; Billoir, Elise; Péry, Alexandre R R; Garric, Jeanne; Charles, Sandrine

2010-05-01

Effects of zinc were studied in the freshwater worm Branchiura sowerbyi using partial and full life-cycle tests. Only newborn and juveniles were sensitive to zinc, displaying effects on survival, growth, and age at first brood at environmentally relevant concentrations. Threshold effect models were proposed to assess toxic effects on individuals. They were fitted to life-cycle test data using Bayesian inference and adequately described life-history trait data in exposed organisms. The daily asymptotic growth rate of theoretical populations was then simulated with a matrix population model, based upon individual-level outputs. Population-level outputs were in accordance with existing literature for controls. Working in a Bayesian framework allowed incorporating parameter uncertainty in the simulation of the population-level response to zinc exposure, thus increasing the relevance of test results in the context of ecological risk assessment.

Development and Psychometric Testing of the Dogs and WalkinG Survey (DAWGS)

ERIC Educational Resources Information Center

Richards, Elizabeth A.; McDonough, Meghan H.; Edwards, Nancy E.; Lyle, Roseann M.; Troped, Philip J.

2013-01-01

Purpose: Dog owners represent 40% of the population, a promising audience to increase population levels of physical activity. The purpose of this study was to develop and test the psychometric properties of a new instrument to assess social-cognitive theory constructs related to dog walking. Method: Dog owners ("N" = 431) completed the…

Learned Helplessness and Depression in a Clinical Population: A Test of Two Behavioral Hypotheses

ERIC Educational Resources Information Center

And Others; Price, Kenneth P.

1978-01-01

This study was undertaken to extend the learned helplessness phenomenon to a clinical population and to test the competing hypotheses of Seligman and Lewinsohn. 96 male hospitalized psychiatric and medical patients were randomly assigned to one of four experimental conditions. Results replicate the learned helplessness phenomenon in a group of…

Prevalence of fragrance contact allergy in the general population of five European countries: a cross-sectional study.

PubMed

Diepgen, T L; Ofenloch, R; Bruze, M; Cazzaniga, S; Coenraads, P J; Elsner, P; Goncalo, M; Svensson, Å; Naldi, L

2015-12-01

Contact allergy to fragrances is assessed mostly in clinical populations of patients. Studies in the general population are scarce and vary in their methodology across countries. To determine the prevalence of fragrance contact allergy in the European general population and to assess the clinical relevance of positive patch test reactions to different fragrances. In five European countries (Germany, Italy, the Netherlands, Portugal and Sweden) a random sample from the general population aged 18-74 years was drawn. In total, 12 377 subjects were interviewed in this cross-sectional study and a random sample (n = 3119) was patch tested using the TRUE Test and Finn Chamber techniques. Patch test procedures were harmonized by mandatory training before the study and monitoring during the study. The highest prevalence for contact allergy of 2·6% [95% confidence interval (CI) 2·1-3·2] was found for fragrance mix (FM) I in petrolatum, with a high content of atranol and chloratranol, followed by 1·9% (95% CI 1·5-2·4) for FM II in petrolatum. The conservatively estimated prevalence of fragrance contact allergy was 1·9% (95% CI 1·5-2·5). This is defined as the existence of a positive patch test to FM I or FM II; any of their individual materials; Myroxylon pereirae; sesquiterpene lactones or 3- and 4-hydroxyisohexyl 3-cyclohexene carboxaldehyde that show clinical relevance, defined conservatively as lifetime avoidance of scented products and an itchy skin rash lasting > 3 days in a lifetime. Using the reported lifetime prevalence of any contact dermatitis instead of the lifetime prevalence of any itchy skin rash, the prevalence is 0·8% (95% CI 0·5-1·2). The prevalence rates of contact allergy to fragrances in women are about twice those in men. This study helps to identify targets for prevention of fragrance allergy. © 2015 British Association of Dermatologists.

Comparison of liver fibrosis blood tests developed for HCV with new specific tests in HIV/HCV co-infection.

PubMed

Calès, Paul; Halfon, Philippe; Batisse, Dominique; Carrat, Fabrice; Perré, Philippe; Penaranda, Guillaume; Guyader, Dominique; d'Alteroche, Louis; Fouchard-Hubert, Isabelle; Michelet, Christian; Veillon, Pascal; Lambert, Jérôme; Weiss, Laurence; Salmon, Dominique; Cacoub, Patrice

2010-08-01

We compared 5 non-specific and 2 specific blood tests for liver fibrosis in HCV/HIV co-infection. Four hundred and sixty-seven patients were included into derivation (n=183) or validation (n=284) populations. Within these populations, the diagnostic target, significant fibrosis (Metavir F > or = 2), was found in 66% and 72% of the patients, respectively. Two new fibrosis tests, FibroMeter HICV and HICV test, were constructed in the derivation population. Unadjusted AUROCs in the derivation population were: APRI: 0.716, Fib-4: 0.722, Fibrotest: 0.778, Hepascore: 0.779, FibroMeter: 0.783, HICV test: 0.822, FibroMeter HICV: 0.828. AUROCs adjusted on classification and distribution of fibrosis stages in a reference population showed similar values in both populations. FibroMeter, FibroMeter HICV and HICV test had the highest correct classification rates in F0/1 and F3/4 (which account for high predictive values): 77-79% vs. 70-72% in the other tests (p=0.002). Reliable individual diagnosis based on predictive values > or = 90% distinguished three test categories: poorly reliable: Fib-4 (2.4% of patients), APRI (8.9%); moderately reliable: Fibrotest (25.4%), FibroMeter (26.6%), Hepascore (30.2%); acceptably reliable: HICV test (40.2%), FibroMeter HICV (45.6%) (p<10(-3) between tests). FibroMeter HICV classified all patients into four reliable diagnosis intervals (< or =F1, F1+/-1, > or =F1, > or =F2) with an overall accuracy of 93% vs. 79% (p<10(-3)) for a binary diagnosis of significant fibrosis. Tests designed for HCV infections are less effective in HIV/HCV infections. A specific test, like FibroMeter HICV, was the most interesting test for diagnostic accuracy, correct classification profile, and a reliable diagnosis. With reliable diagnosis intervals, liver biopsy can therefore be avoided in all patients. Copyright 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Colorectal cancer prevention: adherence patterns and correlates of tests done for screening purposes within United States populations.

PubMed

Ata, Ashar; Elzey, Jared D; Insaf, Tabassum Z; Grau, Ana M; Stain, Steven C; Ahmed, Nasar U

2006-01-01

Studies exploring CRC testing prevalence and correlates within US populations have provided limited and sometimes conflicting information. The most recent national-level reports have described US usage of CRC tests but none have considered only those tests done specifically for screening reasons as an outcome variable. Using the NHIS 2000 sample of >or=50 year-old, we assessed screening behavior using an outcome variable accounting for (1) any combination of recommended tests (2) done within their respective time guidelines, and (3) specifically for screening purposes. Only 25.8% (95% CI: 24.9-26.7%) of the population reported getting a test done for screening purposes within the recommended time. Most (>85%) of the FOBTs and only about 60% of endoscopies were done for screening. Among those who had an endoscopy within the recommended time, Blacks were more likely than Whites to report screening as the purpose of the test. Hispanics had the lowest test usage irrespective of test time, reason or type. Hispanics were 50% (p<0.001) less likely to be adherent, and Blacks approximately 22% (p<0.01) less likely to be adherent, than Whites. After multivariate adjustment, differences between Whites and Blacks disappeared; Hispanics remained less likely. Increasing education predicted higher adherence among Whites but only undergraduate completion did so among Blacks. Male gender predicted adherence only among Blacks and insurance only among Hispanics. Preventive screening for CRC is lower than estimates from previous studies. Future studies should consider accounting for test purpose. Our findings need confirmation through studies based on objective data.

[Sexual behavior characteristics of clients attending the Israel AIDS Task Force anonymous clinic in Tel Aviv].

PubMed

Bar-On, Yaeli; Perry, Zvi H; Nof, Einav; Shiber, Asher; Risenberg, Klaris; Ben Zion, Itzhak

2014-09-01

Until now, research on sexual behavior and HIV in Israel has been carried out mainly on the general population, and focused primarily on defining populations at risk, without adequate consideration given to the reasons bringing these populations to be tested, and their specific sexual behaviors. In Israel, one can choose whether to take an HIV test in confidential centers (giving one's name under medical confidentiality) or in anonymous centers (Israel AIDS Task Force in Tel Aviv and Beer Sheva, Levinsky Clinic in Tel Aviv and Haparsim Clinic in Haifa]. At least 21% of the clients of the anonymous testing centers in Israel belong to a high risk population in contrast to 2.6% in confidential clinics, and so, in this study, we hypothesize that characterization of sexual behavior patterns in anonymous testing centers might enable us to better characterize sexual behavior patterns in high risk populations. In this cross-sectional study, we used questionnaires distributed in the clinics by the Israel AIDS Task Force in order to characterize their clinic's clients. The questionnaires were completed by the Israel AIDS Task Force consultants during the consultation period at which the anonymous test was performed. Data collected included: gender, age, testing history, specific sexual behaviors and reasons for applying for the current test. A total of 926 questionnaires were collected; 29.9% of them were of female patients. The average age was 29.47 years (1±8.66]; 21.3% of the clients were men who have sex with men [MSM]; only 2.3% of the clients belonged to other high risk populations. In all groups, the majority of the patients reported high risk sexual behavior (any sexual contact without a condom) and the average age for the first test was much higher than the average age of first sexual intercourse common in Israel. Women reported more participation in unprotected vaginal intercourse than heterosexual men, and a substantial part of MSM reported performing unprotected anal intercourse. More heterosexuals than MSM stated a new relationship as a reason for applying for the test, and more MSM than heterosexuals reported arriving for a routine check-up. There is a need for comprehensive programs encouraging testing for HIV in all age groups, focusing on Sthe ages 18-25 years, and encouraging the use of a condom as a preventive measure in all populations, especially women. We feel it is essential to emphasize the need for educational programs tailored for each sub-population's psychosocial characteristics and specific issues.

Validation of an arterial tortuosity measure with application to hypertension collection of clinical hypertensive patients

PubMed Central

2011-01-01

Background Hypertension may increase tortuosity or twistedness of arteries. We applied a centerline extraction algorithm and tortuosity metric to magnetic resonance angiography (MRA) brain images to quantitatively measure the tortuosity of arterial vessel centerlines. The most commonly used arterial tortuosity measure is the distance factor metric (DFM). This study tested a DFM based measurement’s ability to detect increases in arterial tortuosity of hypertensives using existing images. Existing images presented challenges such as different resolutions which may affect the tortuosity measurement, different depths of the area imaged, and different artifacts of imaging that require filtering. Methods The stability and accuracy of alternative centerline algorithms was validated in numerically generated models and test brain MRA data. Existing images were gathered from previous studies and clinical medical systems by manually reading electronic medical records to identify hypertensives and negatives. Images of different resolutions were interpolated to similar resolutions. Arterial tortuosity in MRA images was measured from a DFM curve and tested on numerically generated models as well as MRA images from two hypertensive and three negative control populations. Comparisons were made between different resolutions, different filters, hypertensives versus negatives, and different negative controls. Results In tests using numerical models of a simple helix, the measured tortuosity increased as expected with more tightly coiled helices. Interpolation reduced resolution-dependent differences in measured tortuosity. The Korean hypertensive population had significantly higher arterial tortuosity than its corresponding negative control population across multiple arteries. In addition one negative control population of different ethnicity had significantly less arterial tortuosity than the other two. Conclusions Tortuosity can be compared between images of different resolutions by interpolating from lower to higher resolutions. Use of a universal negative control was not possible in this study. The method described here detected elevated arterial tortuosity in a hypertensive population compared to the negative control population and can be used to study this relation in other populations. PMID:22166145

Validation of an arterial tortuosity measure with application to hypertension collection of clinical hypertensive patients.

PubMed

Diedrich, Karl T; Roberts, John A; Schmidt, Richard H; Kang, Chang-Ki; Cho, Zang-Hee; Parker, Dennis L

2011-10-18

Hypertension may increase tortuosity or twistedness of arteries. We applied a centerline extraction algorithm and tortuosity metric to magnetic resonance angiography (MRA) brain images to quantitatively measure the tortuosity of arterial vessel centerlines. The most commonly used arterial tortuosity measure is the distance factor metric (DFM). This study tested a DFM based measurement's ability to detect increases in arterial tortuosity of hypertensives using existing images. Existing images presented challenges such as different resolutions which may affect the tortuosity measurement, different depths of the area imaged, and different artifacts of imaging that require filtering. The stability and accuracy of alternative centerline algorithms was validated in numerically generated models and test brain MRA data. Existing images were gathered from previous studies and clinical medical systems by manually reading electronic medical records to identify hypertensives and negatives. Images of different resolutions were interpolated to similar resolutions. Arterial tortuosity in MRA images was measured from a DFM curve and tested on numerically generated models as well as MRA images from two hypertensive and three negative control populations. Comparisons were made between different resolutions, different filters, hypertensives versus negatives, and different negative controls. In tests using numerical models of a simple helix, the measured tortuosity increased as expected with more tightly coiled helices. Interpolation reduced resolution-dependent differences in measured tortuosity. The Korean hypertensive population had significantly higher arterial tortuosity than its corresponding negative control population across multiple arteries. In addition one negative control population of different ethnicity had significantly less arterial tortuosity than the other two. Tortuosity can be compared between images of different resolutions by interpolating from lower to higher resolutions. Use of a universal negative control was not possible in this study. The method described here detected elevated arterial tortuosity in a hypertensive population compared to the negative control population and can be used to study this relation in other populations.

Association of the oxytocin receptor (OXTR) gene polymorphisms with autism spectrum disorder (ASD) in the Japanese population.

PubMed

Liu, Xiaoxi; Kawamura, Yoshiya; Shimada, Takafumi; Otowa, Takeshi; Koishi, Shinko; Sugiyama, Toshiro; Nishida, Hisami; Hashimoto, Ohiko; Nakagami, Ryoichi; Tochigi, Mamoru; Umekage, Tadashi; Kano, Yukiko; Miyagawa, Taku; Kato, Nobumasa; Tokunaga, Katsushi; Sasaki, Tsukasa

2010-03-01

The oxytocin receptor (OXTR) gene, which is located on chromosome 3p25.3, has been implicated as a candidate gene for susceptibility of autism spectrum disorder (ASD). Positive associations between OXTR and ASD have been reported in earlier studies. However, the results were inconsistent and demand further studies. In this study, we investigated the associations between OXTR and ASD in a Japanese population by analyzing 11 single-nucleotide polymorphisms (SNPs) using both family-based association test (FBAT) and population-based case-control test. No significant signal was detected in the FBAT test. However, significant differences were observed in allelic frequencies of four SNPs, including rs2254298 between patients and controls. The risk allele of rs2254298 was 'A', which was consistent with the previous study in Chinese, and not with the observations in Caucasian. The difference in the risk allele of this SNP in previous studies might be attributable to an ethnic difference in the linkage disequilibrium structure between the Asians and Caucasians. In addition, haplotype analysis exhibits a significant association between a five-SNP haplotype and ASD, including rs22542898. In conclusion, our study might support that OXTR has a significant role in conferring the risk of ASD in the Japanese population.

Efficiency of semi-automated fluorescent multiplex PCRs with 11 microsatellite markers for genetic studies of deer populations.

PubMed

Bonnet, A; Thévenon, S; Maudet, F; Maillard, J C

2002-10-01

Thirty bovine and eight ovine microsatellite primer pairs were tested on four tropical deer species: Eld's and Swamp deer (highly threatened) and Rusa and Vietnamese Sika deer (economically important). Thirty markers gave an amplified product in all four species (78.9%). The number of polymorphic microsatellite markers varied among the species from 14 in Eld's deer (47%) to 20 in Swamp deer (67%). Among them, 11 microsatellite loci were multiplexed in three polymerase chain reactions (PCRs) and labelled with three different fluorochromes that can be loaded in one gel-lane. To test the efficiency of the multiplex, primary genetic studies (mean number of alleles, expected heterozygosities and Fis values) were carried out on four deer populations. Parentage exclusion probability and probability of identity were computed and discussed on a Swamp deer population. These multiplexes PCRs were also tested on several other deer species and subspecies. The aim of this study is to establish a tool useful for genetic studies of population structure and diversity in four tropical deer species which with few modifications can be applied to other species of the genus Cervus.

A Powerful Test for Comparing Multiple Regression Functions.

PubMed

Maity, Arnab

2012-09-01

In this article, we address the important problem of comparison of two or more population regression functions. Recently, Pardo-Fernández, Van Keilegom and González-Manteiga (2007) developed test statistics for simple nonparametric regression models: Y(ij) = θ(j)(Z(ij)) + σ(j)(Z(ij))∊(ij), based on empirical distributions of the errors in each population j = 1, … , J. In this paper, we propose a test for equality of the θ(j)(·) based on the concept of generalized likelihood ratio type statistics. We also generalize our test for other nonparametric regression setups, e.g, nonparametric logistic regression, where the loglikelihood for population j is any general smooth function [Formula: see text]. We describe a resampling procedure to obtain the critical values of the test. In addition, we present a simulation study to evaluate the performance of the proposed test and compare our results to those in Pardo-Fernández et al. (2007).

Septic tank additive impacts on microbial populations.

PubMed

Pradhan, S; Hoover, M T; Clark, G H; Gumpertz, M; Wollum, A G; Cobb, C; Strock, J

2008-01-01

Environmental health specialists, other onsite wastewater professionals, scientists, and homeowners have questioned the effectiveness of septic tank additives. This paper describes an independent, third-party, field scale, research study of the effects of three liquid bacterial septic tank additives and a control (no additive) on septic tank microbial populations. Microbial populations were measured quarterly in a field study for 12 months in 48 full-size, functioning septic tanks. Bacterial populations in the 48 septic tanks were statistically analyzed with a mixed linear model. Additive effects were assessed for three septic tank maintenance levels (low, intermediate, and high). Dunnett's t-test for tank bacteria (alpha = .05) indicated that none of the treatments were significantly different, overall, from the control at the statistical level tested. In addition, the additives had no significant effects on septic tank bacterial populations at any of the septic tank maintenance levels. Additional controlled, field-based research iswarranted, however, to address additional additives and experimental conditions.

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

PubMed

Fung, Tak; Keenan, Kevin

2014-01-01

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

Analysis of the HLA population data (AHPD) submitted to the 15th International Histocompatibility/Immunogenetics Workshop by using the Gene[rate] computer tools accommodating ambiguous data (AHPD project report).

PubMed

Nunes, J M; Riccio, M E; Buhler, S; Di, D; Currat, M; Ries, F; Almada, A J; Benhamamouch, S; Benitez, O; Canossi, A; Fadhlaoui-Zid, K; Fischer, G; Kervaire, B; Loiseau, P; de Oliveira, D C M; Papasteriades, C; Piancatelli, D; Rahal, M; Richard, L; Romero, M; Rousseau, J; Spiroski, M; Sulcebe, G; Middleton, D; Tiercy, J-M; Sanchez-Mazas, A

2010-07-01

During the 15th International Histocompatibility and Immunogenetics Workshop (IHIWS), 14 human leukocyte antigen (HLA) laboratories participated in the Analysis of HLA Population Data (AHPD) project where 18 new population samples were analyzed statistically and compared with data available from previous workshops. To that aim, an original methodology was developed and used (i) to estimate frequencies by taking into account ambiguous genotypic data, (ii) to test for Hardy-Weinberg equilibrium (HWE) by using a nested likelihood ratio test involving a parameter accounting for HWE deviations, (iii) to test for selective neutrality by using a resampling algorithm, and (iv) to provide explicit graphical representations including allele frequencies and basic statistics for each series of data. A total of 66 data series (1-7 loci per population) were analyzed with this standard approach. Frequency estimates were compliant with HWE in all but one population of mixed stem cell donors. Neutrality testing confirmed the observation of heterozygote excess at all HLA loci, although a significant deviation was established in only a few cases. Population comparisons showed that HLA genetic patterns were mostly shaped by geographic and/or linguistic differentiations in Africa and Europe, but not in America where both genetic drift in isolated populations and gene flow in admixed populations led to a more complex genetic structure. Overall, a fruitful collaboration between HLA typing laboratories and population geneticists allowed finding useful solutions to the problem of estimating gene frequencies and testing basic population diversity statistics on highly complex HLA data (high numbers of alleles and ambiguities), with promising applications in either anthropological, epidemiological, or transplantation studies.

The Study of Geographic Differences in the Prevalence of Disability among Taiwanese Population

ERIC Educational Resources Information Center

Lin, Jin-Ding; Li, Chien-De; Lin, Lan-Ping; Hsu, Shang-Wei

2012-01-01

The present study analyzes data of the governmental reported general population and population of persons with disabilities from 2002 to 2009, to describe the disability prevalence and to test the overtime change with particular focused on the geographic differences in Taiwan. In average, the disability prevalence was 42.06% (range = 31.06%-80.04%…

The validity and reliability of the four square step test in different adult populations: a systematic review.

PubMed

Moore, Martha; Barker, Karen

2017-09-11

The four square step test (FSST) was first validated in healthy older adults to provide a measure of dynamic standing balance and mobility. The FSST has since been used in a variety of patient populations. The purpose of this systematic review is to determine the validity and reliability of the FSST in these different adult patient populations. The literature search was conducted to highlight all the studies that measured validity and reliability of the FSST. Six electronic databases were searched including AMED, CINAHL, MEDLINE, PEDro, Web of Science and Google Scholar. Grey literature was also searched for any documents relevant to the review. Two independent reviewers carried out study selection and quality assessment. The methodological quality was assessed using the QUADAS-2 tool, which is a validated tool for the quality assessment of diagnostic accuracy studies, and the COSMIN four-point checklist, which contains standards for evaluating reliability studies on the measurement properties of health instruments. Fifteen studies were reviewed studying community-dwelling older adults, Parkinson's disease, Huntington's disease, multiple sclerosis, vestibular disorders, post stroke, post unilateral transtibial amputation, knee pain and hip osteoarthritis. Three of the studies were of moderate methodological quality scoring low in risk of bias and applicability for all domains in the QUADAS-2 tool. Three studies scored "fair" on the COSMIN four-point checklist for the reliability components. The concurrent validity of the FSST was measured in nine of the studies with moderate to strong correlations being found. Excellent Intraclass Correlation Coefficients were found between physiotherapists carrying out the tests (ICC = .99) with good to excellent test-retest reliability shown in nine of the studies (ICC = .73-.98). The FSST may be an effective and valid tool for measuring dynamic balance and a participants' falls risk. It has been shown to have strong correlations with other measures of balance and mobility with good reliability shown in a number of populations. However, the quality of the papers reviewed was variable with key factors, such as sample size and test set up, needing to be addressed before the tool can be confidently used in these specified populations.

Standardization of the face-hand test in a Brazilian multicultural population: prevalence of sensory extinction and implications for neurological diagnosis.

PubMed

Luvizutto, Gustavo José; Fogaroli, Marcelo Ortolani; Theotonio, Rodolfo Mazeto; Nunes, Hélio Rubens de Carvalho; Resende, Luiz Antônio de Lima; Bazan, Rodrigo

2016-12-01

The face-hand test is a simple, practical, and rapid test to detect neurological syndromes. However, it has not previously been assessed in a Brazilian sample; therefore, the objective of the present study was to standardize the face-hand test for use in the multi-cultural population of Brazil and identify the sociodemographic factors affecting the results. This was a cross sectional study of 150 individuals. The sociodemographic variables that were collected included age, gender, race, body mass index and years of education. Standardization of the face-hand test occurred in 2 rounds of 10 sensory stimuli, with the participant seated to support the trunk and their vision obstructed in a sound-controlled environment. The face-hand test was conducted by applying 2 rounds of 10 sensory stimuli that were applied to the face and hand simultaneously. The associations between the face-hand test and sociodemographic variables were analyzed using Mann-Whitney tests and Spearman correlations. Binomial models were adjusted for the number of face-hand test variations, and ROC curves evaluated sensitivity and specificity of sensory extinction. There was no significant relationship between the sociodemographic variables and the number of stimuli perceived for the face-hand test. There was a high relative frequency of detection, 8 out of 10 stimuli, in this population. Sensory extinction was 25.3%, which increased with increasing age (OR=1.4[1:01-1:07]; p=0.006) and decreased significantly with increasing education (OR=0.82[0.71-0.94]; p=0.005). In the Brazilian population, a normal face-hand test score ranges between 8-10 stimuli, and the results indicate that sensory extinction is associated with increased age and lower levels of education.

Initial report of a hepatitis investigation in rural Belize.

PubMed

Hoffman, K J; Gaydos, J C; Krieg, R E; Duncan, J F; MacArthy, P O; Ticehurst, J R; Jaramillo, R; Reyes, L G; Sjogren, M H; Legters, L J

1993-01-01

In spring 1991, Belizian health officials expressed concern about a possible hepatitis outbreak in a banana farming district. A study was designed to identify cases and to address the serological prevalence of hepatitis virus markers. Three populations were studied: (i) persons meeting a clinical case definition for hepatitis; (ii) designated banana workers; and (iii) people in a random sample of households in the community. Information was collected using questionnaires and sera were collected for laboratory testing. This report presents the preliminary results of a study conducted in June 1991. Among people who met the clinical case definition, 24% of 42 tested had immunoglobulin M antibody to hepatitis B virus (HBV) core antigen (anti-HBc IgM). In the worker and household survey populations, 284 and 280 people, respectively, were tested for anti-HBc IgM. In each group, 4% were positive. HBV surface antigen was found in 37% of 43 clinical cases, 18% of workers, and 13% of people in the household survey. Among the 3 study populations, the prevalence of HBV core antibody (anti-HBc) ranged from 73% to 81%. Almost all tested persons had evidence of prior hepatitis A virus infection. Evidence of prior infection with hepatitis viruses A and B was widespread, but an aetiology could not be established for most of the clinical cases. However, the prevalence of hepatitis B markers in this population was very high compared to other reports from the Caribbean.

The use of a robust capture-recapture design in small mammal population studies: A field example with Microtus pennsylvanicus

USGS Publications Warehouse

Nichols, James D.; Pollock, Kenneth H.; Hines, James E.

1984-01-01

The robust design of Pollock (1982) was used to estimate parameters of a Maryland M. pennsylvanicus population. Closed model tests provided strong evidence of heterogeneity of capture probability, and model M eta (Otis et al., 1978) was selected as the most appropriate model for estimating population size. The Jolly-Seber model goodness-of-fit test indicated rejection of the model for this data set, and the M eta estimates of population size were all higher than the Jolly-Seber estimates. Both of these results are consistent with the evidence of heterogeneous capture probabilities. The authors thus used M eta estimates of population size, Jolly-Seber estimates of survival rate, and estimates of birth-immigration based on a combination of the population size and survival rate estimates. Advantages of the robust design estimates for certain inference procedures are discussed, and the design is recommended for future small mammal capture-recapture studies directed at estimation.

High variance in reproductive success generates a false signature of a genetic bottleneck in populations of constant size: a simulation study

PubMed Central

2013-01-01

Background Demographic bottlenecks can severely reduce the genetic variation of a population or a species. Establishing whether low genetic variation is caused by a bottleneck or a constantly low effective number of individuals is important to understand a species’ ecology and evolution, and it has implications for conservation management. Recent studies have evaluated the power of several statistical methods developed to identify bottlenecks. However, the false positive rate, i.e. the rate with which a bottleneck signal is misidentified in demographically stable populations, has received little attention. We analyse this type of error (type I) in forward computer simulations of stable populations having greater than Poisson variance in reproductive success (i.e., variance in family sizes). The assumption of Poisson variance underlies bottleneck tests, yet it is commonly violated in species with high fecundity. Results With large variance in reproductive success (Vk ≥ 40, corresponding to a ratio between effective and census size smaller than 0.1), tests based on allele frequencies, allelic sizes, and DNA sequence polymorphisms (heterozygosity excess, M-ratio, and Tajima’s D test) tend to show erroneous signals of a bottleneck. Similarly, strong evidence of population decline is erroneously detected when ancestral and current population sizes are estimated with the model based method MSVAR. Conclusions Our results suggest caution when interpreting the results of bottleneck tests in species showing high variance in reproductive success. Particularly in species with high fecundity, computer simulations are recommended to confirm the occurrence of a population bottleneck. PMID:24131797

Synthesizing Information from Language Samples and Standardized Tests in School-Age Bilingual Assessment

ERIC Educational Resources Information Center

Ebert, Kerry Danahy; Pham, Giang

2017-01-01

Purpose: Although language samples and standardized tests are regularly used in assessment, few studies provide clinical guidance on how to synthesize information from these testing tools. This study extends previous work on the relations between tests and language samples to a new population--school-age bilingual speakers with primary language…

First Definition of Reference Intervals of Liver Function Tests in China: A Large-Population-Based Multi-Center Study about Healthy Adults

PubMed Central

Zhang, Chuanbao; Guo, Wei; Huang, Hengjian; Ma, Yueyun; Zhuang, Junhua; Zhang, Jie

2013-01-01

Background Reference intervals of Liver function tests are very important for the screening, diagnosis, treatment, and monitoring of liver diseases. We aim to establish common reference intervals of liver function tests specifically for the Chinese adult population. Methods A total of 3210 individuals (20–79 years) were enrolled in six representative geographical regions in China. Analytes of ALT, AST, GGT, ALP, total protein, albumin and total bilirubin were measured using three analytical systems mainly used in China. The newly established reference intervals were based on the results of traceability or multiple systems, and then validated in 21 large hospitals located nationwide qualified by the National External Quality Assessment (EQA) of China. Results We had been established reference intervals of the seven liver function tests for the Chinese adult population and found there were apparent variances of reference values for the variables for partitioning analysis such as gender(ALT, GGT, total bilirubin), age(ALP, albumin) and region(total protein). More than 86% of the 21 laboratories passed the validation in all subgroup of reference intervals and overall about 95.3% to 98.8% of the 1220 validation results fell within the range of the new reference interval for all liver function tests. In comparison with the currently recommended reference intervals in China, the single side observed proportions of out of range of reference values from our study for most of the tests deviated significantly from the nominal 2.5% such as total bilirubin (15.2%), ALP (0.2%), albumin (0.0%). Most of reference intervals in our study were obviously different from that of other races. Conclusion These used reference intervals are no longer applicable for the current Chinese population. We have established common reference intervals of liver function tests that are defined specifically for Chinese population and can be universally used among EQA-approved laboratories located all over China. PMID:24058449

Selective Attention Deficits in High Test Anxious Children: A Failure to Replicate.

ERIC Educational Resources Information Center

Ford, Carol E.; And Others

1985-01-01

Results of a study involving 5 high test-anxious poor readers failed to replicate an earlier study reporting selective attention deficits in the population. Further, there was a marginal tendency for older poor readers to be high test-anxious. (Author/CL)

Evaluation of the ecological relevance of mysid toxicity tests using population modeling techniques

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

Kuhn-Hines, A.; Munns, W.R. Jr.; Lussier, S.

1995-12-31

A number of acute and chronic bioassay statistics are used to evaluate the toxicity and risks of chemical stressors to the mysid shrimp, Mysidopsis bahia. These include LC{sub 50}S from acute tests, NOECs from 7-day and life-cycle tests, and the US EPA Water Quality Criteria Criterion Continuous Concentrations (CCC). Because these statistics are generated from endpoints which focus upon the responses of individual organisms, their relationships to significant effects at higher levels of ecological organization are unknown. This study was conducted to evaluate the quantitative relationships between toxicity test statistics and a concentration-based statistic derived from exposure-response models describing populationmore » growth rate ({lambda}) to stressor concentration. This statistic, C{sup {sm_bullet}} (concentration where {lambda} = I, zero population growth) describes the concentration above which mysid populations are projected to decline in abundance as determined using population modeling techniques. An analysis of M. bahia responses to 9 metals and 9 organic contaminants indicated the NOEC from life-cycle tests to be the best predictor of C{sup {sm_bullet}}, although the acute LC{sub 50} predicted population-level response surprisingly well. These analyses provide useful information regarding uncertainties of extrapolation among test statistics in assessments of ecological risk.« less

Identification of heterotic loci associated with grain yield and its components using two CSSL test populations in maize

PubMed Central

Wang, Hongqiu; Zhang, Xiangge; Yang, Huili; Liu, Xiaoyang; Li, Huimin; Yuan, Liang; Li, Weihua; Fu, Zhiyuan; Tang, Jihua; Kang, Dingming

2016-01-01

Heterosis has widely been used to increase grain yield and quality. In this study, the genetic basis of heterosis on grain yield and its main components in maize were examined over 2 years in two locations in two test populations constructed from a set of 184 chromosome segment substitution lines (CSSLs) and two inbred lines (Zheng58 and Xun9058). Of the 169 heterotic loci (HL) associated with grain yield and its five components identified in CSSL × Zheng58 and CSSL × Xun9058 test populations, only 25 HL were detected in both populations. The comparison of quantitative trait loci (QTLs) detected in the CSSL population with HL detected in the two test populations revealed that only 15.46% and 17.35% of the HL in the given populations respectively, shared the same chromosomal regions as that of the corresponding QTLs and showed dominant effects as well as pleiotropism with additive and dominant effects. In addition, most of the HL (74.23% and 74.49%) had overdominant effects. These results suggest that overdominance is the main contributor to the effects of heterosis on grain yield and its components in maize, and different HL are associated with heterosis for different traits in different hybrids. PMID:27917917

Correlation of human papilloma virus with oral squamous cell carcinoma in Chinese population.

PubMed

Zhou, Jingping; Tao, Detao; Tang, Daofang; Gao, Zhenlin

2015-01-01

Previous studies indicated that oral squamous cell carcinomas (OSCC) might be related to human papilloma virus (HPV) infection. However, the relationship between OSCC in a Chinese population and oral HPV infection is still unclear. In this study, we evaluate the relationship of OSCC with HPV infection in a Chinese population via a meta-analysis. The reports on HPV and OSCC in a Chinese population published between January, 1994, and October, 2015 were retrieved via CNKI/WANFANG/pubmed databases. According to the inclusion criteria, we selected 26 eligible case-control studies. After testing the heterogeneity of the studies by the Cochran Q test, the meta-analyses for HPV and HPV16 were performed using the random effects model. Quantitative meta-analyses showed that, compared with normal oral mucosa the combined odds ratio of OSCC with HPV infection were 1.98 (95% CI: 1.34-2.92). The test for overall effect showed that the P value was less than 0.05 (Z = 3.46). Forest plot analyses were seen in Figures 2 and 3. Publication bias and bias risk analysis using RevMan 5.3 software were measured indicators of the graphics of the basic symmetry. High incidences of HPV infection were found in the samples of Chinese OSCC. For the Chinese population, HPV infection elevates the risk of OSCC tumorigenesis.

Eliciting population preferences for mass colorectal cancer screening organization.

PubMed

Nayaradou, Maximilien; Berchi, Célia; Dejardin, Olivier; Launoy, Guy

2010-01-01

The implementation of mass colorectal cancer (CRC) screening is a public health priority. Population participation is fundamental for the success of CRC screening as for any cancer screening program. The preferences of the population may influence their likelihood of participation. The authors sought to elicit population preferences for CRC screening test characteristics to improve the design of CRC screening campaigns. A discrete choice experiment was used. Questionnaires were compiled with a set of pairs of hypothetical CRC screening scenarios. The survey was conducted by mail from June 2006 to October 2006 on a representative sample of 2000 inhabitants, aged 50 to 74 years from the northwest of France, who were randomly selected from electoral lists. Questionnaires were sent to 2000 individuals, each of whom made 3 or 4 discrete choices between hypothetical tests that differed in 7 attributes: how screening is offered, process, sensitivity, rate of unnecessary colonoscopy, expected mortality reduction, method of screening test result transmission, and cost. Complete responses were received from 656 individuals (32.8%). The attributes that influenced population preferences included expected mortality reduction, sensitivity, cost, and process. Participants from high social classes were particularly influenced by sensitivity. The results demonstrate that the discrete choice experiment provides information on patient preferences for CRC screening: improving screening program effectiveness, for instance, by improving test sensitivity (the most valued attribute) would increase satisfaction among the general population with regard to CRC screening programs. Additional studies are required to study how patient preferences actually affect adherence to regular screening programs.

Moderate wine consumption is associated with better cognitive test results: a 7 year follow up of 5033 subjects in the Tromsø Study.

PubMed

Arntzen, K A; Schirmer, H; Wilsgaard, T; Mathiesen, E B

2010-01-01

The impact of moderate alcohol consumption on cognitive function and dementia is unclear. We examined the relationship between consumption of different alcoholic beverages and cognitive function in a large population-based study. Subjects were 5033 stroke-free men and women who participated in a longitudinal population-based study in Tromsø, Norway. Alcohol consumption and other cardiovascular risk factors were measured at baseline and cognitive function was assessed after 7 years follow up with verbal memory test, digit-symbol coding test and tapping test. Moderate wine consumption was independently associated with better performance on all cognitive tests in both men and women. There was no consistent association between consumption of beer and spirits and cognitive test results. Alcohol abstention was associated with lower cognitive performance in women. Light-to-moderate wine consumption was associated with better performance on cognitive tests after 7 years follow up.

A Randomized Study of Incentivizing HIV Testing for Parolees in Community Aftercare.

PubMed

Saxena, Preeta; Hall, Elizabeth A; Prendergast, Michael

2016-04-01

HIV risk-behaviors are high in criminal justice populations and more efforts are necessary to address them among criminal justice-involved substance abusers. This study examines the role of incentives in promoting HIV testing among parolees. Participants were randomly assigned to either an incentive (n = 104) or education group (control; n = 98), where the incentive group received a voucher for testing for HIV. Bivariate comparisons showed that a larger proportion of those in the incentive group received HIV testing (59% versus 47%), but this was not statistically significant (p = .09). However, in a multivariate logistic regression model controlling for covariates likely to influence HIV-testing behavior, those in the incentive group had increased odds of HIV testing in comparison to those in the education group (OR = 1.99, p < .05, CI [1.05, 3.78]). As a first of its kind, this study provides a foundation for further research on the utility of incentives in promoting HIV testing and other healthy behaviors in criminal justice populations.

On sample size of the kruskal-wallis test with application to a mouse peritoneal cavity study.

PubMed

Fan, Chunpeng; Zhang, Donghui; Zhang, Cun-Hui

2011-03-01

As the nonparametric generalization of the one-way analysis of variance model, the Kruskal-Wallis test applies when the goal is to test the difference between multiple samples and the underlying population distributions are nonnormal or unknown. Although the Kruskal-Wallis test has been widely used for data analysis, power and sample size methods for this test have been investigated to a much lesser extent. This article proposes new power and sample size calculation methods for the Kruskal-Wallis test based on the pilot study in either a completely nonparametric model or a semiparametric location model. No assumption is made on the shape of the underlying population distributions. Simulation results show that, in terms of sample size calculation for the Kruskal-Wallis test, the proposed methods are more reliable and preferable to some more traditional methods. A mouse peritoneal cavity study is used to demonstrate the application of the methods. © 2010, The International Biometric Society.

Evidence of selection as a cause for racial disparities in fibroproliferative disease

PubMed Central

Velez Edwards, Digna R.

2017-01-01

Fibroproliferative diseases are common complex traits featuring scarring and overgrowth of connective tissue which vary widely in presentation because they affect many organ systems. Most fibroproliferative diseases are more prevalent in African-derived populations than in European populations, leading to pronounced health disparities. It is hypothesized that the increased prevalence of these diseases in African-derived populations is due to selection for pro-fibrotic alleles that are protective against helminth infections. We constructed a genetic risk score (GRS) of fibroproliferative disease risk-increasing alleles using 147 linkage disequilibrium-pruned variants identified through genome-wide association studies of seven fibroproliferative diseases with large African-European prevalence disparities. A comparison of the fibroproliferative disease GRS between 1000 Genomes Phase 3 populations detected a higher mean GRS in AFR (mean = 148 risk alleles) than EUR (mean = 136 risk alleles; T-test p-value = 1.75x10-123). To test whether differences in GRS burden are systematic and may be due to selection, we employed the quantitative trait loci (QTL) sign test. The QTL sign test result indicates that population differences in risk-increasing allele burdens at these fibroproliferative disease variants are systematic and support a model featuring selective pressure (p-value = 0.011). These observations were replicated in an independent sample and were more statistically significant (T-test p-value = 7.26x10-237, sign test p-value = 0.015). This evidence supports the role of selective pressure acting to increase frequency of fibroproliferative alleles in populations of African relative to European ancestry populations. PMID:28792542

Population size predicts technological complexity in Oceania

PubMed Central

Kline, Michelle A.; Boyd, Robert

2010-01-01

Much human adaptation depends on the gradual accumulation of culturally transmitted knowledge and technology. Recent models of this process predict that large, well-connected populations will have more diverse and complex tool kits than small, isolated populations. While several examples of the loss of technology in small populations are consistent with this prediction, it found no support in two systematic quantitative tests. Both studies were based on data from continental populations in which contact rates were not available, and therefore these studies do not provide a test of the models. Here, we show that in Oceania, around the time of early European contact, islands with small populations had less complicated marine foraging technology. This finding suggests that explanations of existing cultural variation based on optimality models alone are incomplete because demography plays an important role in generating cumulative cultural adaptation. It also indicates that hominin populations with similar cognitive abilities may leave very different archaeological records, a conclusion that has important implications for our understanding of the origin of anatomically modern humans and their evolved psychology. PMID:20392733

Crossability and relationships of Pinus muricata (Pinaceae)

Treesearch

Constance I. Millar; William B. Critchfield

1988-01-01

Crossing relationships were studies within and among the variable populations of Pinus muricata to test hypotheses about crossing barriers among certain populations. Crossability was assessed at the level of viable seed production following planned crosses. Populations north of Sea Ranch, Sonoma Co., California, crossed freely with parapatric but...

Acceptability of testing for anorectal sexually transmitted infections and self-collected anal swabs in female sex workers, men who have sex with men and transgender women in Papua New Guinea.

PubMed

Bell, Stephen; Wapling, Johanna; Ase, Sophie; Boli-Neo, Ruthy; Vallely, Andrew J; Kaldor, John M; Nightingale, Claire E; Kelly-Hanku, Angela

2018-06-20

Papua New Guinea (PNG) has some of the highest prevalence of urogenital sexually transmitted infections (STIs) in Pacific Asia, but to date, anorectal STI prevalence data do not exist, and diagnosis of anorectal STIs does not occur. The purpose of this study was to document the acceptability of anorectal STI testing and self-collection of anorectal swabs for testing among populations at risk of anorectal STIs, in advance of a large bio-behavioural survey during which this approach to specimen collection was planned among key populations in PNG. Four focus groups were conducted, collecting data from a purposive sample of 35 members of two civil society groups representing female sex workers, men who have sex with men and transgender women in Port Moresby and Goroka. All participants were in favour of anorectal STI testing in PNG. Reasons given for willingness to undertake anorectal STI testing included that anal sex is practised; that anorectal STIs are not perceived to exist; there are self-reported experiences of anorectal symptoms indicative of anorectal STIs; that anorectal STI testing will enhance personal health; and that anorectal STI testing is not currently available in PNG. All participants were confident they could obtain self-collected specimens, although several stated that support from trained health workers should be available for community members who may not feel comfortable with self-collection. This qualitative research is the first study of acceptability of anorectal STI testing and specimen self-collection procedures in PNG, and Pacific Asia more broadly. Our qualitative findings show support for anorectal STI testing including the use of self-collected swabs among key populations in PNG. Study findings informed the inclusion of anorectal STI testing in a large bio-behavioural survey to be used to estimate anorectal STI prevalence among key populations in PNG for the first time.

Clinical utility of genetic testing in pediatric drug-resistant epilepsy: a pilot study.

PubMed

Ream, Margie A; Mikati, Mohamad A

2014-08-01

The utility of genetic testing in pediatric drug-resistant epilepsy (PDRE), its yield in "real life" clinical practice, and the practical implications of such testing are yet to be determined. To start to address the above gaps in our knowledge as they apply to a patient population seen in a tertiary care center. We retrospectively reviewed our experience with the use of clinically available genetic tests in the diagnosis and management of PDRE in one clinic over one year. Genetic testing included, depending on clinical judgment, one or more of the following: karyotype, chromosomal microarray, single gene sequencing, gene sequencing panels, and/or whole exome sequencing (WES). We were more likely to perform genetic testing in patients with developmental delay, epileptic encephalopathy, and generalized epilepsy. In our unique population, the yield of specific genetic diagnosis was relatively high: karyotype 14.3%, microarray 16.7%, targeted single gene sequencing 15.4%, gene panels 46.2%, and WES 16.7%. Overall yield of diagnosis from at least one of the above tests was 34.5%. Disease-causing mutations that were not clinically suspected based on the patients' phenotypes and representing novel phenotypes were found in 6.9% (2/29), with an additional 17.2% (5/29) demonstrating pharmacologic variants. Three patients were incidentally found to be carriers of recessive neurologic diseases (10.3%). Variants of unknown significance (VUSs) were identified in 34.5% (10/29). We conclude that genetic testing had at least some utility in our patient population of PDRE, that future similar larger studies in various populations are warranted, and that clinics offering such tests must be prepared to address the complicated questions raised by the results of such testing. Copyright © 2014. Published by Elsevier Inc.

Expanding HIV testing efforts in concentrated epidemic settings: a population-based survey from rural Vietnam.

PubMed

Pharris, Anastasia; Nguyen, Thi Kim Chuc; Tishelman, Carol; Brugha, Ruairí; Nguyen, Phuong Hoa; Thorson, Anna

2011-01-11

To improve HIV prevention and care programs, it is important to understand the uptake of HIV testing and to identify population segments in need of increased HIV testing. This is particularly crucial in countries with concentrated HIV epidemics, where HIV prevalence continues to rise in the general population. This study analyzes determinants of HIV testing in a rural Vietnamese population in order to identify potential access barriers and areas for promoting HIV testing services. A population-based cross-sectional survey of 1874 randomly sampled adults was linked to pregnancy, migration and economic cohort data from a demographic surveillance site (DSS). Multivariate logistic regression analysis was used to determine which factors were associated with having tested for HIV. The age-adjusted prevalence of ever-testing for HIV was 7.6%; however 79% of those who reported feeling at-risk of contracting HIV had never tested. In multivariate analysis, younger age (aOR 1.85, 95% CI 1.14-3.01), higher economic status (aOR 3.4, 95% CI 2.21-5.22), and semi-urban residence (aOR 2.37, 95% CI 1.53-3.66) were associated with having been tested for HIV. HIV testing rates did not differ between women of reproductive age who had recently been pregnant and those who had not. We found low testing uptake (6%) among pregnant women despite an existing prevention of mother-to-child HIV testing policy, and lower-than-expected testing among persons who felt that they were at-risk of HIV. Poverty and residence in a more geographically remote location were associated with less HIV testing. In addition to current HIV testing strategies focusing on high-risk groups, we recommend targeting HIV testing in concentrated HIV epidemic settings to focus on a scaled-up provision of antenatal testing. Additional recommendations include removing financial and geographic access barriers to client-initiated testing, and encouraging provider-initiated testing of those who believe that they are at-risk of HIV.

Systematic review of mobile health behavioural interventions to improve uptake of HIV testing for vulnerable and key populations.

PubMed

Conserve, Donaldson F; Jennings, Larissa; Aguiar, Carolina; Shin, Grace; Handler, Lara; Maman, Suzanne

2017-02-01

Introduction This systematic narrative review examined the empirical evidence on the effectiveness of mobile health (mHealth) behavioural interventions designed to increase the uptake of HIV testing among vulnerable and key populations. Methods MEDLINE/PubMed, Embase, Web of Science, and Global Health electronic databases were searched. Studies were eligible for inclusion if they were published between 2005 and 2015, evaluated an mHealth intervention, and reported an outcome relating to HIV testing. We also reviewed the bibliographies of retrieved studies for other relevant citations. The methodological rigor of selected articles was assessed, and narrative analyses were used to synthesize findings from mixed methodologies. Results A total of seven articles met the inclusion criteria. Most mHealth interventions employed a text-messaging feature and were conducted in middle- and high-income countries. The methodological rigor was moderate among studies. The current literature suggests that mHealth interventions can have significant positive effects on HIV testing initiation among vulnerable and key populations, as well as the general public. In some cases, null results were observed. Qualitative themes relating to the use of mobile technologies to increase HIV testing included the benefits of having low-cost, confidential, and motivational communication. Reported barriers included cellular network restrictions, poor linkages with physical testing services, and limited knowledge of appropriate text-messaging dose. Discussion MHealth interventions may prove beneficial in reducing the proportion of undiagnosed persons living with HIV, particularly among vulnerable and key populations. However, more rigorous and tailored interventions are needed to assess the effectiveness of widespread use.

Systematic review of mobile-health behavioral interventions to improve uptake of HIV testing for vulnerable and key populations

PubMed Central

Conserve, Donaldson F.; Jennings, Larissa; Aguiar, Carolina; Shin, Grace; Handler, Lara; Maman, Suzanne

2016-01-01

Objective This systematic narrative review examined the empirical evidence on the effectiveness of mobile health (mHealth) behavioral interventions designed to increase uptake of HIV testing among vulnerable and key populations. Methods MEDLINE/PubMed, Embase, Web of Science, and Global Health electronic databases were searched. Studies were eligible for inclusion if they were published between 2005 and 2015, evaluated an mHealth intervention, and reported an outcome relating to HIV testing. We also reviewed the bibliographies of retrieved studies for other relevant citations. The methodological rigor of selected articles was assessed, and narrative analyses were used to synthesize findings from mixed methodologies. Results A total of seven articles met the inclusion criteria. Most mHealth interventions employed a text-messaging feature and were conducted in middle- and high-income countries. The methodological rigor was moderate among studies. The current literature suggests that mHealth interventions can have significant positive effects on HIV testing initiation among vulnerable and key populations, as well as the general public. In some cases, null results were observed. Qualitative themes relating to use of mobile technologies to increase HIV testing included the benefits of having low-cost, confidential, and motivational communication. Reported barriers included cellular network restrictions, poor linkages with physical testing services, and limited knowledge of appropriate text-messaging dose. Conclusions MHealth interventions may prove beneficial in reducing the proportion of undiagnosed persons living with HIV, particularly among vulnerable and key populations. However, more rigorous and tailored intervention trials are needed to assess the effectiveness of widespread use. PMID:27056905

Development and validation of the Perceived Food Environment Questionnaire in a French-Canadian population.

PubMed

Carbonneau, Elise; Robitaille, Julie; Lamarche, Benoît; Corneau, Louise; Lemieux, Simone

2017-08-01

The present study aimed to develop and validate a questionnaire assessing perceived food environment in a French-Canadian population. A questionnaire, the Perceived Food Environment Questionnaire, was developed assessing perceived accessibility to healthy (nine items) and unhealthy foods (three items). A pre-test sample was recruited for a pilot testing of the questionnaire. For the validation study, another sample was recruited and completed the questionnaire twice. Exploratory factor analysis was performed on the items to assess the number of factors (subscales). Cronbach's α was used to measure internal consistency reliability. Test-retest reliability was assessed with Pearson correlations. Online survey. Men and women from the Québec City area (n 31 in the pre-test sample; n 150 in the validation study sample). The pilot testing did not lead to any change in the questionnaire. The exploratory factor analysis revealed a two-subscale structure. The first subscale is composed of six items assessing accessibility to healthy foods and the second includes three items related to accessibility to unhealthy foods. Three items were removed from the questionnaire due to low loading on the two subscales. The subscales demonstrated adequate internal consistency (Cronbach's α=0·77 for healthy foods and 0·62 for unhealthy foods) and test-retest reliability (r=0·59 and 0·60, respectively; both P<0·0001). The Perceived Food Environment Questionnaire was developed for a French-Canadian population and demonstrated good psychometric properties. Further validation is recommended if the questionnaire is to be used in other populations.

Latent tuberculosis infections in hard-to-reach drug using population-detection, prevention and control.

PubMed

Hwang, Lu-Yu; Grimes, Carolyn Z; Beasley, R Palmer; Graviss, Edward A

2009-12-01

Interferon-gamma release assays (IGRAs) need be evaluated for effectiveness as screening tests for tuberculosis (TB) infection in drug users. These tests have demonstrated improved sensitivity and specificity, but have not been studied in drug users. These one step blood tests are intended to replace the tuberculin skin test (TST), which is difficult to use and requires 48 hour follow-up, so they are expected to be particularly suitable for risk groups, like drug users, in whom follow-up is problematic. Drug users have traditionally been identified as being at increased risk for acquiring TB disease. The results of our pilot study using the TST and simpler and more sensitive interferon-gamma release assays showed that about 45% of current drug users in Houston tested have at least one test positive for latent tuberculosis infection (LTBI). These preliminary data suggest that there is an important reservoir of LTBI in drug using populations, and the risk of progression to active TB disease with other infections is great. However, LTBI in drug using populations has not been studied in depth and deserves further investigation. We need to evaluate the validity of IGRAs for detection of latent TB infection, the factors associated with LTBI, the incidence and risk for developing active TB disease in drug users and the effectiveness of early treatment of LTBI. We believe that using better tuberculosis screening tools will allow us to more accurately measure the prevalence of latent TB infection and incidence of active TB disease in drug using populations and develop more effective TB prevention and treatment interventions in the community.

Set-up and pilot of a population cohort for the study of the natural history of COPD and OSA: the PULSAIB study.

PubMed

Soriano, Joan B; Yáñez, Aina; Renom, Feliu; de la Peña, Mónica; Gómez, Amalia; Duro, Rosa; Uréndez, Ana; Román, Miguel

2010-06-01

We describe the set-up of a population-based study focussed on respiratory conditions, and describe a pilot study - the PULmons SAns Illes Balears (PULSAIB) study - aimed at investigating the natural history of COPD, obstructive sleep apnoea (OSA), and other common chronic diseases. A cross-sectional study was designed to survey two fieldwork areas, one rural and one urban, in the Balearic Islands, Spain. Tests conducted included a questionnaire, spirometry with post-bronchodilator (PBD) test, and portable respiratory polygraphy. We assessed all processes and tools to be used, and piloted them in 175 participants from Bunyola (rural) and 130 participants from the Son Pizà area (urban). Within this first cross-sectional assessment of the Balearic population aged 30 to 80 years, we report the prevalence of airflow limitation defined as a PBD FEV1/FVC ratio <0.7 and the prevalence of OSA defined as an apnoea-hypopnoea index (AHI) >10/hour. A cohort study in the Balearic population to investigate the natural history of COPD and OSA is feasible.

The Impact of Sampling Approach on Population Invariance in Automated Scoring of Essays. Research Report. ETS RR-13-18

ERIC Educational Resources Information Center

Zhang, Mo

2013-01-01

Many testing programs use automated scoring to grade essays. One issue in automated essay scoring that has not been examined adequately is population invariance and its causes. The primary purpose of this study was to investigate the impact of sampling in model calibration on population invariance of automated scores. This study analyzed scores…

Control for Population Structure and Relatedness for Binary Traits in Genetic Association Studies via Logistic Mixed Models

PubMed Central

Chen, Han; Wang, Chaolong; Conomos, Matthew P.; Stilp, Adrienne M.; Li, Zilin; Sofer, Tamar; Szpiro, Adam A.; Chen, Wei; Brehm, John M.; Celedón, Juan C.; Redline, Susan; Papanicolaou, George J.; Thornton, Timothy A.; Laurie, Cathy C.; Rice, Kenneth; Lin, Xihong

2016-01-01

Linear mixed models (LMMs) are widely used in genome-wide association studies (GWASs) to account for population structure and relatedness, for both continuous and binary traits. Motivated by the failure of LMMs to control type I errors in a GWAS of asthma, a binary trait, we show that LMMs are generally inappropriate for analyzing binary traits when population stratification leads to violation of the LMM’s constant-residual variance assumption. To overcome this problem, we develop a computationally efficient logistic mixed model approach for genome-wide analysis of binary traits, the generalized linear mixed model association test (GMMAT). This approach fits a logistic mixed model once per GWAS and performs score tests under the null hypothesis of no association between a binary trait and individual genetic variants. We show in simulation studies and real data analysis that GMMAT effectively controls for population structure and relatedness when analyzing binary traits in a wide variety of study designs. PMID:27018471

Breast, prostate, and thyroid cancer screening tests and overdiagnosis.

PubMed

Jung, Minsoo

The purpose of this study was to examine overdiagnosis and overtreatment related to cancer screening and to review relevant reports and studies. A comprehensive search of peer-reviewed and gray literature was conducted for relevant studies published between January 2000 and December 2015 reporting breast, prostate, and thyroid cancer screening tests and overdiagnosis. This study revealed no dichotomy on where screening would lower risk or cause overdiagnosis and overtreatment. Many screening tests did both, that is, at population level, there were both benefit (decreased disease-specific mortality) and harm (overdiagnosis and overtreatment). Therefore, we need to consider a balanced argument with citations for the potential benefits of screening along with the harms associated with screening. Although the benefits and harms can only be tested through randomized trials, important data from cohort studies, diagnostic accuracy studies, and modeling work can help define the extent of benefits and harms in the population. The health care cycle that prompt patients to undergo periodic screening tests is self-reinforcing. In most developed countries, screening test recommendations encourage periodic testing. Therefore, patients are continuing their screening. It is necessary for patients to become wise consumers of screening tests and make decisions with their physicians regarding further testing and treatments. Copyright © 2017 Elsevier Inc. All rights reserved.

Identifying signatures of positive selection in pigmentation genes in two South Asian populations.

PubMed

Jonnalagadda, Manjari; Bharti, Neeraj; Patil, Yatish; Ozarkar, Shantanu; K, Sunitha Manjari; Joshi, Rajendra; Norton, Heather

2017-09-10

Skin pigmentation is a polygenic trait showing wide phenotypic variations among global populations. While numerous pigmentation genes have been identified to be under positive selection among European and East populations, genes contributing to phenotypic variation in skin pigmentation within and among South Asian populations are still poorly understood. The present study uses data from the Phase 3 of the 1000 genomes project focusing on two South Asian populations-GIH (Gujarati Indian from Houston, Texas) and ITU (Indian Telugu from UK), so as to decode the genetic architecture involved in adaptation to ultraviolet radiation in South Asian populations. Statistical tests included were (1) tests to identify deviations of the Site Frequency Spectrum (SFS) from neutral expectations (Tajima's D, Fay and Wu's H and Fu and Li's D* and F*), (2) tests focused on the identification of high-frequency haplotypes with extended linkage disequilibrium (iHS and Rsb), and (3) tests based on genetic differentiation between populations (LSBL). Twenty-two pigmentation genes fall in the top 1% for at least one statistic in the GIH population, 5 of which (LYST, OCA2, SLC24A5, SLC45A2, and TYR) have been previously associated with normal variation in skin, hair, or eye color. In comparison, 17 genes fall in the top 1% for at least one statistic in the ITU population. Twelve loci which are identified as outliers in the ITU scan were also identified in the GIH population. These results suggest that selection may have affected these loci broadly across the region. © 2017 Wiley Periodicals, Inc.

Effect of antibiotic pretreatment on survival, mutability, and electrophoretic spectrum of soluble proteins in a gamma-irradiated chlorella population

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

Ovsyannikova, M.N.; Osetrova, A.Ya.

1977-01-01

A study was made of the protective action of several antibiotics in a ..gamma..-irradiated chlorella population. It was shown that not all of the antibiotics tested had a protective effect with regard to survival. At the same time, all of the tested antibiotics, with the exception of nistatin, diminished the effectiveness of subsequent ..gamma..-irradiation with respect to induction of mutations. It is assumed that electrophoresis of readily soluble proteins can be used for biochemical identification of mutations in the population.

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.

[Alusti test: New scale for assessment of physical performance in the geriatric population].

PubMed

Calvo Aguirrey, Juan José; Alustiza Navarro, Josu; Uranga Zaldúa, Joana; Sarasqueta Eizaguirre, Cristina; Bueno Yáñez, Olga

2018-06-11

Physical and psychological functional conditions are key factors in the elderly population. Many evaluation tools are available, but they cannot be applied to the whole geriatric population. The use Alusti Test is presented. This test consists of 2versions, which enable it to encompass this wide and complex population spectrum. A prospective study with the institutionalised, hospitalised, and community population, was conducted between September and December 2016. A comparative analysis was conducted using the Barthel Index (BI), Gait Speed Test (GST), Timed «Up & Go» Test (TUG), Short Physical Performance Battery (SPPB), and Tinetti Test. A total of 363 subjects were enrolled (mean age: 83.25 years), with varying levels of functional and cognitive conditions. The test was simple and quick to apply (3-6min), 100% applicable and usable with broad floor and ceiling effects (0-100 points) with an intraclass correlation coefficient (ICC) that shows a high inter-observer reliability (ICC = 0.99), and a good correlation in its full version with BI (ICC = 0.86) (95% CI: 0.82-0.88), and the Tinetti test (ICC = 0.76; 95% CI: 0.71-0.81), as well as in the abbreviated version BI (ICC = 0.71; 95% CI: 0.65-0.75) and Tinetti Test (ICC = 0.90; 95% CI: 0.88-0.92). This allows the variation of the functional condition to be measured, which in our sample showed an increase of 10.9%, after a period of hospital admission. It is considered that Alusti test meets the requirements for physical performance assessment in the whole the geriatric population. The highest level of accuracy is given by the Tinetti test, which has greater applicability. Copyright © 2018 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

Implementing an Internet-Delivered Skin Cancer Genetic Testing Intervention to Improve Sun Protection Behavior in a Diverse Population: Protocol for a Randomized Controlled Trial

PubMed Central

Zielaskowski, Kate; White, Kirsten AM; Rodríguez, Vivian M; Robers, Erika; Guest, Dolores D; Sussman, Andrew; Talamantes, Yvonne; Schwartz, Matthew R; Greb, Jennie; Bigney, Jessica; Kaphingst, Kimberly A; Hunley, Keith; Buller, David B

2017-01-01

Background Limited translational genomic research currently exists to guide the availability, comprehension, and appropriate use of personalized genomics in diverse general population subgroups. Melanoma skin cancers are preventable, curable, common in the general population, and disproportionately increasing in Hispanics. Objective Variants in the melanocortin-1 receptor (MC1R) gene are present in approximately 50% of the population, are major factors in determining sun sensitivity, and confer a 2-to-3-fold increase in melanoma risk in the general population, even in populations with darker skin. Therefore, feedback regarding MC1R risk status may raise risk awareness and protective behavior in the general population. Methods We are conducting a randomized controlled trial examining Internet presentation of the risks and benefits of personalized genomic testing for MC1R gene variants that are associated with increased melanoma risk. We will enroll a total of 885 participants (462 participants are currently enrolled), who will be randomized 6:1 to personalized genomic testing for melanoma risk versus waiting list control. Control participants will be offered testing after outcome assessments. Participants will be balanced across self-reported Hispanic versus non-Hispanic ethnicity (n=750 in personalized genomic testing for melanoma risk arm; n=135 in control arm), and will be recruited from a general population cohort in Albuquerque, New Mexico, which is subject to year-round sun exposure. Baseline surveys will be completed in-person with study staff and follow-up measures will be completed via telephone. Results Aim 1 of the trial will examine the personal utility of personalized genomic testing for melanoma risk in terms of short-term (3-month) sun protection and skin screening behaviors, family and physician communication, and melanoma threat and control beliefs (ie, putative mediators of behavior change). We will also examine potential unintended consequences of testing among those who receive average-risk personalized genomic testing for melanoma risk findings, and examine predictors of sun protection at 3 months as the outcome. These findings will be used to develop messages for groups that receive average-risk feedback. Aim 2 will compare rates of test consideration in Hispanics versus non-Hispanics, including consideration of testing pros and cons and registration of a decision to either accept or decline testing. Aim 3 will examine personalized genomic testing for melanoma risk feedback comprehension, recall, satisfaction, and cancer-related distress in those who undergo testing, and whether these outcomes differ by ethnicity (Hispanic vs non-Hispanic), or sociocultural or demographic factors. Final outcome data collection is anticipated to be complete by October 2017, at which point data analysis will commence. Conclusions This study has important implications for personalized genomics in the context of melanoma risk, and may be broadly applicable as a model for delivery of personalized genomic feedback for other health conditions. PMID:28442450

Private-well stewardship among a general population based sample of private well-owners.

PubMed

Malecki, Kristen M C; Schultz, Amy A; Severtson, Dolores J; Anderson, Henry A; VanDerslice, James A

2017-12-01

Private well stewardship, including on-going testing and treatment, can ensure private well users are able to maintain source-water quality and prevent exposures to potentially harmful constituents in primary drinking water supplies. Unlike municipal water supplies, private well users are largely responsible for their own testing and treatment and well stewardship is often minimal. The importance of factors influencing regular testing, and treatment behaviors, including knowledge, risk perception, convenience and social norms, can vary by geography and population characteristics. The primary goals of this study were to survey a general statewide population of private well users in Wisconsin in order to quantify testing and treatment patterns and gather data on motivations and barriers to well stewardship. The majority of respondents reported using and drinking well water daily but only about one half of respondents reported testing their wells in the last ten years and of these, only 10% reported testing in the last 12months. Bacteria and nitrates were contaminants most often tested; and, a private laboratory most often conducted testing. The most commonly reported water treatment was a water softener. Living in a particular geographic region and income were the most significant predictors of water testing and treatment. Iron and hardness, which influence water aesthetics but not always safety, were the most commonly reported water quality problems. Health concerns or perceived lack thereof were, respectively, motivators and barriers to testing and treatment. Limited knowledge of testing and treatment options were also identified as barriers. Results confirm previous findings that well stewardship practices are minimal and often context specific. Understanding the target population's perceptions of risk and knowledge are important elements to consider in identifying vulnerable populations and developing education and policy efforts to improve well stewardship. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparability of Computer- and Paper-Administered Multiple-Choice Tests for K-12 Populations: A Synthesis

ERIC Educational Resources Information Center

Kingston, Neal M.

2009-01-01

There have been many studies of the comparability of computer-administered and paper-administered tests. Not surprisingly (given the variety of measurement and statistical sampling issues that can affect any one study) the results of such studies have not always been consistent. Moreover, the quality of computer-based test administration systems…

Eliminating Plasmodium falciparum in Hainan, China: a study on the use of behavioural change communication intervention to promote malaria prevention in mountain worker populations.

PubMed

He, Chang-hua; Hu, Xi-min; Wang, Guang-ze; Zhao, Wei; Sun, Ding-wei; Li, Yu-chun; Chen, Chun-xiang; Du, Jian-wei; Wang, Shan-qing

2014-07-13

In the island of Hainan, the great majority of malaria cases occur in mountain worker populations. Using the behavioral change communication (BCC) strategy, an interventional study was conducted to promote mountain worker malaria prevention at a test site. This study found the methods and measures that are suitable for malaria prevention among mountain worker populations. During the Plasmodium falciparum elimination stage in Hainan, a representative sampling method was used to establish testing and control sites in areas of Hainan that were both affected by malaria and had a relatively high density of mountain workers. Two different methods were used: a BCC strategy and a conventional strategy as a control. Before and after the intervention, house visits, core group discussions, and structural surveys were utilized to collect qualitative and quantitative data regarding mountain worker populations (including knowledge, attitudes, and practices [KAPs]; infection status; and serological data), and these data from the testing and control areas were compared to evaluate the effectiveness of BCC strategies in the prevention of malaria. In the BCC malaria prevention strategy testing areas, the accuracy rates of malaria-related KAP were significantly improved among mountain worker populations. The accuracy rates in the 3 aspects of malaria-related KAP increased from 37.73%, 37.00%, and 43.04% to 89.01%, 91.53%, and 92.25%, respectively. The changes in all 3 aspects of KAP were statistically significant (p < 0.01). In the control sites, the changes in the indices were not as marked as in the testing areas, and the change was not statistically significant (p > 0.05). Furthermore, in the testing areas, both the percentage testing positive in the serum malaria indirect fluorescent antibody test (IFAT) and the number of people inflicted decreased more significantly than in the control sites (p < 0.01). The use of the BCC strategy significantly improved the ability of mountain workers in Hainan to avoid malarial infection. Educational and promotional materials and measures were developed and selected in the process, and hands-on experience was gained that will help achieve the goal of total malaria elimination in Hainan.

On the performance of tests for the detection of signatures of selection: a case study with the Spanish autochthonous beef cattle populations.

PubMed

González-Rodríguez, Aldemar; Munilla, Sebastián; Mouresan, Elena F; Cañas-Álvarez, Jhon J; Díaz, Clara; Piedrafita, Jesús; Altarriba, Juan; Baro, Jesús Á; Molina, Antonio; Varona, Luis

2016-10-28

Procedures for the detection of signatures of selection can be classified according to the source of information they use to reject the null hypothesis of absence of selection. Three main groups of tests can be identified that are based on: (1) the analysis of the site frequency spectrum, (2) the study of the extension of the linkage disequilibrium across the length of the haplotypes that surround the polymorphism, and (3) the differentiation among populations. The aim of this study was to compare the performance of a subset of these procedures by using a dataset on seven Spanish autochthonous beef cattle populations. Analysis of the correlations between the logarithms of the statistics that were obtained by 11 tests for detecting signatures of selection at each single nucleotide polymorphism confirmed that they can be clustered into the three main groups mentioned above. A factor analysis summarized the results of the 11 tests into three canonical axes that were each associated with one of the three groups. Moreover, the signatures of selection identified with the first and second groups of tests were shared across populations, whereas those with the third group were more breed-specific. Nevertheless, an enrichment analysis identified the metabolic pathways that were associated with each group; they coincided with canonical axes and were related to immune response, muscle development, protein biosynthesis, skin and pigmentation, glucose metabolism, fat metabolism, embryogenesis and morphology, heart and uterine metabolism, regulation of the hypothalamic-pituitary-thyroid axis, hormonal, cellular cycle, cell signaling and extracellular receptors. We show that the results of the procedures used to identify signals of selection differed substantially between the three groups of tests. However, they can be classified using a factor analysis. Moreover, each canonical factor that coincided with a group of tests identified different signals of selection, which could be attributed to processes of selection that occurred at different evolutionary times. Nevertheless, the metabolic pathways that were associated with each group of tests were similar, which suggests that the selection events that occurred during the evolutionary history of the populations probably affected the same group of traits.

Low literacy self-care management patient education for a multi-lingual heart failure population: Results of a pilot study.

PubMed

Dickson, Victoria Vaughan; Chyun, Deborah; Caridi, Cristina; Gregory, Jill K; Katz, Stuart

2016-02-01

The purpose of this pilot study was to test the impact of language-free, low literacy self-care management patient education materials in an ethnically diverse multilingual heart failure (HF) population. A one group pre-test-post-test design measured changes in self-care, knowledge and health-related quality of life (HRQL) after a 1 month intervention using language-free, low literacy self-care management patient education materials and delivered by a health educator. The ethnically diverse sample (n=21) was predominately male (72%), 48% Black, 42% Hispanic, and 28% marginal/inadequate literacy. There were significant improvements in self-care and knowledge but not HRQL. Language-free, low literacy self-care patient education may facilitate improved self-care and knowledge in diverse populations who are at risk for poor HF outcomes. Copyright © 2015 Elsevier Inc. All rights reserved.

