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Sample records for large sexual populations

  1. The Rate of Adaptation in Large Sexual Populations with Linear Chromosomes

    PubMed Central

    Weissman, Daniel B.; Hallatschek, Oskar

    2014-01-01

    In large populations, multiple beneficial mutations may be simultaneously spreading. In asexual populations, these mutations must either arise on the same background or compete against each other. In sexual populations, recombination can bring together beneficial alleles from different backgrounds, but tightly linked alleles may still greatly interfere with each other. We show for well-mixed populations that when this interference is strong, the genome can be seen as consisting of many effectively asexual stretches linked together. The rate at which beneficial alleles fix is thus roughly proportional to the rate of recombination and depends only logarithmically on the mutation supply and the strength of selection. Our scaling arguments also allow us to predict, with reasonable accuracy, the fitness distribution of fixed mutations when the mutational effect sizes are broad. We focus on the regime in which crossovers occur more frequently than beneficial mutations, as is likely to be the case for many natural populations. PMID:24429280

  2. Genetic Draft and Quasi-Neutrality in Large Facultatively Sexual Populations

    PubMed Central

    Neher, R. A.; Shraiman, B. I.

    2011-01-01

    Large populations may contain numerous simultaneously segregating polymorphisms subject to natural selection. Since selection acts on individuals whose fitness depends on many loci, different loci affect each other’s dynamics. This leads to stochastic fluctuations of allele frequencies above and beyond genetic drift—an effect known as genetic draft. Since recombination disrupts associations between alleles, draft is strong when recombination is rare. Here, we study a facultatively outcrossing population in a regime where the frequency of outcrossing and recombination, r, is small compared to the characteristic scale of fitness differences σ. In this regime, fit genotypes expand clonally, leading to large fluctuations in the number of recombinant offspring genotypes. The power law tail in the distribution of the latter makes it impossible to capture the dynamics of draft by an effective neutral model. Instead, we find that the fixation time of a neutral allele increases only slowly with the population size but depends sensitively on the ratio r/σ. The efficacy of selection is reduced dramatically and alleles behave “quasi-neutrally” even for Ns≫1, provided that |s| < sc, where sc depends strongly on r/σ, but only weakly on population size N. In addition, the anomalous fluctuations due to draft change the spectrum of (quasi)-neutral alleles from f(ν) ∼ ν−1, corresponding to drift, to ∼ ν−2. Finally, draft accelerates the rate of two-step adaptations through deleterious intermediates. PMID:21625002

  3. Genetic draft and quasi-neutrality in large facultatively sexual populations.

    PubMed

    Neher, R A; Shraiman, B I

    2011-08-01

    Large populations may contain numerous simultaneously segregating polymorphisms subject to natural selection. Since selection acts on individuals whose fitness depends on many loci, different loci affect each other's dynamics. This leads to stochastic fluctuations of allele frequencies above and beyond genetic drift-an effect known as genetic draft. Since recombination disrupts associations between alleles, draft is strong when recombination is rare. Here, we study a facultatively outcrossing population in a regime where the frequency of outcrossing and recombination, r, is small compared to the characteristic scale of fitness differences σ. In this regime, fit genotypes expand clonally, leading to large fluctuations in the number of recombinant offspring genotypes. The power law tail in the distribution of the latter makes it impossible to capture the dynamics of draft by an effective neutral model. Instead, we find that the fixation time of a neutral allele increases only slowly with the population size but depends sensitively on the ratio r/σ. The efficacy of selection is reduced dramatically and alleles behave "quasi-neutrally" even for Ns≫1, provided that |s| < s(c), where s(c) depends strongly on r/σ, but only weakly on population size N. In addition, the anomalous fluctuations due to draft change the spectrum of (quasi)-neutral alleles from f(ν) ∼ ν(-1), corresponding to drift, to ∼ ν(-2). Finally, draft accelerates the rate of two-step adaptations through deleterious intermediates. PMID:21625002

  4. Sexual selection hinders adaptation in experimental populations of yeast

    PubMed Central

    Reding, L. P.; Swaddle, J. P.; Murphy, H. A.

    2013-01-01

    Sexual selection, the suite of processes that lead to differential mating success among individuals, probably influences the evolutionary trajectory of populations. Because sexual selection often shifts traits away from their survival optima, strong sexual selection pressures are thought to increase potential for population extinction, especially during environmental change. Sexual selection pressures may also increase the opportunity for speciation by accelerating the generation of pre-zygotic isolation among populations. These relationships remain largely untested experimentally. Here, we allow populations of baker's yeast, Saccharomyces cerevisiae, to evolve for approximately 250 generations with altered sex ratios in order to test the effect of the strength of sexual selection on the fate of populations. We find that populations experiencing stronger sexual selection are less able to adapt to a novel environment compared with populations experiencing weaker sexual selection or no sex, and that strong sexual selection erases the benefits of sexual reproduction. This pattern persists when fitness is assayed in a closely related environment. We also identify a trend that may suggest the beginning of pre-zygotic isolation between populations experiencing stronger sexual selection, though this is not statistically significant. These results highlight the importance of sexual selection in shaping macroevolutionary patterns and biodiversity. PMID:23485874

  5. Emergence of clones in sexual populations

    NASA Astrophysics Data System (ADS)

    Neher, Richard A.; Vucelja, Marija; Mezard, Mark; Shraiman, Boris I.

    2013-01-01

    In sexual population, recombination reshuffles genetic variation and produces novel combinations of existing alleles, while selection amplifies the fittest genotypes in the population. If recombination is more rapid than selection, populations consist of a diverse mixture of many genotypes, as is observed in many populations. In the opposite regime, which is realized for example in the facultatively sexual populations that outcross in only a fraction of reproductive cycles, selection can amplify individual genotypes into large clones. Such clones emerge when the fitness advantage of some of the genotypes is large enough that they grow to a significant fraction of the population despite being broken down by recombination. The occurrence of this ‘clonal condensation’ depends, in addition to the outcrossing rate, on the heritability of fitness. Clonal condensation leads to a strong genetic heterogeneity of the population which is not adequately described by traditional population genetics measures, such as linkage disequilibrium. Here we point out the similarity between clonal condensation and the freezing transition in the random energy model of spin glasses. Guided by this analogy we explicitly calculate the probability, Y, that two individuals are genetically identical as a function of the key parameters of the model. While Y is the analog of the spin-glass order parameter, it is also closely related to rate of coalescence in population genetics: two individuals that are part of the same clone have a recent common ancestor.

  6. Paraphilic Sexual Interests and Sexually Coercive Behavior: A Population-Based Twin Study.

    PubMed

    Baur, Elena; Forsman, Mats; Santtila, Pekka; Johansson, Ada; Sandnabba, Kenneth; Långström, Niklas

    2016-07-01

    Prior research with selected clinical and forensic samples suggests associations between paraphilic sexual interests (e.g., exhibitionism and sexual sadism) and sexually coercive behavior. However, no study to date used a large, representative and genetically informative population sample to address the potential causal nature of this association. We used self-report data on paraphilic and sexually coercive behavior from 5990 18- to 32-year-old male and female twins from a contemporary Finnish population cohort. Logistic regression and co-twin control models were employed to examine if paraphilic behaviors were causally related to coercive behavior or if suggested links were confounded by familial (genetic or common family environment) risk factors. Results indicated that associations between four out of five tested paraphilic behaviors (exhibitionism, masochism, sadism, and voyeurism, respectively) and sexually coercive behavior were moderate to strong. Transvestic fetishism was not independently associated with sexual coercion. Comparisons of twins reporting paraphilic behavior with their paraphilic behavior-discordant twin further suggested that associations were largely independent of shared genetic and environmental confounds, consistent with a causal association. In conclusion, similar to previously reported predictive effects of paraphilias on sexual crime recidivism, paraphilic behavior among young adults in the general population increases sexual offending risk. Further, early identification of paraphilic interest and preventive interventions with at-risk individuals might also reduce perpetration of first-time sexual violence. PMID:26754158

  7. Causes of male sexual trait divergence in introduced populations of guppies

    PubMed Central

    Lindholm, A K; Head, M L; Brooks, R C; Rollins, L A; Ingleby, F C; Zajitschek, S R K

    2014-01-01

    Males from different populations of the same species often differ in their sexually selected traits. Variation in sexually selected traits can be attributed to sexual selection if phenotypic divergence matches the direction of sexual selection gradients among populations. However, phenotypic divergence of sexually selected traits may also be influenced by other factors, such as natural selection and genetic constraints. Here, we document differences in male sexual traits among six introduced Australian populations of guppies and untangle the forces driving divergence in these sexually selected traits. Using an experimental approach, we found that male size, area of orange coloration, number of sperm per ejaculate and linear sexual selection gradients for male traits differed among populations. Within populations, a large mismatch between the direction of selection and male traits suggests that constraints may be important in preventing male traits from evolving in the direction of selection. Among populations, however, variation in sexual selection explained more than half of the differences in trait variation, suggesting that, despite within-population constraints, sexual selection has contributed to population divergence of male traits. Differences in sexual traits were also associated with predation risk and neutral genetic distance. Our study highlights the importance of sexual selection in trait divergence in introduced populations, despite the presence of constraining factors such as predation risk and evolutionary history. PMID:24456226

  8. Causes of male sexual trait divergence in introduced populations of guppies.

    PubMed

    Lindholm, A K; Head, M L; Brooks, R C; Rollins, L A; Ingleby, F C; Zajitschek, S R K

    2014-02-01

    Males from different populations of the same species often differ in their sexually selected traits. Variation in sexually selected traits can be attributed to sexual selection if phenotypic divergence matches the direction of sexual selection gradients among populations. However, phenotypic divergence of sexually selected traits may also be influenced by other factors, such as natural selection and genetic constraints. Here, we document differences in male sexual traits among six introduced Australian populations of guppies and untangle the forces driving divergence in these sexually selected traits. Using an experimental approach, we found that male size, area of orange coloration, number of sperm per ejaculate and linear sexual selection gradients for male traits differed among populations. Within populations, a large mismatch between the direction of selection and male traits suggests that constraints may be important in preventing male traits from evolving in the direction of selection. Among populations, however, variation in sexual selection explained more than half of the differences in trait variation, suggesting that, despite within-population constraints, sexual selection has contributed to population divergence of male traits. Differences in sexual traits were also associated with predation risk and neutral genetic distance. Our study highlights the importance of sexual selection in trait divergence in introduced populations, despite the presence of constraining factors such as predation risk and evolutionary history. PMID:24456226

  9. Does reproductive isolation evolve faster in larger populations via sexually antagonistic coevolution?

    PubMed Central

    Gay, L.; Eady, P.E.; Vasudev, R.; Hosken, D.J.; Tregenza, T.

    2009-01-01

    Sexual conflict over reproductive investment can lead to sexually antagonistic coevolution and reproductive isolation. It has been suggested that, unlike most models of allopatric speciation, the evolution of reproductive isolation through sexually antagonistic coevolution will occur faster in large populations as these harbour greater levels of standing genetic variation, receive larger numbers of mutations and experience more intense sexual selection. We tested this in bruchid beetle populations (Callosobruchus maculatus) by manipulating population size and standing genetic variability in replicated lines derived from founders that had been released from sexual conflict for 90 generations. We found that after 19 generations of reintroduced sexual conflict, none of our treatments had evolved significant overall reproductive isolation among replicate lines. However, as predicted, measures of reproductive isolation tended to be greater among larger populations. We discuss our methodology, arguing that reproductive isolation is best examined by performing a matrix of allopatric and sympatric crosses whereas measurement of divergence requires crosses with a tester line. PMID:19364716

  10. How Large Asexual Populations Adapt

    NASA Astrophysics Data System (ADS)

    Desai, Michael

    2007-03-01

    We often think of beneficial mutations as being rare, and of adaptation as a sequence of selected substitutions: a beneficial mutation occurs, spreads through a population in a selective sweep, then later another beneficial mutation occurs, and so on. This simple picture is the basis for much of our intuition about adaptive evolution, and underlies a number of practical techniques for analyzing sequence data. Yet many large and mostly asexual populations -- including a wide variety of unicellular organisms and viruses -- live in a very different world. In these populations, beneficial mutations are common, and frequently interfere or cooperate with one another as they all attempt to sweep simultaneously. This radically changes the way these populations adapt: rather than an orderly sequence of selective sweeps, evolution is a constant swarm of competing and interfering mutations. I will describe some aspects of these dynamics, including why large asexual populations cannot evolve very quickly and the character of the diversity they maintain. I will explain how this changes our expectations of sequence data, how sex can help a population adapt, and the potential role of ``mutator'' phenotypes with abnormally high mutation rates. Finally, I will discuss comparisons of these predictions with evolution experiments in laboratory yeast populations.

  11. Measuring happiness in large population

    NASA Astrophysics Data System (ADS)

    Wenas, Annabelle; Sjahputri, Smita; Takwin, Bagus; Primaldhi, Alfindra; Muhamad, Roby

    2016-01-01

    The ability to know emotional states for large number of people is important, for example, to ensure the effectiveness of public policies. In this study, we propose a measure of happiness that can be used in large scale population that is based on the analysis of Indonesian language lexicons. Here, we incorporate human assessment of Indonesian words, then quantify happiness on large-scale of texts gathered from twitter conversations. We used two psychological constructs to measure happiness: valence and arousal. We found that Indonesian words have tendency towards positive emotions. We also identified several happiness patterns during days of the week, hours of the day, and selected conversation topics.

  12. FEMALE SEXUALITY, NATIONALISM AND LARGE GROUP IDENTITY.

    PubMed

    Gonzalez-Torres, Miguel Angel; Fernández-Rivas, Aranzazu

    2015-12-01

    Nationalist movements are emerging today everywhere in the world. Many of them display a high level of aggression and a negative attitude toward sexuality and especially female sexuality. Along with this, erotic fiction with a sadomasochistic orientation has achieved great success and has hundreds of millions of readers in the world. This collective fantasy allows some integration of aggression in sexual life while questioning liberal morality and its equality in gender roles and conservative morality and its idea of control over passion. Both phenomena may represent different responses to the appearance of a new female sexuality threatening the social structure we know. PMID:26611132

  13. Natural Selection in Large Populations

    NASA Astrophysics Data System (ADS)

    Desai, Michael

    2011-03-01

    I will discuss theoretical and experimental approaches to the evolutionary dynamics and population genetics of natural selection in large populations. In these populations, many mutations are often present simultaneously, and because recombination is limited, selection cannot act on them all independently. Rather, it can only affect whole combinations of mutations linked together on the same chromosome. Methods common in theoretical population genetics have been of limited utility in analyzing this coupling between the fates of different mutations. In the past few years it has become increasingly clear that this is a crucial gap in our understanding, as sequence data has begun to show that selection appears to act pervasively on many linked sites in a wide range of populations, including viruses, microbes, Drosophila, and humans. I will describe approaches that combine analytical tools drawn from statistical physics and dynamical systems with traditional methods in theoretical population genetics to address this problem, and describe how experiments in budding yeast can help us directly observe these evolutionary dynamics.

  14. Population structure and diversity in sexual and asexual populations of the pathogenic fungus Melampsora lini

    PubMed Central

    BARRETT, LUKE G.; THRALL, PETER H.; BURDON, JEREMY J.; NICOTRA, ADRIENNE B.; LINDE, CELESTE C.

    2009-01-01

    Many pathogens undergo both sexual and asexual reproduction to varying degrees, yet the ecological, genetic and evolutionary consequences of different reproductive strategies remain poorly understood. Here we investigate the population genetic structure of wild populations of the plant pathogen Melampsora lini on its host Linum marginale, using amplified fragment length polymorphism (AFLP) markers, two genes underlying pathogen virulence, and phenotypic variation in virulence. In Australia, M. lini occurs as two genetically and geographically divergent lineages (AA and AB), one of which is completely asexual (AB), and the other able to reproduce both clonally and sexually (AA). To quantify the genetic and evolutionary consequences of these different life histories, we sampled five populations in each of two biogeographical regions. Analysis of AFLP data obtained for 275 isolates revealed largely disjunct geographical distributions for the two different lineages, low genetic diversity within lineages, and strong genetic structure among populations within each region. We also detected significant divergence among populations for both Avr genes and virulence phenotypes, although generally these values were lower than those obtained with AFLP markers. Furthermore, isolates belonging to lineage AA collectively harboured significantly higher genotypic and phenotypic diversity than lineage AB isolates. Together these results illustrate the important roles of reproductive modes and geographical structure in the generation and maintenance of virulence diversity in populations of M. lini. PMID:18573166

  15. The Association between Childhood and Adolescent Sexual Abuse and Proxies for Sexual Risk Behavior: A Random Sample of the General Population of Sweden

    ERIC Educational Resources Information Center

    Steel, Jennifer L.; Herlitz, Claes A.

    2005-01-01

    Objective: Several studies with small and ''high risk'' samples have demonstrated that a history of childhood or adolescent sexual abuse (CASA) is associated with sexual risk behaviors (SRBs). However, few studies with large random samples from the general population have specifically examined the relationship between CASA and SRBs with a…

  16. The Association between Childhood and Adolescent Sexual Abuse and Proxies for Sexual Risk Behavior: A Random Sample of the General Population of Sweden

    ERIC Educational Resources Information Center

    Steel, Jennifer L.; Herlitz, Claes A.

    2005-01-01

    Objective: Several studies with small and ''high risk'' samples have demonstrated that a history of childhood or adolescent sexual abuse (CASA) is associated with sexual risk behaviors (SRBs). However, few studies with large random samples from the general population have specifically examined the relationship between CASA and SRBs with a

  17. Assessment of female sexual arousal in forensic populations.

    PubMed

    Knack, Natasha M; Murphy, Lisa; Ranger, Rebekah; Meston, Cindy; Fedoroff, J Paul

    2015-04-01

    Sexual offenses cause significant harm to victims, their families, and society as a whole and thus are an important social concern. While it is commonly assumed that sexual offenses are committed solely by males, research has shown that approximately 5 % of sex crimes in the USA and Canada are committed by females. Penile plethysmography (PPG) is a method to measure male genital arousal, which is commonly used in the assessment and treatment of male sex offenders and men with paraphilic sexual interests. Similarly, vaginal photoplethysmography (VPP) is a test to measure female genital arousal and is commonly used to assess female sexual dysfunctions. Although VPP is currently the most validated method to measure genital arousal in women, its use with female sex offenders or females with paraphilic sexual interests has been almost nonexistent. One explanation for this is that some research has suggested that female genital arousal may not be category-specific, meaning that women will respond to any sexual cues, not just those involving their preferred sexual interests. However, not all research supports this finding. Due to the potential benefits of using VPP in the assessment and treatment of female sex offenders or females with paraphilic sexual interests, it is important that further research be done before dismissing the use of VPP in forensic populations. The purpose of this article is to review the current research on VPP and its applicability to female sex offenders and females with paraphilic sexual interests. PMID:25749745

  18. Sexually-transmitted disease risk in a Micronesian atoll population.

    PubMed

    Brewis, A A

    1992-10-01

    The potential health threat of AIDS to the native island-based populations in the Pacific is now widely appreciated by those working in the public-health sector throughout the region. Although several countries in the region are yet to identify any cases of AIDS or HIV seropositivity, there is reason to suspect that heterosexual contact may emerge as a predominant mode of spread of HIV infection into native Pacific island populations. Sexual networks and their relationship to potentially 'risky behaviours' are described for a single native Micronesian atoll community on the basis of ethnographic observation and interviewing. This description is combined with the investigation of historic-demographic dimensions of the epidemiology of sexually-transmitted diseases in the same population to draw some conclusions about the opportunities for HIV transmission and acquisition among the sexually-active portions of this community. Although sexually-transmitted diseases have not had an appreciable epidemiological or demographic impact on the population in the past, the sexual networks within the community and beyond provide ample opportunity for the introduction and spread of sexually transmitted diseases, including HIV and its sequel AIDS. PMID:10148657

  19. Are Australian sexual health clinics attracting priority populations?

    PubMed

    Ali, Hammad; Donovan, Basil; Fairley, Christopher K; Ryder, Nathan; McNulty, Anna; Chen, Marcus Y; Marshall, Lewis; O'Connor, Catherine C; Dickson, Bridget; Grulich, Andrew E; Hellard, Margaret E; Kaldor, John M; Guy, Rebecca J

    2013-11-01

    To answer a key question ('Are Australian sexual health clinics attracting priority populations?'), we used data from 44 Australian sexual health clinics between 2004 and 2011. We assessed the proportion of patients that were from priority populations (deemed to be at risk of sexually transmissible infections) and compared this to their proportions in the general population using data from Australian Bureau of Statistics and the Australian Study of Health and Relationships. A χ(2)-test was used. A total of 278154 new patients attended during 2004-2011. The proportions from each priority population were significantly higher (P<0.01 for all) than for the general population: young people aged 15-29 years (58.1% v. 20.1%), men who have sex with men (26.0% v. 6.0%), female sex workers (10.8% v. 0.5%), and Aboriginal and Torres Strait Islander people (4.2% v. 2.3%). This study confirms that Australian sexual health clinics attract higher proportions of priority populations and are thus meeting their mandate as defined in the 2010-2013 National Sexually Transmissible Infections Strategy. PMID:23962540

  20. Sexual reproduction in Aspergillus flavus sclerotia: acquisition of novel alleles from soil populations and uniparental mitochondrial inheritance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus colonizes agricultural commodities worldwide and contaminates them with carcinogenic aflatoxins. The high genetic diversity of A. flavus populations is largely due to sexual reproduction characterized by the formation of ascospore-bearing ascocarps embedded within sclerotia. A. ...

  1. Temporally variable multivariate sexual selection on sexually dimorphic traits in a wild insect population.

    PubMed

    Punzalan, David; Rodd, F Helen; Rowe, Locke

    2010-04-01

    A widely held view is that the strength and form of natural selection varies in time and space in response to varying ecological forces; however, adequate quantitative evaluations of this are relatively scarce. In this study, we measured the strength and form of sexual selection acting on a suite of male morphological traits in a wild ambush bug (Phymata americana) population at 10 sampling dates over 2 years. We tested the prediction that the strength and direction of sexual selection would be associated with one or more important ecological variables. We found that patterns of multivariate selection varied considerably over time, and even within a season. Yet, for this population, a sexually dimorphic color pattern trait was consistently a target of directional selection. The strength of sexual selection on this trait was related to both sex ratio and density, which is consistent with the idea that ecological factors can play an important role in generating patterns of sexual selection. We also demonstrate that the median strength of linear selection obtained from replicated cross-sectional methods was qualitatively similar to the estimates obtained from longitudinal methods, providing multiple lines of evidence that the evolution of sexual color dimorphism in this species is attributable to sexual selection. PMID:20184443

  2. The evolution of harm--effect of sexual conflicts and population size.

    PubMed

    Gay, Laurène; Hosken, David J; Eady, Paul; Vasudev, Ram; Tregenza, Tom

    2011-03-01

    Conflicts of interest between mates can promote the evolution of male traits that reduce female fitness and that drive coevolution between the sexes. The rate of adaptation depends on the intensity of selection and its efficiency, which depends on drift and genetic variability. This leads to the largely untested prediction that coevolutionary adaptations such as those driven by sexual conflict should evolve faster in large populations. We tested this using the bruchid beetle Callosobruchus maculatus, a species where harm inflicted by males is well documented. Although most experimental evolution studies remove sexual conflict, we reintroduced it in populations in which it had been experimentally removed. Both population size and standing genetic variability were manipulated in a factorial experimental design. After 90 generations of relaxed conflict (monogamy), the reintroduction of sexual conflicts for 30 generations favored males that harmed females and females that were more resistant to the genital damage inflicted by males. Males evolved to become more harmful when population size was large rather than when initial genetic variation was enriched. Our study shows that sexual selection can create conditions in which males can benefit from harming females and that selection may tend to be more intense and effective in larger populations. PMID:21050188

  3. An ephemeral sexual population of Phytophthora infestans in the northeastern United States and Canada

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora infestans, the causal agent of late blight disease, has been reported in North America since the mid-nineteenth century. In the United States the lack of or very limited sexual reproduction has resulted in largely clonal populations of P. infestans. In 2010 and 2011, but not in 2012 or ...

  4. Sexual abuse predicts functional somatic symptoms: an adolescent population study.

    PubMed

    Bonvanie, Irma J; van Gils, Anne; Janssens, Karin A M; Rosmalen, Judith G M

    2015-08-01

    The main aim of this study was to investigate the effect of childhood sexual abuse on medically not well explained or functional somatic symptoms (FSSs) in adolescents. We hypothesized that sexual abuse predicts higher levels of FSSs and that anxiety and depression contribute to this relationship. In addition, we hypothesized that more severe abuse is associated with higher levels of FSSs and that sexual abuse is related to gastrointestinal FSSs in particular. This study was part of the Tracking Adolescents' Individual Lives Survey (TRAILS): a general population cohort which started in 2001 (N=2,230; 50.8% girls, mean age 11.1 years). The current study uses data of 1,680 participants over four assessment waves (75% of baseline, mean duration of follow-up: 8 years). FSSs were measured by the Somatic Complaints subscale of the Youth Self-Report at all waves. Sexual abuse before the age of sixteen was assessed retrospectively with a questionnaire at T4. To test the hypotheses linear mixed models were used adjusted for age, sex, socioeconomic status, anxiety and depression. Sexual abuse predicted higher levels of FSSs after adjustment for age sex and socioeconomic status (B=.06) and after additional adjustment for anxiety and depression (B=.03). While sexual abuse involving physical contact significantly predicted the level of FSSs (assault; B=.08, rape; B=.05), non-contact sexual abuse was not significantly associated with FSSs (B=.04). Sexual abuse was not a stronger predictor of gastrointestinal FSSs (B=.06) than of all FSSs. Further research is needed to clarify possible mechanisms underlying relationship between sexual abuse and FSSs. PMID:26142915

  5. Sexual dimorphism in relation to big-game hunting and economy in modern human populations.

    PubMed

    Collier, S

    1993-08-01

    Postcranial skeletal data from two recent Eskimo populations are used to test David Frayer's model of sexual dimorphism reduction in Europe between the Upper Paleolithic and Mesolithic. Frayer argued that a change from big-game hunting and adoption of new technology in the Mesolithic reduced selection for large body size in males and led to a reduction in skeletal sexual dimorphism. Though aspects of Frayer's work have been criticized in the literature, the association of big-game hunting and high sexual dimorphism is untested. This study employs univariate and multivariate analysis to test that association by examining sexual dimorphism of cranial and postcranial bones of two recent Alaskan Eskimo populations, one being big-game (whale and other large marine mammal) hunting people, and the second being salmon fishing, riverine people. While big-game hunting influences skeletal robusticity, it cannot be said to lead to greater sexual dimorphism generally. The two populations had different relative sexual dimorphism levels for different parts of the body. Notably, the big-game hunting (whaling) Eskimos had the lower multivariate dimorphism in the humerus, which could be expected to be the structure under greatest exertion by such hunting in males. While the exertions of the whale hunting economic activities led to high skeletal robusticity, as predicted by Frayer's model, this was true of the females as well as the males, resulting in low sexual dimorphism in some features. Females are half the sexual dimorphism equation, and they cannot be seen as constants in any model of economic behavior. PMID:8372937

  6. Sexual recombination punctuated by outbreaks and clonal expansions predicts Toxoplasma gondii population genetics

    PubMed Central

    Grigg, Michael E.; Sundar, Natarajan

    2009-01-01

    The cosmopolitan parasitic pathogen Toxoplasma gondii is capable of infecting essentially any warm-blooded vertebrate worldwide, including most birds and mammals, and establishes chronic infections in one-third of the globe’s human population. The success of this highly prevalent zoonosis is largely the result of its ability to propagate both sexually and clonally. Frequent genetic exchanges via sexual recombination among extant parasite lineages that mix in the definitive felid host produces new lines that emerge to expand the parasite’s host range and cause outbreaks. Highly successful lines spread clonally via carnivorism and in some cases sweep to pandemic levels. The extent to which sexual reproduction versus clonal expansion shapes Toxoplasma’s current, global population genetic structure is the central question this review will attempt to answer. PMID:19217909

  7. Environmental change disrupts communication and sexual selection in a stickleback population.

    PubMed

    Candolin, Ulrika; Tukiainen, Iina; Bertell, Elina

    2016-04-01

    Environmental change that disrupts communication during mate choice and alters sexual selection could influence population dynamics. Yet little is known about such long-term effects. We investigated experimentally the consequences that disrupted visual communication during mate choice has for the quantity and viability of offspring produced in a threespine stickleback population (Gasterosteus aculeatus). We further related the results to long-term monitoring of population dynamics in the field to determine if changes are apparent under natural conditions. The results show that impaired visual communication because of algal blooms reduces reliability of male visual signals as indicators of offspring survival during their first weeks of life. This relaxes sexual selection but has no effect on the number of offspring hatching, as most males have a high hatching success in turbid water. Despite eutrophication and high turbidity levels that interfere with communication during mate choice, the population has grown during recent decades. Large numbers of offspring hatching, combined with high variation in juvenile fitness, has probably shifted selection to later life history stages and maintained a viable population. Together with reduced cost of sexual selection and ongoing ecosystem changes caused by human activities, this could have promoted population growth. These results point to the complexity of ecosystems and the necessity to consider all influencing factors when attempting to understand impacts of human activities on populations. PMID:27220213

  8. Evaluation of sexual attitude and sexual function in menopausal age; a population based cross-sectional study

    PubMed Central

    Hashemi, Somayeh; Ramezani Tehrani, Fahimeh; Simbar, Masumeh; Abedini, Mehrandokht; Bahreinian, Hamid; Gholami, Roya

    2013-01-01

     Background: Menopause and its physical, hormonal and psychosocial changes could affect women’s sexual function. There are controversial results regarding relationship between sexual attitudes and function. Objective: We aimed to evaluate sexual attitudes and sexual function among Iranian menopausal age women. Materials and Methods: This population based cross-sectional study was carried out on 225 menopausal women, aged 45-65 years. Based on a self-made questionnaire data were collected about women’s socio-demographic characteristics, attitudes regarding sexuality and sexual function. Data were analyzed using SPSS and sexual function was compared between three groups of women who had positive, medium and negative attitudes regarding sexuality. Results: The mean age of women was 53.11±4.56 years. Seventy percent of them had at least one sexual problem. Feeling of dyspareunia was significantly different between three categories of attitudes regarding sexuality (p=0.03). Comparing data obtained on their attitudes, sexual desire, orgasm and dyspareunia demonstrated significant differences (p=0.03, 0.04, and 0.04 respectively). Conclusion: Attitude regarding sexual function has a great impact on sexual activity of postmenopausal women that need to be considered in their health care programming. PMID:24639800

  9. Considerations for Reaching the Latino Population with Sexuality and HIV/AIDS Information and Education.

    ERIC Educational Resources Information Center

    de la Vega, Ernesto

    1990-01-01

    Latino and Latina sexual attitudes and behaviors must be understood if educators and counselors hope to reach this population with effective sexuality and Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (HIV/AIDS) information and education. The general U.S. Latino population is mostly sexually conservative; direct talk in public…

  10. Natural and sexual selection in a monogamous historical human population.

    PubMed

    Courtiol, Alexandre; Pettay, Jenni E; Jokela, Markus; Rotkirch, Anna; Lummaa, Virpi

    2012-05-22

    Whether and how human populations exposed to the agricultural revolution are still affected by Darwinian selection remains controversial among social scientists, biologists, and the general public. Although methods of studying selection in natural populations are well established, our understanding of selection in humans has been limited by the availability of suitable datasets. Here, we present a study comparing the maximum strengths of natural and sexual selection in humans that includes the effects of sex and wealth on different episodes of selection. Our dataset was compiled from church records of preindustrial Finnish populations characterized by socially imposed monogamy, and it contains a complete distribution of survival, mating, and reproductive success for 5,923 individuals born 1760-1849. Individual differences in early survival and fertility (natural selection) were responsible for most variation in fitness, even among wealthier individuals. Variance in mating success explained most of the higher variance in reproductive success in males compared with females, but mating success also influenced reproductive success in females, allowing for sexual selection to operate in both sexes. The detected opportunity for selection is in line with measurements for other species but higher than most previous reports for human samples. This disparity results from biological, demographic, economic, and social differences across populations as well as from failures by most previous studies to account for variation in fitness introduced by nonreproductive individuals. Our results emphasize that the demographic, cultural, and technological changes of the last 10,000 y did not preclude the potential for natural and sexual selection in our species. PMID:22547810

  11. Natural and sexual selection in a monogamous historical human population

    PubMed Central

    Courtiol, Alexandre; Pettay, Jenni E.; Jokela, Markus; Rotkirch, Anna; Lummaa, Virpi

    2012-01-01

    Whether and how human populations exposed to the agricultural revolution are still affected by Darwinian selection remains controversial among social scientists, biologists, and the general public. Although methods of studying selection in natural populations are well established, our understanding of selection in humans has been limited by the availability of suitable datasets. Here, we present a study comparing the maximum strengths of natural and sexual selection in humans that includes the effects of sex and wealth on different episodes of selection. Our dataset was compiled from church records of preindustrial Finnish populations characterized by socially imposed monogamy, and it contains a complete distribution of survival, mating, and reproductive success for 5,923 individuals born 1760–1849. Individual differences in early survival and fertility (natural selection) were responsible for most variation in fitness, even among wealthier individuals. Variance in mating success explained most of the higher variance in reproductive success in males compared with females, but mating success also influenced reproductive success in females, allowing for sexual selection to operate in both sexes. The detected opportunity for selection is in line with measurements for other species but higher than most previous reports for human samples. This disparity results from biological, demographic, economic, and social differences across populations as well as from failures by most previous studies to account for variation in fitness introduced by nonreproductive individuals. Our results emphasize that the demographic, cultural, and technological changes of the last 10,000 y did not preclude the potential for natural and sexual selection in our species. PMID:22547810

  12. Sexual Victimization of Boys: An Ongoing Study of an Adolescent Medicine Clinic Population

    PubMed Central

    Shrier, Diane; Johnson, Robert L.

    1988-01-01

    An ongoing clinical research project on sexual victimization of boys was begun in 1982. The study population is boys aged 12 to 21 years attending an adolescent medicine clinic for reasons other than having been sexually abused. More recently, comparison populations have been obtained from a sexual abuse clinic, from an adolescent medicine clinic for girls, and from a group of adolescent sexual offenders. PMID:3249324

  13. Rate of fixation of beneficial mutations in sexual populations

    NASA Astrophysics Data System (ADS)

    Gouveia, Joseilme F.; de Oliveira, Viviane M.; Sátiro, Caio; Campos, Paulo R. A.

    2009-06-01

    We have investigated the rate of substitution of advantageous mutations in populations of haploid organisms where the rate of recombination can be controlled. We have verified that in all the situations recombination speeds up adaptation through recombination of beneficial mutations from distinct lineages in a single individual, and so reducing the intensity of clonal interference. The advantage of sex for adaptation is even stronger when deleterious mutations occur since now recombination can also restore genetic background free of deleterious mutations. However, our simulation results demonstrate that evidence of clonal interference, as increased mean selective effect of fixed mutations and reduced likelihood of fixation of small-effect mutations, are also present in sexual populations. What we see is that this evidence is delayed when compared to asexual populations.

  14. The Role of Sexual Selection and Conflict in Mediating Among-Population Variation in Mating Strategies and Sexually Dimorphic Traits in Sepsis punctum

    PubMed Central

    Dmitriew, Caitlin; Blanckenhorn, Wolf U.

    2012-01-01

    The black scavenger fly Sepsis punctum exhibits striking among-population variation in the direction and magnitude of sexual size dimorphism, modification to the male forelimb and pre-copulatory behaviour. In some populations, male-biased sexual size dimorphism is observed; in other, less dimorphic, populations males court prior to mating. Such variation in reproductive traits is of interest to evolutionary biologists because it has the potential to limit gene flow among populations, contributing to speciation. Here, we investigate whether large male body size and modified forefemur are associated with higher male mating success within populations, whether these traits are associated with higher mating success among populations, and if these traits carry viability costs that could constrain their response to sexual selection. Flies from five distinct populations were reared at high or low food, generating high and low quality males. The expression of body size, forelimb morphology and courtship rate were each greater at high food, but high food males experienced higher mating success or reduced latency to first copulation in only one of the populations. Among populations, overall mating success increased with the degree of male-bias in overall body size and forelimb modification, suggesting that these traits have evolved as a means of increasing male mating rate. The increased mating success observed in large-male populations raises the question of why variation in magnitude of dimorphism persists among populations. One reason may be that costs of producing a large size constrain the evolution of ever-larger males. We found no evidence that juvenile mortality under food stress was greater for large-male populations, but development time was considerably longer and may represent an important constraint in an ephemeral and competitive growth environment. PMID:23227145

  15. Adolescent sexuality in Asia: new focus for population policy.

    PubMed

    Robey, B

    1989-09-01

    As the age at marriage continues to rise in East and Southeast Asia, the fertility behavior of unmarried teenagers is receiving more attention from population policymakers. In addition to fertility reduction through family planning, Asian societies today consider population planning strategies in relation to national needs and social goals, including such matters as the population's growth rate, age structure, educational quality and skills. The number of single youth in Asia is growing much more rapidly than the total youth population. By the year 2010, for example, India is projected to have nearly 70 million single teenagers, aged 15-19, 188% more than in 1980. In many developing countries today, such as the Philippines and Korea, the rising age at marriage has combined with rapid urbanization, improved status for women, and more educational opportunity to alter both the behavioral norms of young people and the traditional means of social control over youth. Studies of contemporary adolescent sexuality have been conducted in 4 Asian countries. In the Philippines an overt independent youth homosexual culture was found to exist in urban and to some extent rural areas. In Thailand research revealed little conservative resistance to family planning or to contraceptives for young unmarried people. Surveys in Taiwan indicate that behavior related to dating and choice of spouse has become more liberal, and a survey in Hong Kong revealed a higher level of premarital sex and use of prostitutes among Chinese men than expected. Population policy perspectives that need to be considered in these changing times include: 1) issues of access to family planning services by unmarried people below the legal age of maturity; 2) the development of social institutions, such as exist in Thailand and the Philippines, to guide adolescents' behavior; 3) more extensive study of adolescent sexuality; 4) establishment of the scope of family policy. PMID:12315866

  16. Alleles versus genotypes: Genetic interactions and the dynamics of selection in sexual populations

    NASA Astrophysics Data System (ADS)

    Neher, Richard

    2010-03-01

    Physical interactions between amino-acids are essential for protein structure and activity, while protein-protein interactions and regulatory interactions are central to cellular function. As a consequence of these interactions, the combined effect of two mutations can differ from the sum of the individual effects of the mutations. This phenomenon of genetic interaction is known as epistasis. However, the importance of epistasis and its effects on evolutionary dynamics are poorly understood, especially in sexual populations where recombination breaks up existing combinations of alleles to produce new ones. Here, we present a computational model of selection dynamics involving many epistatic loci in a recombining population. We demonstrate that a large number of polymorphic interacting loci can, despite frequent recombination, exhibit cooperative behavior that locks alleles into favorable genotypes leading to a population consisting of a set of competing clones. As the recombination rate exceeds a certain critical value this ``genotype selection'' phase disappears in an abrupt transition giving way to ``allele selection'' - the phase where different loci are only weakly correlated as expected in sexually reproducing populations. Clustering of interacting sets of genes on a chromosome leads to the emergence of an intermediate regime, where localized blocks of cooperating alleles lock into genetic modules. Large populations attain highest fitness at a recombination rate just below critical, suggesting that natural selection might tune recombination rates to balance the beneficial aspect of exploration of genotype space with the breaking up of synergistic allele combinations.

  17. Sexual disorders among elderly: An epidemiological study in south Indian rural population

    PubMed Central

    Sathyanarayana Rao, T. S.; Ismail, Shajahan; Darshan, M. S.; Tandon, Abhinav

    2015-01-01

    Background: Realizing a dearth of data on this topic, especially in the Indian context, an epidemiological study was conducted in a south Indian rural population to identify the sexual activity patterns and sexual problems among the population above 60 years of age. Objectives: (1) Assessment of sexual activity patterns among individuals above 60 years. (2) Assessment of the prevalence of sexual disorders among individuals above 60 years. Materials and Methods: The study sample consisted of 259 participants, which included both males and females above 60 years of age. Subjects who were sexually active and fulfilled the study criteria were administered Arizona Sexual Experience Scale as a screening tool, for the presence of sexual problems. Those who were found to have sexual problems were interviewed further using appropriate questionnaires. Results: Only 27.4% of the individuals above 60 years were sexually active, and it progressively dropped as age advanced and none were sexually active after 75 years of age. Among the sexually active males, erectile dysfunction (ED) was prevalent in 43.5%, premature ejaculation in 10.9%, hypoactive sexual desire disorder (HSSD) in 0.77% and anorgasmia in 0.38% of the subjects. Among females, arousal disorder was prevalent in 28%, HSSD in 16%, anorgasmia in 20% and dyspareunia in 8% of the subjects. Conclusion: The study gives us an insight into the sexual problems of the elderly and brings home the point that sexual problems are very much common among both men and women in the older population. Among elderly males, ED is the most common sexual disorder whereas in elderly females, arousal disorder is the most prevalent female sexual dysfunction, implicating biology plays an important role in men, whereas psychology plays an important role in women sexual functioning. PMID:26600575

  18. Population generation for large-scale simulation

    NASA Astrophysics Data System (ADS)

    Hannon, Andrew C.; King, Gary; Morrison, Clayton; Galstyan, Aram; Cohen, Paul

    2005-05-01

    Computer simulation is used to research phenomena ranging from the structure of the space-time continuum to population genetics and future combat.1-3 Multi-agent simulations in particular are now commonplace in many fields.4, 5 By modeling populations whose complex behavior emerges from individual interactions, these simulations help to answer questions about effects where closed form solutions are difficult to solve or impossible to derive.6 To be useful, simulations must accurately model the relevant aspects of the underlying domain. In multi-agent simulation, this means that the modeling must include both the agents and their relationships. Typically, each agent can be modeled as a set of attributes drawn from various distributions (e.g., height, morale, intelligence and so forth). Though these can interact - for example, agent height is related to agent weight - they are usually independent. Modeling relations between agents, on the other hand, adds a new layer of complexity, and tools from graph theory and social network analysis are finding increasing application.7, 8 Recognizing the role and proper use of these techniques, however, remains the subject of ongoing research. We recently encountered these complexities while building large scale social simulations.9-11 One of these, the Hats Simulator, is designed to be a lightweight proxy for intelligence analysis problems. Hats models a "society in a box" consisting of many simple agents, called hats. Hats gets its name from the classic spaghetti western, in which the heroes and villains are known by the color of the hats they wear. The Hats society also has its heroes and villains, but the challenge is to identify which color hat they should be wearing based on how they behave. There are three types of hats: benign hats, known terrorists, and covert terrorists. Covert terrorists look just like benign hats but act like terrorists. Population structure can make covert hat identification significantly more difficult. Investigators using the Hats Simulator must be able to control population parameters, and population generation must be fast enough to support studies that vary these parameters. This paper reports our experiences developing algorithms to generate populations whose structure is dependent on experimenter controlled parameters. In the next section, we outline the general problem of population generation and the details of building populations for the Hats Simulator. This is followed by a brief description of our initial, brute force algorithm (section 3). It was sufficient for small populations, but scaled horribly. We realized that the Law of Large Numbers would allow randomized methods to generate large populations that satisfied our constraints within acceptable bounds (section 5). It was while developing this algorithm that we discovered the connection between our population generation problem and recent results from the theory of random bipartite graphs (section 4). Finally, section 6 examines the properties and performance of our randomized algorithm. Though we will describe our results in terms of the Hats Simulator, these methods apply to any modeling situation in which populations of agents share multiple, overlapping structures, each of which is independent from the others. Our hope is that our experience will benefit others facing the task of generating large populations that require similar overlapping group structure.

  19. Sexual Reproduction in a Simple Growth Population Model

    NASA Astrophysics Data System (ADS)

    Lemos, Carlos Gentil Oro; Santos, Marcio

    2012-05-01

    One of the most important characteristics in the survival of a species is related to the kind of reproduction responsible for the offspring generation. However, only in the last years the role played by sexual reproduction has been investigated. Then, for a better understanding of this kind of process we introduce, in this work, a surface reaction model that describes the role of the sexual reproduction. In our model two different elements of the species, representing male and female, can interact to reproduce a new element. The sex of this new element is chosen with a given probability and in order to take into account the mortality rate we introduce another kind of individual. The value of the spatial density of this element remains constant during the time evolution of the system. The model is studied using Monte Carlo simulations and mean field approximation. Depending on the values of the control parameters of the model, the system can attain two stationary states: In one of them the population survives and in the other it can be extinguished. Besides, accordingly to our results, the phase diagram of the model shows a discontinuous transition between these two states.

  20. Measuring Community Connectedness among Diverse Sexual Minority Populations

    PubMed Central

    Frost, David M.; Meyer, Ilan H.

    2011-01-01

    Theory and research agree that connectedness to the lesbian, gay, bisexual, and transgender (LGBT) community is an important construct to account for in understanding issues related to health and well-being among gay and bisexual men. However, the measurement of this construct among lesbian and bisexual women or racial/ethnic minority individuals has not yet been adequately investigated. This study examined the reliability and validity of an existing measure of Connectedness to the LGBT Community among a diverse group of sexual minority individuals in New York City and whether differences in connectedness existed across gender and race/ethnicity. Scores on the measure demonstrated both internal consistency and construct stability across subgroups defined by gender and race/ethnicity. The subgroups did not differ in their mean levels of connectedness and scores on the measure demonstrated factorial, convergent, and discriminate validity both generally and within each of the subgroups. Inconsistencies were observed with regard to which scores on the measure demonstrated predictive validity in their associations with indicators of mental health and well-being. The scale is a useful tool for researchers and practitioners interested in understanding the role of community connectedness in the lives of diverse populations of sexual minority individuals. PMID:21512945

  1. Detecting cell assemblies in large neuronal populations.

    PubMed

    Lopes-dos-Santos, Vítor; Ribeiro, Sidarta; Tort, Adriano B L

    2013-11-15

    Recent progress in the technology for single unit recordings has given the neuroscientific community the opportunity to record the spiking activity of large neuronal populations. At the same pace, statistical and mathematical tools were developed to deal with high-dimensional datasets typical of such recordings. A major line of research investigates the functional role of subsets of neurons with significant co-firing behavior: the Hebbian cell assemblies. Here we review three linear methods for the detection of cell assemblies in large neuronal populations that rely on principal and independent component analysis. Based on their performance in spike train simulations, we propose a modified framework that incorporates multiple features of these previous methods. We apply the new framework to actual single unit recordings and show the existence of cell assemblies in the rat hippocampus, which typically oscillate at theta frequencies and couple to different phases of the underlying field rhythm. PMID:23639919

  2. Natural and sexual selection in a wild insect population.

    PubMed

    Rodríguez-Muñoz, R; Bretman, A; Slate, J; Walling, C A; Tregenza, T

    2010-06-01

    The understanding of natural and sexual selection requires both field and laboratory studies to exploit the advantages and avoid the disadvantages of each approach. However, studies have tended to be polarized among the types of organisms studied, with vertebrates studied in the field and invertebrates in the lab. We used video monitoring combined with DNA profiling of all of the members of a wild population of field crickets across two generations to capture the factors predicting the reproductive success of males and females. The factors that predict a male's success in gaining mates differ from those that predict how many offspring he has. We confirm the fundamental prediction that males vary more in their reproductive success than females, and we find that females as well as males leave more offspring when they mate with more partners. PMID:20522773

  3. Predictors of Sexual Bother in a Population of Male North American Medical Students

    PubMed Central

    Smith, James F.; Breyer, Benjamin N.; Shindel, Alan W.

    2013-01-01

    Introduction The prevalence and associations of sexual bother in male medical students has not been extensively studied. Aims The aim of this study is to analyze predictors of sexual bother in a survey of male North American medical students. Methods Students enrolled in allopathic and osteopathic medical schools in North America between February 2008 and July 2008 were invited to participate in an internet-based survey of sexuality and sexual function. Main Outcome Measures The principle outcome measure was a single-item question inquiring about global satisfaction with sexual function. The survey also consisted of a questionnaire that included ethnodemographic factors, student status, sexual history, and a validated scale for the assessment of depression. Respondents completed the International Index of Erectile Function, the premature ejaculation diagnostic tool, and the Self-Esteem and Relationship Quality survey (SEAR). Descriptive statistics, analysis of variance, and multivariable logistic regression were utilized to analyze responses. Results There were 480 male subjects (mean age 26.3 years) with data sufficient for analysis. Forty-three (9%) reported sexual bother. Sexual bother was significantly more common in men with erectile dysfunction (ED), high risk of premature ejaculation (HRPE), depressive symptoms, and lower sexual frequency. However, after multivariate analysis including SEAR scores, ED, and HRPE were no longer independently predictive of sexual bother. Higher scores for all domains of the SEAR were associated with lower odds of sexual bother. Conclusions ED and HRPE are associated with sexual bother in this young and presumably healthy population. However, after controlling for relationship factors neither ED nor HRPE independently predicted sexual bother. It is plausible to hypothesize that sexual dysfunction from organic causes is rare in this population and is seldom encountered outside of relationship perturbations. Attention to relationship and psychological factors is likely of key importance in addressing sexual concerns in this population. PMID:21951580

  4. Sexual functioning among the elderly population in Tehran, Iran.

    PubMed

    Malakouti, Seyed Kazem; Salehi, Mansour; Nojomi, Marzieh; Zandi, Taher; Eftekhar, Mehrdad

    2012-01-01

    This study aims to demonstrate the sexual functioning of elderly Iranian retirees who reside in Tehran, Iran. The participants' sexual interests are also reviewed in association with their physical and mental health status. The authors recruited 390 elders (199 men, 191 women) by convenient sampling from 4 retirement organizations in Tehran from April 2007 to October 2008. Tools for evaluation included use of a demographic questionnaire, modified Brief Index of Sexual Functioning for Women, Brief Sexual Function Inventory for Men, and the General Health Questionnaire. Sexual activity was "important/very important" in 56.6% and 17.0% of men and women, respectively (p < .005), but their satisfaction from sexual life was similar. Sexual desire and activities were more common among men than among women (p < .05). Impotency and ejaculatory problems were 40% and 33%, respectively, among the male study participants. This study indicated that having a sexual partner was the most important variable for sexual activities. This study provides a profile of sexual behaviors among elderly people in Iran and shows that although sexual decline and dysfunction are seen in both genders, both groups express satisfaction with their sexual affairs when they have a partner available. PMID:22712820

  5. Increased condom use without other major changes in sexual behavior among the general population in Switzerland.

    PubMed Central

    Dubois-Arber, F; Jeannin, A; Konings, E; Paccaud, F

    1997-01-01

    OBJECTIVES: This study is part of a continuous evaluation of the Swiss AIDS prevention strategy from 1987 through 1994. METHODS: Annual telephone surveys of samples representative of the general population aged 17 through 45 years have been conducted since 1987 to monitor behavioral change. RESULTS: No major changes in level of sexual activity (lifetime number of partners, frequency of sexual encounters in the past week) or potential exposure to risk of HIV transmission (acquisition of a new steady partner during the year or of casual partners in the last 6 months) were observed. Systematic condom use with a new steady partner increased between 1988 and 1994, from 40% to 64% among 17- to 30-year-olds and from 57% to 72% among those aged 31 to 45. Systematic condom use with casual partners increased from 8% to 56% between 1987 and 1994 among 17- to 30-year-olds and from 22% to 42% between 1989 and 1994 among those aged 31 to 45. Condom use was higher among those with multiple partners. CONCLUSIONS: A general-population approach to AIDS prevention was able to achieve large-scale improvements in condom-based protection against HIV infection without inducing other major changes in sexual behavior. PMID:9146432

  6. An epidemiological study of sexual disorders in south Indian rural population

    PubMed Central

    Sathyanarayana Rao, T. S.; Darshan, M. S.; Tandon, Abhinav

    2015-01-01

    Background: Sexuality is an important aspect of the personality of an individual and influences psychological, physical and social well-being of both men and women. It is a paradox, that in the country where ‘kamasutra’ (by Vatsyayana) took birth, there is a lack of research publications and sexuality related literature; hence the current study was conducted, to estimate the prevalence and association of sexual disorders with various socio-demographic variables, in the selected rural population. Materials and Methods: Subjects who were sexually active and fulfilled the study criteria were administered Arizona Sexual Experience Scale as screening tool for the presence of sexual problems. Those who were found to be having sexual problems were interviewed further using appropriate questionnaires. Results: 21.15% of the male subjects were diagnosed to have one (or more) sexual disorder. Prevalence of erectile dysfunction was found to be 15.77%, male hypoactive sexual desire disorder (HSDD) 2.56%; premature ejaculation was found to be prevalent in 8.76% of the male subjects. Around 14% of the female subjects were diagnosed to have female sexual disorders. Prevalence of female arousal dysfunction was found to be 6.65%, female HSDD 8.87%, female anorgasmia 5.67%, female dyspareunia 2.34% and female sexual aversion disorder was found to be prevalent in 0.37% of the female subjects. Conclusion: This study concluded that one in five males and one in seven females were suffering from one (or more) sexual disorder. Improving the training of undergraduate medical and nursing students in sexuality related issues, increasing trained individuals in sexual medicine by starting new courses, providing sex education to the general population using media and merging sexual health care with primary care, are likely to play a significant role in addressing the increasing sexual health morbidity. PMID:26124520

  7. Sexually coercive behavior in male youth: population survey of general and specific risk factors.

    PubMed

    Kjellgren, Cecilia; Priebe, Gisela; Svedin, Carl Göran; Långström, Niklas

    2010-10-01

    Little is known about risk/protective factors for sexually coercive behavior in general population youth. We used a Swedish school-based population survey of sexual attitudes and experiences (response rate 77%) and investigated literature-based variables across sexually coercive (SEX), non-sexual conduct problem (CP), and normal control (NC) participants to identify general and specific risk/protective factors for sexual coercion. Among 1,933 male youth, 101 (5.2%) reported sexual coercion (ever talked or forced somebody into genital, oral, or anal sex) (SEX), 132 (6.8%) were classified as CP, and the remaining 1,700 (87.9%) as NC. Of 29 tested variables, 25 were more common in both SEX and CP compared to NC youth, including minority ethnicity, separated parents, vocational study program, risk-taking, aggressiveness, depressive symptoms, substance abuse, sexual victimization, extensive sexual experiences, and sexual preoccupation. When compared to CP youth only, SEX youth more often followed academic study programs, used less drugs and were less risk-taking. Further, SEX more frequently than CP youth reported gender stereotypic and pro-rape attitudes, sexual preoccupation, prostitution, and friends using violent porn. Finally, in a multivariate logistic regression, academic study program, pro-rape attitudes, sexual preoccupation, and less risk-taking independently remained more strongly associated with SEX compared to CP offending. In conclusion, several sociodemographic, family, and individual risk/protective factors were common to non-sexual and sexually coercive antisocial behavior in late adolescence. However, pro-rape cognitions, and sexual preoccupation, were sexuality-related, specific risk factors. The findings could inform preventive efforts and the assessment and treatment of sexually coercive male youth. PMID:19888644

  8. Sexual recombination in the Botrytis cinerea populations in Hungarian vineyards.

    PubMed

    Váczy, Kálmán Z; Sándor, Erzsébet; Karaffa, Levente; Fekete, Erzsébet; Fekete, Eva; Arnyasi, Mariann; Czeglédi, Levente; Kövics, György J; Druzhinina, Irina S; Kubicek, Christian P

    2008-12-01

    Botrytis cinerea (anamorph of Botryotinia fuckeliana) causes gray mold on a high number of crop plants including grapes. In this study, we investigated the genetic properties of a grape pathogenic population of B. cinerea in the area of Eger, Hungary. A total of 109 isolates from 12 areas were sampled. Based on the sequence of the beta-tubulin (tub1) locus, they all belong to group II, a phylogenetic species within B. cinerea. Seventy-four isolates were classified as transposa, with both the Flipper and Boty transposons, and 10 were classified as vacuma, lacking both transposons. The remaining isolates contained either only Flipper (13) or Boty (12). Multilocus analysis of sequences from tub1 and two other loci (elongation factor 1-alpha, tef1, and a minisatellite from the intron of an ATPase, MSB1) led to poor phylogenetic resolution of strains in individual clades. Analysis of five microsatellites (Bc2, Bc3, Bc5, Bc6, and Bc10) resulted in 55 microsatellite haplotypes within the 109 strains. No correlation was detected among individual haplotypes and the presence/absence of Flipper and/or Boty, the geographic origin, or the year of isolation. Application of the index of association, the chi-square test, and the phi test consistently indicated that the population of Hungarian isolates of B. cinerea undergoes sexual reproduction. However, the index of association test suggested the presence of some clonality, and the fixation index showed a low or occasionally moderate level of fixation in the Flipper populations. We conclude that the B. cinerea populations in Hungary consist of a strongly recombining group II phylogenetic species. PMID:19000006

  9. A population of sexual Daphnia pulex resists invasion by asexual clones

    PubMed Central

    Innes, David J.; Ginn, Michael

    2014-01-01

    Asexual reproduction avoids the costs associated with sex, predicting that invading asexual clones can quickly replace sexual populations. Daphnia pulex populations in the Great Lakes area are predominately asexual, but the elimination of sexual populations by invading clones is poorly understood. Asexual clones were detected at low frequency in one rare sexual population in 1995, with some increase in frequency during 2003 and 2004. However, these clones remained at low frequency during further yearly sampling (2005–2013) with no evidence that the resident sexual population was in danger of elimination. There was evidence for hybridization between rare males produced by asexual clones and sexual females with the potential to produce new asexual genotypes and spread the genetic factors for asexuality. In a short-term laboratory competition experiment, the two most common asexual clones did not increase in frequency relative to a genetically diverse sexual population due in part to a greater investment in diapausing eggs that trades-off current population growth for increased contribution to the egg bank. Our results suggest that a successful invasion can be prolonged, requiring a combination of clonal genotypes with high fitness, persistence of clones in the egg bank and negative factors affecting the sexual population such as inbreeding depression resulting from population bottlenecks. PMID:24943366

  10. A population of sexual Daphnia pulex resists invasion by asexual clones.

    PubMed

    Innes, David J; Ginn, Michael

    2014-08-01

    Asexual reproduction avoids the costs associated with sex, predicting that invading asexual clones can quickly replace sexual populations. Daphnia pulex populations in the Great Lakes area are predominately asexual, but the elimination of sexual populations by invading clones is poorly understood. Asexual clones were detected at low frequency in one rare sexual population in 1995, with some increase in frequency during 2003 and 2004. However, these clones remained at low frequency during further yearly sampling (2005-2013) with no evidence that the resident sexual population was in danger of elimination. There was evidence for hybridization between rare males produced by asexual clones and sexual females with the potential to produce new asexual genotypes and spread the genetic factors for asexuality. In a short-term laboratory competition experiment, the two most common asexual clones did not increase in frequency relative to a genetically diverse sexual population due in part to a greater investment in diapausing eggs that trades-off current population growth for increased contribution to the egg bank. Our results suggest that a successful invasion can be prolonged, requiring a combination of clonal genotypes with high fitness, persistence of clones in the egg bank and negative factors affecting the sexual population such as inbreeding depression resulting from population bottlenecks. PMID:24943366

  11. Large optic disks in the Marshallese population.

    PubMed

    Maisel, J M; Pearlstein, C S; Adams, W H; Heotis, P M

    1989-02-15

    On routine examination, asymptomatic patients from the Marshall Islands were noted to have large optic disks associated with high cup/disk ratios and normal intraocular pressure. We retrospectively analyzed color fundus photographs of 54 eyes and 22 eyes of 15 patients had optic disks greater than 2.10 mm, or megalopapilla. Of 36 patients with cup/disk ratios exceeding 0.6, 31 (86%) had visual acuities of better than or equal to 20/30. The optic nerve rim and disk areas varied directly as did disk and cup diameters. Three large disks with an 18-year photographic follow-up showed no change. Optic disk characteristics can vary widely among genetically isolated populations. PMID:2913808

  12. Molecular hyperdiversity and evolution in very large populations

    PubMed Central

    Cutter, Asher D.; Jovelin, Richard; Dey, Alivia

    2014-01-01

    The genomic density of sequence polymorphisms critically affects the sensitivity of inferences about ongoing sequence evolution, function, and demographic history. Most animal and plant genomes have relatively low densities of polymorphisms, but some species are hyperdiverse with neutral nucleotide heterozygosity exceeding 5%. Eukaryotes with extremely large populations, mimicking bacterial and viral populations, present novel opportunities for studying molecular evolution in sexually-reproducing taxa with complex development. In particular, hyperdiverse species can help answer controversial questions about the evolution of genome complexity, the limits of natural selection, modes of adaptation, and subtleties of the mutation process. However, such systems have some inherent complications and here we identify topics in need of theoretical developments. Close relatives of the model organisms Caenorhabditis elegans and Drosophila melanogaster provide known examples of hyperdiverse eukaryotes, encouraging functional dissection of resulting molecular evolutionary patterns. We recommend how best to exploit hyperdiverse populations for analysis, for example, in quantifying the impact of non-crossover recombination in genomes and for determining the identity and micro-evolutionary selective pressures on non-coding regulatory elements. PMID:23506466

  13. Differences in male coloration are predicted by divergent sexual selection between populations of a cichlid fish.

    PubMed

    Selz, O M; Thommen, R; Pierotti, M E R; Anaya-Rojas, J M; Seehausen, O

    2016-05-11

    Female mating preferences can influence both intraspecific sexual selection and interspecific reproductive isolation, and have therefore been proposed to play a central role in speciation. Here, we investigate experimentally in the African cichlid fish Pundamilia nyererei if differences in male coloration between three para-allopatric populations (i.e. island populations with gene flow) of P. nyererei are predicted by differences in sexual selection by female mate choice between populations. Second, we investigate if female mating preferences are based on the same components of male coloration and go in the same direction when females choose among males of their own population, their own and other conspecific populations and a closely related para-allopatric sister-species, P. igneopinnis Mate-choice experiments revealed that females of the three populations mated species-assortatively, that populations varied in their extent of population-assortative mating and that females chose among males of their own population based on different male colours. Females of different populations exerted directional intrapopulation sexual selection on different male colours, and these differences corresponded in two of the populations to the observed differences in male coloration between the populations. Our results suggest that differences in male coloration between populations of P. nyererei can be explained by divergent sexual selection and that population-assortative mating may directly result from intrapopulation sexual selection. PMID:27147097

  14. An Ephemeral Sexual Population of Phytophthora infestans in the Northeastern United States and Canada

    PubMed Central

    Danies, Giovanna; Myers, Kevin; Mideros, María F.; Restrepo, Silvia; Martin, Frank N.; Cooke, David E. L.; Smart, Christine D.; Ristaino, Jean B.; Seaman, Abby J.; Gugino, Beth K.; Grünwald, Niklaus J.; Fry, William E.

