Zhivotovsky, Lev A; Malyarchuk, Boris A; Derenko, Miroslava V; Wozniak, Marcin; Grzybowski, Tomasz
2009-09-01
Developing a forensic DNA database on a population that consists of local ethnic groups separated by physical and cultural barriers is questionable as it can be genetically subdivided. On the other side, small sizes of ethnic groups, especially in alpine regions where they are sub-structured further into small villages, prevent collecting a large sample from each ethnic group. For such situations, we suggest to obtain both a total population database on allele frequencies across ethnic groups and a list of theta-values between the groups and the total data. We have genotyped 558 individuals from the native population of South Siberia, consisting of nine ethnic groups, at 17 autosomal STR loci of the kit packages AmpFlSTR SGM Plus i, Cyrillic AmpFlSTR Profiler Plus. The groups differentiate from each other with average theta-values of around 1.1%, and some reach up to three to four percent at certain loci. There exists between-village differentiation as well. Therefore, a database for the population of South Siberia is composed of data on allele frequencies in the pool of ethnic groups and data on theta-values that indicate variation in allele frequencies across the groups. Comparison to additional data on northeastern Asia (the Chukchi and Koryak) shows that differentiation in allele frequencies among small groups that are separated by large geographic distance can be even greater. In contrast, populations of Russians that live in large cities of the European part of Russia are homogeneous in allele frequencies, despite large geographic distance between them, and thus can be described by a database on allele frequencies alone, without any specific information on theta-values.
Emergent patterns in interacting neuronal sub-populations
NASA Astrophysics Data System (ADS)
Kamal, Neeraj Kumar; Sinha, Sudeshna
2015-05-01
We investigate an ensemble of coupled model neurons, consisting of groups of varying sizes and intrinsic dynamics, ranging from periodic to chaotic, where the inter-group coupling interaction is effectively like a dynamic signal from a different sub-population. We observe that the minority group can significantly influence the majority group. For instance, when a small chaotic group is coupled to a large periodic group, the chaotic group de-synchronizes. However, counter-intuitively, when a small periodic group couples strongly to a large chaotic group, it leads to complete synchronization in the majority chaotic population, which also spikes at the frequency of the small periodic group. It then appears that the small group of periodic neurons can act like a pacemaker for the whole network. Further, we report the existence of varied clustering patterns, ranging from sets of synchronized clusters to anti-phase clusters, governed by the interplay of the relative sizes and dynamics of the sub-populations. So these results have relevance in understanding how a group can influence the synchrony of another group of dynamically different elements, reminiscent of event-related synchronization/de-synchronization in complex networks.
Anagnostou, Paolo; Dominici, Valentina; Battaggia, Cinzia; Pagani, Luca; Vilar, Miguel; Wells, R. Spencer; Pettener, Davide; Sarno, Stefania; Boattini, Alessio; Francalacci, Paolo; Colonna, Vincenza; Vona, Giuseppe; Calò, Carla; Destro Bisol, Giovanni; Tofanelli, Sergio
2017-01-01
Human populations are often dichotomized into “isolated” and “open” categories using cultural and/or geographical barriers to gene flow as differential criteria. Although widespread, the use of these alternative categories could obscure further heterogeneity due to inter-population differences in effective size, growth rate, and timing or amount of gene flow. We compared intra and inter-population variation measures combining novel and literature data relative to 87,818 autosomal SNPs in 14 open populations and 10 geographic and/or linguistic European isolates. Patterns of intra-population diversity were found to vary considerably more among isolates, probably due to differential levels of drift and inbreeding. The relatively large effective size estimated for some population isolates challenges the generalized view that they originate from small founding groups. Principal component scores based on measures of intra-population variation of isolated and open populations were found to be distributed along a continuum, with an area of intersection between the two groups. Patterns of inter-population diversity were even closer, as we were able to detect some differences between population groups only for a few multidimensional scaling dimensions. Therefore, different lines of evidence suggest that dichotomizing human populations into open and isolated groups fails to capture the actual relations among their genomic features. PMID:28145502
Density-Dependent Effects on Group Size Are Sex-Specific in a Gregarious Ungulate
Vander Wal, Eric; van Beest, Floris M.; Brook, Ryan K.
2013-01-01
Density dependence can have marked effects on social behaviors such as group size. We tested whether changes in population density of a large herbivore (elk, Cervus canadensis) affected sex-specific group size and whether the response was density- or frequency-dependent. We quantified the probability and strength of changes in group sizes and dispersion as population density changed for each sex. We used group size data from a population of elk in Manitoba, Canada, that was experimentally reduced from 1.20 to 0.67 elk/km2 between 2002 and 2009. Our results indicated that functional responses of group size to population density are sex-specific. Females showed a positive density-dependent response in group size at population densities ≥0.70 elk/km2 and we found evidence for a minimum group size at population density ≤0.70 elk/km2. Changes in male group size were also density-dependent; however, the strength of the relationship was lower than for females. Density dependence in male group size was predominantly a result of fusion of solitary males into larger groups, rather than fusion among existing groups. Our study revealed that density affects group size of a large herbivore differently between males and females, which has important implications for the benefits e.g., alleviating predation risk, and costs of social behaviors e.g., competition for resources and mates, and intra-specific pathogen transmission. PMID:23326502
Greater sage-grouse population trends across Wyoming
Edmunds, David; Aldridge, Cameron L.; O'Donnell, Michael; Monroe, Adrian
2018-01-01
The scale at which analyses are performed can have an effect on model results and often one scale does not accurately describe the ecological phenomena of interest (e.g., population trends) for wide-ranging species: yet, most ecological studies are performed at a single, arbitrary scale. To best determine local and regional trends for greater sage-grouse (Centrocercus urophasianus) in Wyoming, USA, we modeled density-independent and -dependent population growth across multiple spatial scales relevant to management and conservation (Core Areas [habitat encompassing approximately 83% of the sage-grouse population on ∼24% of surface area in Wyoming], local Working Groups [7 regional areas for which groups of local experts are tasked with implementing Wyoming's statewide sage-grouse conservation plan at the local level], Core Area status (Core Area vs. Non-Core Area) by Working Groups, and Core Areas by Working Groups). Our goal was to determine the influence of fine-scale population trends (Core Areas) on larger-scale populations (Working Group Areas). We modeled the natural log of change in population size ( peak M lek counts) by time to calculate the finite rate of population growth (λ) for each population of interest from 1993 to 2015. We found that in general when Core Area status (Core Area vs. Non-Core Area) was investigated by Working Group Area, the 2 populations trended similarly and agreed with the overall trend of the Working Group Area. However, at the finer scale where Core Areas were analyzed separately, Core Areas within the same Working Group Area often trended differently and a few large Core Areas could influence the overall Working Group Area trend and mask trends occurring in smaller Core Areas. Relatively close fine-scale populations of sage-grouse can trend differently, indicating that large-scale trends may not accurately depict what is occurring across the landscape (e.g., local effects of gas and oil fields may be masked by increasing larger populations).
The next generation of LASIK patients.
Freeman, J Christopher; Chuck, Roy S
2009-07-01
With baby boomers aging, and despite a growing global population, there is a decreasing number of potential laser vision correction patients. Some believe that the worldwide economic downturn of these times will limit the number of potential patients as well. This article highlights looking to an alternative segment of the population to identify potential laser vision correction patients and the limitations of reaching this group. The group known as generation Y contains a large number of individuals who may be candidates for laser vision correction. Traditional marketing efforts present challenges in reaching this particular population segment. Many individuals in this group are already patients of eye doctors for contact lenses and glasses and can be reached by these eye doctors to address candidacy and education of laser vision correction. Generation Y represents a large population segment that contains technology-embracing individuals who, although hard to reach with traditional marketing efforts, may be reached by fellow eye doctors already managing these patients. There are many in this age group who would be good laser vision correction candidates.
ERIC Educational Resources Information Center
Quesen, Sarah
2016-01-01
When studying differential item functioning (DIF) with students with disabilities (SWD) focal groups typically suffer from small sample size, whereas the reference group population is usually large. This makes it possible for a researcher to select a sample from the reference population to be similar to the focal group on the ability scale. Doing…
Lichtenstein, James L. L.; Wright, Colin M; McEwen, Brendan; Pinter-Wollman, Noa; Pruitt, Jonathan N.
2018-01-01
Individual animals differ consistently in their behaviour, thus impacting a wide variety of ecological outcomes. Recent advances in animal personality research have established the ecological importance of the multidimensional behavioural volume occupied by individuals and by multispecies communities. Here, we examine the degree to which the multidimensional behavioural volume of a group predicts the outcome of both intra- and interspecific interactions. In particular, we test the hypothesis that a population of conspecifics will experience low intraspecific competition when the population occupies a large volume in behavioural space. We further hypothesize that populations of interacting species will exhibit greater interspecific competition when one or both species occupy large volumes in behavioural space. We evaluate these hypotheses by studying groups of katydids (Scudderia nymphs) and froghoppers (Philaenus spumarius), which compete for food and space on their shared host plant, Solidago canadensis. We found that individuals in single-species groups of katydids positioned themselves closer to one another, suggesting reduced competition, when groups occupied a large behavioural volume. When both species were placed together, we found that the survival of froghoppers was greatest when both froghoppers and katydids occupied a small volume in behavioural space, particularly at high froghopper densities. These results suggest that groups that occupy large behavioural volumes can have low intraspecific competition but high interspecific competition. Thus, behavioural hypervolumes appear to have ecological consequences at both the level of the population and the community and may help to predict the intensity of competition both within and across species. PMID:29681647
Can schooling regulate marine populations and ecosystems?
NASA Astrophysics Data System (ADS)
Maury, Olivier
2017-08-01
Schools, shoals and swarms are pervasive in the oceans. They have to provide very strong advantages to have been selected and generalized in the course of evolution. Auto-organized groups are usually assumed to provide facilitated encounters of reproduction partners, improved protection against predation, better foraging efficiency, and hydrodynamic gains. However, present theories regarding their evolutionary advantages do not provide an unambiguous explanation to their universality. In particular, the mechanisms commonly proposed to explain grouping provide little support to the formation of very large groups that are common in the sea (e.g. Rieucau et al., 2014). From literature review, data analysis and using a simple mathematical model, I show that large auto-organized groups appear at high population density while only small groups or dispersed individuals remain at low population density. Following, an analysis of tuna tagging data and simple theoretical developments show that large groups are likely to expose individuals to a dramatic decrease of individual foraging success and simultaneous increase of predatory and disease mortality, while small groups avoid those adverse feedbacks and provide maximum foraging success and protection against predation, as it is usually assumed. This would create an emergent density-dependent regulation of marine populations, preventing them from outbursts at high density, and protecting them at low density. This would be a major contribution to their resilience and a crucial process of ecosystems dynamics. A two-step evolutionary process acting at the individual level is proposed to explain how this apparently suicidal behaviour could have been selected and generalized. It explains how grouping would have permitted the emergence of extremely high fecundity life histories, despite their notorious propensity to destabilize populations. The potential implications of the ;grouping feedback; on population resilience, ecosystem stability and the persistence of marine biodiversity are discussed. The risk of harvesting marine species with fishing gears that enable catching dispersed individuals (such as longline, gillnet, trawl or using fishing aggregative devices for instance) is underlined. Finally, tropical tunas are used to exemplify the potential importance of schooling in shaping complex life histories and species interaction.
High population density enhances recruitment and survival of a harvested coral reef fish.
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.
Lee, Kenneth K C; Li, Shu Chuen; Kwong, Kai Sun; Chan, Thomas Y K; Lee, Vivian W Y; Lau, Joseph T F
2008-01-01
The incidence, health and economic impacts of influenza-like illness (ILI) among the working population in Hong Kong had never been studied. Due to the nature of the disease, ILIs can have a significant impact on the operation of a corporation in terms of loss of productivity and reduced work performance. The present study was undertaken to determine the health and economic impacts of ILIs under different environmental conditions on the working population of a large corporation. Over 2,000 employees of a large corporation in the travelling and tourism industry were studied with three different types of working environment (confined, typical office and well ventilated) by two structured questionnaires. The most affected group in terms of productivity and health was the group working in a confined area, whilst those working in a well-ventilated area were least affected. However, symptoms of the confined area group seemed to disappear faster. The infection rate appeared to vary according to work environment for the studied population. Policies on preventive measures and early treatment are important for a corporation to reduce loss in productivity due to ILIs.
ABO and Rh blood group genotypes in a cohort of Saudi stem cell donors.
Alzahrani, M; Jawdat, D; Alaskar, A; Cereb, N; Hajeer, A H
2018-04-01
The ABO and rhesus (Rh) blood group antigens are the most frequently studied genetic markers in a large group of people. Blood type frequencies vary in different racial/ethnic groups. Our objective was to investigate the distribution of the ABO and rhesus (Rh) blood groups by molecular typing method in a population of Saudi stem cell donors. Our data indicate that the most common blood group in our population is group O followed by group A then group B, and finally, the least common is group AB. © 2018 John Wiley & Sons Ltd.
Brennan, Angela K.; Cross, Paul C.; Higgs, Megan D.; Edwards, W. Henry; Scurlock, Brandon M.; Creel, Scott
2014-01-01
Understanding how animal density is related to pathogen transmission is important to develop effective disease control strategies, but requires measuring density at a scale relevant to transmission. However, this is not straightforward or well-studied among large mammals with group sizes that range several orders of magnitude or aggregation patterns that vary across space and time. To address this issue, we examined spatial variation in elk (Cervus canadensis) aggregation patterns and brucellosis across 10 regions in the Greater Yellowstone Area where previous studies suggest the disease may be increasing. We hypothesized that rates of increasing brucellosis would be better related to the frequency of large groups than mean group size or population density, but we examined whether other measures of density would also explain rising seroprevalence. To do this, we measured wintering elk density and group size across multiple spatial and temporal scales from monthly aerial surveys. We used Bayesian hierarchical models and 20 years of serologic data to estimate rates of increase in brucellosis within the 10 regions, and to examine the linear relationships between these estimated rates of increase and multiple measures of aggregation. Brucellosis seroprevalence increased over time in eight regions (one region showed an estimated increase from 0.015 in 1991 to 0.26 in 2011), and these rates of increase were positively related to all measures of aggregation. The relationships were weaker when the analysis was restricted to areas where brucellosis was present for at least two years, potentially because aggregation was related to disease-establishment within a population. Our findings suggest that (1) group size did not explain brucellosis increases any better than population density and (2) some elk populations may have high densities with small groups or lower densities with large groups, but brucellosis is likely to increase in either scenario. In this case, any one control method such as reducing population density or group size may not be sufficient to reduce transmission. This study highlights the importance of examining the density-transmission relationship at multiple scales and across populations before broadly applying disease control strategies.
The Rise of Concussions in the Adolescent Population.
Zhang, Alan L; Sing, David C; Rugg, Caitlin M; Feeley, Brian T; Senter, Carlin
2016-08-01
Concussion injuries have been highlighted to the American public through media and research. While recent studies have shown increased traumatic brain injuries (TBIs) diagnosed in emergency departments across the United States, no studies have evaluated trends in concussion diagnoses across the general US population in various age groups. To evaluate the current incidence and trends in concussions diagnosed across varying age groups and health care settings in a large cross-sectional population. Descriptive epidemiological study. Administrative health records of 8,828,248 members of a large private-payer insurance group in the United States were queried. Patients diagnosed with concussion from years 2007 through 2014 were stratified by year of diagnosis, age group, sex, classification of concussion, and health care setting of diagnosis (eg, emergency department vs physician's office). Chi-square testing was used for statistical analysis. From a cohort of 8,828,248 patients, 43,884 patients were diagnosed with a concussion. Of these patients, 55% were male and over 32% were in the adolescent age group (10-19 years old). The highest incidence of concussion was seen in patients aged 15 to 19 years (16.5/1000 patients), followed by those aged 10 to 14 years (10.5/1000 patients), 20 to 24 years (5.2/1000 patients), and 5 to 9 years (3.5/1000 patients). Overall, there was a 60% increase in concussion incidence from 2007 to 2014. The largest increases were in the 10- to 14-year (143%) and 15- to 19-year (87%) age groups. Based on International Classification of Disease-9th Revision classification, 29% of concussions were associated with some form of loss of consciousness. Finally, 56% of concussions were diagnosed in the emergency department and 29% in a physician's office, with the remainder in urgent care clinics or inpatient settings. The incidence of concussion diagnosed in the general US population is increasing, driven largely by a substantial rise in the adolescent age group. The youth population should be prioritized for ongoing work in concussion education, diagnosis, treatment, and prevention. The rise of concussions in the adolescent age group across the general population is concerning, and clinical efforts to prevent these injuries are needed.
Sobrero, Raúl; Quirici, Verónica; Castro, Rodrigo A.; Tolhuysen, Liliana Ortiz; Vargas, Francisco; Burger, Joseph Robert; Quispe, René; Villavicencio, Camila P.; Vásquez, Rodrigo A.; Hayes, Loren D.
2012-01-01
Intraspecific variation in sociality is thought to reflect a trade-off between current fitness benefits and costs that emerge from individuals' decision to join or leave groups. Since those benefits and costs may be influenced by ecological conditions, ecological variation remains a major, ultimate cause of intraspecific variation in sociality. Intraspecific comparisons of mammalian sociality across populations facing different environmental conditions have not provided a consistent relationship between ecological variation and group-living. Thus, we studied two populations of the communally rearing rodent Octodon degus to determine how co-variation between sociality and ecology supports alternative ecological causes of group living. In particular, we examined how variables linked to predation risk, thermal conditions, burrowing costs, and food availability predicted temporal and population variation in sociality. Our study revealed population and temporal variation in total group size and group composition that covaried with population and yearly differences in ecology. In particular, predation risk and burrowing costs are supported as drivers of this social variation in degus. Thermal differences, food quantity and quality were not significant predictors of social group size. In contrast to between populations, social variation within populations was largely uncoupled from ecological differences. PMID:22344477
Group selections among laboratory populations of Tribolium.
Wade, M J
1976-12-01
Selection at the population level or group selection is defined as genetic change that is brought about or maintained by the differential extinction and/or proliferation of populations. Group selection for both increased and decreased adult population size was carried out among laboratory populations of Tribolium castaneum at 37-day intervals. The effect of individual selection within populations on adult population size was evaluated in an additional control series of populations. The response in the group selection treatments occurred rapidly, within three or four generations, and was large in magnitude, at times differing from the controls by over 200%. This response to selection at the populational level occurred despite strong individual selection which caused a decline in the mean size of the control populations from over 200 adults to near 50 adults in nine 37-day intervals. "Assay" experiments indicated that selective changes in fecundity, developmental time, body weight, and cannibalism rates were responsible in part for the observed treatment differences in adult population size. These findings have implications in terms of speciation in organisms whose range is composed of many partially isolated local populations.
Including the Group Quarters Population in the US Synthesized Population Database
Chasteen, Bernadette M.; Wheaton, William D.; Cooley, Philip C.; Ganapathi, Laxminarayana; Wagener, Diane K.
2011-01-01
In 2005, RTI International researchers developed methods to generate synthesized population data on US households for the US Synthesized Population Database. These data are used in agent-based modeling, which simulates large-scale social networks to test how changes in the behaviors of individuals affect the overall network. Group quarters are residences where individuals live in close proximity and interact frequently. Although the Synthesized Population Database represents the population living in households, data for the nation’s group quarters residents are not easily quantified because of US Census Bureau reporting methods designed to protect individuals’ privacy. Including group quarters population data can be an important factor in agent-based modeling because the number of residents and the frequency of their interactions are variables that directly affect modeling results. Particularly with infectious disease modeling, the increased frequency of agent interaction may increase the probability of infectious disease transmission between individuals and the probability of disease outbreaks. This report reviews our methods to synthesize data on group quarters residents to match US Census Bureau data. Our goal in developing the Group Quarters Population Database was to enable its use with RTI’s US Synthesized Population Database in the Modeling of Infectious Diseases Agent Study. PMID:21841972
WKB theory of large deviations in stochastic populations
NASA Astrophysics Data System (ADS)
Assaf, Michael; Meerson, Baruch
2017-06-01
Stochasticity can play an important role in the dynamics of biologically relevant populations. These span a broad range of scales: from intra-cellular populations of molecules to population of cells and then to groups of plants, animals and people. Large deviations in stochastic population dynamics—such as those determining population extinction, fixation or switching between different states—are presently in a focus of attention of statistical physicists. We review recent progress in applying different variants of dissipative WKB approximation (after Wentzel, Kramers and Brillouin) to this class of problems. The WKB approximation allows one to evaluate the mean time and/or probability of population extinction, fixation and switches resulting from either intrinsic (demographic) noise, or a combination of the demographic noise and environmental variations, deterministic or random. We mostly cover well-mixed populations, single and multiple, but also briefly consider populations on heterogeneous networks and spatial populations. The spatial setting also allows one to study large fluctuations of the speed of biological invasions. Finally, we briefly discuss possible directions of future work.
Chiu, Han-Mo; Chen, Sam Li-Sheng; Yen, Amy Ming-Fang; Chiu, Sherry Yueh-Hsia; Fann, Jean Ching-Yuan; Lee, Yi-Chia; Pan, Shin-Liang; Wu, Ming-Shiang; Liao, Chao-Sheng; Chen, Hsiu-Hsi; Koong, Shin-Lan; Chiou, Shu-Ti
2015-09-15
The effectiveness of fecal immunochemical testing (FIT) in reducing colorectal cancer (CRC) mortality has not yet been fully assessed in a large, population-based service screening program. A prospective cohort study of the follow-up of approximately 5 million Taiwanese from 2004 to 2009 was conducted to compare CRC mortality for an exposed (screened) group and an unexposed (unscreened) group in a population-based CRC screening service targeting community residents of Taiwan who were 50 to 69 years old. Given clinical capacity, this nationwide screening program was first rolled out in 2004. In all, 1,160,895 eligible subjects who were 50 to 69 years old (ie, 21.4% of the 5,417,699 subjects of the underlying population) participated in the biennial nationwide screening program by 2009. The actual effectiveness in reducing CRC mortality attributed to the FIT screening was 62% (relative rate for the screened group vs the unscreened group, 0.38; 95% confidence interval, 0.35-0.42) with a maximum follow-up of 6 years. The 21.4% coverage of the population receiving FIT led to a significant 10% reduction in CRC mortality (relative rate, 0.90; 95% confidence interval, 0.84-0.95) after adjustments for a self-selection bias. This large, prospective Taiwanese cohort undergoing population-based FIT screening for CRC had the statistical power to demonstrate a significant CRC mortality reduction, although the follow-up time was short. Although such findings are informative for health decision makers, continued follow-up of this large cohort will be required to estimate the long-term impact of FIT screening if the covered population is expanded. © 2015 American Cancer Society.
Atzmon, Gil; Hao, Li; Pe'er, Itsik; Velez, Christopher; Pearlman, Alexander; Palamara, Pier Francesco; Morrow, Bernice; Friedman, Eitan; Oddoux, Carole; Burns, Edward; Ostrer, Harry
2010-06-11
For more than a century, Jews and non-Jews alike have tried to define the relatedness of contemporary Jewish people. Previous genetic studies of blood group and serum markers suggested that Jewish groups had Middle Eastern origin with greater genetic similarity between paired Jewish populations. However, these and successor studies of monoallelic Y chromosomal and mitochondrial genetic markers did not resolve the issues of within and between-group Jewish genetic identity. Here, genome-wide analysis of seven Jewish groups (Iranian, Iraqi, Syrian, Italian, Turkish, Greek, and Ashkenazi) and comparison with non-Jewish groups demonstrated distinctive Jewish population clusters, each with shared Middle Eastern ancestry, proximity to contemporary Middle Eastern populations, and variable degrees of European and North African admixture. Two major groups were identified by principal component, phylogenetic, and identity by descent (IBD) analysis: Middle Eastern Jews and European/Syrian Jews. The IBD segment sharing and the proximity of European Jews to each other and to southern European populations suggested similar origins for European Jewry and refuted large-scale genetic contributions of Central and Eastern European and Slavic populations to the formation of Ashkenazi Jewry. Rapid decay of IBD in Ashkenazi Jewish genomes was consistent with a severe bottleneck followed by large expansion, such as occurred with the so-called demographic miracle of population expansion from 50,000 people at the beginning of the 15th century to 5,000,000 people at the beginning of the 19th century. Thus, this study demonstrates that European/Syrian and Middle Eastern Jews represent a series of geographical isolates or clusters woven together by shared IBD genetic threads.
Atzmon, Gil; Hao, Li; Pe'er, Itsik; Velez, Christopher; Pearlman, Alexander; Palamara, Pier Francesco; Morrow, Bernice; Friedman, Eitan; Oddoux, Carole; Burns, Edward; Ostrer, Harry
2010-01-01
For more than a century, Jews and non-Jews alike have tried to define the relatedness of contemporary Jewish people. Previous genetic studies of blood group and serum markers suggested that Jewish groups had Middle Eastern origin with greater genetic similarity between paired Jewish populations. However, these and successor studies of monoallelic Y chromosomal and mitochondrial genetic markers did not resolve the issues of within and between-group Jewish genetic identity. Here, genome-wide analysis of seven Jewish groups (Iranian, Iraqi, Syrian, Italian, Turkish, Greek, and Ashkenazi) and comparison with non-Jewish groups demonstrated distinctive Jewish population clusters, each with shared Middle Eastern ancestry, proximity to contemporary Middle Eastern populations, and variable degrees of European and North African admixture. Two major groups were identified by principal component, phylogenetic, and identity by descent (IBD) analysis: Middle Eastern Jews and European/Syrian Jews. The IBD segment sharing and the proximity of European Jews to each other and to southern European populations suggested similar origins for European Jewry and refuted large-scale genetic contributions of Central and Eastern European and Slavic populations to the formation of Ashkenazi Jewry. Rapid decay of IBD in Ashkenazi Jewish genomes was consistent with a severe bottleneck followed by large expansion, such as occurred with the so-called demographic miracle of population expansion from 50,000 people at the beginning of the 15th century to 5,000,000 people at the beginning of the 19th century. Thus, this study demonstrates that European/Syrian and Middle Eastern Jews represent a series of geographical isolates or clusters woven together by shared IBD genetic threads. PMID:20560205
Rajkumar, Revathi; Kashyap, V K
2004-08-19
A large number of microsatellites have been extensively used to comprehend the genetic diversity of different global groups. This paper entails polymorphism at 15 STR in four predominant and endogamous populations representing Karnataka, located on the southwest coast of India. The populations residing in this region are believed to have received gene flow from south Indian populations and world migrants, hence, we carried out a detailed study on populations inhabiting this region to understand their genetic structure, diversity related to geography and linguistic affiliation and relatedness to other Indian and global migrant populations. Various statistical analyses were performed on the microsatellite data to accomplish the objectives of the paper. The heretozygosity was moderately high and similar across the loci, with low average GST value. Iyengar and Lyngayat were placed above the regression line in the R-matrix analysis as opposed to the Gowda and Muslim. AMOVA indicated that majority of variation was confined to individuals within a population, with geographic grouping demonstrating lesser genetic differentiation as compared to linguistic clustering. DA distances show the genetic affinity among the southern populations, with Iyengar, Lyngayat and Vanniyar displaying some affinity with northern Brahmins and global migrant groups from East Asia and Europe. The microsatellite study divulges a common ancestry for the four diverse populations of Karnataka, with the overall genetic differentiation among them being largely confined to intra-population variation. The practice of consanguineous marriages might have attributed to the relatively lower gene flow displayed by Gowda and Muslim as compared to Iyengar and Lyngayat. The various statistical analyses strongly suggest that the studied populations could not be differentiated on the basis of caste or spatial location, although, linguistic affinity was reflected among the southern populations, distinguishing them from the northern groups. Our study also indicates a heterogeneous origin for Lyngayat and Iyengar owing to their genetic proximity with southern populations and northern Brahmins. The high-ranking communities, in particular, Iyengar, Lyngayat, Vanniyar and northern Brahmins might have experienced genetic admixture from East Asian and European ethnic groups.
Rajkumar, Revathi; Kashyap, VK
2004-01-01
Background A large number of microsatellites have been extensively used to comprehend the genetic diversity of different global groups. This paper entails polymorphism at 15 STR in four predominant and endogamous populations representing Karnataka, located on the southwest coast of India. The populations residing in this region are believed to have received gene flow from south Indian populations and world migrants, hence, we carried out a detailed study on populations inhabiting this region to understand their genetic structure, diversity related to geography and linguistic affiliation and relatedness to other Indian and global migrant populations. Results Various statistical analyses were performed on the microsatellite data to accomplish the objectives of the paper. The heretozygosity was moderately high and similar across the loci, with low average GST value. Iyengar and Lyngayat were placed above the regression line in the R-matrix analysis as opposed to the Gowda and Muslim. AMOVA indicated that majority of variation was confined to individuals within a population, with geographic grouping demonstrating lesser genetic differentiation as compared to linguistic clustering. DA distances show the genetic affinity among the southern populations, with Iyengar, Lyngayat and Vanniyar displaying some affinity with northern Brahmins and global migrant groups from East Asia and Europe. Conclusion The microsatellite study divulges a common ancestry for the four diverse populations of Karnataka, with the overall genetic differentiation among them being largely confined to intra-population variation. The practice of consanguineous marriages might have attributed to the relatively lower gene flow displayed by Gowda and Muslim as compared to Iyengar and Lyngayat. The various statistical analyses strongly suggest that the studied populations could not be differentiated on the basis of caste or spatial location, although, linguistic affinity was reflected among the southern populations, distinguishing them from the northern groups. Our study also indicates a heterogeneous origin for Lyngayat and Iyengar owing to their genetic proximity with southern populations and northern Brahmins. The high-ranking communities, in particular, Iyengar, Lyngayat, Vanniyar and northern Brahmins might have experienced genetic admixture from East Asian and European ethnic groups. PMID:15317657
The epidemic of Tuberculosis on vaccinated population
NASA Astrophysics Data System (ADS)
Syahrini, Intan; Sriwahyuni; Halfiani, Vera; Meurah Yuni, Syarifah; Iskandar, Taufiq; Rasudin; Ramli, Marwan
2017-09-01
Tuberculosis is an infectious disease which has caused a large number of mortality in Indonesia. This disease is caused by Mycrobacterium tuberculosis. Besides affecting lung, this disease also affects other organs such as lymph gland, intestine, kidneys, uterus, bone, and brain. This article discusses the epidemic of tuberculosis through employing the SEIR model. Here, the population is divided into four compartments which are susceptible, exposed, infected and recovered. The susceptible population is further grouped into two which are vaccinated group and unvaccinated group. The behavior of the epidemic is investigated through analysing the equilibrium of the model. The result shows that administering vaccine to the susceptible population contributes to the reduction of the tuberculosis epidemic rate.
Optimization models for degrouping population data.
Bermúdez, Silvia; Blanquero, Rafael
2016-07-01
In certain countries population data are available in grouped form only, usually as quinquennial age groups plus a large open-ended range for the elderly. However, official statistics call for data by individual age since many statistical operations, such as the calculation of demographic indicators, require the use of ungrouped population data. In this paper a number of mathematical models are proposed which, starting from population data given in age groups, enable these ranges to be degrouped into age-specific population values without leaving a fractional part. Unlike other existing procedures for disaggregating demographic data, ours makes it possible to process several years' data simultaneously in a coherent way, and provides accurate results longitudinally as well as transversally. This procedure is also shown to be helpful in dealing with degrouped population data affected by noise, such as those affected by the age-heaping phenomenon.
Oi, Manabu; Fujino, Hiroshi; Tsukidate, Naotake; Kamio, Yoko; Yoshimura, Yuko; Kikuchi, Mitsuru; Hasegawa, Chiaki; Gondou, Keiko; Matsui, Tomoko
2017-10-01
The Japanese version of the Children's Communication Checklist-2 (CCC-2) was rated by caregivers in a large national population sample of 22,871 children aged 3-15 years. The General Communication Composite (GCC) of the CCC-2 exhibited a distribution with a single-factor structure. The GCC distribution between autism spectrum disorders (ASD) and language impairment (LI) groups in the general population fit inside a bell curve with significant overlap with the general population, and a continuum was evident between groups. No evidence of a natural cutoff that would differentiate categorically affected from unaffected children was seen. The Social Interaction Deviance Composite (SIDC) supported the notion that ASD and LI are on the opposite endpoints of a SIDC continuum of communication impairment.
NASA Astrophysics Data System (ADS)
Menu, J.; van Boekel, R.; Henning, Th.; Leinert, Ch.; Waelkens, C.; Waters, L. B. F. M.
2015-09-01
Context. The disks around Herbig Ae/Be stars are commonly divided into group I and group II based on their far-infrared spectral energy distribution, and the common interpretation for that is flared and flat disks. Our understanding of the evolution of these disks is rapidly changing. Recent observations suggest that many flaring disks have gaps, whereas flat disks are thought to be gapless. Aims: The different groups of objects can be expected to have different structural signatures in high-angular-resolution data, related to gaps, dust settling, and flaring. We aim to use such data to gain new insight into disk structure and evolution. Methods: Over the past 10 years, the MIDI instrument on the Very Large Telescope Interferometer has collected observations of several tens of protoplanetary disks. We modeled the large set of observations with simple geometric models and compared the characteristic sizes among the different objects. A population of radiative-transfer models was synthesized for interpreting the mid-infrared signatures. Results: Objects with similar luminosities show very different disk sizes in the mid-infrared. This may point to an intrinsic diversity or could also hint at different evolutionary stages of the disks. Restricting this to the young objects of intermediate mass, we confirm that most group I disks are in agreement with being transitional (i.e., they have gaps). We find that several group II objects have mid-infrared sizes and colors that overlap with sources classified as group I, transition disks. This suggests that these sources have gaps, which has been demonstrated for a subset of them. This may point to an intermediate population between gapless and transition disks. Conclusions: Flat disks with gaps are most likely descendants of flat disks without gaps. Potentially related to the formation of massive bodies, gaps may therefore even develop in disks in a far stage of grain growth and settling. The evolutionary implications of this new population could be twofold. Either gapped flat disks form a separate population of evolved disks or some of them may evolve further into flaring disks with large gaps. The latter transformation may be governed by the interaction with a massive planet, carving a large gap and dynamically exciting the grain population in the disk. Appendices A and B are available in electronic form at http://www.aanda.org
A Life-Cycle Model of Human Social Groups Produces a U-Shaped Distribution in Group Size.
Salali, Gul Deniz; Whitehouse, Harvey; Hochberg, Michael E
2015-01-01
One of the central puzzles in the study of sociocultural evolution is how and why transitions from small-scale human groups to large-scale, hierarchically more complex ones occurred. Here we develop a spatially explicit agent-based model as a first step towards understanding the ecological dynamics of small and large-scale human groups. By analogy with the interactions between single-celled and multicellular organisms, we build a theory of group lifecycles as an emergent property of single cell demographic and expansion behaviours. We find that once the transition from small-scale to large-scale groups occurs, a few large-scale groups continue expanding while small-scale groups gradually become scarcer, and large-scale groups become larger in size and fewer in number over time. Demographic and expansion behaviours of groups are largely influenced by the distribution and availability of resources. Our results conform to a pattern of human political change in which religions and nation states come to be represented by a few large units and many smaller ones. Future enhancements of the model should include decision-making rules and probabilities of fragmentation for large-scale societies. We suggest that the synthesis of population ecology and social evolution will generate increasingly plausible models of human group dynamics.
A Life-Cycle Model of Human Social Groups Produces a U-Shaped Distribution in Group Size
Salali, Gul Deniz; Whitehouse, Harvey; Hochberg, Michael E.
2015-01-01
One of the central puzzles in the study of sociocultural evolution is how and why transitions from small-scale human groups to large-scale, hierarchically more complex ones occurred. Here we develop a spatially explicit agent-based model as a first step towards understanding the ecological dynamics of small and large-scale human groups. By analogy with the interactions between single-celled and multicellular organisms, we build a theory of group lifecycles as an emergent property of single cell demographic and expansion behaviours. We find that once the transition from small-scale to large-scale groups occurs, a few large-scale groups continue expanding while small-scale groups gradually become scarcer, and large-scale groups become larger in size and fewer in number over time. Demographic and expansion behaviours of groups are largely influenced by the distribution and availability of resources. Our results conform to a pattern of human political change in which religions and nation states come to be represented by a few large units and many smaller ones. Future enhancements of the model should include decision-making rules and probabilities of fragmentation for large-scale societies. We suggest that the synthesis of population ecology and social evolution will generate increasingly plausible models of human group dynamics. PMID:26381745
[Epidemiological methods used in studies in the prevalence of Tourette syndrome].
Stefanoff, Paweł; Mazurek, Jacek
2003-01-01
Tourette syndrome (TS) prevalence was studied since the early 80-ies. Its clinical course is characterised by co-occurrence of motor and vocal tics. Results of previous epidemiological studies were surprisingly divergent: the prevalence varied from 0.5 to 115 cases per 10,000 population. The disease previously recognised as extremely rare and severe is now considered as quite common, with often moderate course. Selected methods used in studies of TS prevalence and analysis of their possible impact on study results are presented. The studies were divided into 3 groups: studies of the hospitalised population, large-scale screenings and studies involving school population, basing on characteristic and size of population, methods of selection of subjects, diagnostic and screening methods used. Studies of the hospitalised population involved patients with most severe symptoms, in different age groups, different methods of final diagnosis confirmation were used. TS prevalence varied from 0.5 up to 15 cases per 10,000 population. Procedures used in large-scale screening studies made possible the elimination of potential selection bias. Large populations were studied using transparent and repetitive confirmation of diagnoses. Their validity was additionally checked in parallel validity studies. TS prevalence was in the range 4.3 to 10 cases per 10,000 population. The highest TS prevalence was obtained in studies involving schoolchildren. Data were gathered from multiple sources: from parents, teachers and children, as well as from classroom observation. Diagnoses were made by experienced clinicians. TS prevalence obtained in school population studies was between 36.2 up to 115 per 10,000 population.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-19
... Resident Population by Sex and Five-Year Age Groups for the United States: April 1, 2000 to July 1, 2009... and Sex: 2010'' at http://www.census.gov/population/www/socdemo/age/age_sex_2010.html . No numerical... that garments in girls' size Large (L) and boys' size Large (L) are equivalent to size 12. Section 1120...
Guo, Weian; Si, Chengyong; Xue, Yu; Mao, Yanfen; Wang, Lei; Wu, Qidi
2017-05-04
Particle Swarm Optimization (PSO) is a popular algorithm which is widely investigated and well implemented in many areas. However, the canonical PSO does not perform well in population diversity maintenance so that usually leads to a premature convergence or local optima. To address this issue, we propose a variant of PSO named Grouping PSO with Personal- Best-Position (Pbest) Guidance (GPSO-PG) which maintains the population diversity by preserving the diversity of exemplars. On one hand, we adopt uniform random allocation strategy to assign particles into different groups and in each group the losers will learn from the winner. On the other hand, we employ personal historical best position of each particle in social learning rather than the current global best particle. In this way, the exemplars diversity increases and the effect from the global best particle is eliminated. We test the proposed algorithm to the benchmarks in CEC 2008 and CEC 2010, which concern the large scale optimization problems (LSOPs). By comparing several current peer algorithms, GPSO-PG exhibits a competitive performance to maintain population diversity and obtains a satisfactory performance to the problems.
Zhang, X; Platt, R W; Cnattingius, S; Joseph, K S; Kramer, M S
2007-04-01
The objective of this study was to critically examine potential artifacts and biases underlying the use of 'customised' standards of birthweight for gestational age (GA). Population-based cohort study. Sweden. A total of 782,303 singletons > or =28 weeks of gestation born in 1992-2001 to Nordic mothers with complete data on birthweight; GA; and maternal age, parity, height, and pre-pregnancy weight. We compared perinatal mortality in four groups of infants based on the following classification of small for gestational age (SGA): non-SGA based on either population-based or customised standards (the reference group), SGA based on the population-based standard only, SGA based on the customised standard only, and SGA according to both standards. We used graphical methods to compare GA-specific birthweight cutoffs for SGA using the two standards and also used logistic regression to control for differences in GA and maternal pre-pregnancy body mass index (BMI) in the four groups. Perinatal mortality, including stillbirth and neonatal death. Customisation led to a large artifactual increase in the proportion of SGA infants born preterm. Adjustment for differences in GA and maternal BMI markedly reduced the excess risk among infants classified as SGA by customised standards only. The large increase in perinatal mortality risk among infants classified as SGA based on customised standards is largely an artifact due to inclusion of more preterm births.
2000-01-01
The desire of resource managers, risk assessors, and the general public to better understand the consequences of environmental contamination has produced a strong and growing need for information on the effects of contaminants on populations and groups of species, and over moderate to large areas of land or water. However, the problems associated with research involving populations and groups of species or large and complex geographic areas, especially in terrestrial environments, are well known within the scientific community. With the previous thoughts in mind, an interactive symposium was held at the University of Maryland in October 1998. The purpose of the symposium was to review and critically evaluate our understanding of the effects of contaminants on terrestrial vertebrates at levels of organization above that of the individual. Invited background and technical presentations provided a common baseline of information for symposium participants. Discussion groups were then asked to critically evaluate the topics of two technical sessions. Several presentations of recent or ongoing research provided participants with examples of current approaches to assessments of the effects of contaminants on terrestrial vertebrates at the population or higher level of organization. The book consists of 10 chapters written by presenters at the symposium and three chapters conveying the reports of discussion group.
Wang, Yaping; Nie, Jingxin; Yap, Pew-Thian; Li, Gang; Shi, Feng; Geng, Xiujuan; Guo, Lei; Shen, Dinggang
2014-01-01
Accurate and robust brain extraction is a critical step in most neuroimaging analysis pipelines. In particular, for the large-scale multi-site neuroimaging studies involving a significant number of subjects with diverse age and diagnostic groups, accurate and robust extraction of the brain automatically and consistently is highly desirable. In this paper, we introduce population-specific probability maps to guide the brain extraction of diverse subject groups, including both healthy and diseased adult human populations, both developing and aging human populations, as well as non-human primates. Specifically, the proposed method combines an atlas-based approach, for coarse skull-stripping, with a deformable-surface-based approach that is guided by local intensity information and population-specific prior information learned from a set of real brain images for more localized refinement. Comprehensive quantitative evaluations were performed on the diverse large-scale populations of ADNI dataset with over 800 subjects (55∼90 years of age, multi-site, various diagnosis groups), OASIS dataset with over 400 subjects (18∼96 years of age, wide age range, various diagnosis groups), and NIH pediatrics dataset with 150 subjects (5∼18 years of age, multi-site, wide age range as a complementary age group to the adult dataset). The results demonstrate that our method consistently yields the best overall results across almost the entire human life span, with only a single set of parameters. To demonstrate its capability to work on non-human primates, the proposed method is further evaluated using a rhesus macaque dataset with 20 subjects. Quantitative comparisons with popularly used state-of-the-art methods, including BET, Two-pass BET, BET-B, BSE, HWA, ROBEX and AFNI, demonstrate that the proposed method performs favorably with superior performance on all testing datasets, indicating its robustness and effectiveness. PMID:24489639
Yagasaki, Hiroshi; Hamanoue, Satoshi; Oda, Tsukasa; Nakahata, Tatsutoshi; Asano, Shigetaka; Yamashita, Takayuki
2004-12-01
Fanconi anemia (FA) is a rare autosomal recessive disorder of hematopoiesis, with at least 11 complementation groups. FANCA, a gene for group A, accounts for the majority of FA patients. Previous studies of FANCA mutations revealed high allelic heterogeneity, frequent occurrence of large deletions, and interpopulation differences. However, systematic mutational analysis, including gene dosage assay to detect large deletions, has not been documented for Asian populations. A newly developed TaqMan quantitative PCR-based gene dosage assay, combined with sequencing of exons and cDNA fragments, allowed for detection of 48 mutant alleles of FANCA in 27 (77%) of 35 unrelated Japanese FA families with no detectable mutations in FANCC or FANCG. We identified 29 different mutations (21 nucleotide substitutions or small deletions/insertions and eight large deletions), at least 20 of which were novel. The FANCA mutational spectrum of the Japanese was different from that of other ethnic groups so far studied. This is the largest scale of mutation analysis of FANCA in the Japanese population. Characterization of these mutations provided new information regarding the mutagenesis mechanisms and structure-function relationship of FANCA. Specifically, our data suggest that diverse mechanisms including nonhomologous recombination as well as Alu-mediated homologous recombination are involved in the generation of large deletions in FANCA. Copyright 2004 Wiley-Liss, Inc.
Devreese, Lieven; Huynen, Marie-Claude; Stevens, Jeroen M G; Todd, Angelique
2013-01-01
White-eyelid mangabeys (genus Cercocebus) live in groups of highly variable size. Because of their semi-terrestrial behaviour and preference for dense forest habitats, re-liable data on group size are scarce. During a 5-month study, we collected 17 group counts on a habituated group of agile mangabeys (C. agilis) at Bai Hokou in the Central African Republic. We found a stable group size of approximately 135 individuals. This permanent large grouping pattern is known to occur among several populations of white-eyelid mangabeys and is congruent with extreme group sizes reported in mandrills at Lopé in Gabon. Copyright © 2013 S. Karger AG, Basel.
2016-01-01
The whitefly Bemisia tabaci sibling species (sibsp.) group comprises morphologically indiscernible lineages of well-known exemplars referred to as biotypes. It is distributed throughout tropical and subtropical latitudes and includes the contemporary invasive haplotypes, termed B and Q. Several well-studied B. tabaci biotypes exhibit ecological and biological diversity, however, most members are poorly studied or completely uncharacterized. Genetic studies have revealed substantial diversity within the group based on a fragment of the mitochondrial cytochrome oxidase I (mtCOI) sequence (haplotypes), with other tested markers being less useful for deep phylogenetic comparisons. The view of global relationships within the B. tabaci sibsp. group is largely derived from this single marker, making assessment of gene flow and genetic structure difficult at the population level. Here, the population structure was explored for B. tabaci in a global context using nuclear data from variable microsatellite markers. Worldwide collections were examined representing most of the available diversity, including known monophagous, polyphagous, invasive, and indigenous haplotypes. Well-characterized biotypes and other related geographic lineages discovered represented highly differentiated genetic clusters with little or no evidence of gene flow. The invasive B and Q biotypes exhibited moderate to high levels of genetic diversity, suggesting that they stemmed from large founding populations that have maintained ancestral variation, despite homogenizing effects, possibly due to human-mediated among-population gene flow. Results of the microsatellite analyses are in general agreement with published mtCOI phylogenies; however, notable conflicts exist between the nuclear and mitochondrial relationships, highlighting the need for a multifaceted approach to delineate the evolutionary history of the group. This study supports the hypothesis that the extant B. tabaci sibsp. group contains ancient genetic entities and highlights the vast cryptic diversity throughout the genome in the group. PMID:27855173
Scliar, Marilia O; Soares-Souza, Giordano B; Chevitarese, Juliana; Lemos, Livia; Magalhães, Wagner C S; Fagundes, Nelson J; Bonatto, Sandro L; Yeager, Meredith; Chanock, Stephen J; Tarazona-Santos, Eduardo
2012-03-01
Elucidating the pattern of genetic diversity for non-European populations is necessary to make the benefits of human genetics research available to individuals from these groups. In the era of large human genomic initiatives, Native American populations have been neglected, in particular, the Quechua, the largest South Amerindian group settled along the Andes. We characterized the genetic diversity of a Quechua population in a global setting, using autosomal noncoding sequences (nine unlinked loci for a total of 16 kb), 351 unlinked SNPs and 678 microsatellites and tested predictions of the model of the evolution of Native Americans proposed by (Tarazona-Santos et al.: Am J Hum Genet 68 (2001) 1485-1496). European admixture is <5% and African ancestry is barely detectable in the studied population. The largest genetic distances were between African versus Quechua or Melanesian populations, which is concordant with the African origin of modern humans and the fact that South America was the last part of the world to be peopled. The diversity in the Quechua population is comparable with that of Eurasian populations, and the allele frequency spectrum based on resequencing data does not reflect a reduction in the proportion of rare alleles. Thus, the Quechua population is a large reservoir of common and rare genetic variants of South Amerindians. These results are consistent with and complement our evolutionary model of South Amerindians (Tarazona-Santos et al.: Am J Hum Genet 68 (2001) 1485-1496), proposed based on Y-chromosome data, which predicts high genomic diversity due to the high level of gene flow between Andean populations and their long-term effective population size. Copyright © 2012 Wiley Periodicals, Inc.
Multi-ethnic genome-wide association study identifies novel locus for type 2 diabetes susceptibility
Cook, James P; Morris, Andrew P
2016-01-01
Genome-wide association studies (GWAS) have traditionally been undertaken in homogeneous populations from the same ancestry group. However, with the increasing availability of GWAS in large-scale multi-ethnic cohorts, we have evaluated a framework for detecting association of genetic variants with complex traits, allowing for population structure, and developed a powerful test of heterogeneity in allelic effects between ancestry groups. We have applied the methodology to identify and characterise loci associated with susceptibility to type 2 diabetes (T2D) using GWAS data from the Resource for Genetic Epidemiology on Adult Health and Aging, a large multi-ethnic population-based cohort, created for investigating the genetic and environmental basis of age-related diseases. We identified a novel locus for T2D susceptibility at genome-wide significance (P<5 × 10−8) that maps to TOMM40-APOE, a region previously implicated in lipid metabolism and Alzheimer's disease. We have also confirmed previous reports that single-nucleotide polymorphisms at the TCF7L2 locus demonstrate the greatest extent of heterogeneity in allelic effects between ethnic groups, with the lowest risk observed in populations of East Asian ancestry. PMID:27189021
CRISPR Associated Diversity within a Population of Sulfolobus islandicus
Held, Nicole L.; Herrera, Alfa; Cadillo-Quiroz, Hinsby; Whitaker, Rachel J.
2010-01-01
Background Predator-prey models for virus-host interactions predict that viruses will cause oscillations of microbial host densities due to an arms race between resistance and virulence. A new form of microbial resistance, CRISPRs (clustered regularly interspaced short palindromic repeats) are a rapidly evolving, sequence-specific immunity mechanism in which a short piece of invading viral DNA is inserted into the host's chromosome, thereby rendering the host resistant to further infection. Few studies have linked this form of resistance to population dynamics in natural microbial populations. Methodology/Principal Findings We examined sequence diversity in 39 strains of the archeaon Sulfolobus islandicus from a single, isolated hot spring from Kamchatka, Russia to determine the effects of CRISPR immunity on microbial population dynamics. First, multiple housekeeping genetic markers identify a large clonal group of identical genotypes coexisting with a diverse set of rare genotypes. Second, the sequence-specific CRISPR spacer arrays split the large group of isolates into two very different groups and reveal extensive diversity and no evidence for dominance of a single clone within the population. Conclusions/Significance The evenness of resistance genotypes found within this population of S. islandicus is indicative of a lack of strain dominance, in contrast to the prediction for a resistant strain in a simple predator-prey interaction. Based on evidence for the independent acquisition of resistant sequences, we hypothesize that CRISPR mediated clonal interference between resistant strains promotes and maintains diversity in this natural population. PMID:20927396
Do social groups prevent Allee effect related extinctions?: The case of wild dogs.
Angulo, Elena; Rasmussen, Greg S A; Macdonald, David W; Courchamp, Franck
2013-03-15
Allee effects may arise as the number of individuals decreases, thereby reducing opportunities for cooperation and constraining individual fitness, which can lead to population decrease and extinction. Obligate cooperative breeders rely on a minimum group size to subsist and are thus expected to be particularly susceptible to Allee effects. Although Allee effects in some components of the fitness of cooperative breeders have been detected, empirical confirmation of population extinction due to Allee effects is lacking yet. Because previous studies of cooperation have focused on Allee effects affecting individual fitness (component Allee effect) and population dynamics (demographic Allee effect), we argue that a new conceptual level of Allee effect, the group Allee effect, is needed to understand the special case of cooperative breeders. We hypothesize that whilst individuals are vulnerable to Allee effects, the group could act as a buffer against population extinction if: (i) individual fitness and group fate depend on group size but not on population size and (ii) group size is independent of population size (that is, at any population size, populations comprise both large and small groups). We found that both conditions apply for the African wild dog, Lycaon pictus, and data on this species in Zimbabwe support our hypothesis. The importance of groups in obligate cooperative breeders needs to be accounted for within the Allee effect framework, through a group Allee effect, because the group mediates the relationship between individual fitness and population performance. Whilst sociality is associated with a high probability of Allee effects, we suggest that cooperative individuals organized in relatively autonomous groups within populations might be behaving in ways that diminish extinction risks caused by Allee effects. This study opens new avenues to a better understanding of the role of the evolution of group-living on the probability of extinction faced by social species.
Tabikhanov, L E; Osipova, L P
2012-12-01
Genetic and demographic characteristics of populations from two settlements from the Aginskii Buryat district of Trans-Baikal krai (Alkhanai and Orlovskii) were studied. It was demonstrated that the mononational Buryat settlement of Alkhanai, located in the agrarian Dul'durginskii region of the district far from large settlements and transport highways, is characterized by a large prereproductive volume (45%) and by a small share of individuals from the elderly age group (16.4%). A shift in age characteristics in the Buryat group (36.6 and 22.4%, respectively) was detected in the urban settlement of Orlovskii with a population of mixed ethnic composition, located in a densely populated industrialized part of the district. A modified sex ratio was also demonstrated in Alkhanai as opposed to the Buryat part of the Orlovskii population (sex indices were 0.94 and 0.99). Analysis of population mixture was conducted; marriage structure and migrations were described. The endogamy index of the Alkhanai locality was 0.41; in the group of Buryats from Orlovskii, 0.09. A decrease in the amount of pregnancies and births and a larger distribution of family planning practice among Buryats from Orlovskii were detected. The average amount of births of living children per woman in Alkhanai was 5.11; in Buryats from Orlovskii, 3.90. The selection pressure was estimated as low by means of the Crow index (I(tot) 0.28-0.48). In all described groups, a component that characterizes differential fertility (I(f)) exceeds the child mortality component (I(m)).
Greacen, Tim; Kersaudy-Rahib, Delphine; Le Gall, Jean-Marie; Lydié, Nathalie; Ghosn, Jade; Champenois, Karen
2016-01-01
HIV self-tests are currently being introduced in France with the aim of promoting screening both for the general population and for high-risk populations. The current study aimed to identify and compare the information and support needs of the different target population groups. The Delphi process was used to synthesize expert opinions for each population group. Experts were chosen for their experience and expertise in the area of HIV and HIV screening for each population. Each group developed recommendations for a specific population: six high HIV prevalence populations (men who have sex with men; transgender people; substance users; migrants from sub-Saharan Africa; French West Indies; French Guiana) and two low prevalence populations (the general population; people under 25). Each group included expertise from four areas: research, screening and care, policy-making, and community groups. A final total of 263 recommendations were grouped into eight main themes: Communicating at both national and community levels about self-test arrival (24% of all recommendations); Providing information adapted to the different community groups' needs (23%); Providing counselling on self-test use and access to care (15%); Making self-tests available to all in terms of accessibility and cost (13%); Preparing community healthcare and screening systems for the arrival of the self-test (11%); Approving only high quality self-tests (6%); Defending self-test users' legal rights (5%); Evaluating self-test use (3%). Although a large number of recommendations were common to several groups of experts, the study highlighted a certain number of recommendations specific to each different population group, particularly with regard to information content and access both to information and to the self-tests themselves. Results from the current study should make a significant contribution to policy decisions concerning catering for the specific access, information and support needs of different potential HIV self-test user groups in France.
Population health and social governance: analyzing the mainstream incorporation of ethnography.
O'Byrne, Patrick
2012-06-01
Recently, health care workers (researchers, academics, policy writers, clinicians) have begun to view ethnography as an acceptable research methodology for informing public health work. This corresponds with a change in public health practice toward population health, wherein identifiable groups are examined to identify the group-level and contextual factors that affect their health statuses. Although population health-based methodological and outcomes-focused examinations have already occurred regarding ethnography, no extant literature scrutinizes the incorporation of ethnography into mainstream public and population health work from a sociopolitical viewpoint. Consequently, such an investigation occurs here using Foucault's concepts of discipline and Lupton's advancement of Foucault's ideas about the imperative of health. The outcome of this investigation is the assertion that ethnography is a strategic method for disciplining populations that do not respect the imperative of health. In other words, ethnography helps generate the data that can be used to normalize large groups of people.
Rhythmic behavior in a two-population mean-field Ising model
NASA Astrophysics Data System (ADS)
Collet, Francesca; Formentin, Marco; Tovazzi, Daniele
2016-10-01
Many real systems composed of a large number of interacting components, as, for instance, neural networks, may exhibit collective periodic behavior even though single components have no natural tendency to behave periodically. Macroscopic oscillations are indeed one of the most common self-organized behavior observed in living systems. In the present paper we study some dynamical features of a two-population generalization of the mean-field Ising model with the scope of investigating simple mechanisms capable to generate rhythms in large groups of interacting individuals. We show that the system may undergo a transition from a disordered phase, where the magnetization of each population fluctuates closely around zero, to a phase in which they both display a macroscopic regular rhythm. In particular, there exists a region in the parameter space where having two groups of spins with inter- and intrapopulation interactions of different strengths suffices for the emergence of a robust periodic behavior.
Population ecology, nonlinear dynamics, and social evolution. I. Associations among nonrelatives.
Avilés, Leticia; Abbot, Patrick; Cutter, Asher D
2002-02-01
Using an individual-based and genetically explicit simulation model, we explore the evolution of sociality within a population-ecology and nonlinear-dynamics framework. Assuming that individual fitness is a unimodal function of group size and that cooperation may carry a relative fitness cost, we consider the evolution of one-generation breeding associations among nonrelatives. We explore how parameters such as the intrinsic rate of growth and group and global carrying capacities may influence social evolution and how social evolution may, in turn, influence and be influenced by emerging group-level and population-wide dynamics. We find that group living and cooperation evolve under a wide range of parameter values, even when cooperation is costly and the interactions can be defined as altruistic. Greater levels of cooperation, however, did evolve when cooperation carried a low or no relative fitness cost. Larger group carrying capacities allowed the evolution of larger groups but also resulted in lower cooperative tendencies. When the intrinsic rate of growth was not too small and control of the global population size was density dependent, the evolution of large cooperative tendencies resulted in dynamically unstable groups and populations. These results are consistent with the existence and typical group sizes of organisms ranging from the pleometrotic ants to the colonial birds and the global population outbreaks and crashes characteristic of organisms such as the migratory locusts and the tree-killing bark beetles.
Greacen, Tim; Kersaudy-Rahib, Delphine; Le Gall, Jean-Marie; Lydié, Nathalie; Ghosn, Jade; Champenois, Karen
2016-01-01
Context HIV self-tests are currently being introduced in France with the aim of promoting screening both for the general population and for high-risk populations. Objective The current study aimed to identify and compare the information and support needs of the different target population groups. Methods The Delphi process was used to synthesize expert opinions for each population group. Experts were chosen for their experience and expertise in the area of HIV and HIV screening for each population. Each group developed recommendations for a specific population: six high HIV prevalence populations (men who have sex with men; transgender people; substance users; migrants from sub-Saharan Africa; French West Indies; French Guiana) and two low prevalence populations (the general population; people under 25). Each group included expertise from four areas: research, screening and care, policy-making, and community groups. Results A final total of 263 recommendations were grouped into eight main themes: Communicating at both national and community levels about self-test arrival (24% of all recommendations); Providing information adapted to the different community groups’ needs (23%); Providing counselling on self-test use and access to care (15%); Making self-tests available to all in terms of accessibility and cost (13%); Preparing community healthcare and screening systems for the arrival of the self-test (11%); Approving only high quality self-tests (6%); Defending self-test users’ legal rights (5%); Evaluating self-test use (3%). Although a large number of recommendations were common to several groups of experts, the study highlighted a certain number of recommendations specific to each different population group, particularly with regard to information content and access both to information and to the self-tests themselves. Conclusion Results from the current study should make a significant contribution to policy decisions concerning catering for the specific access, information and support needs of different potential HIV self-test user groups in France. PMID:27031234
African genetic diversity provides novel insights into evolutionary history and local adaptations.
Choudhury, Ananyo; Aron, Shaun; Sengupta, Dhriti; Hazelhurst, Scott; Ramsay, Michèle
2018-05-08
Genetic variation and susceptibility to disease are shaped by human demographic history. We can now study the genomes of extant Africans and uncover traces of population migration, admixture, assimilation and selection by applying sophisticated computational algorithms. There are four major ethnolinguistic divisions among present day Africans: Hunter-gatherer populations in southern and central Africa; Nilo-Saharan speakers from north and northeast Africa; Afro-Asiatic speakers from east Africa; and Niger-Congo speakers who are the predominant ethnolinguistic group spread across most of sub-Saharan Africa. The enormous ethnolinguistic diversity in sub-Saharan African populations is largely paralleled by extensive genetic diversity and until a decade ago, little was known about the origins and divergence of these groups. Results from large-scale population genetic studies, and more recently whole genome sequence data, are unraveling the critical role of events like migration and admixture and environment factors including diet, infectious diseases and climatic conditions in shaping current population diversity. It is now possible to start providing quantitative estimates of divergence times, population size and dynamic processes that have affected populations and their genetic risk for disease. Finally, the availability of ancient genomes from Africa is providing historical insights of unprecedented depth. In this review, we highlight some key interpretations that have emerged from recent African genome studies.
Killeen, Gerry F; Smith, Tom A; Ferguson, Heather M; Mshinda, Hassan; Abdulla, Salim; Lengeler, Christian; Kachur, Steven P
2007-01-01
Background Malaria prevention in Africa merits particular attention as the world strives toward a better life for the poorest. Insecticide-treated nets (ITNs) represent a practical means to prevent malaria in Africa, so scaling up coverage to at least 80% of young children and pregnant women by 2010 is integral to the Millennium Development Goals (MDG). Targeting individual protection to vulnerable groups is an accepted priority, but community-level impacts of broader population coverage are largely ignored even though they may be just as important. We therefore estimated coverage thresholds for entire populations at which individual- and community-level protection are equivalent, representing rational targets for ITN coverage beyond vulnerable groups. Methods and Findings Using field-parameterized malaria transmission models, we show that high (80% use) but exclusively targeted coverage of young children and pregnant women (representing <20% of the population) will deliver limited protection and equity for these vulnerable groups. In contrast, relatively modest coverage (35%–65% use, with this threshold depending on ecological scenario and net quality) of all adults and children, rather than just vulnerable groups, can achieve equitable community-wide benefits equivalent to or greater than personal protection. Conclusions Coverage of entire populations will be required to accomplish large reductions of the malaria burden in Africa. While coverage of vulnerable groups should still be prioritized, the equitable and communal benefits of wide-scale ITN use by older children and adults should be explicitly promoted and evaluated by national malaria control programmes. ITN use by the majority of entire populations could protect all children in such communities, even those not actually covered by achieving existing personal protection targets of the MDG, Roll Back Malaria Partnership, or the US President's Malaria Initiative. PMID:17608562
Stellar Populations in the Local Group: Contribution from Planetary Nebulae
NASA Astrophysics Data System (ADS)
Maciel, W. J.; Costa, R. D. D.; Idiart, T. E. P.; Escudero, A. V.
2007-05-01
The role of planetary nebulae (PN) as a key indicator of stellar populations both in the Milky Way and in galaxies of the Local Group has been emphasized in some recent publications (see for example Maciel et al. 2006, Planetary nebulae beyond the Milky Way, ed. L. Stanghellini, J.R. Walsh, N. G. Douglas, Springer, p.209; Richer and McCall 2006, ibid, p. 220; Buzzoni et al. 2006, MNRAS (in press); Ciardullo, R. 2006, IAU Symposium 234, ed. M.J. Barlow, R.H. Mendez, ASP, in press). As the offspring of stars within a reasonably large mass bracket (0.8 to about 8 solar masses), PN encompass an equally large age spread, as well as different spatial and kinematic distributions. For example, in spiral galaxies PN have different properties depending on their location in the disk, bulge or halo populations. They usually present bright emission lines and can be easily distinguished from other emission line objects, so that their chemical composition and spatiokinematical properties are relatively well determined. Therefore, they are particularly suitable for stellar population studies. In this work, we take into account the available data samples of PN in Local Group galaxies and compare the derived information from different objects, particularly regarding the luminosity-specific PN number density, the chemical composition, space distribution and kinematics. Data by our own group on the Milky Way and Magellanic Clouds are combined with recent surveys and theoretical analyses of other galaxies in the Local Group. Special emphasis is given to the disk and bulge populations of PN in the Milky Way and M31, including an analysis of the metallicity distribution, presence of abundance gradients and a determination of the luminosity function from planetary nebulae.
Bill Block
2012-01-01
You may have noticed in the first issue that I arranged manuscripts a bit differently from how they were presented in the past. In previous issues, papers were arranged largely by taxonomic groups. I deviated from that by grouping papers according to their topical focus. For example, those with a focus on habitat are grouped, as are those focusing on population,...
Zubair, Niha; Luis Ambite, Jose; Bush, William S.; Kichaev, Gleb; Lu, Yingchang; Manichaikul, Ani; Sheu, Wayne H-H.; Absher, Devin; Assimes, Themistocles L.; Bielinski, Suzette J.; Bottinger, Erwin P.; Buzkova, Petra; Chuang, Lee-Ming; Chung, Ren-Hua; Cochran, Barbara; Dumitrescu, Logan; Gottesman, Omri; Haessler, Jeffrey W.; Haiman, Christopher; Heiss, Gerardo; Hsiung, Chao A.; Hung, Yi-Jen; Hwu, Chii-Min; Juang, Jyh-Ming J.; Le Marchand, Loic; Lee, I-Te; Lee, Wen-Jane; Lin, Li-An; Lin, Danyu; Lin, Shih-Yi; Mackey, Rachel H.; Martin, Lisa W.; Pasaniuc, Bogdan; Peters, Ulrike; Predazzi, Irene; Quertermous, Thomas; Reiner, Alex P.; Robinson, Jennifer; Rotter, Jerome I.; Ryckman, Kelli K.; Schreiner, Pamela J.; Stahl, Eli; Tao, Ran; Tsai, Michael Y.; Waite, Lindsay L.; Wang, Tzung-Dau; Buyske, Steven; Ida Chen, Yii-Der; Cheng, Iona; Crawford, Dana C.; Loos, Ruth J.F.; Rich, Stephen S.; Fornage, Myriam; North, Kari E.; Kooperberg, Charles; Carty, Cara L.
2016-01-01
Abstract Genome-wide association studies have identified over 150 loci associated with lipid traits, however, no large-scale studies exist for Hispanics and other minority populations. Additionally, the genetic architecture of lipid-influencing loci remains largely unknown. We performed one of the most racially/ethnically diverse fine-mapping genetic studies of HDL-C, LDL-C, and triglycerides to-date using SNPs on the MetaboChip array on 54,119 individuals: 21,304 African Americans, 19,829 Hispanic Americans, 12,456 Asians, and 530 American Indians. The majority of signals found in these groups generalize to European Americans. While we uncovered signals unique to racial/ethnic populations, we also observed systematically consistent lipid associations across these groups. In African Americans, we identified three novel signals associated with HDL-C (LPL, APOA5, LCAT) and two associated with LDL-C (ABCG8, DHODH). In addition, using this population, we refined the location for 16 out of the 58 known MetaboChip lipid loci. These results can guide tailored screening efforts, reveal population-specific responses to lipid-lowering medications, and aid in the development of new targeted drug therapies. PMID:28426890
Correlates to colonizations of new patches by translocated populations of bighorn sheep
Singer, F.J.; Moses, M.E.; Bellew, S.; Sloan, W.
2000-01-01
By 1950, bighorn sheep were extirpated from large areas of their range. Most extant populations of bighorn sheep (Ovis canadensis) in the Intermountain West consist of <100 individuals occurring in a fragmented distribution across the landscape. Dispersal and successful colonizations of unoccupied habitat patches has been rarely reported, and, in particular, translocated populations have been characterized by limited population growth and limited dispersal rates. Restoration of the species is greatly assisted by dispersal and successful colonization of new patches within a metapopulation structure versus the existing scenario of negligible dispersal and fragmented, small populations. We investigated the correlates for the rate of colonizations of 79 suitable, but unoccupied, patches by 31 translocated populations of bighorn sheep released into nearby patches of habitat. Population growth rates of bighorn sheep in the release patches were correlated to Ne of the founder group, and early contact with a second released population in a nearby release patch (logistic regression, p = 0.08). Largest population size of all extant released populations in 1994 was correlated to potential Ne of the founder group, the number of different source populations represented in the founder, and early contact with a second released population (p = 0.016). Dispersal rates were 100% higher in rams than ewes (p = 0.001). Successful colonizations of unoccupied patches (n = 24 of 79 were colonized) were associated with rapid growth rates in the released population, years since release, larger area of suitable habitat in the release patch, larger population sizes, and a seasonal migratory tendency in the released population (p = 0.05). Fewer water barriers, more open vegetation and more rugged, broken terrain in the intervening habitat were also associated with colonizations (p = <0.05). We concluded that high dispersal rates and rapid reoccupation of large areas could occur if bighorn sheep are placed in large patches of habitat with few barriers to movements to other patches and with no domestic sheep present. Many restorations in the past that did not meet these criteria may have contributed to an insular population structure of bighorn sheep with limited observations of dispersal.
Correlates to colonizations of new patches by translocated populations of bighorn sheep
Singer, F.J.; Moses, M.E.; Bellew, S.; Sloan, W.
2000-01-01
By 1950, bighorn sheep were extirpated from large areas of their range. Most extant populations of bighorn sheep (Ovis canadensis) in the Intermountain West consist of <100 individuals occurring in a fragmented distribution across the landscape. Dispersal and successful colonizations of unoccupied habitat patches has been rarely reported, and, in particular, translocated populations have been characterized by limited population growth and limited dispersal rates. Restoration of the species is greatly assisted by dispersal and successful colonization of new patches within a metapopulation structure versus the existing scenario of negligible dispersal and fragmented, small populations. We investigated the correlates for the rate of colonizations of 79 suitable, but unoccupied, patches by 31 translocated populations of bighorn sheep released into nearby patches of habitat. Population growth rates of bighorn sheep in the release patches were correlated to Ne of the founder group, and early contact with a second released population in a nearby release patch (logistic regression, p = 0.08). Largest population size of all extant released populations in 1994 was correlated to potential Ne of the founder group, the number of different source populations represented in the founder, and early contact with a second released population (p = 0.016). Dispersal rates were 100% higher in rams than ewes (p = 0.001). Successful colonizations of unoccupied patches (n = 24 of 79 were colonized) were associated with rapid growth rates in the released population, years since release, larger area of suitable habitat in the release patch, larger population sizes, and a seasonal migratory tendency in the released population (p = 0.05). Fewer water barriers, more open vegetation and more rugged, broken terrain in the intervening habitat were also associated with colonizations (p = <0.05). We concluded that high dispersal rates and rapid reoccupation of large areas could occur if bighorn sheep are placed in large patches of habitat with few barriers to movements to other patches and with no domestic sheep present. Many restorations in the past that did not meet these criteria may have contributed to an insular population structure of bighorn sheep with limited observations of dispersal.
Monte Carlo simulations on marker grouping and ordering.
Wu, J; Jenkins, J; Zhu, J; McCarty, J; Watson, C
2003-08-01
Four global algorithms, maximum likelihood (ML), sum of adjacent LOD score (SALOD), sum of adjacent recombinant fractions (SARF) and product of adjacent recombinant fraction (PARF), and one approximation algorithm, seriation (SER), were used to compare the marker ordering efficiencies for correctly given linkage groups based on doubled haploid (DH) populations. The Monte Carlo simulation results indicated the marker ordering powers for the five methods were almost identical. High correlation coefficients were greater than 0.99 between grouping power and ordering power, indicating that all these methods for marker ordering were reliable. Therefore, the main problem for linkage analysis was how to improve the grouping power. Since the SER approach provided the advantage of speed without losing ordering power, this approach was used for detailed simulations. For more generality, multiple linkage groups were employed, and population size, linkage cutoff criterion, marker spacing pattern (even or uneven), and marker spacing distance (close or loose) were considered for obtaining acceptable grouping powers. Simulation results indicated that the grouping power was related to population size, marker spacing distance, and cutoff criterion. Generally, a large population size provided higher grouping power than small population size, and closely linked markers provided higher grouping power than loosely linked markers. The cutoff criterion range for achieving acceptable grouping power and ordering power differed for varying cases; however, combining all situations in this study, a cutoff criterion ranging from 50 cM to 60 cM was recommended for achieving acceptable grouping power and ordering power for different cases.
Group or ungroup - moose behavioural response to recolonization of wolves.
Månsson, Johan; Prima, Marie-Caroline; Nicholson, Kerry L; Wikenros, Camilla; Sand, Håkan
2017-01-01
Predation risk is a primary motivator for prey to congregate in larger groups. A large group can be beneficial to detect predators, share predation risk among individuals and cause confusion for an attacking predator. However, forming large groups also has disadvantages like higher detection and attack rates of predators or interspecific competition. With the current recolonization of wolves ( Canis lupus ) in Scandinavia, we studied whether moose ( Alces alces ) respond by changing grouping behaviour as an anti-predatory strategy and that this change should be related to the duration of wolf presence within the local moose population. In particular, as females with calves are most vulnerable to predation risk, they should be more likely to alter behaviour. To study grouping behaviour, we used aerial observations of moose ( n = 1335, where each observation included one or several moose) inside and outside wolf territories. Moose mostly stayed solitary or in small groups (82% of the observations consisted of less than three adult moose), and this behavior was independent of wolf presence. The results did not provide unequivocal support for our main hypothesis of an overall change in grouping behaviour in the moose population in response to wolf presence. Other variables such as moose density, snow depth and adult sex ratio of the group were overall more influential on grouping behaviour. However, the results showed a sex specific difference in social grouping in relation to wolf presence where males tended to form larger groups inside as compared to outside wolf territories. For male moose, population- and environmentally related variables were also important for the pattern of grouping. The results did not give support for that wolf recolonization has resulted in an overall change in moose grouping behaviour. If indeed wolf-induced effects do exist, they may be difficult to discern because the effects from moose population and environmental factors may be stronger than any change in anti-predator behaviour. Our results thereby suggest that caution should be taken as to generalize about the effects of returning predators on the grouping behaviour of their prey.
Telecommunications technology and rural education in the United States
NASA Technical Reports Server (NTRS)
Perrine, J. R.
1975-01-01
The rural sector of the US is examined from the point of view of whether telecommunications technology can augment the development of rural education. Migratory farm workers and American Indians were the target groups which were examined as examples of groups with special needs in rural areas. The general rural population and the target groups were examined to identify problems and to ascertain specific educational needs. Educational projects utilizing telecommunications technology in target group settings were discussed. Large scale regional ATS-6 satellite-based experimental educational telecommunications projects were described. Costs and organizational factors were also examined for large scale rural telecommunications projects.
Empirical Distributions of F ST from Large-Scale Human Polymorphism Data
Elhaik, Eran
2012-01-01
Studies of the apportionment of human genetic variation have long established that most human variation is within population groups and that the additional variation between population groups is small but greatest when comparing different continental populations. These studies often used Wright’s F ST that apportions the standardized variance in allele frequencies within and between population groups. Because local adaptations increase population differentiation, high-F ST may be found at closely linked loci under selection and used to identify genes undergoing directional or heterotic selection. We re-examined these processes using HapMap data. We analyzed 3 million SNPs on 602 samples from eight worldwide populations and a consensus subset of 1 million SNPs found in all populations. We identified four major features of the data: First, a hierarchically F ST analysis showed that only a paucity (12%) of the total genetic variation is distributed between continental populations and even a lesser genetic variation (1%) is found between intra-continental populations. Second, the global F ST distribution closely follows an exponential distribution. Third, although the overall F ST distribution is similarly shaped (inverse J), F ST distributions varies markedly by allele frequency when divided into non-overlapping groups by allele frequency range. Because the mean allele frequency is a crude indicator of allele age, these distributions mark the time-dependent change in genetic differentiation. Finally, the change in mean-F ST of these groups is linear in allele frequency. These results suggest that investigating the extremes of the F ST distribution for each allele frequency group is more efficient for detecting selection. Consequently, we demonstrate that such extreme SNPs are more clustered along the chromosomes than expected from linkage disequilibrium for each allele frequency group. These genomic regions are therefore likely candidates for natural selection. PMID:23185452
Empirical distributions of F(ST) from large-scale human polymorphism data.
Elhaik, Eran
2012-01-01
Studies of the apportionment of human genetic variation have long established that most human variation is within population groups and that the additional variation between population groups is small but greatest when comparing different continental populations. These studies often used Wright's F(ST) that apportions the standardized variance in allele frequencies within and between population groups. Because local adaptations increase population differentiation, high-F(ST) may be found at closely linked loci under selection and used to identify genes undergoing directional or heterotic selection. We re-examined these processes using HapMap data. We analyzed 3 million SNPs on 602 samples from eight worldwide populations and a consensus subset of 1 million SNPs found in all populations. We identified four major features of the data: First, a hierarchically F(ST) analysis showed that only a paucity (12%) of the total genetic variation is distributed between continental populations and even a lesser genetic variation (1%) is found between intra-continental populations. Second, the global F(ST) distribution closely follows an exponential distribution. Third, although the overall F(ST) distribution is similarly shaped (inverse J), F(ST) distributions varies markedly by allele frequency when divided into non-overlapping groups by allele frequency range. Because the mean allele frequency is a crude indicator of allele age, these distributions mark the time-dependent change in genetic differentiation. Finally, the change in mean-F(ST) of these groups is linear in allele frequency. These results suggest that investigating the extremes of the F(ST) distribution for each allele frequency group is more efficient for detecting selection. Consequently, we demonstrate that such extreme SNPs are more clustered along the chromosomes than expected from linkage disequilibrium for each allele frequency group. These genomic regions are therefore likely candidates for natural selection.