Landscape-level effects of forest management on bird species in the Ozarks of southeastern Missouri

Treesearch

Richard L. Clawson; John Faaborg; Wendy K. Gram; Paul A. Porneluzi

2002-01-01

This study was designed as an experiment to test how bird populations in an extensively forested landscape respond to small (group and single-tree selection) and large (clearcut) openings. Our objectives are to test the landscape-level effects of even-aged and uneven-aged forest management relative to no-harvest management on population density and reproductive success...

A genetic study of the ghrelin and growth hormone secretagogue receptor (GHSR) genes and stature.

PubMed

Gueorguiev, M; Lecoeur, C; Benzinou, M; Mein, C A; Meyre, D; Vatin, V; Weill, J; Heude, B; Grossman, A B; Froguel, P; Korbonits, M

2009-01-01

Growth and nutrition are interrelated and influenced by multiple genetic and environmental factors. We studied whether common variants in ghrelin and ghrelin receptor (GHSR) genes could play a role in stature variation in the general population and in families ascertained for obesity. Selected tagging SNPs in the ghrelin and GHSR genes were genotyped in 263 Caucasian families recruited for childhood obesity (1,275 subjects), and in 287 families from a general population (1,072 subjects). We performed familial testing for associations in the entire population and in a sub-set of the samples selected for a case-control study. In the case-control study for height (cases were selected from the obese cohort with mean ZH = 3.17 +/- 0.15 confidence interval (CI) versus controls with mean ZH 0.14 +/- 0.09), we found an association with a 2 base-pair intronic deletion in the GHSR gene (rs10618418) (p = 0.006, odds ratio (OR) 1.86, 95% CI [1.26;2.74] under additive model), although when adjusting for BMI, the association disappeared (p = 0.06). Individuals carrying no deletion or who were heterozygous were significantly more frequent among the tall obese population (52% vs. 36% in controls, p = 0.007, OR 1.97, 95%CI [1.22;3.18]). However, the association was not maintained after correcting for multiple testing. Familial association testing of the ghrelin and GHSR genes and their interaction testing failed to show that any combination of SNPs had any significant effect. Thus, our results suggest that common variants of the ghrelin and GHSR genes are not major contributors to height variation in a French population.

The Relation Between Inflation in Type-I and Type-II Error Rate and Population Divergence in Genome-Wide Association Analysis of Multi-Ethnic Populations.

PubMed

Derks, E M; Zwinderman, A H; Gamazon, E R

2017-05-01

Population divergence impacts the degree of population stratification in Genome Wide Association Studies. We aim to: (i) investigate type-I error rate as a function of population divergence (F ST ) in multi-ethnic (admixed) populations; (ii) evaluate the statistical power and effect size estimates; and (iii) investigate the impact of population stratification on the results of gene-based analyses. Quantitative phenotypes were simulated. Type-I error rate was investigated for Single Nucleotide Polymorphisms (SNPs) with varying levels of F ST between the ancestral European and African populations. Type-II error rate was investigated for a SNP characterized by a high value of F ST . In all tests, genomic MDS components were included to correct for population stratification. Type-I and type-II error rate was adequately controlled in a population that included two distinct ethnic populations but not in admixed samples. Statistical power was reduced in the admixed samples. Gene-based tests showed no residual inflation in type-I error rate.

Cryptic genetic diversity, population structure, and gene flow in the Mojave rattlesnake (Crotalus scutulatus).

PubMed

Schield, Drew R; Adams, Richard H; Card, Daren C; Corbin, Andrew B; Jezkova, Tereza; Hales, Nicole R; Meik, Jesse M; Perry, Blair W; Spencer, Carol L; Smith, Lydia L; García, Gustavo Campillo; Bouzid, Nassima M; Strickland, Jason L; Parkinson, Christopher L; Borja, Miguel; Castañeda-Gaytán, Gamaliel; Bryson, Robert W; Flores-Villela, Oscar A; Mackessy, Stephen P; Castoe, Todd A

2018-06-15

The Mojave rattlesnake (Crotalus scutulatus) inhabits deserts and arid grasslands of the western United States and Mexico. Despite considerable interest in its highly toxic venom and the recognition of two subspecies, no molecular studies have characterized range-wide genetic diversity and population structure or tested species limits within C. scutulatus. We used mitochondrial DNA and thousands of nuclear loci from double-digest restriction site associated DNA sequencing to infer population genetic structure throughout the range of C. scutulatus, and to evaluate divergence times and gene flow between populations. We find strong support for several divergent mitochondrial and nuclear clades of C. scutulatus, including splits coincident with two major phylogeographic barriers: the Continental Divide and the elevational increase associated with the Central Mexican Plateau. We apply Bayesian clustering, phylogenetic inference, and coalescent-based species delimitation to our nuclear genetic data to test hypotheses of population structure. We also performed demographic analyses to test hypotheses relating to population divergence and gene flow. Collectively, our results support the existence of four distinct lineages within C. scutulatus, and genetically defined populations do not correspond with currently recognized subspecies ranges. Finally, we use approximate Bayesian computation to test hypotheses of divergence among multiple rattlesnake species groups distributed across the Continental Divide, and find evidence for co-divergence at this boundary during the mid-Pleistocene. Copyright © 2018 Elsevier Inc. All rights reserved.

Knowledge and Concern about STIs/HIV and Sociodemographic Variables Associated with Getting Tested for HIV Among the General Population in Spain.

PubMed

Teva, Inmaculada; de Araújo, Ludgleydson Fernandes; de la Paz Bermúdez, María

2018-07-04

HIV testing is important in terms of prevention and treatment. However, HIV testing rates in the Spanish general population remains low. Therefore, HIV testing promotion constitutes a key issue. A high level of knowledge about HIV/AIDS is associated with having been tested for HIV. The general aim of this study was to determine the prevalence of people who had ever been tested for HIV in Spain. The sample consisted of 1,106 participants from the general population - 60.0% females and 40.0% males - aged between 17 and 55 years old. The assessment instruments were a questionnaire on sociodemographic data and HIV testing, a scale of knowledge about STIs and HIV/AIDS, and a scale of concern about STIs/HIV. Results showed that greater knowledge about STIs and HIV was associated with a greater likelihood of being tested for HIV (OR = .77; 95.0% CI = .73-.82; p < .05). In addition, higher concern about HIV/AIDS decreased the likelihood of not having been tested for HIV (OR = .87; 95.0% CI = .83-.92; p < .05). In fact, the higher participants concern about STIs was, the lower their likelihood of not having been tested for HIV was (OR = .87; 95.0% CI = .83-.91; p < .05). It is necessary to promote HIV testing in the general population as well as to consider their socio-demographic and psychological characteristics.

The performance of the SEPT9 gene methylation assay and a comparison with other CRC screening tests: A meta-analysis.

PubMed

Song, Lele; Jia, Jia; Peng, Xiumei; Xiao, Wenhua; Li, Yuemin

2017-06-08

The SEPT9 gene methylation assay is the first FDA-approved blood assay for colorectal cancer (CRC) screening. Fecal immunochemical test (FIT), FIT-DNA test and CEA assay are also in vitro diagnostic (IVD) tests used in CRC screening. This meta-analysis aims to review the SEPT9 assay performance and compare it with other IVD CRC screening tests. By searching the Ovid MEDLINE, EMBASE, CBMdisc and CJFD database, 25 out of 180 studies were identified to report the SEPT9 assay performance. 2613 CRC cases and 6030 controls were included, and sensitivity and specificity were used to evaluate its performance at various algorithms. 1/3 algorithm exhibited the best sensitivity while 2/3 and 1/1 algorithm exhibited the best balance between sensitivity and specificity. The performance of the blood SEPT9 assay is superior to that of the serum protein markers and the FIT test in symptomatic population, while appeared to be less potent than FIT and FIT-DNA tests in asymptomatic population. In conclusion, 1/3 algorithm is recommended for CRC screening, and 2/3 or 1/1 algorithms are suitable for early detection for diagnostic purpose. The SEPT9 assay exhibited better performance in symptomatic population than in asymptomatic population.

Bootstrap Estimation and Testing for Variance Equality.

ERIC Educational Resources Information Center

Olejnik, Stephen; Algina, James

The purpose of this study was to develop a single procedure for comparing population variances which could be used for distribution forms. Bootstrap methodology was used to estimate the variability of the sample variance statistic when the population distribution was normal, platykurtic and leptokurtic. The data for the study were generated and…

A Pilot Prospective Study of Fetomaternal Hemorrhage Identified by Anemia in Asymptomatic Neonates

PubMed Central

Stroustrup, Annemarie; Plafkin, Callie

2016-01-01

Background Fetomaternal hemorrhage (FMH) is a poorly understood condition in which fetal erythrocytes transfer to the maternal circulation via a faulty placental barrier. Little is known about the true incidence, epidemiology, or pathophysiology of FMH in the general pregnant population as existing studies are based on retrospective cohorts and manifest diagnosis and selection bias. Objective To evaluate the practicability of a prospective study of fetomaternal hemorrhage in the general population based on antepartum maternal blood testing and neonatal anemia. Study Design Prospective cohort study. Result Nineteen pregnant women were enrolled prior to the term delivery of twenty well infants. Five neonates were unexpectedly anemic on first postnatal testing. Antenatal maternal blood samples associated with 2 of 5 anemic newborns had positive Kleihauer-Betke testing while no newborn with a normal postnatal blood count had an associated abnormal Kleihauer-Betke test. Conclusion Clinically significant FMH may be more common than previously thought. Prospective epidemiological study of FMH is feasible. PMID:26765555

A pilot prospective study of fetomaternal hemorrhage identified by anemia in asymptomatic neonates.

PubMed

Stroustrup, A; Plafkin, C

2016-05-01

Fetomaternal hemorrhage (FMH) is a poorly understood condition in which fetal erythrocytes transfer to the maternal circulation via a faulty placental barrier. Little is known about the true incidence, epidemiology or pathophysiology of FMH in the general pregnant population as existing studies are based on retrospective cohorts and manifest diagnosis and selection bias. The objective of this study was to evaluate the practicability of a prospective study of FMH in the general population based on antepartum maternal blood testing and neonatal anemia. Prospective cohort study. Nineteen pregnant women were enrolled prior to the term delivery of 20 well infants. Five neonates were unexpectedly anemic on first postnatal testing. Antenatal maternal blood samples associated with two of the five anemic newborns had positive Kleihauer-Betke testing while no newborn with a normal postnatal blood count had an associated abnormal Kleihauer-Betke test. Clinically significant FMH may be more common than previously thought. Prospective epidemiological study of FMH is feasible.

Cross-reactions among parabens, para-phenylenediamine, and benzocaine: a retrospective analysis of patch testing.

PubMed

Turchin, Irina; Moreau, Linda; Warshaw, Erin; Sasseville, Denis

2006-12-01

Parabens are alkyl ester derivatives of para-hydroxybenzoic acid and are the most commonly used preservatives in the cosmetic industry. Cross-reactions with para-amino compounds, namely, benzocaine and para-phenylenediamine (PPD), have been reported but are thought to be extremely rare. To evaluate the rate of cross-reactivity between parabens, PPD, and benzocaine in a population of patients patch-tested in a hospital-based contact dermatitis clinic. A retrospective analysis of 4,368 patients consecutively patch-tested between July 1989 and June 2005. Our study demonstrated that the rate of cross-reactions to parabens in PPD- and benzocaine-positive patients combined is 2%. This cross-reaction rate is significant in the tested population but still falls within the previously reported rates of sensitivity to parabens in the general population (0 to 3.5%).

Functional performance testing of the hip in athletes: a systematic review for reliability and validity.

PubMed

Kivlan, Benjamin R; Martin, Robroy L

2012-08-01

The purpose of this study was to systematically review the literature for functional performance tests with evidence of reliability and validity that could be used for a young, athletic population with hip dysfunction. A search of PubMed and SPORTDiscus databases were performed to identify movement, balance, hop/jump, or agility functional performance tests from the current peer-reviewed literature used to assess function of the hip in young, athletic subjects. The single-leg stance, deep squat, single-leg squat, and star excursion balance tests (SEBT) demonstrated evidence of validity and normative data for score interpretation. The single-leg stance test and SEBT have evidence of validity with association to hip abductor function. The deep squat test demonstrated evidence as a functional performance test for evaluating femoroacetabular impingement. Hop/Jump tests and agility tests have no reported evidence of reliability or validity in a population of subjects with hip pathology. Use of functional performance tests in the assessment of hip dysfunction has not been well established in the current literature. Diminished squat depth and provocation of pain during the single-leg balance test have been associated with patients diagnosed with FAI and gluteal tendinopathy, respectively. The SEBT and single-leg squat tests provided evidence of convergent validity through an analysis of kinematics and muscle function in normal subjects. Reliability of functional performance tests have not been established on patients with hip dysfunction. Further study is needed to establish reliability and validity of functional performance tests that can be used in a young, athletic population with hip dysfunction. 2b (Systematic Review of Literature).

Relationship between Study Habits and Test Anxiety of Higher Secondary Students

ERIC Educational Resources Information Center

Lawrence, Arul A. S.

2014-01-01

The present study aims to probe the relationship between study habits and test anxiety of higher secondary students. In this normative study survey method was employed. The population for the present study consisted of higher secondary students studying in Tirunelveli district. The investigator used the simple random sampling technique. The sample…

Behavioural adaptations in talitrids from two Atlantic beaches

NASA Astrophysics Data System (ADS)

Rossano, Claudia; Gambineri, Simone; Fanini, Lucia; Durier, Virginie; Rivault, Colette; Scapini, Felicita

2009-12-01

The aim of the present study was to test sun orientation and rhythmic activity of two sandhopper populations from two Atlantic macro-tidal beaches. A population from Le Verger beach (orientated to 346°, Ille et Vilaine, Brittany, France) and a population from Damgan (orientated to 195°, Morbihan, Brittany, France), were tested on the beach under clear sky discriminating for landscape vision. For both populations locomotor activity rhythm was recorded in the laboratory. The two beaches differed for climatic features, tidal range and for human use. Both talitrid populations resulted very well orientated toward the shoreline, and both used solar position and landscape vision to orient. However the multiple regression analysis of orientation with climatic features showed a different use of local cues by the two populations and a slight influence of tidal regime (ebbing and rising tide), in spite of the supralittoral zonation of sandhoppers. In the laboratory they showed a well defined rhythmic behaviour as well as a bimodal rhythmicity, explained as a tidal one. These results are a new brick in the complex picture of orientation and rhythm studies on sandy beach invertebrates.

Socioeconomic characteristics of the population living in Roma settlements and their association with health and health-related behaviour.

PubMed

Gecková, Andrea Madarasová; Babinská, Ingrid; Bobáková, Daniela; Veselská, Zuzana Dankulincová; Bosáková, Lucia; Kolarcik, Peter; Jarcuska, Peter; Pella, Daniel; Halánová, Monika

2014-03-01

The aim of this study was to compare socioeconomic characteristics of the Roma population living in Roma settlements with the majority population. Moreover, it was aimed to assess socioeconomic differences in health and health-related behaviour within the population living in Roma settlements. Data from the cross-sectional HepaMeta study conducted in Slovakia in 2011 were used. The sample consisted of 452 Roma (mean age = 34.7; 35.2% men) and 403 non-Roma (mean age = 33.5; 45.9% men) respondents. Roma in selected settlements were recruited by local Roma community workers. Respondents from the major population were randomly selected from a list of patients from general practitioners. Data were collected via questionnaire, anthropometric measures and analysed blood samples. Differences in socioeconomic characteristics between the population living in Roma settlements and the majority population were tested using the chi-square test. The contribution of selected socioeconomic characteristics on health and health-related behaviour of the population living in Roma settlements was assessed by logistic regression models adjusted for age and gender. The population living in Roma settlements is characterised by significantly lower socioeconomic standards, and the living conditions are significantly worse compared with the majority. With few exceptions, the study did not confirm any significant association between socioeconomic indicators and health and health-related behaviour within the population living in Roma settlements. The deteriorating effect of living in Roma settlement on health and health-related behaviour seems to be immense regardless differences in socioeconomic characteristics or living condition within the settlement population.

QTLs associated with dry matter intake, metabolic mid-test weight, growth and feed efficiency have little overlap across 4 beef cattle studies.

PubMed

Saatchi, Mahdi; Beever, Jonathan E; Decker, Jared E; Faulkner, Dan B; Freetly, Harvey C; Hansen, Stephanie L; Yampara-Iquise, Helen; Johnson, Kristen A; Kachman, Stephen D; Kerley, Monty S; Kim, JaeWoo; Loy, Daniel D; Marques, Elisa; Neibergs, Holly L; Pollak, E John; Schnabel, Robert D; Seabury, Christopher M; Shike, Daniel W; Snelling, Warren M; Spangler, Matthew L; Weaber, Robert L; Garrick, Dorian J; Taylor, Jeremy F

2014-11-20

The identification of genetic markers associated with complex traits that are expensive to record such as feed intake or feed efficiency would allow these traits to be included in selection programs. To identify large-effect QTL, we performed a series of genome-wide association studies and functional analyses using 50 K and 770 K SNP genotypes scored in 5,133 animals from 4 independent beef cattle populations (Cycle VII, Angus, Hereford and Simmental×Angus) with phenotypes for average daily gain, dry matter intake, metabolic mid-test body weight and residual feed intake. A total of 5, 6, 11 and 10 significant QTL (defined as 1-Mb genome windows with Bonferroni-corrected P-value<0.05) were identified for average daily gain, dry matter intake, metabolic mid-test body weight and residual feed intake, respectively. The identified QTL were population-specific and had little overlap across the 4 populations. The pleiotropic or closely linked QTL on BTA 7 at 23 Mb identified in the Angus population harbours a promising candidate gene ACSL6 (acyl-CoA synthetase long-chain family member 6), and was the largest effect QTL associated with dry matter intake and mid-test body weight explaining 10.39% and 14.25% of the additive genetic variance, respectively. Pleiotropic or closely linked QTL associated with average daily gain and mid-test body weight were detected on BTA 6 at 38 Mb and BTA 7 at 93 Mb confirming previous reports. No QTL for residual feed intake explained more than 2.5% of the additive genetic variance in any population. Marker-based estimates of heritability ranged from 0.21 to 0.49 for residual feed intake across the 4 populations. This GWAS study, which is the largest performed for feed efficiency and its component traits in beef cattle to date, identified several large-effect QTL that cumulatively explained a significant percentage of additive genetic variance within each population. Differences in the QTL identified among the different populations may be due to differences in power to detect QTL, environmental variation, or differences in the genetic architecture of trait variation among breeds. These results enhance our understanding of the biology of growth, feed intake and utilisation in beef cattle.

Validity and reliability of the de Morton Mobility Index in the subacute hospital setting in a geriatric evaluation and management population.

PubMed

de Morton, Natalie A; Lane, Kylie

2010-11-01

To investigate the clinimetric properties of the de Morton Mobility Index (DEMMI) in a Geriatric Evaluation and Management (GEM) population. A longitudinal validation study (n = 100) and inter-rater reliability study (n = 29) in a GEM population. Consecutive patients admitted to a GEM rehabilitation ward were eligible for inclusion. At hospital admission and discharge, a physical therapist assessed patients with physical performance instruments that included the 6-metre walk test, step test, Clinical Test of Sensory Organization and Balance, Timed Up and Go test, 6-minute walk test and the DEMMI. Consecutively eligible patients were included in an inter-rater reliability study between physical therapists. DEMMI admission scores were normally distributed (mean 30.2, standard deviation 16.7) and other activity limitation instruments had either a floor or a ceiling effect. Evidence of convergent, discriminant and known groups validity for the DEMMI were obtained. The minimal detectable change with 90% confidence was 10.5 (95% confidence interval 6.1-17.9) points and the minimally clinically important difference was 8.4 points on the 100-point interval DEMMI scale. The DEMMI provides clinicians with an accurate and valid method of measuring mobility for geriatric patients in the subacute hospital setting.

Impact of Huntington Disease Gene-Positive Status on Pre-Symptomatic Young Adults and Recommendations for Genetic Counselors.

PubMed

Gong, Ping; Fanos, Joanna H; Korty, Lauren; Siskind, Carly E; Hanson-Kahn, Andrea K

2016-12-01

Huntington disease (HD) is an autosomal dominant, progressive neurodegenerative disorder for which there is no cure. Predictive testing for HD is available to asymptomatic at-risk individuals. Approximately half of the population undergoing predictive testing for HD consists of young adults (≤35 years old). Finishing one's education, starting a career, engaging in romantic relationships and becoming a parent are key milestones of young adulthood. We conducted a qualitative study to explore how testing gene-positive for HD influences young adults' attainment of these milestones, and to identify major challenges that pre-symptomatic young adults face to aid the development of targeted genetic counseling. Results of our study demonstrate that 1) knowing one's gene-positive status results in an urgency to reach milestones and positively changes young adults' approach to life; 2) testing positive influences young adults' education and career choices, romantic relationships, and family planning; 3) young adults desire flexible and tailored genetic counseling to address needs and concerns unique to this population. Findings of this study contribute to the understanding of the impact of predictive testing for HD on young adults, and highlight issues unique to this population that call for further research, intervention and advocacy.

Insecticide resistance status of the Anopheles funestus population in Central African Republic: a challenge in the war.

PubMed

Sangba, Marina Lidwine Olé; Deketramete, Tanguy; Wango, Solange Patricia; Kazanji, Mirdad; Akogbeto, Martin; Ndiath, Mamadou Ousmane

2016-04-25

In the Central African Republic, malaria is a major public health problem and the leading cause of death among children. This disease appears to be hyperendemic but no substantial entomological data, including data on Anopheles spp. susceptibility to insecticides, is available. This study evaluates, for the first time in the CAR, the status of insecticide resistance in the Anopheles funestus population, the second major vector of malaria in Africa. WHO standard bioassay susceptibility tests were performed on the An. funestus population using F1 generation from gravid females mosquitoes (F0) collected by manual aspirator sampling of households in Gbanikola, Bangui in October 2014 to assess: (i) An. funestus susceptibility to bendiocarb, malathion, permethrin, lamda-cyhalothrin, deltamethrin and DDT, and (ii) the effect of pre-exposure to the piperonyl butoxide (PBO) synergist on insecticide susceptibility. Additional tests were conducted to investigate metabolic resistance status (cytochrome P450 monooxygenases, glutathione S-transferases, and esterases). A high phenotypic resistance of An. funestus population to malathion, DDT and pyrethroids was observed with a mortality rate ranging from 23 to 74%. For the pyrethroid groups, the mortality rate was 35, 31 and 23% for lambda-cyhalothrin, deltamethrin, and permethrin, respectively. In contrast a 100% mortality rate to bendiocarb was recorded. Knockdown time (KDT) was long for all pyrethroids, DDT and malathion with KDT50 higher than 50 min. Pre-exposure of An. funestus to PBO synergist significantly restored susceptibility to all pyrethroids (Fisher's exact test P <0.0001) but not in DDT (Fisher's exact test P = 0.724). Data from biochemical tests suggest the involvement of cytochrome P450 monooxygenases, esterases and glutatione S-transferases in the resistance of An. funestus population from Gbanikola (Wilcoxon test P <0.05). Evidence of biochemical resistance to insecticide was detected in An. funestus population from the district of Gbanikola, Bangui. This study suggests that detoxifying enzymes are involved in insecticide resistance of An. funestus. However, despite disruptive violence, further research is urgently needed to assess the insecticide susceptibility status of An. funestus population in all CAR regions; insecticide resistance could rapidly compromise the success of malaria control programs.

Assessing the phylogeographic history of the montane caddisfly Thremma gallicum using mitochondrial and restriction-site-associated DNA (RAD) markers

PubMed Central

Macher, Jan-Niklas; Rozenberg, Andrey; Pauls, Steffen U; Tollrian, Ralph; Wagner, Rüdiger; Leese, Florian

2015-01-01

Repeated Quaternary glaciations have significantly shaped the present distribution and diversity of several European species in aquatic and terrestrial habitats. To study the phylogeography of freshwater invertebrates, patterns of intraspecific variation have been examined primarily using mitochondrial DNA markers that may yield results unrepresentative of the true species history. Here, population genetic parameters were inferred for a montane aquatic caddisfly, Thremma gallicum, by sequencing a 658-bp fragment of the mitochondrial CO1 gene, and 12,514 nuclear RAD loci. T. gallicum has a highly disjunct distribution in southern and central Europe, with known populations in the Cantabrian Mountains, Pyrenees, Massif Central, and Black Forest. Both datasets represented rangewide sampling of T. gallicum. For the CO1 dataset, this included 352 specimens from 26 populations, and for the RAD dataset, 17 specimens from eight populations. We tested 20 competing phylogeographic scenarios using approximate Bayesian computation (ABC) and estimated genetic diversity patterns. Support for phylogeographic scenarios and diversity estimates differed between datasets with the RAD data favouring a southern origin of extant populations and indicating the Cantabrian Mountains and Massif Central populations to represent highly diverse populations as compared with the Pyrenees and Black Forest populations. The CO1 data supported a vicariance scenario (north–south) and yielded inconsistent diversity estimates. Permutation tests suggest that a few hundred polymorphic RAD SNPs are necessary for reliable parameter estimates. Our results highlight the potential of RAD and ABC-based hypothesis testing to complement phylogeographic studies on non-model species. PMID:25691988

Are human hands and feet affected by climate? A test of Allen's rule.

PubMed

Betti, Lia; Lycett, Stephen J; von Cramon-Taubadel, Noreen; Pearson, Osbjorn M

2015-09-01

In recent years, several studies have shown that populations from cold, high-latitude regions tend to have relatively shorter limbs than populations from tropical regions, with most of the difference due to the relative length of the zeugopods (i.e., radius, ulna, tibia, fibula). This pattern has been explained either as the consequence of long-term climatic selection or of phenotypic plasticity, with temperature having a direct effect on bone growth during development. The aims of this study were to test whether this pattern of intra-limb proportions extended to the bones of the hands and feet, and to determine whether the pattern remained significant after taking into account the effects of neutral evolutionary processes related to population history. Measurements of the limb bones, including the first metatarsal and metacarpal, were collected for 393 individuals from 10 globally distributed human populations. The relationship between intra-limb indices and minimum temperature was tested using generalized least squares regression, correcting for spatial autocorrelation. The results confirmed previous observations of a temperature-related gradient in intra-limb proportions, even accounting for population history. This pattern extends to the hands, with populations from cold regions displaying a relatively shorter and stockier first metacarpal; however, the first metatarsal appears to be wider but not shorter in cold-adapted populations. The results suggest that climatic adaptation played a role in shaping variation in limb proportions between human populations. The different patterns shown by the hands and feet might be due to the presence of evolutionary constraints on the foot to maintain efficient bipedal locomotion. © 2015 Wiley Periodicals, Inc.

The value of cows in reference populations for genomic selection of new functional traits.

PubMed

Buch, L H; Kargo, M; Berg, P; Lassen, J; Sørensen, A C

2012-06-01

Today, almost all reference populations consist of progeny tested bulls. However, older progeny tested bulls do not have reliable estimated breeding values (EBV) for new traits. Thus, to be able to select for these new traits, it is necessary to build a reference population. We used a deterministic prediction model to test the hypothesis that the value of cows in reference populations depends on the availability of phenotypic records. To test the hypothesis, we investigated different strategies of building a reference population for a new functional trait over a 10-year period. The trait was either recorded on a large scale (30 000 cows per year) or on a small scale (2000 cows per year). For large-scale recording, we compared four scenarios where the reference population consisted of 30 sires; 30 sires and 170 test bulls; 30 sires and 2000 cows; or 30 sires, 2000 cows and 170 test bulls in the first year with measurements of the new functional trait. In addition to varying the make-up of the reference population, we also varied the heritability of the trait (h2 = 0.05 v. 0.15). The results showed that a reference population of test bulls, cows and sires results in the highest accuracy of the direct genomic values (DGV) for a new functional trait, regardless of its heritability. For small-scale recording, we compared two scenarios where the reference population consisted of the 2000 cows with phenotypic records or the 30 sires of these cows in the first year with measurements of the new functional trait. The results showed that a reference population of cows results in the highest accuracy of the DGV whether the heritability is 0.05 or 0.15, because variation is lost when phenotypic data on cows are summarized in EBV of their sires. The main conclusions from this study are: (i) the fewer phenotypic records, the larger effect of including cows in the reference population; (ii) for small-scale recording, the accuracy of the DGV will continue to increase for several years, whereas the increases in the accuracy of the DGV quickly decrease with large-scale recording; (iii) it is possible to achieve accuracies of the DGV that enable selection for new functional traits recorded on a large scale within 3 years from commencement of recording; and (iv) a higher heritability benefits a reference population of cows more than a reference population of bulls.

Penicillin skin testing is a safe and effective tool for evaluating penicillin allergy in the pediatric population.

PubMed

Fox, Stephanie J; Park, Miguel A

2014-01-01

Penicillin skin testing has been validated in the evaluation of adult patients with penicillin allergy. However, the commercially available benzylpenicilloyl polylysine (Pre-Pen) is not indicated in the pediatric population. Moreover, the safety and validity of penicillin skin testing in the pediatric population has not been well studied. We describe the safety and validity of penicillin skin testing in the evaluation of children with a history of penicillin allergy. Children (<18 years) with a history of penicillin allergy were evaluated with penicillin skin tests and were reviewed for basic demographics, penicillin skin test results, adverse drug reaction to penicillin after penicillin skin test, and adverse reaction to penicillin skin test. By using the χ(2) test, we compared the differences in the proportion of children and adults with a positive penicillin skin test. P value (<.05) was considered statistically significant. The institutional review board approved the study, and all the subjects signed written informed consents. A total of 778 children underwent penicillin skin testing; 703 of 778 patients had a negative penicillin skin test (90.4%), 66 had a positive test (8.5%), and 9 had an equivocal test (1.1%). Children were more likely to have a positive penicillin skin test (P < .0001) compared with adults (64 of 1759 [3.6%]); 369 of 703 patients with negative penicillin skin test (52%) were challenged with penicillin, and 14 of 369 patients (3.8%) had an adverse drug reaction. No adverse reactions to penicillin skin testing were observed. Penicillin skin testing was safe and effective in the evaluation of children with a history of penicillin allergy. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

The Abbott RealTime High Risk HPV test is a clinically validated human papillomavirus assay for triage in the referral population and use in primary cervical cancer screening in women 30 years and older: a review of validation studies.

PubMed

Poljak, Mario; Oštrbenk, Anja

2013-01-01

Human papillomavirus (HPV) testing has become an essential part of current clinical practice in the management of cervical cancer and precancerous lesions. We reviewed the most important validation studies of a next-generation real-time polymerase chain reaction-based assay, the RealTime High Risk HPV test (RealTime)(Abbott Molecular, Des Plaines, IL, USA), for triage in referral population settings and for use in primary cervical cancer screening in women 30 years and older published in peer-reviewed journals from 2009 to 2013. RealTime is designed to detect 14 high-risk HPV genotypes with concurrent distinction of HPV-16 and HPV-18 from 12 other HPV genotypes. The test was launched on the European market in January 2009 and is currently used in many laboratories worldwide for routine detection of HPV. We concisely reviewed validation studies of a next-generation real-time polymerase chain reaction (PCR)-based assay: the Abbott RealTime High Risk HPV test. Eight validation studies of RealTime in referral settings showed its consistently high absolute clinical sensitivity for both CIN2+ (range 88.3-100%) and CIN3+ (range 93.0-100%), as well as comparative clinical sensitivity relative to the currently most widely used HPV test: the Qiagen/Digene Hybrid Capture 2 HPV DNA Test (HC2). Due to the significantly different composition of the referral populations, RealTime absolute clinical specificity for CIN2+ and CIN3+ varied greatly across studies, but was comparable relative to HC2. Four validation studies of RealTime performance in cervical cancer screening settings showed its consistently high absolute clinical sensitivity for both CIN2+ and CIN3+, as well as comparative clinical sensitivity and specificity relative to HC2 and GP5+/6+ PCR. RealTime has been extensively evaluated in the last 4 years. RealTime can be considered clinically validated for triage in referral population settings and for use in primary cervical cancer screening in women 30 years and older.

A review of testing used in seroprevalence studies on measles and rubella.

PubMed

Dimech, Wayne; Mulders, Mick N

2016-07-29

Seroprevalence studies are an essential tool to monitor the efficacy of vaccination programmes, to understand population immunity and to identify populations at higher risk of infection. An overarching review of all aspects of seroprevalence studies for measles and rubella published between 1998 and June 2014 was undertaken and the findings reported elsewhere. This paper details the considerable variation in the testing formats identified in the review. Apart from serum/plasma samples, testing of oral fluid, breast milk, dry blood spots and capillary whole blood were reported. Numerous different commercial assays were employed, including microtitre plate assays, automated immunoassays and classical haemagglutination inhibition and neutralisation assays. A total of 29 of the 68 (43%) measles and 14 of the 58 (24%) rubella studies reported qualitative test results. Very little information on the testing environment, including quality assurance mechanisms used, was provided. Due to the large numbers of testing systems, the diversity of sample types used and the difficulties in accurate quantification of antibody levels, the results reported in individual studies were not necessarily comparable. Further efforts to standardise seroprevalence studies may overcome this deficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

A population-based survey in Australia of men's and women's perceptions of genetic risk and predictive genetic testing and implications for primary care.

PubMed

Taylor, S

2011-01-01

Community attitudes research regarding genetic issues is important when contemplating the potential value and utilisation of predictive testing for common diseases in mainstream health services. This article aims to report population-based attitudes and discuss their relevance to integrating genetic services in primary health contexts. Men's and women's attitudes were investigated via population-based omnibus telephone survey in Queensland, Australia. Randomly selected adults (n = 1,230) with a mean age of 48.8 years were interviewed regarding perceptions of genetic determinants of health; benefits of genetic testing that predict 'certain' versus 'probable' future illness; and concern, if any, regarding potential misuse of genetic test information. Most (75%) respondents believed genetic factors significantly influenced health status; 85% regarded genetic testing positively although attitudes varied with age. Risk-based information was less valued than certainty-based information, but women valued risk information significantly more highly than men. Respondents reported 'concern' (44%) and 'no concern' (47%) regarding potential misuse of genetic information. This study contributes important population-based data as most research has involved selected individuals closely impacted by genetic disorders. While community attitudes were positive regarding genetic testing, genetic literacy is important to establish. The nature of gender differences regarding risk perception merits further study and has policy and service implications. Community concern about potential genetic discrimination must be addressed if health benefits of testing are to be maximised. Larger questions remain in scientific, policy, service delivery, and professional practice domains before predictive testing for common disorders is efficacious in mainstream health care. Copyright © 2011 S. Karger AG, Basel.

Validation study of human figure drawing test in a Colombian school children population.

PubMed

Vélez van Meerbeke, Alberto; Sandoval-Garcia, Carolina; Ibáñez, Milciades; Talero-Gutiérrez, Claudia; Fiallo, Dolly; Halliday, Karen

2011-05-01

The aim of this article was to assess the validity of the emotional and developmental components of the Koppitz human figure drawing test. 2420 children's drawings available in a database resulting from a previous cross sectional study designed to determine the prevalence of neurological diseases in children between 0 and 12 years old in Bogota schools were evaluated. They were scored using the criteria proposed by Koppitz, and classified into 16 groups according to age, gender, and presence/absence of learning or attention problems. The overall results were then compared with the normative study to assess whether descriptive parameters of the two populations were significantly different. There were no significant differences associated with presence/absence of learning and attention disorders or school attended within the overall sample. An Interrater reliability test has been made to assure the homogeneity of scoring by the evaluator team. There were significant differences between this population and that of the original study. New scoring tables contextualized for our population based on the frequency of appearance in this sample are presented. We can conclude that various ethnic, social, and cultural factors can influence the way children draw the human figure. It is thus important to establish local reference values to adequately distinguish between normality and abnormality. The new scoring tables proposed here should be followed up with a clinical study to corroborate their validity.

The program structure does not reliably recover the correct population structure when sampling is uneven: subsampling and new estimators alleviate the problem.

PubMed

Puechmaille, Sebastien J

2016-05-01

Inferences of population structure and more precisely the identification of genetically homogeneous groups of individuals are essential to the fields of ecology, evolutionary biology and conservation biology. Such population structure inferences are routinely investigated via the program structure implementing a Bayesian algorithm to identify groups of individuals at Hardy-Weinberg and linkage equilibrium. While the method is performing relatively well under various population models with even sampling between subpopulations, the robustness of the method to uneven sample size between subpopulations and/or hierarchical levels of population structure has not yet been tested despite being commonly encountered in empirical data sets. In this study, I used simulated and empirical microsatellite data sets to investigate the impact of uneven sample size between subpopulations and/or hierarchical levels of population structure on the detected population structure. The results demonstrated that uneven sampling often leads to wrong inferences on hierarchical structure and downward-biased estimates of the true number of subpopulations. Distinct subpopulations with reduced sampling tended to be merged together, while at the same time, individuals from extensively sampled subpopulations were generally split, despite belonging to the same panmictic population. Four new supervised methods to detect the number of clusters were developed and tested as part of this study and were found to outperform the existing methods using both evenly and unevenly sampled data sets. Additionally, a subsampling strategy aiming to reduce sampling unevenness between subpopulations is presented and tested. These results altogether demonstrate that when sampling evenness is accounted for, the detection of the correct population structure is greatly improved. © 2016 John Wiley & Sons Ltd.

Double Trouble at High Density: Cross-Level Test of Resource-Related Adaptive Plasticity and Crowding-Related Fitness

PubMed Central

Gergs, André; Preuss, Thomas G.; Palmqvist, Annemette

2014-01-01

Population size is often regulated by negative feedback between population density and individual fitness. At high population densities, animals run into double trouble: they might concurrently suffer from overexploitation of resources and also from negative interference among individuals regardless of resource availability, referred to as crowding. Animals are able to adapt to resource shortages by exhibiting a repertoire of life history and physiological plasticities. In addition to resource-related plasticity, crowding might lead to reduced fitness, with consequences for individual life history. We explored how different mechanisms behind resource-related plasticity and crowding-related fitness act independently or together, using the water flea Daphnia magna as a case study. For testing hypotheses related to mechanisms of plasticity and crowding stress across different biological levels, we used an individual-based population model that is based on dynamic energy budget theory. Each of the hypotheses, represented by a sub-model, is based on specific assumptions on how the uptake and allocation of energy are altered under conditions of resource shortage or crowding. For cross-level testing of different hypotheses, we explored how well the sub-models fit individual level data and also how well they predict population dynamics under different conditions of resource availability. Only operating resource-related and crowding-related hypotheses together enabled accurate model predictions of D. magna population dynamics and size structure. Whereas this study showed that various mechanisms might play a role in the negative feedback between population density and individual life history, it also indicated that different density levels might instigate the onset of the different mechanisms. This study provides an example of how the integration of dynamic energy budget theory and individual-based modelling can facilitate the exploration of mechanisms behind the regulation of population size. Such understanding is important for assessment, management and the conservation of populations and thereby biodiversity in ecosystems. PMID:24626228

Measurements of spatial population synchrony: influence of time series transformations.

PubMed

Chevalier, Mathieu; Laffaille, Pascal; Ferdy, Jean-Baptiste; Grenouillet, Gaël

2015-09-01

Two mechanisms have been proposed to explain spatial population synchrony: dispersal among populations, and the spatial correlation of density-independent factors (the "Moran effect"). To identify which of these two mechanisms is driving spatial population synchrony, time series transformations (TSTs) of abundance data have been used to remove the signature of one mechanism, and highlight the effect of the other. However, several issues with TSTs remain, and to date no consensus has emerged about how population time series should be handled in synchrony studies. Here, by using 3131 time series involving 34 fish species found in French rivers, we computed several metrics commonly used in synchrony studies to determine whether a large-scale climatic factor (temperature) influenced fish population dynamics at the regional scale, and to test the effect of three commonly used TSTs (detrending, prewhitening and a combination of both) on these metrics. We also tested whether the influence of TSTs on time series and population synchrony levels was related to the features of the time series using both empirical and simulated time series. For several species, and regardless of the TST used, we evidenced a Moran effect on freshwater fish populations. However, these results were globally biased downward by TSTs which reduced our ability to detect significant signals. Depending on the species and the features of the time series, we found that TSTs could lead to contradictory results, regardless of the metric considered. Finally, we suggest guidelines on how population time series should be processed in synchrony studies.

Predicting tuberculosis risk in the foreign-born population of British Columbia, Canada: study protocol for a retrospective population-based cohort study.

PubMed

Ronald, Lisa A; Campbell, Jonathon R; Balshaw, Robert F; Roth, David Z; Romanowski, Kamila; Marra, Fawziah; Cook, Victoria J; Johnston, James C

2016-11-25

Improved understanding of risk factors for developing active tuberculosis (TB) will better inform decisions about diagnostic testing and treatment for latent TB infection (LTBI) in migrant populations in low-incidence regions. We aim to examine TB risk factors among the foreign-born population in British Columbia (BC), Canada, and to create and validate a clinically relevant multivariate risk score to predict active TB. This retrospective population-based cohort study will include all foreign-born individuals who acquired permanent resident status in Canada between 1 January 1985 and 31 December 2013 and acquired healthcare coverage in BC at any point during this period. Multiple administrative databases and disease registries will be linked, including a National Immigration Database, BC Provincial Health Insurance Registration, physician billings, hospitalisations, drugs dispensed from community pharmacies, vital statistics, HIV testing and notifications, cancer, chronic kidney disease and dialysis treatment, and all TB and LTBI testing and treatment data in BC. Extended proportional hazards regression will be used to estimate risk factors for TB and to create a prognostic TB risk score. Ethical approval for this study has been obtained from the University of British Columbia Clinical Ethics Review Board. Once completed, study findings will be presented at conferences and published in peer-reviewed journals. An online TB risk score calculator will also be created. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Effects of transgenic Bt rice on growth, reproduction, and superoxide dismutase activity of Folsomia candida (Collembola: Isotomidae) in laboratory studies.

PubMed

Bai, Yaoyu; Yan, Ruihong; Ke, Xin; Ye, Gongyin; Huang, Fangneng; Luo, Yongming; Cheng, Jiaan

2011-12-01

Transgenic rice expressing Bacillus thuringiensis (Bt) CrylAb protein is expected to be commercialized in China in the near future. The use of Bt rice for controlling insect pests sparks intensive debates regarding its biosafety. Folsomia candida is an euedaphic species and is often used as a "standard" test organism in assessing effects of environmental pollutants on soil organisms. In this study, growth, development, reproduction, and superoxide dismutase activity (SOD) of F. candida were investigated in the laboratory for populations reared on leaf tissue or leaf-soil mixtures of two CrylAb rice lines and a non-Bt rice isoline. Two independent tests were performed: 1) a 35-d test using petri dishes containing yeast diet (positive control) or fresh rice leaf tissue, and 2) a 28-d test in soil-litter microcosms containing yeast or a mixture of soil and rice leaf tissue. Biological parameters measured in both tests were number of progeny production, population growth rate, and SOD activity. For the petri dish test, data measured also included insect body length and number of exuviation. There were no significant differences between the populations reared on Bt and non-Bt rice leaf tissue in all measured parameters in both tests and for both Bt rice lines, suggesting no significant effects of the CrylAb protein in Bt rice on F. candida in the laboratory studies. Results of this study should add additional biosafety proofs for use of Bt rice to manage rice pests in China.

Otoacoustic emissions in the general adult population of Nord-Trøndelag, Norway: III. Relationships with pure-tone hearing thresholds.

PubMed

Engdahl, Bo; Tambs, Kristian; Borchgrevink, Hans M; Hoffman, Howard J

2005-01-01

This study aims to describe the association between otoacoustic emissions (OAEs) and pure-tone hearing thresholds (PTTs) in an unscreened adult population (N =6415), to determine the efficiency by which TEOAEs and DPOAEs can identify ears with elevated PTTs, and to investigate whether a combination of DPOAE and TEOAE responses improves this performance. Associations were examined by linear regression analysis and ANOVA. Test performance was assessed by receiver operator characteristic (ROC) curves. The relation between OAEs and PTTs appeared curvilinear with a moderate degree of non-linearity. Combining DPOAEs and TEOAEs improved performance. Test performance depended on the cut-off thresholds defining elevated PTTs with optimal values between 25 and 45 dB HL, depending on frequency and type of OAE measure. The unique constitution of the present large sample, which reflects the general adult population, makes these results applicable to population-based studies and screening programs.

INNULs: A novel design amplification strategy for retrotransposable elements for studying population variation.

PubMed

LaRue, Bobby L; Sinha, Sudhir K; Montgomery, Anne H; Thompson, Robyn; Klaskala, Lauren; Ge, Jianye; King, Jonathan; Turnbough, Meredith; Budowle, Bruce

2012-01-01

Retrotransposable elements (REs), consisting of long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), are a group of markers that can be useful for human identity testing. Until now, however, due to the inherent size difference (up to 6 kb in some instances) associated with insertion and null alleles (or INNULs), the use of REs for facilitated population studies has not been sought or practical. The size of the insertion elements (from a few hundred to several thousand bp) has proven to limit their utility as a marker because of the inefficient amplicon yield with PCR. A novel primer design now facilitates INNUL marker testing. A preliminary panel of single-locus markers was developed to evaluate the potential of typing these insertion elements. Nine INNULs (5 Alu and 4 LINEs) were typed in three major North American populations and analyzed for population genetic features. In addition, the variation of each marker among the sample populations provides insight of its potential use as individual identification or ancestral marker. INNUL markers were developed into fluorescently labeled single-loci PCR. Nine markers were developed with amplicons that were less than 180 bp in length, and, depending on the locus amplicons of the INNULs, alleles varied in size from 50 to 1 bp. This allele size is noteworthy because the insertion alleles of the 9 loci range in size from 297 to 6,195 bp. The allele distribution of the INNULs was assessed and analyzed in three major North American populations. Upon observation of the distribution of the alleles in three major North American populations, the markers generally met Hardy-Weinberg expectations, and there was little evidence of detectable levels of linkage disequilibrium. Due to varying distributions of the alleles in the major population groups tested, some of the markers might be better suited for use as an individual identification marker, while others are better suited for bio-ancestral studies. Using the primer design strategy described in our work, SINEs and (for the first time, to our knowledge) LINEs can be utilized as markers for studying population genetic variation that is more amenable to the limitations of the PCR technique. This study lays the foundation for future work of developing a multiplex panel of INNUL markers that can be used as a single-tube assay for human identity testing utilizing small amplicons (<180 bp), which could be useful for ancient or degraded forensic DNA samples. Copyright © 2012 S. Karger AG, Basel.

The Italian Hub of Population Biobanks as a Potential Tool for Improving Public Health Stewardship

PubMed Central

Napolitano, Mariarosaria; Santoro, Filippo; Belardelli, Filippo; Federici, Antonio

2013-01-01

In Italy, a country that is experiencing the decentralization of health services from central to regional level of government, the Minister of Health is proposing stewardship as a model of governance for the public health system. Stewardship favors efficiency in the policy decision-making process, based on reciprocal trust, and tends to be more ethical. The embryonic proposal to test stewardship in the field of population-based research was advanced during the launching conference Challenges and Opportunities of the Italian Hub of Population Biobanks (HIBP) held in 2012 in Rome. Resources collected by population biobanks (i.e., blood and its derivatives, and/or DNA isolated from any type of biological samples and relative associated data) have, in fact, a recognized scientific value for the investigation of links between genetics, health and life style, and epidemiological outcomes through population biobank-based studies, and are essential to planning effective and qualified interventions for public health. The current economic crisis requires a strong push to rationalize investment in health policies. In particular, population biobank-based studies require financial commitment, often of long duration, for the realization of their goals. Thus, innovative solutions to allow fast integration of scientific knowledge into political health strategy are required. During the conference in Rome, it was proposed to test the stewardship model by its application to the inter-relationship between population biobank-based studies and disease prevention. Stewardship minimizes barriers to innovation and uses information more effectively to better develop new strategies for prevention and/or treatment. In the months following the conference, the proposal was defined more clearly, and the HIBP network became a potential tool for testing and implementing this model in the Italian Public Health prevention system. PMID:23840926

Characterization of [(3)H]harmane binding to rat whole brain membranes.

PubMed

Anderson, N J; Robinson, E S J; Husbands, S M; Delagrange, P; Nutt, D J; Hudson, A L

2003-12-01

This study investigates the binding of [(3)H]harmane to rat whole brain homogenates. Saturation studies revealed [(3)H]harmane labels a single, saturable, high-capacity population with high affinity. All the test compounds displaced [(3)H]harmane completely and in an apparently monophasic manner. The displacement profile of the test ligands indicated labeling of MAO-A. Given the high level of MAO-A binding, it is unlikely that a low-capacity I(2) site would be distinguishable from the total [(3)H]harmane population.

Parker's sneak-guard model revisited: why do reproductively parasitic males heavily invest in testes?

PubMed

Ota, Kazutaka; Kohda, Masanori; Hori, Michio; Sato, Tetsu

2011-10-01

Alternative reproductive tactics are widespread in males and may cause intraspecific differences in testes investment. Parker's sneak-guard model predicts that sneaker males, who mate under sperm competition risk, invest in testes relatively more than bourgeois conspecifics that have lower risk. Given that sneakers are much smaller than bourgeois males, sneakers may increase testes investment to overcome their limited sperm productivity because of their small body sizes. In this study, we examined the mechanism that mediates differential testes investment across tactics in the Lake Tanganyika cichlid fish Lamprologus callipterus. In the Rumonge population of Burundi, bourgeois males are small compared with those in other populations and have a body size close to sneaky dwarf males. Therefore, if differences in relative testis investment depend on sperm competition, the rank order of relative testis investment should be dwarf males > bourgeois males in Rumonge = bourgeois males in the other populations. If differences in relative testis investment depend on body size, the rank order of relative testes investment should be dwarf males > bourgeois males in Rumonge > bourgeois males in the other populations. Comparisons of relative testis investment among the three male groups supported the role of sperm competition, as predicted by the sneak-guard model. Nevertheless, the effects of absolute body size on testes investment should be considered to understand the mechanisms underlying intraspecific variation in testes investment caused by alternative reproductive tactics.

Parker's sneak-guard model revisited: why do reproductively parasitic males heavily invest in testes?

NASA Astrophysics Data System (ADS)

Ota, Kazutaka; Kohda, Masanori; Hori, Michio; Sato, Tetsu

2011-10-01

Alternative reproductive tactics are widespread in males and may cause intraspecific differences in testes investment. Parker's sneak-guard model predicts that sneaker males, who mate under sperm competition risk, invest in testes relatively more than bourgeois conspecifics that have lower risk. Given that sneakers are much smaller than bourgeois males, sneakers may increase testes investment to overcome their limited sperm productivity because of their small body sizes. In this study, we examined the mechanism that mediates differential testes investment across tactics in the Lake Tanganyika cichlid fish Lamprologus callipterus. In the Rumonge population of Burundi, bourgeois males are small compared with those in other populations and have a body size close to sneaky dwarf males. Therefore, if differences in relative testis investment depend on sperm competition, the rank order of relative testis investment should be dwarf males > bourgeois males in Rumonge = bourgeois males in the other populations. If differences in relative testis investment depend on body size, the rank order of relative testes investment should be dwarf males > bourgeois males in Rumonge > bourgeois males in the other populations. Comparisons of relative testis investment among the three male groups supported the role of sperm competition, as predicted by the sneak-guard model. Nevertheless, the effects of absolute body size on testes investment should be considered to understand the mechanisms underlying intraspecific variation in testes investment caused by alternative reproductive tactics.

[The dose estimation to the population as a result of radioactive contamination of the Semipalatinsk Test area].

PubMed

Spiridonova, S I; Mukusheva, M K; Shubina, O A; Solomatin, V M; Epifanova, I E

2008-01-01

The results are presented from estimation of spatial distribution of 137Cs and 90Sr contamination densities in the areas of horses and sheep grazing within the Semipalatinsk Test Site. Dose burdens to various cohorts of the population living within the STS and consuming contaminated animal products are predicted. Doses of shepherds in the most contaminated pasture areas have been found to exceed the accepted limit (1 mSv/y). The conclusion is made about the need for further studies on the risk assessment of the STS population exposure above the accepted limits.

A Danish diabetes risk score for targeted screening: the Inter99 study.

PubMed

Glümer, Charlotte; Carstensen, Bendix; Sandbaek, Annelli; Lauritzen, Torsten; Jørgensen, Torben; Borch-Johnsen, Knut

2004-03-01

To develop a simple self-administered questionnaire identifying individuals with undiagnosed diabetes with a sensitivity of 75% and minimizing the high-risk group needing subsequent testing. A population-based sample (Inter99 study) of 6,784 individuals aged 30-60 years completed a questionnaire on diabetes-related symptoms and risk factors. The participants underwent an oral glucose tolerance test. The risk score was derived from the first half and validated on the second half of the study population. External validation was performed based on the Danish Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care (ADDITION) pilot study. The risk score was developed by stepwise backward multiple logistic regression. The final risk score included age, sex, BMI, known hypertension, physical activity at leisure time, and family history of diabetes, items independently and significantly (P<0.05) associated with the presence of previously undiagnosed diabetes. The area under the receiver operating curve was 0.804 (95% CI 0.765-0.838) for the first half of the Inter99 population, 0.761 (0.720-0.803) for the second half of the Inter99 population, and 0.803 (0.721-0.876) for the ADDITION pilot study. The sensitivity, specificity, and percentage that needed subsequent testing were 76, 72, and 29%, respectively. The false-negative individuals in the risk score had a lower absolute risk of ischemic heart disease compared with the true-positive individuals (11.3 vs. 20.4%; P<0.0001). We developed a questionnaire to be used in a stepwise screening strategy for type 2 diabetes, decreasing the numbers of subsequent tests and thereby possibly minimizing the economical and personal costs of the screening strategy.

Population Parameters of Blainvilles and Cuviers Beaked Whales

DTIC Science & Technology

2015-09-30

cetacean populations. Long-term monitoring of beaked whale populations in El Hierro , a nearly pristine habitat far from areas of sonar testing or...marine industry, enables valuable studies of demographic trends and life history dictated mainly by natural parameters. El Hierro is in process of...functioning (expected in 2018-2019), it is essential to continue monitoring the populations in El Hierro to obtain an uninterrupted long-term dataset of

Incremental value of Veterans Specific Activity Questionnaire and the YMCA-step test for the assessment of cardiorespiratory fitness in population-based studies.

PubMed

Teren, Andrej; Zachariae, Silke; Beutner, Frank; Ubrich, Romy; Sandri, Marcus; Engel, Christoph; Löffler, Markus; Gielen, Stephan

2016-07-01

Cardiorespiratory fitness is a well-established independent predictor of cardiovascular health. However, the relevance of alternative exercise and non-exercise tests for cardiorespiratory fitness assessment in large cohorts has not been studied in detail. We aimed to evaluate the YMCA-step test and the Veterans Specific Activity Questionnaire (VSAQ) for the estimation of cardiorespiratory fitness in the general population. One hundred and five subjects answered the VSAQ, performed the YMCA-step test and a maximal cardiopulmonary exercise test (CPX) and gave BORG ratings for both exercise tests (BORGSTEP, BORGCPX). Correlations of peak oxygen uptake on a treadmill (VO2_PEAK) with VSAQ, BORGSTEP, one-minute, post-exercise heartbeat count, and peak oxygen uptake during the step test (VO2_STEP) were determined. Moreover, the incremental values of the questionnaire and the step test in addition to other fitness-related parameters were evaluated using block-wise hierarchical regression analysis. Eighty-six subjects completed the step test according to the protocol. For completers, correlations of VO2_PEAK with the age- and gender-adjusted VSAQ, heartbeat count and VO2_STEP were 0.67, 0.63 and 0.49, respectively. However, using hierarchical regression analysis, age, gender and body mass index already explained 68.8% of the variance of VO2_PEAK, while the additional benefit of VSAQ was rather low (3.4%). The inclusion of BORGSTEP, heartbeat count and VO2_STEP increased R(2) by a further 2.2%, 3.3% and 5.6%, respectively, yielding a total R(2) of 83.3%. Neither VSAQ nor the YMCA-step test contributes sufficiently to the assessment of cardiorespiratory fitness in population-based studies. © The European Society of Cardiology 2015.

Studies of Health Effects from Nuclear Testing near the Semipalatinsk Nuclear Test Site, Kazakhstan.

PubMed

Grosche, Bernd; Zhunussova, Tamara; Apsalikov, Kazbek; Kesminiene, Ausrele

2015-01-01

The nuclear bomb testing conducted at the Semipalatinsk nuclear test site in Kazakhstan is of great importance for today's radiation protection research, particularly in the area of low dose exposures. This type of radiation is of particular interest due to the lack of research in this field and how it impacts population health. In order to understand the possible health effects of nuclear bomb testing, it is important to determine what studies have been conducted on the effects of low dose exposure and dosimetry, and evaluate new epidemiologic data and biological material collected from populations living in proximity to the test site. With time, new epidemiological data has been made available, and it is possible that these data may be linked to biological samples. Next to linking existing and newly available data to examine health effects, the existing dosimetry system needs to be expanded and further developed to include residential areas, which have not yet been taken into account. The aim of this paper is to provide an overview of previous studies evaluating the health effects of nuclear testing, including some information on dosimetry efforts, and pointing out directions for future epidemiologic studies.

Studies of Health Effects from Nuclear Testing near the Semipalatinsk Nuclear Test Site, Kazakhstan

PubMed Central

Grosche, Bernd; Zhunussova, Tamara; Apsalikov, Kazbek; Kesminiene, Ausrele

2015-01-01

The nuclear bomb testing conducted at the Semipalatinsk nuclear test site in Kazakhstan is of great importance for today’s radiation protection research, particularly in the area of low dose exposures. This type of radiation is of particular interest due to the lack of research in this field and how it impacts population health. In order to understand the possible health effects of nuclear bomb testing, it is important to determine what studies have been conducted on the effects of low dose exposure and dosimetry, and evaluate new epidemiologic data and biological material collected from populations living in proximity to the test site. With time, new epidemiological data has been made available, and it is possible that these data may be linked to biological samples. Next to linking existing and newly available data to examine health effects, the existing dosimetry system needs to be expanded and further developed to include residential areas, which have not yet been taken into account. The aim of this paper is to provide an overview of previous studies evaluating the health effects of nuclear testing, including some information on dosimetry efforts, and pointing out directions for future epidemiologic studies. PMID:29138710

Implementing an Internet-Delivered Skin Cancer Genetic Testing Intervention to Improve Sun Protection Behavior in a Diverse Population: Protocol for a Randomized Controlled Trial.

PubMed

Hay, Jennifer L; Berwick, Marianne; Zielaskowski, Kate; White, Kirsten Am; Rodríguez, Vivian M; Robers, Erika; Guest, Dolores D; Sussman, Andrew; Talamantes, Yvonne; Schwartz, Matthew R; Greb, Jennie; Bigney, Jessica; Kaphingst, Kimberly A; Hunley, Keith; Buller, David B

2017-04-25

Limited translational genomic research currently exists to guide the availability, comprehension, and appropriate use of personalized genomics in diverse general population subgroups. Melanoma skin cancers are preventable, curable, common in the general population, and disproportionately increasing in Hispanics. Variants in the melanocortin-1 receptor (MC1R) gene are present in approximately 50% of the population, are major factors in determining sun sensitivity, and confer a 2-to-3-fold increase in melanoma risk in the general population, even in populations with darker skin. Therefore, feedback regarding MC1R risk status may raise risk awareness and protective behavior in the general population. We are conducting a randomized controlled trial examining Internet presentation of the risks and benefits of personalized genomic testing for MC1R gene variants that are associated with increased melanoma risk. We will enroll a total of 885 participants (462 participants are currently enrolled), who will be randomized 6:1 to personalized genomic testing for melanoma risk versus waiting list control. Control participants will be offered testing after outcome assessments. Participants will be balanced across self-reported Hispanic versus non-Hispanic ethnicity (n=750 in personalized genomic testing for melanoma risk arm; n=135 in control arm), and will be recruited from a general population cohort in Albuquerque, New Mexico, which is subject to year-round sun exposure. Baseline surveys will be completed in-person with study staff and follow-up measures will be completed via telephone. Aim 1 of the trial will examine the personal utility of personalized genomic testing for melanoma risk in terms of short-term (3-month) sun protection and skin screening behaviors, family and physician communication, and melanoma threat and control beliefs (ie, putative mediators of behavior change). We will also examine potential unintended consequences of testing among those who receive average-risk personalized genomic testing for melanoma risk findings, and examine predictors of sun protection at 3 months as the outcome. These findings will be used to develop messages for groups that receive average-risk feedback. Aim 2 will compare rates of test consideration in Hispanics versus non-Hispanics, including consideration of testing pros and cons and registration of a decision to either accept or decline testing. Aim 3 will examine personalized genomic testing for melanoma risk feedback comprehension, recall, satisfaction, and cancer-related distress in those who undergo testing, and whether these outcomes differ by ethnicity (Hispanic vs non-Hispanic), or sociocultural or demographic factors. Final outcome data collection is anticipated to be complete by October 2017, at which point data analysis will commence. This study has important implications for personalized genomics in the context of melanoma risk, and may be broadly applicable as a model for delivery of personalized genomic feedback for other health conditions. ©Jennifer L Hay, Marianne Berwick, Kate Zielaskowski, Kirsten AM White, Vivian M Rodríguez, Erika Robers, Dolores D Guest, Andrew Sussman, Yvonne Talamantes, Matthew R Schwartz, Jennie Greb, Jessica Bigney, Kimberly A Kaphingst, Keith Hunley, David B Buller. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 25.04.2017.

77 FR 55217 - Submission for OMB Review; Comment Request: Cognitive Testing of Instrumentation and Materials...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-07

...; Comment Request: Cognitive Testing of Instrumentation and Materials for the Population Assessment of..., unless it displays a currently valid OMB control number. Proposed Collection: Title: Cognitive Testing of... Administration (FDA). NIDA is requesting generic approval from OMB for cognitive testing of the PATH study's...

Silent Killer: A Study of Job Burnout in a Postsecondary Educational Setting

ERIC Educational Resources Information Center

Swagger, Russell M.

2010-01-01

The problem investigated was job burnout within postsecondary faculty populations. The study purpose was to test theory, add to the body of knowledge, and identify opportunities for effective intervention strategies that reduce job burnout within this population. The primary research question was what relationships exist between age and gender…

Control for Population Structure and Relatedness for Binary Traits in Genetic Association Studies via Logistic Mixed Models.

PubMed

Chen, Han; Wang, Chaolong; Conomos, Matthew P; Stilp, Adrienne M; Li, Zilin; Sofer, Tamar; Szpiro, Adam A; Chen, Wei; Brehm, John M; Celedón, Juan C; Redline, Susan; Papanicolaou, George J; Thornton, Timothy A; Laurie, Cathy C; Rice, Kenneth; Lin, Xihong

2016-04-07

Linear mixed models (LMMs) are widely used in genome-wide association studies (GWASs) to account for population structure and relatedness, for both continuous and binary traits. Motivated by the failure of LMMs to control type I errors in a GWAS of asthma, a binary trait, we show that LMMs are generally inappropriate for analyzing binary traits when population stratification leads to violation of the LMM's constant-residual variance assumption. To overcome this problem, we develop a computationally efficient logistic mixed model approach for genome-wide analysis of binary traits, the generalized linear mixed model association test (GMMAT). This approach fits a logistic mixed model once per GWAS and performs score tests under the null hypothesis of no association between a binary trait and individual genetic variants. We show in simulation studies and real data analysis that GMMAT effectively controls for population structure and relatedness when analyzing binary traits in a wide variety of study designs. Copyright © 2016 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Reliability of reports of childhood trauma in bipolar disorder: A test-retest study over 18 months.

PubMed

Shannon, Ciaran; Hanna, Donncha; Tumelty, Leo; Waldron, Daniel; Maguire, Chrissie; Mowlds, William; Meenagh, Ciaran; Mulholland, Ciaran

2016-01-01

This study aimed to explore the reliability of self-reported trauma histories in a population with a diagnosis of bipolar disorder using the Childhood Trauma Questionnaire. Previous studies in other populations suggest high reliability of trauma histories over time, and it was postulated that a similar high reliability would be demonstrated in this population. A total of 39 patients with a confirmed diagnosis (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, criteria) were followed up and readministered the Childhood Trauma Questionnaire after 18 months. Cohen's kappa scores and intraclass correlations suggested reasonable test-retest reliability over the 18-month time period of the study for all types of childhood abuse, namely, emotional, physical, and sexual abuse and physical and emotional neglect. Intraclass correlations ranged from r = .50 (sexual abuse) to r = .96 (physical abuse). Cohen's kappas ranged from .44 (sexual abuse) to .76 (physical abuse). Retrospective reports of childhood trauma can be seen as reliable and are in keeping with results found with other mental health populations.

Comparative neurobehavioral study of a polybrominated biphenyl-exposed population in Michigan and a nonexposed group in Wisconsin.

PubMed Central

Valciukas, J A; Lilis, R; Wolff, M S; Anderson, H A

1978-01-01

An analysis of findings regarding the prevalence and time course of symptoms and the results of neurobehavioral testing among Michigan and Wisconsin dairy farmers, is reported. Reviewed are: (1) differences in the prevalence of neurological symptoms at the time of examination; (2) differences in the incidence and time course of symptoms for the period 1972--1976; (3) differences among populations and subgroups (sex and age) regarding performance test scores; (4) correlations between performance test scores and neurological symptoms; and (5) correlations between serum PBB levels as indicators of exposure and performance tests and neurological symptoms. PMID:209977

Clinical Characteristics and Outcome of Hepatic Sarcoidosis: A Population-Based Study 1976-2013.

PubMed

Ungprasert, Patompong; Crowson, Cynthia S; Simonetto, Douglas A; Matteson, Eric L

2017-10-01

Data on clinical manifestations and outcome of hepatic sarcoidosis are scarce. This study aimed to use a population-based cohort of patients with incident sarcoidosis to better describe the characteristics of hepatic sarcoidosis. A cohort of incident cases of sarcoidosis in Olmsted County, MN, USA, from 1976 to 2013 was identified from the database. Diagnosis was verified by individual medical record review. Confirmed cases of sarcoidosis were then reviewed for liver involvement. Data on clinical manifestations, imaging study, liver biochemical tests, treatment, and outcome were collected. Cumulative incidence of cirrhosis adjusted for the competing risk of death was estimated. A total of 345 cases of incident sarcoidosis were identified. Of these, 19 cases (6%) had liver involvement (mean age 46.1 years, 53% female and 79% Caucasian). Most patients had asymptomatic liver disease and were discovered in pursuit of abnormal biochemical tests and imaging studies. Alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) were elevated in the majority of patients (88 and 90%, respectively). Elevated transaminases were less common and less severe. About half of patients had abnormal imaging study with hypodense nodular lesions being the most common abnormality (six patients) followed by hepatomegaly (three patients). Liver biopsy revealed non-caseating granuloma in 88% (14 of 16 patients). A total of four patients developed cirrhosis. Involvement of the liver by sarcoidosis was seen in 6% of patients with sarcoidosis. The majority of patients were asymptomatic. Elevated ALP and GGT were the most common abnormal biochemical tests. Liver biopsy revealed non-caseating granuloma in almost all cases. Cirrhosis was seen in a significant number of patients. Generalizability of the observations to other populations may be limited, as the studied population was predominantly Caucasian. The prevalence of liver disease may be higher in more diverse populations.

Testing of microsatellite multiplexes for individual identification of Cape Parrots (Poicephalus robustus): paternity testing and monitoring trade

PubMed Central

Coetzer, Willem G.; Downs, Colleen T.; Perrin, Mike R.

2017-01-01

Background Illegal trade in rare wildlife species is a major threat to many parrot species around the world. Wildlife forensics plays an important role in the preservation of endangered or threatened wildlife species. Identification of illegally harvested or traded animals through DNA techniques is one of the many methods used during forensic investigations. Natural populations of the South African endemic Cape Parrot (Poicephalus robustus) are negatively affected by the removal of eggs and chicks for the pet trade. Methods In this study, 16 microsatellite markers specifically designed for the South African endemic Cape Parrot (P. robustus) are assessed for their utility in forensic casework. Using these 16 loci, the genetic diversity of a subset of the captive Cape Parrot population was also assessed and compared to three wild Cape Parrot populations. Results It was determined that the full 16 locus panel has sufficient discriminatory power to be used in parentage analyses and can be used to determine if a bird has been bred in captivity and so can be legally traded or if it has been illegally removed from the wild. In cases where birds have been removed from the wild, this study suggests that a reduced 12 locus microsatellite panel has sufficient power to assign confiscated birds to geographic population of origin. Discussion The level of genetic diversity observed within the captive Cape Parrot population was similar to that observed in the wild populations, which suggests that the captive population is not suffering from decreased levels of genetic diversity. The captive Cape Parrots did however have double the number of private alleles compared to that observed in the most genetically diverse wild population. This is probably due to the presence of rare alleles present in the founder population, which has not been lost due to genetic drift, as many of the individuals tested in this study are F1–F3 wild descendants. The results from this study provide a suit of markers that can be used to aid conservation and law enforcement authorities to better control legal and illegal trade of this South African endemic. PMID:28344897

Exploring a Source of Uneven Score Equity across the Test Score Range

ERIC Educational Resources Information Center

Huggins-Manley, Anne Corinne; Qiu, Yuxi; Penfield, Randall D.

2018-01-01

Score equity assessment (SEA) refers to an examination of population invariance of equating across two or more subpopulations of test examinees. Previous SEA studies have shown that score equity may be present for examinees scoring at particular test score ranges but absent for examinees scoring at other score ranges. No studies to date have…

Ageing and Dementia in a Longitudinal Study of a Cohort with Down Syndrome

ERIC Educational Resources Information Center

Carr, Janet; Collins, Suzanne

2014-01-01

Background: A population sample of people with Down syndrome has been studied from infancy and has now been followed up again at age 47 years. Methods: Intelligence and language skills were tested and daily living skills assessed. Memory/cognitive deterioration was examined using two test instruments. Results: Scores on verbal tests of…

Pinpointing the Deficit in Executive Functions in Adolescents with Dyslexia Performing the Wisconsin Card Sorting Test: An ERP Study

ERIC Educational Resources Information Center

Horowitz-Kraus, Tzipi

2014-01-01

Adolescents with dyslexia exhibit well-established impairments in executive abilities. The Wisconsin card sorting test (WCST) is an executive test that yields surprisingly inconsistent results with this population. The current study aimed to shed light on the contradictory findings in the literature regarding the performance levels by individuals…

Using eHealth to engage and retain priority populations in the HIV treatment and care cascade in the Asia-Pacific region: a systematic review of literature.