    2014-01-01

    Phytophthora infestans, the causal agent of late blight disease, has been reported in North America since the mid-nineteenth century. In the United States the lack of or very limited sexual reproduction has resulted in largely clonal populations of P. infestans. In 2010 and 2011, but not in 2012 or 2013, 20 rare and diverse genotypes of P. infestans were detected in a region that centered around central New York State. The ratio of A1 to A2 mating types among these genotypes was close to the 50∶50 ratio expected for sexual recombination. These genotypes were diverse at the glucose-6-phosphate isomerase locus, differed in their microsatellite profiles, showed different banding patterns in a restriction fragment length polymorphism assay using a moderately repetitive and highly polymorphic probe (RG57), were polymorphic for four different nuclear genes and differed in their sensitivity to the systemic fungicide mefenoxam. The null hypothesis of linkage equilibrium was not rejected, which suggests the population could be sexual. These new genotypes were monomorphic in their mitochondrial haplotype that was the same as US-22. Through parentage exclusion testing using microsatellite data and sequences of four nuclear genes, recent dominant lineages US-8, US-11, US-23, and US-24 were excluded as possible parents for these genotypes. Further analyses indicated that US-22 could not be eliminated as a possible parent for 14 of the 20 genotypes. We conclude that US-22 could be a parent of some, but not all, of the new genotypes found in 2010 and 2011. There were at least two other parents for this population and the genotypic characteristics of the other parents were identified. PMID:25551215

  15. An ephemeral sexual population of Phytophthora infestans in the Northeastern United States and Canada.

    PubMed

    Danies, Giovanna; Myers, Kevin; Mideros, María F; Restrepo, Silvia; Martin, Frank N; Cooke, David E L; Smart, Christine D; Ristaino, Jean B; Seaman, Abby J; Gugino, Beth K; Grünwald, Niklaus J; Fry, William E

    2014-01-01

    Phytophthora infestans, the causal agent of late blight disease, has been reported in North America since the mid-nineteenth century. In the United States the lack of or very limited sexual reproduction has resulted in largely clonal populations of P. infestans. In 2010 and 2011, but not in 2012 or 2013, 20 rare and diverse genotypes of P. infestans were detected in a region that centered around central New York State. The ratio of A1 to A2 mating types among these genotypes was close to the 50∶50 ratio expected for sexual recombination. These genotypes were diverse at the glucose-6-phosphate isomerase locus, differed in their microsatellite profiles, showed different banding patterns in a restriction fragment length polymorphism assay using a moderately repetitive and highly polymorphic probe (RG57), were polymorphic for four different nuclear genes and differed in their sensitivity to the systemic fungicide mefenoxam. The null hypothesis of linkage equilibrium was not rejected, which suggests the population could be sexual. These new genotypes were monomorphic in their mitochondrial haplotype that was the same as US-22. Through parentage exclusion testing using microsatellite data and sequences of four nuclear genes, recent dominant lineages US-8, US-11, US-23, and US-24 were excluded as possible parents for these genotypes. Further analyses indicated that US-22 could not be eliminated as a possible parent for 14 of the 20 genotypes. We conclude that US-22 could be a parent of some, but not all, of the new genotypes found in 2010 and 2011. There were at least two other parents for this population and the genotypic characteristics of the other parents were identified. PMID:25551215

  16. Sexually Transmitted Diseases and Risk Behaviors among California Farmworkers: Results from a Population-Based Survey

    ERIC Educational Resources Information Center

    Brammeier, Monique; Chow, Joan M.; Samuel, Michael C.; Organista, Kurt C.; Miller, Jamie; Bolan, Gail

    2008-01-01

    Context: The prevalence of sexually transmitted diseases and associated risk behaviors among California farmworkers is not well described. Purpose: To estimate the prevalence of sexually transmitted diseases (STDs) and associated risk behaviors among California farmworkers. Methods: Cross-sectional analysis of population-based survey data from 6

  17. Patterns of Vaginal, Oral, and Anal Sexual Intercourse in an Urban Seventh-Grade Population

    ERIC Educational Resources Information Center

    Markham, Christine M.; Peskin, Melissa Fleschler; Addy, Robert C.; Baumler, Elizabeth R.; Tortolero, Susan R.

    2009-01-01

    Background: This study examines the prevalence of vaginal, oral, and anal intercourse among a population of urban, public middle school students, the characteristics of early sexual initiators, and the sequence of sexual initiation. Such data are limited for early adolescents. Methods: A total of 1279 seventh-grade students (57.3% female, 43.6%…

  18. Sexually Transmitted Diseases and Risk Behaviors among California Farmworkers: Results from a Population-Based Survey

    ERIC Educational Resources Information Center

    Brammeier, Monique; Chow, Joan M.; Samuel, Michael C.; Organista, Kurt C.; Miller, Jamie; Bolan, Gail

    2008-01-01

    Context: The prevalence of sexually transmitted diseases and associated risk behaviors among California farmworkers is not well described. Purpose: To estimate the prevalence of sexually transmitted diseases (STDs) and associated risk behaviors among California farmworkers. Methods: Cross-sectional analysis of population-based survey data from 6…

  19. The rate of fitness-valley crossing in sexual populations.

    PubMed

    Weissman, Daniel B; Feldman, Marcus W; Fisher, Daniel S

    2010-12-01

    Biological traits result in part from interactions between different genetic loci. This can lead to sign epistasis, in which a beneficial adaptation involves a combination of individually deleterious or neutral mutations; in this case, a population must cross a "fitness valley" to adapt. Recombination can assist this process by combining mutations from different individuals or retard it by breaking up the adaptive combination. Here, we analyze the simplest fitness valley, in which an adaptation requires one mutation at each of two loci to provide a fitness benefit. We present a theoretical analysis of the effect of recombination on the valley-crossing process across the full spectrum of possible parameter regimes. We find that low recombination rates can speed up valley crossing relative to the asexual case, while higher recombination rates slow down valley crossing, with the transition between the two regimes occurring when the recombination rate between the loci is approximately equal to the selective advantage provided by the adaptation. In large populations, if the recombination rate is high and selection against single mutants is substantial, the time to cross the valley grows exponentially with population size, effectively meaning that the population cannot acquire the adaptation. Recombination at the optimal (low) rate can reduce the valley-crossing time by up to several orders of magnitude relative to that in an asexual population. PMID:20923976

  20. Sexual conflict and the gender load: correlated evolution between population fitness and sexual dimorphism in seed beetles

    PubMed Central

    Arnqvist, Göran; Tuda, Midori

    2010-01-01

    Although males and females share much of the same genome, selection is often distinct in the two sexes. Sexually antagonistic loci will in theory cause a gender load in populations, because sex-specific selection on a given trait in one sex will compromise the adaptive evolution of the same trait in the other sex. However, it is currently not clear whether such intralocus sexual conflict (ISC) represents a transient evolutionary state, where conflict is rapidly resolved by the evolution of sexual dimorphism (SD), or whether it is a more chronic impediment to adaptation. All else being equal, ISC should manifest itself as correlated evolution between population fitness and SD in traits expressed in both sexes. However, comparative tests of this prediction are problematic and have been unfeasible. Here, we assess the effects of ISC by comparing fitness and SD across distinct laboratory populations of seed beetles that should be well adapted to a shared environment. We show that SD in juvenile development time, a key life-history trait with a history of sexually antagonistic selection in this model system, is positively related to fitness. This effect is due to a correlated evolution between population fitness and development time that is positive in females but negative in males. Loosening the genetic bind between the sexes has evidently allowed the sexes to approach their distinct adaptive peaks. PMID:20031994

  1. Sexual segregation in juvenile New Zealand sea lion foraging ranges: implications for intraspecific competition, population dynamics and conservation.

    PubMed

    Leung, Elaine S; Chilvers, B Louise; Nakagawa, Shinichi; Moore, Antoni B; Robertson, Bruce C

    2012-01-01

    Sexual segregation (sex differences in spatial organisation and resource use) is observed in a large range of taxa. Investigating causes for sexual segregation is vital for understanding population dynamics and has important conservation implications, as sex differences in foraging ecology may affect vulnerability to area-specific human activities. Although behavioural ecologists have proposed numerous hypotheses for this phenomenon, the underlying causes of sexual segregation are poorly understood. We examined the size-dimorphism and niche divergence hypotheses as potential explanations for sexual segregation in the New Zealand (NZ) sea lion (Phocarctos hookeri), a nationally critical, declining species impacted by trawl fisheries. We used satellite telemetry and linear mixed effects models to investigate sex differences in the foraging ranges of juvenile NZ sea lions. Male trip distances and durations were almost twice as long as female trips, with males foraging over the Auckland Island shelf and in further locations than females. Sex was the most important variable in trip distance, maximum distance travelled from study site, foraging cycle duration and percent time at sea whereas mass and age had small effects on these characteristics. Our findings support the predictions of the niche divergence hypothesis, which suggests that sexual segregation acts to decrease intraspecific resource competition. As a consequence of sexual segregation in foraging ranges, female foraging grounds had proportionally double the overlap with fisheries operations than males. This distribution exposes female juvenile NZ sea lions to a greater risk of resource competition and bycatch from fisheries than males, which can result in higher female mortality. Such sex-biased mortality could impact population dynamics, because female population decline can lead to decreased population fecundity. Thus, effective conservation and management strategies must take into account sex differences in foraging behaviour, as well as differential threat-risk to external impacts such as fisheries bycatch. PMID:23028978

  2. Sexual Segregation in Juvenile New Zealand Sea Lion Foraging Ranges: Implications for Intraspecific Competition, Population Dynamics and Conservation

    PubMed Central

    Leung, Elaine S.; Chilvers, B. Louise; Nakagawa, Shinichi; Moore, Antoni B.; Robertson, Bruce C.

    2012-01-01

    Sexual segregation (sex differences in spatial organisation and resource use) is observed in a large range of taxa. Investigating causes for sexual segregation is vital for understanding population dynamics and has important conservation implications, as sex differences in foraging ecology may affect vulnerability to area-specific human activities. Although behavioural ecologists have proposed numerous hypotheses for this phenomenon, the underlying causes of sexual segregation are poorly understood. We examined the size-dimorphism and niche divergence hypotheses as potential explanations for sexual segregation in the New Zealand (NZ) sea lion (Phocarctos hookeri), a nationally critical, declining species impacted by trawl fisheries. We used satellite telemetry and linear mixed effects models to investigate sex differences in the foraging ranges of juvenile NZ sea lions. Male trip distances and durations were almost twice as long as female trips, with males foraging over the Auckland Island shelf and in further locations than females. Sex was the most important variable in trip distance, maximum distance travelled from study site, foraging cycle duration and percent time at sea whereas mass and age had small effects on these characteristics. Our findings support the predictions of the niche divergence hypothesis, which suggests that sexual segregation acts to decrease intraspecific resource competition. As a consequence of sexual segregation in foraging ranges, female foraging grounds had proportionally double the overlap with fisheries operations than males. This distribution exposes female juvenile NZ sea lions to a greater risk of resource competition and bycatch from fisheries than males, which can result in higher female mortality. Such sex-biased mortality could impact population dynamics, because female population decline can lead to decreased population fecundity. Thus, effective conservation and management strategies must take into account sex differences in foraging behaviour, as well as differential threat-risk to external impacts such as fisheries bycatch. PMID:23028978

  3. Social support networks among diverse sexual minority populations.

    PubMed

    Frost, David M; Meyer, Ilan H; Schwartz, Sharon

    2016-01-01

    This article reports a study of the function and composition of social support networks among diverse lesbian, gay, and bisexual (LGB) men and women (n = 396) in comparison to their heterosexual peers (n = 128). Data were collected using a structured social support network matrix in a community sample recruited in New York City. Our findings show that gay and bisexual men may rely on "chosen families" more than lesbian and bisexual women. Both heterosexuals and LGBs relied less on family and more on other people (e.g., friends, coworkers) for everyday social support (e.g., recreational and social activities, talking about problems). Providers of everyday social support were most often of the same sexual orientation and race/ethnicity as participants. In seeking major support (e.g., borrowing large sums of money), heterosexual men and women along with lesbian and bisexual women relied primarily on their families, but gay and bisexual men relied primarily on other LGB individuals. Racial/ethnic minority LGBs relied on LGB similar others at the same rate as did White LGBs but, notably, racial/ethnic minority LGBs reported receiving fewer dimensions of support. PMID:26752447

  4. Evaluation of the potential for sexual reproduction in field populations of Cercospora beticola from USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cercospora leaf spot, caused by the hemibiotrophic fungal pathogen Cercospora beticola, is the most economically damaging foliar disease of sugarbeet worldwide. Although most C. beticola populations display characteristics reminiscent of sexual recombination, no teleomorph has been described. To ass...

  5. Population-based sexual behavior surveys in China: Liuzhou compared with other prefectural cities

    PubMed Central

    Yingying, Huang; Abler, Laurie; Suiming, Pan; Henderson, Gail E.; Xin, Wang; Xingliang, Yao; Parish, William L.

    2013-01-01

    Sexual behaviors in China are rapidly changing; simultaneously, STI/HIV prevalence is increasing in the general population. To investigate these major shifts, we examined sexual behaviors and self-reported sexually transmitted infections (STI) in one prefectural city in southern China, Liuzhou, and compared it to other prefectural cities throughout China. We used adults age 18-39 from two sets of population-based surveys that paralleled each other in both content and method. The first set was the Liuzhou survey conducted in 2008 (n=398). The second set consisted of two national surveys collected in 2006 and 2010 (n=2186). Liuzhou respondents reported more active social and sexual behaviors than their national counterparts, including more socializing, dancing, drinking excessively, sexual activity among never married men and women, purchasing commercial sex among men, one-night stands among men, multiple sexual partnerships and self-reported STI among both men and women. Women in Liuzhou reported greater sexual risk behavior than their national counterparts, although overall they reported less than their male counterparts; they were also more likely to have had an abortion than women in other prefectural cities. Our findings provide a comprehensive overview of the sexual context of Liuzhou among the general population, which may help explain the greater STI/HIV prevalence in Liuzhou. PMID:24174289

  6. Population-based sexual behavior surveys in China: Liuzhou compared with other prefectural cities.

    PubMed

    Huang, Yingying; Abler, Laurie; Pan, Suiming; Henderson, Gail E; Wang, Xin; Yao, Xingliang; Parish, William L

    2014-02-01

    Sexual behaviors in China are rapidly changing; simultaneously, sexually transmitted infections (STI)/HIV prevalence is increasing in the general population. To investigate these major shifts, we examined sexual behaviors and self-reported STI in one prefectural city in southern China, Liuzhou, and compared it to other prefectural cities throughout China. We used adults age 18-39 from two sets of population-based surveys that paralleled each other in both content and method. The first set was the Liuzhou survey conducted in 2008 (n = 398). The second set consisted of two national surveys collected in 2006 and 2010 (n = 2,186). Liuzhou respondents reported more active social and sexual behaviors than their national counterparts, including more socializing, dancing, drinking excessively, sexual activity among never married men and women, purchasing commercial sex among men, one-night stands among men, multiple sexual partnerships and self-reported STI among both men and women. Women in Liuzhou reported greater sexual risk behavior than their national counterparts, although overall they reported less than their male counterparts; they were also more likely to have had an abortion than women in other prefectural cities. Our findings provide a comprehensive overview of the sexual context of Liuzhou among the general population, which may help explain the greater STI/HIV prevalence in Liuzhou. PMID:24174289

  7. Are depression and poor sexual health neglected comorbidities? Evidence from a population sample

    PubMed Central

    Field, Nigel; Prah, Philip; Mercer, Catherine H; Rait, Greta; King, Michael; Cassell, Jackie A; Heath, Laura; Mitchell, Kirstin R; Clifton, Soazig; Datta, Jessica; Wellings, Kaye; Johnson, Anne M; Sonnenberg, Pam

    2016-01-01

    Objective To examine associations between sexual behaviour, sexual function and sexual health service use of individuals with depression in the British general population, to inform primary care and specialist services. Setting British general population. Participants 15 162 men and women aged 16–74 years were interviewed for the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3), undertaken in 2010–2012. Using age-adjusted ORs (aAOR), relative to a comparator group reporting no treatment or symptoms, we compared the sexual health of those reporting treatment for depression in the past year. Outcome measures Sexual risk behaviour, sexual function, sexual satisfaction and sexual health service use. Results 1331 participants reported treatment for depression (5.2% men; 11.8% women). Relative to the comparator group, treatment for depression was associated with reporting 2 or more sexual partners without condoms (men aAOR 2.07 (95% CI 1.38 to 3.10); women 2.22 (1.68 to 2.92)), and concurrent partnerships (men 1.80 (1.18 to 2.76); women 2.06 (1.48 to 2.88)), in the past year. Those reporting depression treatment were more likely to be dissatisfied with their sex lives (men 2.32 (1.74 to 3.11); women 2.30 (1.89 to 2.79)), and to score in the lowest quintile on the Natsal-sexual function measure. They were also more likely to report a recent chlamydia test (men 1.92 (1.15 to 3.20)); women (1.27 (1.01 to 1.60)), and to have sought help regarding their sex life from a healthcare professional (men 2.92 (1.98 to 4.30); women (2.36 (1.83 to 3.04)), most commonly from a family doctor. Women only were more likely to report attending a sexual health clinic (1.91 (1.42 to 2.58)) and use of emergency contraception (1.98 (1.23 to 3.19)). Associations were broadly similar for individuals with depressive symptoms but not reporting treatment. Conclusions Depression, measured by reported treatment, was strongly associated with sexual risk behaviours, reduced sexual function and increased use of sexual health services, with many people reporting help doing so from a family doctor. The sexual health of depressed people needs consideration in primary care, and mental health assessment might benefit people attending sexual health services. PMID:27009148

  8. Implementation and Evaluation of a Values Clarification Activity for a Large Undergraduate Human Sexuality Course

    ERIC Educational Resources Information Center

    Lederer, Alyssa M.

    2016-01-01

    Values clarification is an important tool that helps individuals to clarify their beliefs about sexuality-related issues. This lesson plan provides instructions for a 1-hour values clarification activity for a large undergraduate human sexuality course that serves as an introduction to course content and tone, stimulates students' initial thinking…

  9. Childhood sexual abuse by representatives of the Roman Catholic Church: a prevalence estimate among the Dutch population.

    PubMed

    Langeland, Willemien; Hoogendoorn, Adriaan W; Mager, Daniel; Smit, Jan H; Draijer, Nel

    2015-08-01

    Estimates of the extent of childhood sexual abuse (CSA) within in the Roman Catholic Church (RCC) in the general population are difficult to find. The independent Commission of Inquiry into sexual abuse of minors in the RCC in the Netherlands collected population-based data to estimate its prevalence. A large random online population sample was surveyed using a two-phase stratified sampling procedure. In Phase 1, 34,267 subjects aged 40 years and older were screened for childhood exposure to sexual abuse by non-family members, a history of institutionalization and a Roman Catholic upbringing. In Phase 2, a stratified subset of 2,462 subjects was assessed to obtain more detailed target information about sexual abuse reports within the RCC. We employed multiple imputation for the estimation of RCC CSA in the original Phase 1 sample. The prevalence of non-familial CSA in general (14.0%) was higher among women (17.2%) than among men (10.6%). The prevalence of CSA within the Dutch RCC (1.7%) was higher among men (2.7%) than among women (0.7%). As expected, older subjects reported more often CSA in the RCC than their younger counterparts. Respondents who stayed for some time in RCC run institutions for education or child protection had a higher risk to report sexual abuse. Although sexual abuse of minors by representatives of the RCC was a structural problem during a period that the Church was highly influential in the Netherlands, the estimated prevalence of the phenomenon is only a fraction of the prevalence rate of non-familial CSA. PMID:26003819

  10. Sexual Behaviors among Adults in Puerto Rico: A Population-Based Study

    PubMed Central

    Ortiz, Ana Patricia; Soto-Salgado, Marievelisse; Suárez, Erick; Santos-Ortiz, María del Carmen; Tortolero-Luna, Guillermo; Pérez, Cynthia M.

    2012-01-01

    Introduction Given changes in sexual behaviors and norms in the United States, there is a need for current and representative data on sexual behaviors with particular interest in gender, age, and racial/ethnic group differences. Aim Given the limited data for Hispanics and for Puerto Rico (PR), we described patterns of sexual behaviors and characteristics among a sexually active sample (n = 1,575) of adults aged 21–64 years in PR. Main Outcome Measures The main outcome measures for this study are sexual behaviors including age at sexual initiation, number of sexual partners, vaginal and anal intercourse, and oral sex, among others. Methods Data from a population-based cross-sectional study in PR (2005–2008) was analyzed. The prevalence of sexual behaviors and characteristics was described by age-group and gender during the lifetime and in the past 12 months. Results Overall, 96.8%, 81.6%, and 60.9% of participants had ever engaged in vaginal, oral and anal sex, respectively, whereas 23.7% were seropositive to any of the sexually transmitted infections under study. Sexual initiation ≤15 years was reported by 37.8% of men and 21.4% of women; whereas 47.9% of men and 13.2% of women reported to have had ≥7 sexual partners in their lifetime. Approximately, 3% of women and 6% of men reported same-sex sexual practices, while history of forced sexual relations was reported by 9.6% of women and 2.5% of men. Sexual initiation ≤15 years was more common among individuals aged 21–34 years (41.4% men and 33.6% women) as compared with older cohorts. Although having had ≥7 sexual partners over a lifetime among men was similar across age groups, this behavior decreased in older women cohorts. In both genders, the prevalence of oral and anal sex was also lower in the older age cohorts. Conclusion This study provides essential information than can help health professionals understand the sexual practices and needs of the population of PR. PMID:21676177

  11. How many founders, how large a population?

    PubMed

    Willis, Kevin; Willis, Raymond E

    2010-01-01

    The number of population founders and the size of the population are two important variables in determining how much gene diversity can be retained in a population. A model is developed to determine the most cost-effective balance of those two variables, based on comparing the marginal costs of increasing the number of founders vs. increasing the population size. Marginal costs, in this case, are the costs of increasing the number of founders or the population size by one animal. For a goal of retaining 90% gene diversity for 10-15 generations (approximately 100 years), the current recommendation of 20 effective founders is very close to the least-cost solution when the ratio of the marginal costs is equal to one. However, when the ratio is greater or less than one that number can change considerably. PMID:20127659

  12. Germline Selection: Population Genetic Aspects of the Sexual/Asexual Life Cycle

    PubMed Central

    Hastings, I. M.

    1991-01-01

    Population geneticists make a distinction between sexual and asexual organisms depending on whether individuals inherit genes from one or two parents. When individual genes are considered, this distinction becomes less satisfactory for multicellular sexual organisms. Individual genes pass through numerous asexual mitotic cell divisions in the germline prior to meiosis and sexual recombination. The processes of mitotic mutation, mitotic crossing over, and mitotic gene conversion create genotypic diversity between diploid cells in the germline. Genes expressed in the germline whose products affect cell viability (such as many ``housekeeping'' enzymes) may be subjected to natural selection acting on this variability resulting in a non-Mendelian output of gametes. Such genes will be governed by the population genetics of the sexual/asexual life cycle rather than the conventional sexual/Mendelian life cycle. A model is developed to investigate some properties of the sexual/asexual life cycle. When appropriate parameter values were included in the model, it was found that mutation rates per locus per gamete may vary by a factor of up to 100 if selection acts in the germline. Sexual/asexual populations appear able to evolve to a genotype of higher fitness despite intervening genotypes of lower fitness, reducing the problems of underdominance and Wright's adaptive landscape encountered by purely sexual populations. As might be expected this ability is chiefly determined by the number of asexual mitotic cell divisions within the germline. The evolutionary consequences of ``housekeeping'' loci being governed by the dynamics of the sexual/asexual life cycle are considered. PMID:1783297

  13. Sexual Dimorphism and Population Differences in Structural Properties of Barn Swallow (Hirundo rustica) Wing and Tail Feathers

    PubMed Central

    Pap, Péter L.; Osváth, Gergely; Aparicio, José Miguel; Bărbos, Lőrinc; Matyjasiak, Piotr; Rubolini, Diego; Saino, Nicola; Vágási, Csongor I.; Vincze, Orsolya; Møller, Anders Pape

    2015-01-01

    Sexual selection and aerodynamic forces affecting structural properties of the flight feathers of birds are poorly understood. Here, we compared the structural features of the innermost primary wing feather (P1) and the sexually dimorphic outermost (Ta6) and monomorphic second outermost (Ta5) tail feathers of barn swallows (Hirundo rustica) from a Romanian population to investigate how sexual selection and resistance to aerodynamic forces affect structural differences among these feathers. Furthermore, we compared structural properties of Ta6 of barn swallows from six European populations. Finally, we determined the relationship between feather growth bars width (GBW) and the structural properties of tail feathers. The structure of P1 indicates strong resistance against aerodynamic forces, while the narrow rachis, low vane density and low bending stiffness of tail feathers suggest reduced resistance against airflow. The highly elongated Ta6 is characterized by structural modifications such as large rachis width and increased barbule density in relation to the less elongated Ta5, which can be explained by increased length and/or high aerodynamic forces acting at the leading tail edge. However, these changes in Ta6 structure do not allow for full compensation of elongation, as reflected by the reduced bending stiffness of Ta6. Ta6 elongation in males resulted in feathers with reduced resistance, as shown by the low barb density and reduced bending stiffness compared to females. The inconsistency in sexual dimorphism and in change in quality traits of Ta6 among six European populations shows that multiple factors may contribute to shaping population differences. In general, the difference in quality traits between tail feathers cannot be explained by the GBW of feathers. Our results show that the material and structural properties of wing and tail feathers of barn swallows change as a result of aerodynamic forces and sexual selection, although the result of these changes can be contrasting. PMID:26110255

  14. Importance of Health and Social Care Research into Gender and Sexual Minority Populations in Nepal.

    PubMed

    Regmi, Pramod R; van Teijlingen, Edwin

    2015-11-01

    Despite progressive legislative developments and increased visibility of sexual and gender minority populations in the general population, mass media often report that this population face a wide range of discrimination and inequalities. LGBT (lesbian, gay, and bisexual, and transgender) populations have not been considered as priority research populations in Nepal. Research in other geographical settings has shown an increased risk of poor mental health, violence, and suicide and higher rates of smoking, as well as alcohol and drugs use among LGBT populations. They are also risk for lifestyle-related illness such as cancer, diabetes, and heart diseases. Currently, in Nepal, there is a lack of understanding of health and well-being, social exclusion, stigma, and discrimination as experienced by these populations. Good-quality public health research can help design and implement targeted interventions to the sexual and gender minority populations of Nepal. PMID:26543163

  15. Morphometric modelling of ageing in the human pubic symphysis: sexual dimorphism in an Australian population.

    PubMed

    Lottering, Nicolene; Reynolds, Mikaela S; MacGregor, Donna M; Meredith, Matthew; Gregory, Laura S

    2014-03-01

    Despite the prominent use of the pubic symphysis for age estimation in forensic anthropology, little has been documented regarding the quantitative morphological and micro-architectural changes of this surface. Specifically, utilising post-mortem computed tomography data from a large, contemporary Australian adult population, this study aimed to evaluate sexual dimorphism in the morphology and bone composition of the symphyseal surface; and temporal characterisation of the pubic symphysis in individuals of advancing age. The sample consisted of multi-slice computed tomography (MSCT) scans of the pubic symphysis (slice thickness: 0.5mm, overlap: 0.1mm) of 200 individuals of Caucasian ancestry aged 15-70 years, obtained in 2011. Surface rendering reconstruction of the symphyseal surface was conducted in OsiriX(®) (v.4.1) and quantitative analyses in Rapidform XOS™ and Osteomeasure™. Morphometric variables including inter-pubic distance, surface area, circumference, maximum height and width of the symphyseal surface and micro-architectural assessment of cortical and trabecular bone compositions were quantified using novel automated engineering software capabilities. The major results of this study are correlated with the macroscopic ossification and degeneration pattern of the symphyseal surface, demonstrating significant age-related changes in the morphometric and bone tissue variables between 15 and 70 years. Regardless of sex, the overall dimensions of the symphyseal surface increased with age, coupled with a decrease in bone mass in the trabecular and cortical bone compartments. Significant differences between the ventral, dorsal and medial cortical surfaces were observed, which may be correlated to bone formation activity dependent on muscle activity and ligamentous attachments. Our study demonstrates significant sexual dimorphism at this site, with males exhibiting greater surface dimensions than females. These baseline results provide a detailed insight into the changes in the structure of the pubic symphysis with ageing and sexually dimorphic features associated with the cortical and trabecular bone profiles. PMID:24468016

  16. Poppr: an R package for genetic analysis of populations with mixed (clonal/sexual) reproduction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poppr is an R package for analysis of population genetic data. It extends the adegenet package and provides several novel tools, particularly with regard to analysis of data from admixed, clonal, and/or sexual populations. Currently, poppr can be used for dominant/codominant and haploid/diploid gene...

  17. Characteristics of Victims of Sexual Abuse by Gender and Race in a Community Corrections Population

    ERIC Educational Resources Information Center

    Clark, C. Brendan; Perkins, Adam; McCullumsmith, Cheryl B.; Islam, M. Aminul; Hanover, Erin E.; Cropsey, Karen L.

    2012-01-01

    The purpose of this study was to examine how victims of sexual abuse in a community corrections population differ as a result of their sex and race. Of the 19,422 participants, a total of 1,298 (6.7%) reported a history of sexual abuse and were compared with nonabused participants. The sample was analyzed by race-gender groups (White men, White

  18. Characteristics of Victims of Sexual Abuse by Gender and Race in a Community Corrections Population

    ERIC Educational Resources Information Center

    Clark, C. Brendan; Perkins, Adam; McCullumsmith, Cheryl B.; Islam, M. Aminul; Hanover, Erin E.; Cropsey, Karen L.

    2012-01-01

    The purpose of this study was to examine how victims of sexual abuse in a community corrections population differ as a result of their sex and race. Of the 19,422 participants, a total of 1,298 (6.7%) reported a history of sexual abuse and were compared with nonabused participants. The sample was analyzed by race-gender groups (White men, White…

  19. [Allozyme variation in sexual and apomictic Taraxacum and Pilosella (Asteraceae) populations].

    PubMed

    Kashin, A S; Anfalov, V E; Demochko, Iu A

    2005-02-01

    Allozyme spectra of peroxidase, esterase, superoxid dismutase, tyrosinase, alcohol dehydrogenase, lactate dehydrogenase, and acid phosphatase were examined in populations of sexual (Taraxacum serotinum and Pilosella echioides) and apomictic (T. officinalis and P. officinarum) plant species. The heterozygosity in these populations (0.455-0.620) proved to be considerably higher than the average level characteristic of plant populations (0.058-0.185). The populations examined did not differ in the mean phenotype number mu, i.e., they exhibited the same diversity (3.213-3.380). The proportion of rare phenotypes h also did not differ between the sexual and apomictic species of the same genus, whereas this parameter in the Pilosella populations (0.150-0.174) was significantly higher than in the Taraxacum ones (0.093-0.114). The populations were characterized by numerous isozyme spectra (more than 11 per populations) and displayed multiple allelism (the mean allele frequency was 3.63-4.38 per locus). They exhibited a high percentage of rare (occurring at a frequency lower than 5%) spectra (35-80%). This indicates that agamic complexes, to which these populations belong, may have a more complicated genetic structure of both apomictic and sexual populations than the species that do not belong to agamic complexes. PMID:15810610

  20. High rates of sexual behavior in the general population: correlates and predictors.

    PubMed

    Långström, Niklas; Hanson, R Karl

    2006-02-01

    We studied 2450, 18-60-year-old men and women from a 1996 national survey of sexuality and health in Sweden to identify risk factors and correlates of elevated rates of sexual behavior (hypersexuality) in a representative, non-clinical population. Interviews and questionnaires measured various sexual behaviors, developmental risk factors, behavioral problems, and health indicators. The results suggested that correlates of high rates of intercourse were mostly positive, whereas the correlates of high rates of masturbation and impersonal sex were typically undesirable. For both men and women, high rates of impersonal sex were related to separation from parents during childhood, relationship instability, sexually transmitted disease, tobacco smoking, substance abuse, and dissatisfaction with life in general. The association between hypersexuality and paraphilic sexual interests (exhibitionism, voyeurism, masochism/sadism) was particularly and equally strong for both genders (odds ratios of 4.6-25.6). The results held, with a few exceptions, when controlling for age, being in a stable relationship, living in a major city, and same-sex sexual orientation. We conclude that elevated rates of impersonal sex are associated with a range of negative health indicators in the general population. PMID:16502152

  1. Sexual Reproduction in Aspergillus flavus Sclerotia: Acquisition of Novel Alleles from Soil Populations and Uniparental Mitochondrial Inheritance.

    PubMed

    Horn, Bruce W; Gell, Richard M; Singh, Rakhi; Sorensen, Ronald B; Carbone, Ignazio

    2016-01-01

    Aspergillus flavus colonizes agricultural commodities worldwide and contaminates them with carcinogenic aflatoxins. The high genetic diversity of A. flavus populations is largely due to sexual reproduction characterized by the formation of ascospore-bearing ascocarps embedded within sclerotia. A. flavus is heterothallic and laboratory crosses between strains of the opposite mating type produce progeny showing genetic recombination. Sclerotia formed in crops are dispersed onto the soil surface at harvest and are predominantly produced by single strains of one mating type. Less commonly, sclerotia may be fertilized during co-infection of crops with sexually compatible strains. In this study, laboratory and field experiments were performed to examine sexual reproduction in single-strain and fertilized sclerotia following exposure of sclerotia to natural fungal populations in soil. Female and male roles and mitochondrial inheritance in A. flavus were also examined through reciprocal crosses between sclerotia and conidia. Single-strain sclerotia produced ascospores on soil and progeny showed biparental inheritance that included novel alleles originating from fertilization by native soil strains. Sclerotia fertilized in the laboratory and applied to soil before ascocarp formation also produced ascospores with evidence of recombination in progeny, but only known parental alleles were detected. In reciprocal crosses, sclerotia and conidia from both strains functioned as female and male, respectively, indicating A. flavus is hermaphroditic, although the degree of fertility depended upon the parental sources of sclerotia and conidia. All progeny showed maternal inheritance of mitochondria from the sclerotia. Compared to A. flavus populations in crops, soil populations would provide a higher likelihood of exposure of sclerotia to sexually compatible strains and a more diverse source of genetic material for outcrossing. PMID:26731416

  2. Sexual Reproduction in Aspergillus flavus Sclerotia: Acquisition of Novel Alleles from Soil Populations and Uniparental Mitochondrial Inheritance

    PubMed Central

    Horn, Bruce W.; Gell, Richard M.; Singh, Rakhi; Sorensen, Ronald B.; Carbone, Ignazio

    2016-01-01

    Aspergillus flavus colonizes agricultural commodities worldwide and contaminates them with carcinogenic aflatoxins. The high genetic diversity of A. flavus populations is largely due to sexual reproduction characterized by the formation of ascospore-bearing ascocarps embedded within sclerotia. A. flavus is heterothallic and laboratory crosses between strains of the opposite mating type produce progeny showing genetic recombination. Sclerotia formed in crops are dispersed onto the soil surface at harvest and are predominantly produced by single strains of one mating type. Less commonly, sclerotia may be fertilized during co-infection of crops with sexually compatible strains. In this study, laboratory and field experiments were performed to examine sexual reproduction in single-strain and fertilized sclerotia following exposure of sclerotia to natural fungal populations in soil. Female and male roles and mitochondrial inheritance in A. flavus were also examined through reciprocal crosses between sclerotia and conidia. Single-strain sclerotia produced ascospores on soil and progeny showed biparental inheritance that included novel alleles originating from fertilization by native soil strains. Sclerotia fertilized in the laboratory and applied to soil before ascocarp formation also produced ascospores with evidence of recombination in progeny, but only known parental alleles were detected. In reciprocal crosses, sclerotia and conidia from both strains functioned as female and male, respectively, indicating A. flavus is hermaphroditic, although the degree of fertility depended upon the parental sources of sclerotia and conidia. All progeny showed maternal inheritance of mitochondria from the sclerotia. Compared to A. flavus populations in crops, soil populations would provide a higher likelihood of exposure of sclerotia to sexually compatible strains and a more diverse source of genetic material for outcrossing. PMID:26731416

  3. Population structure influences sexual conflict in wild populations of water striders.

    PubMed

    Eldakar, Omar Tonsi; Dlugos, Michael J; Holt, Galen P; Wilson, David Sloan; Pepper, Johnw

    2010-08-01

    In sexual conflict, aggressive males frequently diminish the long-term reproductive success of females in efforts to gain a short-term advantage over rival males. This short-term advantage can selectively favour high-exploitation males. However, just as the over-exploitation of resources can lead to local extinction, the over-exploitation of females in the form of harassment by aggressive males can yield similar consequences resulting in reduced female fecundity, increased female mortality and overall decline in mating activity. This outcome may often be prevented by selection acting at multiple levels of biological organization. Directional selection favouring aggressive exploitation within groups can be balanced by directional selection amongst groups opposing exploitation. Such between-group selection has recently been demonstrated in laboratory studies of water striders, where the conditional dispersal of individuals increased variation amongst groups and influenced the balance of selection toward reduced male aggression. This multilevel selection (MLS) framework also provides predictive value when investigating natural populations differing in their relative strength of selection within versus among groups. For water striders, the consequences of local exploitation cause fitness differences between groups, favouring less aggressive males. Inconsistently flowing ephemeral streams consist of isolated pools that prevent aggressive male water striders from escaping the consequences of local exploitation. We, therefore, predicted that inconsistently flowing ephemeral streams would favour the evolution of less aggressive males than would perennial streams, which allow aggressive males to move more freely and to escape the group-level costs of their aggression. Comparing two neighbouring streams during the mating season, we found that males dispersed naturally between pools at much higher rates in the perennial stream than in the ephemeral stream. As predicted, we found that males from the perennial stream were significantly more aggressive than those from the ephemeral stream. We also found that dispersers were significantly more aggressive than non-dispersers within each stream. These field results illustrate the relevance of the MLS framework in our understanding of the evolution of sexual conflict. PMID:24049189

  4. Large-Scale Age-Dependent Skewed Sex Ratio in a Sexually Dimorphic Avian Scavenger

    PubMed Central

    Lambertucci, Sergio A.; Carrete, Martina; Donázar, José Antonio; Hiraldo, Fernando

    2012-01-01

    Age-dependent skewed sex ratios have been observed in bird populations, with adult males generally outnumbering females. This trend is mainly driven by higher female mortality, sometimes associated with anthropogenic factors. Despite the large amount of work on bird sex ratios, research examining the spatial stability of adult sex ratios is extremely scarce. The Andean condor (Vultur gryphus) is the only bird of prey with strong sexual dimorphism favouring males (males are 30% heavier than females). By examining data from most of its South-American range, we show that while the juvenile sex ratio is balanced, or even female-skewed, the sex ratio becomes increasing male-skewed with age, with adult males outnumbering females by >20%, and, in some cases by four times more. This result is consistent across regions and independent of the nature of field data. Reasons for this are unknown but it can be hypothesized that the progressive disappearance of females may be associated with mortality caused by anthropogenic factors. This idea is supported by the asymmetric habitat use by the two sexes, with females scavenging in more humanized areas. Whatever the cause, male-skewed adult sex ratios imply that populations of this endangered scavenger face higher risks of extinction than previously believed. PMID:23029488

  5. Large-scale age-dependent skewed sex ratio in a sexually dimorphic avian scavenger.

    PubMed

    Lambertucci, Sergio A; Carrete, Martina; Donázar, José Antonio; Hiraldo, Fernando

    2012-01-01

    Age-dependent skewed sex ratios have been observed in bird populations, with adult males generally outnumbering females. This trend is mainly driven by higher female mortality, sometimes associated with anthropogenic factors. Despite the large amount of work on bird sex ratios, research examining the spatial stability of adult sex ratios is extremely scarce. The Andean condor (Vultur gryphus) is the only bird of prey with strong sexual dimorphism favouring males (males are 30% heavier than females). By examining data from most of its South-American range, we show that while the juvenile sex ratio is balanced, or even female-skewed, the sex ratio becomes increasing male-skewed with age, with adult males outnumbering females by >20%, and, in some cases by four times more. This result is consistent across regions and independent of the nature of field data. Reasons for this are unknown but it can be hypothesized that the progressive disappearance of females may be associated with mortality caused by anthropogenic factors. This idea is supported by the asymmetric habitat use by the two sexes, with females scavenging in more humanized areas. Whatever the cause, male-skewed adult sex ratios imply that populations of this endangered scavenger face higher risks of extinction than previously believed. PMID:23029488

  6. Age of Sexual Consent Law in Canada: Population-Based Evidence for Law and Policy

    PubMed Central

    Miller, Bonnie B.; Cox, David N.; Saewyc, Elizabeth M.

    2015-01-01

    This study evaluated the implications of the 2008 increase in age for sexual consent in Canada using a population health survey of Canadian adolescents. Government rationales for the increase asserted younger adolescents were more likely to experience sexual exploitation and engage in risky sexual behaviour than adolescents 16 and older. Using data from sexually experienced adolescents in the 2008 British Columbia Adolescent Health Survey (BC AHS, N=6,262; age range 12 – 19; 52% female), analyses documented the scope of first intercourse partners who were not within the ‘close in age’ exemptions, then compared sexual behaviours of younger teens (14 and 15 years) with older teens (16 and 17) navigating their first year of sexual activity. Comparisons included: forced sex, sex under the influence of alcohol or drugs, multiple partners, condom use, effective contraception use, self-reported sexually transmitted infections, and pregnancy involvement. Results showed very few 14- and 15-year-olds had first intercourse partners who were not within the ‘close in age’ exemptions based on age (boys: <2%, girls: 3–5%). In contrast, among 12- and 13-year-olds (a group unaffected by the law’s change) between 25% and 50% had first intercourse partners who were not within the ‘close in age’ exemptions, and almost 40% of teens who first had sex before age 12 reported a first partner age 20 years or more. In their first year of intercourse, 14- and 15-year-olds were slightly more likely to report forced sex and 3 or more partners than older teens, but otherwise made similarly healthy decisions. This study demonstrates the feasibility of evaluating policy using population health data and shows that better strategies are needed to protect children 13 and under from sexual abuse. PMID:27087775

  7. Population, sexual and reproductive health, rights and sustainable development: forging a common agenda.

    PubMed

    Newman, Karen; Fisher, Sarah; Mayhew, Susannah; Stephenson, Judith

    2014-05-01

    This article suggests that sexual and reproductive health and rights activists seeking to influence the post-2015 international development paradigm must work with sustainable development advocates concerned with a range of issues, including climate change, environmental issues, and food and water security, and that a way of building bridges with these communities is to demonstrate how sexual and reproductive health and rights are relevant for these issues. An understanding of population dynamics, including urbanization and migration, as well as population growth, can help to clarify these links. This article therefore suggests that whether or not sexual and reproductive health and rights activists can overcome resistance to discussing "population", become more knowledgeable about other sustainable development issues, and work with others in those fields to advance the global sustainable development agenda are crucial questions for the coming months. The article also contends that it is possible to care about population dynamics (including ageing and problems faced by countries with a high proportion of young people) and care about human rights at the same time. It expresses concern that, if sexual and reproductive health and rights advocates do not participate in the population dynamics discourse, the field will be left free for those for whom respecting and protecting rights may be less of a priority. PMID:24908456

  8. Threatened peripheral populations in context: geographical variation in population frequency and size and sexual reproduction in a clonal woody shrub.

    PubMed

    Yakimowski, Sarah B; Eckert, Christopher G

    2007-06-01

    Geographically peripheral populations of widespread species are often the focus of conservation because they are locally rare within political jurisdictions. Yet the ecology and genetics of these populations are rarely evaluated in a broader geographic context. Most expectations concerning the ecology and evolution of peripheral populations derive from the abundant-center model, which predicts that peripheral populations should be less frequent, smaller, less dense, and have a lower reproductive rate than central populations. We tested these predictions and in doing so evaluated the conservation value of peripheral populations for the clonal shrub Vaccinium stamineum L. (Ericaceae, deerberry), which is listed as threatened in Canada. Based on 51 populations sampled from the center to the northern range limits over 2 years, population frequency and size declined toward the range limit, but ramet density increased. Sexual reproductive output varied widely among populations and between years, with many populations producing very few seeds, but did not decline toward range margins. In fact seed mass increased steadily toward range limit, and this was associated with faster germination and seedling growth, which may be adaptive in seasonal northern environments. Our results did not support the prediction that clonal reproduction is more prevalent in peripheral populations or that it contributed antagonistically to the wide variation in seed production. Peripheral populations of V. stamineum are as productive as central populations and may be locally adapted to northern environments. This emphasizes the importance of a broad geographical perspective for evaluating the ecology, evolution, and conservation of peripheral populations. PMID:17531058

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

    ERIC Educational Resources Information Center

    Heller, Janet R.; Johnson, Helen L.

    2013-01-01

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

  10. The Exclusion of Intimacy in the Sexuality of the Contemporary College-Age Population.

    ERIC Educational Resources Information Center

    Cobliner, W. Godfrey

    1988-01-01

    Asserts that heterosexual sexual involvement in the contemporary college population is often sporadic, episodic, without commitment, and accompanied by deliberate effort of both partners to suppress tender, romantic feelings and intimacy. Suggests the sources of this situation lie in changes in the ethos, the ascent of women, advances in…

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

    ERIC Educational Resources Information Center

    Heller, Janet R.; Johnson, Helen L.

    2013-01-01

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

  12. Diet selection and seasonal dietary switch of a large sexually dimorphic herbivore

    NASA Astrophysics Data System (ADS)

    Shannon, Graeme; Mackey, Robin L.; Slotow, Rob

    2013-01-01

    Although diet selection and the physiological adaptations of grazers and browsers have been widely studied, much less is known about mixed-feeders that target both grass and woody species. The ability to switch diet allows the individual to respond to spatial and temporal changes in forage abundance and quality, providing a key mechanism for large herbivores to exploit heterogeneous environments. We compare diet selection and timing of the seasonal dietary switch for a large-bodied, sexually dimorphic mixed-feeder, the African elephant. The study was carried out on a small population of elephants (n = 48) in the Pongola Game Reserve (PGR), South Africa. Sex-specific dietary composition evaluated from feeding behaviour correlated with composition in dung samples from individuals of known sex. Grass was strongly preferred during the wet season and browse in the winter dry season. However, adult male elephants switched from browse to grass earlier, and consumed a greater overall proportion of grass in their diet, compared with adult females and their associated family groups. Male elephants also spent more time in grassland habitats, and expanded their ranges to a greater extent than females following the end of the dry season. Our results suggest that smaller adult body size, high nutritional demands of offspring, and the constraints of sociality have contributed to female elephants in PGR resolving their diet selection strategies to target higher quality foraging opportunities, whilst males appear to be adopting a rate maximizing approach. The behavioural differences between the sexes are pronounced, which has implications for elephant management approaches that are typically focussed at the population level.

  13. Neural activity in catecholaminergic populations following sexual and aggressive interactions in the brown anole, Anolis sagrei.

    PubMed

    Kabelik, David; Alix, Veronica C; Singh, Leah J; Johnson, Alyssa L; Choudhury, Shelley C; Elbaum, Caroline C; Scott, Madeline R

    2014-03-17

    Social behaviors in vertebrates are modulated by catecholamine (CA; dopamine, norepinephrine, epinephrine) release within the social behavior neural network. Few studies have examined activity across CA populations in relation to social behaviors. The involvement of CAs in social behavior regulation is especially underexplored in reptiles, relative to other amniotes. In this study, we mapped CA populations throughout the brain (excluding retina and olfactory bulb) of the male brown anole lizard, Anolis sagrei, via immunofluorescent visualization of the rate-limiting enzyme for CA synthesis, tyrosine hydroxylase (TH). Colocalization of TH with the immediate early gene product Fos, an indirect marker of neural activity, also enabled us to relate activity in TH-immunoreactive (TH-ir) neurons to appetitive and consummatory sexual and aggressive behaviors. We detected most major TH-ir cell populations that are present in other amniotes (within the hypothalamus, midbrain, and hindbrain), although the A15 population was entirely absent. We also detected a few novel or rare cell clusters within the amygdala, medial septum, and inferior raphe. Many CA populations, especially dopaminergic groups, showed increased TH-Fos colocalization in association with appetitive and consummatory sexual behavior expression, while a small number of regions showed increased colocalization in relation to solely consummatory aggression (biting of an opponent). In conclusion, we here map CA populations throughout the brown anole brain and demonstrate evidence for catecholaminergic involvement in appetitive and consummatory sexual behaviors and consummatory aggressive behaviors in this species. PMID:24472578

  14. Religiosity and risky sexual behaviors among an African American church-based population.

    PubMed

    Hawes, Starlyn M; Berkley-Patton, Jannette Y

    2014-04-01

    African Americans are disproportionately burdened by STDs and HIV in the US. This study examined the relationships between demographics, religiosity, and sexual risk behaviors among 255 adult African American church-based participants. Although participants were highly religious, they reported an average of seven lifetime sex partners and most inconsistently used condoms. Several demographic variables and religiosity significantly predicted lifetime HIV-related risk factors. Taken together, findings indicated that this population is at risk for HIV. Future research should continue to identify correlates of risky sexual behavior among African American parishioners to facilitate the development of HIV risk reduction interventions in their church settings. PMID:23054481

  15. Do American States with more religious or conservative populations search more for sexual content on google?

    PubMed

    MacInnis, Cara C; Hodson, Gordon

    2015-01-01

    In America, religiosity and conservatism are generally associated with opposition to non-traditional sexual behavior, but prominent political scandals and recent research suggest a paradoxical private attraction to sexual content on the political and religious right. We examined associations between state-level religiosity/conservatism and anonymized interest in searching for sexual content online using Google Trends (which calculates within-state search volumes for search terms). Across two separate years, and controlling for demographic variables, we observed moderate-to-large positive associations between: (1) greater proportions of state-level religiosity and general web searching for sexual content and (2) greater proportions of state-level conservatism and image-specific searching for sex. These findings were interpreted in terms of the paradoxical hypothesis that a greater preponderance of right-leaning ideologies is associated with greater preoccupation with sexual content in private internet activity. Alternative explanations (e.g., that opposition to non-traditional sex in right-leaning states leads liberals to rely on private internet sexual activity) are discussed, as are limitations to inference posed by aggregate data more generally. PMID:25277691

  16. Evolution of Population with Sexual and Asexual Reproduction in Changing Environment

    NASA Astrophysics Data System (ADS)

    He, Mingfeng; Yu, Changliang; Ruan, Hongbo; Yao, Lei

    Using a lattice model based on Monte Carlo simulations, we study the role of the reproduction pattern on the fate of an evolving population. Each individual is under the selection pressure from the environment and random mutations. The habitat ("climate") is changing periodically. Evolutions of populations following two reproduction patterns are compared, asexual and sexual. We show, via Monte Carlo simulations, that sexual reproduction by keeping more diversified populations gives them better chances to adapt themselves to the changing environment. However, in order to obtain a greater chance to mate, the birth rate should be high. In the case of low birth rate and high mutation probability there is a preference for the asexual reproduction.

  17. Genetic structure of populations of Alternaria brassicicola suggests the occurrence of sexual recombination.

    PubMed

    Bock, Clive H; Thrall, Peter H; Burdon, Jeremy J

    2005-02-01

    Substantial polymorphism was detected between isolates from five populations of Alternaria brassicicola attacking Cakile maritima along the New South Wales coast of Australia, with a maximum of two genotypes being shared between population pairs. Of ten pair-wise population comparisons, six had no pathogen genotypes in common; only one genotype occurred five times, and most (93 %) were found only once. Although an UPGMA based on Nei's measure of genetic distance separated the five populations, a cluster analysis using individual isolates failed to group them according to population, indicating significant gene flow. An analysis of molecular variance indicated ca 14% of the variation occurred between populations, representing moderate population differentiation over the spatial scale of the study. Tests of the relative contribution of clonality and sexual recombination indicated low, albeit significant levels of linkage disequilibrium in all populations. The level of linkage disequilibrium, and the high genotype diversity, provides support for the contention that a hitherto unidentified sexual stage might be a significant factor in the life-cycle of A. brassicicola. PMID:15839106

  18. Sexual violence, mood disorders and suicide risk: a population-based study.

    PubMed

    Mondin, Thase Campos; Cardoso, Taiane de Azevedo; Jansen, Karen; Konradt, Caroline Elizabeth; Zaltron, Rosana Ferrazza; Behenck, Monalisa de Oliveira; Mattos, Luciano Dias de; Silva, Ricardo Azevedo da

    2016-03-01

    This article seeks to analyze the association between sexual violence, manic and depressive episodes, and suicide risk among young adults. This is a cross-sectional population-based study carried out with young people between 18 and 24 years of age in a town in southern Brazil. The sample was selected through clusters. The prevalence of sexual violence, manic, depressive and mixed episodes and suicide risk were evaluated, as well as the association between them. The chi-square test and Poisson regression were used for statistical analysis. The study sample comprised 1,560 subjects. Among these, 3.1% had suffered sexual violence at some point in their life. The prevalence of depressive, mixed episodes, and (hypo)manic episodes were 10%, 2.4% and 2.3%, respectively. Suicide risk had a prevalence of 8.6% in the total sample. Young people who have suffered sexual violence are more likely to be subject to mood changes or suicide risk than those who have not (p < 0.05), except for the occurrence of (hypo)manic episodes. These results revealed a strong association between sexual violence and depressive and mixed episodes and suicide risk. PMID:26960097

  19. The Group-Level Consequences of Sexual Conflict in Multigroup Populations

    PubMed Central

    Eldakar, Omar Tonsi; Gallup, Andrew C.

    2011-01-01

    In typical sexual conflict scenarios, males best equipped to exploit females are favored locally over more prudent males, despite reducing female fitness. However, local advantage is not the only relevant form of selection. In multigroup populations, groups with less sexual conflict will contribute more offspring to the next generation than higher conflict groups, countering the local advantage of harmful males. Here, we varied male aggression within-and between-groups in a laboratory population of water striders and measured resulting differences in local population growth over a period of three weeks. The overall pool fitness (i.e., adults produced) of less aggressive pools exceeded that of high aggression pools by a factor of three, with the high aggression pools essentially experiencing no population growth over the course of the study. When comparing the fitness of individuals across groups, aggression appeared to be under stabilizing selection in the multigroup population. The use of contextual analysis revealed that overall stabilizing selection was a product of selection favoring aggression within groups, but selected against it at the group-level. Therefore, this report provides further evidence to show that what evolves in the total population is not merely an extension of within-group dynamics. PMID:22039491

  20. Reconstructing a Large-Scale Population for Social Simulation

    NASA Astrophysics Data System (ADS)

    Fan, Zongchen; Meng, Rongqing; Ge, Yuanzheng; Qiu, Xiaogang

    The advent of social simulation has provided an opportunity to research on social systems. More and more researchers tend to describe the components of social systems in a more detailed level. Any simulation needs the support of population data to initialize and implement the simulation systems. However, it's impossible to get the data which provide full information about individuals and households. We propose a two-step method to reconstruct a large-scale population for a Chinese city according to Chinese culture. Firstly, a baseline population is generated through gathering individuals into households one by one; secondly, social relationships such as friendship are assigned to the baseline population. Through a case study, a population of 3,112,559 individuals gathered in 1,133,835 households is reconstructed for Urumqi city, and the results show that the generated data can respect the real data quite well. The generated data can be applied to support modeling of some social phenomenon.

  1. Large-scale spatial population databases in infectious disease research

    PubMed Central

    2012-01-01

    Modelling studies on the spatial distribution and spread of infectious diseases are becoming increasingly detailed and sophisticated, with global risk mapping and epidemic modelling studies now popular. Yet, in deriving populations at risk of disease estimates, these spatial models must rely on existing global and regional datasets on population distribution, which are often based on outdated and coarse resolution data. Moreover, a variety of different methods have been used to model population distribution at large spatial scales. In this review we describe the main global gridded population datasets that are freely available for health researchers and compare their construction methods, and highlight the uncertainties inherent in these population datasets. We review their application in past studies on disease risk and dynamics, and discuss how the choice of dataset can affect results. Moreover, we highlight how the lack of contemporary, detailed and reliable data on human population distribution in low income countries is proving a barrier to obtaining accurate large-scale estimates of population at risk and constructing reliable models of disease spread, and suggest research directions required to further reduce these barriers. PMID:22433126

  2. Sexual assault while too intoxicated to resist: a general population study of Norwegian teenage girls

    PubMed Central

    2014-01-01

    Background Underage drinking is widespread, but studies on alcohol-related sexual victimization among teenage girls are almost non-existent. Research on individual correlates and risk factors of sexual victimization more generally is also meager. This study focuses on sexual assault while incapacitated due to drunkenness among 15–18 year-old girls and examines how age, drinking behavior, impulsivity and involvement in norm-violating activities are associated with such victimization experiences. Methods Data stemmed from a school survey (response rate: 85%) in 16 Norwegian municipalities. Almost all analyses were restricted to girls who had been intoxicated in the past year (n = 2701). In addition to bivariate associations, adjusted odds ratios and relative risks of incapacitated sexual assault (ISA) were estimated. Further, population-attributable fractions were calculated to explore how the prevalence of ISA victimization was likely to be affected if effective preventive measures were targeted solely at high-risk groups. Results The majority of the girls (71%) had been intoxicated in the past year, of which 7% had experienced ISA victimization in the same period. The proportion of victims decreased by age within the group that had been intoxicated, reflecting that the youngest girls were more likely to get severely drunk. Impulsivity and involvement in norm-violating behaviors were identified as potential risk factors, but the population-attributable fractions indicated that the groups with the highest risk of ISA victimization accounted for only a minority of all the cases of such victimization. Conclusion Sexual assault against teenage girls who are too drunk to resist seems to be prevalent in Norway – notably among the youngest girls who engage in heavy episodic drinking. This study also suggests that one should reconsider the notion that no individual attributes are related to females’ sexual assault victimization. It also indicates that a high risk approach to prevention, targeting groups with a high level of impulsivity or behavioral problems, may have limited effect on the prevalence of ISA victimization. Thus, from a public health perspective, it may be advisable to give priority to universal preventive measures to curb young girls’ risk of being sexually assaulted in a state of alcohol-induced incapacitation. PMID:24774966

  3. Evolutionary divergence in sexual signals: Insights from within and among barn swallow populations

    NASA Astrophysics Data System (ADS)

    Wilkins, Matthew Reed

    A wealth of studies across diverse animal groups indicate the importance of sexual selection in shaping phenotypes within and across breeding populations. In recent decades, much research has focused on how divergent sexual selection pressures among populations may lead to speciation. For my first dissertation chapter, I performed a literature review on the causes and consequences of evolutionary divergence in acoustic signals and developed the acoustic window conceptual framework for understanding the contributions of selection, genetic drift, and evolutionary constraint to signal divergence. Further, I found that sexual selection explains acoustic differences between recently diverged populations of the best-studied taxa. However, the relative contributions of ecological selection, sexual selection, and drift to acoustic divergence have not typically been considered within the same study systems. The remainder of my dissertation used the Northern Hemisphere-distributed barn swallow ( Hirundo rustica) species complex as a model system to study sender-receiver dynamics, intra- and intersexual selection pressures, and visual and acoustic signal interactions at the local scale, and signal divergence across populations at the global scale. From song recordings taken across 19 sampling sites, spanning five of six described subspecies, I demonstrated considerable conservation in song structure. However, temporal traits were highly divergent across subspecies, and in particular, the speed of the terminal trill of songs. In a detailed study of the multimodal communication system of the barn swallow (including visual and acoustic traits), I demonstrated that males and females use different types of signals to mediate competition and mate choice. One of the only exceptions to this rule was trill rate, which was also implicated in song divergence across populations. In order to test the function of trill rate in communication, I performed a two-year playback study within the North American subspecies, H. r. erythrogaster. Contrary to expectations, males did not have stronger responses to faster trilling (high performance) simulated intruders. Instead, resident males had stronger responses to the high performance stimulus only when the intruder was also darker than the resident. Collectively, my dissertation offers novel insight into the evolutionary dynamics of complex sexual signaling at multiple spatial scales.

  4. Sexual dimorphism of the mandible in a contemporary Chinese Han population.

    PubMed

    Dong, Hongmei; Deng, Mohong; Wang, WenPeng; Zhang, Ji; Mu, Jiao; Zhu, Guanghui

    2015-10-01

    A present limitation of forensic anthropology practice in China is the lack of population-specific criteria on contemporary human skeletons. In this study, a sample of 203 maxillofacial Cone beam computed tomography (CBCT) images, including 96 male and 107 female cases (20-65 years old), was analyzed to explore mandible sexual dimorphism in a population of contemporary adult Han Chinese to investigate the potential use of the mandible as sex indicator. A three-dimensional image from mandible CBCT scans was reconstructed using the SimPlant Pro 11.40 software. Nine linear and two angular parameters were measured. Discriminant function analysis (DFA) and logistic regression analysis (LRA) were used to develop the mathematics models for sex determination. All of the linear measurements studied and one angular measurement were found to be sexually dimorphic, with the maximum mandibular length and bi-condylar breadth being the most dimorphic by univariate DFA and LRA respectively. The cross-validated sex allocation accuracies on multivariate were ranged from 84.2% (direct DFA), 83.5% (direct LRA), 83.3% (stepwise DFA) to 80.5% (stepwise LRA). In general, multivariate DFA yielded a higher accuracy and LRA obtained a lower sex bias, and therefore both DFA and LRA had their own advantages for sex determination by the mandible in this sample. These results suggest that the mandible expresses sexual dimorphism in the contemporary adult Han Chinese population, indicating an excellent sexual discriminatory ability. Cone beam computed tomography scanning can be used as alternative source for contemporary osteometric techniques. PMID:26146162

  5. Natural and sexual selection against immigrants maintains differentiation among micro-allopatric populations.

    PubMed

    Tobler, M; Riesch, R; Tobler, C M; Schulz-Mirbach, T; Plath, M

    2009-11-01

    Local adaptation to divergent environmental conditions can promote population genetic differentiation even in the absence of geographic barriers and hence lead to speciation. But what mechanisms contribute to reproductive isolation among diverging populations? We tested for natural and sexual selection against immigrants in a fish species inhabiting (and adapting to) nonsulphidic surface habitats, sulphidic surface habitats and a sulphidic cave. Gene flow is strong among sample sites situated within the same habitat type, but low among divergent habitat types. Our results indicate that females of both sulphidic populations discriminate against immigrant males during mate choice. Furthermore, using reciprocal translocation experiments, we document natural selection against migrants between nonsulphidic and sulphidic habitats, whereas migrants between sulphidic cave and surface habitats did not exhibit increased mortality within the same time period. Consequently, both natural and sexual selection may contribute to isolation among parapatric populations, and selection against immigrants may be a powerful mechanism facilitating speciation among locally adapted populations even over very small spatial distances. PMID:19807829

  6. Psychotic symptoms with sexual content in the "ultra high risk" for psychosis population: frequency and association with sexual trauma.