Are Isolated Indigenous Populations Headed toward Extinction?
Walker, Robert S; Kesler, Dylan C; Hill, Kim R
2016-01-01
At least 50 indigenous groups spread across lowland South America remain isolated and have only intermittent and mostly hostile interactions with the outside world. Except in emergency situations, the current policy of governments in Brazil, Colombia, and Peru towards isolated tribes is a "leave them alone" strategy, in which isolated groups are left uncontacted. However, these no-contact policies are based on the assumption that isolated populations are healthy and capable of persisting in the face of mounting external threats, and that they can maintain population viability in the long-term. Here, we test this assumption by tracking the sizes and movements of cleared horticultural areas made by 8 isolated groups over the last 10-14 years. We used deforestation data derived from remote sensing Landsat satellite sensors to identify clearings, and those were then validated and assessed with high-resolution imagery. We found only a single example of a relatively large and growing population (c. 50 cleared ha and 400 people), whereas all of the other 7 groups exhibited much smaller villages and gardens with no sizable growth through time. These results indicated that the smaller groups are critically endangered, and it prompts an urgent re-thinking of policies toward isolated populations, including plans for well-organized contacts that may help save lives and rescue isolated indigenous populations from imminent extinction.
Prepaid group practice staffing and U.S. physician supply: lessons for workforce policy.
Weiner, Jonathan P
2004-01-01
This paper describes staffing at eight large prepaid group practices (PGPs) serving more than eight million enrollees at Kaiser Permanente and two other health maintenance organizations (HMOs). Even after characteristics of the patient populations and outside referrals are accounted for, these PGPs have a physician-to-population ratio that is 22-37 percent below the national rate. Two decades of historical data at Kaiser Permanente indicate that its rate of specialist growth was far higher than that of primary care. The study suggests that efficient systems of care can readily meet the demands of patient populations with workforce staffing ratios below current U.S. levels.
Outten, H Robert; Lee, Timothy; Costa-Lopes, Rui; Schmitt, Michael T; Vala, Jorge
2018-01-01
Using concepts from social identity theory (Tajfel and Turner, 1979), we examined whether racial/ethnic majority group members' reactions to future demographic shifts is a function of the degree to which they perceive their ingroup's higher-status in society to be legitimate. In two studies, participants who varied in the degree to which they perceived their group's status to be legitimate were either exposed to real projections for 2060 (i.e., large decline in proportion of population that is the "majority" group), or fake projections for 2060-that resembled current figures (i.e., small decline). In Study 1, White Americans who perceived their status to be highly legitimate expressed greater intergroup threat, and negative feelings (anger and fear) toward minorities after exposure to projections with a large decline in the relative size of the White American population. In contrast, demographic shift condition had no effect on intergroup threat and negative feelings toward minorities among White Americans who perceived their status to be relatively illegitimate; negative feelings and threat remained low across both conditions. Similarly, in Study 2, ethnic Portuguese people in Portugal exposed to projections in which there was a large decline in the relative size of the ethnic Portuguese population experienced more intergroup threat and expressed a greater desire to engage in anti-immigration behaviors. The effect of demographic shift condition on intergroup threat and anti-immigration behaviors was stronger among ethnic Portuguese who perceived their status to be legitimate compared to ethnic Portuguese people who perceived their status to be relatively illegitimate. These results highlight that across different cultural contexts, majority group members' beliefs about the legitimacy of intergroup relations can affect their reactions to the prospect of increased diversity.
MNS, Duffy, and Kell blood groups among the Uygur population of Xinjiang, China.
Lin, G Y; Du, X L; Shan, J J; Zhang, Y N; Zhang, Y Q; Wang, Q H
2017-03-15
Human blood groups are a significant resource for patients, leading to a fierce international competition in the screening of rare blood groups. Some rare blood group screening programs have been implemented in western countries and Japan, but not particularly in China. Recently, the genetic background of ABO and Rh blood groups for different ethnic groups or regions in China has been focused on increasingly. However, rare blood groups such as MN, Duffy, Kidd, MNS, and Diego are largely unexplored. No systematic reports exist concerning the polymorphisms and allele frequencies of rare blood groups in China's ethnic minorities such as Uygur and Kazak populations of Xinjiang, unlike those on the Han population. Therefore, this study aimed to investigate the allele frequencies of rare blood groups, namely, MNS, Duffy, Kell, Dombrock, Diego, Kidd, Scianna, Colton, and Lutheran in the Uygur population of Xinjiang Single specific primer-polymerase chain reaction was performed for genotyping and statistical analysis of 9 rare blood groups in 158 Uygur individuals. Allele frequencies were compared with distribution among other ethnic groups. Observed and expected values of genotype frequencies were compared using the chi-square test. Genotype frequencies obeyed the Hardy-Weinberg equilibrium (P > 0.5) and allele frequencies were stable. Of all subjects detected, 4 cases carried the rare phenotype S - s - of MNS blood group (frequency of 0.0253), and 1 case carried the phenotype Jk a-b- (frequency of 0.0063). Frequencies of the four groups, MNS, Duffy, Dombrock, and Diego, in the Uygur population differed from those in other ethnic groups. Gene distribution of the Kell, Kidd, and Colton was similar to that in Tibetan and Han populations, though there were some discrepancies. Gene distribution of Scianna and Lutheran groups showed monomorphism similar to that in Tibetan and Han populations. These findings could contribute to the investigation of the origin, evolution, and hematology of Uygur population of Xinjiang and assist in screening of rare blood groups in ethnic minorities, meeting of clinical blood supply demands, and building of the national rare blood group library.
ERIC Educational Resources Information Center
Fleisch, Brahm; Taylor, Stephen; Schöer, Volker; Mabogoane, Thabo
2017-01-01
This article illustrates the value of large-scale impact evaluations with counterfactual components. It begins by exploring the limitations of small-scale impact studies, which do not allow reliable inference to a wider population or which do not use valid comparison groups. The paper then describes the design features of a recent large-scale…
2011-01-01
Background The Mon-Khmer speaking peoples inhabited northern Thailand before the arrival of the Tai speaking people from southern China in the thirteenth century A.D. Historical and anthropological evidence suggests a close relationship between the Mon-Khmer groups and the present day majority northern Thai groups. In this study, mitochondrial and Y-chromosomal DNA polymorphisms in more than 800 volunteers from eight Mon-Khmer and ten Tai speaking populations were investigated to estimate the degree of genetic divergence between these major linguistic groups and their internal structure. Results A large fraction of genetic variation is observed within populations (about 80% and 90% for mtDNA and the Y-chromosome, respectively). The genetic divergence between populations is much higher in Mon-Khmer than in Tai speaking groups, especially at the paternally inherited markers. The two major linguistic groups are genetically distinct, but only for a marginal fraction (1 to 2%) of the total genetic variation. Genetic distances between populations correlate with their linguistic differences, whereas the geographic distance does not explain the genetic divergence pattern. Conclusions The Mon-Khmer speaking populations in northern Thailand exhibited the genetic divergence among each other and also when compared to Tai speaking peoples. The different drift effects and the post-marital residence patterns between the two linguistic groups are the explanation for a small but significant fraction of the genetic variation pattern within and between them. PMID:21672265
Kutanan, Wibhu; Kampuansai, Jatupol; Fuselli, Silvia; Nakbunlung, Supaporn; Seielstad, Mark; Bertorelle, Giorgio; Kangwanpong, Daoroong
2011-06-15
The Mon-Khmer speaking peoples inhabited northern Thailand before the arrival of the Tai speaking people from southern China in the thirteenth century A.D. Historical and anthropological evidence suggests a close relationship between the Mon-Khmer groups and the present day majority northern Thai groups. In this study, mitochondrial and Y-chromosomal DNA polymorphisms in more than 800 volunteers from eight Mon-Khmer and ten Tai speaking populations were investigated to estimate the degree of genetic divergence between these major linguistic groups and their internal structure. A large fraction of genetic variation is observed within populations (about 80% and 90% for mtDNA and the Y-chromosome, respectively). The genetic divergence between populations is much higher in Mon-Khmer than in Tai speaking groups, especially at the paternally inherited markers. The two major linguistic groups are genetically distinct, but only for a marginal fraction (1 to 2%) of the total genetic variation. Genetic distances between populations correlate with their linguistic differences, whereas the geographic distance does not explain the genetic divergence pattern. The Mon-Khmer speaking populations in northern Thailand exhibited the genetic divergence among each other and also when compared to Tai speaking peoples. The different drift effects and the post-marital residence patterns between the two linguistic groups are the explanation for a small but significant fraction of the genetic variation pattern within and between them. © 2011 Kutanan et al; licensee BioMed Central Ltd.
Comments on Correlations of IQ with Skin Color and Geographic-Demographic Variables
ERIC Educational Resources Information Center
Jensen, Arthur R.
2006-01-01
A large number of national and geographic population samples were used to test the hypothesis that the variation in mean values of skin color in the diverse populations are consistently correlated with the mean measured or estimated IQs of the various groups, as are some other physical variables, known as an ecological correlation. Straightforward…
Zhang, Dapeng; Arevalo-Gardini, Enrique; Mischke, Sue; Zúñiga-Cernades, Luis; Barreto-Chavez, Alejandro; Del Aguila, Jorge Adriazola
2006-09-01
Cocoa (Theobroma cacao) is indigenous to the Amazon region of South America, and it is well known that the Peruvian Amazon harbours a large number of diverse cocoa populations. A small fraction of the diversity has been collected and maintained as an ex-situ germplasm repository in Peru. However, incorrect labelling of accessions and lack of information on genetic diversity have hindered efficient conservation and use of this germplasm. This study targeted assessment of genetic diversity and population structure in a managed and a semi-natural population. Using a capillary electrophoresis genotyping system, 105 cocoa accessions collected from the Huallaga and Ucayali valleys of Peru were fingerprinted. Based on 15 loci SSR profiles, genetic identity was examined for each accession and duplicates identified, population structure assessed and genetic diversity analysed in these two populations. Ten synonymous mislabelled groups were identified among the 105 accessions. The germplasm group in the Huallaga valley was clearly separated from the group in Ucayali valley by the Bayesian assignment test. The Huallaga group has lower genetic diversity, both in terms of allelic richness and of gene diversity, than the Ucayali group. Analysis of molecular variance suggested genetic substructure in the Ucayali group. Significant spatial correlation between genetic distance and geographical distances was detected in the Ucayali group by Mantel tests. These results substantiate the hypothesis that the Peruvian Amazon hosts a high level of cocoa genetic diversity, and the diversity has a spatial structure. The introduction of exotic seed populations into the Peruvian Amazon is changing the cocoa germplasm spectrum in this region. The spatial structure of cocoa diversity recorded here highlights the need for additional collecting and conservation measures for natural and semi-natural cocoa populations.
Aerial survey methodology for bison population estimation in Yellowstone National Park
Hess, Steven C.
2002-01-01
I developed aerial survey methods for statistically rigorous bison population estimation in Yellowstone National Park to support sound resource management decisions and to understand bison ecology. Survey protocols, data recording procedures, a geographic framework, and seasonal stratifications were based on field observations from February 1998-September 2000. The reliability of this framework and strata were tested with long-term data from 1970-1997. I simulated different sample survey designs and compared them to high-effort censuses of well-defined large areas to evaluate effort, precision, and bias. Sample survey designs require much effort and extensive information on the current spatial distribution of bison and therefore do not offer any substantial reduction in time and effort over censuses. I conducted concurrent ground surveys, or 'double sampling' to estimate detection probability during aerial surveys. Group size distribution and habitat strongly affected detection probability. In winter, 75% of the groups and 92% of individual bison were detected on average from aircraft, while in summer, 79% of groups and 97% of individual bison were detected. I also used photography to quantify the bias due to counting large groups of bison accurately and found that undercounting increased with group size and could reach 15%. I compared survey conditions between seasons and identified optimal time windows for conducting surveys in both winter and summer. These windows account for the habitats and total area bison occupy, and group size distribution. Bison became increasingly scattered over the Yellowstone region in smaller groups and more occupied unfavorable habitats as winter progressed. Therefore, the best conditions for winter surveys occur early in the season (Dec-Jan). In summer, bison were most spatially aggregated and occurred in the largest groups by early August. Low variability between surveys and high detection probability provide population estimates with an overall coefficient of variation of approximately 8% and have high power for detecting trends in population change. I demonstrated how population estimates from winter and summer can be integrated into a comprehensive monitoring program to estimate annual growth rates, overall winter mortality, and an index of calf production, requiring about 30 hours of flight per year.
Hollfelder, Nina; Babiker, Hiba
2017-01-01
Northeast Africa has a long history of human habitation, with fossil-finds from the earliest anatomically modern humans, and housing ancient civilizations. The region is also the gate-way out of Africa, as well as a portal for migration into Africa from Eurasia via the Middle East and the Arabian Peninsula. We investigate the population history of northeast Africa by genotyping ~3.9 million SNPs in 221 individuals from 18 populations sampled in Sudan and South Sudan and combine this data with published genome-wide data from surrounding areas. We find a strong genetic divide between the populations from the northeastern parts of the region (Nubians, central Arab populations, and the Beja) and populations towards the west and south (Nilotes, Darfur and Kordofan populations). This differentiation is mainly caused by a large Eurasian ancestry component of the northeast populations likely driven by migration of Middle Eastern groups followed by admixture that affected the local populations in a north-to-south succession of events. Genetic evidence points to an early admixture event in the Nubians, concurrent with historical contact between North Sudanese and Arab groups. We estimate the admixture in current-day Sudanese Arab populations to about 700 years ago, coinciding with the fall of Dongola in 1315/1316 AD, a wave of admixture that reached the Darfurian/Kordofanian populations some 400–200 years ago. In contrast to the northeastern populations, the current-day Nilotic populations from the south of the region display little or no admixture from Eurasian groups indicating long-term isolation and population continuity in these areas of northeast Africa. PMID:28837655
Hollfelder, Nina; Schlebusch, Carina M; Günther, Torsten; Babiker, Hiba; Hassan, Hisham Y; Jakobsson, Mattias
2017-08-01
Northeast Africa has a long history of human habitation, with fossil-finds from the earliest anatomically modern humans, and housing ancient civilizations. The region is also the gate-way out of Africa, as well as a portal for migration into Africa from Eurasia via the Middle East and the Arabian Peninsula. We investigate the population history of northeast Africa by genotyping ~3.9 million SNPs in 221 individuals from 18 populations sampled in Sudan and South Sudan and combine this data with published genome-wide data from surrounding areas. We find a strong genetic divide between the populations from the northeastern parts of the region (Nubians, central Arab populations, and the Beja) and populations towards the west and south (Nilotes, Darfur and Kordofan populations). This differentiation is mainly caused by a large Eurasian ancestry component of the northeast populations likely driven by migration of Middle Eastern groups followed by admixture that affected the local populations in a north-to-south succession of events. Genetic evidence points to an early admixture event in the Nubians, concurrent with historical contact between North Sudanese and Arab groups. We estimate the admixture in current-day Sudanese Arab populations to about 700 years ago, coinciding with the fall of Dongola in 1315/1316 AD, a wave of admixture that reached the Darfurian/Kordofanian populations some 400-200 years ago. In contrast to the northeastern populations, the current-day Nilotic populations from the south of the region display little or no admixture from Eurasian groups indicating long-term isolation and population continuity in these areas of northeast Africa.
Seroprevalence of Chlamydia trachomatis in Enugu, Nigeria.
Ikeme, A C; Ezegwui, H U; Ikeako, L C; Agbata, I; Agbata, E
2011-01-01
Chlamydia infections in women cause pelvic inflammatory disease, which often results in devastating consequences of infertility, ectopic pregnancy, or chronic pelvic pain. The infection is largely asymptomatic. To determine the seroprevalence of Chlamydia trachomatis in Enugu, South Eastern Nigeria. A population-based prospective study comprising female residents of Enugu, South Eastern Nigeria. Indirect solid phase enzyme immunoassay of Chlamydia antibodies was done using ImmunoComb C0. Trachomatis IgG Kit (Orgenics). The population comprised 136 female undergraduate students and 150 non-student women. The overall prevalence of C. trachomatis in the population studied was 29.4%. The percentage of subjects who admitted to be having multiple sexual partners was higher among the student population (71.2%) compared to those from the non-student population (28.8%). The highest percentage of seroprevalence was 28 (33.3%) in the age group of 20-24 years for the student population and 18 (21.4%) in the age group of 25-29 years for the non-student population. The highest seroprevalence of C. trachomatis antibodies (69.0%) in both populations was observed in females without any history of infection. Females that had pelvic inflammatory disease, sexually transmitted infection, and secondary infertility assayed for C. trachomatis had seroprevalence levels of 19%, 9.5%, and 2.4%, respectively. There was a positive correlation between positive Chlamydia assay and the type of subject population (student or non-student) with r2 value of 1.55 at P < 0.01. C. trachomatis infection is largely underdiagnosed and remains a silent disease in the apparently healthy population of Enugu, South eastern Nigeria.
Wang, Xiaoying; He, Chenxi; Peelen, Marius V; Zhong, Suyu; Gong, Gaolang; Caramazza, Alfonso; Bi, Yanchao
2017-05-03
Human ventral occipital temporal cortex contains clusters of neurons that show domain-preferring responses during visual perception. Recent studies have reported that some of these clusters show surprisingly similar domain selectivity in congenitally blind participants performing nonvisual tasks. An important open question is whether these functional similarities are driven by similar innate connections in blind and sighted groups. Here we addressed this question focusing on the parahippocampal gyrus (PHG), a region that is selective for large objects and scenes. Based on the assumption that patterns of long-range connectivity shape local computation, we examined whether domain selectivity in PHG is driven by similar structural connectivity patterns in the two populations. Multiple regression models were built to predict the selectivity of PHG voxels for large human-made objects from white matter (WM) connectivity patterns in both groups. These models were then tested using independent data from participants with similar visual experience (two sighted groups) and using data from participants with different visual experience (blind and sighted groups). Strikingly, the WM-based predictions between blind and sighted groups were as successful as predictions between two independent sighted groups. That is, the functional selectivity for large objects of a PHG voxel in a blind participant could be accurately predicted by its WM pattern using the connection-to-function model built from the sighted group data, and vice versa. Regions that significantly predicted PHG selectivity were located in temporal and frontal cortices in both sighted and blind populations. These results show that the large-scale network driving domain selectivity in PHG is independent of vision. SIGNIFICANCE STATEMENT Recent studies have reported intriguingly similar domain selectivity in sighted and congenitally blind individuals in regions within the ventral visual cortex. To examine whether these similarities originate from similar innate connectional roots, we investigated whether the domain selectivity in one population could be predicted by the structural connectivity pattern of the other. We found that the selectivity for large objects of a PHG voxel in a blind participant could be predicted by its structural connectivity pattern using the connection-to-function model built from the sighted group data, and vice versa. These results reveal that the structural connectivity underlying domain selectivity in the PHG is independent of visual experience, providing evidence for nonvisual representations in this region. Copyright © 2017 the authors 0270-6474/17/374706-12$15.00/0.
Group Threat and Policy Change: The Spatial Dynamics of Prohibition Politics, 1890-1919.
Andrews, Kenneth T; Seguin, Charles
2015-09-01
The authors argue that group threat is a key driver of the adoption of new and controversial policies. Conceptualizing threat in spatial terms, they argue that group threat is activated through the joint occurrence of (1) proximity to threatening groups and (2) the population density of threatened groups. By analyzing the adoption of county and state "dry laws" banning alcohol from 1890 to 1919, they first show that prohibition victories were driven by the relative strength of supportive constituencies such as native whites and rural residents, vis-à-vis opponents such as Irish, Italian, or German immigrants or Catholics. Second, they show that threat contributed to prohibition victories: counties bordering large immigrant or urban populations, which did not themselves contain similar populations, were more likely to adopt dry laws. Threat arises primarily from interactions between spatially proximate units at the local level, and therefore higher-level policy change is not reducible to the variables driving local policy.
Coulon, A.; Fitzpatrick, J.W.; Bowman, R.; Stith, B.M.; Makarewich, C.A.; Stenzler, L.M.; Lovette, I.J.
2008-01-01
The delimitation of populations, defined as groups of individuals linked by gene flow, is possible by the analysis of genetic markers and also by spatial models based on dispersal probabilities across a landscape. We combined these two complimentary methods to define the spatial pattern of genetic structure among remaining populations of the threatened Florida scrub-jay, a species for which dispersal ability is unusually well-characterized. The range-wide population was intensively censused in the 1990s, and a metapopulation model defined population boundaries based on predicted dispersal-mediated demographic connectivity. We subjected genotypes from more than 1000 individual jays screened at 20 microsatellite loci to two Bayesian clustering methods. We describe a consensus method for identifying common features across many replicated clustering runs. Ten genetically differentiated groups exist across the present-day range of the Florida scrub-jay. These groups are largely consistent with the dispersal-defined metapopulations, which assume very limited dispersal ability. Some genetic groups comprise more than one metapopulation, likely because these genetically similar metapopulations were sundered only recently by habitat alteration. The combined reconstructions of population structure based on genetics and dispersal-mediated demographic connectivity provide a robust depiction of the current genetic and demographic organization of this species, reflecting past and present levels of dispersal among occupied habitat patches. The differentiation of populations into 10 genetic groups adds urgency to management efforts aimed at preserving what remains of genetic variation in this dwindling species, by maintaining viable populations of all genetically differentiated and geographically isolated populations.
ERIC Educational Resources Information Center
Amer, Mona M.; Bagasra, Anisah
2013-01-01
Like other minority groups in North America, Muslim Americans have been largely ignored in the psychological literature. The overwhelming pressures faced by this group, including surveillance, hate crimes, and institutional discrimination, stimulate an urgent need for psychologists to better understand and ensure the well-being of this population.…
Transactional Analysis and the Student Personnel Worker
ERIC Educational Resources Information Center
Hickerson, J. Douglas
1973-01-01
This article cites reasons why Transactional Analysis (as described in Harris' book I'm Okay - You're Okay) is uniquely suited for group mental health counseling in student populations. Ideal in its emphasis on group counseling (the only kind practical for large student masses), its teaching-learning method, and its simplicity of language T.A.…
Polymorphic Alu Insertion/Deletion in Different Caste and Tribal Populations from South India.
Chinniah, Rathika; Vijayan, Murali; Thirunavukkarasu, Manikandan; Mani, Dhivakar; Raju, Kamaraj; Ravi, Padma Malini; Sivanadham, Ramgopal; C, Kandeepan; N, Mahalakshmi; Karuppiah, Balakrishnan
2016-01-01
Seven human-specific Alu markers were studied in 574 unrelated individuals from 10 endogamous groups and 2 hill tribes of Tamil Nadu and Kerala states. DNA was isolated, amplified by PCR-SSP, and subjected to agarose gel electrophoresis, and genotypes were assigned for various Alu loci. Average heterozygosity among caste populations was in the range of 0.292-0.468. Among tribes, the average heterozygosity was higher for Paliyan (0.3759) than for Kani (0.2915). Frequency differences were prominent in all loci studied except Alu CD4. For Alu CD4, the frequency was 0.0363 in Yadavas, a traditional pastoral and herd maintaining population, and 0.2439 in Narikuravars, a nomadic gypsy population. The overall genetic difference (Gst) of 12 populations (castes and tribes) studied was 3.6%, which corresponds to the Gst values of 3.6% recorded earlier for Western Asian populations. Thus, our study confirms the genetic similarities between West Asian populations and South Indian castes and tribes and supported the large scale coastal migrations from Africa into India through West Asia. However, the average genetic difference (Gst) of Kani and Paliyan tribes with other South Indian tribes studied earlier was 8.3%. The average Gst of combined South and North Indian Tribes (CSNIT) was 9.5%. Neighbor joining tree constructed showed close proximity of Kani and Paliyan tribal groups to the other two South Indian tribes, Toda and Irula of Nilgiri hills studied earlier. Further, the analysis revealed the affinities among populations and confirmed the presence of North and South India specific lineages. Our findings have documented the highly diverse (micro differentiated) nature of South Indian tribes, predominantly due to isolation, than the endogamous population groups of South India. Thus, our study firmly established the genetic relationship of South Indian castes and tribes and supported the proposed large scale ancestral migrations from Africa, particularly into South India through West Asian corridor.
Polymorphic Alu Insertion/Deletion in Different Caste and Tribal Populations from South India
Chinniah, Rathika; Vijayan, Murali; Thirunavukkarasu, Manikandan; Mani, Dhivakar; Raju, Kamaraj; Ravi, Padma Malini; Sivanadham, Ramgopal; C, Kandeepan; N, Mahalakshmi; Karuppiah, Balakrishnan
2016-01-01
Seven human-specific Alu markers were studied in 574 unrelated individuals from 10 endogamous groups and 2 hill tribes of Tamil Nadu and Kerala states. DNA was isolated, amplified by PCR-SSP, and subjected to agarose gel electrophoresis, and genotypes were assigned for various Alu loci. Average heterozygosity among caste populations was in the range of 0.292–0.468. Among tribes, the average heterozygosity was higher for Paliyan (0.3759) than for Kani (0.2915). Frequency differences were prominent in all loci studied except Alu CD4. For Alu CD4, the frequency was 0.0363 in Yadavas, a traditional pastoral and herd maintaining population, and 0.2439 in Narikuravars, a nomadic gypsy population. The overall genetic difference (Gst) of 12 populations (castes and tribes) studied was 3.6%, which corresponds to the Gst values of 3.6% recorded earlier for Western Asian populations. Thus, our study confirms the genetic similarities between West Asian populations and South Indian castes and tribes and supported the large scale coastal migrations from Africa into India through West Asia. However, the average genetic difference (Gst) of Kani and Paliyan tribes with other South Indian tribes studied earlier was 8.3%. The average Gst of combined South and North Indian Tribes (CSNIT) was 9.5%. Neighbor joining tree constructed showed close proximity of Kani and Paliyan tribal groups to the other two South Indian tribes, Toda and Irula of Nilgiri hills studied earlier. Further, the analysis revealed the affinities among populations and confirmed the presence of North and South India specific lineages. Our findings have documented the highly diverse (micro differentiated) nature of South Indian tribes, predominantly due to isolation, than the endogamous population groups of South India. Thus, our study firmly established the genetic relationship of South Indian castes and tribes and supported the proposed large scale ancestral migrations from Africa, particularly into South India through West Asian corridor. PMID:27315142
Measuring local depletion of terrestrial game vertebrates by central-place hunters in rural Amazonia
Peres, Carlos A.; Costa, Hugo C. M.
2017-01-01
The degree to which terrestrial vertebrate populations are depleted in tropical forests occupied by human communities has been the subject of an intense polarising debate that has important conservation implications. Conservation ecologists and practitioners are divided over the extent to which community-based subsistence offtake is compatible with ecologically functional populations of tropical forest game species. To quantify depletion envelopes of forest vertebrates around human communities, we deployed a total of 383 camera trap stations and 78 quantitative interviews to survey the peri-community areas controlled by 60 semi-subsistence communities over a combined area of over 3.2 million hectares in the Médio Juruá and Uatumã regions of Central-Western Brazilian Amazonia. Our results largely conform with prior evidence that hunting large-bodied vertebrates reduces wildlife populations near settlements, such that they are only found at a distance to settlements where they are hunted less frequently. Camera trap data suggest that a select few harvest-sensitive species, including lowland tapir, are either repelled or depleted by human communities. Nocturnal and cathemeral species were detected relatively more frequently in disturbed areas close to communities, but individual species did not necessarily shift their activity patterns. Group biomass of all species was depressed in the wider neighbourhood of urban areas rather than communities. Interview data suggest that species traits, especially group size and body mass, mediate these relationships. Large-bodied, large-group-living species are detected farther from communities as reported by experienced informants. Long-established communities in our study regions have not “emptied” the surrounding forest. Low human population density and low hunting offtake due to abundant sources of alternative aquatic protein, suggest that these communities represent a best-case scenario for sustainable hunting of wildlife for food, thereby providing a conservative assessment of game depletion. Given this ‘best-case’ camera trap and interview-based evidence for hunting depletion, regions with higher human population densities, external trade in wildlife and limited access to alternative protein will likely exhibit more severe depletion. PMID:29040340
Abrahams, Mark I; Peres, Carlos A; Costa, Hugo C M
2017-01-01
The degree to which terrestrial vertebrate populations are depleted in tropical forests occupied by human communities has been the subject of an intense polarising debate that has important conservation implications. Conservation ecologists and practitioners are divided over the extent to which community-based subsistence offtake is compatible with ecologically functional populations of tropical forest game species. To quantify depletion envelopes of forest vertebrates around human communities, we deployed a total of 383 camera trap stations and 78 quantitative interviews to survey the peri-community areas controlled by 60 semi-subsistence communities over a combined area of over 3.2 million hectares in the Médio Juruá and Uatumã regions of Central-Western Brazilian Amazonia. Our results largely conform with prior evidence that hunting large-bodied vertebrates reduces wildlife populations near settlements, such that they are only found at a distance to settlements where they are hunted less frequently. Camera trap data suggest that a select few harvest-sensitive species, including lowland tapir, are either repelled or depleted by human communities. Nocturnal and cathemeral species were detected relatively more frequently in disturbed areas close to communities, but individual species did not necessarily shift their activity patterns. Group biomass of all species was depressed in the wider neighbourhood of urban areas rather than communities. Interview data suggest that species traits, especially group size and body mass, mediate these relationships. Large-bodied, large-group-living species are detected farther from communities as reported by experienced informants. Long-established communities in our study regions have not "emptied" the surrounding forest. Low human population density and low hunting offtake due to abundant sources of alternative aquatic protein, suggest that these communities represent a best-case scenario for sustainable hunting of wildlife for food, thereby providing a conservative assessment of game depletion. Given this 'best-case' camera trap and interview-based evidence for hunting depletion, regions with higher human population densities, external trade in wildlife and limited access to alternative protein will likely exhibit more severe depletion.
Lee, Hea-Young; Ro, Na-Young; Jeong, Hee-Jin; Kwon, Jin-Kyung; Jo, Jinkwan; Ha, Yeaseong; Jung, Ayoung; Han, Ji-Woong; Venkatesh, Jelli; Kang, Byoung-Cheorl
2016-11-14
Conservation of genetic diversity is an essential prerequisite for developing new cultivars with desirable agronomic traits. Although a large number of germplasm collections have been established worldwide, many of them face major difficulties due to large size and a lack of adequate information about population structure and genetic diversity. Core collection with a minimum number of accessions and maximum genetic diversity of pepper species and its wild relatives will facilitate easy access to genetic material as well as the use of hidden genetic diversity in Capsicum. To explore genetic diversity and population structure, we investigated patterns of molecular diversity using a transcriptome-based 48 single nucleotide polymorphisms (SNPs) in a large germplasm collection comprising 3,821 accessions. Among the 11 species examined, Capsicum annuum showed the highest genetic diversity (H E = 0.44, I = 0.69), whereas the wild species C. galapagoense showed the lowest genetic diversity (H E = 0.06, I = 0.07). The Capsicum germplasm collection was divided into 10 clusters (cluster 1 to 10) based on population structure analysis, and five groups (group A to E) based on phylogenetic analysis. Capsicum accessions from the five distinct groups in an unrooted phylogenetic tree showed taxonomic distinctness and reflected their geographic origins. Most of the accessions from European countries are distributed in the A and B groups, whereas the accessions from Asian countries are mainly distributed in C and D groups. Five different sampling strategies with diverse genetic clustering methods were used to select the optimal method for constructing the core collection. Using a number of allelic variations based on 48 SNP markers and 32 different phenotypic/morphological traits, a core collection 'CC240' with a total of 240 accessions (5.2 %) was selected from within the entire Capsicum germplasm. Compared to the other core collections, CC240 displayed higher genetic diversity (I = 0.95) and genetic evenness (J' = 0.80), and represented a wider range of phenotypic variation (MD = 9.45 %, CR = 98.40 %). A total of 240 accessions were selected from 3,821 Capsicum accessions based on transcriptome-based 48 SNP markers with genome-wide distribution and 32 traits using a systematic approach. This core collection will be a primary resource for pepper breeders and researchers for further genetic association and functional analyses.
Are Isolated Indigenous Populations Headed toward Extinction?
Walker, Robert S.; Kesler, Dylan C.; Hill, Kim R.
2016-01-01
At least 50 indigenous groups spread across lowland South America remain isolated and have only intermittent and mostly hostile interactions with the outside world. Except in emergency situations, the current policy of governments in Brazil, Colombia, and Peru towards isolated tribes is a “leave them alone” strategy, in which isolated groups are left uncontacted. However, these no-contact policies are based on the assumption that isolated populations are healthy and capable of persisting in the face of mounting external threats, and that they can maintain population viability in the long-term. Here, we test this assumption by tracking the sizes and movements of cleared horticultural areas made by 8 isolated groups over the last 10–14 years. We used deforestation data derived from remote sensing Landsat satellite sensors to identify clearings, and those were then validated and assessed with high-resolution imagery. We found only a single example of a relatively large and growing population (c. 50 cleared ha and 400 people), whereas all of the other 7 groups exhibited much smaller villages and gardens with no sizable growth through time. These results indicated that the smaller groups are critically endangered, and it prompts an urgent re-thinking of policies toward isolated populations, including plans for well-organized contacts that may help save lives and rescue isolated indigenous populations from imminent extinction. PMID:26954672
Zubair, Niha; Graff, Mariaelisa; Luis Ambite, Jose; Bush, William S; Kichaev, Gleb; Lu, Yingchang; Manichaikul, Ani; Sheu, Wayne H-H; Absher, Devin; Assimes, Themistocles L; Bielinski, Suzette J; Bottinger, Erwin P; Buzkova, Petra; Chuang, Lee-Ming; Chung, Ren-Hua; Cochran, Barbara; Dumitrescu, Logan; Gottesman, Omri; Haessler, Jeffrey W; Haiman, Christopher; Heiss, Gerardo; Hsiung, Chao A; Hung, Yi-Jen; Hwu, Chii-Min; Juang, Jyh-Ming J; Le Marchand, Loic; Lee, I-Te; Lee, Wen-Jane; Lin, Li-An; Lin, Danyu; Lin, Shih-Yi; Mackey, Rachel H; Martin, Lisa W; Pasaniuc, Bogdan; Peters, Ulrike; Predazzi, Irene; Quertermous, Thomas; Reiner, Alex P; Robinson, Jennifer; Rotter, Jerome I; Ryckman, Kelli K; Schreiner, Pamela J; Stahl, Eli; Tao, Ran; Tsai, Michael Y; Waite, Lindsay L; Wang, Tzung-Dau; Buyske, Steven; Ida Chen, Yii-Der; Cheng, Iona; Crawford, Dana C; Loos, Ruth J F; Rich, Stephen S; Fornage, Myriam; North, Kari E; Kooperberg, Charles; Carty, Cara L
2016-12-15
Genome-wide association studies have identified over 150 loci associated with lipid traits, however, no large-scale studies exist for Hispanics and other minority populations. Additionally, the genetic architecture of lipid-influencing loci remains largely unknown. We performed one of the most racially/ethnically diverse fine-mapping genetic studies of HDL-C, LDL-C, and triglycerides to-date using SNPs on the MetaboChip array on 54,119 individuals: 21,304 African Americans, 19,829 Hispanic Americans, 12,456 Asians, and 530 American Indians. The majority of signals found in these groups generalize to European Americans. While we uncovered signals unique to racial/ethnic populations, we also observed systematically consistent lipid associations across these groups. In African Americans, we identified three novel signals associated with HDL-C (LPL, APOA5, LCAT) and two associated with LDL-C (ABCG8, DHODH). In addition, using this population, we refined the location for 16 out of the 58 known MetaboChip lipid loci. These results can guide tailored screening efforts, reveal population-specific responses to lipid-lowering medications, and aid in the development of new targeted drug therapies. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Moraes, Evandro M; Perez, Manolo F; Téo, Mariana F; Zappi, Daniela C; Taylor, Nigel P; Machado, Marlon C
2012-09-01
The Pilosocereus aurisetus group contains eight cactus species restricted to xeric habitats in eastern and central Brazil that have an archipelago-like distribution. In this study, 5-11 microsatellite markers previously designed for Pilosocereus machrisii were evaluated for cross-amplification and polymorphisms in ten populations from six species of the P. aurisetus group. The genotypic information was subsequently used to investigate the genetic relationships between the individuals, populations, and species analyzed. Only the Pmac101 locus failed to amplify in all of the six analyzed species, resulting in an 88 % success rate. The number of alleles per polymorphic locus ranged from 2 to 12, and the most successfully amplified loci showed at least one population with a larger number of alleles than were reported in the source species. The population relationships revealed clear genetic clustering in a neighbor-joining tree that was partially incongruent with the taxonomic limits between the P. aurisetus and P. machrisii species, a fact which parallels the problematic taxonomy of the P. aurisetus group. A Bayesian clustering analysis of the individual genotypes confirmed the observed taxonomic incongruence. These microsatellite markers provide a valuable resource for facilitating large-scale genetic studies on population structures, systematics and evolutionary history in this group.
Oettlé, Anna C; Becker, Piet J; de Villiers, Elzabe; Steyn, Maryna
2009-08-01
The mandibular angle is measured in physical anthropological assessments of human remains to possibly assist with the determination of sex and population affinity. The purpose of this investigation was to establish how the mandibular angle changes with age and loss of teeth among the sexes in South African population groups. The angles of 653 dried adult mandibles from the Pretoria Bone Collection were measured with a mandibulometer. Males and females of both South African whites and blacks were included. To compensate for imbalances in numbers among subgroups, type IV ANOVA testing was applied. No association was found between age and angle within either of the populations, within sexes, or within dentition groups. The angle was the most obtuse in individuals without molars and with an uneven distribution of molars, and most acute in the group with an even distribution of molars on both sides. Statistically significant differences (P < 0.001) were found in the angle between the two population groups and sexes in the overall sample as well as in the subgroup with absent molar teeth (P = 0.003 for sex, males more acute angle, and P = 0.001 for population group, blacks more acute angle), although a very large overlap existed. No significant differences could be demonstrated between the sexes or populations within the subgroups with molars. We concluded that the loss of molars, especially if complete or uneven, has a considerable effect on the mandibular angle. In the assessment of human remains, the mandibular angle is not very usable in determining sex.
The Future of Stellar Populations Studies in the Milky Way and the Local Group
NASA Astrophysics Data System (ADS)
Majewski, Steven R.
2010-04-01
The last decade has seen enormous progress in understanding the structure of the Milky Way and neighboring galaxies via the production of large-scale digital surveys of the sky like 2MASS and SDSS, as well as specialized, counterpart imaging surveys of other Local Group systems. Apart from providing snaphots of galaxy structure, these “cartographic” surveys lend insights into the formation and evolution of galaxies when supplemented with additional data (e.g., spectroscopy, astrometry) and when referenced to theoretical models and simulations of galaxy evolution. These increasingly sophisticated simulations are making ever more specific predictions about the detailed chemistry and dynamics of stellar populations in galaxies. To fully exploit, test and constrain these theoretical ventures demands similar commitments of observational effort as has been plied into the previous imaging surveys to fill out other dimensions of parameter space with statistically significant intensity. Fortunately the future of large-scale stellar population studies is bright with a number of grand projects on the horizon that collectively will contribute a breathtaking volume of information on individual stars in Local Group galaxies. These projects include: (1) additional imaging surveys, such as Pan-STARRS, SkyMapper and LSST, which, apart from providing deep, multicolor imaging, yield time series data useful for revealing variable stars (including critical standard candles, like RR Lyrae variables) and creating large-scale, deep proper motion catalogs; (2) higher accuracy, space-based astrometric missions, such as Gaia and SIM-Lite, which stand to provide critical, high precision dynamical data on stars in the Milky Way and its satellites; and (3) large-scale spectroscopic surveys provided by RAVE, APOGEE, HERMES, LAMOST, and the Gaia spectrometer, which will yield not only enormous numbers of stellar radial velocities, but extremely comprehensive views of the chemistry of stellar populations. Meanwhile, previously dust-obscured regions of the Milky Way will continue to be systematically exposed via large infrared surveys underway or on the way, such as the various GLIMPSE surveys from Spitzer's IRAC instrument, UKIDSS, APOGEE, JASMINE and WISE.
ERIC Educational Resources Information Center
Dewinter, J.; De Graaf, H.; Begeer, S.
2017-01-01
This study compared sexual orientation and romantic relationship experience in a large sample of adolescents and adults with autism spectrum disorder (ASD) (n = 675) and general population peers (n = 8064). Gender identity was explored in the ASD group in relation to assigned gender at birth. Compared to general population peers, more people with…
The Genetic Structure of Pacific Islanders
Friedlaender, Jonathan S; Friedlaender, Françoise R; Reed, Floyd A; Kidd, Kenneth K; Kidd, Judith R; Chambers, Geoffrey K; Lea, Rodney A; Loo, Jun-Hun; Koki, George; Hodgson, Jason A; Merriwether, D. Andrew; Weber, James L
2008-01-01
Human genetic diversity in the Pacific has not been adequately sampled, particularly in Melanesia. As a result, population relationships there have been open to debate. A genome scan of autosomal markers (687 microsatellites and 203 insertions/deletions) on 952 individuals from 41 Pacific populations now provides the basis for understanding the remarkable nature of Melanesian variation, and for a more accurate comparison of these Pacific populations with previously studied groups from other regions. It also shows how textured human population variation can be in particular circumstances. Genetic diversity within individual Pacific populations is shown to be very low, while differentiation among Melanesian groups is high. Melanesian differentiation varies not only between islands, but also by island size and topographical complexity. The greatest distinctions are among the isolated groups in large island interiors, which are also the most internally homogeneous. The pattern loosely tracks language distinctions. Papuan-speaking groups are the most differentiated, and Austronesian or Oceanic-speaking groups, which tend to live along the coastlines, are more intermixed. A small “Austronesian” genetic signature (always <20%) was detected in less than half the Melanesian groups that speak Austronesian languages, and is entirely lacking in Papuan-speaking groups. Although the Polynesians are also distinctive, they tend to cluster with Micronesians, Taiwan Aborigines, and East Asians, and not Melanesians. These findings contribute to a resolution to the debates over Polynesian origins and their past interactions with Melanesians. With regard to genetics, the earlier studies had heavily relied on the evidence from single locus mitochondrial DNA or Y chromosome variation. Neither of these provided an unequivocal signal of phylogenetic relations or population intermixture proportions in the Pacific. Our analysis indicates the ancestors of Polynesians moved through Melanesia relatively rapidly and only intermixed to a very modest degree with the indigenous populations there. PMID:18208337
[Epidemiology and clinical characteristics of primary congenital glaucoma].
Aziz, A; Fakhoury, O; Matonti, F; Pieri, E; Denis, D
2015-12-01
Primary congenital glaucoma (PCG) is a rare and sight threatening condition. Few large epidemiological studies are available in the literature concerning this condition. The purpose of the study was to evaluate the epidemiological and clinical characteristics of children affected by PCG. Children affected by PCG, from 1 day to 3 years old at the time of diagnosis were retrospectively included between 1999 and 2014. The analysis concerned the pregnancy, family history, initial referral, clinical presentation with description of the classic findings in this condition, mean age at first consultation, duration of follow-up and presence of a delay in treatment, defined as a delay of over one month from the appearance of clinical signs until diagnosis. Two groups were defined according to age at appearance of the clinical signs: "early" group prior to 2 months old and "late" group beyond 2 months up until 3 years old. One hundred and forty-one eyes of 71 children were included, with 49.3% girls (n=35 children) and 50.7% boys (n=36 children) for a male:female ratio of 1.02. The "early" group included 50 children i.e. 70.3% of the population; the "late" group 21 children or 29.7% of the population. A first-degree family history of congenital glaucoma existed in 28% of cases (n=19). The average age at first consultation was 13.1 months for the entire population, and the mean duration of follow-up was 56.6 months. Involvement was bilateral in 99.3% of cases (n=70 children) and the most frequent clinical sign was buphthalmos in 64.5% of eyes (n=91 eyes). Treatment was delayed in 35.3% of cases (n=25 children). This study is of particular relevance because it was performed over a long period and on a large population, considering the rare prevalence of the pathology, and has found epidemiological and clinical data comparable with those available in the literature for similar populations. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
Watanabe, Masaya; Yukuhiro, Fumiko; Maeda, Taro; Miura, Kazuki; Kageyama, Daisuke
2014-01-01
Spiroplasma, a group of small, wall-less, helical, and motile bacteria belonging to the Mollicutes, contains species with diverse life histories. To date, all the Spiroplasma strains that are known to be transmitted vertically in arthropod lineages belong to either the Spiroplasma ixodetis group or the Spiroplasma poulsonii group. Here, we found that a unique strain of Spiroplasma vertically transmitted in predatory flower bugs of the genus Orius belongs to the Spiroplasma insolitum group, which is a group of bacteria phylogenetically closely related to S. insolitum derived from the tickseed sunflower, Bidens sp. (Asterales: Asteraceae). The infection frequencies in natural populations were16.0% in Orius sauteri (n = 75), 40.5% in Orius nagaii (n = 37), and 8.0% in Orius minutus (n = 87). Orius strigicollis was not infected with Spiroplasma (n = 147). In the early stage of oogenesis (i.e., within the germarium), a large number of bacteria with the typical morphology of Spiroplasma existed, keeping a distance from Wolbachia bacteria. The Spiroplasma population seemed to increase during host development but Wolbachia population did not.
Fremont, Allen; Kranz, Ashley M; Phillips, Jessica; Garber, Chandra
2017-06-01
In 2012, leaders from disparate health care organizations established a data group aligned around a regional goal of preventing heart attacks and strokes in San Diego. The group---now named the Be There San Diego Data for Quality (DFQ) Group---is a safe venue for medical directors and other quality-improvement leaders to share performance data on quality-of-care measures for diabetes, hypertension, and cardiovascular disease, as well as insights, lessons learned, and challenges faced by each organization in treating these conditions. The DFQ Group has focused its efforts on improving the quality of services provided by each participating health care organization, and has placed a strong emphasis on analyzing trends in combined quality data to better understand the health of the entire San Diego population. By fostering collaboration among organizations that collectively serve a large portion of the local population and other key community stakeholders, the DFQ Group has helped form the foundation of a unique, multifaceted, multi-stakeholder, regional effort that is gaining national attention and funding for its community-driven approach.
Haptoglobin gene subtypes in three Brazilian population groups of different ethnicities
2009-01-01
Haptoglobin is a plasma hemoglobin-binding protein that limits iron loss during normal erythrocyte turnover and hemolysis, thereby preventing oxidative damage mediated by iron excess in the circulation. Haptoglobin polymorphism in humans, characterized by the Hp*1 and Hp *2 alleles, results in distinct phenotypes known as Hp1-1, Hp2-1 and Hp2-2, whose frequencies vary according to the ethnic origin of the population. The Hp*1 allele has two subtypes, Hp *1F and Hp *1S , that also vary in their frequencies among populations worldwide. In this work, we examined the distribution frequencies of haptoglobin subtypes in three Brazilian population groups of different ethnicities. The haptoglobin genotypes of Kayabi Amerindians (n = 56), Kalunga Afro-descendants (n = 70) and an urban population (n = 132) were determined by allele-specific PCR. The Hp*1F allele frequency was highest in Kalunga (29.3%) and lowest in Kayabi (2.6%). The Hp*1F/Hp*1S allele frequency ratios were 0.6, 1.0 and 0.26 for the Kayabi, Kalunga and urban populations, respectively. This variation was attributable largely to the Hp*1F allele. However, despite the large variation in Hp*1F frequencies, results of F ST (0.0291) indicated slight genetic differentiation among subpopulations of the general Brazilian population studied here. This is the first Brazilian report of variations in the Hp*1F and Hp*1S frequencies among non-Amerindian Brazilians. PMID:21637505
Haptoglobin gene subtypes in three Brazilian population groups of different ethnicities.
Miranda-Vilela, Ana L; Akimoto, Arthur K; Alves, Penha C Z; Hiragi, Cássia O; Penalva, Guilherme C; Oliveira, Silviene F; Grisolia, Cesar K; Klautau-Guimarães, Maria N
2009-07-01
Haptoglobin is a plasma hemoglobin-binding protein that limits iron loss during normal erythrocyte turnover and hemolysis, thereby preventing oxidative damage mediated by iron excess in the circulation. Haptoglobin polymorphism in humans, characterized by the Hp(*1) and Hp (*2) alleles, results in distinct phenotypes known as Hp1-1, Hp2-1 and Hp2-2, whose frequencies vary according to the ethnic origin of the population. The Hp(*1) allele has two subtypes, Hp (*1F) and Hp (*1S) , that also vary in their frequencies among populations worldwide. In this work, we examined the distribution frequencies of haptoglobin subtypes in three Brazilian population groups of different ethnicities. The haptoglobin genotypes of Kayabi Amerindians (n = 56), Kalunga Afro-descendants (n = 70) and an urban population (n = 132) were determined by allele-specific PCR. The Hp(*1F) allele frequency was highest in Kalunga (29.3%) and lowest in Kayabi (2.6%). The Hp(*1F)/Hp(*1S) allele frequency ratios were 0.6, 1.0 and 0.26 for the Kayabi, Kalunga and urban populations, respectively. This variation was attributable largely to the Hp(*1F) allele. However, despite the large variation in Hp(*1F) frequencies, results of F (ST) (0.0291) indicated slight genetic differentiation among subpopulations of the general Brazilian population studied here. This is the first Brazilian report of variations in the Hp(*1F) and Hp(*1S) frequencies among non-Amerindian Brazilians.
Remote sensing of the biological dynamics of large-scale salt evaporation ponds
NASA Technical Reports Server (NTRS)
Richardson, Laurie L.; Bachoon, Dave; Ingram-Willey, Vebbra; Chow, Colin C.; Weinstock, Kenneth
1992-01-01
Optical properties of salt evaporation ponds associated with Exportadora de Sal, a salt production company in Baja California Sur, Mexico, were analyzed using a combination of spectroradiometer and extracted pigment data, and Landsat-5 Thematic Mapper imagery. The optical characteristics of each pond are determined by the biota, which consists of dense populations of algae and photosynthetic bacteria containing a wide variety of photosynthetic and photoprotective pigments. Analysis has shown that spectral and image data can differentiate between taxonomic groups of the microbiota, detect changes in population distributions, and reveal large-scale seasonal dynamics.
Reeve, John D; Frantz, Alain C; Dawson, Deborah A; Burke, Terry; Roper, Timothy J
2008-09-01
1. Urban and rural populations of animals can differ in their behaviour, both in order to meet their ecological requirements and due to the constraints imposed by different environments. The study of urban populations can therefore offer useful insights into the behavioural flexibility of a species as a whole, as well as indicating how the species in question adapts to a specifically urban environment. 2. The genetic structure of a population can provide information about social structure and movement patterns that is difficult to obtain by other means. Using non-invasively collected hair samples, we estimated the population size of Eurasian badgers Meles meles in the city of Brighton, England, and calculated population-specific parameters of genetic variability and sex-specific rates of outbreeding and dispersal. 3. Population density was high in the context of badger densities reported throughout their range. This was due to a high density of social groups rather than large numbers of individuals per group. 4. The allelic richness of the population was low compared with other British populations. However, the rate of extra-group paternity and the relatively frequent (mainly temporary) intergroup movements suggest that, on a local scale, the population was outbred. Although members of both sexes visited other groups, there was a trend for more females to make intergroup movements. 5. The results reveal that urban badgers can achieve high densities and suggest that while some population parameters are similar between urban and rural populations, the frequency of intergroup movements is higher among urban badgers. In a wider context, these results demonstrate the ability of non-invasive genetic sampling to provide information about the population density, social structure and behaviour of urban wildlife.
Bustillo, Jorge L; Diaz, Jose D; Pacheco, Idarmes C; Gritz, David C
2015-03-01
Serological studies indicate that rates of ocular toxoplasmosis (OT) vary geographically, with higher rates in tropical regions. Little is known about population-based rates of active OT. We aimed to describe the epidemiology of OT in Central Cuba. This large-population, cross-sectional cohort study used a prospective database at a large regional referral centre in Central Cuba. The patient database was searched for all patients who presented with OT during the 12-month study period from 1 April 2011 to 31 March 2012. Inclusion criteria were the clinical diagnosis of OT, characterised by focal retinochoroidal inflammation and a response to therapy as expected. Gender-stratified and age-stratified study population data from the 2012 Cuban Census were used to calculate incidence rates and prevalence ratios. Among 279 identified patients with OT, 158 presented with active OT. Of these, 122 new-onset and 36 prior-onset cases were confirmed. Based on the total population in the Sancti Spiritus province (466,106 persons), the overall incidence of active OT was 26.2 per 100,000 person-years (95% CI 21.7 to 31.3) with an annual prevalence ratio of 33.9 per 100,000 persons (95% CI 28.8 to 39.6). The incidence of active OT was lowest in the oldest age group and highest in patients aged 25-44 years (4.5 and 42.1 per 100,000 person-years, respectively). This first report describing population-based rates of OT in the Cuban population highlights the importance of patient age as a likely risk factor for OT. Disease rates were found to be highest in females and young to middle-aged adults. 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.
An Admittance Survey of Large Volcanoes on Venus: Implications for Volcano Growth
NASA Technical Reports Server (NTRS)
Brian, A. W.; Smrekar, S. E.; Stofan, E. R.
2004-01-01
Estimates of the thickness of the venusian crust and elastic lithosphere are important in determining the rheological and thermal properties of Venus. These estimates offer insights into what conditions are needed for certain features, such as large volcanoes and coronae, to form. Lithospheric properties for much of the large volcano population on Venus are not well known. Previous studies of elastic thickness (Te) have concentrated on individual or small groups of edifices, or have used volcano models and fixed values of Te to match with observations of volcano morphologies. In addition, previous studies use different methods to estimate lithospheric parameters meaning it is difficult to compare their results. Following recent global studies of the admittance signatures exhibited by the venusian corona population, we performed a similar survey into large volcanoes in an effort to determine the range of lithospheric parameters shown by these features. This survey of the entire large volcano population used the same method throughout so that all estimates could be directly compared. By analysing a large number of edifices and comparing our results to observations of their morphology and models of volcano formation, we can help determine the controlling parameters that govern volcano growth on Venus.
Ehlers Smith, David A; Ehlers Smith, Yvette C
2013-08-01
Because of the large-scale destruction of Borneo's rainforests on mineral soils, tropical peat-swamp forests (TPSFs) are increasingly essential for conserving remnant biodiversity, particularly in the lowlands where the majority of habitat conversion has occurred. Consequently, effective strategies for biodiversity conservation are required, which rely on accurate population density and distribution estimates as a baseline. We sought to establish the first population density estimates of the endemic red langur (Presbytis rubicunda) in Sabangau TPSF, the largest remaining contiguous lowland forest-block on Borneo. Using Distance sampling principles, we conducted line transect surveys in two of Sabangau's three principle habitat sub-classes and calculated group density at 2.52 groups km⁻² (95% CI 1.56-4.08) in the mixed-swamp forest sub-class. Based on an average recorded group size of 6.95 individuals, population density was 17.51 ind km⁻², the second highest density recorded in this species. The accessible area of the tall-interior forest, however, was too disturbed to yield density estimates representative of the entire sub-class, and P. rubicunda was absent from the low-pole forest, likely as a result of the low availability of the species' preferred foods. This absence in 30% of Sabangau's total area indicates the importance of in situ population surveys at the habitat-specific level for accurately informing conservation strategies. We highlight the conservation value of TPSFs for P. rubicunda given the high population density and large areas remaining, and recommend 1) quantifying the response of P. rubicunda to the logging and burning of its habitats; 2) surveying degraded TPSFs for viable populations, and 3) effectively delineating TPSF sub-class boundaries from remote imagery to facilitate population estimates across the wider peat landscape, given the stark contrast in densities found across the habitat sub-classes of Sabangau. © 2013 Wiley Periodicals, Inc.
The Nature and Origin of UCDs in the Coma Cluster
NASA Astrophysics Data System (ADS)
Chiboucas, Kristin; Tully, R. Brent; Madrid, Juan; Phillipps, Steven; Carter, David; Peng, Eric
2018-01-01
UCDs are super massive star clusters found largely in dense regions but have also been found around individual galaxies and in smaller groups. Their origin is still under debate but currently favored scenarios include formation as giant star clusters, either as the brightest globular clusters or through mergers of super star clusters, themselves formed during major galaxy mergers, or as remnant nuclei from tidal stripping of nucleated dwarf ellipticals. Establishing the nature of these enigmatic objects has important implications for our understanding of star formation, star cluster formation, the missing satellite problem, and galaxy evolution. We are attempting to disentangle these competing formation scenarios with a large survey of UCDs in the Coma cluster. Using ACS two-passband imaging from the HST/ACS Coma Cluster Treasury Survey, we are using colors and sizes to identify the UCD cluster members. With a large size limited sample of the UCD population within the core region of the Coma cluster, we are investigating the population size, properties, and spatial distribution, and comparing that with the Coma globular cluster and nuclear star cluster populations to discriminate between the threshing and globular cluster scenarios. In previous work, we had found a possible correlation of UCD colors with host galaxy and a possible excess of UCDs around a non-central giant galaxy with an unusually large globular cluster population, both suggestive of a globular cluster origin. With a larger sample size and additional imaging fields that encompass the regions around these giant galaxies, we have found that the color correlation with host persists and the giant galaxy with unusually large globular cluster population does appear to host a large UCD population as well. We present the current status of the survey.
ERIC Educational Resources Information Center
Sturges, Diana; Maurer, Trent W.; Cole, Oladipo
2009-01-01
This study investigated the effectiveness of role play in a large undergraduate science class. The targeted population consisted of 298 students enrolled in 2 sections of an undergraduate Human Anatomy and Physiology course taught by the same instructor. The section engaged in the role-play activity served as the study group, whereas the section…
Landscape-level effects of forest management on bird species in the Ozarks of southeastern Missouri
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...
ERIC Educational Resources Information Center
Hoobler, Ellen
2006-01-01
This article features the museums of Oaxaca, the place where the community museum movement in Mexico got started. Oaxaca has the largest Indigenous population in Mexico, with about 36.6% of the population over five years old, or about 1.027 million people, speaking an Indigenous language. Tourists spend large amounts on group or personalized tours…
World Virtual Observatory Organization
NASA Astrophysics Data System (ADS)
Ignatyev, Mikhail; Pinigin, Gennadij
On the base of experience of our Unoversity and Observatory we investigate the seven blocks model of virtual organization for consolidation of resources. This model consists of the next blocks: 1.Population-scientists students robots and agents. 2.Aspiration of population groups. 3.Territory. 4.Production. 5.Ecology and safety. 6.Finance. 7. External relations - input and output flows of population information resources.The world virtual observatory is the virtual world which consists of three groups of variables - appearances essences and structured uncertainty which defines the number and distribution of arbitrary coefficients in equivalent equations. The consolodation of recources permit to create the large telescopes with distributed structure on our planet and cosmos. Virtual instruments can have the best characteristics by means of collective effects which have investigated in our paper.
Acculturation stress among Maya in the United States.
Millender, Eugenia
2012-01-01
Abstract: As health care disparities become more evident in our multicultural nation, culture sensitive health research needs to be a priority in order for good health care to take place. This article will explore the literature related to acculturation stress and mental health disparities among the Mayan population. Literatures of similar but distinct groups are included due to the limited amount of research of the Mayan population. Using Leiniger's Transcultural nursing theory, these findings suggest that nurses have a large gap to fill to address the mental health disparities of specific cultural groups like the indigenous Maya, thereby satisfying their nursing obligations.
Craen, Saskia de; Commandeur, Jacques J F; Frank, Laurence E; Heiser, Willem J
2006-06-01
K-means cluster analysis is known for its tendency to produce spherical and equally sized clusters. To assess the magnitude of these effects, a simulation study was conducted, in which populations were created with varying departures from sphericity and group sizes. An analysis of the recovery of clusters in the samples taken from these populations showed a significant effect of lack of sphericity and group size. This effect was, however, not as large as expected, with still a recovery index of more than 0.5 in the "worst case scenario." An interaction effect between the two data aspects was also found. The decreasing trend in the recovery of clusters for increasing departures from sphericity is different for equal and unequal group sizes.
Reifegerste, Doreen; Rossmann, Constanze
2017-02-01
Past research in social and health psychology has shown that affiliation motivation is associated with health behavior, especially for high-risk populations, suggesting that targeting this motivation could be a promising strategy to promote physical activity. However, the effects that affiliation appeals (e.g., pictures depicting companionship during physical activities) and accompanying slogans have on motivating physical activity have been largely unexplored. Hence, our two studies experimentally tested the effects of exposure to affiliation-based pictures for overweight or less active people, as well as the moderating effect of affiliation motivation. The results of these two studies give some indication that group pictures (with or without an accompanying slogan) can be an effective strategy to improve high-risk populations' attitudes, self-efficacy, and intentions to engage in physical activity. Affiliation motivation as a personality trait did not interact with these effects, but was positively associated with attitudes, independent of the group picture effect.
Extinction phase transitions in a model of ecological and evolutionary dynamics
NASA Astrophysics Data System (ADS)
Barghathi, Hatem; Tackkett, Skye; Vojta, Thomas
2017-07-01
We study the non-equilibrium phase transition between survival and extinction of spatially extended biological populations using an agent-based model. We especially focus on the effects of global temporal fluctuations of the environmental conditions, i.e., temporal disorder. Using large-scale Monte-Carlo simulations of up to 3 × 107 organisms and 105 generations, we find the extinction transition in time-independent environments to be in the well-known directed percolation universality class. In contrast, temporal disorder leads to a highly unusual extinction transition characterized by logarithmically slow population decay and enormous fluctuations even for large populations. The simulations provide strong evidence for this transition to be of exotic infinite-noise type, as recently predicted by a renormalization group theory. The transition is accompanied by temporal Griffiths phases featuring a power-law dependence of the life time on the population size.
Sonsthagen, Sarah A.; Chesser, R. Terry; Bell, Douglas A.; Dove, Carla J.
2012-01-01
We studied the influence of glacial oscillations on the genetic structure of seven species of white-headed gull that breed at high latitudes (Larus argentatus, L. canus, L. glaucescens, L. glaucoides, L. hyperboreus, L. schistisagus, and L. thayeri). We evaluated localities hypothesized as ice-free areas or glacial refugia in other Arctic vertebrates using molecular data from 11 microsatellite loci, mitochondrial DNA (mtDNA) control region, and six nuclear introns for 32 populations across the Holarctic. Moderate levels of genetic structure were observed for microsatellites (FST= 0.129), introns (ΦST= 0.185), and mtDNA control region (ΦST= 0.461), with among-group variation maximized when populations were grouped based on subspecific classification. Two haplotype and at least two allele groups were observed across all loci. However, no haplotype/allele group was composed solely of individuals of a single species, a pattern consistent with recent divergence. Furthermore, northernmost populations were not well differentiated and among-group variation was maximized when L. argentatus and L. hyberboreus populations were grouped by locality rather than species, indicating recent hybridization. Four populations are located in putative Pleistocene glacial refugia and had larger t estimates than the other 28 populations. However, we were unable to substantiate these putative refugia using coalescent theory, as all populations had genetic signatures of stability based on mtDNA. The extent of haplotype and allele sharing among Arctic white-headed gull species is noteworthy. Studies of other Arctic taxa have generally revealed species-specific clusters as well as genetic structure within species, usually correlated with geography. Aspects of white-headed gull behavioral biology, such as colonization ability and propensity to hybridize, as well as their recent evolutionary history, have likely played a large role in the limited genetic structure observed.
Alves, Isabel; Coelho, Margarida; Gignoux, Christopher; Damasceno, Albertino; Prista, Antonio; Rocha, Jorge
2011-02-01
The large scale spread of Bantu-speaking populations remains one of the most debated questions in African population history. In this work we studied the genetic structure of 19 Bantu-speaking groups from Mozambique and Angola using a multilocus approach based on 14 newly developed compound haplotype systems (UEPSTRs), each consisting of a rapidly evolving short tandem repeat (STR) closely linked to a unique event polymorphism (UEP). We compared the ability of UEPs, STRs and UEPSTRs to document genetic variation at the intercontinental level and among the African Bantu populations, and found that UEPSTR systems clearly provided more resolution than UEPs or STRs alone. The observed patterns of genetic variation revealed high levels of genetic homogeneity between major populations from Angola and Mozambique, with two main outliers: the Kuvale from Angola and the Chopi from Mozambique. Within Mozambique, two Kaskazi-speaking populations from the far north (Yao and Mwani) and two Nyasa-speaking groups from the Zambezi River basin (Nyungwe and Sena) could be differentiated from the remaining groups, but no further population structure was observed across the country. The close genetic relationship between most sampled Bantu populations is consistent with high degrees of interaction between peoples living in savanna areas located to the south of the rainforest. Our results highlight the role of gene flow during the Bantu expansions and show that the genetic evidence accumulated so far is becoming increasingly difficult to reconcile with widely accepted models postulating an early split between eastern and western Bantu populations.
Comparative analysis of gut microbiota associated with body mass index in a large Korean cohort.
Yun, Yeojun; Kim, Han-Na; Kim, Song E; Heo, Seong Gu; Chang, Yoosoo; Ryu, Seungho; Shin, Hocheol; Kim, Hyung-Lae
2017-07-04
Gut microbiota plays an important role in the harvesting, storage, and expenditure of energy obtained from one's diet. Our cross-sectional study aimed to identify differences in gut microbiota according to body mass index (BMI) in a Korean population. 16S rRNA gene sequence data from 1463 subjects were categorized by BMI into normal, overweight, and obese groups. Fecal microbiotas were compared to determine differences in diversity and functional inference analysis related with BMI. The correlation between genus-level microbiota and BMI was tested using zero-inflated Gaussian mixture models, with or without covariate adjustment of nutrient intake. We confirmed differences between 16Sr RNA gene sequencing data of each BMI group, with decreasing diversity in the obese compared with the normal group. According to analysis of inferred metagenomic functional content using PICRUSt algorithm, a highly significant discrepancy in metabolism and immune functions (P < 0.0001) was predicted in the obese group. Differential taxonomic components in each BMI group were greatly affected by nutrient adjustment, whereas signature bacteria were not influenced by nutrients in the obese compared with the overweight group. We found highly significant statistical differences between normal, overweight and obese groups using a large sample size with or without diet confounding factors. Our informative dataset sheds light on the epidemiological study on population microbiome.
D'Cunha, Anitha; Pandit, Lekha; Malli, Chaithra
2017-06-01
Indian data have been largely missing from genome-wide databases that provide information on genetic variations in different populations. This hinders association studies for complex disorders in India. This study was aimed to determine whether the complex genetic structure and endogamy among Indians could potentially influence the design of case-control studies for autoimmune disorders in the south Indian population. A total of 12 single nucleotide variations (SNVs) related to genes associated with autoimmune disorders were genotyped in 370 healthy individuals belonging to six different caste groups in southern India. Allele frequencies were estimated; genetic divergence and phylogenetic relationship within the various caste groups and other HapMap populations were ascertained. Allele frequencies for all genotyped SNVs did not vary significantly among the different groups studied. Wright's FSTwas 0.001 per cent among study population and 0.38 per cent when compared with Gujarati in Houston (GIH) population on HapMap data. The analysis of molecular variance results showed a 97 per cent variation attributable to differences within the study population and <1 per cent variation due to differences between castes. Phylogenetic analysis showed a separation of Dravidian population from other HapMap populations and particularly from GIH population. Despite the complex genetic origins of the Indian population, our study indicated a low level of genetic differentiation among Dravidian language-speaking people of south India. Case-control studies of association among Dravidians of south India may not require stratification based on language and caste.
Khrustaleva, A M; Klovach, N V; Vedischeva, E V; Seeb, J E
2015-10-01
The variability of 45 single nucleotide polymorphism loci (SNP) was studied in sockeye salmon from the Kamchatka River basin and four lake-river systems of the west coast of the Bering Sea. Based on the genetic differentiation estimates for the largest sockeye salmon populations of Eastern Kamchatka and Chukotka, the examined samples were combined into two regional groups represented by the population of the Kamchatka River drainage, which included numerous local subpopulations and seasonal races, and the northern population grouping from the rivers of Olutorsko-Navarinsky raion, wherein the sockeye salmon from Maynypilginskaya Lake-River system was relatively isolated. Considerable divergence was observed between the island (Sarannoe Lake, Bering Island) and continental populations. Genetic heterogeneity was revealed and groups of early- and late-maturing individuals were isolated in the sample of late-run sockeye salmon from Kamchatka River. In Apuka River, subdivision of the spawning run into two genetically distinct spatial and temporal groupings was also observed. The results suggest that the differentiation of sockeye salmon samples by single nucleotide substitution frequencies was largely due to differences in the direction and strength of local selection at some loci in the population complexes and intrapopulation groupings from the examined river basins of Eastern Kamchatka, Chukotka, and Commander Islands.
Saini, J S; Kumar, A; Matharoo, K; Sokhi, J; Badaruddoza; Bhanwer, A J S
2012-12-15
The North West region of India is extremely important to understand the peopling of India, as it acted as a corridor to the foreign invaders from Eurasia and Central Asia. A series of these invasions along with multiple migrations led to intermixture of variable populations, strongly contributing to genetic variations. The present investigation was designed to explore the genetic diversities and affinities among the five major ethnic groups from North West India; Brahmin, Jat Sikh, Bania, Rajput and Gujjar. A total of 327 individuals of the abovementioned ethnic groups were analyzed for 4 Alu insertion marker loci (ACE, PV92, APO and D1) and a Single Nucleotide Polymorphism (SNP) rs2234693 in the intronic region of the ESR1 gene. Statistical analysis was performed to interpret the genetic structure and diversity of the population groups. Genotypes for ACE, APO, ESR1 and PV92 loci were found to be in Hardy-Weinberg equilibrium in all the ethnic groups, while significant departures were observed at the D1 locus in every investigated population after Bonferroni's correction. The average heterozygosity for all the loci in these ethnic groups was fairly substantial ranging from 0.3927 ± 0.1877 to 0.4333 ± 0.1416. Inbreeding coefficient indicated an overall 10% decrease in heterozygosity in these North West Indian populations. The gene differentiation among the populations was observed to be of the order of 0.013. Genetic distance estimates revealed that Gujjars were close to Banias and Jat Sikhs were close to Rajputs. Overall the study favored the recent division of the populations of North West India into largely endogamous groups. It was observed that the populations of North West India represent a more or less homogenous genetic entity, owing to their common ancestral history as well as geographical proximity. Copyright © 2012 Elsevier B.V. All rights reserved.
ZHANG, DAPENG; AREVALO-GARDINI, ENRIQUE; MISCHKE, SUE; ZÚÑIGA-CERNADES, LUIS; BARRETO-CHAVEZ, ALEJANDRO; AGUILA, JORGE ADRIAZOLA DEL
2006-01-01
• Background and Aims Cocoa (Theobroma cacao) is indigenous to the Amazon region of South America, and it is well known that the Peruvian Amazon harbours a large number of diverse cocoa populations. A small fraction of the diversity has been collected and maintained as an ex-situ germplasm repository in Peru. However, incorrect labelling of accessions and lack of information on genetic diversity have hindered efficient conservation and use of this germplasm. This study targeted assessment of genetic diversity and population structure in a managed and a semi-natural population. •Methods Using a capillary electrophoresis genotyping system, 105 cocoa accessions collected from the Huallaga and Ucayali valleys of Peru were fingerprinted. Based on 15 loci SSR profiles, genetic identity was examined for each accession and duplicates identified, population structure assessed and genetic diversity analysed in these two populations. •Key Results Ten synonymous mislabelled groups were identified among the 105 accessions. The germplasm group in the Huallaga valley was clearly separated from the group in Ucayali valley by the Bayesian assignment test. The Huallaga group has lower genetic diversity, both in terms of allelic richness and of gene diversity, than the Ucayali group. Analysis of molecular variance suggested genetic substructure in the Ucayali group. Significant spatial correlation between genetic distance and geographical distances was detected in the Ucayali group by Mantel tests. •Conclusions These results substantiate the hypothesis that the Peruvian Amazon hosts a high level of cocoa genetic diversity, and the diversity has a spatial structure. The introduction of exotic seed populations into the Peruvian Amazon is changing the cocoa germplasm spectrum in this region. The spatial structure of cocoa diversity recorded here highlights the need for additional collecting and conservation measures for natural and semi-natural cocoa populations. PMID:16845139
Fatal injuries among urban children in South Africa: risk distribution and potential for reduction
van Niekerk, Ashley; Laflamme, Lucie
2010-01-01
Abstract Objective To determine the leading causes of fatal injury for urban South African children aged 0–14 years, the distribution of those causes and the current potential for safety improvements. Methods We obtained injury surveillance data from the National Injury Mortality Surveillance System 2001–2003 for six major South African cities varying in size, development and sociodemographic composition. We calculated age-adjusted rates, by sex, population group and city, for death from the five leading causes of fatal injury as well as population attributable risks (PARs). Findings The leading causes of fatal injury in childhood included road traffic injuries – among vehicle passengers and especially among pedestrians – drowning, burns and, in some cities, firearm injuries. Large differences in PARs were observed, particularly for population groups and cities. Disparities between cities and between population groups were largest for deaths from pedestrian injuries, while differences between boys and girls were greatest for drowning deaths. Conclusion In the face of the high variability observed between cities and population groups in the rates of the most common types of fatal injuries, a safety agenda should combine safety-for-all countermeasures – i.e. lowering injury rates for all – and targeted countermeasures that help reduce the burden for those at greatest risk. PMID:20431790
SPSmart: adapting population based SNP genotype databases for fast and comprehensive web access.
Amigo, Jorge; Salas, Antonio; Phillips, Christopher; Carracedo, Angel
2008-10-10
In the last five years large online resources of human variability have appeared, notably HapMap, Perlegen and the CEPH foundation. These databases of genotypes with population information act as catalogues of human diversity, and are widely used as reference sources for population genetics studies. Although many useful conclusions may be extracted by querying databases individually, the lack of flexibility for combining data from within and between each database does not allow the calculation of key population variability statistics. We have developed a novel tool for accessing and combining large-scale genomic databases of single nucleotide polymorphisms (SNPs) in widespread use in human population genetics: SPSmart (SNPs for Population Studies). A fast pipeline creates and maintains a data mart from the most commonly accessed databases of genotypes containing population information: data is mined, summarized into the standard statistical reference indices, and stored into a relational database that currently handles as many as 4 x 10(9) genotypes and that can be easily extended to new database initiatives. We have also built a web interface to the data mart that allows the browsing of underlying data indexed by population and the combining of populations, allowing intuitive and straightforward comparison of population groups. All the information served is optimized for web display, and most of the computations are already pre-processed in the data mart to speed up the data browsing and any computational treatment requested. In practice, SPSmart allows populations to be combined into user-defined groups, while multiple databases can be accessed and compared in a few simple steps from a single query. It performs the queries rapidly and gives straightforward graphical summaries of SNP population variability through visual inspection of allele frequencies outlined in standard pie-chart format. In addition, full numerical description of the data is output in statistical results panels that include common population genetics metrics such as heterozygosity, Fst and In.
Yuan, Jun–hui; Cheng, Fang–Yun; Zhou, Shi–Liang
2012-01-01
Background Tree peonies are great ornamental plants associated with a rich ethnobotanical history in Chinese culture and have recently been used as an evolutionary model. The Qinling Mountains represent a significant geographic barrier in Asia, dividing mainland China into northern (temperate) and southern (semi–tropical) regions; however, their flora has not been well analyzed. In this study, the genetic differentiation and genetic structure of Paeonia rockii and the role of the Qinling Mountains as a barrier that has driven intraspecific fragmentation were evaluated using 14 microsatellite markers. Methodology/Principal Findings Twenty wild populations were sampled from the distributional range of P. rockii. Significant population differentiation was suggested (FST value of 0.302). Moderate genetic diversity at the population level (HS of 0.516) and high population diversity at the species level (HT of 0.749) were detected. Significant excess homozygosity (FIS of 0.076) and recent population bottlenecks were detected in three populations. Bayesian clusters, population genetic trees and principal coordinate analysis all classified the P. rockii populations into three genetic groups and one admixed Wenxian population. An isolation-by-distance model for P. rockii was suggested by Mantel tests (r = 0.6074, P<0.001) and supported by AMOVA (P<0.001), revealing a significant molecular variance among the groups (11.32%) and their populations (21.22%). These data support the five geographic boundaries surrounding the Qinling Mountains and adjacent areas that were detected with Monmonier's maximum-difference algorithm. Conclusions/Significance Our data suggest that the current genetic structure of P. rockii has resulted from the fragmentation of a formerly continuously distributed large population following the restriction of gene flow between populations of this species by the Qinling Mountains. This study provides a fundamental genetic profile for the conservation and responsible exploitation of the extant germplasm of this species and for improving the genetic basis for breeding its cultivars. PMID:22523566
Evolutionary history of Mexican domesticated and wild Meleagris gallopavo.