PubMed

Purnomo, Julianita; Coote, Katherine; Mao, Limin; Fan, Ling; Gold, Julian; Ahmad, Raghib; Zhang, Lei

2018-02-17

The exponential growth in the reach and development of new technologies over the past decade means that mobile technologies and social media play an increasingly important role in service delivery models to maximise HIV testing and access to treatment and care. This systematic review examines the impact of electronic and mobile technologies in medical care (eHealth) in the linkage to and retention of priority populations in the HIV treatment and care cascade, focussing on the Asia-Pacific region. The review was informed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement from the Cochrane Collaboration guidelines. Both grey and published scientific literature from five different databases were searched for all original articles in English published from 2010 to 2017. Studies conducted outside the Asia-Pacific region or not including HIV priority populations were excluded. The methodological quality of studies included in the review was assessed using the Quality Assessment Tool for Quantitative Studies. The database search identified 7309 records. Of the 224 peer-reviewed articles identified for full text review, 16 studies from seven countries met inclusion criteria. Six cross sectional studies found evidence to support the use of eHealth, via text messages, instant messaging, social media and health promotion websites, to increase rates of HIV testing and re-testing among men who have sex with men (MSM). Evidence regarding the efficacy of eHealth interventions to improve antiretroviral treatment (ART) adherence was mixed, where one randomised controlled trial (RCT) showed significant benefit of weekly phone call reminders on improving ART adherence. Three further RCTs found that biofeedback eHealth interventions that provided estimated ART plasma concentration levels, showed promising results for ART adherence. This review found encouraging evidence about how eHealth can be used across the HIV treatment and care cascade in the Asia-Pacific region, including increasing HIV testing and re-testing in priority populations as well as ART adherence. eHealth interventions have an important role to play in the movement towards the end of AIDS, particularly to target harder-to-reach HIV priority populations, such as MSM.

Comparison between urine albumin-to-creatinine ratio and urine protein dipstick testing for prevalence and ability to predict the risk for chronic kidney disease in the general population (Iwate-KENCO study): a prospective community-based cohort study.

PubMed

Koeda, Yorihiko; Tanaka, Fumitaka; Segawa, Toshie; Ohta, Mutsuko; Ohsawa, Masaki; Tanno, Kozo; Makita, Shinji; Ishibashi, Yasuhiro; Itai, Kazuyoshi; Omama, Shin-Ichi; Onoda, Toshiyuki; Sakata, Kiyomi; Ogasawara, Kuniaki; Okayama, Akira; Nakamura, Motoyuki

2016-05-12

This study compared the combination of estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR) vs. eGFR and urine protein reagent strip testing to determine chronic kidney disease (CKD) prevalence, and each method's ability to predict the risk for cardiovascular events in the general Japanese population. Baseline data including eGFR, UACR, and urine dipstick tests were obtained from the general population (n = 22 975). Dipstick test results (negative, trace, positive) were allocated to three levels of UACR (<30, 30-300, >300), respectively. In accordance with Kidney Disease Improving Global Outcomes CKD prognosis heat mapping, the cohort was classified into four risk grades (green: grade 1; yellow: grade 2; orange: grade 3, red: grade 4) based on baseline eGFR and UACR levels or dipstick tests. During the mean follow-up period of 5.6 years, 708 new onset cardiovascular events were recorded. For CKD identified by eGFR and dipstick testing (dipstick test ≥ trace and eGFR <60 mL/min/1.73 m(2)), the incidence of CKD was found to be 9 % in the general population. In comparison to non-CKD (grade 1), although cardiovascular risk was significantly higher in risk grades ≥3 (relative risk (RR) = 1.70; 95 % CI: 1.28-2.26), risk predictive ability was not significant in risk grade 2 (RR = 1.20; 95 % CI: 0.95-1.52). When CKD was defined by eGFR and UACR (UACR ≥30 mg/g Cr and eGFR <60 mL/min/1.73 m(2)), prevalence was found to be 29 %. Predictive ability in risk grade 2 (RR = 1.41; 95 % CI: 1.19-1.66) and risk grade ≥3 (RR = 1.76; 95 % CI: 1.37-2.28) were both significantly greater than for non-CKD. Reclassification analysis showed a significant improvement in risk predictive abilities when CKD risk grading was based on UACR rather than on dipstick testing in this population (p < 0.001). Although prevalence of CKD was higher when detected by UACR rather than urine dipstick testing, the predictive ability for cardiovascular events from UACR-based risk grading was superior to that of dipstick-based risk grading in the general population.

The impact of rapid evolution on population dynamics in the wild: experimental test of eco-evolutionary dynamics.

PubMed

Turcotte, Martin M; Reznick, David N; Hare, J Daniel

2011-11-01

Rapid evolution challenges the assumption that evolution is too slow to impact short-term ecological dynamics. This insight motivates the study of 'Eco-Evolutionary Dynamics' or how evolution and ecological processes reciprocally interact on short time scales. We tested how rapid evolution impacts concurrent population dynamics using an aphid (Myzus persicae) and an undomesticated host (Hirschfeldia incana) in replicated wild populations. We manipulated evolvability by creating non-evolving (single clone) and potentially evolving (two-clone) aphid populations that contained genetic variation in intrinsic growth rate. We observed significant evolution in two-clone populations whether or not they were exposed to predators and competitors. Evolving populations grew up to 42% faster and attained up to 67% higher density, compared with non-evolving control populations but only in treatments exposed to competitors and predators. Increased density also correlates with relative fitness of competing clones suggesting a full eco-evolutionary dynamic cycle defined as reciprocal interactions between evolution and density. © 2011 Blackwell Publishing Ltd/CNRS.

A Monte Carlo Study of Levene's Test of Homogeneity of Variance: Empirical Frequencies of Type I Error in Normal Distributions.

ERIC Educational Resources Information Center

Neel, John H.; Stallings, William M.

An influential statistics test recommends a Levene text for homogeneity of variance. A recent note suggests that Levene's test is upwardly biased for small samples. Another report shows inflated Alpha estimates and low power. Neither study utilized more than two sample sizes. This Monte Carlo study involved sampling from a normal population for…

Outlier Loci and Selection Signatures of Simple Sequence Repeats (SSRs) in Flax (Linum usitatissimum L.).

PubMed

Soto-Cerda, Braulio J; Cloutier, Sylvie

2013-01-01

Genomic microsatellites (gSSRs) and expressed sequence tag-derived SSRs (EST-SSRs) have gained wide application for elucidating genetic diversity and population structure in plants. Both marker systems are assumed to be selectively neutral when making demographic inferences, but this assumption is rarely tested. In this study, three neutrality tests were assessed for identifying outlier loci among 150 SSRs (85 gSSRs and 65 EST-SSRs) that likely influence estimates of population structure in three differentiated flax sub-populations ( F ST  = 0.19). Moreover, the utility of gSSRs, EST-SSRs, and the combined sets of SSRs was also evaluated in assessing genetic diversity and population structure in flax. Six outlier loci were identified by at least two neutrality tests showing footprints of balancing selection. After removing the outlier loci, the STRUCTURE analysis and the dendrogram topology of EST-SSRs improved. Conversely, gSSRs and combined SSRs results did not change significantly, possibly as a consequence of the higher number of neutral loci assessed. Taken together, the genetic structure analyses established the superiority of gSSRs to determine the genetic relationships among flax accessions, although the combined SSRs produced the best results. Genetic diversity parameters did not differ statistically ( P  > 0.05) between gSSRs and EST-SSRs, an observation partially explained by the similar number of repeat motifs. Our study provides new insights into the ability of gSSRs and EST-SSRs to measure genetic diversity and structure in flax and confirms the importance of testing for the occurrence of outlier loci to properly assess natural and breeding populations, particularly in studies considering only few loci.

A systematic review and meta-analysis of community and facility-based approaches to address gaps in HIV testing and linkage in sub-Saharan Africa

PubMed Central

Sharma, Monisha; Ying, Roger; Tarr, Gillian; Barnabas, Ruanne

2016-01-01

HIV testing and counselling is the first crucial step for linkage to HIV treatment and prevention. However, despite high HIV burden in sub-Saharan Africa, testing coverage is low, particularly among young adults and men. Community-based HIV testing and counselling (testing outside of health facilities) has the potential to reduce coverage gaps, but the relative impact of different modalities is not well assessed. We conducted a systematic review of HIV testing and counselling modalities, characterizing facility and community (home, mobile, index, key populations, campaign, workplace and self-testing) approaches by population reached, HIV-positivity, CD4 count at diagnosis and linkage. Of 2,520 abstracts screened, 126 met eligibility criteria. Community HIV testing had high coverage and uptake and identified HIV-positive individuals at higher CD4 counts than facility testing. Mobile HIV testing reached the highest proportion of men of all modalities examined (50%, 95% CI = 47–54%) and home with self-testing reached the highest proportion of young adults (66%, 95% CI = 65–67%). Few studies evaluated HIV testing and counselling for key populations (commercial sex workers and men who have sex with men), but these interventions yielded high HIV positivity (38%, 95% CI = 19–62%) combined with the highest proportion of first-time testers (78%, 95% CI = 63–88%), indicating service gaps. Facilitated linkage (for example, counsellor follow-up to support linkage) achieved high linkage to care (95%, 95% CI = 87–98%) and ART initiation (75%, 95% CI = 68–82%). Expanding mobile HIV testing, self-testing and outreach to key populations with facilitated linkage can increase the proportion of men, young adults and high-risk individuals linked to HIV treatment and prevention. PMID:26633769

Genetic divergence and signatures of natural selection in marginal populations of a keystone, long-lived conifer, Eastern White Pine (Pinus strobus) from Northern Ontario.

PubMed

Chhatre, Vikram E; Rajora, Om P

2014-01-01

Marginal populations are expected to provide the frontiers for adaptation, evolution and range shifts of plant species under the anticipated climate change conditions. Marginal populations are predicted to show genetic divergence from central populations due to their isolation, and divergent natural selection and genetic drift operating therein. Marginal populations are also expected to have lower genetic diversity and effective population size (Ne) and higher genetic differentiation than central populations. We tested these hypotheses using eastern white pine (Pinus strobus) as a model for keystone, long-lived widely-distributed plants. All 614 eastern white pine trees, in a complete census of two populations each of marginal old-growth, central old-growth, and central second-growth, were genotyped at 11 microsatellite loci. The central populations had significantly higher allelic and genotypic diversity, latent genetic potential (LGP) and Ne than the marginal populations. However, heterozygosity and fixation index were similar between them. The marginal populations were genetically diverged from the central populations. Model testing suggested predominant north to south gene flow in the study area with curtailed gene flow to northern marginal populations. Signatures of natural selection were detected at three loci in the marginal populations; two showing divergent selection with directional change in allele frequencies, and one balancing selection. Contrary to the general belief, no significant differences were observed in genetic diversity, differentiation, LGP, and Ne between old-growth and second-growth populations. Our study provides information on the dynamics of migration, genetic drift and selection in central versus marginal populations of a keystone long-lived plant species and has broad evolutionary, conservation and adaptation significance.

Genetic Divergence and Signatures of Natural Selection in Marginal Populations of a Keystone, Long-Lived Conifer, Eastern White Pine (Pinus strobus) from Northern Ontario

PubMed Central

Chhatre, Vikram E.; Rajora, Om P.

2014-01-01

Marginal populations are expected to provide the frontiers for adaptation, evolution and range shifts of plant species under the anticipated climate change conditions. Marginal populations are predicted to show genetic divergence from central populations due to their isolation, and divergent natural selection and genetic drift operating therein. Marginal populations are also expected to have lower genetic diversity and effective population size (N e) and higher genetic differentiation than central populations. We tested these hypotheses using eastern white pine (Pinus strobus) as a model for keystone, long-lived widely-distributed plants. All 614 eastern white pine trees, in a complete census of two populations each of marginal old-growth, central old-growth, and central second-growth, were genotyped at 11 microsatellite loci. The central populations had significantly higher allelic and genotypic diversity, latent genetic potential (LGP) and N e than the marginal populations. However, heterozygosity and fixation index were similar between them. The marginal populations were genetically diverged from the central populations. Model testing suggested predominant north to south gene flow in the study area with curtailed gene flow to northern marginal populations. Signatures of natural selection were detected at three loci in the marginal populations; two showing divergent selection with directional change in allele frequencies, and one balancing selection. Contrary to the general belief, no significant differences were observed in genetic diversity, differentiation, LGP, and N e between old-growth and second-growth populations. Our study provides information on the dynamics of migration, genetic drift and selection in central versus marginal populations of a keystone long-lived plant species and has broad evolutionary, conservation and adaptation significance. PMID:24859159

Physical examination for lumbar radiculopathy due to disc herniation in patients with low-back pain.

PubMed

van der Windt, Daniëlle Awm; Simons, Emmanuel; Riphagen, Ingrid I; Ammendolia, Carlo; Verhagen, Arianne P; Laslett, Mark; Devillé, Walter; Deyo, Rick A; Bouter, Lex M; de Vet, Henrica Cw; Aertgeerts, Bert

2010-02-17

Low-back pain with leg pain (sciatica) may be caused by a herniated intervertebral disc exerting pressure on the nerve root. Most patients will respond to conservative treatment, but in carefully selected patients, surgical discectomy may provide faster relief of symptoms. Primary care clinicians use patient history and physical examination to evaluate the likelihood of disc herniation and select patients for further imaging and possible surgery. (1) To assess the performance of tests performed during physical examination (alone or in combination) to identify radiculopathy due to lower lumbar disc herniation in patients with low-back pain and sciatica;(2) To assess the influence of sources of heterogeneity on diagnostic performance. We searched electronic databases for primary studies: PubMed (includes MEDLINE), EMBASE, and CINAHL, and (systematic) reviews: PubMed and Medion (all from earliest until 30 April 2008), and checked references of retrieved articles. We considered studies if they compared the results of tests performed during physical examination on patients with back pain with those of diagnostic imaging (MRI, CT, myelography) or findings at surgery. Two review authors assessed the quality of each publication with the QUADAS tool, and extracted details on patient and study design characteristics, index tests and reference standard, and the diagnostic two-by-two table. We presented information on sensitivities and specificities with 95% confidence intervals (95% CI) for all aspects of physical examination. Pooled estimates of sensitivity and specificity were computed for subsets of studies showing sufficient clinical and statistical homogeneity. We included 16 cohort studies (median N = 126, range 71 to 2504) and three case control studies (38 to100 cases). Only one study was carried out in a primary care population. When used in isolation, diagnostic performance of most physical tests (scoliosis, paresis or muscle weakness, muscle wasting, impaired reflexes, sensory deficits) was poor. Some tests (forward flexion, hyper-extension test, and slump test) performed slightly better, but the number of studies was small. In the one primary care study, most tests showed higher specificity and lower sensitivity compared to other settings.Most studies assessed the Straight Leg Raising (SLR) test. In surgical populations, characterized by a high prevalence of disc herniation (58% to 98%), the SLR showed high sensitivity (pooled estimate 0.92, 95% CI: 0.87 to 0.95) with widely varying specificity (0.10 to 1.00, pooled estimate 0.28, 95% CI: 0.18 to 0.40). Results of studies using imaging showed more heterogeneity and poorer sensitivity. The crossed SLR showed high specificity (pooled estimate 0.90, 95% CI: 0.85 to 0.94) with consistently low sensitivity (pooled estimate 0.28, 95% CI: 0.22 to 0.35).Combining positive test results increased the specificity of physical tests, but few studies presented data on test combinations. When used in isolation, current evidence indicates poor diagnostic performance of most physical tests used to identify lumbar disc herniation. However, most findings arise from surgical populations and may not apply to primary care or non-selected populations. Better performance may be obtained when tests are combined.

A study of the temporal variability of atrazine in private well water. part ii: analysis of data

USGS Publications Warehouse

Pinsky, Paul; Lorber, Matthew; Johnson, Kent; Kross, Burton; Burmeister, Leon; Wilkins, Amina; Hallberg, George

1997-01-01

In 1988, the Iowa Department of Natural Resources, along withthe University of Iowa, conducted the Statewide Rural WellWater Survey, commonly known as SWRL. A total of 686private rural drinking water wells was selected by use of aprobability sample and tested for pesticides and nitrate. A subsetof these wells, the 10% repeat wells, were additionally sampledin October, 1990 and June, 1991. Starting in November, 1991,the University of Iowa, with sponsorship from the United StatesEnvironmental Protection Agency, revisited the 10% repeat wellsto begin a study of the temporal variability of atrazine and nitratein wells. Other wells, which had originally tested positive foratrazine in SWRL but were not in the 10% population, wereadded to the study population. Temporal sampling for a year-long period began in February of 1992 and concluded in Januaryof 1993. All wells were sampled monthly, a subset was sampledweekly, and a second subset was sampled for 14 day consecutiveperiods. Of the 67 wells in the 10% population tested monthly,7 (10.4%) tested positive for atrazine at least once during theyear, and 3 (4%) were positive each of the 12 months. Theaverage concentration in the 7 wells was 0.10 µg/L. Fornitrate, 15 (22%) wells in the 10% repeat population monthlysampling were above the Maximum Contaminant Level of 10 mg/L at least once. This paper, the second of two papers on thisstudy, describes the analysis of data from the survey. The firstpaper (Lorber et al., 1997) reviews the study design, theanalytical methodologies, and development of the data base.

Measurement of urinary metanephrines to screen for pheochromocytoma in an unselected hospital referral population

PubMed Central

Brain, Keith L.; Kay, Jonathan; Shine, Brian

2009-01-01

Background Despite the rarity of pheochromocytoma, the dangers of uncontrolled severe hypertension and the very effective surgical treatment of this condition mean that diagnosis is important. Urinary or plasma catecholamines or catecholamine-derivatives are commonly used to screen for pheochromocytomas prior to imaging. This study investigates whether derived measures obtained from 24-hour urinary metanephrine results, patient age and sex can better predict tumors in populations with a low pre-test probability. Methods This study takes a pragmatic approach by retrospectively studying the outcomes of an unselected population referred for urinary metanephrine testing (1819 patients) to a tertiary hospital laboratory, and investigates the usefulness of some simple derivative measures for detecting pheochromocytoma. Urinary 24-hour excretion of metanephrine, normetanephrine and 3-methoxytyramine were normalized by dividing by an age- and sex- specific reference range. The ability of products of these normalized measures to predict pheochromocytomas was assessed, compared to a gold standard of biopsy-confirmed tumor. Results The normalized product of urinary metanephrine and normetanephrine excretion (nMAD.nNMT) proved to be a highly sensitive (100%) and specific (99.1%) measure yielding a positive predictive value 82%. Receiver-operator characteristic curves were not improved by including the normalized 3-methoxytyramine concentrations in the product. nMAD.nNMT gave higher sensitivity and specificity than either test alone. Conclusion We suggest that nMAD.nNMT is a useful measure for identifying pheochromocytoma in a population with a low pre-test probability. PMID:16990424

Personality traits in patients with cluster headache: a comparison with migraine patients.

PubMed

Muñoz, I; Hernández, M S; Santos, S; Jurado, C; Ruiz, L; Toribio, E; Sotelo, E M; Guerrero, A L; Molina, V; Uribe, F; Cuadrado, M L

2016-01-01

Cluster headache (CH) has been associated with certain personality traits and lifestyle features, but there are few studies assessing personality profiles in CH. We aimed to analyze personality traits in patients with CH, and to compare them with those found in migraine. We included all consecutive patients with CH attending 5 outpatient offices between January and December 2013. Personality traits were evaluated using the Salamanca screening test, a validated inventory assessing 11 personality traits grouped in 3 clusters. We analyzed the test results in this population, and compared them with those of a migraine population previously assessed with the same test. Eighty patients with CH (75 men, 5 women; mean age, 43.2 ± 9.9 years) were recruited. The reference population consisted of 164 migraine patients (30 men, 134 women; mean age 36.4 ± 12.7 years). In CH patients, the most frequent personality traits were anancastic (52.5 %), anxious (47.5 %), histrionic (45 %), schizoid (42.5 %), impulsive (32.5 %) and paranoid (30 %). When compared to migraine patients, paranoid (p < 0.001; χ2 test), and schizoid traits (p = 0.007; χ2 test) were significantly more prevalent in CH patients. In logistic regression analysis the paranoid trait was significantly associated with CH (p = 0.001; OR: 3.27, 95 % CI [1.66-6.43]). According to the Salamanca screening test, personality traits included in cluster A (odd or eccentric disorders) are more prevalent in CH patients than in a population of migraineurs. Larger studies are needed to determine whether certain personality traits are related to CH.

The effect of periodontal therapy on glycaemic control in a Hispanic population with type 2 diabetes: a randomized controlled trial.

PubMed

Gay, Isabel C; Tran, Duong T; Cavender, Adriana C; Weltman, Robin; Chang, Jennifer; Luckenbach, Estelle; Tribble, Gena D

2014-07-01

In the Mexican-American population, the prevalence of Type 2 diabetes mellitus (T2DM) is as high as 50% of the population. This randomized controlled clinical trial was designed to elucidate how treatment of periodontal disease affects HbA1c values in this population. One hundred and fifty-four T2DM patients with periodontal disease were enrolled in the study. The test group was treated with scaling and root planing (SRP); the control group received oral hygiene instructions. At baseline and 4-6 weeks after therapy, a complete periodontal examination was performed. Blood was collected at baseline and 4 months later for HbA1c levels. One hundred and twenty-six individuals completed the study. Baseline mean ± SD HbA1c for the test and control groups were 9.0 ± 2.3% and 8.4 ± 2.0% respectively. Non-significant difference in HbA1c reductions (0.6 ± 2.1% and 0.3 ± 1.7%) was found between test and control groups at 4 months. Comparisons of the periodontal clinical parameters between the test and control groups found significant differences with improved results in the test subjects. No statistically significant differences were found in the changes of HbA1c levels between test and control groups. Non-surgical periodontal therapy improved the magnitude of change in periodontal parameters as compared to the control subjects. ClinicalTrials.gov Identifier: NCT01128374. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Individuals in food webs: the relationships between trophic position, omnivory and among-individual diet variation.

PubMed

Svanbäck, Richard; Quevedo, Mario; Olsson, Jens; Eklöv, Peter

2015-05-01

Among-individual diet variation is common in natural populations and may occur at any trophic level within a food web. Yet, little is known about its variation among trophic levels and how such variation could affect phenotypic divergence within populations. In this study we investigate the relationships between trophic position (the population's range and average) and among-individual diet variation. We test for diet variation among individuals and across size classes of Eurasian perch (Perca fluviatilis), a widespread predatory freshwater fish that undergoes ontogenetic niche shifts. Second, we investigate among-individual diet variation within fish and invertebrate populations in two different lake communities using stable isotopes. Third, we test potential evolutionary implications of population trophic position by assessing the relationship between the proportion of piscivorous perch (populations of higher trophic position) and the degree of phenotypic divergence between littoral and pelagic perch sub-populations. We show that among-individual diet variation is highest at intermediate trophic positions, and that this high degree of among-individual variation likely causes an increase in the range of trophic positions among individuals. We also found that phenotypic divergence was negatively related to trophic position in a population. This study thus shows that trophic position is related to and may be important for among-individual diet variation as well as to phenotypic divergence within populations.

FUNCTIONAL PERFORMANCE TESTING OF THE HIP IN ATHLETES: A SYSTEMATIC REVIEW FOR RELIABILITY AND VALIDITY

PubMed Central

Martin, RobRoy L.

2012-01-01

Purpose/Background: The purpose of this study was to systematically review the literature for functional performance tests with evidence of reliability and validity that could be used for a young, athletic population with hip dysfunction. Methods: A search of PubMed and SPORTDiscus databases were performed to identify movement, balance, hop/jump, or agility functional performance tests from the current peer-reviewed literature used to assess function of the hip in young, athletic subjects. Results: The single-leg stance, deep squat, single-leg squat, and star excursion balance tests (SEBT) demonstrated evidence of validity and normative data for score interpretation. The single-leg stance test and SEBT have evidence of validity with association to hip abductor function. The deep squat test demonstrated evidence as a functional performance test for evaluating femoroacetabular impingement. Hop/Jump tests and agility tests have no reported evidence of reliability or validity in a population of subjects with hip pathology. Conclusions: Use of functional performance tests in the assessment of hip dysfunction has not been well established in the current literature. Diminished squat depth and provocation of pain during the single-leg balance test have been associated with patients diagnosed with FAI and gluteal tendinopathy, respectively. The SEBT and single-leg squat tests provided evidence of convergent validity through an analysis of kinematics and muscle function in normal subjects. Reliability of functional performance tests have not been established on patients with hip dysfunction. Further study is needed to establish reliability and validity of functional performance tests that can be used in a young, athletic population with hip dysfunction. Level of Evidence: 2b (Systematic Review of Literature) PMID:22893860

Strategies for implementing genomic selection for feed efficiency in dairy cattle breeding schemes.

PubMed

Wallén, S E; Lillehammer, M; Meuwissen, T H E

2017-08-01

Alternative genomic selection and traditional BLUP breeding schemes were compared for the genetic improvement of feed efficiency in simulated Norwegian Red dairy cattle populations. The change in genetic gain over time and achievable selection accuracy were studied for milk yield and residual feed intake, as a measure of feed efficiency. When including feed efficiency in genomic BLUP schemes, it was possible to achieve high selection accuracies for genomic selection, and all genomic BLUP schemes gave better genetic gain for feed efficiency than BLUP using a pedigree relationship matrix. However, introducing a second trait in the breeding goal caused a reduction in the genetic gain for milk yield. When using contracted test herds with genotyped and feed efficiency recorded cows as a reference population, adding an additional 4,000 new heifers per year to the reference population gave accuracies that were comparable to a male reference population that used progeny testing with 250 daughters per sire. When the test herd consisted of 500 or 1,000 cows, lower genetic gain was found than using progeny test records to update the reference population. It was concluded that to improve difficult to record traits, the use of contracted test herds that had additional recording (e.g., measurements required to calculate feed efficiency) is a viable option, possibly through international collaborations. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Celiac disease in non-clinical populations of Japan.

PubMed

Fukunaga, Mai; Ishimura, Norihisa; Fukuyama, Chika; Izumi, Daisuke; Ishikawa, Nahoko; Araki, Asuka; Oka, Akihiko; Mishiro, Tomoko; Ishihara, Shunji; Maruyama, Riruke; Adachi, Kyoichi; Kinoshita, Yoshikazu

2018-02-01

Celiac disease is a chronic autoimmune enteropathy caused by gluten ingestion. While its prevalence in Western countries is reported to be as high as 1%, the prevalence has not been evaluated in a large-scale study of a Japanese population. The aim of our study was to clarify the possible presence of celiac disease in a Japanese non-clinical population as well as in patients showing symptoms suggestive of the disease. Serum samples were collected from 2008 non-clinical adults and 47 patients with chronic unexplained abdominal symptoms between April 2014 and June 2016. The anti-tissue transglutaminase (TTG) immunoglobulin A antibody titer was determined as a screening test for celiac disease in all subjects, and individuals with a value of >2 U/mL subsequently underwent testing for the presence of serum endomysial IgA antibody (EMA) as confirmation. Those testing positive for EMA or with a high concentration (>10 U/mL) of TTG were further investigated by histopathological examinations of duodenal mucosal biopsy specimens and HLA typing tests. Of the 2008 non-clinical adults from whom serum samples were collected, 161 tested positive for TTG, and all tested negative for EMA. Four subjects who had a high TTG titer were invited to undergo confirmatory testing, and the histopathological results confirmed the presence of celiac disease in only a single case (0.05%). Of the 47 symptomatic patients, one (2.1%) was found to have a high TTG titer and was diagnosed with celiac disease based on duodenal histopathological findings. The presence of celiac disease in a non-clinical Japanese population was low at 0.05% and was rarely found in patients with unexplained chronic abdominal symptoms.

Detecting negative selection on recurrent mutations using gene genealogy

PubMed Central

2013-01-01

Background Whether or not a mutant allele in a population is under selection is an important issue in population genetics, and various neutrality tests have been invented so far to detect selection. However, detection of negative selection has been notoriously difficult, partly because negatively selected alleles are usually rare in the population and have little impact on either population dynamics or the shape of the gene genealogy. Recently, through studies of genetic disorders and genome-wide analyses, many structural variations were shown to occur recurrently in the population. Such “recurrent mutations” might be revealed as deleterious by exploiting the signal of negative selection in the gene genealogy enhanced by their recurrence. Results Motivated by the above idea, we devised two new test statistics. One is the total number of mutants at a recurrently mutating locus among sampled sequences, which is tested conditionally on the number of forward mutations mapped on the sequence genealogy. The other is the size of the most common class of identical-by-descent mutants in the sample, again tested conditionally on the number of forward mutations mapped on the sequence genealogy. To examine the performance of these two tests, we simulated recurrently mutated loci each flanked by sites with neutral single nucleotide polymorphisms (SNPs), with no recombination. Using neutral recurrent mutations as null models, we attempted to detect deleterious recurrent mutations. Our analyses demonstrated high powers of our new tests under constant population size, as well as their moderate power to detect selection in expanding populations. We also devised a new maximum parsimony algorithm that, given the states of the sampled sequences at a recurrently mutating locus and an incompletely resolved genealogy, enumerates mutation histories with a minimum number of mutations while partially resolving genealogical relationships when necessary. Conclusions With their considerably high powers to detect negative selection, our new neutrality tests may open new venues for dealing with the population genetics of recurrent mutations as well as help identifying some types of genetic disorders that may have escaped identification by currently existing methods. PMID:23651527

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

PubMed

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

2018-01-01

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

Engagement in the HIV Care Continuum among Key Populations in Tijuana, Mexico.

PubMed

Smith, Laramie R; Patterson, Thomas L; Magis-Rodriguez, Carlos; Ojeda, Victoria D; Burgos, Jose Luis; Rojas, Sarah A; Zúñiga, María Luisa; Strathdee, Steffanie A

2016-05-01

In Tijuana, Mexico, HIV is concentrated in sub-epidemics of key populations: persons who inject drugs (PWID), sex workers (SW), and men who have sex with men (MSM). To date, data on engagement in the HIV care continuum among these key populations, particularly in resource-constrained settings, are sparse. We pooled available epidemiological data from six studies (N = 3368) to examine HIV testing and treatment uptake in these key populations; finding an overall HIV prevalence of 5.7 %. Of the 191 identified HIV-positive persons, only 11.5 % knew their HIV-positive status and 3.7 % were on ART. Observed differences between these HIV-positive key populations suggest PWID (vs. non-PWID) were least likely to have previously tested or initiate HIV care. MSM (vs. non-MSM) were more likely to have previously tested but not more likely to know their HIV-positive status. Of persons aware of their HIV-positive status, SW (vs. non-SW) were more likely to initiate HIV care. Findings suggest engagement of key populations in HIV treatment is far below estimates observed for similarly resource-constrained generalized epidemics in sub-Saharan Africa. These data provide one of the first empirical-snapshots highlighting the extent of HIV treatment disparities in key populations.

First report of pyrethroid resistance in Rhipicephalus (Boophilus) annulatus larvae (Say, 1821) from Iran.

PubMed

Ziapour, Seyyed Payman; Kheiri, Sadegh; Asgarian, Fatemeh; Fazeli-Dinan, Mahmoud; Yazdi, Fariborz; Mohammadpour, Reza Ali; Aarabi, Mohsen; Enayati, Ahmadali

2016-04-01

Rhipicephalus (Boophilus) annulatus is one of the most important hard ticks parasitizing cattle in northern Iran. The aim of this study was to evaluate pyrethroid resistance levels of this species from Nur County, northern Iran. The hard ticks were collected through a multistage cluster randomized sampling method from the study area and fully engorged female R. (B.) annulatus were reared in a controlled insectary until they produced larvae for bioassay. Seventeen populations of the hard ticks were bioassayed with cypermethrin and 12 populations with lambda-cyhalothrin using a modified larval packet test (LPT). Biochemical assays to measure the contents/activity of different enzyme groups including mixed function oxidases (MFOs), glutathione S-transferases (GSTs) and general esterases were performed. Population 75 showed a resistance ratio of 4.05 with cypermethrin when compared with the most susceptible field population 66 at the LC50 level. With lambda-cyhalothrin the resistance ratio based on LC50 was 3.67 when compared with the susceptible population. The results of biochemical assays demonstrated significantly elevated levels of GSTs and esterases in populations tested compared with the heterozygous susceptible filed population and a correlation coefficient of these enzymes was found in association to lambda-cyhalothrin resistance. Based on the results, pyrethroid acaricides may operationally fail to control R. (B.) annulatus in North of Iran. This study is the first document of pyrethroid resistance in R. (B.) annulatus populations from Iran. Copyright © 2016 Elsevier B.V. All rights reserved.

Field evaluation of three blood-based assays for elk (Cervus canadensis) naturally infected with Mycobacterium bovis.

PubMed

Shury, Todd K; Bergeson, Doug; Surujballi, Om; Lyashchenko, Konstantin P; Greenwald, Rena

2014-08-01

Diagnosis of Mycobacterium bovis in wild populations is very challenging due to complications imposed by the use of traditional skin tests, poor sensitivity of gold standard tests which rely on culture of M. bovis from tissues and wide variations in severity of disease. Various combinations of a lymphocyte stimulation test (LST), fluorescence polarization assay (FPA) and the Cervid TB Stat-Pak were evaluated using two different validation approaches: a latent class analysis and classical statistical approach using culture as a gold standard. A validation subsample consisting of animals culled for population control and mortalities from capture provided an unbiased estimate of test performance for comparison. The sensitivity of the LST (0.83, 95% CI: [0.70-0.97] as a single test was similar to existing tuberculin skin tests, but the sensitivity of the FPA (0.40, 95% CI: [0.22-0.58]) and Cervid TB Stat-Pak (0.62, 95% CI: [0.41-0.83]) were lower in this population. Test performance of the LST and Cervid TB Stat-Pak in parallel was similar to the use of all three tests in parallel and inclusion of the FPA did not greatly enhance test performance. Prevalence of M. bovis in elk varied substantially between the high risk area of southern Manitoba (9.1%, 95% CI: [6.09-12.1%]) and lower risk areas outside this zone (0.76%, 95% CI: [0-2.26%]). Bayesian latent class analysis indicated lack of covariance between the two antibody tests (FPA and Cervid TB Stat-Pak) while the classical two-stage analysis indicated there was conditional dependence between the tests. All three tests when used in parallel resulted in 100% NPV using all three validation methods, indicating few elk were misclassified as false negative by post mortem culture. Similar to previous studies, this study found that combinations of blood tests that utilize cell mediated responses along with humoral antibody responses maximize the sensitivity of tests for diagnosis of M. bovis in wild cervid populations. Copyright © 2013 CROWN COPYRIGHT and Elsevier B.V. Published by Elsevier B.V. All rights reserved.

Genetic Variability and Geographic Diversity of the Common Bed Bug (Hemiptera: Cimicidae) Populations from the Midwest Using Microsatellite Markers.

PubMed

Narain, Ralph B; Lalithambika, Sreedevi; Kamble, Shripat T

2015-07-01

With the recent global resurgence of the bed bugs (Cimex lectularius L.), there is a need to better understand its biology, ecology, and ability to establish populations. Bed bugs are domestic pests that feed mainly on mammalian blood. Although bed bugs have not been implicated as vectors of pathogens, their biting activity inflicts severe insomnia and allergic reactions. Moreover, they have recently developed resistance to various insecticides, which requires further molecular research to determine genetic variation and appropriate interventions. Population dynamics, including genetic differentiation and genetic distance of 10 populations from the Midwest were analyzed in this study. The bed bug samples collected by pest control companies were genotyped using eight species-specific microsatellite markers. Results showed all eight markers were polymorphic, with 8-16 alleles per locus, suggesting high genetic diversity. The FST values were >0.25, signifying pronounced genetic differentiation. The G-test results also indicated high genetic differentiation among populations. The frequency of the most common allele across all eight loci was 0.42. The coefficient of relatedness between each of the populations was >0.5, indicative of sibling or parent-offspring relationships, while the FIS and its confidence interval values were statistically insignificant within the populations tested. The populations departed from Hardy-Weinberg equilibrium, possibly because of high heterozygosity. The genetic distance analysis using a neighbor-joining tree showed that the populations from Kansas City, MO, were genetically separate from most of those from Nebraska, indicating a geographic pattern of genetic structure. Our study demonstrated the effectiveness of using microsatellite markers to study bed bugs population structure, thereby improving our understanding of bed bug population dynamics in the Midwest. Overall, this study showed a high genetic diversity and identified several new alleles in the bed bug populations in the Midwest. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Variation of Metallothionein I and II Gene Expression in the Bank Vole (Clethrionomys glareolus) Under Environmental Zinc and Cadmium Exposure.

PubMed

Mikowska, Magdalena; Dziublińska, Barbara; Świergosz-Kowalewska, Renata

2018-07-01

The main idea of the study was to assess how environmental metal pollution activates defence responses at transcription levels in the tissues of bank voles (Clethrionomys glareolus). For this purpose, the metallothioneine (MT) genes expression (a well known biomarker of exposure and response to various metals) was measured. The real-time PCR method was used for relative quantification of metallothionein I and metallothionein II expressions in the livers, kidneys and testes of bank voles from six populations exposed to different contaminants, mainly zinc, cadmium and iron. The assessment of Zn, Cu and Fe concentrations in the tissues allowed to study the MTs gene expression responses to these metals. ANOVA analysis showed differences between populations in terms of metal concentration in tissues, livers and kidneys. Student T test showed significant differences in metal concentration between unpolluted and polluted sites only for the liver tissue: significantly lower Zn levels and significantly higher Fe levels in the unpolluted sites. Kruskal-Wallis test performed on C T data shows differences in the gene expressions between populations for both MT genes for liver and testes. In the liver metallothionein I gene expression was upregulated in populations considered as more polluted (up to 7.5 higher expression in Miasteczko Śląskie comparing to Mikołajki). Expression of metallothionein II revealed a similar pattern. In kidneys, differences in expression of both MT genes were not that evident. In testes, MT upregulation in polluted sites was noted for metallothionein II. For metallothionein however, we found downregulation in populations from more contaminated sites. The expressions of both MTs were positively influenced by cadmium in kidney (concentration data from the previous study) and zinc and copper in liver, while cadmium had effects only on the liver MT II gene expression. Positive relationship was obtained for lead and metallothionein II expression in the liver.

An Asian validation of the TIMI risk score for ST-segment elevation myocardial infarction.

PubMed

Selvarajah, Sharmini; Fong, Alan Yean Yip; Selvaraj, Gunavathy; Haniff, Jamaiyah; Uiterwaal, Cuno S P M; Bots, Michiel L

2012-01-01

Risk stratification in ST-elevation myocardial infarction (STEMI) is important, such that the most resource intensive strategy is used to achieve the greatest clinical benefit. This is essential in developing countries with wide variation in health care facilities, scarce resources and increasing burden of cardiovascular diseases. This study sought to validate the Thrombolysis In Myocardial Infarction (TIMI) risk score for STEMI in a multi-ethnic developing country. Data from a national, prospective, observational registry of acute coronary syndromes was used. The TIMI risk score was evaluated in 4701 patients who presented with STEMI. Model discrimination and calibration was tested in the overall population and in subgroups of patients that were at higher risk of mortality; i.e., diabetics and those with renal impairment. Compared to the TIMI population, this study population was younger, had more chronic conditions, more severe index events and received treatment later. The TIMI risk score was strongly associated with 30-day mortality. Discrimination was good for the overall study population (c statistic 0.785) and in the high risk subgroups; diabetics (c statistic 0.764) and renal impairment (c statistic 0.761). Calibration was good for the overall study population and diabetics, with χ2 goodness of fit test p value of 0.936 and 0.983 respectively, but poor for those with renal impairment, χ2 goodness of fit test p value of 0.006. The TIMI risk score is valid and can be used for risk stratification of STEMI patients for better targeted treatment.

Prevalence of genetic thrombophilic polymorphisms in the Sri Lankan population--implications for association study design and clinical genetic testing services.

PubMed

Dissanayake, Vajira H W; Weerasekera, Lakshini Y; Gammulla, C Gayani; Jayasekara, Rohan W

2009-10-01

We investigated the prevalence of genotypes/alleles of single nucleotide polymorphisms (SNP) and haplotypes defined by them in three genes in which variations are associated with venous thromboembolism in 80 Sinhalese, 80 Sri Lankan Tamils and 80 Moors in the Sri Lankan population and compared the SNP data with that of other populations in Southern India and haplotype data with that of HapMap populations. The genes and polymorphisms investigated were Methylenetetrahydrofolate reductase (MTHFR) - 677C>T (rs1801133), 1298A>C (rs1801131), 1317T>C, 1793G>A (rs2274976); Factor V (F5) - 1691G>A (rs6025) and 4070A>G (rs1800595); and prothrombin (F2) - 20210G>A (rs1799963). The polymorphisms were genotyped using PCR/RFLP methods. The prevalence of the variant alleles of each polymorphism in the Sinhalese, Tamils, and Moors was MTHFR 677T: Sinhalese - 13%, Tamils - 9%, Moors - 9%. 1317T>C: Sinhalese - 0%; Tamils - 0%; Moors - 0%. 1793A: Sinhalese - 19%, Tamils - 19%, Moors - 19%. F5 1691A: Sinhalese - 2%, Tamils - 3%, Moors - 2%. 4070G: Sinhalese - 6%, Tamils - 5%, Moors - 8%. F2 20210A: Sinhalese - 0%, Tamils - 0%, Moors - 0%. The frequencies observed were similar to data from other South Indian populations; the haplotype data showed haplotypes unique to the Sri Lankan population when compared to HapMap populations. rs9651118 was identified as a SNP that splits the haplotypes harbouring the functionally significant 677T allele in the MTHFR gene. This data would be useful in planning genetic association studies in the Sri Lankan population and in deciding on which genetic variants should be tested in a clinical genetic testing service.

Oncogenic Human Papillomavirus (HPV) Type Distribution and HPV Type 16 E6 Variants in Two Spanish Population Groups with Different Levels of HPV Infection Risk

PubMed Central

Ortiz, M.; Torres, M.; Muñoz, L.; Fernández-García, E.; Canals, J.; Cabornero, A. I.; Aguilar, E.; Ballesteros, J.; del Amo, J.; García-Sáiz, A.

2006-01-01

The aim of this study is to determine oncogenic human papillomavirus (HPV) types and HPV type 16 (HPV16) variant distribution in two Spanish population groups, commercial sex workers and imprisoned women (CSW/IPW) and the general population. A multicenter cross-sectional study of 1,889 women from five clinical settings in two Spanish cities was conducted from May to November 2004. Oncogenic HPV infection was tested by an Hybrid Capture II (HC2) test, and positive samples were genotyped by direct sequencing using three different primer sets in L1 (MY09/11 and GP5+/GP6+) and E6/E7. HPV16 variants were identified by sequencing the E6, E2, and L1 regions. Four hundred twenty-five samples were positive for the HC2 test, 31.5% from CSW/IPW and 10.7% from the general population. HPV16 was the most frequent type. Distinct profiles of oncogenic HPV type prevalence were observed across the two populations. In order of decreasing frequency, HPV types 16, 31, 58, 66, 56, and 18 were most frequent in CSW/IPW women, and types 16, 31, 52, 68, 51, and 53 were most frequent in the general population. We analyzed HPV16 intratype variants, and a large majority (78.7%) belonged to the European lineage. AA variants were detected in 16.0% of cases. African variants belonging to classes Af1 (4.0%) and Af2 (1.3%) were detected. Different HPV types and HPV16 intratype variants are involved in oncogenic HPV infections in our population. These results suggest that HPV type distribution differs in CSW/IPW women and in the general population, although further analysis is necessary. PMID:16597872

A Population-Based Approach to Study the Impact of PROP Perception on Food Liking in Populations along the Silk Road

PubMed Central

Robino, Antonietta; Mezzavilla, Massimo; Pirastu, Nicola; Dognini, Maddalena; Tepper, Beverly J.; Gasparini, Paolo

2014-01-01

Taste is one of the main factors determining food choices. Differences in PROP bitter taste perception have been implicated in individual differences in food preferences and selection. The present study examined associations between, PROP phenotypes, self-reported food liking and TAS2R38 polymorphisms, the major gene implicated in PROP bitterness, in six different populations of the Caucasus and Central Asia, located along the ancient Silk Road. Differences in the distribution of PROP phenotypes across populations were detected, with a higher frequency of super tasters in Tajikistan (31.3%) and Armenia (39.0%) and a higher frequency of non tasters in Georgia (50.9%). While no relationships were observed between PROP phenotypes and food liking using standard statistical tests, we used an approach based on comparison of distance matrices derived from these data. The first matrix compared the food liking ratings of each population to all others pairwise using the Kruskal-Wallis test (at p<0.00063), and the second one compared the distribution of PROP phenotypes across all populations in a similar manner calculating the chi-square statistic as a distance measure. A strong correlation between the two matrices was found (Mantel test: r = 0.67, p-value = 0.03), suggesting that the pattern of food liking across populations was closely related to the distribution of PROP phenotypes. This same relationship was not observed when TAS2R38 genotypes were substituted for PROP phenotypes in this analysis. Our data suggest that a population-based approach utilizing distance matrices is a useful technique for detecting PROP-related differences in food liking and can be applied to other taste phenotypes. PMID:24626196

A population-based approach to study the impact of PROP perception on food liking in populations along the Silk Road.

PubMed

Robino, Antonietta; Mezzavilla, Massimo; Pirastu, Nicola; Dognini, Maddalena; Tepper, Beverly J; Gasparini, Paolo

2014-01-01

Taste is one of the main factors determining food choices. Differences in PROP bitter taste perception have been implicated in individual differences in food preferences and selection. The present study examined associations between, PROP phenotypes, self-reported food liking and TAS2R38 polymorphisms, the major gene implicated in PROP bitterness, in six different populations of the Caucasus and Central Asia, located along the ancient Silk Road. Differences in the distribution of PROP phenotypes across populations were detected, with a higher frequency of super tasters in Tajikistan (31.3%) and Armenia (39.0%) and a higher frequency of non tasters in Georgia (50.9%). While no relationships were observed between PROP phenotypes and food liking using standard statistical tests, we used an approach based on comparison of distance matrices derived from these data. The first matrix compared the food liking ratings of each population to all others pairwise using the Kruskal-Wallis test (at p<0.00063), and the second one compared the distribution of PROP phenotypes across all populations in a similar manner calculating the chi-square statistic as a distance measure. A strong correlation between the two matrices was found (Mantel test: r = 0.67, p-value = 0.03), suggesting that the pattern of food liking across populations was closely related to the distribution of PROP phenotypes. This same relationship was not observed when TAS2R38 genotypes were substituted for PROP phenotypes in this analysis. Our data suggest that a population-based approach utilizing distance matrices is a useful technique for detecting PROP-related differences in food liking and can be applied to other taste phenotypes.

Oncogenic human papillomavirus (HPV) type distribution and HPV type 16 E6 variants in two Spanish population groups with different levels of HPV infection risk.

PubMed

Ortiz, M; Torres, M; Muñoz, L; Fernández-García, E; Canals, J; Cabornero, A I; Aguilar, E; Ballesteros, J; Del Amo, J; García-Sáiz, A

2006-04-01

The aim of this study is to determine oncogenic human papillomavirus (HPV) types and HPV type 16 (HPV16) variant distribution in two Spanish population groups, commercial sex workers and imprisoned women (CSW/IPW) and the general population. A multicenter cross-sectional study of 1,889 women from five clinical settings in two Spanish cities was conducted from May to November 2004. Oncogenic HPV infection was tested by an Hybrid Capture II (HC2) test, and positive samples were genotyped by direct sequencing using three different primer sets in L1 (MY09/11 and GP5+/GP6+) and E6/E7. HPV16 variants were identified by sequencing the E6, E2, and L1 regions. Four hundred twenty-five samples were positive for the HC2 test, 31.5% from CSW/IPW and 10.7% from the general population. HPV16 was the most frequent type. Distinct profiles of oncogenic HPV type prevalence were observed across the two populations. In order of decreasing frequency, HPV types 16, 31, 58, 66, 56, and 18 were most frequent in CSW/IPW women, and types 16, 31, 52, 68, 51, and 53 were most frequent in the general population. We analyzed HPV16 intratype variants, and a large majority (78.7%) belonged to the European lineage. AA variants were detected in 16.0% of cases. African variants belonging to classes Af1 (4.0%) and Af2 (1.3%) were detected. Different HPV types and HPV16 intratype variants are involved in oncogenic HPV infections in our population. These results suggest that HPV type distribution differs in CSW/IPW women and in the general population, although further analysis is necessary.

Precision and accuracy of commonly used dental age estimation charts for the New Zealand population.

PubMed

Baylis, Stephanie; Bassed, Richard

2017-08-01

Little research has been undertaken for the New Zealand population in the field of dental age estimation. This research to date indicates there are differences in dental developmental rates between the New Zealand population and other global population groups, and within the New Zealand population itself. Dental age estimation methods range from dental development charts to complex biometric analysis. Dental development charts are not the most accurate method of dental age estimation, but are time saving in their use. They are an excellent screening tool, particularly for post-mortem identification purposes, and for assessing variation from population norms in living individuals. The aim of this study was to test the precision and accuracy of three dental development charts (Schour and Massler, Blenkin and Taylor, and the London Atlas), used to estimate dental age of a sample of New Zealand juveniles between the ages of 5 and 18 years old (n=875). Percentage 'best fit' to correct age category and to expected chart stage were calculated to determine which chart was the most precise for the sample. Chronological ages were compared to estimated dental ages using a two-tailed paired t-test (P<0.05) for each of the three methods. The mean differences between CA and DA were calculated to determine bias and the absolute mean differences were calculated to indicate accuracy. The results of this study show that while accuracy and precision were low for all charts tested against the New Zealand population sample, the Blenkin and Taylor Australian charts performed best overall. Copyright © 2017 Elsevier B.V. All rights reserved.

The use of alcohol use disorders identification test (AUDIT) in detecting alcohol use disorder and risk drinking in the general population: validation of AUDIT using schedules for clinical assessment in neuropsychiatry.

PubMed

Lundin, Andreas; Hallgren, Mats; Balliu, Natalja; Forsell, Yvonne

2015-01-01

The alcohol use disorders identification test (AUDIT) and AUDIT-Consumption (AUDIT-C) are commonly used in population surveys but there are few validations studies in the general population. Validity should be estimated in samples close to the targeted population and setting. This study aims to validate AUDIT and AUDIT-C in a general population sample (PART) in Stockholm, Sweden. We used a general population subsample age 20 to 64 that answered a postal questionnaire including AUDIT who later participated in a psychiatric interview (n = 1,093). Interviews using Schedules for Clinical Assessment in Neuropsychiatry was used as criterion standard. Diagnoses were set according to the fourth version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Agreement between the diagnostic test and criterion standard was measured with area under the receiver operator characteristics curve (AUC). A total of 1,086 (450 men and 636 women) of the interview participants completed AUDIT. There were 96 individuals with DSM-IV-alcohol dependence, 36 DSM-IV-Alcohol Abuse, and 153 Risk drinkers. AUCs were for DSM-IV-alcohol use disorder 0.90 (AUDIT-C 0.85); DSM-IV-dependence 0.94 (AUDIT-C 0.89); risk drinking 0.80 (AUDIT-C 0.80); and any criterion 0.87 (AUDIT-C 0.84). In this general population sample, AUDIT and AUDIT-C performed outstanding or excellent in identifying dependency, risk drinking, alcohol use disorder, any disorder, or risk drinking. Copyright © 2015 by the Research Society on Alcoholism.

An investigation of Bartonella spp., Rickettsia typhi, and Seoul hantavirus in rats (Rattus spp.) from an inner-city neighborhood of Vancouver, Canada: is pathogen presence a reflection of global and local rat population structure?

PubMed

Himsworth, Chelsea G; Bai, Ying; Kosoy, Michael Y; Wood, Heidi; DiBernardo, Antonia; Lindsay, Robbin; Bidulka, Julie; Tang, Patrick; Jardine, Claire; Patrick, David

2015-01-01

Urban Norway and black rats (Rattus norvegicus and Rattus rattus) are reservoirs for variety of zoonotic pathogens. Many of these pathogens, including Rickettsia typhi, Bartonella spp., and Seoul hantavirus (SEOV), are thought to be endemic in rat populations worldwide; however, past field research has found these organisms to be absent in certain rat populations. Rats (Rattus spp.) from an inner city neighborhood of Vancouver, Canada, were tested for exposure to and/or infection with SEOV and R. typhi (using serology and PCR), as well as Bartonella spp. (using culture and sequencing). Approximately 25% of 404 rats tested were infected with Bartonella tribocorum, which demonstrated significant geographic clustering within the study area. Infection was associated with both season and sexual maturity. Seroreactivity against R. typhi and SEOV was observed in 0.36% and 1.45% of 553 rats tested, respectively, although PCR screening results for these pathogens were negative, suggesting that they are not endemic in the study population. Overall, these results suggest that the geographic distribution of rat-associated zoonoses, including R. typhi, SEOV, and Bartonella spp., is less ubiquitous than previously appreciated, and is likely dependent on patterns of dispersion and establishment of the rat reservoir host. Further study on global and local Rattus spp. population structures may help to elucidate the ecology of zoonotic organisms in these species.

Acceptance of Genetic Testing in a General Population: Age, Education and Gender Differences.

ERIC Educational Resources Information Center

Aro, A. R.; Hakonen, A.; Hietala, M.; Lonnqvist, J.; Niemela, P.; Peltonen, L; Aula, P.

1997-01-01

Effects of age, education, and gender on acceptance of genetic testing were studied. Finnish participants responded to a questionnaire presenting reasons for and against genetic testing (N=1,967). Intentions to take genetic tests, worries, and experience of genetic test or hereditary disease were also assessed. Results are presented and discussed.…

Contact Allergy to Hydroperoxides of Linalool and D-Limonene in a US Population.

PubMed

Nath, Neel Som; Liu, Beiyu; Green, Cynthia; Atwater, Amber Reck

Linalool and D-limonene are common fragrance ingredients that readily oxidize on exposure to air. The resulting hydroperoxides of linalool and D-limonene have been shown to have high frequencies of positive patch test reactions in several European and international studies. The aim of the study was to investigate the prevalence of contact allergy to the hydroperoxides of linalool and D-limonene in a US population. In this retrospective study, 103 patients with suspected fragrance allergy were patch tested to linalool 10% petrolatum (pet), hydroperoxides of linalool 1% pet, D-limonene 10% pet, and/or the hydroperoxides of D-limonene 0.3% pet between July 9, 2014, and October 25, 2016. In this study, the frequency of positive patch test reactions to the hydroperoxides of linalool is 20% (19/96), and the frequency of positive reactions to the hydroperoxides of D-limonene is 8% (7/90). These high frequencies suggest that patch testing to the hydroperoxides of linalool and limonene should be performed in all patients with suspected fragrance allergy.

Diagnostic evaluation of rapid tests for scrub typhus in the Indian population is needed.

PubMed

Shivalli, Siddharudha

2016-05-12

Owing to frequent outbreaks witnessed in different parts of the country in the recent past, scrub typhus is being described as a re-emerging infectious disease in India. Differentiating scrub typhus from other endemic diseases like malaria, leptospirosis, dengue fever, typhoid, etc. is difficult due to overlapping clinical features and a lower positivity for eschars in Asian populations. Hence, the diagnosis heavily relies on laboratory tests. Costs and the need of technical expertise limit the wide use of indirect immunoperoxidase or immunofluorescence assays, ELISA and PCR. The Weil-Felix test is the most commonly used and least expensive serological test, but lacks both sensitivity and specificity. Hence, the diagnosis of scrub typhus is often delayed or overlooked. With due consideration of the cost, rapidity, single test result and simplicity of interpretation, rapid diagnostic tests have come into vogue. However, evaluation of rapid diagnostic tests for scrub typhus in the Indian population is needed to justify or discourage their use. Research studies are needed to find the most suitable test in terms of the rapidity of the result, simplicity of the procedure, ease of interpretation and cost to be used in the Indian populace.

Development of a Medium Density Combined-Species SNP Array for Pacific and European Oysters (Crassostrea gigas and Ostrea edulis).

PubMed

Gutierrez, Alejandro P; Turner, Frances; Gharbi, Karim; Talbot, Richard; Lowe, Natalie R; Peñaloza, Carolina; McCullough, Mark; Prodöhl, Paulo A; Bean, Tim P; Houston, Ross D

2017-07-05

SNP arrays are enabling tools for high-resolution studies of the genetic basis of complex traits in farmed and wild animals. Oysters are of critical importance in many regions from both an ecological and economic perspective, and oyster aquaculture forms a key component of global food security. The aim of our study was to design a combined-species, medium density SNP array for Pacific oyster ( Crassostrea gigas ) and European flat oyster ( Ostrea edulis ), and to test the performance of this array on farmed and wild populations from multiple locations, with a focus on European populations. SNP discovery was carried out by whole-genome sequencing (WGS) of pooled genomic DNA samples from eight C. gigas populations, and restriction site-associated DNA sequencing (RAD-Seq) of 11 geographically diverse O. edulis populations. Nearly 12 million candidate SNPs were discovered and filtered based on several criteria, including preference for SNPs segregating in multiple populations and SNPs with monomorphic flanking regions. An Affymetrix Axiom Custom Array was created and tested on a diverse set of samples ( n = 219) showing ∼27 K high quality SNPs for C. gigas and ∼11 K high quality SNPs for O. edulis segregating in these populations. A high proportion of SNPs were segregating in each of the populations, and the array was used to detect population structure and levels of linkage disequilibrium (LD). Further testing of the array on three C. gigas nuclear families ( n = 165) revealed that the array can be used to clearly distinguish between both families based on identity-by-state (IBS) clustering parental assignment software. This medium density, combined-species array will be publicly available through Affymetrix, and will be applied for genome-wide association and evolutionary genetic studies, and for genomic selection in oyster breeding programs. Copyright © 2017 Gutierrez et al.

Genetic susceptibility to Gilbert's syndrome in a valencian population; efficacy of the fasting test.

PubMed

Torres, A K; Escartín, N; Monzó, C; Guzmán, C; Ferrer, I; González-Muñoz, C; Peña, P; Monzó, V; Marcaida, G; Rodríguez-López, R

To describe the populational distribution of the UGT1A1*28 variant (genetic variant code rs8175347) located in the promotor of the UGT gene and correlate its genotypes with the results of the fasting test, as well as its relationship with the biochemical disorder of Gilbert's syndrome (GS) in a Valencian population. We studied the prevalence of the genotypes (TA) 6/6 (TA) 6/7 and (TA) 7/7 of the deleterious variant rs8175347 in 144 patients with hyperbilirubinemia, 38 of whom had previously undergone the fasting test to diagnose GS, and in 150 control patients. By analysing the genomic region of the TATA box of the UGT1A1 gene promotor using Sanger sequencing, we established the correlation between the rs8175347 genotypes and the fasting test results and with the patients' biochemical disorders. The rate of heterozygosity of allele (TA) 7 in the control population was 32% and increased to 87.59% among the patients with suspected GS. The rate of genotype TA 7/7 was 81.94% among the patients with hyperbilirubinemia, compared with 11.33% in the control patients. The fasting test showed a 15.79% rate of false negatives and a 5.26% rate of false positives. The high frequency of allele (TA) 7 among the Valencian control population, almost double the 5% reported for European control patients, confirms the high rate of GS reported in the Spanish population, without observing significant differences between the geographical ends of the country. The efficacy and reliability of the fasting test for the diagnosis of GS is questionable. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Barriers impeding serologic screening for celiac disease in clinically high-prevalence populations

PubMed Central

2014-01-01

Background Celiac disease is present in ~1% of the general population in the United States and Europe. Despite the availability of inexpensive serologic screening tests, ~85% of individuals with celiac disease remain undiagnosed and there is an average delay in diagnosis of symptomatic individuals with celiac disease that ranges from ~5.8-11 years. This delay is often attributed to the use of a case-based approach for detection rather than general population screening for celiac disease, and deficiencies at the level of health care professionals. This study aimed to assess if patient-centered barriers have a role in impeding serologic screening for celiac disease in individuals from populations that are clinically at an increased risk for celiac disease. Methods 119 adults meeting study inclusion criteria for being at a higher risk for celiac disease were recruited from the general population. Participants completed a survey/questionnaire at the William K. Warren Medical Research Center for Celiac Disease that addressed demographic information, celiac disease related symptoms (gastrointestinal and extraintestinal), family history, co-morbid diseases and conditions associated with celiac disease, and patient-centered barriers to screening for celiac disease. All participants underwent serologic screening for celiac disease using the IgA tissue transglutaminase antibody (IgA tTG) and, if positive, testing for IgA anti-endomysial antibody (IgA EMA) as a confirmatory test. Results Two barriers to serologic testing were significant across the participant pool. These were participants not knowing they were at risk for celiac disease before learning of the study, and participants not knowing where to get tested for celiac disease. Among participants with incomes less than $25,000/year and those less than the median age, not having a doctor to order the test was a significant barrier, and this strongly correlated with not having health insurance. Symptoms and co-morbid conditions were similar among those whose IgA tTG were negative and those who tested positive. Conclusion There are significant patient-centered barriers that impede serologic screening and contribute to the delayed detection and diagnosis of celiac disease. These barriers may be lessened by greater education of the public and health care professionals about celiac disease symptoms, risk factors, and serologic testing. PMID:24592899

Genetic variation of drought tolerance in Pinus pinaster at three hierarchical levels: a comparison of induced osmotic stress and field testing.

PubMed

Gaspar, Maria João; Velasco, Tania; Feito, Isabel; Alía, Ricardo; Majada, Juan

2013-01-01

Understanding the survival capacity of forest trees to periods of severe water stress could improve knowledge of the adaptive potential of different species under future climatic scenarios. In long lived organisms, like forest trees, the combination of induced osmotic stress treatments and field testing can elucidate the role of drought tolerance during the early stages of establishment, the most critical in the life of the species. We performed a Polyethylene glycol-osmotic induced stress experiment and evaluated two common garden experiments (xeric and mesic sites) to test for survival and growth of a wide range clonal collection of Maritime pine. This study demonstrates the importance of additive vs non additive effects for drought tolerance traits in Pinus pinaster, and shows differences in parameters determining the adaptive trajectories of populations and family and clones within populations. The results show that osmotic adjustment plays an important role in population variation, while biomass allocation and hydric content greatly influence survival at population level. Survival in the induced osmotic stress experiment presented significant correlations with survival in the xeric site, and height growth at the mesic site, at population level, indicating constraints of adaptation for those traits, while at the within population level no significant correlation existed. These results demonstrate that population differentiation and within population genetic variation for drought tolerance follow different patterns.

Genetic Variation of Drought Tolerance in Pinus pinaster at Three Hierarchical Levels: A Comparison of Induced Osmotic Stress and Field Testing

PubMed Central

Gaspar, Maria João; Velasco, Tania; Feito, Isabel; Alía, Ricardo; Majada, Juan

2013-01-01

Understanding the survival capacity of forest trees to periods of severe water stress could improve knowledge of the adaptive potential of different species under future climatic scenarios. In long lived organisms, like forest trees, the combination of induced osmotic stress treatments and field testing can elucidate the role of drought tolerance during the early stages of establishment, the most critical in the life of the species. We performed a Polyethylene glycol-osmotic induced stress experiment and evaluated two common garden experiments (xeric and mesic sites) to test for survival and growth of a wide range clonal collection of Maritime pine. This study demonstrates the importance of additive vs non additive effects for drought tolerance traits in Pinus pinaster, and shows differences in parameters determining the adaptive trajectories of populations and family and clones within populations. The results show that osmotic adjustment plays an important role in population variation, while biomass allocation and hydric content greatly influence survival at population level. Survival in the induced osmotic stress experiment presented significant correlations with survival in the xeric site, and height growth at the mesic site, at population level, indicating constraints of adaptation for those traits, while at the within population level no significant correlation existed. These results demonstrate that population differentiation and within population genetic variation for drought tolerance follow different patterns. PMID:24223885

Do gifts increase consent to home-based HIV testing? A difference-in-differences study in rural KwaZulu-Natal, South Africa

PubMed Central

McGovern, Mark E; Herbst, Kobus; Tanser, Frank; Mutevedzi, Tinofa; Canning, David; Gareta, Dickman; Pillay, Deenan; Bärnighausen, Till

2016-01-01

Abstract Background: Despite the importance of HIV testing for controlling the HIV epidemic, testing rates remain low. Efforts to scale up testing coverage and frequency in hard-to-reach and at-risk populations commonly focus on home-based HIV testing. This study evaluates the effect of a gift (a US$5 food voucher for families) on consent rates for home-based HIV testing. Methods: We use data on 18 478 individuals (6 418 men and 12 060 women) who were successfully contacted to participate in the 2009 and 2010 population-based HIV surveillance carried out by the Wellcome Trust's Africa Health Research Institute in rural KwaZulu-Natal, South Africa. Of 18 478 potential participants contacted in both years, 35% (6 518) consented to test in 2009, and 41% (7 533) consented to test in 2010. Our quasi-experimental difference-in-differences approach controls for unobserved confounding in estimating the causal effect of the intervention on HIV-testing consent rates. Results: Allocation of the gift to a family in 2010 increased the probability of family members consenting to test in the same year by 25 percentage points [95% confidence interval (CI) 21–30 percentage points; P < 0.001]. The intervention effect persisted, slightly attenuated, in the year following the intervention (2011). Conclusions: In HIV hyperendemic settings, a gift can be highly effective at increasing consent rates for home-based HIV testing. Given the importance of HIV testing for treatment uptake and individual health, as well as for HIV treatment-as-prevention strategies and for monitoring the population impact of the HIV response, gifts should be considered as a supportive intervention for HIV-testing initiatives where consent rates have been low. PMID:27940483

Cost effectiveness of population based BRCA1 founder mutation testing in Sephardi Jewish women.

PubMed

Patel, Shreeya; Legood, Rosa; Evans, D Gareth; Turnbull, Clare; Antoniou, Antonis C; Menon, Usha; Jacobs, Ian; Manchanda, Ranjit

2018-04-01

Population-based BRCA1/BRCA2 founder-mutation testing has been demonstrated as cost effective compared with family history based testing in Ashkenazi Jewish women. However, only 1 of the 3 Ashkenazi Jewish BRCA1/BRCA2 founder mutations (185delAG[c.68_69delAG]), 5382insC[c.5266dupC]), and 6174delT[c.5946delT]) is found in the Sephardi Jewish population (185delAG[c.68_69delAG]), and the overall prevalence of BRCA mutations in the Sephardi Jewish population is accordingly lower (0.7% compared with 2.5% in the Ashkenazi Jewish population). Cost-effectiveness analyses of BRCA testing have not previously been performed at these lower BRCA prevalence levels seen in the Sephardi Jewish population. Here we present a cost-effectiveness analysis for UK and US populations comparing population testing with clinical criteria/family history-based testing in Sephardi Jewish women. A Markov model was built comparing the lifetime costs and effects of population-based BRCA1 testing, with testing using family history-based clinical criteria in Sephardi Jewish women aged ≥30 years. BRCA1 carriers identified were offered magnetic resonance imaging/mammograms and risk-reducing surgery. Costs are reported at 2015 prices. Outcomes include breast cancer, ovarian cancer, and excess deaths from heart disease. All costs and outcomes are discounted at 3.5%. The time horizon is lifetime, and perspective is payer. The incremental cost-effectiveness ratio per quality-adjusted life-year was calculated. Parameter uncertainty was evaluated through 1-way and probabilistic sensitivity analysis. Population testing resulted in gain in life expectancy of 12 months (quality-adjusted life-year = 1.00). The baseline discounted incremental cost-effectiveness ratio for UK population-based testing was £67.04/quality-adjusted life-year and for US population was $308.42/quality-adjusted life-year. Results were robust in the 1-way sensitivity analysis. The probabilistic sensitivity analysis showed 100% of simulations were cost effective at £20,000/quality-adjusted life-year UK and the $100,000/quality-adjusted life-year US willingness-to-pay thresholds. Scenario analysis showed that population testing remains cost effective in UK and US populations, even if premenopausal oophorectomy does not reduce breast cancer risk or if hormone replacement therapy compliance is nil. Population-based BRCA1 testing is highly cost effective compared with clinical criteria-driven approach in Sephardi Jewish women. This supports changing the paradigm to population-based BRCA testing in the Jewish population, regardless of Ashkenazi/Sephardi ancestry. Copyright © 2017 Elsevier Inc. All rights reserved.

Spatial and temporal synchrony in reptile population dynamics in variable environments.

PubMed

Greenville, Aaron C; Wardle, Glenda M; Nguyen, Vuong; Dickman, Chris R

2016-10-01

Resources are seldom distributed equally across space, but many species exhibit spatially synchronous population dynamics. Such synchrony suggests the operation of large-scale external drivers, such as rainfall or wildfire, or the influence of oasis sites that provide water, shelter, or other resources. However, testing the generality of these factors is not easy, especially in variable environments. Using a long-term dataset (13-22 years) from a large (8000 km(2)) study region in arid Central Australia, we tested firstly for regional synchrony in annual rainfall and the dynamics of six reptile species across nine widely separated sites. For species that showed synchronous spatial dynamics, we then used multivariate follow a multivariate auto-regressive state-space (MARSS) models to predict that regional rainfall would be positively associated with their populations. For asynchronous species, we used MARSS models to explore four other possible population structures: (1) populations were asynchronous, (2) differed between oasis and non-oasis sites, (3) differed between burnt and unburnt sites, or (4) differed between three sub-regions with different rainfall gradients. Only one species showed evidence of spatial population synchrony and our results provide little evidence that rainfall synchronizes reptile populations. The oasis or the wildfire hypotheses were the best-fitting models for the other five species. Thus, our six study species appear generally to be structured in space into one or two populations across the study region. Our findings suggest that for arid-dwelling reptile populations, spatial and temporal dynamics are structured by abiotic events, but individual responses to covariates at smaller spatial scales are complex and poorly understood.

Evaluation of a simple test of reaction time for baseline concussion testing in a population of high school athletes.

PubMed

MacDonald, James; Wilson, Julie; Young, Julie; Duerson, Drew; Swisher, Gail; Collins, Christy L; Meehan, William P

2015-01-01

A common sequela of concussions is impaired reaction time. Computerized neurocognitive tests commonly measure reaction time. A simple clinical test for reaction time has been studied previously in college athletes; whether this test is valid and reliable when assessing younger athletes remains unknown. Our study examines the reliability and validity of this test in a population of high school athletes. Cross-sectional study. Two American High Schools. High school athletes (N = 448) participating in American football or soccer during the academic years 2011 to 2012 and 2012 to 2013. All study participants completed a computerized baseline neurocognitive assessment that included a measure of reaction time (RT comp), in addition to a clinical measure of reaction time that assessed how far a standard measuring device would fall prior to the athlete catching it (RT clin). Validity was assessed by determining the correlation between RT clin and RT comp. Reliability was assessed by measuring the intraclass correlation coefficients (ICCs) between the repeated measures of RT clin and RT comp taken 1 year apart. In the first year of study, RT clin and RT comp were positively but weakly correlated (rs = 0.229, P < 0.001). In the second year, there was no significant correlation between RT clin and RT comp (rs = 0.084, P = 0.084). Both RT clin [ICC = 0.608; 95% confidence interval (CI), 0.434-0.728] and RT comp (ICC = 0.691; 95% CI, 0.554-0.786) had marginal reliability. In a population of high school athletes, RT clin had poor validity when compared with RT comp as a standard. Both RT clin and RT comp had marginal test-retest reliability. Before considering the clinical use of RT clin in the assessment of sport-related concussions sustained by high school athletes, the factors affecting reliability and validity should be investigated further. Reaction time impairment commonly results from concussion and is among the most clinically important measures of the condition. The device evaluated in this study has previously been investigated as a reaction time measure in college athletes. This study investigates the clinical generalizability of the device in a younger population. A video abstract showing how the RT clin device is used in practice is available as Supplemental Digital Content 1, http://links.lww.com/JSM/A43.

Testing the mean for dependent business data.