    PubMed

    Thompson, Andrew; Nelson, Barnaby; McNab, Catherine; Simmons, Magenta; Leicester, Steven; McGorry, Patrick D; Bechdolf, Andreas; Yung, Alison R

    2010-05-15

    Individuals at "ultra high risk" (UHR) for psychosis have been found to experience high rates of sexual trauma. An aetiological role for sexual trauma has been proposed for psychotic disorders and may influence psychotic symptom content. We aimed to investigate the relationship between previous sexual trauma and reported psychotic-like experiences, in particular psychotic symptoms with a sexual content in a UHR sample. We investigated the prevalence of "attenuated" or "subthreshold" psychotic symptoms with a sexual content in a consecutive series of patients recruited to a specialist UHR clinic. Patient's experience of general and sexual trauma was rated separately using a trauma questionnaire based on the list of events qualifying as traumas under DSM IV. The sample consisted of 92 patients, 14 (15.2%) had experienced an attenuated psychotic symptom with sexual content. The most common symptom was overvalued ideas/delusions of being watched in the shower/toilet or undressing. A considerable proportion of the sample (36.2%) had experienced sexual trauma (sexually molested or raped). Presence of attenuated psychotic symptoms with sexual content was related to history of previous sexual trauma (OR 7.17, P<0.01). This relationship remained significant when other traumatic experiences, PTSD diagnosis, age and sex were adjusted for. Further research into this relationship with regard to outcome and treatment is warranted. PMID:20304504

  7. Rapid evolution of a sexually selected trait following population establishment in a novel habitat.

    PubMed

    Yeh, Pamela J

    2004-01-01

    Colonization of novel environments creates new selection pressures. Sexually selected traits are affected by the physical and social environment and should be especially susceptible to change, but this has rarely been studied. In southern California, dark-eyed juncos, (Junco hyemalis) naturally breed in mixed-coniferous temperate forests, typically from 1500 m to 3000 m in elevation. In the early 1980s, a small population became established in a coastal habitat, the University of California, San Diego campus, which has a mild, Mediterranean climate. I show that a sexually and socially selected signaling trait--the amount of white in the tail--has declined by approximately 22% as compared to mountain juncos. I address three main factors that could explain the difference between mountain and coastal juncos: phenotypic plasticity, genetic drift, and selection. Results indicate that the first two can be ruled out as the sole cause of the plumage change, which implies that selection contributed to the genetic differentiation from the mountain population. The estimated rate of evolution is about 0.2 haldanes, comparable with rates of change in systems where individuals have been artificially introduced into new environments (e.g., guppies and Drosophila). This is the first study to demonstrate evolution of a sexually selected trait after only several generations resulting from a natural invasion into a novel environment. PMID:15058729

  8. Understanding sexual orientation health disparities in smoking: a population-based analysis.

    PubMed

    Balsam, Kimberly F; Beadnell, Blair; Riggs, Karin R

    2012-10-01

    Lesbian, gay, and bisexual populations are at elevated risk for tobacco use compared to their heterosexual peers. However, there is little research examining reasons for this disparity. Drawing on prior literature regarding psychosocial variables associated with both sexual orientation and smoking, the authors tested a path model of risk and protective factors to help explain sexual orientation differences in smoking using data from the Washington State Behavioral Risk Factor Surveillance System from 2003 to 2007. The authors estimated separate models for men and women, comparing lesbians or gays and bisexuals to heterosexuals. Results indicated that the explanatory variables accounted for most of the variance in this relationship, with both risk-enhancing and risk-reducing pathways. Mental health, life dissatisfaction, alcohol use, exposure to tobacco marketing, and single relationship status were risk enhancers for most LGB participants. Health-care access and income level were risk enhancers for bisexual participants only. Neither emotional support nor attitudes and knowledge about tobacco use helped explain the relationship between sexual orientation and smoking. These findings have significant implications for tobacco prevention and control efforts in this high-risk population. PMID:23039346

  9. Structural stigma and all-cause mortality in sexual minority populations.

    PubMed

    Hatzenbuehler, Mark L; Bellatorre, Anna; Lee, Yeonjin; Finch, Brian K; Muennig, Peter; Fiscella, Kevin

    2014-02-01

    Stigma operates at multiple levels, including intrapersonal appraisals (e.g., self-stigma), interpersonal events (e.g., hate crimes), and structural conditions (e.g., community norms, institutional policies). Although prior research has indicated that intrapersonal and interpersonal forms of stigma negatively affect the health of the stigmatized, few studies have addressed the health consequences of exposure to structural forms of stigma. To address this gap, we investigated whether structural stigma-operationalized as living in communities with high levels of anti-gay prejudice-increases risk of premature mortality for sexual minorities. We constructed a measure capturing the average level of anti-gay prejudice at the community level, using data from the General Social Survey, which was then prospectively linked to all-cause mortality data via the National Death Index. Sexual minorities living in communities with high levels of anti-gay prejudice experienced a higher hazard of mortality than those living in low-prejudice communities (Hazard Ratio [HR] = 3.03, 95% Confidence Interval [CI] = 1.50, 6.13), controlling for individual and community-level covariates. This result translates into a shorter life expectancy of approximately 12 years (95% C.I.: 4-20 years) for sexual minorities living in high-prejudice communities. Analysis of specific causes of death revealed that suicide, homicide/violence, and cardiovascular diseases were substantially elevated among sexual minorities in high-prejudice communities. Strikingly, there was an 18-year difference in average age of completed suicide between sexual minorities in the high-prejudice (age 37.5) and low-prejudice (age 55.7) communities. These results highlight the importance of examining structural forms of stigma and prejudice as social determinants of health and longevity among minority populations. PMID:23830012

  10. Structural Stigma and All-Cause Mortality in Sexual Minority Populations

    PubMed Central

    Hatzenbuehler, Mark L.; Bellatorre, Anna; Lee, Yeonjin; Finch, Brian; Muennig, Peter; Fiscella, Kevin

    2013-01-01

    Stigma operates at multiple levels, including intrapersonal appraisals (e.g., self-stigma), interpersonal events (e.g., hate crimes), and structural conditions (e.g., community norms, institutional policies). Although prior research has indicated that intrapersonal and interpersonal forms of stigma negatively affect the health of the stigmatized, few studies have addressed the health consequences of exposure to structural forms of stigma. To address this gap, we investigated whether structural stigma—operationalized as living in communities with high levels of anti-gay prejudice—increases risk of premature mortality for sexual minorities. We constructed a measure capturing the average level of anti-gay prejudice at the community level, using data from the General Social Survey, which was then prospectively linked to all-cause mortality data via the National Death Index. Sexual minorities living in communities with high levels of anti-gay prejudice experienced a higher hazard of mortality than those living in low-prejudice communities (Hazard Ratio [HR] =3.03, 95% Confidence Interval [CI]=1.50, 6.13), controlling for individual and community-level covariates. This result translates into a shorter life expectancy of approximately 12 years (95% C.I.: 4-20 years) for sexual minorities living in high-prejudice communities. Analysis of specific causes of death revealed that suicide, homicide/violence, and cardiovascular diseases were substantially elevated among sexual minorities in high-prejudice communities. Strikingly, there was an 18-year difference in average age of completed suicide between sexual minorities in the high-prejudice (age 37.5) and low-prejudice (age 55.7) communities. These results highlight the importance of examining structural forms of stigma and prejudice as social determinants of health and longevity among minority populations. PMID:23830012

  11. Sexual dimorphism in finger length ratios and sex determination - A study in Indo-Mauritian population.

    PubMed

    Agnihotri, Arun Kumar; Jowaheer, A Aman; Soodeen-Lalloo, Adiilah K

    2015-10-01

    Many studies have shown that the finger length ratios might be characteristic for sexual dimorphism. The aim of the study was to determine sexual dimorphism in finger length ratios among the representatives of the Indo-Mauritian population. The study group comprised of 200 healthy Indo-Mauritian people (100 male and 100 female) of the age ranged from 19 to 25 years. The lengths of second (2D), third (3D), forth (4D) and fifth (5D) finger of both hands were measured by using a vernier caliper. Our results indicate that all finger length ratios have significant sex differences (p-value < 0.05) except 2D:5D and 3D:5D. To conclude, 2D:4D ratio is the most decisive ratio (predictive accuracy = 0.61) which can demarcate between male and female. PMID:26344459

  12. Evaluation of sexuality in a Paraguayan mid-aged female urban population using the six-item Female Sexual Function Index.

    PubMed

    Sánchez, S C; Chedraui, P; Pérez-López, F R; Ortiz-Benegas, M E; Palacios-De Franco, Y

    2016-06-01

    Background There are scant data related to sexuality assessed among mid-aged women from Paraguay. Objective To assess sexual function in a sample of mid-aged Paraguayan women. Methods This was a cross-sectional study in which 265 urban-living women from Asunción (Paraguay) aged 40-65 years were surveyed with the six-item version of the Female Sexual Function Index (FSFI-6) and a questionnaire containing personal and partner data. Results The median age of the sample was 48 years, 48.2% were postmenopausal (median/interquartile range age at menopause 46/13 years), 11.3% used hormone therapy, 37.0% used psychotropic drugs, 44.5% had hypertension, 7.2% diabetes, 46.1% abdominal obesity and 89.4% had a partner (n = 237). Overall, 84.1% (223/265) of surveyed women were sexually active, presenting a median total FSFI-6 score of 23.0, and 25.6% obtained a total score of 19 or less, suggestive of sexual dysfunction (lower sexual function). Upon bivariate analysis, several factors were associated with lower total FSFI-6 scores; however, multiple linear regression analysis found that lower total FSFI-6 scores (worse sexual function) were significantly correlated to the postmenopausal status and having an older partner, whereas coital frequency was positively correlated to higher scores (better sexual function). Conclusion In this pilot sample of urban-living, mid-aged Paraguayan women, as determined with the FSFI-6, lower sexual function was related to menopausal status, coital frequency and partner age. There is a need for more research in this regard in this population. PMID:26940601

  13. Comparison of sexual assaults by strangers and known assailants in an urban population of women.

    PubMed Central

    Stermac, L E; Du Mont, J A; Kalemba, V

    1995-01-01

    OBJECTIVE: To examine the characteristics of sexual assaults by strangers and those by people known to the victims in an urban community-based population of women. DESIGN: Descriptive study. SETTING: Sexual Assault Care Centre, Women's College Hospital, Toronto. PARTICIPANTS: All 677 women who presented to the centre between June 1, 1991, and Sept. 30, 1993, and for whom the victim-assailant relationship was known. OUTCOME MEASURES: Assailant's relationship to victim, sex of assailant, number of assailants, number, type and location of assaults, use of weapons, type of coercion and extent of physical trauma or injury. RESULTS: Sexual assault by a person known to the victim accounted for 456 (67.4%) of the assaults reported. In 344 cases the person was known more than 24 hours; 99 (28.8%) were current or previous boyfriends or spouses. Assailants who were strangers were more likely to assault the victim more than once (t = -2.42, 355 degrees of freedom [df], p < 0.05), force the victim to perform fellatio (chi 2 = 8.63, 1 df, p < 0.005), use weapons (chi 2 = 12.01, 1 df, p < 0.001) and use physical coercion (chi 2 = 4.42, 1 df, p < 0.05), whereas assailants who were known to the victims were more likely to assault a woman who was sleeping or drugged (chi 2 = 10.38, 1 df, p < 0.005). Sexual assault by a known assailant was more likely to occur in the home of the victim (chi 2 = 36.27, 1 df, p < 0.001) or the assailant (chi 2 = 8.46, 1 df, p < 0.005), whereas sexual assault by a stranger was more likely to occur outdoors (chi 2 = 89.80, 1 df, p < 0.001) or in a vehicle (chi 2 = 32.81, 1 df, p < 0.001). Overall, the mean number of trauma sites was greater among victims assaulted by strangers than among those assaulted by people they knew (t = -4.29, 180 df, p < 0.001). CONCLUSION: Two thirds of the sexual assaults in this urban population were committed by people known to the victims, and over two thirds of these assaults were associated with physical trauma. Improved victim services and prevention strategies should be built on this knowledge. PMID:7553516

  14. Gender moderates the relationship between impulsivity and sexual risk-taking in a cocaine-using psychiatric outpatient population

    PubMed Central

    Black, Anne C.; McMahon, Thomas J.; Potenza, Marc N.; Fiellin, Lynn E.; Rosen, Marc I.

    2014-01-01

    Adults who abuse substances are at increased risk for contracting sexually transmitted infections, including HIV. Within this population, sexual risk behaviors have been associated with increased impulsivity. Studies in non-clinical populations showing gender-related differences in sexual decision-making and casual sexual partnering suggest impulsivity has a greater influence on men than women, but these differences have not been documented in substance-using patients. In a sample of 89 adults with recent cocaine use and receiving outpatient psychiatric treatment, we tested the hypothesis that gender moderates the effect of impulsivity on sexual risk-taking. Using logistic regression modeling, we tested the main and gender-moderated effects of task-related impulsivity on the probability of having a casual sexual partner and multiple sexual partners. Results confirmed a significant gender-by-impulsivity interaction; men who were more impulsive on a continuous performance task had significantly higher rates of sexual risk-taking than less impulsive men, but women's impulsivity was unrelated to these outcomes. Impulsive men were over three times as likely as less impulsive men to have a recent casual partner. Implications of these results and suggestions for future research are discussed. PMID:25554716

  15. Analyses of odontometric sexual dimorphism and sex assessment accuracy on a large sample.

    PubMed

    Angadi, Punnya V; Hemani, S; Prabhu, Sudeendra; Acharya, Ashith B

    2013-08-01

    Correct sex assessment of skeletonized human remains allows investigators to undertake a more focused search of missing persons' files to establish identity. Univariate and multivariate odontometric sex assessment has been explored in recent years on small sample sizes and have not used a test sample. Consequently, inconsistent results have been produced in terms of accuracy of sex allocation. This paper has derived data from a large sample of males and females, and applied logistic regression formulae on a test sample. Using a digital caliper, buccolingual and mesiodistal dimensions of all permanent teeth (except third molars) were measured on 600 dental casts (306 females, 294 males) of young adults (18-32 years), and the data subjected to univariate (independent samples' t-test) and multivariate statistics (stepwise logistic regression analysis, or LRA). The analyses revealed that canines were the most sexually dimorphic teeth followed by molars. All tooth variables were larger in males, with 51/56 (91.1%) being statistically larger (p < 0.05). When the stepwise LRA formulae were applied to a test sample of 69 subjects (40 females, 29 males) of the same age range, allocation accuracy of 68.1% for the maxillary teeth, 73.9% for the mandibular teeth, and 71% for teeth of both jaws combined, were obtained. The high univariate sexual dimorphism observed herein contrasts with some reports of low, and sometimes reverse, sexual dimorphism (the phenomenon of female tooth dimensions being larger than males'); the LRA results, too, are in contradiction to a previous report of virtually 100% sex allocation for a small heterogeneous sample. These reflect the importance of using a large sample to quantify sexual dimorphism in tooth dimensions and the application of the derived formulae on a test dataset to ascertain accuracy which, at best, is moderate in nature. PMID:23910859

  16. Evolution of sexual isolation during secondary contact: genotypic versus phenotypic changes in laboratory populations.

    PubMed

    Alipaz, Julie A; Fang, Shu; Osada, Naoki; Wu, Chung-I

    2005-04-01

    We monitored the phenotypic and genotypic changes that occur when two behavioral races come into contact in laboratory populations. Drosophila melanogaster from Zimbabwe and nearby regions (Z type) show strong but asymmetric sexual isolation from their cosmopolitan counterparts (M type). Crosses of Z females and M males do not take place readily when other choices are available. At least 15 loci are known to control Z-type mating preferences and performance. By thoroughly mixing the genomes of the two types in laboratory populations, we artificially created maximum secondary contact. Despite the strength of sexual selection favoring Z-type male characters, Z-type behavior is eliminated or greatly diminished in all 12 hybrid populations after only 60 generations. This trend is consistent with the spread of the M-type behavior throughout the world as well as a detailed analysis of fitness components. Surprisingly, in contrast with the phenotypic convergence toward the M-type, genotypic samples broadly covering the genomic regions of mapped behavioral loci show no such trend. The genome appears to be "fine grained," with adjacent loci having different evolutionary dynamics and genealogical histories. PMID:15791534

  17. Determination of sexual dimorphism via maxillary first molar teeth in Himachali population

    PubMed Central

    Singla, Swati; Gupta, Rakhi; Puri, Abhiney; Bansal, Sucheta; Singla, Smita; Nangia, Rajat

    2015-01-01

    Context: Sex determination of skeletal remains forms part of archaeological and medicolegal examinations. It is an aspect of forensic odontology. Forensic odontology primarily deals with identification, based on recognition of unique features present in an individual's dental structures. Correct sex determination limits the pool of missing persons to just one half of the population. Aim of Study: Purpose of this study is to evaluate the existence of sexual dimorphism and variation in left and right maxillary first molars using bucco-lingual and mesio-distal dimensions in population of Sirmour District, H.P. Materials and Methods: Base sample comprised 100 subjects (50 males and 50 females) of an age group ranging from 17 to 25 years. Statistical Analysis Used: Unpaired t-test. Results: It was observed that the comparison of mean values of bucco-lingual and mesio-distal parameters showed highly statistically significant differences between males and females, measured both intraorally and on study casts. There were no significant differences between the mean values of both the parameters on the left side as compared to right side. Conclusion: The study concludes that sexual dimorphism is population specific. Among Himachali people, mesio-distal dimensions and bucco-lingual dimensions of first molar can aid in sex determination. PMID:26005295

  18. Prevalence and predictors of concurrent sexual partnerships in a predominantly African American population in Jackson, Mississippi

    PubMed Central

    Nunn, Amy; MacCarthy, Sarah; Barnett, Nancy; Rose, Jennifer; Chan, Philip; Yolken, Annajane; Cornwall, Alexandra; Chamberlain, Nicholas; Barnes, Arti; Riggins, Reginald; Moore, Elya; Simmons, Dantrell; Parker, Sharon; Mena, Leandro

    2014-01-01

    Concurrent sexual partnerships, or sexual partnerships that overlap in time, have been associated with HIV and sexually transmitted infections (STI) infection. How best to measure concurrency and the personal characteristics and predictors of concurrency are not yet well understood. We compared two frequently used concurrency definitions, including a self-reported measure based on participant response regarding overlapping sex with partners, and the UNAIDS measure based on overlapping dates of last sex and intention to have sex again. We performed multivariable logistic regression analyses to identify socio-demographic, behavioral, and structural predictors of concurrency among 1,542 patients at an urban STI clinic in Jackson, Mississippi. Nearly half (44%) reported concurrency based on self-reported sex with other partners, and 26% reported concurrency according to the UNAIDS concurrency measure. Using the self-reported concurrency measure, the strongest predictors of concurrency were perceived partner concurrency, drug use at last sex, having more than 10 lifetime partners, and being recently incarcerated. Strongest predictors of concurrency using the UNAIDS measure were lifetime number of partners and perceived partner concurrency. Concurrency is highly prevalent in this population in the Deep South and social, structural and behavioral factors were important predictors of concurrency for both measures. Future research should use time anchored data collection methods and biomarkers to assess whether both definitions of concurrency are associated with HIV outcomes. PMID:24803130

  19. Protocol Design for Large-Scale Cross-Sectional Studies of Sexual Abuse and Associated Factors in Individual Sports: Feasibility Study in Swedish Athletics

    PubMed Central

    Timpka, Toomas; Janson, Staffan; Jacobsson, Jenny; Ekberg, Joakim; Dahlström, Örjan; Kowalski, Jan; Bargoria, Victor; Mountjoy, Margo; Svedin, Carl G.

    2015-01-01

    To ensure health and well-being for their athletes, sports organizations must offer preventive measures against sexual abuse. The aim of this study was to design and evaluate feasibility of a research protocol for cross-sectional epidemiological studies of sexual abuse in athletics. Examination of the requirements on the study of sexual abuse in athletics was followed by iterated drafting of protocol specifications and formative evaluations. The feasibility of the resulting protocol was evaluated in a national-level study among elite athletics athletes (n = 507) in Sweden. The definition of sexual abuse, the ethical soundness of the protocol, reference populations and study of co-morbidity, and the means for athlete-level data collection were identified as particularly complex issues in the requirements analyses. The web-based survey defined by the protocol facilitates anonymous athlete self-reporting of data on exposure to sexual abuse. 198 athletes (39%) fully completed the feasibility survey. 89% (n = 177) reported that they agreed with that the questions in the survey were important, and 95% (n = 189) reported that they answered truthfully to all questions. Similarly, 91% (n = 180) reported that they did not agree with that the questions were unpleasant for them. However, 16% (n = 32) reported that they did not find the survey to be of personal value, and 12% (n = 23) reported that the survey had caused them to think about issues that they did not want to think about. Responding that participation was not personally gratifying was associated with training more hours (p = 0.01). There is a scarcity of research on the prevention of sexual abuse in individual sports. The present protocol should be regarded as a means to overcome this shortcoming in athletics. When implementing the protocol, it is necessary to encourage athlete compliance and to adapt the web-based survey to the particular infrastructural conditions in the sports setting at hand. Key points A research protocol for cross-sectional epidemiological studies of sexual abuse in athletics was designed and its feasibility evaluated. The definition of sexual abuse, ethical soundness of the protocol, reference populations and study of co-morbidity, and means for athlete-level data collection were in requirements analyses identified as particularly complex design issues. The feasibility evaluation showed a high non-participation rate (61%), but also that the large majority of participants found the study important and that questions were answered truthfully. Responding that partaking in the study was not personally gratifying was associated with training more hours. When implementing cross-sectional epidemiological studies of sexual abuse in athletics, it is necessary to promote and facilitate athlete participation. PMID:25729306

  20. Protocol design for large-scale cross-sectional studies of sexual abuse and associated factors in individual sports: feasibility study in Swedish athletics.

    PubMed

    Timpka, Toomas; Janson, Staffan; Jacobsson, Jenny; Ekberg, Joakim; Dahlström, Örjan; Kowalski, Jan; Bargoria, Victor; Mountjoy, Margo; Svedin, Carl G

    2015-03-01

    To ensure health and well-being for their athletes, sports organizations must offer preventive measures against sexual abuse. The aim of this study was to design and evaluate feasibility of a research protocol for cross-sectional epidemiological studies of sexual abuse in athletics. Examination of the requirements on the study of sexual abuse in athletics was followed by iterated drafting of protocol specifications and formative evaluations. The feasibility of the resulting protocol was evaluated in a national-level study among elite athletics athletes (n = 507) in Sweden. The definition of sexual abuse, the ethical soundness of the protocol, reference populations and study of co-morbidity, and the means for athlete-level data collection were identified as particularly complex issues in the requirements analyses. The web-based survey defined by the protocol facilitates anonymous athlete self-reporting of data on exposure to sexual abuse. 198 athletes (39%) fully completed the feasibility survey. 89% (n = 177) reported that they agreed with that the questions in the survey were important, and 95% (n = 189) reported that they answered truthfully to all questions. Similarly, 91% (n = 180) reported that they did not agree with that the questions were unpleasant for them. However, 16% (n = 32) reported that they did not find the survey to be of personal value, and 12% (n = 23) reported that the survey had caused them to think about issues that they did not want to think about. Responding that participation was not personally gratifying was associated with training more hours (p = 0.01). There is a scarcity of research on the prevention of sexual abuse in individual sports. The present protocol should be regarded as a means to overcome this shortcoming in athletics. When implementing the protocol, it is necessary to encourage athlete compliance and to adapt the web-based survey to the particular infrastructural conditions in the sports setting at hand. Key pointsA research protocol for cross-sectional epidemiological studies of sexual abuse in athletics was designed and its feasibility evaluated.The definition of sexual abuse, ethical soundness of the protocol, reference populations and study of co-morbidity, and means for athlete-level data collection were in requirements analyses identified as particularly complex design issues.The feasibility evaluation showed a high non-participation rate (61%), but also that the large majority of participants found the study important and that questions were answered truthfully.Responding that partaking in the study was not personally gratifying was associated with training more hours.When implementing cross-sectional epidemiological studies of sexual abuse in athletics, it is necessary to promote and facilitate athlete participation. PMID:25729306

  1. Argentine Population Genetic Structure: Large Variance in Amerindian Contribution

    PubMed Central

    Seldin, Michael F.; Tian, Chao; Shigeta, Russell; Scherbarth, Hugo R.; Silva, Gabriel; Belmont, John W.; Kittles, Rick; Gamron, Susana; Allevi, Alberto; Palatnik, Simon A.; Alvarellos, Alejandro; Paira, Sergio; Caprarulo, Cesar; Guillerón, Carolina; Catoggio, Luis J.; Prigione, Cristina; Berbotto, Guillermo A.; García, Mercedes A.; Perandones, Carlos E.; Pons-Estel, Bernardo A.; Alarcon-Riquelme, Marta E.

    2011-01-01

    Argentine population genetic structure was examined using a set of 78 ancestry informative markers (AIMs) to assess the contributions of European, Amerindian, and African ancestry in 94 individuals members of this population. Using the Bayesian clustering algorithm STRUCTURE, the mean European contribution was 78%, the Amerindian contribution was 19.4%, and the African contribution was 2.5%. Similar results were found using weighted least mean square method: European, 80.2%; Amerindian, 18.1%; and African, 1.7%. Consistent with previous studies the current results showed very few individuals (four of 94) with greater than 10% African admixture. Notably, when individual admixture was examined, the Amerindian and European admixture showed a very large variance and individual Amerindian contribution ranged from 1.5 to 84.5% in the 94 individual Argentine subjects. These results indicate that admixture must be considered when clinical epidemiology or case control genetic analyses are studied in this population. Moreover, the current study provides a set of informative SNPs that can be used to ascertain or control for this potentially hidden stratification. In addition, the large variance in admixture proportions in individual Argentine subjects shown by this study suggests that this population is appropriate for future admixture mapping studies. PMID:17177183

  2. Influence of breeding habitat on bear predation and age at maturity and sexual dimorphism of sockeye salmon populations

    USGS Publications Warehouse

    Quinn, Thomas P; Wetzel, Lisa A.; Bishop, Susan; Overberg, Kristi; Rogers, Donald E.

    2001-01-01

    Age structure and morphology differ among Pacific salmon (Oncorhynchus spp.) populations. Sexual selection and reproductive capacity (fecundity and egg size) generally favor large (old), deep-bodied fish. We hypothesized that natural selection from physical access to spawning grounds and size-biased predation by bears, Ursus spp., opposes such large, deep-bodied salmon. Accordingly, size and shape of salmon should vary predictably among spawning habitats. We tested this hypothesis by measuring the age composition and body depth of sockeye salmon, Oncorhynchus nerka, and the intensity of predation in a range of breeding habitats in southwestern Alaska. Stream width was positively correlated with age at maturity and negatively correlated with predation level. However, salmon spawning on lake beaches were not consistently old, indicating that different factors affect age in riverine- and beach-spawning populations. Body depths of male and female salmon were positively correlated with water depth across all sites, as predicted. However, the mouths of some streams were so shallow that they might select against large or deep-bodied salmon, even in the absence of bear predation. Taken together, the results indicated that habitat has direct and indirect effects (via predation) on life history and morphology of mature salmon.

  3. Exponential increases of RNA virus fitness during large population transmissions.

    PubMed Central

    Novella, I S; Duarte, E A; Elena, S F; Moya, A; Domingo, E; Holland, J J

    1995-01-01

    The great adaptability shown by RNA viruses is a consequence of their high mutation rates. Here we investigate the kinetics of virus fitness gains during repeated transfers of large virus populations in cell culture. Results always show that fitness increases exponentially. Low fitness clones exhibit regular increases observed as biphasic periods of exponential evolutionary improvement, while neutral clones show monophasic kinetics. These results are significant for RNA virus epidemiology, optimal handling of attenuated live virus vaccines, and routine laboratory procedures. PMID:7597039

  4. Phenology of Scramble Polygyny in a Wild Population of Chrysolemid Beetles: The Opportunity for and the Strength of Sexual Selection

    PubMed Central

    Baena, Martha Lucía; Macías-Ordóñez, Rogelio

    2012-01-01

    Recent debate has highlighted the importance of estimating both the strength of sexual selection on phenotypic traits, and the opportunity for sexual selection. We describe seasonal fluctuations in mating dynamics of Leptinotarsa undecimlineata (Coleoptera: Chrysomelidae). We compared several estimates of the opportunity for, and the strength of, sexual selection and male precopulatory competition over the reproductive season. First, using a null model, we suggest that the ratio between observed values of the opportunity for sexual selections and their expected value under random mating results in unbiased estimates of the actual nonrandom mating behavior of the population. Second, we found that estimates for the whole reproductive season often misrepresent the actual value at any given time period. Third, mating differentials on male size and mobility, frequency of male fighting and three estimates of the opportunity for sexual selection provide contrasting but complementary information. More intense sexual selection associated to male mobility, but not to male size, was observed in periods with high opportunity for sexual selection and high frequency of male fights. Fourth, based on parameters of spatial and temporal aggregation of female receptivity, we describe the mating system of L. undecimlineata as a scramble mating polygyny in which the opportunity for sexual selection varies widely throughout the season, but the strength of sexual selection on male size remains fairly weak, while male mobility inversely covaries with mating success. We suggest that different estimates for the opportunity for, and intensity of, sexual selection should be applied in order to discriminate how different behavioral and demographic factors shape the reproductive dynamic of populations. PMID:22761675

  5. Factors associated with early sexual debut in Slovenia: results of a general population survey

    PubMed Central

    Klavs, I; Rodrigues, L C; Weiss, H A; Hayes, R

    2006-01-01

    Objectives To investigate time trends in age at first heterosexual intercourse (FHI) and associated factors. Methods Data were collected from a national probability sample of the general population aged 18–49 years. Results Median age at FHI was 17 years for men and 18 years for women, but declined from 18 years to 17 years in men born after the early 1960s and in women born after the early 1970s. Early FHI (before age 16) was reported by 15.2% of men and 7.4% of women, but in recent cohorts (born 1975–82), proportions were similar in both sexes (16.9% and 14.4%, respectively). In women, higher educational level and acquiring most knowledge about sex from parents or in school were associated with later age at FHI. Half the women with early FHI judged the event to have occurred too soon. 4.2% of women with early FHI reported coercion at FHI, compared to 0.9% overall. The main factor associated with early FHI in men was not living with both parents up to the age of 15. Individuals with early FHI were more likely to report higher risk sexual behaviour as well as teenage motherhood and, for men, not having used a condom at FHI and bacterial sexually transmitted infections. Three in four individuals with early FHI thought they had inadequate sexual knowledge at FHI. Many would have liked to have learned more from parents and in school. Conclusions Improved sexual education among young Slovenians should aim to delay FHI until a more mature age and to be better prepared for safer sex. PMID:17151034

  6. Short-term population differences in the genetic architecture of life history traits related to sexuality in an aphid species.

    PubMed

    Nespolo, R F; Figueroa, C C; Plantegenest, M; Simon, J C

    2008-04-01

    One of the most important factors that determine the evolutionary trajectory of a suite of traits in a population is the structure of the genetic variance-covariance matrix (G). We studied the cyclically parthenogenetic aphid Rhopalosiphum padi, whose populations exhibit two types of reproductive lineages respectively specialized in sexuality (that is, cyclically parthenogenetic lineages) and in asexuality (that is, obligate parthenogenetic lineages). We compared the quantitative genetics of life histories in these two lineage types. Our results suggest that both, the elements and the whole structure of the resulting G matrices differ in the very short term, between lineage types. This would involve the evolution toward different evolutionary optima in the same population, depending on whether sexual or asexual lineages predominate. Since sexual and asexual lineages vary seasonally in their abundance, a fluctuating selective regime has been proposed for this species, which would contribute to the maintenance of the reproductive polymorphism that these populations exhibit. PMID:18212808

  7. Heterogeneous population effects of an alcohol excise tax increase on sexually transmitted infections morbidity

    PubMed Central

    Staras, Stephanie A S; Livingston, Melvin D; Christou, Alana M; Jernigan, David H; Wagenaar, Alexander C

    2014-01-01

    Background and Aims Alcohol taxes reduce population-level excessive alcohol use and alcohol-related morbidity and mortality, yet little is known about the distribution of the effects of alcohol taxation across race/ethnicity and age subgroups. We examined the race/ethnicity- and age group-specific effects of an excise alcohol tax increase on a common and routinely collected alcohol-related morbidity indicator, sexually transmitted infections. Methods We used an interrupted time series design to examine the effect of a 2009 alcohol tax increase in Illinois, USA on new cases of two common sexually transmitted infections (chlamydia and gonorrhea) reported to the US National Notifiable Disease Surveillance System from January 2003 to December 2011 (n = 108 repeated monthly observations). We estimated the effects of the tax increase on infection rates in the general population and within specific race/ethnicity and age subgroups using mixed models accounting for temporal trends and median income. Results Following the Illinois alcohol tax increase, state-wide rates of gonorrhea decreased 21% [95% confidence Interval (CI) = −25.7, −16.7] and chlamydia decreased 11% [95% CI = −17.8, −4.4], resulting in an estimated 3506 fewer gonorrhea infections and 5844 fewer chlamydia infections annually. The null hypothesis of homogenous effects by race/ethnicity and age was rejected (P < 0.0001). Significant reductions were observed among non-Hispanic blacks: gonorrhea rates decreased 25.6% (95% CI = −30.0, −21.0) and chlamydia rates decreased 14.7% (95% CI = −20.9, −8.0). Among non-Hispanics, point estimates suggest decreases were highest among 25–29-year-olds. Conclusions Increased alcohol taxes appear to reduce sexually transmitted infections, especially among subpopulations with high disease burdens, such as non-Hispanic blacks. PMID:24450730

  8. Urologic Characteristics and Sexual Behaviors Associated with Prostate Cancer in an African-Caribbean Population in Barbados, West Indies

    PubMed Central

    Hennis, Anselm J. M.; Wu, Suh-Yuh; Nemesure, Barbara; Leske, M. Cristina

    2013-01-01

    Prostate cancer (PC) is the principal malignancy affecting African descent men in the Caribbean and the USA. Disparities in incidence, prevalence, and mortality in these populations are poorly understood. We evaluated the urologic characteristics and sexual behaviors of men with histologically confirmed PC (cases) and age-matched controls in the nationwide Prostate Cancer in a Black Population (PCBP) study conducted in Barbados. Cases were around 1.5 to 3 times more likely to report symptoms of prostatic enlargement, hematuria/hematospermia, and previous prostatitis. Sexually transmitted infections (STIs) were similar among cases (24.5%) and controls (26.7%). First sexual intercourse before the age of 16 was associated with an increased likelihood of both low- (Gleason score < 7; OR 1.63; 95% CI: 1.03–1.66) and high-grade PC (Gleason score ≥ 7; OR 1.82; 1.11–2.99). PC risk decreased with later age of sexual debut (P-trend = 0.004). More lifetime sexual partners was associated with increased odds of high grade PC (P-trend = 0.02). The contribution of sexual behaviors to the development and the outcomes of PC is likely due to multiple mechanisms, and further study will be necessary to elucidate the underlying pathophysiologic mechanisms in this and similar populations. PMID:23533778

  9. Differing mechanisms underlie sexual size-dimorphism in two populations of a sex-changing fish.

    PubMed

    McCormick, Mark I; Ryen, Christopher A; Munday, Philip L; Walker, Stefan P W

    2010-01-01

    Variability in the density of groups within a patchy environment lead to differences in interaction rates, growth dynamics and social organization. In protogynous hermaphrodites there are hypothesised trade-offs among sex-specific growth, reproductive output and mortality. When differences in density lead to changes to social organization the link between growth and the timing of sex-change is predicted to change. The present study explores this prediction by comparing the social organisation and sex-specific growth of two populations of a protogynous tropical wrasse, Halichoeres miniatus, which differ in density. At a low density population a strict harem structure was found, where males maintained a tight monopoly of access and spawning rights to females. In contrast, at a high density population a loosely organised system prevailed, where females could move throughout multiple male territories. Otolith microstructure revealed the species to be annual and deposit an otolith check associated with sex-change. Growth trajectories suggested that individuals that later became males in both populations underwent a growth acceleration at sex-change. Moreover, in the high density population, individuals that later became males were those individuals that had the largest otolith size at hatching and consistently deposited larger increments throughout early larval, juvenile and female life. This study demonstrates that previous growth history and growth rate changes associated with sex change can be responsible for the sexual dimorphism typically found in sex-changing species, and that the relative importance of these may be socially constrained. PMID:20485547

  10. Surrogate population models for large-scale neural simulations.

    PubMed

    Tripp, Bryan P

    2015-06-01

    Because different parts of the brain have rich interconnections, it is not possible to model small parts realistically in isolation. However, it is also impractical to simulate large neural systems in detail. This article outlines a new approach to multiscale modeling of neural systems that involves constructing efficient surrogate models of populations. Given a population of neuron models with correlated activity and with specific, nonrandom connections, a surrogate model is constructed in order to approximate the aggregate outputs of the population. The surrogate model requires less computation than the neural model, but it has a clear and specific relationship with the neural model. For example, approximate spike rasters for specific neurons can be derived from a simulation of the surrogate model. This article deals specifically with neural engineering framework (NEF) circuits of leaky-integrate-and-fire point neurons. Weighted sums of spikes are modeled by interpolating over latent variables in the population activity, and linear filters operate on gaussian random variables to approximate spike-related fluctuations. It is found that the surrogate models can often closely approximate network behavior with orders-of-magnitude reduction in computational demands, although there are certain systematic differences between the spiking and surrogate models. Since individual spikes are not modeled, some simulations can be performed with much longer steps sizes (e.g., 20 ms). Possible extensions to non-NEF networks and to more complex neuron models are discussed. PMID:25774544

  11. Response of human populations to large-scale emergencies

    NASA Astrophysics Data System (ADS)

    Bagrow, James; Wang, Dashun; Barabási, Albert-László

    2010-03-01

    Until recently, little quantitative data regarding collective human behavior during dangerous events such as bombings and riots have been available, despite its importance for emergency management, safety and urban planning. Understanding how populations react to danger is critical for prediction, detection and intervention strategies. Using a large telecommunications dataset, we study for the first time the spatiotemporal, social and demographic response properties of people during several disasters, including a bombing, a city-wide power outage, and an earthquake. Call activity rapidly increases after an event and we find that, when faced with a truly life-threatening emergency, information rapidly propagates through a population's social network. Other events, such as sports games, do not exhibit this propagation.

  12. Testing the "Sexually Abused-Abuser Hypothesis" in Adolescents: A Population-Based Study.

    PubMed

    Aebi, Marcel; Landolt, Markus A; Mueller-Pfeiffer, Christoph; Schnyder, Ulrich; Maier, Thomas; Mohler-Kuo, Meichun

    2015-11-01

    A long-standing belief in the literature on sex offenders is that sexually victimized youths are at increased risk of becoming sex offenders themselves. The present study tested the link between past sexual abuse, either with or without contact, and sexually offending behavior in a representative sample of male and female adolescents while controlling for other types of abuse, mental health problems, substance use, and non-sexual violent behaviors. Self-reported data were collected from a nationally representative sample of 6,628 students attending 9th grade public school in Switzerland (3,434 males, 3,194 females, mean age = 15.50 years, SD = 0.66 years). Exposure to contact and non-contact types of sexual abuse was assessed using the Child Sexual Abuse Questionnaire and sexually offending behavior by the presence of any of three behaviors indicating sexual coercion. Two-hundred-forty-five males (7.1 %) and 40 females (1.2 %) reported having sexually coerced another person. After controlling for non-sexual abuse, low parent education, urban versus rural living, mental health problems, substance use, and non-sexual violent behavior, male adolescents who were victims of contact sexual abuse and non-contact sexual abuse were significantly more likely to report coercive sexual behaviors. Females who experienced contact or non-contact sexual abuse were also found at increased risk of committing sexual coercion after controlling for covariates. The present findings demonstrate a strong relationship between past sexual abuse, with and without physical contact, and sexual-offending behavior in male and female adolescents. Reducing exposure to non-contact sexual abuse (like Internet-based sexual exploitation) should become a new area of sexual violence prevention in youths. PMID:25981223

  13. Rapid population divergence linked with co-variation between coloration and sexual display in strawberry poison frogs.

    PubMed

    Rudh, Andreas; Rogell, Björn; Håstad, Olle; Qvarnström, Anna

    2011-05-01

    The likelihood of speciation is assumed to increase when sexually selected traits diverge together with ecologically important traits. According to sexual selection theory, the evolution of exaggerated display behavior is driven by increased mating success, but limited by natural selection, for example, through predation. However, the evolution of aposematic coloration (i.e., an ecologically important trait) could relieve the evolution of exaggerated display behavior from the bound of predation, resulting in joint divergence in aposematic coloration and sexual display behavior between populations. We tested this idea by examining conspicuousness, using color contrasts between individuals and their native backgrounds, and sexual display of 118 males from genetically diverged populations of the Strawberry poison frog, Dendrobates pumilio. Our results show that the level of conspicuousness of the population predicts the sexual display behavior of males. Males from conspicuous populations used more exposed calling sites. We argue that changes in aposematic coloration may rapidly cause not only postmating isolation due to poorly adapted hybrids, but also premating isolation through shifts in mating behaviors. PMID:21166789

  14. Assessment of Difference in Dimensions of Sexual Orientation: Implications for Substance Use Research in a College-Age Population*

    PubMed Central

    McCABE, SEAN ESTEBAN; HUGHES, TONDA L.; BOSTWICK, WENDY; BOYD, CAROL J.

    2011-01-01

    Objective The present research examines the associations between three distinct dimensions of sexual orientation and substance use in a random sample of undergraduate students. Method A Web-based survey was administered to students attending a large, midwestern research university in the spring of 2003. The sample consisted of 9,161 undergraduate students: 56% female, 68% white, 13% Asian, 6% black, 4% Hispanic and 9% other racial categories. Using multivariate logistic regression analyses, several measures of alcohol and other drug use were compared across three dimensions of sexual orientation: sexual identity, sexual attraction and sexual behavior. Results All three dimensions of sexual orientation were associated with substance use, including heavy episodic drinking, cigarette smoking and illicit drug use. Consistent with results of several other recent studies, “nonheterosexual” identity, attraction or behavior was associated with a more pronounced and consistent risk of substance use in women than in men. Conclusions Study findings suggest substantial variability in substance use across the three dimensions of sexual orientation and reinforce the importance of stratifying by gender and using multiple measures to assess sexual orientation. Study results have implications for future research and for interventions aimed at reducing substance use among college students. PMID:16331847

  15. Genome size variation affects song attractiveness in grasshoppers: evidence for sexual selection against large genomes.

    PubMed

    Schielzeth, Holger; Streitner, Corinna; Lampe, Ulrike; Franzke, Alexandra; Reinhold, Klaus

    2014-12-01

    Genome size is largely uncorrelated to organismal complexity and adaptive scenarios. Genetic drift as well as intragenomic conflict have been put forward to explain this observation. We here study the impact of genome size on sexual attractiveness in the bow-winged grasshopper Chorthippus biguttulus. Grasshoppers show particularly large variation in genome size due to the high prevalence of supernumerary chromosomes that are considered (mildly) selfish, as evidenced by non-Mendelian inheritance and fitness costs if present in high numbers. We ranked male grasshoppers by song characteristics that are known to affect female preferences in this species and scored genome sizes of attractive and unattractive individuals from the extremes of this distribution. We find that attractive singers have significantly smaller genomes, demonstrating that genome size is reflected in male courtship songs and that females prefer songs of males with small genomes. Such a genome size dependent mate preference effectively selects against selfish genetic elements that tend to increase genome size. The data therefore provide a novel example of how sexual selection can reinforce natural selection and can act as an agent in an intragenomic arms race. Furthermore, our findings indicate an underappreciated route of how choosy females could gain indirect benefits. PMID:25200798

  16. Sexual selection and population divergence I: The influence of socially flexible cuticular hydrocarbon expression in male field crickets (Teleogryllus oceanicus).

    PubMed

    Pascoal, Sonia; Mendrok, Magdalena; Mitchell, Christopher; Wilson, Alastair J; Hunt, John; Bailey, Nathan W

    2016-01-01

    Debates about how coevolution of sexual traits and preferences might promote evolutionary diversification have permeated speciation research for over a century. Recent work demonstrates that the expression of such traits can be sensitive to variation in the social environment. Here, we examined social flexibility in a sexually selected male trait-cuticular hydrocarbon (CHC) profiles-in the field cricket Teleogryllus oceanicus and tested whether population genetic divergence predicts the extent or direction of social flexibility in allopatric populations. We manipulated male crickets' social environments during rearing and then characterized CHC profiles. CHC signatures varied considerably across populations and also in response to the social environment, but our prediction that increased social flexibility would be selected in more recently founded populations exposed to fluctuating demographic environments was unsupported. Furthermore, models examining the influence of drift and selection failed to support a role of sexual selection in driving population divergence in CHC profiles. Variation in social environments might alter the dynamics of sexual selection, but our results align with theoretical predictions that the role social flexibility plays in modulating evolutionary divergence depends critically on whether responses to variation in the social environment are homogeneous across populations, or whether gene by social environment interactions occur. PMID:26678168

  17. Species detection and identification in sexual organisms using population genetic theory and DNA sequences.

    PubMed

    Birky, C William

    2013-01-01

    Phylogenetic trees of DNA sequences of a group of specimens may include clades of two kinds: those produced by stochastic processes (random genetic drift) within a species, and clades that represent different species. The ratio of the mean pairwise sequence difference between a pair of clades (K) to the mean pairwise sequence difference within a clade (θ) can be used to determine whether the clades are samples from different species (K/θ ≥ 4) or the same species (K/θ<4) with probability ≥ 0.95. Previously I applied this criterion to delimit species of asexual organisms. Here I use data from the literature to show how it can also be applied to delimit sexual species using four groups of sexual organisms as examples: ravens, spotted leopards, sea butterflies, and liverworts. Mitochondrial or chloroplast genes are used because these segregate earlier during speciation than most nuclear genes and hence detect earlier stages of speciation. In several cases the K/θ ratio was greater than 4, confirming the original authors' intuition that the clades were sufficiently different to be assigned to different species. But the K/θ ratio split each of two liverwort species into two evolutionary species, and showed that support for the distinction between the common and Chihuahuan raven species is weak. I also discuss some possible sources of error in using the K/θ ratio; the most significant one would be cases where males migrate between different populations but females do not, making the use of maternally inherited organelle genes problematic. The K/θ ratio must be used with some caution, like all other methods for species delimitation. Nevertheless, it is a simple theory-based quantitative method for using DNA sequences to make rigorous decisions about species delimitation in sexual as well as asexual eukaryotes. PMID:23308113

  18. Species Detection and Identification in Sexual Organisms Using Population Genetic Theory and DNA Sequences

    PubMed Central

    Birky, C. William

    2013-01-01

    Phylogenetic trees of DNA sequences of a group of specimens may include clades of two kinds: those produced by stochastic processes (random genetic drift) within a species, and clades that represent different species. The ratio of the mean pairwise sequence difference between a pair of clades (K) to the mean pairwise sequence difference within a clade (θ) can be used to determine whether the clades are samples from different species (K/θ≥4) or the same species (K/θ<4) with probability ≥0.95. Previously I applied this criterion to delimit species of asexual organisms. Here I use data from the literature to show how it can also be applied to delimit sexual species using four groups of sexual organisms as examples: ravens, spotted leopards, sea butterflies, and liverworts. Mitochondrial or chloroplast genes are used because these segregate earlier during speciation than most nuclear genes and hence detect earlier stages of speciation. In several cases the K/θ ratio was greater than 4, confirming the original authors' intuition that the clades were sufficiently different to be assigned to different species. But the K/θ ratio split each of two liverwort species into two evolutionary species, and showed that support for the distinction between the common and Chihuahuan raven species is weak. I also discuss some possible sources of error in using the K/θ ratio; the most significant one would be cases where males migrate between different populations but females do not, making the use of maternally inherited organelle genes problematic. The K/θ ratio must be used with some caution, like all other methods for species delimitation. Nevertheless, it is a simple theory-based quantitative method for using DNA sequences to make rigorous decisions about species delimitation in sexual as well as asexual eukaryotes. PMID:23308113

  19. Can sexual selection theory inform genetic management of captive populations? A review

    PubMed Central

    Chargé, Rémi; Teplitsky, Céline; Sorci, Gabriele; Low, Matthew

    2014-01-01

    Captive breeding for conservation purposes presents a serious practical challenge because several conflicting genetic processes (i.e., inbreeding depression, random genetic drift and genetic adaptation to captivity) need to be managed in concert to maximize captive population persistence and reintroduction success probability. Because current genetic management is often only partly successful in achieving these goals, it has been suggested that management insights may be found in sexual selection theory (in particular, female mate choice). We review the theoretical and empirical literature and consider how female mate choice might influence captive breeding in the context of current genetic guidelines for different sexual selection theories (i.e., direct benefits, good genes, compatible genes, sexy sons). We show that while mate choice shows promise as a tool in captive breeding under certain conditions, for most species, there is currently too little theoretical and empirical evidence to provide any clear guidelines that would guarantee positive fitness outcomes and avoid conflicts with other genetic goals. The application of female mate choice to captive breeding is in its infancy and requires a goal-oriented framework based on the needs of captive species management, so researchers can make honest assessments of the costs and benefits of such an approach, using simulations, model species and captive animal data. PMID:25553072

  20. Can sexual selection theory inform genetic management of captive populations? A review.

    PubMed

    Chargé, Rémi; Teplitsky, Céline; Sorci, Gabriele; Low, Matthew

    2014-11-01

    Captive breeding for conservation purposes presents a serious practical challenge because several conflicting genetic processes (i.e., inbreeding depression, random genetic drift and genetic adaptation to captivity) need to be managed in concert to maximize captive population persistence and reintroduction success probability. Because current genetic management is often only partly successful in achieving these goals, it has been suggested that management insights may be found in sexual selection theory (in particular, female mate choice). We review the theoretical and empirical literature and consider how female mate choice might influence captive breeding in the context of current genetic guidelines for different sexual selection theories (i.e., direct benefits, good genes, compatible genes, sexy sons). We show that while mate choice shows promise as a tool in captive breeding under certain conditions, for most species, there is currently too little theoretical and empirical evidence to provide any clear guidelines that would guarantee positive fitness outcomes and avoid conflicts with other genetic goals. The application of female mate choice to captive breeding is in its infancy and requires a goal-oriented framework based on the needs of captive species management, so researchers can make honest assessments of the costs and benefits of such an approach, using simulations, model species and captive animal data. PMID:25553072

  1. Sexual and postmating reproductive isolation between allopatric Drosophila montana populations suggest speciation potential

    PubMed Central

    2011-01-01

    Background Widely distributed species with populations adapted to different environmental conditions can provide valuable opportunities for tracing the onset of reproductive incompatibilities and their role in the speciation process. Drosophila montana, a D. virilis group species found in high latitude boreal forests in Nearctic and Palearctic regions around the globe, could be an excellent model system for studying the early stages of speciation, as a wealth of information concerning this species' ecology, mating system, life history, genetics and phylogeography is available. However, reproductive barriers between populations have hereto not been investigated. Results We report both pre- and postmating barriers to reproduction between flies from European (Finnish) and North American (Canadian) populations of Drosophila montana. Using a series of mate-choice designs, we show that flies from these two populations mate assortatively (i.e., exhibit significant sexual isolation) while emphasizing the importance of experimental design in these kinds of studies. We also assessed potential postmating isolation by quantifying egg and progeny production in intra- and interpopulation crosses and show a significant one-way reduction in progeny production, affecting both male and female offspring equally. Conclusion We provide evidence that allopatric D. montana populations exhibit reproductive isolation and we discuss the potential mechanisms involved. Our data emphasize the importance of experimental design in studies on premating isolation between recently diverged taxa and suggest that postmating barriers may be due to postcopulatory-prezygotic mechanisms. D. montana populations seem to be evolving multiple barriers to gene flow in allopatry and our study lays the groundwork for future investigations of the genetic and phenotypic mechanisms underlying these barriers. PMID:21396136

  2. The effect of variable frequency of sexual reproduction on the genetic structure of natural populations of a cyclical parthenogen.

    PubMed

    Allen, Desiree E; Lynch, Michael

    2012-03-01

    Cyclical parthenogens are a valuable system in which to empirically test theoretical predictions as to the genetic consequences of sexual reproduction in natural populations, particularly if the frequency of sexual relative to asexual reproduction can be quantified. In this study, we used a series of lake populations of the cyclical parthenogen, Daphnia pulicaria, that vary consistently in their investment in sexual reproduction, to address the questions of whether the ecological variation in investment in sex is detectable at the genetic level, and if so, whether the genetic patterns seen are consistent with theoretical predictions. We show that there is variation in the genetic structure of these populations in a manner consistent with their investment in sexual reproduction. Populations engaging in a high frequency of sex were in Hardy-Weinberg and gametic phase equilibrium, and showed little genotypic differentiation across sampled years. In contrast, populations with a lower frequency of sex deviated widely from equilibrium, had reduced multilocus clonal diversity, and showed significant temporal genotypic deviation. PMID:22380451

  3. Trends in sexually transmitted infections in general practice 1990-2000: population based study using data from the UK general practice research database

    PubMed Central

    Cassell, Jackie A; Mercer, Catherine H; Sutcliffe, Lorna; Petersen, Irene; Islam, Amir; Brook, M Gary; Ross, Jonathan D; Kinghorn, George R; Simms, Ian; Hughes, Gwenda; Majeed, Azeem; Stephenson, Judith M; Johnson, Anne M; Hayward, Andrew C

    2006-01-01

    Objective To describe the contribution of primary care to the diagnosis and management of sexually transmitted infections in the United Kingdom, 1990-2000, in the context of increasing incidence of infections in genitourinary medicine clinics. Design Population based study. Setting UK primary care. Participants Patients registered in the UK general practice research database. Main outcome measures Incidence of diagnosed sexually transmitted infections in primary care and estimation of the proportion of major such infections diagnosed in primary care. Results An estimated 23.0% of chlamydia cases in women but only 5.3% in men were diagnosed and treated in primary care during 1998-2000, along with 49.2% cases of non-specific urethritis and urethral discharge in men and 5.7% cases of gonorrhoea in women and 2.9% in men. Rates of diagnosis in primary care rose substantially in the late 1990s. Conclusions A substantial and increasing number of sexually transmitted infections are diagnosed and treated in primary care in the United Kingdom, with sex ratios differing from those in genitourinary medicine clinics. Large numbers of men are treated in primary care for presumptive sexually transmitted infections. PMID:16439371

  4. Predicting sexual infidelity in a population-based sample of married individuals.

    PubMed

    Whisman, Mark A; Gordon, Kristina Coop; Chatav, Yael

    2007-06-01

    Predictors of 12-month prevalence of sexual infidelity were examined in a population-based sample of married individuals (N = 2,291). Predictor variables were organized in terms of involved-partner (e.g., personality, religiosity), marital (e.g., marital dissatisfaction, partner affair), and extradyadic (e.g., parenting) variables. Annual prevalence of infidelity was 2.3%. Controlling for marital dissatisfaction and demographic variables, infidelity was predicted by greater neuroticism and lower religiosity; wives' pregnancy also increased the risk of infidelity for husbands. In comparison, self-esteem and partners' suspected affair were predictive of infidelity when controlling for demographic variables but were not uniquely predictive of infidelity when also controlling for marital dissatisfaction. Religiosity and wives' pregnancy moderated the association between marital dissatisfaction and infidelity. PMID:17605555

  5. Inclusive fitness and sexual conflict: how population structure can modulate the battle of the sexes.

    PubMed

    Pizzari, Tommaso; Biernaskie, Jay M; Carazo, Pau

    2015-02-01

    Competition over reproductive opportunities among members of one sex often harms the opposite sex, creating a conflict of interest between individual males and females. Recently, this battle of the sexes has become a paradigm in the study of intersexual coevolution. Here, we review recent theoretical and empirical advances suggesting that - as in any scenario of intraspecific competition - selfishness (competitiveness) can be influenced by the genetic relatedness of competitors. When competitors are positively related (e.g. siblings), an individual may refrain from harming its competitor(s) and their mate(s) because this can improve the focal individual's inclusive fitness. These findings reveal that population genetic structure might be of paramount importance when studying the battle of the sexes. We conclude by identifying some new lines of research at the interface of sexual selection and social evolution. PMID:25389109

  6. Evaluation of three gears for sampling spawning populations of rainbow trout in a large Alaskan river

    USGS Publications Warehouse

    Schwanke, C.J.; Hubert, W.A.

    2004-01-01

    Alternatives to electrofishing are needed for sampling sexually mature rainbow trout Oncorhynchus mykiss during the spawning season in large Alaskan rivers. We compared hook and line, beach seining, and actively fished gill nets as sampling tools. Beach seining and active gill netting yielded similar catch rates, length frequencies, and sex ratios of sexually mature fish. Hook-and-line sampling was less effective, with a lower catch rate and selectivity for immature fish and sexually mature females. We conclude that both beach seining and active gill netting can serve as alternatives to electrofishing for sampling sexually mature rainbow trout stocks during the spawning season in large rivers with stable spring flows and spawning areas with few snags.

  7. Advances in Substance Abuse Prevention and Treatment Interventions Among Racial, Ethnic, and Sexual Minority Populations

    PubMed Central

    Blume, Arthur W.

    2016-01-01

    Substance abuse research among racial, ethnic, and sexual minority populations historically has lagged behind that conducted with majority samples. However, interesting and potentially important advances in prevention, brief interventions, and treatment have been made in the last few years, at least among some minority populations, such as American Indian youth. New prevention efforts have focused on point-of-sale interventions for alcohol, as well as on family-unit interventions designed with subpopulation cultural values in mind. In addition, previously established evidence-based and culturally relevant interventions are being combined with computer technology. Empirical data support using brief interventions with patients of color in medical settings, capitalizing on teachable and reachable moments during a physical trauma or other health crisis. Finally, use of empirically supported treatment may be helpful, with a caveat that these interventions must appropriately match cultural traditions and respect the values of the clients. More research clearly is needed, especially among certain minority populations in the United States. A greater emphasis should be placed on developing novel, culturally grounded interventions in partnership with communities, in addition to adapting existing mainstream interventions for use by other cultures. PMID:27159811

  8. Use of the Internet for Sexual Health Among Sexually Experienced Persons Aged 16 to 44 Years: Evidence from a Nationally Representative Survey of the British Population

    PubMed Central

    Estcourt, Claudia S; Johnson, Anne M; Sonnenberg, Pam; Wellings, Kaye; Mercer, Catherine H

    2016-01-01

    Background Those who go online regarding their sexual health are potential users of new Internet-based sexual health interventions. Understanding the size and characteristics of this population is important in informing intervention design and delivery. Objective We aimed to estimate the prevalence in Britain of recent use of the Internet for key sexual health reasons (for chlamydia testing, human immunodeficiency virus [HIV] testing, sexually transmitted infection [STI] treatment, condoms/contraceptives, and help/advice with one’s sex life) and to identify associated sociodemographic and behavioral factors. Methods Complex survey analysis of data from 8926 sexually experienced persons aged 16-44 years in a 2010-2012 probability survey of Britain’s resident population. Prevalence of recent (past year) use of Internet sources for key sexual health reasons was estimated. Factors associated with use of information/support websites were identified using logistic regression to calculate age-adjusted odds ratios (AORs). Results Recent Internet use for chlamydia/HIV testing or STI treatment (combined) was very low (men: 0.31%; women: 0.16%), whereas 2.35% of men and 0.51% of women reported obtaining condoms/contraceptives online. Additionally, 4.49% of men and 4.57% of women reported recent use of information/support websites for advice/help with their sex lives. Prevalence declined with age (men 16-24 years: 7.7%; 35-44 years: 1.84%, P<.001; women 16-24 years: 7.8%; 35-44 years: 1.84%, P<.001). Use of information/support websites was strongly associated with men’s higher socioeconomic status (managerial/professional vs semiroutine/routine: AOR 1.93, 95% CI 1.27-2.93, P<.001). Despite no overall association with area-level deprivation, those in densely populated urban areas were more likely to report use of information/support websites than those living in rural areas (men: AOR 3.38, 95% CI 1.68-6.77, P<.001; women: AOR 2.51, 95% CI 1.34-4.70, P<.001). No statistically significant association was observed with number of sex partners reported after age adjustment, but use was more common among men reporting same-sex partners (last 5 years: AOR 2.44, 95% CI 1.27-4.70), women reporting sex with multiple partners without condoms (last year: AOR 1.90, 95% CI 1.11-3.26), and, among both sexes, reporting seeking sex online (last year, men: AOR 1.80, 95% CI 1.16-2.79; women: AOR 3.00, 95% CI 1.76-5.13). No association was observed with reporting STI diagnosis/es (last 5 years) or (after age adjustment) recent use of any STI service or non-Internet sexual health seeking. Conclusions A minority in Britain used the Internet for the sexual health reasons examined. Use of information/support websites was reported by those at greater STI risk, including younger people, indicating that demand for online STI services, and Internet-based sexual health interventions in general, may increase over time in this and subsequent cohorts. However, the impact on health inequalities needs addressing during design and evaluation of online sexual health interventions so that they maximize public health benefit. PMID:26792090

  9. Large scale structure of the globular cluster population in Coma

    NASA Astrophysics Data System (ADS)

    Gagliano, Alexander T.; O'Neill, Conor; Madrid, Juan P.

    2016-01-01

    A search for globular cluster candidates in the Coma Cluster was carried out using Hubble Space Telescope data taken with the Advanced Camera for Surveys. We combine different observing programs including the Coma Treasury Survey in order to obtain the large scale distribution of globular clusters in Coma. Globular cluster candidates were selected through careful morphological inspection and a detailed analysis of their magnitude and colors in the two available wavebands, F475W (Sloan g) and F814W (I). Color Magnitude Diagrams, radial density plots and density maps were then created to characterize the globular cluster population in Coma. Preliminary results show the structure of the intergalactic globular cluster system throughout Coma, among the largest globular clusters catalogues to date. The spatial distribution of globular clusters shows clear overdensities, or bridges, between Coma galaxies. It also becomes evident that galaxies of similar luminosity have vastly different numbers of associated globular clusters.

  10. The Sexual Risk Context among the FEM-PrEP Study Population in Bondo, Kenya and Pretoria, South Africa

    PubMed Central

    Headley, Jennifer; Lemons, Ansley; Corneli, Amy; Agot, Kawango; Ahmed, Khatija; Wang, Meng; Odhiambo, Jacob; Skhosana, Joseph; Tharaldson, Jenae; Van Damme, Lut; MacQueen, Kathleen

    2014-01-01

    Background Incidence rates in the FEM-PrEP and VOICE trials demonstrate that women from diverse sub-Saharan African communities continue to be at substantial HIV risk. Objective To describe and compare the sexual risk context of the study population from two FEM-PrEP trial sites–Bondo, Kenya, and Pretoria, South Africa. Methods At baseline we collected information about demographics, sexual behaviors, and partnership beliefs through quantitative questionnaires with all participants (Bondo, n = 720; Pretoria, n = 750). To explore the sexual risk context, we also conducted qualitative, semi-structured interviews with HIV-negative participants randomly selected at several time points (Bondo, n = 111; Pretoria, n = 69). Results Demographics, sexual behavior, and partnership beliefs varied significantly between the sites. Bondo participants were generally older, had fewer years of schooling, and were more likely to be employed and married compared to Pretoria participants. Bondo participants were more likely to report multiple partners and not knowing whether their partner had HIV than Pretoria participants. A significantly higher percentage of Bondo participants reported engaging in sex without a condom with their primary and other partners compared to Pretoria participants. We found a borderline association between participants who reported not using condoms in the 4 weeks prior to baseline and lower risk of HIV infection, and no association between having more than one sexual partner at baseline and HIV infection. Discussion Despite significantly different demographics, sexual behaviors, and partnership beliefs, many women in the FEM-PrEP trial were at risk of acquiring HIV as demonstrated by the sites’ high HIV incidence. Though gender dynamics differed between the populations, they appear to play a critical role in women’s sexual practices. The findings highlight different ways women from diverse contexts may be at-risk for HIV and the importance of providing HIV prevention options that are both effective and feasible given personal and social circumstances. PMID:25229403

  11. Cryptic sexual populations account for genetic diversity and ecological success in a widely distributed, asexual fungus-growing ant

    PubMed Central

    Rabeling, Christian; Gonzales, Omar; Schultz, Ted R.; Bacci, Maurício; Garcia, Marcos V. B.; Verhaagh, Manfred; Ishak, Heather D.; Mueller, Ulrich G.