Padilla-Jacobo, Gabriela; Cano-Camacho, Horacio; López-Zavala, Rigoberto; Cornejo-Pérez, María E; Zavala-Páramo, María G
2018-04-17
The distribution of the wild turkey (Meleagris gallopavo) extends from Mexico to southeastern Canada and to the eastern and southern regions of the USA. Six subspecies have been described based on morphological characteristics and/or geographical variations in wild and domesticated populations. In this paper, based on DNA sequence data from the mitochondrial D-loop, we investigated the genetic diversity and structure, genealogical relationships, divergence time and demographic history of M. gallopavo populations including domesticated individuals. Analyses of 612 wild and domesticated turkey mitochondrial D-loop sequences, including 187 that were collected for this study and 425 from databases, revealed 64 haplotypes with few mutations, some of which are shared between domesticated and wild turkeys. We found a high level of haplotype and nucleotide diversity, which suggests that the total population of this species is large and stable with an old evolutionary history. The results of genetic differentiation, haplotype network, and genealogical relationships analyses revealed three main genetic groups within the species: mexicana as a population relict (C1), merriami (C2), and mexicana/intermedia/silvestris/osceola (C3). Haplotypes detected in domesticated turkeys belong to group C3. Estimates of divergence times agree with range expansion and diversification events of the relict population of M. gallopavo in northwestern Mexico during the Pliocene-Pleistocene and Pleistocene-Holocene boundaries. Demographic reconstruction showed that an expansion of the population occurred 110,000 to 130,000 years ago (Kya), followed by a stable period 100 Kya and finally a decline ~ 10 Kya (Pleistocene-Holocene boundary). In Mexico, the Trans-Mexican Volcanic Belt may be responsible for the range expansion of the C3 group. Two haplotypes with different divergence times, MGMDgoB/MICH1 and MICH2, are dominant in domesticated and commercial turkeys. During the Pleistocene, a large and stable population of M. gallopavo covered a wide geographic distribution from the north to the center of America (USA and Mexico). The mexicana, merriami, and mexicana/intermedia/silvestris/osceola genetic groups originated after divergence and range expansion from northwestern Mexico during the Pliocene-Pleistocene and Pleistocene-Holocene boundaries. Old and new maternal lines of the mexicana/intermedia/silvestris/osceola genetic group were distributed within the Trans-Mexican Volcanic Belt where individuals were captured for domestication. Two haplotypes are the main founder maternal lines of domesticated turkeys.
Microbial diversity--insights from population genetics.
Mes, Ted H M
2008-01-01
Although many environmental microbial populations are large and genetically diverse, both the level of diversity and the extent to which it is ecologically relevant remain enigmatic. Because the effective (or long-term) population size, N(e), is one of the parameters that determines population genetic diversity, tests and simulations that assume selectively neutral mutations may help to identify the processes that have shaped microbial diversity. Using ecologically important genes, tests of selective neutrality suggest that adaptive as well as non-adaptive types of selection act and that departure from neutrality may be widespread or restricted to small groups of genotypes. Population genetic simulations using population sizes between 10(3) and 10(7) suggest extremely high levels of microbial diversity in environments that sustain large populations. However, census and effective population sizes may differ considerably, and because we know nothing of the evolutionary history of environmental microbial populations, we also have no idea what N(e) of environmental populations is. On the one hand, this reflects our ignorance of the microbial world. On the other hand, the tests and simulations illustrate interactions between microbial diversity and microbial population genetics that should inform our thinking in microbial ecology. Because of the different views on microbial diversity across these disciplines, such interactions are crucial if we are to understand the role of genes in microbial communities.
An Ancestral Recombination Graph for Diploid Populations with Skewed Offspring Distribution
Birkner, Matthias; Blath, Jochen; Eldon, Bjarki
2013-01-01
A large offspring-number diploid biparental multilocus population model of Moran type is our object of study. At each time step, a pair of diploid individuals drawn uniformly at random contributes offspring to the population. The number of offspring can be large relative to the total population size. Similar “heavily skewed” reproduction mechanisms have been recently considered by various authors (cf. e.g., Eldon and Wakeley 2006, 2008) and reviewed by Hedgecock and Pudovkin (2011). Each diploid parental individual contributes exactly one chromosome to each diploid offspring, and hence ancestral lineages can coalesce only when in distinct individuals. A separation-of-timescales phenomenon is thus observed. A result of Möhle (1998) is extended to obtain convergence of the ancestral process to an ancestral recombination graph necessarily admitting simultaneous multiple mergers of ancestral lineages. The usual ancestral recombination graph is obtained as a special case of our model when the parents contribute only one offspring to the population each time. Due to diploidy and large offspring numbers, novel effects appear. For example, the marginal genealogy at each locus admits simultaneous multiple mergers in up to four groups, and different loci remain substantially correlated even as the recombination rate grows large. Thus, genealogies for loci far apart on the same chromosome remain correlated. Correlation in coalescence times for two loci is derived and shown to be a function of the coalescence parameters of our model. Extending the observations by Eldon and Wakeley (2008), predictions of linkage disequilibrium are shown to be functions of the reproduction parameters of our model, in addition to the recombination rate. Correlations in ratios of coalescence times between loci can be high, even when the recombination rate is high and sample size is large, in large offspring-number populations, as suggested by simulations, hinting at how to distinguish between different population models. PMID:23150600
ERIC Educational Resources Information Center
Plotnikoff, Ronald C.; Lippke, Sonia; Reinbold-Matthews, Melissa; Courneya, Kerry S.; Karunamuni, Nandini; Sigal, Ronald J.; Birkett, Nicholas
2007-01-01
This study was designed to test the validity of a transtheoretical model's physical activity (PA) stage measure with intention and different intensities of behavior in a large population-based sample of adults living with diabetes (Type 1 diabetes, n = 697; Type 2 diabetes, n = 1,614) and examine different age groups. The overall…
Ethnic use of the Tonto: geographic extension of the recreation knowledge base
Denver Hospodarsky; Martha Lee
1995-01-01
The recreational use of the Tonto National Forest, Arizona was investigated by using data on ethnic and racial subgroups. The Tonto is a Class 1 urban proximate forest adjoining the large, culturally diverse population of the Phoenix. An on-site survey of 524 recreating groups found sufficiently large numbers of Anglos (n=425) and Hispanics (n=82) who participated in...
Quality Control for Scoring Tests Administered in Continuous Mode: An NCME Instructional Module
ERIC Educational Resources Information Center
Allalouf, Avi; Gutentag, Tony; Baumer, Michal
2017-01-01
Quality control (QC) in testing is paramount. QC procedures for tests can be divided into two types. The first type, one that has been well researched, is QC for tests administered to large population groups on few administration dates using a small set of test forms (e.g., large-scale assessment). The second type is QC for tests, usually…
Mathematical models of human mobility of relevance to malaria transmission in Africa.
Marshall, John M; Wu, Sean L; Sanchez C, Hector M; Kiware, Samson S; Ndhlovu, Micky; Ouédraogo, André Lin; Touré, Mahamoudou B; Sturrock, Hugh J; Ghani, Azra C; Ferguson, Neil M
2018-05-16
As Africa-wide malaria prevalence declines, an understanding of human movement patterns is essential to inform how best to target interventions. We fitted movement models to trip data from surveys conducted at 3-5 sites throughout each of Mali, Burkina Faso, Zambia and Tanzania. Two models were compared in terms of their ability to predict the observed movement patterns - a gravity model, in which movement rates between pairs of locations increase with population size and decrease with distance, and a radiation model, in which travelers are cumulatively "absorbed" as they move outwards from their origin of travel. The gravity model provided a better fit to the data overall and for travel to large populations, while the radiation model provided a better fit for nearby populations. One strength of the data set was that trips could be categorized according to traveler group - namely, women traveling with children in all survey countries and youth workers in Mali. For gravity models fitted to data specific to these groups, youth workers were found to have a higher travel frequency to large population centers, and women traveling with children a lower frequency. These models may help predict the spatial transmission of malaria parasites and inform strategies to control their spread.
Density-body mass relationships: Inconsistent intercontinental patterns among termite feeding-groups
NASA Astrophysics Data System (ADS)
Dahlsjö, Cecilia A. L.; Parr, Catherine L.; Malhi, Yadvinder; Meir, Patrick; Rahman, Homathevi; Eggleton, Paul
2015-02-01
Allometric relationships are useful for estimating and understanding resource distribution in assemblages with species of different masses. Damuth's law states that body mass scales with population density as M-0.75, where M is body mass and -0.75 is the slope. In this study we used Damuth's law (M-0.75) as a null hypothesis to examine the relationship between body mass and population density for termite feeding-groups in three different countries and regions (Cameroon, West Africa; Peru South America; and Malaysia SE Asia). We found that none of the feeding-groups had a relationship where M-0.75 while the data suggested that population density-body mass relationships for true soil-feeding termites in Cameroon (M2.7) and wood-feeding termites in Peru (M1.5) were significantly different from the expected values given by Damuth's law. The dominance of large-bodied true soil-feeding termites in Cameroon and the absence of fungus-growing termites from Peru suggest that these allometric patterns are due to heterogeneities in termite biogeographical evolution. Additionally, as these feeding-groups have higher population density than expected by their body masses it may be suggested that they also have a higher energy throughput than expected. The results presented here may be used to gain further understanding of resource distribution among termite feeding-groups across regions and an insight into the importance of evolutionary history and biogeography on allometric patterns. Further understanding of population density-body mass relationships in termite feeding-groups may also improve understanding of the role these feeding-groups play in ecosystem processes in different regions.
Express saccades in distinct populations: east, west, and in-between.
Knox, Paul C; Wolohan, Felicity D A; Helmy, Mai S
2017-12-01
Express saccades are low latency (80-130 ms), visually guided saccades. While their occurrence is encouraged by the use of gap tasks (the fixation target is extinguished 200 ms prior to the saccade target appearing) and suppressed by the use of overlap tasks (the fixation target remains present when the saccade target appears), there are some healthy, adult participants, "express saccade makers" (ESMs), who persist in generating high proportions (> 30%) of express saccades in overlap conditions. These participants are encountered much more frequently in Chinese participant groups than amongst the Caucasian participants tested to date. What is not known is whether this high number of ESMs is only a feature of Chinese participant groups. More broadly, there are few comparative studies of saccade behaviour across large participant groups drawn from different populations. We, therefore, tested an independent group of 70 healthy adult Egyptian participants, using the same equipment and procedures as employed in the previous studies. Each participant was exposed to two blocks of 200 gap, and two blocks of 200 overlap trials, with block order counterbalanced. Results from the Schwartz Value Survey were used to confirm that this group of participants was culturally distinct from the Chinese and Caucasian (white British) groups tested previously. Fourteen percent (10/70) of this new group were ESMs, and the pattern of latency distribution in these ESMs was identical to that identified in the other participant groups, with a prominent peak in the express latency range in overlap conditions. Overall, we identified three modes in the distribution of saccade latency in overlap conditions, the timing of which (express peak at 110 ms, subsequent peaks at 160 and 210 ms) were strikingly consistent with our previous observations. That these behavioural patterns of saccade latency are observed consistently in large participant groups, drawn from geographically, ethnically, and culturally distinct populations, suggests that they relate to the underlying architecture of the saccade system.
Yokota, Miyo
2005-05-01
In the United States, the biologically admixed population is increasing. Such demographic changes may affect the distribution of anthropometric characteristics, which are incorporated into the design of equipment and clothing for the US Army and other large organizations. The purpose of this study was to examine multivariate craniofacial anthropometric distributions between biologically admixed male populations and single racial groups of Black and White males. Multivariate statistical results suggested that nose breadth and lip length were different between Blacks and Whites. Such differences may be considered for adjustments to respirators and chemical-biological protective masks. However, based on this pilot study, multivariate anthropometric distributions of admixed individuals were within the distributions of single racial groups. Based on the sample reported, sizing and designing for the admixed groups are not necessary if anthropometric distributions of single racial groups comprising admixed groups are known.
Natural bounds on herbivorous coral reef fishes
Hoey, Andrew S.; Williams, Gareth J.; Williams, Ivor D.
2016-01-01
Humans are an increasingly dominant driver of Earth's biological communities, but differentiating human impacts from natural drivers of ecosystem state is crucial. Herbivorous fish play a key role in maintaining coral dominance on coral reefs, and are widely affected by human activities, principally fishing. We assess the relative importance of human and biophysical (habitat and oceanographic) drivers on the biomass of five herbivorous functional groups among 33 islands in the central and western Pacific Ocean. Human impacts were clear for some, but not all, herbivore groups. Biomass of browsers, large excavators, and of all herbivores combined declined rapidly with increasing human population density, whereas grazers, scrapers, and detritivores displayed no relationship. Sea-surface temperature had significant but opposing effects on the biomass of detritivores (positive) and browsers (negative). Similarly, the biomass of scrapers, grazers, and detritivores correlated with habitat structural complexity; however, relationships were group specific. Finally, the biomass of browsers and large excavators was related to island geomorphology, both peaking on low-lying islands and atolls. The substantial variability in herbivore populations explained by natural biophysical drivers highlights the need for locally appropriate management targets on coral reefs. PMID:27881745
Understanding spatial connectivity of individuals with non-uniform population density.
Wang, Pu; González, Marta C
2009-08-28
We construct a two-dimensional geometric graph connecting individuals placed in space within a given contact distance. The individuals are distributed using a measured country's density of population. We observe that while large clusters (group of individuals connected) emerge within some regions, they are trapped in detached urban areas owing to the low population density of the regions bordering them. To understand the emergence of a giant cluster that connects the entire population, we compare the empirical geometric graph with the one generated by placing the same number of individuals randomly in space. We find that, for small contact distances, the empirical distribution of population dominates the growth of connected components, but no critical percolation transition is observed in contrast to the graph generated by a random distribution of population. Our results show that contact distances from real-world situations as for WIFI and Bluetooth connections drop in a zone where a fully connected cluster is not observed, hinting that human mobility must play a crucial role in contact-based diseases and wireless viruses' large-scale spreading.
Ethnic diversity in the genetics of venous thromboembolism.
Tang, Liang; Hu, Yu
2015-11-01
Genetic susceptibility is considered as a crucial factor for the development of venous thromboembolism (VTE). Epidemiologic and genetic studies have revealed clear disparities in the incidence of VTE and the distribution of genetic factors for VTE in populations stratified by ethnicity worldwide. While gain-of-function polymorphisms in the procoagulant genes are common inherited factors in European-origin populations, the most prevalent molecular basis for venous thrombosis in Asians is confirmed to be dysfunctional variants in the anticoagulant genes. With the breakthrough of genomic technologies, a set of novel common alleles and rare mutations associated with VTE have also been identified, in different ethnic groups. Several putative pathways contributing to the pathogenesis of thrombophilia in populations of African-ancestry are largely unknown, as current knowledge of hereditary and acquired risk factors do not fully explain the highest risk of VTE in Black groups. In-depth studies across diverse ethnic populations are needed to unravel the whole genetics of VTE, which will help developing individual risk prediction models and strategies to minimise VTE in all populations.
Optimal city size and population density for the 21st century.
Speare A; White, M J
1990-10-01
The thesis that large scale urban areas result in greater efficiency, reduced costs, and a better quality of life is reexamined. The environmental and social costs are measured for different scales of settlement. The desirability and perceived problems of a particular place are examined in relation to size of place. The consequences of population decline are considered. New York city is described as providing both opportunities in employment, shopping, and cultural activities as well as a high cost of living, crime, and pollution. The historical development of large cities in the US is described. Immigration has contributed to a greater concentration of population than would have otherwise have occurred. The spatial proximity of goods and services argument (agglomeration economies) has changed with advancements in technology such as roads, trucking, and electronic communication. There is no optimal city size. The overall effect of agglomeration can be assessed by determining whether the markets for goods and labor are adequate to maximize well-being and balance the negative and positive aspects of urbanization. The environmental costs of cities increase with size when air quality, water quality, sewage treatment, and hazardous waste disposal is considered. Smaller scale and lower density cities have the advantages of a lower concentration of pollutants. Also, mobilization for program support is easier with homogenous population. Lower population growth in large cities would contribute to a higher quality of life, since large metropolitan areas have a concentration of immigrants, younger age distributions, and minority groups with higher than average birth rates. The negative consequences of decline can be avoided if reduction of population in large cities takes place gradually. For example, poorer quality housing can be removed for open space. Cities should, however, still attract all classes of people with opportunities equally available.
Psychiatric Emergencies in the Elderly.
Sikka, Veronica; Kalra, S; Galwankar, Sagar; Sagar, Galwankar
2015-11-01
With the increasing life expectancy, the geriatric population has been increasing over the past few decades. By the year 2050, it is projected to compose more than a fifth of the entire population, representing a 147% increase in this age group. There has been a steady increase in the number of medical and psychiatric disorders, and a large percentage of geriatric patients are now presenting to the emergency department with such disorders. The management of our progressively complex geriatric patient population will require an integrative team approach involving emergency medicine, psychiatry, and hospitalist medicine. Published by Elsevier Inc.
Brunet, Johanne
2009-01-01
Background and Aims Pollinators together with other biotic and some abiotic factors can select for floral traits. However, variation in pollinator abundance over time and space can weaken such selection. In the present study, the variation in pollinator abundance over time and space was examined in populations of the Rocky Mountain columbine. The variation in three floral traits is described and correlations between pollinator type, functional pollinator groups or altitude and floral traits are examined. Methods Pollinator observations took place in six Aquilegia coerulea populations over 1–4 years and spur length, flower colour and sepal length were measured in 12 populations. Pollinator abundance, measured as visits per flower per hour, was compared among populations and years. Pollinators were grouped into two functional groups: pollen or nectar collectors. The following associations were examined: annual presence of hawkmoths and whiter flowers with longer spurs; the presence of Sphinx vashti and longer spurs; and higher altitudes and whiter flowers. The study looked at whether an increase in the proportion of hawkmoths in a population was associated with whiter and larger flowers with longer spurs. Key Results The abundance of different pollinator groups varied over time and space. Floral traits varied among populations. Higher altitude was correlated with bluer flowers. Whiter flowers were associated with the annual presence of hawkmoths. Populations visited by Sphinx vashti had longer spurs than populations visited only by Hyles lineata. Populations with greater percentage of nectar-collecting pollinators did not have whiter, larger flowers with longer spurs. Conclusions Despite the large variation in pollinator abundance over time and space, one species of bumble-bee or hawkmoth tended to predominate in each population each year. Future studies of Aquilegia coerulea should examine the specific influences of pollinators and the environment on flower colour and of hawkmoth species on spur length. PMID:19414518
Tedim, Ana P.; Ruiz-Garbajosa, Patricia; Corander, Jukka; Rodríguez, Concepción M.; Cantón, Rafael; Willems, Rob J.; Baquero, Fernando
2014-01-01
The diversity of enterococcal populations from fecal samples from hospitalized (n = 133) and nonhospitalized individuals (n = 173) of different age groups (group I, ages 0 to 19 years; group II, ages 20 to 59 years; group III, ages ≥60 years) was analyzed. Enterococci were recovered at similar rates from hospitalized and nonhospitalized persons (77.44% to 79.77%) of all age groups (75.0% to 82.61%). Enterococcus faecalis and Enterococcus faecium were predominant, although seven other Enterococcus species were identified. E. faecalis and E. faecium (including ampicillin-resistant E. faecium) colonization rates in nonhospitalized persons were age independent. For inpatients, E. faecalis colonization rates were age independent, but E. faecium colonization rates (particularly the rates of ampicillin-resistant E. faecium colonization) significantly increased with age. The population structure of E. faecium and E. faecalis was determined by superimposing goeBURST and Bayesian analysis of the population structure (BAPS). Most E. faecium sequence types (STs; 150 isolates belonging to 75 STs) were linked to BAPS groups 1 (22.0%), 2 (31.3%), and 3 (36.7%). A positive association between hospital isolates and BAPS subgroups 2.1a and 3.3a (which included major ampicillin-resistant E. faecium human lineages) and between community-based ampicillin-resistant E. faecium isolates and BAPS subgroups 1.2 and 3.3b was found. Most E. faecalis isolates (130 isolates belonging to 58 STs) were grouped into 3 BAPS groups, BAPS groups 1 (36.9%), 2 (40.0%), and 3 (23.1%), with each one comprising widespread lineages. No positive associations with age or hospitalization were established. The diversity and dynamics of enterococcal populations in the fecal microbiota of healthy humans are largely unexplored, with the available knowledge being fragmented and contradictory. The study offers a novel and comprehensive analysis of enterococcal population landscapes and suggests that E. faecium populations from hospitalized patients and from community-based individuals differ, with a predominance of certain clonal lineages, often in association with elderly individuals, occurring in the hospital setting. PMID:25548052
Zareian, Halimeh; Esmaeili, Hamid Reza; Heidari, Adeleh; Khoshkholgh, Majid Reza; Mousavi-Sabet, Hamed
2016-01-01
Traditionally, Capoeta populations from the southern Caspian Sea basin have been considered as Capoeta capoeta gracilis. Study on the phylogenetic relationship of Capoeta species using mitochondrial cytochrome b gene sequences show that Capoeta population from the southern Caspian Sea basin is distinct species and receive well support (posterior probability of 100%). Based on the tree topologies obtained from Bayesian and Maximum Likelihood methods, three main groups for the studied Capoeta were detected: Clade I) Capoeta trutta group (the Mesopotamian Capoeta group) including closely related taxa (e.g. trutta, turani, barroisi) characterized by having numerous irregular black spots on the dorsal half of the body. This clade was the sister group to all other Capoeta species and its separation occurred very early in evolution possess, so we considered it as O ld Evolutionary Group. Clade II) comprises highly diversified and widespread group, Capoeta damascina complex group (small scale capoeta group), the Anatolian-Iranian group (e.g. banarescui, buhsei, damascina, saadii), characterized by small scales and plain body (absence of irregular black spots on the dorsal half of the body, except in some juveniles) with significantly later speciation event so called Young Evolutionary Group. Clade III) Capoeta capoeta complex group (large scale capoeta group, the Aralo-Caspian group) comprises very closely related taxa characterized by large scales and plain body (absence of irregular black spots on the dorsal half of the body) distributed in Aralo-Caspian water bodies (capoeta, ekmekciae, heratensis, gracilis, sevangi) that has been recently diverged and could be considered as Very Young Evolutionary Group. PMID:28097160
Divergence, convergence, and the ancestry of feral populations in the domestic rock pigeon.
Stringham, Sydney A; Mulroy, Elisabeth E; Xing, Jinchuan; Record, David; Guernsey, Michael W; Aldenhoven, Jaclyn T; Osborne, Edward J; Shapiro, Michael D
2012-02-21
Domestic pigeons are spectacularly diverse and exhibit variation in more traits than any other bird species [1]. In The Origin of Species, Charles Darwin repeatedly calls attention to the striking variation among domestic pigeon breeds-generated by thousands of years of artificial selection on a single species by human breeders-as a model for the process of natural divergence among wild populations and species [2]. Darwin proposed a morphology-based classification of domestic pigeon breeds [3], but the relationships among major groups of breeds and their geographic origins remain poorly understood [4, 5]. We used a large, geographically diverse sample of 361 individuals from 70 domestic pigeon breeds and two free-living populations to determine genetic relationships within this species. We found unexpected relationships among phenotypically divergent breeds as well as convergent evolution of derived traits among several breed groups. Our findings also illuminate the geographic origins of breed groups in India and the Middle East and suggest that racing breeds have made substantial contributions to feral pigeon populations. Copyright © 2012 Elsevier Ltd. All rights reserved.
The impact of recurrent disasters on mental health: a study on seasonal floods in northern India.
Wind, Tim R; Joshi, Pooran C; Kleber, Rolf J; Komproe, Ivan H
2013-06-01
Very little is known on the impact of recurrent disasters on mental health. Aim The present study examines the immediate impact of a recurrent flood on mental health and functioning among an affected population in the rural district of Bahraich, Uttar Pradesh, India, compared with a population in the same region that is not affected by floods. The study compared 318 affected respondents with 308 individuals who were not affected by floods. Symptoms of anxiety and depression were assessed by the Hopkins Symptom Checklist-25 (HSCL-25). Psychological and physical functioning was assessed by using the Short Form-12 (SF-12). The affected group showed large to very large differences with the comparison group on symptoms of anxiety (D = .92) and depression (D = 1.22). The affected group scored significantly lower on psychological and physical functioning than the comparison group (respectively D = .33 and D = .80). However, hierarchical linear regressions showed no significant relationship between mental health and the domains of functioning in the affected group, whereas mental health and the domains of functioning were significantly related in the comparison group. This study found a large negative impact of the recurrent floods on mental health outcomes and psychological and physical functioning. However, in a context with recurrent floods, disaster mental health status is not a relevant predictor of functioning. The findings suggest that the observed mental health status and impaired functioning in this context are also outcomes of another mechanism: Both outcomes are likely to be related to the erosion of the social and environmental and material context. As such, the findings refer to a need to implement psychosocial context-oriented interventions to address the erosion of the context rather than specific mental health interventions.
Cabral, Linda; Muhr, Kathy; Savageau, Judith
2013-12-01
This qualitative study sought to better understand the experiences of deaf and hard of hearing individuals with accessing recovery-oriented mental health services and peer support via a focus group and interviews. Cultural brokers were used to facilitate culturally-sensitive communication with study participants. Findings indicate that access to adequate mental health services, not just recovery-oriented and peer support services, is not widely available for this population, largely due to communication barriers. Feelings of isolation and stigma are high among this population. Public mental health systems need to adapt and expand services for various cultural groups to insure recovery.
Epidemics and dimensionality in hierarchical networks
NASA Astrophysics Data System (ADS)
Zheng, Da-Fang; Hui, P. M.; Trimper, Steffen; Zheng, Bo
2005-07-01
Epidemiological processes are studied within a recently proposed hierarchical network model using the susceptible-infected-refractory dynamics of an epidemic. Within the network model, a population may be characterized by H independent hierarchies or dimensions, each of which consists of groupings of individuals into layers of subgroups. Detailed numerical simulations reveal that for H>1, global spreading results regardless of the degree of homophily of the individuals forming a social circle. For H=1, a transition from global to local spread occurs as the population becomes decomposed into increasingly homophilous groups. Multiple dimensions in classifying individuals (nodes) thus make a society (computer network) highly susceptible to large-scale outbreaks of infectious diseases (viruses).
Wallace, Jennifer L; Levy, Julie K
2006-08-01
Internationally, large populations of feral cats constitute an important and controversial issue due to their impact on cat overpopulation, animal welfare, public health, and the environment, and to disagreement about what are the best methods for their control. Trap-neuter-return (TNR) programs are an increasingly popular alternative to mass euthanasia. The objective of this study was to determine the population characteristics of feral cats admitted to large-scale TNR programs from geographically diverse locations in the United States. Data from 103,643 feral cats admitted to TNR programs from 1993 to 2004 were evaluated. All groups reported more intact females (53.4%) than intact males (44.3%); only 2.3% of the cats were found to be previously sterilized. Overall, 15.9% of female cats were pregnant at the time of surgery. Pregnancy was highly seasonal and peaked between March and April for all of the groups. The average prenatal litter size was 4.1+/-0.1 fetuses per litter. Cryptorchidism was observed in 1.3% of male cats admitted for sterilization. A total of 0.4% of cats was euthanased because of the presence of debilitating conditions, and 0.4% died during the TNR clinics. Remarkably similar populations of cats with comparable seasonal variability were seen at each program, despite their wide geographical distribution. These results suggest that it is feasible to safely sterilize large numbers of feral cats and that the experiences of existing programs are a consistent source of information upon which to model new TNR programs.
Samano, Ninos; Bodin, Lennart; Karlsson, Jan; Geijer, Håkan; Arbeus, Mikael; Souza, Domingos
2017-03-01
The objective of this study was to investigate whether graft patency was associated with higher health-related quality of life in coronary artery bypass grafting patients and to compare this study with the general Swedish population. Patients were included from 3 randomized trials and 1 prospective cohort trial. The generic health-related quality of life instrument, EQ-5D (VAS and index) was used. Graft patency was assessed with computed tomography angiography. Patients were divided into 2 groups according to the number of occluded distal anastomosis: Group I with no to 1 occlusion ( n = 209) and Group II with 2 to 4 occlusions ( n = 24). Two hundred and thirty-three patients underwent computed tomography angiography at a mean of 7.5 (1-18) years post-operatively. The mean difference in EQ-VAS and EQ-5D index between Groups II and I after model adjustment was -19.8 (95% CI -25.3 to -14.3; P < 0.001) and -0.13 (95% CI -0.19 to -0.08; P < 0.001), respectively. The EQ-5D index for the study population was similar compared with the Swedish population, 0.851 and 0.832, respectively, with an effect-size of 0.112 (trivial). The EQ-5D index of the study population was higher compared with the ischemic heart disease group in the Swedish population, 0.851 vs 0.60, with an effect-size of 0.999 (large). Graft patency was associated with higher health-related quality of life in coronary artery bypass patients. This patient group reported similar function and wellbeing compared to the general Swedish population and better health status than those in the same disease group in the general population. Clinicaltrials.gov: NCT02547194 and the Research and Development registry in Sweden: 167861. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
Utility of R0 as a predictor of disease invasion in structured populations
Cross, P.C.; Johnson, P.L.F.; Lloyd-Smith, James O.; Getz, W.M.
2007-01-01
Early theoretical work on disease invasion typically assumed large and well-mixed host populations. Many human and wildlife systems, however, have small groups with limited movement among groups. In these situations, the basic reproductive number, R0, is likely to be a poor predictor of a disease pandemic because it typically does not account for group structure and movement of individuals among groups. We extend recent work by combining the movement of hosts, transmission within groups, recovery from infection and the recruitment of new susceptibles into a stochastic model of disease in a host metapopulation. We focus on how recruitment of susceptibles affects disease invasion and how population structure can affect the frequency of superspreading events (SSEs). We show that the frequency of SSEs may decrease with the reduced movement and the group sizes due to the limited number of susceptible individuals available. Classification tree analysis of the model results illustrates the hierarchical nature of disease invasion in host metapopulations. First, the pathogen must effectively transmit within a group (R0 > 1), and then the pathogen must persist within a group long enough to allow for movement among the groups. Therefore, the factors affecting disease persistence - such as infectious period, group size and recruitment of new susceptibles - are as important as the local transmission rates in predicting the spread of pathogens across a metapopulation. ?? 2006 The Royal Society.
Utility of R0 as a predictor of disease invasion in structured populations.
Cross, Paul C; Johnson, Philip L F; Lloyd-Smith, James O; Getz, Wayne M
2007-04-22
Early theoretical work on disease invasion typically assumed large and well-mixed host populations. Many human and wildlife systems, however, have small groups with limited movement among groups. In these situations, the basic reproductive number, R0, is likely to be a poor predictor of a disease pandemic because it typically does not account for group structure and movement of individuals among groups. We extend recent work by combining the movement of hosts, transmission within groups, recovery from infection and the recruitment of new susceptibles into a stochastic model of disease in a host metapopulation. We focus on how recruitment of susceptibles affects disease invasion and how population structure can affect the frequency of superspreading events (SSEs). We show that the frequency of SSEs may decrease with the reduced movement and the group sizes due to the limited number of susceptible individuals available. Classification tree analysis of the model results illustrates the hierarchical nature of disease invasion in host metapopulations. First, the pathogen must effectively transmit within a group (R0>1), and then the pathogen must persist within a group long enough to allow for movement among the groups. Therefore, the factors affecting disease persistence--such as infectious period, group size and recruitment of new susceptibles--are as important as the local transmission rates in predicting the spread of pathogens across a metapopulation.
Analysis of East Asia Genetic Substructure Using Genome-Wide SNP Arrays
Tian, Chao; Kosoy, Roman; Lee, Annette; Ransom, Michael; Belmont, John W.; Gregersen, Peter K.; Seldin, Michael F.
2008-01-01
Accounting for population genetic substructure is important in reducing type 1 errors in genetic studies of complex disease. As efforts to understand complex genetic disease are expanded to different continental populations the understanding of genetic substructure within these continents will be useful in design and execution of association tests. In this study, population differentiation (Fst) and Principal Components Analyses (PCA) are examined using >200 K genotypes from multiple populations of East Asian ancestry. The population groups included those from the Human Genome Diversity Panel [Cambodian, Yi, Daur, Mongolian, Lahu, Dai, Hezhen, Miaozu, Naxi, Oroqen, She, Tu, Tujia, Naxi, Xibo, and Yakut], HapMap [ Han Chinese (CHB) and Japanese (JPT)], and East Asian or East Asian American subjects of Vietnamese, Korean, Filipino and Chinese ancestry. Paired Fst (Wei and Cockerham) showed close relationships between CHB and several large East Asian population groups (CHB/Korean, 0.0019; CHB/JPT, 00651; CHB/Vietnamese, 0.0065) with larger separation with Filipino (CHB/Filipino, 0.014). Low levels of differentiation were also observed between Dai and Vietnamese (0.0045) and between Vietnamese and Cambodian (0.0062). Similarly, small Fst's were observed among different presumed Han Chinese populations originating in different regions of mainland of China and Taiwan (Fst's <0.0025 with CHB). For PCA, the first two PC's showed a pattern of relationships that closely followed the geographic distribution of the different East Asian populations. PCA showed substructure both between different East Asian groups and within the Han Chinese population. These studies have also identified a subset of East Asian substructure ancestry informative markers (EASTASAIMS) that may be useful for future complex genetic disease association studies in reducing type 1 errors and in identifying homogeneous groups that may increase the power of such studies. PMID:19057645
Latinne, Alice; Waengsothorn, Surachit; Rojanadilok, Prateep; Eiamampai, Krairat; Sribuarod, Kriangsak; Michaux, Johan R.
2012-01-01
Background Historical biogeography and evolutionary processes of cave taxa have been widely studied in temperate regions. However, Southeast Asian cave ecosystems remain largely unexplored despite their high scientific interest. Here we studied the phylogeography of Leopoldamys neilli, a cave-dwelling murine rodent living in limestone karsts of Thailand, and compared the molecular signature of mitochondrial and nuclear markers. Methodology/Principal Findings We used a large sampling (n = 225) from 28 localities in Thailand and a combination of mitochondrial and nuclear markers with various evolutionary rates (two intronic regions and 12 microsatellites). The evolutionary history of L. neilli and the relative role of vicariance and dispersal were investigated using ancestral range reconstruction analysis and Approximate Bayesian computation (ABC). Both mitochondrial and nuclear markers support a large-scale population structure of four main groups (west, centre, north and northeast) and a strong finer structure within each of these groups. A deep genealogical divergence among geographically close lineages is observed and denotes a high population fragmentation. Our findings suggest that the current phylogeographic pattern of this species results from the fragmentation of a widespread ancestral population and that vicariance has played a significant role in the evolutionary history of L. neilli. These deep vicariant events that occurred during Plio-Pleistocene are related to the formation of the Central Plain of Thailand. Consequently, the western, central, northern and northeastern groups of populations were historically isolated and should be considered as four distinct Evolutionarily Significant Units (ESUs). Conclusions/Significance Our study confirms the benefit of using several independent genetic markers to obtain a comprehensive and reliable picture of L. neilli evolutionary history at different levels of resolution. The complex genetic structure of Leopoldamys neilli is supported by congruent mitochondrial and nuclear markers and has been influenced by the geological history of Thailand during Plio-Pleistocene. PMID:23118888
Chhabra, H S; Bhalla, A M
2015-11-01
To assess the influence of financial constraints on access to different components of spinal cord injury (SCI) management in various socio-economic strata of the Indian population. Indian Spinal Injuries Centre (ISIC). One hundred fifty SCI individuals who came for follow-up at ISIC between March 2009 and March 2013 with at least 1 year of community exposure after discharge were included in the study. Socio-economic classification was carried out according to the Kuppuswamy scale, a standard scale for the Indian population. A self-designed questionnaire was administered. No sample was available from the lower group. There was a statistically significant difference (P<0.05) for the levels of difficulty perceived by different socio-economic groups in accessing different components of SCI management. Aided upper lower group was dependent on welfare schemes for in-hospital treatment but could not access other components of management once discharged. Unaided upper lower group either faced severe difficulty or could not access management. Majority of lower middle group faced severe difficulty. Upper middle group was equally divided into facing severe, moderate or no difficulty. Most patients in the upper group faced no difficulty, whereas some faced moderate and a small number of severe difficulty. Financial constraints affected all components of SCI management in all except the upper group. The results of the survey suggest that a very large percentage of the Indian population would find it difficult to access comprehensive SCI management and advocate extension of essential medical coverage to unaided upper lower, lower middle and upper middle groups.
Population equations for degree-heterogenous neural networks
NASA Astrophysics Data System (ADS)
Kähne, M.; Sokolov, I. M.; Rüdiger, S.
2017-11-01
We develop a statistical framework for studying recurrent networks with broad distributions of the number of synaptic links per neuron. We treat each group of neurons with equal input degree as one population and derive a system of equations determining the population-averaged firing rates. The derivation rests on an assumption of a large number of neurons and, additionally, an assumption of a large number of synapses per neuron. For the case of binary neurons, analytical solutions can be constructed, which correspond to steps in the activity versus degree space. We apply this theory to networks with degree-correlated topology and show that complex, multi-stable regimes can result for increasing correlations. Our work is motivated by the recent finding of subnetworks of highly active neurons and the fact that these neurons tend to be connected to each other with higher probability.
Procházka, Vít; Pytlík, Robert; Janíková, Andrea; Belada, David; Sálek, David; Papajík, Tomáš; Campr, Vít; Fürst, Tomáš; Furstova, Jana; Trněný, Marek
2014-01-01
Absolute lymphocyte count (ALC) and absolute monocyte count (AMC) have been documented as independent predictors of survival in patients with newly diagnosed Diffuse Large B-cell Lymphoma (DLBCL). Analysis of the prognostic impact of ALC and AMC in the context of International Prognostic Index (IPI) and other significant variables in elderly population treated in the R-CHOP regime has not been carried out yet. In this retrospective study, a cohort of 443 newly diagnosed DLBCL patients with age ≥ 60 was analyzed. All patients were treated with the R-CHOP therapy. An extensive statistical analysis was performed to identify risk factors of 3-year overall survival (OS). In multivariate analysis, only three predictors proved significant: Eastern Cooperative Oncology Group performance status (ECOG), age and bulky disease presence. These predictors were dichotomized (ECOG ≥ 1, age ≥ 70, bulk ≥ 7.5) to create a novel four-level score. This score predicted 3-year OS of 94.0%, 77.4%, 62.7% and 35.4% in the low-, low-intermediate, high-intermediate and high-risk groups, respectively (P<0.001). Further, a three-level score was tested which stratifies the population better (3-year OS: 91.9%, 67.2%, 36.2% in the low, intermediate and high-risk groups, respectively) but is more difficult to interpret. Both the 3- and 4-level scores were compared to standard scoring systems and, in our population, were shown to be superior in terms of patients risk stratification with respect to 3-year OS prediction. The results were successfully validated on an independent cohort of 162 patients of similar group characteristics. The prognostic role of baseline ALC, AMC or their ratio (LMR) was not confirmed in the multivariate context in elderly population with DLBCL treated with R-CHOP. The newly proposed age-specific index stratifies the elderly population into risk groups more precisely than the conventional IPI and its existing variants.
ERIC Educational Resources Information Center
Gonzalez, Juan Carlos; Portillos, Edwardo L.
2007-01-01
At 40.4 million strong (14% of the U.S. population; U.S. Bureau of the Census 2005), Latinas/os are the largest and fastest growing U.S. ethnic minority group. In the last 15 years, since the Los Angeles riots of 1992, Anglo perceptions that the Latina/o population is too large, growing too fast, and too illegal have both continued and perpetuated…
Genetic structure in village dogs reveals a Central Asian domestication origin.
Shannon, Laura M; Boyko, Ryan H; Castelhano, Marta; Corey, Elizabeth; Hayward, Jessica J; McLean, Corin; White, Michelle E; Abi Said, Mounir; Anita, Baddley A; Bondjengo, Nono Ikombe; Calero, Jorge; Galov, Ana; Hedimbi, Marius; Imam, Bulu; Khalap, Rajashree; Lally, Douglas; Masta, Andrew; Oliveira, Kyle C; Pérez, Lucía; Randall, Julia; Tam, Nguyen Minh; Trujillo-Cornejo, Francisco J; Valeriano, Carlos; Sutter, Nathan B; Todhunter, Rory J; Bustamante, Carlos D; Boyko, Adam R
2015-11-03
Dogs were the first domesticated species, originating at least 15,000 y ago from Eurasian gray wolves. Dogs today consist primarily of two specialized groups--a diverse set of nearly 400 pure breeds and a far more populous group of free-ranging animals adapted to a human commensal lifestyle (village dogs). Village dogs are more genetically diverse and geographically widespread than purebred dogs making them vital for unraveling dog population history. Using a semicustom 185,805-marker genotyping array, we conducted a large-scale survey of autosomal, mitochondrial, and Y chromosome diversity in 4,676 purebred dogs from 161 breeds and 549 village dogs from 38 countries. Geographic structure shows both isolation and gene flow have shaped genetic diversity in village dog populations. Some populations (notably those in the Neotropics and the South Pacific) are almost completely derived from European stock, whereas others are clearly admixed between indigenous and European dogs. Importantly, many populations--including those of Vietnam, India, and Egypt-show minimal evidence of European admixture. These populations exhibit a clear gradient of short--range linkage disequilibrium consistent with a Central Asian domestication origin.
Male group size, female distribution and changes in sexual segregation by Roosevelt elk
Peterson, Leah M.
2017-01-01
Sexual segregation, or the differential use of space by males and females, is hypothesized to be a function of body size dimorphism. Sexual segregation can also manifest at small (social segregation) and large (habitat segregation) spatial scales for a variety of reasons. Furthermore, the connection between small- and large-scale sexual segregation has rarely been addressed. We studied a population of Roosevelt elk (Cervus elaphus roosevelti) across 21 years in north coastal California, USA, to assess small- and large-scale sexual segregation in winter. We hypothesized that male group size would associate with small-scale segregation and that a change in female distribution would associate with large-scale segregation. Variation in forage biomass might also be coupled to small and large-scale sexual segregation. Our findings were consistent with male group size associating with small-scale segregation and a change in female distribution associating with large-scale segregation. Females appeared to avoid large groups comprised of socially dominant males. Males appeared to occupy a habitat vacated by females because of a wider forage niche, greater tolerance to lethal risks, and, perhaps, to reduce encounters with other elk. Sexual segregation at both spatial scales was a poor predictor of forage biomass. Size dimorphism was coupled to change in sexual segregation at small and large spatial scales. Small scale segregation can seemingly manifest when all forage habitat is occupied by females and large scale segregation might happen when some forage habitat is not occupied by females. PMID:29121076
Impact of parasites on salmon recruitment in the Northeast Atlantic Ocean
Krkošek, Martin; Revie, Crawford W.; Gargan, Patrick G.; Skilbrei, Ove T.; Finstad, Bengt; Todd, Christopher D.
2013-01-01
Parasites may have large effects on host population dynamics, marine fisheries and conservation, but a clear elucidation of their impact is limited by a lack of ecosystem-scale experimental data. We conducted a meta-analysis of replicated manipulative field experiments concerning the influence of parasitism by crustaceans on the marine survival of Atlantic salmon (Salmo salar L.). The data include 24 trials in which tagged smolts (totalling 283 347 fish; 1996–2008) were released as paired control and parasiticide-treated groups into 10 areas of Ireland and Norway. All experimental fish were infection-free when released into freshwater, and a proportion of each group was recovered as adult recruits returning to coastal waters 1 or more years later. Treatment had a significant positive effect on survival to recruitment, with an overall effect size (odds ratio) of 1.29 that corresponds to an estimated loss of 39 per cent (95% CI: 18–55%) of adult salmon recruitment. The parasitic crustaceans were probably acquired during early marine migration in areas that host large aquaculture populations of domesticated salmon, which elevate local abundances of ectoparasitic copepods—particularly Lepeophtheirus salmonis. These results provide experimental evidence from a large marine ecosystem that parasites can have large impacts on fish recruitment, fisheries and conservation. PMID:23135680
Punishment can promote defection in group-structured populations.
Powers, Simon T; Taylor, Daniel J; Bryson, Joanna J
2012-10-21
Pro-social punishment, whereby cooperators punish defectors, is often suggested as a mechanism that maintains cooperation in large human groups. Importantly, models that support this idea have to date only allowed defectors to be the target of punishment. However, recent empirical work has demonstrated the existence of anti-social punishment in public goods games. That is, individuals that defect have been found to also punish cooperators. Some recent theoretical studies have found that such anti-social punishment can prevent the evolution of pro-social punishment and cooperation. However, the evolution of anti-social punishment in group-structured populations has not been formally addressed. Previous work has informally argued that group-structure must favour pro-social punishment. Here we formally investigate how two demographic factors, group size and dispersal frequency, affect selection pressures on pro- and anti-social punishment. Contrary to the suggestions of previous work, we find that anti-social punishment can prevent the evolution of pro-social punishment and cooperation under a range of group structures. Given that anti-social punishment has now been found in all studied extant human cultures, the claims of previous models showing the co-evolution of pro-social punishment and cooperation in group-structured populations should be re-evaluated. Copyright © 2012 Elsevier Ltd. All rights reserved.
Air pollution exposure: Who is at high risk?
NASA Astrophysics Data System (ADS)
Peled, Ronit
2011-04-01
This article reviews the sub-population groups who are at high risk and first to be harmed by air pollution coming from anthropogenic combustions. Epidemiological studies from the last few decades contributed to the understanding of the different levels of susceptibility to air pollution. Older people and young infants, people who suffer from allergies, pulmonary and heart diseases, pregnant women and newborn babies, and deprived populations that suffer from low socio-economic status have all been described as populations at risk. A better understanding of the role of air pollution on large as well as specific populations' health, will promote a better protection policy.
Two Populations of Sunspots: Differential Rotation
NASA Astrophysics Data System (ADS)
Nagovitsyn, Yu. A.; Pevtsov, A. A.; Osipova, A. A.
2018-03-01
To investigate the differential rotation of sunspot groups using the Greenwich data, we propose an approach based on a statistical analysis of the histograms of particular longitudinal velocities in different latitude intervals. The general statistical velocity distributions for all such intervals are shown to be described by two rather than one normal distribution, so that two fundamental rotation modes exist simultaneously: fast and slow. The differentiality of rotation for the modes is the same: the coefficient at sin2 in Faye's law is 2.87-2.88 deg/day, while the equatorial rotation rates differ significantly, 0.27 deg/day. On the other hand, an analysis of the longitudinal velocities for the previously revealed two differing populations of sunspot groups has shown that small short-lived groups (SSGs) are associated with the fast rotation mode, while large long-lived groups (LLGs) are associated with both fast and slow modes. The results obtained not only suggest a real physical difference between the two populations of sunspots but also give new empirical data for the development of a dynamo theory, in particular, for the theory of a spatially distributed dynamo.
DNA pooling strategies for categorical (ordinal) traits
USDA-ARS?s Scientific Manuscript database
Despite reduced genotyping costs in recent years, obtaining genotypes for all individuals in a population may still not be feasible when sample size is large. DNA pooling provides a useful alternative to determining genotype effects. Clustering algorithms allow for grouping of individuals (observati...
ERIC Educational Resources Information Center
Clift, Kate
2010-01-01
Transient populations, cultural diversity, language barriers, competing loyalties, and geographic separation are just some of the challenges international schools face in communicating and connecting with their alumni. And these issues are not going to get any easier as the sector grows. Communicating effectively with large, diverse groups of…
Cultural turnover among Galápagos sperm whales
Whitehead, Hal; Rendell, Luke
2016-01-01
While populations may wax and wane, it is rare for an entire population to be replaced by a completely different set of individuals. We document the large-scale relocation of cultural groups of sperm whale off the Galápagos Islands, in which two sympatric vocal clans were entirely replaced by two different ones. Between 1985 and 1999, whales from two clans (called Regular and Plus-One) defined by cultural dialects in coda vocalizations were repeatedly photo-identified off Galápagos. Their occurrence in the area declined through the 1990s; by 2000, none remained. We reassessed Galápagos sperm whales in 2013–2014, identifying 463 new females. However, re-sighting rates were low, with no matches with the Galápagos 1985–1999 population, suggesting an eastward shift to coastal areas. Their vocal repertoires matched those of two other clans (called Short and Four-Plus) found across the Pacific but previously rare or absent around Galápagos. The mechanisms behind this cultural turnover may include large-scale environmental regime shifts favouring clan-specific foraging strategies, and a response to heavy whaling in the region involving redistribution of surviving whales into high-quality habitats. The fall and rise of sperm whale cultures off Galápagos reflect the structuring of the Pacific population into large, enduring clans with dynamic ranges. Long-lasting clan membership illustrates how culture can be bound up in the structure and dynamics of animal populations and so how tracking cultural traits can reveal large-scale population shifts. PMID:27853582
Genetic diversity of disease-associated loci in Turkish population.
Karaca, Sefayet; Cesuroglu, Tomris; Karaca, Mehmet; Erge, Sema; Polimanti, Renato
2015-04-01
Many consortia and international projects have investigated the human genetic variation of a large number of ethno-geographic groups. However, populations with peculiar genetic features, such as the Turkish population, are still absent in publically available datasets. To explore the genetic predisposition to health-related traits of the Turkish population, we analyzed 34 genes associated with different health-related traits (for example, lipid metabolism, cardio-vascular diseases, hormone metabolism, cellular detoxification, aging and energy metabolism). We observed relevant differences between the Turkish population and populations with non-European ancestries (that is, Africa and East Asia) in some of the investigated genes (that is, AGT, APOE, CYP1B1, GNB3, IL10, IL6, LIPC and PON1). As most complex traits are highly polygenic, we developed polygenic scores associated with different health-related traits to explore the genetic diversity of the Turkish population with respect to other human groups. This approach showed significant differences between the Turkish population and populations with non-European ancestries, as well as between Turkish and Northern European individuals. This last finding is in agreement with the genetic structure of European and Middle East populations, and may also agree with epidemiological evidences about the health disparities of Turkish communities in Northern European countries.
Rosenberg, Noah A; Nordborg, Magnus
2006-07-01
In linkage disequilibrium mapping of genetic variants causally associated with phenotypes, spurious associations can potentially be generated by any of a variety of types of population structure. However, mathematical theory of the production of spurious associations has largely been restricted to population structure models that involve the sampling of individuals from a collection of discrete subpopulations. Here, we introduce a general model of spurious association in structured populations, appropriate whether the population structure involves discrete groups, admixture among such groups, or continuous variation across space. Under the assumptions of the model, we find that a single common principle--applicable to both the discrete and admixed settings as well as to spatial populations--gives a necessary and sufficient condition for the occurrence of spurious associations. Using a mathematical connection between the discrete and admixed cases, we show that in admixed populations, spurious associations are less severe than in corresponding mixtures of discrete subpopulations, especially when the variance of admixture across individuals is small. This observation, together with the results of simulations that examine the relative influences of various model parameters, has important implications for the design and analysis of genetic association studies in structured populations.
Interethnic genetic differentiation: HLA class I antigens in the population of Mongolia.
Chimge, Nyam-Osorin; Batsuuri, Jamiyangiin
1999-09-01
A total of 1668 individuals representing 10 major Mongolian ethnic groups were serologically typed for HLA-A, -B, and -C antigens. Antigens A2, A24, B61, B51, B58, Cw3, Cw7, and Cw6 were the most frequent specificities in Mongolians and no case of B42 was noted in all ethnic groups. The cluster analysis of Principal Components I and II shows that Mongolian speaking groups form one cluster vs Turkic-speaking Kazakhs. The analysis reveals a low, but significant differentiation of Mongolian ethnic groups as measured by F(ST) = 0.0100 (P < 0.001). Gene diversity analysis shows that the genetic diversity of the Mongolian population can be attributed largely to its ethnic component, which makes up 64% of total genetic variation. The low degree of interpopulation variation and high level of intrapopulation diversity can be explained by the nomadic way of life of this indigenous population. Three-locus haplotypes A24-B61-Cw3, A33-B58-Cw3 are the most common haplotypic associations in Mongolians. The presence of antigens characteristic of Mongoloid, Caucasoid, and Negroid populations in Mongolians suggests a unique genetic background of this indigenous population. The three-locus haplotype distribution among Mongolians relative to other world populations supports the migration of ancient people from Central Asia to the New World, Korean Peninsula, and Southeast Asia. Am. J. Hum. Biol. 11:603-618, 1999. Copyright 1999 Wiley-Liss, Inc.
Simulation of Yeast Cooperation in 2D.
Wang, M; Huang, Y; Wu, Z
2016-03-01
Evolution of cooperation has been an active research area in evolutionary biology in decades. An important type of cooperation is developed from group selection, when individuals form spatial groups to prevent them from foreign invasions. In this paper, we study the evolution of cooperation in a mixed population of cooperating and cheating yeast strains in 2D with the interactions among the yeast cells restricted to their small neighborhoods. We conduct a computer simulation based on a game theoretic model and show that cooperation is increased when the interactions are spatially restricted, whether the game is of a prisoner's dilemma, snow drifting, or mutual benefit type. We study the evolution of homogeneous groups of cooperators or cheaters and describe the conditions for them to sustain or expand in an opponent population. We show that under certain spatial restrictions, cooperator groups are able to sustain and expand as group sizes become large, while cheater groups fail to expand and keep them from collapse.
Large-scale absence of sharks on reefs in the greater-Caribbean: a footprint of human pressures.
Ward-Paige, Christine A; Mora, Camilo; Lotze, Heike K; Pattengill-Semmens, Christy; McClenachan, Loren; Arias-Castro, Ery; Myers, Ransom A
2010-08-05
In recent decades, large pelagic and coastal shark populations have declined dramatically with increased fishing; however, the status of sharks in other systems such as coral reefs remains largely unassessed despite a long history of exploitation. Here we explore the contemporary distribution and sighting frequency of sharks on reefs in the greater-Caribbean and assess the possible role of human pressures on observed patterns. We analyzed 76,340 underwater surveys carried out by trained volunteer divers between 1993 and 2008. Surveys were grouped within one km2 cells, which allowed us to determine the contemporary geographical distribution and sighting frequency of sharks. Sighting frequency was calculated as the ratio of surveys with sharks to the total number of surveys in each cell. We compared sighting frequency to the number of people in the cell vicinity and used population viability analyses to assess the effects of exploitation on population trends. Sharks, with the exception of nurse sharks occurred mainly in areas with very low human population or strong fishing regulations and marine conservation. Population viability analysis suggests that exploitation alone could explain the large-scale absence; however, this pattern is likely to be exacerbated by additional anthropogenic stressors, such as pollution and habitat degradation, that also correlate with human population. Human pressures in coastal zones have lead to the broad-scale absence of sharks on reefs in the greater-Caribbean. Preventing further loss of sharks requires urgent management measures to curb fishing mortality and to mitigate other anthropogenic stressors to protect sites where sharks still exist. The fact that sharks still occur in some densely populated areas where strong fishing regulations are in place indicates the possibility of success and encourages the implementation of conservation measures.
Specialization of the DNA-Cleaving Activity of a Group I Ribozyme Through In Vitro Evolution
NASA Technical Reports Server (NTRS)
Tsang, Joyce; Joyce, Gerald F.
1996-01-01
In an earlier study, an in vitro evolution procedure was applied to a large population of variants of the Tetrahymena group 1 ribozyme to obtain individuals with a 10(exp 5)-fold improved ability to cleave a target single-stranded DNA substrate under simulated physiological conditions. The evolved ribozymes also showed a twofold improvement, compared to the wild-type, in their ability to cleave a single-stranded RNA substrate. Here, we report continuation of the in vitro evolution process using a new selection strategy to achieve both enhanced DNA and diminished RNA-cleavage activity. Our strategy combines a positive selection for DNA cleavage with a negative selection against RNA binding. After 36 "generations" of in vitro evolution, the evolved population showed an approx. 100-fold increase in the ratio of DNA to RNA-cleavage activity. Site-directed mutagenesis experiment confirmed the selective advantage of two covarying mutations within the catalytic core of ribozyme that are largely responsible for this modified behavior. The population of ribozymes has now undergone a total of 63 successive generations of evolution, resulting in an average 28 mutations relative to the wild-type that are responsible for the altered phenotype.
On the value of the phenotypes in the genomic era.
Gonzalez-Recio, O; Coffey, M P; Pryce, J E
2014-12-01
Genetic improvement programs around the world rely on the collection of accurate phenotypic data. These phenotypes have an inherent value that can be estimated as the contribution of an additional record to genetic gain. Here, the contribution of phenotypes to genetic gain was calculated using traditional progeny testing (PT) and 2 genomic selection (GS) strategies that, for simplicity, included either males or females in the reference population. A procedure to estimate the theoretical economic contribution of a phenotype to a breeding program is described for both GS and PT breeding programs through the increment in genetic gain per unit of increase in estimated breeding value reliability obtained when an additional phenotypic record is added. The main factors affecting the value of a phenotype were the economic value of the trait, the number of phenotypic records already available for the trait, and its heritability. Furthermore, the value of a phenotype was affected by several other factors, including the cost of establishing the breeding program and the cost of phenotyping and genotyping. The cost of achieving a reliability of 0.60 was assessed for different reference populations for GS. Genomic reference populations of more sires with small progeny group sizes (e.g., 20 equivalent daughters) had a lower cost than those reference populations with either large progeny group sizes for fewer genotyped sires, or female reference populations, unless the heritability was large and the cost of phenotyping exceeded a few hundred dollars; then, female reference populations were preferable from an economic perspective. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
The evolutionary history of Afrocanarian blue tits inferred from genomewide SNPs.
Gohli, Jostein; Leder, Erica H; Garcia-Del-Rey, Eduardo; Johannessen, Lars Erik; Johnsen, Arild; Laskemoen, Terje; Popp, Magnus; Lifjeld, Jan T
2015-01-01
A common challenge in phylogenetic reconstruction is to find enough suitable genomic markers to reliably trace splitting events with short internodes. Here, we present phylogenetic analyses based on genomewide single-nucleotide polymorphisms (SNPs) of an enigmatic avian radiation, the subspecies complex of Afrocanarian blue tits (Cyanistes teneriffae). The two sister species, the Eurasian blue tit (Cyanistes caeruleus) and the azure tit (Cyanistes cyanus), constituted the out-group. We generated a large data set of SNPs for analysis of population structure and phylogeny. We also adapted our protocol to utilize degraded DNA from old museum skins from Libya. We found strong population structuring that largely confirmed subspecies monophyly and constructed a coalescent-based phylogeny with full support at all major nodes. The results are consistent with a recent hypothesis that La Palma and Libya are relic populations of an ancient Afrocanarian blue tit, although a small data set for Libya could not resolve its position relative to La Palma. The birds on the eastern islands of Fuerteventura and Lanzarote are similar to those in Morocco. Together they constitute the sister group to the clade containing the other Canary Islands (except La Palma), in which El Hierro is sister to the three central islands. Hence, extant Canary Islands populations seem to originate from multiple independent colonization events. We also found population divergences in a key reproductive trait, viz. sperm length, which may constitute reproductive barriers between certain populations. We recommend a taxonomic revision of this polytypic species, where several subspecies should qualify for species rank. © 2014 John Wiley & Sons Ltd.
The promise of discovering population-specific disease-associated genes in South Asia.
Nakatsuka, Nathan; Moorjani, Priya; Rai, Niraj; Sarkar, Biswanath; Tandon, Arti; Patterson, Nick; Bhavani, Gandham SriLakshmi; Girisha, Katta Mohan; Mustak, Mohammed S; Srinivasan, Sudha; Kaushik, Amit; Vahab, Saadi Abdul; Jagadeesh, Sujatha M; Satyamoorthy, Kapaettu; Singh, Lalji; Reich, David; Thangaraj, Kumarasamy
2017-09-01
The more than 1.5 billion people who live in South Asia are correctly viewed not as a single large population but as many small endogamous groups. We assembled genome-wide data from over 2,800 individuals from over 260 distinct South Asian groups. We identified 81 unique groups, 14 of which had estimated census sizes of more than 1 million, that descend from founder events more extreme than those in Ashkenazi Jews and Finns, both of which have high rates of recessive disease due to founder events. We identified multiple examples of recessive diseases in South Asia that are the result of such founder events. This study highlights an underappreciated opportunity for decreasing disease burden among South Asians through discovery of and testing for recessive disease-associated genes.
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.
Wallace, Tiffany A; Martin, Damali N; Ambs, Stefan
2011-08-01
Cancer incidence and mortality rates show great variations across nations and between population groups. These variations are largely explained by differences in age distribution, diet and lifestyle, access to health care, cultural barriers and exposure to carcinogens and pathogens. Cancers caused by infections are significantly more common in developing than developed countries, and they overproportionally affect immigrant populations in the USA and other countries. The global pattern of cancer is not stagnant. Instead, it is dynamic because of fluctuations in the age distribution of populations, improvements in cancer prevention and early detection in affluent countries and rapid changes in diet and lifestyle in parts of the world. For example, increased smoking rates have caused tobacco-induced cancers to rise in various Asian countries, whereas reduced smoking rates have caused these cancers to plateau or even begin to decline in Western Europe and North America. Some population groups experience a disproportionally high cancer burden. In the USA and the Caribbean, cancer incidence and mortality rates are excessively high in populations of African ancestry when compared with other population groups. The causes of this disparity are multifaceted and may include tumor biological and genetic factors and their interaction with the environment. In this review, we will discuss the magnitude and causes of global cancer health disparities and will, with a focus on African-Americans and selected cancer sites, evaluate the evidence that genetic and tumor biological factors contribute to existing cancer incidence and outcome differences among population groups in the USA.
Wallace, Tiffany A.; Martin, Damali N.; Ambs, Stefan
2011-01-01
Cancer incidence and mortality rates show great variations across nations and between population groups. These variations are largely explained by differences in age distribution, diet and lifestyle, access to health care, cultural barriers and exposure to carcinogens and pathogens. Cancers caused by infections are significantly more common in developing than developed countries, and they overproportionally affect immigrant populations in the USA and other countries. The global pattern of cancer is not stagnant. Instead, it is dynamic because of fluctuations in the age distribution of populations, improvements in cancer prevention and early detection in affluent countries and rapid changes in diet and lifestyle in parts of the world. For example, increased smoking rates have caused tobacco-induced cancers to rise in various Asian countries, whereas reduced smoking rates have caused these cancers to plateau or even begin to decline in Western Europe and North America. Some population groups experience a disproportionally high cancer burden. In the USA and the Caribbean, cancer incidence and mortality rates are excessively high in populations of African ancestry when compared with other population groups. The causes of this disparity are multifaceted and may include tumor biological and genetic factors and their interaction with the environment. In this review, we will discuss the magnitude and causes of global cancer health disparities and will, with a focus on African-Americans and selected cancer sites, evaluate the evidence that genetic and tumor biological factors contribute to existing cancer incidence and outcome differences among population groups in the USA. PMID:21464040
HIV populations are large and accumulate high genetic diversity in a nonlinear fashion.
Maldarelli, Frank; Kearney, Mary; Palmer, Sarah; Stephens, Robert; Mican, JoAnn; Polis, Michael A; Davey, Richard T; Kovacs, Joseph; Shao, Wei; Rock-Kress, Diane; Metcalf, Julia A; Rehm, Catherine; Greer, Sarah E; Lucey, Daniel L; Danley, Kristen; Alter, Harvey; Mellors, John W; Coffin, John M
2013-09-01
HIV infection is characterized by rapid and error-prone viral replication resulting in genetically diverse virus populations. The rate of accumulation of diversity and the mechanisms involved are under intense study to provide useful information to understand immune evasion and the development of drug resistance. To characterize the development of viral diversity after infection, we carried out an in-depth analysis of single genome sequences of HIV pro-pol to assess diversity and divergence and to estimate replicating population sizes in a group of treatment-naive HIV-infected individuals sampled at single (n = 22) or multiple, longitudinal (n = 11) time points. Analysis of single genome sequences revealed nonlinear accumulation of sequence diversity during the course of infection. Diversity accumulated in recently infected individuals at rates 30-fold higher than in patients with chronic infection. Accumulation of synonymous changes accounted for most of the diversity during chronic infection. Accumulation of diversity resulted in population shifts, but the rates of change were low relative to estimated replication cycle times, consistent with relatively large population sizes. Analysis of changes in allele frequencies revealed effective population sizes that are substantially higher than previous estimates of approximately 1,000 infectious particles/infected individual. Taken together, these observations indicate that HIV populations are large, diverse, and slow to change in chronic infection and that the emergence of new mutations, including drug resistance mutations, is governed by both selection forces and drift.
Otwoma, Levy Michael; Kochzius, Marc
2016-01-01
The coral reef sea star Linckia laevigata is common on shallow water coral reefs of the Indo-West Pacific. Its large geographic distribution and comprehensive data from previous studies makes it suitable to examine genetic differentiation and connectivity over large geographical scales. Based on partial sequences of the mitochondrial cytochrome oxidase I (COI) gene this study investigates the genetic population structure and connectivity of L. laevigata in the Western Indian Ocean (WIO) and compares it to previous studies in the Indo-Malay-Philippines Archipelago (IMPA). A total of 138 samples were collected from nine locations in the WIO. AMOVA revealed a low but significant ΦST-value of 0.024 for the WIO populations. In the hierarchical AMOVA, the following grouping rejected the hypothesis of panmixia: (1) Kenya (Watamu, Mombasa, Diani) and Tanzanian Island populations (Misali and Jambiani) and (2) the rest of the WIO sites (mainland Tanzania and Madagascar; ΦCT = 0.03). The genetic population structure was stronger and more significant (ΦST = 0.13) in the comparative analysis of WIO and IMPA populations. Three clades were identified in the haplotype network. The strong genetic differentiation (ΦCT = 0.199, P < 0.001) suggests that Indo-West Pacific populations of L. laevigata can be grouped into four biogeographic regions: (1) WIO (2) Eastern Indian Ocean (3) IMPA and (4) Western Pacific. The findings of this study support the existence of a genetic break in the Indo-West Pacific consistent with the effect of lowered sea level during the Pleistocene, which limited gene flow between the Pacific and Indian Ocean.
Kochzius, Marc
2016-01-01
The coral reef sea star Linckia laevigata is common on shallow water coral reefs of the Indo-West Pacific. Its large geographic distribution and comprehensive data from previous studies makes it suitable to examine genetic differentiation and connectivity over large geographical scales. Based on partial sequences of the mitochondrial cytochrome oxidase I (COI) gene this study investigates the genetic population structure and connectivity of L. laevigata in the Western Indian Ocean (WIO) and compares it to previous studies in the Indo-Malay-Philippines Archipelago (IMPA). A total of 138 samples were collected from nine locations in the WIO. AMOVA revealed a low but significant ΦST-value of 0.024 for the WIO populations. In the hierarchical AMOVA, the following grouping rejected the hypothesis of panmixia: (1) Kenya (Watamu, Mombasa, Diani) and Tanzanian Island populations (Misali and Jambiani) and (2) the rest of the WIO sites (mainland Tanzania and Madagascar; ΦCT = 0.03). The genetic population structure was stronger and more significant (ΦST = 0.13) in the comparative analysis of WIO and IMPA populations. Three clades were identified in the haplotype network. The strong genetic differentiation (ΦCT = 0.199, P < 0.001) suggests that Indo-West Pacific populations of L. laevigata can be grouped into four biogeographic regions: (1) WIO (2) Eastern Indian Ocean (3) IMPA and (4) Western Pacific. The findings of this study support the existence of a genetic break in the Indo-West Pacific consistent with the effect of lowered sea level during the Pleistocene, which limited gene flow between the Pacific and Indian Ocean. PMID:27798700
Collective Motion in Bacterial Populations with Mixed Phenotypic Behaviors
NASA Astrophysics Data System (ADS)
Hoeger, Kentaro; Strickland, Ben; Shoup, Daniel; Ursell, Tristan
The motion of large, densely packed groups of organisms is often qualitatively distinct from the motion of individuals, yet hinges on individual properties and behaviors. Collective motion of bacteria depends strongly on the phenotypic behaviors of individual cells, the physical interactions between cells, and the geometry of their environment, often with multiple phenotypes coexisting in a population. Thus, to characterize how these selectively important interactions affect group traits, such as cell dispersal, spatial segregation of phenotypes, and material transport in groups, we use a library of Bacillus subtilis mutants that modulate chemotaxis, motility, and biofilm formation. By mixing phenotypes and observing bacterial behaviors and motion at single cell resolution, we probe collective motion as a function of phenotypic mixture and environmental geometry. Our work demonstrates that collective microbial motion exhibits a transition, from `turbulence' to semiballistic burrowing, as phenotypic composition varies. This work illuminates the role that individual cell behaviors play in the emergence of collective motion, and may signal qualitatively distinct regimes of material transport in bacterial populations. University of Oregon.
Naming Game on Networks: Let Everyone be Both Speaker and Hearer
Gao, Yuan; Chen, Guanrong; Chan, Rosa H. M.
2014-01-01
To investigate how consensus is reached on a large self-organized peer-to-peer network, we extended the naming game model commonly used in language and communication to Naming Game in Groups (NGG). Differing from other existing naming game models, in NGG everyone in the population (network) can be both speaker and hearer simultaneously, which resembles in a closer manner to real-life scenarios. Moreover, NGG allows the transmission (communication) of multiple words (opinions) for multiple intra-group consensuses. The communications among indirectly-connected nodes are also enabled in NGG. We simulated and analyzed the consensus process in some typical network topologies, including random-graph networks, small-world networks and scale-free networks, to better understand how global convergence (consensus) could be reached on one common word. The results are interpreted on group negotiation of a peer-to-peer network, which shows that global consensus in the population can be reached more rapidly when more opinions are permitted within each group or when the negotiating groups in the population are larger in size. The novel features and properties introduced by our model have demonstrated its applicability in better investigating general consensus problems on peer-to-peer networks. PMID:25143140
Child mental health differences amongst ethnic groups in Britain: a systematic review
Goodman, Anna; Patel, Vikram; Leon, David A
2008-01-01
Background Inter-ethnic differences have been reported for many mental health outcomes in the UK, but no systematic review on child mental health has been published. The aim of this review is to compare the population-based prevalence of child mental disorders between ethnic groups in Britain, and relate these findings to ethnic differences in mental health service use. Methods A systematic search of bibliographic databases for population-based and clinic-based studies of children aged 0–19, including all ethnic groups and the main child mental disorders. We synthesised findings by comparing each minority group to the White British study sample. Results 31 population-based and 18 clinic-based studies met the inclusion criteria. Children in the main minority groups have similar or better mental health than White British children for common disorders, but may have higher rates for some less common conditions. The causes of these differences are unclear. There may be unmet need for services among Pakistani and Bangladeshi children. Conclusion Inter-ethnic differences exist but are largely unexplained. Future studies should address the challenges of cross-cultural psychiatry and investigate reasons for inter-ethnic differences. PMID:18655701
Learning about population-health through a community practice learning project: An evaluation study.
Davenport, Maggie; Ooms, Ann; Marks-Maran, Di
2016-03-01
Increasing student nurse numbers requiring community placement learning opportunities has led to insufficient numbers of community nurses being available to support student nurses in the community. Although the study presented in the article is based in the UK this issue is reported widely in the literature across the globe. Universities in many countries have had to find innovative ways of providing community health learning opportunities for student nurses. This article reports on how one university in the UK has approached this challenge through students engaging in a population-based study in the community through group work. A research study was undertaken into this innovation which found that the student nurses engaged well with the project and with their groups and undertaking the project had positive value and impact on them and their understanding of population-health. Issues that arose for them largely focused on unequal participation in the group work by some with many participants perceiving that they had done more work on the group project and presentation than others in their group. However, working in this way was perceived to be a good learning experience for the majority of participants. Copyright © 2016 Elsevier Ltd. All rights reserved.
Naming Game on Networks: Let Everyone be Both Speaker and Hearer
NASA Astrophysics Data System (ADS)
Gao, Yuan; Chen, Guanrong; Chan, Rosa H. M.
2014-08-01
To investigate how consensus is reached on a large self-organized peer-to-peer network, we extended the naming game model commonly used in language and communication to Naming Game in Groups (NGG). Differing from other existing naming game models, in NGG everyone in the population (network) can be both speaker and hearer simultaneously, which resembles in a closer manner to real-life scenarios. Moreover, NGG allows the transmission (communication) of multiple words (opinions) for multiple intra-group consensuses. The communications among indirectly-connected nodes are also enabled in NGG. We simulated and analyzed the consensus process in some typical network topologies, including random-graph networks, small-world networks and scale-free networks, to better understand how global convergence (consensus) could be reached on one common word. The results are interpreted on group negotiation of a peer-to-peer network, which shows that global consensus in the population can be reached more rapidly when more opinions are permitted within each group or when the negotiating groups in the population are larger in size. The novel features and properties introduced by our model have demonstrated its applicability in better investigating general consensus problems on peer-to-peer networks.
Ashma, R; Kashyap, V K
2003-01-01
The formation of caste groups among the Hindu community and the practice of endogamy exert a great impact on the genetic structure and diversity of the Indian population. Allele frequency data of 15 microsatellite loci clearly portray the genetic diversity and relatedness among four socio-culturally advanced caste groups: Brahmin, Bhumihar, Rajput and Kayasth of Caucasoid ethnicity of Bihar. The study seeks to understand the impact of the man-made caste system on the genetic profile of the four major caste groups of Bihar. Computation of average heterozygosity, most frequent allele, allele diversity and coefficient of gene differentiation (Gst), along with genetic distance (DA)and principal coordinate analysis were performed to assess intra-population and inter-population diversity. The average Gst value for all the loci was 0.012 +/- 0.0033, and the level of average heterozygosity was approximately 75.5%, indicating genetic similarity and intra-population diversity. Genetic distance (DA) values and the phylogenetic tree along with other higher caste groups of India indicate the relative distance between them. The present study clearly depicts the genetic profile of these caste groups, their inherent closeness in the past, and the impact of the imposed caste system that later restricted the gene flow. The study highlights the status of Bhumihar and Kayasth in the Hindu caste system. The former was found clustering with the Brahmin group (as expected, since Bhumihar is known to be a subclass of Brahmin), whereas the distance between the Brahmin and Kayasth caste groups was found to be large. North-eastern Indian Mongoloids form a separate cluster.
Schäfer, Ingmar; von Leitner, Eike-Christin; Schön, Gerhard; Koller, Daniela; Hansen, Heike; Kolonko, Tina; Kaduszkiewicz, Hanna; Wegscheider, Karl; Glaeske, Gerd; van den Bussche, Hendrik
2010-01-01
Objective Multimorbidity is a common problem in the elderly that is significantly associated with higher mortality, increased disability and functional decline. Information about interactions of chronic diseases can help to facilitate diagnosis, amend prevention and enhance the patients' quality of life. The aim of this study was to increase the knowledge of specific processes of multimorbidity in an unselected elderly population by identifying patterns of statistically significantly associated comorbidity. Methods Multimorbidity patterns were identified by exploratory tetrachoric factor analysis based on claims data of 63,104 males and 86,176 females in the age group 65+. Analyses were based on 46 diagnosis groups incorporating all ICD-10 diagnoses of chronic diseases with a prevalence ≥ 1%. Both genders were analyzed separately. Persons were assigned to multimorbidity patterns if they had at least three diagnosis groups with a factor loading of 0.25 on the corresponding pattern. Results Three multimorbidity patterns were found: 1) cardiovascular/metabolic disorders [prevalence female: 30%; male: 39%], 2) anxiety/depression/somatoform disorders and pain [34%; 22%], and 3) neuropsychiatric disorders [6%; 0.8%]. The sampling adequacy was meritorious (Kaiser-Meyer-Olkin measure: 0.85 and 0.84, respectively) and the factors explained a large part of the variance (cumulative percent: 78% and 75%, respectively). The patterns were largely age-dependent and overlapped in a sizeable part of the population. Altogether 50% of female and 48% of male persons were assigned to at least one of the three multimorbidity patterns. Conclusion This study shows that statistically significant co-occurrence of chronic diseases can be subsumed in three prevalent multimorbidity patterns if accounting for the fact that different multimorbidity patterns share some diagnosis groups, influence each other and overlap in a large part of the population. In recognizing the full complexity of multimorbidity we might improve our ability to predict needs and achieve possible benefits for elderly patients who suffer from multimorbidity. PMID:21209965
Cryptic herbivores mediate the strength and form of ungulate impacts on a long-lived savanna tree.