PubMed

Liang, Jiajuan; Martin, Linda

2008-01-01

In business data analysis, it is well known that the comparison of several means is usually carried out by the F-test in analysis of variance under the assumption of independently collected data from all populations. This assumption, however, is likely to be violated in survey data collected from various questionnaires or time-series data. As a result, it is not justifiable or problematic to apply the traditional F-test to comparison of dependent means directly. In this article, we develop a generalized F-test for comparing population means with dependent data. Simulation studies show that the proposed test has a simple approximate null distribution and feasible finite-sample properties. Applications of the proposed test in analysis of survey data and time-series data are illustrated by two real datasets.

Population, sex and body size: determinants of behavioural variations and behavioural correlations among wild zebrafish Danio rerio.

PubMed

Roy, Tamal; Bhat, Anuradha

2018-01-01

This study (1) investigated variation among populations and the effects of sex and body size on boldness, activity and shoal-association tendency among wild zebrafish, and (2) tested for existence of correlations between behaviours, controlling for sex and body size. Individuals across four natural populations were tested for general activity in a novel situation, number of predator inspections undertaken and tendency to associate with a conspecific shoal in the presence of predators. Results showed a significant effect of population on boldness with a population from high-predation habitat being bolder than populations from low-predation habitats. Males showed significantly higher tendencies than females to associate with a conspecific shoal in the presence of predators. Further, a negative relationship was found between activity and boldness only within two low-predation populations. Individual body size had a strong effect on the activity-boldness relationship within the low-predation population from flowing water habitat. Smaller fish were bolder and less active while larger fish were more cautious and active. Overall, the results indicated that while population-level behavioural responses might be shaped by predation pressure, state-dependent factors could determine behavioural correlations among individuals within populations.

Population, sex and body size: determinants of behavioural variations and behavioural correlations among wild zebrafish Danio rerio

PubMed Central

Roy, Tamal

2018-01-01

This study (1) investigated variation among populations and the effects of sex and body size on boldness, activity and shoal-association tendency among wild zebrafish, and (2) tested for existence of correlations between behaviours, controlling for sex and body size. Individuals across four natural populations were tested for general activity in a novel situation, number of predator inspections undertaken and tendency to associate with a conspecific shoal in the presence of predators. Results showed a significant effect of population on boldness with a population from high-predation habitat being bolder than populations from low-predation habitats. Males showed significantly higher tendencies than females to associate with a conspecific shoal in the presence of predators. Further, a negative relationship was found between activity and boldness only within two low-predation populations. Individual body size had a strong effect on the activity–boldness relationship within the low-predation population from flowing water habitat. Smaller fish were bolder and less active while larger fish were more cautious and active. Overall, the results indicated that while population-level behavioural responses might be shaped by predation pressure, state-dependent factors could determine behavioural correlations among individuals within populations. PMID:29410809

[Hospitalization period and nutritional status in hospitalized patients].

PubMed

Merhi, V A Leandro; de Oliveira, Ma R Marques; Caran, A L; Tristão, T Menuzzo Graupner; Ambo, R Miante; Tanner, M A; Vergna, C Marton

2007-01-01

With the objective of studying the nutritional status and its relationship with hospitalization period, a cross-sectional study was done with patients from a private hospital representing a population with a better socioeconomic condition. The anthropometric data of 267 patients, 46% males and 54% females ranging from 20 to 80 years of age, were assessed on the second day of hospitalization. Hospitalization period associated with nutritional status. The data were analyzed by the software Excel and Sigma Stat, using Fisher's exact test and the chi-square test. The studied population presented a body mass index of 25.9 +/- 5.3 and most patients lost weight during hospitalization. The longest hospitalization periods were found among patients with lung diseases (13 days), some being pre-obese (40%) with a small prevalence of undernutrition (4%). The percentage distribution of nutritional status among the groups according to diagnosis was different (P < 0.01) when assessed by the Fisher's exact test and the percentage distribution in weight variation between men and women was different (P < 0.02) when assessed by the chi-square test. When the population was segmented according to age, the percentage distribution of the nutritional status between > 60 and < or = 60 did not present a difference when assessed by the chi-square test. The results of this study show that the nutritional status in some diseases deserves special attention given the greater risk found in these situations, contributing to a longer hospitalization period.

PopHuman: the human population genomics browser

PubMed Central

Mulet, Roger; Villegas-Mirón, Pablo; Hervas, Sergi; Sanz, Esteve; Velasco, Daniel; Bertranpetit, Jaume; Laayouni, Hafid

2018-01-01

Abstract The 1000 Genomes Project (1000GP) represents the most comprehensive world-wide nucleotide variation data set so far in humans, providing the sequencing and analysis of 2504 genomes from 26 populations and reporting >84 million variants. The availability of this sequence data provides the human lineage with an invaluable resource for population genomics studies, allowing the testing of molecular population genetics hypotheses and eventually the understanding of the evolutionary dynamics of genetic variation in human populations. Here we present PopHuman, a new population genomics-oriented genome browser based on JBrowse that allows the interactive visualization and retrieval of an extensive inventory of population genetics metrics. Efficient and reliable parameter estimates have been computed using a novel pipeline that faces the unique features and limitations of the 1000GP data, and include a battery of nucleotide variation measures, divergence and linkage disequilibrium parameters, as well as different tests of neutrality, estimated in non-overlapping windows along the chromosomes and in annotated genes for all 26 populations of the 1000GP. PopHuman is open and freely available at http://pophuman.uab.cat. PMID:29059408

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.

Augmenting the core battery with supplementary subtests: Wechsler adult intelligence scale--IV measurement invariance across the United States and Canada.

PubMed

Bowden, Stephen C; Saklofske, Donald H; Weiss, Lawrence G

2011-06-01

Examination of measurement invariance provides a powerful method to evaluate the hypothesis that the same set of psychological constructs underlies a set of test scores in different populations. If measurement invariance is observed, then the same psychological meaning can be ascribed to scores in both populations. In this study, the measurement model including core and supplementary subtests of the Wechsler Adult Intelligence Scale-Fourth edition (WAIS-IV) were compared across the U.S. and Canadian standardization samples. Populations were compared on the 15 subtest version of the test in people aged 70 and younger and on the 12 subtest version in people aged 70 or older. Results indicated that a slightly modified version of the four-factor model reported in the WAIS-IV technical manual provided the best fit in both populations and in both age groups. The null hypothesis of measurement invariance across populations was not rejected, and the results provide direct evidence for the generalizability of convergent and discriminant validity studies with the WAIS-IV across populations. Small to medium differences in latent means favoring Canadians highlight the value of local norms.

The Potential for Differential Findings among Invariance Testing Strategies for Multisample Measured Variable Path Models

ERIC Educational Resources Information Center

Mann, Heather M.; Rutstein, Daisy W.; Hancock, Gregory R.

2009-01-01

Multisample measured variable path analysis is used to test whether causal/structural relations among measured variables differ across populations. Several invariance testing approaches are available for assessing cross-group equality of such relations, but the associated test statistics may vary considerably across methods. This study is a…

A Longitudinal Investigation of Reading Development from Kindergarten to Grade Eight in a Spanish-Speaking Bilingual Population

ERIC Educational Resources Information Center

Grimm, Ryan P.; Solari, Emily J.; Gerber, Michael M.

2018-01-01

This longitudinal study used latent growth curve modeling to investigate English literacy development in a sample of Spanish-speaking language minority students from third through eighth grade. This study also compared the sample's literacy development to the entire population of California students using state standardized test data. Second, this…

Testing spatial heterogeneity with stock assessment models

PubMed Central

Eero, Margit; Silva, Alexandra; Ulrich, Clara; Pawlowski, Lionel; Holmes, Steven J.; Ibaibarriaga, Leire; De Oliveira, José A. A.; Riveiro, Isabel; Alzorriz, Nekane; Citores, Leire; Scott, Finlay; Uriarte, Andres; Carrera, Pablo; Duhamel, Erwan; Mosqueira, Iago

2018-01-01

This paper describes a methodology that combines meta-population theory and stock assessment models to gain insights about spatial heterogeneity of the meta-population in an operational time frame. The methodology was tested with stochastic simulations for different degrees of connectivity between sub-populations and applied to two case studies, North Sea cod (Gadus morua) and Northeast Atlantic sardine (Sardina pilchardus). Considering that the biological components of a population can be partitioned into discrete spatial units, we extended this idea into a property of additivity of sub-population abundances. If the additivity results hold true for putative sub-populations, then assessment results based on sub-populations will provide information to develop and monitor the implementation of finer scale/local management. The simulation study confirmed that when sub-populations are independent and not too heterogeneous with regards to productivity, the sum of stock assessment model estimates of sub-populations’ SSB is similar to the SSB estimates of the meta-population. It also showed that a strong diffusion process can be detected and that the stronger the connection between SSB and recruitment, the better the diffusion process will be detected. On the other hand it showed that weak to moderate diffusion processes are not easy to identify and large differences between sub-populations productivities may be confounded with weak diffusion processes. The application to North Sea cod and Atlantic sardine exemplified how much insight can be gained. In both cases the results obtained were sufficiently robust to support the regional analysis. PMID:29364901

Revision of the SNPforID 34-plex forensic ancestry test: Assay enhancements, standard reference sample genotypes and extended population studies.

PubMed

Fondevila, M; Phillips, C; Santos, C; Freire Aradas, A; Vallone, P M; Butler, J M; Lareu, M V; Carracedo, A

2013-01-01

A revision of an established 34 SNP forensic ancestry test has been made by swapping the under-performing rs727811 component SNP with the highly informative rs3827760 that shows a near-fixed East Asian specific allele. We collated SNP variability data for the revised SNP set in 66 reference populations from 1000 Genomes and HGDP-CEPH panels and used this as reference data to analyse four U.S. populations showing a range of admixture patterns. The U.S. Hispanics sample in particular displayed heterogeneous values of co-ancestry between European, Native American and African contributors, likely to reflect in part, the way this disparate group is defined using cultural as well as population genetic parameters. The genotyping of over 700 U.S. population samples also provided the opportunity to thoroughly gauge peak mobility variation and peak height ratios observed from routine use of the single base extension chemistry of the 34-plex test. Finally, the genotyping of the widely used DNA profiling Standard Reference Material samples plus other control DNAs completes the audit of the 34-plex assay to allow forensic practitioners to apply this test more readily in their own laboratories. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Validity Tests of the Adolescent Domain Screening Inventory (ADSI) with Older Adolescents

ERIC Educational Resources Information Center

Corrigan, Matthew J.; Forte, James; Bulgaris, Sarah

2017-01-01

The purpose of this replication study is to test the validity of the Adolescent Domain Screening Inventory (ADSI) on an older adolescent population. This cross sectional study used a convenience sample to preliminarily test the validity of the ADSI. Concurrent validity correlations ranged from a high of 0.924 to a low of 0.760. The known…

Childhood Family Instability and Mental Health Problems during Late Adolescence: A Test of Two Mediation Models--The TRAILS Study

ERIC Educational Resources Information Center

Bakker, Martin P.; Ormel, Johan; Verhulst, Frank C.; Oldehinkel, Albertine J.

2012-01-01

This study tested whether childhood family instability is associated with mental health problems during adolescence through continued family instability and/or through a preadolescent onset of mental health problems. This test use data from a prospective population cohort of 2,230 Dutch adolescents ("M" age = 11.09, "SD" = 0.56…

Genetic deletion of HRP2 and HRP3 in Indian Plasmodium falciparum population and false negative malaria rapid diagnostic test.

PubMed

Kumar, Navin; Pande, Veena; Bhatt, R M; Shah, Naman K; Mishra, Neelima; Srivastava, Bina; Valecha, Neena; Anvikar, Anupkumar R

2013-01-01

Genetic polymorphisms in diagnostic antigens are important factors responsible for variable performance of rapid diagnostic tests. Additionally, the failure of antigen expression due to gene deletion may also contribute to variable performance. We report Indian Plasmodium falciparum field isolates lacking both Pfhrp2 and Pfhrp3 genes leading to false negative results of rapid diagnostic tests. The study highlights need to determine the prevalence of P. falciparum isolates lacking these genes in larger field populations in India. Copyright © 2012 Elsevier B.V. All rights reserved.

An Empirical Test of the Theory of Planned Behaviour Applied to Contraceptive Use in Rural Uganda

PubMed Central

Kiene, Susan M.; Hopwood, Sarah; Lule, Haruna; Wanyenze, Rhoda K.

2013-01-01

There is a high unmet need for contraceptives in developing countries such as Uganda, with high population growth, where efforts are needed to promote family planning and contraceptive use. Despite this high need, little research has investigated applications of health behaviour change theories to contraceptive use amongst this population. The present study tested the Theory of Planned Behaviour’s ability to predict contraceptive use-related behaviours among postpartum women in rural Uganda. Results gave modest support to the theory’s application and suggest an urgent need for improved theory-based interventions to promote contraceptive use in the populations of developing countries. PMID:23928989

Transgenerational Adaptation to Pollution Changes Energy Allocation in Populations of Nematodes.

PubMed

Goussen, Benoit; Péry, Alexandre R R; Bonzom, Jean-Marc; Beaudouin, Rémy

2015-10-20

Assessing the evolutionary responses of long-term exposed populations requires multigeneration ecotoxicity tests. However, the analysis of the data from these tests is not straightforward. Mechanistic models allow the in-depth analysis of the variation of physiological traits over many generations, by quantifying the trend of the physiological and toxicological parameters of the model. In the present study, a bioenergetic mechanistic model has been used to assess the evolution of two populations of the nematode Caenorhabditis elegans in control conditions or exposed to uranium. This evolutionary pressure resulted in a brood size reduction of 60%. We showed an adaptation of individuals of both populations to experimental conditions (increase of maximal length, decrease of growth rate, decrease of brood size, and decrease of the elimination rate). In addition, differential evolution was also highlighted between the two populations once the maternal effects had been diminished after several generations. Thus, individuals that were greater in maximal length, but with apparently a greater sensitivity to uranium were selected in the uranium population. In this study, we showed that this bioenergetics mechanistic modeling approach provided a precise, certain, and powerful analysis of the life strategy of C. elegans populations exposed to heavy metals resulting in an evolutionary pressure across successive generations.

Mexican mestizo population sub-structure: effects on genetic and forensic statistical parameters.

PubMed

Noris, Gino; Santana, Carla; Meraz-Ríos, Marco Antonio; de Lourdes Munoz, María; Majluf-Cruz, Abraham; Magaña, Jonathan J; Granados, Julio; Quezada, Rosa; Revilla, María Cristina; Martínez-Salas, Sergio; Xihuitl, Salvador; Martínez de la Escalera, Gonzalo; Díaz-Badillo, Alvaro; Calderon-Aranda, Emma S; Gómez, Rocío

2012-12-01

Since Mexican mestizos are an admixed population, it is necessary to determine the effects that the substructure of the population has on genetic and forensic parameters. With this aim, a study was performed with 15 STR loci (CODIS plus D2S1338 and D19S433) on 1,640 unrelated Mexican mestizos. We determine allele and genotypic frequencies observing departure from Hardy-Weinberg expectation (12 out of 15 loci, with an excess of homozygotes, Fis > 0), as well as pairs of loci in an apparent linkage disequilibrium (13 of 92 loci). We conducted a test for genetic population stratification, the results show that the Mexican mestizo population is substructured into three subgroups, which are in HW and linkage equilibrium. The combination of the 15 loci in the whole population has high forensic efficiency with the capacity to genetically discriminate one individual in one quintillion (1/10(18)). Our data potentially validates the use of these 15 STR loci to establish forensic identity and parentage testing for legal purposes, and offers a powerful tool for genetic variation analysis. However, given that the population is stratified, we highly recommend applying a correction with the inbreeding coefficient in calculations of paternity and forensic studies to avoid erroneous assumptions.

Complex spatial dynamics maintain northern leopard frog (Lithobates pipiens) genetic diversity in a temporally varying landscape

USGS Publications Warehouse

Mushet, David M.; Euliss, Ned H.; Chen, Yongjiu; Stockwell, Craig A.

2013-01-01

In contrast to most local amphibian populations, northeastern populations of the Northern Leopard Frog (Lithobates pipiens) have displayed uncharacteristically high levels of genetic diversity that have been attributed to large, stable populations. However, this widely distributed species also occurs in areas known for great climatic fluctuations that should be reflected in corresponding fluctuations in population sizes and reduced genetic diversity. To test our hypothesis that Northern Leopard Frog genetic diversity would be reduced in areas subjected to significant climate variability, we examined the genetic diversity of L. pipiens collected from 12 sites within the Prairie Pothole Region of North Dakota. Despite the region's fluctuating climate that includes periods of recurring drought and deluge, we found unexpectedly high levels of genetic diversity approaching that of northeastern populations. Further, genetic structure at a landscape scale was strikingly homogeneous; genetic differentiation estimates (Dest) averaged 0.10 (SD = 0.036) across the six microsatellite loci we studied, and two Bayesian assignment tests (STRUCTURE and BAPS) failed to reveal the development of significant population structure across the 68 km breadth of our study area. These results suggest that L. pipiens in the Prairie Pothole Region consists of a large, panmictic population capable of maintaining high genetic diversity in the face of marked climate variability.

Influence of erroneous patient records on population pharmacokinetic modeling and individual bayesian estimation.

PubMed

van der Meer, Aize Franciscus; Touw, Daniël J; Marcus, Marco A E; Neef, Cornelis; Proost, Johannes H

2012-10-01

Observational data sets can be used for population pharmacokinetic (PK) modeling. However, these data sets are generally less precisely recorded than experimental data sets. This article aims to investigate the influence of erroneous records on population PK modeling and individual maximum a posteriori Bayesian (MAPB) estimation. A total of 1123 patient records of neonates who were administered vancomycin were used for population PK modeling by iterative 2-stage Bayesian (ITSB) analysis. Cut-off values for weighted residuals were tested for exclusion of records from the analysis. A simulation study was performed to assess the influence of erroneous records on population modeling and individual MAPB estimation. Also the cut-off values for weighted residuals were tested in the simulation study. Errors in registration have limited the influence on outcomes of population PK modeling but can have detrimental effects on individual MAPB estimation. A population PK model created from a data set with many registration errors has little influence on subsequent MAPB estimates for precisely recorded data. A weighted residual value of 2 for concentration measurements has good discriminative power for identification of erroneous records. ITSB analysis and its individual estimates are hardly affected by most registration errors. Large registration errors can be detected by weighted residuals of concentration.

Snail phenotypic variation and stress proteins: do different heat response strategies contribute to Waddington's widget in field populations?

PubMed

Köhler, Heinz-R; Lazzara, Raimondo; Dittbrenner, Nils; Capowiez, Yvan; Mazzia, Christophe; Triebskorn, Rita

2009-03-15

On the basis of studies with laboratory strains of Drosophila and Arabidopsis, it has been hypothesized that potential buffers to the expression of phenotypic morphological variation, such as Hsp90 and possibly Hsp70, represent important components of Waddington's widget, which may confer capacitive evolution. As studies on field populations of living organisms to test this hypothesis are lacking, we tested whether a heat response strategy involving high stress protein levels is associated with low morphological variation and vice versa, using four natural populations of Mediterranean pulmonate snails. In response to 8 hr of elevated temperatures, a population of Xeropicta derbentina with uniform shell pigmentation pattern showed remarkably high Hsp70 but low Hsp90 levels. In contrast, a highly variable population of Cernuella virgata kept both Hsp90 and Hsp70 levels low when held at diverse though environmentally relevant temperatures. Two other populations (Theba pisana and another X. derbentina population) with intermediate variation in shell pigmentation pattern were also intermediate in inducing Hsp70, though Hsp90 was maintained at a low level. The observed correlation of stress protein levels and coloration pattern variation provide the first indirect evidence for an association of stress proteins with Waddington's widget under natural conditions.

A systematic review of economic models used to assess the cost-effectiveness of strategies for identifying latent tuberculosis in high-risk groups.

PubMed

Auguste, Peter; Tsertsvadze, Alexander; Court, Rachel; Pink, Joshua

2016-07-01

Timely diagnosis and treatment of latent tuberculosis infection (LTBI) through screening remains a key public health priority. Although globally it is recommended to screen people at high risk of developing TB, the economic evidence underpinning these recommendations is limited. This review critically appraised studies that had used a decision-analytical modelling framework to estimate the cost-effectiveness of interferon gamma release assays (IGRAs) compared to tuberculin skin test (TST) for detecting LTBI in high risk populations. A comprehensive search of MEDLINE, EMBASE, NHS-EED was undertaken from 2009 up to June 2015. Studies were screened and extracted by independent reviewers. The study quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) and the Philips' checklist, respectively. A narrative synthesis of the included studies was undertaken. Ten studies were included in this review. Two economic evaluations were conducted in a child population, six in an immunocompromised population and two in a recently arrived population from a country with a high incidence of TB. Most studies (n = 7) used a decision tree structure with Markov nodes. In general, all models were clearly described in terms of reporting quality, but were subject to limitations to structure and model inputs. Models have not elaborated on their setting or the perspective of the studies was not consistent with their analyses. Other concerns were related to derivation of prevalence, test accuracy and transition probabilities. Current methods available highlight limitations in the clinical effectiveness literature, model structures and assumptions, which impact on the robustness of the cost-effectiveness results. These models available are useful, but limited on the information that can be used to inform on future cost-effectiveness analysis. Until consideration is given on deriving the performance of tests used to identify LTBI that progresses to active TB, and the development of more comprehensive models, the economic benefit of LTBI testing with TST/IGRAs in high risk populations will remain unanswered. Copyright © 2016 Elsevier Ltd. All rights reserved.

Designing instruction to support mechanical reasoning: Three alternatives in the simple machines learning environment

NASA Astrophysics Data System (ADS)

McKenna, Ann Frances

2001-07-01

Creating a classroom environment that fosters a productive learning experience and engages students in the learning process is a complex endeavor. A classroom environment is dynamic and requires a unique synergy among students, teacher, classroom artifacts and events to achieve robust understanding and knowledge integration. This dissertation addresses this complex issue by developing, implementing, and investigating the simple machines learning environment (SIMALE) to support students' mechanical reasoning and understanding. SIMALE was designed to support reflection, collaborative learning, and to engage students in generative learning through multiple representations of concepts and successive experimentation and design activities. Two key components of SIMALE are an original web-based software tool and hands-on Lego activities. A research study consisting of three treatment groups was created to investigate the benefits of hands-on and web-based computer activities on students' analytic problem solving ability, drawing/modeling ability, and conceptual understanding. The study was conducted with two populations of students that represent a diverse group with respect to gender, ethnicity, academic achievement and social/economic status. One population of students in this dissertation study participated from the Mathematics, Engineering, and Science Achievement (MESA) program that serves minorities and under-represented groups in science and mathematics. The second group was recruited from the Academic Talent Development Program (ATDP) that is an academically competitive outreach program offered through the University of California at Berkeley. Results from this dissertation show success of the SIMALE along several dimensions. First, students in both populations achieved significant gains in analytic problem solving ability, drawing/modeling ability, and conceptual understanding. Second, significant differences that were found on pre-test measures were eliminated on post-test measures. Specifically, female students scored significantly lower than males on the overall pre-tests but scored as well as males on the same post-test measures. MESA students also scored significantly lower than ATDP students on pre-test measures but both populations scored equally well on the post-tests. This dissertation has therefore shown the SIMALE to support a collaborative, reflective, and generative learning environment. Furthermore, the SIMALE clearly contributes to students' mechanical reasoning and understanding of simple machines concepts for a diverse population of students.

Diagnostic test accuracy and prevalence inferences based on joint and sequential testing with finite population sampling.

PubMed

Su, Chun-Lung; Gardner, Ian A; Johnson, Wesley O

2004-07-30

The two-test two-population model, originally formulated by Hui and Walter, for estimation of test accuracy and prevalence estimation assumes conditionally independent tests, constant accuracy across populations and binomial sampling. The binomial assumption is incorrect if all individuals in a population e.g. child-care centre, village in Africa, or a cattle herd are sampled or if the sample size is large relative to population size. In this paper, we develop statistical methods for evaluating diagnostic test accuracy and prevalence estimation based on finite sample data in the absence of a gold standard. Moreover, two tests are often applied simultaneously for the purpose of obtaining a 'joint' testing strategy that has either higher overall sensitivity or specificity than either of the two tests considered singly. Sequential versions of such strategies are often applied in order to reduce the cost of testing. We thus discuss joint (simultaneous and sequential) testing strategies and inference for them. Using the developed methods, we analyse two real and one simulated data sets, and we compare 'hypergeometric' and 'binomial-based' inferences. Our findings indicate that the posterior standard deviations for prevalence (but not sensitivity and specificity) based on finite population sampling tend to be smaller than their counterparts for infinite population sampling. Finally, we make recommendations about how small the sample size should be relative to the population size to warrant use of the binomial model for prevalence estimation. Copyright 2004 John Wiley & Sons, Ltd.

Evaluation of BRCA1 and BRCA2 mutations and risk-prediction models in a typical Asian country (Malaysia) with a relatively low incidence of breast cancer.

PubMed

Thirthagiri, E; Lee, S Y; Kang, P; Lee, D S; Toh, G T; Selamat, S; Yoon, S-Y; Taib, N A Mohd; Thong, M K; Yip, C H; Teo, S H

2008-01-01

The cost of genetic testing and the limited knowledge about the BRCA1 and BRCA2 genes in different ethnic groups has limited its availability in medium- and low-resource countries, including Malaysia. In addition, the applicability of many risk-assessment tools, such as the Manchester Scoring System and BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) which were developed based on mutation rates observed primarily in Caucasian populations using data from multiplex families, and in populations where the rate of breast cancer is higher, has not been widely tested in Asia or in Asians living elsewhere. Here, we report the results of genetic testing for mutations in the BRCA1 or BRCA2 genes in a series of families with breast cancer in the multi-ethnic population (Malay, Chinese and Indian) of Malaysia. A total of 187 breast cancer patients with either early-onset breast cancer (at age

Osteoporosis management and fractures in the Métis of Ontario, Canada.

PubMed

Jandoc, Racquel; Jembere, Nathaniel; Khan, Saba; Russell, Storm J; Allard, Yvon; Cadarette, Suzanne M

2015-01-01

Half of Métis citizens, compared to less than 10 % of the general population of Ontario, reside in northern regions, with little access to bone mineral density (BMD) testing. Métis citizens had lower sex-specific and age-standardized rates of BMD testing, yet similar rates of fracture (both sexes) and pharmacotherapy (women only). To examine osteoporosis management and common osteoporosis-related fractures among Métis citizens compared to the general population of older adults residing in Ontario. We linked healthcare (medical and pharmacy) utilization and administrative (demographic) databases with the Métis Nation of Ontario citizenship registry to estimate osteoporosis management (bone mineral density [BMD] testing, pharmacotherapy) and fractures (hip, humerus, radius/ulna) among adults aged ≥50 years, from April 1, 2006 to March 31, 2011. Pharmacotherapy data were limited to residents aged ≥65 years. Sex-specific and age-standardized rates were compared between the Métis and the general population. Multivariable logistic regression was used to compare rates of BMD testing after controlling for differences in age and region of residence between the Métis and the general population. We studied 4219 Métis citizens (55 % men), and 140 (3 %) experienced a fracture. Half of Métis citizens, compared to less than 10 % of the general population of Ontario, resided in northern regions. We identified significantly lower sex-specific and age-standardized rates of BMD testing among Métis compared to the general population, yet found little difference in fracture rates (both sexes) or pharmacotherapy (women only). Differences in BMD testing disappeared after adjusting for region of residence among women yet remained significant among men. Despite finding significantly lower rates of osteoporosis management among men, Métis men and women were found to have similar age-standardized fracture rates to the general population.

Microsatellites for Oenothera gayleana and O. hartwegii subsp. filifolia (Onagraceae), and their utility in section Calylophus1

PubMed Central

Lewis, Emily M.; Fant, Jeremie B.; Moore, Michael J.; Hastings, Amy P.; Larson, Erica L.; Agrawal, Anurag A.; Skogen, Krissa A.

2016-01-01

Premise of the study: Eleven nuclear and four plastid microsatellite markers were screened for two gypsum endemic species, Oenothera gayleana and O. hartwegii subsp. filifolia, and tested for cross-amplification in the remaining 11 taxa within Oenothera sect. Calylophus (Onagraceae). Methods and Results: Microsatellite markers were tested in two to three populations spanning the ranges of both O. gayleana and O. hartwegii subsp. filifolia. The nuclear microsatellite loci consisted of both di- and trinucleotide repeats with one to 17 alleles per population. Several loci showed significant deviation from Hardy–Weinberg equilibrium, which may be evidence of chromosomal rings. The plastid microsatellite markers identified one to seven haplotypes per population. The transferability of these markers was confirmed in all 11 taxa within Oenothera sect. Calylophus. Conclusions: The microsatellite loci characterized here are the first developed and tested in Oenothera sect. Calylophus. These markers will be used to assess whether pollinator foraging distance influences population genetic parameters in predictable ways. PMID:26949578

Modeling the brain morphology distribution in the general aging population

NASA Astrophysics Data System (ADS)

Huizinga, W.; Poot, D. H. J.; Roshchupkin, G.; Bron, E. E.; Ikram, M. A.; Vernooij, M. W.; Rueckert, D.; Niessen, W. J.; Klein, S.

2016-03-01

Both normal aging and neurodegenerative diseases such as Alzheimer's disease cause morphological changes of the brain. To better distinguish between normal and abnormal cases, it is necessary to model changes in brain morphology owing to normal aging. To this end, we developed a method for analyzing and visualizing these changes for the entire brain morphology distribution in the general aging population. The method is applied to 1000 subjects from a large population imaging study in the elderly, from which 900 were used to train the model and 100 were used for testing. The results of the 100 test subjects show that the model generalizes to subjects outside the model population. Smooth percentile curves showing the brain morphology changes as a function of age and spatiotemporal atlases derived from the model population are publicly available via an interactive web application at agingbrain.bigr.nl.

Trail Making Test: normative data for Turkish elderly population by age, sex and education.

PubMed

Cangoz, Banu; Karakoc, Ebru; Selekler, Kaynak

2009-08-15

Trail Making Test (TMT) is a neuropsychological test, which has parts A and B that can precisely measure executive functions, like complex visual-motor conceptual screening, planning, organization, abstract thinking and response inhibition. The main purpose of this study is to standardize TMT for Turkish adults and/or elderly population. This study primarily consists of two main parts; norm determination study and reliability/validity studies, respectively. The standardization study was carried on 484 participants (238 female and 246 male). Participants at the age of 50 years and older were selected from a pool of people employed in or retired from governmental and/or private institutions. The research design of this study involves the following variables mainly; age (7 subgroups), sex (2 subgroups) and education (3 subgroups). Age, sex and education variables have significant influence on eight different kinds of TMT scores. Statistical analysis by ANOVA revealed a major effect of age (p<0.001) and education (p<0.001) on time spent in Part A or B, or time difference between Parts B and A, or sum of Parts A and B. Similarly, influence of sex (p<0.05) on time spent on Part A or B, or sum of Parts A and B was shown to be significant. Kruskal-Wallis Test was performed and chi-square (chi(2)) values revealed that, correction scores for Part A and B were found to be influenced by age groups (p<0.001). Test-retest reliability and inter-rater reliability coefficients for time scores of Parts A and B were estimated as 0.78, 0.99 and 0.73, 0.93, respectively. This study provides normative data for a psychometric tool that reliably measures the executive functions in Turkish elderly population at the age of 50 and over.

Influence of interspecific interactions on avoidance response to contamination.

PubMed

Silva, Daniel C V R; Araújo, Cristiano V M; Marassi, Rodrigo J; Cardoso-Silva, Sheila; Neto, Morun B; Silva, Gilmar C; Ribeiro, Rui; Silva, Flávio T; Paiva, Teresa C B; Pompêo, Marcelo L M

2018-06-17

An increasing number of studies have shown the ability of organisms to escape from toxic effects due to contamination, by moving spatially towards less contaminated habitats. However, this issue has been investigated in monospecific scenarios, without considering possible interactions between species during the contamination avoidance process. It is widely known that the spatial distribution of one species can be affected by another one, in different ways. Therefore, the main question addressed in the present study was as follows: Might interspecific interaction between the freshwater fish Danio rerio (zebrafish) and Poecilia reticulata (guppy) change their behavior patterns in terms of avoidance in the presence of a copper gradient? Zebrafish and guppies exposed to a copper gradient were tested for avoidance responses in a free-choice, non-forced, static, multi-compartmented exposure system, using two distinct approaches: (1) monospecific tests, in which only one species was exposed to the copper gradient, at two different population densities; and (2) multispecific tests, in which both species were tested simultaneously. In the control (with no copper) monospecific tests, both species were randomly distributed; however, in the control multispecific test, P. reticulata tended to aggregate. In the monospecific tests with a copper gradient, both species avoided copper in a similar way, with AC 50 (concentration triggering avoidance in 50% of the exposed population) values between 15 and 18 μg·L -1 , irrespective of the population density. However, in the multispecific tests, P. reticulata displaced D. rerio to previously avoided copper levels, consequently increasing the AC 50 of D. rerio to 75 μg·L -1 . This study shows the importance of understanding the interactions among species in contaminated areas, and the way that one species can prevent the avoidance behavior of another. Copyright © 2018 Elsevier B.V. All rights reserved.

[COOP/WONCA: Reliability and validity of the test administered by telephone].

PubMed

Pedrero-Pérez, Eduardo J; Díaz-Olalla, José Manuel

2016-01-01

The COOP/WONCA test was initially proposed as a self-report in which the answers were supported by drawings illustrating the state investigated. Subsequent studies have confirmed its usefulness as a mere verbal self-report face-to-face administered. No data have been found about its useful when administered by telephone interview. The aim of this study was to determine the psychometric properties of the COOP / WONCA test to measure Related Quality of Life (HRQoL) administered by telephone and compare them with those obtained in other forms of prior administration. Cross-sectional study on a random. City of Madrid. Random sample of 802 adult subjects, representative of the adult population in Madrid, obtained by stratification from the population census. Questionnaire COOP/WONCA with 9 ítems included in a broader battery, administered by telephone interview. The unrestricted factor analysis points to the unifactoriality of the scale, which measures a single latent construct (HRQOL), showing high internal consistency, not significantly different from those found by face-to-face administration, ruling out the existence of biases in the phone modality. The COOP/WONCA test appears as a reliable and valid measure of HRQOL and telephonic administration allows to assume no changes in the results, which can reduce costs in population studies, increasing efficiency without loss of quality in the information collected. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Reliability of Different Mark-Recapture Methods for Population Size Estimation Tested against Reference Population Sizes Constructed from Field Data

PubMed Central

Grimm, Annegret; Gruber, Bernd; Henle, Klaus

2014-01-01

Reliable estimates of population size are fundamental in many ecological studies and biodiversity conservation. Selecting appropriate methods to estimate abundance is often very difficult, especially if data are scarce. Most studies concerning the reliability of different estimators used simulation data based on assumptions about capture variability that do not necessarily reflect conditions in natural populations. Here, we used data from an intensively studied closed population of the arboreal gecko Gehyra variegata to construct reference population sizes for assessing twelve different population size estimators in terms of bias, precision, accuracy, and their 95%-confidence intervals. Two of the reference populations reflect natural biological entities, whereas the other reference populations reflect artificial subsets of the population. Since individual heterogeneity was assumed, we tested modifications of the Lincoln-Petersen estimator, a set of models in programs MARK and CARE-2, and a truncated geometric distribution. Ranking of methods was similar across criteria. Models accounting for individual heterogeneity performed best in all assessment criteria. For populations from heterogeneous habitats without obvious covariates explaining individual heterogeneity, we recommend using the moment estimator or the interpolated jackknife estimator (both implemented in CAPTURE/MARK). If data for capture frequencies are substantial, we recommend the sample coverage or the estimating equation (both models implemented in CARE-2). Depending on the distribution of catchabilities, our proposed multiple Lincoln-Petersen and a truncated geometric distribution obtained comparably good results. The former usually resulted in a minimum population size and the latter can be recommended when there is a long tail of low capture probabilities. Models with covariates and mixture models performed poorly. Our approach identified suitable methods and extended options to evaluate the performance of mark-recapture population size estimators under field conditions, which is essential for selecting an appropriate method and obtaining reliable results in ecology and conservation biology, and thus for sound management. PMID:24896260

Compensatory mortality in mule deer populations: Technical progress report. [Odocoileus hemionus

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

White, G.C.

1987-07-15

The hypothesis of compensatory mortality is critical to understanding population dynamics of wildlife species. This research tested for compensatory mortality in the juvenile (fawn) portion of a mule deer population. In the fall of 1986, 60 fawns were telemetered on both the control and treatment sites of the Little Hills study area. Thirteen adult females also were telemetered which, together with 31 telemetered adults already present, brought the total instrumented population to 164 at the onset of winter. Experimental manipulation to test for compensation in the population was successful, with 18% of the population on the treatment area (328 animals)more » removed. Line transect estimates of deer groups/ha were 0.12 +- 0.030 (D +- SE) for the control area and 0.14 +- 0.028 for the treatment area, giving 1727 individuals on the control area and 1490 on the treatment area. Thus the number of deer was measurably decreased on the treatment area by the removal operation.« less

The appropriateness of the NC state-mandated reading competency test for deaf students as a criterion for high school graduation.

PubMed

Lollis, Jana; LaSasso, Carol

2009-01-01

Deaf students consistently score lower on standardized measures of reading comprehension than their hearing peers. Most of the studies that have been conducted to explain this phenomenon have focused on variables within the reader, and important differences have been found between deaf and hearing readers. More recently, in the face of increasingly high-stakes consequences, researchers are looking "outside" the reader, at the tests themselves, to determine whether there are fairness issues for special populations, such as deaf students. The study reported here, the first of its kind with deaf students, examines the North Carolina (NC) reading comprehension test. The study employs the same method used originally by NC to determine its appropriateness of the test for the general population of NC students. The experts in this article, like those in the original construction of the NC test, are familiar with the content of the reading curriculum in NC; however, the raters in this article bring a special perspective related to teaching and testing reading of students who are deaf. Findings from this study raise questions about the appropriateness of the NC reading test for deaf students. Implications for future research and instructional practice are discussed.

Patterns of population structure and dispersal in the long-lived "redwood" of the coral reef, the giant barrel sponge ( Xestospongia muta)

NASA Astrophysics Data System (ADS)

Richards, Vincent P.; Bernard, Andrea M.; Feldheim, Kevin A.; Shivji, Mahmood S.

2016-09-01

Sponges are one of the dominant fauna on Florida and Caribbean coral reefs, with species diversity often exceeding that of scleractinian corals. Despite the key role of sponges as structural components, habitat providers, and nutrient recyclers in reef ecosystems, their dispersal dynamics are little understood. We used ten microsatellite markers to study the population structure and dispersal patterns of a prominent reef species, the giant barrel sponge ( Xestospongia muta), the long-lived "redwood" of the reef, throughout Florida and the Caribbean. F-statistics, exact tests of population differentiation, and Bayesian multi-locus genotype analyses revealed high levels of overall genetic partitioning ( F ST = 0.12, P = 0.001) and grouped 363 individuals collected from the Bahamas, Honduras, US Virgin Islands, Key Largo (Florida), and the remainder of the Florida reef tract into at minimum five genetic clusters ( K = 5). Exact tests, however, revealed further differentiation, grouping sponges sampled from five locations across the Florida reef tract (~250 km) into three populations, suggesting a total of six genetic populations across the eight locations sampled. Assignment tests showed dispersal over ecological timescales to be limited to relatively short distances, as the only migration detected among populations was within the Florida reef tract. Consequently, populations of this major coral reef benthic constituent appear largely self-recruiting. A combination of levels of genetic differentiation, genetic distance, and assignment tests support the important role of the Caribbean and Florida currents in shaping patterns of contemporary and historical gene flow in this widespread coral reef species.

Distance to human populations influences epidemiology of respiratory disease in desert tortoises

USGS Publications Warehouse

Berry, Kristin H.; Ashley A. Coble (formerly Emerson), no longer USGS; Yee, Julie L.; Mack, Jeremy S.; Perry, William M.; Anderson, Kemp M.; Brown, Mary B.

2014-01-01

We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) in a 1,183-km2 study area in the central Mojave Desert of California between 2005 and 2008. We evaluated 1,004 tortoises for prevalence and spatial distribution of 2 pathogens, Mycoplasma agassizii and M. testudineum, that cause upper respiratory tract disease. We defined tortoises as test-positive if they were positive by culture and/or DNA identification or positive or suspect for specific antibody for either of the two pathogens. We used covariates of habitat (vegetation, elevation, slope, and aspect), tortoise size and sex, distance from another test-positive tortoise, and anthropogenic variables (distances to roads, agricultural areas, playas, urban areas, and centroids of human-populated census blocks). We used both logistic regression models and regression trees to evaluate the 2 species of Mycoplasma separately. The prevalence of test-positive tortoises was low: 1.49% (15/1,004) for M. agassizii and 2.89% (29/1,004) for M. testudineum. The spatial distributions of test-positive tortoises for the 2 Mycoplasma species showed little overlap; only 2 tortoises were test-positive for both diseases. However, the spatial distributions did not differ statistically between the 2 species. We consistently found higher prevalence of test-positive tortoises with shorter distances to centroids of human-populated census blocks. The relationship between distance to human-populated census blocks and tortoises that are test-positive for M. agassizii and potentially M. testudineum may be related to release or escape of captive tortoises because the prevalence of M. agassizii in captive tortoises is high. Our findings have application to other species of chelonians where both domestic captive and wild populations exist. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Promoting effects on reproduction increase population vulnerability of Daphnia magna.

PubMed

Agatz, Annika; Hammers-Wirtz, Monika; Gabsi, Faten; Ratte, Hans Toni; Brown, Colin D; Preuss, Thomas G

2012-07-01

Environmental risk assessment of chemicals is based on single species tests at the individual level with single compounds. However, the protection goal is the sustainability of a population, which faces several natural stressors and mixtures of chemicals in the environment. Therefore, experiments were undertaken to quantify the combined effects of chemicals with different modes of action on Daphnia magna populations. Populations continuously exposed to dispersogen A and at abundance equilibrium were treated with a 2-d pulse of p353-nonylphenol. In previous studies, dispersogen A was shown to act as a natural info-chemical, promoting the reproduction of daphnids (higher offspring quantity) coupled with reduced offspring fitness, whereas nonylphenol in pulsed-exposure caused size-selective mortality. Dispersogen A caused accelerated population growth to maximum abundance, shifted the population structure towards smaller individuals, and increased the population sensitivity to nonylphenol. The authors showed that a positive effect observed at the individual level can be transposed to a negative effect when monitored at the population level. So far, positive effects are not addressed in environmental risk assessment, and even in higher-tier testing, population structure is not quantified. Both factors indicate a potential mismatch between protection aim and risk assessment practice. Copyright © 2012 SETAC.

Host and Aquatic Environment Shape the Amphibian Skin Microbiome but Effects on Downstream Resistance to the Pathogen Batrachochytrium dendrobatidis Are Variable

PubMed Central

Jani, Andrea J.; Briggs, Cheryl J.

2018-01-01

Symbiotic microbial communities play key roles in the health and development of their multicellular hosts. Understanding why microbial communities vary among different host species or individuals is an important step toward understanding the diversity and function of the microbiome. The amphibian skin microbiome may affect resistance to the fungal pathogen Batrachochytrium dendrobatidis (Bd). Still, the factors that determine the diversity and composition of the amphibian skin microbiome, and therefore may ultimately contribute to disease resistance, are not well understood. We conducted a two-phase experiment to first test how host and environment shape the amphibian skin microbiome, and then test if the microbiome affects or is affected by Bd infection. Most lab experiments testing assembly of the amphibian skin microbiome so far have compared sterile to non-sterile environments or heavily augmented to non-augmented frogs. A goal of this study was to evaluate, in an experimental setting, realistic potential drivers of microbiome assembly that would be relevant to patterns observed in nature. We tested effects of frog genetic background (2 source populations) and 6 natural lake water sources in shaping the microbiome of the frog Rana sierrae. Water in which frogs were housed affected the microbiome in a manner that partially mimicked patterns observed in natural populations. In particular, frogs housed in water from disease-resistant populations had greater bacterial richness than frogs housed in water from populations that died out due to Bd. However, in the experiment this difference in microbiomes did not lead to differences in host mortality or rates of pathogen load increase. Frog source population also affected the microbiome and, although none of the frogs in this study showed true resistance to infection, host source population had a small effect on the rate of pathogen load increase. This difference in infection trajectories could be due to the observed differences in the microbiome, but could also be due to other traits that differ between frogs from the two populations. In addition to examining effects of the microbiome on Bd, we tested the effect of Bd infection severity on the microbiome. Specifically, we studied a time series of the microbiome over the course of infection to test if the effects of Bd on the microbiome are dependent on Bd infection severity. Although limited to a small subset of frogs, time series analysis suggested that relative abundances of several bacterial phylotypes changed as Bd loads increased through time, indicating that Bd-induced disturbance of the R. sierrae microbiome is not a binary effect but instead is dependent on infection severity. We conclude that both host and aquatic environment help shape the R. sierrae skin microbiome, with links to small changes in disease resistance in some cases, but in this study the effect of Bd on the microbiome was greater than the effect of the microbiome on Bd. Assessment of the microbiome differences between more distantly related populations than those studied here is needed to fully understand the role of the microbiome in resistance to Bd. PMID:29619014

Development of a Pediatric Visual Field Test

PubMed Central

Miranda, Marco A.; Henson, David B.; Fenerty, Cecilia; Biswas, Susmito; Aslam, Tariq

2016-01-01

Purpose We describe a pediatric visual field (VF) test based on a computer game where software and hardware combine to provide an enjoyable test experience. Methods The test software consists of a platform-based computer game presented to the central VF. A storyline was created around the game as was a structure surrounding the computer monitor to enhance patients' experience. The patient is asked to help the central character collect magic coins (stimuli). To collect these coins a series of obstacles need to be overcome. The test was presented on a Sony PVM-2541A monitor calibrated from a central midpoint with a Minolta CS-100 photometer placed at 50 cm. Measurements were performed at 15 locations on the screen and the contrast calculated. Retinal sensitivity was determined by modulating stimulus in size. To test the feasibility of the novel approach 20 patients (4–16 years old) with no history of VF defects were recruited. Results For the 14 subjects completing the study, 31 ± 15 data points were collected on 1 eye of each patient. Mean background luminance and stimulus contrast were 9.9 ± 0.3 cd/m2 and 27.9 ± 0.1 dB, respectively. Sensitivity values obtained were similar to an adult population but variability was considerably higher – 8.3 ± 9.0 dB. Conclusions Preliminary data show the feasibility of a game-based VF test for pediatric use. Although the test was well accepted by the target population, test variability remained very high. Translational Relevance Traditional VF tests are not well tolerated by children. This study describes a child-friendly approach to test visual fields in the targeted population. PMID:27980876

Prevalence of latent tuberculous infection among adults in the general population of Ca Mau, Viet Nam.

PubMed

Marks, G B; Nhung, N V; Nguyen, T A; Hoa, N B; Khoa, T H; Son, N V; Phuong, N T B; Tin, D M; Ho, J; Fox, G J

2018-03-01

The study was conducted in a randomly selected sample of persons aged 15 years living in Ca Mau Province, southern Viet Nam. To estimate the prevalence of latent tuberculous infection (LTBI) in the general adult population of this province of Viet Nam. The secondary objective was to examine age and sex differences in prevalence. A cross-sectional survey was conducted in a cluster-random sample of the population. Clusters were subcommunes. The presence of LTBI was assessed using the QuantiFERON®-TB Gold In-Tube test system. QuantiFERON tests were performed among 1319 persons aged 15 years (77.7% of those selected). The overall prevalence of positive tests was 36.8% (95%CI 33.4-40.3). The prevalence of a positive test was lower in females than in males (31.0% vs. 44.7%, OR 0.57, 95%CI 0.45-0.72, P < 0.0001). The prevalence of positive tests increased with increasing age quintile (P < 0.0001). More than one third of the general adult population in a province in southern Viet Nam have evidence of LTBI. Although LTBI prevalence is higher in males, the sex difference is not as great as that for TB notification rates.

Point-of-care HIV tests done by peers, Brazil

PubMed Central

Dutra de Barros, Clarissa Habckost; Lobo, Tainah Dourado de Miranda; Pasini, Elisiane Nelcina; Comparini, Regina Aparecida; Caldas de Mesquita, Fábio

2016-01-01

Abstract Problem Early diagnosis of infections with human immunodeficiency virus (HIV) is needed – especially among key populations such as sex workers, transgender people, men who have sex with men and people who use drugs. Approach The Brazilian Ministry of Health developed a strategy called Viva Melhor Sabendo (“live better knowing”) to increase HIV testing among key populations. In partnership with nongovernmental organizations (NGOs), a peer point-of-care testing intervention, using an oral fluid rapid test, was introduced at social venues for key populations at different times of the day. Local setting Key populations in Brazil can have 40 times higher HIV prevalence than the general population (14.8% versus 0.4%). Relevant changes Legislation was reinterpreted, so that oral fluid rapid tests could be administered by any person trained in rapid testing by the health ministry. Between January 2014 and March 2015, 29 723 oral fluid tests were administered; 791 (2.7%) were positive. Among the key populations, transgender people had the greatest proportion of positive results (10.7%; 172/1612), followed by men who declared themselves as commercial sex workers (8.7%; 165/1889) and men who have sex with men (4.8%; 292/6055). Lessons learnt The strategy improved access to HIV testing. Testing done by peers at times and locations suitable for key populations increased acceptance of testing. Working with relevant NGOs is a useful approach when reaching out to these key populations. PMID:27516641

Experimental studies on comparison of the vector competence of four Italian Culex pipiens populations for West Nile virus.

PubMed

Fortuna, Claudia; Remoli, Maria Elena; Di Luca, Marco; Severini, Francesco; Toma, Luciano; Benedetti, Eleonora; Bucci, Paola; Montarsi, Fabrizio; Minelli, Giada; Boccolini, Daniela; Romi, Roberto; Ciufolini, Maria Grazia

2015-09-17

West Nile virus (WNV) is a vector-borne disease responsible for causing epidemics in many areas of the world. The virus is maintained in nature by an enzootic bird-mosquito-bird cycle and occasionally transmitted to other hosts, such as equines and humans. Culex species, in particular the ubiquitous species Culex pipiens is thought to play a major vector role both in enzootic and epizootic maintenance and transmission of WNV. Introduced in Europe in recent years, since 2008 WNV has been stably circulating mainly in the Northeastern regions of Italy, although sporadic equine and/or human cases, as well as WNV infected Cx. pipiens pools, have been recorded in other Italian areas. The scope of our study was to evaluate the potential competence of some Italian populations of Cx. pipiens to transmit WNV and to assess their ability for vertical transmission of the virus. For this purpose four Italian populations, from different areas, were experimentally infected. After the infectious blood meal, fed females were monitored for 32 days to determine the length of viral extrinsic incubation period. WNV titre of infected mosquitoes was evaluated both by quantitative Real Time PCR and viral titration by Plaque Forming Units/ml (PFU/mL) in VERO cells. Potential Infection, Dissemination, Transmission rates (IR, DR, TR) were assessed by detection of the virus in body, legs plus wings and saliva of the fed females, respectively. All tested populations were susceptible to the WNV infection. The viral presence in legs and wings demonstrated the ability of WNV to disseminate in the mosquitoes. Viral RNA was detected in the saliva of tested populations. No significant differences in TR values were observed among the four studied populations. The offspring of the Cx. pipiens infected females were WNV negative. Our study addressed an important issue in the knowledge on the complex WNV-vector relationships in Italy, indicating that all Italian Cx. pipiens populations tested exhibited vector competence for WNV. Further studies should be performed in order to better clarify the role of other factors (vector density, climatic conditions, reservoir presence etc.) in order to predict where and when WNV outbreaks could occur.

[Results of a cytogenetic study of populations with different radiation risks in the Semipalatinsk region].

PubMed

Sviatova, G S; Abil'dinova, G Z; Berezina, G M

2002-03-01

A cytogenetic study was conducted for the first time on human populations neighboring the Semipalatinsk nuclear test site (STS) and exposed to ionizing radiation for a long period of time. In populations with the extreme and maximum radiation risks, high frequencies of radiation-induced chromosomal markers, including acentric fragments (1.99 +/- 0.10 per 100 cells), dicentrics (0.23 +/- 0.01), ring chromosomes (0.38 +/- 0.14), and stable chromosomal aberrations (1.17 +/- 0.02), were found. These frequencies significantly exceeded those in control populations. The spectrum of chromosomal aberrations and the frequencies of the aberrations of different types in persons living in the areas with the highest radionuclide contamination confirmed the mutagenic effect of radiation on chromosomes in the human populations studied.

Genetic structure in the Anaxyrus boreas species group (anura, Bufonidae): an evaluation of the Southern Rocky Mountain population

USGS Publications Warehouse

Switzer, John F.; Johnson, Robin L.; Lubinski, Barbara A.; King, Tim L.

2009-01-01

The Anaxyrus boreas species group is comprised of four species endemic to the western United States: A. boreas, A. canorus, A. exsul, and A. nelsoni. Disjunct populations of the widespread western toad Anaxyrus boreas from Colorado and southern Wyoming, the southern rocky mountain population (SRMP), were previously candidates for listing under the United States Endangered Species Act (ESA) as a distinct population segment (DPS), but were removed due to a lack of significant genetic differentiation in preliminary studies. The purpose of this study was to conduct phylogeographic and population genetic analyses of A. boreas and three related species using mitochondrial DNA sequence data and nuclear microsatellite genotype data. The study is specifically focused on testing the evolutionary significance of the SRMP.

The Association Between Fall History and Physical Performance Tests in the Community-Dwelling Elderly: A Cross-Sectional Analysis.

PubMed

Kim, Jin Chul; Chon, Jinmann; Kim, Hee Sang; Lee, Jong Ha; Yoo, Seung Don; Kim, Dong Hwan; Lee, Seung Ah; Han, Yoo Jin; Lee, Hyun Seok; Lee, Bae Youl; Soh, Yun Soo; Won, Chang Won

2017-04-01

To evaluate the association between baseline characteristics, three physical performance tests and fall history in a sample of the elderly from Korean population. A total of 307 participants (mean age, 76.70±4.85 years) were categorized into one of two groups, i.e., fallers and non-fallers. Fifty-two participants who had reported falling unexpectedly at least once in the previous 12 months were assigned to the fallers group. Physical performance tests included Short Physical Performance Battery (SPPB), Berg Balance Scale (BBS), Timed Up and Go test. The differences between the two study groups were compared and we analyzed the correlations between fall histories and physical performance tests. SPPB demonstrated a significant association with fall history. Although the BBS total scores did not show statistical significance, two dynamic balance test items of BBS (B12 and B13) showed a significant association among fallers. This study suggests that SPPB and two dynamic balance test items of the BBS can be used in screening for risk of falls in an ambulatory elderly population.

Landscape attributes and life history variability shape genetic structure of trout populations in a stream network

USGS Publications Warehouse

Neville, H.M.; Dunham, J.B.; Peacock, M.M.

2006-01-01

Spatial and temporal landscape patterns have long been recognized to influence biological processes, but these processes often operate at scales that are difficult to study by conventional means. Inferences from genetic markers can overcome some of these limitations. We used a landscape genetics approach to test hypotheses concerning landscape processes influencing the demography of Lahontan cutthroat trout in a complex stream network in the Great Basin desert of the western US. Predictions were tested with population- and individual-based analyses of microsatellite DNA variation, reflecting patterns of dispersal, population stability, and local effective population sizes. Complementary genetic inferences suggested samples from migratory corridors housed a mixture of fish from tributaries, as predicted based on assumed migratory life histories in those habitats. Also as predicted, populations presumed to have greater proportions of migratory fish or from physically connected, large, or high quality habitats had higher genetic variability and reduced genetic differentiation from other populations. Populations thought to contain largely non-migratory individuals generally showed the opposite pattern, suggesting behavioral isolation. Estimated effective sizes were small, and we identified significant and severe genetic bottlenecks in several populations that were isolated, recently founded, or that inhabit streams that desiccate frequently. Overall, this work suggested that Lahontan cutthroat trout populations in stream networks are affected by a combination of landscape and metapopulation processes. Results also demonstrated that genetic patterns can reveal unexpected processes, even within a system that is well studied from a conventional ecological perspective. ?? Springer 2006.

Genetic variation and forensic efficiency of autosomal insertion/deletion polymorphisms in Chinese Bai ethnic group: phylogenetic analysis to other populations

PubMed Central

Yang, Chun-Hua; Yin, Cai-Yong; Shen, Chun-Mei; Guo, Yu-Xin; Dong, Qian; Yan, Jiang-Wei; Wang, Hong-Dan; Zhang, Yu-Dang; Meng, Hao-Tian; Jin, Rui

2017-01-01

Thirty insertion/deletion loci were utilized to study the genetic diversities of 125 bloodstain samples collected from Bai group in Yunnan Dali region, China. The observed heterozygosity and expected heterozygosity of the 30 loci ranged from 0.1520 to 0.5680, and 0.1927 to 0.4997, respectively. No deviations from Hardy-Weinberg equilibrium tests after Bonferroni correction were found at all 30 loci in Bai group. The cumulative probability of exclusion and combined discrimination power were 0.9859 and 0.9999999999887, respectively, which indicated the 30 loci could be used as complementary genetic markers for paternity testing and were qualified for personal identification in forensic cases. We found the studied Bai group had close relationships with Tibetan, Yi and Han groups from China by the population structure, principal component analysis, population differentiations, and phylogenetic reconstruction studies. Even so, for a better understanding of Bai ethnicity's genetic milieu, DNA genotyping at various genetic markers is necessary in future studies. PMID:28465476

Genetic variation and forensic efficiency of autosomal insertion/deletion polymorphisms in Chinese Bai ethnic group: phylogenetic analysis to other populations.

PubMed

Yang, Chun-Hua; Yin, Cai-Yong; Shen, Chun-Mei; Guo, Yu-Xin; Dong, Qian; Yan, Jiang-Wei; Wang, Hong-Dan; Zhang, Yu-Dang; Meng, Hao-Tian; Jin, Rui; Chen, Feng; Zhu, Bo-Feng

2017-06-13

Thirty insertion/deletion loci were utilized to study the genetic diversities of 125 bloodstain samples collected from Bai group in Yunnan Dali region, China. The observed heterozygosity and expected heterozygosity of the 30 loci ranged from 0.1520 to 0.5680, and 0.1927 to 0.4997, respectively. No deviations from Hardy-Weinberg equilibrium tests after Bonferroni correction were found at all 30 loci in Bai group. The cumulative probability of exclusion and combined discrimination power were 0.9859 and 0.9999999999887, respectively, which indicated the 30 loci could be used as complementary genetic markers for paternity testing and were qualified for personal identification in forensic cases. We found the studied Bai group had close relationships with Tibetan, Yi and Han groups from China by the population structure, principal component analysis, population differentiations, and phylogenetic reconstruction studies. Even so, for a better understanding of Bai ethnicity's genetic milieu, DNA genotyping at various genetic markers is necessary in future studies.

Comparison of Scores on Two Visual-Motor Tests for Children Referred for Learning or Adjustment Difficulties.

ERIC Educational Resources Information Center

DeMers, Stephen T.; And Others

1981-01-01

This study compared the performance of school-aged children referred for learning or adjustment difficulties on Beery's Developmental Test of Visual-Motor Integration and Koppitz's version of the Bender-Gestalt test. Results indicated that the tests are related but not equivalent when administered to referred populations. (Author/AL)

Test-Optional Admission Policies and Their Effect on the Composition of the Student Body at King's College

ERIC Educational Resources Information Center

Schmude, Michelle

2011-01-01

This study examined test-optional admission policies and their effect on the composition of the student body at King's College. According to the College Board (2009), students from underrepresented populations do not perform as well as White students on standardized tests. Therefore, higher education institutions have established test-optional…

An International Comparison Using a Diagnostic Testing Model: Turkish Students' Profile of Mathematical Skills on TIMSS-R

ERIC Educational Resources Information Center

Dogan, Enis; Tatsuoka, Kikumi

2008-01-01

This study illustrates how a diagnostic testing model can be used to make detailed comparisons between student populations participating in international assessments. The performance of Turkish students on the TIMSS-R mathematics test was reanalyzed with a diagnostic testing model called the Rule Space Model. First, mathematical and cognitive…

The Effect of Repeaters on Equating

ERIC Educational Resources Information Center

Kim, HeeKyoung; Kolen, Michael J.

2010-01-01

Test equating might be affected by including in the equating analyses examinees who have taken the test previously. This study evaluated the effect of including such repeaters on Medical College Admission Test (MCAT) equating using a population invariance approach. Three-parameter logistic (3-PL) item response theory (IRT) true score and…

A kinetic study of solar wind electrons in the transition region from collision dominated to collisionless flow

NASA Technical Reports Server (NTRS)

Lie-Svendsen, O.; Leer, E.

1995-01-01

We have studied the evolution of the velocity distribution function of a test population of electrons in the solar corona and inner solar wind region, using a recently developed kinetic model. The model solves the time dependent, linear transport equation, with a Fokker-Planck collision operator to describe Coulomb collisions between the 'test population' and a thermal background of charged particles, using a finite differencing scheme. The model provides information on how non-Maxwellian features develop in the distribution function in the transition region from collision dominated to collisionless flow. By taking moments of the distribution the evolution of higher order moments, such as the heat flow, can be studied.

The Six-Minute Walk Test for Adults with Intellectual Disability: A Study of Validity and Reliability

ERIC Educational Resources Information Center

Nasuti, Gabriella; Stuart-Hill, Lynneth; Temple, Viviene A.

2013-01-01

Background: The Six-Minute Walk Test (6MWT) has been used with clinical and healthy populations to assess functional capacity and cardiovascular fitness. The aim of this study was to determine the test-retest reliability of a modified-6MWT as well as concurrent validity of walk distance with peak oxygen uptake (VO[subscript 2] peak). Method:…

Pilot test of new roadside survey methodology for impaired driving

DOT National Transportation Integrated Search

2007-01-01

This study developed and tested procedures to enhance roadside survey procedures to include collecting and analyzing oral fluid and blood samples from the nighttime weekend driving population. Roadside surveys involve collecting information from a ra...

Exploring the Potential of Direct-To-Consumer Genomic Test Data for Predicting Adverse Drug Events.

PubMed

Zhang, Patrick M; Sarkar, Indra Neil

2018-01-01

Recent technological advancements in genetic testing and the growing accessibility of public genomic data provide researchers with a unique avenue to approach personalized medicine. This feasibility study examined the potential of direct-to-consumer (DTC) genomic tests (focusing on 23andMe) in research and clinical applications. In particular, we combined population genetics information from the Personal Genome Project with adverse event reports from AEOLUS and pharmacogenetic information from PharmGKB. Primarily, associations between drugs based on co-occurring genetic variations and associations between variants and adverse events were used to assess the potential for leveraging single nucleotide polymorphism information from 23andMe. The results of this study suggest potential clinical uses of DTC tests in light of potential drug interactions. Furthermore, the results suggest great potential for analyzing associations at a population level to facilitate knowledge discovery in the realm of predicting adverse drug events.

African perceptions of female attractiveness.

PubMed

Coetzee, Vinet; Faerber, Stella J; Greeff, Jaco M; Lefevre, Carmen E; Re, Daniel E; Perrett, David I

2012-01-01

Little is known about mate choice preferences outside Western, educated, industrialised, rich and democratic societies, even though these Western populations may be particularly unrepresentative of human populations. To our knowledge, this is the first study to test which facial cues contribute to African perceptions of African female attractiveness and also the first study to test the combined role of facial adiposity, skin colour (lightness, yellowness and redness), skin homogeneity and youthfulness in the facial attractiveness preferences of any population. Results show that youthfulness, skin colour, skin homogeneity and facial adiposity significantly and independently predict attractiveness in female African faces. Younger, thinner women with a lighter, yellower skin colour and a more homogenous skin tone are considered more attractive. These findings provide a more global perspective on human mate choice and point to a universal role for these four facial cues in female facial attractiveness.

Anticholinergics and Central Nervous System Effects: Are We Confused?

PubMed Central

Staskin, David R; Zoltan, Edward

2007-01-01

The central nervous system (CNS) effects of anticholinergic agents have been documented in various patient populations and to varying degrees in case reports, brain-activity surrogates, and computerized cognitive testing. The older patient population with overactive bladder represents a group at increased risk of cognitive impairment and other CNS side effects associated with antimuscarinic agents. The complexity of the effect of anticholinergic agents on CNS function requires an increased level of careful investigation. Studies need to be performed in the at-risk population with multiple, validated tests at clinically prescribed doses in acute and chronic situations. These studies need to take into account the effect of commonly prescribed dosing regimens, with doses selected to represent with equivalent bladder potency. The alterations in the serum levels and parent/metabolite effects contributed by metabolic issues or drug delivery systems require special attention. PMID:18231615

Genetic effects on life-history traits in the Glanville fritillary butterfly.

PubMed

Duplouy, Anne; Wong, Swee C; Corander, Jukka; Lehtonen, Rainer; Hanski, Ilkka

2017-01-01

Adaptation to local habitat conditions may lead to the natural divergence of populations in life-history traits such as body size, time of reproduction, mate signaling or dispersal capacity. Given enough time and strong enough selection pressures, populations may experience local genetic differentiation. The genetic basis of many life-history traits, and their evolution according to different environmental conditions remain however poorly understood. We conducted an association study on the Glanville fritillary butterfly, using material from five populations along a latitudinal gradient within the Baltic Sea region, which show different degrees of habitat fragmentation. We investigated variation in 10 principal components, cofounding in total 21 life-history traits, according to two environmental types, and 33 genetic SNP markers from 15 candidate genes. We found that nine SNPs from five genes showed strong trend for trait associations ( p -values under 0.001 before correction). These associations, yet non-significant after multiple test corrections, with a total number of 1,086 tests, were consistent across the study populations. Additionally, these nine genes also showed an allele frequency difference between the populations from the northern fragmented versus the southern continuous landscape. Our study provides further support for previously described trait associations within the Glanville fritillary butterfly species across different spatial scales. Although our results alone are inconclusive, they are concordant with previous studies that identified these associations to be related to climatic changes or habitat fragmentation within the Åland population.

Genetic effects on life-history traits in the Glanville fritillary butterfly

PubMed Central

Corander, Jukka

2017-01-01

Background Adaptation to local habitat conditions may lead to the natural divergence of populations in life-history traits such as body size, time of reproduction, mate signaling or dispersal capacity. Given enough time and strong enough selection pressures, populations may experience local genetic differentiation. The genetic basis of many life-history traits, and their evolution according to different environmental conditions remain however poorly understood. Methods We conducted an association study on the Glanville fritillary butterfly, using material from five populations along a latitudinal gradient within the Baltic Sea region, which show different degrees of habitat fragmentation. We investigated variation in 10 principal components, cofounding in total 21 life-history traits, according to two environmental types, and 33 genetic SNP markers from 15 candidate genes. Results We found that nine SNPs from five genes showed strong trend for trait associations (p-values under 0.001 before correction). These associations, yet non-significant after multiple test corrections, with a total number of 1,086 tests, were consistent across the study populations. Additionally, these nine genes also showed an allele frequency difference between the populations from the northern fragmented versus the southern continuous landscape. Discussion Our study provides further support for previously described trait associations within the Glanville fritillary butterfly species across different spatial scales. Although our results alone are inconclusive, they are concordant with previous studies that identified these associations to be related to climatic changes or habitat fragmentation within the Åland population. PMID:28560112

Comparison of cognitive functioning as measured by the Ruff Figural Fluency Test and the CogState computerized battery within the LifeLines Cohort Study.

PubMed

Kuiper, Jisca S; Oude Voshaar, Richard C; Verhoeven, Floor E A; Zuidema, Sytse U; Smidt, Nynke

2017-05-12

The Ruff Figural Fluency Test (RFFT; a pencil and paper test) and the CogState (a computerized cognitive test battery) are well-validated and suitable tests to evaluate cognitive functioning in large observational studies at the population level. The LifeLines Cohort Study includes the RFFT as baseline measurement and incorporated the CogState as replacement for the RFFT at follow-up. It is unknown how these two tests relate to each other. Therefore, the aim of this study is to examine the correlation between the RFFT and the CogState and the impact of demographic characteristics on this association. A subcohort of the LifeLines Cohort Study, a large population based cohort study, participated in this study. Correlations between the RFFT and six subtasks of the CogState were examined. Subgroup analyses were performed to investigate the influence of age, education, and gender on the results. With sensitivity analyses we investigated the influence of computer experience and (physical) impairments. A total of 509 participants (mean age (SD): 53 years (14.6); range 18-87 years) participated in this study. All correlations between the RFFT and the CogState were statistically significant (except for the correlation between the RFFT error ratio and the CogState One Back Task), ranging from -0.39 to 0.28. Stratifying the analyses for age, education, and gender did not substantially affect our conclusions. Sensitivity analyses showed no substantial influence of level of computer experience or (physical) impairments. Correlations found in the present study were only weak to moderate, indicating that cognitive functioning measured by the RFFT does not measure the same components of cognitive functioning as six subtasks of the CogState. Computerized testing such as the CogState may be very well suited for large cohort studies to assess cognitive functioning in the general population and to identify cognitive changes as early as possible, as it is a less time- and labor intensive tool.

Urban–rural disparities in colorectal cancer screening: cross-sectional analysis of 1998–2005 data from the Centers for Disease Control's Behavioral Risk Factor Surveillance Study

PubMed Central

Cole, Allison M; Jackson, J Elizabeth; Doescher, Mark

2012-01-01

Despite the existence of effective screening, colorectal cancer remains the second leading cause of cancer death in the United States. Identification of disparities in colorectal cancer screening will allow for targeted interventions to achieve national goals for screening. The objective of this study was to contrast colorectal cancer screening rates in urban and rural populations in the United States. The study design comprised a cross-sectional study in the United States 1998–2005. Behavioral Risk Factor Surveillance System data from 1998 to 2005 were the method and data source. The primary outcome was self-report up-to-date colorectal cancer screening (fecal occult blood test in last 12 months, flexible sigmoidoscopy in last 5 years, or colonoscopy in last 10 years). Geographic location (urban vs. rural) was used as independent variable. Multivariate analysis controlled for demographic and health characteristics of respondents. After adjustment for demographic and health characteristics, rural residents had lower colorectal cancer screening rates (48%; 95% CI 48, 49%) as compared with urban residents (54%, 95% CI 53, 55%). Remote rural residents had the lowest screening rates overall (45%, 95% CI 43, 46%). From 1998 to 2005, rates of screening by colonoscopy or flexible sigmoidoscopy increased in both urban and rural populations. During the same time, rates of screening by fecal occult blood test decreased in urban populations and increased in rural populations. Persistent disparities in colorectal cancer screening affect rural populations. The types of screening tests used for colorectal cancer screening are different in rural and urban areas. Future research to reduce this disparity should focus on screening methods that are acceptable and feasible in rural areas. PMID:23342284

Oxidative stress and metabolic syndrome in a Japanese female population.