    2011-01-01

    Sex and recombination are central processes in life generating genetic diversity. Organisms that rely on asexual propagation risk extinction due to the loss of genetic diversity and the inability to adapt to changing environmental conditions. The fungus-growing ant species Mycocepurus smithii was thought to be obligately asexual because only parthenogenetic populations have been collected from widely separated geographic localities. Nonetheless, M. smithii is ecologically successful, with the most extensive distribution and the highest population densities of any fungus-growing ant. Here we report that M. smithii actually consists of a mosaic of asexual and sexual populations that are nonrandomly distributed geographically. The sexual populations cluster along the Rio Amazonas and the Rio Negro and appear to be the source of independently evolved and widely distributed asexual lineages, or clones. Either apomixis or automixis with central fusion and low recombination rates is inferred to be the cytogenetic mechanism underlying parthenogenesis in M. smithii. Males appear to be entirely absent from asexual populations, but their existence in sexual populations is indicated by the presence of sperm in the reproductive tracts of queens. A phylogenetic analysis of the genus suggests that M. smithii is monophyletic, rendering a hybrid origin of asexuality unlikely. Instead, a mitochondrial phylogeny of sexual and asexual populations suggests multiple independent origins of asexual reproduction, and a divergence-dating analysis indicates that M. smithii evolved 0.5–1.65 million years ago. Understanding the evolutionary origin and maintenance of asexual reproduction in this species contributes to a general understanding of the adaptive significance of sex. PMID:21768368

  12. Treatment-seeking behavior for sexually transmitted infections in a high-risk population.

    PubMed

    Rosenheck, Rachel; Ngilangwa, David; Manongi, Rachael; Kapiga, Saidi

    2010-11-01

    The World Health Organization estimates that 340 million new cases of curable sexually transmitted infections (STIs) occur every year, while 33 million individuals are estimated to be living with HIV. The AIDS and STI epidemics are not independent with untreated STIs increasing HIV acquisition and transmission. Female sex workers have increased prevalence of untreated STIs and have been hypothesized to affect the health and HIV incidence of the general population. This paper aims to investigate why some female sex workers who experience symptoms of vaginal discharge or genital ulcers seek treatment while others do not. Data were collected from a cohort study conducted between 2002 and 2005 among female bar and hotel workers in Moshi, Tanzania. Study subjects were recruited from 7 out of 15 administrative wards in Moshi as part of the Moshi's Women's Health Project. Data were restricted to women self-reporting symptoms of vaginal discharge or genital ulcers (n=459) within the past year. Logistic regression was performed with SAS 9.1. Qualitative analysis was performed using in-depth interviews and focus group discussions among a convenience sample (n=42) of women already enrolled in the study. All interviews and focus group discussions were tape-recorded and transcribed, and data were analyzed thematically. Sixty-four percent of the sample sought treatment for either ailment. Multivariate analysis identified relationship to man of last sexual intercourse, ever experiencing a pregnancy, and age as significant predictors to seeking treatment. Four salient themes of threats to fertility, stigma correlated with prostitution, discomfort with the physical exam, and perceived views of clients were revealed as predictors to why women seek or intentionally ignore symptoms. Understanding the motivations and barriers for seeking treatment of STIs has far ranging public health implications that could help curtail the unnecessary associated morbidity and mortality and curtail the transmission of HIV. PMID:20635239

  13. Prevalence of sexually transmitted pathogens associated with HPV infection in cervical samples in a Mexican population.

    PubMed

    Magaa-Contreras, Mariana; Contreras-Paredes, Adriana; Chavez-Blanco, Alma; Lizano, Marcela; De la Cruz-Hernandez, Yanira; De la Cruz-Hernandez, Erick

    2015-12-01

    Cervical cancer development has been mainly associated with persistent human papillomavirus (HPV) infections. However, HPV infection is unlikely to be sufficient to cause cervical cancer, and the contribution of other sexually transmitted infections (STIs) could be the determining factor for cervical lesion-progression. The aim of this study was to estimate the prevalence of STIs associated with HPV-positivity in 201 cervical samples from patients who underwent annual routine gynecological exams. The overall prevalence of STIs was 57.7%, and the most frequent infection was Ureaplasma spp (UP) (39.8%), followed by Gardnerella vaginalis (GV) (25.9%), ?-HPV (18.4%), Chlamydia trachomatis (CT) (1.5%), and Mycoplasma genitalium (MG) (0.5%). The highest prevalence rate of multiple non-HPV infections was observed for the age-range 31-40; for papillomavirus infection, the age-range was 21-30. In normal cervical samples, HPV16 was the most prevalent genotype (24.3%), followed by genotypes 58 (13.5%) and 52 (10.8%). Intriguingly, HPV18 was not detected in the study population, and genotypes 52 and 58 were found exclusively in samples with abnormal cytology. Papillomavirus infection with oncogenic types was significantly associated with GV (P?=?0.025) and strongly associated with multiple non-HPV pathogens (P?=?0.002). The following variables correlated significantly with cytological diagnosis of low-grade squamous intraepithelial lesion (LSIL): GV (P?=?0.028), multiple non-HPV infections (P?=?0.001), and high-risk HPV positivity (P?=?0.001). Epidemiological data from this study will contribute to the molecular detection of sexually transmitted pathogens from screening programs to identify those women who are at risk for developing cervical lesions. PMID:26010580

  14. Contrasting Life Histories in Neighbouring Populations of a Large Mammal

    PubMed Central

    Mason, Tom H. E.; Chirichella, Roberta; Richards, Shane A.; Stephens, Philip A.; Willis, Stephen G.; Apollonio, Marco

    2011-01-01

    Background A fundamental life history question is how individuals should allocate resources to reproduction optimally over time (reproductive allocation). The reproductive restraint hypothesis predicts that reproductive effort (RE; the allocation of resources to current reproduction) should peak at prime-age, whilst the terminal investment hypothesis predicts that individuals should continue to invest more resources in reproduction throughout life, owing to an ever-decreasing residual reproductive value. There is evidence supporting both hypotheses in the scientific literature. Methodology/Principal Findings We used an uncommonly large, 38 year dataset on Alpine chamois (Rupicapra rupicapra) shot at various times during the rutting period to test these two hypotheses. We assumed that body mass loss in rutting males was strongly related to RE and, using a process-based approach, modelled how male relative mass loss rates varied with age. For different regions of our study area, we provide evidence consistent with different hypotheses for reproductive allocation. In sites where RE declined in older age, this appears to be strongly linked to declining body condition in old males. In this species, terminal investment may only occur in areas with lower rates of body mass senescence. Conclusions/Significance Our results show that patterns of reproductive allocation may be more plastic than previously thought. It appears that there is a continuum from downturns in RE at old age to terminal investment that can be manifest, even across adjacent populations. Our work identifies uncertainty in the relationship between reproductive restraint and a lack of competitive ability in older life (driven by body mass senescence); both could explain a decline in RE in old age and may be hard to disentangle in empirical data. We discuss a number of environmental and anthropogenic factors which could influence reproductive life histories, underlining that life history patterns should not be generalised across different populations. PMID:22125651

  15. The denominator problem: Estimating MSM-specific incidence of sexually transmitted infections and prevalence of HIV using population sizes of MSM derived from Internet surveys

    PubMed Central

    Marcus, Ulrich; Schmidt, Axel J; Kollan, Christian; Hamouda, Osamah

    2009-01-01

    Background Measuring prevalence and incidence of sexually transmitted infections in hard to reach populations like men who have sex with men (MSM) is hampered by unknown size and regional distribution of this population. Community sample – and study-based measurements are often fraught with participation biases and do not allow generalization of the results for other regions or the whole population group of MSM. Methods We used the proportional regional distribution of participants of large internet-based surveys among MSM from Germany together with a general population survey-derived estimate of the MSM population to estimate regional population sizes. Based on transmission group category from surveillance data and regional MSM population size we calculated regional population-specific incidence rates of newly diagnosed HIV infection and syphilis. For HIV prevalence we compared estimates of prevalent HIV infections in MSM from a surveillance data-based model with a mixed model in which we used the proportional regional distribution of HIV positive participants from surveys and the estimated total number of prevalent HIV infections from the surveillance based model. Results Assuming a similar regional distribution of survey participants and the MSM population as a whole, the regional proportion of MSM in the general population can be estimated. Regional incidence calculated with the estimated MSM population as denominator and national surveillance data as numerator results in regional peak incidence rates of 7–8 per 1,000 MSM for newly diagnosed HIV infection and syphilis. The gradient between metropolitan and rural areas narrows considerably compared with calculations which use the total (male) population as denominator. Regional HIV prevalence estimates are comparable in the two models. Conclusion Considering the difficulties to obtain regionally representative data by other sampling methods for MSM, in Western post-industrialized countries internet-based surveys may provide an easy and low cost tool to estimate regional population distributions. With national surveillance data, which categorize transmission groups, regional population-specific incidence rates for reportable sexually transmitted infections can be estimated. HIV prevalence estimates for regional MSM populations show differences related to the level of urbanization, MSM concentration, and starting points of the HIV epidemic in western and eastern Germany. PMID:19519889

  16. Preferential sexual transmission of pseudorabies virus in feral swine populations may not account for observed seroprevalence in the USA

    PubMed Central

    Smith, Gary

    2013-01-01

    This paper compares the behavior of two competing models for the transmission of pseudorabies virus in feral swine in the USA. In first model, horizontal (non-sexual) density dependent transmission is the only transmission modality. In the second model, the only transmission modality is sexual transmission between mature males and females. The comparison of model behavior was carried out to test the hypothesis that preferential sexual transmission of PRV in feral swine can account for the seroprevalence observed in the field. The observed range of seroprevalence of PRV in mature feral swine in the USA is consistent with a preferential sexual transmission only if the feral swine mating system is a random mating system or a polygynous system in which there is a relatively large rate of acquisition of new mates. The observed range of seroprevalence of PRV in mature feral swine in the USA is not consistent with a preferential sexual transmission if there is mate guarding. This is important because the National Pseudorabies Surveillance Plan deems monitoring the risk of PRV introduction from feral swine to be a “minor objective” both in terms of the scope of the plan and with respect to the resources allocated. The rationale for this statement was derived from experimental studies, which suggested that the PRV indigenous to feral swine in the USA is preferentially sexually transmitted. PMID:21962753

  17. Large scale genotyping study for asthma in the Japanese population

    PubMed Central

    Imada, Yoshiko; Fujimoto, Masaya; Hirata, Kenji; Hirota, Tomomitsu; Suzuki, Yoichi; Saito, Hirohisa; Matsumoto, Kenji; Akazawa, Akira; Katsunuma, Toshio; Yoshihara, Shigemi; Ebisawa, Motohiro; Shibasaki, Masanao; Arinami, Tadao; Tamari, Mayumi; Noguchi, Emiko

    2009-01-01

    Background Asthma is a complex phenotype that is influenced by both genetic and environmental factors. Genome-wide linkage and association studies have been performed to identify susceptibility genes for asthma. These studies identified new genes and pathways implicated in this disease, many of which were previously unknown. Objective To perform a large-scale genotyping study to identify asthma-susceptibility genes in the Japanese population. Methods We performed a large-scale, three-stage association study on 288 atopic asthmatics and 1032 controls, by using multiplex PCR-Invader assay methods at 82,935 single nucleotide polymorphisms (SNPs) (1st stage). SNPs that were strongly associated with asthma were further genotyped in samples from asthmatic families (216 families, 762 members, 2nd stage), 541 independent patients, and 744 controls (3rd stage). Results SNPs located in the 5' region of PEX19 (rs2820421) were significantly associated with P < 0.05 through the 1st to the 3rd stage analyses; however, the P values did not reach statistically significant levels (combined, P = 3.8 × 10-5; statistically significant levels with Bonferroni correction, P = 6.57 × 10-7). SNPs on HPCAL1 (rs3771140) and on IL18R1 (rs3213733) were associated with asthma in the 1st and 2nd stage analyses, but the associations were not observed in the 3rd stage analysis. Conclusion No association attained genome-wide significance, but several loci for possible association emerged. Future studies are required to validate these results for the prevention and treatment of asthma. PMID:19335888

  18. The role of sexual and asexual reproduction in structuring high latitude populations of the reef coral Pocillopora damicornis.

    PubMed

    Miller, K J; Ayre, D J

    2004-06-01

    The genotypic composition of populations of the asexually viviparous coral Pocillopora damicornis varies in a manner that challenges classical models of the roles of sexual and asexual reproduction. On the geographically isolated Hawaiian reefs and high latitude reefs in Western Australia, P. damicornis populations are highly clonal although it has been argued that sexual reproduction via broadcast spawning generates widely dispersed colonists. In contrast, on eastern Australia's tropical Great Barrier Reef populations show little evidence of clonality. Here, we compare the genotypic diversity of adult and juvenile colonies of P. damicornis at seven sites on eastern Australia's high latitude Lord Howe Island reefs to determine if levels of clonality vary with habitat heterogeneity and age of colonies (as predicted by theory) or alternatively if clonality is again always high as for other isolated reef systems. We found 55-100% of the genotypic diversity expected for random mating at all seven sites and little evidence of asexual recruitment irrespective of habitat heterogeneity (sheltered versus wave exposed) or colony age. We found reduced levels of genetic diversity compared with tropical reefs (2.75 versus 4 alleles/locus), which supports earlier findings that Lord Howe Island is an isolated reef system. Furthermore, heterozygote deficits coupled with significant genetic subdivision among sites (FST=0.102+/-0.03) is typical of populations that have limited larval connections and are inbred. We conclude that the genetic structure of P. damicornis at Lord Howe Island reflects populations that are maintained through localised recruitment of sexually produced larvae. PMID:15100708

  19. Sexual and topological differences in palmprint and ridge density in the caucasian Spanish population.

    PubMed

    Gutiérrez-Redomero, Esperanza; Alonso-Rodríguez, Concepción

    2013-06-10

    Despite the fact that variation in ridge breadth is of biological, medical, and genetic interest, it has not received as much attention as other dermatoglyphic characteristics. Recently, sex differences in mean epidermal ridge breadth have been proposed in the field of forensic identification in order to infer gender from fingerprints found at the scene of a crime left by an unknown donor. The aim of this research was to analyze sexual, bimanual, and topological variations in epidermal ridge breadth on palmprints taken from a Spanish population sample for subsequent application in inferring gender from the palm marks. The material used in the present study was obtained from the palmprints of 200 individuals (100 males and 100 females) from the Caucasian Spanish. Since ridge breadth varies according to age, subjects of similar ages were recruited to ensure that growth had finished. Therefore, in order to assess topological variation in ridge density or number of ridges in a given space, the count was carried out for the five palmar areas: hypothenar, thenar/first interdigital, second interdigital, third interdigital, and fourth interdigital. This allowed the segmentation of 2000 ridge count areas for analysis. For this, two methods were used, one described by Cummins et al. (the ridge count was carried out along a 1cm line) and the other by Acree (the number of ridges per 25 mm(2) of surface area). The results obtained by the second method can be compared with those obtained for the ten fingers from this same sample and evaluated in a previous study. The results have demonstrated the existence of topological differences in ridge thickness on the epidermal palm surface; also females present a significantly higher ridge density than men and, therefore, have narrower ridges over the entire palmar surface. Those sexual differences found in the sample population can be used for inferring the gender from palm marks left by an unknown donor. The hypotheses that could explain the variability in ridge breadth are evaluated according to the obtained results. PMID:23601151

  20. Men's sexual interest in children: one-year incidence and correlates in a population-based sample of Finnish male twins.

    PubMed

    Santtila, Pekka; Antfolk, Jan; Räfså, Anna; Hartwig, Maria; Sariola, Heikki; Sandnabba, N Kenneth; Mokros, Andreas

    2015-01-01

    In a study of 1,310 Finnish adult male twins we found that sexual interest in children aged 12 or younger was reported by 0.2% of the sample. Sexual interest in children aged 15 or younger was reported by 3.3%. Participants reporting sexual interest in children aged 15 or younger were younger, reported stronger sexual desire, and had experienced more childhood sexual and nonsexual abuse. The present study is the first to give a population-based estimate of the incidence of sexual interest in children among adult men. The 12-month incidence of sexual interest in children below the age of 16 years is roughly comparable to the one-year incidence of major depression or the lifetime prevalence of transvestitic fetishism. PMID:25747416

  1. Validation and cross-cultural adaptation of sexual dysfunction modified scale in multiple sclerosis for Brazilian population.

    PubMed

    Silva, Raquel Ataíde Peres da; Olival, Guilherme Sciascia do; Stievano, Lívia Palma; Toller, Vania Balardin; Jordy, Sergio Semeraro; Eloi, Marina; Tilbery, Charles Peter

    2015-08-01

    Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). These patients suffer from various comorbidities, including sexual dysfunction (SD). The lesions of MS may affect regions of the CNS along the pathway of sexual response. The Multiple Sclerosis Intimacy and Sexuality Questionnaire-19 (MSISQ-19) is a scale that assesses sexual dysfunction. Adapt and validate the MSISQ-19 to Brazilian patients with MS. 204 individuals were evaluated, 134 patients with MS and 70 healthy persons for the control group. It was determined reproducibility, validity, internal consistency and sensitivity of the MSISQ-19-BR. Among patients with MS, 54.3% of male and 71.7% of female presented some kind of SD. In the control group the results were 12.5% and 19.5%, respectively. The MSISQ-19-BR is reproducible, reliable and valid for the Brazilian population and may be used as a tool for assessing the impact of sexual dysfunction in patients with MS. PMID:26222360

  2. Multi-level sexual selection: Individual and family-level selection for mating success in a historical human population

    PubMed Central

    Moorad, Jacob

    2013-01-01

    Precopulatory sexual selection is the association between fitness and traits associated with mate acquisition. While sexual selection is generally recognized to be a powerful evolutionary force, most investigations are limited to characters belonging to individuals. A broader multi-level perspective acknowledges that individual fitness can be affected by aspects of mating success that are characters of groups, such as families. Parental mating success in polygynous or polyandrous human societies may exemplify traits under group-level sexual selection. Using fitness measures that account for age-structure, I measure multi-level selection for mate number over 55 years in a human population with declining rates of polygyny. Sexual selection had three components: individual-level selection for ever-mating (whether or not an individual mated) and individual- and family-level selection for polyandry and polygyny. Family- and individual-level selection for polygyny was equally strong, three times stronger than family-level selection for polyandry and more than an order of magnitude stronger than individual-level selection for polyandry. However, individual-level selection for polyandry and polygyny was more effective at explaining relative fitness variance than family-level selection. Selection for ever-mating was the most important source of sexual selection for fitness; variation for ever-mating explained 23% of relative fitness variance. PMID:23730758

  3. Antarctic krill population genomics: apparent panmixia, but genome complexity and large population size muddy the water.

    PubMed

    Deagle, Bruce E; Faux, Cassandra; Kawaguchi, So; Meyer, Bettina; Jarman, Simon N

    2015-10-01

    Antarctic krill (Euphausia superba; hereafter krill) are an incredibly abundant pelagic crustacean which has a wide, but patchy, distribution in the Southern Ocean. Several studies have examined the potential for population genetic structuring in krill, but DNA-based analyses have focused on a limited number of markers and have covered only part of their circum-Antarctic range. We used mitochondrial DNA and restriction site-associated DNA sequencing (RAD-seq) to investigate genetic differences between krill from five sites, including two from East Antarctica. Our mtDNA results show no discernible genetic structuring between sites separated by thousands of kilometres, which is consistent with previous studies. Using standard RAD-seq methodology, we obtained over a billion sequences from >140 krill, and thousands of variable nucleotides were identified at hundreds of loci. However, downstream analysis found that markers with sufficient coverage were primarily from multicopy genomic regions. Careful examination of these data highlights the complexity of the RAD-seq approach in organisms with very large genomes. To characterize the multicopy markers, we recorded sequence counts from variable nucleotide sites rather than the derived genotypes; we also examined a small number of manually curated genotypes. Although these analyses effectively fingerprinted individuals, and uncovered a minor laboratory batch effect, no population structuring was observed. Overall, our results are consistent with panmixia of krill throughout their distribution. This result may indicate ongoing gene flow. However, krill's enormous population size creates substantial panmictic inertia, so genetic differentiation may not occur on an ecologically relevant timescale even if demographically separate populations exist. PMID:26340718

  4. Sexual and reproductive knowledge, attitudes and behaviours in a school going population of Sri Lankan adolescents.

    PubMed

    Rajapaksa-Hewageegana, Neelamani; Piercy, Hilary; Salway, Sarah; Samarage, Sarath

    2015-03-01

    The reproductive and sexual health of adolescents is an important health concern and a focus of global attention. In Sri Lanka, a lack of understanding about adolescent reproductive and sexual health needs is a matter of national concern. A survey was undertaken to examine the sexual knowledge, attitudes and behaviours of school going adolescents in Sri Lanka. A random sample of schools was selected from one district. Data were collected by a self-completion questionnaire and analysed using SPSS. Response rate was 90%. 2020 pupils (26% boys, 74% girls) aged 16-19 years (mean=16.9) participated, the majority Sinhalese (97%). Most reported a good parent-child relationship (88%). A minority (34%) discussed sexual issues with parents. Health professionals were the preferred source of sexual information (32%) rather than parents (12.5%) or friends (5.6%). Less than 1% demonstrated satisfactory sexual and reproductive knowledge levels. 1.7% were sexually active (30 boys vs 5 girls), the majority with same age partners. 57% used contraception at first intercourse. There is an imperative to address the lack of sexual and reproductive knowledge. A minority of school going adolescents become sexually active. These individuals are potentially vulnerable and services need to be developed to meet their needs. PMID:25637417

  5. Sexual Abuse and Suicidality: Gender Differences in a Large Community Sample of Adolescents

    ERIC Educational Resources Information Center

    Martin, Graham; Bergen, Helen A.; Richardson, Angela S.; Roeger, Leigh; Allison, Stephen

    2004-01-01

    Objective: A cross-sectional study of gender specific relationships between self-reported child sexual abuse and suicidality in a community sample of adolescents. Method: Students aged 14 years on average (N=2,485) from 27 schools in South Australia completed a questionnaire including items on sexual abuse and suicidality, and measures of…

  6. Psychopathology in a Large Cohort of Sexually Abused Children Followed up to 43 Years

    ERIC Educational Resources Information Center

    Cutajar, Margaret C.; Mullen, Paul E.; Ogloff, James R. P.; Thomas, Stuart D.; Wells, David L.; Spataro, Josie

    2010-01-01

    Objective: To determine the rate and risk of clinical and personality disorders diagnosed in childhood and adulthood in those known to have been sexually abused during childhood. Methods: Forensic medical records of 2,759 sexually abused children assessed between 1964 and 1995 were linked with a public psychiatric database between 12 and 43 years…

  7. Psychopathology in a Large Cohort of Sexually Abused Children Followed up to 43 Years

    ERIC Educational Resources Information Center

    Cutajar, Margaret C.; Mullen, Paul E.; Ogloff, James R. P.; Thomas, Stuart D.; Wells, David L.; Spataro, Josie

    2010-01-01

    Objective: To determine the rate and risk of clinical and personality disorders diagnosed in childhood and adulthood in those known to have been sexually abused during childhood. Methods: Forensic medical records of 2,759 sexually abused children assessed between 1964 and 1995 were linked with a public psychiatric database between 12 and 43 years

  8. The Speed of Evolution in Large Asexual Populations

    NASA Astrophysics Data System (ADS)

    Park, Su-Chan; Simon, Damien; Krug, Joachim

    2010-02-01

    We consider an asexual biological population of constant size N evolving in discrete time under the influence of selection and mutation. Beneficial mutations appear at rate U and their selective effects s are drawn from a distribution g( s). After introducing the required models and concepts of mathematical population genetics, we review different approaches to computing the speed of logarithmic fitness increase as a function of N, U and g( s). We present an exact solution of the infinite population size limit and provide an estimate of the population size beyond which it is valid. We then discuss approximate approaches to the finite population problem, distinguishing between the case of a single selection coefficient, g( s)= δ( s- s b ), and a continuous distribution of selection coefficients. Analytic estimates for the speed are compared to numerical simulations up to population sizes of order 10300.

  9. Sex in an uncertain world: environmental stochasticity helps restore competitive balance between sexually and asexually reproducing populations.

    PubMed

    Park, A W; Vandekerkhove, J; Michalakis, Y

    2014-08-01

    Like many organisms, individuals of the freshwater ostracod species Eucypris virens exhibit either obligate sexual or asexual reproductive modes. Both types of individual routinely co-occur, including in the same temporary freshwater pond (their natural habitat in which they undergo seasonal diapause). Given the well-known two-fold cost of sex, this begs the question of how sexually reproducing individuals are able to coexist with their asexual counterparts in spite of such overwhelming costs. Environmental stochasticity in the form of 'false dawn' inundations (where the first hydration is ephemeral and causes loss of early hatching individuals) may provide an advantage to the sexual subpopulation, which shows greater variation in hatching times following inundation. We explore the potential role of environmental stochasticity in this system using life-history data analysis, climate data, and matrix projection models. In the absence of environmental stochasticity, the population growth rate is significantly lower in sexual subpopulations. Climate data reveal that 'false dawn' inundations are common. Using matrix projection modelling with and without environmental stochasticity, we demonstrate that this phenomenon can restore appreciable balance to the system, in terms of population growth rates. This provides support for the role of environmental stochasticity in helping to explain the maintenance of sex and the occurrence of geographical parthenogenesis. PMID:24836646

  10. Alcohol and Sexuality Research in the AIDS Era: Trends in Publication Activity, Target Populations and Research Design

    PubMed Central

    George, William H.

    2009-01-01

    Research addressing relationships between alcohol and human sexuality has proliferated, due in part to efforts to characterize alcohol's role in HIV risk behavior. This study provides a descriptive review of the alcohol–sexuality literature, using abstracts from 264 identified studies to estimate changes in publication activity, target populations, and the prevalence of HIV-related studies over time. We also examine methodological trends by estimating the prevalence of experimental vs. non-experimental studies. Findings show considerable increases in research activity and diversity of populations studied since the mid-1980's and highlight the emergence of HIV-related studies as a focal point of alcohol–sexuality research efforts. Results also demonstrate a substantial decline in the proportion of studies utilizing experimental methods, in part because of frequent use of non-experimental approaches in studies of alcohol and HIV risk behavior. We discuss implications and review the role of experiments in evaluating causal relationships between alcohol and sexual risk behavior. PMID:16897352

  11. Twenty years after International Conference on Population and Development: where are we with adolescent sexual and reproductive health and rights?

    PubMed

    Chandra-Mouli, Venkatraman; Svanemyr, Joar; Amin, Avni; Fogstad, Helga; Say, Lale; Girard, Françoise; Temmerman, Marleen

    2015-01-01

    The International Conference on Population and Development in Cairo in 1994 laid out a bold, clear, and comprehensive definition of reproductive health and called for nations to meet the educational and service needs of adolescents to enable them to deal in a positive and responsible way with their sexuality. In the context of the ongoing review of the International Conference on Population and Development Programme of Action and the considerations for a post-2015 development agenda, this article summarizes the findings of the articles presented in this volume and identifies key challenges and critical answers that need to be tackled in addressing adolescent sexual and reproductive health and rights. The key recommendations are to link the provision of sexuality education and sexual and reproductive health (SRH) services; build awareness, acceptance, and support for youth-friendly SRH education and services; address gender inequality in terms of beliefs, attitudes, and norms; and target the early adolescent period (10-14 years). The many knowledge gaps, however, point to the pressing need for further research on how to best design effective adolescent SRH intervention packages and how best to deliver them. PMID:25528975

  12. Oral potentially malignant disorders in a large dental population

    PubMed Central

    Alessandro, VILLA; Anita, GOHEL

    2014-01-01

    Objectives Oral cancer (OC) may be preceded by clinically evident oral potentially malignant disorders (OPMDs). Oral carcinogenesis is a multistep process that begins as epithelial hyperplasia and progresses to oral epithelial dysplasia and finally to fully malignant phenotypes. The aim of our study was to estimate the prevalence of OPMDs in a large population of dental patients. Methods Patients were seen in the Oral Diagnosis and Oral Medicine clinics at Boston University Henry M. Goldman School of Dental Medicine between July 2013 and February 2014 and received a comprehensive oral examination to identify any possible mucosal lesions. Patients with a suspected OPMD (submucous fibrosis, oral lichen planus, leukoplakia and erythroplakia) that did not resolve in 2–3 weeks received a biopsy for definitive diagnosis. Logistic regression models were used to explore the relationship between OPMDs and associated risk factors. Results A total of 3,142 patients received a comprehensive oral examination [median age: 43 (range: 18–97); 54.3% females]. Among these, 4.5% had an oral mucosal lesion with 0.9% being an OPMD (one submucous fibrosis, three epithelial dysplasias, fourteen with hyperkeratosis/epithelial hyperplasia and nine with oral lichen planus). Males and current smokers were associated with higher odds of having OPMD (OR 1.7, 95% CI 0.8–3.8; OR 1.9, 95%CI 0.8–4.1). Increasing age was associated with having OPMDs (p<0.01). Conclusion Optimal oral visual screening for OC remains a simple and essential tool to identify any suspicious lesions and potentially increase survival. Although OPMDs were rare, our results confirm the importance of a thorough chairside screening by dentists and dental students to detect any mucosal changes. PMID:25591015

  13. Poppr: an R package for genetic analysis of populations with clonal, partially clonal, and/or sexual reproduction

    PubMed Central

    Tabima, Javier F.; Grünwald, Niklaus J.

    2014-01-01

    Many microbial, fungal, or oomcyete populations violate assumptions for population genetic analysis because these populations are clonal, admixed, partially clonal, and/or sexual. Furthermore, few tools exist that are specifically designed for analyzing data from clonal populations, making analysis difficult and haphazard. We developed the R package poppr providing unique tools for analysis of data from admixed, clonal, mixed, and/or sexual populations. Currently, poppr can be used for dominant/codominant and haploid/diploid genetic data. Data can be imported from several formats including GenAlEx formatted text files and can be analyzed on a user-defined hierarchy that includes unlimited levels of subpopulation structure and clone censoring. New functions include calculation of Bruvo’s distance for microsatellites, batch-analysis of the index of association with several indices of genotypic diversity, and graphing including dendrograms with bootstrap support and minimum spanning networks. While functions for genotypic diversity and clone censoring are specific for clonal populations, several functions found in poppr are also valuable to analysis of any populations. A manual with documentation and examples is provided. Poppr is open source and major releases are available on CRAN: http://cran.r-project.org/package=poppr. More supporting documentation and tutorials can be found under ‘resources’ at: http://grunwaldlab.cgrb.oregonstate.edu/. PMID:24688859

  14. Sensation Seeking and Impulsivity: Combined Associations with Risky Sexual Behavior in a Large Sample of Young Adults

    PubMed Central

    Charnigo, Richard; Noar, Seth M.; Garnett, Christopher; Crosby, Richard; Palmgreen, Philip; Zimmerman, Rick S.

    2015-01-01

    Although prior studies have shown that sensation seeking and impulsive decision-making are related to sexual risk-taking, it is still unclear whether these personality traits operate independently or synergistically. The purpose of this study was to elucidate the joint contribution of these personality traits to HIV and sexually transmitted disease (STD) risk behaviors using data from a large sample of sexually active young adults (N = 2,386). Regression modeling indicated that both sensation seeking and impulsive decision-making were consistently associated with sexual risk behaviors across 11 risk-related outcomes. Results further indicated that sensation seeking and impulsive decision-making operated synergistically with respect to the outcome variables of sex acts using drugs, acts with a partner using alcohol, and acts with a partner using drugs. In contrast to this, sensation seeking and impulsive decision-making operated independently with respect to the other sexual risk outcomes. Theoretical implications, as well as implications for HIV/STD prevention among high sensation seekers and impulsive decision-makers, are discussed. PMID:22456443

  15. Times to extinction for small populations of large birds.

    PubMed Central

    Pimm, S L; Diamond, J; Reed, T M; Russell, G J; Verner, J

    1993-01-01

    A major practical problem in conservation biology is to predict the survival times-"lifetimes"-for small populations under alternative proposed management regimes. Examples in the United States include the 'Alala (Hawaiian Crow; Corvus hawaiiensis) and Northern Spotted Owl (Strix occidentalis caurina). To guide such decisions, we analyze counts of all crow, owl, and hawk species in the most complete available data set: counts of bird breeding pairs on 14 European islands censused for 29-66 consecutive years. The data set yielded 129 records for analysis. We define the population ceiling as the highest number of breeding pairs observed from colonization to extinction, within a consecutive series of counts for a given species on a given island. The resulting distributions of population lifetimes as a function of population size prove to be highly skewed: most small populations disappear quickly, but a few last for a long time. Median (i.e., 50th percentile) lifetimes are calculated as only 1-5 yr for hawk, owl, and crow populations with ceilings of one or two breeding pairs. As expected if demographic accidents are the main cause of extinction for small populations, lifetimes rise by a factor of 3-4 for each additional pair up to three pairs. They rise more slowly thereafter. These observations suggest that lifetimes of the 'Alala (now reduced to about three pairs in the wild), and of populations of Northern Spotted Owl in the smallest forest fragments, will be short unless active management is implemented. PMID:11607439

  16. Abortion Research: Attitudes, Sexual Behavior, and Problems in a Community College Population.

    ERIC Educational Resources Information Center

    Bryan, Janice Westlund; Freed, Florence Wallach

    1993-01-01

    Surveys of 70 male and 80 female community college students about their attitudes toward abortion, sexual behavior, and life problems support abortion rights. Antiabortion students were more religious, less sexually active, and less likely to know someone who had an abortion. Many students currently experienced serious problems. (SLD)

  17. Criminal Behavior as a Function of Clinical and Actuarial Variables in a Sexual Offender Population.

    ERIC Educational Resources Information Center

    Hall, Gordon C. Nagayama

    1988-01-01

    Investigated ability of clinical and actuarial variables to predict criminal behavior of 342 sexual offenders previously studied in 1987. Results suggested linear combination of actuarial variables was significantly predictive of sexual reoffenses against adults and of nonsexual reoffending. Clinical judgment was not significantly predictive of…

  18. Inferring Very Recent Population Growth Rate from Population-Scale Sequencing Data: Using a Large-Sample Coalescent Estimator.

    PubMed

    Chen, Hua; Hey, Jody; Chen, Kun

    2015-11-01

    Large-sample or population-level sequencing data provide unprecedented opportunities for inferring detailed population histories, especially recent demographic histories. On the other hand, it challenges most existing population genetic methods: Simulation-based approaches require intensive computation, and analytical approaches are often numerically intractable when the sample size is large. We propose a computationally efficient method for simultaneous estimation of population size, the rate, and onset time of population growth in the very recent history, using the pattern of the total number of segregating sites as a function of sample size. Coalescent simulation shows that it can accurately and efficiently estimate the parameters of recent population growth from large-scale data. This approach has the flexibility to model population history with multiple growth stages or other epochs, and it is robust when the sample size is very large or at the population scale, for which the Kingman's coalescent assumption is not valid. This approach is applied to recently published data and estimates the recent population growth rate in the European population to be 1.49% with the onset time 7.26 ka, and the rate in the African population to be 0.735% with the onset time 10.01 ka. PMID:26187437

  19. Extensive Genetic Diversity, Unique Population Structure and Evidence of Genetic Exchange in the Sexually Transmitted Parasite Trichomonas vaginalis

    PubMed Central

    Conrad, Melissa D.; Gorman, Andrew W.; Schillinger, Julia A.; Fiori, Pier Luigi; Arroyo, Rossana; Malla, Nancy; Dubey, Mohan Lal; Gonzalez, Jorge; Blank, Susan; Secor, William E.; Carlton, Jane M.

    2012-01-01

    Background Trichomonas vaginalis is the causative agent of human trichomoniasis, the most common non-viral sexually transmitted infection world-wide. Despite its prevalence, little is known about the genetic diversity and population structure of this haploid parasite due to the lack of appropriate tools. The development of a panel of microsatellite makers and SNPs from mining the parasite's genome sequence has paved the way to a global analysis of the genetic structure of the pathogen and association with clinical phenotypes. Methodology/Principal Findings Here we utilize a panel of T. vaginalis-specific genetic markers to genotype 235 isolates from Mexico, Chile, India, Australia, Papua New Guinea, Italy, Africa and the United States, including 19 clinical isolates recently collected from 270 women attending New York City sexually transmitted disease clinics. Using population genetic analysis, we show that T. vaginalis is a genetically diverse parasite with a unique population structure consisting of two types present in equal proportions world-wide. Parasites belonging to the two types (type 1 and type 2) differ significantly in the rate at which they harbor the T. vaginalis virus, a dsRNA virus implicated in parasite pathogenesis, and in their sensitivity to the widely-used drug, metronidazole. We also uncover evidence of genetic exchange, indicating a sexual life-cycle of the parasite despite an absence of morphologically-distinct sexual stages. Conclusions/Significance Our study represents the first robust and comprehensive evaluation of global T. vaginalis genetic diversity and population structure. Our identification of a unique two-type structure, and the clinically relevant phenotypes associated with them, provides a new dimension for understanding T. vaginalis pathogenesis. In addition, our demonstration of the possibility of genetic exchange in the parasite has important implications for genetic research and control of the disease. PMID:22479659

  20. Predictors of Inconsistent Condom Use among a Hard to Reach Population of Young Women with Multiple Sexual Partners in Peri-Urban South Africa

    PubMed Central

    Zembe, Yanga Z.; Townsend, Loraine; Thorson, Anna; Ekström, Anna Mia

    2012-01-01

    Background Evidence suggests that multiple concurrent sexual partnering may be a key driver of the high HIV prevalence among young women in South Africa. However, little is known about whether and to what extent women who have multiple sexual partners also engage in other high risk sexual behaviors such as inconsistent condom use. And yet, multiple concurrent sexual partnering is of little epidemiological relevance if all partners in these sexual networks use condoms consistently. This study assesses the prevalence of sexual risk behaviors and HIV, and predictors of inconsistent condom use among women aged 16–24 with multiple sexual partners in a peri-urban setting in South Africa. Methods We used Respondent Driven Sampling, a sampling strategy for hard-to-reach populations to recruit 259 women aged 16–24 in a bio-behavioral cross-sectional survey in the Western Cape province. Estimates of population proportions and 95% confidence intervals (CIs) were calculated using the Respondent-Driven Sampling Analysis Tool 5.6 (RDSAT). The primary outcome was inconsistent condom use in the past three months. Results Young women reported an average of 7 partners in the past 3 months and a high prevalence of sexual risk behaviors: concurrency (87%), transactional sex (91%) and age mixing (59%). Having >5 sexual partners in the last 3 months doubled the risk of unprotected sex (OR 2.43, CI 1.39–4.25). HIV prevalence was 4% among 16–19 year olds, increasing threefold (12%) at age 20–24. Discussion Multiple sexual partnering, where a high number of partners are acquired in a short space of time, is a fertile context for unprotected and risky sexual behavior. The young women featured in this survey present with a constellation of high-risk sexual behaviors that cluster to form a risk syndrome. Carefully tailored repeat bio-behavioral surveillance surveys are recommended for this sub-population. PMID:23284847

  1. Genetic STRs variation in a large population from Tuscany (Italy).

    PubMed

    Carboni, Ilaria; Nutini, Anna Lucia; Porfirio, Berardino; Genuardi, Maurizio; Ricci, Ugo

    2007-12-01

    Allele frequencies for 17 STRs, together with some parameters of forensic interest, were estimated in a sample of 835 unrelated individuals born in Tuscany, an Italian region. These data were compared with Italian, Chinese, Kosovo Albanian, Romanian and Tunisian populations, strongly represented in this area. No significant differences in single loci were detected, except for Chinese in comparison with all the other populations. PMID:19083764

  2. The relationship between contraceptives, sexual practices, and cervical human papillomavirus infection among a college population.

    PubMed

    Burkett, B J; Peterson, C M; Birch, L M; Brennan, C; Nuckols, M L; Ward, B E; Crum, C P

    1992-11-01

    Four hundred and sixty-five college women were evaluated to determine if specific variables of social and sexual behavior correlated with the presence of human papillomavirus (HPV) DNA in the genital tract, and if these associations differed between women who were HPV DNA positive, HPV DNA positive/clinically (cytologically) negative, or who reported previous HPV-related disease by a history of an abnormal Papanicolaou (Pap) smear or genital warts. HPV positive women had more sexual partners in the recent past, more sexual episodes per month, and used spermacides less commonly than controls. Similarly, self-reporters were more likely to have more lifetime sexual partners and earlier age of onset for sexual activity. Cytologically negative HPV positive women were distinguished only by more sexual episodes per month and sexual partners in the past year (borderline significance). Alcohol use was significantly more frequent in all groups, underscoring this variable as a risk factor for both HPV DNA positivity and related disease in young women. Potential explanations for differences between women with clinically and non-clinically related HPV positivity are discussed, with emphasis on the need for followup studies to determine if an epidemiologically distinct subset of HPV DNA positive but clinically negative women are at risk for subsequent cervical disease. PMID:1331341

  3. Sexual Cannibalism: High Incidence in a Natural Population with Benefits to Females

    PubMed Central

    Rabaneda-Bueno, Rubén; Rodríguez-Gironés, Miguel Á.; Aguado-de-la-Paz, Sara; Fernández-Montraveta, Carmen; De Mas, Eva; Wise, David H.; Moya-Laraño, Jordi

    2008-01-01

    Background Sexual cannibalism may be a form of extreme sexual conflict in which females benefit more from feeding on males than mating with them, and males avoid aggressive, cannibalistic females in order to increase net fitness. A thorough understanding of the adaptive significance of sexual cannibalism is hindered by our ignorance of its prevalence in nature. Furthermore, there are serious doubts about the food value of males, probably because most studies that attempt to document benefits of sexual cannibalism to the female have been conducted in the laboratory with non-natural alternative prey. Thus, to understand more fully the ecology and evolution of sexual cannibalism, field experiments are needed to document the prevalence of sexual cannibalism and its benefits to females. Methodology/Principal Findings We conducted field experiments with the Mediterranean tarantula (Lycosa tarantula), a burrowing wolf spider, to address these issues. At natural rates of encounter with males, approximately a third of L. tarantula females cannibalized the male. The rate of sexual cannibalism increased with male availability, and females were more likely to kill and consume an approaching male if they had previously mated with another male. We show that females benefit from feeding on a male by breeding earlier, producing 30% more offspring per egg sac, and producing progeny of higher body condition. Offspring of sexually cannibalistic females dispersed earlier and were larger later in the season than spiderlings of non-cannibalistic females. Conclusions/Significance In nature a substantial fraction of female L. tarantula kill and consume approaching males instead of mating with them. This behaviour is more likely to occur if the female has mated previously. Cannibalistic females have higher rates of reproduction, and produce higher-quality offspring, than non-cannibalistic females. Our findings further suggest that female L. tarantula are nutrient-limited in nature and that males are high-quality prey. The results of these field experiments support the hypothesis that sexual cannibalism is adaptive to females. PMID:18941517

  4. New insights into the variability of reproduction modes in European populations of Rubus subgen. Rubus: how sexual are polyploid brambles?

    PubMed

    Šarhanová, Petra; Vašut, Radim J; Dančák, Martin; Bureš, Petr; Trávníček, Bohumil

    2012-12-01

    Rubus subgen. Rubus includes common European species with highly complicated taxonomy, ongoing hybridisation and facultative apomixis. Out of approximately 750 species recognised in Europe, only 3 diploid sexual species are known, along with numerous apomictic brambles that are highly connected to polyploidy. One exception of a tetraploid taxon is R. ser. Glandulosi, which is known for prevalent sexuality. This taxon highly hybridises with tetraploid members of R. ser. Discolores and leads to the origin of many hybridogenous populations and individuals. In this study, we verify reproduction modes in different diploid, triploid and tetraploid species of subgen. Rubus, with focus on taxa putatively involved in such hybridisation by applying flow cytometric seed screen analysis. We found 100 % sexuality of diploid species, whereas triploid species had obligate unreduced embryo sac development. In contrast, tetraploid plants had varying degrees of sexuality. Additionally, we discovered that R. bifrons has the ability to undergo a reproduction mode switch as a reaction to environmental conditions. These results provide insight into reproductive modes of European brambles and shed light on their reticulate evolution and speciation. PMID:23114637

  5. Age at sexual maturity, sex ratio, fecundity, and longevity of isolated headwater populations of Westslope cutthroat trout

    USGS Publications Warehouse

    Downs, Christopher C.; White, R.G.; Shepard, B.B.

    1997-01-01

    We sampled 19 isolated headwater populations of westslope cutthroat trout Oncorhynchus clarki lewisi in Montana to provide estimates of fecundity, longevity, sex ratio, and age at sexual maturity. Fecundity was estimated for 31 fish collected from two streams in the upper Missouri River drainage. Females smaller than 149 mm fork length (FL) were generally immature and their fecundities could not be estimated. Mean fecundities (SD) were 227 eggs (41.1) for 150-174-mm fish, 346 eggs (85.6) for 175-199-mm fish, and 459 eggs (150.8) for 200-mm and larger fish. A linear regression model (two stream samples combined) to predict fecundity (E) from fork length was developed (E = -494.9 + 4.4.FL: r2 = 0.51, P < 0.001) for westslope cutthroat trout in the upper Missouri River drainage. Regression slopes of fecundity against fish length differed significantly (P < 0.01) between these and some of the previously studied populations. Steeper slopes were associated with lacustrine-adfluvial populations. The average sex ratio was 1.3 males per female across all sampled streams. Males began to mature sexually at age 2 and all were mature by age 4. Some females (27%) were sexually mature at age 3 and most of them (93%) were mature by age 5. Length was a better predictor of sexual maturity than age. Males matured at 110-160 mm and females at 150-180 mm FL. The maximum estimated age was 8 years based on otoliths from 475 fish collected from our 19 study streams and 14 additional streams.

  6. Limited Sexual Reproduction and Quick Turnover in the Population Genetic Structure of Phytophthora infestans in Fujian, China

    PubMed Central

    Zhu, Wen; Yang, Li-Na; Wu, E-Jiao; Qin, Chun-Fang; Shang, Li-Ping; Wang, Zong-Hua; Zhan, Jiasui

    2015-01-01

    The mating system plays an important role in the spatiotemporal dynamics of pathogen populations through both its direct and indirect impact on the generation and distribution of genetic variation. Here, we used a combination of microsatellite and phenotypic markers to investigate the spatiotemporal distribution of genetic variation in Phytophthora infestans isolates collected from Fujian, China and to determine the role of sexual reproduction in the dynamics. Although the pathogen populations in this region were dominated by self-fertile genotypes, sexual reproduction only occurred occasionally and its contributions to the population genetic structure of P. infestans and epidemics of late blight in the region were limited. Only 49 genotypes were detected among the 534 isolates assayed and the pathogen populations displayed significant heterozygosity excess. Hierarchical analysis revealed that 21.42% of genetic variation was attributed to the difference among sampling years while only 4.45% was attributed to the difference among locations, suggesting temporal factors play a more important role in the population genetic dynamics of P. infestans than spatial factors in this region. We propose that clonal reproduction, combined with founder effects and long distance dispersal of sporangia, is responsible for the observed pattern of spatiotemporal dynamics in P. infestans. PMID:25970264

  7. Limited Sexual Reproduction and Quick Turnover in the Population Genetic Structure of Phytophthora infestans in Fujian, China.

    PubMed

    Zhu, Wen; Yang, Li-Na; Wu, E-Jiao; Qin, Chun-Fang; Shang, Li-Ping; Wang, Zong-Hua; Zhan, Jiasui

    2015-01-01

    The mating system plays an important role in the spatiotemporal dynamics of pathogen populations through both its direct and indirect impact on the generation and distribution of genetic variation. Here, we used a combination of microsatellite and phenotypic markers to investigate the spatiotemporal distribution of genetic variation in Phytophthora infestans isolates collected from Fujian, China and to determine the role of sexual reproduction in the dynamics. Although the pathogen populations in this region were dominated by self-fertile genotypes, sexual reproduction only occurred occasionally and its contributions to the population genetic structure of P. infestans and epidemics of late blight in the region were limited. Only 49 genotypes were detected among the 534 isolates assayed and the pathogen populations displayed significant heterozygosity excess. Hierarchical analysis revealed that 21.42% of genetic variation was attributed to the difference among sampling years while only 4.45% was attributed to the difference among locations, suggesting temporal factors play a more important role in the population genetic dynamics of P. infestans than spatial factors in this region. We propose that clonal reproduction, combined with founder effects and long distance dispersal of sporangia, is responsible for the observed pattern of spatiotemporal dynamics in P. infestans. PMID:25970264

  8. Bowel, Urinary, and Sexual Problems Among Long-Term Prostate Cancer Survivors: A Population-Based Study

    SciTech Connect

    Mols, Floortje Korfage, Ida J.; Vingerhoets, Ad J.J.M.; Kil, Paul J.M.; Coebergh, Jan Willem W.; Essink-Bot, Marie-Louise; Poll-Franse, Lonneke V. van de

    2009-01-01

    Purpose: To obtain insight into the long-term (5- to 10-year) effects of prostate cancer and treatment on bowel, urinary, and sexual function, we performed a population-based study. Prostate-specific function was compared with an age-matched normative population without prostate cancer. Methods and Materials: Through the population-based Eindhoven Cancer Registry, we selected all men diagnosed with prostate cancer between 1994 and 1998 in the southern Netherlands. In total, 964 patients, alive in November 2004, received questionnaire; 780 (81%) responded. Results: Urinary problems were most common after a prostatectomy; bowel problems were most common after radiotherapy. Compared with an age-matched normative population both urinary and bowel functioning and bother were significantly worse among survivors. Urinary incontinence was reported by 23-48% of survivors compared with 4% of the normative population. Bowel leakage occurred in 5-14% of patients compared with 2% of norms. Erection problems occurred in 40-74% of patients compared with 18% of norms. Conclusions: These results form an important contribution to the limited information available on prostate-specific problems in the growing group of long-term prostate cancer survivors. Bowel, urinary, and sexual problems occur more often among long-term survivors compared with a reference group and cannot be explained merely by age. Because these problems persist for many years, urologists should provide patients with adequate information before treatment. After treatment, there should be an appropriate focus on these problems.

  9. Population and habitat assessment: Monitoring bird populations over large areas: Introduction

    USGS Publications Warehouse

    Sauer, J.R.; Cooper, R.J.

    2000-01-01

    Monitoring provides essential information about status and change in bird populations. For Neotropical Migrant Birds (NTMBs), the North American Breeding Bird Survey (BBS) has been particularly influential in documenting regional population change and often is cited as justification for management actions. However, as with most bird surveys, the design of the BBS, and the geographic scale of the information, often limits its use either in evaluating the response of bird populations to management, or in identifying causes of population change.

  10. Multivariate sexual selection on male song structure in wild populations of sagebrush crickets, Cyphoderris strepitans (Orthoptera: Haglidae)

    PubMed Central

    Ower, Geoffrey D; Judge, Kevin A; Steiger, Sandra; Caron, Kyle J; Smith, Rebecca A; Hunt, John; Sakaluk, Scott K

    2013-01-01

    While a number of studies have measured multivariate sexual selection acting on sexual signals in wild populations, few have confirmed these findings with experimental manipulation. Sagebrush crickets are ideally suited to such investigations because mating imposes an unambiguous phenotypic marker on males arising from nuptial feeding by females. We quantified sexual selection operating on male song by recording songs of virgin and mated males captured from three wild populations. To determine the extent to which selection on male song is influenced by female preference, we conducted a companion study in which we synthesized male songs and broadcast them to females in choice trials. Multivariate selection analysis revealed a saddle-shaped fitness surface, the highest peak of which corresponded to longer train and pulse durations, and longer intertrain intervals. Longer trains and pulses likely promote greater mate attraction, but selection for longer intertrain durations suggests that energetic constraints may necessitate “time outs”. Playback trials confirmed the selection for longer train and pulse durations, and revealed significant stabilizing selection on dominant frequency, suggesting that the female auditory system is tightly tuned to the species-specific call frequency. Collectively, our results revealed a complex pattern of multivariate nonlinear selection characterized primarily by strong stabilizing and disruptive selection on male song traits. PMID:24223293

  11. Multivariate sexual selection on male song structure in wild populations of sagebrush crickets, Cyphoderris strepitans (Orthoptera: Haglidae).

    PubMed

    Ower, Geoffrey D; Judge, Kevin A; Steiger, Sandra; Caron, Kyle J; Smith, Rebecca A; Hunt, John; Sakaluk, Scott K

    2013-09-01

    While a number of studies have measured multivariate sexual selection acting on sexual signals in wild populations, few have confirmed these findings with experimental manipulation. Sagebrush crickets are ideally suited to such investigations because mating imposes an unambiguous phenotypic marker on males arising from nuptial feeding by females. We quantified sexual selection operating on male song by recording songs of virgin and mated males captured from three wild populations. To determine the extent to which selection on male song is influenced by female preference, we conducted a companion study in which we synthesized male songs and broadcast them to females in choice trials. Multivariate selection analysis revealed a saddle-shaped fitness surface, the highest peak of which corresponded to longer train and pulse durations, and longer intertrain intervals. Longer trains and pulses likely promote greater mate attraction, but selection for longer intertrain durations suggests that energetic constraints may necessitate "time outs". Playback trials confirmed the selection for longer train and pulse durations, and revealed significant stabilizing selection on dominant frequency, suggesting that the female auditory system is tightly tuned to the species-specific call frequency. Collectively, our results revealed a complex pattern of multivariate nonlinear selection characterized primarily by strong stabilizing and disruptive selection on male song traits. PMID:24223293

  12. Computing Ro in a population with heterogeneity in sexual activity and proportionate mixing using a STM-solver

    NASA Astrophysics Data System (ADS)

    Gutierrez A., Natalia A.

    2014-06-01

    A model to determinate the reproductive basic number, detonated Ro, for the case of population with heterogeneity in sexual activity and proportionate mixing is solved using computer algebra and SMT solvers. Specifically Maple and Z3 were used. The code for the solution of the model was written in Z3-Python, but it can also be played by Z3-SMT-Lib. Ro represents an algebraic synthesis of every epidemiological parameter. Numerical simulations were done to prove the effectiveness of the model and the code. The algebraic structure of Ro suggests the possible control measurements that should be implemented to avoid the propagation of the sexual transmitted diseases. The obtained results are important on the computational epidemiology field. As a future investigation, it is suggested to apply the STM solvers to analyze models for other kinds of epidemic diseases.

  13. Comparing cestode infections and their consequences for host fitness in two sexual branchiopods: alien Artemia franciscana and native A. salina from syntopic-populations

    PubMed Central

    Amat, Francisco; Sánchez, Marta I.; Green, Andy J.

    2015-01-01

    The American brine shrimp Artemia franciscana is invasive in the Mediterranean region where it has displaced native species (the sexual A. salina, and the clonal A. parthenogenetica) from many salt pond complexes. Artemia populations are parasitized by numerous avian cestodes whose effects have been studied in native species. We present a study from the Ebro Delta salterns (NE Spain), in a salt pond where both A. franciscana and native A. salina populations coexist, providing a unique opportunity to compare the parasite loads of the two sexual species in syntopy. The native species had consistently higher infection parameters, largely because the dominant cestode in A. salina adults and juveniles (Flamingolepis liguloides) was much rarer in A. franciscana. The most abundant cestodes in the alien species were Eurycestus avoceti (in adults) and Flamingolepis flamingo (in juveniles). The abundance of E. avoceti and F. liguloides was higher in the A. franciscana population syntopic with A. salina than in a population sampled at the same time in another pond where the native brine shrimp was absent, possibly because the native shrimp provides a better reservoir for parasite circulation. Infection by cestodes caused red colouration in adult and juvenile A. salina, and also led to castration in a high proportion of adult females. Both these effects were significantly stronger in the native host than in A. franciscana with the same parasite loads. However, for the first time, significant castration effects (for E. avoceti and F. liguloides) and colour change (for six cestode species) were observed in infected A. franciscana. Avian cestodes are likely to help A. franciscana outcompete native species. At the same time, they are likely to reduce the production of A. franciscana cysts in areas where they are harvested commercially. PMID:26157636

  14. Comparing cestode infections and their consequences for host fitness in two sexual branchiopods: alien Artemia franciscana and native A. salina from syntopic-populations.

    PubMed

    Redón, Stella; Amat, Francisco; Sánchez, Marta I; Green, Andy J

    2015-01-01

    The American brine shrimp Artemia franciscana is invasive in the Mediterranean region where it has displaced native species (the sexual A. salina, and the clonal A. parthenogenetica) from many salt pond complexes. Artemia populations are parasitized by numerous avian cestodes whose effects have been studied in native species. We present a study from the Ebro Delta salterns (NE Spain), in a salt pond where both A. franciscana and native A. salina populations coexist, providing a unique opportunity to compare the parasite loads of the two sexual species in syntopy. The native species had consistently higher infection parameters, largely because the dominant cestode in A. salina adults and juveniles (Flamingolepis liguloides) was much rarer in A. franciscana. The most abundant cestodes in the alien species were Eurycestus avoceti (in adults) and Flamingolepis flamingo (in juveniles). The abundance of E. avoceti and F. liguloides was higher in the A. franciscana population syntopic with A. salina than in a population sampled at the same time in another pond where the native brine shrimp was absent, possibly because the native shrimp provides a better reservoir for parasite circulation. Infection by cestodes caused red colouration in adult and juvenile A. salina, and also led to castration in a high proportion of adult females. Both these effects were significantly stronger in the native host than in A. franciscana with the same parasite loads. However, for the first time, significant castration effects (for E. avoceti and F. liguloides) and colour change (for six cestode species) were observed in infected A. franciscana. Avian cestodes are likely to help A. franciscana outcompete native species. At the same time, they are likely to reduce the production of A. franciscana cysts in areas where they are harvested commercially. PMID:26157636

  15. Distinct Human Stem Cell Populations in Small and Large Intestine

    PubMed Central

    Cramer, Julie M.; Thompson, Timothy; Geskin, Albert; LaFramboise, William; Lagasse, Eric

    2015-01-01

    The intestine is composed of an epithelial layer containing rapidly proliferating cells that mature into two regions, the small and the large intestine. Although previous studies have identified stem cells as the cell-of-origin for intestinal epithelial cells, no studies have directly compared stem cells derived from these anatomically distinct regions. Here, we examine intrinsic differences between primary epithelial cells isolated from human fetal small and large intestine, after in vitro expansion, using the Wnt agonist R-spondin 2. We utilized flow cytometry, fluorescence-activated cell sorting, gene expression analysis and a three-dimensional in vitro differentiation assay to characterize their stem cell properties. We identified stem cell markers that separate subpopulations of colony-forming cells in the small and large intestine and revealed important differences in differentiation, proliferation and disease pathways using gene expression analysis. Single cells from small and large intestine cultures formed organoids that reflect the distinct cellular hierarchy found in vivo and respond differently to identical exogenous cues. Our characterization identified numerous differences between small and large intestine epithelial stem cells suggesting possible connections to intestinal disease. PMID:25751518

  16. Distinct human stem cell populations in small and large intestine.

    PubMed

    Cramer, Julie M; Thompson, Timothy; Geskin, Albert; LaFramboise, William; Lagasse, Eric

    2015-01-01

    The intestine is composed of an epithelial layer containing rapidly proliferating cells that mature into two regions, the small and the large intestine. Although previous studies have identified stem cells as the cell-of-origin for intestinal epithelial cells, no studies have directly compared stem cells derived from these anatomically distinct regions. Here, we examine intrinsic differences between primary epithelial cells isolated from human fetal small and large intestine, after in vitro expansion, using the Wnt agonist R-spondin 2. We utilized flow cytometry, fluorescence-activated cell sorting, gene expression analysis and a three-dimensional in vitro differentiation assay to characterize their stem cell properties. We identified stem cell markers that separate subpopulations of colony-forming cells in the small and large intestine and revealed important differences in differentiation, proliferation and disease pathways using gene expression analysis. Single cells from small and large intestine cultures formed organoids that reflect the distinct cellular hierarchy found in vivo and respond differently to identical exogenous cues. Our characterization identified numerous differences between small and large intestine epithelial stem cells suggesting possible connections to intestinal disease. PMID:25751518

  17. Assessing Health Issues in States with Large Minority Populations.

    PubMed

    Long, Michelle; Menifield, Charles E; Fletcher, Audwin B

    2015-09-01

    Health care spending is often addressed in discussions of budgeting and deficits in the United States. It is important to many Americans that funds allocated for health care spending be allocated and spent in the most efficient and effective manner, leading to improved health outcomes, particularly for underserved populations. Many studies address health care spending, but few address the issue of spending as it relates to societal well-being, or certain health outcomes that adversely impact communities. This study seeks to expand the available literature by analyzing data from national sources at the state level. PMID:26333605

  18. Effectiveness of bilateral tubotubal anastomosis in a large outpatient population

    PubMed Central

    Berger, Gary S.; Thorp, John M.; Weaver, Mark A.