Maclean, Janet E; Goheen, Jacob R; Doak, Daniel F; Palmer, Todd M; Young, Truman P
2011-08-01
Plant populations are regulated by a diverse array of herbivores that impose demographic filters throughout their life cycle. Few studies, however, simultaneously quantify the impacts of multiple herbivore guilds on the lifetime performance or population growth rate of plants. In African savannas, large ungulates (such as elephants) are widely regarded as important drivers of woody plant population dynamics, while the potential impacts of smaller, more cryptic herbivores (such as rodents) have largely been ignored. We combined a large-scale ungulate exclusion experiment with a five-year manipulation of rodent densities to quantify the impacts of three herbivore guilds (wild ungulates, domestic cattle, and rodents) on all life stages of a widespread savanna tree. We utilized demographic modeling to reveal the overall role of each guild in regulating tree population dynamics, and to elucidate the importance of different demographic hurdles in driving population growth under contrasting consumer communities. We found that wild ungulates dramatically reduced population growth, shifting the population trajectory from increase to decline, but that the mechanisms driving these effects were strongly mediated by rodents. The impact of wild ungulates on population growth was predominantly driven by their negative effect on tree reproduction when rodents were excluded, and on adult tree survival when rodents were present. By limiting seedling survival, rodents also reduced population growth; however, this effect was strongly dampened where wild ungulates were present. We suggest that these complex interactions between disparate consumer guilds can have important consequences for the population demography of long-lived species, and that the effects of a single consumer group are often likely to vary dramatically depending on the larger community in which interactions are embedded.
Böndel, Katharina B; Lainer, Hilde; Nosenko, Tetyana; Mboup, Mamadou; Tellier, Aurélien; Stephan, Wolfgang
2015-11-01
After colonization population sizes may vary across the species range depending on environmental conditions and following colonizations. An interesting question is whether local adaptation occurs more frequently in large ancestral populations or in small derived populations. A higher number of new mutations and a lower effect of genetic drift should favor selection in large populations, whereas small derived populations may require an initial local adaptation event to facilitate the colonization of new habitats. Wild tomatoes are native to a broad range of different habitats characterized by variable abiotic conditions in South America, and represent an ideal system to study this interplay between demography and natural selection. Population genetic analyses and statistical inference of past demography were conducted on pooled-sequencing data from 30 genes (8,080 single nucleotide polymorphisms) from an extensive sampling of 23 Solanum chilense populations over Chile and Peru. We reveal first a north-south colonization associated with relaxed purifying selection in the south as shown by a decrease of genetic variation and an increasing proportion of nonsynonymous polymorphism from north to south, and population substructure with at least four genetic groups. Second, we uncover a dual picture of adaptation consisting of 1) a decreasing proportion of adaptive amino acid substitutions from north to south suggesting that adaptation is favored in large populations, whereas 2) signatures of local adaptation predominantly occur in the smaller populations from the marginal ranges in the south. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Genetic analysis of floating Enteromorpha prolifera in the Yellow Sea with AFLP marker
NASA Astrophysics Data System (ADS)
Liu, Cui; Zhang, Jing; Sun, Xiaoyu; Li, Jian; Zhang, Xi; Liu, Tao
2011-09-01
Extremely large accumulation of green algae Enteromorpha prolifera floated along China' coastal region of the Yellow Sea ever since the summer of 2008. Amplified Fragment Length Polymorphism (AFLP) analysis was applied to assess the genetic diversity and relationships among E. prolifera samples collected from 9 affected areas of the Yellow Sea. Two hundred reproducible fragments were generated with 8 AFLP primer combinations, of which 194 (97%) were polymorphic. The average Nei's genetic diversity, the coefficiency of genetic differentiation (Gst), and the average gene flow estimated from Gst in the 9 populations were 0.4018, 0.6404 and 0.2807 respectively. Cluster analysis based on the unweighed pair group method with arithmetic averages (UPGMA) showed that the genetic relationships within one population or among different populations were all related to their collecting locations and sampling time. Large genetic differentiation was detected among the populations. The E. prolifera originated from different areas and were undergoing a course of mixing.
Novikov, I; Fund, N; Freedman, L S
2010-01-15
Different methods for the calculation of sample size for simple logistic regression (LR) with one normally distributed continuous covariate give different results. Sometimes the difference can be large. Furthermore, some methods require the user to specify the prevalence of cases when the covariate equals its population mean, rather than the more natural population prevalence. We focus on two commonly used methods and show through simulations that the power for a given sample size may differ substantially from the nominal value for one method, especially when the covariate effect is large, while the other method performs poorly if the user provides the population prevalence instead of the required parameter. We propose a modification of the method of Hsieh et al. that requires specification of the population prevalence and that employs Schouten's sample size formula for a t-test with unequal variances and group sizes. This approach appears to increase the accuracy of the sample size estimates for LR with one continuous covariate.
Estimating attendance for breast cancer screening in ethnic groups in London.
Renshaw, Christine; Jack, Ruth H; Dixon, Steve; Møller, Henrik; Davies, Elizabeth A
2010-03-25
Breast screening uptake in London is below the Government's target of 70% and we investigate whether ethnicity affects this. Information on the ethnicity for the individual women invited is unavailable, so we use an area-based method similar to that routinely used to derive a geographical measure for socioeconomic deprivation. We extracted 742,786 observations on attendance for routine appointments between 2004 and 2007 collected by the London Quality Assurance Reference Centre. Each woman was assigned to a lower super output (LSOA) based on her postcode of residence. The proportions of the ethnic groups within each LSOA are known, so that the likelihood of a woman belonging to White, Black and Asian groups can be assigned. We investigated screening attendance by age group, socioeconomic deprivation using the Index of Deprivation 2004 income quintile, invitation type and breast screening service. Using logistic regression analysis we calculated odds ratios for attendance based on ethnic composition of the population, adjusting for age, socioeconomic status, the invitation type and screening service. The unadjusted attendance odds ratios were high for the White population (OR: 3.34 95% CI [3.26-3.42]) and low for the Black population (0.13 [0.12-0.13]) and the Asian population (0.55 [0.53-0.56]). Multivariate adjustment reduced the differences, but the Black population remained below unity (0.47 [0.44-0.50]); while the White (1.30 [1.26-1.35]) and Asian populations (1.10 [1.05-1.15]) were higher. There was little difference in the attendance between age groups. Attendance was highest for the most affluent group and fell sharply with increasing deprivation. For invitation type, the routine recall was higher than the first call. There were wide variations in the attendance for different ethnic groups between the individual screening services. Overall breast screening attendance is low in communities with large Black populations, suggesting the need to improve participation of Black women. Variations in attendance for the Asian population require further investigation at an individual screening service level.
Antonini, Tanya N; Beer, Stacey S; Miloh, Tamir; Dreyer, William J; Caudle, Susan E
2017-02-01
The purpose of this study was to review the current literature on neuropsychological functioning in two groups of children requiring organ transplants (liver or heart) and present recent clinical data collected through the liver and cardiac transplantation programs at a large pediatric academic medical center. Data included in this study came from 18 patients who completed evaluations for heart transplant (n = 8) or liver transplant (n = 10) between the ages of 2 and 6 years (inclusive). Measures examining neurocognitive, emotional-behavioral, and adaptive functioning were collected as part of standard pre-transplant clinical neuropsychological evaluations. Within each organ group, mean scores were calculated and compared with normative population mean scores using one sample t-tests. In addition, non-parametric binomial tests were calculated to examine whether the proportion of individuals falling more than one standard deviation below the population mean was significantly greater in the patient groups than the normative population base rate of 16%. Patients in both groups performed below normative expectation in several neurocognitive and adaptive domains. However, neither group showed significant difficulties in behavioral or emotional regulation. Results from this study document cognitive delays in preschool-aged children undergoing evaluations for liver transplant or heart transplant, highlighting the importance of intervention and long-term monitoring of these two patient populations, as well as the need for neuropsychologist involvement with transplant teams.
Afghanistan's Ethnic Groups Share a Y-Chromosomal Heritage Structured by Historical Events
Haber, Marc; Platt, Daniel E.; Ashrafian Bonab, Maziar; Youhanna, Sonia C.; Soria-Hernanz, David F.; Martínez-Cruz, Begoña; Douaihy, Bouchra; Ghassibe-Sabbagh, Michella; Rafatpanah, Hoshang; Ghanbari, Mohsen; Whale, John; Balanovsky, Oleg; Wells, R. Spencer; Comas, David; Tyler-Smith, Chris; Zalloua, Pierre A.
2012-01-01
Afghanistan has held a strategic position throughout history. It has been inhabited since the Paleolithic and later became a crossroad for expanding civilizations and empires. Afghanistan's location, history, and diverse ethnic groups present a unique opportunity to explore how nations and ethnic groups emerged, and how major cultural evolutions and technological developments in human history have influenced modern population structures. In this study we have analyzed, for the first time, the four major ethnic groups in present-day Afghanistan: Hazara, Pashtun, Tajik, and Uzbek, using 52 binary markers and 19 short tandem repeats on the non-recombinant segment of the Y-chromosome. A total of 204 Afghan samples were investigated along with more than 8,500 samples from surrounding populations important to Afghanistan's history through migrations and conquests, including Iranians, Greeks, Indians, Middle Easterners, East Europeans, and East Asians. Our results suggest that all current Afghans largely share a heritage derived from a common unstructured ancestral population that could have emerged during the Neolithic revolution and the formation of the first farming communities. Our results also indicate that inter-Afghan differentiation started during the Bronze Age, probably driven by the formation of the first civilizations in the region. Later migrations and invasions into the region have been assimilated differentially among the ethnic groups, increasing inter-population genetic differences, and giving the Afghans a unique genetic diversity in Central Asia. PMID:22470552
Afghanistan's ethnic groups share a Y-chromosomal heritage structured by historical events.
Haber, Marc; Platt, Daniel E; Ashrafian Bonab, Maziar; Youhanna, Sonia C; Soria-Hernanz, David F; Martínez-Cruz, Begoña; Douaihy, Bouchra; Ghassibe-Sabbagh, Michella; Rafatpanah, Hoshang; Ghanbari, Mohsen; Whale, John; Balanovsky, Oleg; Wells, R Spencer; Comas, David; Tyler-Smith, Chris; Zalloua, Pierre A
2012-01-01
Afghanistan has held a strategic position throughout history. It has been inhabited since the Paleolithic and later became a crossroad for expanding civilizations and empires. Afghanistan's location, history, and diverse ethnic groups present a unique opportunity to explore how nations and ethnic groups emerged, and how major cultural evolutions and technological developments in human history have influenced modern population structures. In this study we have analyzed, for the first time, the four major ethnic groups in present-day Afghanistan: Hazara, Pashtun, Tajik, and Uzbek, using 52 binary markers and 19 short tandem repeats on the non-recombinant segment of the Y-chromosome. A total of 204 Afghan samples were investigated along with more than 8,500 samples from surrounding populations important to Afghanistan's history through migrations and conquests, including Iranians, Greeks, Indians, Middle Easterners, East Europeans, and East Asians. Our results suggest that all current Afghans largely share a heritage derived from a common unstructured ancestral population that could have emerged during the Neolithic revolution and the formation of the first farming communities. Our results also indicate that inter-Afghan differentiation started during the Bronze Age, probably driven by the formation of the first civilizations in the region. Later migrations and invasions into the region have been assimilated differentially among the ethnic groups, increasing inter-population genetic differences, and giving the Afghans a unique genetic diversity in Central Asia.
Urban Indians: Hope and Hopelessness.
ERIC Educational Resources Information Center
Fogarty, Mark
1999-01-01
Describes problems faced by Americans Indians and Alaska Natives in U.S. urban centers with large Native populations. Describes social services, health and employment services, job training, and cultural events provided by nonprofit community groups to Native communities in Anchorage, Los Angeles, and New York City. (CDS)
Matsumoto, Toshimi; Okumura, Naohiko; Uenishi, Hirohide; Hayashi, Takeshi; Hamasima, Noriyuki; Awata, Takashi
2012-01-01
We have collected more than 190000 porcine expressed sequence tags (ESTs) from full-length complementary DNA (cDNA) libraries and identified more than 2800 single nucleotide polymorphisms (SNPs). In this study, we tentatively chose 222 SNPs observed in assembled ESTs to study pigs of different breeds; 104 were selected by comparing the cDNA sequences of a Meishan pig and samples of three-way cross pigs (Landrace, Large White, and Duroc: LWD), and 118 were selected from LWD samples. To evaluate the genetic variation between the chosen SNPs from pig breeds, we determined the genotypes for 192 pig samples (11 pig groups) from our DNA reference panel with matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Of the 222 reference SNPs, 186 were successfully genotyped. A neighbor-joining tree showed that the pig groups were classified into two large clusters, namely, Euro-American and East Asian pig populations. F-statistics and the analysis of molecular variance of Euro-American pig groups revealed that approximately 25% of the genetic variations occurred because of intergroup differences. As the F(IS) values were less than the F(ST) values(,) the clustering, based on the Bayesian inference, implied that there was strong genetic differentiation among pig groups and less divergence within the groups in our samples. © 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.
Bosch, F X; Muñoz, N; de Sanjosé, S; Guerrerro, E; Ghaffari, A M; Kaldor, J; Castellsagué, X; Shah, K V; Gaffari, A M
1994-01-01
The risk of cervical cancer for a woman depends largely on the probability of being infected with some specific types of Human Papillomavirus (HPV). In the control groups of four case-control studies in Colombia and Spain we have shown a strong correlation between the number of sexual partners of males and females and HPV DNA prevalence in the genital tract. Our results suggest that the lifetime number of sexual partners in both sexes are surrogates of the probability of HPV infection and, as such, insufficiently explain the geographical variation in the incidence of cervical cancer. It is proposed that the high rates of cervical cancer in Latin America are linked to the largely unknown characteristics of the HPV endemicity in the population and to the absence of widespread screening for cervical neoplasia. Reliable surveys on the HPV prevalences in selected social groups (i.e., young males and prostitutes) as well as in populations in countries at different risk of cervical cancer are required.
Gubili, Chrysoula; Sims, David W.; Veríssimo, Ana; Domenici, Paolo; Ellis, Jim; Grigoriou, Panagiotis; Johnson, Andrew F.; McHugh, Matthew; Neat, Francis; Satta, Andrea; Scarcella, Giuseppe; Serra-Pereira, Bárbara; Soldo, Alen; Genner, Martin J.; Griffiths, Andrew M.
2014-01-01
Elasmobranchs represent important components of marine ecosystems, but they can be vulnerable to overexploitation. This has driven investigations into the population genetic structure of large-bodied pelagic sharks, but relatively little is known of population structure in smaller demersal taxa, which are perhaps more representative of the biodiversity of the group. This study explores spatial population genetic structure of the small-spotted catshark (Scyliorhinus canicula), across European seas. The results show significant genetic differences among most of the Mediterranean sample collections, but no significant structure among Atlantic shelf areas. The data suggest the Mediterranean populations are likely to have persisted in a stable and structured environment during Pleistocene sea-level changes. Conversely, the Northeast Atlantic populations would have experienced major changes in habitat availability during glacial cycles, driving patterns of population reduction and expansion. The data also provide evidence of male-biased dispersal and female philopatry over large spatial scales, implying complex sex-determined differences in the behaviour of elasmobranchs. On the basis of this evidence, we suggest that patterns of connectivity are determined by trends of past habitat stability that provides opportunity for local adaptation in species exhibiting philopatric behaviour, implying that resilience of populations to fisheries and other stressors may differ across the range of species. PMID:26064555
Pometti, Carolina L; Bessega, Cecilia F; Saidman, Beatriz O; Vilardi, Juan C
2014-03-01
Bayesian clustering as implemented in STRUCTURE or GENELAND software is widely used to form genetic groups of populations or individuals. On the other hand, in order to satisfy the need for less computer-intensive approaches, multivariate analyses are specifically devoted to extracting information from large datasets. In this paper, we report the use of a dataset of AFLP markers belonging to 15 sampling sites of Acacia caven for studying the genetic structure and comparing the consistency of three methods: STRUCTURE, GENELAND and DAPC. Of these methods, DAPC was the fastest one and showed accuracy in inferring the K number of populations (K = 12 using the find.clusters option and K = 15 with a priori information of populations). GENELAND in turn, provides information on the area of membership probabilities for individuals or populations in the space, when coordinates are specified (K = 12). STRUCTURE also inferred the number of K populations and the membership probabilities of individuals based on ancestry, presenting the result K = 11 without prior information of populations and K = 15 using the LOCPRIOR option. Finally, in this work all three methods showed high consistency in estimating the population structure, inferring similar numbers of populations and the membership probabilities of individuals to each group, with a high correlation between each other.
Effects of Large Financial Incentives for Long-Term Smoking Cessation: A Randomized Trial.
Etter, Jean-François; Schmid, Felicia
2016-08-23
It is not known whether large financial incentives enhance long-term smoking cessation rates outside clinical or workplace settings. The goal of this study was to test whether large financial incentives improved long-term smoking cessation rates in low-income smokers, in a general population setting, without face-to-face or telephone counseling. This was a 2-arm, parallel group, individually randomized controlled trial, with follow-up after 3, 6, and 18 months. Participants were 805 low-income smokers enrolled between 2011 and 2013 from the general population in Geneva, Switzerland. We randomly assigned participants to receive either booklets plus access to a smoking cessation website (control group, n = 404), or the same intervention plus financial incentives (intervention group, n = 401). Incremental financial rewards, to a maximum of U.S. $1,650, were offered for biochemically verified abstinence at 1, 2, and 3 weeks, and 1, 3, and 6 months. No in-person counseling, telephone counseling, or medications were provided. The primary outcome was continuous abstinence between 6 months (end of incentives) and 18 months (12 months after the incentives ended), verified by expired carbon monoxide and salivary cotinine. We also assessed biochemically verified 7-day abstinence at 3, 6, and 18 months. Rates of continuous abstinence between months 6 and 18 were 9.5% in the incentive group and 3.7% in the control group (p = 0.001). Rates of 7-day abstinence were higher in the incentive group than in the control group at 3 (54.9% vs. 11.9%; p < 0.001), 6 (44.6% vs. 11.1%; p < 0.001), and 18 months (18.2% vs. 11.4%; p = 0.006). In low-income smokers who did not receive face-to-face or telephone smoking cessation counseling, large financial incentives increased long-term rates of smoking cessation. (Financial incentives for smoking cessation in low-income smokers; ISRCTN04019434). Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
ERIC Educational Resources Information Center
Maes, Johanna B.
2012-01-01
The Latina population in the United States is one of the largest of all racial and ethnic groups, and it is expected to grow exponentially within the next forty years. Despite these large numbers of Latinas in the U.S., there is a disparity with this population who are leading our nation's four-year colleges and universities. A reason for…
Revealing the nebular properties and Wolf-Rayet population of IC10 with Gemini/GMOS
NASA Astrophysics Data System (ADS)
Tehrani, Katie; Crowther, Paul A.; Archer, I.
2017-12-01
We present a deep imaging and spectroscopic survey of the Local Group irregular galaxy IC10 using Gemini North and GMOS to unveil its global Wolf-Rayet (WR) population. We obtain a star formation rate (SFR) of 0.045 ± 0.023 M⊙ yr-1, for IC10 from the nebular H α luminosity, which is comparable to the Small Magellanic Cloud. We also present a revised nebular oxygen abundance of log(O/H) + 12 = 8.40 ± 0.04, comparable to the LMC. It has previously been suggested that for IC10 to follow the WR subtype-metallicity dependance seen in other Local Group galaxies, a large WN population awaits discovery. Our search revealed three new WN stars, and six candidates awaiting confirmation, providing little evidence to support this claim. The new global WR star total of 29 stars is consistent with the Large Magellanic Cloud population when scaled to the reduced SFR of IC10. For spectroscopically confirmed WR stars, the WC/WN ratio is lowered to 1.0; however, including all potential candidates, and assuming those unconfirmed to be WN stars, would reduce the ratio to ∼0.7. We attribute the high WC/WN ratio to the high star formation surface density of IC10 relative to the Magellanic Clouds, which enhances the frequency of high-mass stars capable of producing WC stars.
NASA Technical Reports Server (NTRS)
Rivera, Myrna Syamara
1995-01-01
The purpose of this project was to produce a CD-ROM for the Technology Applications Group. The CD was being developed to allow interested people, organizations, or companies to view the technologies available to them that were developed by NASA research. The CD's main audience however, is any small business. The CD will give the small business an opportunity to see what technologies are available in an inexpensive manner. Most companies probably have a CD-ROM drive on their computers but may not have access to the internet. By using only the internet to inform on the technologies, NASA was not considering a large segment of the population. The CD-ROM can now cover that group of the population.
Correction of Population Stratification in Large Multi-Ethnic Association Studies
Serre, David; Montpetit, Alexandre; Paré, Guillaume; Engert, James C.; Yusuf, Salim; Keavney, Bernard; Hudson, Thomas J.; Anand, Sonia
2008-01-01
Background The vast majority of genetic risk factors for complex diseases have, taken individually, a small effect on the end phenotype. Population-based association studies therefore need very large sample sizes to detect significant differences between affected and non-affected individuals. Including thousands of affected individuals in a study requires recruitment in numerous centers, possibly from different geographic regions. Unfortunately such a recruitment strategy is likely to complicate the study design and to generate concerns regarding population stratification. Methodology/Principal Findings We analyzed 9,751 individuals representing three main ethnic groups - Europeans, Arabs and South Asians - that had been enrolled from 154 centers involving 52 countries for a global case/control study of acute myocardial infarction. All individuals were genotyped at 103 candidate genes using 1,536 SNPs selected with a tagging strategy that captures most of the genetic diversity in different populations. We show that relying solely on self-reported ethnicity is not sufficient to exclude population stratification and we present additional methods to identify and correct for stratification. Conclusions/Significance Our results highlight the importance of carefully addressing population stratification and of carefully “cleaning” the sample prior to analyses to obtain stronger signals of association and to avoid spurious results. PMID:18196181
Natural bounds on herbivorous coral reef fishes.
Heenan, Adel; Hoey, Andrew S; Williams, Gareth J; Williams, Ivor D
2016-11-30
Humans are an increasingly dominant driver of Earth's biological communities, but differentiating human impacts from natural drivers of ecosystem state is crucial. Herbivorous fish play a key role in maintaining coral dominance on coral reefs, and are widely affected by human activities, principally fishing. We assess the relative importance of human and biophysical (habitat and oceanographic) drivers on the biomass of five herbivorous functional groups among 33 islands in the central and western Pacific Ocean. Human impacts were clear for some, but not all, herbivore groups. Biomass of browsers, large excavators, and of all herbivores combined declined rapidly with increasing human population density, whereas grazers, scrapers, and detritivores displayed no relationship. Sea-surface temperature had significant but opposing effects on the biomass of detritivores (positive) and browsers (negative). Similarly, the biomass of scrapers, grazers, and detritivores correlated with habitat structural complexity; however, relationships were group specific. Finally, the biomass of browsers and large excavators was related to island geomorphology, both peaking on low-lying islands and atolls. The substantial variability in herbivore populations explained by natural biophysical drivers highlights the need for locally appropriate management targets on coral reefs. © 2016 The Authors.
The active galactic nucleus population in X-ray-selected galaxy groups at 0.5 < Z < 1.1
DOE Office of Scientific and Technical Information (OSTI.GOV)
Oh, Semyeong; Woo, Jong-Hak; Matsuoka, Kenta
2014-07-20
We use Chandra data to study the incidence and properties of active galactic nuclei (AGNs) in 16 intermediate redshift (0.5 < z < 1.1) X-ray-selected galaxy groups in the Chandra Deep Field-South. We measure an AGN fraction of f(L{sub X,H}>10{sup 42};M{sub R}<−20)=8.0{sub −2.3}{sup +3.0}% at z-bar ∼0.74, approximately a factor of two higher than the AGN fraction found for rich clusters at comparable redshift. This extends the trend found at low redshift for groups to have higher AGN fractions than clusters. Our estimate of the AGN fraction is also more than a factor of three higher than that of lowmore » redshift X-ray-selected groups. Using optical spectra from various surveys, we also constrain the properties of emission-line selected AGNs in these groups. In contrast to the large population of X-ray AGNs (N(L{sub X,{sub H}} > 10{sup 41} erg s{sup –1}) = 25), we find only four emission-line AGNs, three of which are also X-ray bright. Furthermore, most of the X-ray AGNs in our groups are optically dull (i.e., lack strong emission-lines), similar to those found in low redshift X-ray groups and clusters of galaxies. This contrasts with the AGN population found in low redshift optically selected groups which are dominated by emission-line AGNs. The differences between the optically and X-ray-selected AGNs populations in groups are consistent with a scenario where most AGNs in the densest environments are currently in a low accretion state.« less
Kaya, Sarp; Korkmaz, E Mahir; Ciplak, Battal
2013-12-17
Psorodonotus (Orthoptera, Tettigoniidae) includes 11 species distributed in Caucasus, Anatolia and Balkans. Although its present taxonomy is problematic, mainly three species groups can be distinguished; (i) The Specularis Group, (ii) The Caucasicus Group and (iii) The Venosus Group. Our recent studies on the genus have revealed presence of two new species in the last species group. Morphology of the species group studied both qualitatively and quantitatively using linear metric data of pronotum, tegmina and hind femur, and geometric data of male cerci and ovipositor. Morphological data were accompanied by data obtained from male calling song. Morphological and song data were produced from six different populations from North and Eastern part of Turkey: (1) Hakkari, (2) Tendürek, (3) Giresun, (4) Artvin, (5) Kars and (6) Ağrı. Qualitative and quantitative morphology, either linear-metric or geometric, suggest last three population as members of the same unit, but each of other three as different units. Song data are also largely in support of the morphological results. Necessary illustrations were provided to document results visually. Following conclusions were made: (1) the Artvin, Kars and Ağrı populations represent typical P. venosus and the Giresun population P. rugulosus, (2) each of the Hakkari and Tendürek populations represents a new species and P. hakkari sp. n. and P. tendurek sp. n. described by comparing with other members of P. venosus group, (3) P. rugulosus, P. hakkari sp. n. and P. tendurek sp. n. differ from P. venosus mainly by the longer cerci (extend to or beyond end of abdomen) and indistinct tubercles on surface of pronotal disc in female. P. rugulosus and P. tendurek sp. n. are also similar by sharing presence of two loud elements in a syllable (one in P. venosus, song of P. hakkari sp. n. is not available). But, similarities in phenotype are in conflict with relationships suggested by genetic data.
Copy number variations and genetic admixtures in three Xinjiang ethnic minority groups
Lou, Haiyi; Li, Shilin; Jin, Wenfei; Fu, Ruiqing; Lu, Dongsheng; Pan, Xinwei; Zhou, Huaigu; Ping, Yuan; Jin, Li; Xu, Shuhua
2015-01-01
Xinjiang is geographically located in central Asia, and it has played an important historical role in connecting eastern Eurasian (EEA) and western Eurasian (WEA) people. However, human population genomic studies in this region have been largely underrepresented, especially with respect to studies of copy number variations (CNVs). Here we constructed the first CNV map of the three major ethnic minority groups, the Uyghur, Kazakh and Kirgiz, using Affymetrix Genome-Wide Human SNP Array 6.0. We systematically compared the properties of CNVs we identified in the three groups with the data from representatives of EEA and WEA. The analyses indicated a typical genetic admixture pattern in all three groups with ancestries from both EEA and WEA. We also identified several CNV regions showing significant deviation of allele frequency from the expected genome-wide distribution, which might be associated with population-specific phenotypes. Our study provides the first genome-wide perspective on the CNVs of three major Xinjiang ethnic minority groups and has implications for both evolutionary and medical studies. PMID:25026903
Kaufman, Bridget P; Guttman-Yassky, Emma; Alexis, Andrew F
2018-04-01
Atopic dermatitis (AD) is a chronic inflammatory skin condition that affects diverse ethnic groups with varying prevalence. Despite a predominance of studies in individuals of European ancestry, AD has been found to occur more frequently in Asian and Black individuals than Whites. Therefore, an understanding of the unique clinical features of AD in diverse ethnic groups, as well as the differences in genetic polymorphisms that influence susceptibility to AD and response to current therapies, is paramount for management of an increasingly diverse patient population. In this article, we review key nuances in the epidemiology, pathophysiology, clinical presentation and treatment of AD in non-White ethnic groups, which are largely underappreciated in the literature. We highlight the need for studies evaluating the tissue molecular and cellular phenotypes of AD in non-White patients, as well as greater inclusion of minority groups in clinical trials, to develop targeted treatments for a multi-ethnic population. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Copy number variations and genetic admixtures in three Xinjiang ethnic minority groups.
Lou, Haiyi; Li, Shilin; Jin, Wenfei; Fu, Ruiqing; Lu, Dongsheng; Pan, Xinwei; Zhou, Huaigu; Ping, Yuan; Jin, Li; Xu, Shuhua
2015-04-01
Xinjiang is geographically located in central Asia, and it has played an important historical role in connecting eastern Eurasian (EEA) and western Eurasian (WEA) people. However, human population genomic studies in this region have been largely underrepresented, especially with respect to studies of copy number variations (CNVs). Here we constructed the first CNV map of the three major ethnic minority groups, the Uyghur, Kazakh and Kirgiz, using Affymetrix Genome-Wide Human SNP Array 6.0. We systematically compared the properties of CNVs we identified in the three groups with the data from representatives of EEA and WEA. The analyses indicated a typical genetic admixture pattern in all three groups with ancestries from both EEA and WEA. We also identified several CNV regions showing significant deviation of allele frequency from the expected genome-wide distribution, which might be associated with population-specific phenotypes. Our study provides the first genome-wide perspective on the CNVs of three major Xinjiang ethnic minority groups and has implications for both evolutionary and medical studies.
Tephritid fruit fly transgenesis and applications
USDA-ARS?s Scientific Manuscript database
Tephritid fruit flies are among the most serious agricultural pests in the world, owing in large part to those species having broad host ranges including hundreds of fruits and vegetables. They are the largest group of insects subject to population control by a biologically-based systems, most notab...
Higher Education in California
ERIC Educational Resources Information Center
Public Policy Institute of California, 2016
2016-01-01
Higher education enhances Californians' lives and contributes to the state's economic growth. But population and education trends suggest that California is facing a large shortfall of college graduates. Addressing this shortfall will require strong gains for groups that have been historically underrepresented in higher education. Substantial…
Adiabatic theory for the population distribution in the evolutionary minority game
NASA Astrophysics Data System (ADS)
Chen, Kan; Wang, Bing-Hong; Yuan, Baosheng
2004-02-01
We study the evolutionary minority game (EMG) using a statistical mechanics approach. We derive a theory for the steady-state population distribution of the agents. The theory is based on an “adiabatic approximation” in which short time fluctuations in the population distribution are integrated out to obtain an effective equation governing the steady-state distribution. We discover the mechanism for the transition from segregation (into opposing groups) to clustering (towards cautious behaviors). The transition is determined by two generic factors: the market impact (of the agents’ own actions) and the short time market inefficiency (arbitrage opportunities) due to fluctuations in the numbers of agents using opposite strategies. A large market impact favors “extreme” players who choose fixed opposite strategies, while large market inefficiency favors cautious players. The transition depends on the number of agents (N) and the effective rate of strategy switching. When N is small, the market impact is relatively large; this favors the extreme behaviors. Frequent strategy switching, on the other hand, leads to a clustering of the cautious agents.
NASA Astrophysics Data System (ADS)
Chang, Chan-Kao; Lin, Hsing-Wen; Ip, Wing-Huen; iPTF Team
2016-10-01
In order to look for kilometer-sized super-fast rotators (large SFRs) and understand the spin-rate distributions of small (i.e. D of several kilometers) asteroids, we have been conducting asteroid rotation period surveys of large sky area using intermediate Palomar Transient Factory (iPTF) since 2014. So far, we have observed 261 deg2 with 20 min cadence, 188 deg2 with 10 min cadence, and 65 deg2 with 5 min cadence. From these surveys, we found that the spin-rate distributions of small asteroids at different locations in the main-belt are very similar. Moreover, the distributions of asteroids with 3 < D < 15 km show number decrease along with increase of spin rate for frequency > 5 rev/day, and that of asteroids with D < 3 km have a significant number drop at frequency = 5 rev/day. However, we only discover two new large SFRs and 24 candidates. Comparing with the ordinary asteroids, the population of large SFR seems to be far less than the whole asteroid population. This might indicate a peculiar group of asteroid for large SFRs.
Wu, Zhu-hua; Shi, Jisen; Xi, Meng-li; Jiang, Fu-xing; Deng, Ming-wen; Dayanandan, Selvadurai
2015-01-01
Lilium regale E.H. Wilson is endemic to a narrow geographic area in the Minjiang River valley in southwestern China, and is considered an important germplasm for breeding commercially valuable lily varieties, due to its vigorous growth, resistance to diseases and tolerance for low moisture. We analyzed the genetic diversity of eight populations of L. regale sampled across the entire natural distribution range of the species using Inter-Simple Sequence Repeat markers. The genetic diversity (expected heterozygosity= 0.3356) was higher than those reported for other narrowly distributed endemic plants. The levels of inbreeding (F st = 0.1897) were low, and most of the genetic variability was found to be within (80.91%) than amongpopulations (19.09%). An indirect estimate of historical levels of gene flow (N m =1.0678) indicated high levels of gene flow among populations. The eight analyzed populations clustered into three genetically distinct groups. Based on these results, we recommend conservation of large populations representing these three genetically distinct groups. PMID:25799495
2010-01-01
For a study of diversity and genetic structuring in Melipona quadrifasciata, 61 colonies were collected in eight locations in the state of Minas Gerais, Brazil. By means of PCR analysis, 119 ISSR bands were obtained, 80 (68%) being polymorphic. He and H B were 0.20 and 0.16, respectively. Two large groups were obtained by the UPGMA method, one formed by individuals from Januária, Urucuia, Rio Vermelho and Caeté and the other by individuals from São João Del Rei, Barbacena, Ressaquinha and Cristiano Otoni. The Φst and θB values were 0.65 and 0.58, respectively, thereby indicating high population structuring. UPGMA grouping did not reveal genetic structuring of M. quadrifasciata in function of the tergite stripe pattern. The significant correlation between dissimilarity values and geographic distances (r = 0.3998; p < 0.05) implies possible geographic isolation. The genetic differentiation in population grouping was probably the result of an interruption in gene flow, brought about by geographic barriers between mutually close geographical locations. Our results also demonstrate the potential of ISSR markers in the study of Melipona quadrifasciata population structuring, possibly applicable to the studies of other bee species. PMID:21637500
Nascimento, Marcília A; Batalha-Filho, Henrique; Waldschmidt, Ana M; Tavares, Mara G; Campos, Lucio A O; Salomão, Tânia M F
2010-04-01
For a study of diversity and genetic structuring in Melipona quadrifasciata, 61 colonies were collected in eight locations in the state of Minas Gerais, Brazil. By means of PCR analysis, 119 ISSR bands were obtained, 80 (68%) being polymorphic. H(e) and H (B) were 0.20 and 0.16, respectively. Two large groups were obtained by the UPGMA method, one formed by individuals from Januária, Urucuia, Rio Vermelho and Caeté and the other by individuals from São João Del Rei, Barbacena, Ressaquinha and Cristiano Otoni. The Φst and θ(B) values were 0.65 and 0.58, respectively, thereby indicating high population structuring. UPGMA grouping did not reveal genetic structuring of M. quadrifasciata in function of the tergite stripe pattern. The significant correlation between dissimilarity values and geographic distances (r = 0.3998; p < 0.05) implies possible geographic isolation. The genetic differentiation in population grouping was probably the result of an interruption in gene flow, brought about by geographic barriers between mutually close geographical locations. Our results also demonstrate the potential of ISSR markers in the study of Melipona quadrifasciata population structuring, possibly applicable to the studies of other bee species.
[Genetic polymorphism of Tulipa gesneriana L. evaluated on the basis of the ISSR marking data].
Kashin, A S; Kritskaya, T A; Schanzer, I A
2016-10-01
Using the method of ISSR analysis, the genetic diversity of 18 natural populations of Tulipa gesneriana L. from the north of the Lower Volga region was examined. The ten ISSR primers used in the study provided identification of 102 PCR fragments, of which 50 were polymorphic (49.0%). According to the proportion of polymorphic markers, two population groups were distinguished: (1) the populations in which the proportion of polymorphic markers ranged from 0.35 to 0.41; (2) the populations in which the proportion of polymorphic markers ranged from 0.64 to 0.85. UPGMA clustering analysis provided subdivision of the sample into two large clusters. The unrooted tree constructed using the Neighbor Joining algorithm had similar topology. The first cluster included slightly variable populations and the second cluster included highly variable populations. The AMOVA analysis showed statistically significant differences (F CT = 0.430; p = 0.000) between the two groups. Local populations are considerably genetically differentiated from each other (F ST = 0.632) and have almost no links via modern gene flow, as evidenced by the results of the Mantel test (r =–0.118; p = 0.819). It is suggested that the degree of genetic similarities and differences between the populations depends on the time and the species dispersal patterns on these territories.
Population delineation of polar bears using satellite collar data
Bethke, R.; Taylor, Mitchell K.; Amstrup, Steven C.; Messier, François
1996-01-01
To produce reliable estimates of the size or vital rates of a given population, it is important that the boundaries of the population under study are clearly defined. This is particularly critical for large, migratory animals where levels of sustainable harvest are based on these estimates, and where small errors may have serious long-term consequences for the population. Once populations are delineated, rates of exchange between adjacent populations can be determined and accounted/corrected for when calculating abundance (e.g., based on mark-recapture data). Using satellite radio-collar locations for polar bears in the western Canadian Arctic, we illustrate one approach to delineating wildlife populations that integrates cluster analysis methods for determining group membership with home range plotting procedures to define spatial utilization. This approach is flexible with respect to the specific procedures used and provides an objective and quantitative basis for defining population boundaries.
Lin, Long-Hui; Hua, Lei; Qu, Yan-Fu; Gao, Jian-Fang; Ji, Xiang
2014-01-01
The vulnerable Chinese cobra (Naja atra) ranges from southeastern China south of the Yangtze River to northern Vietnam and Laos. Large mountain ranges and water bodies may influence the pattern of genetic diversity of this species. We sequenced the mitochondrial DNA control region (1029 bp) using 285 individuals collected from 23 localities across the species' range and obtained 18 sequences unique to Taiwan from GenBank for phylogenetic and population analysis. Two distinct clades were identified, one including haplotypes from the two westernmost localities (Hekou and Miyi) and the other including haplotypes from all sampling sites except Miyi. A strong population structure was found (Φst = 0.76, P<0.0001) with high haplotype diversity (h = 1.00) and low nucleotide diversity (π = 0.0049). The Luoxiao and Nanling Mountains act as historical geographical barriers limiting gene exchange. In the haplotype network there were two “star” clusters. Haplotypes from populations east of the Luoxiao Mountains were represented within one cluster and haplotypes from populations west of the mountain range within the other, with haplotypes from populations south of the Nanling Mountains in between. Lineage sorting between mainland and island populations is incomplete. It remains unknown as to how much adaptive differentiation there is between population groups or within each group. We caution against long-distance transfers within any group, especially when environmental differences are apparent. PMID:25184236
Lin, Long-Hui; Hua, Lei; Qu, Yan-Fu; Gao, Jian-Fang; Ji, Xiang
2014-01-01
The vulnerable Chinese cobra (Naja atra) ranges from southeastern China south of the Yangtze River to northern Vietnam and Laos. Large mountain ranges and water bodies may influence the pattern of genetic diversity of this species. We sequenced the mitochondrial DNA control region (1029 bp) using 285 individuals collected from 23 localities across the species' range and obtained 18 sequences unique to Taiwan from GenBank for phylogenetic and population analysis. Two distinct clades were identified, one including haplotypes from the two westernmost localities (Hekou and Miyi) and the other including haplotypes from all sampling sites except Miyi. A strong population structure was found (Φst = 0.76, P<0.0001) with high haplotype diversity (h = 1.00) and low nucleotide diversity (π = 0.0049). The Luoxiao and Nanling Mountains act as historical geographical barriers limiting gene exchange. In the haplotype network there were two "star" clusters. Haplotypes from populations east of the Luoxiao Mountains were represented within one cluster and haplotypes from populations west of the mountain range within the other, with haplotypes from populations south of the Nanling Mountains in between. Lineage sorting between mainland and island populations is incomplete. It remains unknown as to how much adaptive differentiation there is between population groups or within each group. We caution against long-distance transfers within any group, especially when environmental differences are apparent.
Runstadler, J A; Angles, J M; Pedersen, N C
2006-11-01
The genetic polymorphism at the dog leucocyte antigen (DLA) class II loci DQA1, DQB1 and DRB1 was studied in a large genetically diverse population of feral and wild-type dogs from the large island nations of Indonesia (Bali), Australia and New Guinea (Bali street dog, dingo and New Guinea singing dog, respectively). Sequence-based typing (SBT) of the hypervariable region of DLA-DRB1, -DQA1 and -DQB1 alleles was used to determine genetic diversity. No new DQA1 alleles were recognized among the three dog populations, but five novel DLA-DRB1 and 2 novel DLA-DQB1 allele sequences were detected. Additional unknown alleles were postulated to exist in Bali street dogs, as indicated by the large percentage of individuals (15%-33%) that had indeterminate DRB1, DQA1 and DQB1 alleles by SBT. All three groups of dogs possessed alleles that were relatively uncommon in conventional purebreds. The New Guinea singing dog and dingo shared alleles that were not present in the Bali street dogs. These findings suggested that the dingo was more closely related to indigenous dogs from New Guinea. Feral dog populations, in particular large ones such as that of Bali, show genetic diversity that existed prior to phenotypic selection for breeds originating from their respective regions. This diversity needs to be identified and maintained in the face of progressive Westernization. These populations deserve further study as potential model populations for the evolution of major histocompatibility complex alleles, for the study of canine genetic diversity, for the development of dog breeds and for studies on the comigration of ancestral human and dog populations.
Kopelman, Naama M; Stone, Lewi; Wang, Chaolong; Gefel, Dov; Feldman, Marcus W; Hillel, Jossi; Rosenberg, Noah A
2009-12-08
Genetic studies have often produced conflicting results on the question of whether distant Jewish populations in different geographic locations share greater genetic similarity to each other or instead, to nearby non-Jewish populations. We perform a genome-wide population-genetic study of Jewish populations, analyzing 678 autosomal microsatellite loci in 78 individuals from four Jewish groups together with similar data on 321 individuals from 12 non-Jewish Middle Eastern and European populations. We find that the Jewish populations show a high level of genetic similarity to each other, clustering together in several types of analysis of population structure. Further, Bayesian clustering, neighbor-joining trees, and multidimensional scaling place the Jewish populations as intermediate between the non-Jewish Middle Eastern and European populations. These results support the view that the Jewish populations largely share a common Middle Eastern ancestry and that over their history they have undergone varying degrees of admixture with non-Jewish populations of European descent.
2009-01-01
Background Genetic studies have often produced conflicting results on the question of whether distant Jewish populations in different geographic locations share greater genetic similarity to each other or instead, to nearby non-Jewish populations. We perform a genome-wide population-genetic study of Jewish populations, analyzing 678 autosomal microsatellite loci in 78 individuals from four Jewish groups together with similar data on 321 individuals from 12 non-Jewish Middle Eastern and European populations. Results We find that the Jewish populations show a high level of genetic similarity to each other, clustering together in several types of analysis of population structure. Further, Bayesian clustering, neighbor-joining trees, and multidimensional scaling place the Jewish populations as intermediate between the non-Jewish Middle Eastern and European populations. Conclusion These results support the view that the Jewish populations largely share a common Middle Eastern ancestry and that over their history they have undergone varying degrees of admixture with non-Jewish populations of European descent. PMID:19995433
Cruz, Theresa H; Hess, Julia Meredith; Woelk, Leona; Bear, Samantha
2016-01-01
Sexual violence is of special concern in New Mexico because of the presence of large priority populations in which its prevalence is high. This article describes a 3-component approach to developing a strategic plan to prevent sexual violence in the state that consisted of an advisory group, subject matter experts, and focus groups from geographically and demographically diverse communities. Both common and community-specific themes emerged from the focus groups and were included in the strategic plan. By incorporating community needs and experiences, this approach fosters increased investment in plan implementation.
Restricted Gene Flow among Hospital Subpopulations of Enterococcus faecium
Willems, Rob J. L.; Top, Janetta; van Schaik, Willem; Leavis, Helen; Bonten, Marc; Sirén, Jukka; Hanage, William P.; Corander, Jukka
2012-01-01
ABSTRACT Enterococcus faecium has recently emerged as an important multiresistant nosocomial pathogen. Defining population structure in this species is required to provide insight into the existence, distribution, and dynamics of specific multiresistant or pathogenic lineages in particular environments, like the hospital. Here, we probe the population structure of E. faecium using Bayesian-based population genetic modeling implemented in Bayesian Analysis of Population Structure (BAPS) software. The analysis involved 1,720 isolates belonging to 519 sequence types (STs) (491 for E. faecium and 28 for Enterococcus faecalis). E. faecium isolates grouped into 13 BAPS (sub)groups, but the large majority (80%) of nosocomial isolates clustered in two subgroups (2-1 and 3-3). Phylogenetic and eBURST analysis of BAPS groups 2 and 3 confirmed the existence of three separate hospital lineages (17, 18, and 78), highlighting different evolutionary trajectories for BAPS 2-1 (lineage 78) and 3-3 (lineage 17 and lineage 18) isolates. Phylogenomic analysis of 29 E. faecium isolates showed agreement between BAPS assignment of STs and their relative positions in the phylogenetic tree. Odds ratio calculation confirmed the significant association between hospital isolates with BAPS 3-3 and lineages 17, 18, and 78. Admixture analysis showed a scarce number of recombination events between the different BAPS groups. For the E. faecium hospital population, we propose an evolutionary model in which strains with a high propensity to colonize and infect hospitalized patients arise through horizontal gene transfer. Once adapted to the distinct hospital niche, this subpopulation becomes isolated, and recombination with other populations declines. PMID:22807567
Advances in segmentation modeling for health communication and social marketing campaigns.
Albrecht, T L; Bryant, C
1996-01-01
Large-scale communication campaigns for health promotion and disease prevention involve analysis of audience demographic and psychographic factors for effective message targeting. A variety of segmentation modeling techniques, including tree-based methods such as Chi-squared Automatic Interaction Detection and logistic regression, are used to identify meaningful target groups within a large sample or population (N = 750-1,000+). Such groups are based on statistically significant combinations of factors (e.g., gender, marital status, and personality predispositions). The identification of groups or clusters facilitates message design in order to address the particular needs, attention patterns, and concerns of audience members within each group. We review current segmentation techniques, their contributions to conceptual development, and cost-effective decision making. Examples from a major study in which these strategies were used are provided from the Texas Women, Infants and Children Program's Comprehensive Social Marketing Program.
Borrell, Asunción; Velásquez Vacca, Adriana; Pinela, Ana M.; Kinze, Carl; Lockyer, Christina H.; Vighi, Morgana; Aguilar, Alex
2013-01-01
In pelagic species inhabiting large oceans, genetic differentiation tends to be mild and populations devoid of structure. However, large cetaceans have provided many examples of structuring. Here we investigate whether the sperm whale, a pelagic species with large population sizes and reputedly highly mobile, shows indication of structuring in the eastern North Atlantic, an ocean basin in which a single population is believed to occur. To do so, we examined stable isotope values in sequential growth layer groups of teeth from individuals sampled in Denmark and NW Spain. In each layer we measured oxygen- isotope ratios (δ18O) in the inorganic component (hydroxyapatite), and nitrogen and carbon isotope ratios (δ15N: δ13C) in the organic component (primarily collagenous). We found significant differences between Denmark and NW Spain in δ15N and δ18O values in the layer deposited at age 3, considered to be the one best representing the baseline of the breeding ground, in δ15N, δ13C and δ18O values in the period up to age 20, and in the ontogenetic variation of δ15N and δ18O values. These differences evidence that diet composition, use of habitat and/or migratory destinations are dissimilar between whales from the two regions and suggest that the North Atlantic population of sperm whales is more structured than traditionally accepted. PMID:24324782
de Souza, Bento Sousa; Bichara, Livia Monteiro; Guerreiro, João Farias; Quintão, Cátia Cardoso Abdo; Normando, David
2015-09-01
Indigenous people of the Xingu river present a similar tooth wear pattern, practise exclusive breast-feeding, no pacifier use, and have a large intertribal genetic distance. To revisit the etiology of dental malocclusion features considering these population characteristics. Occlusion and facial features of five semi-isolated Amazon indigenous populations (n=351) were evaluated and compared to previously published data from urban Amazon people. Malocclusion prevalence ranged from 33.8% to 66.7%. Overall this prevalence is lower when compared to urban people mainly regarding posterior crossbite. A high intertribal diversity was found. The Arara-Laranjal village had a population with a normal face profile (98%) and a high rate of normal occlusion (66.2%), while another group from the same ethnicity presented a high prevalence of malocclusion, the highest occurrence of Class III malocclusion (32.6%) and long face (34.8%). In Pat-Krô village the population had the highest prevalence of Class II malocclusion (43.9%), convex profile (38.6%), increased overjet (36.8%) and deep bite (15.8%). Another village's population, from the same ethnicity, had a high frequency of anterior open bite (22.6%) and anterior crossbite (12.9%). The highest occurrence of bi-protrusion was found in the group with the lowest prevalence of dental crowding, and vice versa. Supported by previous genetic studies and given their similar environmental conditions, the high intertribal diversity of occlusal and facial features suggests that genetic factors contribute substantially to the morphology of occlusal and facial features in the indigenous groups studied. The low prevalence of posterior crossbite in the remote indigenous populations compared with urban populations may relate to prolonged breastfeeding and an absence of pacifiers in the indigenous groups. Copyright © 2015 Elsevier Ltd. All rights reserved.
An overview of the population dynamics in Malaysia.
Arshat, H; Tey Nai Peng
1988-06-01
Between 1900 and 1985 the population of Malaysia has increased from 2 million to 16 million. Before World War II most of the growth was due to immigration from China and India; after World War II it was due to natural increase. The crude birth rate appears to be leveling off at about 31.3 and the crude death rate at 5.3. At the current rate of growth the total population will be about 32 million by 2015. The proportion of urban population increased from 27% in 1979 to 34% in 1980. In 1980 83% of the population lived in Peninsular Malaysia (39% of the land area), and 17% lived in Sabah and Sarawak (61% of the land area). Population density ranges from 12 persons per square kilometer in Sarawak to 4521 in the Federal Republic of Kuala Lumpur. The median age of the population is 17.4 years; 40% are under 14, and 3.6% are over 65. In most age groups there are more women than men. The annual growth rate for Malays is higher than for Chinese and Indians, and Malays constituted 55% of the population in 1980. 34% are Chinese and 10% are Indian. Total fertility rate declined from 68/1000 in 1957 to 39/1000 in 1985. Malay fertility (4.8 children) is higher than either Indian (2.9) or Chinese (2.7) Malay fertility has been increasing while that of Indians and Chinese is decreasing due to contraception. Also, among all 3 groups age at marriage has increased. Data from the 1984/85 Malaysian Population and Family Survey show that the differential fertility of the 3 groups is due largely to rural/urban distribution, education, and work patterns. Ideal family size, according to the survey, is 4.8. The National Population and Family Development Program would like to achieve a growth rate of 2%/year, and family planning knowledge has become virtually universal. KAP surveys show that by 1984 contraceptive prevalence was 51%; however 42% of all eligible women were using unreliable methods. In terms of efficient methods, contraceptive prevalence rate was 16% for Malays, 47% for Chinese, and 40% for Indians. Crude death rate has declined to less than 6/1000, largely due to reductions in infant and child mortality. Internal migration to the cities has done much to achieve the objectives of the New Economic Policy to equalize location and vocations of the 3 ethnic groups. Urbanization has slowed since the launching of various land development schemes in the 1960s. The population policy of the government is to achieve a stabilized population of 70 million by year 2070, which means that the fertility level must decrease from 4 to 2 children per woman. By 2000 when the population is expected to reach 22.4 million, the percentages of Malays, Chinese, and Indians is expected to be 61.5%, 28.7%, and 9.8% respectively.
Exposure of the general population to gasoline.
Akland, G G
1993-01-01
This paper summarizes the currently available information on gasoline exposure to the general population. In general, the largest contribution to the time weighted exposures results from exposures while indoors, which are influenced by the outside air, indoor sources, and attached garages. Personal activities, including refueling and commuting, contribute significantly higher exposures but last for only a small portion of the 24-hr time weighted average. The highest exposed group includes those individuals living near large service stations and those with contaminated water supplies. PMID:8020446
Dispersal similarly shapes both population genetics and community patterns in the marine realm
NASA Astrophysics Data System (ADS)
Chust, Guillem; Villarino, Ernesto; Chenuil, Anne; Irigoien, Xabier; Bizsel, Nihayet; Bode, Antonio; Broms, Cecilie; Claus, Simon; Fernández de Puelles, María L.; Fonda-Umani, Serena; Hoarau, Galice; Mazzocchi, Maria G.; Mozetič, Patricija; Vandepitte, Leen; Veríssimo, Helena; Zervoudaki, Soultana; Borja, Angel
2016-06-01
Dispersal plays a key role to connect populations and, if limited, is one of the main processes to maintain and generate regional biodiversity. According to neutral theories of molecular evolution and biodiversity, dispersal limitation of propagules and population stochasticity are integral to shaping both genetic and community structure. We conducted a parallel analysis of biological connectivity at genetic and community levels in marine groups with different dispersal traits. We compiled large data sets of population genetic structure (98 benthic macroinvertebrate and 35 planktonic species) and biogeographic data (2193 benthic macroinvertebrate and 734 planktonic species). We estimated dispersal distances from population genetic data (i.e., FST vs. geographic distance) and from β-diversity at the community level. Dispersal distances ranked the biological groups in the same order at both genetic and community levels, as predicted by organism dispersal ability and seascape connectivity: macrozoobenthic species without dispersing larvae, followed by macrozoobenthic species with dispersing larvae and plankton (phyto- and zooplankton). This ranking order is associated with constraints to the movement of macrozoobenthos within the seabed compared with the pelagic habitat. We showed that dispersal limitation similarly determines the connectivity degree of communities and populations, supporting the predictions of neutral theories in marine biodiversity patterns.
Rural Housing--Need and Non-Response.
ERIC Educational Resources Information Center
Rural Housing Alliance, Washington, DC.
Rural areas contain 25 percent of the nation's population and 60 percent of its substandard housing, a fact primarily attributable to maldistribution of income, geographic distribution, and racial discrimination. Federal intervention in housing has been largely indirect and to the benefit of upper income groups, with tax subsidies accounting for…
Epidemic Varicella Zoster Virus among University Students, India.
Meyers, Josh; Logaraj, Muthunarayanan; Ramraj, Balaji; Narasimhan, Padmanesan; MacIntyre, C Raina
2018-02-01
We investigated a yearlong varicella zoster virus outbreak in a highly susceptible young adult population at a large university in India. Outbreaks of varicella infection among adults are not well described in the literature. Infection control measures and vaccination policy for this age group and setting are needed.
Epidemic Varicella Zoster Virus among University Students, India
Logaraj, Muthunarayanan; Ramraj, Balaji; Narasimhan, Padmanesan; MacIntyre, C. Raina
2018-01-01
We investigated a yearlong varicella zoster virus outbreak in a highly susceptible young adult population at a large university in India. Outbreaks of varicella infection among adults are not well described in the literature. Infection control measures and vaccination policy for this age group and setting are needed. PMID:29350152
Information-Seeking Behaviors of Education Literature User Populations
ERIC Educational Resources Information Center
Wright, Carol S.
2010-01-01
Background/Context: A thorough understanding of the information-seeking behaviors of specific disciplines, as well as distinct user groups within a discipline, is fundamental to the process of development of disciplinary informatics. Significant research has been conducted, largely by library and information science scholars across a range of…
The Gifted Disadvantaged of Israel.
ERIC Educational Resources Information Center
Shmueli, Eliezer
The immigrant population of Israel falls into two large groups: those of European descent and those from North African and Middle Eastern countries. Families from traditionally agrarian Arab countries generally have a lower socioeconomic status, and their children have difficulty competing in school with children from a more urban, industrialized,…
Learner Groups in Massive Open Online Courses
ERIC Educational Resources Information Center
Arora, Skand; Goel, Manav; Sabitha, A. Sai; Mehrotra, Deepti
2017-01-01
The open nature of Massive Open Online Courses (MOOCs) attracts a large number of learners with different backgrounds, skills, motivations, and goals. This has brought a need to understand such heterogeneity in populations of MOOC learners. Categorizing these learners based upon their interaction with the course can help address this need and…
Information Portals: The Next Generation Catalog
ERIC Educational Resources Information Center
Allison, DeeAnn
2010-01-01
Libraries today face an increasing challenge: to provide relevant information to diverse populations with differing needs while competing with Web search engines like Google. In 2009, a large group of libraries, including the University of Nebraska-Lincoln Libraries, joined with Innovative Interfaces as development partners to design a new type of…
When is bigger better? The effects of group size on the evolution of helping behaviours.
Powers, Simon T; Lehmann, Laurent
2017-05-01
Understanding the evolution of sociality in humans and other species requires understanding how selection on social behaviour varies with group size. However, the effects of group size are frequently obscured in the theoretical literature, which often makes assumptions that are at odds with empirical findings. In particular, mechanisms are suggested as supporting large-scale cooperation when they would in fact rapidly become ineffective with increasing group size. Here we review the literature on the evolution of helping behaviours (cooperation and altruism), and frame it using a simple synthetic model that allows us to delineate how the three main components of the selection pressure on helping must vary with increasing group size. The first component is the marginal benefit of helping to group members, which determines both direct fitness benefits to the actor and indirect fitness benefits to recipients. While this is often assumed to be independent of group size, marginal benefits are in practice likely to be maximal at intermediate group sizes for many types of collective action problems, and will eventually become very small in large groups due to the law of decreasing marginal returns. The second component is the response of social partners on the past play of an actor, which underlies conditional behaviour under repeated social interactions. We argue that under realistic conditions on the transmission of information in a population, this response on past play decreases rapidly with increasing group size so that reciprocity alone (whether direct, indirect, or generalised) cannot sustain cooperation in very large groups. The final component is the relatedness between actor and recipient, which, according to the rules of inheritance, again decreases rapidly with increasing group size. These results explain why helping behaviours in very large social groups are limited to cases where the number of reproducing individuals is small, as in social insects, or where there are social institutions that can promote (possibly through sanctioning) large-scale cooperation, as in human societies. Finally, we discuss how individually devised institutions can foster the transition from small-scale to large-scale cooperative groups in human evolution. © 2016 Cambridge Philosophical Society.
Sheff, Alex; Park, Elyse R; Neagle, Mary; Oreskovic, Nicolas M
2017-07-25
Care coordination programs for high-risk, high-cost patients are a critical component of population health management. These programs aim to improve outcomes and reduce costs and have proliferated over the last decade. Some programs, originally designed for Medicare patients, are now transitioning to also serve Medicaid populations. However, there are still gaps in the understanding of what barriers to care Medicaid patients experience, and what supports will be most effective for providing them care coordination. We conducted two focus groups (n = 13) and thematic analyses to assess the outcomes drivers and programmatic preferences of Medicaid patients enrolled in a high-risk care coordination program at a major academic medical center in Boston, MA. Two focus groups identified areas where care coordination efforts were having a positive impact, as well as areas of unmet needs among the Medicaid population. Six themes emerged from the focus groups that clustered in three groupings: In the first group (1) enrollment in an existing medical care coordination programs, and (2) provider communication largely presented as positive accounts of assistance, and good relationships with providers, though participants also pointed to areas where these efforts fell short. In the second group (3) trauma histories, (4) mental health challenges, and (5) executive function difficulties all presented challenges faced by high-risk Medicaid patients that would likely require redress through additional programmatic supports. Finally, in the third group, (6) peer-to-peer support tendencies among patients suggested an untapped resource for care coordination programs. Programs aimed at high-risk Medicaid patients will want to consider programmatic adjustments to attend to patient needs in five areas: (1) provider connection/care coordination, (2) trauma, (3) mental health, (4) executive function/paperwork and coaching support, and (5) peer-to-peer support.
Lau, Cathrine J; Pisinger, Charlotta; Husemoen, Lise Lotte N; Jacobsen, Rikke Kart; Linneberg, Allan; Jørgensen, Torben; Glümer, Charlotte
2016-10-01
We aimed to examine the effect of a large population-based multifactorial screening and lifestyle intervention programme on 10-year incidence of diabetes. In a randomised trial of the general Danish population initiated in 1999-2001 59,616 men and women aged 30-60years were assigned to a five year screening and lifestyle counselling programme (n=11,629) or control group (n=47,987) and followed for ten years in nationwide registers. Intention to treat was applied and risk of diabetes was modeled by Cox regression and expressed as hazard ratios (HRs). We found that 1692 individuals had diabetes at baseline. Among 57,924 individuals without diabetes at baseline, 1267 emigrated, 2593 died and 3369 (Intervention group=684, Control group=2685) developed diabetes. We saw no significant difference in diabetes incidence between the groups after 10-year follow-up (Grey's test: p=0.22). In the first year of follow-up, incidence of diabetes was significantly higher in the intervention group than the control group (HR=1.68, 95%CI 1.29 to 2.29). We observed no difference in incidence of diabetes between the groups in the follow-up intervals from 1 to 6years or after 6-10years (HR=0.94, 0.83 to 1.06; HR=1.03, 0.91 to 1.17). Inviting the general population to participate in a repeated screening and lifestyle counselling programme over five years did not result in lower incidence of diabetes after 10years of follow-up. As expected, significantly more individuals were diagnosed with diabetes in the intervention group during the first year, but this was not followed by a decrease in the following years. Clinical trials NCT00289237. Copyright © 2016 Elsevier Inc. All rights reserved.
New insights into the origin and the genetic status of the Balkan donkey from Serbia.
Stanisic, L J; Aleksic, J M; Dimitrijevic, V; Simeunovic, P; Glavinic, U; Stevanovic, J; Stanimirovic, Z
2017-10-01
The Balkan donkey (Equus asinus L.) is commonly regarded as a large-sized, unselected, unstructured and traditionally managed donkey breed. We assessed the current genetic status of the three largest E. asinus populations in the central Balkans (Serbia) by analysing the variability of nuclear microsatellites and the mitochondrial (mtDNA) control region of 77 and 49 individuals respectively. We further analysed our mtDNA dataset along with 209 published mtDNA sequences of ancient and modern individuals from 19 European and African populations to provide new insights into the origin and the history of the Balkan donkey. Serbian donkey populations are highly genetically diverse at both the nuclear and mtDNA levels despite severe population decline. Traditional Balkan donkeys in Serbia are rather heterogeneous; we found two groups of individuals with similar phenotypic features, somewhat distinct nuclear backgrounds and different proportions of mtDNA haplotypes belonging to matrilineal Clades 1 and 2. Another group, characterized by larger body size, different coat colour, distinct nuclear gene pool and predominantly Clade 2 haplotypes, was delineated as the Banat donkey breed. The maternal landscape of the large Balkan donkey population is highly heterogeneous and more complex than previously thought. Given the two independent domestication events in donkeys, multiple waves of introductions into the Balkans from Greece are hypothesized. Clade 2 donkeys probably appeared in Greece prior to those belonging to Clade 1, whereas expansion and diversification of Clade 1 donkeys within the Balkans predated that of Clade 2 donkeys. © 2017 Stichting International Foundation for Animal Genetics.
Bertrand, J A M; Delahaie, B; Bourgeois, Y X C; Duval, T; García-Jiménez, R; Cornuault, J; Pujol, B; Thébaud, C; Milá, B
2016-04-01
Adaptation to local environmental conditions and the range dynamics of populations can influence evolutionary divergence along environmental gradients. Thus, it is important to investigate patterns of both phenotypic and genetic variations among populations to reveal the respective roles of these two types of factors in driving population differentiation. Here, we test for evidence of phenotypic and genetic structure across populations of a passerine bird (Zosterops borbonicus) distributed along a steep elevational gradient on the island of Réunion. Using 11 microsatellite loci screened in 401 individuals from 18 localities distributed along the gradient, we found that genetic differentiation occurred at two spatial levels: (i) between two main population groups corresponding to highland and lowland areas, respectively, and (ii) within each of these two groups. In contrast, several morphological traits varied gradually along the gradient. Comparison of neutral genetic differentiation (FST ) and phenotypic differentiation (PST ) showed that PST largely exceeds FST at several morphological traits, which is consistent with a role for local adaptation in driving morphological divergence along the gradient. Overall, our results revealed an area of secondary contact midway up the gradient between two major, cryptic, population groups likely diverged in allopatry. Remarkably, local adaptation has shaped phenotypic differentiation irrespective of population history, resulting in different patterns of variation along the elevational gradient. Our findings underscore the importance of understanding both historical and selective factors when trying to explain variation along environmental gradients. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.
Teaching population health as a basic science at Harvard Medical School.
Finkelstein, Jonathan A; McMahon, Graham T; Peters, Antoinette; Cadigan, Rebecca; Biddinger, Paul; Simon, Steven R
2008-04-01
In 2006-2007, Harvard Medical School implemented a new, required course for first-year medical and dental students entitled Clinical Epidemiology and Population Health. Conceived of as a "basic science" course, its primary goal is to allow students to develop an understanding of caring for individuals and promoting the health of populations as a continuum of strategies, all requiring the engagement of physicians. In the course's first iteration, topical content accessible to first-year students was selected to exemplify physicians' roles in addressing current threats to population health. Methodological areas included domains of clinical epidemiology, decision sciences, population-level prevention and health promotion, physicians' roles in the public health system, and population-level surveillance and intervention strategies. Large-group settings were selectively used to frame the relevance of each topic, and conceptual learning of statistical and epidemiologic methods occurred in conference groups of 24 students. Finally, tutorials of eight students and one or two faculty were used for critical reading of published studies, review of problem sets, and group discussion of population health issues. To help students appreciate the structure and function of the public health system and physicians' role in public health emergencies, the course included a role-playing exercise simulating response to an influenza pandemic. The first iteration of the course was well received, and assessment of students suggested mastery of basic skills. Preclinical courses represent a progressive step in developing a workforce of physicians who embrace their responsibility to improve the health of the population as a whole, as well as the health of the patient in front of them.
Wood, Jacquelyn L A; Yates, Matthew C; Fraser, Dylan J
2016-06-01
It is widely thought that small populations should have less additive genetic variance and respond less efficiently to natural selection than large populations. Across taxa, we meta-analytically quantified the relationship between adult census population size (N) and additive genetic variance (proxy: h (2)) and found no reduction in h (2) with decreasing N; surveyed populations ranged from four to one million individuals (1735 h (2) estimates, 146 populations, 83 species). In terms of adaptation, ecological conditions may systematically differ between populations of varying N; the magnitude of selection these populations experience may therefore also differ. We thus also meta-analytically tested whether selection changes with N and found little evidence for systematic differences in the strength, direction or form of selection with N across different trait types and taxa (7344 selection estimates, 172 populations, 80 species). Collectively, our results (i) indirectly suggest that genetic drift neither overwhelms selection more in small than in large natural populations, nor weakens adaptive potential/h (2) in small populations, and (ii) imply that natural populations of varying sizes experience a variety of environmental conditions, without consistently differing habitat quality at small N. However, we caution that the data are currently insufficient to determine whether some small populations may retain adaptive potential definitively. Further study is required into (i) selection and genetic variation in completely isolated populations of known N, under-represented taxonomic groups, and nongeneralist species, (ii) adaptive potential using multidimensional approaches and (iii) the nature of selective pressures for specific traits.
Cayres-Vallinoto, Izaura M. V.; Vallinoto, Antonio C. R.; Azevedo, Vânia N.; Machado, Luis Fernando Almeida; Ishak, Marluísa de Oliveira Guimarães; Ishak, Ricardo
2012-01-01
JC polyomavirus (JCV) is a member of the Polyomaviridae family. It presents a tropism to kidney cells, and the infection occurs in a variety of human population groups of different ethnic background. The present study investigated the prevalence of JCV infection among human populations from the Brazilian Amazon region, and describes the molecular and phylogenetic features of the virus. Urine samples from two urban groups of Belém (healthy subjects), one Brazilian Afro-descendant “quilombo” from the Rio Trombetas region, and native Indians from the Wai-Wai, Urubu-Kaapor, Tembé, Assurini, Arara do Laranjal, Aukre, Parakanã, Surui and Munduruku villages were investigated for the presence of the virus by amplifying VP1 (230 bp) and IG (610 bp) regions using a polymerase chain reaction. Nucleotide sequences (440 nucleotides, nt) from 48 samples were submitted to phylogenetic analysis. The results confirmed the occurrence of types A (subtype EU), B (subtypes Af-2, African and MY, Asiatic) and C (subtype Af-1) among healthy subjects; type B, subtypes Af-2 and MY, among the Afro-Brazilians; and type B, subtype MY, within the Surui Indians. An unexpected result was the detection of another polyomavirus, the BKV, among Afro-descendants. The present study shows, for the first time, the occurrence of JC and BK polyomaviruses infecting humans from the Brazilian Amazon region. The results show a large genetic variability of strains circulating in the region, infecting a large group of individuals. The presence of European, Asiatic and African subtypes associated to the ethnic origin of the population samples investigated herein, highlights the idea that JCV is a fairly good marker for studying the early migration of human populations, reflecting their early and late history. Furthermore, the identification of the specific mutations associated to the virus subtypes, suggests that these mutations have occurred after the entrance of the virus in the Amazon region of Brazil. PMID:23071582
Population-Adjusted Street Connectivity, Urbanicity and Risk of Obesity in the U.S
Wang, Fahui; Wen, Ming; Xu, Yanqing
2013-01-01
Street connectivity, defined as the number of (3-way or more) intersections per area unit, is an important index of built environments as a proxy for walkability in a neighborhood. This paper examines its geographic variations across the rural-urban continuum (urbanicity), major racial-ethnic groups and various poverty levels. The population-adjusted street connectivity index is proposed as a better measure than the regular index for a large area such as county due to likely concentration of population in limited space within the large area. Based on the data from the Behavioral Risk Factor Surveillance System (BRFSS), this paper uses multilevel modeling to analyze its association with physical activity and obesity while controlling for various individual and county-level variables. Analysis of data subsets indicates that the influences of individual and county-level variables on obesity risk vary across areas of different urbanization levels. The positive influence of street connectivity on obesity control is limited to the more but not the mostly urbanized areas. This demonstrates the value of obesogenic environment research in different geographic settings, helps us reconcile and synthesize some seemingly contradictory results reported in different studies, and also promotes that effective policies need to be highly sensitive to the diversity of demographic groups and geographically adaptable. PMID:23667278
Edelmann, Lisa; Wasserstein, Melissa P.; Kornreich, Ruth; Sansaricq, Claude; Snyderman, Selma E.; Diaz, George A.
2001-01-01
Maple syrup urine disease (MSUD) is a rare, autosomal recessive disorder of branched-chain amino acid metabolism. We noted that a large proportion (10 of 34) of families with MSUD that were followed in our clinic were of Ashkenazi Jewish (AJ) descent, leading us to search for a common mutation within this group. On the basis of genotyping data suggestive of a conserved haplotype at tightly linked markers on chromosome 6q14, the BCKDHB gene encoding the E1β subunit was sequenced. Three novel mutations were identified in seven unrelated AJ patients with MSUD. The locations of the affected residues in the crystal structure of the E1β subunit suggested possible mechanisms for the deleterious effects of these mutations. Large-scale population screening of AJ individuals for R183P, the mutation present in six of seven patients, revealed that the carrier frequency of the mutant allele was ∼1/113; the patient not carrying R183P had a previously described homozygous mutation in the gene encoding the E2 subunit. These findings suggested that a limited number of mutations might underlie MSUD in the AJ population, potentially facilitating prenatal diagnosis and carrier detection of MSUD in this group. PMID:11509994
Edelmann, L; Wasserstein, M P; Kornreich, R; Sansaricq, C; Snyderman, S E; Diaz, G A
2001-10-01
Maple syrup urine disease (MSUD) is a rare, autosomal recessive disorder of branched-chain amino acid metabolism. We noted that a large proportion (10 of 34) of families with MSUD that were followed in our clinic were of Ashkenazi Jewish (AJ) descent, leading us to search for a common mutation within this group. On the basis of genotyping data suggestive of a conserved haplotype at tightly linked markers on chromosome 6q14, the BCKDHB gene encoding the E1beta subunit was sequenced. Three novel mutations were identified in seven unrelated AJ patients with MSUD. The locations of the affected residues in the crystal structure of the E1beta subunit suggested possible mechanisms for the deleterious effects of these mutations. Large-scale population screening of AJ individuals for R183P, the mutation present in six of seven patients, revealed that the carrier frequency of the mutant allele was approximately 1/113; the patient not carrying R183P had a previously described homozygous mutation in the gene encoding the E2 subunit. These findings suggested that a limited number of mutations might underlie MSUD in the AJ population, potentially facilitating prenatal diagnosis and carrier detection of MSUD in this group.
Population genetic structure of rare and endangered plants using molecular markers
Raji, Jennifer; Atkinson, Carter T.
2013-01-01
This study was initiated to assess the levels of genetic diversity and differentiation in the remaining populations of Phyllostegia stachyoides and Melicope zahlbruckneri in Hawai`i Volcanoes National Park and determine the extent of gene flow to identify genetically distinct individuals or groups for conservation purposes. Thirty-six Amplified Fragment Length Polymorphic (AFLP) primer combinations generated a total of 3,242 polymorphic deoxyribonucleic acid (DNA) fragments in the P. stachyoides population with a percentage of polymorphic bands (PPB) ranging from 39.3 to 65.7% and 2,780 for the M. zahlbruckneri population with a PPB of 18.8 to 64.6%. Population differentiation (Fst) of AFLP loci between subpopulations of P. stachyoides was low (0.043) across populations. Analysis of molecular variance of P. stachyoides showed that 4% of the observed genetic differentiation occurred between populations in different kīpuka and 96% when individuals were pooled from all kīpuka. Moderate genetic diversity was detected within the M. zahlbruckneri population. Bayesian and multivariate analyses both classified the P. stachyoides and M. zahlbruckneri populations into genetic groups with considerable sub-structuring detected in the P. stachyoides population. The proportion of genetic differentiation among populations explained by geographical distance was estimated by Mantel tests. No spatial correlation was found between genetic and geographic distances in both populations. Finally, a moderate but significant gene flow that could be attributed to insect or bird-mediated dispersal of pollen across the different kīpuka was observed. The results of this study highlight the utility of a multi-allelic DNA-based marker in screening a large number of polymorphic loci in small and closely related endangered populations and revealed the presence of genetically unique groups of individuals in both M. zahlbruckneri and P. stachyoides populations. Based on these findings, approaches that can assist conservation efforts of these species are proposed.
LACEwING: A New Moving Group Analysis Code
DOE Office of Scientific and Technical Information (OSTI.GOV)
Riedel, Adric R.; Blunt, Sarah C.; Faherty, Jacqueline K.
We present a new nearby young moving group (NYMG) kinematic membership analysis code, LocAting Constituent mEmbers In Nearby Groups (LACEwING), a new Catalog of Suspected Nearby Young Stars, a new list of bona fide members of moving groups, and a kinematic traceback code. LACEwING is a convergence-style algorithm with carefully vetted membership statistics based on a large numerical simulation of the Solar Neighborhood. Given spatial and kinematic information on stars, LACEwING calculates membership probabilities in 13 NYMGs and three open clusters within 100 pc. In addition to describing the inputs, methods, and products of the code, we provide comparisons ofmore » LACEwING to other popular kinematic moving group membership identification codes. As a proof of concept, we use LACEwING to reconsider the membership of 930 stellar systems in the Solar Neighborhood (within 100 pc) that have reported measurable lithium equivalent widths. We quantify the evidence in support of a population of young stars not attached to any NYMGs, which is a possible sign of new as-yet-undiscovered groups or of a field population of young stars.« less
Do wealth disparities contribute to health disparities within racial/ethnic groups?
Pollack, Craig Evan; Cubbin, Catherine; Sania, Ayesha; Hayward, Mark; Vallone, Donna; Flaherty, Brian; Braveman, Paula A
2013-05-01
Though wide disparities in wealth have been documented across racial/ethnic groups, it is largely unknown whether differences in wealth are associated with health disparities within racial/ethnic groups. Data from the Survey of Consumer Finances (2004, ages 25-64) and the Health and Retirement Survey (2004, ages 50+), containing a wide range of assets and debts variables, were used to calculate net worth (a standard measure of wealth). Among non-Hispanic black, Hispanic and non-Hispanic white populations, we tested whether wealth was associated with self-reported poor/fair health status after accounting for income and education. Except among the younger Hispanic population, net worth was significantly associated with poor/fair health status within each racial/ethnic group in both data sets. Adding net worth attenuated the association between education and poor/fair health (in all racial/ethnic groups) and between income and poor/fair health (except among older Hispanics). The results add to the literature indicating the importance of including measures of wealth in health research for what they may reveal about disparities not only between but also within different racial/ethnic groups.