PubMed

Kotani, Kazuhiko; Yamada, Toshiyuki

2012-06-01

One of the methods to evaluate oxidative stress in clinical medical settings is the reactive oxygen metabolites (d-ROMs) test. While metabolic syndrome (MetS) is considered an oxidative condition, the oxidative status in MetS has not been fully examined using this test. The aim of the present study was to investigate the possible association between oxidative stress as evaluated by the d-ROMs test and the MetS component number, in a Japanese female population. The serum oxidant capacity (measured by the d-ROMs test) was cross-sectionally determined in cardiovascular disease-free and non-smoking women who were not taking medications (n = 180; mean age, 60 ± 10 (standard deviation) years). Their MetS state was determined by the National Cholesterol Education Program Adult Treatment Panel recommendations with minor modifications for a Japanese population. Patients with MetS (n = 60, 362 ± 53 CARR U) showed a significantly higher oxidant capacity by d-ROMs than those without MetS (n = 120, 324 ± 55 CARR U, P < 0.01). Moreover, the significant increase in the oxidant capacity by d-ROMs was closely associated with an increase in the MetS component number (trend P < 0.01). These results showed a significantly positive association between the oxidant capacity (by d-ROMs) and the MetS component number in this population. Further studies are required to establish the clinical applications of this test to MetS practice and clarify the biological mechanisms of the observed relationships. © 2012 The Authors. Australasian Journal on Ageing © 2012 ACOTA.

Geolocalization of Influenza Outbreak Within an Acute Care Population: A Layered-Surveillance Approach.

PubMed

Kannan, Vijay Christopher; Hodgson, Nicole; Lau, Andrew; Goodin, Kate; Dugas, Andrea Freyer; LoVecchio, Frank

2016-11-01

We seek to use a novel layered-surveillance approach to localize influenza clusters within an acute care population. The first layer of this system is a syndromic surveillance screen to guide rapid polymerase chain reaction testing. The second layer is geolocalization and cluster analysis of these patients. We posit that any identified clusters could represent at-risk populations who could serve as high-yield targets for preventive medical interventions. This was a prospective observational surveillance study. Patients were screened with a previously derived clinical decision guideline that has a 90% sensitivity and 30% specificity for influenza. Patients received points for the following signs and symptoms within the past 7 days: cough (2 points), headache (1 point), subjective fever (1 point), and documented fever at triage (temperature >38°C [100.4°F]) (1 point). Patients scoring 3 points or higher were indicated for influenza testing. Patients were tested with Xpert Flu (Cepheid, Sunnyvale, CA), a rapid polymerase chain reaction test. Positive results were mapped with ArcGIS (ESRI, Redlands, CA) and analyzed with kernel density estimation to create heat maps. There were 1,360 patients tested with Xpert Flu with retrievable addresses within the greater Phoenix metro area. One hundred sixty-seven (12%) of them tested positive for influenza A and 23 (2%) tested positive for influenza B. The influenza A virus exhibited a clear cluster pattern within this patient population. The densest cluster was located in an approximately 1-square-mile region southeast of our hospital. Our layered-surveillance approach was effective in localizing a cluster of influenza A outbreak. This region may house a high-yield target population for public health intervention. Further collaborative efforts will be made between our hospital and the Maricopa County Department of Public Health to perform a series of community vaccination events before the next influenza season. We hope these efforts will ultimately serve to reduce the burden of this disease on our patient population, and that this system will serve as a framework for future investigations locating at-risk populations. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Health literacy among Saudi population: a cross-sectional study.

PubMed

Abdel-Latif, Mohamed M M; Saad, Sherif Y

2017-09-12

Health literacy is a major problem worldwide and adversely affects an individual's health. The aim of the present study was to assess health literacy level among Saudi population. A cross-sectional study was conducted among a randomly selected population (n = 500) in Saudi Arabia. The questionnaire comprised of questions pertaining to demographic characteristics, health literacy and health information. Health literacy was measured by REALM-R test. Internal reliability was determined using Cronbach's alpha coefficient. The majority of the respondents had intermediate (43.8%) and basic (34.4%) health literacy levels. A higher percentage among men had intermediate (59.8%) and basic (70.93%) health literacy levels compared with women. About 30% of respondents had difficulty in understanding health screening tests and disease treatment. More than half of participants (52.4%) had difficulty in finding health information. The REALM-R test revealed that about 42.6% of individuals with score of >6 had adequate health literacy compared with 57.4% with score of ≤6 had inadequate health literacy. The present study demonstrated that a majority of Saudi individuals had inadequate health literacy that associated with poor knowledge of health information. Our findings highlighted the importance of understanding the status of health literacy among Saudis and the need for educational programs to raise the health literacy awareness among Saudi population. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Factors associated with HIV testing among young men who have sex with men in Myanmar: a cross-sectional study.

PubMed

Pham, Minh D; Aung, Poe Poe; Paing, Aye Kyawt; Pasricha, Naanki; Agius, Paul A; Tun, Waimar; Bajracharya, Ashish; Luchters, Stanley

2017-11-01

In Myanmar, men who have sex with men (MSM) experience high risk of HIV infection. However, access to HIV testing and prevention services remains a challenge among this marginalized population. The objective of this study was to estimate population prevalence and correlates of prior HIV testing among young MSM (YMSM) and informs the development of HIV testing and intervention programmes that respond to the specific needs of this population. Five hundred and eighty-five YMSM aged 18 to 24 years were recruited using respondent-driven sampling (RDS) in a cross-sectional survey conducted in six townships of Myanmar. RDS-adjusted population estimates were calculated to estimate prevalence of HIV testing; RDS-weighted logistic regression was used to examine correlates of HIV testing in the past 6 months and in a lifetime. There were 12 participants who reported receiving a HIV-positive test; of those, five were tested in the past 6 months. The RDS-weighted prevalence estimates of lifetime (any prior) HIV testing was 60.6% (95% CI: 53.3% to 66.4%) and of recent (≤ 6 months) HIV testing was 50.1% (95% CI: 44.1% to 55.5%). In multivariable analysis, sexual identity was associated with lifetime but not recent HIV testing. Lifetime and recent HIV testing were associated with having three or more male sexual partners in the past 12 months (adjusted ORs (aORs) = 2.28, 95% CIs: 1.21 to 4.32 and 2.69, 95% CI: 1.59 to 4.56), having good HIV-related knowledge (aORs = 1.96, 95% CIs: 1.11 to 3.44 and 1.77, 95% CI: 1.08 to 2.89), reporting high HIV testing self-efficacy (aORs = 13.5, 95% CIs: 6.0 to 30.1 and 9.81, 95% CI: 4.27 to 22.6) and having access to and use of non-HIV health-related services in the past 12 months (aORs = 13.2, 95% CIs: 6.85 to 25.6 and 7.15, 95% CI: 4.08 to 12.5) respectively. HIV testing coverage among YMSM aged 18 to 24 years old in Myanmar is still suboptimal. Integrated HIV testing and prevention services in existing health service provision systems with tailored HIV information and education programmes targeting YMSM to improve HIV-related knowledge and self-efficacy may help to promote regular HIV testing behaviour and contribute to sustainable control of the HIV epidemic among this marginalized population in Myanmar. © 2017 The Authors. Journal of the International AIDS Society published by John Wiley & sons Ltd on behalf of the International AIDS Society.

Using mass media and the Internet as tools to diagnose hepatitis C infections in the general population.

PubMed

Zuure, Freke R; Davidovich, Udi; Coutinho, Roel A; Kok, Gerjo; Hoebe, Christian J P A; van den Hoek, Anneke; Jansen, Peter L M; van Leeuwen-Gilbert, Paula; Verheuvel, Nicole C; Weegink, Christine J; Prins, Maria

2011-03-01

Many individuals with hepatitis C virus (HCV) infection are undiagnosed. This study describes the development and the use and outcomes of a mass media campaign, combined with an Internet risk assessment and an Internet-mediated blood-testing procedure for HCV to identify individuals infected with HCV in the general population. From April 2007 to December 2008, individuals in HCV risk groups were referred to an online, previously validated risk-assessment questionnaire at www.heptest.nl. Individuals at risk could download a referral letter for a free, anonymous HCV blood test in a nonclinical setting. Test results could be obtained online, 1 week later, using a personal log-in code. Anti-HCV-positive participants were requested to visit the Public Health Service for confirmation and RNA testing. Chronically HCV-infected individuals were referred for treatment. Data were analyzed in 2009-2010. The website attracted 40,902 visitors. Of the 9653 who completed the questionnaire, 2553 were at risk for HCV (26.4%). Main reported risk factors were a blood transfusion prior to 1992 and noninjecting drug use. Of the 1480 eligible for the blood test, 420 opted for testing (28%). HCV antibodies were detected in 3.6% (n=15, 95% CI=2.1%, 5.7%); of the 12 with a chronic HCV infection, six began treatment. Internet-mediated risk-based testing for HCV has proved to be a feasible and effective strategy to identify undiagnosed HCV infection in the general population. All HCV-infected individuals belonged to hard-to-reach populations. Test uptake was 28%, which is high for an online project that includes blood testing. Because Internet-mediated testing is low-cost, this strategy holds promise for future screening. Copyright © 2011 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Integrating macro- and micro-level approaches in the explanation of population change

PubMed Central

Billari, Francesco C.

2015-01-01

Demographers study population change across time and place, and traditionally they place a strong emphasis on a long-range view of population change. This paper builds on current reflections on how to structure the study of population change and proposes a two-stage perspective. The first stage, discovery, focuses on the production of novel evidence at the population level. The second stage, explanation, develops accounts of demographic change and tests how the action and interaction of individuals generate what is discovered in the first stage. This explanatory stage also provides the foundation for the prediction of demographic change. The transformation of micro-level actions and interactions into macro-level population outcomes is identified as a key challenge for the second stage. Specific instances of research are discussed. PMID:25912913

Photo-identification as a simple tool for studying invasive lionfish Pterois volitans populations.

PubMed

Chaves, L C T; Hall, J; Feitosa, J L L; Côté, I M

2016-02-01

Photo-tagging, i.e. using a specific software to match colour patterns on photographs, was tested as a means to identify individual Indo-Pacific Pterois volitans to assist with population and movement studies of this invasive species. The stripe pattern on the flank of adult P. volitans (n = 48) was the most individually distinctive of three body regions tested, leading to correct individual identification on 68 and 82% of tests with a single and two images of the reference individual, respectively. Photo-tagging is inexpensive, logistically simple and can involve citizen scientists, making it a viable alternative to traditional tagging to provide information on P. volitans distribution, movement patterns and recolonization rates after removals. © 2015 The Fisheries Society of the British Isles.

Awareness and uptake of direct-to-consumer genetic testing among cancer cases, their relatives, and controls: the Northwest Cancer Genetics Network.

PubMed

Hall, Taryn O; Renz, Anne D; Snapinn, Katherine W; Bowen, Deborah J; Edwards, Karen L

2012-07-01

To determine if awareness of, interest in, and use of direct-to-consumer (DTC) genetic testing is greater in a sample of high-risk individuals (cancer cases and their relatives), compared to controls. Participants were recruited from the Northwest Cancer Genetics Network. A follow-up survey was mailed to participants to assess DTC genetic testing awareness, interest, and use. One thousand two hundred sixty-seven participants responded to the survey. Forty-nine percent of respondents were aware of DTC genetic testing. Of those aware, 19% indicated interest in obtaining and <1% reported having used DTC genetic testing. Additional information supplied by respondents who reported use of DTC genetic tests indicated that 55% of these respondents likely engaged in clinical genetic testing, rather than DTC genetic testing. Awareness of DTC genetic testing was greater in our sample of high-risk individuals than in controls and population-based studies. Although interest in and use of these tests among cases in our sample were equivalent to other population-based studies, interest in testing was higher among relatives and people who self-referred for a registry focused on cancer than among cases and controls. Additionally, our results suggest that there may be some confusion about what constitutes DTC genetic testing.

On the occurrence of false positives in tests of migration under an isolation with migration model

PubMed Central

Hey, Jody; Chung, Yujin; Sethuraman, Arun

2015-01-01

The population genetic study of divergence is often done using a Bayesian genealogy sampler, like those implemented in IMa2 and related programs, and these analyses frequently include a likelihood-ratio test of the null hypothesis of no migration between populations. Cruickshank and Hahn (2014, Molecular Ecology, 23, 3133–3157) recently reported a high rate of false positive test results with IMa2 for data simulated with small numbers of loci under models with no migration and recent splitting times. We confirm these findings and discover that they are caused by a failure of the assumptions underlying likelihood ratio tests that arises when using marginal likelihoods for a subset of model parameters. We also show that for small data sets, with little divergence between samples from two populations, an excellent fit can often be found by a model with a low migration rate and recent splitting time and a model with a high migration rate and a deep splitting time. PMID:26456794

Cytogenetic biomonitoring carried out in a village (Dolon) adjacent to the Semipalatinsk nuclear weapon test site.

PubMed

Testa, A; Stronati, L; Ranaldi, R; Spanò, M; Steinhäusler, F; Gastberger, M; Hubmer, A; Ptitskaya, L; Akhmetov, M

2001-06-01

The Semipalatinsk region (Kazakhstan Republic) has been affected by extensive radioactive contamination due to more than 450 nuclear tests of which almost 100 were exploded in the atmosphere. The present results refer to cytogenetic assessments in a study cohort of the population of Dolon, a settlement located on the NE boundary of the nuclear weapon test site, which was exposed to elevated doses of ionising radiation primarily due to the first Soviet nuclear test in 1949. Conventional cytogenetic analyses were carried out on 21 blood samples from individuals (more than 50 years old) living in Dolon since the very beginning of nuclear testing. A matched control group included 20 individuals living in non-contaminated areas. Higher frequencies of chromosome aberrations were found in the Dolon cohort compared to the control group, even though they remain within the range of the background levels reported for large normal human population studies on elderly individuals.

Meiotic sex ratio variation in natural populations of Ceratodon purpureus (Ditrichaceae).

PubMed

Norrell, Tatum E; Jones, Kelly S; Payton, Adam C; McDaniel, Stuart F

2014-09-01

• Sex ratio variation is a common but often unexplained phenomenon in species across the tree of life. Here we evaluate the hypothesis that meiotic sex ratio variation can contribute to the biased sex ratios found in natural populations of the moss Ceratodon purpureus.• We obtained sporophytes from several populations of C. purpureus from eastern North America. From each sporophyte, we estimated the mean spore viability by germinating replicate samples on agar plates. We estimated the meiotic sex ratio of each sporophyte by inferring the sex of a random sample of germinated spores (mean = 77) using a PCR-RFLP test. We tested for among-sporophyte variation in viability using an ANOVA and for deviations from 1:1 sex ratio using a χ(2)-test and evaluated the relationship between these quantities using a linear regression.• We found among-sporophyte variation in spore viability and meiotic sex ratio, suggesting that genetic variants that contribute to variation in both of these traits segregate within populations of this species. However, we found no relationship between these quantities, suggesting that factors other than sex ratio distorters contribute to variation in spore viability within populations.• These results demonstrate that sex ratio distortion may partially explain the population sex ratio variation seen in C. purpureus, but more generally that genetic conflict over meiotic segregation may contribute to fitness variation in this species. Overall, this study lays the groundwork for future studies on the genetic basis of meiotic sex ratio variation. © 2014 Botanical Society of America, Inc.

A dental public health approach based on computational mathematics: Monte Carlo simulation of childhood dental decay.

PubMed

Tennant, Marc; Kruger, Estie

2013-02-01

This study developed a Monte Carlo simulation approach to examining the prevalence and incidence of dental decay using Australian children as a test environment. Monte Carlo simulation has been used for a half a century in particle physics (and elsewhere); put simply, it is the probability for various population-level outcomes seeded randomly to drive the production of individual level data. A total of five runs of the simulation model for all 275,000 12-year-olds in Australia were completed based on 2005-2006 data. Measured on average decayed/missing/filled teeth (DMFT) and DMFT of highest 10% of sample (Sic10) the runs did not differ from each other by more than 2% and the outcome was within 5% of the reported sampled population data. The simulations rested on the population probabilities that are known to be strongly linked to dental decay, namely, socio-economic status and Indigenous heritage. Testing the simulated population found DMFT of all cases where DMFT<>0 was 2.3 (n = 128,609) and DMFT for Indigenous cases only was 1.9 (n = 13,749). In the simulation population the Sic25 was 3.3 (n = 68,750). Monte Carlo simulations were created in particle physics as a computational mathematical approach to unknown individual-level effects by resting a simulation on known population-level probabilities. In this study a Monte Carlo simulation approach to childhood dental decay was built, tested and validated. © 2013 FDI World Dental Federation.

The Shozu Herpes Zoster (SHEZ) study: rationale, design, and description of a prospective cohort study.

PubMed

Takao, Yukiko; Miyazaki, Yoshiyuki; Onishi, Fumitake; Kumihashi, Hideaki; Gomi, Yasuyuki; Ishikawa, Toyokazu; Okuno, Yoshinobu; Mori, Yasuko; Asada, Hideo; Yamanishi, Koichi; Iso, Hiroyasu

2012-01-01

The incidence and risk factors for herpes zoster have been studied in cross-sectional and cohort studies, although most such studies have been conducted in Western countries. Evidence from Asian populations is limited, and no cohort study has been conducted in Asia. We are conducting a 3-year prospective cohort study in Shozu County in Kagawa Prefecture, Japan to determine the incidence and predictive and immunologic factors for herpes zoster among Japanese. The participants are followed for 3 years, and a telephone survey is conducted every 4 weeks. The participants were assigned to 1 of 3 studies. Participants in study A gave information on past history of herpes zoster and completed health questionnaires. Study B participants additionally underwent varicella-zoster virus (VZV) skin testing, and study C participants additionally underwent blood testing. If the participants develop herpes zoster, we evaluate clinical symptoms, measure cell-mediated immunity and humoral immunity using venous blood sampling, photograph skin areas with rash, conduct virus identification testing by polymerase chain reaction (PCR) and virus isolation from crust sampling, and evaluate postherpetic pain. We recruited 12 522 participants aged 50 years or older in Shozu County from December 2009 through November 2010. The participation rate was 65.7% of the target population. The present study is likely to provide valuable data on the incidence and predictive and immunologic factors for herpes zoster in a defined community-based population of Japanese.

The Shozu Herpes Zoster (SHEZ) Study: Rationale, Design, and Description of a Prospective Cohort Study

PubMed Central

Takao, Yukiko; Miyazaki, Yoshiyuki; Onishi, Fumitake; Kumihashi, Hideaki; Gomi, Yasuyuki; Ishikawa, Toyokazu; Okuno, Yoshinobu; Mori, Yasuko; Asada, Hideo; Yamanishi, Koichi; Iso, Hiroyasu

2012-01-01

Background The incidence and risk factors for herpes zoster have been studied in cross-sectional and cohort studies, although most such studies have been conducted in Western countries. Evidence from Asian populations is limited, and no cohort study has been conducted in Asia. We are conducting a 3-year prospective cohort study in Shozu County in Kagawa Prefecture, Japan to determine the incidence and predictive and immunologic factors for herpes zoster among Japanese. Methods The participants are followed for 3 years, and a telephone survey is conducted every 4 weeks. The participants were assigned to 1 of 3 studies. Participants in study A gave information on past history of herpes zoster and completed health questionnaires. Study B participants additionally underwent varicella-zoster virus (VZV) skin testing, and study C participants additionally underwent blood testing. If the participants develop herpes zoster, we evaluate clinical symptoms, measure cell-mediated immunity and humoral immunity using venous blood sampling, photograph skin areas with rash, conduct virus identification testing by polymerase chain reaction (PCR) and virus isolation from crust sampling, and evaluate postherpetic pain. Results We recruited 12 522 participants aged 50 years or older in Shozu County from December 2009 through November 2010. The participation rate was 65.7% of the target population. Conclusions The present study is likely to provide valuable data on the incidence and predictive and immunologic factors for herpes zoster in a defined community-based population of Japanese. PMID:22343323

Antibiotic prescribing and C-reactive protein testing for pulmonary infections in patients with intellectual disabilities

PubMed Central

Peters, Catharina M; Schouwenaars, Francesca M; Haagsma, Ellen; Evenhuis, Heleen M; Echteld, Michael A

2013-01-01

Background Excessive prescribing of antibiotics in patients with lower respiratory tract infections (LRTIs) is common in the general population. Due to communication difficulties, it is hypothesised that prescriptions are even more commonplace in the primary care of individuals with intellectual disabilities. Point-of-care C-reactive protein (POC-CRP) testing might lead to more efficient prescribing of antibiotics. Aim To evaluate the effect of POC-CRP testing on antibiotic prescriptions for LRTIs by physicians specialising in the care of individuals with intellectual disabilities. Design and setting A prospective case-control study in four care centres for individuals with intellectual disabilities in The Netherlands. Method Between 27 October 2010 and 27 October 2011, a prospective efficiency study was performed with a base population of 1472 individuals. This population consisted of 882 individuals in whom POC-CRP tests were used and a control group (n = 590) in whom no POC-CRP test was performed. Results Of the 48 patients in the control group who were diagnosed as having an LRTI, 43 (90%) received antibiotics, compared with 59 out of the 144 patients (41%) in the case group (OR = 12.0; 95% CI = 4.1–35.3). No significant differences in outcome were found between both groups during a follow-up period of 1 month. Conclusion This study shows that the use of POC-CRP testing in patients with intellectual disabilities and LRTIs can lead to a significant reduction in antibiotic prescriptions, with no significant differences in outcome during follow-up. PMID:23643230

Repeated faecal occult blood testing is associated with decreased advanced colorectal cancer risk: A population-based study.

PubMed

James, Paul D; Rabeneck, Linda; Yun, Lingsong; Paszat, Lawrence; Baxter, Nancy N; Govindarajan, Anand; Antonova, Lilia; Tinmouth, Jill M

2017-01-01

Objective To evaluate the association between repeated faecal occult blood testing and advanced colorectal cancer risk at population level in Canada. Methods A retrospective cohort study of all Ontario residents aged 56-74 diagnosed with colorectal cancer from 1 April 2007 to 31 March 2010, identified using health administrative data. The primary outcome was stage IV colorectal cancer, and primary exposure was faecal occult blood testing use within five years prior to colorectal cancer diagnosis. Patients were categorized into four mutually exclusive groups based on their exposure to faecal occult blood testing in the five years prior to colorectal cancer diagnosis: none, pre-diagnostic, repeated, and sporadic. Logistic regression was utilized to adjust for confounders. Results Of 7753 patients (median age 66, interquartile range 61-70, 62% male) identified, 1694 (22%) presented with stage I, 2056 (27%) with stage II, 2428 (31%) with stage III, and 1575 (20%) with stage IV colorectal cancer. There were 4092 (53%) with no record of prior faecal occult blood testing, 1485 (19%) classified as pre-diagnostic, 1693 (22%) as sporadic, and 483 (6%) as repeated faecal occult blood testing. After adjusting for confounders, patients who had repeated faecal occult blood testing were significantly less likely to present with stage IV colorectal cancer at diagnosis (Odds ratio 0.46, 95% Confidence Interval 0.34-0.62) than those with no prior faecal occult blood testing. Conclusions Repeated faecal occult blood testing is associated with a decreased risk of advanced colorectal cancer. Our findings support the use of organized screening programmes that employ repeated faecal occult blood testing to improve colorectal cancer outcomes at population level.

Comparison of the Spectral-Temporally Modulated Ripple Test With the Arizona Biomedical Institute Sentence Test in Cochlear Implant Users.

PubMed

Lawler, Marshall; Yu, Jeffrey; Aronoff, Justin M

Although speech perception is the gold standard for measuring cochlear implant (CI) users' performance, speech perception tests often require extensive adaptation to obtain accurate results, particularly after large changes in maps. Spectral ripple tests, which measure spectral resolution, are an alternate measure that has been shown to correlate with speech perception. A modified spectral ripple test, the spectral-temporally modulated ripple test (SMRT) has recently been developed, and the objective of this study was to compare speech perception and performance on the SMRT for a heterogeneous population of unilateral CI users, bilateral CI users, and bimodal users. Twenty-five CI users (eight using unilateral CIs, nine using bilateral CIs, and eight using a CI and a hearing aid) were tested on the Arizona Biomedical Institute Sentence Test (AzBio) with a +8 dB signal to noise ratio, and on the SMRT. All participants were tested with their clinical programs. There was a significant correlation between SMRT and AzBio performance. After a practice block, an improvement of one ripple per octave for SMRT corresponded to an improvement of 12.1% for AzBio. Additionally, there was no significant difference in slope or intercept between any of the CI populations. The results indicate that performance on the SMRT correlates with speech recognition in noise when measured across unilateral, bilateral, and bimodal CI populations. These results suggest that SMRT scores are strongly associated with speech recognition in noise ability in experienced CI users. Further studies should focus on increasing both the size and diversity of the tested participants, and on determining whether the SMRT technique can be used for early predictions of long-term speech scores, or for evaluating differences among different stimulation strategies or parameter settings.

High genetic diversity with moderate differentiation in Juniperus excelsa from Lebanon and the eastern Mediterranean region

PubMed Central

Douaihy, Bouchra; Vendramin, Giovanni G.; Boratyński, Adam; Machon, Nathalie; Bou Dagher-Kharrat, Magda

2011-01-01

Background and aims Juniperus excelsa is an important woody species in the high mountain ecosystems of the eastern Mediterranean Basin where it constitutes the only coniferous species found at the tree line. The genetic diversity within and among J. excelsa populations of the eastern Mediterranean Basin is studied in the light of their historical fragmentation. Methodology Nuclear microsatellites originally developed for Juniperus communis and J. przewalskii were tested on 320 individuals from 12 different populations originating from Lebanon, Turkey, Cyprus, Greece and the Ukraine. Principal results Among the 31 nuclear microsatellite primers tested, only three produced specific amplification products, with orthology confirmed by sequence analysis. They were then used for genetic diversity studies. The mean number of alleles and the expected heterozygosity means were Na=8.78 and He=0.76, respectively. The fixation index showed a significant deviation from Hardy–Weinberg equilibrium and an excess of homozygotes (FIS=0.27–0.56). A moderate level of genetic differentiation was observed among the populations (FST=0.075, P<0.001). The most differentiated populations corresponded to old vestigial stands found at the tree line (>2000 m) in Lebanon. These populations were differentiated from the other populations that are grouped into three sub-clusters. Conclusions High levels of genetic diversity were observed at species and population levels. The high level of differentiation in the high-mountain Lebanese populations reflects a long period of isolation or possibly a different origin. The admixture observed in other populations from Lebanon suggests a more recent separation from the Turkish–southeastern European populations. PMID:22476474

High genetic diversity with moderate differentiation in Juniperus excelsa from Lebanon and the eastern Mediterranean region.

PubMed

Douaihy, Bouchra; Vendramin, Giovanni G; Boratyński, Adam; Machon, Nathalie; Bou Dagher-Kharrat, Magda

2011-01-01

Juniperus excelsa is an important woody species in the high mountain ecosystems of the eastern Mediterranean Basin where it constitutes the only coniferous species found at the tree line. The genetic diversity within and among J. excelsa populations of the eastern Mediterranean Basin is studied in the light of their historical fragmentation. Nuclear microsatellites originally developed for Juniperus communis and J. przewalskii were tested on 320 individuals from 12 different populations originating from Lebanon, Turkey, Cyprus, Greece and the Ukraine. Among the 31 nuclear microsatellite primers tested, only three produced specific amplification products, with orthology confirmed by sequence analysis. They were then used for genetic diversity studies. The mean number of alleles and the expected heterozygosity means were N(a)=8.78 and H(e)=0.76, respectively. The fixation index showed a significant deviation from Hardy-Weinberg equilibrium and an excess of homozygotes (F(IS)=0.27-0.56). A moderate level of genetic differentiation was observed among the populations (F(ST)=0.075, P<0.001). The most differentiated populations corresponded to old vestigial stands found at the tree line (>2000 m) in Lebanon. These populations were differentiated from the other populations that are grouped into three sub-clusters. High levels of genetic diversity were observed at species and population levels. The high level of differentiation in the high-mountain Lebanese populations reflects a long period of isolation or possibly a different origin. The admixture observed in other populations from Lebanon suggests a more recent separation from the Turkish-southeastern European populations.

Differential Item Functioning in the SF-36 Physical Functioning and Mental Health Sub-Scales: A Population-Based Investigation in the Canadian Multicentre Osteoporosis Study.

PubMed

Lix, Lisa M; Wu, Xiuyun; Hopman, Wilma; Mayo, Nancy; Sajobi, Tolulope T; Liu, Juxin; Prior, Jerilynn C; Papaioannou, Alexandra; Josse, Robert G; Towheed, Tanveer E; Davison, K Shawn; Sawatzky, Richard

2016-01-01

Self-reported health status measures, like the Short Form 36-item Health Survey (SF-36), can provide rich information about the overall health of a population and its components, such as physical, mental, and social health. However, differential item functioning (DIF), which arises when population sub-groups with the same underlying (i.e., latent) level of health have different measured item response probabilities, may compromise the comparability of these measures. The purpose of this study was to test for DIF on the SF-36 physical functioning (PF) and mental health (MH) sub-scale items in a Canadian population-based sample. Study data were from the prospective Canadian Multicentre Osteoporosis Study (CaMos), which collected baseline data in 1996-1997. DIF was tested using a multiple indicators multiple causes (MIMIC) method. Confirmatory factor analysis defined the latent variable measurement model for the item responses and latent variable regression with demographic and health status covariates (i.e., sex, age group, body weight, self-perceived general health) produced estimates of the magnitude of DIF effects. The CaMos cohort consisted of 9423 respondents; 69.4% were female and 51.7% were less than 65 years. Eight of 10 items on the PF sub-scale and four of five items on the MH sub-scale exhibited DIF. Large DIF effects were observed on PF sub-scale items about vigorous and moderate activities, lifting and carrying groceries, walking one block, and bathing or dressing. On the MH sub-scale items, all DIF effects were small or moderate in size. SF-36 PF and MH sub-scale scores were not comparable across population sub-groups defined by demographic and health status variables due to the effects of DIF, although the magnitude of this bias was not large for most items. We recommend testing and adjusting for DIF to ensure comparability of the SF-36 in population-based investigations.

Development of a scale to assess cancer stigma in the non-patient population

PubMed Central

2014-01-01

Background 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. Methods 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. Results 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. Conclusions 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. PMID:24758482

Normative data for a battery of free recall, cued recall and recognition tests in the elderly Italian population.

PubMed

Coluccia, Emanuele; Gamboz, Nadia; Brandimonte, Maria A

2011-12-01

The present study aimed to provide normative data on a large sample of the elderly Italian population (N = 464; range of age = 49-94; range of education = 3-25) on both the word and the picture versions of a battery of free recall, cued recall, and recognition tests of memory. Results from multiple regression analyses showed that both age and education were significant predictors of performance. Therefore, norms were calculated taking into account these demographic variables. The availability of normative data based on a large sample will allow a more reliable use of the battery for clinical assessment in Italian-speaking dementia population.

An empirical test of the Theory of Planned Behaviour applied to contraceptive use in rural Uganda.

PubMed

Kiene, Susan M; Hopwood, Sarah; Lule, Haruna; Wanyenze, Rhoda K

2014-12-01

There is a high unmet need for contraceptives in developing countries such as Uganda, with high population growth, where efforts are needed to promote family planning and contraceptive use. Despite this high need, little research has investigated applications of health-behaviour-change theories to contraceptive use among this population. This study tested the Theory of Planned Behaviour's ability to predict contraceptive-use-related behaviours among post-partum women in rural Uganda. Results gave modest support to the theory's application and suggest an urgent need for improved theory-based interventions to promote contraceptive use in the populations of developing countries. © The Author(s) 2013.

A quantitative test of population genetics using spatiogenetic patterns in bacterial colonies.

PubMed

Korolev, Kirill S; Xavier, João B; Nelson, David R; Foster, Kevin R

2011-10-01

It is widely accepted that population-genetics theory is the cornerstone of evolutionary analyses. Empirical tests of the theory, however, are challenging because of the complex relationships between space, dispersal, and evolution. Critically, we lack quantitative validation of the spatial models of population genetics. Here we combine analytics, on- and off-lattice simulations, and experiments with bacteria to perform quantitative tests of the theory. We study two bacterial species, the gut microbe Escherichia coli and the opportunistic pathogen Pseudomonas aeruginosa, and show that spatiogenetic patterns in colony biofilms of both species are accurately described by an extension of the one-dimensional stepping-stone model. We use one empirical measure, genetic diversity at the colony periphery, to parameterize our models and show that we can then accurately predict another key variable: the degree of short-range cell migration along an edge. Moreover, the model allows us to estimate other key parameters, including effective population size (density) at the expansion frontier. While our experimental system is a simplification of natural microbial community, we argue that it constitutes proof of principle that the spatial models of population genetics can quantitatively capture organismal evolution.

LOD score exclusion analyses for candidate genes using random population samples.

PubMed

Deng, H W; Li, J; Recker, R R

2001-05-01

While extensive analyses have been conducted to test for, no formal analyses have been conducted to test against, the importance of candidate genes with random population samples. We develop a LOD score approach for exclusion analyses of candidate genes with random population samples. Under this approach, specific genetic effects and inheritance models at candidate genes can be analysed and if a LOD score is < or = - 2.0, the locus can be excluded from having an effect larger than that specified. Computer simulations show that, with sample sizes often employed in association studies, this approach has high power to exclude a gene from having moderate genetic effects. In contrast to regular association analyses, population admixture will not affect the robustness of our analyses; in fact, it renders our analyses more conservative and thus any significant exclusion result is robust. Our exclusion analysis complements association analysis for candidate genes in random population samples and is parallel to the exclusion mapping analyses that may be conducted in linkage analyses with pedigrees or relative pairs. The usefulness of the approach is demonstrated by an application to test the importance of vitamin D receptor and estrogen receptor genes underlying the differential risk to osteoporotic fractures.

Utilizing population controls in rare-variant case-parent association tests.

PubMed

Jiang, Yu; Satten, Glen A; Han, Yujun; Epstein, Michael P; Heinzen, Erin L; Goldstein, David B; Allen, Andrew S

2014-06-05

There is great interest in detecting associations between human traits and rare genetic variation. To address the low power implicit in single-locus tests of rare genetic variants, many rare-variant association approaches attempt to accumulate information across a gene, often by taking linear combinations of single-locus contributions to a statistic. Using the right linear combination is key-an optimal test will up-weight true causal variants, down-weight neutral variants, and correctly assign the direction of effect for causal variants. Here, we propose a procedure that exploits data from population controls to estimate the linear combination to be used in an case-parent trio rare-variant association test. Specifically, we estimate the linear combination by comparing population control allele frequencies with allele frequencies in the parents of affected offspring. These estimates are then used to construct a rare-variant transmission disequilibrium test (rvTDT) in the case-parent data. Because the rvTDT is conditional on the parents' data, using parental data in estimating the linear combination does not affect the validity or asymptotic distribution of the rvTDT. By using simulation, we show that our new population-control-based rvTDT can dramatically improve power over rvTDTs that do not use population control information across a wide variety of genetic architectures. It also remains valid under population stratification. We apply the approach to a cohort of epileptic encephalopathy (EE) trios and find that dominant (or additive) inherited rare variants are unlikely to play a substantial role within EE genes previously identified through de novo mutation studies. Copyright © 2014 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Significant genetic differentiation among populations of Anomalocardia brasiliana (Gmelin, 1791): A bivalve with planktonic larval dispersion

PubMed Central

2009-01-01

Four Brazilian populations of Anomalocardia brasiliana were tested for mutual genetic homogeneity, using data from 123 sequences of the mtDNA cytochrome oxidase c subunit I gene. A total of 36 haplotypes were identified, those shared being H3 (Canela Island, Prainha and Acupe) and both H5 and H9 (Prainha and Acupe). Haplotype diversity values were high, except for the Camurupim population, whereas nucleotide values were low in all the populations, except for that of Acupe. Only the Prainha population showed a deviation from neutrality and the SSD test did not reject the demographic expansion hypothesis. Fst values showed that the Prainha and Acupe populations represent a single stock, whereas in both the Canela Island and Camurupim stocks, population structures are different and independent. The observed structure at Canela Island may be due to the geographic distance between this population and the remainder. The Camurupim population does not share any haplotype with the remaining populations in northeastern Brazil. The apparent isolation could be due to the rocky barrier located facing the mouth of the Mamanguape River. The results highlight the importance of wide-scale studies to identify and conserve local genetic diversity, especially where migration is restricted. PMID:21637701

Gender Differences in HIV Risk Behaviors Among Persons Involved in the U.S. Criminal Justice System and Living with HIV or at Risk for HIV: A "Seek, Test, Treat, and Retain" Harmonization Consortium.

PubMed

Loeliger, Kelsey B; Biggs, Mary L; Young, Rebekah; Seal, David W; Beckwith, Curt G; Kuo, Irene; Gordon, Michael S; Altice, Frederick L; Ouellet, Lawrence J; Cunningham, William E; Young, Jeremy D; Springer, Sandra A

2017-10-01

The U.S. female criminal justice (CJ) population is rapidly growing, yet large-scale studies exploring gender-specific HIV risk behaviors in the CJ population are lacking. This analysis uses baseline data on adults with a CJ history from eight U.S. studies in an NIH-funded "Seek, Test, Treat, Retain" harmonization consortium. Data were collected using a standardized HIV risk behavior assessment tool and pooled across studies to describe participants' characteristics and risk behaviors. Multilevel mixed-effects logistic regression models were used to test for gender-based behavior differences. Among 784 HIV-positive (21.4% female) and 5521 HIV-negative (8.5% female) participants, HIV-positive women had higher odds than HIV-positive men of engaging in condomless sexual intercourse (AOR 1.84 [1.16-2.95]) with potentially sero-discordant partners (AOR 2.40 [1.41-4.09]) and of sharing injection equipment (AOR 3.36 [1.31-8.63]). HIV risk reduction interventions targeting CJ-involved women with HIV are urgently needed as this population may represent an under-recognized potential source of HIV transmission.

Sample size for positive and negative predictive value in diagnostic research using case–control designs

PubMed Central

Steinberg, David M.; Fine, Jason; Chappell, Rick

2009-01-01

Important properties of diagnostic methods are their sensitivity, specificity, and positive and negative predictive values (PPV and NPV). These methods are typically assessed via case–control samples, which include one cohort of cases known to have the disease and a second control cohort of disease-free subjects. Such studies give direct estimates of sensitivity and specificity but only indirect estimates of PPV and NPV, which also depend on the disease prevalence in the tested population. The motivating example arises in assay testing, where usage is contemplated in populations with known prevalences. Further instances include biomarker development, where subjects are selected from a population with known prevalence and assessment of PPV and NPV is crucial, and the assessment of diagnostic imaging procedures for rare diseases, where case–control studies may be the only feasible designs. We develop formulas for optimal allocation of the sample between the case and control cohorts and for computing sample size when the goal of the study is to prove that the test procedure exceeds pre-stated bounds for PPV and/or NPV. Surprisingly, the optimal sampling schemes for many purposes are highly unbalanced, even when information is desired on both PPV and NPV. PMID:18556677

Adapting a computer-delivered brief alcohol intervention for veterans with Hepatitis C.

PubMed

Cucciare, Michael A; Jamison, Andrea L; Combs, Ann S; Joshi, Gauri; Cheung, Ramsey C; Rongey, Catherine; Huggins, Joe; Humphreys, Keith

2017-12-01

This study adapted an existing computer-delivered brief alcohol intervention (cBAI) for use in Veterans with the hepatitis C virus (HCV) and examined its acceptability and feasibility in this patient population. A four-stage model consisting of initial pilot testing, qualitative interviews with key stakeholders, development of a beta version of the cBAI, and usability testing was used to achieve the study objectives. In-depth interviews gathered feedback for modifying the cBAI, including adding HCV-related content such as the health effects of alcohol on liver functioning, immune system functioning, and management of HCV, a preference for concepts to be displayed through "newer looking" graphics, and limiting the use of text to convey key concepts. Results from usability testing indicated that the modified cBAI was acceptable and feasible for use in this patient population. The development model used in this study is effective for gathering actionable feedback that can inform the development of a cBAI and can result in the development of an acceptable and feasible intervention for use in this population. Findings also have implications for developing computer-delivered interventions targeting behavior change more broadly.

The predictive value of skin prick testing for challenge-proven food allergy: a systematic review.

PubMed

Peters, Rachel L; Gurrin, Lyle C; Allen, Katrina J

2012-06-01

Immunoglobulin E-mediated (IgE) food allergy affects 6-8% of children, and the prevalence is believed to be increasing. The gold standard of food allergy diagnosis is oral food challenges (OFCs); however, they are resource-consuming and potentially dangerous. Skin prick tests (SPTs) are able to detect the presence of allergen-specific IgE antibodies (sensitization), but they have low specificity for clinically significant food allergy. To reduce the need for OFCs, it has been suggested that children forgo an OFC if their SPT wheal size exceeds a cutoff that has a high predictability for food allergy. Although data for these studies are almost always gathered from high-risk populations, the 95% positive predictive values (PPVs) vary substantially between studies. SPT thresholds with a high probability of food allergy generated from these studies may not be generalizable to other populations, because of highly selective samples and variability in participant's age, test allergens, and food challenge protocol. Standardization of SPT devices and allergens, OFC protocols including standardized cessation criteria, and population-based samples would all help to improve generalizability of PPVs of SPTs. © 2011 John Wiley & Sons A/S.

Burden of celiac disease in Europe: a review of its childhood and adulthood prevalence and incidence as of September 2014.

PubMed

Altobelli, E; Paduano, R; Petrocelli, R; Di Orio, F

2014-01-01

Recent epidemiological studies have demonstrated that coeliac disease (CD) prevalence is still underestimated both in Europe and in Mediterranean regions. Here we review the latest data on CD prevalence and incidence in the European Union (EU) as of September 2014. The current epidemiological scenario of CD prevalence and incidence was investigated by searching PubMed for papers in English using the following key words: "celiac disease", "celiac disease plus prevalence" (limits: 1990-2014), "incidence" (limits: 1970-2014), and "frequency", plus "in Europe". Another search was performed with the same key words plus the name of each European country. Only prevalence data obtained by serology using anti-gliadin antibodies (AGA), EMA test, tTG test, and/or duodenal biopsy were included. The study designs considered were retrospective and prospective studies: population-based (PB), cross-sectional, case-control and cohort studies. Extensive research based on serological screening has demonstrated that 0.5-1% of the EU population suffers from undiagnosed CD, whereas the highest estimate reported in PB studies is approximately 1%. Considering data from different periods, incidence seems to range from 0.1 to 3.7/1000 live births in the child population and from 1.3 to 39/100,000/year in the adult population. The present data disclose marked geographical variation in CD incidence and prevalence in different European countries. Here we document rising CD occurrence in recent decades in European countries due partly to the advent of improved serological testing (tTG + EMA) and partly to increased awareness of its clinical presentation.

Climate-related genetic variation in drought-resistance of Douglas-fir (Pseudotsuga menziesii).

PubMed

Bansal, Sheel; Harrington, Constance A; Gould, Peter J; St Clair, J Bradley

2015-02-01

There is a general assumption that intraspecific populations originating from relatively arid climates will be better adapted to cope with the expected increase in drought from climate change. For ecologically and economically important species, more comprehensive, genecological studies that utilize large distributions of populations and direct measures of traits associated with drought-resistance are needed to empirically support this assumption because of the implications for the natural or assisted regeneration of species. We conducted a space-for-time substitution, common garden experiment with 35 populations of coast Douglas-fir (Pseudotsuga menziesii var. menziesii) growing at three test sites with distinct summer temperature and precipitation (referred to as 'cool/moist', 'moderate', or 'warm/dry') to test the hypotheses that (i) there is large genetic variation among populations and regions in traits associated with drought-resistance, (ii) the patterns of genetic variation are related to the native source-climate of each population, in particular with summer temperature and precipitation, (iii) the differences among populations and relationships with climate are stronger at the warm/dry test site owing to greater expression of drought-resistance traits (i.e., a genotype × environment interaction). During midsummer 2012, we measured the rate of water loss after stomatal closure (transpiration(min)), water deficit (% below turgid saturation), and specific leaf area (SLA, cm(2) g(-1)) on new growth of sapling branches. There was significant genetic variation in all plant traits, with populations originating from warmer and drier climates having greater drought-resistance (i.e., lower transpiration(min), water deficit and SLA), but these trends were most clearly expressed only at the warm/dry test site. Contrary to expectations, populations from cooler climates also had greater drought-resistance across all test sites. Multiple regression analysis indicated that Douglas-fir populations from regions with relatively cool winters and arid summers may be most adapted to cope with drought conditions that are expected in the future. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Effects of an invasive plant on population dynamics in toads.

PubMed

Greenberg, Daniel A; Green, David M

2013-10-01

When populations decline in response to unfavorable environmental change, the dynamics of their population growth shift. In populations that normally exhibit high levels of variation in recruitment and abundance, as do many amphibians, declines may be difficult to identify from natural fluctuations in abundance. However, the onset of declines may be evident from changes in population growth rate in sufficiently long time series of population data. With data from 23 years of study of a population of Fowler's toad (Anaxyrus [ = Bufo] fowleri) at Long Point, Ontario (1989-2011), we sought to identify such a shift in dynamics. We tested for trends in abundance to detect a change point in population dynamics and then tested among competing population models to identify associated intrinsic and extrinsic factors. The most informative models of population growth included terms for toad abundance and the extent of an invasive marsh plant, the common reed (Phragmites australis), throughout the toads' marshland breeding areas. Our results showed density-dependent growth in the toad population from 1989 through 2002. After 2002, however, we found progressive population decline in the toads associated with the spread of common reeds and consequent loss of toad breeding habitat. This resulted in reduced recruitment and population growth despite the lack of significant loss of adult habitat. Our results underscore the value of using long-term time series to identify shifts in population dynamics coincident with the advent of population decline. © 2013 Society for Conservation Biology.

Explaining leptokurtic movement distributions: intrapopulation variation in boldness and exploration.

PubMed

Fraser, D F; Gilliam, J F; Daley, M J; Le, A N; Skalski, G T

2001-08-01

Leptokurtic distributions of movement distances observed in field-release studies, in which some individuals move long distances while most remain at or near their release point, are a common feature of mobile animals. However, because leptokurtosis is predicted to be transient in homogeneous populations, persistent leptokurtosis suggests a population heterogeneity. We found evidence for a heterogeneity that may generate persistent leptokurtosis. We tested individuals of the Trinidad killifish Rivulus hartii for boldness in a tank test and released them back into their native stream. Boldness in the tank test predicted distance moved in the field releases, even after effects of size and sex were removed. Further, data from a 19-mo mark-recapture study showed that individual growth correlated positively with movement in a predator-threatened river zone where the Rivulus population is spatially fragmented and dispersal is likely to be a hazardous activity. In contrast, no such correlation existed in a predator-absent zone where the population is unfragmented. These results show that a behavioral trait, not discernible from body size or sex, contributes to dispersal and that a component of fitness of surviving "dispersers" is elevated above that of "stayers," a fundamental assumption or prediction of many models of the evolution of dispersal through hazardous habitat.

Estimating the positive predictive value of opportunistic population testing for gonorrhoea as part of the English Chlamydia Screening Programme.

PubMed

Fowler, T; Edeghere, O; Inglis, N; Bradshaw, S

2013-03-01

Advances in technology have raised the possibility of including gonorrhoea testing as part of chlamydia screening. In England this is recommended only where the positive predictive value (PPV) of the test is ≥90%. This study assessed the PPV for gonorrhoea testing using routine testing data. Routine data (including gonorrhoea testing) from the Greater Manchester Chlamydia Screening Programme (GMCSP) in 2009/2010, were used to estimate the PPV for gonorrhoea testing. Of those screened, 0.3% (59/18044) of men and 0.4% (174/41873) of women tested positive for gonorrhoea. The PPV was 82.3% in women and 73.6% in men, in those who also tested positive for chlamydia. For women and men testing negative for chlamydia the PPV for a positive gonorrhoea test was incalculable. The low PPV observed in most groups suggests that where population testing for gonorrhoea occurs there is a need for further confirmatory testing of positive results before treatment decisions are made. Clinicians should be aware of screening test result limitations in this context.

PopHuman: the human population genomics browser.

PubMed

Casillas, Sònia; Mulet, Roger; Villegas-Mirón, Pablo; Hervas, Sergi; Sanz, Esteve; Velasco, Daniel; Bertranpetit, Jaume; Laayouni, Hafid; Barbadilla, Antonio

2018-01-04

The 1000 Genomes Project (1000GP) represents the most comprehensive world-wide nucleotide variation data set so far in humans, providing the sequencing and analysis of 2504 genomes from 26 populations and reporting >84 million variants. The availability of this sequence data provides the human lineage with an invaluable resource for population genomics studies, allowing the testing of molecular population genetics hypotheses and eventually the understanding of the evolutionary dynamics of genetic variation in human populations. Here we present PopHuman, a new population genomics-oriented genome browser based on JBrowse that allows the interactive visualization and retrieval of an extensive inventory of population genetics metrics. Efficient and reliable parameter estimates have been computed using a novel pipeline that faces the unique features and limitations of the 1000GP data, and include a battery of nucleotide variation measures, divergence and linkage disequilibrium parameters, as well as different tests of neutrality, estimated in non-overlapping windows along the chromosomes and in annotated genes for all 26 populations of the 1000GP. PopHuman is open and freely available at http://pophuman.uab.cat. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

High population density enhances recruitment and survival of a harvested coral reef fish.

PubMed

Wormald, Clare L; Steele, Mark A; Forrester, Graham E

2013-03-01

A negative relationship between population growth and population density (direct density dependence) is necessary for population regulation and is assumed in most models of harvested populations. Experimental tests for density dependence are lacking for large-bodied, harvested fish because of the difficulty of manipulating population density over large areas. We studied a harvested coral reef fish, Lutjanus apodus (schoolmaster snapper), using eight large, isolated natural reefs (0.4-1.6 ha) in the Bahamas as replicates. An initial observational test for density dependence was followed by a manipulation of population density. The manipulation weakened an association between density and shelter-providing habitat features and revealed a positive effect of population density on recruitment and survival (inverse density dependence), but no effect of density on somatic growth. The snappers on an individual reef were organized into a few shoals, and we hypothesize that large shoals on high-density reefs were less vulnerable to large piscivores (groupers and barracudas) than the small shoals on low-density reefs. Reductions in predation risk for individuals in large social groups are well documented, but because snapper shoals occupied reefs the size of small marine reserves, these ecological interactions may influence the outcome of management actions.

A Monte Carlo Study on the Performance of a Corrected Formula for Epsilon Approximate Suggested by Lecoutre.

ERIC Educational Resources Information Center

Chen, Ru San; Dunlap, William P.

1994-01-01

The present simulation study confirms that the corrected epsilon approximate test of B. Lecoutre yields a less biased estimation of population epsilon and reduces Type I error rates when compared to the epsilon approximate test of H. Huynh and L. S. Feldt. (SLD)

Occurrence of Parthenogenesis in Potato Tuber Moth

PubMed Central

Liu, Yan; Hu, Chun-Hua; Wang, Chun-Ya; Xiong, Yan; Li, Zong-Kai; Xiao, Chun

2018-01-01

Abstract Parthenogenesis, a natural form of asexual reproduction produced from unfertilized eggs, occurs in many insects in Hemiptera and Hymenoptera, but very rarely in Lepidoptera. The current study aimed to test the larval density dependent occurrence of parthenogenesis in potato tuber moth, Phthorimaea operculella (Zeller; Lepidoptera: Gelechiidae) under laboratory conditions. More than 10% of females out of 25 tested females that developed from the high larval density treatment at 45 larvae per tuber were capable to reproduce asexually. Both male and female offspring were produced parthenogenetically. The sexually reproductive offspring of a laboratory parthenogenetic population had a lower egg hatch rate, shorter larval stage, and shorter male life span when compared with the non-parthenogenetic population. This suggests that the sexually reproductive offspring of parthenogenetic population have a decreased overall fitness compared to the sexually reproductive offspring of non-parthenogenetic population.

The Mandarin Childhood Autism Spectrum Test (CAST): Sex Differences

ERIC Educational Resources Information Center

Sun, Xiang; Allison, Carrie; Auyeung, Bonnie; Matthews, Fiona E.; Sharp, Stephen J.; Baron-Cohen, Simon; Brayne, Carol

2014-01-01

Sex differences in social and communication behaviours related to autism spectrum conditions (ASC) have been investigated mainly in Western populations. Little research has been done in Chinese populations. This study explored sex differences related to ASC characteristics by examining differences in item responses and score distributions in…

ASSESSMENT OF CADMIUM EXPOSURE AND TOXICITY RISK IN AN AMERICAN VEGETARIAN POPULATION

EPA Science Inventory

It has been postulated that nonvegetarians may be exposed to less cadmium than vegetarians because of the cadmium-poor meat in their diet. This study attempts to test this possibility by measuring the cadmium exposure and accumulation in a population subgroup that includes many v...

Socio-Demographic Determinants of Economic Growth: Age-Structure, Preindustrial Heritage and Sociolinguistic Integration

ERIC Educational Resources Information Center

Crenshaw, Edward; Robison, Kristopher

2010-01-01

This study establishes a socio-demographic theory of international development derived from selected classical and contemporary sociological theories. Four hypotheses are tested: (1. population growth's effect on development depends on age-structure; (2. historic population density (used here as an indicator of preindustrial social complexity)…

Dynamical properties of the Penna aging model applied to the population of wolves

NASA Astrophysics Data System (ADS)

Makowiec, Danuta

1997-02-01

The parameters of th Penna bit-string model of aging of biological systems are systematically tested to better understand the model itself as well as the results arising from applying this model to studies of the development of the stationary population of Alaska wolves.

Development and assessment of plant-based synthetic odor baits for surveillance and control of Malaria vectors

USDA-ARS?s Scientific Manuscript database

Recent malaria vector control measures have considerably reduced indoor biting mosquito populations. However, reducing the outdoor biting populations remains a challenge because of the unavailability of appropriate lures to achieve this. This study sought to test the efficacy of plant-based syntheti...

Allozyme diversity of selected and natural loblolly pine populations

Treesearch

Ronald C. Schmidtling; E. Carroll; T. LaFarge

1999-01-01

Loblolly pine (Pinus taeda L.) megagametophytes and embryos were examined electrophoretically to compare the extent and distribution of genetic variability in allozymes of selected and wild populations. Range-wide collections of three different types were investigated in this study. These consisted of seed sampled from (1) a provenance test...

Testing the link between population genetic differentiation and clade diversification in Costa Rican orchids.

PubMed

Kisel, Yael; Moreno-Letelier, Alejandra C; Bogarín, Diego; Powell, Martyn P; Chase, Mark W; Barraclough, Timothy G

2012-10-01

Species population genetics could be an important factor explaining variation in clade species richness. Here, we use newly generated amplified fragment length polymorphism (AFLP) data to test whether five pairs of sister clades of Costa Rican orchids that differ greatly in species richness also differ in average neutral genetic differentiation within species, expecting that if the strength of processes promoting differentiation within species is phylogenetically heritable, then clades with greater genetic differentiation should diversify more. Contrary to expectation, neutral genetic differentiation does not correlate directly with total diversification in the clades studied. Neutral genetic differentiation varies greatly among species and shows no heritability within clades. Half of the variation in neutral genetic differentiation among populations can be explained by ecological variables, and species-level traits explain the most variation. Unexpectedly, we find no isolation by distance in any species, but genetic differentiation is greater between populations occupying different niches. This pattern corresponds with those observed for microscopic eukaryotes and could reflect effective widespread dispersal of tiny and numerous orchid seeds. Although not providing a definitive answer to whether population genetics processes affect clade diversification, this work highlights the potential for addressing new macroevolutionary questions using a comparative population genetic approach. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Nucleotide variation at the dopa decarboxylase (Ddc) gene in natural populations of Drosophila melanogaster.

PubMed

Tatarenkov, Andrey; Ayala, Francisco J

2007-08-01

We studied nucleotide sequence variation at the gene coding for dopa decarboxylase (Ddc) in seven populations of Drosophila melanogaster. Strength and pattern of linkage disequilibrium are somewhat distinct in the extensively sampled Spanish and Raleigh populations. In the Spanish population, a few sites are in strong positive association, whereas a large number of sites in the Raleigh population are associated nonrandomly but the association is not strong. Linkage disequilibrium analysis shows presence of two groups of haplotypes in the populations, each of which is fairly diverged, suggesting epistasis or inversion polymorphism. There is evidence of two forms of natural selection acting on Ddc. The McDonald-Kreitman test indicates a deficit of fixed amino acid differences between D. melanogaster and D. simulans, which may be due to negative selection. An excess of derived alleles at high frequency, significant according to the H-test, is consistent with the effect of hitchhiking. The hitchhiking may have been caused by directional selection downstream of the locus studied, as suggested by a gradual decrease of the polymorphism-to-divergence ratio. Altogether, the Ddc locus exhibits a complicated pattern of variation apparently due to several evolutionary forces. Such a complex pattern may be a result of an unusually high density of functionally important genes.

Determinants of uptake of hepatitis B testing and healthcare access by migrant Chinese in the England: a qualitative study.

PubMed

Lee, Andrew Chee Keng; Vedio, Alicia; Liu, Eva Zhi Hong; Horsley, Jason; Jesurasa, Amrita; Salway, Sarah

2017-09-26

Global migration from hepatitis B endemic countries poses a significant public health challenge in receiving low-prevalence countries. In the UK, Chinese migrants are a high risk group for hepatitis B. However, they are an underserved population that infrequently accesses healthcare. This study sought to increase understanding of the determinants of hepatitis B testing and healthcare access among migrants of Chinese ethnicity living in England. We sought to obtain and integrate insights from different key stakeholders in the system. We conducted six focus group discussions and 20 in-depth interviews with community members and patients identifying themselves as 'Chinese', and interviewed 21 clinicians and nine health service commissioners. Data were thematically analysed and findings were corroborated through two validation workshops. Three thematic categories emerged: knowledge and awareness, visibility of the disease, and health service issues. Low disease knowledge and awareness levels among community members contributed to erroneous personal risk perception and suboptimal engagement with services. Limited clinician knowledge led to missed opportunities to test and inaccurate assessments of infection risks in Chinese patients. There was little social discourse and considerable stigma linked to the disease among some sub-sections of the Chinese population. A lack of visibility of the issue and the population within the health system meant that these health needs were not prioritised by clinicians or commissioners. Service accessibility was also affected by the lack of language support. Greater use of community outreach, consultation aids, 'cultural competency' training, and locally adapted testing protocols may help. Hepatitis B among migrants of Chinese ethnicity in England can be characterised as an invisible disease in an invisible population. Multi-modal solutions are needed to tackle barriers within this population and the health system.

Assessment of dysglycemia risk in the Kitikmeot region of Nunavut: using the CANRISK tool

PubMed Central

Ying, Jiang; Susan, Rogers Van Katwyk; Yang, Mao; Heather, Orpana; Gina, Agarwal; Margaret, de Groh; Monique, Skinner; Robyn, Clarke

2017-01-01

Abstract Introduction: The Public Health Agency of Canada adapted a Finnish diabetes screening tool (FINDRISC) to create a tool (CANRISK) tailored to Canada’s multi-ethnic population. CANRISK was developed using data collected in seven Canadian provinces. In an effort to extend the applicability of CANRISK to northern territorial populations, we completed a study with the mainly Inuit population in the Kitikmeot region of Nunavut. Methods: We obtained CANRISK questionnaires, physical measures and blood samples from participants in five Nunavut communities in Kitikmeot. We used logistic regression to test model fit using the original CANRISK risk factors for dysglycemia (prediabetes and diabetes). Dysglycemia was assessed using fasting plasma glucose (FPG) alone and/or oral glucose tolerance test. We generated participants’ CANRISK scores to test the functioning of this tool in the Inuit population. Results: A total of 303 individuals participated in the study. Half were aged less than 45 years, two-thirds were female and 84% were Inuit. A total of 18% had prediabetes, and an additional 4% had undiagnosed diabetes. The odds of having dysglycemia rose exponentially with age, while the relationship with BMI was U-shaped. Compared with lab test results, using a cut-off point of 32 the CANRISK tool achieved a sensitivity of 61%, a specificity of 66%, a positive predictive value of 34% and an accuracy rate of 65%. Conclusion: The CANRISK tool achieved a similar accuracy in detecting dysglycemia in this mainly Inuit population as it did in a multi-ethnic sample of Canadians. We found the CANRISK tool to be adaptable to the Kitikmeot region, and more generally to Nunavut. PMID:28402800

Postal urine specimens: are they a feasible method for genital chlamydial infection screening?

PubMed Central

Macleod, J; Rowsell, R; Horner, P; Crowley, T; Caul, E O; Low, N; Smith, G D

1999-01-01

BACKGROUND: A United Kingdom (UK) screening programme for Chlamydia trachomatis has recently been announced. Pilot projects involving the opportunistic testing of women attending health facilities are due to commence in several sites. There is a danger that this approach will fail to obtain adequate population coverage. The alternative--true systematic population screening--is generally assumed to be unfeasible. Studies in Denmark using postal urine specimens have challenged this assumption. No such studies have been reported from the UK. AIM: To assess the potential of urine specimens sent by post as the basis for a UK population screening strategy for genital chlamydial infection. METHOD: Two hundred patients (100 men, 100 women) aged 18 to 45 years were randomly sampled from the list of one urban group practice. Subjects were mailed an explanatory letter, a urine sample container, a sexual lifestyle questionnaire, and a prepaid return envelope. Non-responders were contacted by telephone; persistent non-responders were visited at home. Samples were tested for Chlamydia by DNA amplification and enzyme immunoassay. RESULTS: Sixty-four (32%) subjects were no longer living at their GP registered address. Of the remaining 136, 126 (93%) responded to the survey and 113 (83%) accepted the request for a urine sample and completed a questionnaire. Acceptance rates were similar for men and women and across age groups. Four samples (3%) were Chlamydia positive. CONCLUSION: Home mailed urine specimen collection in conjunction with a self-completed postal questionnaire is feasible. This could provide a viable basis both for determining population Chlamydia prevalence and for a UK Chlamydia population screening strategy. Overall cost effectiveness of such a strategy will depend on the cost of the test used. Comparative performance characteristics of the different currently available tests in this setting have yet to be fully determined. PMID:10562745

Adherence in the Cancer Care Setting: a Systematic Review of Patient Navigation to Traverse Barriers.

PubMed

Bush, Matthew L; Kaufman, Michael R; Shackleford, Taylor

2017-06-01

Patient navigation is an evidence-based intervention involving trained healthcare workers who assist patients in assessing and mitigating personal and environmental factors to promote healthy behaviors. The purpose of this research is to systematically assess the efficacy of patient navigation and similar programs to improve diagnosis and treatment of diseases affecting medically underserved populations. A systematic review was performed by searching PubMed, MEDLINE, PsychINFO, and CINAHL to identify potential studies. Eligible studies were those containing original peer-reviewed research reports in English on patient navigation, community health workers, vulnerable and underserved populations, and healthcare disparity. Specific outcomes regarding patient navigator including the effect of the intervention on definitive diagnosis and effect on initiation of treatment were extracted from each study. The search produced 1428 articles, and 16 were included for review. All studies involved patient navigation in the field of oncology in underserved populations. Timing of initial contact with a patient navigator after diagnostic or screening testing is correlated to the effectiveness of the navigator intervention. The majority of the studies reported significantly shorter time intervals to diagnosis and to treatment with patient navigation. Patient navigation expedites oncologic diagnosis and treatment of patients in underserved populations. This intervention is more efficacious when utilized shortly after screening or diagnostic testing.

Effect of genotyped cows in the reference population on the genomic evaluation of Holstein cattle.

PubMed

Uemoto, Y; Osawa, T; Saburi, J

2017-03-01

This study evaluated the dependence of reliability and prediction bias on the prediction method, the contribution of including animals (bulls or cows), and the genetic relatedness, when including genotyped cows in the progeny-tested bull reference population. We performed genomic evaluation using a Japanese Holstein population, and assessed the accuracy of genomic enhanced breeding value (GEBV) for three production traits and 13 linear conformation traits. A total of 4564 animals for production traits and 4172 animals for conformation traits were genotyped using Illumina BovineSNP50 array. Single- and multi-step methods were compared for predicting GEBV in genotyped bull-only and genotyped bull-cow reference populations. No large differences in realized reliability and regression coefficient were found between the two reference populations; however, a slight difference was found between the two methods for production traits. The accuracy of GEBV determined by single-step method increased slightly when genotyped cows were included in the bull reference population, but decreased slightly by multi-step method. A validation study was used to evaluate the accuracy of GEBV when 800 additional genotyped bulls (POPbull) or cows (POPcow) were included in the base reference population composed of 2000 genotyped bulls. The realized reliabilities of POPbull were higher than those of POPcow for all traits. For the gain of realized reliability over the base reference population, the average ratios of POPbull gain to POPcow gain for production traits and conformation traits were 2.6 and 7.2, respectively, and the ratios depended on heritabilities of the traits. For regression coefficient, no large differences were found between the results for POPbull and POPcow. Another validation study was performed to investigate the effect of genetic relatedness between cows and bulls in the reference and test populations. The effect of genetic relationship among bulls in the reference population was also assessed. The results showed that it is important to account for relatedness among bulls in the reference population. Our studies indicate that the prediction method, the contribution ratio of including animals, and genetic relatedness could affect the prediction accuracy in genomic evaluation of Holstein cattle, when including genotyped cows in the reference population.

Interferon Gamma-Based Detection of Latent Tuberculosis Infection in the Border States of Nuevo Leon and Tamaulipas, Mexico

PubMed Central

Oren, Eyal; Alatorre-Izaguirre, Gabriela; Vargas-Villarreal, Javier; Moreno-Treviño, Maria Guadalupe; Garcialuna-Martinez, Javier; Gonzalez-Salazar, Francisco

2015-01-01

Nearly one-third of the world’s population is infected with latent tuberculosis (LTBI). Tuberculosis (TB) rates in the border states are higher than national rates in both the US and Mexico, with the border accounting for 30% of total registered TB cases in both countries. However, LTBI rates in the general population in Mexican border states are unknown. In this region, LTBI is diagnosed using the tuberculin skin test (TST). New methods of detection more specific than TST have been developed, although there is currently no gold standard for LTBI detection. Our objective is to demonstrate utility of the Quantiferon TB gold In-Tube (QFT-GIT) test compared with the TST to detect LTBI among border populations. This is an observational, cross-sectional study carried out in border areas of the states of Nuevo Leon and Tamaulipas, Mexico. Participants (n = 210) provided a TST and blood sample for the QFT-GIT. Kappa coefficients assessed the agreement between TST and QFT-GIT. Participant characteristics were compared using Fisher exact tests. Thirty-eight percent of participants were diagnosed with LTBI by QFT-GIT. The proportion of LTBI detected using QFT-GIT was almost double [38% (79/210)] that found by TST [19% (39/210)] (P < 0.001). Concordance between TST and QFT-GIT was low (kappa = 0.37). We recommend further studies utilizing the QFT-GIT test to detect LTBI among border populations. PMID:26484340

Interferon Gamma-Based Detection of Latent Tuberculosis Infection in the Border States of Nuevo Leon and Tamaulipas, Mexico.

PubMed

Oren, Eyal; Alatorre-Izaguirre, Gabriela; Vargas-Villarreal, Javier; Moreno-Treviño, Maria Guadalupe; Garcialuna-Martinez, Javier; Gonzalez-Salazar, Francisco

2015-01-01

Nearly one-third of the world's population is infected with latent tuberculosis (LTBI). Tuberculosis (TB) rates in the border states are higher than national rates in both the US and Mexico, with the border accounting for 30% of total registered TB cases in both countries. However, LTBI rates in the general population in Mexican border states are unknown. In this region, LTBI is diagnosed using the tuberculin skin test (TST). New methods of detection more specific than TST have been developed, although there is currently no gold standard for LTBI detection. Our objective is to demonstrate utility of the Quantiferon TB gold In-Tube (QFT-GIT) test compared with the TST to detect LTBI among border populations. This is an observational, cross-sectional study carried out in border areas of the states of Nuevo Leon and Tamaulipas, Mexico. Participants (n = 210) provided a TST and blood sample for the QFT-GIT. Kappa coefficients assessed the agreement between TST and QFT-GIT. Participant characteristics were compared using Fisher exact tests. Thirty-eight percent of participants were diagnosed with LTBI by QFT-GIT. The proportion of LTBI detected using QFT-GIT was almost double [38% (79/210)] that found by TST [19% (39/210)] (P < 0.001). Concordance between TST and QFT-GIT was low (kappa = 0.37). We recommend further studies utilizing the QFT-GIT test to detect LTBI among border populations.

Beliefs about chlamydia testing amongst young people living in relatively deprived areas.

PubMed

Booth, A R; Harris, P R; Goyder, E; Norman, P

2013-06-01

This study uses the theory of planned behaviour (TPB) as a framework to investigate salient beliefs about chlamydia testing, amongst young people living in relatively deprived areas. These beliefs may form targets for intervention to increase testing in this high-risk population. Participants recruited from colleges in deprived areas of a UK city, completed open-ended questions designed to elicit salient beliefs. Responses were content analysed and categorized as describing behavioural, normative or control beliefs. Beliefs were elicited from 128 respondents (51% male; median age = 17). The commonest behavioural belief, which could have a positive or negative impact on screening intentions, was that testing provides information about health status. Partners were referred to most commonly amongst the normative beliefs. Practical aspects and concerns about social implications of testing were common control beliefs. References to several negative emotions emerged throughout. This study indicates that raising awareness of chlamydia as a serious sexual health problem may not be the best way to increase the uptake of testing in a high-risk population. Promoting chlamydia testing as potentially providing reassurance may be an alternative. It may also be important to reduce perceptions of social disapproval as well as negative emotion regarding chlamydia testing.

Measurement Invariance of the Internet Addiction Test Among Hong Kong, Japanese, and Malaysian Adolescents.

PubMed

Lai, Ching-Man; Mak, Kwok-Kei; Cheng, Cecilia; Watanabe, Hiroko; Nomachi, Shinobu; Bahar, Norharlina; Young, Kimberly S; Ko, Huei-Chen; Kim, Dongil; Griffiths, Mark D

2015-10-01

There has been increased research examining the psychometric properties on the Internet Addiction Test (IAT) in different populations. This population-based study examined the psychometric properties and measurement invariance of the IAT in adolescents from three Asian countries. In the Asian Adolescent Risk Behavior Survey (AARBS), 2,535 secondary school students (55.9% girls) aged 12-18 years from Hong Kong (n=844), Japan (n=744), and Malaysia (n=947) completed a survey in 2012-2013 school year. A nested hierarchy of hypotheses concerning the IAT cross-country invariance was tested using multigroup confirmatory factor analyses. Replicating past findings in Hong Kong adolescents, the construct of the IAT is best represented by a second-order three-factor structure in Malaysian and Japanese adolescents. Configural, metric, scalar, and partial strict factorial invariance was established across the three samples. No cross-country differences on Internet addiction were detected at the latent mean level. This study provided empirical support for the IAT as a reliable and factorially stable instrument, and valid to be used across Asian adolescent populations.