    2016-01-01

    STUDY QUESTION Is bilateral tubotubal anastomosis a successful treatment in an outpatient patient population? SUMMARY ANSWER For women wanting children after tubal sterilization, bilateral tubotubal anastomosis is an effective outpatient treatment. WHAT IS KNOWN ALREADY With the current emphasis in reproductive medicine on high technology procedures, the effectiveness of female surgical sterilization reversal is often overlooked. Previous clinical studies of tubal sterilization reversal have been mostly retrospective analyses of small patient populations. STUDY DESIGN, SIZE, DURATION A cohort of women who underwent outpatient bilateral tubotubal anastomosis from January 2000 to June 2013 was followed prospectively until December 2014 to determine the proportions of women undergoing the procedure who became pregnant and who had live births. Data were collected at the time of pregnancy. Differences in pregnancy rates and live birth rates associated with age, race and sterilization method were evaluated. PARTICIPANTS/MATERIALS, SETTING, METHODS A total of 6692 women, aged 20–51 years, underwent outpatient bilateral tubotubal anastomosis. MAIN RESULTS AND THE ROLE OF CHANCE The crude overall pregnancy rate was 69%. The crude overall birth rate was 35%. Results varied according to age at sterilization reversal and the method of sterilization. Women under 30 years of age at reversal of ring/clip sterilizations had an 88% pregnancy rate and 62% birth rate. Pregnancy and birth rates declined as age increased at sterilization reversal. Coagulation sterilization reversals resulted in the lowest rates of pregnancies and births. Ligation/resection reversals had intermediate success rates. LIMITATIONS, REASONS FOR CAUTION Limitations of our study include probable underreporting of pregnancies based on patient-initiated reports; possible errors in the reporting of pregnancies or early miscarriages that may have been based solely on home pregnancy tests; and probable over-reporting of the diagnosis of ectopic pregnancies. We identified age and sterilization method as being associated with subsequent pregnancy, however, in order to be considered predictive, the associations would need to be validated in an independent second prospectively studied group of representative patients. Finally, we also included patients in the study population who had additional surgical procedures performed at the time of tubotubal anastomosis (e.g. uterine myomectomy, fimbrioplasty, ovarian cystectomy and adhesiolysis), factors that could result in differences in pregnancy statistics in our study versus other patient populations. WIDER IMPLICATIONS OF THE FINDINGS The results of this study can help inform patients and clinicians about this low technology alternative to IVF. STUDY FUNDING/COMPETING INTEREST(S) None. TRIAL REGISTRATION NUMBER N/A. PMID:26980770

  19. Quantifying prion disease penetrance using large population control cohorts.

    PubMed

    Minikel, Eric Vallabh; Vallabh, Sonia M; Lek, Monkol; Estrada, Karol; Samocha, Kaitlin E; Sathirapongsasuti, J Fah; McLean, Cory Y; Tung, Joyce Y; Yu, Linda P C; Gambetti, Pierluigi; Blevins, Janis; Zhang, Shulin; Cohen, Yvonne; Chen, Wei; Yamada, Masahito; Hamaguchi, Tsuyoshi; Sanjo, Nobuo; Mizusawa, Hidehiro; Nakamura, Yosikazu; Kitamoto, Tetsuyuki; Collins, Steven J; Boyd, Alison; Will, Robert G; Knight, Richard; Ponto, Claudia; Zerr, Inga; Kraus, Theo F J; Eigenbrod, Sabina; Giese, Armin; Calero, Miguel; de Pedro-Cuesta, Jesús; Haïk, Stéphane; Laplanche, Jean-Louis; Bouaziz-Amar, Elodie; Brandel, Jean-Philippe; Capellari, Sabina; Parchi, Piero; Poleggi, Anna; Ladogana, Anna; O'Donnell-Luria, Anne H; Karczewski, Konrad J; Marshall, Jamie L; Boehnke, Michael; Laakso, Markku; Mohlke, Karen L; Kähler, Anna; Chambert, Kimberly; McCarroll, Steven; Sullivan, Patrick F; Hultman, Christina M; Purcell, Shaun M; Sklar, Pamela; van der Lee, Sven J; Rozemuller, Annemieke; Jansen, Casper; Hofman, Albert; Kraaij, Robert; van Rooij, Jeroen G J; Ikram, M Arfan; Uitterlinden, André G; van Duijn, Cornelia M; Daly, Mark J; MacArthur, Daniel G

    2016-01-20

    More than 100,000 genetic variants are reported to cause Mendelian disease in humans, but the penetrance-the probability that a carrier of the purported disease-causing genotype will indeed develop the disease-is generally unknown. We assess the impact of variants in the prion protein gene (PRNP) on the risk of prion disease by analyzing 16,025 prion disease cases, 60,706 population control exomes, and 531,575 individuals genotyped by 23andMe Inc. We show that missense variants in PRNP previously reported to be pathogenic are at least 30 times more common in the population than expected on the basis of genetic prion disease prevalence. Although some of this excess can be attributed to benign variants falsely assigned as pathogenic, other variants have genuine effects on disease susceptibility but confer lifetime risks ranging from <0.1 to ~100%. We also show that truncating variants in PRNP have position-dependent effects, with true loss-of-function alleles found in healthy older individuals, a finding that supports the safety of therapeutic suppression of prion protein expression. PMID:26791950

  20. Child Sexual Abuse Is Largely Hidden from the Adult Society: An Epidemiological Study of Adolescents' Disclosures

    ERIC Educational Resources Information Center

    Priebe, Gisela; Svedin, Carl Goran

    2008-01-01

    Objectives: The aim of this study was to investigate disclosure rates and disclosure patterns and to examine predictors of non-disclosure in a sample of male and female adolescents with self-reported experiences of sexual abuse. Method: A sample of 4,339 high school seniors (2,324 girls, 2,015 boys) was examined with a questionnaire concerning…

  1. Child Sexual Abuse Is Largely Hidden from the Adult Society: An Epidemiological Study of Adolescents' Disclosures

    ERIC Educational Resources Information Center

    Priebe, Gisela; Svedin, Carl Goran

    2008-01-01

    Objectives: The aim of this study was to investigate disclosure rates and disclosure patterns and to examine predictors of non-disclosure in a sample of male and female adolescents with self-reported experiences of sexual abuse. Method: A sample of 4,339 high school seniors (2,324 girls, 2,015 boys) was examined with a questionnaire concerning

  2. Ginkgo and Warfarin Interaction in a Large Veterans Administration Population

    PubMed Central

    Stoddard, Gregory J.; Archer, Melissa; Shane-McWhorter, Laura; Bray, Bruce E.; Redd, Doug F.; Proulx, Joshua; Zeng-Treitler, Qing

    2015-01-01

    Ginkgo biloba is a widely used herbal product that could potentially have a severe interaction with warfarin, which is the most frequently prescribed anticoagulant agent in North America. Literature, however, provides conflicting evidence on the presence and severity of the interaction. In this study, we developed text processing methods to extract the ginkgo usage and combined it with prescription data on warfarin from a very large clinical data respository. Our statistical analysis suggests that taking concurrently with warfarin, gingko does significantly increase patients’ risk of a bleeding adverse event (hazard ratio = 1.38, 95%CI: 1.20 to 1.58, p<.001). This study also is the first attempt of using a large medical record databaseto confirm a suspected herb-drug interaction. PMID:26958257

  3. Collective response of human populations to large-scale emergencies.

    PubMed

    Bagrow, James P; Wang, Dashun; Barabsi, Albert-Lszl

    2011-01-01

    Despite recent advances in uncovering the quantitative features of stationary human activity patterns, many applications, from pandemic prediction to emergency response, require an understanding of how these patterns change when the population encounters unfamiliar conditions. To explore societal response to external perturbations we identified real-time changes in communication and mobility patterns in the vicinity of eight emergencies, such as bomb attacks and earthquakes, comparing these with eight non-emergencies, like concerts and sporting events. We find that communication spikes accompanying emergencies are both spatially and temporally localized, but information about emergencies spreads globally, resulting in communication avalanches that engage in a significant manner the social network of eyewitnesses. These results offer a quantitative view of behavioral changes in human activity under extreme conditions, with potential long-term impact on emergency detection and response. PMID:21479206

  4. Detecting differential protein expression in large-scale population proteomics

    SciTech Connect

    Ryu, Soyoung; Qian, Weijun; Camp, David G.; Smith, Richard D.; Tompkins, Ronald G.; Davis, Ronald W.; Xiao, Wenzhong

    2014-06-17

    Mass spectrometry-based high-throughput quantitative proteomics shows great potential in clinical biomarker studies, identifying and quantifying thousands of proteins in biological samples. However, methods are needed to appropriately handle issues/challenges unique to mass spectrometry data in order to detect as many biomarker proteins as possible. One issue is that different mass spectrometry experiments generate quite different total numbers of quantified peptides, which can result in more missing peptide abundances in an experiment with a smaller total number of quantified peptides. Another issue is that the quantification of peptides is sometimes absent, especially for less abundant peptides and such missing values contain the information about the peptide abundance. Here, we propose a Significance Analysis for Large-scale Proteomics Studies (SALPS) that handles missing peptide intensity values caused by the two mechanisms mentioned above. Our model has a robust performance in both simulated data and proteomics data from a large clinical study. Because varying patients’ sample qualities and deviating instrument performances are not avoidable for clinical studies performed over the course of several years, we believe that our approach will be useful to analyze large-scale clinical proteomics data.

  5. Partner Violence and Sexual Jealousy in China: A Population-Based Survey

    PubMed Central

    Wang, Tianfu; Parish, William L.; Laumann, Edward O.; Luo, Ye

    2013-01-01

    Using data from a nationally representative survey of China, this paper examines the prevalence and risk factors for partner violence with a special focus on the important role of sexual jealousy. Among women age 20–49, 7.2% reported that they were hit by their partner last year. Comparison shows that the Chinese prevalence is modestly below the overall median for other societies. Net of other factors, jealousy exacerbates hitting for both men and women in a reactive pattern, with the jealous partner getting hit. This suggests a rethinking of the role of sexual jealousy in spousal violence in some social settings. PMID:19451317

  6. A Call to Develop Evidence-based Interventions to Reduce Sexually Transmitted Infections in Juvenile Justice Populations.

    PubMed

    Gates, Madison L; Staples-Horne, Michelle; Cartier, Jeanne; Best, Candace; Stone, Rebecca; Walker, Veronica; Hastings, Beverly; Yoo, Wonsuk; Webb, Nancy C; Braithwaite, Ronald L

    2016-01-01

    Sexually transmitted infections (STIs), including human immunodeficiency virus (HIV) risk, are a significant health issue for young women (ages 16-21), especially African Americans with a juvenile justice history. Studies have found that 44% of young African American women have had at least one STI compared to 24.1% for all young women. The rate of STIs among young women with juvenile justice histories, particularly African Americans, is likely much higher than their non-detained peers. Yet, there are few evidence-based interventions (EBIs) designed specifically for the detained population. In 2014, the Centers for Disease Control and Prevention's Compendium of Evidence-Based Interventions and Best Practices for HIV Prevention listed few programs that comprehensively included components related to mental health, intimate relationships and high risk sexual behaviors that would be salient for a detained population. Further, many EBIs have had limited or no long-term protective effect. We propose that interrelated factors (mental health, substance use, trauma and intimate relationships) can effectively decrease risk and increase protective behaviors for the detained population most at risk. PMID:27133511

  7. The Link between Childhood Sexual Abuse and Myocardial Infarction in a Population-Based Study

    ERIC Educational Resources Information Center

    Fuller-Thomson, Esme; Bejan, Raluca; Hunter, John T.; Grundland, Tamara; Brennenstuhl, Sarah

    2012-01-01

    Objectives: This study examined the relationship between childhood sexual abuse (CSA) and myocardial infarction in men and women, while controlling for social determinants (i.e., socioeconomic status, social support, mental health) and traditional cardiovascular risk factors (i.e., age, race, obesity, smoking, physical inactivity, diabetes…

  8. The Link between Childhood Sexual Abuse and Myocardial Infarction in a Population-Based Study

    ERIC Educational Resources Information Center

    Fuller-Thomson, Esme; Bejan, Raluca; Hunter, John T.; Grundland, Tamara; Brennenstuhl, Sarah

    2012-01-01

    Objectives: This study examined the relationship between childhood sexual abuse (CSA) and myocardial infarction in men and women, while controlling for social determinants (i.e., socioeconomic status, social support, mental health) and traditional cardiovascular risk factors (i.e., age, race, obesity, smoking, physical inactivity, diabetes

  9. Extending Sexual Objectification Theory and Research to Minority Populations, Couples, and Men

    ERIC Educational Resources Information Center

    Heimerdinger-Edwards, Sarah R.; Vogel, David L.; Hammer, Joseph H.

    2011-01-01

    This reaction highlights several strengths of this major contribution and discusses some future directions in this line of research. The authors offer research ideas in the areas of cultural and cross-cultural issues, couples and relationships, as well as direct and indirect effects of sexual objectification on men. In terms of providing…

  10. Phenology of scramble polygyny in a wild population of chrysomelid beetles: the opportunity for and the strength of sexual selection [corrected].

    PubMed

    Baena, Martha Lucía; Macías-Ordóñez, Rogelio

    2012-01-01

    Recent debate has highlighted the importance of estimating both the strength of sexual selection on phenotypic traits, and the opportunity for sexual selection. We describe seasonal fluctuations in mating dynamics of Leptinotarsa undecimlineata (Coleoptera: Chrysomelidae). We compared several estimates of the opportunity for, and the strength of, sexual selection and male precopulatory competition over the reproductive season. First, using a null model, we suggest that the ratio between observed values of the opportunity for sexual selections and their expected value under random mating results in unbiased estimates of the actual nonrandom mating behavior of the population. Second, we found that estimates for the whole reproductive season often misrepresent the actual value at any given time period. Third, mating differentials on male size and mobility, frequency of male fighting and three estimates of the opportunity for sexual selection provide contrasting but complementary information. More intense sexual selection associated to male mobility, but not to male size, was observed in periods with high opportunity for sexual selection and high frequency of male fights. Fourth, based on parameters of spatial and temporal aggregation of female receptivity, we describe the mating system of L. undecimlineata as a scramble mating polygyny in which the opportunity for sexual selection varies widely throughout the season, but the strength of sexual selection on male size remains fairly weak, while male mobility inversely covaries with mating success. We suggest that different estimates for the opportunity for, and intensity of, sexual selection should be applied in order to discriminate how different behavioral and demographic factors shape the reproductive dynamic of populations. PMID:22761675

  11. Highly Recombinant VGII Cryptococcus gattii Population Develops Clonal Outbreak Clusters through both Sexual Macroevolution and Asexual Microevolution

    PubMed Central

    Croll, Daniel; Li, Wenjun; Mieczkowski, Piotr; Carter, Dee A.; Cuomo, Christina A.; Kronstad, James W.

    2014-01-01

    ABSTRACT An outbreak of the fungal pathogen Cryptococcus gattii began in the Pacific Northwest (PNW) in the late 1990s. This outbreak consists of three clonal subpopulations: VGIIa/major, VGIIb/minor, and VGIIc/novel. Both VGIIa and VGIIc are unique to the PNW and exhibit increased virulence. In this study, we sequenced the genomes of isolates from these three groups, as well as global isolates, and analyzed a total of 53 isolates. We found that VGIIa/b/c populations show evidence of clonal expansion in the PNW. Whole-genome sequencing provided evidence that VGIIb originated in Australia, while VGIIa may have originated in South America, and these were likely independently introduced. Additionally, the VGIIa outbreak lineage may have arisen from a less virulent clade that contained a mutation in the MSH2 ortholog, but this appears to have reverted in the VGIIa outbreak strains, suggesting that a transient mutator phenotype may have contributed to adaptation and evolution of virulence in the PNW outbreak. PNW outbreak isolates share genomic islands, both between the clonal lineages and with global isolates, indicative of sexual recombination. This suggests that VGII C. gattii has undergone sexual reproduction, either bisexual or unisexual, in multiple locales contributing to the production of novel, virulent subtypes. We also found that the genomes of two basal VGII isolates from HIV+ patients contain an introgression tract spanning three genes. Introgression substantially contributed to intra-VGII polymorphism and likely occurred through sexual reproduction with VGI. More broadly, these findings illustrate how both microevolution and sexual reproduction play central roles in the development of infectious outbreaks from avirulent or less virulent progenitors. PMID:25073643

  12. Male-male contests for mates, sexual size dimorphism, and sex ratio in a natural population of a solitary parasitoid.

    PubMed

    Macedo, Margarete V; Monteiro, Ricardo F; Silveira, Mariana P; Mayhew, Peter J

    2013-11-01

    Understanding how different behavioural and life history traits interact is fundamental to developing ethological theory. Here we study the interaction of male-male competition for mates and sexual size dimorphism in a solitary wasp, with implications for sex allocation. In Hymenoptera, females are normally larger than males suggesting that males do not benefit as much as females from larger size. However, in our focal species, a solitary Eurytoma wasp, males compete for mates by pairwise contests at female emergence sites, suggesting that male size may strongly affect fitness. In contests observed in the field, larger males were more likely to win fights, and males fighting at female emergence sites were much larger than average males. Males showed higher variance in body size than females, such that all the smallest individuals were males, a majority of medium-to-large individuals were female, but the majority of largest individuals were male. Our data suggest that sexual size dimorphism in this species has been affected by intra-sexual selection for male size, which may have implications for sex allocation. PMID:23872503

  13. Romantic and Sexual Behavior in Young Adolescents: Repeated Surveys in a Population-Based Cohort

    ERIC Educational Resources Information Center

    Waylen, Andrea E.; Ness, Andrew; McGovern, Phil; Wolke, Dieter; Low, Nicola

    2010-01-01

    Adverse outcomes of teenage sexual activity are common in the United Kingdom. The authors used a computer-assisted interview to ask young adolescents aged 11 to 12 years (N = 6,856) and 12 to 13 years (N = 6,801) who were part of the Avon Longitudinal Study of Parents and Children about romantic and intimate behaviors. A total of 24% of 11- to…

  14. Sexual and geographic organisation of men who have sex with men in a large East African city: opportunities for outreach

    PubMed Central

    Ross, Michael W; Nyoni, Joyce; Bowen, Anne M; Williams, Mark L; Kashiha, John J

    2012-01-01

    Objectives To describe geographical and dispersion patterns of men who have sex with men (MSM)-related venues in a large East African city and their associations with times, participants and venue type. Methods Mapping of MSM sites in Dar es Salaam was carried out by community research workers who catalogued, observed and reported data on venue sites, formality, times of operation, type of participant, police or vigilante activity, length of operation and the degree to which it is known both in and outside the MSM and gay communities. Results There is a large and widely disseminated MSM/gay satellite cultures of at least 98 sites, which has some formal sites, but is largely informal and operates within mixed entertainment environments and at particular times (including some weekend-only locales) across the city. There is a mix of places for sexual contact, largely social venues and sex on location sites. Cruising appears to be limited to open spaces and parks, with no vehicular component and almost no internet component. They are widely disseminated across all suburbs and there is no central location for MSM activities. MSM sex workers (SWs) operate at a third of these sites. Conclusions There is a large number of ‘local’ MSM contact, social and sex sites and any work with MSM will have to include these less-formal and less-known sites. The widely disseminated nature of the MSM sites, however, also suggests that sexual networks may not be closely linked between sites. The climate of stigma, abuse and potential violence appear to be limiting the development of more formal sites. This pattern is probably typical of other large urban areas in East Africa and perhaps across sub-Saharan Africa (SSA). PMID:23180391

  15. Highly recombinant VGII Cryptococcus gattii population develops clonal outbreak clusters through both sexual macroevolution and asexual microevolution.

    PubMed

    Billmyre, R Blake; Croll, Daniel; Li, Wenjun; Mieczkowski, Piotr; Carter, Dee A; Cuomo, Christina A; Kronstad, James W; Heitman, Joseph

    2014-01-01

    An outbreak of the fungal pathogen Cryptococcus gattii began in the Pacific Northwest (PNW) in the late 1990s. This outbreak consists of three clonal subpopulations: VGIIa/major, VGIIb/minor, and VGIIc/novel. Both VGIIa and VGIIc are unique to the PNW and exhibit increased virulence. In this study, we sequenced the genomes of isolates from these three groups, as well as global isolates, and analyzed a total of 53 isolates. We found that VGIIa/b/c populations show evidence of clonal expansion in the PNW. Whole-genome sequencing provided evidence that VGIIb originated in Australia, while VGIIa may have originated in South America, and these were likely independently introduced. Additionally, the VGIIa outbreak lineage may have arisen from a less virulent clade that contained a mutation in the MSH2 ortholog, but this appears to have reverted in the VGIIa outbreak strains, suggesting that a transient mutator phenotype may have contributed to adaptation and evolution of virulence in the PNW outbreak. PNW outbreak isolates share genomic islands, both between the clonal lineages and with global isolates, indicative of sexual recombination. This suggests that VGII C. gattii has undergone sexual reproduction, either bisexual or unisexual, in multiple locales contributing to the production of novel, virulent subtypes. We also found that the genomes of two basal VGII isolates from HIV(+) patients contain an introgression tract spanning three genes. Introgression substantially contributed to intra-VGII polymorphism and likely occurred through sexual reproduction with VGI. More broadly, these findings illustrate how both microevolution and sexual reproduction play central roles in the development of infectious outbreaks from avirulent or less virulent progenitors. Importance: Cryptococcus gattii is the causative agent responsible for ongoing infections in the Pacific Northwest of the United States and western Canada. The incidence of these infections increased dramatically in the 1990s and remains elevated. These infections are attributable to three clonal lineages of C. gattii, VGIIa, VGIIb, and VGIIc, with only VGIIa identified once previously in the Pacific Northwest prior to the start of the outbreak, albeit in a less virulent form. This study addresses the origin and emergence of this outbreak, using whole-genome sequencing and comparison of both outbreak and global isolates. We show that VGIIa arose mitotically from a less virulent clonal group, possibly via the action of a mutator phenotype, while VGIIb was likely introduced from Australia, and VGIIc appears to have emerged in the United States or in an undersampled locale via sexual reproduction. This work shows that multiple processes can contribute to the emergence of an outbreak. PMID:25073643

  16. Sexual orientation, social capital and daily tobacco smoking: a population-based study

    PubMed Central

    2014-01-01

    Background Studies have suggested poorer health in the homosexual and bisexual groups compared to heterosexuals. Tobacco smoking, which is a health-related behavior associated with psychosocial stress, may be one explanation behind such health differences. Social capital, i.e. the generalized trust in other people and social participation/social networks which decreases the costs of social interaction, has been suggested to affect health through psychosocial pathways and through norms connected with health related behaviours, The aim of this study is to investigate the association between sexual orientation and daily tobacco smoking, taking social capital into account and analyzing the attenuation of the logit after the introduction of social participation, trust and their combination in the models. Methods In 2008 a cross-sectional public health survey was conducted in southern Sweden with a postal questionnaire with 28,198 participants aged 18–80 (55% participation rate). This study was restricted to 24,348 participants without internally missing values on all included variables. Associations between sexual orientation and tobacco smoking were analyzed with logistic regression analysis. Results Overall, 11.9% of the men and 14.8% of the women were daily tobacco smokers. Higher and almost unaltered odds ratios of daily smoking compared to heterosexuals were observed for bisexual men and women, and for homosexual men throughout the analyses. The odds ratios of daily smoking among homosexual women were not significant. Only for the “other” sexual orientation group the odds ratios of daily smoking were reduced to not significant levels among both men and women, with a corresponding 54% attenuation of the logit in the “other” group among men and 31.5% among women after the inclusion of social participation and trust. In addition, only the “other” sexual orientation group had higher odds ratios of low participation than heterosexuals. Conclusions Bisexual men and women and homosexual men, but not homosexual women, are daily smokers to a higher extent than heterosexuals. Only for the “other” sexual orientation group the odds ratios of daily smoking were reduced to not significant levels after adjustments for covariates including trust and social participation. PMID:24903892

  17. Changes in Sexual Behavior and Attitudes Across Generations and Gender Among a Population-Based Probability Sample From an Urbanizing Province in Thailand.

    PubMed

    Techasrivichien, Teeranee; Darawuttimaprakorn, Niphon; Punpuing, Sureeporn; Musumari, Patou Masika; Lukhele, Bhekumusa Wellington; El-Saaidi, Christina; Suguimoto, S Pilar; Feldman, Mitchell D; Ono-Kihara, Masako; Kihara, Masahiro

    2016-02-01

    Thailand has undergone rapid modernization with implications for changes in sexual norms. We investigated sexual behavior and attitudes across generations and gender among a probability sample of the general population of Nonthaburi province located near Bangkok in 2012. A tablet-based survey was performed among 2,138 men and women aged 15-59 years identified through a three-stage, stratified, probability proportional to size, clustered sampling. Descriptive statistical analysis was carried out accounting for the effects of multistage sampling. Relationship of age and gender to sexual behavior and attitudes was analyzed by bivariate analysis followed by multivariate logistic regression analysis to adjust for possible confounding. Patterns of sexual behavior and attitudes varied substantially across generations and gender. We found strong evidence for a decline in the age of sexual initiation, a shift in the type of the first sexual partner, and a greater rate of acceptance of adolescent premarital sex among younger generations. The study highlighted profound changes among young women as evidenced by a higher number of lifetime sexual partners as compared to older women. In contrast to the significant gender gap in older generations, sexual profiles of Thai young women have evolved to resemble those of young men with attitudes gradually converging to similar sexual standards. Our data suggest that higher education, being never-married, and an urban lifestyle may have been associated with these changes. Our study found that Thai sexual norms are changing dramatically. It is vital to continue monitoring such changes, considering the potential impact on the HIV/STIs epidemic and unintended pregnancies. PMID:25403321

  18. Compulsory sexuality.

    PubMed

    Emens, Elizabeth F

    2014-02-01

    Asexuality is an emerging identity category that challenges the common assumption that everyone is defined by some type of sexual attraction. Asexuals--those who report feeling no sexual attraction to others--constitute one percent of the population, according to one prominent study. In recent years, some individuals have begun to identify as asexual and to connect around their experiences interacting with a sexual society. Asexuality has also become a protected classification under the antidiscrimination law of one state and several localities, but legal scholarship has thus far neglected the subject. This Article introduces asexuality to the legal literature as a category of analysis, an object of empirical study, and a phenomenon of medical science. It then offers a close examination of the growing community of self-identified asexuals. Asexual identity has revealing intersections with the more familiar categories of gender, sexual orientation, and disability, and inspires new models for understanding sexuality. Thinking about asexuality also sheds light on our legal system. Ours is arguably a sexual law, predicated on the assumption that sex is important. This Article uses asexuality to develop a framework for identifying the ways that law privileges sexuality. Across various fields, these interactions include legal requirements of sexual activity, special carve-outs to shield sexuality from law, legal protections from others' sexuality, and legal protections for sexual identity. Applying this framework, the Article traces several ways that our sexual law burdens, and occasionally benefits, asexuals. This Article concludes by closely examining asexuality's prospects for broader inclusion into federal, state, and local antidiscrimination laws. PMID:24654293

  19. Do pre- and post-copulatory sexually selected traits covary in large herbivores?

    PubMed Central

    2014-01-01

    Background In most species, males compete to gain both matings (via pre-copulatory competition) and fertilizations (via post-copulatory competition) to maximize their reproductive success. However, the quantity of resources devoted to sexual traits is finite, and so males are predicted to balance their investment between pre- and post-copulatory expenditure depending on the expected pay-offs that should vary according to mating tactics. In Artiodactyla species, males can invest in weapons such as horns or antlers to increase their mating gains or in testes mass/sperm dimensions to increase their fertilization efficiency. Moreover, it has been suggested that in these species, males with territory defence mating tactic might preferentially increase their investment in post-copulatory traits to increase their fertilization efficiency whereas males with female defence mating tactic might increase their investment in pre-copulatory sexually selected traits to prevent other males from copulating with females. In this study, we thus test the prediction that males weapon length (pre-copulatory trait) covaries negatively with relative testes size and/or sperm dimensions (post-copulatory traits) across Artiodactyla using a phylogenetically controlled framework. Results Surprisingly no association between weapon length and testes mass is found but a negative association between weapon length and sperm length is evidenced. In addition, neither pre- nor post-copulatory traits were found to be affected by male mating tactics. Conclusions We propose several hypotheses that could explain why male ungulates may not balance their reproductive investment between pre- and post-copulatory traits. PMID:24716470

  20. Complex Population Patterns of Eunica tatila Herrich-Schäffer (Lepidoptera: Nymphalidae), with Special Emphasis on Sexual Dimorphism.

    PubMed

    Cavanzón-Medrano, L; Pozo, C; Hénaut, Y; Legal, L; Salas-Suárez, N; Machkour-M'Rabet, S

    2016-04-01

    The species Eunica tatila (Herrich-Schäffer) is present in the Neotropical region and comprises three subspecies. In Mexico, only one subspecies is reported: E. t. tatila (Herrich-Schäffer). The Yucatan Peninsula, in southeastern Mexico, is located in a transitional geographical position, between southern Florida, the West Indies and Central America. It is part of a transitional region, important for the dispersion of insects from southern Florida via Cuba and the Yucatan Peninsula. Considering the possibility of the overlapping and delimitation of described subspecies, we sampled different populations in the Yucatan Peninsula to possibly assign a subspecies name and evaluate the magnitude of sexual dimorphism. We collected 591 individuals (♀284, ♂307) in conserved areas. The study of male genitalia led to the identification of Eunica tatila tatilista (Kaye) as a subspecies; however, hypandrium structure and wing pattern analysis suggest a mix of E. t. tatila and E. t. tatilista characteristics. The analysis of sexual dimorphism provided evidence of more complex wing morphs for females, with 12 patterns instead of four as previously described. Our results demonstrate the complexity of characterizing E. tatila and suggest that the Yucatan Peninsula is a transitional zone for subspecies of some butterflies. PMID:26677083

  1. Using behavior-analytic implicit tests to assess sexual interests among normal and sex-offender populations

    PubMed Central

    Roche, Bryan; O’Reilly, Anthony; Gavin, Amanda; Ruiz, Maria R.; Arancibia, Gabriela

    2012-01-01

    Background The development of implicit tests for measuring biases and behavioral predispositions is a recent development within psychology. While such tests are usually researched within a social-cognitive paradigm, behavioral researchers have also begun to view these tests as potential tests of conditioning histories, including in the sexual domain. Objective The objective of this paper is to illustrate the utility of a behavioral approach to implicit testing and means by which implicit tests can be built to the standards of behavioral psychologists. Design Research findings illustrating the short history of implicit testing within the experimental analysis of behavior are reviewed. Relevant parallel and overlapping research findings from the field of social cognition and on the Implicit Association Test are also outlined. Results New preliminary data obtained with both normal and sex offender populations are described in order to illustrate how behavior-analytically conceived implicit tests may have potential as investigative tools for assessing histories of sexual arousal conditioning and derived stimulus associations. Conclusion It is concluded that popular implicit tests are likely sensitive to conditioned and derived stimulus associations in the history of the test-taker rather than ‘unconscious cognitions’, per se. PMID:24693346

  2. Genetic structure in large, continuous mammal populations: the example of brown bears in northwestern Eurasia.

    PubMed

    Tammeleht, E; Remm, J; Korsten, M; Davison, J; Tumanov, I; Saveljev, A; Männil, P; Kojola, I; Saarma, U

    2010-12-01

    Knowledge of population structure and genetic diversity and the spatio-temporal demographic processes affecting populations is crucial for effective wildlife preservation, yet these factors are still poorly understood for organisms with large continuous ranges. Available population genetic data reveal that widespread mammals have for the most part only been carefully studied at the local population scale, which is insufficient for understanding population processes at larger scales. Here, we provide data on population structure, genetic diversity and gene flow in a brown bear population inhabiting the large territory of northwestern Eurasia. Analysis of 17 microsatellite loci indicated significant population substructure, consisting of four genetic groups. While three genetic clusters were confined to small geographical areas-located in Estonia, southern Finland and Leningrad oblast, Russia-the fourth cluster spanned a very large area broadly falling between northern Finland and the Arkhangelsk and Kirov oblasts of Russia. Thus, the data indicate a complex pattern where a fraction of the population exhibits large-scale gene flow that is unparalleled by other wild mammals studied to date, while the remainder of the population appears to have been structured by a combination of demographic history and landscape barriers. These results based on nuclear data are generally in good agreement with evidence previously derived using mitochondrial markers, and taken together, these markers provide complementary information about female-specific and population-level processes. Moreover, this study conveys information about spatial processes occurring over multiple generations that cannot be readily gained using other approaches, e.g. telemetry. PMID:21044194

  3. Smoking Initiation, Tobacco Product Use, and Secondhand Smoke Exposure Among General Population and Sexual Minority Youth, Missouri, 2011–2012

    PubMed Central

    McElroy, Jane A.; Everett, Kevin D.

    2014-01-01

    Introduction Research indicates disparities in risky health behaviors between heterosexual and sexual minority (referred to as LGBQ; also known as lesbian, gay, bisexual, queer, and questioning) youth. Limited data are available for tobacco-use–related behaviors beyond smoking status. We compared data on tobacco age of initiation, product use, and secondhand smoke exposure between general population and LGBQ youth. Methods Data for general population youth were from the statewide, representative 2011 Missouri Youth Tobacco Survey, and data for LGBQ youth were from the 2012 Out, Proud and Healthy survey (collected at Missouri Pride Festivals). Age-adjusted Cochran-Mantel-Haenszel tests were used to examine differences between general population (N = 1,547) and LGBQ (N = 410) youth, aged 14 to 18 years. Logistic regression models identified variables associated with current smoking. Results The 2 groups differed significantly on many tobacco-use–related factors. General population youth initiated smoking at a younger age, and LGBQ youth did not catch up in smoking initiation until age 15 or 16. LGBQ youth (41.0%) soon surpassed general population youth (11.2%) in initiation and proportion of current smokers. LGBQ youth were more likely to use cigars/cigarillos, be poly-tobacco users, and be exposed to secondhand smoke (SHS) in a vehicle (for never smokers). Older age (odds ratio [OR] = 1.39, 95% confidence interval [95% CI] = 1.18–1.62), female sex (OR = 1.64, 95% CI = 1.13–2.37), LGBQ identity (OR = 3.86, 95% CI = 2.50–5.94), other tobacco product use (OR = 8.67, 95% CI = 6.01–12.51), and SHS exposure in a vehicle (OR = 5.97, 95% CI = 3.83–9.31) all significantly increased the odds of being a current smoker. Conclusion This study highlights a need for the collection of data on sexual orientation on youth tobacco surveys to address health disparities among LGBQ youth. PMID:24995655

  4. Population diversity of Puccinia graminis is sustained through sexual cycle on alternate hosts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A high degree of virulence diversity has been maintained in the population of Puccinia graminis f. sp. tritici (Pgt) in northwestern United States. Although Berberis vulgaris is present in the region and Pgt has been isolated from aecial infections on B. vulgaris, the population is too diverse to be...

  5. Sex, health, and years of sexually active life gained due to good health: evidence from two US population based cross sectional surveys of ageing

    PubMed Central

    2010-01-01

    Objectives To examine the relation between health and several dimensions of sexuality and to estimate years of sexually active life across sex and health groups in middle aged and older adults. Design Cross sectional study. Setting Two samples representative of the US population: MIDUS (the national survey of midlife development in the United States, 1995-6) and NSHAP (the national social life, health and ageing project, 2005-6). Participants 3032 adults aged 25 to 74 (1561 women, 1471 men) from the midlife cohort (MIDUS) and 3005 adults aged 57 to 85 (1550 women, 1455 men) from the later life cohort (NSHAP). Main outcome measures Sexual activity, quality of sexual life, interest in sex, and average remaining years of sexually active life, referred to as sexually active life expectancy. Results Overall, men were more likely than women to be sexually active, report a good quality sex life, and be interested in sex. These gender differences increased with age and were greatest among the 75 to 85 year old group: 38.9% of men compared with 16.8% of women were sexually active, 70.8% versus 50.9% of those who were sexually active had a good quality sex life, and 41.2% versus 11.4% were interested in sex. Men and women reporting very good or excellent health were more likely to be sexually active compared with their peers in poor or fair health: age adjusted odds ratio 2.2 (P<0.01) for men and 1.6 (P<0.05) for women in the midlife study and 4.6 (P<0.001) for men and 2.8 (P<0.001) for women in the later life study. Among sexually active people, good health was also significantly associated with frequent sex (once or more weekly) in men (adjusted odds ratio 1.6 to 2.1), with a good quality sex life among men and women in the midlife cohort (adjusted odds ratio 1.7), and with interest in sex. People in very good or excellent health were 1.5 to 1.8 times more likely to report an interest in sex than those in poorer health. At age 30, sexually active life expectancy was 34.7 years for men and 30.7 years for women compared with 14.9 to 15.3 years for men and 10.6 years for women at age 55. This gender disparity attenuated for people with a spouse or other intimate partner. At age 55, men in very good or excellent health on average gained 5-7 years of sexually active life compared with their peers in poor or fair health. Women in very good or excellent health gained 3-6 years compared with women in poor or fair health. Conclusion Sexual activity, good quality sexual life, and interest in sex were higher for men than for women and this gender gap widened with age. Sexual activity, quality of sexual life, and interest in sex were positively associated with health in middle age and later life. Sexually active life expectancy was longer for men, but men lost more years of sexually active life as a result of poor health than women. PMID:20215365

  6. Structural approaches for prevention of sexually transmitted HIV in general populations: definitions and an operational approach

    PubMed Central

    Parkhurst, Justin O

    2014-01-01

    Introduction Although biomedical HIV prevention efforts have seen a number of recent promising developments, behavioural interventions have often been described as failing. However, clear lessons have been identified from past efforts, including the need to address influential social, economic and legal structures; to tailor efforts to local contexts; and to address multiple influencing factors in combination. Despite these insights, there remains a pervasive strategy to try to achieve sexual behaviour change through single, decontextualized, interventions or sets of activities. With current calls for structural approaches to HIV as part of combination HIV prevention, though, there is a unique opportunity to define a structural approach to HIV prevention as one which moves beyond these past limitations and better incorporates our knowledge of the social world and the lessons from past efforts. Discussion A range of interlinked concepts require delineation and definition within the broad concept of a structural approach to HIV. This includes distinguishing between “structural factors,” which can be seen as any number of elements (other than knowledge) which influence risk and vulnerability, and “structural drivers,” which should be reserved for situations where an empirically established relationship to a target group is known. Operationalizing structural approaches similarly can take different paths, either working to alter structural drivers or alternatively working to build individual and community resilience to infection. A “structural diagnostic approach” is further defined as the process one undertakes to develop structural intervention strategies tailored to target groups. Conclusions For three decades, the HIV prevention community has struggled to reduce the spread of HIV through sexual risk behaviours with limited success, but equally with limited engagement with the lessons that have been learned about the social realities shaping patterns of sexual practices. Future HIV prevention efforts must address the multiple factors influencing risk and vulnerability, and they must do so in ways tailored to particular settings. Clarity on the concepts, terminology and approaches that can allow structural HIV prevention efforts to achieve this is therefore essential to improve the (social) science of HIV prevention. PMID:25204872

  7. Weight Misperception and Unhealthy Weight Control Behaviors Among Sexual Minorities in the General Adolescent Population

    PubMed Central

    Hadland, Scott E.; Austin, S. Bryn; Goodenow, Carol S.; Calzo, Jerel P.

    2013-01-01

    Purpose Gay, lesbian and bisexual youth may experience significant body dissatisfaction. We examined sexual orientation differences in self-perceived weight status and prevalence of potentially dangerous weight control behaviors in a representative sample of adolescents. Methods Data were obtained from 12,984 youth between 2003–2009 over four cycles of the Massachusetts Youth Risk Behavior Survey, a statewide survey of 9th–12th grade students. Self-perceived weight status and past-month unhealthy weight control behaviors (fasting >24 hours, using diet pills, and vomiting/using laxatives) were compared among gay/lesbian, bisexual, self-identified heterosexual youth with same-sex partners, unsure youth, and exclusively heterosexual youth using logistic regression, adjusting for age and race/ethnicity. Results Compared to exclusively heterosexual males, heterosexual males with prior same-sex partners and bisexual males were more likely to self-perceive as overweight despite being of healthy weight/underweight (respectively, adjusted odds ratio [AOR], 2.61; 95% confidence interval [CI], 1.68–4.05; and AOR, 2.56; 95% CI, 1.64–4.00). Compared to exclusively heterosexual females, lesbians and bisexual females were more likely to self-perceive as being of healthy weight/underweight despite being overweight/obese (respectively, AOR, 3.17; 95% CI, 1.15–8.71; and AOR, 2.00; 95% CI, 1.20–3.33). Unhealthy weight control behaviors were significantly more prevalent among sexual minority males (32.5%; AOR, 4.38; 95% CI, 3.38–5.67) and females (34.7%; AOR, 2.27; 95% CI, 1.85–2.78) when considered together relative to exclusively heterosexual males (9.7%) and females (18.8%). Conclusions One-third of sexual minority youth engage in hazardous weight control behaviors. Future research should investigate underlying mechanisms and determine whether clinicians should routinely screen for these behaviors. PMID:24182939

  8. Prevalence of Consensual Male–Male Sex and Sexual Violence, and Associations with HIV in South Africa: A Population-Based Cross-Sectional Study

    PubMed Central

    Dunkle, Kristin L.; Jewkes, Rachel K.; Murdock, Daniel W.; Sikweyiya, Yandisa; Morrell, Robert

    2013-01-01

    Background In sub-Saharan Africa the population prevalence of men who have sex with men (MSM) is unknown, as is the population prevalence of male-on-male sexual violence, and whether male-on-male sexual violence may relate to HIV risk. This paper describes lifetime prevalence of consensual male–male sexual behavior and male-on-male sexual violence (victimization and perpetration) in two South African provinces, socio-demographic factors associated with these experiences, and associations with HIV serostatus. Methods and Findings In a cross-sectional study conducted in 2008, men aged 18–49 y from randomly selected households in the Eastern Cape and KwaZulu-Natal provinces provided anonymous survey data and dried blood spots for HIV serostatus assessment. Interviews were completed in 1,737 of 2,298 (75.6%) of enumerated and eligible households. From these households, 1,705 men (97.1%) provided data on lifetime history of same-sex experiences, and 1,220 (70.2%) also provided dried blood spots for HIV testing. 5.4% (n = 92) of participants reported a lifetime history of any consensual sexual activity with another man; 9.6% (n = 164) reported any sexual victimization by a man, and 3.0% (n = 51) reported perpetrating sexual violence against another man. 85.0% (n = 79) of men with a history of consensual sex with men reported having a current female partner, and 27.7% (n = 26) reported having a current male partner. Of the latter, 80.6% (n = 21/26) also reported having a female partner. Men reporting a history of consensual male–male sexual behavior are more likely to have been a victim of male-on-male sexual violence (adjusted odds ratio [aOR] = 7.24; 95% CI 4.26–12.3), and to have perpetrated sexual violence against another man (aOR = 3.10; 95% CI 1.22–7.90). Men reporting consensual oral/anal sex with a man were more likely to be HIV+ than men with no such history (aOR = 3.11; 95% CI 1.24–7.80). Men who had raped a man were more likely to be HIV+ than non-perpetrators (aOR = 3.58; 95% CI 1.17–10.9). Conclusions In this sample, one in 20 men (5.4%) reported lifetime consensual sexual contact with a man, while about one in ten (9.6%) reported experience of male-on-male sexual violence victimization. Men who reported having had sex with men were more likely to be HIV+, as were men who reported perpetrating sexual violence towards other men. Whilst there was no direct measure of male–female concurrency (having overlapping sexual relationships with men and women), the data suggest that this may have been common. These findings suggest that HIV prevention messages regarding male–male sex in South Africa should be mainstreamed with prevention messages for the general population, and sexual health interventions and HIV prevention interventions for South African men should explicitly address male-on-male sexual violence. Please see later in the article for the Editors' Summary PMID:23853554

  9. Highly active antiretroviral therapy is associated with decreased incidence of sexually transmitted diseases in a Taiwanese HIV-positive population.

    PubMed

    Cheng, Shu-Hsing; Yang, Chin-Hui; Hsueh, Yu-Mei

    2013-03-01

    There are reports of increased sexual risk behaviors in the HIV-positive population since the introduction of highly active antiretroviral therapy (HAART). Little is known about the effects of the case management (CM) program and HAART on sexually transmitted diseases (STDs) in Taiwan. HIV-positive subjects, who visited the outpatient clinics of Taoyuan General Hospital between 2007 and 2010, were enrolled. A total of 574 subjects and 14,462 person-months were reviewed. Incident STDs occurred in 104 (18.1%) subjects, and the incidence rate was 8.6 (95% confidence interval [CI], 7.1-10.5) per 100 person-years (PY). For men who have sex with men (MSM), heterosexual men and women, and injection drug users (IDU), 19.4 per 100 PY(95% CI, 15.7-24.0), 3.5 per 100 PY (95% CI, 1.4-7.3), and 1.1 per 100 PY (95% CI, 0.4-2.4) of STDs were noted, respectively; (MSM versus IDU and MSM versus heterosexual subjects, p<0.000001; heterosexual subjects versus IDU, p=0.061). Syphilis (59.6%) was the most common STD. Regular CM and no HAART (hazard ratio, 2.58; 95% CI, 1.14-5.84; p=0.02) was significantly associated with STDs in MSM. Though this retrospective study might underestimate the incidence of STDs and not draw the conclusion of causality, we concluded that the CM program and HAART are associated with lower acquisition of STDs in the Taiwanese HIV-positive population. PMID:23442028

  10. Rapid declines of large mammal populations after the collapse of the Soviet Union.

    PubMed

    Bragina, Eugenia V; Ives, A R; Pidgeon, A M; Kuemmerle, T; Baskin, L M; Gubar, Y P; Piquer-Rodríguez, M; Keuler, N S; Petrosyan, V G; Radeloff, V C

    2015-06-01

    Anecdotal evidence suggests that socioeconomic shocks strongly affect wildlife populations, but quantitative evidence is sparse. The collapse of socialism in Russia in 1991 caused a major socioeconomic shock, including a sharp increase in poverty. We analyzed population trends of 8 large mammals in Russia from 1981 to 2010 (i.e., before and after the collapse). We hypothesized that the collapse would first cause population declines, primarily due to overexploitation, and then population increases due to adaptation of wildlife to new environments following the collapse. The long-term Database of the Russian Federal Agency of Game Mammal Monitoring, consisting of up to 50,000 transects that are monitored annually, provided an exceptional data set for investigating these population trends. Three species showed strong declines in population growth rates in the decade following the collapse, while grey wolf (Canis lupus) increased by more than 150%. After 2000 some trends reversed. For example, roe deer (Capreolus spp.) abundance in 2010 was the highest of any period in our study. Likely reasons for the population declines in the 1990s include poaching and the erosion of wildlife protection enforcement. The rapid increase of the grey wolf populations is likely due to the cessation of governmental population control. In general, the widespread declines in wildlife populations after the collapse of the Soviet Union highlight the magnitude of the effects that socioeconomic shocks can have on wildlife populations and the possible need for special conservation efforts during such times. PMID:25581070

  11. Diversity lost: are all Holarctic large mammal species just relict populations?

    PubMed

    Hofreiter, Michael; Barnes, Ian

    2010-01-01

    Population genetic analyses of Eurasian wolves published recently in BMC Evolutionary Biology suggest that a major genetic turnover took place in Eurasian wolves after the Pleistocene. These results add to the growing evidence that large mammal species surviving the late Pleistocene extinctions nevertheless lost a large share of their genetic diversity. PMID:20409351

  12. Premating isolation is determined by larval rearing substrates in cactophilic Drosophila mojavensis. IX. Host plant and population specific epicuticular hydrocarbon expression influences mate choice and sexual selection.

    PubMed

    Havens, J A; Etges, W J

    2013-03-01

    Sexual signals in cactophilic Drosophila mojavensis include cuticular hydrocarbons (CHCs), contact pheromones that mediate female discrimination of males during courtship. CHCs, along with male courtship songs, cause premating isolation between diverged populations, and are influenced by genotype × environment interactions caused by different host cacti. CHC profiles of mated and unmated adult flies from a Baja California and a mainland Mexico population of D. mojavensis reared on two host cacti were assayed to test the hypothesis that male CHCs mediate within-population female discrimination of males. In multiple choice courtship trials, mated and unmated males differed in CHC profiles, indicating that females prefer males with particular blends of CHCs. Mated and unmated females significantly differed in CHC profiles as well. Adults in the choice trials had CHC profiles that were significantly different from those in pair-mated adults from no-choice trials revealing an influence of sexual selection. Females preferred different male CHC blends in each population, but the influence of host cactus on CHC variation was significant only in the mainland population indicating population-specific plasticity in CHCs. Different groups of CHCs mediated female choice-based sexual selection in each population suggesting that geographical and ecological divergence has the potential to promote divergence in mate communication systems. PMID:23286346

  13. Sexual Abuse and Sexual Functioning in a Chronic Pelvic Pain Sample

    ERIC Educational Resources Information Center

    Randolph, Mary E.; Reddy, Diane M.

    2006-01-01

    Sexual abuse, particularly childhood sexual abuse, has been linked to chronic pelvic pain and to sexual dysfunction, though the sexual functioning of survivors of sexual abuse has not been studied in a chronic pain population. Sixty-three women with chronic pelvic pain completed measures of sexual function, sexual abuse, and pain. Using an index

  14. Sexual Abuse and Sexual Functioning in a Chronic Pelvic Pain Sample

    ERIC Educational Resources Information Center

    Randolph, Mary E.; Reddy, Diane M.

    2006-01-01

    Sexual abuse, particularly childhood sexual abuse, has been linked to chronic pelvic pain and to sexual dysfunction, though the sexual functioning of survivors of sexual abuse has not been studied in a chronic pain population. Sixty-three women with chronic pelvic pain completed measures of sexual function, sexual abuse, and pain. Using an index…

  15. Simulating natural conditions in the laboratory: a re-examination of sexual isolation between sympatric and allopatric populations of Drosophila pseudoobscura and D. persimilis.

    PubMed

    Noor, Mohamed A F; Ortz-Barrientos, Daniel

    2006-03-01

    Simulating natural conditions in the laboratory poses one of the most significant challenges to behavioral studies. Some authors have argued that laboratory "choice" experiments reflect mate choice in nature more accurately than "no-choice" experiments. A recent choice experiment study questioned the conclusions of several earlier studies by failing to detect a published difference in sexual isolation between populations of Drosophila pseudoobscura, and suggested their result was more robust because of the more realistic design. Here, we re-examine the methods and analyses of this recent study, and we find there was indeed a difference in sexual isolation between populations of D. pseudoobscura. We also conduct a more rigorously controlled choice experiment and, in agreement with previous studies, note that D. pseudoobscura females from populations sympatric to their sibling species, D. persimilis, exhibit greater sexual isolation than those from allopatric populations. Our results confirm the existence of a geographic pattern in sexual isolation in D. pseudoobscura, and we discuss differences in experimental designs in light of the biology of this species. PMID:16502138

  16. Population structure and the evolution of sexual size dimorphism and sex ratios in an insular population of Florida box turtles (Terrapene carolina bauri)

    USGS Publications Warehouse

    Dodd, C.K., Jr.

    1997-01-01

    Hypotheses in the chelonian literature suggest that in species with sexual size dimorphism, the smaller sex will mature at a smaller size and a younger age than the larger sex, sex ratios should be biased in favor of the earlier maturing sex, and deviations from a 1:1 sex ratio result from maturation of the smaller sex at a younger age. I tested these hypotheses using data collected from 1991 to 1995 on an insular (Egmont Key) population of Florida box turtles, Terrapene carolina bauri. Contrary to predictions, the earlier maturing sex (males) grew to larger sizes than the late maturing sex. Males were significantly larger than females in mean carapace length but not mean body mass. Sex ratios were not balanced, favoring the earlier maturing sex (1.6 males:1 female), but the sex-ratio imbalance did not result from faster maturation of the smaller sex. The imbalance in the sex ratio in Egmont Key's box turtles is not the result of sampling biases; it may result from nest placement. Size-class structure and sex ratios can provide valuable insights into the status and trends of populations of long-lived turtles.

  17. Census vs. effective population size in chinook salmon: large- and small-scale environmental perturbation effects.

    PubMed

    Shrimpton, J Mark; Heath, Daniel D

    2003-10-01

    Population viability has often been assessed by census of reproducing adults. Recently this method has been called into question and estimation of the effective population size (Ne) proposed as a complementary method to determine population health. We examined genetic diversity in five populations of chinook salmon (Oncorhynchus tshawytscha) from the upper Fraser River watershed (British Columbia, Canada) at 11 microsatellite loci over 20 years using DNA extracted from archived scale samples. We tested for changes in genetic diversity, calculated the ratio of the number of alleles to the range in allele size to give the statistic M, calculated Ne from the temporal change in allele frequency, used the maximum likelihood method to calculate effective population size (NeM), calculated the harmonic mean of population size, and compared these statistics to annual census estimates. Over the last two decades population size has increased in all five populations of chinook examined; however, Ne calculated for each population was low (81-691) and decreasing over the time interval measured. Values of NeM were low, but substantially higher than Ne calculated using the temporal method. The calculated values for M were generally low (M < 0.70), indicating recent population reductions for all five populations. Large-scale historic barriers to migration and development activities do not appear to account for the low values of Ne; however, available spawning area is positively correlated with Ne. Both Ne and M estimates indicate that these populations are potentially susceptible to inbreeding effects and may lack the ability to respond adaptively to stochastic events. Our findings question the practice of relying exclusively on census estimates for interpreting population health and show the importance of determining genetic diversity within populations. PMID:12969462

  18. Abortion research: attitudes, sexual behavior, and problems in a community college population.

    PubMed

    Bryan, J W; Freed, F W

    1993-02-01

    150 (80 females and 70 males) community college students were surveyed regarding their attitudes toward abortion, their sexual behavior, and their problems. The profile of the students was Caucasian (95%), young (18-24 years = 87%), single (87%), middle and lower middle class, and Catholic (70%). 82% supported abortion choice, 86% had engaged in premarital sex, 70% used contraception, and 26% had premarital pregnancies. The hard reasons for abortion (rape, the woman's life, is endangered, and the fetus is defective) received high support. The soft reasons (the family cannot afford more children or the woman does not want to marry the man) received lower support. The students were divided into 3 groups of 50 students based on the number of abortion reasons they supported out of 43 reasons. The low-group that accepted 0-10 reasons was called anti-abortion. 50% of them still believed a woman has a right to an abortion vs. 97% of the pro-abortion students. The students reported many problems in their families: alcoholic home (39%), loss of a parent through death, divorce, or separation (33%), victims of severe corporal punishment (31%), one or more family members physically abused (20%), and deprived of parental affection while growing up (20%). When the anti-abortion females (N=30) were compared with the pro-abortion females (N=50), they reported significantly (p.01) more hospitalization, a greater number of physical handicaps, and more shyness (p.1). When the anti-abortion males (N=20) were compared with the pro-abortion males (N=50), they reported significantly more obesity and agoraphobia (p.05) and more convictions for a crime (p.1). Comparison of women who had abortion (N=13) with the women who had their baby (N=8) indicated that the latter reported significantly (p.01) more battering by their boyfriend or husband, significantly (p.05) more battering in their family of origin and childhood sexual abuse, and a greater tendency (p.1) to have been raped. PMID:12345019

  19. Is female preference for large sexual ornaments due to a bias to escape predation risk?

    PubMed Central

    2012-01-01

    Background A female preference for intense sexual visual signals is widespread in animals. Although the preferences for a signal per se and for the intensity of the signal were often regarded to have the identical origin, no study has demonstrated if this is true. It was suggested that the female fiddler crabs prefer males with courtship structures because of direct benefit to escape predation. Here we tested if female preference for both components (i.e. presence and size) of the courtship structure in Uca lactea is from the sensory bias to escape predation. If both components have the identical origin, females should show the same response to different-sized courtship structures regardless of predation risk. Results First, we observed responses of mate-searching female U. lactea to courting males with full-sized, half-sized and no semidomes which were experimentally manipulated. Females had a directional preference for males with bigger semidomes within normal variation. Thereafter, we tested the effect of predation risk on the female bias in the non-courtship context. When threatened by an avian mock predator, females preferentially approached burrows with full-sized semidomes regardless of reproductive cycles (i.e. reproductive periods and non-reproductive periods). When the predator cue was absent, however, females preferred burrows with semidomes without discriminating structure size during reproductive periods but did not show any bias during non-reproductive periods. Conclusions Results indicate that selection for the size of courtship structures in U. lactea may have an origin in the function to reduce predation risk, but that the preference for males with structures may have evolved by female choice, independent of predation pressure. PMID:22413838

  20. Minireview: Hormones and Human Sexual Orientation

    PubMed Central

    2011-01-01

    Many people believe that sexual orientation (homosexuality vs. heterosexuality) is determined by education and social constraints. There are, however, a large number of studies indicating that prenatal factors have an important influence on this critical feature of human sexuality. Sexual orientation is a sexually differentiated trait (over 90% of men are attracted to women and vice versa). In animals and men, many sexually differentiated characteristics are organized during early life by sex steroids, and one can wonder whether the same mechanism also affects human sexual orientation. Two types of evidence support this notion. First, multiple sexually differentiated behavioral, physiological, or even morphological traits are significantly different in homosexual and heterosexual populations. Because some of these traits are known to be organized by prenatal steroids, including testosterone, these differences suggest that homosexual subjects were, on average, exposed to atypical endocrine conditions during development. Second, clinical conditions associated with significant endocrine changes during embryonic life often result in an increased incidence of homosexuality. It seems therefore that the prenatal endocrine environment has a significant influence on human sexual orientation but a large fraction of the variance in this behavioral characteristic remains unexplained to date. Genetic differences affecting behavior either in a direct manner or by changing embryonic hormone secretion or action may also be involved. How these biological prenatal factors interact with postnatal social factors to determine life-long sexual orientation remains to be determined. PMID:21693676

  1. Minireview: Hormones and human sexual orientation.

    PubMed

    Balthazart, Jacques

    2011-08-01

    Many people believe that sexual orientation (homosexuality vs. heterosexuality) is determined by education and social constraints. There are, however, a large number of studies indicating that prenatal factors have an important influence on this critical feature of human sexuality. Sexual orientation is a sexually differentiated trait (over 90% of men are attracted to women and vice versa). In animals and men, many sexually differentiated characteristics are organized during early life by sex steroids, and one can wonder whether the same mechanism also affects human sexual orientation. Two types of evidence support this notion. First, multiple sexually differentiated behavioral, physiological, or even morphological traits are significantly different in homosexual and heterosexual populations. Because some of these traits are known to be organized by prenatal steroids, including testosterone, these differences suggest that homosexual subjects were, on average, exposed to atypical endocrine conditions during development. Second, clinical conditions associated with significant endocrine changes during embryonic life often result in an increased incidence of homosexuality. It seems therefore that the prenatal endocrine environment has a significant influence on human sexual orientation but a large fraction of the variance in this behavioral characteristic remains unexplained to date. Genetic differences affecting behavior either in a direct manner or by changing embryonic hormone secretion or action may also be involved. How these biological prenatal factors interact with postnatal social factors to determine life-long sexual orientation remains to be determined. PMID:21693676

  2. Sexually Transmitted Diseases as a Risk for Acquiring HIV Infection among the Population of Men Who Have Sex with Men--A Case-Control Study.

    PubMed

    Lakoseljac, Danijela; Gjenero-Margan, Ira; Kolarić, Branko; Rukavina, Tomislav; Blazić, Tatjana Nemeth

    2015-09-01

    At the beginning of the 1980-ies, HIV infection and AIDS were described for the first time, this among the population of men who have sex with other men. Nearly thirty years later, the MSM population is still a population under heightened risk for acquiring HIV infection and other sexually transmitted diseases. This study investigates sexually transmitted diseases as a risk for HIV infection. A total of 296 men who have sex with men (MSM) were included in this case control study. Differences among the frequencies of sexually transmitted diseases among the MSM of HIV positive and HIV negative status were tested. The history of HIV positive more often states falling ill with sexually transmitted diseases than this was the case before they became HIV positive, unlike those MSM who are not HIV infected (45.9%:11.1% that is OR 6.79, 95% CI 3.49-13.19). Hepatitis B infection is more frequent in HIV positive MSM (11.5%:1.9%; OR 6.58, 95% CI 1.86-23.3). The frequency of gonorrhea in case history of HIV positive MSM is significantly higher than in the HIV negative group (11.5%:3.8%, OR 3.24, 95% CI 1.13-9.34). In the group of HIV positive MSM, unlike the HIV negative group, syphilis (14.8:1.0%, OR 1774, 95% CI 3.43-122.87) and genital herpes (8.2%:0.5%, OR 18.39, 95% CI 2.03-424.7) are more frequent. The results of this study will be used in future preventive activities focused on the population of MSM, as a population under particular risk for acquiring sexually transmitted infections. PMID:26898074

  3. Involvement of different mesotocin (oxytocin homologue) populations in sexual and aggressive behaviours of the brown anole

    PubMed Central

    Kabelik, David; Magruder, D. Sumner

    2014-01-01

    The oxytocin (OT) family of neuropeptides are known to modulate social behaviours and anxiety in mammals and birds. We investigated cell numbers and neural activity, assessed as Fos induction, within magnocellular and parvocellular populations of neurons producing the OT homologue mesotocin (MT, Ile8-oxytocin). This was conducted within the male brown anole lizard, Anolis sagrei, following agonistic or courtship encounters with a conspecific. Both neurons colocalizing and not colocalizing corticotropin-releasing factor (CRF) were examined. Parvocellular neurons of the paraventricular nucleus exhibited a positive correlation between courtship frequency and Fos colocalization, regardless of whether they produce just MT or MT + CRF. Magnocellular populations showed only trends towards positive relationships with courtship and no cell populations showed aggression-related Fos induction. These findings are novel because they demonstrate the involvement of MT neurons in male social behaviour, especially in reptiles for whom the involvement of MT in social behaviour was previously unknown. PMID:25165455

  4. Involvement of different mesotocin (oxytocin homologue) populations in sexual and aggressive behaviours of the brown anole.

    PubMed

    Kabelik, David; Magruder, D Sumner

    2014-08-01

    The oxytocin (OT) family of neuropeptides are known to modulate social behaviours and anxiety in mammals and birds. We investigated cell numbers and neural activity, assessed as Fos induction, within magnocellular and parvocellular populations of neurons producing the OT homologue mesotocin (MT, Ile(8)-oxytocin). This was conducted within the male brown anole lizard, Anolis sagrei, following agonistic or courtship encounters with a conspecific. Both neurons colocalizing and not colocalizing corticotropin-releasing factor (CRF) were examined. Parvocellular neurons of the paraventricular nucleus exhibited a positive correlation between courtship frequency and Fos colocalization, regardless of whether they produce just MT or MT + CRF. Magnocellular populations showed only trends towards positive relationships with courtship and no cell populations showed aggression-related Fos induction. These findings are novel because they demonstrate the involvement of MT neurons in male social behaviour, especially in reptiles for whom the involvement of MT in social behaviour was previously unknown. PMID:25165455

  5. Higher reproductive success of small males and greater recruitment of large females may explain strong reversed sexual dimorphism (RSD) in the northern goshawk.

    PubMed

    Prez-Camacho, L; Garca-Salgado, G; Rebollo, S; Martnez-Hesterkamp, S; Fernndez-Pereira, J M

    2015-02-01

    Reversed sexual dimorphism (RSD), which occurs when the female of a species is larger than the male, is the rule for most birds of prey but the exception among other bird and mammal species. The selective pressures that favour RSD are an intriguing issue in animal ecology. Despite the large number of hypotheses proposed to explain the evolution of RSD, there is still no consensus about the mechanisms involved and whether they act on one or both sexes, mainly because few intrapopulation studies have been undertaken and few raptor species have been investigated. Using the strongly size-dimorphic northern goshawk (Accipiter gentilis L.) as a model, we studied a population with one of the highest densities of breeding pairs reported in the literature in order to understand selective pressures that may favour RSD. We evaluated life-history processes, including recruitment of adult breeders and reproductive success, and we explored the mechanisms thought to act on each sex, including hunting efficiency, diet, body condition and mate choice. We found that smaller males produced more fledglings than larger ones, but there was no relationship between size and reproductive success for females. The mean body size of female breeders was larger than that of female fledglings, but male fledglings and breeders did not differ in size. Male body size was related to the type but not to the amount of prey captured during the nestling stage. We conclude that RSD may be favoured in this goshawk population because small males tend to enjoy higher reproductive success and large females greater recruitment. Our results do not support the hypotheses that evolutionary reduction in male size is driven by hunting efficiency, at least during the nestling stage, or the hypotheses that it is driven by greater recruitment. Our findings also suggest that increase in female size is driven by recruitment, rather than by reproductive success as previously postulated. PMID:25424156

  6. Sexual dimorphism for water balance mechanisms in montane populations of Drosophila kikkawai

    PubMed Central

    Parkash, Ravi; Sharma, Vineeta; Kalra, Bhawna

    2010-01-01

    Conservation of water is critical to the ecological success of Drosophila species living in the drier montane localities of the Western Himalayas. We observed clinal variation in desiccation resistance for both sexes of Drosophila kikkawai from an altitudinal transect (512–2226 m above sea level). Since more than 90 per cent of body water is lost through cuticular transpiration, the target of selection may be cuticular lipids or cuticular melanization. We tested whether melanic females and non-melanic males of D. kikkawai have similar mechanisms of desiccation resistance. There is clinal variation in the amount of cuticular lipids per fly in males, but not in females. By contrast, for females, elevational increase in melanization is positively correlated with desiccation resistance and negatively with cuticular water loss, but there is no variation in the amount of cuticular lipids. Thus, sexual dimorphism for the mechanism of desiccation resistance in D. kikkawai matches the water proofing role of body melanization as well as cuticular lipids. PMID:20106858

  7. Religious Climate and Health Risk Behaviors in Sexual Minority Youths: A Population-Based Study

    PubMed Central

    Pachankis, John E.; Wolff, Joshua

    2012-01-01

    Objectives. We examined whether the health risk behaviors of lesbian, gay, and bisexual (LGB) youths are determined in part by the religious composition of the communities in which they live. Methods. Data were collected from 31 852 high school students, including 1413 LGB students, who participated in the Oregon Healthy Teens survey in 2006 through 2008. Supportive religious climate was operationalized according to the proportion of individuals (of the total number of religious adherents) who adhere to a religion supporting homosexuality. Comprehensive data on religious climate were derived from 85 denominational groups in 34 Oregon counties. Results. Among LGB youths, living in a county with a religious climate that was supportive of homosexuality was associated with significantly fewer alcohol abuse symptoms (odds ratio [OR] = 0.58; 95% confidence interval [CI] = 0.40, 0.85) and fewer sexual partners (OR = 0.77; 95% CI = 0.60, 0.99). The effect of religious climate on health behaviors was stronger among LGB than heterosexual youths. Results remained robust after adjustment for multiple confounding factors. Conclusions. The religious climate surrounding LGB youths may serve as a determinant of their health risk behaviors. PMID:22397347

  8. Large-scale control site selection for population monitoring: an example assessing Sage-grouse trends

    USGS Publications Warehouse

    Fedy, Bradley C.; O'Donnell, Michael; Bowen, Zachary H.