Crawford, Gemma; Burns, Sharyn K; Chih, Hui Jun; Hunt, Kristen; Tilley, P J Matt; Hallett, Jonathan; Coleman, Kim; Smith, Sonya
2015-02-19
The impact of mental health problems and disorders in Australia is significant. Mental health problems often start early and disproportionately affect young people. Poor adolescent mental health can predict educational achievement at school and educational and occupational attainment in adulthood. Many young people attend higher education and have been found to experience a range of mental health issues. The university setting therefore presents a unique opportunity to trial interventions to reduce the burden of mental health problems. Mental Health First Aid (MHFA) aims to train participants to recognise symptoms of mental health problems and assist an individual who may be experiencing a mental health crisis. Training nursing students in MHFA may increase mental health literacy and decrease stigma in the student population. This paper presents a protocol for a trial to examine the efficacy of the MHFA training for students studying nursing at a large university in Perth, Western Australia. This randomised controlled trial will follow the CONSORT guidelines. Participants will be randomly allocated to the intervention group (receiving a MHFA training course comprising two face to face 6.5 hour sessions run over two days during the intervention period) or a waitlisted control group (not receiving MHFA training during the study). The source population will be undergraduate nursing students at a large university located in Perth, Western Australia. Efficacy of the MHFA training will be assessed by following the intention-to-treat principle and repeated measures analysis. Given the known burden of mental health disorders among student populations, it is important universities consider effective strategies to address mental health issues. Providing MHFA training to students offers the advantage of increasing mental health literacy, among the student population. Further, students trained in MHFA are likely to utilise these skills in the broader community, when they graduate to the workforce. It is anticipated that this trial will demonstrate the scalability of MHFA in the university environment for pre-service nurses and that implementation of MHFA courses, with comprehensive evaluation, could yield positive improvements in the mental health literacy amongst this target group as well as other tertiary student groups. Australian New Zealand Clinical Trials Registry ACTRN12614000861651 .
Mapping human genetic diversity in Asia.
Abdulla, Mahmood Ameen; Ahmed, Ikhlak; Assawamakin, Anunchai; Bhak, Jong; Brahmachari, Samir K; Calacal, Gayvelline C; Chaurasia, Amit; Chen, Chien-Hsiun; Chen, Jieming; Chen, Yuan-Tsong; Chu, Jiayou; Cutiongco-de la Paz, Eva Maria C; De Ungria, Maria Corazon A; Delfin, Frederick C; Edo, Juli; Fuchareon, Suthat; Ghang, Ho; Gojobori, Takashi; Han, Junsong; Ho, Sheng-Feng; Hoh, Boon Peng; Huang, Wei; Inoko, Hidetoshi; Jha, Pankaj; Jinam, Timothy A; Jin, Li; Jung, Jongsun; Kangwanpong, Daoroong; Kampuansai, Jatupol; Kennedy, Giulia C; Khurana, Preeti; Kim, Hyung-Lae; Kim, Kwangjoong; Kim, Sangsoo; Kim, Woo-Yeon; Kimm, Kuchan; Kimura, Ryosuke; Koike, Tomohiro; Kulawonganunchai, Supasak; Kumar, Vikrant; Lai, Poh San; Lee, Jong-Young; Lee, Sunghoon; Liu, Edison T; Majumder, Partha P; Mandapati, Kiran Kumar; Marzuki, Sangkot; Mitchell, Wayne; Mukerji, Mitali; Naritomi, Kenji; Ngamphiw, Chumpol; Niikawa, Norio; Nishida, Nao; Oh, Bermseok; Oh, Sangho; Ohashi, Jun; Oka, Akira; Ong, Rick; Padilla, Carmencita D; Palittapongarnpim, Prasit; Perdigon, Henry B; Phipps, Maude Elvira; Png, Eileen; Sakaki, Yoshiyuki; Salvador, Jazelyn M; Sandraling, Yuliana; Scaria, Vinod; Seielstad, Mark; Sidek, Mohd Ros; Sinha, Amit; Srikummool, Metawee; Sudoyo, Herawati; Sugano, Sumio; Suryadi, Helena; Suzuki, Yoshiyuki; Tabbada, Kristina A; Tan, Adrian; Tokunaga, Katsushi; Tongsima, Sissades; Villamor, Lilian P; Wang, Eric; Wang, Ying; Wang, Haifeng; Wu, Jer-Yuarn; Xiao, Huasheng; Xu, Shuhua; Yang, Jin Ok; Shugart, Yin Yao; Yoo, Hyang-Sook; Yuan, Wentao; Zhao, Guoping; Zilfalil, Bin Alwi
2009-12-11
Asia harbors substantial cultural and linguistic diversity, but the geographic structure of genetic variation across the continent remains enigmatic. Here we report a large-scale survey of autosomal variation from a broad geographic sample of Asian human populations. Our results show that genetic ancestry is strongly correlated with linguistic affiliations as well as geography. Most populations show relatedness within ethnic/linguistic groups, despite prevalent gene flow among populations. More than 90% of East Asian (EA) haplotypes could be found in either Southeast Asian (SEA) or Central-South Asian (CSA) populations and show clinal structure with haplotype diversity decreasing from south to north. Furthermore, 50% of EA haplotypes were found in SEA only and 5% were found in CSA only, indicating that SEA was a major geographic source of EA populations.
Clinical prediction and the idea of a population.
Armstrong, David
2017-04-01
Using an analysis of the British Medical Journal over the past 170 years, this article describes how changes in the idea of a population have informed new technologies of medical prediction. These approaches have largely replaced older ideas of clinical prognosis based on understanding the natural histories of the underlying pathologies. The 19 th -century idea of a population, which provided a denominator for medical events such as births and deaths, was constrained in its predictive power by its method of enumerating individual bodies. During the 20 th century, populations were increasingly constructed through inferential techniques based on patient groups and samples seen to possess variable characteristics. The emergence of these new virtual populations created the conditions for the emergence of predictive algorithms that are used to foretell our medical futures.
Werner-Wasik, M; Scott, C; Cox, J D; Sause, W T; Byhardt, R W; Asbell, S; Russell, A; Komaki, R; Lee, J S
2000-12-01
Survival of patients with locally-advanced non-small-cell lung cancer (LA-NSCLC) is predicted by the stage of the disease and other characteristics. This analysis was undertaken to identify these characteristics in a large cooperative group patient population, as well as to define subgroups of the population with differing outcomes. Analysis included 1,999 patients treated in 9 RTOG trials between 1983 and 1994 with thoracic irradiation (RT) with (n = 355) or without chemotherapy (CT). In univariate analysis, the following characteristics were significantly associated with an improved survival: use of CT, CT delivered without major deviation, abnormal pulmonary function tests, normal hemoglobin, protein, LDH and BUN, presence of dyspnea, hemoptysis, cough or hoarseness, uninvolved lymph nodes, T1 or T2 stage, no malignant pleural effusion (PE), weight loss of < 8%, Karnofsky performance status (KPS) of at least 90, adenocarcinoma histology, female gender, and age less than 70 years. Recursive partitioning analysis (RPA) was subsequently applied to identify 5 patient subgroups with significantly different median survival times (MST): Group I, KPS of > or = 90, who received chemotherapy (MST 16.2 months); Group II, KPS of > or = 90, who received no CT, but had no PE (MST 11.9 months); Group III, KPS < 90, younger than 70 years, with non-large cell histology (MST 9.6 months); Group IV, KPS > or = 90, but with PE, or KPS < 90, younger than 70 years, and with large cell histology, or older than 70 years, but without PE (MST 5.6-6.4 months); Group V, older than 70, with PE (MST 2.9 months). Cisplatinum-based CT improves survival, for excellent prognosis of LA-NSCLC patients, over RT alone. The presence of a malignant pleural effusion is a major negative prognostic factor for survival. The identification of RPA prognostic groups among patients with LA-NSCLC provides prognostic information and may serve as a basis of stratification in future trials.
Makarova, Nataliya; Brand, Tilman; Brünings-Kuppe, Claudia; Pohlabeln, Hermann; Luttmann, Sabine
2016-03-21
The main objective of this study was to explore differences in mortality patterns among two large immigrant groups in Germany: one from Turkey and the other from the former Soviet Union (FSU). To this end, we investigated indicators of premature mortality. This study was conducted as a retrospective population-based study based on mortality register linkage. Using mortality data for the period 2004-2010, we calculated age-standardised death rates (SDR) and standardised mortality ratios (SMR) for premature deaths (
A mechanism that maintains alternative life histories in a loggerhead sea turtle population.
Hatase, Hideo; Omuta, Kazuyoshi; Tsukamoto, Katsumi
2013-11-01
Intrapopulation variation in habitat use is commonly seen among mobile animals, yet the mechanisms maintaining it have rarely been researched among untrackable species. To investigate how alternative life histories are maintained in a population of the loggerhead sea turtle (Caretta caretta), cumulative reproductive output was evaluated and compared between small planktivores inhabiting oceanic areas (with water depths > 200 m) and large benthivores inhabiting neritic areas (depths < 200 m) that sympatrically nested at Yakushima Island, Japan, from 1986 to 2011. In total, 362 nesting females sampled in three different years were classified into the two foraging groups based on stable isotope ratios in egg yolks. There were significant differences between the two foraging groups in most recorded life history parameters (clutch size, clutch frequency, breeding frequency, and remigration intervals), with the exception of emergence success. We did not find evidence of life history trade-offs, nor age-related changes in fecundity. Over the 26-year study period, we calculated a 2.4-fold greater reproductive output for neritic foragers than for oceanic ones, accounting for breeding and clutch frequency. Temporal consistencies in stable isotope ratios and remigration intervals within females suggested that female Japanese loggerheads show fidelity to respective foraging habitats throughout the adult stage. The large difference in productivity between the two groups was unlikely to be offset by the difference in survival during the period from aboveground emergence to first reproduction, suggesting that oceanic foragers have a lower level of fitness than neritic ones. Together with an absence of genetic structure between foraging groups, we infer that alternative life histories in a loggerhead turtle population are maintained by a conditional strategy.
Towards a realistic population of simulated galaxy groups and clusters
NASA Astrophysics Data System (ADS)
Le Brun, Amandine M. C.; McCarthy, Ian G.; Schaye, Joop; Ponman, Trevor J.
2014-06-01
We present a new suite of large-volume cosmological hydrodynamical simulations called cosmo-OWLS. They form an extension to the OverWhelmingly Large Simulations (OWLS) project, and have been designed to help improve our understanding of cluster astrophysics and non-linear structure formation, which are now the limiting systematic errors when using clusters as cosmological probes. Starting from identical initial conditions in either the Planck or WMAP7 cosmologies, we systematically vary the most important `sub-grid' physics, including feedback from supernovae and active galactic nuclei (AGN). We compare the properties of the simulated galaxy groups and clusters to a wide range of observational data, such as X-ray luminosity and temperature, gas mass fractions, entropy and density profiles, Sunyaev-Zel'dovich flux, I-band mass-to-light ratio, dominance of the brightest cluster galaxy and central massive black hole (BH) masses, by producing synthetic observations and mimicking observational analysis techniques. These comparisons demonstrate that some AGN feedback models can produce a realistic population of galaxy groups and clusters, broadly reproducing both the median trend and, for the first time, the scatter in physical properties over approximately two decades in mass (1013 M⊙ ≲ M500 ≲ 1015 M⊙) and 1.5 decades in radius (0.05 ≲ r/r500 ≲ 1.5). However, in other models, the AGN feedback is too violent (even though they reproduce the observed BH scaling relations), implying that calibration of the models is required. The production of realistic populations of simulated groups and clusters, as well as models that bracket the observations, opens the door to the creation of synthetic surveys for assisting the astrophysical and cosmological interpretation of cluster surveys, as well as quantifying the impact of selection effects.
Vriz, Olga; Aboyans, Victor; Minisini, Rosalba; Magne, Julien; Bertin, Nicole; Pirisi, Mario; Bossone, Eduardo
2017-07-01
Arterial stiffness can predict cardiovascular events, and the aim of this study was to produce age- and sex-specific reference values for echo-tracking carotid stiffness in healthy subjects. A total of 900 subjects (500 males, mean age 45.8±19 years) were enrolled. Common carotid artery stiffness and compliance, using a high-definition echo-tracking ultrasound system, were evaluated. To compare stiffness parameters across the different age groups, individual scores were transformed into T-scores, indicating how many standard deviation (s.d.) units an individual's score was above or below the mean that was observed in the group including same-sex individuals aged 36 to 44 years. Carotid stiffness was similar among genders, except compliance, which was lower in women (P<0.0001). These characteristics were also maintained when the studied population was divided into seven age groups. Stiffness parameters increased significantly with age, but the opposite occurred for compliance. The T-score was found to increase significantly across all age groups, with a steeper increase in stiffness around the age of 60 years in women. For each T-score s.d., the corresponding carotid absolute values for arterial stiffness and compliance were obtained. In a multivariate model, carotid stiffness parameters were constantly and independently associated with age, mean arterial pressure, pulse pressure, heart rate and body mass index. Our study provides a normogram of carotid arterial stiffness and compliance indices obtained with the echo-tracking method in a large population of healthy subjects stratified by gender and age that can be used in clinical practice.
The impact of real-world cardiovascular-related pharmacogenetic testing in an insured population.
Billings, Jennifer; Racsa, Patrick N; Bordenave, Kristine; Long, Charron L; Ellis, Jeffrey J
2018-06-01
Pharmacogenomics is intended to help clinicians provide the right drug to the right patient at an appropriate dose. However, limited evidence of clinical utility has slowed uptake of pharmacogenomic testing (PGT). To evaluate the impact of real-world cardiovascular (CV)-related PGT on clinical outcomes, healthcare resource utilisation (HCRU) and cost in a large, heterogeneous population. Individuals with Medicare Advantage Prescription Drug, Medicaid, or commercial coverage between 1/1/2011 and 9/30/2015 and ≥1 atherosclerotic CV-related diagnosis were identified. Those with ≥1 claim for CV-related PGT were included in the test group (index date = 1st PGT claim) and matched 1:2 to controls without PGT. Individuals aged <22 or ≥90 years old on the index date, with <12 months continuous enrollment before and after the index date, or without an ASCVD-related diagnosis in the 12-month pre-index period were excluded. The primary outcome was occurrence of a major CV event during the 12-month post-index period. After adjustment, the PGT group was significantly more likely to experience ischaemic stroke, pulmonary embolism, deep vein thrombosis or a composite event compared with controls. Adjusting for baseline characteristics, HCRU was significantly higher for the test group across all measured outcomes except all-cause and ASCVD-related inpatient admissions. Median all-cause and ASCVD-related healthcare costs were significantly higher for the test group. Real world PGT in a large population did not improve outcomes. Tailoring medication therapy to each patient holds great promise for providing quality care but a deeper understanding of how widespread utilisation of PGT might impact objective health outcomes is needed. © 2018 John Wiley & Sons Ltd.
Pometti, Carolina L.; Bessega, Cecilia F.; Saidman, Beatriz O.; Vilardi, Juan C.
2014-01-01
Bayesian clustering as implemented in STRUCTURE or GENELAND software is widely used to form genetic groups of populations or individuals. On the other hand, in order to satisfy the need for less computer-intensive approaches, multivariate analyses are specifically devoted to extracting information from large datasets. In this paper, we report the use of a dataset of AFLP markers belonging to 15 sampling sites of Acacia caven for studying the genetic structure and comparing the consistency of three methods: STRUCTURE, GENELAND and DAPC. Of these methods, DAPC was the fastest one and showed accuracy in inferring the K number of populations (K = 12 using the find.clusters option and K = 15 with a priori information of populations). GENELAND in turn, provides information on the area of membership probabilities for individuals or populations in the space, when coordinates are specified (K = 12). STRUCTURE also inferred the number of K populations and the membership probabilities of individuals based on ancestry, presenting the result K = 11 without prior information of populations and K = 15 using the LOCPRIOR option. Finally, in this work all three methods showed high consistency in estimating the population structure, inferring similar numbers of populations and the membership probabilities of individuals to each group, with a high correlation between each other. PMID:24688293
Mekonnen, Addisu; Fashing, Peter J; Bekele, Afework; Hernandez-Aguilar, R Adriana; Rueness, Eli K; Stenseth, Nils Chr
2018-02-06
Understanding the effects of habitat modification on the feeding strategies of threatened species is essential to designing effective conservation management plans. Bale monkeys (Chlorocebus djamdjamensis) are endemic to the rapidly shrinking montane forests of the southern Ethiopian Highlands. Most populations inhabit continuous bamboo forest subsisting largely on the young leaves and shoots of a single species of bamboo. Because of habitat disturbance in recent decades, however, there are now also several dozen small populations inhabiting isolated forest fragments where bamboo has been degraded. During 12-months, we assessed Bale monkey responses to habitat degradation by comparing habitat composition, phenological patterns, and feeding ecology in a largely undisturbed continuous forest (Continuous groups A and B) and in two fragments (Patchy and Hilltop groups). We found that habitat quality and food availability were much lower in fragments than in continuous forest. In response to the relative scarcity of bamboo in fragments, Bale monkeys spent significantly less time feeding on the young leaves and shoots of bamboo and significantly more time feeding on non-bamboo young leaves, fruits, seeds, stems, petioles, and insects in fragments than in continuous forest. Groups in fragments also broadened their diets to incorporate many more plant species (Patchy: ≥ 47 and Hilltop: ≥ 35 species)-including several forbs, graminoids and cultivated crops-than groups in continuous forest (Continuous A: 12 and Continuous B: 8 species). Nevertheless, bamboo was still the top food species for Patchy group (30% of diet) as well as for both continuous forest groups (mean = 81%). However, in Hilltop group, for which bamboo was especially scarce, Bothriochloa radicans (Poaceae), a grass, was the top dietary species (15% of diet) and bamboo ranked 10th (2%). We demonstrate that Bale monkeys are more dietarily flexible than previously thought and able to cope with some degradation of their primary bamboo forest habitat. However, crop raiding and other terrestrial foraging habits more common among fragment groups may place them at greater risk of hunting by humans. Thus, longitudinal monitoring is necessary to evaluate the long-term viability of Bale monkey populations in fragmented habitats.
Smooth pursuit eye movements in 1,087 men: effects of schizotypy, anxiety, and depression.
Smyrnis, Nikolaos; Evdokimidis, Ioannis; Mantas, Asimakis; Kattoulas, Emmanouil; Stefanis, Nicholas C; Constantinidis, Theodoros S; Avramopoulos, Dimitrios; Stefanis, Costas N
2007-05-01
Individuals with schizotypal personality disorder or high scores in questionnaires measuring schizotypy are at high risk for the development of schizophrenia and they also share some of the same phenotypic characteristics such as eye-tracking dysfunction (ETD). The question arises whether these individuals form a distinct high-risk group in the general population or whether schizotypy and ETD co-vary in the general population with no distinct cutoff point for a high-risk group. A large sample of military conscripts aged 18-25 were screened using oculomotor, cognitive and psychometric tools for the purposes of a prospective study on predisposing factors for the development of psychosis. Schizotypy measured using the perceptual aberration scale (PAS) and the schizotypal personality questionnaire (SPQ), anxiety and depression, measured using the Symptom Checklist 90-R, had no effect on pursuit performance in the total sample. Small groups of individuals with very high scores in schizotypy questionnaires were then identified. These groups were not mutually exclusive. The high PAS group had higher root-mean-square error scores (a quantitative measure for pursuit quality) than the total sample, and the high disorganized factor of SPQ group had lower gain and higher saccade frequencies in pursuit than the total sample. The presence of significant differences in pursuit performance only for predefined high schizotypy groups favors the hypothesis that individuals with high schizotypy might present one or more high-risk groups, distinct from the general population, that are prone to ETD as that observed in schizophrenia.
A new window on galactic suburbia with CSI, CANDELS, and GOODS-S
NASA Astrophysics Data System (ADS)
Williams, Rik
2013-10-01
While environmental effects on galaxies are seen clearly in dramatic environments like clusters and voids, most galaxies live in far more prosaic group environments of varying richness. Since typical groups consist of a relatively small handful of galaxies spread over a relatively large area, they have proven particularly difficult to detect and characterize up to high redshifts. With the Carnegie-Spitzer-IMACS {CSI} survey, we have developed the first large-scale, stellar mass-selected group catalog extending to z=1.2, and directly measured the hierarchical growth of groups therefrom. We are now embarking on a program to study in detail the influence of these groups on their galaxy populations through a combination of Magellan follow-up spectroscopy and deep public near-IR datasets. With the HST archival study proposed here, we will fold in the spectacular CANDELS and GOODS WFC3/ACS imaging in two of the CSI fields, tracking for the first time the morphological and structural transformations in 30 stellar mass-selected groups {containing 300-400 group galaxies} to z=1.2.
He, Yungang; Wang, Wei R.; Li, Ran; Wang, Sijia; Jin, Li
2012-01-01
An accurate estimate of the divergence time between Native Americans is important for understanding the initial entry and early dispersion of human beings in the New World. Current methods for estimating the genetic divergence time of populations could seriously depart from a linear relationship with the true divergence for multiple populations of a different population size and significant population expansion. Here, to address this problem, we propose a novel measure to estimate the genetic divergence time of populations. Computer simulation revealed that the new measure maintained an excellent linear correlation with the population divergence time in complicated multi-population scenarios with population expansion. Utilizing the new measure and microsatellite data of 21 Native American populations, we investigated the genetic divergences of the Native American populations. The results indicated that genetic divergences between North American populations are greater than that between Central and South American populations. None of the divergences, however, were large enough to constitute convincing evidence supporting the two-wave or multi-wave migration model for the initial entry of human beings into America. The genetic affinity of the Native American populations was further explored using Neighbor-Net and the genetic divergences suggested that these populations could be categorized into four genetic groups living in four different ecologic zones. The divergence of the population groups suggests that the early dispersion of human beings in America was a multi-step procedure. Further, the divergences suggest the rapid dispersion of Native Americans in Central and South Americas after a long standstill period in North America. PMID:22970308
Daya, Michelle; van der Merwe, Lize; Galal, Ushma; Möller, Marlo; Salie, Muneeb; Chimusa, Emile R.; Galanter, Joshua M.; van Helden, Paul D.; Henn, Brenna M.; Gignoux, Chris R.; Hoal, Eileen
2013-01-01
Admixture is a well known confounder in genetic association studies. If genome-wide data is not available, as would be the case for candidate gene studies, ancestry informative markers (AIMs) are required in order to adjust for admixture. The predominant population group in the Western Cape, South Africa, is the admixed group known as the South African Coloured (SAC). A small set of AIMs that is optimized to distinguish between the five source populations of this population (African San, African non-San, European, South Asian, and East Asian) will enable researchers to cost-effectively reduce false-positive findings resulting from ignoring admixture in genetic association studies of the population. Using genome-wide data to find SNPs with large allele frequency differences between the source populations of the SAC, as quantified by Rosenberg et. al's -statistic, we developed a panel of AIMs by experimenting with various selection strategies. Subsets of different sizes were evaluated by measuring the correlation between ancestry proportions estimated by each AIM subset with ancestry proportions estimated using genome-wide data. We show that a panel of 96 AIMs can be used to assess ancestry proportions and to adjust for the confounding effect of the complex five-way admixture that occurred in the South African Coloured population. PMID:24376522
[The general survey for chondromalacia of 2,743 Chinese population].
Guo, K; Ye, Q; Zeng, X; Lin, J; Wu, Z
1998-06-01
To evaluate the distribution of chondromalacia patella in Chinese population. A random cluster sampling survey was performed covering 2,743 subjects varied in age, sex and occupation in 1995. The prevalence rate is 36.2%. The occurrence in women was higher than that in men (P < 0.01), while in the age group, 30 to 39 years was the highest being 55.8%. The prevalence rate in soldier being 47.5% was the highest among varied occupations. Our study is the first survey to be performed in a large number of Chinese population. This investigation may reflect the prevalence rate of chondromalacia patella in China.
5-HTTLPR polymorphism: analysis in South African autistic individuals.
Arieff, Zainunisha; Kaur, Mandeep; Gameeldien, Hajirah; van der Merwe, Lize; Bajic, Vladimir B
2010-06-01
The serotonin transporter promoter length polymorphism (5-hydroxytryptamine transporter length polymorphism; 5-HTTLPR) has long been implicated in autism and other psychiatric disorders. The use of selective serotonin reuptake inhibitors (SSRIs) has a positive effect on treating some symptoms of autism. The effects of these drugs vary in individuals because of the presence of the S or L allele of 5-HTTLPR. Studies performed on various autistic populations have found different allele frequencies for the L and S alleles. Allele frequencies and genotypes of the South African autistic populations (African, mixed, and Caucasian) were compared with matching South African ethnic control populations. The *S/*S genotype was found to be highly significantly associated with all the South African autistic ethnic populations. In the South African African population the *S/*S genotype was present in 7 (33%) of the autistic individuals but in none of the control subjects, yielding infinitely large odds of developing autism. The odds of developing autism with the *S/*S genotype compared to the *L/*L genotype increased 10.15-fold in the South African mixed group and 2.74-fold in the South African Caucasian population. The allele frequency of the South African autistic population was also compared with studies of other autistic populations around the world, and highly significant differences were found with the Japanese, Korean, and Indian population groups. The difference was not significant for the French, German, Israeli, Portuguese, and American groups. This is the first South African study of autistic individuals of different ethnic backgrounds that shows significant differences in allele and genotype frequencies of 5-HTTLPR. The results of this study open new avenues for investigating the role of transmission of the L and S alleles in families with autism in South Africa.
Selikoff, Irving J.
1976-01-01
Experiences in the past decade provide guidance in selecting priorities for investigation of health hazards in chemical industries. Pride of place should be given to the experience of large industrial populations, in part simply because large numbers of people are at risk and in part because such studies are more likely to give reliable answers. This recommendation has further strength when there is community exposure as well. Parenthetically, large populations provide opportunity to study multiple factor interaction; without this, toxic potential of a single agent may be obscured. Second, investigations should be mounted when there is reason for suspicion, as with particular chemical configurations, observed organ toxicity, animal carcinogenicity, unusual clinical experience (“signal” tumors). It may be added that when agents have already been used several decades, evaluation of human experience with them is now in order, if only to document absence of toxicity. The same recommendations hold for planned introduction of new agents or widened distribution of existing ones, until we have better information concerning validity of “pretesting” programs. Major advances have been made in epidemiological methods for these investigations. These now allow us to successfully focus on small defined groups as well as to manage large populations. PMID:1026418
The Search for Wolf-Rayet Stars in IC10
NASA Astrophysics Data System (ADS)
Tehrani, Katie; Crowther, Paul; Archer, Isabelle
2017-11-01
We present a deep imaging and spectroscopic survey of the Local Group starburst galaxy IC10 using Gemini North/GMOS to unveil the global Wolf-Rayet population. It has previously been suggested that for IC10 to follow the WC/WN versus metallicity dependence seen in other Local Group galaxies, a large WN population must remain undiscovered. Our search revealed 3 new WN stars, and 5 candidates awaiting confirmation, providing little evidence to support this claim. We also compute an updated nebular derived metallicity of log(O/H)+12=8.40 +/- 0.04 for the galaxy using the direct method. Inspection of IC10 WR average line luminosities show these stars are more similar to their LMC, rather than SMC counterparts.
Population Screening for Chronic Q-Fever Seven Years after a Major Outbreak
Morroy, Gabriëlla; van der Hoek, Wim; Albers, Jelle; Coutinho, Roel A.; Bleeker-Rovers, Chantal P.; Schneeberger, Peter M.
2015-01-01
Introduction From 2007 through 2010, the Netherlands experienced a large Q-fever epidemic, with 4,107 notifications. The most serious complication of Q-fever is chronic Q-fever. Method In 2014, we contacted all 2,161 adult inhabitants of the first village in the Netherlands affected by the Q-fever epidemic and offered to test for antibodies against Coxiella burnetii using immunofluorescence assay (IFA) to screen for chronic infections and assess whether large-scale population screening elsewhere is warranted. Results Of the 1,517 participants, 33.8% were IFA-positive. Six IFA-positive participants had an IgG phase I titer ≥1:512. Two of these six participants were previously diagnosed with chronic Q-fever. Chronic infection was diagnosed in one of the other four participants after clinical examination. Conclusions Seven years after the initial outbreak, seroprevalence remains high, but the yield of screening the general population for chronic Q-fever is low. A policy of screening known high-risk groups for chronic Q-fever in outbreak areas directly following an outbreak might be more efficient than population screening. A cost-effectiveness analysis should also be performed before initiating a population screening program for chronic Q-fever. PMID:26132155
The impact of large terrestrial carnivores on Pleistocene ecosystems
Van Valkenburgh, Blaire; Ripple, William J.; Meloro, Carlo; Roth, V. Louise
2016-01-01
Large mammalian terrestrial herbivores, such as elephants, have dramatic effects on the ecosystems they inhabit and at high population densities their environmental impacts can be devastating. Pleistocene terrestrial ecosystems included a much greater diversity of megaherbivores (e.g., mammoths, mastodons, giant ground sloths) and thus a greater potential for widespread habitat degradation if population sizes were not limited. Nevertheless, based on modern observations, it is generally believed that populations of megaherbivores (>800 kg) are largely immune to the effects of predation and this perception has been extended into the Pleistocene. However, as shown here, the species richness of big carnivores was greater in the Pleistocene and many of them were significantly larger than their modern counterparts. Fossil evidence suggests that interspecific competition among carnivores was relatively intense and reveals that some individuals specialized in consuming megaherbivores. To estimate the potential impact of Pleistocene large carnivores, we use both historic and modern data on predator–prey body mass relationships to predict size ranges of their typical and maximum prey when hunting as individuals and in groups. These prey size ranges are then compared with estimates of juvenile and subadult proboscidean body sizes derived from extant elephant growth data. Young proboscideans at their most vulnerable age fall within the predicted prey size ranges of many of the Pleistocene carnivores. Predation on juveniles can have a greater impact on megaherbivores because of their long interbirth intervals, and consequently, we argue that Pleistocene carnivores had the capacity to, and likely did, limit megaherbivore population sizes. PMID:26504224
A simple rule for the evolution of contingent cooperation in large groups
Schonmann, Roberto H.; Boyd, Robert
2016-01-01
Humans cooperate in large groups of unrelated individuals, and many authors have argued that such cooperation is sustained by contingent reward and punishment. However, such sanctioning systems can also stabilize a wide range of behaviours, including mutually deleterious behaviours. Moreover, it is very likely that large-scale cooperation is derived in the human lineage. Thus, understanding the evolution of mutually beneficial cooperative behaviour requires knowledge of when strategies that support such behaviour can increase when rare. Here, we derive a simple formula that gives the relatedness necessary for contingent cooperation in n-person iterated games to increase when rare. This rule applies to a wide range of pay-off functions and assumes that the strategies supporting cooperation are based on the presence of a threshold fraction of cooperators. This rule suggests that modest levels of relatedness are sufficient for invasion by strategies that make cooperation contingent on previous cooperation by a small fraction of group members. In contrast, only high levels of relatedness allow the invasion by strategies that require near universal cooperation. In order to derive this formula, we introduce a novel methodology for studying evolution in group structured populations including local and global group-size regulation and fluctuations in group size. PMID:26729938
Sugandhi, Ayushi; Mangal, Brijesh; Mishra, Amit Kumar; Sethia, Bhavna
2014-01-01
AIM: To study a service model that enables a clinic to be open to all members of the community, irrespective of their ability to pay. METHODS: Sampling methodology was used to gather information in two phases, with the city of Indore as the target region. In the first phase, dental professionals were surveyed to gather the cost of the facility, land and equipment and the cost of sustaining the practice. In the second phase, the residents of Indore were surveyed to collect information regarding their oral health problems and their expenditure for the same. Assessing the current situation, the questions to answer are related to the issues of dental health care access problems and the resources required, human and financial. RESULTS: (1) People younger than 20 years of age form a large proportion (43%) of the population of the city and also a large proportion (54%) of people who visit dental clinics; (2) Dental caries are commonly found in the population younger than 20 years of age and mobile teeth in those older than 50 years of age; (3) Dental caries and mobile teeth are almost equally found in people of the age group 20-50 years old; (4) A significantly large proportion of those older than 50 years old have had all their teeth extracted; and (5) A significantly large proportion of the 20-30 years of age group has had no teeth extracted. CONCLUSION: The model which we propose works well for low income patients; however, it places a lot of extra burden on the higher income group. A lot of effort can be put into generating revenue from other sources, including events and donations. PMID:25232547
Sugandhi, Ayushi; Mangal, Brijesh; Mishra, Amit Kumar; Sethia, Bhavna
2014-09-16
To study a service model that enables a clinic to be open to all members of the community, irrespective of their ability to pay. Sampling methodology was used to gather information in two phases, with the city of Indore as the target region. In the first phase, dental professionals were surveyed to gather the cost of the facility, land and equipment and the cost of sustaining the practice. In the second phase, the residents of Indore were surveyed to collect information regarding their oral health problems and their expenditure for the same. Assessing the current situation, the questions to answer are related to the issues of dental health care access problems and the resources required, human and financial. (1) People younger than 20 years of age form a large proportion (43%) of the population of the city and also a large proportion (54%) of people who visit dental clinics; (2) Dental caries are commonly found in the population younger than 20 years of age and mobile teeth in those older than 50 years of age; (3) Dental caries and mobile teeth are almost equally found in people of the age group 20-50 years old; (4) A significantly large proportion of those older than 50 years old have had all their teeth extracted; and (5) A significantly large proportion of the 20-30 years of age group has had no teeth extracted. The model which we propose works well for low income patients; however, it places a lot of extra burden on the higher income group. A lot of effort can be put into generating revenue from other sources, including events and donations.
Sex ratio of congenital abnormalities in the function of maternal age: a population-based study.
Csermely, Gyula; Urbán, Robert; Czeizel, Andrew E; Veszprémi, Béla
2015-05-01
Maternal age effect is well-known in the origin of numerical chromosomal aberrations and some isolated congenital abnormalities (CAs). The sex ratio (SR), i.e. number of males divided by the number of males and females together, of most CAs deviates from the SR of newborn population (0.51). The objective of this analysis was to evaluate the possible association of maternal age with the SR of isolated CAs in a population-based large dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996. First, SR of 24 CA entities/groups was estimated in 21,494 patients with isolated CA. In the next step SR of different maternal age groups was compared to the mean SR of the given CA-groups. The SR of four CA-groups showed some deviation in certain maternal age groups. Cases with anencephaly had female excess in young mothers (<25 years). Cases with skull's CAs particularly craniosynostosis had a male excess in cases born to women over 30 years. Two other CA groups (cleft lip ± palate and valvar pulmonic stenosis within the group of right-sided obstructive defect of heart) had significant deviation in SR of certain maternal age groups from the mean SR, but these deviations were not harmonized with joining age groups and thus were considered as a chance effect due to multiple testing. In conclusion, our study did not suggest that in general SR of isolated CAs might be modified by certain maternal age groups with some exception such as anencephaly and craniosynostosis. © 2014 Japanese Teratology Society.
NASA Astrophysics Data System (ADS)
Dooley, Gregory A.; Peter, Annika H. G.; Yang, Tianyi; Willman, Beth; Griffen, Brendan F.; Frebel, Anna
2017-11-01
A recent surge in the discovery of new ultrafaint dwarf satellites of the Milky Way has inspired the idea of searching for faint satellites, 103 M⊙
The Australian Longitudinal Study on Women's Health: Using Focus Groups to Inform Recruitment
2016-01-01
Background Recruitment and retention of participants to large-scale, longitudinal studies can be a challenge, particularly when trying to target young women. Qualitative inquiries with members of the target population can prove valuable in assisting with the development of effective recruiting techniques. Researchers in the current study made use of focus group methodology to identify how to encourage young women aged 18-23 to participate in a national cohort online survey. Objective Our objectives were to gain insight into how to encourage young women to participate in a large-scale, longitudinal health survey, as well as to evaluate the survey instrument and mode of administration. Methods The Australian Longitudinal Study on Women’s Health used focus group methodology to learn how to encourage young women to participate in a large-scale, longitudinal Web-based health survey and to evaluate the survey instrument and mode of administration. Nineteen groups, involving 75 women aged 18-23 years, were held in remote, regional, and urban areas of New South Wales and Queensland. Results Focus groups were held in 2 stages, with discussions lasting from 19 minutes to over 1 hour. The focus groups allowed concord to be reached regarding survey promotion using social media, why personal information was needed, strategies to ensure confidentiality, how best to ask sensitive questions, and survey design for ease of completion. Recruitment into the focus groups proved difficult: the groups varied in size between 1 and 8 participants, with the majority conducted with 2 participants. Conclusions Intense recruitment efforts and variation in final focus group numbers highlights the “hard to reach” character of young women. However, the benefits of conducting focus group discussions as a preparatory stage to the recruitment of a large cohort for a longitudinal Web-based health survey were upheld. PMID:26902160
Effectiveness of Acupuncture Therapy on Stress in a Large Urban College Population.
Schroeder, Stefanie; Burnis, James; Denton, Antony; Krasnow, Aaron; Raghu, T S; Mathis, Kimberly
2017-06-01
This study is a randomized controlled clinical trial to study the effectiveness of acupuncture on the perception of stress in patients who study or work on a large, urban college campus. The hypothesis was that verum acupuncture would demonstrate a significant positive impact on perceived stress as compared to sham acupuncture. This study included 111 participants with high self-reported stress levels who either studied or worked at a large, urban public university in the southwestern United States. However, only 62 participants completed the study. The participants were randomized into a verum acupuncture or sham acupuncture group. Both the groups received treatment once a week for 12 weeks. The Cohen's global measure of perceived stress scale (PSS-14) was completed by each participant prior to treatment, at 6 weeks, at 12 weeks, and 6 weeks and 12 weeks post-treatment completion. While participants of both the groups showed a substantial initial decrease in perceived stress scores, at 12 weeks post treatment, the verum acupuncture group showed a significantly greater treatment effect than the sham acupuncture group. This study indicates that acupuncture may be successful in decreasing the perception of stress in students and staff at a large urban university, and this effect persists for at least 3 months after the completion of treatment. Copyright © 2017. Published by Elsevier B.V.
The foundations of the human cultural niche
Derex, Maxime; Boyd, Robert
2015-01-01
Technological innovations have allowed humans to settle in habitats for which they are poorly suited biologically. However, our understanding of how humans produce complex technologies is limited. We used a computer-based experiment, involving humans and learning bots, to investigate how reasoning abilities, social learning mechanisms and population structure affect the production of virtual artefacts. We found that humans' reasoning abilities play an important role in the production of innovations, but that groups of individuals are able to produce artefacts that are more complex than any isolated individual can produce during the same amount of time. We show that this group-level ability to produce complex innovations is maximized when social information is easy to acquire and when individuals are organized into large and partially connected populations. These results suggest that the transition to behavioural modernity could have been triggered by a change in ancestral between-group interaction patterns. PMID:26400015
Port, Markus; Johnstone, Rufus A
2013-01-01
Recent theory in social evolution has been mainly concerned with competition and cooperation within social groups of animals and their impact on the stability of those groups. Much less attention has been paid to conflicts arising as a result of solitary floaters (outsiders) attempting to join groups of established residents (insiders). We model such conflicts over group-membership using a demographically explicit approach in which the rates of births and deaths in a population determine the availability of group-vacancies and the number of floaters competing over these vacancies. We find that the outcome of within-group competition, reflected in the partitioning of reproduction among group members, exerts surprisingly little influence on the resolution of insider-outsider conflict. The outcome of such conflict is also largely unaffected by differences in resource holding potential between insiders and outsiders. By contrast, whether or not groups form is mainly determined by demographic factors (variation in vital rates such as fecundity and mortality) and the resulting population dynamics. In particular, at high floater densities territory defense becomes too costly, and groups form because insiders give in to the intruder pressure imposed on them by outsiders. We emphasize the importance of insider-outsider conflicts in social evolution theory and highlight avenues for future research. PMID:23762508
Group A streptococcal infections in children.
Steer, Andrew C; Danchin, Margaret H; Carapetis, Jonathan R
2007-04-01
The group A streptococcus causes the widest range of disease in humans of all bacterial pathogens. Group A streptococcal diseases are more common in children than adults with diseases ranging from pharyngitis and impetigo to invasive infections and the post-streptococcal sequelae--acute rheumatic fever and acute post-streptococcal glomerulonephritis. The global burden of severe group A streptococcal disease is concentrated largely in developing countries and Indigenous populations such as Aboriginal Australians. Control of group A streptococcal disease is poor in these settings and the need for a vaccine has been argued. With an ever-increasing understanding of the group A streptococcus at a molecular level, new and sophisticated vaccines are currently in human trials and the next decade holds exciting prospects for curbing group A streptococcal diseases.
Brennan, Meagan
2017-05-01
Recent research from the United Kingdom (UK) has highlighted some of the differences in breast cancer presentations between women of different ethnic groups. Analysis of a large database showed that Black women of African or Caribbean heritage living in England and Wales are more likely to present with stage 3 or 4 cancer than White British women and less likely to have their cancer detected through screening. In many countries around the world, migrant and cultural minority groups experience social and economic disadvantage and this is reflected in their health outcomes. With world migration at record levels, it is timely to reflect on ethnic disparities and to consider how developed nations can care for their minority groups, which are increasing in number and diversity. These issues and challenges are discussed, using the UK's migrant population and Australia's Indigenous and migrant populations as case studies. Copyright © 2017 Elsevier B.V. All rights reserved.
Browne, Julia; Mihas, Paul; Penn, David L
2016-05-01
The health benefits of exercise are well established, yet individuals with serious mental illness (SMI) have a shorter life expectancy due in large part to physical health complications associated with poor diet and lack of exercise. There is a paucity of research examining exercise in this population with the majority of studies having examined interventions with limited feasibility and sustainability. Before developing an intervention, a thorough exploration of client and clinician perspectives on exercise and its associated barriers is warranted. Twelve clients and fourteen clinicians participated in focus groups aimed at examining exercise, barriers, incentives, and attitudes about walking groups. Results indicated that clients and clinicians identified walking as the primary form of exercise, yet barriers impeded consistent participation. Distinct themes arose between groups; however, both clients and clinicians reported interest in a combination group/pedometer based walking program for individuals with SMI. Future research should consider examining walking programs for this population.
Khanolkar, Amal R; Hanley, Gillian E; Koupil, Ilona; Janssen, Patricia A
2017-11-13
To determine whether the Institute Of Medicine's (IOM) 2009 guidelines for weight-gain during pregnancy are predictive of maternal and infant outcomes in ethnic minority populations. We designed a population-based study using administrative data on 181,948 women who delivered live singleton births in Washington State between 2006-2008. We examined risks of gestational hypertension, preeclampsia/eclampsia, cesarean delivery, and extended hospital stay in White, Black, Native-American, East-Asian, Hispanic, South-Asian and Hawaiian/Pacific islander women according to whether they gained more or less weight during pregnancy than recommended by IOM guidelines. We also examined risks of neonatal outcomes including Apgar score <7 at 5 min, admission to NICU, requirement for ventilation, and a diagnosis of small or large for gestational age at birth. Gaining too much weight was associated with increased odds for gestational hypertension (adjusted OR (aOR) ranged between 1.53-2.22), preeclampsia/eclampsia (aOR 1.44-1.81), cesarean delivery (aOR 1.07-1.38) and extended hospital stay (aOR 1.06-1.28) in all ethnic groups. Gaining too little weight was associated with decreased odds for gestational hypertension and delivery by cesarean section in Whites, Blacks and Hispanics. Gaining less weight or more weight than recommended was associated with increased odds for small for gestational age and large for gestational age infants respectively, in all ethnic groups. Adherence to the 2009 IOM guidelines for weight gain during pregnancy reduces risk for various adverse maternal outcomes in all ethnic groups studied. However, the guidelines were less predictive of infant outcomes with the exception of small and large for gestational age. GWG: Gestational weight gain; IOM/NRC; Institute of Medicine and National Research Council; NICU: Neonatal intensive care need for ventilation; SGA: Small for gestational age; LGA: Large for gestational age; BERD: Birth Events Records Database; CHARS: Comprehensive Hospital Discharge Abstract Reporting System; ICD: International Classification of Disease; LMP: Last menstrual period; OR: Odds ratio.
Zedrosser, Andreas; Pelletier, Fanie; Bischof, Richard; Festa-Bianchet, Marco; Swenson, Jon E
2013-01-01
In iteroparous mammals, conditions experienced early in life may have long-lasting effects on lifetime reproductive success. Human-induced mortality is also an important demographic factor in many populations of large mammals and may influence lifetime reproductive success. Here, we explore the effects of early development, population density, and human hunting on survival and lifetime reproductive success in brown bear (Ursus arctos) females, using a 25-year database of individually marked bears in two populations in Sweden. Survival of yearlings to 2 years was not affected by population density or body mass. Yearlings that remained with their mother had higher survival than independent yearlings, partly because regulations prohibit the harvest of bears in family groups. Although mass as a yearling did not affect juvenile survival, it was positively associated with measures of lifetime reproductive success and individual fitness. The majority of adult female brown bear mortality (72%) in our study was due to human causes, mainly hunting, and many females were killed before they reproduced. Therefore, factors allowing females to survive several hunting seasons had a strong positive effect on lifetime reproductive success. We suggest that, in many hunted populations of large mammals, sport harvest is an important influence on both population dynamics and life histories.
Austin, P C; Shah, B R; Newman, A; Anderson, G M
2012-09-01
There are limited validated methods to ascertain comorbidities for risk adjustment in ambulatory populations of patients with diabetes using administrative health-care databases. The objective was to examine the ability of the Johns Hopkins' Aggregated Diagnosis Groups to predict mortality in population-based ambulatory samples of both incident and prevalent subjects with diabetes. Retrospective cohorts constructed using population-based administrative data. The incident cohort consisted of all 346,297 subjects diagnosed with diabetes between 1 April 2004 and 31 March 2008. The prevalent cohort consisted of all 879,849 subjects with pre-existing diabetes on 1 January, 2007. The outcome was death within 1 year of the subject's index date. A logistic regression model consisting of age, sex and indicator variables for 22 of the 32 Johns Hopkins' Aggregated Diagnosis Group categories had excellent discrimination for predicting mortality in incident diabetes patients: the c-statistic was 0.87 in an independent validation sample. A similar model had excellent discrimination for predicting mortality in prevalent diabetes patients: the c-statistic was 0.84 in an independent validation sample. Both models demonstrated very good calibration, denoting good agreement between observed and predicted mortality across the range of predicted mortality in which the large majority of subjects lay. For comparative purposes, regression models incorporating the Charlson comorbidity index, age and sex, age and sex, and age alone had poorer discrimination than the model that incorporated the Johns Hopkins' Aggregated Diagnosis Groups. Logistical regression models using age, sex and the John Hopkins' Aggregated Diagnosis Groups were able to accurately predict 1-year mortality in population-based samples of patients with diabetes. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.
Characterizing the galaxy populations within different environments in the RCS2319 supercluster
NASA Astrophysics Data System (ADS)
Delahaye, Anna; Webb, Tracy
We present the results of a multi-wavelength photometric study of the high redshift supercluster RCS2319+00. RCS2319+00 is a high-redshift (z ~ 0.9) supercluster comprising three spectroscopically confrmed cluster cores discovered in the Red Sequence Cluster Survey (RCS) (Gladders & Yee 2005). Core proximities and merger rates estimate coalescence into a 1015 M ⊙ cluster by z ~ 0.5 (Gilbank et al. 2008). Spectroscopic studies of the system have revealed over 300 supercluster members located in the cores and several infalling groups (Faloon et al. 2013). RCS2319 presents a diverse range of dynamical systems and densities making it an ideal laboratory in which to study the effects of environment on galaxy properties. Imaging in optical and near infrared (griz' from MegaCam, JK s from WIRCam, both at CFHT), as well as 3.6 μm and 4.5μm from IRAC have enabled the assembly of a large photometric catalogue. Coupled with an extensive spectroscopic survey (Faloon et al. 2013) providing nearly 2400 redshifts across the field, photometric redshifts were determined using the template fitting code EAZY (Brammer et al. 2008). Nearly 80 000 photometric redshifts were measured providing a sample of nearly 3000 cluster members. To investigate effects of global environment, analysis was done utilizing a friend-of-friends group finding algorithm identifying several large and small infalling groups along with the three cluster cores. The cores are found to be dominated by massive, red galaxies and the field galaxies are populated by low mass, blue galaxies, as is the case in the local universe. Interestingly, the large groups exhibit intermediate properties between field and core populations, suggesting possible pre-processing as they are being accreted into the core halos. Relative fifth-nearest neighbour overdensity, log(1+δ5), is used as a proxy for local environment to investigate environmental dependence on galaxy colour. While there is an overall dependence of colour on local density, when controlled for stellar mass the dependence largely disappears. Indeed, galaxy mass is the dominant factor in determining colour, with local density a secondary effect only noticeable in lower mass galaxies at the 3 σ level for both colour and red fraction. RCS2319+00 presents a rare opportunity to probe many different densities and environments all located within the same object. We're able to investigate how galaxy evolution is affected by the environment, from field galaxies to infalling to groups to dense cluster cores, as well as the different density regions within each environment.
Emergence of social cooperation in threshold public goods games with collective risk
NASA Astrophysics Data System (ADS)
Wang, Jing; Fu, Feng; Wu, Te; Wang, Long
2009-07-01
In real situations, people are often faced with the option of voluntary contribution to achieve a collective goal, for example, building a dam or a fence, in order to avoid an unfavorable loss. Those who do not donate, however, can free ride on others’ sacrifices. As a result, cooperation is difficult to maintain, leading to an enduring collective-risk social dilemma. To address this issue, here we propose a simple yet effective theoretical model of threshold public goods game with collective risk and focus on the effect of risk on the emergence of social cooperation. To do this, we consider the population dynamics represented by replicator equation for two simplifying scenarios, respectively: one with fair sharers, who contribute the minimum average amount versus defectors and the other with altruists contributing more than average versus defectors. For both cases, we find that the dilemma is relieved in high-risk situations where cooperation is likely to persist and dominate defection in the population. Large initial endowment to individuals also encourages the risk-averse action, which means that, as compared to poor players (with small initial endowment), wealthy individuals (with large initial endowment) are more likely to cooperate in order to protect their private accounts. In addition, we show that small donation amount and small threshold (collective target) can encourage and sustain cooperation. Furthermore, for other parameters fixed, the impacts of group size act differently on the two scenarios because of distinct mechanisms: in the former case where the cost of cooperation depends on the group size, large size of group readily results in defection, while easily maintains cooperation in the latter case where the cost of cooperation is fixed irrespective of the group size. Our theoretical results of the replicator dynamics are in excellent agreement with the individual based simulation results.
Healey, Andrew; Roberts, Sarah; Sevdalis, Nick; Goulding, Lucy; Wilson, Sophie; Shaw, Kate; Jolley, Caroline; Robson, Deborah
2018-05-04
Tobacco smoking is highly prevalent among people attending treatment for a substance use disorder (SUD). In the UK, specialist support to stop smoking is largely delivered by a national network of Stop Smoking Services, and typically comprises of behavioural support delivered by trained practitioners on an individual (one-to-one) or group basis combined with a pharmacological smoking cessation aid. We evaluate the cost-effectiveness of these interventions, and compare cost-effectiveness for interventions using group- and individual-based support, in populations under treatment for SUD. Economic modelling was used to evaluate the incremental cost-per-quality adjusted life years (QALYs) gained for smoking cessation interventions compared to alternative methods of quitting for the SUD treatment population. Allowance was made for potentially lower abstinence rates in the SUD population. The incremental cost per QALY gained from quit attempts supported through more frequently provided interventions in England ranged from around £4,700 to £12,200. These values are below the maximum cost-effectiveness threshold adopted by policy makers in England for judging whether health programmes are a cost-effective use of resources. The estimated cost-per QALY gained for Interventions using group-based behavioural support were estimated to be at least half the magnitude of those using individual support due to lower intervention costs and higher reported quit rates. Conclusions reached regarding the cost-effectiveness of group-based interventions were also found to be more robust to changes in modelling assumptions. Smoking cessation interventions were found to be cost-effective when applied to the SUD population, particularly when grouped-based behavioural support is offered alongside pharmacological treatment. This analysis has shown that smoking cessation interventions combining pharmacological treatment with behavioural support can offer a cost-effective method for increasing rates of smoking cessation in populations being treated for a substance use disorder. This is despite evidence of lower comparative success rates in terms of smoking abstinence in populations with SUD. Our evaluation suggests that medication combined with group-based behavioural support may offer better value for money in this population compared to interventions using individual support, though further evidence on the comparative effectiveness and cost of interventions delivered to SUD treatment populations would facilitate a more robust comparison.
Using Ethnobotany as a Topic To Make Connections between Culture and Science.
ERIC Educational Resources Information Center
Keating, Joseph F.
Ethnobotany is the study of the relationships between plants and people. Ethnobotanists study a large range of interests related to indigenous populations, including the use of plants for foodstuffs, medicines, dyes, transportation, clothing, shelter, and ritual. The Navajo, like other indigenous groups, have developed a wealth of knowledge about…
ERIC Educational Resources Information Center
Lewis, M. Jane; West, Bernadette; Bautista, Leyna; Greenberg, Alexandra M.; Done-Perez, Iris
2005-01-01
This study examined perceptions regarding intimate partner abuse (IPV) in a largely Latino community in New Jersey through focus groups with Latino community members and key informant interviews with providers of services to this population. Questions examined definitions of partner abuse; perceptions of factors contributing to, or protecting…
Leisure Patterns and Needs of the Elderly in Rural Galicia (Spain)
ERIC Educational Resources Information Center
Conde, Maria Dapia
2012-01-01
A large percentage of the Galician population is aged and lives in rural environments--parishes, hamlets, and villages. This study employed semistructured interviews and focus groups to obtain a qualitative assessment both of (a) the opinions of the elderly living in rural areas regarding their leisure and recreational habits and the provision…
The Demographics of Deafness Resulting from Maternal Rubella.
ERIC Educational Resources Information Center
Trybus, Raymond J.; And Others
1980-01-01
The paper reviews data on the size and major characteristics of the population of rubella deafened children, with emphasis on those born during 1963-65. The focus is on the impact that this large group of deaf youngsters will have on postsecondary educational institutions and rehabilitation agencies during the decade of the 1980s. (Author)
Prevalence, Comorbidity and Course of Trauma Reactions in Young Burn-Injured Children
ERIC Educational Resources Information Center
De Young, Alexandra C.; Kenardy, Justin A.; Cobham, Vanessa E.; Kimble, Roy
2012-01-01
Background: Infants, toddlers and preschoolers are the highest risk group for burn injury. However, to date this population has been largely neglected. This study examined the prevalence, onset, comorbidity and recovery patterns of posttrauma reactions in young children with burns. Methods: Parents of 130 unintentionally burned children (1-6…
Nursery Annexes and Parent Involvement in Hillfields, Coventry, England.
ERIC Educational Resources Information Center
Dermy, Janet M.
This paper tells the story of the implementation of the first inner city Community Education Project in the disadvantaged Hillfields area of Coventry, England. The population of the "ghetto-like" Hillfields, numbering 20,000, was made up largely of families from Asia with small groups from the West Indies, Ireland and Europe. A survey…
USDA-ARS?s Scientific Manuscript database
Strong host resistance to root-knot nematode (RKN; Meloidogyne arenaria) introgressed from a wild diploid species to cultivated peanut was previously shown to be located on a large chromosomal region of linkage group A09. Little to no recombination in mapping populations has hindered fine mapping o...
Gaining Insight into Hispanic Students' Postsecondary Plans
ERIC Educational Resources Information Center
Brown, Neel A.
2012-01-01
While the growth of the Hispanic population in the United States is outpacing other ethnicities, college enrollment and graduation rates of Hispanic students continue to lag behind other groups. This longitudinal, qualitative case study explored when, how, and why a sample of Hispanic high school seniors at a large high school in North Central…
Is alloparenting helpful for Mednyi Island arctic foxes, Alopex lagopus semenovi?
Kruchenkova, Elena P; Goltsman, Michael; Sergeev, Sergei; Macdonald, David W
2009-04-01
The Arctic Fox Alopex lagopus semenovi population on Mednyi Island is completely isolated and subsists largely by scavenging on seabird colonies, which have remained abundant and spatio-temporally predictable for many years. We compared population data at the beginning of 1976/1978 and some time after 1994-2005, finding an 85% decline in fox numbers due to disease, to assess the effect of population size on social structure. A total of 81 groups of known size and composition was observed during this 29-year period. Overall, helpers (usually non-lactating yearling females) occurred in 25.7% of groups, and in 32.4% of groups there were two or three lactating females. Female engagement in alloparental behaviour decreased, but not statistically significantly, after the decline in population density. Total food availability was apparently constant throughout the study period, and therefore, the amount available per individual was much higher later in the study. Both communally nursing females and helpers brought food and helped to guard the litter. However, the benefits of communal rearing were unclear. While cubs were left without guards significantly more rarely in the groups with an additional adult, the number of cubs weaned per lactating female was greater in groups with one (3.93 +/- 1.60), as opposed to two or three (3.06 +/- 0.92), lactating females. Survival of cubs to 1 year of age in the groups with two lactating females and/or with helpers was lower than that in the families with one lactating female without helpers (22.2% vs 32.2%). Fewer second-generation litters were born to foxes produced by composite families than to those produced by pairs. Reproductive adults producing by pairs had, on average, 1.23 (+/-1.72) second-generation litters. In groups that initially included additional adults, the average number of second-generation litters per reproductive female was 0.21 (+/-0.49) and 0.46 (+/-0.81) litters per male. Thus, according to three measures, increased group size had no apparent positive impact on reproductive success. The increased parental investment and enhanced guarding of the cubs in the larger families could be beneficial under conditions of high population density and a saturated biotope to which the island fox population was presumably adapted before the population crash in the late 1970s.
Is alloparenting helpful for Mednyi Island arctic foxes, Alopex lagopus semenovi?
NASA Astrophysics Data System (ADS)
Kruchenkova, Elena P.; Goltsman, Michael; Sergeev, Sergei; MacDonald, David W.
2009-04-01
The Arctic Fox Alopex lagopus semenovi population on Mednyi Island is completely isolated and subsists largely by scavenging on seabird colonies, which have remained abundant and spatio-temporally predictable for many years. We compared population data at the beginning of 1976/1978 and some time after 1994-2005, finding an 85% decline in fox numbers due to disease, to assess the effect of population size on social structure. A total of 81 groups of known size and composition was observed during this 29-year period. Overall, helpers (usually non-lactating yearling females) occurred in 25.7% of groups, and in 32.4% of groups there were two or three lactating females. Female engagement in alloparental behaviour decreased, but not statistically significantly, after the decline in population density. Total food availability was apparently constant throughout the study period, and therefore, the amount available per individual was much higher later in the study. Both communally nursing females and helpers brought food and helped to guard the litter. However, the benefits of communal rearing were unclear. While cubs were left without guards significantly more rarely in the groups with an additional adult, the number of cubs weaned per lactating female was greater in groups with one (3.93 ± 1.60), as opposed to two or three (3.06 ± 0.92), lactating females. Survival of cubs to 1 year of age in the groups with two lactating females and/or with helpers was lower than that in the families with one lactating female without helpers (22.2% vs 32.2%). Fewer second-generation litters were born to foxes produced by composite families than to those produced by pairs. Reproductive adults producing by pairs had, on average, 1.23 (±1.72) second-generation litters. In groups that initially included additional adults, the average number of second-generation litters per reproductive female was 0.21 (±0.49) and 0.46 (±0.81) litters per male. Thus, according to three measures, increased group size had no apparent positive impact on reproductive success. The increased parental investment and enhanced guarding of the cubs in the larger families could be beneficial under conditions of high population density and a saturated biotope to which the island fox population was presumably adapted before the population crash in the late 1970s.
Automated Operant Conditioning in the Mouse Home Cage.
Francis, Nikolas A; Kanold, Patrick O
2017-01-01
Recent advances in neuroimaging and genetics have made mice an advantageous animal model for studying the neurophysiology of sensation, cognition, and locomotion. A key benefit of mice is that they provide a large population of test subjects for behavioral screening. Reflex-based assays of hearing in mice, such as the widely used acoustic startle response, are less accurate than operant conditioning in measuring auditory processing. To date, however, there are few cost-effective options for scalable operant conditioning systems. Here, we describe a new system for automated operant conditioning, the Psibox. It is assembled from low cost parts, designed to fit within typical commercial wire-top cages, and allows large numbers of mice to train independently in their home cages on positive reinforcement tasks. We found that groups of mice trained together learned to accurately detect sounds within 2 weeks of training. In addition, individual mice isolated from groups also showed good task performance. The Psibox facilitates high-throughput testing of sensory, motor, and cognitive skills in mice, and provides a readily available animal population for studies ranging from experience-dependent neural plasticity to rodent models of mental disorders.
van Hooijdonk, Carolien; Droomers, Mariël; Deerenberg, Ingeborg M; Mackenbach, Johan P; Kunst, Anton E
2008-12-01
Literature on the effect of community social capital on health is inconsistent and could be related to differences in social capital measures, health outcomes, population groups and locations studied. Therefore this study examines the diversity in associations between community social capital and health by investigating different diseases, populations groups and locations. Mortality records and individual data on sex, age, marital status, ethnic origin and place of residence were available for 6 years (1995-2000). Neighbourhood data, i.e. community social capital, socio-economic level and urbanicity, were linked through postcode information. Community social capital was indicated by measures of community interaction, belongingness, satisfaction and involvement. Variations in all-cause and cause-specific mortality across low and high social capital neighbourhoods were estimated through Poisson regression. In addition, analyses were stratified according to population group and to urbanization level. In the total population, community social capital was not related to all-cause mortality (RR = 1.00; CI: 0.99-1.01). However, residents of high social capital neighbourhoods had lower mortality risks for cancer [especially lung cancer (RR = 0.92; CI: 0.89-0.96)] and for suicide (RR = 0.90; CI: 0.83-0.98). Slightly lower mortality risks were also found for men (RR = 0.98; CI: 0.97-0.99), married individuals (RR = 0.96; CI: 0.94-0.97) and for residents living in socially strong neighbourhoods located in large cities (RR = 0.95; CI: 0.91-0.99). The association between community social capital and health differs per health outcome, study population and location studied. This underlines the need to take such diversity into account when aiming to conceptualize the relation between community social capital and health.
NASA Astrophysics Data System (ADS)
Jemaa, Sharif; Bacha, Mahmoud; Khalaf, Gaby; Dessailly, David; Rabhi, Khalef; Amara, Rachid
2015-02-01
The European sardine, Sardina pilchardus, exhibits a complex population structure, which has produced conflicting results in previous genetic studies. Despite its importance in the fisheries industry, stock delineation for management and conservation purposes is still a matter of debate throughout the distribution range of the species. This study examines whether otolith shapes are more efficient than genetic markers to detect population structure in pelagic species with large population sizes. Sardines were analyzed from 15 sampling localities in the Northeast Atlantic and Mediterranean Sea covering almost the whole distribution range of the species. A combination of otolith shape indices and elliptic Fourier descriptors was investigated by multivariate statistical procedures. Within the studied area, three distinct groups were identified with an overall correct classification of 77%. Group A: northern Mediterranean Sea and Gulf of Gabès; group B: Atlantic Morocco-south Alboran-Algero-provençal coasts; and group C: European Atlantic coast. The Almeria-Oran front and the Gibraltar strait are not an efficient barrier for sardine population separation as there seems to be exchanges between populations of the south-western Mediterranean Sea and those of the Moroccan Atlantic Ocean coast or Gulf of Cadiz. The results are discussed in relation to environmental conditions, oceanographic features, and physical barriers to dispersal in the study area, and compared with those obtained by previous genetic, morphometric, and meristic data. For pelagic species with high gene flow, present results highlighted the need to take into account the identification of phenotypic stocks to ensure sustainable fishery benefits and efficient conservation as they may have unique demographic properties and responses to exploitation.
A double-observer method for reducing bias in faecal pellet surveys of forest ungulates
Jenkins, K.J.; Manly, B.F.J.
2008-01-01
1. Faecal surveys are used widely to study variations in abundance and distribution of forest-dwelling mammals when direct enumeration is not feasible. The utility of faecal indices of abundance is limited, however, by observational bias and variation in faecal disappearance rates that obscure their relationship to population size. We developed methods to reduce variability in faecal surveys and improve reliability of faecal indices. 2. We used double-observer transect sampling to estimate observational bias of faecal surveys of Roosevelt elk Cervus elaphus roosevelti and Columbian black-tailed deer Odocoileus hemionus columbianus in Olympic National Park, Washington, USA. We also modelled differences in counts of faecal groups obtained from paired cleared and uncleared transect segments as a means to adjust standing crop faecal counts for a standard accumulation interval and to reduce bias resulting from variable decay rates. 3. Estimated detection probabilities of faecal groups ranged from < 0.2-1.0 depending upon the observer, whether the faecal group was from elk or deer, faecal group size, distance of the faecal group from the sampling transect, ground vegetation cover, and the interaction between faecal group size and distance from the transect. 4. Models of plot-clearing effects indicated that standing crop counts of deer faecal groups required 34% reduction on flat terrain and 53% reduction on sloping terrain to represent faeces accumulated over a standard 100-day interval, whereas counts of elk faecal groups required 0% and 46% reductions on flat and sloping terrain, respectively. 5. Synthesis and applications. Double-observer transect sampling provides a cost-effective means of reducing observational bias and variation in faecal decay rates that obscure the interpretation of faecal indices of large mammal abundance. Given the variation we observed in observational bias of faecal surveys and persistence of faeces, we emphasize the need for future researchers to account for these comparatively manageable sources of bias before comparing faecal indices spatially or temporally. Double-observer sampling methods are readily adaptable to study variations in faecal indices of large mammals at the scale of the large forest reserve, natural area, or other forested regions when direct estimation of populations is problematic. ?? 2008 The Authors.
Sources and assessment of occupational stress in the police.
Deschamps, Frédéric; Paganon-Badinier, Isabelle; Marchand, Annie-Claude; Merle, Corinne
2003-11-01
The role of the police in Western society is undergoing a transformation that reflects the economic social and technological changes in the community and the assertion of individual rights within a democracy. The aim of this study is to evaluate level of stress among a group of French policemen and to examine the association between policing, potential stressors and stress levels. The sample is drawn from a large metropolitan police force (n=617). The population extends from the first line policeman to top senior management. Each policeman is matched for age (more or less five years) and sex, to a control. Policemen and controls complete a self administered questionnaire including demographic, occupational and health characteristics, and a stress level assessment with the help of a visual analogue scale. The average age of the two groups is 40 yr. Eighty-four percent are men. The total score for average sources is not statistically significantly different for policemen and controls. Comparison of a police group with a high stress level to a police population with a low and moderate stress level is made. The comparison is done first only with men, and second with the whole population. Policemen with a high stress level (same results only for men and the whole population) belong to the following groups: more than 15 yr service, sergeant, officer and administrative employee rank, divorced experience, age over 30, no leisure-time activities and no hobbies. Multivariate analysis shows that the two last parameters are bound to the stress level. For the whole population, age over 30 has to be added, and for the group of men, length of service over five years should be noted. Stress at work is an ill-health provoking factor. Police from minority groups such as ageing subjects or police officers have been reported to experience greater stress. This population is adversely affected by lack of available manpower and long working hours. In fact sources of stress in the police population are found both in the weariness of the job and private life planning.
Reducing Individual Variation for fMRI Studies in Children by Minimizing Template Related Errors
Weng, Jian; Dong, Shanshan; He, Hongjian; Chen, Feiyan; Peng, Xiaogang
2015-01-01
Spatial normalization is an essential process for group comparisons in functional MRI studies. In practice, there is a risk of normalization errors particularly in studies involving children, seniors or diseased populations and in regions with high individual variation. One way to minimize normalization errors is to create a study-specific template based on a large sample size. However, studies with a large sample size are not always feasible, particularly for children studies. The performance of templates with a small sample size has not been evaluated in fMRI studies in children. In the current study, this issue was encountered in a working memory task with 29 children in two groups. We compared the performance of different templates: a study-specific template created by the experimental population, a Chinese children template and the widely used adult MNI template. We observed distinct differences in the right orbitofrontal region among the three templates in between-group comparisons. The study-specific template and the Chinese children template were more sensitive for the detection of between-group differences in the orbitofrontal cortex than the MNI template. Proper templates could effectively reduce individual variation. Further analysis revealed a correlation between the BOLD contrast size and the norm index of the affine transformation matrix, i.e., the SFN, which characterizes the difference between a template and a native image and differs significantly across subjects. Thereby, we proposed and tested another method to reduce individual variation that included the SFN as a covariate in group-wise statistics. This correction exhibits outstanding performance in enhancing detection power in group-level tests. A training effect of abacus-based mental calculation was also demonstrated, with significantly elevated activation in the right orbitofrontal region that correlated with behavioral response time across subjects in the trained group. PMID:26207985
Growth dynamics and the evolution of cooperation in microbial populations
NASA Astrophysics Data System (ADS)
Cremer, Jonas; Melbinger, Anna; Frey, Erwin
2012-02-01
Microbes providing public goods are widespread in nature despite running the risk of being exploited by free-riders. However, the precise ecological factors supporting cooperation are still puzzling. Following recent experiments, we consider the role of population growth and the repetitive fragmentation of populations into new colonies mimicking simple microbial life-cycles. Individual-based modeling reveals that demographic fluctuations, which lead to a large variance in the composition of colonies, promote cooperation. Biased by population dynamics these fluctuations result in two qualitatively distinct regimes of robust cooperation under repetitive fragmentation into groups. First, if the level of cooperation exceeds a threshold, cooperators will take over the whole population. Second, cooperators can also emerge from a single mutant leading to a robust coexistence between cooperators and free-riders. We find frequency and size of population bottlenecks, and growth dynamics to be the major ecological factors determining the regimes and thereby the evolutionary pathway towards cooperation.
Non-symbiotic Bradyrhizobium ecotypes dominate North American forest soils.
VanInsberghe, David; Maas, Kendra R; Cardenas, Erick; Strachan, Cameron R; Hallam, Steven J; Mohn, William W
2015-11-01
The genus Bradyrhizobium has served as a model system for studying host-microbe symbiotic interactions and nitrogen fixation due to its importance in agricultural productivity and global nitrogen cycling. In this study, we identify a bacterial group affiliated with this genus that dominates the microbial communities of coniferous forest soils from six distinct ecozones across North America. Representative isolates from this group were obtained and characterized. Using quantitative population genomics, we show that forest soil populations of Bradyrhizobium represent ecotypes incapable of nodulating legume root hairs or fixing atmospheric nitrogen. Instead, these populations appear to be free living and have a greater potential for metabolizing aromatic carbon sources than their close symbiotic relatives. In addition, we identify fine-scaled differentiation between populations inhabiting neighboring soil layers that illustrate how diversity within Bradyrhizobium is structured by habitat similarity. These findings reconcile incongruent observations about this widely studied and important group of bacteria and highlight the value of ecological context to interpretations of microbial diversity and taxonomy. These results further suggest that the influence of this genus likely extends well beyond facilitating agriculture, especially as forest ecosystems are large and integral components of the biosphere. In addition, this study demonstrates how focusing research on economically important microorganisms can bias our understanding of the natural world.
Non-symbiotic Bradyrhizobium ecotypes dominate North American forest soils
VanInsberghe, David; Maas, Kendra R; Cardenas, Erick; Strachan, Cameron R; Hallam, Steven J; Mohn, William W
2015-01-01
The genus Bradyrhizobium has served as a model system for studying host–microbe symbiotic interactions and nitrogen fixation due to its importance in agricultural productivity and global nitrogen cycling. In this study, we identify a bacterial group affiliated with this genus that dominates the microbial communities of coniferous forest soils from six distinct ecozones across North America. Representative isolates from this group were obtained and characterized. Using quantitative population genomics, we show that forest soil populations of Bradyrhizobium represent ecotypes incapable of nodulating legume root hairs or fixing atmospheric nitrogen. Instead, these populations appear to be free living and have a greater potential for metabolizing aromatic carbon sources than their close symbiotic relatives. In addition, we identify fine-scaled differentiation between populations inhabiting neighboring soil layers that illustrate how diversity within Bradyrhizobium is structured by habitat similarity. These findings reconcile incongruent observations about this widely studied and important group of bacteria and highlight the value of ecological context to interpretations of microbial diversity and taxonomy. These results further suggest that the influence of this genus likely extends well beyond facilitating agriculture, especially as forest ecosystems are large and integral components of the biosphere. In addition, this study demonstrates how focusing research on economically important microorganisms can bias our understanding of the natural world. PMID:25909973
Home educating in an extended family culture and aging society may fare best during a pandemic.
Dawson, Wayne; Yamamoto, Kenji
2009-09-28
Large cities can contain populations that move rapidly from one section to another in an efficient transportation network. An emerging air-borne or contact based pathogen could use these transportation routes to rapidly spread an infection throughout an entire population in a short time. Further, in many developed countries, the aging population is increasing. The family structure in these societies may also affect the course of a disease. To help understand the impact of an epidemic on family structure in a networked population, an individual based computer model that randomly generates networked cities with a specified range of population and disease characteristics and individual schedules, infectivity, transmission and hygiene factors was developed. Several salient issues emerged. First, a city of highly active individuals may in fact diminish the number of fatalities because the average duration of the interactions between agents is reduced. Second, home schooling can significantly improve survival because the institutional clustering of weak individuals is minimized. Third, the worst scenario for an aging population is the nuclear family where the aged population is confined to large housing facilities. Naturally, hygiene is the first barrier to infection. The results suggest that societies where extended families and small groups manage most of their own affairs may also be the most suitable for defense against a pandemic. This may prove applicable in city planning and policy making.
Radiation exposure from consumer products and miscellaneous sources
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1977-01-01
This review of the literature indicates that there is a variety of consumer products and miscellaneous sources of radiation that result in exposure to the U.S. population. A summary of the number of people exposed to each such source, an estimate of the resulting dose equivalents to the exposed population, and an estimate of the average annual population dose equivalent are tabulated. A review of the data in this table shows that the total average annual contribution to the whole-body dose equivalent of the U.S. population from consumer products is less than 5 mrem; about 70 percent of this arisesmore » from the presence of naturally-occurring radionuclides in building materials. Some of the consumer product sources contribute exposure mainly to localized tissues or organs. Such localized estimates include: 0.5 to 1 mrem to the average annual population lung dose equivalent (generalized); 2 rem to the average annual population bronchial epithelial dose equivalent (localized); and 10 to 15 rem to the average annual population basal mucosal dose equivalent (basal mucosa of the gum). Based on these estimates, these sources may be grouped or classified as those that involve many people and the dose equivalent is relative large or those that involve many people but the dose equivalent is relatively small, or the dose equivalent is relatively large but the number of people involved is small.« less
Population clustering based on copy number variations detected from next generation sequencing data.
Duan, Junbo; Zhang, Ji-Gang; Wan, Mingxi; Deng, Hong-Wen; Wang, Yu-Ping
2014-08-01
Copy number variations (CNVs) can be used as significant bio-markers and next generation sequencing (NGS) provides a high resolution detection of these CNVs. But how to extract features from CNVs and further apply them to genomic studies such as population clustering have become a big challenge. In this paper, we propose a novel method for population clustering based on CNVs from NGS. First, CNVs are extracted from each sample to form a feature matrix. Then, this feature matrix is decomposed into the source matrix and weight matrix with non-negative matrix factorization (NMF). The source matrix consists of common CNVs that are shared by all the samples from the same group, and the weight matrix indicates the corresponding level of CNVs from each sample. Therefore, using NMF of CNVs one can differentiate samples from different ethnic groups, i.e. population clustering. To validate the approach, we applied it to the analysis of both simulation data and two real data set from the 1000 Genomes Project. The results on simulation data demonstrate that the proposed method can recover the true common CNVs with high quality. The results on the first real data analysis show that the proposed method can cluster two family trio with different ancestries into two ethnic groups and the results on the second real data analysis show that the proposed method can be applied to the whole-genome with large sample size consisting of multiple groups. Both results demonstrate the potential of the proposed method for population clustering.
Kim, Tae-Kyu; Han, Taeman; Kim, Tae-Woo; Park, In Gyun; Kim, Seonghyun; Park, Haechul
2016-03-15
In Korea, members of the genus Tettigonia have been known as two species, T. ussuriana and T. dolichoptera dolichoptera. However, the taxonomic status of the Jeju Island population of T. ussuriana (JJ-TU) is in question, relative to the mainland population (ML-TU), because of their different body sizes and ratios of wing length. To clarify the relatedness of JJ-TU and ML-TU, we examined the genetic variation and phylogenetic relationships within and between T. ussuriana and related species collected in South Korea, using five genetic loci: three mitochondrial genes (cytochrome c oxidase subunit 1 [CO1], cytochrome c oxidase subunit 2 [CO2], NADH dehydrogenase 1 [ND1]) and two nuclear loci (second internal transcribed spacer [ITS2], and tubulin alpha-1 [TA1]). Unexpectedly, the JJ-TU population is explicitly sister to T. d. dolichoptera, with low genetic distance (0.76-1.22% in CO1), indicating no direct connection with the ML-TU population; this finding suggests a recent divergence involving rapid morphological change without gene flow between JJ-TU and mainland T. d. dolichoptera. The separation of these populations from their common ancestor was caused by geographical isolation during last glacial age. This finding indicates that the JJ-TU population should be elevated to the rank of subspecies, at the very least. Furthermore, the ML-TU population was also revealed to have four genetically divided groups (group A-D) from four localized populations, but no significant morphological differences exist among them. The genetic difference (range 3.19-4.10% in CO1) between group A + B and C + D was especially large, suggesting that cryptic speciation has widely occurred within the mainland areas, caused by allopatric isolations resulting from mountain barriers.