Population Size and the Rate of Language Evolution: A Test Across Indo-European, Austronesian, and Bantu Languages

PubMed Central

Greenhill, Simon J.; Hua, Xia; Welsh, Caela F.; Schneemann, Hilde; Bromham, Lindell

2018-01-01

What role does speaker population size play in shaping rates of language evolution? There has been little consensus on the expected relationship between rates and patterns of language change and speaker population size, with some predicting faster rates of change in smaller populations, and others expecting greater change in larger populations. The growth of comparative databases has allowed population size effects to be investigated across a wide range of language groups, with mixed results. One recent study of a group of Polynesian languages revealed greater rates of word gain in larger populations and greater rates of word loss in smaller populations. However, that test was restricted to 20 closely related languages from small Oceanic islands. Here, we test if this pattern is a general feature of language evolution across a larger and more diverse sample of languages from both continental and island populations. We analyzed comparative language data for 153 pairs of closely-related sister languages from three of the world's largest language families: Austronesian, Indo-European, and Niger-Congo. We find some evidence that rates of word loss are significantly greater in smaller languages for the Indo-European comparisons, but we find no significant patterns in the other two language families. These results suggest either that the influence of population size on rates and patterns of language evolution is not universal, or that it is sufficiently weak that it may be overwhelmed by other influences in some cases. Further investigation, for a greater number of language comparisons and a wider range of language features, may determine which of these explanations holds true. PMID:29755387

Predicting Stereotype Threat, Test Anxiety, and Cognitive Ability Test Performance: An Examination of Three Models

ERIC Educational Resources Information Center

Sawyer, Jr., Thomas P.; Hollis-Sawyer, Lisa A.

2005-01-01

As the classroom and workplace, among other contexts, become more diverse in their population characteristics, the need to be aware of specific factors impacting testing outcome issues correspondingly increases. The focus in this study, among other purposes, was to identify possible interactions between examinee's individual-difference…

Microsatellite primers for a species of South African everlasting daisy (Helichrysum odoratissimum; Gnaphalieae, Asteraceae)1

PubMed Central

Glennon, Kelsey L.; Cron, Glynis V.

2016-01-01

Premise of the study: Microsatellites were developed for the widespread Helichrysum odoratissimum (Asteraceae) to estimate gene flow across diploid populations and to test if gene flow occurs among other closely related lineages within this genus. Methods and Results: Ten primer pairs were developed and tested using populations across South Africa; however, only seven primer pairs were polymorphic for the target species. The seven polymorphic primers amplified di- and trinucleotide repeats with up to 16 alleles per locus among 125 diploid individuals used for analyses. Conclusions: These markers can be used to estimate gene flow among populations of known ploidy level of H. odoratissimum to test evolutionary hypotheses. Furthermore, these markers amplify successfully in other Helichrysum species, including the other three taxonomic Group 4 species, and therefore can be used to inform taxonomic work on these species. PMID:27213125

A public platform for the verification of the phenotypic effect of candidate genes for resistance to aflatoxin accumulation and Aspergillus flavus infection in maize.

PubMed

Warburton, Marilyn L; Williams, William Paul; Hawkins, Leigh; Bridges, Susan; Gresham, Cathy; Harper, Jonathan; Ozkan, Seval; Mylroie, J Erik; Shan, Xueyan

2011-07-01

A public candidate gene testing pipeline for resistance to aflatoxin accumulation or Aspergillus flavus infection in maize is presented here. The pipeline consists of steps for identifying, testing, and verifying the association of selected maize gene sequences with resistance under field conditions. Resources include a database of genetic and protein sequences associated with the reduction in aflatoxin contamination from previous studies; eight diverse inbred maize lines for polymorphism identification within any maize gene sequence; four Quantitative Trait Loci (QTL) mapping populations and one association mapping panel, all phenotyped for aflatoxin accumulation resistance and associated phenotypes; and capacity for Insertion/Deletion (InDel) and SNP genotyping in the population(s) for mapping. To date, ten genes have been identified as possible candidate genes and put through the candidate gene testing pipeline, and results are presented here to demonstrate the utility of the pipeline.

Use of healthcare consumer voices to increase empathy in nursing students.

PubMed

Heidke, Penny; Howie, Virginia; Ferdous, Tabassum

2018-03-01

Nurses need to be well prepared to address the needs of a diverse population and facilitate positive experiences in an equitable and inclusive approach to care. The aim of the study was to determine whether the integration of consumer lived experience interviews into the content of a first-year course influenced empathy in nursing students. A one group pre-test, post-test design was used. A convenience sample of first-year undergraduate nursing students (N = 32) from a regional Australian university was recruited for the study. The pre and post tests were conducted using the Kiersma Chen Empathy Scale and t-tests performed to analyse the data. Results showed overall that nursing students demonstrated moderate levels of empathy; pre-test score of (M = 75.53; SD = 5.76). After the intervention the post-test results showed that there was a statistically significant increase in students' empathy towards vulnerable, disadvantaged and stigmatised population groups. The healthcare consumer voice has the potential to strengthen current teaching practices that promote caring behaviours in nursing students. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of BRCA1 and BRCA2 mutation prevalence, risk prediction models and a multistep testing approach in French‐Canadian families with high risk of breast and ovarian cancer

PubMed Central

Simard, Jacques; Dumont, Martine; Moisan, Anne‐Marie; Gaborieau, Valérie; Vézina, Hélène; Durocher, Francine; Chiquette, Jocelyne; Plante, Marie; Avard, Denise; Bessette, Paul; Brousseau, Claire; Dorval, Michel; Godard, Béatrice; Houde, Louis; Joly, Yann; Lajoie, Marie‐Andrée; Leblanc, Gilles; Lépine, Jean; Lespérance, Bernard; Malouin, Hélène; Parboosingh, Jillian; Pichette, Roxane; Provencher, Louise; Rhéaume, Josée; Sinnett, Daniel; Samson, Carolle; Simard, Jean‐Claude; Tranchant, Martine; Voyer, Patricia; BRCAs, INHERIT; Easton, Douglas; Tavtigian, Sean V; Knoppers, Bartha‐Maria; Laframboise, Rachel; Bridge, Peter; Goldgar, David

2007-01-01

Background and objective In clinical settings with fixed resources allocated to predictive genetic testing for high‐risk cancer predisposition genes, optimal strategies for mutation screening programmes are critically important. These depend on the mutation spectrum found in the population under consideration and the frequency of mutations detected as a function of the personal and family history of cancer, which are both affected by the presence of founder mutations and demographic characteristics of the underlying population. The results of multistep genetic testing for mutations in BRCA1 or BRCA2 in a large series of families with breast cancer in the French‐Canadian population of Quebec, Canada are reported. Methods A total of 256 high‐risk families were ascertained from regional familial cancer clinics throughout the province of Quebec. Initially, families were tested for a panel of specific mutations known to occur in this population. Families in which no mutation was identified were then comprehensively tested. Three algorithms to predict the presence of mutations were evaluated, including the prevalence tables provided by Myriad Genetics Laboratories, the Manchester Scoring System and a logistic regression approach based on the data from this study. Results 8 of the 15 distinct mutations found in 62 BRCA1/BRCA2‐positive families had never been previously reported in this population, whereas 82% carried 1 of the 4 mutations currently observed in ⩾2 families. In the subset of 191 families in which at least 1 affected individual was tested, 29% carried a mutation. Of these 27 BRCA1‐positive and 29 BRCA2‐positive families, 48 (86%) were found to harbour a mutation detected by the initial test. Among the remaining 143 inconclusive families, all 8 families found to have a mutation after complete sequencing had Manchester Scores ⩾18. The logistic regression and Manchester Scores provided equal predictive power, and both were significantly better than the Myriad Genetics Laboratories prevalence tables (p<0.001). A threshold of Manchester Score ⩾18 provided an overall sensitivity of 86% and a specificity of 82%, with a positive predictive value of 66% in this population. Conclusion In this population, a testing strategy with an initial test using a panel of reported recurrent mutations, followed by full sequencing in families with Manchester Scores ⩾18, represents an efficient test in terms of overall cost and sensitivity. PMID:16905680

'If she is a good woman …' and 'to be a real man …': gender, risk and access to HIV services among key populations in Tajikistan.

PubMed

King, Elizabeth J; Maksymenko, Kateryna M; Almodovar-Diaz, Yadira; Johnson, Sarah

2016-01-01

The HIV epidemic continues to grow in Tajikistan, especially among people who inject drugs, sex workers, men who have sex with men and incarcerated populations. Despite their susceptibility to HIV, members of these groups do not always have access to HIV prevention, testing and treatment. The purpose of this study was to identify and understand the gender constraints in accessing HIV services for key populations in Tajikistan. Using focus-group discussions and key-informant interviews the assessment team collected information from members of key populations and those who work with them. Several themes emerged from the data, including: low levels of HIV knowledge, gender constraints to condom use and safer drug use, gender constraints limit HIV testing opportunities, gender-based violence, stigma and discrimination, and the lack of female spaces in the HIV response. The results of this study show that there are well-defined gender norms in Tajikistan, and these gender norms influence key populations' access to HIV services. Addressing these gender constraints may offer opportunities for more equitable access to HIV services in Tajikistan.

Rationale and design of the Baptist Employee Healthy Heart Study: a randomized trial assessing the efficacy of the addition of an interactive, personalized, web-based, lifestyle intervention tool to an existing health information web platform in a high-risk employee population.

PubMed

Post, Janisse M; Ali, Shozab S; Roberson, Lara L; Aneni, Ehimen C; Shaharyar, Sameer; Younus, Adnan; Jamal, Omar; Ahmad, Rameez; Aziz, Muhammad A; Malik, Rehan; Spatz, Erica S; Feldman, Theodore; Fialkow, Jonathan; Veledar, Emir; Cury, Ricardo C; Agatston, Arthur S; Nasir, Khurram

2016-07-01

Metabolic syndrome (MetS) and diabetes confer a high risk for developing subsequent cardiovascular disease (CVD). Persons with MetS constitute 24-34 % of the employee population at Baptist Health South Florida (BHSF), a self-insured healthcare organization. The Baptist Employee Healthy Heart Study (BEHHS) aims to assess the addition of a personalized, interactive, web-based, nutrition-management and lifestyle-management program to the existing health-expertise web platform available to BHSF employees in reducing and/or stabilizing CVD and lifestyle risk factors and markers of subclinical CVD. Subjects with MetS or Type II Diabetes will be recruited from an employee population at BHSF and randomized to either an intervention or a control arm. The intervention arm will be given access to a web-based personalized diet-modification and weight-modification program. The control arm will be reminded to use the standard informational health website available and accessible to all BHSF employees. Subjects will undergo coronary calcium testing, carotid intima-media thickness scans, peripheral arterial tonometry, and advanced lipid panel testing at visit 1, in addition to lifestyle and medical history questionnaires. All tests will be repeated at visits 2 and 4 with the exception of the coronary calcium test, which will only be performed at baseline and visit 4. Visit 3 will capture vitals, anthropometrics, and responses to the questionnaires only. Results of this study will provide information on the effectiveness of personalized, web-based, lifestyle-management tools in reducing healthcare costs, promoting healthy choices, and reducing cardiovascular risk in an employee population. It will also provide information about the natural history of carotid atherosclerosis and endothelial dysfunction in asymptomatic but high-risk populations. ClinicalTrials.gov registry, NCT01912209 . Registered on 3 July 2013.

A Population-Based Nationwide Cross-Sectional Study on Preventive Health Services Utilization in Portugal—What Services (and Frequencies) Are Deemed Necessary by Patients?

PubMed Central

Martins, Carlos; Azevedo, Luís F.; Ribeiro, Orquídea; Sá, Luísa; Santos, Paulo; Couto, Luciana; Costa-Pereira, Altamiro; Hespanhol, Alberto P.

2013-01-01

Background Most of the strategies to induce a more rational use of preventive health services are oriented to the medical side of the doctor-patient relationship. However, the consultation model has changed, and patients now have a more important role in medical consultation. The aim of this study was to assess which healthcare services are deemed necessary, and with what frequency, by adults from the general Portuguese population. Methods Design: Population-based nationwide cross-sectional study Setting: Portuguese population Participants: One thousand Portuguese adults, surveyed by computer-assisted telephone interviewing and selected by a stratified cluster sampling design. Measurements: Proportions and population prevalence estimates were determined for each healthcare service, taking into account whether respondents considered them necessary, and with what frequency. Results Respondent ages ranged between 18 and 97 years, and 520 of 1000 (52%) respondents were women. Among Portuguese adults, 99.2% (95% confidence interval (CI): 98.5 to 99.6) believe that they should undergo general routine blood and urine tests, to be repeated every 12.0 months on average (95% CI: 11.4 to 12.6); 87.4% (95% CI: 85.3 to 89.3) of the respondents reported having actually performed these tests. Of the 15 services surveyed, 14 were considered periodically necessary by more than 60% of respondents. Among the respondents, 37.7% (95% CI: 34.5 to 41.1) reported using healthcare services by their own initiative. Conclusions The majority of Portuguese adults believe that they should utilize a great number of healthcare services, on a nearly annual basis; most actually follow this schedule. Our findings indicate a tendency towards the overuse of resources. Adequate patient-oriented strategies regarding the use of medical tests and preventive interventions—with appropriate information and discussion of risks and harms—are urgently needed, and crucial for achieving a more rational use of healthcare services and for preventing the consequences of over-testing. PMID:24278405

The undiagnosed chronically-infected HCV population in France. Implications for expanded testing recommendations in 2014.

PubMed

Brouard, Cécile; Le Strat, Yann; Larsen, Christine; Jauffret-Roustide, Marie; Lot, Florence; Pillonel, Josiane

2015-01-01

Recent HCV therapeutic advances make effective screening crucial for potential HCV eradication. To identify the target population for a possible population-based screening strategy to complement current risk-based testing in France, we aimed to estimate the number of adults with undiagnosed chronic HCV infection and age and gender distribution at two time points: 2004 and 2014. A model taking into account mortality, HCV incidence and diagnosis rates was applied to the 2004 national seroprevalence survey. In 2014, an estimated 74,102 individuals aged 18 to 80 were undiagnosed for chronic HCV infection (plausible interval: 64,920-83,283) compared with 100,868 [95%CI: 58,534-143,202] in 2004. Men aged 18-59 represented approximately half of the undiagnosed population in 2014. The proportion of undiagnosed individuals in 2004 (43%) varied from 21.9% to 74.1% in the 1945-1965 and 1924-1944 birth cohorts. Consequently, age and gender distributions between the chronically-infected (diagnosed and undiagnosed) and undiagnosed HCV populations were different, the 1945-1965 birth cohort representing 48.9% and 24.7%, respectively. Many individuals were still undiagnosed in 2014 despite a marked reduction with respect to 2004. The present work contributed to the 2014 recommendation of a new French complementary screening strategy, consisting in one-time simultaneous HCV, HBV and HIV testing in men aged 18-60. Further studies are needed to assess the cost-effectiveness and feasibility of such a strategy. We also demonstrated that data on the undiagnosed HCV population are crucial to help adapt testing strategies, as the features of the chronically-infected HCV population are very distinct.

Internal consistency and stability of the CANTAB neuropsychological test battery in children.

PubMed

Syväoja, Heidi J; Tammelin, Tuija H; Ahonen, Timo; Räsänen, Pekka; Tolvanen, Asko; Kankaanpää, Anna; Kantomaa, Marko T

2015-06-01

The Cambridge Neuropsychological Test Automated Battery (CANTAB) is a computer-assessed test battery widely use in different populations. The internal consistency and 1-year stability of CANTAB tests were examined in school-age children. Two hundred-thirty children (57% girls) from five schools in the Jyväskylä school district in Finland participated in the study in spring 2011. The children completed the following CANTAB tests: (a) visual memory (pattern recognition memory [PRM] and spatial recognition memory [SRM]), (b) executive function (spatial span [SSP], Stockings of Cambridge [SOC], and intra-extra dimensional set shift [IED]), and (c) attention (reaction time [RTI] and rapid visual information processing [RVP]). Seventy-four children participated in the follow-up measurements (64% girls) in spring 2012. Cronbach's alpha reliability coefficient was used to estimate the internal consistency of the nonhampering test, and structural equation models were applied to examine the stability of these tests. The reliability and the stability could not be determined for IED or SSP because of the nature of these tests. The internal consistency was acceptable only in the RTI task. The 1-year stability was moderate-to-good for the PRM, RTI, and RVP. The SSP and IED showed a moderate correlation between the two measurement points. The SRM and the SOC tasks were not reliable or stable measures in this study population. For research purposes, we recommend using structural equation modeling to improve reliability. The results suggest that the reliability and the stability of computer-based test batteries should be confirmed in the target population before using them for clinical or research purposes. (c) 2015 APA, all rights reserved).

RAPID-COMMUNICATION Genetic diversity and differentiation in natural populations of Arapaima gigas from lower Amazon revealed by microsatellites.

PubMed

Fazzi-Gomes, P F; Melo, N; Palheta, G; Guerreiro, S; Amador, M; Ribeiro-Dos-Santos, A K; Santos, S; Hamoy, I

2017-02-08

Genetic variability is one of the important criteria for species conservation decisions. This study aimed to analyze the genetic diversity and the population differentiation of two natural populations of Arapaima gigas, a species with a long history of being commercially exploited. We collected 87 samples of A. gigas from Grande Curuai Lake and Paru Lake, located in the Lower Amazon region of Amazônia, Brazil, and genotyped these samples using a multiplex panel of microsatellite markers. Our results showed that the populations of A. gigas analyzed had high levels of genetic variability, which were similar to those described in previous studies. These two populations had a significant population differentiation supported by the estimates of F ST and R ST (0.06), by Bayesian analysis (K = 2), and by population assignment tests, which revealed a moderate genetic distance.

Comparing the effect of a decision aid plus patient navigation with usual care on colorectal cancer screening completion in vulnerable populations: study protocol for a randomized controlled trial

PubMed Central

2014-01-01

Background Screening can reduce colorectal cancer (CRC) incidence and mortality. However, screening is underutilized in vulnerable patient populations, particularly among Latinos. Patient-directed decision aids can increase CRC screening knowledge, self-efficacy, and intent; however, their effect on actual screening test completion tends to be modest. This is probably because decision aids do not address some of the patient-specific barriers that prevent successful completion of CRC screening in these populations. These individual barriers might be addressed though patient navigation interventions. This study will test a combined decision aid and patient navigator intervention on screening completion in diverse populations of vulnerable primary care patients. Methods/Design We will conduct a multisite, randomized controlled trial with patient-level randomization. Planned enrollment is 300 patients aged 50 to 75 years at average CRC risk presenting for appointments at two primary clinics in North Carolina and New Mexico. Intervention participants will view a video decision aid immediately before the clinic visit. The 14 to 16 minute video presents information about fecal occult blood tests and colonoscopy and will be viewed on a portable computer tablet in English or Spanish. Clinic-based patient navigators are bilingual and bicultural and will provide both face-to-face and telephone-based navigation. Control participants will view an unrelated food safety video and receive usual care. The primary outcome is completion of a CRC screening test at six months. Planned subgroup analyses include examining intervention effectiveness in Latinos, who will be oversampled. Secondarily, the trial will evaluate the intervention effects on knowledge of CRC screening, self-efficacy, intent, and patient-provider communication. The study will also examine whether patient ethnicity, acculturation, language preference, or health insurance status moderate the intervention effect on CRC screening. Discussion This pragmatic randomized controlled trial will test a combined decision aid and patient navigator intervention targeting CRC screening completion. Findings from this trial may inform future interventions and implementation policies designed to promote CRC screening in vulnerable patient populations and to reduce screening disparities. Clinical trial registration ClinicalTrials.gov NCT02054598. PMID:25004983

Comparing the effect of a decision aid plus patient navigation with usual care on colorectal cancer screening completion in vulnerable populations: study protocol for a randomized controlled trial.

PubMed

Brenner, Alison T; Getrich, Christina M; Pignone, Michael; Rhyne, Robert L; Hoffman, Richard M; McWilliams, Andrew; de Hernandez, Brisa Urquieta; Weaver, Mark A; Tapp, Hazel; Harbi, Khalil; Reuland, Daniel

2014-07-08

Screening can reduce colorectal cancer (CRC) incidence and mortality. However, screening is underutilized in vulnerable patient populations, particularly among Latinos. Patient-directed decision aids can increase CRC screening knowledge, self-efficacy, and intent; however, their effect on actual screening test completion tends to be modest. This is probably because decision aids do not address some of the patient-specific barriers that prevent successful completion of CRC screening in these populations. These individual barriers might be addressed though patient navigation interventions. This study will test a combined decision aid and patient navigator intervention on screening completion in diverse populations of vulnerable primary care patients. We will conduct a multisite, randomized controlled trial with patient-level randomization. Planned enrollment is 300 patients aged 50 to 75 years at average CRC risk presenting for appointments at two primary clinics in North Carolina and New Mexico. Intervention participants will view a video decision aid immediately before the clinic visit. The 14 to 16 minute video presents information about fecal occult blood tests and colonoscopy and will be viewed on a portable computer tablet in English or Spanish. Clinic-based patient navigators are bilingual and bicultural and will provide both face-to-face and telephone-based navigation. Control participants will view an unrelated food safety video and receive usual care. The primary outcome is completion of a CRC screening test at six months. Planned subgroup analyses include examining intervention effectiveness in Latinos, who will be oversampled. Secondarily, the trial will evaluate the intervention effects on knowledge of CRC screening, self-efficacy, intent, and patient-provider communication. The study will also examine whether patient ethnicity, acculturation, language preference, or health insurance status moderate the intervention effect on CRC screening. This pragmatic randomized controlled trial will test a combined decision aid and patient navigator intervention targeting CRC screening completion. Findings from this trial may inform future interventions and implementation policies designed to promote CRC screening in vulnerable patient populations and to reduce screening disparities. ClinicalTrials.gov NCT02054598.

The relationship between area deprivation and contact with community intellectual disability psychiatry.

PubMed

Nicholson, L; Hotchin, H

2015-05-01

People with intellectual disabilities (ID) have high rates of psychiatric illness and are known to live in more deprived areas than the general population. This study investigated the relationship between area deprivation and contact with ID psychiatry. Psychiatric case notes and electronic records were used to identify all patients who had face-to-face contact with community ID psychiatric services over 1 year in the North East Community Health Partnership of Greater Glasgow and Clyde (estimated population 177,867). The Scottish Index of Multiple Deprivation (SIMD) were determined for the patient sample and for the general population living in the same area. Between 1 June 2012 and 1 June 2013, 184 patients were seen by ID psychiatry over a total of 553 contacts, with valid SIMD data for 179 patients and 543 contacts. Fifty-two per cent of patients (n = 93) lived in the most deprived SIMD decile, and 90.5% (n = 152) in the lowest 5 deciles. Compared with the general population, there were significantly more patients than expected living in the most deprived decile (Fisher's Exact test, P = 0.009) and in the most deprived 5 deciles (Fisher's Exact test, P = 0.001). The median number of contacts was 2 (interquartile range = 1-3). There was no significant association between the number of contacts and SIMD decile. Forty-eight point one per cent (n = 261) of all contacts were with patients living in the most deprived decile and 88.6% (n = 481) in the most deprived 5 deciles. This was significantly more than expected compared with general population data (Fisher's Exact test, P = 0.008 and Fisher's Exact test, P ≤ 0.001). In the area under study, contact with ID psychiatry was greater in more deprived areas. Given the high psychiatric morbidity of people with ID, if services do not adjust for deprivation, this may lead to further discrimination in an already disadvantaged population. © 2014 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

The association between ALS and population density: A population based study.

PubMed

Scott, Kirsten M; Abhinav, Kumar; Wijesekera, Lokesh; Ganesalingam, Jeban; Goldstein, Laura H; Janssen, Anna; Dougherty, Andrew; Willey, Emma; Stanton, Biba R; Turner, Martin R; Ampong, Mary-Ann; Sakel, Mohammed; Orrell, Richard; Howard, Robin; Shaw, Christopher E; Nigel Leigh, P; Al-Chalabi, Ammar

2010-10-01

We aimed to assess whether rural residence is associated with amyotrophic lateral sclerosis in the south-east of England using a population based register. Previous studies in different populations have produced contradictory findings. Residence defined by London borough or non-metropolitan district at time of diagnosis was recorded for each incident case in the South-East England ALS Register between 1995 and 2005. Each of the 26 boroughs or districts of the catchment area of the register was classified according to population density. Age- and sex-adjusted incidence of ALS was calculated for each region and the relationship with population density tested by linear regression, thereby controlling for the underlying population structure. We found that population density in region of residence at diagnosis explained 25% of the variance in ALS rates (r = 0.5, p < 0.01). Thus, in this cohort in the south-east of England, people with ALS were more likely to be resident in areas of high population density at diagnosis.

The association between ALS and population density: A population based study

PubMed Central

SCOTT, KIRSTEN M.; ABHINAV, KUMAR; WIJESEKERA, LOKESH; GANESALINGAM, JEBAN; GOLDSTEIN, LAURA H.; JANSSEN, ANNA; DOUGHERTY, ANDREW; WILLEY, EMMA; STANTON, BIBA R.; TURNER, MARTIN R.; AMPONG, MARY-ANN; SAKEL, MOHAMMED; ORRELL, RICHARD; HOWARD, ROBIN; SHAW, CHRISTOPHER E.; LEIGH, P. NIGEL; AL-CHALABI, AMMAR

2011-01-01

We aimed to assess whether rural residence is associated with amyotrophic lateral sclerosis in the south-east of England using a population based register. Previous studies in different populations have produced contradictory findings. Residence defined by London borough or non-metropolitan district at time of diagnosis was recorded for each incident case in the South-East England ALS Register between 1995 and 2005. Each of the 26 boroughs or districts of the catchment area of the register was classified according to population density. Age- and sex-adjusted incidence of ALS was calculated for each region and the relationship with population density tested by linear regression, thereby controlling for the underlying population structure. We found that population density in region of residence at diagnosis explained 25% of the variance in ALS rates (r = 0.5, p < 0.01). Thus, in this cohort in the south-east of England, people with ALS were more likely to be resident in areas of high population density at diagnosis. PMID:20429684

Colour assortative pairing in a colour polymorphic lizard is independent of population morph diversity

NASA Astrophysics Data System (ADS)

Pérez i de Lanuza, Guillem; Font, Enrique; Carretero, Miguel Ángel

2016-10-01

Previous work with a colour polymorphic population of Podarcis muralis (Lacertidae) revealed that lizards pair by ventral colour, favouring the same colour (i.e. homomorphic) pairs. Such assortative pairing, which probably results in colour assortative mating, can have consequences for the genetic structure of the population and potentially promote speciation. The population previously studied, located in the Pyrenees, encompasses white, yellow and orange animals, as well as intermediate white-orange and yellow-orange morphs. However, other Pyrenean populations of P. muralis have less ventral colour morphs. Our aim in this study is to test the generality of the assortative colour pairing system, extending our previous analyses to populations with different morph compositions and frequencies. The results show that the assortative pattern of pairing is similar in all the populations analysed and, hence, independent of morph composition and not restricted to pentamorphic populations. This suggests that assortative pairing by colour is a general phenomenon for colour polymorphic populations of P. muralis.

The Trail Making test: a study of its ability to predict falls in the acute neurological in-patient population.

PubMed

Mateen, Bilal Akhter; Bussas, Matthias; Doogan, Catherine; Waller, Denise; Saverino, Alessia; Király, Franz J; Playford, E Diane

2018-05-01

To determine whether tests of cognitive function and patient-reported outcome measures of motor function can be used to create a machine learning-based predictive tool for falls. Prospective cohort study. Tertiary neurological and neurosurgical center. In all, 337 in-patients receiving neurosurgical, neurological, or neurorehabilitation-based care. Binary (Y/N) for falling during the in-patient episode, the Trail Making Test (a measure of attention and executive function) and the Walk-12 (a patient-reported measure of physical function). The principal outcome was a fall during the in-patient stay ( n = 54). The Trail test was identified as the best predictor of falls. Moreover, addition of other variables, did not improve the prediction (Wilcoxon signed-rank P < 0.001). Classical linear statistical modeling methods were then compared with more recent machine learning based strategies, for example, random forests, neural networks, support vector machines. The random forest was the best modeling strategy when utilizing just the Trail Making Test data (Wilcoxon signed-rank P < 0.001) with 68% (± 7.7) sensitivity, and 90% (± 2.3) specificity. This study identifies a simple yet powerful machine learning (Random Forest) based predictive model for an in-patient neurological population, utilizing a single neuropsychological test of cognitive function, the Trail Making test.

Anti-hepatitis C virus seroprevalence in the working age population in Poland, 2004 to 2014

PubMed Central

Walewska-Zielecka, Bożena; Religioni, Urszula; Juszczyk, Grzegorz; Wawrzyniak, Zbigniew M; Czerw, Aleksandra; Soszyński, Piotr; Fronczak, Adam

2017-01-01

Hepatitis C virus (HCV) infection is considered by the World Health Organization (WHO) to be a serious public health concern and one of the major public health priorities. In 2005, it was estimated that there are 185 million anti-HCV positive people in the world, which constitutes 2.8% of the global population. Our study estimates the anti-HCV seroprevalence in the working age population (15–64 years-old), mostly urban and suburban residents, in Poland from 2004 to 2014. The studied group consisted of 61,805 working-age population representatives whose data were obtained from electronic medical records of an outpatient clinic network operating on a countrywide level. Positive anti-HCV test results were obtained in 957 patients, representing 1.5% of the whole population studied throughout the analysed period. The average age of all anti-HCV positive patients was 36.8 years. Analysis of the data suggests that the proportion of anti-HCV positive patients decreased over the study period (mean positive anti-HCV = -0.0017 × year + 3.3715; R2 = 0.7558). In 2004, positive results were noted among 3.2% of patients undergoing HCV antibody tests, but in 2014, the percentage of patients with a positive result stood at 1.1%. The apparent decrease affected men and women similarly. Our study also provides evidence that screening people born before 1965 could be beneficial. PMID:28106526

Traumatic brain injury in a county jail population: prevalence, neuropsychological functioning and psychiatric disorders.

PubMed

Slaughter, Bill; Fann, Jesse R; Ehde, Dawn

2003-09-01

To determine the prevalence of traumatic brain injury (TBI) among inmates in a county jail population. Cross-sectional, observational study. A standardized interview was used to determine prevalence of TBI in 69 randomly selected inmates. To examine cognitive and emotional differences between subjects with and without recent TBI, neuropsychological tests and structured psychiatric diagnostic interviews were conducted with 50 subjects (the first 25 with TBI and the first 25 without TBI in the prior year). Sixty (87.0%) reported TBI over their lifetime; 25 (36.2%) reported TBI in the prior year. The latter group had significantly worse anger and aggression scores and had a trend towards poorer cognitive test results and a higher prevalence of psychiatric disorders than the group without TBI in the prior year. This study suggests the need for increased attention to TBI and its cognitive, behavioural and psychiatric sequelae in jail populations.

Effect of Lower Extremity Stretching Exercises on Balance in Geriatric Population.

PubMed

Reddy, Ravi Shankar; Alahmari, Khalid A

2016-07-01

The purpose of this study was to find "Effect of lower extremity stretching exercises on balance in the geriatric population. 60 subjects (30 male and 30 female) participated in the study. The subjects underwent 10 weeks of lower limb stretching exercise program. Pre and post 10 weeks stretching exercise program, the subjects were assessed for balance, using single limb stance time in seconds and berg balance score. These outcome measures were analyzed. Pre and post lower extremity stretching on balance was analyzed using paired t test. Of 60 subjects 50 subjects completed the stretching exercise program. Paired sample t test analysis showed a significant improvement in single limb stance time (eyes open and eyes closed) (p<0.001) and berg balance score (p<0.001). Lower extremity stretching exercises enhances balance in the geriatric population and thereby reduction in the number of falls.

[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.

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.

Mannitol challenge testing for asthma in a community cohort of young adults.

PubMed

White, Elisha C; de Klerk, Nicholas; Hantos, Zoltan; Priston, Monique; Hollams, Elysia M; James, Alan; Sly, Peter D; Holt, Patrick G; Hall, Graham L

2017-05-01

Mannitol challenge testing is an established tool for clinical asthma diagnosis, and can be performed outside of specialized respiratory laboratories. Despite applicability in both clinical and non-clinical populations, with different pre-test asthma probabilities, differences in diagnostic properties have not been well explored. This study aimed to quantify the diagnostic utility of mannitol challenge testing for asthma in a community cohort and a symptomatic wheezing subset of this cohort. During the 22-year follow-up of the Western Australian Pregnancy (Raine) Cohort, 772 participants (384 males) completed mannitol challenge and skin prick testing and respiratory health questionnaires, of whom 148 reporting wheeze in the past 12 months were included in a wheezing subset. Responsiveness to mannitol had low sensitivity (19%) and high specificity (97%) to identify current asthma in the complete cohort, with positive and negative predictive values (PPV and NPV) of 45% and 92%, respectively. Within the wheezing subset, sensitivity (19%) and specificity (94%) remained similar, but PPV increased to 79%, and NPV decreased to 52%. Our findings support previously reported high specificity and good PPV for mannitol challenge testing in symptomatic wheezing populations, and highlight the need for caution when interpreting mannitol test results in non-clinical populations. © 2016 Asian Pacific Society of Respirology.

Interest and Uptake of MC1R Testing for Melanoma Risk in a Diverse Primary Care Population: A Randomized Clinical Trial.

PubMed

Hay, Jennifer L; Zielaskowski, Kate; Meyer White, Kirsten; Kaphingst, Kimberly; Robers, Erika; Guest, Dolores; Sussman, Andrew; Talamantes, Yvonne; Schwartz, Matthew; Rodríguez, Vivian M; Li, Yuelin; Schofield, Elizabeth; Bigney, Jessica; Hunley, Keith; Buller, David; Berwick, Marianne

2018-06-01

Germline variants in the MC1R gene are common and confer moderate melanoma risk in those with varied skin types. Approaches to precision skin cancer prevention that include genetic information may promote risk awareness and risk reduction in the general population, including Hispanics. To examine prevalence of interest in and uptake of MC1R testing in the general population and examine patterns across demographic and skin cancer risk factors. A randomized clinical trial examined interest in and uptake of MC1R testing among patients at University of New Mexico General Internal Medicine clinics. Study participants were randomized to either a usual-care condition (National Cancer Institute skin cancer pamphlet for diverse skin types) or an MC1R test offer. Participants were registered clinic patients (≥6 months) and English or Spanish fluent. Of the 600 participants recruited to the overall trial, the present study included those 499 participants randomized to the MC1R test offer. Participants were presented with the option to log onto the study website to read 3 educational modules presenting the rationale, benefits, and drawbacks of MC1R testing. Main outcomes include website log on (yes vs no), saliva test kit request (yes vs no), and saliva test kit return for MC1R testing (yes vs no). Demographic and skin cancer risk factors were examined as potential predictors of test interest and uptake. Of the 499 participants (220 [44%] non-Hispanic white, 242 [48%] Hispanic, 396 [79%] female; mean [SD] age, 54 [14.3] years), 232 (46%) elected to learn about MC1R testing by logging onto the website; 204 (88%) of those who logged on decided to request testing; and 167 (82%) of those who requested testing returned the kit. The strongest predictors of website log on were race/ethnicity and education (non-Hispanic whites were more likely to log on [odds ratio for Hispanics vs non-Hispanic whites, 0.5; 95% CI, 0.3-0.7], as were more highly educated individuals [odds ratio for more than high school vs high school or less, 2.7; 95% CI, 1.7-4.3]). The strongest predictor of ordering the test was sunburn history (odds ratio, 5.4; 95% CI, 2.3-12.9 vs no sunburn history). There were moderately high levels of MC1R test interest and uptake in this diverse sample. Addressing potential barriers to testing may be warranted as genomic information becomes integrated into general population approaches to the precision prevention of skin cancer. ClinicalTrials.gov identifier: NCT03130569.

Psychometric properties of the Compulsive Exercise Test in an adolescent eating disorder population.

PubMed

Formby, Pam; Watson, Hunna J; Hilyard, Anna; Martin, Kate; Egan, Sarah J

2014-12-01

The objective of this study was to evaluate the factor structure, validity, and reliability of the Compulsive Exercise Test (CET) in an adolescent clinical eating disorder population. The data source was the Helping to Outline Paediatric Eating Disorders (HOPE) Project, a prospective ongoing registry study comprising consecutive pediatric tertiary eating disorder referrals. Adolescents (N=104; 12-17years) with eating disorders completed the CET and other measures. Factor structure, convergent validity, and internal consistency were evaluated. Despite failing to identify a factor structure, the study provided clear evidence of the multidimensionality of the measure. The total score correlated significantly with measures of eating pathology, perfectionism, and frequency of exercise for shape and weight control (r=0.32-0.70, ps<0.05). More research into the multidimensional nature of compulsive exercise in clinical populations is needed. Further, research into compulsive exercise offers promise as an addition to existing cognitive behavioral models and treatments for eating disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

Associations between incident ischemic stroke events and stroke and cardiovascular disease-related genome-wide association studies single nucleotide polymorphisms in the Population Architecture Using Genomics and Epidemiology study.

PubMed

Carty, Cara L; Buzková, Petra; Fornage, Myriam; Franceschini, Nora; Cole, Shelley; Heiss, Gerardo; Hindorff, Lucia A; Howard, Barbara V; Mann, Sue; Martin, Lisa W; Zhang, Ying; Matise, Tara C; Prentice, Ross; Reiner, Alexander P; Kooperberg, Charles

2012-04-01

Genome-wide association studies (GWAS) have identified loci associated with ischemic stroke (IS) and cardiovascular disease (CVD) in European-descent individuals, but their replication in different populations has been largely unexplored. Nine single nucleotide polymorphisms (SNPs) selected from GWAS and meta-analyses of stroke, and 86 SNPs previously associated with myocardial infarction and CVD risk factors, including blood lipids (high density lipoprotein [HDL], low density lipoprotein [LDL], and triglycerides), type 2 diabetes, and body mass index (BMI), were investigated for associations with incident IS in European Americans (EA) N=26 276, African-Americans (AA) N=8970, and American Indians (AI) N=3570 from the Population Architecture using Genomics and Epidemiology Study. Ancestry-specific fixed effects meta-analysis with inverse variance weighting was used to combine study-specific log hazard ratios from Cox proportional hazards models. Two of 9 stroke SNPs (rs783396 and rs1804689) were significantly associated with [corrected] IS hazard in AA; none were significant in this large EA cohort. Of 73 CVD risk factor SNPs tested in EA, 2 (HDL and triglycerides SNPs) were associated with IS. In AA, SNPs associated with LDL, HDL, and BMI were significantly associated with IS (3 of 86 SNPs tested). Out of 58 SNPs tested in AI, 1 LDL SNP was significantly associated with IS. Our analyses showing lack of replication in spite of reasonable power for many stroke SNPs and differing results by ancestry highlight the need to follow up on GWAS findings and conduct genetic association studies in diverse populations. We found modest IS associations with BMI and lipids SNPs, though these findings require confirmation.

PM₁₀ exposure and non-accidental mortality in Asian populations: a meta-analysis of time-series and case-crossover studies.

PubMed

Park, Hye Yin; Bae, Sanghyuk; Hong, Yun-Chul

2013-01-01

We investigated the association between particulate matter less than 10 µm in aerodynamic diameter (PM₁₀) exposure and non-accidental mortality in Asian populations by meta-analysis, using both time-series and case-crossover analysis. Among the 819 published studies searched from PubMed and EMBASE using key words related to PM₁₀ exposure and non-accidental mortality in Asian countries, 8 time-series and 4 case-crossover studies were selected for meta-analysis after exclusion by selection criteria. We obtained the relative risk (RR) and 95% confidence intervals (CI) of non-accidental mortality per 10 µg/m³ increase of daily PM₁₀ from each study. We used Q statistics to test the heterogeneity of the results among the different studies and evaluated for publication bias using Begg funnel plot and Egger test. Testing for heterogeneity showed significance (p<0.001); thus, we applied a random-effects model. RR (95% CI) per 10 µg/m³ increase of daily PM₁₀ for both the time-series and case-crossover studies combined, time-series studies relative risk only, and case-crossover studies only, were 1.0047 (1.0033 to 1.0062), 1.0057 (1.0029 to 1.0086), and 1.0027 (1.0010 to 1.0043), respectively. The non-significant Egger test suggested that this analysis was not likely to have a publication bias. We found a significant positive association between PM₁₀ exposure and non-accidental mortality among Asian populations. Continued investigations are encouraged to contribute to the health impact assessment and public health management of air pollution in Asian countries.

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

PubMed

van Strien, Maarten J

2017-07-01

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

Using parentage analysis to examine gene flow and spatial genetic structure.

PubMed

Kane, Nolan C; King, Matthew G

2009-04-01

Numerous approaches have been developed to examine recent and historical gene flow between populations, but few studies have used empirical data sets to compare different approaches. Some methods are expected to perform better under particular scenarios, such as high or low gene flow, but this, too, has rarely been tested. In this issue of Molecular Ecology, Saenz-Agudelo et al. (2009) apply assignment tests and parentage analysis to microsatellite data from five geographically proximal (2-6 km) and one much more distant (1500 km) panda clownfish populations, showing that parentage analysis performed better in situations of high gene flow, while their assignment tests did better with low gene flow. This unusually complete data set is comprised of multiple exhaustively sampled populations, including nearly all adults and large numbers of juveniles, enabling the authors to ask questions that in many systems would be impossible to answer. Their results emphasize the importance of selecting the right analysis to use, based on the underlying model and how well its assumptions are met by the populations to be analysed.

Prostate-Specific Antigen (PSA)–Based Population Screening for Prostate Cancer: An Economic Analysis

PubMed Central

Tawfik, A

2015-01-01

Background The prostate-specific antigen (PSA) blood test has become widely used in Canada to test for prostate cancer (PC), the most common cancer among Canadian men. Data suggest that population-based PSA screening may not improve overall survival. Objectives This analysis aimed to review existing economic evaluations of population-based PSA screening, determine current spending on opportunistic PSA screening in Ontario, and estimate the cost of introducing a population-based PSA screening program in the province. Methods A systematic literature search was performed to identify economic evaluations of population-based PSA screening strategies published from 1998 to 2013. Studies were assessed for their methodological quality and applicability to the Ontario setting. An original cost analysis was also performed, using data from Ontario administrative sources and from the published literature. One-year costs were estimated for 4 strategies: no screening, current (opportunistic) screening of men aged 40 years and older, current (opportunistic) screening of men aged 50 to 74 years, and population-based screening of men aged 50 to 74 years. The analysis was conducted from the payer perspective. Results The literature review demonstrated that, overall, population-based PSA screening is costly and cost-ineffective but may be cost-effective in specific populations. Only 1 Canadian study, published 15 years ago, was identified. Approximately $119.2 million is being spent annually on PSA screening of men aged 40 years and older in Ontario, including close to $22 million to screen men younger than 50 and older than 74 years of age (i.e., outside the target age range for a population-based program). A population-based screening program in Ontario would cost approximately $149.4 million in the first year. Limitations Estimates were based on the synthesis of data from a variety of sources, requiring several assumptions and causing uncertainty in the results. For example, where Ontario-specific data were unavailable, data from the United States were used. Conclusions PSA screening is associated with significant costs to the health care system when the cost of the PSA test itself is considered in addition to the costs of diagnosis, staging, and treatment of screen-detected PCs. PMID:26366237

A phased approach to clinical testing: criteria for progressing from Phase I to Phase II to Phase III studies.

PubMed

André, F E; Foulkes, M A

1998-01-01

The overall intent of clinical testing is to establish, in a series of phased studies, the clinical tolerance and acceptable "safety" of the candidate vaccine, as well as the type, level and persistence of the immune response after its inoculation, to a representative target population, according to a convenient administration schedule. The final stages involve the direct or indirect demonstration of protective efficacy, if possible in the population(s) for which the vaccine is intended. In addition, consistency of production must be demonstrated. At all these stages, the amount of prior information from preclinical and other studies affects and informs the objectives and design of subsequent studies. Progression from one testing phase to the next is dependent upon attaining the pre-set objectives of each series of studies. The precise objectives to be met will be decided on a case-by-case basis. The earliest assessments in humans (Phase I) involve evaluation of short-term clinical tolerance as measured by local and general reactogenicity, and gross assessments of immunogenicity, in a small number of highly selected individuals in an idealised situation. The selection of "optimal" dose and schedule are the result of further dose-ranging investigations (Phase II), involving more volunteers, with longer, more detailed follow-up assessments. It is at this stage that the accumulated evidence on its immunogenicity profile should be sufficient to assess whether or not the vaccine is worthy of further development. The next level of investigation (Phase III) aims to measure with greater precision the vaccine protective efficacy in the intended target population(s) by comparison of infection and/or disease attack rates in vaccine and placebo recipients. In consistency studies different production lots, manufactured at commercial scale, are tested to demonstrate consistency of manufacture. Additional bridging studies to establish similarity of lots at different production scales, or studies of the duration of the immunity conferred, are conducted in parallel with the progression of the studies in the different phases mentioned above. These latter types of studies are usually carried out concurrently with Phase III studies. This progression continues into the post-marketing period (Phase IV) with surveillance of long term efficacy and observational studies of possible rare adverse events to establish "safety" with more confidence. This paper examines, in general, the aims and designs of studies in each phase as an introduction to the more specific publications that follow.

Genetic evidence for an East Asian origin of Chinese Muslim populations Dongxiang and Hui

PubMed Central

Yao, Hong-Bing; Wang, Chuan-Chao; Tao, Xiaolan; Shang, Lei; Wen, Shao-Qing; Zhu, Bofeng; Kang, Longli; Jin, Li; Li, Hui

2016-01-01

There is a long-going debate on the genetic origin of Chinese Muslim populations, such as Uygur, Dongxiang, and Hui. However, genetic information for those Muslim populations except Uygur is extremely limited. In this study, we investigated the genetic structure and ancestry of Chinese Muslims by analyzing 15 autosomal short tandem repeats in 652 individuals from Dongxiang, Hui, and Han Chinese populations in Gansu province. Both genetic distance and Bayesian-clustering methods showed significant genetic homogeneity between the two Muslim populations and East Asian populations, suggesting a common genetic ancestry. Our analysis found no evidence of substantial gene flow from Middle East or Europe into Dongxiang and Hui people during their Islamization. The dataset generated in present study are also valuable for forensic identification and paternity tests in China. PMID:27924949

Patterns of Senescence in Human Cardiovascular Fitness: VO2max in Subsistence and Industrialized Populations

PubMed Central

Pisor, Anne C.; Gurven, Michael; Blackwell, Aaron D.; Kaplan, Hillard; Yetish, Gandhi

2014-01-01

Objectives This study explores whether cardiovascular fitness levels and senescent decline are similar in the Tsimane of Bolivia and Canadians, as well as other subsistence and industrialized populations. Among Tsimane, we examine whether morbidity predicts lower levels and faster decline of cardiovascular fitness, or whether their lifestyle (e.g., high physical activity) promotes high levels and slow decline. Alternatively, high activity levels and morbidity might counterbalance such that Tsimane fitness levels and decline are similar to those in industrialized populations. Methods Maximal oxygen uptake (VO2max) was estimated using a step test heart rate method for 701 participants. We compared these estimates to the Canadian Health Measures Survey and previous studies in industrialized and subsistence populations. We evaluated whether health indicators and proxies for market integration were associated with VO2max levels and rate of decline for the Tsimane. Results The Tsimane have significantly higher levels of VO2max and slower rates of decline than Canadians; initial evidence suggests differences in VO2max levels between other subsistence and industrialized populations. Low hemoglobin predicts low VO2max for Tsimane women while helminth infection predicts high VO2max for Tsimane men, though results might be specific to the VO2max scaling parameter used. No variables tested interact with age to moderate decline. Conclusions The Tsimane demonstrate higher levels of cardiovascular fitness than industrialized populations, but levels similar to other subsistence populations. The high VO2max of Tsimane is consistent with their high physical activity and few indicators of cardiovascular disease, measured in previous studies. PMID:24022886

Larval transport modeling of deep-sea invertebrates can aid the search for undiscovered populations.

PubMed

Yearsley, Jon M; Sigwart, Julia D

2011-01-01

Many deep-sea benthic animals occur in patchy distributions separated by thousands of kilometres, yet because deep-sea habitats are remote, little is known about their larval dispersal. Our novel method simulates dispersal by combining data from the Argo array of autonomous oceanographic probes, deep-sea ecological surveys, and comparative invertebrate physiology. The predicted particle tracks allow quantitative, testable predictions about the dispersal of benthic invertebrate larvae in the south-west Pacific. In a test case presented here, using non-feeding, non-swimming (lecithotrophic trochophore) larvae of polyplacophoran molluscs (chitons), we show that the likely dispersal pathways in a single generation are significantly shorter than the distances between the three known population centres in our study region. The large-scale density of chiton populations throughout our study region is potentially much greater than present survey data suggest, with intermediate 'stepping stone' populations yet to be discovered. We present a new method that is broadly applicable to studies of the dispersal of deep-sea organisms. This test case demonstrates the power and potential applications of our new method, in generating quantitative, testable hypotheses at multiple levels to solve the mismatch between observed and expected distributions: probabilistic predictions of locations of intermediate populations, potential alternative dispersal mechanisms, and expected population genetic structure. The global Argo data have never previously been used to address benthic biology, and our method can be applied to any non-swimming larvae of the deep-sea, giving information upon dispersal corridors and population densities in habitats that remain intrinsically difficult to assess.

Larval Transport Modeling of Deep-Sea Invertebrates Can Aid the Search for Undiscovered Populations

PubMed Central

Yearsley, Jon M.; Sigwart, Julia D.

2011-01-01

Background Many deep-sea benthic animals occur in patchy distributions separated by thousands of kilometres, yet because deep-sea habitats are remote, little is known about their larval dispersal. Our novel method simulates dispersal by combining data from the Argo array of autonomous oceanographic probes, deep-sea ecological surveys, and comparative invertebrate physiology. The predicted particle tracks allow quantitative, testable predictions about the dispersal of benthic invertebrate larvae in the south-west Pacific. Principal Findings In a test case presented here, using non-feeding, non-swimming (lecithotrophic trochophore) larvae of polyplacophoran molluscs (chitons), we show that the likely dispersal pathways in a single generation are significantly shorter than the distances between the three known population centres in our study region. The large-scale density of chiton populations throughout our study region is potentially much greater than present survey data suggest, with intermediate ‘stepping stone’ populations yet to be discovered. Conclusions/Significance We present a new method that is broadly applicable to studies of the dispersal of deep-sea organisms. This test case demonstrates the power and potential applications of our new method, in generating quantitative, testable hypotheses at multiple levels to solve the mismatch between observed and expected distributions: probabilistic predictions of locations of intermediate populations, potential alternative dispersal mechanisms, and expected population genetic structure. The global Argo data have never previously been used to address benthic biology, and our method can be applied to any non-swimming larvae of the deep-sea, giving information upon dispersal corridors and population densities in habitats that remain intrinsically difficult to assess. PMID:21857992

Do gifts increase consent to home-based HIV testing? A difference-in-differences study in rural KwaZulu-Natal, South Africa.

PubMed

McGovern, Mark E; Herbst, Kobus; Tanser, Frank; Mutevedzi, Tinofa; Canning, David; Gareta, Dickman; Pillay, Deenan; Bärnighausen, Till

2016-12-01

Despite the importance of HIV testing for controlling the HIV epidemic, testing rates remain low. Efforts to scale up testing coverage and frequency in hard-to-reach and at-risk populations commonly focus on home-based HIV testing. This study evaluates the effect of a gift (a US$5 food voucher for families) on consent rates for home-based HIV testing. We use data on 18 478 individuals (6 418 men and 12 060 women) who were successfully contacted to participate in the 2009 and 2010 population-based HIV surveillance carried out by the Wellcome Trust's Africa Health Research Institute in rural KwaZulu-Natal, South Africa. Of 18 478 potential participants contacted in both years, 35% (6 518) consented to test in 2009, and 41% (7 533) consented to test in 2010. Our quasi-experimental difference-in-differences approach controls for unobserved confounding in estimating the causal effect of the intervention on HIV-testing consent rates. Allocation of the gift to a family in 2010 increased the probability of family members consenting to test in the same year by 25 percentage points [95% confidence interval (CI) 21-30 percentage points; P  < 0.001]. The intervention effect persisted, slightly attenuated, in the year following the intervention (2011). In HIV hyperendemic settings, a gift can be highly effective at increasing consent rates for home-based HIV testing. Given the importance of HIV testing for treatment uptake and individual health, as well as for HIV treatment-as-prevention strategies and for monitoring the population impact of the HIV response, gifts should be considered as a supportive intervention for HIV-testing initiatives where consent rates have been low. © The Author 2016. Published by Oxford University Press on behalf of the International Epidemiological Association

Cost-effectiveness of population based BRCA testing with varying Ashkenazi Jewish ancestry.

PubMed

Manchanda, Ranjit; Patel, Shreeya; Antoniou, Antonis C; Levy-Lahad, Ephrat; Turnbull, Clare; Evans, D Gareth; Hopper, John L; Macinnis, Robert J; Menon, Usha; Jacobs, Ian; Legood, Rosa

2017-11-01

Population-based BRCA1/BRCA2 testing has been found to be cost-effective compared with family history-based testing in Ashkenazi-Jewish women were >30 years old with 4 Ashkenazi-Jewish grandparents. However, individuals may have 1, 2, or 3 Ashkenazi-Jewish grandparents, and cost-effectiveness data are lacking at these lower BRCA prevalence estimates. We present an updated cost-effectiveness analysis of population BRCA1/BRCA2 testing for women with 1, 2, and 3 Ashkenazi-Jewish grandparents. Decision analysis model. Lifetime costs and effects of population and family history-based testing were compared with the use of a decision analysis model. 56% BRCA carriers are missed by family history criteria alone. Analyses were conducted for United Kingdom and United States populations. Model parameters were obtained from the Genetic Cancer Prediction through Population Screening trial and published literature. Model parameters and BRCA population prevalence for individuals with 3, 2, or 1 Ashkenazi-Jewish grandparent were adjusted for the relative frequency of BRCA mutations in the Ashkenazi-Jewish and general populations. Incremental cost-effectiveness ratios were calculated for all Ashkenazi-Jewish grandparent scenarios. Costs, along with outcomes, were discounted at 3.5%. The time horizon of the analysis is "life-time," and perspective is "payer." Probabilistic sensitivity analysis evaluated model uncertainty. Population testing for BRCA mutations is cost-saving in Ashkenazi-Jewish women with 2, 3, or 4 grandparents (22-33 days life-gained) in the United Kingdom and 1, 2, 3, or 4 grandparents (12-26 days life-gained) in the United States populations, respectively. It is also extremely cost-effective in women in the United Kingdom with just 1 Ashkenazi-Jewish grandparent with an incremental cost-effectiveness ratio of £863 per quality-adjusted life-years and 15 days life gained. Results show that population-testing remains cost-effective at the £20,000-30000 per quality-adjusted life-years and $100,000 per quality-adjusted life-years willingness-to-pay thresholds for all 4 Ashkenazi-Jewish grandparent scenarios, with ≥95% simulations found to be cost-effective on probabilistic sensitivity analysis. Population-testing remains cost-effective in the absence of reduction in breast cancer risk from oophorectomy and at lower risk-reducing mastectomy (13%) or risk-reducing salpingo-oophorectomy (20%) rates. Population testing for BRCA mutations with varying levels of Ashkenazi-Jewish ancestry is cost-effective in the United Kingdom and the United States. These results support population testing in Ashkenazi-Jewish women with 1-4 Ashkenazi-Jewish grandparent ancestry. Copyright © 2017 Elsevier Inc. All rights reserved.

A minimum version of log-rank test for testing the existence of cancer cure using relative survival data.

PubMed

Yu, Binbing

2012-01-01

Cancer survival is one of the most important measures to evaluate the effectiveness of treatment and early diagnosis. The ultimate goal of cancer research and patient care is the cure of cancer. As cancer treatments progress, cure becomes a reality for many cancers if patients are diagnosed early and get effective treatment. If a cure does exist for a certain type of cancer, it is useful to estimate the time of cure. For cancers that impose excess risk of mortality, it is informative to understand the difference in survival between cancer patients and the general cancer-free population. In population-based cancer survival studies, relative survival is the standard measure of excess mortality due to cancer. Cure is achieved when the survival of cancer patients is equivalent to that of the general population. This definition of cure is usually called the statistical cure, which is an important measure of burden due to cancer. In this paper, a minimum version of the log-rank test is proposed to test the equivalence of cancer patients' survival using the relative survival data. Performance of the proposed test is evaluated by simulation. Relative survival data from population-based cancer registries in SEER Program are used to examine patients' survival after diagnosis for various major cancer sites. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Screening for Syphilis: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.

PubMed

Cantor, Amy G; Pappas, Miranda; Daeges, Monica; Nelson, Heidi D

2016-06-07

Screening for syphilis infection is currently recommended for high-risk individuals, including those with previous syphilis infection, an infected sexual partner, HIV infection, or more than 4 sex partners in the preceding year. To update a 2004 systematic review of studies of syphilis screening effectiveness, test accuracy, and screening harms in nonpregnant adults and adolescents. Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews through October 2015 and Ovid MEDLINE (January 2004 to October 2015), with updated search through March 2016. English-language trials and observational studies of screening effectiveness, test accuracy, and screening harms in nonpregnant adults and adolescents. One investigator abstracted data, a second checked data for accuracy, and 2 investigators independently assessed study quality using predefined criteria. Transmission of disease, including HIV; complications of syphilis; diagnostic accuracy; and harms of screening. No evidence was identified regarding the effectiveness of screening on clinical outcomes or the effectiveness of risk assessment instruments; the harms of screening; or the effectiveness of screening in average-risk, nonpregnant adolescents or adults or high-risk individuals other than men who have sex with men (MSM) or men who are HIV positive. Four non-US studies indicated higher rates of syphilis detection with screening every 3 months vs 6 or 12 months for early syphilis in HIV-positive men or MSM. For example, there was an increased proportion of asymptomatic, higher-risk MSM in Australia (n = 6789 consultations) receiving a diagnosis of early syphilis when tested every 3 months vs annually (53% vs 16%, P = .001), but no difference among low-risk MSM. Treponemal and nontreponemal tests were accurate in asymptomatic individuals (sensitivity >85%, specificity >91%) in 3 studies but required confirmatory testing. Reverse sequence testing with an initial automated treponemal test yielded more false reactive test results than with rapid plasma reagin in 2 studies, one with a low-prevalence US population (0.6% vs 0.0%, P = .03) and another in a higher-prevalence Canadian population (0.26% vs 0.13%). Screening HIV-positive men or MSM for syphilis every 3 months is associated with improved syphilis detection. Treponemal or nontreponemal tests are accurate screening tests but require confirmation. Research is needed on the effect of screening on clinical outcomes; effective screening strategies, including reverse sequence screening, in various patient populations; and harms of screening.

Fine-scale patterns of population stratification confound rare variant association tests.

PubMed

O'Connor, Timothy D; Kiezun, Adam; Bamshad, Michael; Rich, Stephen S; Smith, Joshua D; Turner, Emily; Leal, Suzanne M; Akey, Joshua M

2013-01-01

Advances in next-generation sequencing technology have enabled systematic exploration of the contribution of rare variation to Mendelian and complex diseases. Although it is well known that population stratification can generate spurious associations with common alleles, its impact on rare variant association methods remains poorly understood. Here, we performed exhaustive coalescent simulations with demographic parameters calibrated from exome sequence data to evaluate the performance of nine rare variant association methods in the presence of fine-scale population structure. We find that all methods have an inflated spurious association rate for parameter values that are consistent with levels of differentiation typical of European populations. For example, at a nominal significance level of 5%, some test statistics have a spurious association rate as high as 40%. Finally, we empirically assess the impact of population stratification in a large data set of 4,298 European American exomes. Our results have important implications for the design, analysis, and interpretation of rare variant genome-wide association studies.

Fine-scale population dynamics in a marine fish species inferred from dynamic state-space models.

PubMed

Rogers, Lauren A; Storvik, Geir O; Knutsen, Halvor; Olsen, Esben M; Stenseth, Nils C

2017-07-01

Identifying the spatial scale of population structuring is critical for the conservation of natural populations and for drawing accurate ecological inferences. However, population studies often use spatially aggregated data to draw inferences about population trends and drivers, potentially masking ecologically relevant population sub-structure and dynamics. The goals of this study were to investigate how population dynamics models with and without spatial structure affect inferences on population trends and the identification of intrinsic drivers of population dynamics (e.g. density dependence). Specifically, we developed dynamic, age-structured, state-space models to test different hypotheses regarding the spatial structure of a population complex of coastal Atlantic cod (Gadus morhua). Data were from a 93-year survey of juvenile (age 0 and 1) cod sampled along >200 km of the Norwegian Skagerrak coast. We compared two models: one which assumes all sampled cod belong to one larger population, and a second which assumes that each fjord contains a unique population with locally determined dynamics. Using the best supported model, we then reconstructed the historical spatial and temporal dynamics of Skagerrak coastal cod. Cross-validation showed that the spatially structured model with local dynamics had better predictive ability. Furthermore, posterior predictive checks showed that a model which assumes one homogeneous population failed to capture the spatial correlation pattern present in the survey data. The spatially structured model indicated that population trends differed markedly among fjords, as did estimates of population parameters including density-dependent survival. Recent biomass was estimated to be at a near-record low all along the coast, but the finer scale model indicated that the decline occurred at different times in different regions. Warm temperatures were associated with poor recruitment, but local changes in habitat and fishing pressure may have played a role in driving local dynamics. More generally, we demonstrated how state-space models can be used to test evidence for population spatial structure based on survey time-series data. Our study shows the importance of considering spatially structured dynamics, as the inferences from such an approach can lead to a different ecological understanding of the drivers of population declines, and fundamentally different management actions to restore populations. © 2017 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

Prevalence of Mycoplasma genitalium in different population groups: systematic review andmeta-analysis.

PubMed

Baumann, Lukas; Cina, Manuel; Egli-Gany, Dianne; Goutaki, Myrofora; Halbeisen, Florian S; Lohrer, Gian-Reto; Ali, Hammad; Scott, Pippa; Low, Nicola

2018-06-01

Mycoplasma genitalium is a common cause of non-gonococcal non-chlamydial urethritis and cervicitis. Testing of asymptomatic populations has been proposed, but prevalence in asymptomatic populations is not well established. We aimed to estimate the prevalence of M. genitalium in the general population, pregnant women, men who have sex with men (MSM), commercial sex workers (CSWs) and clinic-based samples, METHODS: We searched Embase, Medline, IndMED, African Index Medicus and LILACS from 1 January 1991 to 12 July 2016 without language restrictions. We included studies with 500 participants or more. Two reviewers independently screened and selected studies and extracted data. We examined forest plots and conducted random-effects meta-analysis to estimate prevalence, if appropriate. Between-study heterogeneity was examined using the I 2 statistic and meta-regression. Of 3316 screened records, 63 were included. In randomly selected samples from the general population, the summary prevalence was 1.3% (95% CI 1.0% to 1.8%, I 2 41.5%, three studies, 9091 people) in countries with higher levels of development and 3.9% (95% CI 2.2 to 6.7, I 2 89.2%, three studies, 3809 people) in countries with lower levels. Prevalence was similar in women and men (P=0.47). In clinic based samples, prevalence estimates were higher, except in asymptomatic patients (0.8%, 95% CI 0.4 to 1.4, I 2 0.0%, three studies, 2889 people). Summary prevalence estimates were, in the following groups: pregnant women 0.9% (95% CI 0.6% to 1.4%, I 2 0%, four studies, 3472 people), MSM in the community 3.2% (95% CI 2.1 to 5.1, I 2 78.3%, five studies, 3012 people) and female CSWs in the community 15.9% (95% CI 13.5 to 18.9, I 2 79.9%, four studies, 4006 people). This systematic review can inform testing guidelines for M. genitalium . The low estimated prevalence of M. genitalium in the general population, pregnant women and asymptomatic attenders at clinics does not support expansion of testing to these groups. PROSPERO: CRD42015020420. © 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.

Introduction beyond a species range: a relationship between population origin, adaptive potential and plant performance.

PubMed

Volis, S; Ormanbekova, D; Yermekbayev, K; Song, M; Shulgina, I

2014-09-01

The adaptive potential of a population defines its importance for species survival in changing environmental conditions such as global climate change. Very few empirical studies have examined adaptive potential across species' ranges, namely, of edge vs core populations, and we are unaware of a study that has tested adaptive potential (namely, variation in adaptive traits) and measured performance of such populations in conditions not currently experienced by the species but expected in the future. Here we report the results of a Triticum dicoccoides population study that employed transplant experiments and analysis of quantitative trait variation. Two populations at the opposite edges of the species range (1) were locally adapted; (2) had lower adaptive potential (inferred from the extent of genetic quantitative trait variation) than the two core populations; and (3) were outperformed by the plants from the core population in the novel environment. The fact that plants from the species arid edge performed worse than plants from the more mesic core in extreme drought conditions beyond the present climatic envelope of the species implies that usage of peripheral populations for conservation purposes must be based on intensive sampling of among-population variation.

A GHEP-ISFG collaborative study on the genetic variation of 38 autosomal indels for human identification in different continental populations.

PubMed

Pereira, R; Alves, C; Aler, M; Amorim, A; Arévalo, C; Betancor, E; Braganholi, D; Bravo, M L; Brito, P; Builes, J J; Burgos, G; Carvalho, E F; Castillo, A; Catanesi, C I; Cicarelli, R M B; Coufalova, P; Dario, P; D'Amato, M E; Davison, S; Ferragut, J; Fondevila, M; Furfuro, S; García, O; Gaviria, A; Gomes, I; González, E; Gonzalez-Liñan, A; Gross, T E; Hernández, A; Huang, Q; Jiménez, S; Jobim, L F; López-Parra, A M; Marino, M; Marques, S; Martínez-Cortés, G; Masciovecchio, V; Parra, D; Penacino, G; Pinheiro, M F; Porto, M J; Posada, Y; Restrepo, C; Ribeiro, T; Rubio, L; Sala, A; Santurtún, A; Solís, L S; Souto, L; Streitemberger, E; Torres, A; Vilela-Lamego, C; Yunis, J J; Yurrebaso, I; Gusmão, L

2018-01-01

A collaborative effort was carried out by the Spanish and Portuguese Speaking Working Group of the International Society for Forensic Genetics (GHEP-ISFG) to promote knowledge exchange between associate laboratories interested in the implementation of indel-based methodologies and build allele frequency databases of 38 indels for forensic applications. These databases include populations from different countries that are relevant for identification and kinship investigations undertaken by the participating laboratories. Before compiling population data, participants were asked to type the 38 indels in blind samples from annual GHEP-ISFG proficiency tests, using an amplification protocol previously described. Only laboratories that reported correct results contributed with population data to this study. A total of 5839 samples were genotyped from 45 different populations from Africa, America, East Asia, Europe and Middle East. Population differentiation analysis showed significant differences between most populations studied from Africa and America, as well as between two Asian populations from China and East Timor. Low F ST values were detected among most European populations. Overall diversities and parameters of forensic efficiency were high in populations from all continents. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

Population movement can sustain STI prevalence in remote Australian indigenous communities.

PubMed

Hui, Ben B; Gray, Richard T; Wilson, David P; Ward, James S; Smith, Anthony M A; Philip, David J; Law, Matthew G; Hocking, Jane S; Regan, David G

2013-04-25

For almost two decades, chlamydia and gonorrhoea diagnosis rates in remote Indigenous communities have been up to 30 times higher than for non-Indigenous Australians. The high levels of population movement known to occur between remote communities may contribute to these high rates. We developed an individual-based computer simulation model to study the relationship between population movement and the persistence of gonorrhoea and chlamydia transmission within hypothetical remote communities. Results from our model suggest that short-term population movement can facilitate gonorrhoea and chlamydia persistence in small populations. By fixing the number of short-term travellers in accordance with census data, we found that these STIs can persist if at least 20% of individuals in the population seek additional partners while away from home and if the time away from home is less than 21 days. Periodic variations in travel patterns can contribute to increased sustainable levels of infection. Expanding existing STI testing and treatment programs to cater for short-term travellers is shown to be ineffective due to their short duration of stay. Testing and treatment strategies tailored to movement patterns, such as encouraging travellers to seek testing and treatment upon return from travel, will likely be more effective. High population mobility is likely to contribute to the high levels of STIs observed in remote Indigenous communities of Australia. More detailed data on mobility patterns and sexual behaviour of travellers will be invaluable for designing and assessing STI control programs in highly mobile communities.

Seroprevalence of Antibodies against Human Herpesvirus 8 in a Population of Renal Transplant Recipients at Hôtel-Dieu de Québec Hospital

PubMed Central

Delorme, S.; Houde, I.; Deschênes, L.

2003-01-01

We conducted a seroepidemiologic study to determine the prevalence of anti-human herpesvirus 8 antibodies in a renal transplant population at Hôtel-Dieu de Québec Hospital. Testing for immunoglobulin G antibodies against lytic and latent antigens was performed on serum samples from 150 renal transplant patients. Human immunodeficiency virus-positive patients with confirmed Kaposi's sarcoma were used as positive controls. None of the renal transplant patients tested positive. PMID:14605164

A comprehensive assessment of visual impairment in a population of older Americans. The SEE Study. Salisbury Eye Evaluation Project.

PubMed

Rubin, G S; West, S K; Muñoz, B; Bandeen-Roche, K; Zeger, S; Schein, O; Fried, L P

1997-03-01

The Salisbury Eye Evaluation Project is a longitudinal study of risk factors for age-related eye diseases and the impact of eye disease and visual impairment on physical disability. In this article, the authors report the prevalence of visual impairment in their population and explore the relations among the various measures of visual function. A population-based sample of 2520 residents of Salisbury, Maryland, between the ages of 65 and 84 years were enrolled in the study. Twenty-six percent of participants were black. Vision tests included best-corrected Early Treatment Diabetic Retinopathy Study acuity, Pelli-Robson contrast sensitivity with and without glare, Randot stereoacuity, and 60 degrees Humphrey visual fields. Visual function decreased linearly with age for the acuity, contrast sensitivity, glare, and visual field tests. Stereoacuity remained constant into the mid-70s and declined at an accelerating rate thereafter. Black participants had lower contrast sensitivity, reduced stereoacuity, and worse visual fields, at all ages compared to white participants; however, white participants were more sensitive to glare. The overall prevalence of visual acuity impairment in blacks was 5.6% versus 3.0% for whites, using the traditional United States definition (worse than 20/40 to better than 20/200) and 3.3% for blacks versus 1.6% for whites, using the World Health Organization definition (worse than 20/60 to 20/400). Acuity was correlated moderately with contrast sensitivity, stereoacuity, and visual fields (Spearman rho = 0.50, 0.35, and 0.34, respectively). The correlation between acuity and glare sensitivity was low (rho = 0.12). Many aspects of visual function, not just acuity, decline with age. Black participants have more visual impairement than do white participants for all tests except glare sensitivity. The prevalence of visual acuity impairement in the Salisbury Eye Evaluation population is lower than that reported by other studies using similar test procedures. Low-to-moderate correlations among vision test scores suggest that several different dimensions of visual function are being assessed.

Test-retest reliability, smallest real difference and concurrent validity of six different balance tests on young people with mild to moderate intellectual disability.