    2015-01-01

    Human impacts on wildlife populations are widespread and prolific and understanding wildlife responses to human impacts is a fundamental component of wildlife management. The first step to understanding wildlife responses is the documentation of changes in wildlife population parameters, such as population size. Meaningful assessment of population changes in potentially impacted sites requires the establishment of monitoring at similar, nonimpacted, control sites. However, it is often difficult to identify appropriate control sites in wildlife populations. We demonstrated use of Geographic Information System (GIS) data across large spatial scales to select biologically relevant control sites for population monitoring. Greater sage-grouse (Centrocercus urophasianus; hearafter, sage-grouse) are negatively affected by energy development, and monitoring of sage-grouse population within energy development areas is necessary to detect population-level responses. Weused population data (1995–2012) from an energy development area in Wyoming, USA, the Atlantic Rim Project Area (ARPA), and GIS data to identify control sites that were not impacted by energy development for population monitoring. Control sites were surrounded by similar habitat and were within similar climate areas to the ARPA. We developed nonlinear trend models for both the ARPA and control sites and compared long-term trends from the 2 areas. We found little difference between the ARPA and control sites trends over time. This research demonstrated an approach for control site selection across large landscapes and can be used as a template for similar impact-monitoring studies. It is important to note that identification of changes in population parameters between control and treatment sites is only the first step in understanding the mechanisms that underlie those changes. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  9. Sexual dimorphism of body size and sternopleural bristle number: a comparison of geographic populations of an invasive cosmopolitan drosophilid.

    PubMed

    David, Jean R; Araripe, Luciana O; Bitner-Mathé, Blanche C; Capy, Pierre; Goñi, Beatriz; Klaczko, Louis Bernard; Legout, Hélène; Martins, Marlucia B; Vouidibio, Joseph; Yassin, Amir; Moreteau, Brigitte

    2006-01-01

    Zaprionus indianus is a cosmopolitan drosophilid, of Afrotropical origin, which has recently colonized South America. The sexual dimorphism (SD) of body size is low, males being almost as big as females. We investigated 10 natural populations, 5 from America and 5 from Africa, using the isofemale line technique. Three traits were measured on each fly: wing and thorax length and sternopleural bristle number. Two indices of SD were compared, and found to be highly correlated (r > 0.99). For the sake of simplicity, only the female/male (F/M) ratio was further considered. A significant genetic variability of SD was found in all cases, although with a low heritability (intra-class correlation of 0.13), about half the value found for the traits themselves. For size SD, we did not find any variation among continents or any latitudinal trend, and average values were 1.02 for wing length and 1.01 for thorax length. Bristle number SD was much greater (1.07). Among mass laboratory strains, SD was genetically much more variable than in recently collected populations, a likely consequence of laboratory drift. Altogether, SD, although genetically variable and prone to laboratory drift, is independent of size variations and presumably submitted to a stabilizing selection in nature. PMID:17028944

  10. Challenges of Cardiac Image Analysis in Large-Scale Population-Based Studies

    PubMed Central

    Medrano-Gracia, Pau; Cowan, Brett R.; Suinesiaputra, Avan

    2015-01-01

    Large-scale population-based imaging studies of preclinical and clinical heart disease are becoming possible due to the advent of standardized robust non-invasive imaging methods and infrastructure for big data analysis. This gives an exciting opportunity to gain new information about the development and progression of heart disease across population groups. However, the large amount of image data and prohibitive time required for image analysis present challenges for obtaining useful derived data from the images. Automated analysis tools for cardiac image analysis are only now becoming available. This paper reviews the challenges and possible solutions to the analysis of big imaging data in population studies. We also highlight the potential of recent large epidemiological studies using cardiac imaging to discover new knowledge on heart health and well-being. PMID:25648627

  11. Resolved Stellar Populations with MAD: Preparing for the Era of Extremely Large Telescopes

    NASA Astrophysics Data System (ADS)

    Fiorentino, G.; Tolstoy, E.; Diolaiti, E.; Valenti, E.; Cignoni, M.; Mackey, A. D.

    2012-03-01

    Deep images in J, H and Ks filters using the Multi-conjugate Adaptive optics Demonstrator (MAD) on the VLT have been made of a region of the Large Magellanic Cloud near the globular cluster NGC 1928. Our aim was to assess if accurate photometry could be carried out down to faint limits over the whole MAD field of view. In addition we tested how accurate a basic analysis of the properties of the stellar population could be made using the near-infrared MAD photometry, compared to the Hubble Space Telescope optical photometry. This study has implications for understanding the issues involved in Extremely Large Telescope imaging of resolved stellar populations.

  12. Recruitment using mobile telephones in an Irish general population sexual health survey: challenges and practical solutions

    PubMed Central

    2012-01-01

    Background Non-coverage of households without a landline telephone is a major concern of telephone survey researchers. Sampling mobile telephone users in national surveys is vital in order to gain access to the growing proportion of households that use mobile telephones extensively or exclusively. The complex logistics of conducting surveys with mobile telephones have been discussed in the literature. This paper outlines the actual challenges encountered during a recent national sexual health survey in Ireland, which utilized a mobile telephone sampling frame to recruit approximately half of the sample. Method The 2010 Irish Contraception and Crisis Pregnancy Survey (ICCP-2010) is a nationally representative sample of adults aged 18-45 years living in Ireland (n = 3002; 1416 recruited by landline telephone and 1586 recruited by mobile telephone). The overall response rate for the survey was 69% (79% for the landline telephone strand; 61% for the mobile telephone strand). All interviews were conducted using computer-assisting telephone interviewing. Results During the 18-week fieldwork period, five main challenges relating to the use of mobile telephones were encountered: (1) explaining to respondents how random digit dialling works in relation to mobile telephones; (2) establishing the respondent's eligibility; (3) calling the respondent with the Caller ID blocked or withheld; (4) calling the respondent when they are in any number of locations or situations; and (5) explaining to respondents the importance of refusal conversion calls for the response rate calculation. Details of how the survey protocols and procedures were monitored and adapted throughout the study to ensure a high response rate are outlined. Conclusion It is undeniably more challenging to recruit respondents using mobile telephones as opposed to landline telephones. Respondents are generally not familiar with being contacted on their personal mobile telephone for the purposes of being recruited for a research study. The main challenge for survey methodologists and interviewers is to devise simple protocols to explain to respondents why they are being contacted on a mobile telephone. Recommendations for survey researchers interested in using this methodological approach in the future are discussed. PMID:22475155

  13. Sexual Health

    MedlinePlus

    ... Sexual Attraction and Orientation Sexual Harassment and Sexual Bullying Talking to Your Partner About Condoms Tampons, Pads, ... Sexual Attraction and Orientation Sexual Harassment and Sexual Bullying Talking to Your Partner About Condoms Testicular Exams ...

  14. Lesbian, Gay, Bisexual, and Transgender Hate Crimes and Suicidality Among a Population-Based Sample of Sexual-Minority Adolescents in Boston

    PubMed Central

    Hatzenbuehler, Mark L.

    2014-01-01

    Objectives. We examined whether past-year suicidality among sexual-minority adolescents was more common in neighborhoods with a higher prevalence of hate crimes targeting lesbian, gay, bisexual, and transgender (LGBT) individuals. Methods. Participants’ data came from a racially/ethnically diverse population-based sample of 9th- through 12th-grade public school students in Boston, Massachusetts (n = 1292). Of these, 108 (8.36%) reported a minority sexual orientation. We obtained data on LGBT hate crimes involving assaults or assaults with battery between 2005 and 2008 from the Boston Police Department and linked the data to the adolescent’s residential address. Results. Sexual-minority youths residing in neighborhoods with higher rates of LGBT assault hate crimes were significantly more likely to report suicidal ideation (P = .013) and suicide attempts (P = .006), than were those residing in neighborhoods with lower LGBT assault hate crime rates. We observed no relationships between overall neighborhood-level violent and property crimes and suicidality among sexual-minority adolescents (P > .05), providing evidence for specificity of the results to LGBT assault hate crimes. Conclusions. Neighborhood context (i.e., LGBT hate crimes) may contribute to sexual-orientation disparities in adolescent suicidality, highlighting potential targets for community-level suicide-prevention programs. PMID:24328619

  15. Age biases in a large HIV and sexual behaviour-related internet survey among MSM

    PubMed Central

    2013-01-01

    Background Behavioural data from MSM are usually collected in non-representative convenience samples, increasingly on the internet. Epidemiological data from such samples might be useful for comparisons between countries, but are subject to unknown participation biases. Methods Self-reported HIV diagnoses from participants of the European MSM Internet Survey (EMIS) living in the Czech Republic, Germany, the Netherlands, Portugal, Sweden and the United Kingdom were compared with surveillance data, for both the overall diagnosed prevalence and for new diagnoses made in 2009. Country level prevalence and new diagnoses rates per 100 MSM were calculated based on an assumed MSM population size of 3% of the adult male population. Survey-surveillance discrepancies (SSD) for survey participation, diagnosed HIV prevalence and new HIV diagnoses were determined as ratios of proportions. Results are calculated and presented by 5-year age groups for MSM aged 15–64. Results Surveillance derived estimates of diagnosed HIV prevalence among MSM aged 15–64 ranged from 0.63% in the Czech Republic to 4.93% in the Netherlands. New HIV diagnoses rates ranged between 0.10 per 100 MSM in the Czech Republic and 0.48 per 100 in the Netherlands. Self-reported rates from EMIS were consistently higher, with prevalence ranging from 2.68% in the Czech Republic to 12.72% in the Netherlands, and new HIV diagnoses rates from 0.36 per 100 in Sweden to 1.44 per 100 in the Netherlands. Across age groups, the survey surveillance discrepancies (SSD) for new HIV diagnoses were between 1.93 in UK and 5.95 in the Czech Republic, and for diagnosed prevalence between 1.80 in Germany and 4.26 in the Czech Republic. Internet samples of MSM were skewed towards younger age groups when compared to an age distribution of the general adult male population. Survey-surveillance discrepancies (SSD) for EMIS participation were inverse u-shaped across the age range. The two HIV-related SSD were u- or j-shaped with higher values for the very young and for older MSM. The highest discrepancies between survey and surveillance data regarding HIV-prevalence were observed in the oldest age group in Sweden and the youngest age group in Portugal. Conclusion Internet samples are biased towards a lower median age because younger men are over-represented on MSM dating websites and therefore may be more likely to be recruited into surveys. Men diagnosed with HIV were over-represented in the internet survey, and increasingly so in the older age groups. A similar effect was observed in the age groups younger than 25 years. Self-reported peak prevalence and peak HIV diagnoses rates are often shifted to higher age groups in internet samples compared to surveillance data. Adjustment for age-effects on online accessibility should be considered when linking data from internet surveys with surveillance data. PMID:24020518

  16. Warning signal brightness variation: sexual selection may work under the radar of natural selection in populations of a polytypic poison frog.

    PubMed

    Crothers, Laura R; Cummings, Molly E

    2013-05-01

    Though theory predicts consistency of warning signals in aposematic species to facilitate predator learning, variation in these signals often occurs in nature. The strawberry poison frog Dendrobates pumilio is an exceptionally polytypic (populations are phenotypically distinct) aposematic frog exhibiting variation in warning color and brightness. In the Solarte population, males and females both respond differentially to male brightness variation. Here, we demonstrate through spectrophotometry and visual modeling that aposematic brightness variation within this population is likely visible to two putative predators (crabs, snakes) and conspecifics but not to the presumed major predator (birds). This study thus suggests that signal brightness within D. pumilio populations can be shaped by sexual selection, with limited opportunity for natural selection to influence this trait due to predator sensory constraints. Because signal brightness changes can ultimately lead to changes in hue, our findings at the within-population level can provide insights into understanding this polytypism at across-population scales. PMID:23594556

  17. Tail probabilities of extinction time in a large number of experimental populations.

    PubMed

    Drake, John M

    2014-05-01

    Determining the distribution of population extinction times is a fundamental problem in theoretical population biology. In particular, the tail properties, patterns in the probability of long-term persistence, have not been studied. Further, until now there have been no experimental or observational data sets with which to empirically test the "rare event" predictions of the standard stochastic theory of extinction, which holds that extinction times should be exponentially distributed. I performed an experimental study of extinction in a large number of replicate (n = 1076) laboratory populations of the waterflea Daphnia pulicaria. Observed extinction time ranged from 1 to 1239 days. Statistical models supported the hypothesis of a power-law distribution over the exponential distribution and other alternatives. This pattern contradicts the notion that population extinction time has an exponential tail, questioning its ubiquitous use in theoretical ecology. It is also a rare instance of a data set that exhibits power-law scaling under appropriate statistical criteria. PMID:25000743

  18. Global distribution of large lunar craters: implications for resurfacing and impactor populations.

    PubMed

    Head, James W; Fassett, Caleb I; Kadish, Seth J; Smith, David E; Zuber, Maria T; Neumann, Gregory A; Mazarico, Erwan

    2010-09-17

    By using high-resolution altimetric measurements of the Moon, we produced a catalog of all impact craters ≥20 kilometers in diameter on the lunar surface and analyzed their distribution and population characteristics. The most-densely cratered portion of the highlands reached a state of saturation equilibrium. Large impact events, such as Orientale Basin, locally modified the prebasin crater population to ~2 basin radii from the basin center. Basins such as Imbrium, Orientale, and Nectaris, which are important stratigraphic markers in lunar history, are temporally distinguishable on the basis of crater statistics. The characteristics of pre- and postmare crater populations support the hypothesis that there were two populations of impactors in early solar system history and that the transition occurred near the time of the Orientale Basin event. PMID:20847265

  19. HIV risk behaviors in the U.S. transgender population: prevalence and predictors in a large internet sample.

    PubMed

    Feldman, Jamie; Romine, Rebecca Swinburne; Bockting, Walter O

    2014-01-01

    To study the influence of gender on HIV risk, a sample of the U.S. transgender population (N = 1,229) was recruited via the Internet. HIV risk and prevalence were lower than reported in prior studies of localized, urban samples but higher than the overall U.S. population. Findings suggest that gender nonconformity alone does not itself result in markedly higher HIV risk. Sex with nontransgender men emerged as the strongest independent predictor of unsafe sex for both male-to-female (MtF) and female-to-male (FtM) participants. These sexual relationships constitute a process that may either affirm or problematize gender identity and sexual orientation, with different emphases for MtFs and FtMs, respectively. PMID:25022491

  20. HIV Risk Behaviors in the U.S. Transgender Population: Prevalence and Predictors in a Large Internet Sample

    PubMed Central

    Feldman, Jamie; Romine, Rebecca Swinburne; Bockting, Walter O.

    2014-01-01

    To study the influence of gender on HIV risk, a sample of the U.S. transgender population (N = 1,229) was recruited via the Internet. HIV risk and prevalence were lower than reported in prior studies of localized, urban samples, but higher than the overall U.S. population. Findings suggest that gender nonconformity alone does not itself result in markedly higher HIV risk. Sex with nontransgender men emerged as the strongest independent predictor of unsafe sex for both male-to-female (MtF) and female-to-male (FtM) participants. These sexual relationships constitute a process that may either affirm or problematize gender identity and sexual orientation, with different emphases for MtFs and FtMs, respectively. PMID:25022491

  1. Sexual Harassment and Sexual Bulllying

    MedlinePlus

    ... a Friend Who Cuts? Sexual Harassment and Sexual Bullying KidsHealth > For Teens > Sexual Harassment and Sexual Bullying ... being sexually harassed or bullied. What Are Sexual Bullying and Harassment? Just like other kinds of bullying, ...

  2. How populations differentiate despite gene flow: sexual and natural selection drive phenotypic divergence within a land fish, the Pacific leaping blenny

    PubMed Central

    2014-01-01

    Background Divergence between populations in reproductively important features is often vital for speciation. Many studies attempt to identify the cause of population differentiation in phenotype through the study of a specific selection pressure. Holistic studies that consider the interaction of several contrasting forms of selection are more rare. Most studies also fail to consider the history of connectivity among populations and the potential for genetic drift or gene flow to facilitate or limit phenotypic divergence. We examined the interacting effects of natural selection, sexual selection and the history of connectivity on phenotypic differentiation among five populations of the Pacific leaping blenny (Alticus arnoldorum), a land fish endemic to the island of Guam. Results We found key differences among populations in two male ornaments—the size of a prominent head crest and conspicuousness of a coloured dorsal fin—that reflected a trade-off between the intensity of sexual selection (male biased sex ratios) and natural selection (exposure to predators). This differentiation in ornamentation has occurred despite evidence suggesting extensive gene flow among populations, which implies that the change in ornament expression has been recent (and potentially plastic). Conclusions Our study provides an early snapshot of divergence in reproductively important features that, regardless of whether it reflects genetic or plastic changes in phenotype, could ultimately form a reproductive barrier among populations. PMID:24884492

  3. Sexual dimorphism of the scapula and the clavicle in a contemporary Greek population: applications in forensic identification.

    PubMed

    Papaioannou, Vasiliki A; Kranioti, Elena F; Joveneaux, Perrine; Nathena, Despoina; Michalodimitrakis, Manolis

    2012-04-10

    Sex estimation is the grounds for an accurate identification of unknown human skeletal elements. The need for reliable methods distinguishing males from females based upon various skeletal elements is evident in cases of commingled, eroded and/or missing remains. The aim of this work lays on establishing criteria for sex estimation from the scapula and the clavicle in modern Greeks. A total of 147 left scapulae and 147 clavicles (66 females and 81 males) were used in the study. Eight and six measurements were taken on the scapula and clavicle respectively and data were subjected to principal components analysis (PCA) and discriminant function analysis (DFA). Posterior probabilities for the classification of each individual are also calculated. Statistical analysis was carried out using the software PAST (Paleontological Statistics) and SPSS (Statistical Package for Social Sciences) 18. The results supported the existence of pronounced sexual dimorphism, which was mainly attributed to size differences among the two groups. Univariate and multivariate methods of statistical classification showed high accuracy for all scapular and most clavicular measurements, verifying their value as sex indicators in the under study population. We recommend the use of this method for sex assessment from the scapula and the clavicle in cases exhibiting over 95% probability of correct classification. This is regardless of the overall high degree of accuracy reported here, as the method of choice in forensic contexts should always be case-driven. PMID:22138028

  4. Sexuality education groups in juvenile detention.

    PubMed

    Farrow, J A; Schroeder, E

    1984-01-01

    Several major studies have described the magnitude and character of adolescent sexual activity and sexual knowledge related to contraception and sexually transmitted diseases (Diepold & Young, 1979; Hass, 1979; Sorenson, 1973; Zelnick & Kantner, 1980). Few systematic studies have been conducted, however, which analyze the attitudes toward sexuality and contraception of delinquent adolescents who are generally school dropouts and who may engage in socially unacceptable behaviors such as running away, drug abuse, and prostitution. Delinquent youths, especially delinquent girls, have been characterized as being more sexually active and less sexually knowledgeable than their nondelinquent peers (Gibbon, 1981; Mannarino & Marsh, 1978). Despite the assumed high-risk nature of this delinquent population, few juvenile detention facilities have offered systematically evaluated coeducational sex education programs. One barrier to implementation of such programs in juvenile detention centers is the lack of a treatment or program orientation of most staff, and/or staff denial of adolescent sexuality in general, an attitude which suppresses the development of healthier sexual values and often promotes pathologic sexual interaction within institutions (Shore & Gochros, 1981). A recent survey of adolescent sexuality (Diepold, 1979) points out that teenagers' feelings about their "sexual selves" impacts greatly upon their general self-image. Low self-esteem is more frequently found among delinquents than nondelinquents (Jones & Swain, 1977; Lund & Salury, 1980), and treatment for delinquent girls often focuses on increasing self-esteem and developing assertiveness skills based on feelings of self-worth (DeLange, Lanahan, & Barton, 1981; NiCarthy, 1981). Two studies carried out with juvenile detainees from a large urban center confirmed that sexual activity among delinquent adolescents is significantly greater than that of the general adolescent population, and that the delinquents have little or no knowledge of birth control methods or venereal disease (Deisher, 1980; Schroeder, 1981). Further, these adolescents appear to endorse constricted and conventional values related to sexual activity, abortion, and relationship issues and frequently have a background of sexual abuse and prostitution. These findings form the basis of the current study which attempts to develop an effective coeducational sex education program for this population within a detention facility. This program is specifically designed for a sexually active adolescent group aged 14 to 17. PMID:6516931

  5. Large population solution of the stochastic Luria–Delbrück evolution model

    PubMed Central

    Kessler, David A.; Levine, Herbert

    2013-01-01

    Luria and Delbrück introduced a very useful and subsequently widely adopted framework for quantitatively understanding the emergence of new cellular lineages. Here, we provide an analytical treatment of the fully stochastic version of the model, enabled by the fact that population sizes at the time of measurement are invariably very large and mutation rates are low. We show that the Lea–Coulson generating function describes the “inner solution,” where the number of mutants is much smaller than the total population. We find that the corresponding distribution function interpolates between a monotonic decrease at relatively small populations, (compared with the inverse of the mutation probability), whereas it goes over to a Lévy α-stable distribution in the very large population limit. The moments are completely determined by the outer solution, and so are devoid of practical significance. The key to our solution is focusing on the fixed population size ensemble, which we show is very different from the fixed time ensemble due to the extreme variability in the evolutionary process. PMID:23818583

  6. Managing Natural and Reintroduced Rare Plant Populations within a Large Government Reservation

    SciTech Connect

    Carlsen, T M; Paterson, L E; Alfaro, T M

    2009-07-15

    California is home to many large government reservations that have been in existence for decades. Many of these reservations were formed to support various Department of Defense and Department of Energy national defense activities. Often, only a very small percentage of the reservation is actively used for programmatic activities, resulting in large areas of intact habitat. In some cases, this has benefited rare plant populations, as surrounding lands have been developed for residential or industrial use. However, land management activities such as the suppression or active use of fire and other disturbance (such as fire trail grading) can also work to either the detriment or benefit of rare plant populations at these sites. A management regime that is beneficial to the rare plant populations of interest and is at best consistent with existing site programmatic activities, and at a minimum does not impact such activities, has the best potential for a positive outcome. As a result, some species may be 'difficult' while others may be 'easy' to manage in this context, depending on how closely the species biological requirements match the programmatic activities on the reservation. To illustrate, we compare and contrast two rare annual plant species found at Lawrence Livermore National Laboratory's Site 300. Although several populations of Amsinckia grandiflora have been restored on the site, and all populations are intensively managed, this species continues to decline. In contrast, Blepharizonia plumosa appears to take advantage of the annual controlled burns conducted on the site, and is thriving.

  7. 4P: fast computing of population genetics statistics from large DNA polymorphism panels.

    PubMed

    Benazzo, Andrea; Panziera, Alex; Bertorelle, Giorgio

    2015-01-01

    Massive DNA sequencing has significantly increased the amount of data available for population genetics and molecular ecology studies. However, the parallel computation of simple statistics within and between populations from large panels of polymorphic sites is not yet available, making the exploratory analyses of a set or subset of data a very laborious task. Here, we present 4P (parallel processing of polymorphism panels), a stand-alone software program for the rapid computation of genetic variation statistics (including the joint frequency spectrum) from millions of DNA variants in multiple individuals and multiple populations. It handles a standard input file format commonly used to store DNA variation from empirical or simulation experiments. The computational performance of 4P was evaluated using large SNP (single nucleotide polymorphism) datasets from human genomes or obtained by simulations. 4P was faster or much faster than other comparable programs, and the impact of parallel computing using multicore computers or servers was evident. 4P is a useful tool for biologists who need a simple and rapid computer program to run exploratory population genetics analyses in large panels of genomic data. It is also particularly suitable to analyze multiple data sets produced in simulation studies. Unix, Windows, and MacOs versions are provided, as well as the source code for easier pipeline implementations. PMID:25628874

  8. Lifestyle and Risk of Premature Sexual Activity in a High School Population of Seventh-Day Adventists: Valuegenesis 1989.

    ERIC Educational Resources Information Center

    Weinbender, Miriam L. M.; Rossignol, Annette MacKay

    1996-01-01

    Evaluated Adventist lifestyle as a modification of popular American culture which reduces the risk of early sexual activity in adolescents and thus also reduces the risk for both STDs and teen pregnancy. Data analysis demonstrated a wide variety of behaviors were associated with premature sexual activity, including previously reported high-risk…

  9. A Population-Based Study of Childhood Sexual Contact in China: Prevalence and Long-Term Consequences

    ERIC Educational Resources Information Center

    Luo, Ye; Parish, William L.; Laumann, Edward O.

    2008-01-01

    Objectives: This study provides national estimates of the prevalence of childhood sexual contact and its association with sexual well-being and psychological distress among adults in China. Method: A national stratified probability sample of 1,519 women and 1,475 men aged 20-64 years in urban China completed a computer-administered survey in…

  10. fastSTRUCTURE: variational inference of population structure in large SNP data sets.

    PubMed

    Raj, Anil; Stephens, Matthew; Pritchard, Jonathan K

    2014-06-01

    Tools for estimating population structure from genetic data are now used in a wide variety of applications in population genetics. However, inferring population structure in large modern data sets imposes severe computational challenges. Here, we develop efficient algorithms for approximate inference of the model underlying the STRUCTURE program using a variational Bayesian framework. Variational methods pose the problem of computing relevant posterior distributions as an optimization problem, allowing us to build on recent advances in optimization theory to develop fast inference tools. In addition, we propose useful heuristic scores to identify the number of populations represented in a data set and a new hierarchical prior to detect weak population structure in the data. We test the variational algorithms on simulated data and illustrate using genotype data from the CEPH-Human Genome Diversity Panel. The variational algorithms are almost two orders of magnitude faster than STRUCTURE and achieve accuracies comparable to those of ADMIXTURE. Furthermore, our results show that the heuristic scores for choosing model complexity provide a reasonable range of values for the number of populations represented in the data, with minimal bias toward detecting structure when it is very weak. Our algorithm, fastSTRUCTURE, is freely available online at http://pritchardlab.stanford.edu/structure.html. PMID:24700103

  11. Population Analysis of Large Copy Number Variants and Hotspots of Human Genetic Disease

    PubMed Central

    Itsara, Andy; Cooper, Gregory M.; Baker, Carl; Girirajan, Santhosh; Li, Jun; Absher, Devin; Krauss, Ronald M.; Myers, Richard M.; Ridker, Paul M.; Chasman, Daniel I.; Mefford, Heather; Ying, Phyllis; Nickerson, Deborah A.; Eichler, Evan E.

    2009-01-01

    Copy number variants (CNVs) contribute to human genetic and phenotypic diversity. However, the distribution of larger CNVs in the general population remains largely unexplored. We identify large variants in ∼2500 individuals by using Illumina SNP data, with an emphasis on “hotspots” prone to recurrent mutations. We find variants larger than 500 kb in 5%–10% of individuals and variants greater than 1 Mb in 1%–2%. In contrast to previous studies, we find limited evidence for stratification of CNVs in geographically distinct human populations. Importantly, our sample size permits a robust distinction between truly rare and polymorphic but low-frequency copy number variation. We find that a significant fraction of individual CNVs larger than 100 kb are rare and that both gene density and size are strongly anticorrelated with allele frequency. Thus, although large CNVs commonly exist in normal individuals, which suggests that size alone can not be used as a predictor of pathogenicity, such variation is generally deleterious. Considering these observations, we combine our data with published CNVs from more than 12,000 individuals contrasting control and neurological disease collections. This analysis identifies known disease loci and highlights additional CNVs (e.g., 3q29, 16p12, and 15q25.2) for further investigation. This study provides one of the first analyses of large, rare (0.1%–1%) CNVs in the general population, with insights relevant to future analyses of genetic disease. PMID:19166990

  12. Prevalence of Sexual Dysfunction and its Associated Factors in Women Aged 40–65 Years with 11 Years or More of Formal Education: A Population-Based Household Survey

    PubMed Central

    Valadares, Ana L. R.; Pinto-Neto, Aarão M.; Osis, Maria J.; Sousa, Maria H.; Costa-Paiva, Lúcia; Conde, Délio M.

    2008-01-01

    OBJECTIVE To evaluate the prevalence of sexual dysfunction and its associated factors in middle-aged women with 11 years or more of formal education. METHODS A cross-sectional, population-based study was carried out using an anonymous, self-response questionnaire. A total of 315 Brazilian-born women, 40–65 years of age with 11 years or more of schooling, participated in the study. The instrument used in the evaluation was based on the Short Personal Experiences Questionnaire. Sexual dysfunction was calculated from the mean score of sexual responsiveness (pleasure in sexual activities, excitation and orgasm), frequency of sexual activities and libido. Sociodemographic and clinical factors were evaluated. Poisson multiple regression analysis was carried out and the prevalence ratios with respective 95% confidence intervals (95%CI) were calculated. RESULTS The prevalence of sexual dysfunction was 35.9% among our study population. Multiple regression analysis showed that sexual dysfunction was positively associated with older age (prevalence ratios=1.04; 95%CI:1.01–1.07) and with the presence of hot flashes (prevalence ratios=1.37; 95%CI:1.04–1.80). Having a sexual partner (PR=0.47; 95%CI:0.34–0.65) and feeling well or excellent (prevalence ratios= 0.68; 95%CI: 0.52–0.88) were factors associated with lower sexual dysfunction scores. CONCLUSIONS Sexual dysfunction was present in more than one-third of women that were 40–65 years of age with 11 years or more of formal education. Within that age group, older age and hot flashes were associated with higher sexual dysfunction scores, whereas feeling well and having a sexual partner were associated with better sexuality. PMID:19061000

  13. Female sexual partners of injection drug users in Vietnam: an at-risk population in urgent need of HIV prevention services.

    PubMed

    Hammett, Theodore M; Van, Nghiem Thi Ha; Kling, Ryan; Binh, Kieu Thanh; Oanh, Khuat Thi Hai

    2010-12-01

    Vietnam's HIV epidemic has been driven by injection drug use, with HIV prevalence among injection drug users (IDUs) of ~30%. Most IDUs are sexually active and may infect their female sexual partners (SPs). Male dominance in sexual decisions is deeply embedded in Vietnamese culture. There have been few HIV prevention interventions for SPs, who represent an important potential bridging population in the epidemic. We report findings from a baseline survey of SPs conducted in 2008 in Hanoi, Vietnam, where peer-based HIV prevention interventions targeting this population are now being implemented. The survey revealed HIV prevalence of 14% among SPs in Hanoi and only 27% reported condom use with their primary male partners half the time or more. About 69% of SPs were in serodiscordant or unknown HIV status relationships but condom use was not more frequent in these relationships than in concordant partnerships. Many SPs feared angry or violent responses if they requested condom use, problems that were even more likely in serodiscordant/unknown status relationships. SPs also reported limited prior access to HIV prevention services. Many SPs in Vietnam are at high risk for HIV and in need of HIV prevention interventions. However, to date, this population has been seriously underserved. Our interventions are in progress and results will be reported subsequently. PMID:21154034

  14. Selfish Mitochondrial DNA Proliferates and Diversifies in Small, but not Large, Experimental Populations of Caenorhabditis briggsae.

    PubMed

    Phillips, Wendy S; Coleman-Hulbert, Anna L; Weiss, Emily S; Howe, Dana K; Ping, Sita; Wernick, Riana I; Estes, Suzanne; Denver, Dee R

    2015-07-01

    Evolutionary interactions across levels of biological organization contribute to a variety of fundamental processes including genome evolution, reproductive mode transitions, species diversification, and extinction. Evolutionary theory predicts that so-called "selfish" genetic elements will proliferate when the host effective population size (Ne) is small, but direct tests of this prediction remain few. We analyzed the evolutionary dynamics of deletion-containing mitochondrial DNA (ΔmtDNA) molecules, previously characterized as selfish elements, in six different natural strains of the nematode Caenorhabditis briggsae allowed to undergo experimental evolution in a range of population sizes (N = 1, 10, 100, and 1,000) for a maximum of 50 generations. Mitochondrial DNA (mtDNA) was analyzed for replicate lineages at each five-generation time point. Ten different ΔmtDNA molecule types were observed and characterized across generations in the experimental populations. Consistent with predictions from evolutionary theory, lab lines evolved in small-population sizes (e.g., nematode N = 1) were more susceptible to accumulation of high levels of preexisting ΔmtDNA compared with those evolved in larger populations. New ΔmtDNA elements were observed to increase in frequency and persist across time points, but almost exclusively at small population sizes. In some cases, ΔmtDNA levels decreased across generations when population size was large (nematode N = 1,000). Different natural strains of C. briggsae varied in their susceptibilities to ΔmtDNA accumulation, owing in part to preexisting compensatory mtDNA alleles in some strains that prevent deletion formation. This analysis directly demonstrates that the evolutionary trajectories of ΔmtDNA elements depend upon the population-genetic environments and molecular-genetic features of their hosts. PMID:26108490

  15. Selfish Mitochondrial DNA Proliferates and Diversifies in Small, but not Large, Experimental Populations of Caenorhabditis briggsae

    PubMed Central

    Phillips, Wendy S.; Coleman-Hulbert, Anna L.; Weiss, Emily S.; Howe, Dana K.; Ping, Sita; Wernick, Riana I.; Estes, Suzanne; Denver, Dee R.

    2015-01-01

    Evolutionary interactions across levels of biological organization contribute to a variety of fundamental processes including genome evolution, reproductive mode transitions, species diversification, and extinction. Evolutionary theory predicts that so-called “selfish” genetic elements will proliferate when the host effective population size (Ne) is small, but direct tests of this prediction remain few. We analyzed the evolutionary dynamics of deletion-containing mitochondrial DNA (ΔmtDNA) molecules, previously characterized as selfish elements, in six different natural strains of the nematode Caenorhabditis briggsae allowed to undergo experimental evolution in a range of population sizes (N = 1, 10, 100, and 1,000) for a maximum of 50 generations. Mitochondrial DNA (mtDNA) was analyzed for replicate lineages at each five-generation time point. Ten different ΔmtDNA molecule types were observed and characterized across generations in the experimental populations. Consistent with predictions from evolutionary theory, lab lines evolved in small-population sizes (e.g., nematode N = 1) were more susceptible to accumulation of high levels of preexisting ΔmtDNA compared with those evolved in larger populations. New ΔmtDNA elements were observed to increase in frequency and persist across time points, but almost exclusively at small population sizes. In some cases, ΔmtDNA levels decreased across generations when population size was large (nematode N = 1,000). Different natural strains of C. briggsae varied in their susceptibilities to ΔmtDNA accumulation, owing in part to preexisting compensatory mtDNA alleles in some strains that prevent deletion formation. This analysis directly demonstrates that the evolutionary trajectories of ΔmtDNA elements depend upon the population-genetic environments and molecular-genetic features of their hosts. PMID:26108490

  16. Large-scale natural disturbance alters genetic population structure of the sailfin molly, Poecilia latipinna.

    PubMed

    Apodaca, Joseph J; Trexler, Joel C; Jue, Nathaniel K; Schrader, Matthew; Travis, Joseph

    2013-02-01

    Many inferences about contemporary rates of gene flow are based on the assumption that the observed genetic structure among populations is stable. Recent studies have uncovered several cases in which this assumption is tenuous. Most of those studies have focused on the effects that regular environmental fluctuations can have on genetic structure and gene flow patterns. Occasional catastrophic disturbances could also alter either the distribution of habitat or the spatial distribution of organisms in a way that affects population structure. However, evidence of such effects is sparse in the literature because it is difficult to obtain. Hurricanes, in particular, have the potential to exert dramatic effects on population structure of organisms found on islands or coral reefs or in near shore and coastal habitats. Here we draw on a historic genetic data set and new data to suggest that the genetic structure of sailfin molly (Poecilia latipinna) populations in north Florida was altered dramatically by an unusually large and uncommon type of storm surge associated with Hurricane Dennis in 2005. We compare the spatial pattern of genetic variation in these populations after Hurricane Dennis to the patterns described in an earlier study in this same area. We use comparable genetic data from another region of Florida, collected in the same two periods, to estimate the amount of change expected from typical temporal variation in population structure. The comparative natural history of sailfin mollies in these two regions indicates that the change in population structure produced by the storm surge is not the result of many local extinctions with recolonization from a few refugia but emerged from a pattern of mixing and redistribution. PMID:23348779

  17. Evidence for an Intervening Stellar Population Toward the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Zaritsky, Dennis; Lin, D. N. C.

    1997-12-01

    We identify a vertical extension of the red clump stars in the color magnitude diagram (CMD) of a section of the Large Magellanic Cloud (LMC). The distribution of stars in this extension is indistinguishable in the U, B, V, and I bands - confirming that the detection is real and placing a strong constraint on models of this stellar population. After subtracting the principal red clump component, we find a peak in the residual stellar distribution that is ˜0.9 mag brighter than the peak of the principal red clump distribution. We consider and reject the following possible explanations for this population: inhomogeneous reddening, Galactic disk stars, random blends of red clump stars, correlated blends of red clump stars (binaries), evolution of the red clump stars, and red clump stars from a younger LMC stellar population. Combinations of these effects cannot be ruled out as the origin of this stellar population. A natural interpretation of this new population is that it consists of red clump stars that are closer to us than those in the LMC. We derive a distance for this population of 33 to 35 kpc, although the measurement is sensitive to the modeling of the LMC red clump component. We find corroborating evidence for this interpretation in Holtzman et al.'s (1997, AJ, 113, 656) Hubble Space Telescope CMD of the LMC field stars. The derived distance and projected angular surface density of these stars relative to the LMC stars ( ≤5 to 7%) are consistent with (1) models that attribute the observed microlensing lensing optical depth (Alcock et al. 1997, ApJ, 486, 697) to a distinct foreground stellar population (Zhao 1997, preprint, astro-ph/9703097) and (2) tidal models of the interaction between the LMC and the Milky Way (Lin et al. 1995, ApJ, 439, 652). The first result suggests that the Galactic halo may contain few, if any, purely halo MACHO objects. The second result suggests that this new population may be evidence of a tidal tail from the interaction between the LMC and the Galaxy (although other interpretations, such as debris from the LMC-SMC interaction, are possible). We conclude that the standard assumption of a smoothly distributed halo population out to the LMC cannot be substantiated without at least a detailed understanding of several of the following: red clump stellar evolution, binary fractions, binary mass ratios, the spatial correlation of stars within the LMC, possible variations in the stellar populations of satellite galaxies, and differential reddening - all of which are highly complex.

  18. Population genetic structure of Bellamya aeruginosa (Mollusca: Gastropoda: Viviparidae) in China: weak divergence across large geographic distances.

    PubMed

    Gu, Qian H; Husemann, Martin; Ding, Baoqing; Luo, Zhi; Xiong, Bang X

    2015-11-01

    Bellamya aeruginosa is a widely distributed Chinese freshwater snail that is heavily harvested, and its natural habitats are under severe threat due to fragmentation and loss. We were interested whether the large geographic distances between populations and habitat fragmentation have led to population differentiation and reduced genetic diversity in the species. To estimate the genetic diversity and population structure of B. aeruginosa, 277 individuals from 12 populations throughout its distribution range across China were sampled: two populations were sampled from the Yellow River system, eight populations from the Yangtze River system, and two populations from isolated plateau lakes. We used seven microsatellite loci and mitochondrial cytochrome oxidase I sequences to estimate population genetic parameters and test for demographic fluctuations. Our results showed that (1) the genetic diversity of B. aeruginosa was high for both markers in most of the studied populations and effective population sizes appear to be large, (2) only very low and mostly nonsignificant levels of genetic differentiation existed among the 12 populations, gene flow was generally high, and (3) relatively weak geographic structure was detected despite large geographic distances between populations. Further, no isolation by linear or stream distance was found among populations within the Yangtze River system and no signs of population bottlenecks were detected. Gene flow occurred even between far distant populations, possibly as a result of passive dispersal during flooding events, zoochoric dispersal, and/or anthropogenic translocations explaining the lack of stronger differentiation across large geographic distances. The high genetic diversity of B. aeruginosa and the weak population differentiation are likely the results of strong gene flow facilitated by passive dispersal and large population sizes suggesting that the species currently is not of conservation concern. PMID:26640670

  19. Extreme genetic diversity in asexual grass thrips populations.

    PubMed

    Fontcuberta García-Cuenca, A; Dumas, Z; Schwander, T

    2016-05-01

    The continuous generation of genetic variation has been proposed as one of the main factors explaining the maintenance of sexual reproduction in nature. However, populations of asexual individuals may attain high levels of genetic diversity through within-lineage diversification, replicate transitions to asexuality from sexual ancestors and migration. How these mechanisms affect genetic variation in populations of closely related sexual and asexual taxa can therefore provide insights into the role of genetic diversity for the maintenance of sexual reproduction. Here, we evaluate patterns of intra- and interpopulation genetic diversity in sexual and asexual populations of Aptinothrips rufus grass thrips. Asexual A. rufus populations are found throughout the world, whereas sexual populations appear to be confined to few locations in the Mediterranean region. We found that asexual A. rufus populations are characterized by extremely high levels of genetic diversity, both in comparison with their sexual relatives and in comparison with other asexual species. Migration is extensive among asexual populations over large geographic distances, whereas close sexual populations are strongly isolated from each other. The combination of extensive migration with replicate evolution of asexual lineages, and a past demographic expansion in at least one of them, generated high local clone diversities in A. rufus. These high clone diversities in asexual populations may mimic certain benefits conferred by sex via genetic diversity and could help explain the extreme success of asexual A. rufus populations. PMID:26864612

  20. Testosterone and Sexual Function.

    PubMed

    Gannon, John R; Walsh, Thomas J

    2016-05-01

    Testosterone and sexual function are related. Current evidence suggests that testosterone replacement therapy (TRT) may improve sexual dysfunction. Sexual dysfunction in men who are hypogonadal, mixed, or eugonadal have all been examined through numerous studies. The most recent large analysis showed an overall improvement in sexual function outcomes in men treated with TRT. This improvement is difficult to measure and seems to differ based on the baseline hormonal status of the patient at the beginning of treatment. PMID:27132579

  1. HIV-Related Risk Behaviors Among Male High School Students Who Had Sexual Contact with Males - 17 Large Urban School Districts, United States, 2009-2013.

    PubMed

    Kann, Laura; Olsen, Emily O'Malley; Kinchen, Steve; Morris, Elana; Wolitski, Richard J

    2016-01-01

    Young persons aged 13-24 years accounted for an estimated 22% of all new diagnoses of human immunodeficiency virus (HIV) infection in the United States in 2014. Most new HIV diagnoses among youths occur among males who have sex with males (MSM). Among all MSM, young black MSM accounted for the largest number of new HIV diagnoses in 2014 (1). To determine whether the prevalence of HIV-related risk behaviors among black male high school students who had sexual contact with males differed from the prevalence among white and Hispanic male students who had sexual contact with males, potentially contributing to the racial/ethnic disparities in new HIV diagnoses, CDC analyzed data from Youth Risk Behavior Surveys conducted by 17 large urban school districts during 2009-2013. Although other studies have examined HIV-related risk behaviors among MSM (2,3), less is known about MSM aged <18 years. Black male students who had sexual contact with males had a lower or similar prevalence of most HIV-related risk behaviors than did white and Hispanic male students who had sexual contact with males. These findings highlight the need to increase access to effective HIV prevention strategies for all young MSM. PMID:26867146

  2. Incidence of insecticide resistance alleles in sexually-reproducing populations of the peach-potato aphid Myzus persicae (Hemiptera: Aphididae) from southern France.

    PubMed

    Guillemaud, T; Guillemaud, T; Brun, A; Anthony, N; Sauge, M-H; Boll, R; Delorme, R; Fournier, D; Lapchin, L; Vanlerberghe-Masutti, F

    2003-08-01

    Intensive chemical treatments have led to the development of a number of insecticide resistance mechanisms in the peach-potato aphid Myzus persicae (Sulzer). Some of these mechanisms are known to be associated with negative pleiotropic effects (resistance costs). Molecular and biochemical methods were used to determine the genotypes or phenotypes associated with four insecticide resistance mechanisms in single aphids from sexually-reproducing populations in southern France. The mechanisms considered were E4 and FE4 carboxylesterase overproduction, modified acetycholinesterase, and kdr and rdl resistance-associated mutations. A new method for determining individual kdr genotypes is presented. Almost all resistant individuals overproduced FE4 carboxylesterase, whereas modified acetylcholinesterase was rare. Both the kdr and rdl resistance mutations were present at high frequencies in French sexually-reproducing populations. The frequencies of insecticide resistance genes were compared before and after sexual reproduction in one peach orchard at Avignon to evaluate the potential impact of selection on the persistence of resistance alleles in the over-wintering phase. The frequencies of the kdr and rdl mutations varied significantly between autumn and spring sampling periods. The frequency of the kdr mutation increased, probably due to pyrethroid treatments at the end of the winter. Conversely, the frequency of the rdl mutation decreased significantly during winter, probably because of a fitness cost associated with this mutation. PMID:12908914

  3. Sexuality and breast cancer: prime time for young patients

    PubMed Central

    2013-01-01

    Sexuality and sexual functioning is a cardinal domain of health-related quality of life in breast cancer patients, namely in the younger population. Young women below 40 years of age go through a time in their lives where sexual self-identity has recently matured, their professional obligations are demanding and they bear interpersonal and childbearing expectations, all of which can suffer a devastating turnaround with cancer diagnosis and its physical and psychological aftermath. Although these women’s sexuality and directed interventions have remained largely unaddressed so far, concepts are evolving and treatment options are becoming diversified, chiefly on the field of non-hormonal pharmacological therapy of sexual dysfunction. This review will examine the definitions of female sexual dysfunction, the etiology of the disorders in young breast cancer patients, the assessment methods, the non-pharmacological and pharmacological treatment options and the challenges that lie ahead. PMID:23819031

  4. Influences of clonality on plant sexual reproduction

    PubMed Central

    Barrett, Spencer C. H.

    2015-01-01

    Flowering plants possess an unrivaled diversity of mechanisms for achieving sexual and asexual reproduction, often simultaneously. The commonest type of asexual reproduction is clonal growth (vegetative propagation) in which parental genotypes (genets) produce vegetative modules (ramets) that are capable of independent growth, reproduction, and often dispersal. Clonal growth leads to an expansion in the size of genets and increased fitness because large floral displays increase fertility and opportunities for outcrossing. Moreover, the clonal dispersal of vegetative propagules can assist “mate finding,” particularly in aquatic plants. However, there are ecological circumstances in which functional antagonism between sexual and asexual reproductive modes can negatively affect the fitness of clonal plants. Populations of heterostylous and dioecious species have a small number of mating groups (two or three), which should occur at equal frequency in equilibrium populations. Extensive clonal growth and vegetative dispersal can disrupt the functioning of these sexual polymorphisms, resulting in biased morph ratios and populations with a single mating group, with consequences for fertility and mating. In populations in which clonal propagation predominates, mutations reducing fertility may lead to sexual dysfunction and even the loss of sex. Recent evidence suggests that somatic mutations can play a significant role in influencing fitness in clonal plants and may also help explain the occurrence of genetic diversity in sterile clonal populations. Highly polymorphic genetic markers offer outstanding opportunities for gaining novel insights into functional interactions between sexual and clonal reproduction in flowering plants. PMID:26195747

  5. Influences of clonality on plant sexual reproduction.

    PubMed

    Barrett, Spencer C H

    2015-07-21

    Flowering plants possess an unrivaled diversity of mechanisms for achieving sexual and asexual reproduction, often simultaneously. The commonest type of asexual reproduction is clonal growth (vegetative propagation) in which parental genotypes (genets) produce vegetative modules (ramets) that are capable of independent growth, reproduction, and often dispersal. Clonal growth leads to an expansion in the size of genets and increased fitness because large floral displays increase fertility and opportunities for outcrossing. Moreover, the clonal dispersal of vegetative propagules can assist "mate finding," particularly in aquatic plants. However, there are ecological circumstances in which functional antagonism between sexual and asexual reproductive modes can negatively affect the fitness of clonal plants. Populations of heterostylous and dioecious species have a small number of mating groups (two or three), which should occur at equal frequency in equilibrium populations. Extensive clonal growth and vegetative dispersal can disrupt the functioning of these sexual polymorphisms, resulting in biased morph ratios and populations with a single mating group, with consequences for fertility and mating. In populations in which clonal propagation predominates, mutations reducing fertility may lead to sexual dysfunction and even the loss of sex. Recent evidence suggests that somatic mutations can play a significant role in influencing fitness in clonal plants and may also help explain the occurrence of genetic diversity in sterile clonal populations. Highly polymorphic genetic markers offer outstanding opportunities for gaining novel insights into functional interactions between sexual and clonal reproduction in flowering plants. PMID:26195747

  6. Sexually coercive behavior following childhood maltreatment.

    PubMed

    Forsman, Mats; Johansson, Ada; Santtila, Pekka; Sandnabba, Kenneth; Långström, Niklas

    2015-01-01

    Child maltreatment is associated with adult sexually coercive behavior. The association may be causal or confounders that increase the risk of both childhood victimization and sexually coercive behavior might explain the observed links. We examined if childhood maltreatment was related to sexual coercion independently of familial (genetic or common family environment) risk factors, thereby addressing potential causality. Participants were 6,255 18 to 33-year-old twins from the Finnish population-based study "Genetics of Sex and Aggression" who responded to self-report questionnaires of child maltreatment and sexually coercive behavior. We used generalized estimating equations to elucidate risk of sexual coercion in maltreated compared to unrelated, non-maltreated individuals. To adjust for unmeasured familial factors, we used the co-twin control method and compared sexual coercion risk within maltreatment-discordant twin pairs. Further, we examined possible differential effects of maltreatment subtypes and compared mean differences in maltreatment summary scores between sexually coercive individuals and controls. Sexual coercion was moderately more common among individuals maltreated as children versus unrelated controls (38.3 vs. 22.8 %; age- and gender-adjusted odds ratio, aOR = 2.31, 95 % CI 1.75-3.05) and the risk increase remained similar within maltreatment-discordant twins (OR = 2.82, 95 % CI 1.42-5.61). Moreover, different maltreatment subtypes predicted sexual coercion equally well and effect sizes remained similar within discordant twin pairs. We conclude that associations between child maltreatment and sexual coercion are largely independent of shared familial confounds, consistent with a causal inference. Importantly, detection and targeted interventions for maltreated children should remain a priority to reduce societal sexually coercive behavior. PMID:24752790

  7. The effect of overdominance on characterizing deleterious mutations in large natural populations.

    PubMed Central

    Li, J L; Li, J; Deng, H W

    1999-01-01

    Alternatives to the mutation-accumulation approach have been developed to characterize deleterious genomic mutations. However, they all depend on the assumption that the standing genetic variation in natural populations is solely due to mutation-selection (M-S) balance and therefore that overdominance does not contribute to heterosis. Despite tremendous efforts, the extent to which this assumption is valid is unknown. With different degrees of violation of the M-S balance assumption in large equilibrium populations, we investigated the statistical properties and the robustness of these alternative methods in the presence of overdominance. We found that for dominant mutations, estimates for U (genomic mutation rate) will be biased upward and those for h (mean dominance coefficient) and s (mean selection coefficient), biased downward when additional overdominant mutations are present. However, the degree of bias is generally moderate and depends largely on the magnitude of the contribution of overdominant mutations to heterosis or genetic variation. This renders the estimates of U and s not always biased under variable mutation effects that, when working alone, cause U and s to be underestimated. The contributions to heterosis and genetic variation from overdominant mutations are monotonic but not linearly proportional to each other. Our results not only provide a basis for the correct inference of deleterious mutation parameters from natural populations, but also alleviate the biggest concern in applying the new approaches, thus paving the way for reliably estimating properties of deleterious mutations. PMID:9927478

  8. Could sewage epidemiology be a strategy to assess lifestyle and wellness of a large scale population?

    PubMed

    Santos, Julia M; Jurban, Michael; Kim, Hyesook

    2015-10-01

    The use of sewage epidemiology to estimate the behavior of a large scale population has mainly been used to assess illicit drug use within a community. The systemic oxidative stress marker, 8-isoprostane, is a wildly accepted biomarker for various diseases such as diabetes, and cardiovascular and renal diseases. 8-Isoprostane is detected in urine and, as with illicit drugs, is excreted into urban sewer networks. Initially, we tested the hypothesis that differential 8-isoprostane levels are detected in wastewater of different communities and that 8-isoprostane values adjusted for the flow rate and population size will remain constant over a 2 months period. Sewage samples were collected from three sewage collection points supplied by different communities located in the Detroit metropolitan area and concentration of 8-isoprostane and synthetic plastic component, bisphenol A (BPA), were measured. Levels of 8-isoprostane were constant during the two measured months at each collection point in oppose to BPA levels. When the levels were compared among communities, 8-isoprostane levels in 24h flow and their concentrations per capita in each community varied by more than 5-fold among them. Considering the fact that 8-isoprostane is a biomarker of several diseases, we hypothesize that measurement of 8-isoprostane levels in sewage may serve as a risk assessment tool of oxidative stress-related diseases in a large scale population. Thus, sewage epidemiology can be utilized to obtain an early warning in a community to facilitate intervention for improvement of the community health. PMID:26146131

  9. Connectivity structures local population dynamics: a long-term empirical test in a large metapopulation system.

    PubMed

    Castorani, Max C N; Reed, Daniel C; Alberto, Filipe; Bell, Tom W; Simons, Rachel D; Cavanaugh, Kyle C; Siegel, David A; Raimondi, Peter T

    2015-12-01

    Ecological theory predicts that demographic connectivity structures the dynamics of local populations within metapopulation systems, but empirical support has been constrained by major limitations in data and methodology. We tested this prediction for giant kelp Macrocystis pyrifera, a key habitat-forming species in temperate coastal ecosystems worldwide, in southern California, USA. We combined a long-term (22 years), large-scale (~500 km coastline), high-resolution census of abundance with novel patch delineation methods and an innovative connectivity measure incorporating oceanographic transport and source fecundity. Connectivity strongly predicted local dynamics (well-connected patches had lower probabilities of extinction and higher probabilities of colonization, leading to greater likelihoods of occupancy) but this relationship was mediated by patch size. Moreover, the relationship between connectivity and local population dynamics varied over time, possibly due to temporal variation in oceanographic transport processes. Surprisingly, connectivity had a smaller influence on colonization relative to extinction, possibly because local ecological factors differ greatly between extinct and extant patches. Our results provide the first comprehensive evidence that southern California giant kelp populations function as a metapopulation system, challenging the view that populations of this important foundation species are governed exclusively by self-replenishment. PMID:26909421

  10. High Accuracy Decoding of Dynamical Motion from a Large Retinal Population

    PubMed Central

    Marre, Olivier; Botella-Soler, Vicente; Simmons, Kristina D.; Mora, Thierry; Tkačik, Gašper; Berry, Michael J.

    2015-01-01

    Motion tracking is a challenge the visual system has to solve by reading out the retinal population. It is still unclear how the information from different neurons can be combined together to estimate the position of an object. Here we recorded a large population of ganglion cells in a dense patch of salamander and guinea pig retinas while displaying a bar moving diffusively. We show that the bar’s position can be reconstructed from retinal activity with a precision in the hyperacuity regime using a linear decoder acting on 100+ cells. We then took advantage of this unprecedented precision to explore the spatial structure of the retina’s population code. The classical view would have suggested that the firing rates of the cells form a moving hill of activity tracking the bar’s position. Instead, we found that most ganglion cells in the salamander fired sparsely and idiosyncratically, so that their neural image did not track the bar. Furthermore, ganglion cell activity spanned an area much larger than predicted by their receptive fields, with cells coding for motion far in their surround. As a result, population redundancy was high, and we could find multiple, disjoint subsets of neurons that encoded the trajectory with high precision. This organization allows for diverse collections of ganglion cells to represent high-accuracy motion information in a form easily read out by downstream neural circuits. PMID:26132103

  11. Population genetic divergence corresponds with species-level biodiversity patterns in the large genus Begonia.

    PubMed

    Hughes, M; Hollingsworth, P M

    2008-06-01

    Begonia is one of the largest angiosperm genera, containing over 1500 species. Some aspects of the distribution of biodiversity in the genus, such as the geographical restrictions of monophyletic groups, the rarity and morphological variability of widespread species, and a preponderance of narrow endemics, suggest that restricted gene flow may have been a factor in the formation of so many species. In order to investigate whether this inference based on large-scale patterns is supported by data at the population level, we examined the distribution of genetic variation within Begonia sutherlandii in the indigenous forests of Kwazulu-Natal, South Africa, using microsatellite markers. Despite the species being predominantly outbreeding, we found high and significant levels of population structure (standardized =F'ST= 0.896). Even within individual populations, there was evidence for clear differentiation of subpopulations. There is thus congruence in evolutionary patterns ranging from interspecific phylogeny, the distribution of individual species, to the levels of population differentiation. Despite this species-rich genus showing a pan-tropical distribution, these combined observations suggest that differentiation occurs over very local scales. Although strongly selected allelic variants can maintain species cohesion with only low levels of gene flow, we hypothesize that in Begonia, gene flow levels are often so low, that divergence in allopatry is likely to be a frequent occurrence, and the lack of widespread species may in part be attributable to a lack of a mechanism for holding them together. PMID:18466228

  12. Patient Population Loss At A Large Pioneer Accountable Care Organization And Implications For Refining The Program.

    PubMed

    Hsu, John; Price, Mary; Spirt, Jenna; Vogeli, Christine; Brand, Richard; Chernew, Michael E; Chaguturu, Sreekanth K; Mohta, Namita; Weil, Eric; Ferris, Timothy

    2016-03-01

    There is an ongoing move toward payment models that hold providers increasingly accountable for the care of their patients. The success of these new models depends in part on the stability of patient populations. We investigated the amount of population turnover in a large Medicare Pioneer accountable care organization (ACO) in the period 2012-14. We found that substantial numbers of beneficiaries became part of or left the ACO population during that period. For example, nearly one-third of beneficiaries who entered in 2012 left before 2014. Some of this turnover reflected that of ACO physicians-that is, beneficiaries whose physicians left the ACO were more likely to leave than those whose physicians remained. Some of the turnover also reflected changes in care delivery. For example, beneficiaries who were active in a care management program were less likely to leave the ACO than similar beneficiaries who had not yet started such a program. We recommend policy changes to increase the stability of ACO beneficiary populations, such as permitting lower cost sharing for care received within an ACO and requiring all beneficiaries to identify their primary care physician before being linked to an ACO. PMID:26953296

  13. SEXUALLY TRANSMITTED DISEASES SURVEILLANCE SYSTEM

    EPA Science Inventory

    The Sexually Transmitted Disease Surveillance System presents statistics and trends for sexually transmitted diseases (STDs). Data demonstrate details which provide information about STD morbidity in the United States, STD prevalence with subgroups and populations which are the f...

  14. Plant regeneration methods for rapid generation of a large scale Ds transposant population in rice.

    PubMed

    Xuan, Yuan Hu; Huang, Jin; Yi, Gihwan; Park, Dong-Soo; Park, Soo Kwon; Eun, Moo Young; Yun, Doh Won; Lee, Gang-Seob; Kim, Tae Ho; Han, Chang-deok

    2013-01-01

    To mutagenize rice genomes, a two-element system is utilized. This system comprises an immobile Ac element driven by the CaMV 35S promoter, and a gene trap Ds carrying a partial intron with alternative splice acceptors fused to the GUS coding region. Rapid, large-scale generation of a Ds transposant population was achieved using a plant regeneration procedure involving the tissue culture of seed-derived calli carrying Ac and Ds elements. During tissue cultures, Ds mobility accompanies changes in methylation patterns of a terminal region of Ds, where over 70% of plants contained independent Ds insertions. In the transposon population, around 12% of plants expressed GUS at the early seedling stage. A flanking-sequence-tag (FST) database has been established by cloning over 19,968 Ds insertion sites and the Ds map shows relatively uniform distribution across the rice chromosomes. PMID:23918423

  15. Hepatitis B (surface) antigen testing by radioimmunoassaymexperience in a very large volunteer donor population.

    PubMed

    Dodd, R Y; Ni, L Y; Mallin, W S; Greenwalt, T J

    1975-06-01

    The results of hepatitis B surface antigen (HBs-Ag) testing in a large volunteer blood donor population are described. Counterelectrophoresis and three versions of solid-phase radioimmunoassay technic are compared and evaluated. Initial results suggested that the radioimmunoassay technic are compared and evaluated. Initial results suggested that the radioimmunoassay technic detected more than five times as many reactive donors as did counterelectrophoresis. The specificity of the radioimmunoassay technic has been increased by successive modifications, and recent results show that the technic detects 73 percent more reactive donors than does counterelectrophoresis. Not all of these reactions are specific, and it is estimated that the true gain in detection of HBsAg carriers is 49 percent of the value found by counterelectroesis. The incidence of HBsAg carriers in the America Red Cross donor population is about 1.25 per 1,000. PMID:1146760

  16. HIV-1 Thai B strain has spread out of former plasma donors into general population through sexual contact in Henan, China.

    PubMed

    Li, Lin; Sun, Guoqing; Zhong, Ping; Han, Jingwan; Li, Tianyi; Jia, Dijing; Liu, Yongjian; Sun, Changrong; Wang, Zhe; Li, Hanping; Wang, Xiaolin; Li, Jingyun

    2016-04-01

    Henan, China is characterized by the outbreak of HIV epidemic of Thai B strain in former plasma donors in 1990s. After the forbidden of paid blood donation, whether Thai B strain will spread out of former plasma donors into sexual transmitted population is unknown. To answer the question, phylogenetic analysis was used to explore relationships of HIV strains circulating in those two populations in the study. HIV-1 sero-positive drug-naïve patients infected through sexual contact were enrolled into the study. Full length gag and pol genes were amplified with nested RT-PCR followed by sequencing and phylogenetic analysis. The genotypes of anti-HIV drug resistance were also analyzed with available pol genes. HIV subtypes were determined in 249 individuals from 288 participants. Subtype B was dominant (202/249, 81.1%), followed by CRF01_AE (25/249, 10.0%), CRF07_BC (14/249, 5.6%), C (4/249, 1.6%), URF (3/249, 1.2%), and CRF08_BC (1/249, 0.4%). Most of subtype B strains belong to Thailand B lineage. All of Thai B strains identified in sexual transmitted population intermixed with those from former blood donors in phylogenetic tree, suggesting close phylogenetic relationship between strains epidemic in those two populations. TDR was identified in 9.9% individuals. Thai B strain has spread out of former blood donors in Henan province. The finding will contribute to understanding the distribution and evolution of HIV-1 in Henan province and also provide clue to behavior change intervention. J. Med. Virol. 88:614-621, 2016. © 2015 Wiley Periodicals, Inc. PMID:26381060

  17. Emergence of a super-synchronized mobbing state in a large population of coupled chemical oscillators.

    PubMed

    Ghoshal, Gourab; Muñuzuri, Alberto P; Pérez-Mercader, Juan

    2016-01-01

    Oscillatory phenomena are ubiquitous in Nature. The ability of a large population of coupled oscillators to synchronize constitutes an important mechanism to express information and establish communication among members. To understand such phenomena, models and experimental realizations of globally coupled oscillators have proven to be invaluable in settings as varied as chemical, biological and physical systems. A variety of rich dynamical behavior has been uncovered, although usually in the context of a single state of synchronization or lack thereof. Through the experimental and numerical study of a large population of discrete chemical oscillators, here we report on the unexpected discovery of a new phenomenon revealing the existence of dynamically distinct synchronized states reflecting different degrees of communication. Specifically, we discover a novel large-amplitude super-synchronized state separated from the conventionally reported synchronized and quiescent states through an unusual sharp jump transition when sampling the strong coupling limit. Our results assume significance for further elucidating globally coherent phenomena, such as in neuropathologies, bacterial cell colonies, social systems and semiconductor lasers. PMID:26753772

  18. Spike Detection for Large Neural Populations Using High Density Multielectrode Arrays

    PubMed Central

    Muthmann, Jens-Oliver; Amin, Hayder; Sernagor, Evelyne; Maccione, Alessandro; Panas, Dagmara; Berdondini, Luca; Bhalla, Upinder S.; Hennig, Matthias H.