Khan, Bilal; Lee, Hsuan-Wei; Fellows, Ian; Dombrowski, Kirk
2018-01-01
Size estimation is particularly important for populations whose members experience disproportionate health issues or pose elevated health risks to the ambient social structures in which they are embedded. Efforts to derive size estimates are often frustrated when the population is hidden or hard-to-reach in ways that preclude conventional survey strategies, as is the case when social stigma is associated with group membership or when group members are involved in illegal activities. This paper extends prior research on the problem of network population size estimation, building on established survey/sampling methodologies commonly used with hard-to-reach groups. Three novel one-step, network-based population size estimators are presented, for use in the context of uniform random sampling, respondent-driven sampling, and when networks exhibit significant clustering effects. We give provably sufficient conditions for the consistency of these estimators in large configuration networks. Simulation experiments across a wide range of synthetic network topologies validate the performance of the estimators, which also perform well on a real-world location-based social networking data set with significant clustering. Finally, the proposed schemes are extended to allow them to be used in settings where participant anonymity is required. Systematic experiments show favorable tradeoffs between anonymity guarantees and estimator performance. Taken together, we demonstrate that reasonable population size estimates are derived from anonymous respondent driven samples of 250-750 individuals, within ambient populations of 5,000-40,000. The method thus represents a novel and cost-effective means for health planners and those agencies concerned with health and disease surveillance to estimate the size of hidden populations. We discuss limitations and future work in the concluding section.
The fine-scale genetic structure and evolution of the Japanese population.
Takeuchi, Fumihiko; Katsuya, Tomohiro; Kimura, Ryosuke; Nabika, Toru; Isomura, Minoru; Ohkubo, Takayoshi; Tabara, Yasuharu; Yamamoto, Ken; Yokota, Mitsuhiro; Liu, Xuanyao; Saw, Woei-Yuh; Mamatyusupu, Dolikun; Yang, Wenjun; Xu, Shuhua; Teo, Yik-Ying; Kato, Norihiro
2017-01-01
The contemporary Japanese populations largely consist of three genetically distinct groups-Hondo, Ryukyu and Ainu. By principal-component analysis, while the three groups can be clearly separated, the Hondo people, comprising 99% of the Japanese, form one almost indistinguishable cluster. To understand fine-scale genetic structure, we applied powerful haplotype-based statistical methods to genome-wide single nucleotide polymorphism data from 1600 Japanese individuals, sampled from eight distinct regions in Japan. We then combined the Japanese data with 26 other Asian populations data to analyze the shared ancestry and genetic differentiation. We found that the Japanese could be separated into nine genetic clusters in our dataset, showing a marked concordance with geography; and that major components of ancestry profile of Japanese were from the Korean and Han Chinese clusters. We also detected and dated admixture in the Japanese. While genetic differentiation between Ryukyu and Hondo was suggested to be caused in part by positive selection, genetic differentiation among the Hondo clusters appeared to result principally from genetic drift. Notably, in Asians, we found the possibility that positive selection accentuated genetic differentiation among distant populations but attenuated genetic differentiation among close populations. These findings are significant for studies of human evolution and medical genetics.
A new method for finding and characterizing galaxy groups via low-frequency radio surveys
NASA Astrophysics Data System (ADS)
Croston, J. H.; Ineson, J.; Hardcastle, M. J.; Mingo, B.
2017-09-01
We describe a new method for identifying and characterizing the thermodynamic state of large samples of evolved galaxy groups at high redshifts using high-resolution, low-frequency radio surveys, such as those that will be carried out with LOFAR and the Square Kilometre Array. We identify a sub-population of morphologically regular powerful [Fanaroff-Riley type II (FR II)] radio galaxies and demonstrate that, for this sub-population, the internal pressure of the radio lobes is a reliable tracer of the external intragroup/intracluster medium (ICM) pressure, and that the assumption of a universal pressure profile for relaxed groups enables the total mass and X-ray luminosity to be estimated. Using a sample of well-studied FR II radio galaxies, we demonstrate that our method enables the estimation of group/cluster X-ray luminosities over three orders of magnitude in luminosity to within a factor of ˜2 from low-frequency radio properties alone. Our method could provide a powerful new tool for building samples of thousands of evolved galaxy groups at z > 1 and characterizing their ICM.
Sources of variation in waterfowl survival rates
Krementz, D.G.; Barker, R.J.; Nichols, J.D.
1997-01-01
Because of the need to manage hunted populations of waterfowl (Anatidae), biologists have studied many demographic traits of waterfowl by analyzing band recoveries. These analyses have produced the most extensive and best estimates of survival available for any group of birds. Using these data, we examined several factors that might explain variation among annual survival rates to explore large-scale patterns that might be useful in understanding waterfowl population dynamics. We found that geography, body mass, and tribe (i.e. phylogeny) were important in explaining variation in average waterfowl survival rates.
Effect of L-arginine supplementation on immune responsiveness in patients with sickle cell disease.
Scavella, Arnette; Leiva, Lily; Monjure, Hanh; Zea, Arnold H; Gardner, Renee V
2010-08-01
L-arginine (L-Arg) is deficient in sickle cell disease (SSD) during vasoocclusion. We investigated possible causal relationship between L-Arg deficiency and immune dysfunction in SSD in steady-state. Fifteen patients with SSD in steady-state and 13 controls were studied. Plasma L-Arg levels were measured using liquid chromatography. T cell subsets and CD3zeta (CD3zeta) chain expression were analyzed using flow cytometry. Lymphocyte proliferative response to phytohemagglutinin (PHA) and production of IL-6 and interferon-gamma (IFN-gamma) were evaluated with and without L-Arg. SSD patients had significantly lower L-Arg levels than controls. CD3 and CD19 cell populations were comparable for both groups, but SSD patients had above normal numbers of natural killer cells (P = 0.06). Patients and controls exhibited significantly increased lymphocyte blastogenesis to PHA after introduction of L-Arg to cultures; response of patients was significantly greater than values for control individuals. Proliferative response to candida in SSD patients was significantly lower than in controls; L-Arg supplementation did not increase this response. L-Arg had no effect on blastogenic response to PPD and candida albicans. No effect was likewise seen in production of IL-6 and IFN-gamma after addition of L-Arg. CD3zeta chain expression increased after addition of L-Arg in both groups; differences were insignificant. L-Arg levels in steady-state SSD are significantly lower than in controls. L-Arg supplementation enhanced lymphocyte blastogenesis to PHA for both controls and patients, but not in response to antigen. There were no significant differences in CD3zeta chain expression although upregulation of expression occurred after L-Arg supplementation for both groups. (c) 2010 Wiley-Liss, Inc.
The Genetics of Mexico Recapitulates Native American Substructure and Affects Biomedical Traits
Moreno-Estrada, Andrés; Gignoux, Christopher R.; Fernández-López, Juan Carlos; Zakharia, Fouad; Sikora, Martin; Contreras, Alejandra V.; Acuña-Alonzo, Victor; Sandoval, Karla; Eng, Celeste; Romero-Hidalgo, Sandra; Ortiz-Tello, Patricia; Robles, Victoria; Kenny, Eimear E.; Nuño-Arana, Ismael; Barquera-Lozano, Rodrigo; Macín-Pérez, Gastón; Granados-Arriola, Julio; Huntsman, Scott; Galanter, Joshua M.; Via, Marc; Ford, Jean G.; Chapela, Rocío; Rodriguez-Cintron, William; Rodríguez-Santana, Jose R.; Romieu, Isabelle; Sienra-Monge, Juan José; Navarro, Blanca del Rio; London, Stephanie J.; Ruiz-Linares, Andrés; Garcia-Herrera, Rodrigo; Estrada, Karol; Hidalgo-Miranda, Alfredo; Jimenez-Sanchez, Gerardo; Carnevale, Alessandra; Soberón, Xavier; Canizales-Quinteros, Samuel; Rangel-Villalobos, Héctor; Silva-Zolezzi, Irma; Burchard, Esteban Gonzalez; Bustamante, Carlos D.
2014-01-01
Mexico harbors great cultural and ethnic diversity, yet fine-scale patterns of human genome-wide variation from this region remain largely uncharacterized. We studied genomic variation within Mexico from over 1,000 individuals representing 20 indigenous and 11 mestizo populations. We found striking genetic stratification among indigenous populations within Mexico at varying degrees of geographic isolation. Some groups were as differentiated as Europeans are from East Asians. Pre-Columbian genetic substructure is recapitulated in the indigenous ancestry of admixed mestizo individuals across the country. Furthermore, two independently phenotyped cohorts of Mexicans and Mexican Americans showed a significant association between sub-continental ancestry and lung function. Thus, accounting for fine-scale ancestry patterns is critical for medical and population genetic studies within Mexico, in Mexican-descent populations, and likely in many other populations worldwide. PMID:24926019
Paquet, Victor; Joseph, Caroline; D'Souza, Clive
2012-01-01
Anthropometric studies typically require a large number of individuals that are selected in a manner so that demographic characteristics that impact body size and function are proportionally representative of a user population. This sampling approach does not allow for an efficient characterization of the distribution of body sizes and functions of sub-groups within a population and the demographic characteristics of user populations can often change with time, limiting the application of the anthropometric data in design. The objective of this study is to demonstrate how demographically representative user populations can be developed from samples that are not proportionally representative in order to improve the application of anthropometric data in design. An engineering anthropometry problem of door width and clear floor space width is used to illustrate the value of the approach.
Bittkau, C; Comes, H P
2005-11-01
Continental shelf island systems, created by rising sea levels, provide a premier setting for studying the effects of past fragmentation, dispersal, and genetic drift on taxon diversification. We used phylogeographical (nested clade) and population genetic analyses to elucidate the relative roles of these processes in the evolutionary history of the Aegean Nigella arvensis alliance (= 'coenospecies'). We surveyed chloroplast DNA (cpDNA) variation in 455 individuals from 47 populations (nine taxa) of the alliance throughout its core range in the Aegean Archipelago and surrounding mainland areas of Greece and Turkey. The study revealed the presence of three major lineages, with largely nonoverlapping distributions in the Western, Central, and Eastern Aegean. There is evidence supporting the idea that these major lineages evolved in situ from a widespread (pan-Aegean) ancestral stock as a result of multiple fragmentation events, possibly due to the influence of post-Messinian sea flooding, Pleistocene eustatic changes and corresponding climate fluctuations. Over-sea dispersal and founder events appear to have played a rather insignificant role in the group's history. Rather, all analytical approaches identified the alliance as an organism group with poor seed dispersal capabilities and a susceptibility to genetic drift. In particular, we inferred that the observed level of cpDNA differentiation between Kikladian island populations of Nigella degenii largely reflects population history, (viz. Holocene island fragmentation) and genetic drift in the near absence of seed flow since their time of common ancestry. Overall, our cpDNA data for the N. arvensis alliance in general, and N. degenii in particular, indicate that historical events were important in determining the phylogeographical patterns seen, and that genetic drift has historically been relatively more influential on population structure than has cytoplasmic gene flow.
Yi, Stella S; Tabaei, Bahman P; Angell, Sonia Y; Rapin, Anne; Buck, Michael D; Pagano, William G; Maselli, Frank J; Simmons, Alvaro; Chamany, Shadi
2015-03-01
Hypertension is a leading risk factor for cardiovascular disease. Although control rates have improved over time, racial/ethnic disparities in hypertension control persist. Self-blood pressure monitoring, by itself, has been shown to be an effective tool in predominantly white populations, but less studied in minority, urban communities. These types of minimally intensive approaches are important to test in all populations, especially those experiencing related health disparities, for broad implementation with limited resources. The New York City Health Department in partnership with community clinic networks implemented a randomized clinical trial (n=900, 450 per arm) to investigate the effectiveness of self-blood pressure monitoring in medically underserved and largely black and Hispanic participants. Intervention participants received a home blood pressure monitor and training on use, whereas control participants received usual care. After 9 months, systolic blood pressure decreased (intervention, 14.7 mm Hg; control, 14.1 mm Hg; P=0.70). Similar results were observed when incorporating longitudinal data and calculating a mean slope over time. Control was achieved in 38.9% of intervention and 39.1% of control participants at the end of follow-up; the time-to-event experience of achieving blood pressure control in the intervention versus control groups were not different from each other (logrank P value =0.91). Self-blood pressure monitoring was not shown to improve control over usual care in this largely minority, urban population. The patient population in this study, which included a high proportion of Hispanics and uninsured persons, is understudied. Results indicate these groups may have additional meaningful barriers to achieving blood pressure control beyond access to the monitor itself. http://clinicaltrials.gov. Unique Identifier: NCT01123577. © 2015 American Heart Association, Inc.
Teitelbaum, M S
1992-01-01
Commentary is provided on the challenges faced by the new Clinton administration in formulating US key foreign policy initiatives. There is an urgent need to provide balanced and effective foreign aid for reducing high fertility rates in the developing world. There is also a need to effectively monitor the large migrations of populations. Over the past 10 years, the US has not been actively practicing world leadership on population issues. 3 changes in 1993 give impetus to redirect foreign policy: 1) the waning influence of fringe groups who controlled population issues; 2) the campaign promises to restore UN population stabilization programs; and 3) the evidence from the Persian Gulf and Yugoslavia that demographic issues require planning and assessment. Global population growth has been concentrated in the past 40 years, in part due to mortality declines and sustained high fertility. Of significance is the rapidness and momentum of growth. A high percentage are and will be children. Urban population is also growing rapidly in high fertility countries. Countries with high fertility and significant rural-to-urban migration also have large international migrations. The evolution of policy since the 1950s, which for the most part ignored population issues, is discussed. The American debates have been charged with emotionalism: about human sexuality, legitimacy of voluntary fertility control, the role and status of women and men, abortion, intergenerational transfer of obligations, ethnic solidarity and the sovereignty of national borders, and the proper roles of the state versus the marketplace. There have been over 200 years of ideological argument over population issues. The Malthusian argument was that large population size did not increase prosperity, and growth should be limited. The Marxist-Leninist position was that contraception was Malthusian, abortion was a woman's right, and population growth was neutral. By late 1970 the Chinese Maoists adopted the moral contraints urged by Malthus. US policies in the 1980s amounted to defunding of population programs and ideological suppression. Seven steps in US policy change are indicated. Centralization of responsibilities for population issues should be determined within government; the Department of State or the National Security Council are likely choices.
Dispersal similarly shapes both population genetics and community patterns in the marine realm
Chust, Guillem; Villarino, Ernesto; Chenuil, Anne; Irigoien, Xabier; Bizsel, Nihayet; Bode, Antonio; Broms, Cecilie; Claus, Simon; Fernández de Puelles, María L.; Fonda-Umani, Serena; Hoarau, Galice; Mazzocchi, Maria G.; Mozetič, Patricija; Vandepitte, Leen; Veríssimo, Helena; Zervoudaki, Soultana; Borja, Angel
2016-01-01
Dispersal plays a key role to connect populations and, if limited, is one of the main processes to maintain and generate regional biodiversity. According to neutral theories of molecular evolution and biodiversity, dispersal limitation of propagules and population stochasticity are integral to shaping both genetic and community structure. We conducted a parallel analysis of biological connectivity at genetic and community levels in marine groups with different dispersal traits. We compiled large data sets of population genetic structure (98 benthic macroinvertebrate and 35 planktonic species) and biogeographic data (2193 benthic macroinvertebrate and 734 planktonic species). We estimated dispersal distances from population genetic data (i.e., FST vs. geographic distance) and from β-diversity at the community level. Dispersal distances ranked the biological groups in the same order at both genetic and community levels, as predicted by organism dispersal ability and seascape connectivity: macrozoobenthic species without dispersing larvae, followed by macrozoobenthic species with dispersing larvae and plankton (phyto- and zooplankton). This ranking order is associated with constraints to the movement of macrozoobenthos within the seabed compared with the pelagic habitat. We showed that dispersal limitation similarly determines the connectivity degree of communities and populations, supporting the predictions of neutral theories in marine biodiversity patterns. PMID:27344967
SARGENT, DANIEL J.; GEIBEL, M.; HAWKINS, J. A.; WILKINSON, M. J.; BATTEY, N. H.; SIMPSON, D. W.
2004-01-01
• Background and Aims The aims of this investigation were to highlight the qualitative and quantitative diversity apparent between nine diploid Fragaria species and produce interspecific populations segregating for a large number of morphological characters suitable for quantitative trait loci analysis. • Methods A qualitative comparison of eight described diploid Fragaria species was performed and measurements were taken of 23 morphological traits from 19 accessions including eight described species and one previously undescribed species. A principal components analysis was performed on 14 mathematically unrelated traits from these accessions, which partitioned the species accessions into distinct morphological groups. Interspecific crosses were performed with accessions of species that displayed significant quantitative divergence and, from these, populations that should segregate for a range of quantitative traits were raised. • Key Results Significant differences between species were observed for all 23 morphological traits quantified and three distinct groups of species accessions were observed after the principal components analysis. Interspecific crosses were performed between these groups, and F2 and backcross populations were raised that should segregate for a range of morphological characters. In addition, the study highlighted a number of distinctive morphological characters in many of the species studied. • Conclusions Diploid Fragaria species are morphologically diverse, yet remain highly interfertile, making the group an ideal model for the study of the genetic basis of phenotypic differences between species through map-based investigation using quantitative trait loci. The segregating interspecific populations raised will be ideal for such investigations and could also provide insights into the nature and extent of genome evolution within this group. PMID:15469944
Ischemic stroke subtypes: a population-based study of incidence rates among blacks and whites.
Schneider, Alexander T; Kissela, Brett; Woo, Daniel; Kleindorfer, Dawn; Alwell, Kathleen; Miller, Rosemary; Szaflarski, Jerzy; Gebel, James; Khoury, Jane; Shukla, Rakesh; Moomaw, Charles; Pancioli, Arthur; Jauch, Edward; Broderick, Joseph
2004-07-01
Blacks have an excess burden of stroke compared with whites; however, data comparing ischemic stroke subtypes among the 2 groups are limited and typically involve relative frequencies. The objective of this study is to compare the incidence rates of ischemic stroke subtypes between blacks and whites within a large, representative, biracial population. The Greater Cincinnati/Northern Kentucky Stroke Study is designed to measure incidence rates and trends of all strokes within a well-defined, large, biracial population. Hospitalized cases were ascertained by International Classification of Disease (9th revision; ICD-9) discharge codes. Out-of-hospital events were ascertained by prospective screening of emergency department admission logs, review of coroners' cases, and monitoring all public health and hospital-based primary care clinics. A sampling scheme was used to ascertain events from nursing homes and all other primary care physician offices. All potential cases underwent detailed chart abstraction and confirmed by physician review. Based on all available clinical, laboratory, and radiographic information, ischemic stroke cases were subtyped into the following categories: cardioembolic, large-vessel, small-vessel, other, and stroke of undetermined cause. Race-specific incidence rates were calculated and compared after adjusting for age and gender, and standardizing to the 1990 US population. Between July 1, 1993, and June 30, 1994, 1956 first-ever ischemic strokes occurred among blacks and whites in the study population. Small-vessel strokes and strokes of undetermined cause were nearly twice as common among blacks. Large-vessel strokes were 40% more common among blacks than whites, and there was a trend toward cardioembolic strokes being more common among blacks. The excess burden of ischemic strokes among blacks compared with whites is not uniformly spread across the different subtypes. Large-vessel strokes are more common and cardioembolic stroke are as common among blacks, traditionally thought to be more common among whites.
Orthobiologics in the augmentation of osteoporotic fractures.
Watson, J Tracy; Nicolaou, Daemeon A
2015-02-01
Many orthobiologic adjuvants are available and widely utilized for general skeletal restoration. Their use for the specific task of osteoporotic fracture augmentation is less well recognized. Common conductive materials are reviewed for their value in this patient population including the large group of allograft adjuvants categorically known as the demineralized bone matrices (DBMs). Another large group of alloplastic materials is also examined-the calcium phosphate and sulfate ceramics. Both of these materials, when used for the proper indications, demonstrate efficacy for these patients. The inductive properties of bone morphogenic proteins (BMPs) and platelet concentrates show no clear advantages for this group of patients. Systemic agents including bisphosphonates, receptor activator of nuclear factor κβ ligand (RANKL) inhibitors, and parathyroid hormone augmentation all demonstrate positive effects with this fracture cohort. Newer modalities, such as trace ion bioceramic augmentation, are also reviewed for their positive effects on osteoporotic fracture healing.
Capredon, Mélanie; Brucato, Nicolas; Tonasso, Laure; Choesmel-Cadamuro, Valérie; Ricaut, François-Xavier; Razafindrazaka, Harilanto; Rakotondrabe, Andriamihaja Bakomalala; Ratolojanahary, Mamisoa Adelta; Randriamarolaza, Louis-Paul; Champion, Bernard; Dugoujon, Jean-Michel
2013-01-01
Madagascar is located at the crossroads of the Asian and African worlds and is therefore of particular interest for studies on human population migration. Within the large human diversity of the Great Island, we focused our study on a particular ethnic group, the Antemoro. Their culture presents an important Arab-Islamic influence, but the question of an Arab biological inheritance remains unresolved. We analyzed paternal (n=129) and maternal (n=135) lineages of this ethnic group. Although the majority of Antemoro genetic ancestry comes from sub-Saharan African and Southeast Asian gene pools, we observed in their paternal lineages two specific haplogroups (J1 and T1) linked to Middle Eastern origins. This inheritance was restricted to some Antemoro sub-groups. Statistical analyses tended to confirm significant Middle Eastern genetic contribution. This study gives a new perspective to the large human genetic diversity in Madagascar. PMID:24278350
Occurence of internet addiction in a general population sample: a latent class analysis.
Rumpf, Hans-Jürgen; Vermulst, Ad A; Bischof, Anja; Kastirke, Nadin; Gürtler, Diana; Bischof, Gallus; Meerkerk, Gert-Jan; John, Ulrich; Meyer, Christian
2014-01-01
Prevalence studies of Internet addiction in the general population are rare. In addition, a lack of approved criteria hampers estimation of its occurrence. This study conducted a latent class analysis (LCA) in a large general population sample to estimate prevalence. A telephone survey was conducted based on a random digit dialling procedure including landline telephone (n=14,022) and cell phone numbers (n=1,001) in participants aged 14-64. The Compulsive Internet Use Scale (CIUS) served as the basis for a LCA used to look for subgroups representing participants with Internet addiction or at-risk use. CIUS was given to participants reporting to use the Internet for private purposes at least 1 h on a typical weekday or at least 1 h on a day at the weekend (n=8,130). A 6-class model showed best model fit and included two groups likely to represent Internet addiction and at-risk Internet use. Both groups showed less social participation and the Internet addiction group less general trust in other people. Proportions of probable Internet addiction were 1.0% (CI 0.9-1.2) among the entire sample, 2.4% (CI 1.9-3.1) in the age group 14-24, and 4.0% (CI 2.7-5.7) in the age group 14-16. No difference in estimated proportions between males and females was found. Unemployment (OR 3.13; CI 1.74-5.65) and migration background (OR 3.04; CI 2.12-4.36) were related to Internet addiction. This LCA-based study differentiated groups likely to have Internet addiction and at-risk use in the general population and provides characteristics to further define this rather new disorder. © 2013 S. Karger AG, Basel.
Prehispanic adaptation in the ixtapalapa region, Mexico.
Blanton, R E
1972-03-24
Data accumulated during an intensive survey of Prehispanic settlements in the Ixtapalapa Peninsula region enables me to formulate hypotheses regarding the nature of sociocultural change and adaptation during the Prehispanic period. A summary of these hypotheses follows. The Early and Middle Formative period was a time of low population, when most communities were located on or near the agriculturally productive lakeshore plain zone. During the subsequent period, attendant upon the development in the central highlands of more productive varieties of maize, population increased, and for the first time the agriculturally marginal piedmont zone was colonized. This process may have resulted in the enhancement of status differentiation in these societies because some communities maintained access to the preferred land along the lakeshore plain zone. Also, occupation of a variety of environmental zones may have encouraged symbiosis, which could have further enhanced status differentiation as some individuals or groups became the focuses of exchange networks. During the Late Formative period, developments along this line proceeded throughout the Valley of Mexico, but later, during the Terminal Formative period, some groups prospered more than others because they were favorably situated for the construction of large-scale irrigation systems. The foremost example of the latter is Teotihuacan, which eventually dominated the population of the Ixtapalapa Peninsula region, as well as the remainder of the Valley of Mexico and probably adjacent groups in the central highlands. From A.D. 0 to A.D. 700, the region was dominated by Teotihuacan. This was a period of low population and apparently rural settlement patterns. A similar situation existed during the Late Toltec period as Tula dominated the region. I suggest that Teotihuacan and Tula had similar relationships with their rural peripheries; specifically, they were largely extractive and so dominated rural populations that they were the only important focuses of exchange and craft specialization. Population declined in the rural areas in part because they were too far from the urban centers to participate effectively in the exchange networks. In contrast, the Aztec period was characterized by the presence of a number of urban centers scattered widely over the valley; these centers served as the focuses of exchange and specialization. A similar situation may have characterized the Early Toltec period. During the Aztec period, the combination of intensive local and valleywide symbiosis plus the introduction of chinampas allowed the population to reach the greatest density of the Prehispanic period.
Ayada, C; Toru, U; Genç, O; Yerlikaya, A; Sahin, S; Turgut, S; Turgut, G
2014-12-12
Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow obstruction that occurs as a result of the normal inflammatory process to protect against harmful irritants and chemicals. Another physiological regulatory process, the renin angiotensin system (RAS), plays an important role in the pathology of many diseases. Angiotensin converting enzyme (ACE) is a key enzyme of RAS. We investigated the frequency of the ACE gene I/D polymorphism in patients with COPD in Turkey. This study was performed on 47 unrelated patients with COPD and 64 healthy subjects. DNA samples were isolated from peripheral blood, and ACE DNA was amplified by polymerase chain reaction. The frequencies of ACE genotypes were 27.7, 55.3, and 17% for DD, ID, and II in the COPD group, respectively, and 43.8, 43.8, and 12.4% in the control group. There was no statistically significant difference between groups (X(2) = 3.078; df = 2; P = 0.220). The distributions of ACE gene D alleles were 38.2% (N = 52) in the COPD group and 61.8% (N = 84) in the control group; and those of I alleles were 48.8% (N = 42) in the COPD group and 51.2% (N = 44) in the control group. There was no statistically significant difference between groups for allele frequency (X(2) = 2.419; df = 2; P = 0.120). We believe these results can be useful for large-scale population genetic research considering the frequency of the ACE gene variation in COPD patients in the Turkish population.
Probabilistic models for neural populations that naturally capture global coupling and criticality
2017-01-01
Advances in multi-unit recordings pave the way for statistical modeling of activity patterns in large neural populations. Recent studies have shown that the summed activity of all neurons strongly shapes the population response. A separate recent finding has been that neural populations also exhibit criticality, an anomalously large dynamic range for the probabilities of different population activity patterns. Motivated by these two observations, we introduce a class of probabilistic models which takes into account the prior knowledge that the neural population could be globally coupled and close to critical. These models consist of an energy function which parametrizes interactions between small groups of neurons, and an arbitrary positive, strictly increasing, and twice differentiable function which maps the energy of a population pattern to its probability. We show that: 1) augmenting a pairwise Ising model with a nonlinearity yields an accurate description of the activity of retinal ganglion cells which outperforms previous models based on the summed activity of neurons; 2) prior knowledge that the population is critical translates to prior expectations about the shape of the nonlinearity; 3) the nonlinearity admits an interpretation in terms of a continuous latent variable globally coupling the system whose distribution we can infer from data. Our method is independent of the underlying system’s state space; hence, it can be applied to other systems such as natural scenes or amino acid sequences of proteins which are also known to exhibit criticality. PMID:28926564
Piziak, Veronica
2014-12-01
The prevalence of obesity in the Hispanic preschool population remains elevated, particularly among children in low income families below the poverty level. Obesity leads to the early onset of metabolic syndrome and Type 2 diabetes. The Head Start population of Texas is largely comprised of this high risk group. Their physical activity level is suboptimal in part due to lack of available outside play areas and time spent watching television and playing sedentary video games. Dietary intake is frequently high in sugar sweetened beverages and low in vegetables. The group is frequently bilingual with limited vocabulary and has not learned to read. Preserving their Mexican American culture is a concern. This article describes the development and assessment of a group of bilingual interactive video interventions to improve age appropriate physical activity while providing basic nutrition education focusing on increasing vegetable and water intake and decreasing sugar sweetened beverages. Suggestions for development and assessment of content were provided by focus groups of Head Start teachers, managers and dietitians in the Texas counties of Bastrop, Hidalgo and McLennon. A demonstration of the videos was conducted in Bastrop County. Teachers, students and managers felt that the videos provided excellent information, improved exercise participation and engaged the children.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nieves, L.A.; Wernette, D.R.
1997-02-01
Differences among racial and ethnic groups in morbidity and mortality rates for diseases, including diseases with environmental causes, have been extensively documented. However, documenting the linkages between environmental contaminants, individual exposures, and disease incidence has been hindered by difficulties in measuring exposure for the population in general and for minority populations in particular. After briefly discussing research findings on associations of common air pollutants with disease incidence, the authors summarize recent studies of radial/ethnic subgroup differences in incidence of these diseases in the US. They then present evidence of both historic and current patterns of disproportionate minority group exposure tomore » air pollution as measured by residence in areas where ambient air quality standards are violated. The current indications of disproportionate potential exposures of minority and low-income populations to air pollutants represent the continuation of a historical trend. The evidence of linkage between disproportionate exposure to air pollution of racial/ethnic minorities and low-income groups and their higher rates of some air pollution-related diseases is largely circumstantial. Differences in disease incidence and mortality rates among racial/ethnic groups are discussed for respiratory diseases, cancers, and lead poisoning. Pollutants of concern include CO, Pb, SO{sub 2}, O{sub 3}, and particulates.« less
The co-evolution of social institutions, demography, and large-scale human cooperation.
Powers, Simon T; Lehmann, Laurent
2013-11-01
Human cooperation is typically coordinated by institutions, which determine the outcome structure of the social interactions individuals engage in. Explaining the Neolithic transition from small- to large-scale societies involves understanding how these institutions co-evolve with demography. We study this using a demographically explicit model of institution formation in a patch-structured population. Each patch supports both social and asocial niches. Social individuals create an institution, at a cost to themselves, by negotiating how much of the costly public good provided by cooperators is invested into sanctioning defectors. The remainder of their public good is invested in technology that increases carrying capacity, such as irrigation systems. We show that social individuals can invade a population of asocials, and form institutions that support high levels of cooperation. We then demonstrate conditions where the co-evolution of cooperation, institutions, and demographic carrying capacity creates a transition from small- to large-scale social groups. © 2013 John Wiley & Sons Ltd/CNRS.
Outlining the Ancestry Landscape of Colombian Admixed Populations
Ossa, Humberto; Aquino, Juliana; Pereira, Rui; Ibarra, Adriana; Ossa, Rafael H; Pérez, Luz Adriana; Granda, Juan David; Lattig, Maria Claudia; Groot, Helena; Fagundes de Carvalho, Elizeu; Gusmão, Leonor
2016-01-01
The ancestry of the Colombian population comprises a large number of well differentiated Native communities belonging to diverse linguistic groups. In the late fifteenth century, a process of admixture was initiated with the arrival of the Europeans, and several years later, Africans also became part of the Colombian population. Therefore, the genepool of the current Colombian population results from the admixture of Native Americans, Europeans and Africans. This admixture occurred differently in each region of the country, producing a clearly stratified population. Considering the importance of population substructure in both clinical and forensic genetics, we sought to investigate and compare patterns of genetic ancestry in Colombia by studying samples from Native and non-Native populations living in its 5 continental regions: the Andes, Caribe, Amazonia, Orinoquía, and Pacific regions. For this purpose, 46 AIM-Indels were genotyped in 761 non-related individuals from current populations. Previously published genotype data from 214 Colombian Natives from five communities were used for population comparisons. Significant differences were observed between Native and non-Native populations, among non-Native populations from different regions and among Native populations from different ethnic groups. The Pacific was the region with the highest African ancestry, Amazonia harboured the highest Native ancestry and the Andean and Orinoquían regions showed the highest proportion of European ancestry. The Andean region was further sub-divided into 6 sub-regions: North East, Central West, Central East, West, South West and South East. Among these regions, the South West region showed a significantly lower European admixture than the other regions. Hardy-Weinberg equilibrium and variance values of ancestry among individuals within populations showed a potential stratification of the Pacific population. PMID:27736937
ERIC Educational Resources Information Center
Silvestri, Lynette; Bonis, Marc
2009-01-01
Health education can improve the health of the nation. Emphasis is on promoting health, maintaining good health and preventing health problems. A segment of society that tends to ignore their health is college students. They are a large group that makes up 31% of 18-24 year olds in the U.S. (Hingson, et al, 2001). This population is considered to…
Impairment in Movement Skills of Children with Autistic Spectrum Disorders
ERIC Educational Resources Information Center
Green, Dido; Charman, Tony; Pickles, Andrew; Chandler, Susie; Loucas, Tom; Simonoff, Emily; Baird, Gillian
2009-01-01
Aim: We undertook this study to explore the degree of impairment in movement skills in children with autistic spectrum disorders (ASD) and a wide IQ range. Method: Movement skills were measured using the Movement Assessment Battery for Children (M-ABC) in a large, well defined, population-derived group of children (n=101: 89 males,12 females; mean…
Measures of Strength and Fitness for Older Populations.
ERIC Educational Resources Information Center
Osness, Wayne H.; Hiebert, Lujean M.
The overall strength of the musculature does not require testing of large numbers of muscle groups and can be accomplished from three or four tests. Small batteries of strength tests have been devised to predict total strength. The best combination of tests for males are thigh flexors, leg extensors, arm flexors, and pectoralis major. The battery…
ERIC Educational Resources Information Center
Shaver, Annis; Cuevas, Peggy; Lee, Okhee; Avalos, Mary
2007-01-01
This study asked elementary school teachers how educational policies affected their science instruction with a majority of English language learners. The study employed a questionnaire followed by focus group interviews with 43 third and fourth grade teachers from six elementary schools in a large urban school district with high populations of…
Knowledge and Attitude of Nigerian Adolescents to Premarital Genotying.
ERIC Educational Resources Information Center
Egbochuku, E. O.; Imogie, A. O.
Sickle cell disease (SCD) refers to a group of hereditary disorders of the structure of hemoglobin of red blood cells. This disorder involves the inheritance of two abnormal genes, which are related to the hemoglobin promotion, at least, one of which is the sickle cell gene. Nigeria, by virtue of her large population, has the greatest number of…
The Role of Social Capital and School Structure on Latino Access to Elite Colleges
ERIC Educational Resources Information Center
Gonzalez, Jeremiah J.
2013-01-01
Latinos make up the fastest growing population in the United States. However, this group has some of the lowest educational outcomes (Gandara & Contreras, 2009). Although large numbers of Latinos fail to achieve high levels of academic success, some Latinos are able to accomplish educational outcomes that compare with those of the most…
Individual and Group Reflection Strategies: What We Learned from Preservice Teachers
ERIC Educational Resources Information Center
Lin, Miranda; Lucey, Thomas A.
2010-01-01
As classrooms become more diverse, one of the necessary goals of teacher education programs is to prepare preservice teachers (PSTs) to work with children of diverse populations. PSTs who derive largely from a dominant White culture will clearly face this challenge. One effective approach used to assist PSTs to grasp the issues of cultural…
ERIC Educational Resources Information Center
Salem, Jamie; Fehrmann, Paul
2013-01-01
With the growing population of undergraduate students on our campus and an increased focus on their success, librarians at a large midwestern university were interested in the citation management styles of this university cohort. Our university library spends considerable resources each year to maintain and promote access to the robust…
The Family in the Structure of Values of Young People
ERIC Educational Resources Information Center
Rean, A. A.
2018-01-01
Despite the fact that the family is extremely significant in the system of values of young people (in Russia), the number of divorces is increasing in this population group. Our analysis of this contradiction establishes that young people need to be specially prepared for family life. The paper presents the results of a large empirical study…
Wasfi, Rania; Steinmetz-Wood, Madeleine; Kestens, Yan
2017-01-01
This study examined the influence of walkability on walking behaviour and assessed whether associations varied according to life-stage and population center (PC) size. Walkability scores were obtained for the six-digit postal codes of residential neighbourhoods of 11,200 Canadians, who participated in biennial assessments of the National Population Health Survey from 1994 to 2010. Participants were stratified by age-group. Mixed-effects logistic regression models were used to estimate the influence of cumulative exposure to neighborhood walkability on utilitarian and exercise walking by PC size and life-stage. Associations of neighbourhood walkability with utilitarian and exercise walking varied according to age-group and PC size. Exposure to high walkable neighborhoods was associated with utilitarian walking in younger and older adults in all PC sizes, except for older adults living in a medium PC. Living in a highly walkable neighborhood in a large PC was associated with walking for exercise in younger (OR: 1.42; 95%CI: 1.20-1.67) and older adults (OR: 2.09; 95%CI: 1.51-2.89). Living in highly walkable neighbourhood in a medium PC was associated with walking for exercise in older adults (OR: 1.62; 95%CI: 1.15-2.29). These results emphasize the need to consider the size and nature of every community, and the age-group of a population when implementing strategies to promote walking.
Steinmetz-Wood, Madeleine; Kestens, Yan
2017-01-01
This study examined the influence of walkability on walking behaviour and assessed whether associations varied according to life-stage and population center (PC) size. Walkability scores were obtained for the six-digit postal codes of residential neighbourhoods of 11,200 Canadians, who participated in biennial assessments of the National Population Health Survey from 1994 to 2010. Participants were stratified by age-group. Mixed-effects logistic regression models were used to estimate the influence of cumulative exposure to neighborhood walkability on utilitarian and exercise walking by PC size and life-stage. Associations of neighbourhood walkability with utilitarian and exercise walking varied according to age-group and PC size. Exposure to high walkable neighborhoods was associated with utilitarian walking in younger and older adults in all PC sizes, except for older adults living in a medium PC. Living in a highly walkable neighborhood in a large PC was associated with walking for exercise in younger (OR: 1.42; 95%CI: 1.20–1.67) and older adults (OR: 2.09; 95%CI: 1.51–2.89). Living in highly walkable neighbourhood in a medium PC was associated with walking for exercise in older adults (OR: 1.62; 95%CI: 1.15–2.29). These results emphasize the need to consider the size and nature of every community, and the age-group of a population when implementing strategies to promote walking. PMID:29261706
Hruschka, Daniel J.; Hadley, Craig; Brewis, Alexandra A.; Stojanowski, Christopher M.
2015-01-01
Contemporary human populations conform to ecogeographic predictions that animals will become more compact in cooler climates and less compact in warmer ones. However, it remains unclear to what extent this pattern reflects plastic responses to current environments or genetic differences among populations. Analyzing anthropometric surveys of 232,684 children and adults from across 80 ethnolinguistic groups in sub-Saharan Africa, Asia and the Americas, we confirm that body surface-to-volume correlates with contemporary temperature at magnitudes found in more latitudinally diverse samples (Adj. R2 = 0.14-0.28). However, far more variation in body surface-to-volume is attributable to genetic population structure (Adj. R2 = 0.50-0.74). Moreover, genetic population structure accounts for nearly all of the observed relationship between contemporary temperature and body surface-to-volume among children and adults. Indeed, after controlling for population structure, contemporary temperature accounts for no more than 4% of the variance in body form in these groups. This effect of genetic affinity on body form is also independent of other ecological variables, such as dominant mode of subsistence and household wealth per capita. These findings suggest that the observed fit of human body surface-to-volume with current climate in this sample reflects relatively large effects of existing genetic population structure of contemporary humans compared to plastic response to current environments. PMID:25816235
Li, Zhenghui; Zhang, Jian; Zhang, Hantao; Lin, Ziqing; Ye, Jian
2018-05-01
Short tandem repeats (STRs) play a vitally important role in forensics. Population data is needed to improve the field. There is currently no large population data-based data set in Chamdo Tibetan. In our study, the allele frequencies and forensic statistical parameters of 18 autosomal STR loci (D5S818, D21S11, D7S820, CSF1PO, D2S1338, D3S1358, VWA, D8S1179, D16S539, PentaE, TPOX, TH01, D19S433, D18S51, FGA, D6S1043, D13S317, and D12S391) included in the DNATyper™19 kit were investigated in 2249 healthy, unrelated Tibetan subjects living in Tibet Chamdo, Southwest China. The combined power of discrimination and the combined probability of exclusion of all 18 loci were 0.9999999999999999999998174 and 0.99999994704, respectively. Furthermore, the genetic relationship between our Tibetan group and 33 previously published populations was also investigated. Phylogenetic analyses revealed that the Chamdo Tibetan population is more closely related genetically with the Lhasa Tibetan group. Our results suggest that these autosomal STR loci are highly polymorphic in the Tibetan population living in Tibet Chamdo and can be used as a powerful tool in forensics, linguistics, and population genetic analyses.
Hruschka, Daniel J; Hadley, Craig; Brewis, Alexandra A; Stojanowski, Christopher M
2015-01-01
Contemporary human populations conform to ecogeographic predictions that animals will become more compact in cooler climates and less compact in warmer ones. However, it remains unclear to what extent this pattern reflects plastic responses to current environments or genetic differences among populations. Analyzing anthropometric surveys of 232,684 children and adults from across 80 ethnolinguistic groups in sub-Saharan Africa, Asia and the Americas, we confirm that body surface-to-volume correlates with contemporary temperature at magnitudes found in more latitudinally diverse samples (Adj. R2 = 0.14-0.28). However, far more variation in body surface-to-volume is attributable to genetic population structure (Adj. R2 = 0.50-0.74). Moreover, genetic population structure accounts for nearly all of the observed relationship between contemporary temperature and body surface-to-volume among children and adults. Indeed, after controlling for population structure, contemporary temperature accounts for no more than 4% of the variance in body form in these groups. This effect of genetic affinity on body form is also independent of other ecological variables, such as dominant mode of subsistence and household wealth per capita. These findings suggest that the observed fit of human body surface-to-volume with current climate in this sample reflects relatively large effects of existing genetic population structure of contemporary humans compared to plastic response to current environments.
Moura-Neto, R S; Mello, I C T; Silva, R; Maette, A P C; Bottino, C G; Woerner, A; King, J; Wendt, F; Budowle, B
2018-01-01
The use of bi-allelic markers such as retrotransposable element insertion polymorphisms or Innuls (for insertion/null) can overcome some limitations of short tandem repeat (STR) loci in typing forensic biological evidence. This study investigated the efficiency of the InnoTyper® 21 Innul markers in an urban admixed population sample in Rio de Janeiro (n = 40) and one highly compromised sample collected as evidence by the Rio de Janeiro police. No significant departures from Hardy-Weinberg equilibrium were detected after the Bonferroni correction (α' ≈ 0.05/20, p < 0.0025), and no significant linkage disequilibrium was observed between markers. Assuming loci independence, the cumulative random match probability (RMP) was 2.3 × 10 -8 . A lower mean Fis value was obtained for this sample population compared with those of three North American populations (African-American, Southwest Hispanic, US Caucasian). Principal component analysis with the three North American populations and one from 21 East Asian population showed that African Americans segregated as an independent group while US Caucasian, Southwest Hispanic, East Asian, and Rio de Janeiro populations are in a single large heterogeneous group. Also, a full Innuls profile was produced from an evidence sample, despite the DNA being highly degraded. In conclusion, this system is a useful complement to standard STR kits.
Terto, Veriano
2015-09-01
On the basis of an ethnographic narrative on sexual interactions observed in urban parks in large Brazilian cities, the article discusses the adoption of new strategies and methods for AIDS prevention in vulnerable populations, especially in men who have sex with men (MSM). By following some guiding questions, the text debates when, why, with whom, and in which context the new prevention methods should be adopted. It emphasizes, in agreement to the initial narrative, the importance of taking into account the prevention strategies created by the population itself to manage HIV risk infection. It also addresses how prevention practices and messages are adapted and recreated by individuals and groups in an attempt to suit them to their sexual desires, practices, and choices. In this perspective, the article recommends the inclusion of the experiences and voices of individuals and groups considered vulnerable in the new AIDS prevention methods and programs targeted to them.
Creating an outcomes framework.
Doerge, J B
2000-01-01
Four constructs used to build a framework for outcomes management for a large midwestern tertiary hospital are described in this article. A system framework outlining a model of clinical integration and population management based in Steven Shortell's work is discussed. This framework includes key definitions of high-risk patients, target groups, populations and community. Roles for each level of population management and how they were implemented in the health care system are described. A point of service framework centered on seven dimensions of care is the next construct applied on each nursing unit. The third construct outlines the framework for role development. Three roles for nursing were created to implement strategies for target groups that are strategic disease categories; two of those roles are described in depth. The philosophy of nursing practice is centered on caring and existential advocacy. The final construct is the modification of the Dartmouth model as a common framework for outcomes. System applications of the scorecard and lessons learned in the 2-year process of implementation are shared
Smits, Gaby; Mollema, Liesbeth; Hahné, Susan; de Melker, Hester; Tcherniaeva, Irina; Waaijenborg, Sandra; van Binnendijk, Rob; van der Klis, Fiona; Berbers, Guy
2013-01-01
Here we present mumps virus specific antibody levels in a large cross-sectional population-based serosurveillance study performed in the Netherlands in 2006/2007 (n = 7900). Results were compared with a similar study (1995/1996) and discussed in the light of recent outbreaks. Mumps antibodies were tested using a fluorescent bead-based multiplex immunoassay. Overall seroprevalence was 90.9% with higher levels in the naturally infected cohorts compared with vaccinated cohorts. Mumps virus vaccinations at 14 months and 9 years resulted in an increased seroprevalence and antibody concentration. The second vaccination seemed to be important in acquiring stable mumps antibody levels in the long term. In conclusion, the Dutch population is well protected against mumps virus infection. However, we identified specific age- and population groups at increased risk of mumps infection. Indeed, in 2007/2008 an outbreak has occurred in the low vaccination coverage groups emphasizing the predictive value of serosurveillance studies. PMID:23520497
Genovesi, Benjamin; Berrebi, Patrick; Nagai, Satoshi; Reynaud, Nathalie; Wang, Jinhui; Masseret, Estelle
2015-09-15
The intra-specific diversity and genetic structure within the Alexandrium pacificum Litaker (A. catenella - Group IV) populations along the Temperate Asian coasts, were studied among individuals isolated from Japan to China. The UPGMA dendrogram and FCA revealed the existence of 3 clusters. Assignment analysis suggested the occurrence of gene flows between the Japanese Pacific coast (cluster-1) and the Chinese Zhejiang coast (cluster-2). Human transportations are suspected to explain the lack of genetic difference between several pairs of distant Japanese samples, hardly explained by a natural dispersal mechanism. The genetic isolation of the population established in the Sea of Japan (cluster-3) suggested the existence of a strong ecological and geographical barrier. Along the Pacific coasts, the South-North current allows limited exchanges between Chinese and Japanese populations. The relationships between Temperate Asian and Mediterranean individuals suggested different scenario of large-scale dispersal mechanisms. Copyright © 2015. Published by Elsevier Ltd.
Comorbidity of gout and rheumatoid arthritis in a large population database.
Merdler-Rabinowicz, Rona; Tiosano, Shmuel; Comaneshter, Doron; Cohen, Arnon D; Amital, Howard
2017-03-01
Coexistence of rheumatoid arthritis and gout is considered to be unusual. The current study was designed as a population-based cross-sectional study, utilizing the medical database of Clalit Health Services, the largest healthcare provider organization in Israel. Data of adult patients who were previously diagnosed with rheumatoid arthritis was retrieved. For each patient, five age- and sex-matched control patients were randomly selected. Different parameters including BMI, socioeconomic status, and existence of gout as well as smoking and hypertension were examined for both groups. The study included 11,540 patients with rheumatoid arthritis and 56,763 controls. The proportion of gout in the study group was high compared to controls (1.61 vs. 0.92%, P < 0.001). In a multivariate analysis, rheumatoid arthritis was associated with gout (OR = 1.72, 95% CI 1.45-2.05, P = 0.00). The proportion of gout in rheumatoid arthritis patients is not lower than in the general population.
An anthropometric data bank for the Iranian working population with ethnic diversity.
Sadeghi, Fatemeh; Mazloumi, Adel; Kazemi, Zeinab
2015-05-01
This study constructed an anthropometric data bank for the Iranian working population. In total, thirty-seven body dimensions were measured among 3720 Iranian workers with different ethnicities (3000 male and 720 female; aged 20-60 years). Statistical analysis revealed significant differences for most of body dimensions among the ethnical groups. Moreover, the authors compared Iranian anthropometric characteristics with those of four Asian populations: Taiwanese, Chinese, Japanese, and Korean. Overall, 16 body dimensions for the five Asian populations were selected and compared. Accordingly, different morphological characteristics of these five populations were observed. The Iranian population showed wide shoulders and hips and long legs; the Chinese population showed narrow hips and shoulders and a short height relative to the other populations. The Korean sample recorded moderate body size comparing the other populations. The Taiwanese had large hands, relatively wide shoulders and short upper limbs. These differences in population dimensions should be taken into consideration for product and process design when expanding regional markets. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.
Leonard, W R; Keenleyside, A; Ivakine, E
1997-06-01
We examine mortality and fertility patterns of aboriginal (primarily Evenki and Keto) and Russian (i.e., nonaboriginal) populations from the Baykit District of Central Siberia for the period 1982-1994. Mortality rates in the aboriginal population of Baykit are substantially greater than those observed in the Russians and are comparable to levels recently reported for other indigenous Siberian groups. Infant mortality rates average 48 per 1000 live births among Baykit aboriginals, three times greater than the Russians of the district (15 per 1000 births) and more than double the rates for Inuit and Indian populations of Canada. Similarly, crude death rates of the Baykit aboriginals are twice as high as those observed in either the Baykit Russians or the Canadian aboriginal populations (13 vs 6-7 deaths per 1000 individuals). Birth rates of the indigenous population of Baykit are higher than those of the Russians (33 vs. 15 births per 1000 individuals) but are comparable to those of Canadian aboriginal groups. Violence and accidents are the leading causes of adult male mortality in both ethnic groups, whereas circulatory diseases have emerged as the prime cause of death in women. The greater male mortality resulting from violence and accidents is a widely observed cross-cultural phenomenon. The emergence of circulatory diseases as a major mortality risk for women, however, appears to be linked to specific lifestyle changes associated with Soviet reorganization of indigenous Siberian societies. Marked declines in mortality and increases in fertility were observed in the Baykit aboriginal population during the mid to late 1980s with the government's implementation of anti-alcohol policies. The decline in mortality, however, was largely erased during the early 1990s, as the region became increasingly isolated and marginalized following the collapse of the Soviet Union. Demographic trends in the Baykit District suggest that because the indigenous groups have become more isolated, many are returning to a more traditional subsistence lifestyle.
Makarova, Nataliya; Brand, Tilman; Brünings-Kuppe, Claudia; Pohlabeln, Hermann; Luttmann, Sabine
2016-01-01
Objectives The main objective of this study was to explore differences in mortality patterns among two large immigrant groups in Germany: one from Turkey and the other from the former Soviet Union (FSU). To this end, we investigated indicators of premature mortality. Design This study was conducted as a retrospective population-based study based on mortality register linkage. Using mortality data for the period 2004–2010, we calculated age-standardised death rates (SDR) and standardised mortality ratios (SMR) for premature deaths (
THE MINIMUM OF SOLAR CYCLE 23: AS DEEP AS IT COULD BE?
DOE Office of Scientific and Technical Information (OSTI.GOV)
Muñoz-Jaramillo, Andrés; Longcope, Dana W.; Senkpeil, Ryan R.
2015-05-01
In this work we introduce a new way of binning sunspot group data with the purpose of better understanding the impact of the solar cycle on sunspot properties and how this defined the characteristics of the extended minimum of cycle 23. Our approach assumes that the statistical properties of sunspots are completely determined by the strength of the underlying large-scale field and have no additional time dependencies. We use the amplitude of the cycle at any given moment (something we refer to as activity level) as a proxy for the strength of this deep-seated magnetic field. We find that themore » sunspot size distribution is composed of two populations: one population of groups and active regions and a second population of pores and ephemeral regions. When fits are performed at periods of different activity level, only the statistical properties of the former population, the active regions, are found to vary. Finally, we study the relative contribution of each component (small-scale versus large-scale) to solar magnetism. We find that when hemispheres are treated separately, almost every one of the past 12 solar minima reaches a point where the main contribution to magnetism comes from the small-scale component. However, due to asymmetries in cycle phase, this state is very rarely reached by both hemispheres at the same time. From this we infer that even though each hemisphere did reach the magnetic baseline, from a heliospheric point of view the minimum of cycle 23 was not as deep as it could have been.« less
Fan, Pengfei; Fei, Hanlan; Xiang, Zuofu; Zhang, Wen; Ma, Changyong; Huang, Tao
2010-01-01
The Cao Vit gibbon (Nomascus nasutus) was rediscovered in 2002 in Vietnam and then in 2006 in China. This is the only known population with about 110 individuals located along the China-Vietnam border. Little is known about it other than its population size and distribution. We describe the social structure and group dynamics of the Cao Vit gibbons in China based on 2 years of monitoring from 2007 to 2009. Four established study groups at this site consisted of 1 adult male, 2 adult females and 2-6 offspring. Two juveniles in 2 groups disappeared during the research. Four infants were born in 3 groups from November 2008 to February 2009. In 2 of the groups, both adult females had dependent infants. These observations suggest that Cao Vit gibbons live in polygynous groups, contrary to the usual monogamous group with only 1 adult female, but nevertheless similar to the social organization of both N. concolor and N. hainanus. We observed a coordinated dispersal of 1 adult male and 2 large juveniles, and the male formed a pair with a newly arrived female. Our observations support a growing awareness of variability in gibbon social organization. Copyright © 2010 S. Karger AG, Basel.
Sturges, Diana; Maurer, Trent W; Cole, Oladipo
2009-06-01
This study investigated the effectiveness of role play in a large undergraduate science class. The targeted population consisted of 298 students enrolled in 2 sections of an undergraduate Human Anatomy and Physiology course taught by the same instructor. The section engaged in the role-play activity served as the study group, whereas the section presented with a traditional lecture served as the control group. A pretest/posttest assessment and a survey were administered to both sections and used in data analysis. In addition, overall test scores and item analysis were examined. The analysis revealed that participants in both groups improved significantly from pretest to posttest, but there were no significant differences between the groups in posttest scores. Neither group showed a significant change from posttest to the exam. However, there was a moderate positive effect on engagement and satisfaction survey questions from being in the study group (based on 255 total surveys returned by both groups). The role-play activity was at least as effective as the lecture in terms of student performance on the above-mentioned assessments. In addition, it proved successful in engaging students in the learning process and increasing their satisfaction.
Social Capital and Women's Reduced Vulnerability to HIV infection in Rural Zimbabwe
GREGSON, SIMON; MUSHATI, PHYLLIS; GRUSIN, HARRY; NHAMO, MERCY; SCHUMACHER, CHRISTINA; SKOVDAL, MORTEN; NYAMUKAPA, CONSTANCE; CAMPBELL, CATHERINE
2012-01-01
Social capital - especially through its ‘network’ dimension (high levels of participation in local community groups) - is thought to be an important determinant of health in many contexts. We investigate its effect on HIV prevention, using prospective data from a general population cohort in eastern Zimbabwe spanning a period of extensive behaviour change (1998-2003). Almost half of the initially uninfected women interviewed were members of at least one community group. In an ecological analysis of 88 communities, those with higher levels of community group participation had lower incidence of new HIV infections and more had adopted safer behaviours, although these effects were largely accounted for by differences in socio-demographic composition. Individual women in community groups had lower HIV incidence and more extensive behaviour change, even after controlling for confounding factors. Community group membership was not associated with lower HIV incidence in men, possibly reflecting a propensity amongst men to participate in groups that allow them to develop and demonstrate their masculine identities – often at the expense of their health. Support for women’s community groups could be an effective HIV prevention strategy in countries with large-scale HIV epidemics. PMID:22066129
Heslehurst, Nicola; Sattar, Naveed; Rajasingam, Daghni; Wilkinson, John; Summerbell, Carolyn D; Rankin, Judith
2012-12-18
Asians are at increased risk of morbidity at a lower body mass index (BMI) than European Whites, particularly relating to metabolic risk. UK maternal obesity guidelines use general population BMI criteria to define obesity, which do not represent the risk of morbidity among Asian populations. This study compares incidence of first trimester obesity using Asian-specific and general population BMI criteria. A retrospective epidemiological study of 502,474 births between 1995 and 2007, from 34 maternity units across England. Data analyses included a comparison of trends over time between ethnic groups using Asian-specific and general population BMI criteria. Logistic regression estimated odds ratios for first trimester obesity among ethnic groups following adjustment for population demographics. Black and South Asian women have a higher incidence of first trimester obesity compared with White women. This is most pronounced for Pakistani women following adjustment for population structure (OR 2.19, 95% C.I. 2.08, 2.31). There is a twofold increase in the proportion of South Asian women classified as obese when using the Asian-specific BMI criteria rather than general population BMI criteria. The incidence of obesity among Black women is increasing at the most rapid rate over time (p=0.01). The twofold increase in maternal obesity among South Asians when using Asian-specific BMI criteria highlights inequalities among pregnant women. A large proportion of South Asian women are potentially being wrongly assigned to low risk care using current UK guidelines to classify obesity and determine care requirements. Further research is required to identify if there is any improvement in pregnancy outcomes if Asian-specific BMI criteria are utilised in the clinical management of maternal obesity to ensure the best quality of care is provided for women irrespective of ethnicity.
Investigation of orbitofrontal sulcogyral pattern in chronic schizophrenia.
Cropley, Vanessa L; Bartholomeusz, Cali F; Wu, Peter; Wood, Stephen J; Proffitt, Tina; Brewer, Warrick J; Desmond, Patricia M; Velakoulis, Dennis; Pantelis, Christos
2015-11-30
Abnormalities of orbitofrontal cortex (OFC) pattern type distribution have been associated with schizophrenia-spectrum disorders. We investigated OFC pattern type in a large sample of chronic schizophrenia patients and healthy controls. We found an increased frequency of Type II but no difference in Type I or III folding pattern in the schizophrenia group in comparison to controls. Further large studies are required to investigate the diagnostic specificity of altered OFC pattern type and to confirm the distribution of pattern type in the normal population. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Nalini Junko Negi
2011-08-01
Day labor is largely comprised of young Latino immigrant men, many of who are undocumented, and thus vulnerable to a myriad of workers' rights abuses. The difficult work and life conditions of this marginalized population may place them at heightened risk for mental health problems and substance use and abuse. However, factors related to Latino day laborers' well-being and substance misuse are largely unknown. This article utilizes ethnographic and focus group methodology to elucidate participant identified factors associated to well-being and substance use and abuse. This study has implications for informing public health and social service programming as it provides thick description regarding the context and circumstances associated to increased vulnerability to substance abuse and lack of well-being among this hard-to-reach population of Latino immigrants.
2012-01-01
Day labor is largely comprised of young Latino immigrant men, many of who are undocumented, and thus vulnerable to a myriad of workers’ rights abuses. The difficult work and life conditions of this marginalized population may place them at heightened risk for mental health problems and substance use and abuse. However, factors related to Latino day laborers’ well-being and substance misuse are largely unknown. This article utilizes ethnographic and focus group methodology to elucidate participant identified factors associated to well-being and substance use and abuse. This study has implications for informing public health and social service programming as it provides thick description regarding the context and circumstances associated to increased vulnerability to substance abuse and lack of well-being among this hard-to-reach population of Latino immigrants. PMID:21107694
Risky Decision Making Assessed With the Gambling Task in Adults with HIV
Hardy, David J.; Hinkin, Charles H.; Castellon, Steven A.; Levine, Andrew J.; Lam, Mona N.
2010-01-01
Decision making was assessed using a laboratory gambling task in 67 adults with the Human Immunodeficiency Virus (HIV+) and in 19 HIV-seronegative (HIV−) control participants. Neurocognitive test performance across several domains was also analyzed to examine potential cognitive mechanisms of gambling task performance. As predicted, the HIV+ group performed worse on the gambling task, indicating greater risky decision making. Specifically, the HIV+ group selected more cards from the “risky” or disadvantageous deck that included relatively large payoffs but infrequent large penalties. The control group also selected such risky cards but quickly learned to avoid them. Exploratory analyses also indicated that in the HIV+ group, but not in the control group, gambling task performance was correlated with Stroop Interference performance and long delay free recall on the California Verbal Learning Test, suggesting the role of inhibitory processes and verbal memory in the poorer gambling task performance in HIV. These findings indicate the usefulness of the gambling task as a laboratory tool to examine risky decision making and cognition in the HIV population. PMID:16719628
Self-insurance and the potential effects of health reform on the small-group market.
Linehan, Kathryn
2010-12-21
The Patient Protection and Affordable Care Act (PPACA) as amended by the Health Care Education Reconciliation Act of 2010 makes landmark changes to health insurance markets. Individual and small-group insurance plans and markets will see the biggest changes, but PPACA also affects large employer and self-insured plans by imposing rules for benefit design and health plan practices. Over half of workers--most often those in very large firms--are covered by self-insured health plans in which employers (or employee groups) bear all or some of the risk of providing insurance coverage to a defined population of workers and their dependents. As PPACA provisions become effective, some have argued that smaller firms that offer insurance may opt to self-insure their health benefits because of new small-group market rules. Such a shift could affect risk pooling in the small-group market. This paper examines the definition and prevalence of self-insured health plans, the application of PPACA provisions to these plans, and the possible effects on the broader health insurance market, should many more employers decide to self-insure.
Hirooka, Nobutaka; Shin, Chol; Masaki, Kamal H.; Edmundowicz, Daniel; Choo, Jina; Barinas-Mitchell, Emma J.M.; Willcox, Bradley J.; Sutton-Tyrrell, Kim; El-Saed, Aiman; Miljkovic-Gacic, Iva; Ohkubo, Takayoshi; Miura, Katsuyuki; Ueshima, Hirotsugu; Kuller, Lewis H.; Sekikawa, Akira
2013-01-01
Background Both indices of obesity and lipoprotein subfractions contribute to coronary heart disease risk. However, associations between indices of obesity and lipoprotein subfractions remain undetermined across different ethnic groups. This study aims to examine the associations of indices of obesity in Japanese Americans (JA), African Americans (AA) and Koreans with lipoprotein subfractions. Methods A population-based sample of 230 JA, 91 AA, and 291 Korean men aged 40–49 was examined for indices of obesity, i.e., visceral and subcutaneous adipose tissue (VAT and SAT, respectively), waist circumference (WC), and body-mass index (BMI), and for lipoprotein subfractions by nuclear-magnetic-resonance spectroscopy. Multiple regression analyses were performed in each of the three ethnic groups to examine the associations of each index of obesity with lipoprotein. Results VAT had significant positive associations with total and small low-density lipoprotein (LDL) and a significant negative association with large high-density lipoprotein (HDL) in all three ethnicities (p < 0.01). SAT, WC, and BMI had significant positive associations with total and small LDL in only JA and Koreans, while these indices had significant inverse associations with large HDL in all ethnic groups (p < 0.01). Compared to SAT, VAT had larger R2 values in the associations with total and small LDL and large HDL in all three ethnic groups. Conclusions VAT is significantly associated with total and small LDL and large HDL in all three ethnic groups. The associations of SAT, WC, and BMI with lipoprotein subfractions are weaker compared to VAT in all three ethnic groups. PMID:25068101
Luce, Danièle; Stücker, Isabelle
2011-12-14
Occupational causes of respiratory cancers need to be further investigated: the role of occupational exposures in the aetiology of head and neck cancers remains largely unknown, and there are still substantial uncertainties for a number of suspected lung carcinogens. The main objective of the study is to examine occupational risk factors for lung and head and neck cancers. ICARE is a multi-center, population-based case-control study, which included a group of 2926 lung cancer cases, a group of 2415 head and neck cancer cases, and a common control group of 3555 subjects. Incident cases were identified in collaboration with cancer registries, in 10 geographical areas. The control group was a random sample of the population of these areas, with a distribution by sex and age comparable to that of the cases, and a distribution by socioeconomic status comparable to that of the population. Subjects were interviewed face to face, using a standardized questionnaire collecting particularly information on tobacco and alcohol consumption, residential history and a detailed description of occupational history. Biological samples were also collected from study subjects. The main occupational exposures of interest are asbestos, man-made mineral fibers, formaldehyde, polycyclic aromatic hydrocarbons, chromium and nickel compounds, arsenic, wood dust, textile dust, solvents, strong acids, cutting fluids, silica, diesel fumes, welding fumes. The complete list of exposures of interest includes more than 60 substances. Occupational exposure assessment will use several complementary methods: case-by-case evaluation of exposure by experts; development and use of algorithms to assess exposure from the questionnaires; application of job-exposure matrices. The large number of subjects should allow to uncover exposures associated with moderate increase in risks, and to evaluate risks associated with infrequent or widely dispersed exposures. It will be possible to study joint effects of exposure to different occupational risk factors, to examine the interactions between occupational exposures, tobacco smoking, alcohol drinking, and genetic risk factors, and to estimate the proportion of respiratory cancers attributable to occupational exposures in France. In addition, information on many non-occupational risk factors is available, and the study will provide an excellent framework for numerous studies in various fields.
Andreoli, A; Bazzocchi, A; Celi, M; Lauro, D; Sorge, R; Tarantino, U; Guglielmi, G
2011-10-01
The knowledge of factors modulating the behaviour of bone mass is crucial for preventing and treating osteoporotic disease; among these factors, body weight (BW) has been shown to be of primary importance in postmenopausal women. Nevertheless, the relative effects of body composition indices are still being debated. Our aim was to analyze the relationship between body mass index (BMI), fat and lean mass and bone mineral density (BMD) in a large population of women. Moreover, this study represents a first important report on reference standard values for body composition in Italian women. Between 2005 and 2008, weight and height of 6,249 Italian women (aged 30-80 years) were measured and BMI was calculated; furthermore BMD, bone mineral content, fat and lean mass were measured by dual-energy X-ray absorptiometry. Individuals were divided into five groups by decades (group 1, 30.0-39.9; group 2, 40.0-49.9; group 3, 50.0-59.9; group 4, 60.0-69.9; group 5, 70.0-79.9). Differences among decades for all variables were calculated using a one-way analysis of variance (ANOVA) and Bonferroni test by the SPSS programme. Mean BW was 66.8±12.1 kg, mean height 159.1±6.3 cm and mean BMI 26.4±4.7 kg/m(2). According to BW and BMI, there was an increase of obesity with age, especially in women older than 50 years (p<0.001). Lean mass increased until 50 years of age but significantly decreased after this age (p<0.001). The percentage of osteopenia and osteoporosis in the examined population was 43.0% and 16.7%, respectively. Our data show that obesity significantly decreased the risk for osteoporosis but did not decrease the risk for osteopenia. It is strongly recommended that a strong policy regarding prevention of osteopenia and osteoporosis be commenced. An overall examination of our results suggests that both fat and lean body mass can influence bone mass and that their relative effect on bone could be modulated by their absolute amount and ratio to total BW.
Prevalence of chronic atrophic gastritis in different parts of the world.
Weck, Melanie Nicole; Brenner, Hermann
2006-06-01
Chronic atrophic gastritis (CAG) is a well-established precursor of intestinal gastric cancer, but epidemiologic data about its occurrence are sparse. We provide an overview on studies that examined the prevalence of CAG in different parts of the world. Articles containing data about the prevalence of chronic atrophic gastritis in unselected population samples and published until November 2005 were identified by searching the MEDLINE database. Furthermore, the references in the identified publications were screened for additional suitable studies. Studies comprising at least 50 subjects were included. Forty-one studies providing data on the prevalence of CAG in unselected population samples could be identified. CAG was determined by gastroscopy in 15 studies and by pepsinogen serum levels in 26 studies. Although results are difficult to compare due to the various definitions of CAG used, a strong increase with age, the lack of major gender differences, and strong variations between populations and population groups (in particular, relatively high rates in certain Asian populations) could be observed quite consistently. We conclude that CAG is relatively common among older adults in different parts of the world, but large variations exist. Large-scale international comparative studies with standardized methodology to determine CAG are needed to provide a coherent picture of the epidemiology of CAG in various populations. Noninvasive measurements of CAG by pepsinogen levels may be particularly suited for that purpose.
Seven challenges for metapopulation models of epidemics, including households models.
Ball, Frank; Britton, Tom; House, Thomas; Isham, Valerie; Mollison, Denis; Pellis, Lorenzo; Scalia Tomba, Gianpaolo
2015-03-01
This paper considers metapopulation models in the general sense, i.e. where the population is partitioned into sub-populations (groups, patches,...), irrespective of the biological interpretation they have, e.g. spatially segregated large sub-populations, small households or hosts themselves modelled as populations of pathogens. This framework has traditionally provided an attractive approach to incorporating more realistic contact structure into epidemic models, since it often preserves analytic tractability (in stochastic as well as deterministic models) but also captures the most salient structural inhomogeneity in contact patterns in many applied contexts. Despite the progress that has been made in both the theory and application of such metapopulation models, we present here several major challenges that remain for future work, focusing on models that, in contrast to agent-based ones, are amenable to mathematical analysis. The challenges range from clarifying the usefulness of systems of weakly-coupled large sub-populations in modelling the spread of specific diseases to developing a theory for endemic models with household structure. They include also developing inferential methods for data on the emerging phase of epidemics, extending metapopulation models to more complex forms of human social structure, developing metapopulation models to reflect spatial population structure, developing computationally efficient methods for calculating key epidemiological model quantities, and integrating within- and between-host dynamics in models. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.
Atopkin, D M; Bogdanov, A S; Chelomina, G N
2007-06-01
Genetic variation and differentiation of the trans-Palearctic species Apodemus agrarius (striped field mouse), whose range consists of two large isolates-European-Siberian and Far Eastern-Chinese, were examined using RAPD-PCR analysis. The material from the both parts of the range was examined (41 individual of A. agrarius from 18 localities of Russia, Ukraine, Moldova, and Kazakhstan); the Far-Eastern part was represented by samples from the Amur region, Khabarovsk krai, and Primorye (Russia). Differences in frequencies of polymorphic RAPD loci were found between the European-Siberian and the Far Eastern population groups of striped field mouse. No "fixed" differences between them in RAPD spectra were found, and none of the used statistical methods permitted to distinguish with absolute certainty animals from the two range parts. Thus, genetic isolation of the European-Siberian and the Far Eastern population groups of A. agrarius is not strict. These results support the hypothesis on recent dispersal of striped field mouse from East to West Palearctics (during the Holocene climatic optimum, 7000 to 4500 years ago) and subsequent disjunction of the species range (not earlier than 4000-4500 years ago). The Far Eastern population group is more polymorphic than the European-Siberian one, while genetic heterogeneity is more uniformly distributed within it. This is probably explained by both historical events that happened during the species dispersal in the past, and different environmental conditions for the species in different parts of its range. The Far Eastern population group inhabits the area close to the distribution center of A. agrarius. It is likely that this group preserved genetic variation of the formerly integral ancestral form, while some amount of genetic polymorphism could be lost during the species colonization of the Siberian and European areas. To date, the settlement density and population number in general are higher than within the European-Siberian isolate, which seems to account for closer interpopulation associations, intense genetic exchange, and "smoothing" of polymorphism within the Far Eastern population group of A. agrarius.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Allen, E.L.; Edmonds, J.A.
Since World War II, US energy demand has grown more rapidly than population, so that per capita consumption of energy was about 60% higher in 1978 than in 1947. Population growth and the expansion of per capita real incomes have led to a greater use of energy. The aging of the US population is expected to increase per capita energy consumption, despite the increase in the proportion of persons over 65, who consume less energy than employed persons. The sharp decline in the population under 18 has led to an expansion in the relative proportion of population in the prime-labor-forcemore » age groups. Employed persons are heavy users of energy. The growth of the work force and GNP is largely attributable to the growing participation of females. Another important consequence of female employment is the growth in ownership of personal automobiles. A third factor pushing up labor-force growth is the steady influx of illegal aliens.« less
Martinez-Maza, Cayetana; Alberdi, Maria Teresa; Nieto-Diaz, Manuel; Prado, José Luis
2014-01-01
Histological analyses of fossil bones have provided clues on the growth patterns and life history traits of several extinct vertebrates that would be unavailable for classical morphological studies. We analyzed the bone histology of Hipparion to infer features of its life history traits and growth pattern. Microscope analysis of thin sections of a large sample of humeri, femora, tibiae and metapodials of Hipparion concudense from the upper Miocene site of Los Valles de Fuentidueña (Segovia, Spain) has shown that the number of growth marks is similar among the different limb bones, suggesting that equivalent skeletochronological inferences for this Hipparion population might be achieved by means of any of the elements studied. Considering their abundance, we conducted a skeletechronological study based on the large sample of third metapodials from Los Valles de Fuentidueña together with another large sample from the Upper Miocene locality of Concud (Teruel, Spain). The data obtained enabled us to distinguish four age groups in both samples and to determine that Hipparion concudense tended to reach skeletal maturity during its third year of life. Integration of bone microstructure and skeletochronological data allowed us to identify ontogenetic changes in bone structure and growth rate and to distinguish three histologic ontogenetic stages corresponding to immature, subadult and adult individuals. Data on secondary osteon density revealed an increase in bone remodeling throughout the ontogenetic stages and a lesser degree thereof in the Concud population, which indicates different biomechanical stresses in the two populations, likely due to environmental differences. Several individuals showed atypical growth patterns in the Concud sample, which may also reflect environmental differences between the two localities. Finally, classification of the specimens’ age within groups enabled us to characterize the age structure of both samples, which is typical of attritional assemblages. PMID:25098950
Bertinchamp, Rémi; Gérard, Laurence; Boutboul, David; Malphettes, Marion; Fieschi, Claire; Oksenhendler, Eric
In 2014, the European Society for Immune Deficiencies (ESID) revised the common variable immunodeficiency (CVID) diagnosis criteria by incorporating new clinical and biological markers. The new definition appeared more restrictive but had not yet been evaluated in a large cohort of patients. The objective of this study was to evaluate the impact of this new definition in a large cohort of patients with primary hypogammaglobulinemia. Evaluation of 3 different CVID definitions (ESID/Pan-American Group for Immunodeficiency [PAGID] 1999, ESID 2014, DEFI 2015) in 521 patients included in the French DEFI study with a diagnosis of primary hypogammaglobulinemia. Using the ESID/PAGID 1999 definition, 351 patients were classified as CVID. The new ESID 2014 definition excluded 62 (18%) patients. Most of them (n = 56; 90%) had a less severe disease, whereas 6 (10%) presented with a severe disease with major T-cell defect. We propose different criteria (occurrence of opportunistic infection or very low naive CD4+ T-cell count) to define this population with severe T-cell defect. Sixty-two patients fulfilled these criteria, represented 20% of the initial CVID population but accounted for 77% of the deaths, with a 5-year overall survival of 67.6% (95% confidence interval, 51.0-79.6), and were considered as late onset combined immunodeficiency (LOCID). The new ESID definition for CVID still fails to exclude a large number of patients with severe T-cell defect. We propose a new definition (DEFI 2015) that excluded more patients with a T-cell defect and consider these patients as LOCID. This population has a poor outcome and should be considered as a distinct group requiring specific care. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
A profile of travelers--an analysis from a large swiss travel clinic.
Bühler, Silja; Rüegg, Rolanda; Steffen, Robert; Hatz, Christoph; Jaeger, Veronika K
2014-01-01
Globally, the Swiss have one of the highest proportions of the population traveling to tropical and subtropical countries. Large travel clinics serve an increasing number of customers with specific pre-travel needs including uncommon destinations and preexisting medical conditions. This study aims to identify health characteristics and travel patterns of travelers seeking advice in the largest Swiss travel clinic so that tailored advice can be delivered. A descriptive analysis was performed on pre-travel visits between July 2010 and August 2012 at the Travel Clinic of the Institute of Social and Preventive Medicine, University of Zurich, Switzerland. A total of 22,584 travelers sought pre-travel advice. Tourism was the main reason for travel (17,875, 81.5%), followed by visiting friends and relatives (VFRs; 1,715, 7.8%), traveling for business (1,223, 5.6%), and "other reasons" (ie, volunteer work, pilgrimage, study abroad, and emigration; 1,112, 5.1%). The main travel destination was Thailand. In the VFR group, the highest proportions of traveling children (258, 15.1%) and of pregnant or breastfeeding women (23, 3.9%) were observed. Mental disorders were more prominent in VFRs (93, 5.4%) and in travel for "other reasons" (63, 5.7%). The latter stayed for the longest periods abroad; 272 (24.9%) stayed longer than 6 months. VFR travelers received the highest percentage of yellow fever vaccinations (523, 30.5%); in contrast, rabies (269, 24.2%) and typhoid vaccinations (279, 25.1%) were given more often to the "other travel reasons" group. New insights into the characteristics of a selected and large population of Swiss international travelers results in improved understanding of the special needs of an increasingly diverse population and, thus, in targeted preventive advice and interventions. © 2014 International Society of Travel Medicine.