PubMed

Blomqvist, Sven; Wester, Anita; Sundelin, Gunnevi; Rehn, Börje

2012-12-01

Some studies have reported that people with intellectual disability may have reduced balance ability compared with the population in general. However, none of these studies involved adolescents, and the reliability and validity of balance tests in this population are not known. The purpose of this study was to examine the reliability of six different balance tests and to investigate their concurrent validity. Test-retest reliability assessment. All subjects were recruited from a special school for people with intellectual disability in Bollnäs, Sweden. Eighty-nine adolescents (35 females and 54 males) with mild to moderate intellectual disability with a mean age of 18 years (range 16 to 20 years). All subjects followed the same test protocol on two occasions within an 11-day period. Balance test performances. Intraclass correlation coefficients greater than 0.80 were achieved for four of the balance tests: Extended Timed Up and Go Test, Modified Functional Reach Test, One-leg Stance Test and Force Platform Test. The smallest real differences ranged from 12% to 40%; less than 20% is considered to be low. Concurrent validity among these balance tests varied between no and low correlation. The results indicate that these tests could be used to evaluate changes in balance ability over time in people with mild to moderate intellectual disability. The low concurrent validity illustrates the importance of knowing more about the influence of various sensory subsystems that are significant for balance among adolescents with intellectual disability. Copyright © 2011 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Latent tuberculosis infection in rural China: baseline results of a population-based, multicentre, prospective cohort study.

PubMed

Gao, Lei; Lu, Wei; Bai, Liqiong; Wang, Xinhua; Xu, Jinsheng; Catanzaro, Antonino; Cárdenas, Vicky; Li, Xiangwei; Yang, Yu; Du, Jiang; Sui, Hongtao; Xia, Yinyin; Li, Mufei; Feng, Boxuan; Li, Zhen; Xin, Henan; Zhao, Rong; Liu, Jianmin; Pan, Shouguo; Shen, Fei; He, Jian; Yang, Shumin; Si, Hongyan; Wang, Yi; Xu, Zuhui; Tan, Yunhong; Chen, Tianzhu; Xu, Weiguo; Peng, Hong; Wang, Zhijian; Zhu, Tao; Zhou, Feng; Liu, Haiying; Zhao, Yanlin; Cheng, Shiming; Jin, Qi

2015-03-01

Prophylactic treatment of individuals with latent Mycobacterium tuberculosis infection is an essential component of tuberculosis control in some settings. In China, the prevalence of latent tuberculosis infection, and preventive interventions against this disease, have not been systematically studied. We aimed to assess the prevalence of latent tuberculosis and its associated risk factors in rural populations in China. Between July 1, and Sept 30, 2013, we undertook a baseline survey of a population-based, multicentre, prospective cohort study of registered residents (≥5 years old) at four study sites in rural China. Eligible participants were identified by door-to-door survey with a household sampling design. We screened participants for active tuberculosis and history of tuberculosis then used a tuberculin skin test and an interferon-γ release assay (QuantiFERON [QFT]) to test for latent infection. We used odds ratios (ORs) and 95% CIs to assess variables associated with positivity of QFT and tuberculin skin tests. 21,022 (90%) of 23,483 eligible participants completed a baseline survey. Age-standardised and sex-standardised rates of skin-test positivity (≥10 mm) ranged from 15% to 42%, and QFT positivity rates ranged from 13% to 20%. Rates of positivity for the tuberculin skin test and the QFT test were low in study participants younger than 20 years and gradually increased with age (p for trend <0·0001). Rates of latent tuberculosis infection were higher for men than women (p<0·0001). Overall agreement between the tuberculin skin test and the QFT test was moderate (81·06%; kappa coefficient 0·485), with skin-test-only positive results associated with the presence of BCG scar, male sex, and ages of 60 years and older, and QFT-only positive results associated with male sex and ages of 60 years and older. On the basis of findings showing that the performance of the tuberculin skin test might be affected by various factors including BCG vaccination and age, our results suggest that the prevalence of latent tuberculosis in China might be overestimated by skin tests compared with interferon-γ release assays. The National Science and Technology Major Project of China, the Program for Changjiang Scholars and Innovative Research Team in University of China. Copyright © 2015 Elsevier Ltd. All rights reserved.

Validity Evidence for Eating Attitudes Test Scores in a Sample of Female College Athletes

ERIC Educational Resources Information Center

Doninger, Gretchen L.; Enders, Craig K.; Burnett, Kent F.

2005-01-01

The purpose of this study was to examine the psychometric properties of the 26-item Eating Attitudes Test (EAT-26; Garner, Olmsted, Bohr, & Garfinkel, 1982) using a sample of 207 female college athletes. Previous studies using nonathlete populations have supported a number of factor structures, but a series of confirmatory factor analyses…

Reliability of Total Test Scores When Considered as Ordinal Measurements

ERIC Educational Resources Information Center

Biswas, Ajoy Kumar

2006-01-01

This article studies the ordinal reliability of (total) test scores. This study is based on a classical-type linear model of observed score (X), true score (T), and random error (E). Based on the idea of Kendall's tau-a coefficient, a measure of ordinal reliability for small-examinee populations is developed. This measure is extended to large…

A Nationwide Population-Based Approach to Study Health-Related and Psychosocial Aspects of Neurofibromatosis Type 1

DTIC Science & Technology

2016-07-31

the relatively narrow focus on Wechsler’s IQ test (WAIS-IV) – a test chosen primarily due to budget constraints. Thus, to meet the requests from the...consultants allows us to re-allocate financial resources to address the limitations of our study 7 raised by the reviewers. Jens Richardt Møllegaard

A normative study of the Children's Color Trails Test (CCTT) in the Cypriot population.

PubMed

Konstantopoulos, K; Vogazianos, P; Thodi, C; Nikopoulou-Smyrni, P

2015-01-01

The Children's Color Trails Test (CCTT) is a neuropsychological test that measures attention, divided attention, and speed of mental processing. It has been increasingly used in the assessment of children in cross-cultural environments for neurological and psychiatric disorders such as seizures and closed head injuries, learning and/or language disabilities, attention deficit/hyperactivity disorder, children with manganese exposure, and children diagnosed with HIV virus. However, there is a paucity of studies presenting normative data. The aim of the present study was to provide normative data for the CCTT in the Cypriot population. A total of 709 native Cypriot children aged 7-16 years, recruited from various public schools across the island, took part in the study. Exclusion criteria involved the existence of neurological, psychiatric, cardiological, and metabolic diseases, premature birth, history of maternal alcohol and drug abuse during pregnancy, low birth weight, hearing loss, visual problems, native language other than Greek, and abnormality in fine-motor movements. Age and gender were found to be important factors for the interpretation of scores in all CCTT variables. Older children required less time and exhibited fewer errors, near misses, and prompts compared to younger children. There was a consistent pattern of a 3-4 seconds improvement (less time in seconds) in the CCTT completion time as age increased. CCTT is a promising tool for the measurement of attention in the native Cypriot population. Further research is needed in children diagnosed with various neurological and psychiatric diseases in order to estimate validity of the CCTT in clinical populations.

Self-reported quality of life measure is reliable and valid in adult patients suffering from schizophrenia with executive impairment.

PubMed

Baumstarck, Karine; Boyer, Laurent; Boucekine, Mohamed; Aghababian, Valérie; Parola, Nathalie; Lançon, Christophe; Auquier, Pascal

2013-06-01

Impaired executive functions are among the most widely observed in patients suffering from schizophrenia. The use of self-reported outcomes for evaluating treatment and managing care of these patients has been questioned. The aim of this study was to provide new evidence about the suitability of self-reported outcome for use in this specific population by exploring the internal structure, reliability and external validity of a specific quality of life (QoL) instrument, the Schizophrenia Quality of Life questionnaire (SQoL18). cross-sectional study. age over 18 years, diagnosis of schizophrenia according to the DSM-IV criteria. sociodemographic (age, gender, and education level) and clinical data (duration of illness, Positive and Negative Syndrome Scale, Calgary Depression Scale for Schizophrenia); QoL (SQoL18); and executive performance (Stroop test, lexical and verbal fluency, and trail-making test). Non-impaired and impaired populations were defined for each of the three tests. For the six groups, psychometric properties were compared to those reported from the reference population assessed in the validation study. One hundred and thirteen consecutive patients were enrolled. The factor analysis performed in the impaired groups showed that the questionnaire structure adequately matched the initial structure of the SQoL18. The unidimensionality of the dimensions was preserved, and the internal/external validity indices were close to those of the non-impaired groups and the reference population. Our study suggests that executive dysfunction did not compromise the reliability or validity of self-reported disease-specific QoL questionnaire. Copyright © 2013 Elsevier B.V. All rights reserved.

Using Y-Chromosomal Haplogroups in Genetic Association Studies and Suggested Implications.

PubMed

Erzurumluoglu, A Mesut; Baird, Denis; Richardson, Tom G; Timpson, Nicholas J; Rodriguez, Santiago

2018-01-22

Y-chromosomal (Y-DNA) haplogroups are more widely used in population genetics than in genetic epidemiology, although associations between Y-DNA haplogroups and several traits, including cardiometabolic traits, have been reported. In apparently homogeneous populations defined by principal component analyses, there is still Y-DNA haplogroup variation which will result from population history. Therefore, hidden stratification and/or differential phenotypic effects by Y-DNA haplogroups could exist. To test this, we hypothesised that stratifying individuals according to their Y-DNA haplogroups before testing for associations between autosomal single nucleotide polymorphisms (SNPs) and phenotypes will yield difference in association. For proof of concept, we derived Y-DNA haplogroups from 6537 males from two epidemiological cohorts, Avon Longitudinal Study of Parents and Children (ALSPAC) ( n = 5080; 816 Y-DNA SNPs) and the 1958 Birth Cohort ( n = 1457; 1849 Y-DNA SNPs), and studied the robust associations between 32 SNPs and body mass index (BMI), including SNPs in or near Fat Mass and Obesity-associated protein ( FTO ) which yield the strongest effects. Overall, no association was replicated in both cohorts when Y-DNA haplogroups were considered and this suggests that, for BMI at least, there is little evidence of differences in phenotype or SNP association by Y-DNA structure. Further studies using other traits, phenome-wide association studies (PheWAS), other haplogroups and/or autosomal SNPs are required to test the generalisability and utility of this approach.

Are RA patients from a non-endemic HCV population screened for HCV? A cross-sectional analysis of three different settings.

PubMed

Skinner-Taylor, Cassandra Michelle; Erhard-Ramírez, Alejandro; Garza-Elizondo, Mario Alberto; Esquivel-Valerio, Jorge Antonio; Abud-Mendoza, Carlos; Martínez-Martínez, Marco Ulises; Vega-Morales, David; Arana-Guajardo, Ana

In Mexico, other risk factors are associated with hepatitis C virus (HCV): prior heroin users, living alone, widower, and northern region residence. Rheumatoid arthritis (RA) patients are considered immunosuppressed and HCV testing is recommended before treatment. The aim of the study was to describe the characteristics of HCV testing in RA patients in three different medical care settings in a non-endemic area. A retrospective observational study was performed using medical records from 960 RA patients describing the indications for HCV testing. The test was performed in 28.6% and the HCV overall frequency was 0.36%. Population characteristics were not associated with an increased risk of HCV infection; therefore, anti-HCV positivity was low. The main reason for testing was before starting biological agents. Due to the low pre-test probability, testing for HCV infection should be personalized; i.e., according to disease prevalence in a particular geographical location and the individual risk factors. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

Toxicity and bioaccumulation of sediment-associated contaminants using freshwater invertebrates: A review of methods and applications

USGS Publications Warehouse

Ingersoll, C.G.; Ankley, G.T.; Benoit, D.A.; Brunson, E.L.; Burton, G.A.; Dwyer, F.J.; Hoke, R.A.; Landrum, P.F.; Norberg-King, T. J.; Winger, P.V.

1995-01-01

This paper reviews recent developments in methods for evaluating the toxicity and bioaccumulation of contaminants associated with freshwater sediments and summarizes example case studies demonstrating the application of these methods. Over the past decade, research has emphasized development of more specific testing procedures for conducting 10-d toxicity tests with the amphipod Hyalella azteca and the midge Chironomus tentans. Toxicity endpoints measured in these tests are survival for H. azteca and survival and growth for C. tentans. Guidance has also been developed for conducting 28-d bioaccumulation tests with the oligochaete Lumbriculus variegatus, including determination of bioaccumulation kinetics for different compound classes. These methods have been applied to a variety of sediments to address issues ranging from site assessments to bioavailability of organic and inorganic contaminants using field-collected and laboratory-spiked samples. Survival and growth of controls routinely meet or exceed test acceptability criteria. Results of laboratory bioaccumulation studies with L. variegatus have been confirmed with comparisons to residues (PCBs, PAHs, DDT) present from synoptically collected field populations of oligochaetes. Additional method development is currently underway to develop chronic toxicity tests and to provide additional data-confirming responses observed in laboratory sediment tests with natural benthic populations.

Source-sink dynamics sustain central stonerollers (Campostoma anomalum) in a heavily urbanized catchment

Treesearch

Eric R. Waits; Mark J. Bagley; Michael J. Blum; Frank H. McCormick; James M. Lazorchak

2008-01-01

Relating local demographic processes to spatial structure (e.g. habitat heterogeneity) is essential for understanding population and species persistence (Hanski & Gilpin, 1997; Fagan, 2002). Yet few studies have tested general hypotheses about the importance of spatial patterns in determining population dynamics within river­stream networks (Lowe, Likens &...

Gene flow in complex landscapes: Testing multiple hypotheses with causal modeling

Treesearch

Samuel A. Cushman; Kevin S. McKelvey; Jim Hayden; Michael K. Schwartz

2006-01-01

Predicting population-level effects of landscape change depends on identifying factors that influence population connectivity in complex landscapes. However, most putative movement corridors and barriers have not been based on empirical data. In this study, we identify factors that influence connectivity by comparing patterns of genetic similarity among 146 black bears...

Meta-Analysis of Explicit Memory Studies in Populations with Intellectual Disability

ERIC Educational Resources Information Center

Lifshitz, Hefziba; Shtein, Sarit; Weiss, Izhak; Vakil, Eli

2011-01-01

This meta-analysis combines the effect size (ES) of 40 explicit memory experiments in populations with intellectual disability (ID). Eight meta-analyses were performed, as well as contrast tests between ES. The explicit memory of participants with ID was inferior to that of participants with typical development (TD). Relatively preserved explicit…

Establishing the Validity of the Task-Based English Speaking Test (TBEST) for International Teaching Assistants

ERIC Educational Resources Information Center

Witt, Autumn Song

2010-01-01

This dissertation follows an oral language assessment tool from initial design and implementation to validity analysis. The specialized variables of this study are the population: international teaching assistants and the purpose: spoken assessment as a hiring prerequisite. However, the process can easily be applied to other populations and…

Sustainability Behaviors among College Students: An Application of the VBN Theory

ERIC Educational Resources Information Center

Whitley, Cameron T.; Takahashi, Bruno; Zwickle, Adam; Besley, John C.; Lertpratchya, Alisa P.

2018-01-01

While Value-Belief-Norm (VBN) theory has been widely applied to various populations, it has seldom been tested on college students. This study extends VBN theory to examine what socio-psychological factors influence sustainability behaviors among university students. Undergraduate students are an interesting and novel population, as they are still…

Deleterious BRCA1/2 mutations in an urban population of Black women

PubMed Central

Smith, Karen Lisa; Stein, Julie; DeMarco, Tiffani; Wang, Yiru; Wang, Hongkun; Fries, Melissa; Peshkin, Beth N.; Isaacs, Claudine

2018-01-01

Information on the prevalence of deleterious BRCA1 and BRCA2 (BRCA1/2) mutations in clinic-based populations of Black women is limited. In order to address this gap, we performed a retrospective study to determine the prevalence of deleterious BRCA1/2 mutations, predictors of having a mutation, and acceptance of risk-reducing surgeries in Black women. In an urban unselected clinic-based population, we evaluated 211 self-identified Black women who underwent genetic counseling for hereditary breast–ovarian cancer syndrome. BRCA1/2 mutations were identified in 13.4 % of the participants who received genetic testing. Younger age at diagnosis, higher BRCA-PRO score, significant family history, and diagnosis of triple-negative breast cancer were associated with identification of a BRCA1/2 mutation. Of the affected patients found to have a deleterious mutation, almost half underwent prophylactic measures. In our study population, 1 in 7 Black women who underwent genetic testing harbored a deleterious BRCA1/2 mutation independent of age at diagnosis or family history. PMID:26250392

Project TwEATs: a feasibility study testing the use of automated text messaging to monitor appetite ratings in a free-living population

PubMed Central

Schembre, Susan M.; Yuen, Jessica

2011-01-01

There are no standardized methods for monitoring appetite in free-living populations. Fifteen participants tested a computer-automated text-messaging system designed to track hunger ratings over seven days. Participants were sent text-messages (SMS) hourly and instructed to reply during waking hours with their current hunger rating. Of 168 SMS, 0.6-7.1% were undelivered, varying by mobile service provider, On average 12 SMS responses were received daily with minor variations by observation day or day of the week. Compliance was over 74% and 93% of the ratings were received within 30-minutes. Automated text-messaging is a feasible method to monitor appetite ratings in this population. PMID:21251941

High burden of STI and HIV in male sex workers working as internet escorts for men in an observational study: a hidden key population compared with female sex workers and other men who have sex with men.

PubMed

Verhaegh-Haasnoot, Amanja; Dukers-Muijrers, Nicole H T M; Hoebe, Christian J P A

2015-07-29

Male sex work in the western countries has changed, including now a subculture of male sex workers who have paid sex with men arranged for via the internet. The men involved in this subculture do not easily identify themselves as sex workers nor as homosexual, and are therefore missed by regular health care and public health interventions. These male sex workers may form a hidden key population for sexually transmitted infections (STIs) and HIV, bridging towards other persons outside this context. This clinic-based observational study included consultations by male sex workers (n = 212), female sex workers (n = 801) and in men having sex with men who did not report being paid for sexual contacts (MSM, n = 2703) who received STI and HIV testing and counselling at our clinic during the study period. In this study we compare the consultations in male sex workers to those in in female sex workers and MSM. Demographic characteristics and sexual behaviour of the male sex workers, female sex workers and MSM were compared using chi-square tests and non-parametric tests. Using univariate and multivariate regression analyses, determinants for STI positivity in male sex workers were evaluated. Male sex workers tested positive for STI (including HIV) in 40 % of the consultations; female sex workers and MSM respectively in 9 and 14 % of the consultations. A new HIV infection was found in 8 % of the consultations of male sex workers. Male sex workers were a young population of migrant sex workers from Eastern Europe. They reported more often to also have sex contacts with women and other sex workers. Male sex workers are at a higher risk for one or more new STI than female sex workers and other MSM, even after correction for age, ethnicity, known HIV positivity and behavioural variables. Male sex workers form a hidden key population that impacts the transmission of STI and HIV within the MSM population and, possibly, to the heterosexual population. They require specific targeted interventions. Although targeting male sex workers is labour intensive it is feasible and important to reduce STI transmission.

A population-based study of demographical variables and ability to perform activities of daily living in adults with osteogenesis imperfecta.

PubMed

Wekre, Lena Lande; Frøslie, Kathrine Frey; Haugen, Lena; Falch, Jan A

2010-01-01

To describe demographical variables, and to study functional ability to perform activities of daily life in adults with osteogenesis imperfecta (OI). Population-based study. Ninety-seven patients aged 25 years and older, 41 men and 56 women, were included. For the demographical variables, comparison was made to a matched control-group (475 persons) from the Norwegian general population. Structured interviews concerning social conditions, employment and educational issues and clinical examination were performed. The Sunnaas Activities of Daily Living (ADL) Index was used to assess the ability to perform ADL. The prevalence of clinical manifestations according to Sillence was in accordance with other studies. Demographical variables showed that most adults with OI are married and have children. They had a higher educational level than the control group, but the employment rate was significantly lower. However, the rate of employed men was similar in both groups. Adult persons with OI achieved a high score when tested for ADL. Adults with OI are well educated compared with the general population, and most of them are employed. High scores when tested for ADL indicate that most of them are able to live their lives independently, even though there are some differences according to the severity of the disorder.

No evidence of critical slowing down in two endangered Hawaiian honeycreepers

PubMed Central

Camp, Richard J.; Reed, J. Michael

2017-01-01

There is debate about the current population trends and predicted short-term fates of the endangered forest birds, Hawai`i Creeper (Loxops mana) and Hawai`i `Ākepa (L. coccineus). Using long-term population size estimates, some studies report forest bird populations as stable or increasing, while other studies report signs of population decline or impending extinction associated with introduced Japanese White-eye (Zosterops japonicus) increase. Reliable predictors of impending population collapse, well before the collapse begins, have been reported in simulations and microcosm experiments. In these studies, statistical indicators of critical slowing down, a phenomenon characterized by longer recovery rates after population size perturbation, are reported to be early warning signals of an impending regime shift observable prior to the tipping point. While the conservation applications of these metrics are commonly discussed, early warning signal detection methods are rarely applied to population size data from natural populations, so their efficacy and utility in species management remain unclear. We evaluated two time series of state-space abundance estimates (1987–2012) from Hakalau Forest National Wildlife Refuge, Hawai`i to test for evidence of early warning signals of impending population collapse for the Hawai`i Creeper and Hawai`i `Ākepa. We looked for signals throughout the time series, and prior to 2000, when white-eye abundance began increasing. We found no evidence for either species of increasing variance, autocorrelation, or skewness, which are commonly reported early warning signals. We calculated linear rather than ordinary skewness because the latter is biased, particularly for small sample sizes. Furthermore, we identified break-points in trends over time for both endangered species, indicating shifts in slopes away from strongly increasing trends, but they were only weakly supported by Bayesian change-point analyses (i.e., no step-wise changes in abundance). The break-point and change-point test results, in addition to the early warning signal analyses, support that the two populations do not appear to show signs of critical slowing down or decline. PMID:29131835

No evidence of critical slowing down in two endangered Hawaiian honeycreepers

USGS Publications Warehouse

Rozek, Jessica C.; Camp, Richard J.; Reed, J. Michael

2017-01-01

There is debate about the current population trends and predicted short-term fates of the endangered forest birds, Hawai`i Creeper (Loxops mana) and Hawai`i `Ākepa (L. coccineus). Using long-term population size estimates, some studies report forest bird populations as stable or increasing, while other studies report signs of population decline or impending extinction associated with introduced Japanese White-eye (Zosterops japonicus) increase. Reliable predictors of impending population collapse, well before the collapse begins, have been reported in simulations and microcosm experiments. In these studies, statistical indicators of critical slowing down, a phenomenon characterized by longer recovery rates after population size perturbation, are reported to be early warning signals of an impending regime shift observable prior to the tipping point. While the conservation applications of these metrics are commonly discussed, early warning signal detection methods are rarely applied to population size data from natural populations, so their efficacy and utility in species management remain unclear. We evaluated two time series of state-space abundance estimates (1987–2012) from Hakalau Forest National Wildlife Refuge, Hawai`i to test for evidence of early warning signals of impending population collapse for the Hawai`i Creeper and Hawai`i `Ākepa. We looked for signals throughout the time series, and prior to 2000, when white-eye abundance began increasing. We found no evidence for either species of increasing variance, autocorrelation, or skewness, which are commonly reported early warning signals. We calculated linear rather than ordinary skewness because the latter is biased, particularly for small sample sizes. Furthermore, we identified break-points in trends over time for both endangered species, indicating shifts in slopes away from strongly increasing trends, but they were only weakly supported by Bayesian change-point analyses (i.e., no step-wise changes in abundance). The break-point and change-point test results, in addition to the early warning signal analyses, support that the two populations do not appear to show signs of critical slowing down or decline.

Diagnostic performance of HbA1c for diabetes in Arab vs. European populations: a systematic review and meta-analysis.

PubMed

Bertran, E A; Berlie, H D; Taylor, A; Divine, G; Jaber, L A

2017-02-01

To examine differences in the performance of HbA 1c for diagnosing diabetes in Arabs compared with Europeans. The PubMed, Embase and Cochrane library databases were searched for records published between 1998 and 2015. Estimates of sensitivity, specificity and log diagnostic odds ratios for an HbA 1c cut-point of 48 mmol/mol (6.5%) were compared between Arabs and Europeans, using a bivariate linear mixed-model approach. For studies reporting multiple cut-points, population-specific summary receiver operating characteristic (SROC) curves were constructed. In addition, sensitivity, specificity and Youden Index were estimated for strata defined by HbA 1c cut-point and population type. Database searches yielded 1912 unique records; 618 full-text articles were reviewed. Fourteen studies met the inclusion criteria; hand-searching yielded three additional eligible studies. Three Arab (N = 2880) and 16 European populations (N = 49 127) were included in the analysis. Summary sensitivity and specificity for a HbA 1c cut-point of 48 mmol/mol (6.5%) in both populations were 42% (33-51%), and 97% (95-98%). There was no difference in area under SROC curves between Arab and European populations (0.844 vs. 0.847; P = 0.867), suggesting no difference in HbA 1c diagnostic accuracy between populations. Multiple cut-point summary estimates stratified by population suggest that Arabs have lower sensitivity and higher specificity at a HbA 1c cut-point of 44 mmol/mol (6.2%) compared with European populations. Estimates also suggest similar test performance at cut-points of 44 mmol/mol (6.2%) and 48 mmol/mol (6.5%) for Arabs. Given the low sensitivity of HbA 1c in the high-risk Arab American population, we recommend a combination of glucose-based and HbA 1c testing to ensure an accurate and timely diagnosis of diabetes. © 2016 Diabetes UK.

Evolution and ecology meet molecular genetics: adaptive phenotypic plasticity in two isolated Negev desert populations of Acacia raddiana at either end of a rainfall gradient

PubMed Central

Ward, David; Shrestha, Madan K.; Golan-Goldhirsh, Avi

2012-01-01

Background and Aims The ecological, evolutionary and genetic bases of population differentiation in a variable environment are often related to the selection pressures that plants experience. We compared differences in several growth- and defence-related traits in two isolated populations of Acacia raddiana trees from sites at either end of an extreme environmental gradient in the Negev desert. Methods We used random amplified polymorphic DNA (RAPD) to determine the molecular differences between populations. We grew plants under two levels of water, three levels of nutrients and three levels of herbivory to test for phenotypic plasticity and adaptive phenotypic plasticity. Key Results The RAPD analyses showed that these populations are highly genetically differentiated. Phenotypic plasticity in various morphological traits in A. raddiana was related to patterns of population genetic differentiation between the two study sites. Although we did not test for maternal effects in these long-lived trees, significant genotype × environment (G × E) interactions in some of these traits indicated that such plasticity may be adaptive. Conclusions The main selection pressure in this desert environment, perhaps unsurprisingly, is water. Increased water availability resulted in greater growth in the southern population, which normally receives far less rain than the northern population. Even under the conditions that we defined as low water and/or nutrients, the performance of the seedlings from the southern population was significantly better, perhaps reflecting selection for these traits. Consistent with previous studies of this genus, there was no evidence of trade-offs between physical and chemical defences and plant growth parameters in this study. Rather, there appeared to be positive correlations between plant size and defence parameters. The great variation in several traits in both populations may result in a diverse potential for responding to selection pressures in different environments. PMID:22039007

Testing the effect of the Himalayan mountains as a physical barrier to gene flow in Hippophae tibetana Schlect. (Elaeagnaceae)

PubMed Central

Qiong, La; Zhang, Wenju; Wang, Hao; Zeng, Liyan; Birks, H. John B.; Zhong, Yang

2017-01-01

Hippophae tibetana is a small, dioecious wind-pollinated shrub endemic to the Tibetan-Qinghai Plateau. It is one of the shrubs that occur at very high elevations (5250 m a.s.l.). The Himalayan mountains provides a significant geographical barrier to the Qinghai-Tibetan Plateau, dividing the Himalayan area into two regions with Nepal to the south and Tibet to the north. There is no information on how the Himalayan mountains influence gene flow and population differentiation of alpine plants. In this study, we analyzed eight nuclear microsatellite markers and cpDNA trnT-trnF regions to test the role of the Himalayan mountains as a barrier to gene flow between populations of H. tibetana. We also examined the fine-scale genetic structure within a population of H. tibetana on the north slope of Mount (Mt.) Everest. For microsatellite analyses, a total of 241 individuals were sampled from seven populations in our study area (4 from Nepal, 3 from Tibet), including 121 individuals that were spatially mapped within a 100 m × 100 m plot. To test for seed flow, the cpDNA trnT-trnF regions of 100 individuals from 6 populations (4 from Nepal, 2 from Tibet) were also sequenced. Significant genetic differentiation was detected between the two regions by both microsatellite and cpDNA data analyses. These two datasets agree about southern and northern population differentiation, indicating that the Himalayan mountains represent a barrier to H. tibetana limiting gene flow between these two areas. At a fine scale, spatial autocorrelation analysis suggests significant genetic structure within a distance of less than 45 m, which may be attributed mainly to vegetative reproduction and habitat fragmentation, as well as limited gene flow. PMID:28489850

Testing the effect of the Himalayan mountains as a physical barrier to gene flow in Hippophae tibetana Schlect. (Elaeagnaceae).

PubMed

Qiong, La; Zhang, Wenju; Wang, Hao; Zeng, Liyan; Birks, H John B; Zhong, Yang

2017-01-01

Hippophae tibetana is a small, dioecious wind-pollinated shrub endemic to the Tibetan-Qinghai Plateau. It is one of the shrubs that occur at very high elevations (5250 m a.s.l.). The Himalayan mountains provides a significant geographical barrier to the Qinghai-Tibetan Plateau, dividing the Himalayan area into two regions with Nepal to the south and Tibet to the north. There is no information on how the Himalayan mountains influence gene flow and population differentiation of alpine plants. In this study, we analyzed eight nuclear microsatellite markers and cpDNA trnT-trnF regions to test the role of the Himalayan mountains as a barrier to gene flow between populations of H. tibetana. We also examined the fine-scale genetic structure within a population of H. tibetana on the north slope of Mount (Mt.) Everest. For microsatellite analyses, a total of 241 individuals were sampled from seven populations in our study area (4 from Nepal, 3 from Tibet), including 121 individuals that were spatially mapped within a 100 m × 100 m plot. To test for seed flow, the cpDNA trnT-trnF regions of 100 individuals from 6 populations (4 from Nepal, 2 from Tibet) were also sequenced. Significant genetic differentiation was detected between the two regions by both microsatellite and cpDNA data analyses. These two datasets agree about southern and northern population differentiation, indicating that the Himalayan mountains represent a barrier to H. tibetana limiting gene flow between these two areas. At a fine scale, spatial autocorrelation analysis suggests significant genetic structure within a distance of less than 45 m, which may be attributed mainly to vegetative reproduction and habitat fragmentation, as well as limited gene flow.

The Prevalence of E-Cigarette Use in a Sample of U.S. Air Force Recruits

PubMed Central

Little, Melissa A.; Derefinko, Karen J.; Colvin, Lauren; Ebbert, Jon O.; Bursac, Zoran; Talcott, Gerald W.; Richey, Phyllis A.; Klesges, Robert C.

2015-01-01

Introduction The prevalence of electronic cigarette (e-cigarette) use is increasing markedly in the general population. Yet, remarkably little research exists to examine these ongoing trends in at-risk populations, and nothing is known about the prevalence of e-cigarette use among military personnel. The purpose of the current study is to provide recent (2013–2014) data on the prevalence of regular e-cigarette use in a population of recruits prior to their entry into the U.S. military. Methods The study utilized a cross-sectional assessment of e-cigarette and other tobacco and nicotine–containing product (TNCP) use in 2013–2014 among 10,043 U.S. Air Force (USAF) recruits in Technical Training. Chi-square tests, the Cochran–Armitage test for trend, and logistic regression models tested differences and trends across time for e-cigarette use. Results The rate of e-cigarette use among recruits was 5.2%, which doubled (3% to 6.5%, p<0.0001) across a 1-year period. E-cigarette use was associated with increased odds of all measured TNCPs, as well as dual and poly use (all p<0.0001). Conclusions Rates of e-cigarette use are slightly higher in young USAF recruits than in the general population, and e-cigarette users are likely to be using other TNCPs in tandem. Although additional work is needed to understand the reasons for this concomitant use, this is a necessary first step to understanding e-cigarette use prevalence in military populations. Historic trends suggest that, like general populations, e-cigarette use is on the rise for those entering the USAF and should be monitored to inform future prevention programming. PMID:25896193

Penicillin skin testing in cardiac surgery.

PubMed

Cook, David J; Barbara, David W; Singh, Karen E; Dearani, Joseph A

2014-06-01

Penicillin is the most commonly reported allergy in cardiac surgical patients and a history of penicillin allergy frequently results in the use of vancomycin for antibiotic prophylaxis. However, clinical history is unreliable and true allergy is rare. Penicillin allergy testing has the potential to reduce vancomycin use and indirectly the potential for selection of vancomycin-resistant organisms, a national priority. After the publication of the 2007 Society of Thoracic Surgeons practice guideline report, we initiated a penicillin allergy testing service for cardiac surgical patients in 2009. We sought to determine the true incidence of penicillin allergy in the tested population, whether testing availability reduced vancomycin use in those tested, and if vancomycin use was reduced in the entire cardiac surgical population as a whole. A total of 276 patients were skin tested for allergy to penicillin or cephalosporin. Testing recommended no penicillin use in 13.8% of those tested giving a true penicillin allergy incidence of 0.9%. Only 24 of the 276 patients tested (9%) received vancomycin. However, given the small percentage of the total population that underwent allergy testing, the overall use of vancomycin in the cardiac surgery practice was not reduced in the posttesting period. The true rate of contraindication to penicillin in a cardiac surgical population is very low. Penicillin allergy testing can reduce vancomycin use in the tested population, but better means of conducting the testing and making the results available are necessary to reduce unnecessary vancomycin use in a broader cardiac surgical population. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

A Population Genetic Signal of Polygenic Adaptation

PubMed Central

Berg, Jeremy J.; Coop, Graham

2014-01-01

Adaptation in response to selection on polygenic phenotypes may occur via subtle allele frequencies shifts at many loci. Current population genomic techniques are not well posed to identify such signals. In the past decade, detailed knowledge about the specific loci underlying polygenic traits has begun to emerge from genome-wide association studies (GWAS). Here we combine this knowledge from GWAS with robust population genetic modeling to identify traits that may have been influenced by local adaptation. We exploit the fact that GWAS provide an estimate of the additive effect size of many loci to estimate the mean additive genetic value for a given phenotype across many populations as simple weighted sums of allele frequencies. We use a general model of neutral genetic value drift for an arbitrary number of populations with an arbitrary relatedness structure. Based on this model, we develop methods for detecting unusually strong correlations between genetic values and specific environmental variables, as well as a generalization of comparisons to test for over-dispersion of genetic values among populations. Finally we lay out a framework to identify the individual populations or groups of populations that contribute to the signal of overdispersion. These tests have considerably greater power than their single locus equivalents due to the fact that they look for positive covariance between like effect alleles, and also significantly outperform methods that do not account for population structure. We apply our tests to the Human Genome Diversity Panel (HGDP) dataset using GWAS data for height, skin pigmentation, type 2 diabetes, body mass index, and two inflammatory bowel disease datasets. This analysis uncovers a number of putative signals of local adaptation, and we discuss the biological interpretation and caveats of these results. PMID:25102153

Statistical analyses of the relative risk.

PubMed Central

Gart, J J

1979-01-01

Let P1 be the probability of a disease in one population and P2 be the probability of a disease in a second population. The ratio of these quantities, R = P1/P2, is termed the relative risk. We consider first the analyses of the relative risk from retrospective studies. The relation between the relative risk and the odds ratio (or cross-product ratio) is developed. The odds ratio can be considered a parameter of an exponential model possessing sufficient statistics. This permits the development of exact significance tests and confidence intervals in the conditional space. Unconditional tests and intervals are also considered briefly. The consequences of misclassification errors and ignoring matching or stratifying are also considered. The various methods are extended to combination of results over the strata. Examples of case-control studies testing the association between HL-A frequencies and cancer illustrate the techniques. The parallel analyses of prospective studies are given. If P1 and P2 are small with large samples sizes the appropriate model is a Poisson distribution. This yields a exponential model with sufficient statistics. Exact conditional tests and confidence intervals can then be developed. Here we consider the case where two populations are compared adjusting for sex differences as well as for the strata (or covariate) differences such as age. The methods are applied to two examples: (1) testing in the two sexes the ratio of relative risks of skin cancer in people living in different latitudes, and (2) testing over time the ratio of the relative risks of cancer in two cities, one of which fluoridated its drinking water and one which did not. PMID:540589

The Use of Published Language Tests with the Mentally Retarded: A National Survey.

ERIC Educational Resources Information Center

Rushakoff, Gary E.; Johnson, Pamela C.

This study reports the results of a nationwide questionnaire survey of 204 speech and language clinicians from 65 facilities for mentally retarded individuals. Information was requested from clinicians about which language test they used with the mentally retarded population, why they used these tests, and how often they used them. Residential and…

T wave alternans as a predictor of recurrent ventricular tachyarrhythmias in ICD recipients: prospective comparison with conventional risk markers

NASA Technical Reports Server (NTRS)

Hohnloser, S. H.; Klingenheben, T.; Li, Y. G.; Zabel, M.; Peetermans, J.; Cohen, R. J.

1998-01-01

INTRODUCTION: The current standard for arrhythmic risk stratification is electrophysiologic (EP) testing, which, due to its invasive nature, is limited to patients already known to be at high risk. A number of noninvasive tests, such as determination of left ventricular ejection fraction (LVEF) or heart rate variability, have been evaluated as additional risk stratifiers. Microvolt T wave alternans (TWA) is a promising new risk marker. Prospective evaluation of noninvasive risk markers in low- or moderate-risk populations requires studies involving very large numbers of patients, and in such studies, documentation of the occurrence of ventricular tachyarrhythmias is difficult. In the present study, we identified a high-risk population, recipients of an implantable cardioverter defibrillator (ICD), and prospectively compared microvolt TWA with invasive EP testing and other risk markers with respect to their ability to predict recurrence of ventricular tachyarrhythmias as documented by ICD electrograms. METHODS AND RESULTS: Ninety-five patients with a history of ventricular tachyarrhythmias undergoing implantation of an ICD underwent EP testing, assessment of TWA, as well as determination of LVEF, baroreflex sensitivity, signal-averaged ECG, analysis of 24-hour Holter monitoring, and QT dispersion from the 12-lead surface ECG. The endpoint of the study was first appropriate ICD therapy for electrogram-documented ventricular fibrillation or tachycardia during follow-up. Kaplan-Meier survival analysis revealed that TWA (P < 0.006) and LVEF (P < 0.04) were the only significant univariate risk stratifiers. EP testing was not statistically significant (P < 0.2). Multivariate Cox regression analysis revealed that TWA was the only statistically significant independent risk factor. CONCLUSIONS: Measurement of microvolt TWA compared favorably with both invasive EP testing and other currently used noninvasive risk assessment methods in predicting recurrence of ventricular tachyarrhythmias in ICD recipients. This study suggests that TWA might also be a powerful tool for risk stratification in low- or moderate-risk patients, and needs to be prospectively evaluated in such populations.

Genetic and Ecological Outcomes of Inga vera Subsp. affinis (Leguminosae) Tree Plantations in a Fragmented Tropical Landscape

PubMed Central

Cruz Neto, Oswaldo; Aguiar, Antonio V.; Twyford, Alex D.; Neaves, Linda E.; Pennington, R. Toby; Lopes, Ariadna V.

2014-01-01

Planting of native trees for habitat restoration is a widespread practice, but the consequences for the retention and transmission of genetic diversity in planted and natural populations are unclear. Using Inga vera subsp. affinis as a model species, we genotyped five natural and five planted populations in the Atlantic forest of northeastern Brazil at polymorphic microsatellite loci. We studied the breeding system and population structure to test how much genetic diversity is retained in planted relative to natural populations. We then genotyped seedlings from these populations to test whether genetic diversity in planted populations is restored by outcrossing to natural populations of I. vera. The breeding system of natural I. vera populations was confirmed to be highly outcrossing (t = 0.92; FIS = −0.061, P = 0.04), with populations showing weak population substructure (FST = 0.028). Genetic diversity in planted populations was 50% less than that of natural populations (planted: AR = 14.9, HO = 0.865 and natural: AR = 30.8, HO = 0.655). However, seedlings from planted populations showed a 30% higher allelic richness relative to their parents (seedlings AR = 10.5, parents AR = 7.6). Understanding the processes and interactions that shape this system are necessary to provide ecologically sensible goals and successfully restore hyper-fragmented habitats. Future restoration plans for I. vera must consider the genetic diversity of planted populations and the potential for gene flow between natural populations in the landscape, in order to preserve ecological interactions (i.e. pollination), and promote opportunities for outcrossing. PMID:24932729

Genetic and ecological outcomes of Inga vera subsp. affinis (Leguminosae) tree plantations in a fragmented tropical landscape.

PubMed

Cruz Neto, Oswaldo; Aguiar, Antonio V; Twyford, Alex D; Neaves, Linda E; Pennington, R Toby; Lopes, Ariadna V

2014-01-01

Planting of native trees for habitat restoration is a widespread practice, but the consequences for the retention and transmission of genetic diversity in planted and natural populations are unclear. Using Inga vera subsp. affinis as a model species, we genotyped five natural and five planted populations in the Atlantic forest of northeastern Brazil at polymorphic microsatellite loci. We studied the breeding system and population structure to test how much genetic diversity is retained in planted relative to natural populations. We then genotyped seedlings from these populations to test whether genetic diversity in planted populations is restored by outcrossing to natural populations of I. vera. The breeding system of natural I. vera populations was confirmed to be highly outcrossing (t = 0.92; FIS = -0.061, P = 0.04), with populations showing weak population substructure (FST = 0.028). Genetic diversity in planted populations was 50% less than that of natural populations (planted: AR = 14.9, HO = 0.865 and natural: AR = 30.8, HO = 0.655). However, seedlings from planted populations showed a 30% higher allelic richness relative to their parents (seedlings AR = 10.5, parents AR = 7.6). Understanding the processes and interactions that shape this system are necessary to provide ecologically sensible goals and successfully restore hyper-fragmented habitats. Future restoration plans for I. vera must consider the genetic diversity of planted populations and the potential for gene flow between natural populations in the landscape, in order to preserve ecological interactions (i.e. pollination), and promote opportunities for outcrossing.

NEUROTOXICITY TESTING IN HUMAN POPULATIONS: WORKSHOP OVERVIEW

EPA Science Inventory

A workshop was held in October 1983 at Rougemont, NC to review strategies and methods for neurotoxicity testing in human populations. Behavioral and electrophysiological testing methods were discussed with a major focus on computerized test batteries. Brief reviews of test method...

Great influence of geographic isolation on the genetic differentiation of Myriophyllum spicatum under a steep environmental gradient

PubMed Central

Wu, Zhigang; Yu, Dan; Wang, Zhong; Li, Xing; Xu, Xinwei

2015-01-01

Understanding how natural processes affect population genetic structures is an important issue in evolutionary biology. One effective method is to assess the relative importance of environmental and geographical factors in the genetic structure of populations. In this study, we examined the spatial genetic variation of thirteen Myriophyllum spicatum populations from the Qinghai-Tibetan Plateau (QTP) and adjacent highlands (Yunnan-Guizhou Plateau, YGP) by using microsatellite loci and environmental and geographical factors. Bioclim layers, hydrological properties and elevation were considered as environmental variables and reduced by principal component analysis. The genetic isolation by geographic distance (IBD) was tested by Mantel tests and the relative importance of environmental variables on population genetic differentiation was determined by a partial Mantel test and multiple matrix regression with randomization (MMRR). Two genetic clusters corresponding to the QTP and YGP were identified. Both tests and MMRR revealed a significant and strong correlation between genetic divergence and geographic isolation under the influence of environmental heterogeneity at the overall and finer spatial scales. Our findings suggested the dominant role of geography on the evolution of M. spicatum under a steep environmental gradient in the alpine landscape as a result of dispersal limitation and genetic drift. PMID:26494202

Species-specific selection on soil fungal population after olive mill waste-water treatment.

PubMed

Tardioli, S; Bànnè, E; Santori, F

1997-06-01

Soil was treated with olive mill waste water (OMW) in order to study the effect of this agriculture waste on soil fungal population. Changes in fungal composition were observed after soil pollution. In order to test OMW selective pressure, growth kinetics of Penicillium cyclopium, Scopulariopsis brevicaulis and Cladosporium cladosporioides were studied on solid media supplemented with different OMW concentrations. S. brevicaulis and C. cladosporioides did not grow at OMW concentration higher than 50%, while at concentrations lower than 50% a growth decrease was observed. Instead, P. cyclopium was able to actively grow at all concentrations of OMW tested. Therefore the OMW can influence and modify the soil fungal homeostasis.

Correlations between self-assessed hearing handicap and standard audiometric tests in elderly persons.

PubMed

Pedersen, K; Rosenhall, U

1991-01-01

The relationship between self-assessed hearing handicap and audiometric measures using pure-tone and speech audiometry was studied in a group of elderly persons representative of an urban Swedish population. The study population consisted of two cohorts, one of which was followed longitudinally. Significant correlations between measured and self-assessed hearing were found. Speech discrimination scores showed lower correlations with the self-estimated hearing than pure-tone averages and speech reception threshold. Questions concerning conversation with one person and concerning difficulty in hearing the doorbell showed lower correlations with measured hearing than the other questions. The discrimination score test is an inadequate tool for measuring hearing handicap.

Statistical properties of interval mapping methods on quantitative trait loci location: impact on QTL/eQTL analyses

PubMed Central

2012-01-01

Background Quantitative trait loci (QTL) detection on a huge amount of phenotypes, like eQTL detection on transcriptomic data, can be dramatically impaired by the statistical properties of interval mapping methods. One of these major outcomes is the high number of QTL detected at marker locations. The present study aims at identifying and specifying the sources of this bias, in particular in the case of analysis of data issued from outbred populations. Analytical developments were carried out in a backcross situation in order to specify the bias and to propose an algorithm to control it. The outbred population context was studied through simulated data sets in a wide range of situations. The likelihood ratio test was firstly analyzed under the "one QTL" hypothesis in a backcross population. Designs of sib families were then simulated and analyzed using the QTL Map software. On the basis of the theoretical results in backcross, parameters such as the population size, the density of the genetic map, the QTL effect and the true location of the QTL, were taken into account under the "no QTL" and the "one QTL" hypotheses. A combination of two non parametric tests - the Kolmogorov-Smirnov test and the Mann-Whitney-Wilcoxon test - was used in order to identify the parameters that affected the bias and to specify how much they influenced the estimation of QTL location. Results A theoretical expression of the bias of the estimated QTL location was obtained for a backcross type population. We demonstrated a common source of bias under the "no QTL" and the "one QTL" hypotheses and qualified the possible influence of several parameters. Simulation studies confirmed that the bias exists in outbred populations under both the hypotheses of "no QTL" and "one QTL" on a linkage group. The QTL location was systematically closer to marker locations than expected, particularly in the case of low QTL effect, small population size or low density of markers, i.e. designs with low power. Practical recommendations for experimental designs for QTL detection in outbred populations are given on the basis of this bias quantification. Furthermore, an original algorithm is proposed to adjust the location of a QTL, obtained with interval mapping, which co located with a marker. Conclusions Therefore, one should be attentive when one QTL is mapped at the location of one marker, especially under low power conditions. PMID:22520935

Experimental test of an eco-evolutionary dynamic feedback loop between evolution and population density in the green peach aphid.

PubMed

Turcotte, Martin M; Reznick, David N; Daniel Hare, J

2013-05-01

An eco-evolutionary feedback loop is defined as the reciprocal impacts of ecology on evolutionary dynamics and evolution on ecological dynamics on contemporary timescales. We experimentally tested for an eco-evolutionary feedback loop in the green peach aphid, Myzus persicae, by manipulating initial densities and evolution. We found strong evidence that initial aphid density alters the rate and direction of evolution, as measured by changes in genotype frequencies through time. We also found that evolution of aphids within only 16 days, or approximately three generations, alters the rate of population growth and predicts density compared to nonevolving controls. The impact of evolution on population dynamics also depended on density. In one evolution treatment, evolution accelerated population growth by up to 10.3% at high initial density or reduced it by up to 6.4% at low initial density. The impact of evolution on population growth was as strong as or stronger than that caused by a threefold change in intraspecific density. We found that, taken together, ecological condition, here intraspecific density, alters evolutionary dynamics, which in turn alter concurrent population growth rate (ecological dynamics) in an eco-evolutionary feedback loop. Our results suggest that ignoring evolution in studies predicting population dynamics might lead us to over- or underestimate population density and that we cannot predict the evolutionary outcome within aphid populations without considering population size.

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.

Transcultural validation of the Oxford Shoulder Score for the French-speaking population.

PubMed

Tuton, D; Barbe, C; Salmon, J-H; Dramé, M; Nérot, C; Ohl, X

2016-09-01

Patient-reported outcome measures (PROMs) have been gaining in popularity over the last decade. The Oxford Shoulder Score (OSS) is a well-established self-administered questionnaire for shoulder evaluation adapted for the English-speaking population. The aim of the present study was to develop a translation and a transcultural adaptation of the OSS and to assess its validity in native French-speaker patients with shoulder pain. The translation process was carried out following a translation/back-translation methodology by two translators. All patients completed the French OSS, the Subjective Shoulder Value (SSV), and the Constant score. Internal consistency was tested using Cronbach's α coefficient. Validity was assessed by calculating the Pearson correlation coefficient between the OSS and the Constant score and the SSV. One hundred forty-four patients suffering from degenerative or inflammatory diseases of the shoulder were included in this study. The average time required to complete the French OSS was 2min and 45s. Seventy patients were asked to complete the questionnaire twice (test/retest reliability). Internal consistency was high with Cronbach's α coefficient=0.93. The intraclass correlation coefficient was 0.91 (95% CI: 0.88-0.94) for test/retest reliability. The French OSS score was significantly correlated with the Constant-Murley score (r=0.73 and P<0.0001) and with the SSV (r=0.68 and P<0.0001). The present study shows that the French version of the OSS is reliable, valid, and reproducible. The sensitivity to change now needs to be evaluated. This score was adapted to the French-speaking population for the self-assessment of patients with degenerative or inflammatory disorders of the shoulder. Level 1, Test of previously developed criteria, diagnostic test study. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Integrating evolutionary and functional approaches to infer adaptation at specific loci.

PubMed

Storz, Jay F; Wheat, Christopher W

2010-09-01

Inferences about adaptation at specific loci are often exclusively based on the static analysis of DNA sequence variation. Ideally,population-genetic evidence for positive selection serves as a stepping-off point for experimental studies to elucidate the functional significance of the putatively adaptive variation. We argue that inferences about adaptation at specific loci are best achieved by integrating the indirect, retrospective insights provided by population-genetic analyses with the more direct, mechanistic insights provided by functional experiments. Integrative studies of adaptive genetic variation may sometimes be motivated by experimental insights into molecular function, which then provide the impetus to perform population genetic tests to evaluate whether the functional variation is of adaptive significance. In other cases, studies may be initiated by genome scans of DNA variation to identify candidate loci for recent adaptation. Results of such analyses can then motivate experimental efforts to test whether the identified candidate loci do in fact contribute to functional variation in some fitness-related phenotype. Functional studies can provide corroborative evidence for positive selection at particular loci, and can potentially reveal specific molecular mechanisms of adaptation.

Artistic creativity and risk for schizophrenia, bipolar disorder and unipolar depression: a Swedish population-based case-control study and sib-pair analysis.

PubMed

MacCabe, J H; Sariaslan, A; Almqvist, C; Lichtenstein, P; Larsson, H; Kyaga, S

2018-06-01

Many studies have addressed the question of whether mental disorder is associated with creativity, but high-quality epidemiological evidence has been lacking.AimsTo test for an association between studying a creative subject at high school or university and later mental disorder. In a case-control study using linked population-based registries in Sweden (N = 4 454 763), we tested for associations between tertiary education in an artistic field and hospital admission with schizophrenia (N = 20 333), bipolar disorder (N = 28 293) or unipolar depression (N = 148 365). Compared with the general population, individuals with an artistic education had increased odds of developing schizophrenia (odds ratio = 1.90, 95% CI = [1.69; 2.12]) bipolar disorder (odds ratio = 1.62 [1.50; 1.75]) and unipolar depression (odds ratio = 1.39 [1.34; 1.44]. The results remained after adjustment for IQ and other potential confounders. Students of artistic subjects at university are at increased risk of developing schizophrenia, bipolar disorder and unipolar depression in adulthood.Declaration of interestNone.

Detecting Directional Selection in the Presence of Recent Admixture in African-Americans

PubMed Central

Lohmueller, Kirk E.; Bustamante, Carlos D.; Clark, Andrew G.

2011-01-01

We investigate the performance of tests of neutrality in admixed populations using plausible demographic models for African-American history as well as resequencing data from African and African-American populations. The analysis of both simulated and human resequencing data suggests that recent admixture does not result in an excess of false-positive results for neutrality tests based on the frequency spectrum after accounting for the population growth in the parental African population. Furthermore, when simulating positive selection, Tajima's D, Fu and Li's D, and haplotype homozygosity have lower power to detect population-specific selection using individuals sampled from the admixed population than from the nonadmixed population. Fay and Wu's H test, however, has more power to detect selection using individuals from the admixed population than from the nonadmixed population, especially when the selective sweep ended long ago. Our results have implications for interpreting recent genome-wide scans for positive selection in human populations. PMID:21196524

A probabilistic method for testing and estimating selection differences between populations

PubMed Central

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

2015-01-01

Human populations around the world encounter various environmental challenges and, consequently, develop genetic adaptations to different selection forces. Identifying the differences in natural selection between populations is critical for understanding the roles of specific genetic variants in evolutionary adaptation. Although numerous methods have been developed to detect genetic loci under recent directional selection, a probabilistic solution for testing and quantifying selection differences between populations is lacking. Here we report the development of a probabilistic method for testing and estimating selection differences between populations. By use of a probabilistic model of genetic drift and selection, we showed that logarithm odds ratios of allele frequencies provide estimates of the differences in selection coefficients between populations. The estimates approximate a normal distribution, and variance can be estimated using genome-wide variants. This allows us to quantify differences in selection coefficients and to determine the confidence intervals of the estimate. Our work also revealed the link between genetic association testing and hypothesis testing of selection differences. It therefore supplies a solution for hypothesis testing of selection differences. This method was applied to a genome-wide data analysis of Han and Tibetan populations. The results confirmed that both the EPAS1 and EGLN1 genes are under statistically different selection in Han and Tibetan populations. We further estimated differences in the selection coefficients for genetic variants involved in melanin formation and determined their confidence intervals between continental population groups. Application of the method to empirical data demonstrated the outstanding capability of this novel approach for testing and quantifying differences in natural selection. PMID:26463656

Couple-level Motivations to Test for HIV for Gay Men in Relationships

PubMed Central

Beougher, Sean C.; Bircher, Anja E.; Chakravarty, Deepalika; Darbes, Lynae A.; Gómez Mandic, Carmen; Neilands, Torsten B.; Garcia, Carla C.; Hoff, Colleen C.

2015-01-01

Previous studies of HIV testing among gay men describe the motivations, facilitators and barriers, behaviors, and demographic characteristics of individuals who test. What little research focuses on HIV testing among gay men in relationships shows that they do not test regularly or, in some cases, at all – their motivations to test have not been investigated. With so little data on HIV testing for this population, and the continued privileging of individually-focused approaches, gay men in relationships fall into a blind spot of research and prevention efforts. This study examined motivations to test for HIV using qualitative data from both partners in 20 gay male couples. Analysis revealed that the partners’ motivations were either event-related (e.g., participants testing the beginning of their relationship or HIV-negative participants in an HIV-discordant relationship testing after risky episode with their discordant primary partner) or partner-related (e.g., participants testing in response to a request or suggestion to test from their primary partner or participants testing out of concern for their primary partner’s health and wellbeing). These data provide insight into relationship-oriented motivations to test for HIV for gay men in relationships and, in doing so, demonstrates their commitment to their primary partner and relationship. These motivations can be leveraged to increase HIV testing among gay men in relationships, a population that tests less often than single gay men, yet, until recently, has been underserved by prevention efforts. PMID:25550145

Validation of the Asthma Control Test questionnaire in a North African population.

PubMed

El Hasnaoui, Abdelkader; Martin, Jennifer; Salhi, Hocine; Doble, Adam

2009-12-01

Patient-reported outcome measures are required to measure asthma control. The Asthma Control Test (ACT) is one such measure which was used in the AIRMAG study, a general population study of asthma in the Maghreb. Three dialectal Arabic versions of the ACT (Algerian, Moroccan and Tunisian) were developed. To perform a psychometric evaluation of the properties of dialectal Arabic versions of the ACT used in the AIRMAG study. The test data came from 624 adult subjects in a random general population sample in Algeria, Morocco and Tunisia. The internal consistency of the ACT was analysed using Cronbach's a coefficient. The factorial structure was explored by primary component analysis with varimax rotation. Test-retest reproducibility was assessed in a subgroup of 61 subjects. Face and discriminant validity were assessed. Cronbach's a coefficient ranged from 0.58 for the Algerian version to 0.67 for the Moroccan version. The 'use-of-rescue-treatment' item was identified as discordant, since its removal resulted in an increase in Cronbach's a coefficient. The discordance of this item was confirmed by primary component analysis, where the four remaining items were aligned along a single dimension, and the 'use-of-rescue-treatment' item offset along a second dimension. Test and retest scores were well correlated (r =0.704). The ACT showed good face and discriminant validity. The ACT is a valid measure of asthma control in a North African context, although its internal consistency is compromised by the 'use-of-rescue-treatment' item, probably due to limited access to care and use of short-acting beta-agonists. (c) 2009 Elsevier Ltd. All rights reserved.

Community-based intermittent mass testing and treatment for malaria in an area of high transmission intensity, western Kenya: study design and methodology for a cluster randomized controlled trial.

PubMed

Samuels, Aaron M; Awino, Nobert; Odongo, Wycliffe; Abong'o, Benard; Gimnig, John; Otieno, Kephas; Shi, Ya Ping; Were, Vincent; Allen, Denise Roth; Were, Florence; Sang, Tony; Obor, David; Williamson, John; Hamel, Mary J; Patrick Kachur, S; Slutsker, Laurence; Lindblade, Kim A; Kariuki, Simon; Desai, Meghna

2017-06-07

Most human Plasmodium infections in western Kenya are asymptomatic and are believed to contribute importantly to malaria transmission. Elimination of asymptomatic infections requires active treatment approaches, such as mass testing and treatment (MTaT) or mass drug administration (MDA), as infected persons do not seek care for their infection. Evaluations of community-based approaches that are designed to reduce malaria transmission require careful attention to study design to ensure that important effects can be measured accurately. This manuscript describes the study design and methodology of a cluster-randomized controlled trial to evaluate a MTaT approach for malaria transmission reduction in an area of high malaria transmission. Ten health facilities in western Kenya were purposively selected for inclusion. The communities within 3 km of each health facility were divided into three clusters of approximately equal population size. Two clusters around each health facility were randomly assigned to the control arm, and one to the intervention arm. Three times per year for 2 years, after the long and short rains, and again before the long rains, teams of community health volunteers visited every household within the intervention arm, tested all consenting individuals with malaria rapid diagnostic tests, and treated all positive individuals with an effective anti-malarial. The effect of mass testing and treatment on malaria transmission was measured through population-based longitudinal cohorts, outpatient visits for clinical malaria, periodic population-based cross-sectional surveys, and entomological indices.

Controversial opinion: evaluation of EGR1 and LAMA2 loci for high myopia in Chinese populations.

PubMed

Lin, Fang-yu; Huang, Zhu; Lu, Ning; Chen, Wei; Fang, Hui; Han, Wei

2016-03-01

Functional studies have suggested the important role of early growth response 1 (EGR1) and Laminin α2-chain (LAMA2) in human eye development. Genetic studies have reported a significant association of the single nucleotide polymorphism (SNP) in the LAMA2 gene with myopia. This study aimed to evaluate the association of the tagging SNPs (tSNPs) in the EGR1 and LAMA2 genes with high myopia in two independent Han Chinese populations. Four tSNPs (rs11743810 in the EGR1 gene; rs2571575, rs9321170, and rs1889891 in the LAMA2 gene) were selected, according to the HapMap database (http://hapmap.ncbi.nlm.nih.gov), and were genotyped using the ligase detection reaction (LDR) approach for 167 Han Chinese nuclear families with extremely highly myopic offspring (<-10.0 diopters) and an independent group with 485 extremely highly myopic cases (<-10.0 diopters) and 499 controls. Direct sequencing was used to confirm the LDR results in twenty randomly selected subjects. Family-based association analysis was performed using the family-based association test (FBAT) software package (Version 1.5.5). Population-based association analysis was performed using the Chi-square test. The association analysis power was estimated using online software (http://design.cs.ucla.edu). The FBAT demonstrated that all four tSNPs tested did not show association with high myopia (P>0.05). Haplotype analysis of tSNPs in the LAMA2 genes also did not show a significant association (P>0.05). Meanwhile, population-based association analysis also showed no significant association results with high myopia (P>0.05). On the basis of our family- and population-based analyses for the Han Chinese population, we did not find positive association signals of the four SNPs in the LAMA2 and EGR1 genes with high myopia.

Why is the age-standardized incidence of low-trauma fractures rising in many elderly populations?

PubMed

Kannus, Pekka; Niemi, Seppo; Parkkari, Jari; Palvanen, Mika; Heinonen, Ari; Sievänen, Harri; Järvinen, Teppo; Khan, Karim; Järvinen, Markku

2002-08-01

Low-trauma fractures of elderly people are a major public health burden worldwide, and as the number and mean age of older adults in the population continue to increase, the number of fractures is also likely to increase. Epidemiologically, however, an additional concern is that, for unknown reasons, the age-standardized incidence (average individual risk) of fracture has also risen in many populations during the recent decades. Possible reasons for this rise include a birth cohort effect, deterioration in the average bone strength by time, and increased average risk of (serious) falls. Literature provides evidence that the rise is not due to a birth cohort effect, whereas no study shows whether bone fragility has increased during this relatively short period of time. This osteoporosis hypothesis could, however, be tested if researchers would now repeat the population measurements of bone mass and density that were made in the late 1980s and the 1990s. If such studies proved that women's and men's age-standardized mean values of bone mass and density have declined over time, the osteoporosis hypothesis would receive scientific support. The third explanation is based on the hypothesis that the number and/or severity of falls has risen in elderly populations during the recent decades. Although no study has directly tested this hypothesis, a great deal of indirect epidemiologic evidence supports this contention. For example, the age-standardized incidence of fall-induced severe head injuries, bruises and contusions, and joint distortions and dislocations has increased among elderly people similarly to the low-trauma fractures. The fall hypothesis could also be tested in the coming years because the 1990s saw many research teams reporting age- and sex-specific incidences of falling for elderly populations, and the same could be done now to provide data comparing the current incidence rates of falls with the earlier ones.

Diagnosing soft tissue rheumatic disorders of the upper limb in epidemiological studies of vibration-exposed populations

PubMed Central

Palmer, Keith T

2013-01-01

Objectives To investigate approaches adopted to diagnose soft tissue rheumatic disorders of the upper limb (ULDs) in vibration-exposed populations and in other settings, and to compare their methodological qualities. Methods Systematic searches were made of the Medline, Embase, and CINAHL electronic bibliographic databases, and of various supplementary sources (textbooks, reviews, conference and workshop proceedings, personal files). For vibration-exposed populations, qualifying papers were scored in terms of the provenance of their measuring instruments (adequacy of documentation, standardisation, reliability, criterion-related and content validity). Similar criteria were applied to general proposals for whole diagnostic schemes, and evidence was collated on the test-retest reliability of symptom histories and clinical signs. Results In total, 23 relevant reports were identified concerning vibration-exposed populations - 21 involving symptoms and 9 involving examination/diagnosis. Most of the instruments employed scored poorly in terms of methodological quality. The search also identified, from the wider literature, more than a dozen schemes directed at classifying ULDs, and 18 studies of test-retest reliability of symptoms and physical signs in the upper limb. Findings support the use of the standardised Nordic questionnaire for symptom inquiry and suggest that a range of physical signs can be elicited with reasonable between-observer agreement. Four classification schemes rated well in terms of content validity. One of these had excellent documentation, and one had been tested for repeatability, agreement with an external reference standard, and utility in distinguishing groups that differed in disability, prognosis and associated risk factors. Conclusions Hitherto, most studies of ULDs in vibration-exposed populations have used custom-specified diagnostic methods, poorly documented, and non-stringent in terms of standardisation and supporting evidence of reliability and/or validity. The broader literature contains several question sets and procedures that improve upon this, and offer scope in vibration-exposed populations to diagnose ULDs more systematically. PMID:17909839

Memory-related subjective cognitive symptoms in the adult population: prevalence and associated factors - results of the LIFE-Adult-Study.

PubMed

Luck, Tobias; Roehr, Susanne; Rodriguez, Francisca S; Schroeter, Matthias L; Witte, A Veronica; Hinz, Andreas; Mehnert, Anja; Engel, Christoph; Loeffler, Markus; Thiery, Joachim; Villringer, Arno; Riedel-Heller, Steffi G

2018-05-21

Subjectively perceived memory problems (memory-related Subjective Cognitive Symptoms/SCS) can be an indicator of a pre-prodromal or prodromal stage of a neurodegenerative disease such as Alzheimer's disease. We therefore sought to provide detailed empirical information on memory-related SCS in the dementia-free adult population including information on prevalence rates, associated factors and others. We studied 8834 participants (40-79 years) of the population-based LIFE-Adult-Study. Weighted prevalence rates with confidence intervals (95%-CI) were calculated. Associations of memory-related SCS with participants' socio-demographic characteristics, physical and mental comorbidity, and cognitive performance (Verbal Fluency Test Animals, Trail-Making-Test, CERAD Wordlist tests) were analyzed. Prevalence of total memory-related SCS was 53.0% (95%-CI = 51.9-54.0): 26.0% (95%-CI = 25.1-27.0) of the population had a subtype without related concerns, 23.6% (95%-CI = 22.7-24.5) a subtype with some related concerns, and 3.3% (95%-CI = 2.9-3.7) a subtype with strong related concerns. Report of memory-related SCS was unrelated to participants' socio-demographic characteristics, physical comorbidity (except history of stroke), depressive symptomatology, and anxiety. Adults with and without memory-related SCS showed no significant difference in cognitive performance. About one fifth (18.1%) of the participants with memory-related SCS stated that they did consult/want to consult a physician because of their experienced memory problems. Memory-related SCS are very common and unspecific in the non-demented adult population aged 40-79 years. Nonetheless, a substantial proportion of this population has concerns related to experienced memory problems and/or seeks help. Already available information on additional features associated with a higher likelihood of developing dementia in people with SCS may help clinicians to decide who should be monitored more closely.

Population variation and individual maximum size in two leech populations: energy extraction from cannibalism or niche widening?

PubMed

Persson, Lennart; Elliott, J Malcolm

2013-05-01

The theory of cannibal dynamics predicts a link between population dynamics and individual life history. In particular, increased individual growth has, in both modeling and empirical studies, been shown to result from a destabilization of population dynamics. We used data from a long-term study of the dynamics of two leech (Erpobdella octoculata) populations to test the hypothesis that maximum size should be higher in a cycling population; one of the study populations exhibited a delayed feedback cycle while the other population showed no sign of cyclicity. A hump-shaped relationship between individual mass of 1-year-old leeches and offspring density the previous year was present in both populations. As predicted from the theory, the maximum mass of individuals was much larger in the fluctuating population. In contrast to predictions, the higher growth rate was not related to energy extraction from cannibalism. Instead, the higher individual mass is suggested to be due to increased availability of resources due to a niche widening with increased individual body mass. The larger individual mass in the fluctuating population was related to a stronger correlation between the densities of 1-year-old individuals and 2-year-old individuals the following year in this population. Although cannibalism was the major mechanism regulating population dynamics, its importance was negligible in terms of providing cannibalizing individuals with energy subsequently increasing their fecundity. Instead, the study identifies a need for theoretical and empirical studies on the largely unstudied interplay between ontogenetic niche shifts and cannibalistic population dynamics.

Analysis of the curve of Spee and the curve of Wilson in adult Indian population: A three-dimensional measurement study.

PubMed

Surendran, Sowmya Velekkatt; Hussain, Sharmila; Bhoominthan, S; Nayar, Sanjna; Jayesh, Ragavendra

2016-01-01

When reconstructing the occlusal curvatures dentists often use a 4-inch radii arc as a rough standard based on Monson spherical theory. The use of an identical radius for the curve of Spee for all patients may not be appropriate because each patient is individually different. The validity of application of this theory in the Indian population and the present study has been undertaken. This study is an attempt to evaluate the curve of Spee and curve of Wilson in young Indian population using three dimensional analysis. This study compared the radius and the depth of right and left, maxillary and mandibular curves of Spee and the radius of maxillary and mandibular curves of Wilson in males and females. The cusp tips of canines, buccal cusp tips of premolars and molars and palatal/lingual cusp tips of second molars of 60 maxillary and 60 mandibular casts were obtained. Three-dimensional (x, y, z) coordinates of the cusp tips of the molars, premolars, and canines of the right and left sides of the maxilla and mandible were obtained with three dimensional coordinate measuring machine. The radius and the depth of right and left, maxillary and mandibular curves of Spee and the radius of maxillary and mandibular curves of Wilson were measured by means of computer software Metrologic-XG. Pearson's correlation test and Independent t-test were used to test the statistical significance (α=.05). The values of curve of Spee and curve of Wilson in Indian population obtained from this study were higher than the 4 inch (100 mm) radius proposed by Monson. These findings suggest ethnic differences in the radius of curve of Spee and curve of Wilson.

Confusion about Pap smears: lack of knowledge among high-risk women.

PubMed

Daley, Ellen; Perrin, Kay; Vamos, Cheryl; Hernandez, Natalie; Anstey, Erica; Baker, Elizabeth; Kolar, Stephanie; Ebbert, Judith

2013-01-01

The impact of the Papanicolaou (Pap) smear on the prevention of cervical cancer is one of the greatest public health success stories. However, it is not clear if women understand the purpose of the Pap smear despite recent advancements and national attention over cervical cancer prevention. The purpose of this study was to examine Pap smear knowledge among three high-risk populations at different points in time. Women from three separate human papillomavirus (HPV) psychosocial studies completed surveys assessing Pap smear knowledge: (1) HPV-positive women (prevaccine population in 2005-2006, n=154, mean age 23.5), (2) college women (postvaccine population in 2008, n=276, mean age 18.9), and (3) minority college women (postvaccine population in 2011, n=711, mean age 23.3). Frequencies and logistic regression were employed to examine associations between demographic factors and accurate knowledge of Pap smear testing within each study. Approximately one quarter of participants across all three samples did not know that the Pap smear is a test for cervical cancer. Participants also incorrectly believed that the Pap smear tests for HPV (82%-91%), vaginal infections (76%-92%), yeast infections (65%-86%), gonorrhea (55%-81%), herpes (53%-80%), HIV/AIDS (22%-59%), and pregnancy (17%-38%). Among all three studies, older age was the only factor significant with higher Pap knowledge. Higher HPV knowledge scores were significantly associated with higher Pap knowledge in studies 2 and 3 only. Knowledge about the purpose of the Pap smear remains low. Findings underscore the significant need for clear and consistent messages among high-risk women regarding the prevention of cervical cancer and other reproductive health conditions.