    2015-01-01

    An emerging generation of high-density microelectrode arrays (MEAs) is now capable of recording spiking activity simultaneously from thousands of neurons with closely spaced electrodes. Reliable spike detection and analysis in such recordings is challenging due to the large amount of raw data and the dense sampling of spikes with closely spaced electrodes. Here, we present a highly efficient, online capable spike detection algorithm, and an offline method with improved detection rates, which enables estimation of spatial event locations at a resolution higher than that provided by the array by combining information from multiple electrodes. Data acquired with a 4096 channel MEA from neuronal cultures and the neonatal retina, as well as synthetic data, was used to test and validate these methods. We demonstrate that these algorithms outperform conventional methods due to a better noise estimate and an improved signal-to-noise ratio (SNR) through combining information from multiple electrodes. Finally, we present a new approach for analyzing population activity based on the characterization of the spatio-temporal event profile, which does not require the isolation of single units. Overall, we show how the improved spatial resolution provided by high density, large scale MEAs can be reliably exploited to characterize activity from large neural populations and brain circuits. PMID:26733859

  19. Emergence of a super-synchronized mobbing state in a large population of coupled chemical oscillators

    NASA Astrophysics Data System (ADS)

    Ghoshal, Gourab; Muñuzuri, Alberto P.; Pérez-Mercader, Juan

    2016-01-01

    Oscillatory phenomena are ubiquitous in Nature. The ability of a large population of coupled oscillators to synchronize constitutes an important mechanism to express information and establish communication among members. To understand such phenomena, models and experimental realizations of globally coupled oscillators have proven to be invaluable in settings as varied as chemical, biological and physical systems. A variety of rich dynamical behavior has been uncovered, although usually in the context of a single state of synchronization or lack thereof. Through the experimental and numerical study of a large population of discrete chemical oscillators, here we report on the unexpected discovery of a new phenomenon revealing the existence of dynamically distinct synchronized states reflecting different degrees of communication. Specifically, we discover a novel large-amplitude super-synchronized state separated from the conventionally reported synchronized and quiescent states through an unusual sharp jump transition when sampling the strong coupling limit. Our results assume significance for further elucidating globally coherent phenomena, such as in neuropathologies, bacterial cell colonies, social systems and semiconductor lasers.

  20. Emergence of a super-synchronized mobbing state in a large population of coupled chemical oscillators

    PubMed Central

    Ghoshal, Gourab; Muñuzuri, Alberto P.; Pérez-Mercader, Juan

    2016-01-01

    Oscillatory phenomena are ubiquitous in Nature. The ability of a large population of coupled oscillators to synchronize constitutes an important mechanism to express information and establish communication among members. To understand such phenomena, models and experimental realizations of globally coupled oscillators have proven to be invaluable in settings as varied as chemical, biological and physical systems. A variety of rich dynamical behavior has been uncovered, although usually in the context of a single state of synchronization or lack thereof. Through the experimental and numerical study of a large population of discrete chemical oscillators, here we report on the unexpected discovery of a new phenomenon revealing the existence of dynamically distinct synchronized states reflecting different degrees of communication. Specifically, we discover a novel large-amplitude super-synchronized state separated from the conventionally reported synchronized and quiescent states through an unusual sharp jump transition when sampling the strong coupling limit. Our results assume significance for further elucidating globally coherent phenomena, such as in neuropathologies, bacterial cell colonies, social systems and semiconductor lasers. PMID:26753772

  1. Extremely low genotypic diversity and sexual reproduction in isolated populations of the self-incompatible lily-of-the-valley (Convallaria majalis) and the role of the local forest environment

    PubMed Central

    Vandepitte, Katrien; Roldán-Ruiz, Isabel; Jacquemyn, Hans; Honnay, Olivier

    2010-01-01

    Background and Aims Clonal growth is a common phenomenon in plants and allows them to persist when sexual life-cycle completion is impeded. Very low levels of recruitment from seed will ultimately result in low levels of genotypic diversity. The situation can be expected to be exacerbated in spatially isolated populations of obligated allogamous species, as low genotypic diversities will result in low availability of compatible genotypes and low reproductive success. Populations of the self-incompatible forest herb lily-of-the-valley (Convallaria majalis) were studied with the aim of inferring the relative importance of sexual and asexual recruitment. Then the aim was to establish a relationship between genotypic diversity, sexual reproduction and the local forest environment. Methods Highly polymorphic microsatellite markers were used to investigate clonal diversities and population genetic structure of 20 populations of C. majalis in central Belgium. Key Results Most of the populations studied consisted of a single genotype and linkage disequilibrium within populations was high, manifesting clonal growth as the main mode of reproduction. A population consisting of multiple genotypes mainly occurred in locations with a thin litter layer and high soil phosphorus levels, suggesting environment-mediated sporadic recruitment from seed. Highly significant genetic differentiation indicated that populations are reproductively isolated. In agreement with the self-incompatibility of C. majalis, monoclonal populations showed very low or even absent fruit set. Conclusions Lack of sexual recruitment in spatially isolated C. majalis populations has resulted in almost monoclonal populations with reduced or absent sexual reproduction, potentially constraining their long-term persistence. The local forest environment may play an important role in mediating sexual recruitment in clonal forest plant species. PMID:20228091

  2. Fixation in large populations: a continuous view of a discrete problem.

    PubMed

    Chalub, Fabio A C C; Souza, Max O

    2016-01-01

    We study fixation in large, but finite, populations with two types, and dynamics governed by birth-death processes. By considering a restricted class of such processes, which includes many of the evolutionary processes usually discussed in the literature, we derive a continuous approximation for the probability of fixation that is valid beyond the weak-selection (WS) limit. Indeed, in the derivation three regimes naturally appear: selection-driven, balanced, and quasi-neutral--the latter two require WS, while the former can appear with or without WS. From the continuous approximations, we then obtain asymptotic approximations for evolutionary dynamics with at most one equilibrium, in the selection-driven regime, that does not preclude a weak-selection regime. As an application, we study the fixation pattern when the infinite population limit has an interior evolutionary stable strategy (ESS): (1) we show that the fixation pattern for the Hawk and Dove game satisfies what we term the one-half law: if the ESS is outside a small interval around 1/2, the fixation is of dominance type; (2) we also show that, outside of the weak-selection regime, the long-term dynamics of large populations can have very little resemblance to the infinite population case; in addition, we also present results for the case of two equilibria, and show that even when there is weak-selection the long-term dynamics can be dramatically different from the one predicted by the replicator dynamics. Finally, we present continuous restatements valid for large populations of two classical concepts naturally defined in the discrete case: (1) the definition of an ESSN strategy; (2) the definition of a risk-dominant strategy. We then present three applications of these restatements: (1) we obtain an asymptotic definition valid in the quasi-neutral regime that recovers both the one-third law under linear fitness and the generalised one-third law for d-player games; (2) we extend the ideas behind the (generalised) one-third law outside the quasi-neutral regime and, as a generalisation, we introduce the concept of critical-frequency; (3) we recover the classification of risk-dominant strategies for d-player games. PMID:25917604

  3. Lifestyle and risk of premature sexual activity in a high school population of Seventh-Day Adventists: Valuegenesis 1989.

    PubMed

    Weinbender, M L; Rossignol, A M

    1996-01-01

    In the past 20 years, sexually transmitted diseases (STDs), including AIDS, and the physical, psychological, and economic difficulties associated with unwanted pregnancy have increased steadily among American adolescents. The objective of this study was to evaluate Adventist lifestyle as a modification of popular American culture which reduces the risk of early sexual activity in adolescents and thus also reduces the risk for both STDs and teen pregnancy. The study was based on 8,321 respondents to a questionnaire concerning specific behaviors, beliefs, and attitudes among Seventh-Day Adventist youth attending 58 high schools in North American. Analysis of the data demonstrated that a wide variety of behaviors were associated with premature sexual activity, including previously reported high-risk behaviors such as drug or alcohol use. In addition, several behaviors that are discouraged within Adventist culture, such as going to a movie theater or participating in competitive sports, also were associated with early sexual activity. It is hypothesized that these latter behaviors may predict the emergence of other high-risk behaviors, such as early sexual activity, in both Adventist and popular cultures, and thus may be "transition-marking behaviors" as described by Jessor and Jessor (1975). PMID:8726888

  4. Patterns of Variation at Ustilago maydis Virulence Clusters 2A and 19A Largely Reflect the Demographic History of Its Populations

    PubMed Central

    Kellner, Ronny; Hanschke, Christian; Begerow, Dominik

    2014-01-01

    The maintenance of an intimate interaction between plant-biotrophic fungi and their hosts over evolutionary times involves strong selection and adaptative evolution of virulence-related genes. The highly specialised maize pathogen Ustilago maydis is assigned with a high evolutionary capability to overcome host resistances due to its high rates of sexual recombination, large population sizes and long distance dispersal. Unlike most studied fungus-plant interactions, the U. maydis – Zea mays pathosystem lacks a typical gene-for-gene interaction. It exerts a large set of secreted fungal virulence factors that are mostly organised in gene clusters. Their contribution to virulence has been experimentally demonstrated but their genetic diversity within U. maydis remains poorly understood. Here, we report on the intraspecific diversity of 34 potential virulence factor genes of U. maydis. We analysed their sequence polymorphisms in 17 isolates of U. maydis from Europe, North and Latin America. We focused on gene cluster 2A, associated with virulence attenuation, cluster 19A that is crucial for virulence, and the cluster-independent effector gene pep1. Although higher compared to four house-keeping genes, the overall levels of intraspecific genetic variation of virulence clusters 2A and 19A, and pep1 are remarkably low and commensurate to the levels of 14 studied non-virulence genes. In addition, each gene is present in all studied isolates and synteny in cluster 2A is conserved. Furthermore, 7 out of 34 virulence genes contain either no polymorphisms or only synonymous substitutions among all isolates. However, genetic variation of clusters 2A and 19A each resolve the large scale population structure of U. maydis indicating subpopulations with decreased gene flow. Hence, the genetic diversity of these virulence-related genes largely reflect the demographic history of U. maydis populations. PMID:24887029

  5. A Connectionist Modeling Approach to Rapid Analysis of Emergent Social Cognition Properties in Large-Populations

    SciTech Connect

    Perumalla, Kalyan S; Schryver, Jack C

    2009-01-01

    Traditional modeling methodologies, such as those based on rule-based agent modeling, are exhibiting limitations in application to rich behavioral scenarios, especially when applied to large population aggregates. Here, we propose a new modeling methodology based on a well-known "connectionist approach," and articulate its pertinence in new applications of interest. This methodology is designed to address challenges such as speed of model development, model customization, model reuse across disparate geographic/cultural regions, and rapid and incremental updates to models over time.

  6. Use of a large multiparent wheat mapping population in genomic dissection of coleoptile and seedling growth.

    PubMed

    Rebetzke, Greg J; Verbyla, Arunas P; Verbyla, Klara L; Morell, Matthew K; Cavanagh, Colin R

    2014-02-01

    Identification of alleles towards the selection for improved seedling vigour is a key objective of many wheat breeding programmes. A multiparent advanced generation intercross (MAGIC) population developed from four commercial spring wheat cultivars (cvv. Baxter, Chara, Westonia and Yitpi) and containing ca. 1000 F(2) -derived, F(6:7) RILs was assessed at two contrasting soil temperatures (12 and 20 °C) for shoot length and coleoptile characteristics length and thickness. Narrow-sense heritabilities were high for coleoptile and shoot length (h(2) = 0.68-0.70), indicating a strong genetic basis for the differences among progeny. Genotypic variation was large, and distributions of genotype means were approximately Gaussian with evidence for transgressive segregation for all traits. A number of significant QTL were identified for all early growth traits, and these were commonly repeatable across the different soil temperatures. The largest negative effects on coleoptile lengths were associated with Rht-B1b (-8.2%) and Rht-D1b (-10.9%) dwarfing genes varying in the population. Reduction in coleoptile length with either gene was particularly large at the warmer soil temperature. Other large QTL for coleoptile length were identified on chromosomes 1A, 2B, 4A, 5A and 6B, but these were relatively smaller than allelic effects at the Rht-B1 and Rht-D1 loci. A large coleoptile length effect allele (a = 5.3 mm at 12 °C) was identified on chromosome 1AS despite the relatively shorter coleoptile length of the donor Yitpi. Strong, positive genetic correlations for coleoptile and shoot lengths (r(g) = 0.85-0.90) support the co-location of QTL for these traits and suggest a common physiological basis for both. The multiparent population has enabled the identification of promising shoot and coleoptile QTL despite the potential for the confounding of large effect dwarfing gene alleles present in the commercial parents. The incidence of these alleles in commercial wheat breeding programmes should facilitate their ready implementation in selection of varieties with improved establishment and early growth. PMID:24151921

  7. The stellar accretion origin of stellar population gradients in massive galaxies at large radii

    NASA Astrophysics Data System (ADS)

    Hirschmann, Michaela; Naab, Thorsten; Ostriker, Jeremiah P.; Forbes, Duncan A.; Duc, Pierre-Alain; Dav, Romeel; Oser, Ludwig; Karabal, Emin

    2015-05-01

    We investigate the evolution of stellar population gradients from z = 2 to 0 in massive galaxies at large radii (r > 2Reff) using 10 cosmological zoom simulations of haloes with 6 1012 M? < Mhalo < 2 1013 M?. The simulations follow metal cooling and enrichment from SNII, SNIa and asymptotic giant branch winds. We explore the differential impact of an empirical model for galactic winds that reproduces the mass-metallicity relation and its evolution with redshift. At larger radii the galaxies, for both models, become more dominated by stars accreted from satellite galaxies in major and minor mergers. In the wind model, fewer stars are accreted, but they are significantly more metal-poor resulting in steep global metallicity ( = -0.35 dex dex-1) and colour (e.g. = -0.13 dex dex-1) gradients in agreement with observations. In contrast, colour and metallicity gradients of the models without winds are inconsistent with observations. Age gradients are in general mildly positive at z = 0 ( = 0.04 dex dex-1) with significant differences between the models at higher redshift. We demonstrate that for the wind model, stellar accretion is steepening existing in situ metallicity gradients by about 0.2 dex by the present day and helps to match observed gradients of massive early-type galaxies at large radii. Colour and metallicity gradients are significantly steeper for systems which have accreted stars in minor mergers, while galaxies with major mergers have relatively flat gradients, confirming previous results. The effect of stellar migration of in situ formed stars to large radii is discussed. This study highlights the importance of stellar accretion for stellar population properties of massive galaxies at large radii, which can provide important constraints for formation models.

  8. Voluntary rewards mediate the evolution of pool punishment for maintaining public goods in large populations

    NASA Astrophysics Data System (ADS)

    Sasaki, Tatsuya; Uchida, Satoshi; Chen, Xiaojie

    2015-03-01

    Punishment is a popular tool when governing commons in situations where free riders would otherwise take over. It is well known that sanctioning systems, such as the police and courts, are costly and thus can suffer from those who free ride on other's efforts to maintain the sanctioning systems (second-order free riders). Previous game-theory studies showed that if populations are very large, pool punishment rarely emerges in public good games, even when participation is optional, because of second-order free riders. Here we show that a matching fund for rewarding cooperation leads to the emergence of pool punishment, despite the presence of second-order free riders. We demonstrate that reward funds can pave the way for a transition from a population of free riders to a population of pool punishers. A key factor in promoting the transition is also to reward those who contribute to pool punishment, yet not abstaining from participation. Reward funds eventually vanish in raising pool punishment, which is sustainable by punishing the second-order free riders. This suggests that considering the interdependence of reward and punishment may help to better understand the origins and transitions of social norms and institutions.

  9. Large Magellanic Cloud Planetary Nebula Morphology: Probing Stellar Populations and Evolution.

    PubMed

    Stanghellini; Shaw; Balick; Blades

    2000-05-10

    Planetary nebulae (PNe) in the Large Magellanic Cloud (LMC) offer the unique opportunity to study both the population and evolution of low- and intermediate-mass stars, by means of the morphological type of the nebula. Using observations from our LMC PN morphological survey, and including images available in the Hubble Space Telescope Data Archive and published chemical abundances, we find that asymmetry in PNe is strongly correlated with a younger stellar population, as indicated by the abundance of elements that are unaltered by stellar evolution (Ne, Ar, and S). While similar results have been obtained for Galactic PNe, this is the first demonstration of the relationship for extragalactic PNe. We also examine the relation between morphology and abundance of the products of stellar evolution. We found that asymmetric PNe have higher nitrogen and lower carbon abundances than symmetric PNe. Our two main results are broadly consistent with the predictions of stellar evolution if the progenitors of asymmetric PNe have on average larger masses than the progenitors of symmetric PNe. The results bear on the question of formation mechanisms for asymmetric PNe-specifically, that the genesis of PNe structure should relate strongly to the population type, and by inference the mass, of the progenitor star and less strongly on whether the central star is a member of a close binary system. PMID:10813674

  10. Voluntary rewards mediate the evolution of pool punishment for maintaining public goods in large populations.

    PubMed

    Sasaki, Tatsuya; Uchida, Satoshi; Chen, Xiaojie

    2015-01-01

    Punishment is a popular tool when governing commons in situations where free riders would otherwise take over. It is well known that sanctioning systems, such as the police and courts, are costly and thus can suffer from those who free ride on other's efforts to maintain the sanctioning systems (second-order free riders). Previous game-theory studies showed that if populations are very large, pool punishment rarely emerges in public good games, even when participation is optional, because of second-order free riders. Here we show that a matching fund for rewarding cooperation leads to the emergence of pool punishment, despite the presence of second-order free riders. We demonstrate that reward funds can pave the way for a transition from a population of free riders to a population of pool punishers. A key factor in promoting the transition is also to reward those who contribute to pool punishment, yet not abstaining from participation. Reward funds eventually vanish in raising pool punishment, which is sustainable by punishing the second-order free riders. This suggests that considering the interdependence of reward and punishment may help to better understand the origins and transitions of social norms and institutions. PMID:25753335

  11. Low but significant genetic differentiation underlies biologically meaningful phenotypic divergence in a large Atlantic salmon population.

    PubMed

    Aykanat, Tutku; Johnston, Susan E; Orell, Panu; Niemelä, Eero; Erkinaro, Jaakko; Primmer, Craig R

    2015-10-01

    Despite decades of research assessing the genetic structure of natural populations, the biological meaning of low yet significant genetic divergence often remains unclear due to a lack of associated phenotypic and ecological information. At the same time, structured populations with low genetic divergence and overlapping boundaries can potentially provide excellent models to study adaptation and reproductive isolation in cases where high-resolution genetic markers and relevant phenotypic and life history information are available. Here, we combined single nucleotide polymorphism (SNP)-based population inference with extensive phenotypic and life history data to identify potential biological mechanisms driving fine-scale subpopulation differentiation in Atlantic salmon (Salmo salar) from the Teno River, a major salmon river in Europe. Two sympatrically occurring subpopulations had low but significant genetic differentiation (FST  = 0.018) and displayed marked differences in the distribution of life history strategies, including variation in juvenile growth rate, age at maturity and size within age classes. Large, late-maturing individuals were virtually absent from one of the two subpopulations, and there were significant differences in juvenile growth rates and size at age after oceanic migration between individuals in the respective subpopulations. Our findings suggest that different evolutionary processes affect each subpopulation and that hybridization and subsequent selection may maintain low genetic differentiation without hindering adaptive divergence. PMID:26363183

  12. Artemia parthenogenetica (Branchiopoda: Anostraca) from the Large Aral Sea: Abundance, distribution, population structure and cyst production

    NASA Astrophysics Data System (ADS)

    Arashkevich, Elena G.; Sapozhnikov, P. V.; Soloviov, K. A.; Kudyshkin, T. V.; Zavialov, P. O.

    2009-03-01

    The brine shrimp Artemia parthenogenetica appeared in the Large Aral Sea (Central Asia) in 1998 when mineralization reached 63 ppt. Data on Artemia abundance and biomass, along with temperature and salinity measurements were collected in the western basin during 2002-2006, primarily in the autumn. During the study period, population density grew progressively, both in terms of number, from 250 to 1260 individuals per m 3, and in terms of biomass, from 0.3 to 1.3 g per m 3. In 2005, the population density and spatial distribution in the different parts of the sea (western and eastern basins and strait) was assessed. The horizontal distribution of the Artemia population was uniform in the deep central part of the western basin, although the distribution was quite patchy in the shallow coastal zone. Depth habitat of Artemia was restricted to the upper 20-25 m of depth, as the oxygen depletion and formation of anoxic layer prevented distribution of Artemia to the deeper waters. In autumn, all females reproduced oviparously, with an average clutch size of 30-35 eggs per female. The number of eggs in a clutch was positively correlated with female body length ( r2 = 0.36-0.44).

  13. Detection of recombination events in bacterial genomes from large population samples

    PubMed Central

    Marttinen, Pekka; Hanage, William P.; Croucher, Nicholas J.; Connor, Thomas R.; Harris, Simon R.; Bentley, Stephen D.; Corander, Jukka

    2012-01-01

    Analysis of important human pathogen populations is currently under transition toward whole-genome sequencing of growing numbers of samples collected on a global scale. Since recombination in bacteria is often an important factor shaping their evolution by enabling resistance elements and virulence traits to rapidly transfer from one evolutionary lineage to another, it is highly beneficial to have access to tools that can detect recombination events. Multiple advanced statistical methods exist for such purposes; however, they are typically limited either to only a few samples or to data from relatively short regions of a total genome. By harnessing the power of recent advances in Bayesian modeling techniques, we introduce here a method for detecting homologous recombination events from whole-genome sequence data for bacterial population samples on a large scale. Our statistical approach can efficiently handle hundreds of whole genome sequenced population samples and identify separate origins of the recombinant sequence, offering an enhanced insight into the diversification of bacterial clones at the level of the whole genome. A data set of 241 whole genome sequences from an important pandemic lineage of Streptococcus pneumoniae is used together with multiple simulated data sets to demonstrate the potential of our approach. PMID:22064866

  14. Sexual Health and Risk Behaviour among East Asian Adolescents in British Columbia

    PubMed Central

    Homma, Yuko; Saewyc, Elizabeth M.; Wong, Sabrina T.; Zumbo, Bruno D.

    2015-01-01

    Despite the large number of adolescents of East Asian origin in Canada, there is limited research on sexual health among this population. A first step to develop strategies for sexual health promotion for adolescents is to document the prevalence of sexual behaviours. This study thus estimated the prevalence of sexual health and risk behaviours among East Asian adolescents in grades 7 to 12, using the province-wide, school-based 2008 British Columbia Adolescent Health Survey (unweighted N = 4,311). Less than 10% of East Asian adolescents have ever had sexual intercourse. However, most of these sexually active adolescents have engaged in risky sexual behaviours, including multiple sexual partners and non-condom use at last intercourse. In particular, nearly half of sexually active girls reported not using a condom at last intercourse. Compared to immigrant students whose primary language at home was not English, immigrant and Canadian-born students speaking English at home were more likely to experience sexual intercourse. Among students who have never had sexual intercourse, two most common reasons for sexual abstinence were not feeling ready and waiting to meet the right person. Findings suggest the need for sexual health interventions tailored to gender and sociocultural contexts in which adolescents live.

  15. The association between body esteem and sexual desire among college women.

    PubMed

    Seal, Brooke N; Bradford, Andrea; Meston, Cindy M

    2009-10-01

    Relationships between body image variables and sexuality have been found among several groups of women. However, research has largely focused on generalized experiences of sexuality. With the exception of two studies which focused on specific medical populations, to our knowledge there has been no investigation of the relationship between body image and acute measures of sexual response. In the current study, we investigated the relationships between body esteem, sexual response to erotica in a laboratory-setting, and self-reported sexual functioning in a non-clinical sample of 85 college women. Women participated in one study session, during which mental sexual arousal, perceptions of physical arousal, and sexual desire were assessed. Results showed that higher body esteem was significantly positively related to sexual desire in response to erotica in the laboratory setting. Similarly, higher body esteem was positively related to self-reported measures of sexual desire, as assessed by a validated measure of sexual function. The sexual attractiveness and weight concern subscales of the Body Esteem Scale, which relate to body characteristics that are most likely to be under public scrutiny, were particularly linked to sexual desire. This is the first study to show that body esteem is related to sexual responses to a standardized erotic stimulus in a laboratory setting. PMID:19280331

  16. Prevalence and predictors of Axis I disorders in a large sample of treatment-seeking victims of sexual abuse and incest

    PubMed Central

    McElroy, Eoin; Shevlin, Mark; Elklit, Ask; Hyland, Philip; Murphy, Siobhan; Murphy, Jamie

    2016-01-01

    Background Childhood sexual abuse (CSA) is a common occurrence and a robust, yet non-specific, predictor of adult psychopathology. While many demographic and abuse factors have been shown to impact this relationship, their common and specific effects remain poorly understood. Objective This study sought to assess the prevalence of Axis I disorders in a large sample of help-seeking victims of sexual trauma, and to examine the common and specific effects of demographic and abuse characteristics across these different diagnoses. Method The participants were attendees at four treatment centres in Denmark that provide psychological therapy for victims of CSA (N=434). Axis I disorders were assessed using the Millon Clinical Multiaxial Inventory-III (MCMI-III). Multivariate logistic regression analysis was used to examine the associations between CSA characteristics (age of onset, duration, number of abusers, number of abusive acts) and 10 adult clinical syndromes. Results There was significant variation in the prevalence of disorders and the abuse characteristics were differentially associated with the outcome variables. Having experienced sexual abuse from more than one perpetrator was the strongest predictor of psychopathology. Conclusions The relationship between CSA and adult psychopathology is complex. Abuse characteristics have both unique and shared effects across different diagnoses. Highlights of the article The prevalence of Axis I disorders were assessed in a large sample of sexual abuse and incest survivors. The impact of demographic and abuse characteristics were also examined. There was significant variation in the prevalence of disorders. Abuse characteristics were differentially associated with the disorders. Abuse from multiple perpetrators was the strongest overall predictor of psychopathology. PMID:27064976

  17. Epidemiologic study of the sexually dimorphic second to fourth digit ratio (2D:4D) and other finger ratios in Greek population.

    PubMed

    Kyriakidis, Ioannis; Papaioannidou, Paraskevi

    2008-12-01

    The 2nd to 4th digit ratio (2D:4D) is a sexually dimorphic biometric marker, related to prenatal estrogen and testosterone levels in utero, and determined genetically by the HOX genes. 2D:4D presents a population variation, which seems to be dependent on geographical position or ethnicity, and may reflect differences in prenatal steroid hormone levels among different ethnic groups. In view of its clinical importance, this study investigates the 2D:4D ratio, as well as other digit ratios, in Greek population. A sample of 60 Greek men and 60 Greek women (age range 19-25 years) was selected by random procedures. Fingers' length was measured twice, using an electronic vernier calliper (precision 0.01 mm). Men had lower 2D:4D ratio (0.974 +/- 0.035 for the right hand and 0.973 +/- 0.044 for the left hand) than women (1.002 +/- 0.04 for the right hand and 1.001 +/- 0.045 for the left hand). This difference in 2D:4D ratio between sexes was statistically significant (p < 0.0001 for the right hand and p < 0.001 for the left hand). The other digit ratios were also lower in men than women for both hands; this difference was statistically significant for all digit ratios of the right hand and for the 2nd to 3rd (2D:3D) and 2nd to 5th (2D:5D) digit ratios of the left hand. The digit ratios are lateralized and sexually dimorphic in Greek population. The sexual dimorphism of all digit ratios (except 2D:3D) is stronger in right than left hand. PMID:19149213

  18. Problems of adolescents sexuality.

    PubMed Central

    Whatley, J; Thin, N; Reynolds, B; Blackwell, A

    1989-01-01

    Recent discussions highlighted adolescents' sexual behaviour, but published studies concentrate on specific problems or subgroups of patients without addressing factors related to sexuality. To obtain a broad picture we studied two groups of adolescents attending genito-urinary medicine/sexually transmitted disease (STD) clinics in contrasting areas of Britain, inner London and Swansea. These were evaluated for referral pattern, sexual partner, contraception, obstetric history, sexually transmitted disease, and cervical cytology findings. Over half the adolescents referred themselves but few doctors other than general practitioners referred patients. Sexual partners were regarded by males as casual but by females as regular. Only 66% (81) of females practised contraception. Adolescents had more STD's than the total clinic population except for genital herpes simplex infection, and a high prevalence of genital warts in females has important future implications. The main conclusions were that there is a need for sexually related education targetted at adolescents and their health care providers, especially doctors. PMID:2614765

  19. [Sexual violence--sexualized violence].

    PubMed

    Springer, Alfred

    2005-12-01

    The fusion of sexuality and violence is a major issue of concern and has become a central issue of social policy. That fusion can be observed in private circumstances as well as in society at large. Children and young people as well as women and men can fall victim to that phenomenon. Eventually, due to gender stereotyping, the awareness of the victimization of the male gender is somewhat weak. In the social-political discourse the male is seen as dominant and powerful and the female gender as the weak one. Sexual violence and/or domination therefore is interpreted as mirroring the genderized balance of power in society. Otherwise the phenomenon is very complex and cannot be explained by simplistic or one-dimensional interpretations. In respect of definitions it is necessary to separate "sexual violence", as an aspect of sexual behavior, and "sexualized power". The latter means the use of sexuality for the display of power and violence. That kind of fusion is visible in all kinds of interactions--on the private level as well as in the sense of "structural power" (like in war, torture, etc.). To theory and practice of psychiatry and psychotherapy the situation brings a whole series of objectives. On the one hand these disciplines have the task to study the phenomenon in different contexts and to contribute to the understanding of the psychic and psychosocial processes which lead to the fusion of the drives. On the other hand it is their obligation to treat the victims of sexual trauma. In recent times much insight has been gained in that context. Nevertheless there has to be much future work done, to understand the phenomenon more deeply and to develop adapted and efficient concepts for prevention and treatment. PMID:16392425

  20. Health benefits of legal services for criminalized populations: the case of people who use drugs, sex workers and sexual and gender minorities.

    PubMed

    Csete, Joanne; Cohen, Jonathan

    2010-01-01

    Social exclusion and legal marginalization are important determinants of health outcomes for people who use illicit drugs, sex workers, and persons who face criminal penalties because of homosexuality or transgenderism. Incarceration may add to the health risks associated with police repression and discrimination for these persons. Access to legal services may be essential to positive health outcomes in these populations. Through concrete examples, this paper explores types of legal problems and legal services linked to health outcomes for drug users, sex workers, and sexual minorities and makes recommendations for donors, legal service providers, and civil society organizations. PMID:21105945

  1. Sexual dimorphism in a dioecious population of the wind-pollinated herb Mercurialis annua: the interactive effects of resource availability and competition

    PubMed Central

    Hesse, Elze; Pannell, John R.

    2011-01-01

    Background and Aims Male-biased sex allocation commonly occurs in wind-pollinated hermaphroditic plants, and is often positively associated with size, notably in terms of height. Currently, it is not well established whether a corresponding pattern holds for dioecious plants: do males of wind-pollinated species exhibit greater reproductive allocation than females? Here, sexual dimorphism is investigated in terms of life history trade-offs in a dioecious population of the wind-pollinated ruderal herb Mercurialis annua. Methods The allocation strategies of males and females grown under different soil nutrient availability and competitive (i.e. no, male or female competitor) regimes were compared. Key Results Male reproductive allocation increased disproportionately with biomass, and was greater than that of females when grown in rich soils. Sexual morphs differentially adjusted their reproductive allocation in response to local environmental conditions. In particular, males reduced their reproductive allocation in poor soils, whereas females increased theirs, especially when competing with another female rather than growing alone. Finally, males displayed smaller above-ground vegetative sizes than females, but neither nutrient availability nor competition had a strong independent effect on relative size disparities between the sexes. Conclusions Selection appears to favour plasticity in reproductive allocation in dioecious M. annua, thereby maintaining a relatively constant size hierarchy between sexual morphs. In common with other dioecious species, there seems to be little divergence in the niches occupied by males and females of M. annua. PMID:21385775

  2. Is Child Sexual Abuse Declining? Evidence from a Population-Based Survey of Men and Women in Australia.

    ERIC Educational Resources Information Center

    Dunne, Michael P.; Purdie, David M.; Cook, Michelle D.; Boyle, Frances M.; Najman, Jake M.

    2003-01-01

    A study examined age-cohort differences of self-reported child sexual abuse (CSA) experiences of 1,784 Australian adults. CSA was reported significantly less by younger males than older males. Among females who had intercourse before 16, older women were more likely to say they were an unwilling partner on the first occasion. (Contains…

  3. Self-Reported Hostility as a Function of Offense Characteristics and Response Style in a Sexual Offender Population.

    ERIC Educational Resources Information Center

    Hall, Gordon C. Nagayana

    1989-01-01

    Examined Buss-Durkee Hostility Inventory (BDHI), Hostility Toward Women Scale (HTWS), and Minnesota Multiphasic Personality Inventory (MMPI) Social Desirability and Defensiveness scales in 239 sexual offenders. Offenders against adolescents and adults had higher BDHI scores than offenders against children. MMPI Defensiveness scale accounted for…

  4. Is religiosity a barrier to sexual and reproductive health? Results from a population-based study of young Croatian adults.

    PubMed

    Puzek, Ivan; Stulhofer, Aleksandar; Božičević, Ivana

    2012-12-01

    Following the demise of socialism in 1989, religious identification substantially increased in most countries of Central, East, and Southeast Europe. Considering that there is evidence that religiosity is associated with reduced sexual risk taking among young people, this study explored associations between religiosity--assessed at three different levels (religious upbringing, personal religiosity, and social network religiosity)--and sexual risks among young Croatian adults. In addition, we examined whether religiosity predicted chlamydial infection among women and men aged 18-25. The data were collected in a national probability survey carried out in 2010 (n = 1,005). Overall, the effects of religiosity were sporadic, present primarily among women, and of small size. This lack of a sizeable impact of religiosity on young adults' sexuality was likely related to a particular type of religiosity, characterized by individualized morality, found among young people in the country. Although Croatia seems to be one of the most religious countries in Europe, our findings suggest that promoting religious morality--as recently attempted by an abstinence-based educational program--may not be an efficient tool in reducing sexual risks. PMID:22441770

  5. Sexual Abuse Histories of Youth in Child Welfare Residential Treatment Centers: Analysis of the Odyssey Project Population

    ERIC Educational Resources Information Center

    Baker, Amy J. L.; Curtis, Patrick A.; Papa-Lentini, Cynthia

    2006-01-01

    This multi-site examination of sexual abuse histories of youth in residential treatment centers asked, for the sample as a whole and by youth's gender: (a) How many perpetrators did each youth have? (b) What was the gender of the perpetrator? (c) What proportion of youth was abused by family members? (d) What proportion of youth was abused in a

  6. Sexual dysfunctions among people living with AIDS in Brazil

    PubMed Central

    de Tubino Scanavino, Marco; Abdo, Carmita Helena Najjar

    2010-01-01

    INTRODUCTION Sexual dysfunction symptoms in patients with HIV have not been fully investigated in Brazil. OBJECTIVES To investigate the association between sexual dysfunction symptoms and AIDS among participants in the Brazilian Sex Life Study. METHODS The Brazilian Sex Life Study is a cross-sectional population study. The participants answered an anonymous self-responsive inquiry. It was applied to a population sample in 18 large Brazilian cities. Answers given by those who reported having AIDS (75) were compared with those who reported not having AIDS (control; 150). This was a case-control study nested in a cross-sectional population study. RESULTS In females, AIDS was associated with “sexual inactivity over the last 12 months” and “does not maintain sexual arousal until the end of the sex act” (P < 0.05) after adjusting for race and thyroid disease. Compared to the control group, men with AIDS had more difficulty becoming sexually aroused (they required more help from their partner to begin the sex act, they required longer foreplay than they wished, they reported losing sexual desire before the end of the sex act, and they required longer to ejaculate than they desired) (P < 0.05). After adjusting for sexual orientation, sex hormone deficiency, depression, and alcoholism, only “does not have sexual desire,” “have longer foreplay,” and dyspareunia were associated with AIDS. DISCUSSION AND CONCLUSIONS The results support the hypothesis that sexual dysfunctions are associated with AIDS. Men with AIDS need more time and stimulation to develop a sexual response, and a significant portion (37%) of women with AIDS reported sexual inactivity over the last 12 months. PMID:20535370

  7. Studying populations of eclipsing binaries using large scale multi-epoch photometric surveys

    NASA Astrophysics Data System (ADS)

    Mowlavi, Nami; Barblan, Fabio; Holl, Berry; Rimoldini, Lorenzo; Lecoeur-Taïbi, Isabelle; Süveges, Maria; Eyer, Laurent; Guy, Leanne; Nienartowicz, Krzysztof; Ordonez, Diego; Charnas, Jonathan; Jévardat de Fombelle, Grégory

    2015-08-01

    Large scale multi-epoch photometric surveys provide unique opportunities to study populations of binary stars through the study of eclipsing binaries, provided the basic properties of binary systems can be derived from their light curves without the need to fully model the binary system. Those systems can then be classified into various types from, for example, close to wide systems, from circular to highly elliptical systems, or from systems with similar components to highly asymmetric systems. The challenge is to extract physically relevant information from the light curve geometry.In this contribution, we present the study of eclipsing binaries in the Large Magellanic Clouds (LMC) from the OGLE-III survey. The study is based on the analysis of the geometry of their light curves parameterized using a two-Gaussian model. We show what physical parameters could be extracted from such an analysis, and the results for the LMC eclipsing binaries. The method is very well adapted to process large-scale surveys containing millions of eclipsing binaries, such as is expected from the current Gaia mission or the future LSST survey.

  8. A WASHINGTON PHOTOMETRIC SURVEY OF THE LARGE MAGELLANIC CLOUD FIELD STAR POPULATION

    SciTech Connect

    Piatti, Andres E.; Geisler, Doug; Mateluna, Renee

    2012-10-01

    We present photometry for an unprecedented database of some 5.5 million stars distributed throughout the Large Magellanic Cloud main body, from 21 fields covering a total area of 7.6 deg{sup 2}, obtained from Washington CT{sub 1} T{sub 2} CTIO 4 m MOSAIC data. Extensive artificial star tests over the whole mosaic image data set and the observed behavior of the photometric errors with magnitude demonstrate the accuracy of the morphology and clearly delineate the position of the main features in the color-magnitude diagrams (CMDs). The representative T{sub 1}(MS TO) mags are on average {approx}0.5 mag brighter than the T{sub 1} mags for the 100% completeness level of the respective field, allowing us to derive an accurate age estimate. We have analyzed the CMD Hess diagrams and used the peaks in star counts at the main sequence turnoff and red clump (RC) locations to age date the most dominant sub-population (or 'representative' population) in the stellar population mix. The metallicity of this representative population is estimated from the locus of the most populous red giant branch track. We use these results to derive age and metallicity estimates for all of our fields. The analyzed fields span age and metallicity ranges covering most of the galaxy's lifetime and chemical enrichment, i.e., ages and metallicities between {approx}1 and 13 Gyr and {approx}-0.2 and -1.2 dex, respectively. We show that the dispersions associated with the mean ages and metallicities represent in general a satisfactory estimate of the age/metallicity spread ({approx}1-3 Gyr/0.2-0.3 dex), although a few subfields have a slightly larger age/metallicity spread. Finally, we revisit the study of the vertical structure (VS) phenomenon, a striking feature composed of stars that extend from the bottom, bluest end of the RC to {approx}0.45 mag fainter. We confirm that the VS phenomenon is not clearly seen in most of the studied fields and suggest that its occurrence is linked to some other condition(s) in addition to the appropriate age, metallicity, and the necessary red giant star density.

  9. Reproductive and resource benefits to large female body size in a mammal with female-biased sexual size dimorphism

    SciTech Connect

    Fokidis, H.B., T.S. Risch and T.C. Glenn

    2007-01-01

    Factors underlying the evolution of female-biased sexual size dimorphism in mammals are poorly understood. In an effort to better understand these factors we tested whether larger female southern flying squirrels, Glaucomys volans, gained reproductive advantages (larger litters or more male mates) and direct resource benefits, such as larger home ranges or access to more food (i.e. mast-producing trees). As dimorphism can vary with age in precocial breeding species, we compared females during their first reproduction and during a subsequent breeding attempt. Females were not significantly larger or heavier than males at first reproduction, but became about 7% heavier and 22% larger than males at subsequent breeding. Larger females produced larger litters and had home ranges containing a greater proportion of upland hardwood trees. Female body size was not associated with either multiple male mating or home range size, but females with larger home ranges had higher indexes of body condition. Females in precocial breeding flying squirrels initiate reproduction before sexual size dimorphism is evident, and thus, may be allocating resources to both reproduction and growth simultaneously, or delaying growth entirely. Larger females produce more pups and have access to more food resources. Thus, selection for increased female size may partly explain how female-biased sexual size dimorphism is maintained in this species.

  10. Canadian fishery closures provide a large-scale test of the impact of gillnet bycatch on seabird populations

    PubMed Central

    Regular, Paul; Montevecchi, William; Hedd, April; Robertson, Gregory; Wilhelm, Sabina

    2013-01-01

    In 1992, the eastern Canadian gillnet fisheries for northern cod and Atlantic salmon were largely closed. These large-scale fishery closures resulted in the removal of tens of thousands of gillnets known to inflict high levels of seabird mortality. We used this unprecedented opportunity to test the effects of gillnet removal on seabird populations. Consistent with predictions, we show that the breeding populations of divers (auks, gannets; susceptible to gillnet bycatch) have increased from pre-closure levels, whereas the populations of scavenging surface-feeders (gulls; low vulnerability to gillnet bycatch but susceptible to removal of fisheries discards) have decreased. Using the most complete series of seabird census data for the species most vulnerable to bycatch, we demonstrate a positive population response of common murres to reduction in gillnet fishing within its foraging range. These findings support the widespread but seldom documented contention that fisheries bycatch negatively impacts populations of non-target large vertebrates. PMID:23720519

  11. The knowledge and attitudes of a female at-risk population towards the prevention of AIDS and sexually transmitted infections in Tehran

    PubMed Central

    Kolahi, Ali-Asghar; Rastegarpour, Ali; Abadi, Ali-Reza; Nabavi, Mahmood; Sayyarifard, Azadeh; Sohrabi, Mohammad-Reza

    2011-01-01

    BACKGROUND: The female at-risk population represents a subgroup that is both a crucial determining factor in acquired immune deficiency syndrome (AIDS) transmission and a gap in the existing literature in Iran. The objective of this study was to evaluate the level of sex workers knowledge towards to safe procedures of sexually transmitted infection and AIDS prevention as well as attitudes towards AIDS. METHODS: A sample of 256 female sex workers working in Tehran was obtained by a variety of methods. Appropriate questions for the assessment of knowledge and attitude were developed based on previous studies. RESULTS: The mean age of the subjects was 26.8 6.1 years (ranging from 16 to 45). Methods of transmission were widely recognized, despite the exception that few realized oral (23.4%) and anal (44.9%) intercourse as methods of human immunodeficiency virus (HIV) transmission. Most subjects knew that AIDS currently has no cure (81.2%) and no vaccine (73.4%). Most also acknowledged that HIV is transmissible from people who do not know they are HIV positive (59.4%), proper condom use can reduce the possibility of infection (78.1%), and so can having a single sexual partner (68.8%). Of the participants, 43.4% knew that an HIV-positive person can seem perfectly healthy. CONCLUSIONS: Knowledge towards sexually transmitted infections (STIs) and condom use is still inadequate, especially regarding risky behaviors such as anal sex, and attitudes are mainly negative. Identifying at-risk populations, HIV-positive sex workers, education and campaigns to change the attitudes towards AIDS should be regarded a high priority in Iran. PMID:22973347

  12. Comparison of large crater and multiringed basin populations on Mars, Mercury, and the moon

    NASA Technical Reports Server (NTRS)

    Malin, M. C.

    1976-01-01

    The maximum regional areal densities of large impact craters on Mars, Mercury, and the moon appear to be inversely proportional to the surface areas of the planets. This would not be expected if the objects impacting the planetary surfaces came from common sources and were moving with high velocities relative to the planets; rather, a uniform areal density would be anticipated. Another way of stating the observation is that each planet was bombarded by the same number of objects. Two speculative explanations for the observation are that: (1) all planets underwent a uniform bombardment but were resurfaced by processes proportional to planetary surface area, or (2) equally populated families of objects, moving about the sun in orbits similar to those of the planets, were independently depopulated by the respective planets.

  13. Leveraging domain knowledge to facilitate visual exploration of large population datasets.

    PubMed

    Hsu, William; Bui, Alex A T

    2013-01-01

    Observational patient data provides an unprecedented opportunity to gleam new insights into diseases and assess patient quality of care, but a challenge lies in matching our ability to collect data with a comparable ability to understand and apply this information. Visual analytic techniques are promising as they permit the exploration and manipulation of complex datasets through a graphical user interface. Nevertheless, current visualization tools rely on users to manually configure which aspects of the dataset are shown and how they are presented. In this paper, we describe an approach that utilizes characteristics of the data and domain knowledge to assist users with summarizing the information space of a large population. We present a representation that captures contextual information about the data and constructs that operate on this information to tailor the data's presentation. We describe a use case of this approach in exploring a claims dataset of individuals with spinal dysraphism. PMID:24551363

  14. Large Magellanic Cloud Planetary Nebula Morphology: Probing Stellar Populations and Evolution

    NASA Astrophysics Data System (ADS)

    Stanghellini, Letizia; Shaw, Richard A.; Balick, Bruce; Blades, J. Chris

    2000-05-01

    Planetary nebulae (PNe) in the Large Magellanic Cloud (LMC) offer the unique opportunity to study both the population and evolution of low- and intermediate-mass stars, by means of the morphological type of the nebula. Using observations from our LMC PN morphological survey, and including images available in the Hubble Space Telescope Data Archive and published chemical abundances, we find that asymmetry in PNe is strongly correlated with a younger stellar population, as indicated by the abundance of elements that are unaltered by stellar evolution (Ne, Ar, and S). While similar results have been obtained for Galactic PNe, this is the first demonstration of the relationship for extragalactic PNe. We also examine the relation between morphology and abundance of the products of stellar evolution. We found that asymmetric PNe have higher nitrogen and lower carbon abundances than symmetric PNe. Our two main results are broadly consistent with the predictions of stellar evolution if the progenitors of asymmetric PNe have on average larger masses than the progenitors of symmetric PNe. The results bear on the question of formation mechanisms for asymmetric PNe-specifically, that the genesis of PNe structure should relate strongly to the population type, and by inference the mass, of the progenitor star and less strongly on whether the central star is a member of a close binary system. Based on observations made with the NASA/ESA Hubble Space Telescope, and from the HST Data Archive, obtained at the Space Telescope Science Institute, which is operated by the Association of universities for research in Astronomy, Inc., under NASA contract NAS5-26555.

  15. Impact of seasonality on the prevalence of dyslipidemia: a large population study.

    PubMed

    Moura, Filipe A; Dutra-Rodrigues, Marcelo S; Cassol, Angela S; Parra, Eliane S; Zago, Vanessa H S; Panzoldo, Natalia B; Alexandre, Fernanda; Vieira, Isabela C; Vendrame, Felipe; Virginio, Vitor W; Castanho, Vera S; Danelon, Mirian R G; Nunes, Valeria S; Leança, Camila C; Saraiva, Francisco K; Coelho, Otavio R; Nakandakare, Edna; Quintão, Eder C R; de Faria, Eliana Cotta; Sposito, Andrei C

    2013-10-01

    Assessment of lipid profile parameters has been considered a cornerstone in classifying individuals and populations at risk for cardiovascular disease. Recently, however, preliminary data have raised the possibility of seasonal variations in these parameters, which may cause under- or overestimation. Biological rhythms and seasonal variation of lipid profile was investigated in 227 359 consecutive individuals who underwent health checkups in primary care centers between 2008 and 2010. Plasma low-density lipoprotein cholesterol (LDL-C) >130 mg/dL was 8% more prevalent during winter than summer, with a larger difference among women and middle-aged adults (p < 0.001). High-density lipoprotein cholesterol (HDL-C) <40 mg/dL and triglycerides (TG) >150 mg/dL were respectively 9% and 5% more prevalent during the summer (p < 0.001). Variation amplitude was 3.4 ± 0.3 mg/dL for HDL-C (p = 0.005), 7 ± 2 mg/dL for LDL-C (p = 0.047), and 12 ± 9 mg/dL for TG (p = 0.058). Based on a large population sample, this study confirms the existence of biological rhythms and seasonal variation in lipid profile. This finding must be particularly accounted for in cross-sectional analyses of relative risk, prevalence, or the rate of goal achievement for lipid parameters. PMID:23837747

  16. Subterranean phylogeography of freshwater crayfishes shows extensive gene flow and surprisingly large population sizes.

    PubMed

    Buhay, Jennifer E; Crandall, Keith A

    2005-12-01

    Subterranean animals are currently viewed as highly imperiled, precariously avoiding extinction in an extreme environment of darkness. This assumption is based on a hypothesis that the reduction in visual systems and morphology common in cave faunas reflects a genetic inability to adapt and persist coupled with the perception of a habitat that is limited, disconnected, and fragile. Accordingly, 95% of cave fauna in the United States are presumed endangered due to surface environmental degradation and limited geographic distributions. Our study explores the subterranean phylogeography of stygobitic crayfishes in the southeastern United States, a global hotspot of groundwater biodiversity, using extensive geographic sampling and molecular data. Despite their endangered status, our results show that subterranean crayfish species have attained moderate to high levels of genetic diversity over their evolutionary histories with large population sizes and extensive gene flow among karst systems. We then compare the subterranean population histories to those of common surface stream-dwelling crayfishes. Our results show recent drastic declines in genetic variability in the surface crayfish and suggest that these species also warrant conservation attention. PMID:16313591

  17. Did Large-Scale Vaccination Drive Changes in the Circulating Rotavirus Population in Belgium?

    PubMed Central

    Pitzer, Virginia E.; Bilcke, Joke; Heylen, Elisabeth; Crawford, Forrest W.; Callens, Michael; De Smet, Frank; Van Ranst, Marc; Zeller, Mark; Matthijnssens, Jelle

    2015-01-01

    Vaccination can place selective pressures on viral populations, leading to changes in the distribution of strains as viruses evolve to escape immunity from the vaccine. Vaccine-driven strain replacement is a major concern after nationwide rotavirus vaccine introductions. However, the distribution of the predominant rotavirus genotypes varies from year to year in the absence of vaccination, making it difficult to determine what changes can be attributed to the vaccines. To gain insight in the underlying dynamics driving changes in the rotavirus population, we fitted a hierarchy of mathematical models to national and local genotype-specific hospitalization data from Belgium, where large-scale vaccination was introduced in 2006. We estimated that natural- and vaccine-derived immunity was strongest against completely homotypic strains and weakest against fully heterotypic strains, with an intermediate immunity amongst partially heterotypic strains. The predominance of G2P[4] infections in Belgium after vaccine introduction can be explained by a combination of natural genotype fluctuations and weaker natural and vaccine-induced immunity against infection with strains heterotypic to the vaccine, in the absence of significant variation in strain-specific vaccine effectiveness against disease. However, the incidence of rotavirus gastroenteritis is predicted to remain low despite vaccine-driven changes in the distribution of genotypes. PMID:26687288

  18. Exploratory factor analysis of self-reported symptoms in a large, population-based military cohort

    PubMed Central

    2010-01-01

    Background US military engagements have consistently raised concern over the array of health outcomes experienced by service members postdeployment. Exploratory factor analysis has been used in studies of 1991 Gulf War-related illnesses, and may increase understanding of symptoms and health outcomes associated with current military conflicts in Iraq and Afghanistan. The objective of this study was to use exploratory factor analysis to describe the correlations among numerous physical and psychological symptoms in terms of a smaller number of unobserved variables or factors. Methods The Millennium Cohort Study collects extensive self-reported health data from a large, population-based military cohort, providing a unique opportunity to investigate the interrelationships of numerous physical and psychological symptoms among US military personnel. This study used data from the Millennium Cohort Study, a large, population-based military cohort. Exploratory factor analysis was used to examine the covariance structure of symptoms reported by approximately 50,000 cohort members during 2004-2006. Analyses incorporated 89 symptoms, including responses to several validated instruments embedded in the questionnaire. Techniques accommodated the categorical and sometimes incomplete nature of the survey data. Results A 14-factor model accounted for 60 percent of the total variance in symptoms data and included factors related to several physical, psychological, and behavioral constructs. A notable finding was that many factors appeared to load in accordance with symptom co-location within the survey instrument, highlighting the difficulty in disassociating the effects of question content, location, and response format on factor structure. Conclusions This study demonstrates the potential strengths and weaknesses of exploratory factor analysis to heighten understanding of the complex associations among symptoms. Further research is needed to investigate the relationship between factor analytic results and survey structure, as well as to assess the relationship between factor scores and key exposure variables. PMID:20950474

  19. Large sequence divergence among mitochondrial DNA genotypes within populations of eastern African black-backed jackals.

    PubMed

    Wayne, R K; Meyer, A; Lehman, N; Van Valkenburgh, B; Kat, P W; Fuller, T K; Girman, D; O'Brien, S J

    1990-03-01

    In discussions about the relative rate of molecular evolution, intraspecific variability in rate is rarely considered. An underlying assumption is that intraspecific sequence differences are small, and thus variations in rate would be difficult to detect or would not affect comparisons among distantly related taxa. However, several studies on mammalian mitochondrial DNA (mtDNA) have revealed considerable intraspecific sequence divergence. In this report, we test for differences in the rate of intraspecific evolution by comparing mtDNA sequences, as inferred from restriction site polymorphisms and direct sequencing, between mtDNA genotypes of the eastern African black-backed jackal, Canis mesomelas elongae, and those of two other sympatric jackal species. Our results are unusual for several reasons. First, mtDNA sequence divergence within several contiguous black-backed jackal populations is large (8.0%). Previous intraspecific studies of terrestrial mammals have generally found values of less than 5% within a single population, with larger divergence values most often occurring among mtDNA genotypes from geographically distant or isolated localities. Second, only 4 mtDNA genotypes were present in our sample of 64 jackals. The large sequence divergence observed among these mtDNA genotypes suggests there should be many more genotypes of intermediate sequence divergence if they had evolved in sympatry. Finally, estimates of the rate of mtDNA sequence evolution differ by approximately 2- to 4-fold among black-backed jackal mtDNA genotypes, thus indicating a substantial heterogeneity in the rate of sequence evolution. The results are difficult to reconcile with ideas of a constant molecular clock based on random fixation of selectively neutral or nearly neutral mtDNA sequence mutations. PMID:1968637

  20. Large sequence divergence among mitochondrial DNA genotypes within populations of eastern African black-backed jackals.

    PubMed Central

    Wayne, R K; Meyer, A; Lehman, N; Van Valkenburgh, B; Kat, P W; Fuller, T K; Girman, D; O'Brien, S J

    1990-01-01

    In discussions about the relative rate of molecular evolution, intraspecific variability in rate is rarely considered. An underlying assumption is that intraspecific sequence differences are small, and thus variations in rate would be difficult to detect or would not affect comparisons among distantly related taxa. However, several studies on mammalian mitochondrial DNA (mtDNA) have revealed considerable intraspecific sequence divergence. In this report, we test for differences in the rate of intraspecific evolution by comparing mtDNA sequences, as inferred from restriction site polymorphisms and direct sequencing, between mtDNA genotypes of the eastern African black-backed jackal, Canis mesomelas elongae, and those of two other sympatric jackal species. Our results are unusual for several reasons. First, mtDNA sequence divergence within several contiguous black-backed jackal populations is large (8.0%). Previous intraspecific studies of terrestrial mammals have generally found values of less than 5% within a single population, with larger divergence values most often occurring among mtDNA genotypes from geographically distant or isolated localities. Second, only 4 mtDNA genotypes were present in our sample of 64 jackals. The large sequence divergence observed among these mtDNA genotypes suggests there should be many more genotypes of intermediate sequence divergence if they had evolved in sympatry. Finally, estimates of the rate of mtDNA sequence evolution differ by approximately 2- to 4-fold among black-backed jackal mtDNA genotypes, thus indicating a substantial heterogeneity in the rate of sequence evolution. The results are difficult to reconcile with ideas of a constant molecular clock based on random fixation of selectively neutral or nearly neutral mtDNA sequence mutations. Images PMID:1968637

  1. Ab initio phenomenological simulation of the growth of large tumor cell populations

    NASA Astrophysics Data System (ADS)

    Chignola, Roberto; DelFabbro, Alessio; Dalla Pellegrina, Chiara; Milotti, Edoardo

    2007-06-01

    In a previous paper we have introduced a phenomenological model of cell metabolism and of the cell cycle to simulate the behavior of large tumor cell populations (Chignola and Milotti 2005 Phys. Biol. 2 8). Here we describe a refined and extended version of the model that includes some of the complex interactions between cells and their surrounding environment. The present version takes into consideration several additional energy-consuming biochemical pathways such as protein and DNA synthesis, the tuning of extracellular pH and of the cell membrane potential. The control of the cell cycle, which was previously modeled by means of ad hoc thresholds, has been directly addressed here by considering checkpoints from proteins that act as targets for phosphorylation on multiple sites. As simulated cells grow, they can now modify the chemical composition of the surrounding environment which in turn acts as a feedback mechanism to tune cell metabolism and hence cell proliferation: in this way we obtain growth curves that match quite well those observed in vitro with human leukemia cell lines. The model is strongly constrained and returns results that can be directly compared with actual experiments, because it uses parameter values in narrow ranges estimated from experimental data, and in perspective we hope to utilize it to develop in silico studies of the growth of very large tumor cell populations (106 cells or more) and to support experimental research. In particular, the program is used here to make predictions on the behavior of cells grown in a glucose-poor medium: these predictions are confirmed by experimental observation.

  2. Circadian analysis of large human populations: inferences from the power grid.

    PubMed

    Stowie, Adam C; Amicarelli, Mario J; Crosier, Caitlin J; Mymko, Ryan; Glass, J David

    2015-03-01

    Few, if any studies have focused on the daily rhythmic nature of modern industrialized populations. The present study utilized real-time load data from the U.S. Pacific Northwest electrical power grid as a reflection of human operative household activity. This approach involved actigraphic analyses of continuously streaming internet data (provided in 5 min bins) from a human subject pool of approximately 43 million primarily residential users. Rhythm analyses reveal striking seasonal and intra-week differences in human activity patterns, largely devoid of manufacturing and automated load interference. Length of the diurnal activity period (alpha) is longer during the spring than the summer (16.64 h versus 15.98 h, respectively; p < 0.01). As expected, significantly more activity occurs in the solar dark phase during the winter than during the summer (6.29 h versus 2.03 h, respectively; p < 0.01). Interestingly, throughout the year a "weekend effect" is evident, where morning activity onset occurs approximately 1 h later than during the work week (5:54 am versus 6:52 am, respectively; p < 0.01). This indicates a general phase-delaying response to the absence of job-related or other weekday morning arousal cues, substantiating a preference or need to sleep longer on weekends. Finally, a shift in onset time can be seen during the transition to Day Light Saving Time, but not the transition back to Standard Time. The use of grid power load as a means for human actimetry assessment thus offers new insights into the collective diurnal activity patterns of large human populations. PMID:25286134

  3. A POPULATION OF ACCRETED SMALL MAGELLANIC CLOUD STARS IN THE LARGE MAGELLANIC CLOUD

    SciTech Connect

    Olsen, Knut A. G.; Blum, Robert D.; Zaritsky, Dennis; Boyer, Martha L.; Gordon, Karl D. E-mail: rblum@noao.edu E-mail: mboyer@stsci.edu

    2011-08-10

    We present an analysis of the stellar kinematics of the Large Magellanic Cloud (LMC) based on {approx}5900 new and existing velocities of massive red supergiants, oxygen-rich and carbon-rich asymptotic giant branch (AGB) stars, and other giants. After correcting the line-of-sight velocities for the LMC's space motion and accounting for asymmetric drift in the AGB population, we derive a rotation curve that is consistent with all of the tracers used, as well as that of published H I data. The amplitude of the rotation curve is v{sub 0} = 87 {+-} 5 km s{sup -1} beyond a radius R{sub 0} = 2.4 {+-} 0.1 kpc and has a position angle of the kinematic line of nodes of {theta} = 142 deg. {+-} 5 deg. By examining the outliers from our fits, we identify a population of 376 stars, or {approx}>5% of our sample, that have line-of-sight velocities that apparently oppose the sense of rotation of the LMC disk. We find that these kinematically distinct stars are either counter-rotating in a plane closely aligned with the LMC disk, or rotating in the same sense as the LMC disk, but in a plane that is inclined by 54 deg. {+-} 2 deg. to the LMC. Their kinematics clearly link them to two known H I arms, which have previously been interpreted as being pulled out from the LMC. We measure metallicities from the Ca triplet lines of {approx}1000 LMC field stars and 30 stars in the kinematically distinct population. For the LMC field, we find a median [Fe/H] = -0.56 {+-} 0.02 with dispersion of 0.5 dex, while for the kinematically distinct stars the median [Fe/H] is -1.25 {+-} 0.13 with a dispersion of 0.7 dex. The metallicity differences provide strong evidence that the kinematically distinct population originated in the Small Magellanic Cloud. This interpretation has the consequence that the H I arms kinematically associated with the stars are likely falling into the LMC, instead of being pulled out.

  4. Prevalence of metabolic syndrome-related disorders in a large adult population in Turkey

    PubMed Central

    Sanisoglu, S Yavuz; Oktenli, Cagatay; Hasimi, Adnan; Yokusoglu, Mehmet; Ugurlu, Mehmet

    2006-01-01

    Background There are few existing large population studies on the epidemiology of metabolic syndrome-related disorders of Turkey. The purpose of this study was to assess the prevalence of metabolic syndrome-related disorders in the Turkish adult population, to address sex, age, educational and geographical differences, and to examine blood pressure, body mass index, fasting blood glucose and serum lipids in Turkey. Methods This study was executed under the population study "The Healthy Nutrition for Healthy Heart Study" conducted between December 2000 and December 2002 by the Health Ministry of Turkey. Overall, 15,468 Caucasian inhabitants aged over 30 were recruited in 14 centers in the seven main different regions of Turkey. The data were analyzed with the Students' t, ANOVA or Chi-Square tests. Results Overall, more than one-third (35.08 %) of the participants was obese. The hypertensive people ratio in the population was 13.66 %, while these ratios for DM and metabolic syndrome were 4.16 % and 17.91 %, respectively. The prevalence of hypertension, metabolic syndrome and obesity were higher in females than males, whereas diabetes mellitus was higher in males than females. The prevalence of metabolic syndrome and related disorders were found to be significantly different across educational attainments for both men and women. The prevalence of hypertension increased with age, while it was remarkable that in the age group of 60–69 years, prevalence of diabetes mellitus and metabolic syndrome reached a peak value and than decreased. For obesity, the peak prevalence occurred in the 50–59 year old group. The prevalence of metabolic syndrome and related disorders were found to be significantly different according to geographical region. Conclusion In conclusion, high prevalence of obesity and metabolic syndrome, particularly among women, is one of the major public health problems in Turkey. Interestingly, obesity prevalence is relatively high, but the prevalence of hypertension and hypercholesterolemia is relatively low in Turkish people. Future studies may focus on elucidating the reasons behind this controversy. Our findings may be helpful in formulating public health policy and prevention strategies on future health in Turkey. PMID:16606462

  5. Gambling behavior and problem gambling reflecting social transition and traumatic childhood events among Greenland Inuit: a cross-sectional study in a large indigenous population undergoing rapid change.