Barański, Bogusław; Boczkowski, Andrzej
2009-01-01
Health and safety at work is frequently perceived as a domain to be protected exclusively against occupational hazards without taking into account socio-demographic determinants and non-occupational factors dependent on work culture and quality of life. This study aimed at evaluating the impact of socio-demographic determinants on self-assessed health status and frequency of health complaints in workers employed in a large institution as well as the perception of the influence of working conditions on their health and the occurrence of selected diseases and health complaints. The study was carried out in the entire population of employees of a large institution. Information that remained anonymous was collected using a questionnaire completed by the employees themselves. The strength of relationship was analyzed between the following three groups of variables: (1) self-assessed health status; (2) objectivized (based on reported facts) evaluation of health status; and (3) socio-demographic determinants. The socio-demographic determinants have considerable impact on self-reported health status and frequency of health complaints and diseases linked and not-linked by respondents with working conditions. The frequency of responses indicating the relationship between work and health complaints were dependent on gender and duration of employment in the institution. The number of reported diseases and health complaints was influenced by gender, age, duration of employment and the respondents' level of education. Summing up, the following groups of respondents evaluated their health as worse than that of others: (1) persons aged over 50 years; (2) persons working 16 or more years in the institution, (3) persons with other than university education; (4) person with overweight. The results indicate that the health policy of institutions and enterprises should take into account socio-demographic determinants in the working population.
Asada, Yukiko; Whipp, Alyce; Kindig, David; Billard, Beverly; Rudolph, Barbara
2014-06-13
Regular reporting of health inequalities is essential to monitoring progress of efforts to reduce health inequalities. While reporting of population health became increasingly common, reporting of a subpopulation group breakdown of each indicator of the health of the population is rarely a standard practice. This study reports education-, sex-, and race-related inequalities in four health outcomes in each of the selected 93 counties in the United States in a systematic and comparable manner. This study is a cross-sectional analysis of large, publicly available data, 2008, 2009, and 2010 Behavioral Risk Factor Surveillance System (BRFSS) Selected Metropolitan/Micropolitan Area Risk Trends (SMART) and 2008, 2009, and 2010 United States Birth Records from the National Vital Statistics System. The study population is American adults older than 25 years of age residing in the selected 93 counties, representing about 30% of the US population, roughly equally covering all geographic regions of the country. Main outcome measures are: (1) Attribute (group characteristic)-specific inequality: education-, sex-, or race-specific inequality in each of the four health outcomes (poor or fair health, poor physical health days, poor mental health days, and low birthweight) in each county; (2) Overall inequality: the average of these three attribute-specific inequalities for each health outcome in each county; and (3) Summary inequality in total morbidity: the weighted average of the overall inequalities across the four health outcomes in each county. The range of inequality across the counties differed considerably by health outcome; inequality in poor or fair health had the widest range and the highest median among inequalities in all health outcomes. In more than 70% of the counties, education-specific inequality was the largest in all health outcomes except for low birthweight. It is feasible to extend population health reporting to include reporting of a subpopulation group breakdown of each indicator of the health of the population at a small jurisdictional level using publicly available data. No single group characteristic or health outcome represents the whole picture of health inequalities in a population. Examining multiple group characteristics and outcomes in a comparable manner is essential in reporting health inequalities.
Van Meter, Page E; French, Jeffrey A; Dloniak, Stephanie M; Watts, Heather E; Kolowski, Joseph M; Holekamp, Kay E
2009-02-01
Our aim was to identify natural and anthropogenic influences on the stress physiology of large African carnivores, using wild spotted hyenas (Crocuta crocuta) as model animals. With both longitudinal data from a single social group, and cross-sectional data from multiple groups, we used fecal glucocorticoids (fGC) to examine potential stressors among spotted hyenas. Longitudinal data from adult members of a group living on the edge of the Masai Mara National Reserve, Kenya, revealed that fGC concentrations were elevated during two periods of social upheaval among adults, especially among younger females; however, prey availability, rainfall, and presence of lions did not influence fGC concentrations among hyenas. Our results suggested that anthropogenic disturbance in the form of pastoralist activity, but not tourism, influenced fGC concentrations among adult male hyenas; rising concentrations of fGC among males over 12 years were significantly correlated with increasing human population density along the edge of the group's home range. As hyenas from this social group were frequently exposed to anthropogenic disturbance, we compared fGC concentrations among these hyenas with those obtained concurrently from hyenas living in three other groups undisturbed by pastoralist activity. We found that fGC concentrations from the undisturbed groups were significantly lower than those in the disturbed group, and we were able to rule out tourism and ecological stressors as sources of variation in fGC among the populations. Thus it appears that both social instability and anthropogenic disturbance, but not the ecological variables examined, elevate fGC concentrations and represent stressors for wild spotted hyenas. Further work will be necessary to determine whether interpopulation variation in stress physiology predicts population decline in groups exposed to intensive anthropogenic disturbance.
The relation between obesity and depressed mood in a multi-ethnic population. The HELIUS study.
Gibson-Smith, Deborah; Bot, Mariska; Snijder, Marieke; Nicolaou, Mary; Derks, Eske M; Stronks, Karien; Brouwer, Ingeborg A; Visser, Marjolein; Penninx, Brenda W J H
2018-06-01
To examine the association between obesity and depressed mood in a large multi-ethnic population and check for consistency in this association across six ethnic groups. Data of 21,030 persons (18-70 years) were sourced from the HELIUS study. Cross-sectional relationships between obesity measures [body mass index (kg/m 2 ) and waist circumference (cm)] and depressed mood (PHQ-9 score ≥ 10) were analysed. Consistency of associations was investigated across ethnic groups by interaction terms (ethnicity*obesity measures) in basic (age, sex, education) and fully (health behaviours and somatic health) adjusted models. Obesity was prevalent in all ethnic groups, but varied substantially. After sociodemographic adjustment, obesity measures were associated with increased odds of depressed mood but this was inconsistent across ethnic groups. Obesity (BMI ≥ 30 or highest waist circumference quartile) was strongly and significantly associated with depressed mood in the Dutch [Odds Ratio (OR) = 1.72; 95% Confidence intervals (CI) 1.24-2.40, and OR = 1.86; 95% CI 1.38-2.50], respectively, and African Surinamese (OR = 1.60; 95% CI 1.29-1.98 and OR = 1.59; 95% CI 1.27-2.00, respectively) but had a weaker, non-significant association in other ethnic groups (South-Asian Surinamese, Ghanaian, Moroccan, Turkish groups). Adjustment for health behaviours and somatic health had limited effect on this pattern. Obesity was associated with a higher risk of depressed mood. However, ethnic differences were found: the obesity-depressed mood association was strong in the Dutch and African Surinamese populations, but not in other ethnic groups. Future studies should explore whether differential normative values or pathophysiology across ethnic groups explain why the obesity-depression association is inconsistent across ethnic groups.
Verdu, Paul; Becker, Noémie S A; Froment, Alain; Georges, Myriam; Grugni, Viola; Quintana-Murci, Lluis; Hombert, Jean-Marie; Van der Veen, Lolke; Le Bomin, Sylvie; Bahuchet, Serge; Heyer, Evelyne; Austerlitz, Frédéric
2013-04-01
Sociocultural phenomena, such as exogamy or phylopatry, can largely determine human sex-specific demography. In Central Africa, diverging patterns of sex-specific genetic variation have been observed between mobile hunter-gatherer Pygmies and sedentary agricultural non-Pygmies. However, their sex-specific demography remains largely unknown. Using population genetics and approximate Bayesian computation approaches, we inferred male and female effective population sizes, sex-specific migration, and admixture rates in 23 Central African Pygmy and non-Pygmy populations, genotyped for autosomal, X-linked, Y-linked, and mitochondrial markers. We found much larger effective population sizes and migration rates among non-Pygmy populations than among Pygmies, in agreement with the recent expansions and migrations of non-Pygmies and, conversely, the isolation and stationary demography of Pygmy groups. We found larger effective sizes and migration rates for males than for females for Pygmies, and vice versa for non-Pygmies. Thus, although most Pygmy populations have patrilocal customs, their sex-specific genetic patterns resemble those of matrilocal populations. In fact, our results are consistent with a lower prevalence of polygyny and patrilocality in Pygmies compared with non-Pygmies and a potential female transmission of reproductive success in Pygmies. Finally, Pygmy populations showed variable admixture levels with the non-Pygmies, with often much larger introgression from male than from female lineages. Social discrimination against Pygmies triggering complex movements of spouses in intermarriages can explain these male-biased admixture patterns in a patrilocal context. We show how gender-related sociocultural phenomena can determine highly variable sex-specific demography among populations, and how population genetic approaches contrasting chromosomal types allow inferring detailed human sex-specific demographic history.
Verdu, Paul; Becker, Noémie S.A.; Froment, Alain; Georges, Myriam; Grugni, Viola; Quintana-Murci, Lluis; Hombert, Jean-Marie; Van der Veen, Lolke; Le Bomin, Sylvie; Bahuchet, Serge; Heyer, Evelyne; Austerlitz, Frédéric
2013-01-01
Sociocultural phenomena, such as exogamy or phylopatry, can largely determine human sex-specific demography. In Central Africa, diverging patterns of sex-specific genetic variation have been observed between mobile hunter–gatherer Pygmies and sedentary agricultural non-Pygmies. However, their sex-specific demography remains largely unknown. Using population genetics and approximate Bayesian computation approaches, we inferred male and female effective population sizes, sex-specific migration, and admixture rates in 23 Central African Pygmy and non-Pygmy populations, genotyped for autosomal, X-linked, Y-linked, and mitochondrial markers. We found much larger effective population sizes and migration rates among non-Pygmy populations than among Pygmies, in agreement with the recent expansions and migrations of non-Pygmies and, conversely, the isolation and stationary demography of Pygmy groups. We found larger effective sizes and migration rates for males than for females for Pygmies, and vice versa for non-Pygmies. Thus, although most Pygmy populations have patrilocal customs, their sex-specific genetic patterns resemble those of matrilocal populations. In fact, our results are consistent with a lower prevalence of polygyny and patrilocality in Pygmies compared with non-Pygmies and a potential female transmission of reproductive success in Pygmies. Finally, Pygmy populations showed variable admixture levels with the non-Pygmies, with often much larger introgression from male than from female lineages. Social discrimination against Pygmies triggering complex movements of spouses in intermarriages can explain these male-biased admixture patterns in a patrilocal context. We show how gender-related sociocultural phenomena can determine highly variable sex-specific demography among populations, and how population genetic approaches contrasting chromosomal types allow inferring detailed human sex-specific demographic history. PMID:23300254
A preliminary assessment of mouflon abundance at the Kahuku Unit of Hawaii Volcanoes National Park
Hess, Steven C.; Kawakami, Ben; Okita, David; Medeiros, Keola
2006-01-01
Hawaii Volcanoes National Park (HAVO) recently acquired the 115,653 acre Kahuku Ranch unit adjacent to the existing Mauna Loa section of HAVO. Kahuku contains numerous exceptional natural resources including many federally listed threatened and endangered species. An apparently large and growing population of alien mouflon sheep (Ovis gmelini musimon), however, threatens sensitive native plants and forest bird habitats. Population composition and abundance estimates were urgently needed to determine the magnitude of resources required to manage this species and justify costs. We surveyed 32,433 acres from helicopter over 2 days in November 2004 during breeding to determine the abundance and population structure. We estimated that there were more than 2,586 ? 705 (90% CI) mouflon at Kahuku. Overall, group sizes averaged 7.8 and the sex ratio was 1:2.4 rams:ewes, but approximately 44% of the population was concentrated in forested areas near ranching operations where group sizes averaged >15 and the sex ratio was 1:3.9 rams:ewes. The remaining 56% of the population occurred widely dispersed in subalpine shrubland and barren lava flows. Abundance estimates are likely to be conservative because they were not adjusted for detection probability. Ground-based surveys of lambs suggest upper biological limit to annual population increase of 33.1% under existing environmental conditions. Historical information used to calculate population trends indicated the apparent rate of population increase to be 21.1%. In the absence of removals, the population increment for 2004-2005, would be more than 546-856, and the population doubling time with these growth rates is 3-4 years.
The Comoros Show the Earliest Austronesian Gene Flow into the Swahili Corridor.
Brucato, Nicolas; Fernandes, Veronica; Mazières, Stéphane; Kusuma, Pradiptajati; Cox, Murray P; Ng'ang'a, Joseph Wainaina; Omar, Mohammed; Simeone-Senelle, Marie-Claude; Frassati, Coralie; Alshamali, Farida; Fin, Bertrand; Boland, Anne; Deleuze, Jean-Francois; Stoneking, Mark; Adelaar, Alexander; Crowther, Alison; Boivin, Nicole; Pereira, Luisa; Bailly, Pascal; Chiaroni, Jacques; Ricaut, François-Xavier
2018-01-04
At the dawn of the second millennium, the expansion of the Indian Ocean trading network aligned with the emergence of an outward-oriented community along the East African coast to create a cosmopolitan cultural and trading zone known as the Swahili Corridor. On the basis of analyses of new genome-wide genotyping data and uniparental data in 276 individuals from coastal Kenya and the Comoros islands, along with large-scale genetic datasets from the Indian Ocean rim, we reconstruct historical population dynamics to show that the Swahili Corridor is largely an eastern Bantu genetic continuum. Limited gene flows from the Middle East can be seen in Swahili and Comorian populations at dates corresponding to historically documented contacts. However, the main admixture event in southern insular populations, particularly Comorian and Malagasy groups, occurred with individuals from Island Southeast Asia as early as the 8 th century, reflecting an earlier dispersal from this region. Remarkably, our results support recent archaeological and linguistic evidence-based suggestions that the Comoros archipelago was the earliest location of contact between Austronesian and African populations in the Swahili Corridor. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.
Synthetic Survey of the Kepler Field
NASA Astrophysics Data System (ADS)
Wells, Mark; Prša, Andrej
2018-01-01
In the era of large scale surveys, including LSST and Gaia, binary population studies will flourish due to the large influx of data. In addition to probing binary populations as a function of galactic latitude, under-sampled groups such as low mass binaries will be observed at an unprecedented rate. To prepare for these missions, binary population simulations need to be carried out at high fidelity. These simulations will enable the creation of simulated data and, through comparison with real data, will allow the underlying binary parameter distributions to be explored. In order for the simulations to be considered robust, they should reproduce observed distributions accurately. To this end we have developed a simulator which takes input models and creates a synthetic population of eclipsing binaries. Starting from a galactic single star model, implemented using Galaxia, a code by Sharma et al. (2011), and applying observed multiplicity, mass-ratio, period, and eccentricity distributions, as reported by Raghavan et al. (2010), Duchêne & Kraus (2013), and Moe & Di Stefano (2017), we are able to generate synthetic binary surveys that correspond to any survey cadences. In order to calibrate our input models we compare the results of our synthesized eclipsing binary survey to the Kepler Eclipsing Binary catalog.
Birth order and post-traumatic stress disorder.
Green, Ben; Griffiths, Emily C
2014-01-01
To compare the birth order of patients with post-traumatic stress disorder (PTSD) and adjustment disorder (AD) with population norms. 83 PTSD patients and 104 AD control patients from a psychiatric trauma clinic were diagnosed according to DCR-10 guidelines. A family history was taken as to number of siblings, and their birth order. We compared the distribution of birth order for each patient group against birth order distributions expected by chance for the same years of birth using UK population-level birth order from the Office for National Statistics. Psychiatric patients with PTSD were more likely to be from a large family, specifically to be the fifth child or later (OR 4.78, p < .001) and less likely to be the eldest child (OR .65, p < .001) than the general population in England and Wales. There were no differences for birth order between AD patients and the general population. People with PTSD are more likely to be the youngest children from large families than expected from a random sample of people born in the same years. This association with birth order was not found for another psychiatric diagnosis AD from the same clinic. We discuss possible psychosocial and biological causes, and implications for further research.
Raaum, Ryan L; Al-Meeri, Ali; Mulligan, Connie J
2013-04-01
Studies of the impact of post-marital residence patterns on the distribution of genetic variation within populations have returned conflicting results. These studies have generally examined genetic diversity within and between groups with different post-marriage residence patterns. Here, we directly examine Y chromosome microsatellite variation in individuals carrying a chromosome in the same Y haplogroup. We analyze Y chromosome data from two samples of Yemeni males: a sample representing the entire country and a sample from a large highland village. Our results support a normative patrilocality in highland Yemeni tribal populations, but also suggest that patrilocality is violated often enough to break down the expected correlation of genetic and geographic distance. We propose that a great deal of variation in male dispersal distance distributions is subsumed under the "patrilocal" label and that few human societies are likely to realize the idealized male dispersal distribution expected under strict patrilocality. In addition, we found almost no specific correspondence between social kinship and genetic patriline at the level of the clan (large, extended patrilineal kinship group) within a large, highland Yemeni village. We discuss ethnographic accounts that offer several cultural practices that explain exceptions to patrilocality and means by which social kinship and genetic patriline may become disentangled. Copyright © 2013 Wiley Periodicals, Inc.
Mandák, Bohumil; Hadincová, Věroslava; Mahelka, Václav; Wildová, Radka
2013-01-01
Background North American Pinus strobus is a highly invasive tree species in Central Europe. Using ten polymorphic microsatellite loci we compared various aspects of the large-scale genetic diversity of individuals from 30 sites in the native distribution range with those from 30 sites in the European adventive distribution range. To investigate the ascertained pattern of genetic diversity of this intercontinental comparison further, we surveyed fine-scale genetic diversity patterns and changes over time within four highly invasive populations in the adventive range. Results Our data show that at the large scale the genetic diversity found within the relatively small adventive range in Central Europe, surprisingly, equals the diversity found within the sampled area in the native range, which is about thirty times larger. Bayesian assignment grouped individuals into two genetic clusters separating North American native populations from the European, non-native populations, without any strong genetic structure shown over either range. In the case of the fine scale, our comparison of genetic diversity parameters among the localities and age classes yielded no evidence of genetic diversity increase over time. We found that SGS differed across age classes within the populations under study. Old trees in general completely lacked any SGS, which increased over time and reached its maximum in the sapling stage. Conclusions Based on (1) the absence of difference in genetic diversity between the native and adventive ranges, together with the lack of structure in the native range, and (2) the lack of any evidence of any temporal increase in genetic diversity at four highly invasive populations in the adventive range, we conclude that population amalgamation probably first happened in the native range, prior to introduction. In such case, there would have been no need for multiple introductions from previously isolated populations, but only several introductions from genetically diverse populations. PMID:23874648
Saidel, Tobi; Adhikary, Rajatashuvra; Mainkar, Mandar; Dale, Jayesh; Loo, Virginia; Rahman, Motiur; Ramesh, Banadakoppa M; Paranjape, Ramesh S
2008-12-01
This paper presents key methodological approaches and challenges in implementing and analysing the first round of the integrated biobehavioural assessment of most-at-risk populations, conducted in conjunction with evaluation of Avahan, the India AIDS initiative. The survey collected data on HIV risk behaviours, sexually transmitted infections and HIV prevalence in 29 districts in six high-prevalence states of India. Groups included female sex workers and clients, men who have sex with men, injecting drug users and truck drivers. Strategies for overcoming some challenges of the large-scale surveys among vulnerable populations, including sampling hidden populations, involvement of the communities targeted by the survey, laboratory and quality control in remote, non-clinic field settings, and data analysis and data use are presented. Satisfying the need for protocols, guidelines and tools that allowed for sufficient standardization, while being tailored enough to fit diverse local situations on such a large scale, with so many implementing partners, emerged as a major management challenge. A major lesson from the first round is the vital importance of investing upfront time in tailoring the sampling methods, data collection instruments, and analysis plan to match measurement objectives. Despite the challenges, the integrated biobehavioural assessment was a huge achievement, and was largely successful in providing previously unavailable information about the HIV situation among populations that are critical to the curtailment of HIV spread in India. Lessons from the first round will be used to evolve the second round into an exercise with increased evaluative capability for Avahan.
Genome-wide selective sweeps and gene-specific sweeps in natural bacterial populations
Bendall, Matthew L.; Stevens, Sarah L.R.; Chan, Leong-Keat; ...
2016-01-08
Multiple models describe the formation and evolution of distinct microbial phylogenetic groups. These evolutionary models make different predictions regarding how adaptive alleles spread through populations and how genetic diversity is maintained. Processes predicted by competing evolutionary models, for example, genome-wide selective sweeps vs gene-specific sweeps, could be captured in natural populations using time-series metagenomics if the approach were applied over a sufficiently long time frame. Direct observations of either process would help resolve how distinct microbial groups evolve. Using a 9-year metagenomic study of a freshwater lake (2005–2013), we explore changes in single-nucleotide polymorphism (SNP) frequencies and patterns of genemore » gain and loss in 30 bacterial populations. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied by >1000-fold among populations. SNP allele frequencies also changed dramatically over time within some populations. Interestingly, nearly all SNP variants were slowly purged over several years from one population of green sulfur bacteria, while at the same time multiple genes either swept through or were lost from this population. Furthermore, these patterns were consistent with a genome-wide selective sweep in progress, a process predicted by the ‘ecotype model’ of speciation but not previously observed in nature. In contrast, other populations contained large, SNP-free genomic regions that appear to have swept independently through the populations prior to the study without purging diversity elsewhere in the genome. Finally, evidence for both genome-wide and gene-specific sweeps suggests that different models of bacterial speciation may apply to different populations coexisting in the same environment.« less
An Internet intervention as adjunctive therapy for pediatric encopresis.
Ritterband, Lee M; Cox, Daniel J; Walker, Lynn S; Kovatchev, Boris; McKnight, Lela; Patel, Kushal; Borowitz, Stephen; Sutphen, James
2003-10-01
This study evaluated the benefits of enhanced toilet training delivered through the Internet for children with encopresis. Twenty-four children with encopresis were randomly assigned to the Internet intervention group (Web) or no Internet intervention group (No-Web). All participants continued to receive routine care from their primary care physician. The Web participants demonstrated greater improvements in terms of reduced fecal soiling, increased defecation in the toilet, and increased unprompted trips to the toilet (ps<.02). Both groups demonstrated similar improvements in knowledge and toileting behaviors. Internet interventions may be an effective way of delivering sophisticated behavioral interventions to a large and dispersed population in a convenient format.
Blue ellipticals in compact groups
NASA Technical Reports Server (NTRS)
Zepf, Stephen E.; Whitmore, Bradley C.
1990-01-01
By studying galaxies in compact groups, the authors examine the hypothesis that mergers of spiral galaxies make elliptical galaxies. The authors combine dynamical models of the merger-rich compact group environment with stellar evolution models and predict that roughly 15 percent of compact group ellipticals should be 0.15 mag bluer in B - R color than normal ellipticals. The published colors of these galaxies suggest the existence of this predicted blue population, but a normal distribution with large random errors can not be ruled out based on these data alone. However, the authors have new ultraviolet blue visual data which confirm the blue color of the two ellipticals with blue B - R colors for which they have their own colors. This confirmation of a population of blue ellipticals indicates that interactions are occurring in compact groups, but a blue color in one index alone does not require that these ellipticals are recent products of the merger of two spirals. The authors demonstrate how optical spectroscopy in the blue may distinguish between a true spiral + spiral merger and the swallowing of a gas-rich system by an already formed elliptical. The authors also show that the sum of the luminosity of the galaxies in each group is consistent with the hypothesis that the final stage in the evolution of compact group is an elliptical galaxy.
Polymorphic admixture typing in human ethnic populations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dean, M.; Stephens, J.C.; Boaze, R.
1994-10-01
A panel of 257 RFLP loci was selected on the basis of high heterozygosity in Caucasian DNA surveys and equivalent spacing throughout the human genome. Probes from each locus were used in a Southern blot survey of allele frequency distribution for four human ethnic groups: Caucasian, African American, Asian (Chinese), and American Indian (Cheyenne). Nearly all RFLP loci were polymorphic in each group, albeit with a broad range of differing allele frequencies ({delta}). The distribution of frequency differences ({delta} values) was used for three purposes: (1) to provide estimates for genetic distance (differentiation) among these ethnic groups, (2) to revisitmore » with a large data set the proportion of human genetic variation attributable to differentiation within ethnic groups, and (3) to identify loci with high {delta} values between recently admixed populations of use in mapping by admixture linkage disequilibrium (MALD). Although most markers display significant allele frequency differences between ethnic groups, the overall genetic distances between ethnic groups were small (.066-.098), and <10% of the measured overall molecular genetic diversity in these human samples can be attributed to {open_quotes}racial{close_quotes} differentiation. The median {delta} values for pairwise comparisons between groups fell between .15 and .20, permitting identification of highly informative RFLP loci for MALD disease association studies. 43 refs., 5 figs., 5 tabs.« less
Health Correlates of Criminal Justice Involvement in 4,793 Transgender Veterans.
Brown, George R; Jones, Kenneth T
2015-12-01
Transgender (TG) persons are overrepresented in prison settings and in the U.S. veteran population. Health disparities studies of large populations of transgender people involved with the criminal justice system have not been published to date. We studied a large cohort of TG veterans who received care in Veterans Health Administration (VHA) facilities during 2007-2013 (n = 4,793) and a 3:1 matched control group of veterans without known TG identification (n = 13,625). Three hundred twenty six (n = 138 TG, 188 non-TG) had received VHA services in programs designed to address the needs of justice involved (JI) veterans. We linked patients in each of the three groups to their medical and administrative data. TG veterans were more likely to be justice involved than controls (2.88% vs. 1.38%; P < .0001). Compared to non-TG JI veterans, TG JI veterans were more likely to have a history of homelessness (80% vs. 67%; P < .05) and to have reported sexual trauma while serving in the military (23% vs. 12%; P < .01). Significant health disparities were noted for TG JI veterans for depression, hypertension, obesity, posttraumatic stress disorder, serious mental illness, and suicidal ideation/attempts. These data suggest that TG veterans experience a number of health risks compared to non-TG veterans, including an increased likelihood of justice involvement. TG veterans involved with the criminal justice system are a particularly vulnerable group and services designed to address the health care needs of this population, both while incarcerated and when in the community, should take these findings into account in the development of health screenings and treatment plans.
Consuming fire ants reduces northern bobwhite survival and weight gain
Myers, P.E.; Allen, Craig R.; Birge, Hannah E.
2014-01-01
Northern bobwhite quail, Colinus virginianus (L.) (Galliformes: Odontophoridae), population declines are well documented, but pinpointing the reasons for these decreases has proven elusive. Bobwhite population declines are attributed primarily to loss of habitat and land use changes. This, however, does not entirely explain population declines in areas intensively managed for bobwhites. Although previous research demonstrates the negative impact of red imported fire ant (Solenopsis invicta Buren) (Hymenoptera: Formicidae) on northern bobwhites, the mechanisms underlying this effect are largely unknown. To meet the protein demands of early growth and development, bobwhite chicks predominantly consume small insects, of which ants are a substantial proportion. Fire ants alter ant community dynamics by often reducing native ant diversity and abundance while concurrently increasing the abundance of individuals. Fire ants have negative effects on chicks, but they are also a large potential protein source, making it difficult to disentangle their net effect on bobwhite chicks. To help investigate these effects, we conducted a laboratory experiment to understand (1) whether or not bobwhites consume fire ants, and (2) how the benefits of this consumption compare to the deleterious impacts of bobwhite chick exposure to fire ants. Sixty bobwhite chicks were separated into two groups of 30; one group was provided with starter feed only and the second group was provided with feed and fire ants. Bobwhite chicks were observed feeding on fire ants. Chicks that fed on fire ants had reduced survival and weight gain. Our results show that, while fire ants increase potential food sources for northern bobwhite, their net effect on bobwhite chicks is deleterious. This information will help inform land managers and commercial bobwhite rearing operations.
Brenner, Hermann; Weyermann, Maria; Rothenbacher, Dietrich
2006-07-01
Several mostly small-scale studies reported clustering of Helicobacter pylori infections as a possible indicator of conjugal transmission, but results have been inconsistent. We assessed clustering of H pylori infections in a large community-based study from Germany that included both high-prevalence and low-prevalence population subgroups. Current H pylori infection was determined among 670 couples by means of carbon-13-urea breath test ((13)C-UBT) breath test and a monoclonal antigen immunoassay for H pylori in stool. Prevalences of infection among women were 34.9% (51 of 146 women) if the partner was infected and 14.5% (76 of 524 women) if the partner was not infected. Stratification by nationality showed a strong association of infection for partners with other than German nationality (adjusted odds ratio [OR], 6.05; 95% confidence interval [CI], 1.31-17.96), for whom prevalence of infection was greater than 50%, whereas no association was seen for German partners born in Germany (OR, 1.10; 95% CI, 0.47-2.61), for whom infection prevalence was approximately 10% (p for interaction = 0.048). Conjugal transmission of infection caused by H pylori is unlikely to be of relevance in low-prevalence population groups. Our results are consistent with the hypothesis of a potential role of conjugal transmission of H pylori infection in high-prevalence population groups.
Gillis, Artha J; Bath, Eraka
2016-01-01
There is a large proportion of minority youth involved in the juvenile justice system. Disproportionate minority contact (DMC) occurs when the proportion of any ethnic group is higher at any given stage in the juvenile justice process than the proportion of this group in the general population. There are several theories explaining the presence and persistence of DMC. This article reviews the history of DMC and the theories and implications of this problem. It discusses several targets for interventions designed to reduce DMC and offer resources in this area. Copyright © 2016 Elsevier Inc. All rights reserved.
Public Perspectives on Informed Consent for Biobanking
Scott, Joan; Kaufman, David; Geller, Gail; LeRoy, Lisa; Hudson, Kathy
2009-01-01
The National Institutes of Health and other federal health agencies are considering establishing a national biobank to study the roles of genes and environment in health. We assessed the public's attitudes toward the proposed biobank, including preferences for providing informed consent. Sixteen focus groups were conducted, and themes arising from the focus groups were tested in a large, representative survey (n = 4659) of the general population. Our research demonstrates that when considering participating in a genomic biobank, individuals want ongoing choices and control over access to their samples and information. PMID:19833988
ERIC Educational Resources Information Center
Van der Haegen, Lise; Cai, Qing; Seurinck, Ruth; Brysbaert, Marc
2011-01-01
The best established lateralized cerebral function is speech production, with the majority of the population having left hemisphere dominance. An important question is how to best assess the laterality of this function. Neuroimaging techniques such as functional Magnetic Resonance Imaging (fMRI) are increasingly used in clinical settings to…
ERIC Educational Resources Information Center
Chen, Hsing-Jung; Balan, Sundari; Price, Rumi Kato
2012-01-01
Large-scale surveys have shown elevated risk for many indicators of substance abuse among Native American and Mixed-Race adolescents compared to other minority groups in the United States. This study examined underlying contextual factors associated with substance abuse among a nationally representative sample of White, Native American, and…
Diverse users of four urban national forests: participation, preferences, and perceptions
Deborah J. Chavez; David D. Olson
2008-01-01
Diversity at outdoor recreation sites, particularly those near large and diverse urban populations, is occurring across the United States. It is likely that individuals who belong to these changing groups bring a set of values and behaviors to public lands that differ from that of White visitors, and perhaps, land managers. Reported here are findings from studies...
ERIC Educational Resources Information Center
Schwartz, Heather
2011-01-01
Montgomery County, Maryland, operates one of the most acclaimed large public school systems in the United States. Although an increasing share of the population of this suburban school district just outside Washington, District of Columbia, is low income, and the majority of its students belongs to racial minority groups, the county graduates 9 in…
ERIC Educational Resources Information Center
Banning, James H.
2014-01-01
First-generation college students are students whose parents or guardians did not obtain a four year college degree (Davis, 2012). As a group these students make up a large part of the college student population and are often reported to encounter difficulties in their campus experience. While the topic of first-generation student has received…
Serving the needs of Latino recreation visitors to urban proximate natural resource recreation areas
Deborah J. Chavez
2008-01-01
A major shift has occurred in the ethnic and racial profile of the United States, with large increases in the Latino population. Beyond the demographic profiles are the influences on other aspects of life in the United States, including urban-proximate natural resource recreation area management. Latino groups may have different expectations about natural resource...
Young Children of Black Immigrants in America: Changing Flows, Changing Faces
ERIC Educational Resources Information Center
Capps, Randy, Ed.; Fix, Michael, Ed.
2012-01-01
The child population in the United States is rapidly changing and diversifying--in large part because of immigration. Today, nearly one in four US children under the age of 18 is the child of an immigrant. While research has focused on the largest of these groups (Latinos and Asians), far less academic attention has been paid to the changing Black…
Prevalence of Autism in Children Born to Somali Parents Living in Sweden: A Brief Report
ERIC Educational Resources Information Center
Barnevik-Olsson, Martina; Gillberg, Christopher; Fernell, Elisabeth
2008-01-01
In a geographical area of Stockholm, with a relatively large Somali immigrant population, parents as well as teachers in special schools and staff at habilitation centres have raised concerns over whether children with a Somali background are over-represented in the total group of children with autism. The aim of the study was, therefore, to…
Anthropometric and computerized tomographic measurements of lower extremity lean body mass.
Buckley, D C; Kudsk, K A; Rose, B S; Fatzinger, P; Koetting, C A; Schlatter, M
1987-02-01
The loss of lean muscle mass is one of the hallmarks of protein-calorie malnutrition. Anthropometry is a standardized technique used to assess the response of muscle mass to nutrition therapy by quantifying the muscle and fat compartments. That technique does not accurately reflect actual limb composition, whereas computerized tomography does. Twenty lower extremities on randomly chosen men and women patients were evaluated by anthropometry and computerized tomography. Total area, muscle plus bone area, total volume, and muscle plus bone volume were correlated, using Heymsfield's equation and computerized tomography-generated areas. Anthropometrics overestimated total and muscle plus bone cross-sectional areas at almost every level. Anthropometry overestimated total area and total volume by 5% to 10% but overestimated muscle plus bone area and muscle plus bone volume by as much as 40%. Anthropometry, while easily performed and useful in large population groups for epidemiological studies, offers a poor assessment of lower extremity composition. On the other hand, computerized tomography is also easily performed and, while impractical for large population groups, does offer an accurate assessment of the lower extremity tissue compartments and is an instrument that might be used in research on lean muscle mass.
Collaborative Research in Childhood Cancer Survivorship: The Current Landscape
Bhatia, Smita; Armenian, Saro H.; Armstrong, Gregory T.; van Dulmen-den Broeder, Eline; Hawkins, Michael M.; Kremer, Leontien C.M.; Kuehni, Claudia E.; Olsen, Jørgen H.; Robison, Leslie L.; Hudson, Melissa M.
2015-01-01
Survivors of childhood cancer carry a substantial burden of morbidity and are at increased risk for premature death. Furthermore, clear associations exist between specific therapeutic exposures and the risk for a variety of long-term complications. The entire landscape of health issues encountered for decades after successful completion of treatment is currently being explored in various collaborative research settings. These settings include large population-based or multi-institutional cohorts and single-institution studies. The ascertainment of outcomes has depended on self-reporting, linkage to registries, or clinical assessments. Survivorship research in the cooperative group setting, such as the Children's Oncology Group, has leveraged the clinical trials infrastructure to explore the molecular underpinnings of treatment-related adverse events, and to understand specific complications in the setting of randomized risk-reduction strategies. This review highlights the salient findings from these large collaborative initiatives, emphasizing the need for life-long follow-up of survivors of childhood cancer, and describing the development of several guidelines and efforts toward harmonization. Finally, the review reinforces the need to identify populations at highest risk, facilitating the development of risk prediction models that would allow for targeted interventions across the entire trajectory of survivorship. PMID:26304891
TWO LOCAL VOLUME DWARF GALAXIES DISCOVERED IN 21 cm EMISSION: PISCES A AND B
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tollerud, Erik J.; Geha, Marla C.; Grcevich, Jana
2015-01-01
We report the discovery of two dwarf galaxies, Pisces A and B, from a blind 21 cm H I search. These were the only two galaxies found via optical imaging and spectroscopy of 22 H I clouds identified in the GALFA-H I survey as dwarf galaxy candidates. They have properties consistent with being in the Local Volume (<10 Mpc), and one has resolved stellar populations such that it may be on the outer edge of the Local Group (∼1 Mpc from M31). While the distance uncertainty makes interpretation ambiguous, these may be among the faintest star-forming galaxies known. Additionally, rough estimatesmore » comparing these galaxies to ΛCDM dark matter simulations suggest consistency in number density, implying that the dark matter halos likely to host these galaxies are primarily H I-rich. The galaxies may thus be indicative of a large population of dwarfs at the limit of detectability that are comparable to the faint satellites of the Local Group. Because they are outside the influence of a large dark matter halo to alter their evolution, these galaxies can provide critical anchors to dwarf galaxy formation models.« less
Developing a Multiple Caregiver Group for Caregivers of Adolescents With Disruptive Behaviors.
Oruche, Ukamaka M; Robb, Sheri L; Aalsma, Matt; Pescosolido, Bernice; Brown-Podgorski, Brittany; Draucker, Claire Burke
2017-12-01
This article describes the development of a 6-week multiple caregiver group intervention for primary caregivers of adolescents diagnosed with Oppositional Defiant Disorder or Conduct Disorder in low-income African American families. The intervention is aimed at increasing the primary caregivers' self-efficacy in managing interactions within the family and especially with child serving educational, mental health, juvenile justice, and child welfare systems. Development of the intervention involved seven iterative activities performed in a collaborative effort between an interdisciplinary academic team, community engagement specialists, members of the targeted population, and clinical partners from a large public mental health system. The intervention development process described in this article can provide guidance for teams that aim to develop new mental health interventions that target specific outcomes in populations with unique needs. Copyright © 2017 Elsevier Inc. All rights reserved.
Social networks and spreading of epidemics
NASA Astrophysics Data System (ADS)
Trimper, Steffen; Zheng, Dafang; Brandau, Marian
2004-05-01
Epidemiological processes are studied within a recently proposed social network model using the susceptible-infected-refractory dynamics (SIR) of an epidemic. Within the network model, a population of individuals may be characterized by H independent hierarchies or dimensions, each of which consists of groupings of individuals into layers of subgroups. Detailed numerical simulations reveals that for H > 1, the global spreading results regardless of the degree of homophily α of the individuals forming a social circle. For H = 1, a transition from a global to a local spread occurs as the population becomes decomposed into increasingly homophilous groups. Multiple dimensions in classifying individuals (nodes) thus make a society (computer network) highly susceptible to large scale outbreaks of infectious diseases (viruses). The SIR-model can be extended by the inclusion of waiting times resulting in modified distribution function of the recovered.
Bartels, Meike; Cath, Danielle C.; Boomsma, Dorret I.
2008-01-01
The factor structure of the Dutch translation of the Autism-Spectrum Quotient (AQ; a continuous, quantitative measure of autistic traits) was evaluated with confirmatory factor analyses in a large general population and student sample. The criterion validity of the AQ was examined in three matched patient groups (autism spectrum conditions (ASC), social anxiety disorder, and obsessive–compulsive disorder). A two factor model, consisting of a “Social interaction” factor and “Attention to detail” factor could be identified. The internal consistency and test–retest reliability of the AQ were satisfactory. High total AQ and factor scores were specific to ASC patients. Men scored higher than women and science students higher than non-science students. The Dutch translation of the AQ is a reliable instrument to assess autism spectrum conditions. PMID:18302013
Yamaguchi-Kabata, Yumi; Nakazono, Kazuyuki; Takahashi, Atsushi; Saito, Susumu; Hosono, Naoya; Kubo, Michiaki; Nakamura, Yusuke; Kamatani, Naoyuki
2008-10-01
Because population stratification can cause spurious associations in case-control studies, understanding the population structure is important. Here, we examined Japanese population structure by "Eigenanalysis," using the genotypes for 140,387 SNPs in 7003 Japanese individuals, along with 60 European, 60 African, and 90 East-Asian individuals, in the HapMap project. Most Japanese individuals fell into two main clusters, Hondo and Ryukyu; the Hondo cluster includes most of the individuals from the main islands in Japan, and the Ryukyu cluster includes most of the individuals from Okinawa. The SNPs with the greatest frequency differences between the Hondo and Ryukyu clusters were found in the HLA region in chromosome 6. The nonsynonymous SNPs with the greatest frequency differences between the Hondo and Ryukyu clusters were the Val/Ala polymorphism (rs3827760) in the EDAR gene, associated with hair thickness, and the Gly/Ala polymorphism (rs17822931) in the ABCC11 gene, associated with ear-wax type. Genetic differentiation was observed, even among different regions in Honshu Island, the largest island of Japan. Simulation studies showed that the inclusion of different proportions of individuals from different regions of Japan in case and control groups can lead to an inflated rate of false-positive results when the sample sizes are large.
Vanasse, Alain; Cohen, Alan; Courteau, Josiane; Bergeron, Patrick; Dault, Roxanne; Gosselin, Pierre; Blais, Claudia; Bélanger, Diane; Rochette, Louis; Chebana, Fateh
2016-01-01
Background: Floods represent a serious threat to human health beyond the immediate risk of drowning. There is few data on the potential link between floods and direct consequences on health such as on cardiovascular health. This study aimed to explore the impact of one of the worst floods in the history of Quebec, Canada on acute cardiovascular diseases (CVD). Methods: A cohort study with a time series design with multiple control groups was built with the adult population identified in the Quebec Integrated Chronic Disease Surveillance System. A geographic information system approach was used to define the study areas. Logistic regressions were performed to compare the occurrence of CVD between groups. Results: The results showed a 25%–27% increase in the odds in the flooded population in spring 2011 when compared with the population in the same area in springs 2010 and 2012. Besides, an increase up to 69% was observed in individuals with a medical history of CVD. Conclusion: Despite interesting results, the association was not statistically significant. A possible explanation to this result can be that the population affected by the flood was probably too small to provide the statistical power to answer the question, and leaves open a substantial possibility for a real and large effect. PMID:26828511
Vanasse, Alain; Cohen, Alan; Courteau, Josiane; Bergeron, Patrick; Dault, Roxanne; Gosselin, Pierre; Blais, Claudia; Bélanger, Diane; Rochette, Louis; Chebana, Fateh
2016-01-28
Floods represent a serious threat to human health beyond the immediate risk of drowning. There is few data on the potential link between floods and direct consequences on health such as on cardiovascular health. This study aimed to explore the impact of one of the worst floods in the history of Quebec, Canada on acute cardiovascular diseases (CVD). A cohort study with a time series design with multiple control groups was built with the adult population identified in the Quebec Integrated Chronic Disease Surveillance System. A geographic information system approach was used to define the study areas. Logistic regressions were performed to compare the occurrence of CVD between groups. The results showed a 25%-27% increase in the odds in the flooded population in spring 2011 when compared with the population in the same area in springs 2010 and 2012. Besides, an increase up to 69% was observed in individuals with a medical history of CVD. Despite interesting results, the association was not statistically significant. A possible explanation to this result can be that the population affected by the flood was probably too small to provide the statistical power to answer the question, and leaves open a substantial possibility for a real and large effect.
Analysis of iris surface features in populations of diverse ancestry
Edwards, Melissa; Cha, David; Krithika, S.; Johnson, Monique; Parra, Esteban J.
2016-01-01
There are many textural elements that can be found in the human eye, including Fuchs’ crypts, Wolfflin nodules, pigment spots, contraction furrows and conjunctival melanosis. Although iris surface features have been well-studied in populations of European ancestry, the worldwide distribution of these traits is poorly understood. In this paper, we develop a new method of characterizing iris features from photographs of the iris. We then apply this method to a diverse sample of East Asian, European and South Asian ancestry. All five iris features showed significant differences in frequency between the three populations, indicating that iris features are largely population dependent. Although none of the features were correlated with each other in the East and South Asian groups, Fuchs’ crypts were significantly correlated with contraction furrows and pigment spots and contraction furrows were significantly associated with pigment spots in the European group. The genetic marker SEMA3A rs10235789 was significantly associated with Fuchs’ crypt grade in the European, East Asian and South Asian samples and a borderline association between TRAF3IP1 rs3739070 and contraction furrow grade was found in the European sample. The study of iris surface features in diverse populations may provide valuable information of forensic, biomedical and ophthalmological interest. PMID:26909168
Terry, Paul E; Fowles, Jinnet Briggs; Xi, Min; Harvey, Lisa
2011-01-01
PURPOSE. This study compares a traditional worksite-based health promotion program with an activated consumer program and a control program DESIGN. Group randomized controlled trial with 18-month intervention. SETTING. Two large Midwestern companies. SUBJECTS. Three hundred and twenty employees (51% response). INTERVENTION. The traditional health promotion intervention offered population-level campaigns on physical activity, nutrition, and stress management. The activated consumer intervention included population-level campaigns for evaluating health information, choosing a health benefits plan, and understanding the risks of not taking medications as prescribed. The personal development intervention (control group) offered information on hobbies. The interventions also offered individual-level coaching for high risk individuals in both active intervention groups. MEASURES. Health risk status, general health status, consumer activation, productivity, and the ability to evaluate health information. ANALYSIS. Multivariate analyses controlled for baseline differences among the study groups. RESULTS. At the population level, compared with baseline performance, the traditional health promotion intervention improved health risk status, consumer activation, and the ability to recognize reliable health websites. Compared with baseline performance, the activated consumer intervention improved consumer activation, productivity, and the ability to recognize reliable health websites. At the population level, however, only the activated consumer intervention improved any outcome more than the control group did; that outcome was consumer activation. At the individual level for high risk individuals, both traditional health coaching and activated consumer coaching positively affected health risk status and consumer activation. In addition, both coaching interventions improved participant ability to recognize a reliable health website. Consumer activation coaching also significantly improved self-reported productivity. CONCLUSION. An effective intervention can change employee health risk status and activation both at the population level and at the individual high risk level. However, program engagement at the population level was low, indicating that additional promotional strategies, such as greater use of incentives, need to be examined. Less intensive coaching can be as effective as more intensive, albeit both interventions produced modest behavior change and retention in the consumer activation arm was most difficult. Further research is needed concerning recruitment and retention methods that will enable populations to realize the full potential of activated consumerism.
Modelling radicalization: how small violent fringe sects develop into large indoctrinated societies
2017-01-01
We model radicalization in a society consisting of two competing religious, ethnic or political groups. Each of the ‘sects’ is divided into moderate and radical factions, with intra-group transitions occurring either spontaneously or through indoctrination. We also include the possibility of one group violently attacking the other. The intra-group transition rates of one group are modelled to explicitly depend on the actions and characteristics of the other, including violent episodes, effectively coupling the dynamics of the two sects. We use a game theoretic framework and assume that radical factions may tune ‘strategic’ parameters to optimize given utility functions aimed at maximizing their ranks while minimizing the damage inflicted by their rivals. Constraints include limited overall resources that must be optimally allocated between indoctrination and external attacks on the other group. Various scenarios are considered, from symmetric sects whose behaviours mirror each other, to totally asymmetric ones where one sect may have a larger population or a superior resource availability. We discuss under what conditions sects preferentially employ indoctrination or violence, and how allowing sects to readjust their strategies allows for small, violent sects to grow into large, indoctrinated communities. PMID:28879010
Modelling radicalization: how small violent fringe sects develop into large indoctrinated societies
NASA Astrophysics Data System (ADS)
Short, Martin B.; McCalla, Scott G.; D'Orsogna, Maria R.
2017-08-01
We model radicalization in a society consisting of two competing religious, ethnic or political groups. Each of the `sects' is divided into moderate and radical factions, with intra-group transitions occurring either spontaneously or through indoctrination. We also include the possibility of one group violently attacking the other. The intra-group transition rates of one group are modelled to explicitly depend on the actions and characteristics of the other, including violent episodes, effectively coupling the dynamics of the two sects. We use a game theoretic framework and assume that radical factions may tune `strategic' parameters to optimize given utility functions aimed at maximizing their ranks while minimizing the damage inflicted by their rivals. Constraints include limited overall resources that must be optimally allocated between indoctrination and external attacks on the other group. Various scenarios are considered, from symmetric sects whose behaviours mirror each other, to totally asymmetric ones where one sect may have a larger population or a superior resource availability. We discuss under what conditions sects preferentially employ indoctrination or violence, and how allowing sects to readjust their strategies allows for small, violent sects to grow into large, indoctrinated communities.
Shrikhande, Anuradha V; Arjunan, Aishwarya; Agarwal, Amit; Dani, Aarti; Tijare, Jayashri; Gettig, Elizabeth; Krishnamurti, Lakshmanan
2014-01-01
Sickle cell disease is an inherited disorder of the blood, and characterized by vasoocclusive crises (VOC), risks for pneumococcal infections and organ toxicities, is associated with morbidity and premature mortality. India, with a population of 1.2 billion individuals, is estimated to be home to over 50.0% of the world's patients with sickle cell disease. The β(S) gene [β6(A3)Glu→Val; HBB: c.20A>T] has the highest prevalence in three socio-economically disadvantaged ethnic categories: the Scheduled Castes (SC), the Scheduled Tribes (ST), and Other Backward Class (OBC) groups in India. The tradition of endogamy practiced by the ethnic groups in India provides the rationale for the screening of individual populations to better understand the distribution of the β(S) gene, guide counseling and awareness programs and aid development of public policy. We undertook a study to describe the prevalence of the β(S) gene in these ethnic groups in the district of Nagpur, Maharashtra in Central India. Through community screening and subsequent targeted screening of high risk individuals, 35,636 individuals were screened, of whom 5466 were found to have sickle cell trait and 1010 were identified with sickle cell disease. Community screening revealed a sickle cell trait prevalence of 13.0% in the SC, 12.0% in the ST and 3.4% in the OBC population. This study describes the prevalence of the β(S) gene within these groups in Central India determined by large scale community screening. This program has uncovered previously undiagnosed cases, provided detailed information to guide population-based disease counseling, prevention and comprehensive care programs.
Phenotypic plasticity in sex allocation for a simultaneously hermaphroditic coral reef fish
NASA Astrophysics Data System (ADS)
Hart, M. K.; Svoboda, A.; Mancilla Cortez, D.
2011-06-01
Phenotypic plasticity can facilitate reproductive strategies that maximize mating success in variable environments and lead to differences in sex allocation among populations. For simultaneous hermaphrodites with sperm competition, including Serranus tortugarum a small coral reef fish, proportional male allocation (testis in total gonad) is often greater where local density or mating group size is higher. We tested whether S. tortugarum reduced male allocation when transplanted from a higher density site to a lower density site. After 4 months, transplants mirrored the sex-allocation patterns of the resident population on their new reef. Transplants had significantly lower male allocation than representatives from their source population, largely as a result of reduced testis mass relative to body size.
Espinosa, Santiago; Branch, Lyn C.; Cueva, Rubén
2014-01-01
Protected areas are essential for conservation of wildlife populations. However, in the tropics there are two important factors that may interact to threaten this objective: 1) road development associated with large-scale resource extraction near or within protected areas; and 2) historical occupancy by traditional or indigenous groups that depend on wildlife for their survival. To manage wildlife populations in the tropics, it is critical to understand the effects of roads on the spatial extent of hunting and how wildlife is used. A geographical analysis can help us answer questions such as: How do roads affect spatial extent of hunting? How does market vicinity relate to local consumption and trade of bushmeat? How does vicinity to markets influence choice of game? A geographical analysis also can help evaluate the consequences of increased accessibility in landscapes that function as source-sink systems. We applied spatial analyses to evaluate the effects of increased landscape and market accessibility by road development on spatial extent of harvested areas and wildlife use by indigenous hunters. Our study was conducted in Yasuní Biosphere Reserve, Ecuador, which is impacted by road development for oil extraction, and inhabited by the Waorani indigenous group. Hunting activities were self-reported for 12–14 months and each kill was georeferenced. Presence of roads was associated with a two-fold increase of the extraction area. Rates of bushmeat extraction and trade were higher closer to markets than further away. Hunters located closer to markets concentrated their effort on large-bodied species. Our results clearly demonstrate that placing roads within protected areas can seriously reduce their capacity to sustain wildlife populations and potentially threaten livelihoods of indigenous groups who depend on these resources for their survival. Our results critically inform current policy debates regarding resource extraction and road building near or within protected areas. PMID:25489954
Chiyo, Patrick I.; Grieneisen, Laura E.; Wittemyer, George; Moss, Cynthia J.; Lee, Phyllis C.; Douglas-Hamilton, Iain; Archie, Elizabeth A.
2014-01-01
Social structure is proposed to influence the transmission of both directly and environmentally transmitted infectious agents. However in natural populations, many other factors also influence transmission, including variation in individual susceptibility and aspects of the environment that promote or inhibit exposure to infection. We used a population genetic approach to investigate the effects of social structure, environment, and host traits on the transmission of Escherichia coli infecting two populations of wild elephants: one in Amboseli National Park and another in Samburu National Reserve, Kenya. If E. coli transmission is strongly influenced by elephant social structure, E. coli infecting elephants from the same social group should be genetically more similar than E. coli sampled from members of different social groups. However, we found no support for this prediction. Instead, E. coli was panmictic across social groups, and transmission patterns were largely dominated by habitat and host traits. For instance, habitat overlap between elephant social groups predicted E. coli genetic similarity, but only in the relatively drier habitat of Samburu, and not in Amboseli, where the habitat contains large, permanent swamps. In terms of host traits, adult males were infected with more diverse haplotypes, and males were slightly more likely to harbor strains with higher pathogenic potential, as compared to adult females. In addition, elephants from similar birth cohorts were infected with genetically more similar E. coli than elephants more disparate in age. This age-structured transmission may be driven by temporal shifts in genetic structure of E. coli in the environment and the effects of age on bacterial colonization. Together, our results support the idea that, in elephants, social structure often will not exhibit strong effects on the transmission of generalist, fecal-oral transmitted bacteria. We discuss our results in the context of social, environmental, and host-related factors that influence transmission patterns. PMID:24705319
Chiyo, Patrick I; Grieneisen, Laura E; Wittemyer, George; Moss, Cynthia J; Lee, Phyllis C; Douglas-Hamilton, Iain; Archie, Elizabeth A
2014-01-01
Social structure is proposed to influence the transmission of both directly and environmentally transmitted infectious agents. However in natural populations, many other factors also influence transmission, including variation in individual susceptibility and aspects of the environment that promote or inhibit exposure to infection. We used a population genetic approach to investigate the effects of social structure, environment, and host traits on the transmission of Escherichia coli infecting two populations of wild elephants: one in Amboseli National Park and another in Samburu National Reserve, Kenya. If E. coli transmission is strongly influenced by elephant social structure, E. coli infecting elephants from the same social group should be genetically more similar than E. coli sampled from members of different social groups. However, we found no support for this prediction. Instead, E. coli was panmictic across social groups, and transmission patterns were largely dominated by habitat and host traits. For instance, habitat overlap between elephant social groups predicted E. coli genetic similarity, but only in the relatively drier habitat of Samburu, and not in Amboseli, where the habitat contains large, permanent swamps. In terms of host traits, adult males were infected with more diverse haplotypes, and males were slightly more likely to harbor strains with higher pathogenic potential, as compared to adult females. In addition, elephants from similar birth cohorts were infected with genetically more similar E. coli than elephants more disparate in age. This age-structured transmission may be driven by temporal shifts in genetic structure of E. coli in the environment and the effects of age on bacterial colonization. Together, our results support the idea that, in elephants, social structure often will not exhibit strong effects on the transmission of generalist, fecal-oral transmitted bacteria. We discuss our results in the context of social, environmental, and host-related factors that influence transmission patterns.
Waterloo Eye Study: data abstraction and population representation.
Machan, Carolyn M; Hrynchak, Patricia K; Irving, Elizabeth L
2011-05-01
To determine data quality in the Waterloo Eye Study (WatES) and compare the WatES age/sex distribution to the general population. Six thousand three hundred ninety-seven clinic files were reviewed at the University of Waterloo, School of Optometry. Abstracted information included patient age, sex, presenting chief complaint, entering spectacle prescription, refraction, binocular vision, and disease data. Mean age and age distributions were determined for the entire study group and both sexes. These results were compared with Statistics Canada (2006) estimates and information on Canadian optometric practices. Inter- and intraabstractor reliability was determined through double entry of 425 and 50 files, respectively; the Cohen kappa statistic (K) was calculated for qualitative data and the intraclass correlation coefficient (ICC) for quantitative data. Availability of data within the files was determined through missing data rates. The age of the patients in the WatES ranged from 0.2 to 93.9 years (mean age, 42.5 years), with all age groups younger than 85 years well represented. Females comprised 54.1% and males 45.9% of the study group. There were more older patients (>65 years) and younger patients (<10 years) than in the population at large. K values were highest for demographic information (e.g., sex, 0.96) and averaged slightly less for most clinical data requiring some abstractor interpretation (0.71 to 1.00). The two lowest interabstractor values, migraine (0.41) and smoking (0.26), had low reporting frequencies and definition ambiguity between abstractors. Intraclass correlation coefficient values were >0.90 for all but one continuous data type. Missing data rates were <2% for all but near phoria, which was 7.4%. The WatES database includes patients from all age groups and both sexes. It provides a fair representation of optometric patients in Canada. Its large sample size, good interabstractor repeatability, and low missing data rates demonstrates sufficient data quality for future analysis.
Espinosa, Santiago; Branch, Lyn C; Cueva, Rubén
2014-01-01
Protected areas are essential for conservation of wildlife populations. However, in the tropics there are two important factors that may interact to threaten this objective: 1) road development associated with large-scale resource extraction near or within protected areas; and 2) historical occupancy by traditional or indigenous groups that depend on wildlife for their survival. To manage wildlife populations in the tropics, it is critical to understand the effects of roads on the spatial extent of hunting and how wildlife is used. A geographical analysis can help us answer questions such as: How do roads affect spatial extent of hunting? How does market vicinity relate to local consumption and trade of bushmeat? How does vicinity to markets influence choice of game? A geographical analysis also can help evaluate the consequences of increased accessibility in landscapes that function as source-sink systems. We applied spatial analyses to evaluate the effects of increased landscape and market accessibility by road development on spatial extent of harvested areas and wildlife use by indigenous hunters. Our study was conducted in Yasuní Biosphere Reserve, Ecuador, which is impacted by road development for oil extraction, and inhabited by the Waorani indigenous group. Hunting activities were self-reported for 12-14 months and each kill was georeferenced. Presence of roads was associated with a two-fold increase of the extraction area. Rates of bushmeat extraction and trade were higher closer to markets than further away. Hunters located closer to markets concentrated their effort on large-bodied species. Our results clearly demonstrate that placing roads within protected areas can seriously reduce their capacity to sustain wildlife populations and potentially threaten livelihoods of indigenous groups who depend on these resources for their survival. Our results critically inform current policy debates regarding resource extraction and road building near or within protected areas.
Recent Historical Migrations Have Shaped the Gene Pool of Arabs and Berbers in North Africa
Arauna, Lara R.; Mendoza-Revilla, Javier; Mas-Sandoval, Alex; Izaabel, Hassan; Bekada, Asmahan; Benhamamouch, Soraya; Fadhlaoui-Zid, Karima; Zalloua, Pierre; Hellenthal, Garrett
2017-01-01
North Africa is characterized by its diverse cultural and linguistic groups and its genetic heterogeneity. Genomic data has shown an amalgam of components mixed since pre-Holocean times. Though no differences have been found in uniparental and classical markers between Berbers and Arabs, the two main ethnic groups in the region, the scanty genomic data available have highlighted the singularity of Berbers. We characterize the genetic heterogeneity of North African groups, focusing on the putative differences of Berbers and Arabs, and estimate migration dates. We analyze genome-wide autosomal data in five Berber and six Arab groups, and compare them to Middle Easterns, sub-Saharans, and Europeans. Haplotype-based methods show a lack of correlation between geographical and genetic populations, and a high degree of genetic heterogeneity, without strong differences between Berbers and Arabs. Berbers enclose genetically diverse groups, from isolated endogamous groups with high autochthonous component frequencies, large homozygosity runs and low effective population sizes, to admixed groups with high frequencies of sub-Saharan and Middle Eastern components. Admixture time estimates show a complex pattern of recent historical migrations, with a peak around the 7th century C.E. coincident with the Arabization of the region; sub-Saharan migrations since the 1st century B.C. in agreement with Roman slave trade; and a strong migration in the 17th century C.E., coincident with a huge impact of the trans-Atlantic and trans-Saharan trade of sub-Saharan slaves in the Modern Era. The genetic complexity found should be taken into account when selecting reference groups in population genetics and biomedical studies. PMID:27744413
Recent Historical Migrations Have Shaped the Gene Pool of Arabs and Berbers in North Africa.
Arauna, Lara R; Mendoza-Revilla, Javier; Mas-Sandoval, Alex; Izaabel, Hassan; Bekada, Asmahan; Benhamamouch, Soraya; Fadhlaoui-Zid, Karima; Zalloua, Pierre; Hellenthal, Garrett; Comas, David
2017-02-01
North Africa is characterized by its diverse cultural and linguistic groups and its genetic heterogeneity. Genomic data has shown an amalgam of components mixed since pre-Holocean times. Though no differences have been found in uniparental and classical markers between Berbers and Arabs, the two main ethnic groups in the region, the scanty genomic data available have highlighted the singularity of Berbers. We characterize the genetic heterogeneity of North African groups, focusing on the putative differences of Berbers and Arabs, and estimate migration dates. We analyze genome-wide autosomal data in five Berber and six Arab groups, and compare them to Middle Easterns, sub-Saharans, and Europeans. Haplotype-based methods show a lack of correlation between geographical and genetic populations, and a high degree of genetic heterogeneity, without strong differences between Berbers and Arabs. Berbers enclose genetically diverse groups, from isolated endogamous groups with high autochthonous component frequencies, large homozygosity runs and low effective population sizes, to admixed groups with high frequencies of sub-Saharan and Middle Eastern components. Admixture time estimates show a complex pattern of recent historical migrations, with a peak around the 7th century C.E. coincident with the Arabization of the region; sub-Saharan migrations since the 1st century B.C. in agreement with Roman slave trade; and a strong migration in the 17th century C.E., coincident with a huge impact of the trans-Atlantic and trans-Saharan trade of sub-Saharan slaves in the Modern Era. The genetic complexity found should be taken into account when selecting reference groups in population genetics and biomedical studies. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Ecological correlates of group-size variation in a resource-defense ungulate, the sedentary guanaco.
Marino, Andrea; Baldi, Ricardo
2014-01-01
For large herbivores, predation-risk, habitat structure and population density are often reported as major determinants of group size variation within and between species. However, whether the underlying causes of these relationships imply an ecological adaptation or are the result of a purely mechanistic process in which fusion and fragmentation events only depend on the rate of group meeting, is still under debate. The aim of this study was to model guanaco family and bachelor group sizes in contrasting ecological settings in order to test hypotheses regarding the adaptive significance of group-size variation. We surveyed guanaco group sizes within three wildlife reserves located in eastern Patagonia where guanacos occupy a mosaic of grasslands and shrublands. Two of these reserves have been free from predators for decades while in the third, pumas often prey on guanacos. All locations have experienced important changes in guanaco abundance throughout the study offering the opportunity to test for density effects. We found that bachelor group size increased with increasing density, as expected by the mechanistic approach, but was independent of habitat structure or predation risk. In contrast, the smaller and territorial family groups were larger in the predator-exposed than in the predator-free locations, and were larger in open grasslands than in shrublands. However, the influence of population density on these social units was very weak. Therefore, family group data supported the adaptive significance of group-size variation but did not support the mechanistic idea. Yet, the magnitude of the effects was small and between-population variation in family group size after controlling for habitat and predation was negligible, suggesting that plasticity of these social units is considerably low. Our results showed that different social units might respond differentially to local ecological conditions, supporting two contrasting hypotheses in a single species, and highlight the importance of taking into account the proximate interests and constraints to which group members may be exposed to when deriving predictions about group-size variation.
Fumanelli, Laura; Ajelli, Marco; Manfredi, Piero; Vespignani, Alessandro; Merler, Stefano
2012-01-01
Social contact patterns among individuals encode the transmission route of infectious diseases and are a key ingredient in the realistic characterization and modeling of epidemics. Unfortunately, the gathering of high quality experimental data on contact patterns in human populations is a very difficult task even at the coarse level of mixing patterns among age groups. Here we propose an alternative route to the estimation of mixing patterns that relies on the construction of virtual populations parametrized with highly detailed census and demographic data. We present the modeling of the population of 26 European countries and the generation of the corresponding synthetic contact matrices among the population age groups. The method is validated by a detailed comparison with the matrices obtained in six European countries by the most extensive survey study on mixing patterns. The methodology presented here allows a large scale comparison of mixing patterns in Europe, highlighting general common features as well as country-specific differences. We find clear relations between epidemiologically relevant quantities (reproduction number and attack rate) and socio-demographic characteristics of the populations, such as the average age of the population and the duration of primary school cycle. This study provides a numerical approach for the generation of human mixing patterns that can be used to improve the accuracy of mathematical models in the absence of specific experimental data. PMID:23028275
Local differentiation amidst extensive allele sharing in Oryza nivara and O. rufipogon
Banaticla-Hilario, Maria Celeste N; van den Berg, Ronald G; Hamilton, Nigel Ruaraidh Sackville; McNally, Kenneth L
2013-01-01
Genetic variation patterns within and between species may change along geographic gradients and at different spatial scales. This was revealed by microsatellite data at 29 loci obtained from 119 accessions of three Oryza series Sativae species in Asia Pacific: Oryza nivara Sharma and Shastry, O. rufipogon Griff., and O. meridionalis Ng. Genetic similarities between O. nivara and O. rufipogon across their distribution are evident in the clustering and ordination results and in the large proportion of shared alleles between these taxa. However, local-level species separation is recognized by Bayesian clustering and neighbor-joining analyses. At the regional scale, the two species seem more differentiated in South Asia than in Southeast Asia as revealed by FST analysis. The presence of strong gene flow barriers in smaller spatial units is also suggested in the analysis of molecular variance (AMOVA) results where 64% of the genetic variation is contained among populations (as compared to 26% within populations and 10% among species). Oryza nivara (HE = 0.67) exhibits slightly lower diversity and greater population differentiation than O. rufipogon (HE = 0.70). Bayesian inference identified four, and at a finer structural level eight, genetically distinct population groups that correspond to geographic populations within the three taxa. Oryza meridionalis and the Nepalese O. nivara seemed diverged from all the population groups of the series, whereas the Australasian O. rufipogon appeared distinct from the rest of the species. PMID:24101993
Renal disease disparities in Asian and Pacific-based populations in Hawai'i.
Mau, Marjorie K.; West, Margaret; Sugihara, Jared; Kamaka, Martina; Mikami, Judy; Cheng, Shiuh-Feng
2003-01-01
The prevalence of end-stage renal disease (ESRD) in the United States is expected to double over the next 10 years. The identification of ethnic differences in the prevalence, treatment, morbidity, and mortality related to chronic kidney disease (CKD) is of great concern. Asian Americans comprise a rapidly expanding sector of the U.S. population and are reported to have ESRD growth rates that are approximately 50% higher than caucasians. Hawai'i has a large, well-established Asian and Pacific-based population that facilitates the examination of disparities in renal disease among the state's diverse ethnic groups. The prevalence of ESRD in Hawai'i has continued to rise due, in part, to high rates of diabetes, glomerulonephritis, and hypertension reported in Asian Americans and Pacific-based populations. ESRD patients in Hawai'i have a two-fold higher prevalence of glomerulonephritis, compared with the general ESRD population in the United States. Other potential sources of renal disparities-such as cultural factors, language barriers, and health access factors-among Hawaii's major ethnic groups are assessed. However, few studies have examined the relative contribution of these potential factors. Consequently, efforts to reduce and eventually eliminate renal disease disparities will require a better understanding of the major sources of health disparities, such as timely medical care, a diverse health workforce, and cultural/social barriers, that affect optimal health care practices in Asian and Pacific-based populations. PMID:14620708
Radiography-based score indicative for the pathogenicity of bacteria in odontogenic infections.
Cachovan, Georg; Blessmann, Marco; Schön, Gerhard; Rother, Uwe; Heiland, Max; Stürenburg, Enno; Platzer, Ursula; Sobottka, Ingo
2014-10-01
To develop a new radiography-based score to assess the potential of bacteria to cause odontogenic infections derived from the occurrence of bacteria at small or large radiographical lesions. The patients analyzed were a sub-population from a large randomized clinical trial comparing moxifloxacin and clindamycin in the treatment of inflammatory infiltrates and odontogenic abscesses. Routine radiographs were used to analyze the area of the periapical radiolucent lesions. Lesions were stratified by their radiographically measured area as large (>9 mm(2)) or small (≤9 mm(2)). A risk ratio was calculated for each species from the frequency of their occurrence in large vs in small lesions. Fifty-one patients, 19 with abscesses and 32 with infiltrates, were evaluated. Overall, the radiographical lesion areas ranged from 0.4-46.2 mm(2) (median = 9 mm(2)). An increased risk (risk ratio >1) to occur at large abscess lesions was observed for Prevotella (P.) oralis, P. buccae, P. oris, P. intermedia, Fusobacterium nucleatum and Streptococcus (Strep.) anginosus group. An increased risk to occur at large infiltrate lesions was found for Strep. salivarius, Strep. parasanguis, Strep. anginosus group, Capnocytophaga spp., Neisseria (N.) sicca, Neisseria spp., Staphylococcus (Staph.) aureus, P. intermedia, P. buccae, Prevotella spp. and P. melaninogenica. The radiography-based score suggests that certain Prevotella spp., F. nucleatum and Strep. anginosus groups play a crucial role in the pathogenesis of odontogenic abscesses, and that various streptococci, Neisseria spp., Capnocytophaga spp., Staph. aureus and Prevotella spp. are involved in the pathogenesis of odontogenic infiltrates.
Does source population size affect performance in new environments?
Yates, Matthew C; Fraser, Dylan J
2014-01-01
Small populations are predicted to perform poorly relative to large populations when experiencing environmental change. To explore this prediction in nature, data from reciprocal transplant, common garden, and translocation studies were compared meta-analytically. We contrasted changes in performance resulting from transplantation to new environments among individuals originating from different sized source populations from plants and salmonids. We then evaluated the effect of source population size on performance in natural common garden environments and the relationship between population size and habitat quality. In ‘home-away’ contrasts, large populations exhibited reduced performance in new environments. In common gardens, the effect of source population size on performance was inconsistent across life-history stages (LHS) and environments. When transplanted to the same set of new environments, small populations either performed equally well or better than large populations, depending on life stage. Conversely, large populations outperformed small populations within native environments, but only at later life stages. Population size was not associated with habitat quality. Several factors might explain the negative association between source population size and performance in new environments: (i) stronger local adaptation in large populations and antagonistic pleiotropy, (ii) the maintenance of genetic variation in small populations, and (iii) potential environmental differences between large and small populations. PMID:25469166
Population structure and infectious disease risk in southern Africa.
Uren, Caitlin; Möller, Marlo; van Helden, Paul D; Henn, Brenna M; Hoal, Eileen G
2017-06-01
The KhoeSan populations are the earliest known indigenous inhabitants of southern Africa. The relatively recent expansion of Bantu-speaking agropastoralists, as well as European colonial settlement along the south-west coast, dramatically changed patterns of genetic diversity in a region which had been largely isolated for thousands of years. Owing to this unique history, population structure in southern Africa reflects both the underlying KhoeSan genetic diversity as well as differential recent admixture. This population structure has a wide range of biomedical and sociocultural implications; such as changes in disease risk profiles. Here, we consolidate information from various population genetic studies that characterize admixture patterns in southern Africa with an aim to better understand differences in adverse disease phenotypes observed among groups. Our review confirms that ancestry has a direct impact on an individual's immune response to infectious diseases. In addition, we emphasize the importance of collaborative research, especially for populations in southern Africa that have a high incidence of potentially fatal infectious diseases such as HIV and tuberculosis.
Vander Wal, E; Festa-Bianchet, M; Réale, D; Coltman, D W; Pelletier, F
2015-03-01
The adaptive nature of sociality has long been a central question in ecology and evolution. However, the relative importance of social behavior for fitness, compared to morphology and environment, remains largely unknown. We assessed the importance of sociality for fitness (lamb production and survival) in a population of mark6d bighorn sheep (Ovis canadensis) over 16 years (n = 1022 sheep-years). We constructed social networks from observations (n = 38,350) of group membership (n = 3150 groups). We then tested whether consistent individual differences in social behavior (centrality) exist and evaluated their relative importance compared to factors known to affect fitness: mass, age, parental effects, and population density. Sheep exhibited consistent individual differences in social centrality. Controlling for maternal carryover effects and age, the positive effect of centrality in a social network on adult female lamb production and survival was equal or greater than the effect of body mass or population density. Social centrality had less effect on male survival and no effect on adult male lamb production or lamb survival. Through its effect on lamb production and survival, sociality in fission-fusion animal societies may ultimately influence population dynamics equally or more than morphological or environmental effects.
Korean Variant Archive (KOVA): a reference database of genetic variations in the Korean population.
Lee, Sangmoon; Seo, Jihae; Park, Jinman; Nam, Jae-Yong; Choi, Ahyoung; Ignatius, Jason S; Bjornson, Robert D; Chae, Jong-Hee; Jang, In-Jin; Lee, Sanghyuk; Park, Woong-Yang; Baek, Daehyun; Choi, Murim
2017-06-27
Despite efforts to interrogate human genome variation through large-scale databases, systematic preference toward populations of Caucasian descendants has resulted in unintended reduction of power in studying non-Caucasians. Here we report a compilation of coding variants from 1,055 healthy Korean individuals (KOVA; Korean Variant Archive). The samples were sequenced to a mean depth of 75x, yielding 101 singleton variants per individual. Population genetics analysis demonstrates that the Korean population is a distinct ethnic group comparable to other discrete ethnic groups in Africa and Europe, providing a rationale for such independent genomic datasets. Indeed, KOVA conferred 22.8% increased variant filtering power in addition to Exome Aggregation Consortium (ExAC) when used on Korean exomes. Functional assessment of nonsynonymous variant supported the presence of purifying selection in Koreans. Analysis of copy number variants detected 5.2 deletions and 10.3 amplifications per individual with an increased fraction of novel variants among smaller and rarer copy number variable segments. We also report a list of germline variants that are associated with increased tumor susceptibility. This catalog can function as a critical addition to the pre-existing variant databases in pursuing genetic studies of Korean individuals.
[Arterial hypertension in elderly patients - from pathophysiology to rational treatment].
Kucharska, Ewa
2013-01-01
According to the WHO, arterial hypertension is a major cause of death in adult populations all over the world, regardless of the socio-economic level of a specific population. In Poland, the presence of hypertension is estimated to be about 1/3 in the population of adult Poles. Although hypertension may occur in people of all ages, as the population is ageing, a large group of patients are those over 65. In this age group, the dominant form of arterial hypertension is the isolated systolic hypertension (ISH), in which increased systolic blood pressure is disclosed (higher than or equal to 140 mm Hg), with diastolic blood pressure values remaining within the normal range (<90 mm Hg). Even 15 years ago, the therapeutic approach to ISH in the elderly was a subject of a broad debate. Until the results of main clinical trials and meta-analyzes summarising these results were announced, it was not certain whether active treatment of these patients was beneficial. Moreover, the drug selection issue was hotly debated. The last major problem was the question concerning benefits resulting from the treatment of isolated systolic hypertension in patients aged 80 years and older.
Coagulation-Fragmentation Model for Animal Group-Size Statistics
NASA Astrophysics Data System (ADS)
Degond, Pierre; Liu, Jian-Guo; Pego, Robert L.
2017-04-01
We study coagulation-fragmentation equations inspired by a simple model proposed in fisheries science to explain data for the size distribution of schools of pelagic fish. Although the equations lack detailed balance and admit no H-theorem, we are able to develop a rather complete description of equilibrium profiles and large-time behavior, based on recent developments in complex function theory for Bernstein and Pick functions. In the large-population continuum limit, a scaling-invariant regime is reached in which all equilibria are determined by a single scaling profile. This universal profile exhibits power-law behavior crossing over from exponent -2/3 for small size to -3/2 for large size, with an exponential cutoff.
On the number of independent cultural traits carried by individuals and populations.
Lehmann, Laurent; Aoki, Kenichi; Feldman, Marcus W
2011-02-12
In species subject to individual and social learning, each individual is likely to express a certain number of different cultural traits acquired during its lifetime. If the process of trait innovation and transmission reaches a steady state in the population, the number of different cultural traits carried by an individual converges to some stationary distribution. We call this the trait-number distribution. In this paper, we derive the trait-number distributions for both individuals and populations when cultural traits are independent of each other. Our results suggest that as the number of cultural traits becomes large, the trait-number distributions approach Poisson distributions so that their means characterize cultural diversity in the population. We then analyse how the mean trait number varies at both the individual and population levels as a function of various demographic features, such as population size and subdivision, and social learning rules, such as conformism and anti-conformism. Diversity at the individual and population levels, as well as at the level of cultural homogeneity within groups, depends critically on the details of population demography and the individual and social learning rules.