The Impact of Population Demography and Selection on the Genetic Architecture of Complex Traits

PubMed Central

Lohmueller, Kirk E.

2014-01-01

Population genetic studies have found evidence for dramatic population growth in recent human history. It is unclear how this recent population growth, combined with the effects of negative natural selection, has affected patterns of deleterious variation, as well as the number, frequency, and effect sizes of mutations that contribute risk to complex traits. Because researchers are performing exome sequencing studies aimed at uncovering the role of low-frequency variants in the risk of complex traits, this topic is of critical importance. Here I use simulations under population genetic models where a proportion of the heritability of the trait is accounted for by mutations in a subset of the exome. I show that recent population growth increases the proportion of nonsynonymous variants segregating in the population, but does not affect the genetic load relative to a population that did not expand. Under a model where a mutation's effect on a trait is correlated with its effect on fitness, rare variants explain a greater portion of the additive genetic variance of the trait in a population that has recently expanded than in a population that did not recently expand. Further, when using a single-marker test, for a given false-positive rate and sample size, recent population growth decreases the expected number of significant associations with the trait relative to the number detected in a population that did not expand. However, in a model where there is no correlation between a mutation's effect on fitness and the effect on the trait, common variants account for much of the additive genetic variance, regardless of demography. Moreover, here demography does not affect the number of significant associations detected. These findings suggest recent population history may be an important factor influencing the power of association tests and in accounting for the missing heritability of certain complex traits. PMID:24875776

Cost-effectiveness of alternative strategies for interferon-γ release assays and tuberculin skin test in tuberculous uveitis.

PubMed

Ang, Marcus; Nguyen, Hai V; Kiew, Sieh Yean; Chen, Shu; Chee, Soon-Phaik; Finkelstein, Eric

2015-07-01

Although tuberculous uveitis remains a major cause of ocular morbidity in the developing world, there is no consensus on which diagnostic test or testing strategy is the most cost effective. In this study we carried out a cost-effectiveness analysis to determine the most cost-effective diagnostic test strategy. In this prospective study, we recruited 102 patients from Singapore National Eye Centre with signs suggestive of tuberculous uveitis. Using prospective data from this cohort and from published meta-analyses, we modelled the incremental cost effectiveness of the following strategies: tuberculin skin test (TST) only; interferon-γ release assay (IGRA) only; IGRA following a positive TST result; and dual-test strategy, conducting TST and IGRA at presentation. Incremental cost-effectiveness ratios (ICERs) were calculated for each strategy and analysed using a willingness-to-pay threshold of $50,000 per quality-adjusted life year (QALY) gained. In our population, the least cost effective was the IGRA-only strategy. The dual-test strategy was the most cost effective, with an improvement of 0.017 QALY at an incremental cost of $190 relative to the TST-only strategy (ICER $11,500); while the TST-only strategy was more cost effective than the third strategy, using IGRA following a positive TST result (ICER $3610). This remained consistent while varying the costs of IGRA and TST, the incidence of tuberculosis and tuberculous uveitis, as well as the diagnostic accuracy of IGRA and TST found in previous studies in various populations. The dual-test strategy (performing TST and IGRA at presentation) was the most cost effective strategy for the diagnosis of tuberculous uveitis in our population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Prevalence of Latent Mycobacterium Tuberculosis Infection (LTBI) in Saudi Arabia; Population based survey.

PubMed

Balkhy, Hanan H; El Beltagy, Kamel; El-Saed, Aiman; Aljasir, Badr; Althaqafi, Abdulhakeem; Alothman, Adel F; Alshalaan, Mohammad; Al-Jahdali, Hamdan

2017-07-01

The annual risk of tuberculosis infection (ARTI) data in Saudi Arabia has not been updated since 1993. To estimate the prevalence of latent TB infection (LTBI) and ARTI in a population-based sample in Saudi Arabia using Tuberculin skin test (TST) and QuantiFERON TB Gold in tube (QFT-GIT) test. A population-based cross sectional study was conducted between July 2010 and March 2013. Participants were randomly selected from the population served by the primary healthcare centers of the Ministry of National Guard Health Affairs in Riyadh, Jeddah, Alhassa and Dammam, Saudi Arabia. A total of 1369 participants were included. The overall prevalence of LTBI was similar using TST and QFT-GIT (9.3% and 9.1% respectively, p=0.872) but stratified prevalence rates were variable in all sociodemographic groups except marital status. Additionally, the prevalence rates of LTBI using either test alone showed significant differences by several sociodemographic and behavioral characteristics. The overall ARTI was 0.36% using TST and 0.35% using QFT-GIT. We are reporting much lower estimates for the prevalence of LTBI and the ARTI in a population-based sample in Saudi Arabia relative to the data that have been used for more than two decades. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Reliability of Autism-Tics, AD/HD, and other Comorbidities (A-TAC) inventory in a test-retest design.

PubMed

Larson, Tomas; Kerekes, Nóra; Selinus, Eva Norén; Lichtenstein, Paul; Gumpert, Clara Hellner; Anckarsäter, Henrik; Nilsson, Thomas; Lundström, Sebastian

2014-02-01

The Autism-Tics, AD/HD, and other Comorbidities (A-TAC) inventory is used in epidemiological research to assess neurodevelopmental problems and coexisting conditions. Although the A-TAC has been applied in various populations, data on retest reliability are limited. The objective of the present study was to present additional reliability data. The A-TAC was administered by lay assessors and was completed on two occasions by parents of 400 individual twins, with an average interval of 70 days between test sessions. Intra- and inter-rater reliability were analysed with intraclass correlations and Cohen's kappa. A-TAC showed excellent test-retest intraclass correlations for both autism spectrum disorder and attention deficit hyperactivity disorder (each at .84). Most modules in the A-TAC had intra- and inter-rater reliability intraclass correlation coefficients of > or = .60. Cohen's kappa indi- cated acceptable reliability. The current study provides statistical evidence that the A-TAC yields good test-retest reliability in a population-based cohort of children.

A population-based descriptive study of housefire deaths in North Carolina.

PubMed Central

Patetta, M J; Cole, T B

1990-01-01

We report a population-based study of housefire deaths in North Carolina in 1985 using data obtained from fire investigators and the North Carolina medical examiner system. The crude death rate was 3.2 per 100,000 population; age-specific death rates were highest for ages 75-84 years. Death rates for Whites were one-third as high as death rates for other races. Of those decedents tested for alcohol, 56 percent had blood alcohol levels greater than or equal to 22 mmol/L. Most fatal fires were caused by heating units or cigarettes. PMID:2382752

Linguistic Adaptation of the Clinical Dementia Rating Scale for a Spanish-Speaking Population

PubMed Central

Oquendo-Jiménez, Ilia; Mena, Rafaela; Antoun, Mikhail D.; Wojna, Valerie

2012-01-01

Background Alzheimer's disease (AD) is the most common form of dementia worldwide. In Hispanic populations there are few validated tests for the accurate identification and diagnosis of AD. The Clinical Dementia Rating (CDR) scale is an internationally recognized questionnaire used to stage dementia. This study's objective was to develop a linguistic adaptation of the CDR for the Puerto Rican population. Methods The linguistic adaptation consisted of the evaluation of each CDR question (item) and the questionnaire's instructions, for similarities in meaning (semantic equivalence), relevance of content (content equivalence), and appropriateness of the questionnaire's format and measuring technique (technical equivalence). A focus group methodology was used to assess cultural relevance, clarity, and suitability of the measuring technique in the Argentinean version of the CDR for use in a Puerto Rican population. Results A total of 27 semantic equivalence changes were recommended in four categories: higher than 6th grade level of reading, meaning, common use, and word preference. Four content equivalence changes were identified, all focused on improving the applicability of the test questions to the general population's concept of street addresses and common dietary choices. There were no recommendations for changes in the assessment of technical equivalence. Conclusions We developed a linguistically adapted CDR instrument for the Puerto Rican population, preserving the semantic, content, and technical equivalences of the original version. Further studies are needed to validate the CDR instrument with the staging of Alzheimer's disease in the Puerto Rican population. PMID:20496524

An investigation of retronasal testing of olfactory function in a Turkish population

PubMed Central

Salihoglu, Murat; Altundag, Aytug; Cayonu, Melih; Tekeli, Hakan

2014-01-01

Background The aim of this study was: (1) to perform a preliminary study for the validation of “retronasal olfactory testing” in the Turkish population to find the best way to evaluate smell and taste disorders in Turkey; (2) to determine if cultural differences make application of the test more difficult; and (3) to determine the flavors that participants had not yet tasted by using the survey method. Material/Methods The study included 330 volunteers. Orthonasal olfactory function was assessed psycho-physically using the “Sniffin’ Sticks” olfactory test. Retronasal olfaction was assessed using a collection of 20 available food powders applied to the oral cavity. Also, all participants filled in a questionnaire of 50 items about the flavors they had not tasted before. Results The mean age of the participants was 26±7.3 years. Participants were divided into 3 groups according to the “Sniffin’ Sticks” test results: anosmia, hyposmia, and normosmia groups. Differences in retronasal olfaction scores were significant among the 3 groups. Conclusions The retronasal olfactory test appeared to perform well, but modifications of odorized powders or granules and distracters used in the retronasal olfactory test, taking into account Turkish cultural differences, is likely to improve its performance. PMID:24704823

Statistical considerations for agroforestry studies

Treesearch

James A. Baldwin

1993-01-01

Statistical topics that related to agroforestry studies are discussed. These included study objectives, populations of interest, sampling schemes, sample sizes, estimation vs. hypothesis testing, and P-values. In addition, a relatively new and very much improved histogram display is described.

Cosmic ray interactions in starbursting galaxies

NASA Astrophysics Data System (ADS)

Yoast-Hull, Tova M.

High quality gamma-ray and radio observations of nearby galaxies offer an unprecedented opportunity to quantitatively study the properties of their cosmic ray populations. Accounting for various interactions and energy losses, I developed a multi-component, single-zone model of the cosmic ray populations in the central molecular zones of star-forming galaxies. Using observational knowledge of the interstellar medium and star formation, I successfully predicted the radio, gamma-ray, and neutrino spectra for nearby starbursts. Using chi-squared tests to compare the models with observational radio and gamma-ray data, I placed constraints on magnetic field strengths, cosmic ray energy densities, and galactic wind (advection) speeds. The initial models were applied to and tested on the prototypical starburst galaxy M82. To further test the model and to explore the differences in environment between starbursts and active galactic nuclei, I studied NGC 253 and NGC 1068, both nearby giant spiral galaxies which have been detected in gamma-rays. Additionally, I demonstrated that the excess GeV energy gamma-ray emission in the Galactic Center is likely not diffuse emission from an additional population of cosmic rays accelerated in supernova remnants. Lastly, I investigated cosmic ray populations in the starburst nuclei of Arp 220, a nearby ultraluminous infrared galaxy which displays a high-intensity mode of star formation more common in young galaxies, and I showed that the nuclei are efficient cosmic-ray proton calorimeters.

Carbon dioxide emissions, GDP, energy use, and population growth: a multivariate and causality analysis for Ghana, 1971-2013.

PubMed

Asumadu-Sarkodie, Samuel; Owusu, Phebe Asantewaa

2016-07-01

In this study, the relationship between carbon dioxide emissions, GDP, energy use, and population growth in Ghana was investigated from 1971 to 2013 by comparing the vector error correction model (VECM) and the autoregressive distributed lag (ARDL). Prior to testing for Granger causality based on VECM, the study tested for unit roots, Johansen's multivariate co-integration and performed a variance decomposition analysis using Cholesky's technique. Evidence from the variance decomposition shows that 21 % of future shocks in carbon dioxide emissions are due to fluctuations in energy use, 8 % of future shocks are due to fluctuations in GDP, and 6 % of future shocks are due to fluctuations in population. There was evidence of bidirectional causality running from energy use to GDP and a unidirectional causality running from carbon dioxide emissions to energy use, carbon dioxide emissions to GDP, carbon dioxide emissions to population, and population to energy use. Evidence from the long-run elasticities shows that a 1 % increase in population in Ghana will increase carbon dioxide emissions by 1.72 %. There was evidence of short-run equilibrium relationship running from energy use to carbon dioxide emissions and GDP to carbon dioxide emissions. As a policy implication, the addition of renewable energy and clean energy technologies into Ghana's energy mix can help mitigate climate change and its impact in the future.

Improving detection of dementia in Asian patients with low education: combining the Mini-Mental State Examination and the Informant Questionnaire on Cognitive Decline in the Elderly.

PubMed

Narasimhalu, Kaavya; Lee, June; Auchus, Alexander P; Chen, Christopher P L H

2008-01-01

Previous work combining the Mini-Mental State Examination (MMSE) and Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) has been conducted in western populations. We ascertained, in an Asian population, (1) the best method of combining the tests, (2) the effects of educational level, and (3) the effect of different dementia etiologies. Data from 576 patients were analyzed (407 nondemented controls, 87 Alzheimer's disease and 82 vascular dementia patients). Sensitivity, specificity and AUC values were obtained using three methods, the 'And' rule, the 'Or' rule, and the 'weighted sum' method. The 'weighted sum' rule had statistically superior AUC and specificity results, while the 'Or' rule had the best sensitivity results. The IQCODE outperformed the MMSE in all analyses. Patients with no education benefited more from combined tests. There was no difference between Alzheimer's disease and vascular dementia populations in the predictive value of any of the combined methods. We recommend that the IQCODE be used to supplement the MMSE whenever available and that the 'weighted sum' method be used to combine the MMSE and the IQCODE, particularly in populations with low education. As the study population selected may not be representative of the general population, further studies are required before generalization to nonclinical samples. (c) 2007 S. Karger AG, Basel.

Histopathologic Differences between Jewish and Arab Population in Israel at First-Time Presentation with Bladder Cancer.

PubMed

Avitan, Ofir; Bahouth, Zaher; Halachmi, Sarel; Shprits, Sagi; Masarwa, Ismail; Sabo, Edmond; Moskovitz, Boaz; Nativ, Ofer

2017-01-01

Pathology of urothelial carcinoma may vary in different populations at diagnosis. Our aim was to evaluate the histopathologic differences between Jewish and Arab patients in Israel at first diagnosis of urothelial cancer. We retrospectively collected data of all patients with confirmed urothelial cancer, treated at our department between January 2010 and January 2015. We examined the distribution of the histopathologic data among the studied populations. To compare the categorical variables we used the Chi-Square Pearson test. Comparison of independent variables was made by Student's t -test. P value below 0.05 was considered significant. The study group included 413 patients, 345 Jews and 68 Arabs. The major differences were that Arab patients were younger (62.61 versus 68.55 years, P = 0.001), had more aggressive tumors that were detected at a more advanced stage, and had also a higher rate of metastatic disease (7.4% versus 3.2%, P = 0.05). Nonurothelial cell tumors were 2.3 times more prevalent in Arab population. Unlike Jewish population, Arab women had higher rate of invasive/metastatic disease compared with Arab men (40% versus 22.4%). At time of diagnosis the tumors were more aggressive in Arab patients, especially in Arab women. The reasons for those differences constitute a target for a separate research. These results should have an impact on prevention medicine and education of physicians treating mixed populations.

In search of causal variants: refining disease association signals using cross-population contrasts.

PubMed

Saccone, Nancy L; Saccone, Scott F; Goate, Alison M; Grucza, Richard A; Hinrichs, Anthony L; Rice, John P; Bierut, Laura J

2008-08-29

Genome-wide association (GWA) using large numbers of single nucleotide polymorphisms (SNPs) is now a powerful, state-of-the-art approach to mapping human disease genes. When a GWA study detects association between a SNP and the disease, this signal usually represents association with a set of several highly correlated SNPs in strong linkage disequilibrium. The challenge we address is to distinguish among these correlated loci to highlight potential functional variants and prioritize them for follow-up. We implemented a systematic method for testing association across diverse population samples having differing histories and LD patterns, using a logistic regression framework. The hypothesis is that important underlying biological mechanisms are shared across human populations, and we can filter correlated variants by testing for heterogeneity of genetic effects in different population samples. This approach formalizes the descriptive comparison of p-values that has typified similar cross-population fine-mapping studies to date. We applied this method to correlated SNPs in the cholinergic nicotinic receptor gene cluster CHRNA5-CHRNA3-CHRNB4, in a case-control study of cocaine dependence composed of 504 European-American and 583 African-American samples. Of the 10 SNPs genotyped in the r2 > or = 0.8 bin for rs16969968, three demonstrated significant cross-population heterogeneity and are filtered from priority follow-up; the remaining SNPs include rs16969968 (heterogeneity p = 0.75). Though the power to filter out rs16969968 is reduced due to the difference in allele frequency in the two groups, the results nevertheless focus attention on a smaller group of SNPs that includes the non-synonymous SNP rs16969968, which retains a similar effect size (odds ratio) across both population samples. Filtering out SNPs that demonstrate cross-population heterogeneity enriches for variants more likely to be important and causative. Our approach provides an important and effective tool to help interpret results from the many GWA studies now underway.

Beta Testing a Novel Smartphone Application to Improve Medication Adherence.

PubMed

Sarzynski, Erin; Decker, Brian; Thul, Aaron; Weismantel, David; Melaragni, Ronald; Cholakis, Elizabeth; Tewari, Megha; Beckholt, Kristy; Zaroukian, Michael; Kennedy, Angie C; Given, Charles

2017-04-01

We developed and beta-tested a patient-centered medication management application, PresRx optical character recognition (OCR), a mobile health (m-health) tool that auto-populates drug name and dosing instructions directly from patients' medication labels by OCR. We employed a single-subject design study to evaluate PresRx OCR for three outcomes: (1) accuracy of auto-populated medication dosing instructions, (2) acceptability of the user interface, and (3) patients' adherence to chronic medications. Eight patients beta-tested PresRx OCR. Five patients used the software for ≥6 months, and four completed exit interviews (n = 4 completers). At baseline, patients used 3.4 chronic prescription medications and exhibited moderate-to-high adherence rates. Accuracy of auto-populated information by OCR was 95% for drug name, 98% for dose, and 96% for frequency. Study completers rated PresRx OCR 74 on the System Usability Scale, where scores ≥70 indicate an acceptable user interface (scale 0-100). Adherence rates measured by PresRx OCR were high during the first month of app use (93%), but waned midway through the 6-month testing period (78%). Compared with pharmacy fill rates, PresRx OCR underestimated adherence among completers by 3%, while it overestimated adherence among noncompleters by 8%. Results suggest smartphone applications supporting medication management are feasible and accurately assess adherence compared with objective measures. Future efforts to improve medication-taking behavior using m-health tools should target specific patient populations and leverage common application programming interfaces to promote generalizability. Our medication management application PresRx OCR is innovative, acceptable for patient use, and accurately tracks medication adherence.

The work role functioning questionnaire 2.0 (Dutch version): examination of its reliability, validity and responsiveness in the general working population.

PubMed

Abma, Femke I; van der Klink, Jac J L; Bültmann, Ute

2013-03-01

The promotion of a sustainable, healthy and productive working life attracts more and more attention. Recently the Work Role Functioning Questionnaire (WRFQ) has been cross-culturally translated and adapted to Dutch. This questionnaire aims to measure the health-related work functioning of workers with health problems. The aim of this study is to evaluate the reliability, validity (including five new items) and responsiveness of the WRFQ 2.0 in the working population. A longitudinal study was conducted among workers. The reliability (internal consistency, test-retest reliability, measurement error), validity (structural validity-factor analysis, construct validity by means of hypotheses testing) and responsiveness of the WRFQ 2.0 were evaluated. A total of N = 553 workers completed the survey. The final WRFQ 2.0 has four subscales and showed very good internal consistency, moderate test-retest reliability, good construct validity and moderate responsiveness in the working population. The WRFQ was able to distinguish between groups with different levels of mental health, physical health, fatigue and need for recovery. A moderate correlation was found between WRFQ and related constructs respectively work ability and work productivity. A weak relationship was found with general self-rated health, work engagement and work involvement. The WRFQ 2.0 is a reliable and valid instrument to measure health-related work functioning in the working population. Further validation in larger samples is recommended, especially for test-retest reliability, responsiveness and the questionnaire's ability to predict the future course of health-related work functioning.

Using probability modelling and genetic parentage assignment to test the role of local mate availability in mating system variation.

PubMed

Blyton, Michaela D J; Banks, Sam C; Peakall, Rod; Lindenmayer, David B

2012-02-01

The formal testing of mating system theories with empirical data is important for evaluating the relative importance of different processes in shaping mating systems in wild populations. Here, we present a generally applicable probability modelling framework to test the role of local mate availability in determining a population's level of genetic monogamy. We provide a significance test for detecting departures in observed mating patterns from model expectations based on mate availability alone, allowing the presence and direction of behavioural effects to be inferred. The assessment of mate availability can be flexible and in this study it was based on population density, sex ratio and spatial arrangement. This approach provides a useful tool for (1) isolating the effect of mate availability in variable mating systems and (2) in combination with genetic parentage analyses, gaining insights into the nature of mating behaviours in elusive species. To illustrate this modelling approach, we have applied it to investigate the variable mating system of the mountain brushtail possum (Trichosurus cunninghami) and compared the model expectations with the outcomes of genetic parentage analysis over an 18-year study. The observed level of monogamy was higher than predicted under the model. Thus, behavioural traits, such as mate guarding or selective mate choice, may increase the population level of monogamy. We show that combining genetic parentage data with probability modelling can facilitate an improved understanding of the complex interactions between behavioural adaptations and demographic dynamics in driving mating system variation. © 2011 Blackwell Publishing Ltd.

Impacts of biogeographic history and marginal population genetics on species range limits: a case study of Liriodendron chinense.

PubMed

Yang, Aihong; Dick, Christopher W; Yao, Xiaohong; Huang, Hongwen

2016-05-10

Species ranges are influenced by past climate oscillations, geographical constraints, and adaptive potential to colonize novel habitats at range limits. This study used Liriodendron chinense, an important temperate Asian tree species, as a model system to evaluate the roles of biogeographic history and marginal population genetics in determining range limits. We examined the demographic history and genetic diversity of 29 L. chinense populations using both chloroplast and nuclear microsatellite loci. Significant phylogeographic structure was recovered with haplotype clusters coinciding with major mountain regions. Long-term demographical stability was suggested by mismatch distribution analyses, neutrality tests, and ecological niche models (ENM) and suggested the existence of LGM refuges within mountain regions. Differences in genetic diversity between central and marginal populations were not significant for either genomic region. However, asymmetrical gene flow was inferred from central populations to marginal populations, which could potentially limit range adaptation and expansion of L. chinense.

The association between unemployment and depression-Results from the population-based LIFE-adult-study.

PubMed

Zuelke, Andrea E; Luck, Tobias; Schroeter, Matthias L; Witte, A Veronica; Hinz, Andreas; Engel, Christoph; Enzenbach, Cornelia; Zachariae, Silke; Loeffler, Markus; Thiery, Joachim; Villringer, Arno; Riedel-Heller, Steffi G

2018-08-01

Unemployment is a risk factor for impaired mental health. Based on a large population-based sample, in this study we therefore sought to provide detailed information on the association between unemployment and depression including information on (i) differences between men and women, (ii) differences between different types of unemployment, and (iii) on the impact of material and social resources on the association. We studied 4,842 participants (18-65 years) of the population-based LIFE-Adult-Study. Depression was assessed using the Center for Epidemiological Studies Depression Scale. Employment status was divided into three groups: being employed, being unemployed receiving entitlement-based benefits, being unemployed receiving means-tested benefits. Multivariate logistic regression models were applied to assess the association between employment status and depression. Statistically significantly increased depression risk was solely found for unemployed persons receiving means-tested benefits. Adjusting for differences in sociodemographic factors, net personal income and risk of social isolation, comparable associations of being unemployed and receiving means-tested benefits with elevated depression risk were found for men (Odds Ratio/OR = 2.17, 95%-CI = 1.03-4.55) and women (OR = 1.98, 95%-CI:1.22-3.20). No conclusions regarding causality can be drawn due to the cross-sectional study design. It was not possible to assess length of unemployment spells. Unemployed persons receiving means-tested benefits in Germany constitute a risk group for depression that needs specific attention in the health care and social security system. The negative impact of unemployment on depression risk cannot be explained solely by differences in material and social resources. Contrasting earlier results, women are equally affected as men. Copyright © 2018 Elsevier B.V. All rights reserved.

Measuring limitations in activities of daily living: a population-based validation of a short questionnaire.

PubMed

Elfering, Achim; Cronenberg, Sonja; Grebner, Simone; Tamcan, Oezguer; Müller, Urs

2017-12-01

A newly developed questionnaire assessing limitations in activity of daily living (LADL-Q) that should improve assessment of LADL is tested in a large population-based validation study. This survey was paper-based. Overall, 16,634 individuals who were representative of the working population in the German-speaking part of Switzerland participated in the study. Item analysis was used the final version of the LADL-Q to four items per subscale that correspond to potential problems in three body regions (back and neck, upper extremities, lower extremities). Analysis included tests for reliability, internal consistency, dimensionality and convergent validity. Test-retest reliability coefficients after 2 weeks ranged from 0.82 to 0.99 (Mdn = 0.87), with no item having a coefficient below 0.60. The median item-total coefficients ranged between moderate and good. Correlation coefficients between LADL-Q subscales and three validated clinical instruments (Western Ontario and McMaster Universities osteoarthritis index, shoulder pain disability index, Oswestry) ranged from 0.63 to 0.81. In structural equation modeling the three subscales were significantly related with two important outcomes in occupational rehabilitation: self-reported general health and daily task performance. The new LADL-Q is a brief, reliable and valid tool for assessment of LADL in studies on musculoskeletal health.

Effect of geographical and ethnic variation on Dysphonia Severity Index: a study of Indian population.

PubMed

Jayakumar, T; Savithri, S R

2012-01-01

Dysphonia Severity Index (DSI) is a widely used multiparametric approach to objectively quantify the voice quality. Few research groups have investigated the test-retest, interobserver variability, and influence of age and gender. They have also verified the application of DSI in various voice rehabilitation conditions. However, all these studies have been conducted on European population. There is a possibility of variation in the basic parameters of DSI across geographical and ethnic groups. Hence, the present study evaluated DSI in Indian population. One hundred twenty voluntary participants (60 males, 60 females) who had G(0) on the Grade, Roughness, Breathiness, Aesthenia, Strain (GRBAS) scale participated in the study (age range of 18-25 years, M=21.8, standard deviation=2.7). Maximum phonation time (MPT), frequency intensity, and jitter measurements were made using CSL 4500 (Kay Elemetrics, Pine Brook, NJ). Results showed noticeable difference between Indian and European population on MPT, Highest frequency (F(0)-High), and DSI values. Significant gender difference was also observed on MPT and F(0)-High. Test-retest reliability showed >95% for all the parameters. The MPT decrement lead to a reduction in the overall DSI value in both the genders. These results of the study caution voice professionals to reinvestigate and establish their own norms for their geographical and ethnic groups. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Development and verification of a model for estimating the screening utility in the detection of PCBs in transformer oil.

PubMed

Terakado, Shingo; Glass, Thomas R; Sasaki, Kazuhiro; Ohmura, Naoya

2014-01-01

A simple new model for estimating the screening performance (false positive and false negative rates) of a given test for a specific sample population is presented. The model is shown to give good results on a test population, and is used to estimate the performance on a sampled population. Using the model developed in conjunction with regulatory requirements and the relative costs of the confirmatory and screening tests allows evaluation of the screening test's utility in terms of cost savings. Testers can use the methods developed to estimate the utility of a screening program using available screening tests with their own sample populations.

HIV rapid testing in the framework of an STI prevention project on a cohort of vulnerable Italians and immigrants.

PubMed

Uccella, Ilaria; Petrelli, Alessio; Vescio, Maria Fenicia; De Carolis, Silvia; Fazioli, Cecilia; Pezzotti, Patrizio; Rezza, Gianni

2017-08-01

Uptake of HIV tests is a challenging issue in vulnerable populations including immigrants, normally using standard diagnostic tools. Objectives of this study were to evaluate the acceptability of HIV rapid test; estimate the percentage of newly HIV diagnoses and evaluate knowledge, attitudes and perception (KAP) about HIV/AIDS and other STIs in a specific set of immigrants and vulnerable population in Rome (Italy). All immigrant and Italian people, aged 16-70 years, attending the infectious disease outpatient clinic of the National Institute for Health, Migration and Poverty (INMP) in Rome (Italy), during the period December 2012 to December 2013 were enrolled. HIV rapid testing was provided for free and patients were asked to fill in a questionnaire evaluating KAP about HIV/STIs. All patients with risky sexual behaviours or with a recent diagnosis of STIs were invited to come back after 3-6 months and a post-counselling questionnaire was offered. Out of the total sample, 99.2% (n = 825) accepted the "rapid test" and 10 new HIV diagnoses were found (1.22%; 95% CI 0.58%-2.22%). Three hundred and eighty-five participants (47%) answered the entry questionnaire and 58 (15%) completed the follow-up. Overall, we found high knowledge about HIV/AIDS; however, lower educational level and immigrant status were associated with poor knowledge about HIV, other STIs and prevention methods. Immigrants have lower perception of sexual risk and higher prejudice than Italians. Our study showed high acceptance of rapid test in this specific vulnerable population and this allowed to identify new HIV diagnoses in unaware people. Socioeconomic inequalities observed in the KAP questionnaire suggest the need for actions to support the reduction of cultural differences in knowledge of HIV/AIDS and for policies aimed at improving access to health services and preventions programmes of marginalized populations.

TEST BIAS--VALIDITY OF THE SCHOLASTIC APTITUDE TEST FOR NEGRO AND WHITE STUDENTS IN INTEGRATED COLLEGES.

ERIC Educational Resources Information Center

CLEARY, T. ANNE

FOR THIS RESEARCH, A TEST WAS SAID TO BE BIASED FOR MEMBERS OF A SUBGROUP OF THE POPULATION IF, IN THE PREDICTION OF A CRITERION FOR WHICH THE TEST WAS DESIGNED, CONSISTENT NONZERO ERRORS OF PREDICTION ARE MADE FOR MEMBERS OF THE SUBGROUP. SAMPLES OF NEGRO AND WHITE STUDENTS FROM THREE INTEGRATED COLLEGES WERE STUDIED. IN THE TWO EASTERN COLLEGES,…

Attitudes Toward Breast Cancer Genetic Testing in Five Special Population Groups.

PubMed

Ramirez, Amelie G; Chalela, Patricia; Gallion, Kipling J; Muñoz, Edgar; Holden, Alan E; Burhansstipanov, Linda; Smith, Selina A; Wong-Kim, Evaon; Wyatt, Stephen W; Suarez, Lucina

2015-01-01

This study examined interest in and attitudes toward genetic testing in 5 different population groups. The survey included African American, Asian American, Latina, Native American, and Appalachian women with varying familial histories of breast cancer. A total of 49 women were interviewed in person. Descriptive and nonparametric statistical techniques were used to assess ethnic group differences. Overall, interest in testing was high. All groups endorsed more benefits than risks. There were group differences regarding endorsement of specific benefits and risks: testing to "follow doctor recommendations" (p=0.017), "concern for effects on family" (p=0.044), "distrust of modern medicine" (p=0.036), "cost" (p=0.025), and "concerns about communication of results to others" (p=0.032). There was a significant inverse relationship between interest and genetic testing cost (p<0.050), with the exception of Latinas, who showed the highest level of interest regardless of increasing cost. Cost may be an important barrier to obtaining genetic testing services, and participants would benefit by genetic counseling that incorporates the unique cultural values and beliefs of each group to create an individualized, culturally competent program. Further research about attitudes toward genetic testing is needed among Asian Americans, Native Americans, and Appalachians for whom data are severely lacking. Future study of the different Latina perceptions toward genetic testing are encouraged.

Normative Data for the Hayling and Brixton Tests in an Italian Population.

PubMed

Spitoni, Grazia Fernanda; Bevacqua, Sara; Cerini, Claudia; Ciurli, Paola; Piccardi, Laura; Guariglia, Paola; Pezzuti, Lina; Antonucci, Gabriella

2018-06-01

The Hayling and Brixton tests constitute a short test battery that quickly assesses verbal and spatial inhibition and flexibility. This battery has shown high construct validity and strong reliability in clinical and experimental settings. The aim of this study was to develop an Italian version of the Hayling and Brixton tests and obtain normative values. We collected normative data from 301 healthy Italian participants aged between 16 and 94 years, taking into account all demographics. To maximize the sample size, we used the overlapping interval strategy. Adjusted scores for demographics were obtained by linear regression analysis. The performance on the Hayling and Brixton tests was influenced by age and education. In particular, age affected verbal accuracy and response time on the Hayling Sentence Completion Test, whereas education only affected the former. Differently, the spatial component, as measured by the Brixton Spatial Anticipation Test, was shaped only by age, which decreased the number of correct responses. Our study provides normative data that have been adjusted for relevant demographics and percentile grids in an Italian population. Our data support the use of the Hayling and Brixton tests as a valid instrument for performing neuropsychological evaluations and longitudinal analyses of executive functions in clinical practice and for research purposes.

Cost-effectiveness of Population Screening for BRCA Mutations in Ashkenazi Jewish Women Compared With Family History–Based Testing

PubMed Central

Manchanda, Ranjit; Legood, Rosa; Burnell, Matthew; McGuire, Alistair; Raikou, Maria; Loggenberg, Kelly; Wardle, Jane; Sanderson, Saskia; Gessler, Sue; Side, Lucy; Balogun, Nyala; Desai, Rakshit; Kumar, Ajith; Dorkins, Huw; Wallis, Yvonne; Chapman, Cyril; Taylor, Rohan; Jacobs, Chris; Tomlinson, Ian; Beller, Uziel; Menon, Usha

2015-01-01

Background: Population-based testing for BRCA1/2 mutations detects the high proportion of carriers not identified by cancer family history (FH)–based testing. We compared the cost-effectiveness of population-based BRCA testing with the standard FH-based approach in Ashkenazi Jewish (AJ) women. Methods: A decision-analytic model was developed to compare lifetime costs and effects amongst AJ women in the UK of BRCA founder-mutation testing amongst: 1) all women in the population age 30 years or older and 2) just those with a strong FH (≥10% mutation risk). The model assumes that BRCA carriers are offered risk-reducing salpingo-oophorectomy and annual MRI/mammography screening or risk-reducing mastectomy. Model probabilities utilize the Genetic Cancer Prediction through Population Screening trial/published literature to estimate total costs, effects in terms of quality-adjusted life-years (QALYs), cancer incidence, incremental cost-effectiveness ratio (ICER), and population impact. Costs are reported at 2010 prices. Costs/outcomes were discounted at 3.5%. We used deterministic/probabilistic sensitivity analysis (PSA) to evaluate model uncertainty. Results: Compared with FH-based testing, population-screening saved 0.090 more life-years and 0.101 more QALYs resulting in 33 days’ gain in life expectancy. Population screening was found to be cost saving with a baseline-discounted ICER of -£2079/QALY. Population-based screening lowered ovarian and breast cancer incidence by 0.34% and 0.62%. Assuming 71% testing uptake, this leads to 276 fewer ovarian and 508 fewer breast cancer cases. Overall, reduction in treatment costs led to a discounted cost savings of £3.7 million. Deterministic sensitivity analysis and 94% of simulations on PSA (threshold £20000) indicated that population screening is cost-effective, compared with current NHS policy. Conclusion: Population-based screening for BRCA mutations is highly cost-effective compared with an FH-based approach in AJ women age 30 years and older. PMID:25435542

Screening athletes with Down syndrome for ocular disease.

PubMed

Gutstein, Walter; Sinclair, Stephen H; North, Rachel V; Bekiroglu, N

2010-02-01

Persons with Down syndrome are well known to have a high prevalence of vision and eye health problems, many of which are undetected or untreated primarily because of infrequent ocular examinations. Public screening programs, directed toward the pediatric population, have become more popular and commonly use letter or symbol charts. This study compares 2 vision screening methods, the Lea Symbol chart and a newly developed interactive computer program, the Vimetrics Central Vision Analyzer (CVA), in their ability to identify ocular disease in the Down syndrome population. Athletes with Down syndrome participating in the European Special Olympics underwent an ocular screening including history, auto-refraction, colour vision assessment, stereopsis assessment, motility assessment, pupil reactivity, and tonometry testing, as well as anterior segment and fundus examinations to evaluate for ocular disease. Visual acuity was tested with the Lea chart and CVA to evaluate these as screening tests for detecting ocular disease as well as significant, uncorrected refractive errors. Among the 91 athletes that presented to the screening, 79 (158 eyes) were sufficiently cooperative for the examination to be completed. Mean age was 26 years +/-10.8 SD. Significant, uncorrected refractive errors (>/=1.00 spherical equivalent) were detected in 28 (18%) eyes and ocular pathology in 51 (32%) eyes. The Lea chart sensitivity and specificity were 43% and 74%, respectively, for detecting ocular pathology and 58% and 100% for detecting uncorrected refractive errors. The CVA sensitivity and specificity were 70% and 86% for detecting pathology and 71% and 100% for detecting uncorrected refractive errors. This study confirmed the findings of prior studies in identifying a significant presence of uncorrected refractive errors and ocular pathology in the Down syndrome population. Screening with the Lea symbol chart found borderline sufficient sensitivity and specificity for the test to be used for screening in this population. The better sensitivity and specificity of the CVA, if adjusted normative values are utilized, appear to make this test sufficient for testing Down syndrome children for identifying both refractive errors and ocular pathology. Copyright 2010 American Optometric Association. Published by Elsevier Inc. All rights reserved.

Academic performance in adolescence after inguinal hernia repair in infancy: a nationwide cohort study.

PubMed

Hansen, Tom G; Pedersen, Jacob K; Henneberg, Steen W; Pedersen, Dorthe A; Murray, Jeffrey C; Morton, Neil S; Christensen, Kaare

2011-05-01

Although animal studies have indicated that general anesthetics may result in widespread apoptotic neurodegeneration and neurocognitive impairment in the developing brain, results from human studies are scarce. We investigated the association between exposure to surgery and anesthesia for inguinal hernia repair in infancy and subsequent academic performance. Using Danish birth cohorts from 1986-1990, we compared the academic performance of all children who had undergone inguinal hernia repair in infancy to a randomly selected, age-matched 5% population sample. Primary analysis compared average test scores at ninth grade adjusting for sex, birth weight, and paternal and maternal age and education. Secondary analysis compared the proportions of children not attaining test scores between the two groups. From 1986-1990 in Denmark, 2,689 children underwent inguinal hernia repair in infancy. A randomly selected, age-matched 5% population sample consists of 14,575 individuals. Although the exposure group performed worse than the control group (average score 0.26 lower; 95% CI, 0.21-0.31), after adjusting for known confounders, no statistically significant difference (-0.04; 95% CI, -0.09 to 0.01) between the exposure and control groups could be demonstrated. However, the odds ratio for test score nonattainment associated with inguinal hernia repair was 1.18 (95% CI, 1.04-1.35). Excluding from analyses children with other congenital malformations, the difference in mean test scores remained nearly unchanged (0.05; 95% CI, 0.00-0.11). In addition, the increased proportion of test score nonattainment within the exposure group was attenuated (odds ratio = 1.13; 95% CI, 0.98-1.31). In the ethnically and socioeconomically homogeneous Danish population, we found no evidence that a single, relatively brief anesthetic exposure in connection with hernia repair in infancy reduced academic performance at age 15 or 16 yr after adjusting for known confounding factors. However, the higher test score nonattainment rate among the hernia group could suggest that a subgroup of these children are developmentally disadvantaged compared with the background population.

Validity of the Medical College Admission Test for Predicting MD-PhD Student Outcomes

ERIC Educational Resources Information Center

Bills, James L.; VanHouten, Jacob; Grundy, Michelle M.; Chalkley, Roger; Dermody, Terence S.

2016-01-01

The Medical College Admission Test (MCAT) is a quantitative metric used by MD and MD-PhD programs to evaluate applicants for admission. This study assessed the validity of the MCAT in predicting training performance measures and career outcomes for MD-PhD students at a single institution. The study population consisted of 153 graduates of the…

A proposed framework for evaluating and comparing efficacy estimates in clinical trials of new rotavirus vaccines.

PubMed

Neuzil, Kathleen M; Zaman, K; Victor, John C

2014-08-11

Oral rotavirus vaccines have yielded different point estimates of efficacy when tested in different populations. While population and environmental factors may account for these differences, study design characteristics should also be considered. We review the study design elements of rotavirus vaccine trials that may affect point estimates of efficacy, and propose a framework for evaluating new rotavirus vaccines. Copyright © 2014. Published by Elsevier Ltd.

Ancestry informative markers for distinguishing between Thai populations based on genome-wide association datasets

PubMed Central

Vongpaisarnsin, Kornkiat; Listman, Jennifer Beth; Malison, Robert T; Gelernter, Joel

2015-01-01

The main purpose of this work was to identify a set of AIMs that stratify the genetic structure and diversity of the Thai population from a high-throughput autosomal genome-wide association study. In this study, more than one million SNPs from the International HapMap database and the Thai depression genome-wide association study have been examined to identify ancestry informative markers (AIMs) that distinguish between Thai populations. An efficient strategy is proposed to identify and characterize such SNPs and to test high-resolution SNP data from international HapMap populations. The best AIMs are identified to stratify the population and to infer genetic ancestry structure. A total of 124 AIMs were clearly clustered geographically across the continent, whereas only 89 AIMs stratified the Thai population from East Asian populations. Finally, a set of 273 AIMs was able to distinguish northern from southern Thai subpopulations. These markers will be of particular value in identifying the ethnic origins in regions where matching by self-reports is unavailable or unreliable, which usually occurs in real forensic cases. PMID:25759192

Ancestry informative markers for distinguishing between Thai populations based on genome-wide association datasets.

PubMed

Vongpaisarnsin, Kornkiat; Listman, Jennifer Beth; Malison, Robert T; Gelernter, Joel

2015-07-01

The main purpose of this work was to identify a set of AIMs that stratify the genetic structure and diversity of the Thai population from a high-throughput autosomal genome-wide association study. In this study, more than one million SNPs from the international HapMap database and the Thai depression genome-wide association study have been examined to identify ancestry informative markers (AIMs) that distinguish between Thai populations. An efficient strategy is proposed to identify and characterize such SNPs and to test high-resolution SNP data from international HapMap populations. The best AIMs are identified to stratify the population and to infer genetic ancestry structure. A total of 124 AIMs were clearly clustered geographically across the continent, whereas only 89 AIMs stratified the Thai population from East Asian populations. Finally, a set of 273 AIMs was able to distinguish northern from southern Thai subpopulations. These markers will be of particular value in identifying the ethnic origins in regions where matching by self-reports is unavailable or unreliable, which usually occurs in real forensic cases. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Disease, predation and demography: Assessing the impacts of bovine tuberculosis on African buffalo by monitoring at individual and population levels

USGS Publications Warehouse

Cross, P.C.; Heisey, D.M.; Bowers, J.A.; Hay, C.T.; Wolhuter, J.; Buss, P.; Hofmeyr, M.; Michel, A.L.; Bengis, Roy G.; Bird, T.L.F.; du Toit, Johan T.; Getz, W.M.

2009-01-01

1. Understanding the effects of disease is critical to determining appropriate management responses, but estimating those effects in wildlife species is challenging. We used bovine tuberculosis (BTB) in the African buffalo Syncerus caffer population of Kruger National Park, South Africa, as a case study to highlight the issues associated with estimating chronic disease effects in a long-lived host. 2. We used known and radiocollared buffalo, aerial census data, and a natural gradient in pathogen prevalence to investigate if: (i) at the individual level, BTB infection reduces reproduction; (ii) BTB infection increases vulnerability to predation; and (iii) at the population level, increased BTB prevalence causes reduced population growth. 3. There was only a marginal reduction in calving success associated with BTB infection, as indexed by the probability of sighting a known adult female with or without a calf (P = 0??065). 4. Since 1991, BTB prevalence increased from 27 to 45% in the southern region and from 4 to 28% in the central region of Kruger National Park. The prevalence in the northern regions was only 1??5% in 1998. Buffalo population growth rates, however, were neither statistically different among regions nor declining over time. 5. Lions Panthera leo did not appear to preferentially kill test-positive buffalo. The best (Akaike's Information Criterion corrected for small sample size) AICc model with BTB as a covariate [exp(??) = 0??49; 95% CI = (0??24-1??02)] suggested that the mortality hazard for positive individuals was no greater than for test-negative individuals. 6. Synthesis and applications. Test accuracy, time-varying disease status, and movement among populations are some of the issues that make the detection of chronic disease impacts challenging. For these reasons, the demographic impacts of bovine tuberculosis in the Kruger National Park remain undetectable despite 6 years of study on known individuals and 40 years of population counts. However, the rainfall and forage conditions during this study were relatively good and the impacts of many chronic diseases may be a non-linear function of environmental conditions such that they are only detectable in stressful periods. ?? 2008 British Ecological Society.

Evidence of carbamate resistance in urban populations of Anopheles gambiae s.s. mosquitoes resistant to DDT and deltamethrin insecticides in Lagos, South-Western Nigeria

PubMed Central

2012-01-01

Background Resistance monitoring is essential in ensuring the success of insecticide based vector control programmes. This study was carried out to assess the susceptibility status of urban populations of Anopheles gambiae to carbamate insecticide being considered for vector control in mosquito populations previously reported to be resistant to DDT and permethrin. Methods Two – three day old adult female Anopheles mosquitoes reared from larval collections in 11 study sites from Local Government Areas of Lagos were exposed to test papers impregnated with DDT 4%, deltamethrin 0.05% and propoxur 0.1% insecticides. Additional tests were carried out to determine the susceptibility status of the Anopheles gambiae population to bendiocarb insecticide. Members of the A. gambiae complex, the molecular forms, were identified by PCR assays. The involvement of metabolic enzymes in carbamate resistance was assessed using Piperonyl butoxide (PBO) synergist assays. The presence of kdr-w/e and ace-1R point mutations responsible for DDT-pyrethroid and carbamate resistance mechanisms was also investigated by PCR. Results Propoxur resistance was found in 10 out of the 11 study sites. Resistance to three classes of insecticides was observed in five urban localities. Mortality rates in mosquitoes exposed to deltamethrin and propoxur did not show any significant difference (P > 0.05) but was significantly higher (P < 0.05) in populations exposed to DDT. All mosquitoes tested were identified as A. gambiae s.s (M form). The kdr -w point mutation at allelic frequencies between 45%-77% was identified as one of the resistant mechanisms responsible for DDT and pyrethroid resistance. Ace-1R point mutation was absent in the carbamate resistant population. However, the possible involvement of metabolic resistance was confirmed by synergistic assays conducted. Conclusion Evidence of carbamate resistance in A. gambiae populations already harbouring resistance to DDT and permethrin is a clear indication that calls for the implementation of insecticide resistance management strategies to combat the multiple resistance identified. PMID:22686575

Population genetic structure in Atlantic and Pacific Ocean common murres (Uria aalge): Natural replicate tests of post-Pleistocene evolution

USGS Publications Warehouse

Morris-Pocock, J. A.; Taylor, S.A.; Birt, T.P.; Damus, M.; Piatt, John F.; Warheit, K.I.; Friesen, Vicki L.

2008-01-01

Understanding the factors that influence population differentiation in temperate taxa can be difficult because the signatures of both historic and contemporary demographics are often reflected in population genetic patterns. Fortunately, analyses based on coalescent theory can help untangle the relative influence of these historic and contemporary factors. Common murres (Uria aalge) are vagile seabirds that breed in the boreal and low arctic waters of the Northern Hemisphere. Previous analyses revealed that Atlantic and Pacific populations are genetically distinct; however, less is known about population genetic structure within ocean basins. We employed the mitochondrial control region, four microsatellite loci and four intron loci to investigate population genetic structure throughout the range of common murres. As in previous studies, we found that Atlantic and Pacific populations diverged during the Pleistocene and do not currently exchange migrants. Therefore, Atlantic and Pacific murre populations can be used as natural replicates to test mechanisms of population differentiation. While we found little population genetic structure within the Pacific, we detected significant east-west structuring among Atlantic colonies. The degree that population genetic structure reflected contemporary population demographics also differed between ocean basins. Specifically, while the low levels of population differentiation in the Pacific are at least partially due to high levels of contemporary gene flow, the east-west structuring of populations within the Atlantic appears to be the result of historic fragmentation of populations rather than restricted contemporary gene flow. The contrasting results in the Atlantic and Pacific Oceans highlight the necessity of carefully considering multilocus nonequilibrium population genetic approaches when reconstructing the demographic history of temperate Northern Hemisphere taxa. ?? 2008 The Authors.

Evaluation of the genetic parameters and mutation analysis of 22 STR loci in the central Chinese Han population.

PubMed

Hongdan, Wang; Bing, Kang; Ning, Su; Miao, He; Bo, Zhang; Yuxin, Guo; Bofeng, Zhu; Shixiu, Liao; Zhaoshu, Zeng

2017-01-01

At present, the Han nationality is China's main ethnic group and also the most populous nation in the world. This is a great resource to study microsatellite mutations and for the study of ethnogeny. The aim of this study is to investigate the genetic polymorphisms and mutations of 22 autosomal STR loci in 2475 individuals from Henan province, China. DNA is amplified and genotyped using PowerPlex™24 system. The gene frequencies, forensic parameters, and the mutation rate of the 22 STR loci are analyzed. A total of 295 alleles are observed in this Henan Han population, and the allelic frequencies ranged from 0.0003 to 0.5036. In order to investigate the genetic relationships between the Henan Han and the other 14 different populations, our present data were compared with previously published data for the same 15 STR loci. The results indicated that the Henan Han had closer genetic relationships the groups including Minnan Han, Maonan, Yi and Guangdong Han groups while the South morocco population, the Moroccan population, the Malay group, and the Uigur stand away from Henan Han. Except of D2S441, D13S317, PentaE, D2S1338, D5S818, TPOX and D19S433, the mutation events are found in the other 15 STR loci. A total of 40 mutation events are observed in the 15 STR loci. The mutation rates are ranged from 0 to 4.85 × 10 -3 . In this study, 39 mutations are single-step mutations, and only one at FGA comprised two steps. STR mutation is commonly existed in paternity testing, while there are no STR mutation studies of the 22 STR loci in the Henan Han population. It is of great importance in forensic individual discrimination and paternal testing.

Adaptive variation in Pinus ponderosa from Intermountain Regions. I. Snake and Salmon River Basins

Treesearch

Gerald Rehfeldt

1986-01-01

Genetic differentiation of 64 populations from central Idaho was studied in field, greenhouse and laboratory tests. Analyses of variables reflecting growth potential, phenology, morphology, cold hardiness and periodicity of shoot elongation revealed population differentiation for a variety of traits. Regression models related as much as 61 percent of the variance among...

From American City to Japanese Village: A Cross-Cultural Investigation of Implicit Race Attitudes

ERIC Educational Resources Information Center

Dunham, Yarrow; Baron, Andrew Scott; Banaji, Mahzarin R.

2006-01-01

This study examined the development of implicit race attitudes in American and Japanese children and adults. Implicit ingroup bias was present early in both populations, and remained stable at each age tested (age 6, 10, and adult). Similarity in magnitude and developmental course across these 2 populations suggests that implicit intergroup bias…

Subjective Evaluations of Intelligence and Academic Self-Concept Predict Academic Achievement: Evidence from a Selective Student Population

ERIC Educational Resources Information Center

Kornilova, Tatiana V.; Kornilov, Sergey A.; Chumakova, Maria A.

2009-01-01

The study examined the relationship between implicit theories, goal orientations, subjective and test estimates of intelligence, academic self-concept, and achievement in a selective student population (N=300). There was no direct impact of implicit theories of intelligence and goal orientations on achievement. However, subjective evaluations of…

Collaborative Analysis of DRD4 and DAT Genotypes in Population-Defined ADHD Subtypes

ERIC Educational Resources Information Center

Todd, Richard D.; Huang, Hongyan; Smalley, Susan L.; Nelson, Stanley F.; Willcutt, Erik G.; Pennington, Bruce F.; Smith, Shelley D.; Faraone, Stephen V.; Neuman, Rosalind J.

2005-01-01

Background: It has been proposed that some of the variability in reporting of associations between attention deficit hyperactivity disorder (ADHD) and candidate genes may result from mixing of genetically heterogeneous forms of ADHD using DSM-IV criteria. The goal of the current study is to test whether population-based ADHD subtypes defined by…

Inferring the origin of populations introduced from a genetically structured native range by approximate Bayesian computation: case study of the invasive ladybird Harmonia axyridis

USDA-ARS?s Scientific Manuscript database

The correct identification of the source population of an invasive species is a prerequisite for defining and testing different hypotheses concerning the environmental and evolutionary factors responsible for biological invasions. The native area of invasive species may be large, barely known and/or...

Estimating chlamydia screening coverage: a comparison of self-report and health care effectiveness data and information set measures.

PubMed

Khosropour, Christine M; Broad, Jennifer M; Scholes, Delia; Saint-Johnson, Jacquelyn; Manhart, Lisa E; Golden, Matthew R

2014-11-01

Population-based surveys (self-report) and health insurance administrative data (Healthcare Effectiveness Data and Information Set [HEDIS]) are used to estimate chlamydia screening coverage in the United States. Estimates from these methods differ, but few studies have compared these 2 indices in the same population. In 2010, we surveyed a random sample of women aged 18 to 25 years enrolled in a Washington State-managed care organization. Respondents were asked if they were sexually active in last year and if they tested for chlamydia in that time. We linked survey responses to administrative records of chlamydia testing and reproductive/testing services used, which comprise the HEDIS definition of the screened population and the sexually active population, respectively. We compared self-report and HEDIS using 3 outcomes: (1) sexual activity (gold standard = self-report), (2) any chlamydia screening (no gold standard), and (3) within-plan chlamydia screening (gold standard = HEDIS). Of 954 eligible respondents, 377 (40%) completed the survey and consented to administrative record linkage. Chlamydia screening estimates for HEDIS and self-report were 47% and 53%, respectively. The sensitivity and specificity of HEDIS to define sexually active women were 84.8% (95% confidence interval [CI], 79.6%-89.1%) and 63.5% (95% CI, 52.4%-73.7%), respectively. Forty percent of women had a chlamydia test in their administrative record, but 53% self-reported being tested for chlamydia (κ = 0.35); 19% reported out-of-plan chlamydia testing. The sensitivity of self-reported within-plan chlamydia testing was 71.3% (95% CI, 61.0%-80.1%); the specificity was 80.6% (95% CI, 72.6%-87.2%). The Healthcare Effectiveness Data and Information Set does not accurately identify sexually active women and may underestimate chlamydia testing coverage. Self-reported testing may not be an accurate measure of true chlamydial testing coverage.

Periorbital Biometric Measurements using ImageJ Software: Standardisation of Technique and Assessment Of Intra- and Interobserver Variability

PubMed Central

Rajyalakshmi, R.; Prakash, Winston D.; Ali, Mohammad Javed; Naik, Milind N.

2017-01-01

Purpose: To assess the reliability and repeatability of periorbital biometric measurements using ImageJ software and to assess if the horizontal visible iris diameter (HVID) serves as a reliable scale for facial measurements. Methods: This study was a prospective, single-blind, comparative study. Two clinicians performed 12 periorbital measurements on 100 standardised face photographs. Each individual’s HVID was determined by Orbscan IIz and used as a scale for measurements using ImageJ software. All measurements were repeated using the ‘average’ HVID of the study population as a measurement scale. Intraclass correlation coefficient (ICC) and Pearson product-moment coefficient were used as statistical tests to analyse the data. Results: The range of ICC for intra- and interobserver variability was 0.79–0.99 and 0.86–0.99, respectively. Test-retest reliability ranged from 0.66–1.0 to 0.77–0.98, respectively. When average HVID of the study population was used as scale, ICC ranged from 0.83 to 0.99, and the test-retest reliability ranged from 0.83 to 0.96 and the measurements correlated well with recordings done with individual Orbscan HVID measurements. Conclusion: Periorbital biometric measurements using ImageJ software are reproducible and repeatable. Average HVID of the population as measured by Orbscan is a reliable scale for facial measurements. PMID:29403183

Effect of Instruction in Emotional Intelligence Skills on Locus of Control and Academic Self-Efficacy among Junior Secondary School Students in Niger State, Nigeria

ERIC Educational Resources Information Center

Umaru, Yunusa; Umma, Abdulwahid

2015-01-01

This study investigated the effect of instruction in emotional intelligence Skills on locus of control and academic self-efficacy among junior secondary school students in Niger state, Nigeria. This study employed a quasi-experimental, non-equivalent control group, pre-test - post-test design. The population of this study was 105,034 secondary…

Which One Is Better? Jigsaw II versus Jigsaw IV on the Subject of the Building Blocks of Matter and Atom

ERIC Educational Resources Information Center

Turkmen, Hakan; Buyukaltay, Didem

2015-01-01

In this study, the effect of using Jigsaw II and Jigsaw IV techniques on the subject of "Atoms-The Basic Unit of Matter" in science course of 6th grade on academic achievement was examined. Pre-test post-test control group research was used in the study. Study population is all secondary schools in Turgutlu district of Manisa province…

Repeatability and degree of territorial aggression differs among urban and rural great tits (Parus major).

PubMed

Hardman, Samuel I; Dalesman, Sarah

2018-03-22

Animals in urban habitats face many novel selection pressures such as increased human population densities and human disturbance. This is predicted to favour bolder and more aggressive individuals together with greater flexibility in behaviour. Previous work has focussed primarily on studying these traits in captive birds and has shown increased aggression and reduced consistency between traits (behavioural syndromes) in birds from urban populations. However, personality (consistency within a behavioural trait) has not been well studied in the wild. Here we tested whether urban free-living male great tits show greater territorial aggression than rural counterparts. We also tested predictions that both behavioural syndromes and personality would show lower consistency in urban populations. We found that urban populations were more aggressive than rural populations and urban birds appeared to show lower levels of individual behavioural repeatability (personality) as predicted. However, we found no effect of urbanisation on behavioural syndromes (correlations between multiple behavioural traits). Our results indicate that urban environments may favour individuals which exhibit increased territorial aggression and greater within-trait flexibility which may be essential to success in holding urban territories. Determining how urban environments impact key fitness traits will be important in predicting how animals cope with ongoing urbanisation.

Chloroplast microsatellites reveal colonization and metapopulation dynamics in the Canary Island pine

PubMed Central

Navascués, Miguel; Vaxevanidou, Zafeiro; González-Martínez, Santiago C; Climent, José; Gil, Luis; Emerson, Brent C

2006-01-01

Chloroplast microsatellites are becoming increasingly popular markers for population genetic studies in plants, but there has been little focus on their potential for demographic inference. In this work the utility of chloroplast microsatellites for the study of population expansions was explored. First, we investigated the power of mismatch distribution analysis and the FS test with coalescent simulations of different demographic scenarios. We then applied those methods to empirical data obtained for the Canary Island pine (Pinus canariensis). The results of the simulations showed that chloroplast microsatellites are sensitive to sudden population growth. The power of the FS test and accuracy of demographic parameter estimates, such as the time of expansion, were reduced proportionally to the level of homoplasy within the data. The analysis of Canary Island pine chloroplast microsatellite data indicated population expansions for almost all sample localities. Demographic expansions at the island level can be explained by the colonisation of the archipelago by the pine, while population expansions of different ages in different localities within an island appear to be the result of local extinctions and recolonisation dynamics. Comparable mitochondrial DNA sequence data from a parasite of P. canariensis, the weevil Brachyderes rugatus, supports this scenario, suggesting a key role for volcanism in the evolution of pine forest communities in the Canary Islands. PMID:16911194

Deeper Insights into the Circumgalactic Medium using Multivariate Analysis Methods

NASA Astrophysics Data System (ADS)

Lewis, James; Churchill, Christopher W.; Nielsen, Nikole M.; Kacprzak, Glenn

2017-01-01

Drawing from a database of galaxies whose surrounding gas has absorption from MgII, called the MgII-Absorbing Galaxy Catalog (MAGIICAT, Neilsen et al 2013), we studied the circumgalactic medium (CGM) for a sample of 47 galaxies. Using multivariate analysis, in particular the k-means clustering algorithm, we determined that simultaneously examining column density (N), rest-frame B-K color, virial mass, and azimuthal angle (the projected angle between the galaxy major axis and the quasar line of sight) yields two distinct populations: (1) bluer, lower mass galaxies with higher column density along the minor axis, and (2) redder, higher mass galaxies with lower column density along the major axis. We support this grouping by running (i) two-sample, two-dimensional Kolmogorov-Smirnov (KS) tests on each of the six bivariate planes and (ii) two-sample KS tests on each of the four variables to show that the galaxies significantly cluster into two independent populations. To account for the fact that 16 of our 47 galaxies have upper limits on N, we performed Monte-Carlo tests whereby we replaced upper limits with random deviates drawn from a Schechter distribution fit, f(N). These tests strengthen the results of the KS tests. We examined the behavior of the MgII λ2796 absorption line equivalent width and velocity width for each galaxy population. We find that equivalent width and velocity width do not show similar characteristic distinctions between the two galaxy populations. We discuss the k-means clustering algorithm for optimizing the analysis of populations within datasets as opposed to using arbitrary bivariate subsample cuts. We also discuss the power of the k-means clustering algorithm in extracting deeper physical insight into the CGM in relationship to host galaxies.

Feasibility of nonselective testing for hemoglobinopathies in early pregnancy in The Netherlands.

PubMed

Kaufmann, Judith O; Demirel-Güngör, Gönül; Selles, Anke; Hudig, Cisca; Steen, Gerard; Ponjee, Gabrielle; Holleboom, Cas; Freeman, Liv M; Hendiks, Joris; Wijermans, Pierre; Giordano, Piero C; Kerkhoffs, Jean-Louis

2011-12-01

To examine the feasibility of standardized hemoglobinopathy (HBP) carrier testing for pregnant women in The Netherlands in addition to the standard anemia screening. We assessed the prevalence of HBP in women at the time of the first pregnancy visit using both a prospective cohort (N = 703) and a retrospective series of women selected at random (N = 588). For the purpose of analysis, the population was divided into a high risk and a low risk group for HBP based on maternal ethnicity. Screening for HBP utilized standard screening tests for anemia, with additional high performance liquid chromatography (Variant II); molecular analysis was performed by Gap-polymerase chain reaction (Gap-PCR) and if necessary, direct sequencing and multiplex ligation-dependent probe amplification (MLPA). Family history was reported or collected from the medical records. β-Globin defects were found in 3.9% of the total population (50/1291). The frequency in the high risk population was 5.6% (37/656), compared with 1.2% (6/501) in the low risk group. In the prospective study we found 30 HBP carriers, leading to testing of 16 partners and identification of two couples at risk. One affected child was born. Mean gestational age at the screening was 11.3 weeks with a standard deviation (SD) of 5.8. We found that the prevalence of HBP carriers is high enough in our population to warrant HBP testing for the entire multiethnic population in early pregnancy at the time of anemia screening. This is feasible as most women had their booking early in their first trimester. Copyright © 2011 John Wiley & Sons, Ltd.

Family welfare and health practices increase after exposure to population education.

PubMed

1994-01-01

Since 1987, the State Resource Center of Jamia Millia Islamia of New Delhi has been implementing a program which integrates population education contents into its literacy education classes for adult learners. Using the core messages on family size, spacing of children, responsible parenthood, right age of marriage, population-related beliefs and customs and population and development, the Center undertook many activities such as: i) integrating population contents in literacy primers, readers and supplementary reading books; ii) development of teaching aids and instructor's resource materials; iii) organization of training for instructors and iv) holding outreach activities such as street corner plays, fairs, etc. To evaluate the impact of the program, the Center undertook an impact survey to measure the level of knowledge, attitude and practices of randomly selected beneficiaries of the project, i.e. 934 learners from 85 literacy learning centers, 5 years after the introduction of the population education program. The study used pre-test and post-test method for collecting data and to compare results. In terms of practice, the study has shown that the respondents having knowledge about family planning methods increased from 67 to 87%, after being exposed to the project's activities. There was also an increase of 61% in cases adopting family planning methods over the pre-measurement level. More importantly, there was not only an increase in awareness of public health and family welfare services but a 137% increase was registered in the use of public health and family welfare facilities for family planning counseling and services. With regard to knowledge and attitude on the various population education messages promoted by the project, the study has shown a 40% increase in "high" knowledge category and 25% increase in favorable attitude after the exposure to the project. full text

Trans-ethnic fine mapping identifies a novel independent locus at the 3' end of CDKAL1 and novel variants of several susceptibility loci for type 2 diabetes in a Han Chinese population.

PubMed

Kuo, Jane Z; Sheu, Wayne Huey-Herng; Assimes, Themistocles L; Hung, Yi-Jen; Absher, Devin; Chiu, Yen-Feng; Mak, Jordan; Wang, Jun-Sing; Kwon, Soonil; Hsu, Chih-Cheng; Goodarzi, Mark O; Lee, I-Te; Knowles, Joshua W; Miller, Brittany E; Lee, Wen-Jane; Juang, Jyh-Ming J; Wang, Tzung-Dau; Guo, Xiuqing; Taylor, Kent D; Chuang, Lee-Ming; Hsiung, Chao A; Quertermous, Thomas; Rotter, Jerome I; Chen, Yii-Der I

2013-12-01

Candidate gene and genome-wide association studies have identified ∼60 susceptibility loci for type 2 diabetes. A majority of these loci have been discovered and tested only in European populations. The aim of this study was to assess the presence and extent of trans-ethnic effects of these loci in an East Asian population. A total of 9,335 unrelated Chinese Han individuals, including 4,535 with type 2 diabetes and 4,800 non-diabetic ethnically matched controls, were genotyped using the Illumina 200K Metabochip. We tested 50 established loci for type 2 diabetes and related traits (fasting glucose, fasting insulin, 2 h glucose). Disease association with the additive model of inheritance was analysed with logistic regression. We found that 14 loci significantly transferred to the Chinese population, with two loci (p = 5.7 × 10(-12) for KCNQ1; p = 5.0 × 10(-8) for CDKN2A/B-CDKN2BAS) reaching independent genome-wide statistical significance. Five of these 14 loci had similar lead single-nucleotide polymorphisms (SNPs) as were found in the European studies while the other nine were different. Further stepwise conditional analysis identified a total of seven secondary signals and an independent novel locus at the 3' end of CDKAL1. These results suggest that many loci associated with type 2 diabetes are commonly shared between European and Chinese populations. Identification of population-specific SNPs may increase our understanding of the genetic architecture underlying type 2 diabetes in different ethnic populations.

An NCME Instructional Module on Population Invariance in Linking and Equating

ERIC Educational Resources Information Center

Huggins, Anne C.; Penfield, Randall D.

2012-01-01

A goal for any linking or equating of two or more tests is that the linking function be invariant to the population used in conducting the linking or equating. Violations of population invariance in linking and equating jeopardize the fairness and validity of test scores, and pose particular problems for test-based accountability programs that…

Comparison of Estrogen Receptor Assay Results from Pathology Reports with Results from Central Laboratory Testing: Implications for Population-Based Studies of Breast Cancer

PubMed Central

Collins, LC; Marotti, J; Baer, HJ; Deitz, AC; Colditz, GA; Tamimi, RM

2014-01-01

Population-based studies of women with breast cancer commonly utilize information culled from pathology reports rather than central pathology review. The reliability of this information, particularly with regard to tumor biomarker results, is of concern. To address this, we evaluated the concordance between estrogen receptor (ER) results as determined from the original pathology reports and ER results obtained on the same specimens following testing in a single laboratory. Tissue microarrays (TMAs) were constructed from paraffin blocks of 3,167 breast cancers that developed in women enrolled in the Nurses’ Health Study. ER immunostains were performed on all TMA sections in single run. Results of ER immunostains performed on the TMA sections were compared with ER assay results abstracted from pathology reports. Among 1,851 cases of invasive breast cancer in which both ER results from pathology reports and central ER test results were available, the reported ER status and the ER status as determined from immunostains on TMAs were in agreement in 1,651 cases (87.3 %; kappa value 0.64, p<0.0001). When the comparison was restricted to ER assays originally performed by immunohistochemistry, the agreement rate increased to 92.3% (kappa value 0.78, p<0.0001). These results provide a framework for the accuracy of ER results abstracted from clinical records. Further, they suggest that utilizing ER assay results from pathology reports is a reasonable, albeit imperfect, alternative to central laboratory ER testing for large, population-based studies of patients with breast cancer. PMID:18230800

Diagnostic accuracy of tests to detect Hepatitis C antibody: a meta-analysis and review of the literature.

PubMed

Tang, Weiming; Chen, Wen; Amini, Ali; Boeras, Debi; Falconer, Jane; Kelly, Helen; Peeling, Rosanna; Varsaneux, Olivia; Tucker, Joseph D; Easterbrook, Philippa

2017-11-01

Although direct-acting antivirals can achieve sustained virological response rates greater than 90% in Hepatitis C Virus (HCV) infected persons, at present the majority of HCV-infected individuals remain undiagnosed and therefore untreated. While there are a wide range of HCV serological tests available, there is a lack of formal assessment of their diagnostic performance. We undertook a systematic review and meta-analysis to evaluate he diagnostic accuracy of available rapid diagnostic tests (RDT) and laboratory based EIA assays in detecting antibodies to HCV. We used the PRISMA checklist and Cochrane guidance to develop our search protocol. The search strategy was registered in PROSPERO (CRD42015023567). The search focused on hepatitis C, diagnostic tests, and diagnostic accuracy within eight databases (MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Science Citation Index Expanded, Conference Proceedings Citation Index-Science, SCOPUS, Literatura Latino-Americana e do Caribe em Ciências da Saúde and WHO Global Index Medicus. Studies were included if they evaluated an assay to determine the sensitivity and specificity of HCV antibody (HCV Ab) in humans. Two reviewers independently extracted data and performed a quality assessment of the studies using the QUADAS tool. We pooled test estimates using the DerSimonian-Laird method, by using the software R and RevMan. 5.3. A total of 52 studies were identified that included 52,673 unique test measurements. Based on five studies, the pooled sensitivity and specificity of HCV Ab rapid diagnostic tests (RDTs) were 98% (95% CI 98-100%) and 100% (95% CI 100-100%) compared to an enzyme immunoassay (EIA) reference standard. High HCV Ab RDTs sensitivity and specificity were observed across screening populations (general population, high risk populations, and hospital patients) using different reference standards (EIA, nucleic acid testing, immunoblot). There were insufficient studies to undertake subanalyses based on HIV co-infection. Oral HCV Ab RDTs also had excellent sensitivity and specificity compared to blood reference tests, respectively at 94% (95% CI 93-96%) and 100% (95% CI 100-100%). Among studies that assessed individual oral RDTs, the eight studies revealed that OraQuick ADVANCE® had a slightly higher sensitivity (98%, 95% CI 97-98%) compared to the other oral brands (pooled sensitivity: 88%, 95% CI 84-92%). RDTs, including oral tests, have excellent sensitivity and specificity compared to laboratory-based methods for HCV antibody detection across a wide range of settings. Oral HCV Ab RDTs had good sensitivity and specificity compared to blood reference standards.