Genetic Structure and Gene Flows within Horses: A Genealogical Study at the French Population Scale
Pirault, Pauline; Danvy, Sophy; Verrier, Etienne; Leroy, Grégoire
2013-01-01
Since horse breeds constitute populations submitted to variable and multiple outcrossing events, we analyzed the genetic structure and gene flows considering horses raised in France. We used genealogical data, with a reference population of 547,620 horses born in France between 2002 and 2011, grouped according to 55 breed origins. On average, individuals had 6.3 equivalent generations known. Considering different population levels, fixation index decreased from an overall species FIT of 1.37%, to an average of −0.07% when considering the 55 origins, showing that most horse breeds constitute populations without genetic structure. We illustrate the complexity of gene flows existing among horse breeds, a few populations being closed to foreign influence, most, however, being submitted to various levels of introgression. In particular, Thoroughbred and Arab breeds are largely used as introgression sources, since those two populations explain together 26% of founder origins within the overall horse population. When compared with molecular data, breeds with a small level of coancestry also showed low genetic distance; the gene pool of the breeds was probably impacted by their reproducer exchanges. PMID:23630596
Song, Tian; Ding, Yan-wei; Sun, Yan; He, Yi-Ni; Qi, Dian-Jun; Wu, Ying; Wu, Bin; Lang, Lang; Yu, Kai; Zhao, Xin; Zhu, Liang-liang; Wang, Shuang; Yu, Xiao-Song
2015-09-19
Due to the rising standard of living environment and advances in public health and medical care in China, it has been a tendency in recent years that health-related quality of life (HRQoL) has been increasingly acknowledged in community health management. However, large-scale population-based study on evaluating HQRoL in northeast of China was not conducted. This article aims to investigate the HRQoL in community residents in Northeast China and explore the associated factors. Stratified multiple-stage sampling method was used in the cross-sectional survey to investigate HRQoL of community residents in northeast of China. Univariate analysis and multiple linear regressions were used to analyze the factors associated to HRQoL of the community residents. The results were confirmed that HRQoL in general population was well performed for the first time in northeast of China in a large scale population. Community residents had better mental health than physical health. The factors influencing HRQoL included gender, age, educational level, marital status, ethnic group, chronic disease status, having breakfast frequency weekly and sleep quality. However, drinking and smoking habits did not affect residents' HRQoL. In this study, the result of the large-scale survey was satisfactory in northeast of China, providing HRQoL status of community residents. Policies on specific health management in community public health would emphasize on lifestyle behaviors especially eating habits in order to improving HRQoL.
Singh, Balwant; Singh, Nisha; Mishra, Shefali; Tripathi, Kabita; Singh, Bikram P; Rai, Vandna; Singh, Ashok K; Singh, Nagendra K
2018-01-01
Wild relatives of crops possess adaptive mutations for agronomically important traits, which could play significant role in crop improvement for sustainable agriculture. However, global climate change and human activities pose serious threats to the natural habitats leading to erosion of genetic diversity of wild rice populations. The purpose of this study was to explore and characterize India's huge untapped wild rice diversity in Oryza rufipogon Griff. species complex from a wide range of ecological niches. We made strategic expeditions around diversity hot spots in 64 districts of nine different agro-climatic zones of the country and collected 418 wild rice accessions. Significant variation was observed among the accessions for 46 morphological descriptors, allowing classification into O. nivara, O. rufipogon , and O. sativa f. spontanea morpho-taxonomic groups. Genome-specific pSINE1 markers confirmed all the accessions having AA genome, which were further classified using ecotype-specific pSINE1 markers into annual, perennial, intermediate, and an unknown type. Principal component analysis revealed continuous variation for the morphological traits in each ecotype group. Genetic diversity analysis based on multi-allelic SSR markers clustered these accessions into three major groups and analysis of molecular variance for nine agro-climatic zones showed that 68% of the genetic variation was inherent amongst individuals while only 11% of the variation separated the zones, though there was significant correlation between genetic and spatial distances of the accessions. Model based population structure analysis using genome wide bi-allelic SNP markers revealed three sub-populations designated 'Pro-Indica,' 'Pro-Aus,' and 'Mid-Gangetic,' which showed poor correspondence with the morpho - taxonomic classification or pSINE1 ecotypes. There was Pan-India distribution of the 'Pro-Indica' and 'Pro-Aus' sub-populations across agro-climatic zones, indicating a more fundamental grouping based on the ancestry closely related to 'Indica' and 'Aus' groups of rice cultivars. The Pro-Indica population has substantial presence in the Eastern Himalayan Region and Lower Gangetic Plains, whereas 'Pro-Aus' sub-population was predominant in the Upper Gangetic Plains, Western Himalayan Region, Gujarat Plains and Hills, and Western Coastal Plains. In contrast 'Mid-Gangetic' population was largely concentrated in the Mid Gangetic Plains. The information presented here will be useful in the utilization of wild rice resources for varietal improvement.
Two methods for parameter estimation using multiple-trait models and beef cattle field data.
Bertrand, J K; Kriese, L A
1990-08-01
Two methods are presented for estimating variances and covariances from beef cattle field data using multiple-trait sire models. Both methods require that the first trait have no missing records and that the contemporary groups for the second trait be subsets of the contemporary groups for the first trait; however, the second trait may have missing records. One method uses pseudo expectations involving quadratics composed of the solutions and the right-hand sides of the mixed model equations. The other method is an extension of Henderson's Simple Method to the multiple trait case. Neither of these methods requires any inversions of large matrices in the computation of the parameters; therefore, both methods can handle very large sets of data. Four simulated data sets were generated to evaluate the methods. In general, both methods estimated genetic correlations and heritabilities that were close to the Restricted Maximum Likelihood estimates and the true data set values, even when selection within contemporary groups was practiced. The estimates of residual correlations by both methods, however, were biased by selection. These two methods can be useful in estimating variances and covariances from multiple-trait models in large populations that have undergone a minimal amount of selection within contemporary groups.
Aburahma, Mona Hassan
2015-01-01
Like most of the pharmacy colleges in developing countries with high population growth, public pharmacy colleges in Egypt are experiencing a significant increase in students’ enrollment annually due to the large youth population, accompanied with the keenness of students to join pharmacy colleges as a step to a better future career. In this context, large lectures represent a popular approach for teaching the students as economic and logistic constraints prevent splitting them into smaller groups. Nevertheless, the impact of large lectures in relation to student learning has been widely questioned due to their educational limitations, which are related to the passive role the students maintain in lectures. Despite the reported feebleness underlying large lectures and lecturing in general, large lectures will likely continue to be taught in the same format in these countries. Accordingly, to soften the negative impacts of large lectures, this article describes a simple and feasible 5-step paper-based model to transform lectures from a passive information delivery space into an active learning environment. This model mainly suits educational establishments with financial constraints, nevertheless, it can be applied in lectures presented in any educational environment to improve active participation of students. The components and the expected advantages of employing the 5-step paper-based model in large lectures as well as its limitations and ways to overcome them are presented briefly. The impact of applying this model on students’ engagement and learning is currently being investigated. PMID:28975906
Conference considers low fertility.
1997-01-01
At present, at least 51 countries--representing 44% of the world's population--are showing below-replacement fertility rates. In some of these countries, where the number of new births is not adequate to replace aging populations, this trend is problematic. In other countries, most notably China, declining fertility has conferred significant benefits. At an Economic and Social Commission for Asia and the Pacific (ESCAP) Population Commission meeting held in New York in 1997, staff from China's State Statistical Bureau reported the country has a current total fertility rate of 1.8. The birth rate remains high, however, because of the large numbers of Chinese women in the 15-49 year reproductive age group (336 million in 1997). Also buffering the impact of a low fertility rate is a large labor surplus (130 million excess workers in rural China). To keep fertility below the replacement level, China plans to improve the quality of its family planning service, enhance poverty alleviation programs, and increase incentives for small families in rural areas. China's low fertility rate has provided an important impetus for economic development.
Hitchhiking and epistasis give rise to cohort dynamics in adapting populations
Buskirk, Sean W.; Peace, Ryan Emily; Lang, Gregory I.
2017-01-01
Beneficial mutations are the driving force of adaptive evolution. In asexual populations, the identification of beneficial alleles is confounded by the presence of genetically linked hitchhiker mutations. Parallel evolution experiments enable the recognition of common targets of selection; yet these targets are inherently enriched for genes of large target size and mutations of large effect. A comprehensive study of individual mutations is necessary to create a realistic picture of the evolutionarily significant spectrum of beneficial mutations. Here we use a bulk-segregant approach to identify the beneficial mutations across 11 lineages of experimentally evolved yeast populations. We report that nearly 80% of detected mutations have no discernible effects on fitness and less than 1% are deleterious. We determine the distribution of driver and hitchhiker mutations in 31 mutational cohorts, groups of mutations that arise synchronously from low frequency and track tightly with one another. Surprisingly, we find that one-third of cohorts lack identifiable driver mutations. In addition, we identify intracohort synergistic epistasis between alleles of hsl7 and kel1, which arose together in a low-frequency lineage. PMID:28720700
Energy investment advisory series No. 3: Investment opportunities in the Persian Gulf energy sector
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hadgen, R.E.
1994-12-01
Sometimes the greatest investment opportunities are in those areas where the least progress seems to be taking place. This report describes energy-based developments taking place in the Persian/Arabian Gulf. The 8 Gulf states are building their nations; each has large minority groups and swelling populations; their economies are built on one product (hydrocarbons). Large expatriate populations, being integrated into local societies and economies, have led to hostility and guarded access to contacts with the outside world. Gulf nations cannot benefit from any oil price rise as they did in the past, as their populations have grown too rapidly. Policies changemore » daily and can be changed back to original ones as well as into new ones. Since the oil and gas industries are the primary source of government revenue, oil and gas are likely to remain longest under government control. A breakdown of energy-base investment potentials in the Middle East is tabulated: upstream oil, refining, domestic oil marketing, upstream gas, LNG, electricity, petrochemical.« less
Weis, Jennifer A.; Olney, Marilynn W.; Alemán, Marty; Sullivan, Susan; Millington, Kendra; O'Hara, Connie; Nigon, Julie A.; Sia, Irene G.
2011-01-01
Objectives. We used a community-based participatory research (CBPR) approach to plan and implement free TB skin testing at an adult education center to determine the efficacy of CBPR with voluntary tuberculosis (TB) screening and the prevalence of TB infection among immigrant and refugee populations. Methods. We formed a CBPR partnership to address TB screening at an adult education center that serves a large immigrant and refugee population in Rochester, Minnesota. We conducted focus groups involving educators, health providers, and students of the education center, and used this input to implement TB education and TB skin testing among the center's students. Results. A total of 259 adult learners volunteered to be skin-tested in April 2009; 48 (18.5%) had positive TB skin tests. Conclusions. Our results imply that TB skin testing at adult education centers that serve large foreign-born populations may be effective. Our findings also show that a participatory process may enhance the willingness of foreign-born persons to participate in TB skin-testing efforts. PMID:21653249
Scandinavian epidemiological research in gastroenterology and hepatology.
Björnsson, Einar S; Ekbom, Anders
2015-06-01
In the last decades, a large number of epidemiological studies in gastroenterology and hepatology have originated from the Scandinavian countries. With the help of large health databases, with good validity and other registries related to patient outcomes, researchers from the Scandinavian countries have been able to make some very important contributions to the field. These countries, Sweden, Norway, Finland, Denmark and Iceland, have all universal access to health care and have shown to be ideal for epidemiological research. Population-based studies have been frequent and follow-up studies have been able to describe the temporal trends and changes in phenotypes. Our ability in Scandinavia to follow up defined groups of patients over time has been crucial to learn the natural history of many gastrointestinal and liver diseases and often in a population-based setting. Patient-related outcomes measures will probably gain increasing importance in the future, but Scandinavian gastroenterologists and surgeons are likely to have a better infrastructure for such endeavors compared to most other populations. Thus, there is a bright future for international competitive research within the field of gastrointestinal and liver diseases in Scandinavia.
Creel, Scott; Christianson, David; Schuette, Paul
2013-01-01
Large carnivore populations are in global decline, and conflicts between large carnivores and humans or their livestock contribute to low tolerance of large carnivores outside of protected areas. African lions (Panthera leo) are a conflict-prone species, and their continental range has declined by 75% in the face of human pressures. Nonetheless, large carnivore populations persist (or even grow) in some areas that are occupied by humans. Lions attain locally high density in the Olkiramatian and Shompole Group Ranches of Kenya's South Rift region, despite residence by pastoralist Maasai people and their sheep, goats, and cattle. We have previously found that these lions respond to seasonal movements of people by moving away from occupied settlements, shifting into denser habitats when people are nearby, and moving into a protected conservation area when people move into the adjacent buffer zone. Here, we examined lion stress responses to anthropogenic activities, using enzyme-linked immunoassay to measure the concentration of faecal glucocorticoid metabolites in 136 samples collected from five lion groups over 2 years. Faecal glucocorticoid metabolite concentrations were significantly lower for lions in the conservation area than for lions in the human-settled buffer zone, and decreased significantly with increasing distance to the nearest occupied human settlement. Faecal glucocorticoid metabolite concentrations were not detectably related to fine-scaled variation in prey or livestock density, and surprisingly, faecal glucocorticoid metabolite concentrations were higher in the wet season, when regional prey abundance was high. Lions coexist with people and livestock on this landscape by adjusting their movements, but they nonetheless mount an appreciable stress response when conditions do not allow them to maintain adequate separation. Thus, physiological data confirm inferences from prior data on lion movements and habitat use, showing that access to undisturbed and protected areas facilitates human-lion coexistence in a broader landscape that is used by people and livestock.
Gouveia, Nelson; Junger, Washington Leite
2018-01-01
Air pollution is an important public health concern especially for children who are particularly susceptible. Latin America has a large children population, is highly urbanized and levels of pollution are substantially high, making the potential health impact of air pollution quite large. We evaluated the effect of air pollution on children respiratory mortality in four large urban centers: Mexico City, Santiago, Chile, and Sao Paulo and Rio de Janeiro in Brazil. Generalized Additive Models in Poisson regression was used to fit daily time-series of mortality due to respiratory diseases in infants and children, and levels of PM 10 and O 3 . Single lag and constrained polynomial distributed lag models were explored. Analyses were carried out per cause for each age group and each city. Fixed- and random-effects meta-analysis was conducted in order to combine the city-specific results in a single summary estimate. These cities host nearly 43 million people and pollution levels were above the WHO guidelines. For PM 10 the percentage increase in risk of death due to respiratory diseases in infants in a fixed effect model was 0.47% (0.09-0.85). For respiratory deaths in children 1-5 years old, the increase in risk was 0.58% (0.08-1.08) while a higher effect was observed for lower respiratory infections (LRI) in children 1-14 years old [1.38% (0.91-1.85)]. For O 3 , the only summarized estimate statistically significant was for LRI in infants. Analysis by season showed effects of O 3 in the warm season for respiratory diseases in infants, while negative effects were observed for respiratory and LRI deaths in children. We provided comparable mortality impact estimates of air pollutants across these cities and age groups. This information is important because many public policies aimed at preventing the adverse effects of pollution on health consider children as the population group that deserves the highest protection. Copyright © 2017 Elsevier Ltd. All rights reserved.
Barbosa, M; Vieira, E P; Quintão, C C A; Normando, D
2016-08-01
To evaluate facial morphology of non-mixed indigenous people living in the Xingu region. Studies on these populations report that the total genetic diversity is as high as that observed for other continental populations. On the other hand, eating habits are different between indigenous and urban population, as indigenous people still have traditional habits. The sample consisted of 106 indigenous subjects, in permanent dentition stage, belonging to four groups: Arara-Laranjal (n = 35), Arara-Iriri (n = 20), Xikrin-Kaiapó (n = 24), and Assurini (n = 27). Standardized facial photographs were obtained, and fourteen measurements were analyzed. Intra- and intergroup homogeneities were examined by discriminant analysis, followed by anova and Kruskal-Wallis tests. Sexual dimorphism to each village was analyzed by Student's t-test or Mann-Whitney test, at p < 0.05. Significant facial differences were found between male and female, indicating that sex data should not be grouped for intergroup comparison. Discriminant analysis showed a large intergroup heterogeneity, while an intragroup homogeneity was found, especially for females. It was also observed that some morphological features of the face are specific to some villages, regardless of ethnicity. Facial morphological characteristics were strongly different among groups, even comparing villages from the same ethnicity. Furthermore, a low diversity within groups was observed. Our findings, supported by previous reports on genetics and eating habits in these populations, reinforce the role of the genetic determination on craniofacial morphology. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Reichard, Amanda; Fox, Michael H
2013-04-01
Individuals dually eligible for Medicaid and Medicare constitute a small percentage of these program's populations but account for a disproportionately large percent of their total costs. While much work has examined high expenditures, little is known about their health and details of their health care utilization. Utilize an important public health surveillance tool to better understand preventive service use among the dual eligible population. This study involved descriptive and regression analyses of dual eligibles in the Medical Expenditure Panel Survey data from pooled alternate years 2000-2008. We classified the sample into 4 mutually exclusive groups: cognitive limitations, physical disabilities, double diagnosis (cognitive limitations and physical disability), or neither cognitive limitations nor physical disability. For most groups, age was significantly associated with preventive services, though direction varies. Older age was linked to greater receipt of flu shots while younger age was associated with greater receipt of Pap tests, mammograms and dental services. Black women in all groups (except cognitive limitations) had an increased likelihood of receiving a Pap test and a mammogram. A subset of dual eligibles drives the majority of expenditures. People with physical disabilities, regardless of whether they also have a cognitive limitation, are among the highest costing and sickest of our non-institutionalized dual eligible population. Efforts to understand and address the challenges faced by women with physical disabilities in accessing Pap tests or mammograms may be helpful in improving the overall health status for this disability group, but also for all dual eligibles. Published by Elsevier Inc.
O'Neill, Colette M; Kazantzidis, Andreas; Kiely, Mairead; Cox, Lorna; Meadows, Sarah; Goldberg, Gail; Prentice, Ann; Kift, Richard; Webb, Ann R; Cashman, Kevin D
2017-10-01
Within Europe, dark-skinned ethnic groups have been shown to be at much increased risk of vitamin D deficiency compared to their white counterparts. Increasing the dietary supply of vitamin D is potentially the only modifiable environmental component that can be used to prevent vitamin D deficiency among dark-skinned ethnic groups living at high latitude. Empirical data to support development of such strategies is largely lacking. This paper presents the development and validation of an integrated model that may be adapted within the UK population to design fortification strategies for vitamin D, for application in both white and black and Asian minority ethnic (BAME) population groups. Using a step-wise approach, models based on available ultraviolet B (UVB) data, hours of sunlight and two key components (the dose-response of serum 25-hydroxyvitamin D [25(OH)D] to UVB in white and BAME persons and the dose-response of 25(OH)D to vitamin D) were used to predict changes population serum 25(OH)D concentrations throughout the year, stratified by ethnicity, 'via increases' in dietary intake arising from food fortification simulations. The integrated model successfully predicted measured average wintertime 25(OH)D concentrations in addition to the prevalence of serum 25(OH)D <30nmol/L in adult white and BAME individuals (18-70y) in the UK-based National Diet and Nutrition Survey both separately (21.7% and 49.3% predicted versus 20.2% and 50.5% measured, for white and BAME, respectively) and when combined at UK population-relevant proportions of 97% white and 7% BAME (23.2% predicted versus 23.1% measured). Thus this integrated model presents a viable approach to estimating changes in the population concentrations of 25(OH)D that may arise from various dietary fortification approaches. Copyright © 2016 Elsevier Ltd. All rights reserved.
Praline, Julien; Blasco, Hélène; Vourc'h, Patrick; Rat, Valérian; Gendrot, Chantal; Camu, William; Andres, Christian R
2012-06-15
Our objective was to investigate whether the C282Y (p.Cys 282 Tyr) and H63D (p. His 63 Asp) HFE polymorphisms were associated with sporadic amyotrophic lateral sclerosis (SALS) in the French population. We searched for a relation of HFE polymorphisms with the clinical characteristics of the disease. The HFE polymorphisms were studied in 824 patients with SALS and 583 controls. We compared the frequency of the polymorphisms between SALS and controls groups by univariate and multivariate statistics, taking into account gender, site, age-at-onset and survival. We did not observe significant difference in the frequency of H63D polymorphism between SALS and control group. We observed a significant difference for C282Y between patients and controls with a low frequency of the Y allele in patients (3.2%) compared to our control group (5.9%). Disease duration, distribution of gender, site-of-onset, age-at-onset did not differ between groups taking into account genotypes of each polymorphism. Our results in this large cohort of ALS patients indicate that H63D polymorphism is not associated with SALS in the French population. This conclusion does not exclude a weak effect of the HFE gene polymorphisms in certain ALS populations, or an effect of other rare HFE gene variants. Copyright © 2012 Elsevier B.V. All rights reserved.
Cooperation, Norms, and Revolutions: A Unified Game-Theoretical Approach
Helbing, Dirk; Johansson, Anders
2010-01-01
Background Cooperation is of utmost importance to society as a whole, but is often challenged by individual self-interests. While game theory has studied this problem extensively, there is little work on interactions within and across groups with different preferences or beliefs. Yet, people from different social or cultural backgrounds often meet and interact. This can yield conflict, since behavior that is considered cooperative by one population might be perceived as non-cooperative from the viewpoint of another. Methodology and Principal Findings To understand the dynamics and outcome of the competitive interactions within and between groups, we study game-dynamical replicator equations for multiple populations with incompatible interests and different power (be this due to different population sizes, material resources, social capital, or other factors). These equations allow us to address various important questions: For example, can cooperation in the prisoner's dilemma be promoted, when two interacting groups have different preferences? Under what conditions can costly punishment, or other mechanisms, foster the evolution of norms? When does cooperation fail, leading to antagonistic behavior, conflict, or even revolutions? And what incentives are needed to reach peaceful agreements between groups with conflicting interests? Conclusions and Significance Our detailed quantitative analysis reveals a large variety of interesting results, which are relevant for society, law and economics, and have implications for the evolution of language and culture as well. PMID:20967256
Stavrakos, S-K; Ahmed-Kristensen, S; Goldman, T
2016-09-01
Designers at the conceptual phase of products such as headphones, stress the importance of comfort, e.g. executing comfort studies and the need for a reliable user panel. This paper proposes a methodology to issue a reliable user panel to represent large populations and validates the proposed framework to predict comfort factors, such as physical fit. Data of 200 heads was analyzed by forming clusters, 9 archetypal people were identified out of a 200 people's ear database. The archetypes were validated by comparing the archetypes' responses on physical fit against those of 20 participants interacting with 6 headsets. This paper suggests a new method of selecting representative user samples for prototype testing compared to costly and time consuming methods which relied on the analysis of human geometry of large populations. Copyright © 2016 Elsevier Ltd. All rights reserved.
Towards a global human embryonic stem cell bank.
Lott, Jason P; Savulescu, Julian
2007-08-01
An increasingly unbridgeable gap exists between the supply and demand of transplantable organs. Human embryonic stem cell technology could solve the organ shortage problem by restoring diseased or damaged tissue across a range of common conditions. However, such technology faces several largely ignored immunological challenges in delivering cell lines to large populations. We address some of these challenges and argue in favor of encouraging contribution or intentional creation of embryos from which widely immunocompatible stem cell lines could be derived. Further, we argue that current immunological constraints in tissue transplantation demand the creation of a global stem cell bank, which may hold particular promise for minority populations and other sub-groups currently marginalized from organ procurement and allocation systems. Finally, we conclude by offering a number of practical and ethically oriented recommendations for constructing a human embryonic stem cell bank that we hope will help solve the ongoing organ shortage problem.
Rotator cuff tear and sarcopenia: are these related?
Chung, Seok Won; Yoon, Jong Pil; Oh, Kyung-Soo; Kim, Hyung Sup; Kim, Young Gun; Lee, Hyun-Joo; Jeong, Won-Ju; Kim, Dong-Hyun; Lee, Jong Soo; Yoon, Jee Wook
2016-09-01
Sarcopenia is the loss of muscle mass and consequent loss of muscle function with aging. Its prevalence among the general population is 12% to 30% in those aged >60 years. We evaluated (1) the difference in the prevalence of sarcopenia between patients with rotator cuff tear and controls and (2) the sarcopenia severity according to the size of the rotator cuff tear. Group 1 included 48 consecutive patients with chronic symptomatic full-thickness rotator cuff tears (mean age, 60.1 ± 6.5 years; range, 46-76 years), and group 2 included 48 age- and sex-matched patients. The sarcopenic index was evaluated by using the grip strength of the asymptomatic contralateral side and the skeletal muscle mass. No significant differences were found in the baseline data and demographic factors between the groups. The sarcopenic index was significantly inferior in the rotator cuff tear group than in the age- and sex-matched control groups (P = .041, .007, and .05, respectively). Patients with large to massive tears had a significantly inferior sarcopenic index than those with small and medium tears. The results showed that sarcopenia was more severe in patients with a chronic symptomatic full-thickness rotator cuff tear than in the age- and sex-matched control population and was correlated with the size of the tear, with the numbers available. Despite the individual variance in the underlying medical condition and physical activities, this study suggests that clinicians should consider the sarcopenic condition of patients with a rotator cuff tear, especially in elderly patients with large to massive tears. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.
Sleep quality, use of hypnotics and sleeping habits in different age-groups among older people.
Hägg, Miriam; Houston, Britta; Elmståhl, Sölve; Ekström, Henrik; Wann-Hansson, Christine
2014-12-01
Sleep disturbances are common among older people (>65 years). Further, long-term use of sedative hypnoticsin older people is associated with morbidity and mortality. However, older people represent a large span of life years, and few studies have included the oldest-old above 85 years. To investigate and compare sleep quality, use of hypnotics and sleeping habits in different age groups of the older population in the Scania region, Sweden and in relation to sociodemographic- and functional status. A cross-sectional population-based study including 2931 people aged 60-93 years from five different municipalities in Scania was performed during 2001-2004. The sample was divided into age groups, young old (60-72 years), old-old (78-84 years) and oldest-old (87-93) years. Data constitutes of sleep related questions, sociodemographic- and functional status from the study 'Good Ageing in Skane'. Descriptive statistics were used to describe sleep quality, hypnotics use and sleeping habitsin relation to sociodemographic- and functional status. The aim was to investigate associations, not the magnitude of associations between variables. In all age groups, those who used hypnotics and were living alone had significantly poorer sleep quality and shortest sleeping time than nonhypnotic users and those who lived together. A significant increase of hypnotics and frequency of use was seen with increasing age. Frequency of napping increased significantly with degree of dependence in all age groups and with increasing age. Insomnia is still a problem and hypnotic use has not improved sleep for a large number of older people. Hypnotics are effective as short-term treatment, however, nonpharmacological interventions and psychological and behavioural therapies should be considered for treating older people with chronic insomnia.
Hein, L; Sørensen, L P; Kargo, M; Buitenhuis, A J
2018-03-01
The objective of this study was to assess the genetic variability of the detailed fatty acid (FA) profiles of Danish Holstein (DH) and Danish Jersey (DJ) cattle populations. We estimated genetic parameters for 11 FA or groups of FA in milk samples from the Danish milk control system between May 2015 and October 2016. Concentrations of different FA and FA groups in milk samples were measured by mid-infrared spectroscopy. Data used for parameter estimation were from 132,732 first-parity DH cows and 21,966 first-parity DJ cows. We found the highest heritabilities for test day measurements in both populations for short-chain FA (DH = 0.16; DJ = 0.16) and C16:0 (DH = 0.14; DJ = 0.16). In DH, the highest heritabilities were also found for saturated FA and monounsaturated FA (both populations: 0.15). Genetic correlations between the fatty acid traits showed large differences between DH and DJ for especially short-chain FA with the other FA traits measured. Furthermore, genetic correlations of total fat with monounsaturated FA, polyunsaturated FA, short-chain FA, and C16:0 differed markedly between DH and DJ populations. In conclusion, we found genetic variation in the mid-infrared spectroscopy-predicted FA and FA groups of the DH and DJ cattle populations. This finding opens the possibility of using genetic selection to change the FA profiles of dairy cattle. The Authors. Published by FASS Inc. and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).
Navigating complex sample analysis using national survey data.
Saylor, Jennifer; Friedmann, Erika; Lee, Hyeon Joo
2012-01-01
The National Center for Health Statistics conducts the National Health and Nutrition Examination Survey and other national surveys with probability-based complex sample designs. Goals of national surveys are to provide valid data for the population of the United States. Analyses of data from population surveys present unique challenges in the research process but are valuable avenues to study the health of the United States population. The aim of this study was to demonstrate the importance of using complex data analysis techniques for data obtained with complex multistage sampling design and provide an example of analysis using the SPSS Complex Samples procedure. Illustration of challenges and solutions specific to secondary data analysis of national databases are described using the National Health and Nutrition Examination Survey as the exemplar. Oversampling of small or sensitive groups provides necessary estimates of variability within small groups. Use of weights without complex samples accurately estimates population means and frequency from the sample after accounting for over- or undersampling of specific groups. Weighting alone leads to inappropriate population estimates of variability, because they are computed as if the measures were from the entire population rather than a sample in the data set. The SPSS Complex Samples procedure allows inclusion of all sampling design elements, stratification, clusters, and weights. Use of national data sets allows use of extensive, expensive, and well-documented survey data for exploratory questions but limits analysis to those variables included in the data set. The large sample permits examination of multiple predictors and interactive relationships. Merging data files, availability of data in several waves of surveys, and complex sampling are techniques used to provide a representative sample but present unique challenges. In sophisticated data analysis techniques, use of these data is optimized.
Yi, SoJeong; An, Hyungmi; Lee, Howard; Lee, Sangin; Ieiri, Ichiro; Lee, Youngjo; Cho, Joo-Youn; Hirota, Takeshi; Fukae, Masato; Yoshida, Kenji; Nagatsuka, Shinichiro; Kimura, Miyuki; Irie, Shin; Sugiyama, Yuichi; Shin, Dong Wan; Lim, Kyoung Soo; Chung, Jae-Yong; Yu, Kyung-Sang; Jang, In-Jin
2014-10-01
Interethnic differences in genetic polymorphism in genes encoding drug-metabolizing enzymes and transporters are one of the major factors that cause ethnic differences in drug response. This study aimed to investigate genetic polymorphisms in genes involved in drug metabolism, transport, and excretion among Korean, Japanese, and Chinese populations, the three major East Asian ethnic groups. The frequencies of 1936 variants representing 225 genes encoding drug-metabolizing enzymes and transporters were determined from 786 healthy participants (448 Korean, 208 Japanese, and 130 Chinese) using the Affymetrix Drug-Metabolizing Enzymes and Transporters Plus microarray. To compare allele or genotype frequencies in the high-dimensional data among the three East Asian ethnic groups, multiple testing, principal component analysis (PCA), and regularized multinomial logit model through least absolute shrinkage and selection operator were used. On microarray analysis, 1071 of 1936 variants (>50% of markers) were found to be monomorphic. In a large number of genetic variants, the fixation index and Pearson's correlation coefficient of minor allele frequencies were less than 0.034 and greater than 0.95, respectively, among the three ethnic groups. PCA identified 47 genetic variants with multiple testing, but was unable to discriminate ethnic groups by the first three components. Multinomial least absolute shrinkage and selection operator analysis identified 269 genetic variants that showed different frequencies among the three ethnic groups. However, none of those variants distinguished between the three ethnic groups during subsequent PCA. Korean, Japanese, and Chinese populations are not pharmacogenetically distant from one another, at least with regard to drug disposition, metabolism, and elimination.
2013-01-01
Background Although screening, brief intervention, and referral to treatment (SBIRT) is an evidence-based technique that, in some health-care settings, has been shown to cost-effectively reduce alcohol and drug use, research on the efficacy of SBIRT among criminal offender populations is limited. Such populations have a high prevalence of drug and alcohol use but limited access to intervention, and many are at risk for post-release relapse and recidivism. Thus, there exists a need for treatment options for drug-involved offenders of varying risk levels to reduce risky behaviors or enter treatment. Methods/design This protocol describes an assessment of SBIRT feasibility and effectiveness in a criminal justice environment. Eight-hundred persons will be recruited from a large metropolitan jail, with the experimental group receiving an intervention depending on risk level and the control group receiving minimal intervention. The intervention will assess the risk level for drug and alcohol misuse by inmates, providing those at low or medium risk a brief intervention in the jail and referring those at high risk to community treatment following release. In addition, a brief treatment (eight-session) option will be available. Using data from a 12-month follow-up interview, the primary study outcomes are a reduction in drug and alcohol use, while secondary outcomes include participation in treatment, rearrest, quality of life, reduction in HIV risk behaviors, and costs of SBIRT. Expected value Individual reductions in alcohol and drug use can have significant effects on public health and safety when observed over a large population at risk for substance-use problems. With wider dissemination statewide or nationwide, a relatively low-cost intervention such as SBIRT could offer demonstrated benefits in this population. Trial registration Clinical Trials Government Identifier, NCT01683643. PMID:24499609
The Chernobyl accident and its consequences.
Saenko, V; Ivanov, V; Tsyb, A; Bogdanova, T; Tronko, M; Demidchik, Yu; Yamashita, S
2011-05-01
The accident at the Chernobyl nuclear power plant was the worst industrial accident of the last century that involved radiation. The unprecedented release of multiple different radioisotopes led to radioactive contamination of large areas surrounding the accident site. The exposure of the residents of these areas was varied and therefore the consequences for health and radioecology could not be reliably estimated quickly. Even though some studies have now been ongoing for 25 years and have provided a better understanding of the situation, these are yet neither complete nor comprehensive enough to determine the long-term risk. A true assessment can only be provided after following the observed population for their natural lifespan. Here we review the technical aspects of the accident and provide relevant information on radioactive releases that resulted in exposure of this large population to radiation. A number of different groups of people were exposed to radiation: workers involved in the initial clean-up response, and members of the general population who were either evacuated from the settlements in the Chernobyl nuclear power plant vicinity shortly after the accident, or continued to live in the affected territories of Belarus, Russia and Ukraine. Through domestic efforts and extensive international co-operation, essential information on radiation dose and health status for this population has been collected. This has permitted the identification of high-risk groups and the use of more specialised means of collecting information, diagnosis, treatment and follow-up. Because radiation-associated thyroid cancer is one of the major health consequences of the Chernobyl accident, a particular emphasis is placed on this malignancy. The initial epidemiological studies are reviewed, as are the most significant studies and/or aid programmes in the three affected countries. Copyright © 2011 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Churg, A.; Wiggs, B.
1986-01-01
We analyzed chrysotile and chrysotile-associated amphibole (largely tremolite) asbestos fibers in 21 workers exposed to various types of processed (milled) chrysotile ore, 20 long-term chrysotile miners, and 20 members of the general population (controls). Significantly greater amounts of both chrysotile and tremolite were found in processed-ore workers and miners than in controls. On average, the mean fiber lengths and aspect ratios for the mining and processed-ore-exposed workers were similar and were significantly greater than the values seen in the controls; within the processed-ore group, there was a marked variation in these parameters, and some workers appeared to be exposed tomore » fairly long, thin fibers. It was found empirically that the fiber size data, and to a lesser extent the concentration data, could be used to classify workers accurately into those with processed-ore exposure and controls. We conclude that fiber sizes in the lungs of processed-ore-exposed workers are similar to those of chrysotile miners and are considerably longer than those found in the general population; some processed-ore workers have longer fibers which might be responsible for higher disease incidences in certain working groups; tremolite accompanies chrysotile in a variable proportion of workers exposed to processed chrysotile products and might be important in the genesis of mesothelioma in such workers; and mineralogic analysis will usually detect exposure even when chrysotile has largely disappeared from lung tissue.« less
Prevalence of gastroesophageal reflux symptoms in a large unselected general population in Japan
Yamagishi, Hatsushi; Koike, Tomoyuki; Ohara, Shuichi; Kobayashi, Shigeyuki; Ariizumi, Ken; Abe, Yasuhiko; Iijima, Katsunori; Imatani, Akira; Inomata, Yoshifumi; Kato, Katsuaki; Shibuya, Daisuke; Aida, Shigemitsu; Shimosegawa, Tooru
2008-01-01
AIM: To examine the prevalence of gastroesophageal reflux disease (GERD) symptoms in a large unselected general population in Japan. METHODS: In Japan, mature adults are offered regular check-ups for the prevention of gastric cancer. A notice was sent by mail to all inhabitants aged > 40 years. A total of 160 983 Japanese (60 774 male, 100 209 female; mean age 61.9 years) who underwent a stomach check up were enrolled in this study. In addition, from these 160 983 subjects, we randomly selected a total of 82 894 (34 275 male, 48 619 female; mean age 62.4 years) to evaluate the prevalence of abdominal pain. The respective subjects were prospectively asked to complete questionnaires concerning the symptoms of heartburn, dysphagia, and abdominal pain for a 1 mo period. RESULTS: The respective prevalences of the symptoms in males and females were: heartburn, 15.8% vs 20.7%; dysphagia, 5.4% vs 7.8%; and abdominal pain, 6.6% vs 9.6%. Among these symptoms, heartburn was significantly high compared with the other symptoms, and the prevalence of heartburn was significantly more frequent in females than in males in the 60-89-year age group. Dysphagia was also significantly more frequent in female patients. CONCLUSION: The prevalence of typical GERD symptoms (heartburn) was high, at about 20% of the Japan population, and the frequency was especially high in females in the 60-89 year age group. PMID:18322948
Incidence and Epidemiology of Patellar Fractures.
Larsen, Peter; Court-Brown, Charles M; Vedel, Julie Odgaard; Vistrup, Sabina; Elsoe, Rasmus
2016-11-01
The literature lacks large-scale, up-to-date, population-based epidemiology studies on the incidence of patellar fractures based on complete populations. The purpose of this study was to provide up-to-date information concerning the incidence of patellar fractures in a large and complete population spanning a decade and to report on the distribution of fracture classification, trauma mechanisms, and patient baseline demographics. A retrospective review of clinical and radiological records of 756 patellar fractures treated between 2005 and 2014 was conducted. Mean age at the time of fracture was 54±21 years. Mean age was 46±22 years for males and 61±18 years for females. The sex distribution was 425 (56%) females and 331 (44%) males. The incidence of patellar fractures between 2005 and 2014 was 13.1/100,000/ year with a year-to-year variation between 10.5 and 16.5/100,000/year during the 10-year observation period. The distribution of incidence shows an increase with increasing age. Males have the highest incidence of fracture in the 10-to-19-year age group, approximately 15.4/100,000/year. Females in the 60-to-80-year age group have the highest incidence, approximately 36/100,000/year. AO type 34-C3 was the most common fracture type, representing 25% of all patellar fractures, followed by AO type 34-C1, representing 23%. [Orthopedics. 2016; 39(6):e1154-e1158.]. Copyright 2016, SLACK Incorporated.
Dobie, Robert A
2006-10-01
To discuss appropriate and inappropriate methods for comparing distributions of hearing thresholds of a study group with distributions in population standards and to determine whether the thresholds of Washington State Ferries engineers are different from those of men in the general population, using both frequency-by-frequency comparisons and analysis of audiometric shape. The most recent hearing conservation program audiograms of 321 noise-exposed engineers, ages 35 to 64, were compared with the predictions of Annexes A, B, and C from ANSI S3.44. There was no screening by history or otoscopy; all audiograms were included. 95% confidence intervals (95% CIs) were calculated for the engineers' median thresholds for each ear, for the better ear (defined two ways), and for the binaural average. For Annex B, where 95% CIs are also available, it was possible to calculate z scores for the differences between Annex B and the engineers' better ears. Bulge depth, an audiometric shape statistic, measured curvature between 1 and 6 kHz. Engineers' better-ear median thresholds were worse than those in Annex A but (except at 1 kHz) were as good as or better than those in Annexes B and C, which are more appropriate for comparison to an unscreened noise-exposed group like the engineers. Average bulge depth for the engineers was similar to that of the Annex B standard (no added occupational noise) and was much less than that of audiograms created by using the standard with added occupational noise between 90 and 100 dBA. Audiograms from groups that have been selected for a particular exposure, but, without regard to severity, can appropriately be compared with population standards, if certain pitfalls are avoided. For unscreened study groups with large age-sex subgroups, a simple method to assess statistical significance, taking into consideration uncertainties in both the study group and the comparison standard, is the calculation of z scores for the proportion of better-ear thresholds above the Annex B median. A less powerful method combines small age-sex subgroups after age correction. Small threshold differences, even if statistically significant, may not be due to genuine differences in hearing sensitivity between study group and standard. Audiometric shape analysis offers an independent dimension of comparison between the study group and audiograms predicted from the ANSI S3.44 standard, with and without occupational noise exposure. Important pitfalls in comparison to population standards include nonrandom selection of study groups, inappropriate choice of population standard, use of the right and left ear thresholds instead of the better-ear threshold for comparison to Annex B, and comparing means with medians. The thresholds of the engineers in this study were similar to published standards for an unscreened population.
Hierarchical prisoner’s dilemma in hierarchical game for resource competition
NASA Astrophysics Data System (ADS)
Fujimoto, Yuma; Sagawa, Takahiro; Kaneko, Kunihiko
2017-07-01
Dilemmas in cooperation are one of the major concerns in game theory. In a public goods game, each individual cooperates by paying a cost or defecting without paying it, and receives a reward from the group out of the collected cost. Thus, defecting is beneficial for each individual, while cooperation is beneficial for the group. Now, groups (say, countries) consisting of individuals also play games. To study such a multi-level game, we introduce a hierarchical game in which multiple groups compete for limited resources by utilizing the collected cost in each group, where the power to appropriate resources increases with the population of the group. Analyzing this hierarchical game, we found a hierarchical prisoner’s dilemma, in which groups choose the defecting policy (say, armament) as a Nash strategy to optimize each group’s benefit, while cooperation optimizes the total benefit. On the other hand, for each individual, refusing to pay the cost (say, tax) is a Nash strategy, which turns out to be a cooperation policy for the group, thus leading to a hierarchical dilemma. Here the group reward increases with the group size. However, we find that there exists an optimal group size that maximizes the individual payoff. Furthermore, when the population asymmetry between two groups is large, the smaller group will choose a cooperation policy (say, disarmament) to avoid excessive response from the larger group, and the prisoner’s dilemma between the groups is resolved. Accordingly, the relevance of this hierarchical game on policy selection in society and the optimal size of human or animal groups are discussed.
Kwon, Il; An, Sunho; Kim, Jayoung; Yang, Seung-Hee; Yoo, Joonsang; Baek, Jang-Hyun; Nam, Hyo Suk; Kim, Young Dae; Lee, Hye Sun; Choi, Hyun-Jung; Heo, Ji Hoe
2017-10-01
It is uncertain whether hemorrhagic transformation (HT) after large cerebral infarction is less frequent in dabigatran users than warfarin users. We compared the occurrence of HT after large cerebral infarction among rats pretreated with dabigatran, warfarin, or placebo. This was a triple-blind, randomized, and placebo-controlled experiment. After treatment with warfarin (0.2 mg/kg), dabigatran (20 mg/kg), or saline for 7 days, Wistar rats were subjected to transient middle cerebral artery occlusion. As the primary outcome, HT was determined by gradient-recalled echo imaging. For the secondary outcome, intracranial hemorrhage was assessed via gradient-recalled echo imaging in surviving rats and via autopsy for dead rats. Of 62 rats, there were 33 deaths (53.2%, 17 technical reasons). Of the intention-to-treat population, 33 rats underwent brain imaging. HT was less frequent in the dabigatran group than the warfarin group (placebo 2/14 [14%], dabigatran 0/10 [0%], and warfarin 9/9 [100%]; dabigatran versus warfarin; P <0.001). In all 62 rats, compared with the placebo (2/14 [14.3%]), the incidence of intracranial hemorrhage was significantly higher in the warfarin group (19/29 [65.5%]; P =0.003), but not in the dabigatran group (6/19 [31.6%]; P =0.420). Mortality was significantly higher in the warfarin group than the dabigatran group (79.3% versus 47.4%; P =0.022), but not related to the hemorrhage frequency. The risk of HT after a large cerebral infarction was significantly increased in rats pretreated with warfarin than those with dabigatran. However, the results here may not have an exact clinical translation. © 2017 American Heart Association, Inc.
Kim, Kyoung-Ah; Song, Wan-Geun; Lee, Hae-Mi; Joo, Hyun-Jin; Park, Ji-Young
2014-11-01
Warfarin is an anticoagulant that is difficult to administer because of the wide variation in dose requirements to achieve a therapeutic effect. CYP2C9, VKROC1, and CYP4F2 play important roles in warfarin metabolism, and their genetic polymorphisms are related to the variability in dose determination. In this study we describe a new multiplex pyrosequencing method to identify CYP2C9*3 (rs1057910), VKORC1*2 (rs9923231), and CYP4F2*3 (rs2108661) simultaneously. A multiplex pyrosequencing method to simultaneously detect CYP2C9*3, VKORC1*2, and CYP4F2*3 alleles was designed. We assessed the allele frequencies of the polymorphisms in 250 Korean subjects using the multiplex pyrosequencing method. The results showed 100 % concordance between single and multiplex pyrosequencing methods, and the polymorphisms identified by pyrosequencing were also validated with the direct sequencing method. The allele frequencies of these polymorphisms in this population were as follows: 0.040 for CYP2C9*3, 0.918 for VKORC1*2, and 0.416 for CYP4F2*3. Although the allele frequencies of the CYP2C9*3 and VKROC1*2 were comparable to those in Japanese and Chinese populations, their frequencies in this Korean population differed from those in other ethnic groups; the CYP4F2*3 frequency was the highest among other ethnic populations including Chinese and Japanese populations. The pyrosequencing methods developed were rapid and reliable for detecting CYP2C9*3, VKORC1*2, and CYP4F2*3. Large ethnic differences in the frequency of these genetic polymorphisms were noted among ethnic groups. CYP4F2*3 exhibited its highest allele frequency among other ethnic populations compared to that in a Korean population.
Ethnicity and Population Structure in Personal Naming Networks
Mateos, Pablo; Longley, Paul A.; O'Sullivan, David
2011-01-01
Personal naming practices exist in all human groups and are far from random. Rather, they continue to reflect social norms and ethno-cultural customs that have developed over generations. As a consequence, contemporary name frequency distributions retain distinct geographic, social and ethno-cultural patterning that can be exploited to understand population structure in human biology, public health and social science. Previous attempts to detect and delineate such structure in large populations have entailed extensive empirical analysis of naming conventions in different parts of the world without seeking any general or automated methods of population classification by ethno-cultural origin. Here we show how ‘naming networks’, constructed from forename-surname pairs of a large sample of the contemporary human population in 17 countries, provide a valuable representation of cultural, ethnic and linguistic population structure around the world. This innovative approach enriches and adds value to automated population classification through conventional national data sources such as telephone directories and electoral registers. The method identifies clear social and ethno-cultural clusters in such naming networks that extend far beyond the geographic areas in which particular names originated, and that are preserved even after international migration. Moreover, one of the most striking findings of this approach is that these clusters simply ‘emerge’ from the aggregation of millions of individual decisions on parental naming practices for their children, without any prior knowledge introduced by the researcher. Our probabilistic approach to community assignment, both at city level as well as at a global scale, helps to reveal the degree of isolation, integration or overlap between human populations in our rapidly globalising world. As such, this work has important implications for research in population genetics, public health, and social science adding new understandings of migration, identity, integration and social interaction across the world. PMID:21909399
Kazyak, David C.; Rash, Jacob; Lubinski, Barbara A.; King, Tim L.
2018-01-01
The release of hatchery-origin fish into streams with endemics can degrade the genetics of wild populations if interbreeding occurs. Starting in the 1800s, brook trout descendent from wild populations in the northeastern United States were stocked from hatcheries into streams across broad areas of North America to create and enhance fishery resources. Across the southeastern United States, many millions of hatchery-origin brook trout have been released into hundreds of streams, but the extent of introgression with native populations is not well resolved despite large phylogeographic distances between these groups. We used three assessment approaches based on 12 microsatellite loci to examine the extent of hatchery introgression in 406 wild brook trout populations in North Carolina. We found high levels of differentiation among most collections (mean F′ST = 0.718), and among most wild collections and hatchery strains (mean F′ST = 0.732). Our assessment of hatchery introgression was consistent across the three metrics, and indicated that most wild populations have not been strongly influenced by supplemental stocking. However, a small proportion of wild populations in North Carolina appear to have been strongly influenced by stocked conspecifics, or in some cases, may have been founded entirely by hatchery lineages. In addition, we found significant differences in the apparent extent of hatchery introgression among major watersheds, with the Savannah River being the most strongly impacted. Conversely, populations in the Pee Dee River watershed showed little to no evidence of hatchery introgression. Our study represents the first large-scale effort to quantify the extent of hatchery introgression across brook trout populations in the southern Appalachians using highly polymorphic microsatellite markers.
Kim, Jaehwan; Oh, Chil-Hwan; Jeon, Jiehyun; Baek, Yoosang; Ahn, Jaewoo; Kim, Dong Joo; Lee, Hyun-Soo; da Rosa, Joel Correa; Suárez-Fariñas, Mayte; Lowes, Michelle A.; Krueger, James G.
2015-01-01
Psoriasis is present in all racial groups, but in varying frequencies and severity. Considering that small plaque psoriasis is specific to the Asian population and severe psoriasis is more predominant in the Western population, we defined Asian small and intermediate plaque psoriasis as psoriasis subtypes, and compared their molecular signatures with classic subtype of Western large plaque psoriasis. Two different characteristics of psoriatic spreading—vertical growth and radial expansion—were contrasted between subtypes, and genomic data were correlated to histologic and clinical measurements. Compared to Western large plaque psoriasis, Asian small plaque psoriasis revealed limited psoriasis spreading, but IL-17A and IL-17-regulated pro-inflammatory cytokines were highly expressed. Paradoxically, IL-17A and IL-17-regulated pro-inflammatory cytokines were lower in Western large plaque psoriasis, while T cells and dendritic cells in total psoriatic skin area were exponentially increased. Negative immune regulators, such as CD69 and FAS, were decreased in both Western large plaque psoriasis and psoriasis with accompanying arthritis or obesity, and their expression was correlated with psoriasis severity index. Based on the disease subtype comparisons, we propose that dysregulation of T cell expansion enabled by downregulation of immune negative regulators is the main mechanism for development of large plaque psoriasis subtypes. PMID:26763436
Cluster-Randomized Trial to Increase Hepatitis B Testing among Koreans in Los Angeles
Bastani, Roshan; Glenn, Beth A.; Maxwell, Annette E.; Jo, Angela M.; Herrmann, Alison K.; Crespi, Catherine M.; Wong, Weng K.; Chang, L. Cindy; Stewart, Susan L.; Nguyen, Tung T.; Chen, Moon S.; Taylor, Victoria M.
2015-01-01
Background In the United States, Korean immigrants experience a disproportionately high burden of chronic hepatitis B (HBV) viral infection and associated liver cancer compared to the general population. However, despite clear clinical guidelines, HBV serologic testing among Koreans remains persistently sub-optimal. Methods We conducted a cluster-randomized trial to evaluate a church-based small group intervention to improve HBV testing among Koreans in Los Angeles. Fifty-two Korean churches, stratified by size (small, medium, large) and location (Koreatown versus other), were randomized to intervention or control conditions. Intervention church participants attended a single-session small-group discussion on liver cancer and HBV testing and control church participants attended a similar session on physical activity and nutrition. Outcome data consisted of self-reported HBV testing obtained via 6-month telephone follow-up interviews. Results We recruited 1123 individuals, 18-64 years of age, across the 52 churches. Ninety-two percent of the sample attended the assigned intervention session and 86% completed the 6-month follow-up. Sample characteristics included: mean age 46 years, 65% female, 97% born in Korea, 69% completed some college, and 43% insured. In an intent-to-treat analysis, the intervention produced a statistically significant effect (OR = 4.9, p < .001), with 19% of intervention and 6% of control group participants reporting a HBV test. Conclusion Our intervention was successful in achieving a large and robust effect in a population at high risk of HBV infection and sequelae. Impact The intervention was fairly resource efficient and thus has high potential for replication in other high-risk Asian groups. PMID:26104909
Combining matched and unmatched control groups in case-control studies.
le Cessie, Saskia; Nagelkerke, Nico; Rosendaal, Frits R; van Stralen, Karlijn J; Pomp, Elisabeth R; van Houwelingen, Hans C
2008-11-15
Multiple control groups in case-control studies are used to control for different sources of confounding. For example, cases can be contrasted with matched controls to adjust for multiple genetic or unknown lifestyle factors and simultaneously contrasted with an unmatched population-based control group. Inclusion of different control groups for a single exposure analysis yields several estimates of the odds ratio, all using only part of the data. Here the authors introduce an easy way to combine odds ratios from several case-control analyses with the same cases. The approach is based upon methods used for meta-analysis but takes into account the fact that the same cases are used and that the estimated odds ratios are therefore correlated. Two ways of estimating this correlation are discussed: sandwich methodology and the bootstrap. Confidence intervals for the pooled estimates and a test for checking whether the odds ratios in the separate case-control studies differ significantly are derived. The performance of the method is studied by simulation and by applying the methods to a large study on risk factors for thrombosis, the MEGA Study (1999-2004), wherein cases with first venous thrombosis were included with a matched control group of partners and an unmatched population-based control group.
Ríos, A; Carrillo, J; López-Navas, A I; Martínez-Alarcón, L; Ayala, M A; Garrido, G; Ramis, G; Hernández, A M; Ramírez, P; Parrilla, P
2018-03-01
The Guinean population is an emerging group in Europe, but the group's awareness of organ donation and transplantation has not been studied. To analyze the attitude toward organ donation among the population born in Guinea living in Spain. The population older than 15 years, born in Guinea, and resident in Spain was studied, stratified by age and sex, according to census data and immigrant assistance associations. The valuation tool used was the attitude questionnaire toward organ donation PCID-DTO RIOS (questionnaire on "Donor International Collaborative Project" on organ donation and transplantation developed by Dr Ríos). A random selection of people to survey was based on stratification. Support from African immigration support associations was needed to advise on the location of potential respondents. The completion was anonymous and self-administered. A descriptive statistic was performed, and Student t, χ 2 , and Fisher tests and a logistic regression analysis were applied. In all, 181 Guineans were surveyed, of whom 32% (n = 58) were in favor of the donation of their own organs after death, 32% (n = 57) were against, and 36% (n = 66) were undecided. The variables that are associated with attitude toward donation are separated mainly into 4 large groups (P < .001): (1) knowledge about the process of donation and organ transplantation; (2) attitude toward the manipulation of the body; (3) religious variables; and (4) sociofamily variables, especially in relation to the couple. The Guinean population emigrant to Spain has an unfriendly attitude toward organ donation. Copyright © 2017 Elsevier Inc. All rights reserved.
Hansson, Bengt; Ljungqvist, Marcus; Illera, Juan-Carlos; Kvist, Laura
2014-01-01
Evolutionary molecular studies of island radiations may lead to insights in the role of vicariance, founder events, population size and drift in the processes of population differentiation. We evaluate the degree of population genetic differentiation and fixation of the Canary Islands blue tit subspecies complex using microsatellite markers and aim to get insights in the population history using coalescence based methods. The Canary Island populations were strongly genetically differentiated and had reduced diversity with pronounced fixation including many private alleles. In population structure models, the relationship between the central island populations (La Gomera, Tenerife and Gran Canaria) and El Hierro was difficult to disentangle whereas the two European populations showed consistent clustering, the two eastern islands (Fuerteventura and Lanzarote) and Morocco weak clustering, and La Palma a consistent unique lineage. Coalescence based models suggested that the European mainland forms an outgroup to the Afrocanarian population, a split between the western island group (La Palma and El Hierro) and the central island group, and recent splits between the three central islands, and between the two eastern islands and Morocco, respectively. It is clear that strong genetic drift and low level of concurrent gene flow among populations have shaped complex allelic patterns of fixation and skewed frequencies over the archipelago. However, understanding the population history remains challenging; in particular, the pattern of extreme divergence with low genetic diversity and yet unique genetic material in the Canary Island system requires an explanation. A potential scenario is population contractions of a historically large and genetically variable Afrocanarian population, with vicariance and drift following in the wake. The suggestion from sequence-based analyses of a Pleistocene extinction of a substantial part of North Africa and a Pleistocene/Holocene eastward re-colonisation of western North Africa from the Canaries remains possible.
Hansson, Bengt; Ljungqvist, Marcus; Illera, Juan-Carlos; Kvist, Laura
2014-01-01
Evolutionary molecular studies of island radiations may lead to insights in the role of vicariance, founder events, population size and drift in the processes of population differentiation. We evaluate the degree of population genetic differentiation and fixation of the Canary Islands blue tit subspecies complex using microsatellite markers and aim to get insights in the population history using coalescence based methods. The Canary Island populations were strongly genetically differentiated and had reduced diversity with pronounced fixation including many private alleles. In population structure models, the relationship between the central island populations (La Gomera, Tenerife and Gran Canaria) and El Hierro was difficult to disentangle whereas the two European populations showed consistent clustering, the two eastern islands (Fuerteventura and Lanzarote) and Morocco weak clustering, and La Palma a consistent unique lineage. Coalescence based models suggested that the European mainland forms an outgroup to the Afrocanarian population, a split between the western island group (La Palma and El Hierro) and the central island group, and recent splits between the three central islands, and between the two eastern islands and Morocco, respectively. It is clear that strong genetic drift and low level of concurrent gene flow among populations have shaped complex allelic patterns of fixation and skewed frequencies over the archipelago. However, understanding the population history remains challenging; in particular, the pattern of extreme divergence with low genetic diversity and yet unique genetic material in the Canary Island system requires an explanation. A potential scenario is population contractions of a historically large and genetically variable Afrocanarian population, with vicariance and drift following in the wake. The suggestion from sequence-based analyses of a Pleistocene extinction of a substantial part of North Africa and a Pleistocene/Holocene eastward re-colonisation of western North Africa from the Canaries remains possible. PMID:24587269
Theoretical models of the influence of genomic architecture on the dynamics of speciation.
Flaxman, Samuel M; Wacholder, Aaron C; Feder, Jeffrey L; Nosil, Patrik
2014-08-01
A long-standing problem in evolutionary biology has been determining whether and how gradual, incremental changes at the gene level can account for rapid speciation and bursts of adaptive radiation. Using genome-scale computer simulations, we extend previous theory showing how gradual adaptive change can generate nonlinear population transitions, resulting in the rapid formation of new, reproductively isolated species. We show that these transitions occur via a mechanism rooted in a basic property of biological heredity: the organization of genes in genomes. Genomic organization of genes facilitates two processes: (i) the build-up of statistical associations among large numbers of genes and (ii) the action of divergent selection on persistent combinations of alleles. When a population has accumulated a critical amount of standing, divergently selected variation, the combination of these two processes allows many mutations of small effect to act synergistically and precipitously split one population into two discontinuous, reproductively isolated groups. Periods of allopatry, chromosomal linkage among loci, and large-effect alleles can facilitate this process under some conditions, but are not required for it. Our results complement and extend existing theory on alternative stable states during population divergence, distinct phases of speciation and the rapid emergence of multilocus barriers to gene flow. The results are thus a step towards aligning population genomic theory with modern empirical studies. © 2014 John Wiley & Sons Ltd.
von Cramon-Taubadel, Noreen; Schroeder, Lauren
2016-10-01
Estimation of the variance-covariance (V/CV) structure of fragmentary bioarchaeological populations requires the use of proxy extant V/CV parameters. However, it is currently unclear whether extant human populations exhibit equivalent V/CV structures. Random skewers (RS) and hierarchical analyses of common principal components (CPC) were applied to a modern human cranial dataset. Cranial V/CV similarity was assessed globally for samples of individual populations (jackknifed method) and for pairwise population sample contrasts. The results were examined in light of potential explanatory factors for covariance difference, such as geographic region, among-group distance, and sample size. RS analyses showed that population samples exhibited highly correlated multivariate responses to selection, and that differences in RS results were primarily a consequence of differences in sample size. The CPC method yielded mixed results, depending upon the statistical criterion used to evaluate the hierarchy. The hypothesis-testing (step-up) approach was deemed problematic due to sensitivity to low statistical power and elevated Type I errors. In contrast, the model-fitting (lowest AIC) approach suggested that V/CV matrices were proportional and/or shared a large number of CPCs. Pairwise population sample CPC results were correlated with cranial distance, suggesting that population history explains some of the variability in V/CV structure among groups. The results indicate that patterns of covariance in human craniometric samples are broadly similar but not identical. These findings have important implications for choosing extant covariance matrices to use as proxy V/CV parameters in evolutionary analyses of past populations. © 2016 Wiley Periodicals, Inc.
ERIC Educational Resources Information Center
Tomon, Jennifer E.; Ting, S. Raymond
2010-01-01
College student-athletes comprise a special group on the college campus owing to their dual roles as students and athletes. Although many positives are associated with being a student-athlete, researchers have found that this population is faced with unique academic, physical, and social stressors that put student-athletes at greater risk for…
ERIC Educational Resources Information Center
Marty, Phillip J.; McDermott, Robert J.
A study determined whether changes in knowledge, selected attitudes, and self-examination behavior occurred among college-aged men after exposure to alternative cancer education programs. College-aged men (n=128) from two large health education classes at a mid-western university were randomly assigned to two treatment groups. The first group…
Integrative Lifecourse and Genetic Analysis of Military Working Dogs
2015-12-01
done as the samples are collected in order to avoid experimental variability and batch effects . Detailed description and discussion of this task...associated loss of power to detect all associations but those of large effect sizes) and latent variables (e.g., population structure – addressed in...processes associated with tissue development and maintenance are thus grouped with external environmental effects . This in turn suggests how those
1978 Archeological Investigations at ELK City Lake, Kansas,
1978-01-01
Kansas continued to be hunters and gatherers. Their populations began to increase suggesting further adaptation to the environment. This era is...bone (Marshall 1972:229). By approximately A.D. 1000, cultural changes through adaptation and diffusion brought about a pcpulation group which is...identification has not been made. A large number of gastropods were recovered from the surface and test excavations at 14MY1310. Archeologists are
Cripps, Jemma; Beveridge, Ian; Ploeg, Richard; Coulson, Graeme
2014-01-01
Large mammalian herbivores are commonly infected with gastrointestinal helminths. In many host species, these helminths cause clinical disease and may trigger conspicuous mortality events. However, they may also have subclinical impacts, reducing fitness as well as causing complex changes to host growth patterns and body condition. Theoretically, juveniles should experience significantly greater costs from parasites, being immunologically naive and undergoing a significant growth phase. The aims of our study were to quantify the subclinical effects of helminths in juvenile eastern grey kangaroos (Macropus giganteus), which commonly harbour large burdens of gastrointestinal nematodes and are susceptible to associated mass mortality during cold, wet conditions. We conducted a field experiment on a population of free-ranging kangaroos, removing nematodes from one group of juveniles using an anthelmintic treatment. We then compared growth parameters (body condition and growth rates) and haematological parameters of this group with an age-matched, parasitised (untreated) control group. Treated juvenile kangaroos had significantly higher levels of plasma protein (albumin) but, contrary to our predictions, showed negligible changes in all the other parameters measured. Our results suggest that juvenile kangaroos are largely unaffected by their gastrointestinal helminth burdens, and may be able to compensate for the costs of parasites. PMID:25161906
Hofer, T; Ray, N; Wegmann, D; Excoffier, L
2009-01-01
Several studies have found strikingly different allele frequencies between continents. This has been mainly interpreted as being due to local adaptation. However, demographic factors can generate similar patterns. Namely, allelic surfing during a population range expansion may increase the frequency of alleles in newly colonised areas. In this study, we examined 772 STRs, 210 diallelic indels, and 2834 SNPs typed in 53 human populations worldwide under the HGDP-CEPH Diversity Panel to determine to which extent allele frequency differs among four regions (Africa, Eurasia, East Asia, and America). We find that large allele frequency differences between continents are surprisingly common, and that Africa and America show the largest number of loci with extreme frequency differences. Moreover, more STR alleles have increased rather than decreased in frequency outside Africa, as expected under allelic surfing. Finally, there is no relationship between the extent of allele frequency differences and proximity to genes, as would be expected under selection. We therefore conclude that most of the observed large allele frequency differences between continents result from demography rather than from positive selection.
The impact of population growth on environment: the debate heats up.
Shaw, R P
1992-02-01
A proposed framework, which was introduced at the 1989 meetings of the American Association for the Advancement of Science, included political constraints as well as population growth as a proximate cause with potentially important impacts on the environment in Paul and Ann Ehrlich's well-known PAT equation. PAT limitations are identified as the 1.2 billion people caught in the debt-poverty trap, less developed countries' balance of payments deficits, and "distortionary factors" that undermined economic incentives and contributed to mismanagement of resources. Such factors could be keeping farm prices low and have an impact on deterring use of environmentally sound traditional agricultural practices. Mismanagement of public lands occurs when large commercial enterprises or large scale mechanization displace population onto marginal or less productive lands. Intergroup warfare is a new form impacting on the environment. In Burma loggers are authorized to clear cut large tracts of teak forests in order to ferret out Karen guerrillas. Over 15 million refugees were thus displaced and forced to live in encampments that require trees for shelter, firewood for survival, and overgrazing of livestock. Social and economic environments are also undermined by "dependency" factors such as trade protectionism, brain drain, and limited foreign aid. The Group of 77 Non-Aligned Developing Countries proposed that discussions of the links between population and the environment be omitted from the agenda of the 1994 UN Conference on Population and Development. Basic clarifications are needed to distinguish ultimate versus proximate factors and current versus future concerns. The debate ignores distribution patterns, migration, or changing age structures. The debate blames unjustifiably rapid population growth as the ultimate cause of global environmental degradation and links population growth to a host of other social problems such as famine and refugees, while ignoring civil unrest. The evidence suggests that population limitation will probably prevent environmental degradation in poor, resource constrained countries from getting worse. Resource conservation will remain unaffected. The World Bank proposes National Environmental Action Plans or the Cleaver Schreiber proposal for a "nexus strategy" for balancing food supply and population in Africa.
Kocmarek, Andrea L; Ferguson, Moira M; Danzmann, Roy G
2015-04-01
All-female lines of fish are created by crossing sex reversed (XX genotype) males with normal females. All-female lines avoid the deleterious phenotypic effects that are typical of precocious maturation in males. To determine whether all-female and mixed sex populations of rainbow trout (Oncorhynchus mykiss) differ in performance, we compared the growth and gene expression profiles in progeny groups produced by crossing a XX male and a XY male to the same five females. Body weight and length were measured in the resulting all-female (XX) and mixed sex (XX/XY) offspring groups. Microarray experiments with liver and white muscle were used to determine if the gene expression profiles of large and small XX offspring differ from those in large and small XX/XY offspring. We detected no significant differences in body length and weight between offspring groups but XX offspring were significantly less variable in the value of these traits. A large number of upregulated genes were shared between the large XX and large XX/XY offspring; the small XX and small XX/XY offspring also shared similar expression profiles. No GO category differences were seen in the liver or between the large XX and large XX/XY offspring in the muscle. The greatest differences between the small XX and small XX/XY offspring were in the genes assigned to the "small molecule metabolic process" and "cellular metabolic process" GO level 3 categories. Similarly, genes within these categories as well as the category "macromolecule metabolic process" were more highly expressed in small compared to large XX fish.
Gamm, Larry; Bolin, Jane Nelson; Kash, Bita A
2005-01-01
Four large rural multispecialty group practice systems employ a mix of organizational technologies to provide chronic disease management with measurable impacts on their patient populations and costs. Four technologies-administrative, clinical, information, and social-are proposed as key dimensions for examining disease management programs. The benefits of disease management are recognized by these systems despite marked variability in the organization of the programs. Committees spanning health plans and clinics in the 4 systems and electronic medical records and/or other disease management information systems are important coordinating mechanisms. Increased reliance on nurses for patient education and care coordination in all 4 systems reflects significant extension of clinical and social technologies in the management of patient care. The promise of disease management as offered by these systems and other auspices are considered.
Multiple tolerances dilute the second order cooperative dilemma
NASA Astrophysics Data System (ADS)
Sui, Xiukai; Wu, Bin; Wang, Long
2017-12-01
A peer punisher directly imposes fines upon defectors at a cost to himself. It is one of the mechanisms promoting cooperation, which is ubiquitous in nature. Typically, it is assumed that a peer punisher punishes provided that there is one defector in the group. The threshold that triggers punishment, however, is not necessarily one. The larger the threshold is, the more tolerant the peer punisher is. We study the evolutionary dynamics of those diverse tolerant peer punishment strategies in public goods game. We find that, i) less tolerant punishers prevail over tolerant ones; ii) large group size could enhance punishment, in contrast with the case in the first-order cooperative dilemma. Our analytical results are based on weak selection limit and large population size, which are verified by simulations. Our work sheds light on how punishment of diverse tolerance evolves.
Hightower, Joseph E.; Pollock, Kenneth H.
2013-01-01
Striped bass Morone saxatilis in inland reservoirs play an important role ecologically and in supporting recreational fishing. To manage these populations, biologists need information about abundance and mortality. Abundance estimates can be used to assess the effectiveness of stocking programs that maintain most reservoir striped bass populations. Mortality estimates can indicate the relative impact of fishing versus natural mortality and the need for harvest regulation. The purpose of this chapter is to evaluate tagging studies as a way of obtaining information about abundance and mortality. These approaches can be grouped into three broad categories: tag recapture, tag return, and telemetry. Tag-recapture methods are typically used to estimate population size and other demographic parameters but are often difficult to apply in large systems. A fishing tournament can be an effective way of generating tagging or recapture effort in large systems, compared to using research sampling only. Tag-return methods that rely on angler harvest and catch and release can be used to estimate fishing (F) and natural (M) mortality rates and are a practical approach in large reservoirs. The key to success in tag-return studies is to build in auxiliary studies to estimate short-term tagging mortality, short- and longterm tag loss, reporting rate, and mortality associated with catch and release. F and M can also be estimated using telemetry tags. Advantages of this approach are that angler nonreporting does not bias estimates and fish with transmitters provide useful ecological data. Cost can be a disadvantage of telemetry studies; thus, combining telemetry tags with conventional tag returns in an integrated analysis is often the optimal approach. In summary, tagging methods can be a powerful tool for assessing the effectiveness of inland striped bass stocking programs and the relative impact of fishing versus natural mortality
Azim, Hatem A; Metzger-Filho, Otto; de Azambuja, Evandro; Loibl, Sibylle; Focant, Florine; Gresko, Ekaterina; Arfi, Mounir; Piccart-Gebhart, Martine
2012-05-01
Only few case reports describe the pregnancy course and outcome of breast cancer patients, who were under treatment with trastuzumab at the time of conception or who have completed trastuzumab therapy before becoming pregnant. The HERA trial is a large phase III randomized clinical trial in which patients with early HER2-positive breast cancer were randomized to receive 1 or 2 years of trastuzumab or observation following completion of primary chemotherapy. To examine the effect of trastuzumab on pregnancy outcome, we report all pregnancy events that occurred until March 2010 in patients enrolled in the study. For the sake of this analysis, patients were assigned to three groups: (1) pregnancy occurring during and up to 3 months after trastuzumab exposure (group 1); (2) pregnancy occurring >3 months of last trastuzumab dose (group 2); and (3) pregnancy occurring in patients without prior exposure to trastuzumab (group 3). Sixteen, 45 and 9 pregnancies took place in groups 1, 2, and 3, respectively. 25 and 16% of patients in groups 1 and 2 experienced spontaneous abortion, the former being higher than figures reported in the general population. However, short-term fetal outcome appeared normal across the three groups. Only 2 congenital anomalies were reported, one in group 2 and one in group 3. No congenital anomalies were reported in those exposed to trastuzumab in utero. This is the first report from a large randomized trial assessing the effect of trastuzumab on pregnancy course and outcome. Based on our results, trastuzumab does not appear to affect fetal outcome in patients who manage to complete their pregnancy. We are currently initiating a collaboration to collect similar data from the other large adjuvant trastuzumab trials to confirm these findings.
Perspectives on population growth.
1996-09-01
Assume that everyone has the same information on population growth. There are many different opinions on what that information means and what should be done about it. Some people worry about current rates of growth, especially in the context of growing per capita consumption, and believe that all reasonable steps should be taken to reduce rates and stabilize population size. Others believe that growing populations can be accommodated by reducing consumption in rich countries, that technological progress will supply the new resources needed, that the development needed to support a larger population can be sustained, that large population size fosters prosperity, or that birth rates are falling and current growth is just temporary. These are all valid positions worthy of at least debate. Interest groups commonly acknowledgement population growth as a significant issue, but offer no response to it. Sometimes the issue goes unrecognized because it conflicts with a more highly valued personal agenda item. Finally, some responses come from confusion and anger rather than reasoning or self-interest. The proponents of these latter arguments bring nothing constructive to the debate.
No evidence from genome-wide data of a Khazar origin for the Ashkenazi Jews.
Behar, Doron M; Metspalu, Mait; Baran, Yael; Kopelman, Naama M; Yunusbayev, Bayazit; Gladstein, Ariella; Tzur, Shay; Sahakyan, Hovhannes; Bahmanimehr, Ardeshir; Yepiskoposyan, Levon; Tambets, Kristina; Khusnutdinova, Elza K; Kushniarevich, Alena; Balanovsky, Oleg; Balanovsky, Elena; Kovacevic, Lejla; Marjanovic, Damir; Mihailov, Evelin; Kouvatsi, Anastasia; Triantaphyllidis, Costas; King, Roy J; Semino, Ornella; Torroni, Antonio; Hammer, Michael F; Metspalu, Ene; Skorecki, Karl; Rosset, Saharon; Halperin, Eran; Villems, Richard; Rosenberg, Noah A
2013-12-01
The origin and history of the Ashkenazi Jewish population have long been of great interest, and advances in high-throughput genetic analysis have recently provided a new approach for investigating these topics. We and others have argued on the basis of genome-wide data that the Ashkenazi Jewish population derives its ancestry from a combination of sources tracing to both Europe and the Middle East. It has been claimed, however, through a reanalysis of some of our data, that a large part of the ancestry of the Ashkenazi population originates with the Khazars, a Turkic-speaking group that lived to the north of the Caucasus region ~1,000 years ago. Because the Khazar population has left no obvious modern descendants that could enable a clear test for a contribution to Ashkenazi Jewish ancestry, the Khazar hypothesis has been difficult to examine using genetics. Furthermore, because only limited genetic data have been available from the Caucasus region, and because these data have been concentrated in populations that are genetically close to populations from the Middle East, the attribution of any signal of Ashkenazi-Caucasus genetic similarity to Khazar ancestry rather than shared ancestral Middle Eastern ancestry has been problematic. Here, through integration of genotypes from newly collected samples with data from several of our past studies, we have assembled the largest data set available to date for assessment of Ashkenazi Jewish genetic origins. This data set contains genome-wide single-nucleotide polymorphisms in 1,774 samples from 106 Jewish and non-Jewish populations that span the possible regions of potential Ashkenazi ancestry: Europe, the Middle East, and the region historically associated with the Khazar Khaganate. The data set includes 261 samples from 15 populations from the Caucasus region and the region directly to its north, samples that have not previously been included alongside Ashkenazi Jewish samples in genomic studies. Employing a variety of standard techniques for the analysis of population-genetic structure, we found that Ashkenazi Jews share the greatest genetic ancestry with other Jewish populations and, among non-Jewish populations, with groups from Europe and the Middle East. No particular similarity of Ashkenazi Jews to populations from the Caucasus is evident, particularly populations that most closely represent the Khazar region. Thus, analysis of Ashkenazi Jews together with a large sample from the region of the Khazar Khaganate corroborates the earlier results that Ashkenazi Jews derive their ancestry primarily from populations of the Middle East and Europe, that they possess considerable shared ancestry with other Jewish populations, and that there is no indication of a significant genetic contribution either from within or from north of the Caucasus region. Copyright © 2014 Wayne State University Press, Detroit, Michigan 48201-1309.
Genetic structuring of northern myotis (Myotis septentrionalis) at multiple spatial scales
Johnson, Joshua B.; Roberts, James H.; King, Timothy L.; Edwards, John W.; Ford, W. Mark; Ray, David A.
2014-01-01
Although groups of bats may be genetically distinguishable at large spatial scales, the effects of forest disturbances, particularly permanent land use conversions on fine-scale population structure and gene flow of summer aggregations of philopatric bat species are less clear. We genotyped and analyzed variation at 10 nuclear DNA microsatellite markers in 182 individuals of the forest-dwelling northern myotis (Myotis septentrionalis) at multiple spatial scales, from within first-order watersheds scaling up to larger regional areas in West Virginia and New York. Our results indicate that groups of northern myotis were genetically indistinguishable at any spatial scale we considered, and the collective population maintained high genetic diversity. It is likely that the ability to migrate, exploit small forest patches, and use networks of mating sites located throughout the Appalachian Mountains, Interior Highlands, and elsewhere in the hibernation range have allowed northern myotis to maintain high genetic diversity and gene flow regardless of forest disturbances at local and regional spatial scales. A consequence of maintaining high gene flow might be the potential to minimize genetic founder effects following population declines caused currently by the enzootic White-nose Syndrome.
Social Determinants of LGBT Cancer Health Inequities.
Matthews, Alicia K; Breen, Elizabeth; Kittiteerasack, Priyoth
2018-02-01
To describe the extant literature on social determinants of health as they relate to the cancer disparities and to highlight the research findings relating to lesbian, gay, bisexual, and transgender (LGBT) populations. Published scientific literature and clinical literature, and published reports from the World Health Organization and US Department of Health and Human Services. The larger literature on health inequities is moving beyond individual-level predictors of risk to evaluate the influence of social determinants of health on the persistent health inequalities in a population. As it has for other groups, additional research into social determinants of health for LGBT persons of color may play an important role in identifying and reducing cancer inequities for this group. Increased awareness of the factors that contribute to health inequities for the LGBT population may provide insight into improving patient-provider relationships with LGBT patients. A large body of experiential and clinical knowledge positions nurses to conduct meaningful research to expand the current understanding of the social determinants of LGBT cancer health inequities. Copyright © 2017 Elsevier Inc. All rights reserved.