    PubMed

    Larsen, Christina Viskum Lytken; Curtis, Tine; Bjerregaard, Peter

    2013-12-01

    An increase in social pathologies is a key feature in indigenous populations undergoing transition. The Greenland Inuit are a large indigenous population constituting a majority in their own country, which makes it possible to investigate differences within the population. This led us to study gambling behavior and problem gambling among Greenland Inuit in relation to the ongoing social transition and traumatic events during childhood. A large representative cross-sectional study was conducted among Greenland Inuit (n = 2,189). Data was collected among adults (18+) in 9 towns and 13 villages in Greenland from 2005 to 2010. Problem gambling, gambling behavior and traumatic childhood events were measured through a self-administered questionnaire. The lie/bet screen was used to identify past year and lifetime problem gambling. Social transition was measured as place of residence and a combination of residence, education and occupation. The lifetime prevalence of problem gambling was 16 % among men and 10 % among women (p < 0.0001); and higher in towns (19 %) compared to the capital of Nuuk (11 %) and in villages (12 %) (men only, p = 0.020). Lifetime problem gambling was associated with social transition (p = 0.023), alcohol problems in childhood home (p = 0.001/p = 0.002) and sexual abuse in childhood (women only, p = 0.030). A comparably high prevalence of lifetime problem gambling among Greenland Inuit adds problem gambling to the list of social pathologies in Greenland. A significant association between lifetime problem gambling, social transition and traumatic childhood events suggests people caught between tradition and modern ways of life are more vulnerable to gambling problems. PMID:23065180

  6. Sexual Behavior Disorders in Adolescents.

    ERIC Educational Resources Information Center

    Erickson, William D.

    The paper reviews the literature on sexual delinquency in male and female adolescents and considers guidelines for effective intervention in nonspecialized treatment programs. A section on sexual delinquency in females touches on prostitution and incest, while a section on males notes the changing composition of the sexually delinquent population.…

  7. Heritability of metabolic syndrome traits in a large population-based sample[S

    PubMed Central

    van Dongen, Jenny; Willemsen, Gonneke; Chen, Wei-Min; de Geus, Eco J. C.; Boomsma, Dorret I.

    2013-01-01

    Heritability estimates of metabolic syndrome traits vary widely across studies. Some studies have suggested that the contribution of genes may vary with age or sex. We estimated the heritability of 11 metabolic syndrome-related traits and height as a function of age and sex in a large population-based sample of twin families (N = 2,79227,021, for different traits). A moderate-to-high heritability was found for all traits [from H2 = 0.47 (insulin) to H2 = 0.78 (BMI)]. The broad-sense heritability (H2) showed little variation between age groups in women; it differed somewhat more in men (e.g., for glucose, H2 = 0.61 in young females, H2 = 0.56 in older females, H2 = 0.64 in young males, and H2= 0.27 in older males). While nonadditive genetic effects explained little variation in the younger subjects, nonadditive genetic effects became more important at a greater age. Our findings show that in an unselected sample (age range, ?1898 years), the genetic contribution to individual differences in metabolic syndrome traits is moderate to large in both sexes and across age. Although the prevalence of the metabolic syndrome has greatly increased in the past decades due to lifestyle changes, our study indicates that most of the variation in metabolic syndrome traits between individuals is due to genetic differences. PMID:23918046

  8. Sexual behaviors relevant to HIV transmission in a rural African population. How much can a KAP survey tell us?

    PubMed

    Schopper, D; Doussantousse, S; Orav, J

    1993-08-01

    KAP surveys have been proposed as a means to gather quantitative information on AIDS-related sexual behaviors, but the validity of survey results has not been tested. The validity of data gathered during a KAP survey in a rural district in Northern Uganda (N = 1486) was examined analyzing expected behavioral patterns, agreement of partner reports, and concordance of number of sexual contacts across gender. Patterns of sexual behavior and age trends are as expected. More men (50%) than women (18.5%) reported premarital sex. The likelihood of sexual intercourse before marriage increases with age at first marriage and with education. Women marry 5 years earlier than men, and the number of marriages increases with age. Peak incidence of casual sex occurs before age 25. The male/female ratio of casual sex is 4, as compared to about 3 in other African surveys. Single men are 2.5 times more likely to engage in casual sex than married males. Agreement of partner reports was examined for 392 couples selected by chance. 86% of the couples agreed on being polygamous or monogamous. On average men reported 1.3 (SD = 0.7) wives as compared to women reporting 1.5 (SD = 0.89) wives (P < 0.001). 16.8% of women declared more, and 2.8% less cowives than their husband (r = 0.65). Self-reports on frequency of sexual intercourse in the past month were examined for 256 monogamous couples. Mean frequencies differ (5.24 +/- 5.1 for men, 4.43 +/- 4.7 for women, P < 0.001). 42.8% of couples are in agreement within +/- 1 unit (r = 0.44). The total number of extra-marital and marital sex acts, as well as the total number of partners reported by each gender are similar. There is, however, a striking gender difference in reporting of casual partners in the past year. Data were found to be accurate at the aggregate level. However, accuracy of reporting at the individual level was found to be low. The gender difference in reporting of casual partners may be due to female underreporting, to not having captured prostitutes or to a different perception of the meaning of casual partnership. All KAP surveys should include a validity analysis, so as to provide a sense of the accuracy of the surveys and allow for comparison of the quality of different KAP surveys. There is an urgent need for a standardized approach to validating the findings from AIDS-related KAP surveys. Some of the indirect methods described here could be relevant for further use. PMID:8356488

  9. The influence of population dynamics and environmental conditions on salmon re-colonization after large-scale distrubance

    NASA Astrophysics Data System (ADS)

    Pess, G. R.; Hilborn, R.; Kloehn, K.; Quinn, T.

    2010-12-01

    The transition from dispersal into unoccupied habitat to the establishment of a self-sustaining new population depends on the dynamics of the source and recipient populations, and the environmental conditions that facilitate or hinder exchange and successful reproduction. We used population growth rate, inter-annual variability estimates, habitat condition and size, hydrologic data, and an estimated dispersal effect to determine when colonizing pink salmon (Oncorhynchus gorbuscha) populations became self-sustaining after a long-term migration blockage (Hell’s Gate) was mitigated in the Fraser River, British Columbia, Canada. We used pink salmon spawning data from 1947 to 1987 in 66 streams to define populations, population growth rates, and the level of dispersal to newly accessible habitats. We also quantified the distance from source populations, the amount of newly accessible habitat, and determined whether stream flow conditions impeded fish passage at Hell’s Gate. Population dynamics models fit to observed data indicated that the combination of an initially large source population in the Fraser River below Hell’s Gate, high intrinsic growth rates linked to favorable climate-driven conditions, a constant supply of dispersers, and large amounts of newly available habitat resulted in the development of self-sustaining pink salmon populations in the Fraser River upstream of the historic barrier. Self-sustaining populations were developed within years of barrier removal and have continued to help expand the overall population of Fraser River pink salmon. However, not all locations had the same productivity and the magnitude of exchange among them was partly mediated by river conditions that permit or impede passage. Both re-colonized abundance levels were reduced and population spatial structure shifted relative to historic population abundance and spatial structure estimates.

  10. Prevalence, Characteristics, and Associations of Sexual Abuse with Sociodemographics and Consensual Sex in a Population-Based Sample of Swedish Adolescents

    ERIC Educational Resources Information Center

    Priebe, Gisela; Svedin, Carl Goran

    2009-01-01

    The purpose of this study was to investigate lifetime prevalence and characteristics of self-reported child sexual abuse and associations between child sexual abuse, gender, sociodemographic data, and consensual sexual experiences. A questionnaire was completed by 4,339 Swedish high school seniors. Three categories of child sexual abuse were…

  11. Prevalence, Characteristics, and Associations of Sexual Abuse with Sociodemographics and Consensual Sex in a Population-Based Sample of Swedish Adolescents

    ERIC Educational Resources Information Center

    Priebe, Gisela; Svedin, Carl Goran

    2009-01-01

    The purpose of this study was to investigate lifetime prevalence and characteristics of self-reported child sexual abuse and associations between child sexual abuse, gender, sociodemographic data, and consensual sexual experiences. A questionnaire was completed by 4,339 Swedish high school seniors. Three categories of child sexual abuse were

  12. Characterizing Pre-Main Sequence Populations in Stellar Associations of the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Gouliermis, Dimitrios

    2007-07-01

    The Large Magellanic Cloud {LMC} offers an extremely rich sample of resolved low-mass stars {below 1 Solar Mass} in the act of formation that has not been explored sufficiently yet. These pre-main sequence {PMS} stars provide a unique snapshot of the star formation process, as it is being recorded for the last 20 Myr, and they give important information on the low-mass Initial Mass Function {IMF} of their host stellar systems. Studies of young, rich LMC clusters like 30 Doradus are crowding limited, even at the angular resolution facilitated by HST in the optical. To learn more about low-mass PMS stars in the LMC, one has to study less crowded regions like young stellar assocations. We propose to employ WFPC2 to obtain deep photometry {V 25.5 mag} of four selected LMC stellar associations in order to perform an original optical analysis of their red PMS and blue bright MS stellar populations. With these observations we aim at a comprehensive study, which will add substantial information on the most recent star formation and the IMF in the LMC. The data reduction and analysis will be performed with a 2D photometry software package especially developped by us for WFPC2 imaging of extended stellar associations with variable background. Our targets have been selected optimizing a combination of criteria, namely spatial resolution, crowding, low extinction, nebular contamination, and background confusion in comparison to other regions in the Local Group. Parallel NICMOS imaging will provide additional information on near-infrared properties of the stellar population in the regions surrounding these systems.

  13. Effects of a large northern European no-take zone on flatfish populations.

    PubMed

    Florin, A-B; Bergström, U; Ustups, D; Lundström, K; Jonsson, P R

    2013-10-01

    In March 2006, a 360 km² no-take zone (NTZ) was established north of Gotland in the central Baltic Sea, with the purpose to scientifically evaluate the effects of a fishing ban on flatfish populations. A monitoring programme was set up to study the populations in the NTZ and in a reference area east of Gotland where the fishing pressure was high. The programme included fishing with multimesh survey nets, modelling of potential larval export and estimation of fish consumption by large marine predators. Overall, the results showed a clear positive effect of the NTZ on turbot Scophthalmus maximus, with higher densities in the closed area compared with the fished area and also higher densities after closure compared with before. The NTZ also had older individuals and a more even sex ratio. This, in combination with a high potential for larval export from the NTZ to Gotland, shows that the marine reserve may be important for maintaining a viable S. maximus stock at Gotland. Also, for flounder Platichthys flesus, the densities were higher in the NTZ compared to the reference area and there was a net larval export to the fished area. For both species, density-dependent growth was evident, with a lower length at age in the closed area. Potential predation by grey seal Halichoerus grypus and great cormorant Phalacrocorax carbo sinesis on flatfishes, that could hamper the evaluation of the marine reserve, was also addressed. Taken together, the results show that there are clear benefits of the fishing ban for both flatfish species within the NTZ, while the net effects on fisheries are difficult to quantify. PMID:24090556

  14. Star formation history and X-ray binary populations: the case of the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Antoniou, V.; Zezas, A.

    2016-06-01

    In this work we investigate the link between high-mass X-ray binaries (HMXBs) and star formation in the Large Magellanic Cloud (LMC), our nearest star-forming galaxy. Using optical photometric data, we identify the most likely counterpart of 44 X-ray sources. Among the 40 HMXBs classified in this work, we find 33 Be/X-ray binaries (Be-XRBs), and 4 supergiant XRBs. Using this census and the published spatially resolved star formation history map of the LMC, we find that the HMXBs (and as expected the X-ray pulsars) are present in regions with star formation bursts ∼6-25 Myr ago, in contrast to the Small Magellanic Cloud (SMC), for which this population peaks at later ages (∼25-60 Myr ago). We also estimate the HMXB production rate to be equal to one system per ∼23.0-4.1+4.4× 10-3 M⊙ yr-1 or one system per ∼143M⊙ of stars formed during the associated star formation episode. Therefore, the formation efficiency of HMXBs in the LMC is ∼17 times lower than that in the SMC. We attribute this difference primarily in the different ages and metallicity of the HMXB populations in the two galaxies. We also set limits on the kicks imparted on the neutron star during the supernova explosion. We find that the time elapsed since the supernova kick is ∼3 times shorter in the LMC than the SMC. This in combination with the average offsets of the HMXBs from their nearest star clusters results in ∼4 times faster transverse velocities for HMXBs in the LMC than in the SMC.

  15. Survival of women with inflammatory breast cancer: a large population-based study†

    PubMed Central

    Dawood, S.; Lei, X.; Dent, R.; Gupta, S.; Sirohi, B.; Cortes, J.; Cristofanilli, M.; Buchholz, T.; Gonzalez-Angulo, A. M.

    2014-01-01

    Background Our group has previously reported that women with inflammatory breast cancer (IBC) continue to have worse outcome compared with those with non-IBC. We undertook this population-based study to see if there have been improvements in survival among women with stage III IBC, over time. Patient and methods We searched the Surveillance, Epidemiology and End Results Registry to identify female patients diagnosed with stage III IBC between 1990 and 2010. Patients were divided into four groups according to year of diagnosis: 1990–1995, 1996–2000, 2001–2005, and 2006–2010. Breast cancer-specific survival (BCSS) was estimated using the Kaplan–Meier method and compared across groups using the log-rank test. Cox models were then fit to determine the association of year of diagnosis and BCSS after adjusting for patient and tumor characteristics. Results A total of 7679 patients with IBC were identified of whom 1084 patients (14.1%) were diagnosed between 1990 and 1995, 1614 patients (21.0%) between 1996 and 2000, 2683 patients (34.9%) between 2001 and 2005, and 2298 patients (29.9%) between 2006 and 2010. The 2-year BCSS for the whole cohort was 71%. Two-year BCSS were 62%, 67%, 72%, and 76% for patients diagnosed between 1990–1995, 1996–2000, 2001–2005, and 2006–2010, respectively (P < 0.0001). In the multivariable analysis, increasing year of diagnosis (modeled as a continuous variable) was associated with decreasing risks of death from breast cancer (HR = 0.98, 95% confidence interval 0.97–0.99, P < 0.0001). Conclusion There has been a significant improvement in survival of patients diagnosed with IBC over a two-decade time span in this large population-based study. This suggests that therapeutic strategies researched and evolved in the context of non-IBC have also had a positive impact in women with IBC. PMID:24669011

  16. Trends and Milestones: Continuing Reduction in Populations of Large State Residential Facilities for Persons with Intellectual and Developmental Disabilities.

    ERIC Educational Resources Information Center

    Coucouvanis, Kathie; Polister, Barbara; Prouty, Robert; Lakin, K. Charlie

    2003-01-01

    This article discusses the continuing trend of downsizing and closure of large state institutions for persons with mental retardation. Between 1987 and 2001, nine states closed all of their large state residential facilities, reducing the total national population of such facilities by 2,414 residents. A chart illustrates state reductions. (CR)

  17. Genetics of single-cell protein abundance variation in large yeast populations

    PubMed Central

    Albert, Frank W.; Treusch, Sebastian; Shockley, Arthur H.; Bloom, Joshua S.; Kruglyak, Leonid

    2014-01-01

    Variation among individuals arises in part from differences in DNA sequences, but the genetic basis for variation in most traits, including common diseases, remains only partly understood. Many DNA variants influence phenotypes by altering the expression level of one or multiple genes. The effects of such variants can be detected as expression quantitative trait loci (eQTL) 1. Traditional eQTL mapping requires large-scale genotype and gene expression data for each individual in the study sample, which limits sample sizes to hundreds of individuals in both humans and model organisms and reduces statistical power 2–6. Consequently, many eQTL are likely missed, especially those with smaller effects 7. Further, most studies use mRNA rather than protein abundance as the measure of gene expression. Studies that have used mass-spectrometry proteomics 8–13 reported surprising differences between eQTL and protein QTL (pQTL) for the same genes 9,10, but these studies have been even more limited in scope. Here, we introduce a powerful method for identifying genetic loci that influence protein expression in the yeast Saccharomyes cerevisiae. We measure single-cell protein abundance through the use of green-fluorescent-protein tags in very large populations of genetically variable cells, and use pooled sequencing to compare allele frequencies across the genome in thousands of individuals with high vs. low protein abundance. We applied this method to 160 genes and detected many more loci per gene than previous studies. We also observed closer correspondence between loci that influence protein abundance and loci that influence mRNA abundance of a given gene. Most loci cluster at hotspot locations that influence multiple proteins—in some cases, more than half of those examined. The variants that underlie these hotspots have profound effects on the gene regulatory network and provide insights into genetic variation in cell physiology between yeast strains. PMID:24402228

  18. Genetics of single-cell protein abundance variation in large yeast populations.

    PubMed

    Albert, Frank W; Treusch, Sebastian; Shockley, Arthur H; Bloom, Joshua S; Kruglyak, Leonid

    2014-02-27

    Variation among individuals arises in part from differences in DNA sequences, but the genetic basis for variation in most traits, including common diseases, remains only partly understood. Many DNA variants influence phenotypes by altering the expression level of one or several genes. The effects of such variants can be detected as expression quantitative trait loci (eQTL). Traditional eQTL mapping requires large-scale genotype and gene expression data for each individual in the study sample, which limits sample sizes to hundreds of individuals in both humans and model organisms and reduces statistical power. Consequently, many eQTL are probably missed, especially those with smaller effects. Furthermore, most studies use messenger RNA rather than protein abundance as the measure of gene expression. Studies that have used mass-spectrometry proteomics reported unexpected differences between eQTL and protein QTL (pQTL) for the same genes, but these studies have been even more limited in scope. Here we introduce a powerful method for identifying genetic loci that influence protein expression in the yeast Saccharomyces cerevisiae. We measure single-cell protein abundance through the use of green fluorescent protein tags in very large populations of genetically variable cells, and use pooled sequencing to compare allele frequencies across the genome in thousands of individuals with high versus low protein abundance. We applied this method to 160 genes and detected many more loci per gene than previous studies. We also observed closer correspondence between loci that influence protein abundance and loci that influence mRNA abundance of a given gene. Most loci that we detected were clustered in 'hotspots' that influence multiple proteins, and some hotspots were found to influence more than half of the proteins that we examined. The variants that underlie these hotspots have profound effects on the gene regulatory network and provide insights into genetic variation in cell physiology between yeast strains. PMID:24402228

  19. Genetics of single-cell protein abundance variation in large yeast populations

    NASA Astrophysics Data System (ADS)

    Albert, Frank W.; Treusch, Sebastian; Shockley, Arthur H.; Bloom, Joshua S.; Kruglyak, Leonid

    2014-02-01

    Variation among individuals arises in part from differences in DNA sequences, but the genetic basis for variation in most traits, including common diseases, remains only partly understood. Many DNA variants influence phenotypes by altering the expression level of one or several genes. The effects of such variants can be detected as expression quantitative trait loci (eQTL). Traditional eQTL mapping requires large-scale genotype and gene expression data for each individual in the study sample, which limits sample sizes to hundreds of individuals in both humans and model organisms and reduces statistical power. Consequently, many eQTL are probably missed, especially those with smaller effects. Furthermore, most studies use messenger RNA rather than protein abundance as the measure of gene expression. Studies that have used mass-spectrometry proteomics reported unexpected differences between eQTL and protein QTL (pQTL) for the same genes, but these studies have been even more limited in scope. Here we introduce a powerful method for identifying genetic loci that influence protein expression in the yeast Saccharomyces cerevisiae. We measure single-cell protein abundance through the use of green fluorescent protein tags in very large populations of genetically variable cells, and use pooled sequencing to compare allele frequencies across the genome in thousands of individuals with high versus low protein abundance. We applied this method to 160 genes and detected many more loci per gene than previous studies. We also observed closer correspondence between loci that influence protein abundance and loci that influence mRNA abundance of a given gene. Most loci that we detected were clustered in `hotspots' that influence multiple proteins, and some hotspots were found to influence more than half of the proteins that we examined. The variants that underlie these hotspots have profound effects on the gene regulatory network and provide insights into genetic variation in cell physiology between yeast strains.

  20. Sleep and use of electronic devices in adolescence: results from a large population-based study

    PubMed Central

    Hysing, Mari; Pallesen, Ståle; Stormark, Kjell Morten; Jakobsen, Reidar; Lundervold, Astri J; Sivertsen, Børge

    2015-01-01

    Objectives Adolescents spend increasingly more time on electronic devices, and sleep deficiency rising in adolescents constitutes a major public health concern. The aim of the present study was to investigate daytime screen use and use of electronic devices before bedtime in relation to sleep. Design A large cross-sectional population-based survey study from 2012, the youth@hordaland study, in Hordaland County in Norway. Setting Cross-sectional general community-based study. Participants 9846 adolescents from three age cohorts aged 16–19. The main independent variables were type and frequency of electronic devices at bedtime and hours of screen-time during leisure time. Outcomes Sleep variables calculated based on self-report including bedtime, rise time, time in bed, sleep duration, sleep onset latency and wake after sleep onset. Results Adolescents spent a large amount of time during the day and at bedtime using electronic devices. Daytime and bedtime use of electronic devices were both related to sleep measures, with an increased risk of short sleep duration, long sleep onset latency and increased sleep deficiency. A dose–response relationship emerged between sleep duration and use of electronic devices, exemplified by the association between PC use and risk of less than 5 h of sleep (OR=2.70, 95% CI 2.14 to 3.39), and comparable lower odds for 7–8 h of sleep (OR=1.64, 95% CI 1.38 to 1.96). Conclusions Use of electronic devices is frequent in adolescence, during the day as well as at bedtime. The results demonstrate a negative relation between use of technology and sleep, suggesting that recommendations on healthy media use could include restrictions on electronic devices. PMID:25643702

  1. No Evidence of Causal Effects of Blood Pressure on Cognition in the Population at Large.

    PubMed

    Swagerman, Suzanne C; van Bergen, Elsje; Kan, Kees-Jan; Koenis, Marinka M G; Hulshoff Pol, Hilleke E; Boomsma, Dorret I; de Geus, Eco J C

    2016-02-01

    The large body of literature on the association between blood pressure (BP) and cognitive functioning has yielded mixed results, possibly due to the presence of non-linear effects across age, or because BP affects specific brain areas differently, impacting more on some cognitive skills than on others. If a robust association was detected among BP and specific cognitive tasks, the causal nature of reported associations between BP and cognition could be investigated in twin data, which allow a test of alternative explanations, including genetic pleiotropy. The present study first examines the association between BP and cognition in a sample of 1,140 participants with an age range between 10 and 86 years. Linear and quadratic effects of systolic BP (SBP) and diastolic BP (DBP) on cognitive functioning were examined for 17 tests across five functions. Associations were corrected for effects of sex and linear and quadratic effects of age. Second, to test a causal model, data from 123 monozygotic (MZ) twin pairs were analyzed to test whether cognitive functioning of the twins with the higher BP was different from that of the co-twins with lower BP. Associations between BP and cognitive functioning were absent for the majority of the cognitive tests, with the exception of a lower speed of emotion identification and verbal reasoning in subjects with high diastolic BP. In the MZ twin pair analyses, no effects of BP on cognition were found. We conclude that in the population at large, BP level is not associated with cognitive functioning in a clinically meaningful way. PMID:26810864

  2. Nonprobability Web Surveys to Measure Sexual Behaviors and Attitudes in the General Population: A Comparison With a Probability Sample Interview Survey

    PubMed Central

    Burkill, Sarah; Couper, Mick P; Conrad, Frederick; Clifton, Soazig; Tanton, Clare; Phelps, Andrew; Datta, Jessica; Mercer, Catherine H; Sonnenberg, Pam; Prah, Philip; Mitchell, Kirstin R; Wellings, Kaye; Johnson, Anne M; Copas, Andrew J

    2014-01-01

    Background Nonprobability Web surveys using volunteer panels can provide a relatively cheap and quick alternative to traditional health and epidemiological surveys. However, concerns have been raised about their representativeness. Objective The aim was to compare results from different Web panels with a population-based probability sample survey (n=8969 aged 18-44 years) that used computer-assisted self-interview (CASI) for sensitive behaviors, the third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3). Methods Natsal-3 questions were included on 4 nonprobability Web panel surveys (n=2000 to 2099), 2 using basic quotas based on age and sex, and 2 using modified quotas based on additional variables related to key estimates. Results for sociodemographic characteristics were compared with external benchmarks and for sexual behaviors and opinions with Natsal-3. Odds ratios (ORs) were used to express differences between the benchmark data and each survey for each variable of interest. A summary measure of survey performance was the average absolute OR across variables. Another summary measure was the number of key estimates for which the survey differed significantly (at the 5% level) from the benchmarks. Results For sociodemographic variables, the Web surveys were less representative of the general population than Natsal-3. For example, for men, the average absolute OR for Natsal-3 was 1.14, whereas for the Web surveys the average absolute ORs ranged from 1.86 to 2.30. For all Web surveys, approximately two-thirds of the key estimates of sexual behaviors were different from Natsal-3 and the average absolute ORs ranged from 1.32 to 1.98. Differences were appreciable even for questions asked by CASI in Natsal-3. No single Web survey performed consistently better than any other did. Modified quotas slightly improved results for men, but not for women. Conclusions Consistent with studies from other countries on less sensitive topics, volunteer Web panels provided appreciably biased estimates. The differences seen with Natsal-3 CASI questions, where mode effects may be similar, suggest a selection bias in the Web surveys. The use of more complex quotas may lead to some improvement, but many estimates are still likely to differ. Volunteer Web panels are not recommended if accurate prevalence estimates for the general population are a key objective. PMID:25488851

  3. On the Etiology of Sexual Dysfunction

    ERIC Educational Resources Information Center

    Apfelbaum, Bernard

    1977-01-01

    Lack of consideration of the sexually functional population has led to misconceptions about causes of sexual dysfunction functioning. Automatic functioning can mask effects of pathogenic influences on sexuality, making these effects appear random, confounding etiological issues and creating the belief that causes of sexual dysfunction and disorder…

  4. Sexual competitiveness and compatibility between mass-reared sterile flies and wild populations of Anastrepha Ludens (Diptera: Tephritidae) from different regions in Mexico

    SciTech Connect

    Orozco-Davila, D.; Hernandez, R.; Meza, S.; Dominguez, J.

    2007-03-15

    The mass-reared colony of Anastrepha ludens (Loew) currently used in Mexico for suppression of the Mexican fruit fly has been in use for over 10 years. Sterile flies are released into a wide range of environmental conditions as part of an integrated area-wide approach to suppress diverse populations of this pest in the Mexican Republic. This paper assesses the performance of the sterile flies interacting with wild populations from the different environments. We investigated the sexual compatibility and competitiveness of the sterile flies when competing with wild populations from 6 representatives Mexican states: Nuevo Leon, Tamaulipas, Sinaloa, Nayarit, Michoacan, and Chiapas. Results show that the males of the wild populations differed in the time to the onset and peak of sexual activity. Nevertheless, the index of sexual isolation (ISI) reflected sexual compatibility between the populations and the mass-reared strain, indicating that the sterile individuals mate satisfactorily with the wild populations from the 6 states. The male relative performance index (MRPI) showed that the sterile male is as effective in copulating as the wild males. The female relative performance index (FRPI) reflected a general tendency for wild females to copulate in greater proportion than the sterile females, except for the strains from Tamaulipas and Chiapas. In general, the lower participation of the sterile females in copulation increases the possibilities of sterile males to mate with wild females. The relative sterility index (RSI) showed that the acceptance by wild females of the sterile males (25-55%) was similar to that of wild males. Females of the Chiapas strain showed the lowest acceptance of sterile males. Finally, the results obtained in the Fried test (which measures induced sterility in eggs) showed a competitiveness coefficient ranging from 0.2 to 0.5. This suggests that sterile males successfully compete and are compatible with flies from different geographic origins. (author) [Spanish] La colonia actualmente usada para controlar la mosca mexicana de la fruta, Anastrepha ludens (Loew), en Mexico tiene mas de 10 anos en cria masiva. Los insectos esteriles son liberados en una gran variedad de condiciones ambientales como parte de un control integrado para suprimir diversas poblaciones de esta plaga dentro de la Republica Mexicana. El objetivo de este documento esta dirigido a revisar el desempeno de las moscas esteriles frente a poblaciones silvestres procedentes de diferentes ambientes y para esto se realizaron comparaciones de compatibilidad y competitividad sexual de las moscas esteriles contra poblaciones silvestres de seis estados representativos de la Republica Mexicana: Nuevo Leon, Tamaulipas, Sinaloa, Nayarit, Michoacan y Chiapas. Los resultados obtenidos manifiestan diferencias en el horario de inicio de llamado y mayor actividad sexual del macho entre las moscas provenientes de cada estado. Sin embargo el indice de aislamiento (ISI) reflejo compatibilidad sexual entre la cepa de laboratorio y todas las poblaciones analizadas, indicando que los individuos esteriles pueden aparearse satisfactoriamente con las poblaciones silvestres de los seis estados. El indice de efectividad de apareamiento del macho (MRPI) reflejo de manera global que los machos esteriles son tan efectivos para copular como los silvestres. El indice de efectividad de apareamiento de la hembra (FRPI) reflejo que en la mayoria de los estados las hembras silvestres copularon en mayor proporcion que las hembras esteriles, excepto para las poblaciones de Tamaulipas y Chiapas. En general, la baja participacion de las hembras esteriles en el campo permitio al macho esteril ampliar su probabilidad de apareamiento con las hembras silvestres. En cuanto al indice de esterilidad relativa (RSI), observamos que la aceptacion de las hembras silvestres al macho esteril (25-55%) fue similar a la de los machos silvestres. Las hembras de la poblacion de Chiapas registro la menor aceptacion. Finalmente, los resultados obtenidos en la prueba de Fried, la cual determina la esterilidad inducida presentaron un coeficiente de competitividad entre 0.2 y 0.5. Esto sugiere que los machos esteriles compliten exitosamente y son compatibles con moscas de diferentes origenes geograficos. (author)

  5. A Deployable In Vivo EPR Tooth Dosimeter for Triage After a Radiation Event Involving Large Populations

    PubMed Central

    Williams, Benjamin B.; Dong, Ruhong; Flood, Ann Barry; Grinberg, Oleg; Kmiec, Maciej; Lesniewski, Piotr N.; Matthews, Thomas P.; Nicolalde, Roberto J.; Raynolds, Tim; Salikhov, Ildar K.; Swartz, Harold M.

    2011-01-01

    In order to meet the potential need for emergency large-scale retrospective radiation biodosimetry following an accident or attack, we have developed instrumentation and methodology for in vivo electron paramagnetic resonance spectroscopy to quantify concentrations of radiation-induced radicals within intact teeth. This technique has several very desirable characteristics for triage, including independence from confounding biologic factors, a non-invasive measurement procedure, the capability to make measurements at any time after the event, suitability for use by non-expert operators at the site of an event, and the ability to provide immediate estimates of individual doses. Throughout development there has been a particular focus on the need for a deployable system, including instrumental requirements for transport and field use, the need for high throughput, and use by minimally trained operators. Numerous measurements have been performed using this system in clinical and other non-laboratory settings, including in vivo measurements with unexposed populations as well as patients undergoing radiation therapies. The collection and analyses of sets of three serially-acquired spectra with independent placements of the resonator, in a data collection process lasting approximately five minutes, provides dose estimates with standard errors of prediction of approximately 1 Gy. As an example, measurements were performed on incisor teeth of subjects who had either received no irradiation or 2 Gy total body irradiation for prior bone marrow transplantation; this exercise provided a direct and challenging test of our capability to identify subjects who would be in need of acute medical care. PMID:21966241

  6. A large outbreak of shigellosis commencing in an internally displaced population, Papua New Guinea, 2013

    PubMed Central

    Benny, Edwin; Mesere, Kelly; Pavlin, Boris I; Yakam, Logan; Ford, Rebecca; Yoannes, Mition; Kisa, Debbie; Abdad, Mohammad Y; Menda, Lincoln; Greenhill, Andrew R

    2014-01-01

    Objective The objective of this study was to investigate a large outbreak of shigellosis in Papua New Guinea that began in a camp for internally displaced persons before spreading throughout the general community. Methods Outbreak mitigation strategies were implemented in the affected area to curtail the spread of the disease. Data were collected from the surveillance system and analysed by time, place and person. Rectal swab samples were tested by standard culture methods and real-time polymerase chain reaction to determine the etiology of the outbreak. Results Laboratory analysis at two independent institutions established that the outbreak was caused by Shigella sp., with one strain further characterized as Shigella flexneri serotype 2. Approximately 1200 suspected cases of shigellosis were reported in a two-month period from two townships in Morobe Province, Papua New Guinea. The outbreak resulted in at least five deaths, all in young children. Discussion This outbreak of shigellosis highlights the threat of enteric diseases to vulnerable populations such as internally displaced persons in Papua New Guinea, as has been observed in other global settings. PMID:25648967

  7. Reducing NIR prediction errors with nonlinear methods and large populations of intact compound feedstuffs

    NASA Astrophysics Data System (ADS)

    Fernández-Ahumada, E.; Fearn, T.; Gómez, A.; Vallesquino, P.; Guerrero, J. E.; Pérez-Marín, D.; Garrido-Varo, A.

    2008-08-01

    According to the current demands of the authorities, the manufacturers and the consumers, controls and assessments of the feed compound manufacturing process have become a key concern. Among others, it must be assured that a given compound feed is well manufactured and labelled in terms of the ingredient composition. When near-infrared spectroscopy (NIRS) together with linear models were used for the prediction of the ingredient composition, the results were not always acceptable. Therefore, the performance of nonlinear methods has been investigated. Artificial neural networks and least squares support vector machines (LS-SVM) have been applied to a large (N = 20 320) and heterogeneous population of non-milled feed compounds for the NIR prediction of the inclusion percentage of wheat and sunflower meal, as representative of two different classes of ingredients. Compared to partial least squares regression, results showed considerable reductions of standard error of prediction values for both methods and ingredients: reductions of 45% with ANN and 49% with LS-SVM for wheat and reductions of 44% with ANN and 46% with LS-SVM for sunflower meal. These improvements together with the facility of NIRS technology to be implemented in the process make it ideal for meeting the requirements of the animal feed industry.

  8. The Impact of Sexual Orientation on Sexuality and Sexual Practices in North American Medical Students

    PubMed Central

    Breyer, Benjamin N.; Smith, James F.; Eisenberg, Michael L.; Ando, Kathryn A.; Rowen, Tami S.; Shindel, Alan W.

    2013-01-01

    Introduction There has been limited investigation of the sexuality and sexual dysfunction in non-heterosexual subjects by the sexual medicine community. Additional research in these populations is needed. Aims To investigate and compare sexuality and sexual function in students of varying sexual orientations. Methods An internet-based survey on sexuality was administered to medical students in North American between the months of February and July of 2008. Main Outcome Measures All subjects provided information on their ethnodemographic characteristics, sexual orientation, and sexual history. Subjects also completed a series of widely-utilized instruments for the assessment of human sexuality (International Index of Erectile Function [IIEF], Female Sexual Function Index [FSFI], Premature Ejaculation Diagnostic Tool [PEDT], Index of Sex Life [ISL]). Results There were 2,276 completed responses to the question on sexual orientation. 13.2% of male respondents and 4.7% of female respondents reported a homosexual orientation; 2.5% of male and 5.7% of female respondents reported a bisexual orientation. Many heterosexual males and females reported same-sex sexual experiences (4% and 10%, respectively). Opposite-sex experiences were very common in the male and female homosexual population (37% and 44%, respectively). The prevalence of premature ejaculation (PEDT > 8) was similar among heterosexual and homosexual men (16% and 17%, P = 0.7, respectively). Erectile dysfunction (IIEF-EF < 26) was more common in homosexual men relative to heterosexual men (24% vs. 12%, P = 0.02). High risk for female sexual dysfunction (FSFI < 26.55) was more common in heterosexual and bisexual women compared with lesbians (51%, 45%, and 29%, respectively, P = 0.005). Conclusion In this survey of highly educated young professionals, numerous similarities and some important differences in sexuality and sexual function were noted based on sexual orientation. It is unclear whether the dissimilarities represent differing relative prevalence of sexual problems or discrepancies in patterns of sex behavior and interpretation of the survey questions. PMID:20384941

  9. Population Structure and Dispersal Patterns within and between Atlantic and Mediterranean Populations of a Large-Range Pelagic Seabird

    PubMed Central

    Genovart, Meritxell; Thibault, Jean-Claude; Igual, José Manuel; Bauzà-Ribot, Maria del Mar; Rabouam, Corinne; Bretagnolle, Vincent

    2013-01-01

    Dispersal is critically linked to the demographic and evolutionary trajectories of populations, but in most seabird species it may be difficult to estimate. Using molecular tools, we explored population structure and the spatial dispersal pattern of a highly pelagic but philopatric seabird, the Cory's shearwater Calonectris diomedea. Microsatellite fragments were analysed from samples collected across almost the entire breeding range of the species. To help disentangle the taxonomic status of the two subspecies described, the Atlantic form C. d. borealis and the Mediterranean form C. d. diomedea, we analysed genetic divergence between subspecies and quantified both historical and recent migration rates between the Mediterranean and Atlantic basins. We also searched for evidence of isolation by distance (IBD) and addressed spatial patterns of gene flow. We found a low genetic structure in the Mediterranean basin. Conversely, strong genetic differentiation appeared in the Atlantic basin. Even if the species was mostly philopatric (97%), results suggest recent dispersal between basins, especially from the Atlantic to the Mediterranean (aprox. 10% of migrants/generation across the last two generations). Long-term gene flow analyses also suggested an historical exchange between basins (about 70 breeders/generation). Spatial analysis of genetic variation indicates that distance is not the main factor in shaping genetic structure in this species. Given our results we recommend gathering more data before concluded whether these taxa should be treated as two species or subspecies. PMID:23950986

  10. The Effective Population Size of Malaria Mosquitoes: Large Impact of Vector Control

    PubMed Central

    Athrey, Giridhar; Hodges, Theresa K.; Reddy, Michael R.; Overgaard, Hans J.; Matias, Abrahan; Ridl, Frances C.; Kleinschmidt, Immo; Caccone, Adalgisa; Slotman, Michel A.

    2012-01-01

    Malaria vectors in sub-Saharan Africa have proven themselves very difficult adversaries in the global struggle against malaria. Decades of anti-vector interventions have yielded mixed results—with successful reductions in transmission in some areas and limited impacts in others. These varying successes can be ascribed to a lack of universally effective vector control tools, as well as the development of insecticide resistance in mosquito populations. Understanding the impact of vector control on mosquito populations is crucial for planning new interventions and evaluating existing ones. However, estimates of population size changes in response to control efforts are often inaccurate because of limitations and biases in collection methods. Attempts to evaluate the impact of vector control on mosquito effective population size (Ne) have produced inconclusive results thus far. Therefore, we obtained data for 13–15 microsatellite markers for more than 1,500 mosquitoes representing multiple time points for seven populations of three important vector species—Anopheles gambiae, An. melas, and An. moucheti—in Equatorial Guinea. These populations were exposed to indoor residual spraying or long-lasting insecticidal nets in recent years. For comparison, we also analyzed data from two populations that have no history of organized vector control. We used Approximate Bayesian Computation to reconstruct their demographic history, allowing us to evaluate the impact of these interventions on the effective population size. In six of the seven study populations, vector control had a dramatic impact on the effective population size, reducing Ne between 55%–87%, the exception being a single An. melas population. In contrast, the two negative control populations did not experience a reduction in effective population size. This study is the first to conclusively link anti-vector intervention programs in Africa to sharply reduced effective population sizes of malaria vectors. PMID:23271973

  11. Understanding sexual harassment using aggregate construct models.

    PubMed

    Nye, Christopher D; Brummel, Bradley J; Drasgow, Fritz

    2014-11-01

    Sexual harassment has received a substantial amount of empirical attention over the past few decades, and this research has consistently shown that experiencing these behaviors has a detrimental effect on employees' well-being, job attitudes, and behaviors at work. However, these findings, and the conclusions that are drawn from them, make the implicit assumption that the empirical models used to examine sexual harassment are properly specified. This article presents evidence that properly specified aggregate construct models are more consistent with theoretical structures and definitions of sexual harassment and can result in different conclusions about the nomological network of harassment. Results from 3 large samples, 2 military and 1 from a civilian population, are used to illustrate the differences between aggregate construct and reflective indicator models of sexual harassment. These analyses suggested that the factor structure and the nomological network of sexual harassment differ when modeling harassment as an aggregate construct. The implications of these results for the continued study of sexual harassment are discussed. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:25265486

  12. Teenage Sexuality

    MedlinePlus

    ... Print Share Teenage Sexuality Page Content Article Body Sex and sexuality During this time, many young people ... be ready to have sexual intercourse? Will having sex help my relationship? If I am attracted to ...

  13. Sexual Assault

    MedlinePlus

    Sexual assault is any sexual activity to which you haven't freely given your consent. This includes completed ... trust, a friend, an acquaintance, or a stranger. Sexual assault can affect your health in many ways. It ...

  14. Elderly Sexual Offenders.

    PubMed

    Booth, Brad D

    2016-04-01

    With the ever-aging population, the number of elderly sexual offenders are also on the rise. The courts and correctional system are increasingly faced with older individuals who have offended sexually. Previously, these older offenders were thought to be similar to younger sexual offenders. However, closer analysis suggests that many of these individuals pose a much lower risk to recidivate than the risk to recidivate of their younger counterparts. Still, an individualized approach to manage the risk of older offenders is required, as some may have particular risk factors relevant for their treatment and future stability, such as dementia or other mental health issues. Further, this population often has particular physical health issues and requires special consideration when being placed in the community. Assessment, treatment, and risk management in this special population of sexual offenders are discussed. PMID:26893232

  15. Towards a Sumudu based estimation of large scale disasters environmental fitness changes adversely affecting population dispersal and persistence

    NASA Astrophysics Data System (ADS)

    Belgacem, Fethi Bin Muhammad; Al-Shemas, Eman Hamad Nasser

    2014-12-01

    In this paper, we propose ideas towards the mathematical investigations of the environmental fitness effects on populations dispersal and persistence, following large scale disasters, that are expected to yield mathematical estimates of connected the principal eigenvalue. We propose to characterize a criteria for what is considered a large scale disaster vis a vis a given population. To this end, a sharp drop in environmental fitness leading a population extinction from its given habitat would then be qualitatively be classified as a catastrophic disaster. As an application to our resulting theory, we intend to give qualitative guidelines and quantitative criteria, as to whether it would be feasible or futile, to attempt to bring to persistence a population from the brink of extinction, after a given disaster has gravely affected their natural habitat.

  16. Population.

    ERIC Educational Resources Information Center

    King, Pat; Landahl, John

    This pamphlet has been prepared in response to a new problem, a rapidly increasing population, and a new need, population education. It is designed to help teachers provide their students with some basic population concepts with stress placed on the elements of decision making. In the first section of the pamphlet, some of the basic concepts of…

  17. Comparison of three replication strategies in complex multicellular organisms: Asexual replication, sexual replication with identical gametes, and sexual replication with distinct sperm and egg gametes

    NASA Astrophysics Data System (ADS)

    Tannenbaum, Emmanuel

    2008-01-01

    This paper studies the mutation-selection balance in three simplified replication models. The first model considers a population of organisms replicating via the production of asexual spores. The second model considers a sexually replicating population that produces identical gametes. The third model considers a sexually replicating population that produces distinct sperm and egg gametes. All models assume diploid organisms whose genomes consist of two chromosomes, each of which is taken to be functional if equal to some master sequence, and defective otherwise. In the asexual population, the asexual diploid spores develop directly into adult organisms. In the sexual populations, the haploid gametes enter a haploid pool, where they may fuse with other haploids. The resulting immature diploid organisms then proceed to develop into mature organisms. Based on an analysis of all three models, we find that, as organism size increases, a sexually replicating population can only outcompete an asexually replicating population if the adult organisms produce distinct sperm and egg gametes. A sexual replication strategy that is based on the production of large numbers of sperm cells to fertilize a small number of eggs is found to be necessary in order to maintain a sufficiently low cost for sex for the strategy to be selected for over a purely asexual strategy. We discuss the usefulness of this model in understanding the evolution and maintenance of sexual replication as the preferred replication strategy in complex, multicellular organisms.

  18. The population of X-ray supernova remnants in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Maggi, P.; Haberl, F.; Kavanagh, P. J.; Sasaki, M.; Bozzetto, L. M.; Filipović, M. D.; Vasilopoulos, G.; Pietsch, W.; Points, S. D.; Chu, Y.-H.; Dickel, J.; Ehle, M.; Williams, R.; Greiner, J.

    2016-01-01

    Aims: We present a comprehensive X-ray study of the population of supernova remnants (SNRs) in the Large Magellanic Cloud (LMC). Using primarily XMM-Newton observations, we conduct a systematic spectral analysis of LMC SNRs to gain new insight into their evolution and the interplay with their host galaxy. Methods: We combined all the archival XMM-Newton observations of the LMC with those of our Very Large Programme LMC survey. We produced X-ray images and spectra of 51 SNRs, out of a list of 59 objects compiled from the literature and augmented with newly found objects. Using a careful modelling of the background, we consistently analysed all the X-ray spectra and measure temperatures, luminosities, and chemical compositions. The locations of SNRs are compared to the distributions of stars, cold gas, and warm gas in the LMC, and we investigated the connection between the SNRs and their local environment, characterised by various star formation histories. We tentatively typed all LMC SNRs, in order to constrain the ratio of core-collapse to type Ia SN rates in the LMC. We also compared the column densities derived from X-ray spectra to H i maps, thus probing the three-dimensional structure of the LMC. Results: This work provides the first homogeneous catalogue of the X-ray spectral properties of SNRs in the LMC. It offers a complete census of LMC remnants whose X-ray emission exhibits Fe K lines (13% of the sample), or reveals the contribution from hot supernova ejecta (39%), which both give clues to the progenitor types. The abundances of O, Ne, Mg, Si, and Fe in the hot phase of the LMC interstellar medium are found to be between 0.2 and 0.5 times the solar values with a lower abundance ratio [α/Fe] than in the Milky Way. The current ratio of core-collapse to type Ia SN rates in the LMC is constrained to NCC/NIa=1.35(-0.24+0.11), which is lower than in local SN surveys and galaxy clusters. Our comparison of the X-ray luminosity functions of SNRs in Local Group galaxies (LMC, SMC, M31, and M33) reveals an intriguing excess of bright objects in the LMC. Finally, we confirm that 30 Doradus and the LMC Bar are offset from the main disc of the LMC to the far and near sides, respectively. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.

  19. Sexual Functioning in Men Living with a Spinal Cord Injury–A Narrative Literature Review

    PubMed Central

    Sunilkumar, MM; Boston, Patricia; Rajagopal, MR

    2015-01-01

    Background: Sexual dysfunction is a major concern for Indian men living with a spinal cord injury Objectives: To examine the literature related to sexuality traumatic cord injury and its impact on sexual functioning. Materials and Methods: Databases using Cumulative Index to Nursing and Allied Health Literature (CINAHL) 2000–2012, Medline 1989–2012, Applied Social Sciences Index and Abstracts (ASSIA) 1989–2012 and Google Scholar were the search engines used used for literature review. Results: The search yielded a total of 457 articles and only 75 of them were found relevant. The minimum number of articles required to meet the inclusion criteria for this review was 25–30 articles. Out of the 75 articles, 33 were considered relevant or related to the topic of sexual functioning, spinal cord injury, and paraplegia. Six areas were identified: Sexual stigmatization, physiological barriers to sexual satisfaction, clinical aspects of sexual functioning, biomedical approaches to sexual dysfunction, partner satisfaction, and lack of accessibility to sexual education. Conclusion: Spinal cord injury and sexual functioning affects a large segment of the male Indian population, yet most current research focuses on quantitative measurement with the emphasis on ejaculatory dysfunction, orgasm impairment, incontinence, and other physiological dysfunction. Further research is needed to address the subjective accounts of patients themselves with respect to the emotional and social impact of sexual disability. This would help to identify the best possible outcomes for both treatment and rehabilitation. PMID:26600694

  20. Development and representativeness of a large population-based cohort of native Californian twins.

    PubMed

    Cockburn, M G; Hamilton, A S; Zadnick, J; Cozen, W; Mack, T M

    2001-08-01

    We have established a large cohort of twins to facilitate studies of the role of genetics and environment in the development of disease. The cohort has been derived from all multiple births occurring in California between 1908-82 (256,616 in total). We report here on our efforts to contact these twins and their completion of a detailed 16 page risk factor questionnaire. Addresses of the individuals were obtained by linking the birth records with the California Department of Motor Vehicles (DMV) roster of licensees. To date this has been completed for twins born between 1908 and 1972 (200,589 individuals). The linkage has revealed 112,468 matches and, because of less complete DMV records in some years, was less successful in older females than in younger females and all males. Over 41,000 twins have participated by completing the questionnaire. Based on estimates of numbers of individuals receiving a questionnaire, we estimate our crude response rate to be between 42.2% and 49.6%, highest among females in their 40s (62.8%). We describe the representativeness of the twins in the original birth cohort, those identified by the linkage, and those completing the questionnaire. Compared to the 1990 resident population of California-born resident singletons, the respondents were of similar age, sex, race and residential distribution (for although we were able to locate fewer older females, they had a higher response rate), but were less likely to have been educated for more than 12 years. We provide a brief synopsis of studies nested within this cohort. We also elucidate our plans for expanding the cohort in the near future. PMID:11665304

  1. Ecological risk assessment in a large river-reservoir. 6: Bioindicators of fish population health

    SciTech Connect

    Adams, S.M.; Bevelhimer, M.S.; Greeley, M.S. Jr.; Levine, D.A.; Teh, S.J.

    1999-04-01

    Spatial distribution of contaminants in the sediments and biota of a large reservoir ecosystem were related to a variety of biological responses in fish populations and communities to determine possible relationships between contaminant loading in the environment and fish health. Much of the contaminant inventory in the Clinch River/Watts Bar Reservoir (CR/WBR) system has originated from three US Department of Energy facilities on the Oak Ridge Reservation, which borders this system in its upper reaches. Fish sampled from areas of the CR/WBR system with the highest levels of contaminants in the sediments and biota, primarily mercury and PCBs, had the most dramatic bioindicator responses. The major changes observed were induction of detoxification enzymes, organ dysfunction, increased frequency of histopathological lesions, impaired reproduction, and reduced fish community integrity. Mercury, the dominant contaminant, displayed a decreasing concentration gradient from the upper reaches of Poplar Creek to the lower Clinch River, which was consistent with a downstream gradient in several of the biological responses. A multivariate analysis using all of the individual fish health responses at each site in a discriminant analysis procedure also revealed a downstream gradient in integrated fish health. In Poplar Creek where contaminant concentrations were the highest, statistical correlations were observed between individual bioindicator responses such as contaminant exposure indicators, organ dysfunction, histopathological damage, and reproductive impairment. Relationships between contaminant loading and fish community indices such as species richness and relative abundance, however, were more difficult to establish in Poplar Creek because of the possible dominating influence of food and habitat availability on fish community dynamics. Using a suite of bioindicators that encompass a range of levels of biological organization and response-sensitivity scales improves the probability of identifying cause and effect and helps in distinguishing between natural and anthropogenic sources of stress in aquatic ecosystems.

  2. Prevalence and determinants of white coat effect in a large UK hypertension clinic population.

    PubMed

    Thomas, O; Shipman, K E; Day, K; Thomas, M; Martin, U; Dasgupta, I

    2016-06-01

    White coat hypertension (WCH) is common and termed white coat effect (WCE) in those on treatment for hypertension. The UK guideline suggests that all patients in stage 1 and 2 hypertension, but not stage 3 hypertension, should have ambulatory blood pressure monitoring (ABPM) performed before commencing treatment. The relationship between office blood pressure (BP) and ABPM and the factors that influence the WCE were examined in a large British cohort (n=2056) from 2 hypertension clinics (1998-2011). Data were collected prospectively: the median age was 56 years: 53% were female, 76% Caucasian, 9% African Caribbean, 15% South Asian and 86% taking antihypertensives. Fifty-one percent had WCE and differences between clinic BP and ABPM measurements increased with the stage of hypertension varying from 2/4 (normotensive), 13/10 (stage 1 hypertension), 24/14 (stage 2) and 40/20 mm Hg (stage 3). The degree of difference is greater in this study than described in other populations. A positive correlation was found between clinic systolic and diastolic BP and the WCE (r=0.74 and r=0.56, respectively, P<0.0001). Significant (P<0.05) independent associations of systolic WCE were clinic systolic BP (β=0.707), Caucasian ethnicity (South Asian β=-0.06; African Caribbean β=-0.043), female gender (male β=-0.047), nonsmoking status (smoker β=-0.100) and reduced renal function (estimated glomerular filtration rate β=-0.036). Significant independent associations of diastolic WCH were clinic diastolic BP (β=0.624), age (β=0.207), female gender (male β=-0.104), Caucasian ethnicity (South Asian β=-0.052, African Caribbean β=-0.079) and being a nonsmoker (β=-0.082) or ex-smoker (β=0.046). The results support current UK guidelines but suggest those with stage 3 hypertension would also benefit from ABPM. PMID:26377355

  3. Population Census of a Large Common Tern Colony with a Small Unmanned Aircraft

    PubMed Central

    Chabot, Dominique; Craik, Shawn R.; Bird, David M.

    2015-01-01

    Small unmanned aircraft systems (UAS) may be useful for conducting high-precision, low-disturbance waterbird surveys, but limited data exist on their effectiveness. We evaluated the capacity of a small UAS to census a large (>6,000 nests) coastal Common tern (Sterna hirundo) colony of which ground surveys are particularly disruptive and time-consuming. We compared aerial photographic tern counts to ground nest counts in 45 plots (5-m radius) throughout the colony at three intervals over a nine-day period in order to identify sources of variation and establish a coefficient to estimate nest numbers from UAS surveys. We also compared a full colony ground count to full counts from two UAS surveys conducted the following day. Finally, we compared colony disturbance levels over the course of UAS flights to matched control periods. Linear regressions between aerial and ground counts in plots had very strong correlations in all three comparison periods (R2 = 0.972–0.989, P < 0.001) and regression coefficients ranged from 0.928–0.977 terns/nest. Full colony aerial counts were 93.6% and 94.0%, respectively, of the ground count. Varying visibility of terns with ground cover, weather conditions and image quality, and changing nest attendance rates throughout incubation were likely sources of variation in aerial detection rates. Optimally timed UAS surveys of Common tern colonies following our method should yield population estimates in the 93–96% range of ground counts. Although the terns were initially disturbed by the UAS flying overhead, they rapidly habituated to it. Overall, we found no evidence of sustained disturbance to the colony by the UAS. We encourage colonial waterbird researchers and managers to consider taking advantage of this burgeoning technology. PMID:25874997

  4. Population census of a large common tern colony with a small unmanned aircraft.

    PubMed

    Chabot, Dominique; Craik, Shawn R; Bird, David M

    2015-01-01

    Small unmanned aircraft systems (UAS) may be useful for conducting high-precision, low-disturbance waterbird surveys, but limited data exist on their effectiveness. We evaluated the capacity of a small UAS to census a large (>6,000 nests) coastal Common tern (Sterna hirundo) colony of which ground surveys are particularly disruptive and time-consuming. We compared aerial photographic tern counts to ground nest counts in 45 plots (5-m radius) throughout the colony at three intervals over a nine-day period in order to identify sources of variation and establish a coefficient to estimate nest numbers from UAS surveys. We also compared a full colony ground count to full counts from two UAS surveys conducted the following day. Finally, we compared colony disturbance levels over the course of UAS flights to matched control periods. Linear regressions between aerial and ground counts in plots had very strong correlations in all three comparison periods (R2 = 0.972-0.989, P < 0.001) and regression coefficients ranged from 0.928-0.977 terns/nest. Full colony aerial counts were 93.6% and 94.0%, respectively, of the ground count. Varying visibility of terns with ground cover, weather conditions and image quality, and changing nest attendance rates throughout incubation were likely sources of variation in aerial detection rates. Optimally timed UAS surveys of Common tern colonies following our method should yield population estimates in the 93-96% range of ground counts. Although the terns were initially disturbed by the UAS flying overhead, they rapidly habituated to it. Overall, we found no evidence of sustained disturbance to the colony by the UAS. We encourage colonial waterbird researchers and managers to consider taking advantage of this burgeoning technology. PMID:25874997

  5. [Can we treat sexual addiction ?].

    PubMed

    Inescu Cismaru, A; Andrianne, R; Triffaux, F; Triffaux, J-M

    2013-01-01

    Sexual addiction or sexual dependence is characterized by hypersexuality, impaired regulation of sexual desire and sexual compulsivity, including having sex with uncontrolled excessive frequency (5 to 15 sexual acts per day for more than 6 months, from 15 years old). Between 3% and 6% of the adult population (> or =18 years) would have the characteristics of sexual addiction, disorder prevalent in the male population. The addictive processes affect three behavioral domains : motivation-reward, affect regulation and behavioral inhibition. Sex addiction is usually accompanied by other addictions, such as abuse of drugs or alcohol or sex toys that enhance sexual performance. Psychiatric comorbidities can be found : anxiety disorders, mood disorders. Several forms of treatment have been tried, using medication, cognitive-behavioral therapy and psychotherapy sessions alternated with exposure therapy in virtual reality. In this article, we will discuss the multiple definitions of hypersexuality and the possibilities of therapeutic approaches. PMID:23888589

  6. POPULATION III STAR FORMATION IN LARGE COSMOLOGICAL VOLUMES. I. HALO TEMPORAL AND PHYSICAL ENVIRONMENT

    SciTech Connect

    Crosby, Brian D.; O'Shea, Brian W.; Smith, Britton D.; Turk, Matthew J.; Hahn, Oliver

    2013-08-20

    We present a semi-analytic, computationally inexpensive model to identify halos capable of forming a Population III star in cosmological simulations across a wide range of times and environments. This allows for a much more complete and representative set of Population III star forming halos to be constructed, which will lead to Population III star formation simulations that more accurately reflect the diversity of Population III stars, both in time and halo mass. This model shows that Population III and chemically enriched stars coexist beyond the formation of the first generation of stars in a cosmological simulation until at least z {approx} 10, and likely beyond, though Population III stars form at rates that are 4-6 orders of magnitude lower than chemically enriched stars by z = 10. A catalog of more than 40,000 candidate Population III forming halos were identified, with formation times temporally ranging from z = 30 to z = 10, and ranging in mass from 2.3 Multiplication-Sign 10{sup 5} M{sub Sun} to 1.2 Multiplication-Sign 10{sup 10} M{sub Sun }. At early times, the environment that Population III stars form in is very similar to that of halos hosting chemically enriched star formation. At later times Population III stars are found to form in low-density regions that are not yet chemically polluted due to a lack of previous star formation in the area. Population III star forming halos become increasingly spatially isolated from one another at later times, and are generally closer to halos hosting chemically enriched star formation than to another halo hosting Population III star formation by z {approx} 10.

  7. Men with Sexual Problems and Their Partners: Findings from the International Survey of Relationships.

    PubMed

    Rosen, Raymond C; Heiman, Julia R; Long, J Scott; Fisher, William A; Sand, Michael S

    2016-01-01

    Epidemiologic studies of sexual function problems in men have focused on the individual male and related sociodemographic characteristics, individual risk factors and lifestyle concomitants, or medical comorbidities. Insufficient attention has been given to the role of sexual and relationship satisfaction and, more particularly, to the perspective of the couple as causes or correlates of sexual problems in men or women. Previously, we reported results of the first large, multi-national study of sexual satisfaction and relationship happiness in 1,009 midlife and older couples in five countries (Brazil, Germany, Japan, Spain, U.S.). For the present study, we examined, within each problem, the association of four major sexual problems in men (loss of sexual desire, erectile problems, premature ejaculation, delayed/absent orgasm) and multiple problems, with male and female partners' assessments of physical intimacy, sexual satisfaction, and relationship happiness, as well as associations with well-known health and psychosocial correlates of sexual problems in men. Sexual problem rates of men in our survey were generally similar to rates observed in past surveys in the general population, and similar risk factors (age, relationship duration, overall health) were associated with lack of desire, anorgasmia, or erection difficulties in our sample. As in previous surveys, there were few correlates of premature ejaculation. As predicted, men with one or more sexual problems reported decreased relationship happiness as well as decreased sexual satisfaction compared to men without sexual problems. Moreover, female partners of men with sexual problems had reduced relationship happiness and sexual satisfaction, although these latter outcomes were less affected in the women than the men. The association of men's sexual problems with men's and women's satisfaction and relationship happiness were modest, as these couples in long-term, committed relationships were notable for their relatively high levels of physical affection and relationship happiness. PMID:26228991

  8. Are Sex Drive and Hypersexuality Associated with Pedophilic Interest and Child Sexual Abuse in a Male Community Sample?

    PubMed

    Klein, Verena; Schmidt, Alexander F; Turner, Daniel; Briken, Peer

    2015-01-01

    Although much is currently known about hypersexuality (in the form of excessive sexual behavior) among sexual offenders, the degree to which hypersexual behavior is linked to paraphilic and especially pedophilic interests in non-forensic populations has not been established.The purpose of the present study was to elucidate the associations between total sexual outlets(TSO) and other sex drive indicators, antisocial behavior, pedophilic interests, and sexual offending behavior in a large population-based community sample of males. The sample included 8,718 German men who participated in an online study. Hypersexual behavior as measured by self-reported TSO, self-reported sex drive, criminal history, and pedophilic interests were assessed. In moderated hierarchical logistic regression analyses self-reported contact sexual offending against children was linked to sexual fantasizing about children and anti sociality.There was no association between aggregated sex drive, and sexual abusive behaviour in the multivariate analyses. In contrast, self-reported child pornography consumption was associated with sex drive, sexual fantasies involving children, and anti sociality. Nevertheless, in convicted sexual offenders anti sociality, sexual preoccupation (like hypersexuality), and pedophilic interest are important predictors of sexual reoffending against prepubescent children.Therefore, in clinical practice an assessment of criminal history and pedophilic interests in hypersexual individuals and vice versa hypersexuality in antisocial or pedophilic men should be considered [corrected]. PMID:26147099

  9. Multivariate sexual selection in a rapidly evolving speciation phenotype.

    PubMed

    Oh, Kevin P; Shaw, Kerry L

    2013-06-22

    Estimating the fitness surface of rapidly evolving secondary sexual traits can elucidate the origins of sexual isolation and thus speciation. Evidence suggests that sexual selection is highly complex in nature, often acting on multivariate sexual characters that sometimes include non-heritable components of variation, thus presenting a challenge for predicting patterns of sexual trait evolution. Laupala crickets have undergone an explosive species radiation marked by divergence in male courtship song and associated female preferences, yet patterns of sexual selection that might explain this diversification remain unknown. We used female phonotaxis trials to estimate the fitness surface for acoustic characters within one population of Laupala cerasina, a species with marked geographical variation in male song and female preferences. Results suggested significant directional sexual selection on three major song traits, while canonical rotation of the matrix of nonlinear selection coefficients (γ) revealed the presence of significant convex (stabilizing) sexual selection along combinations of characters. Analysis of song variation within and among males indicated significantly higher repeatability along the canonical axis of greatest stabilizing selection than along the axis of greatest linear selection. These results are largely consistent with patterns of song divergence that characterize speciation and suggest that different song characters have the potential to indicate distinct information to females during courtship. PMID:23760640

  10. Multivariate sexual selection in a rapidly evolving speciation phenotype

    PubMed Central

    Oh, Kevin P.; Shaw, Kerry L.

    2013-01-01

    Estimating the fitness surface of rapidly evolving secondary sexual traits can elucidate the origins of sexual isolation and thus speciation. Evidence suggests that sexual selection is highly complex in nature, often acting on multivariate sexual characters that sometimes include non-heritable components of variation, thus presenting a challenge for predicting patterns of sexual trait evolution. Laupala crickets have undergone an explosive species radiation marked by divergence in male courtship song and associated female preferences, yet patterns of sexual selection that might explain this diversification remain unknown. We used female phonotaxis trials to estimate the fitness surface for acoustic characters within one population of Laupala cerasina, a species with marked geographical variation in male song and female preferences. Results suggested significant directional sexual selection on three major song traits, while canonical rotation of the matrix of nonlinear selection coefficients (γ) revealed the presence of significant convex (stabilizing) sexual selection along combinations of characters. Analysis of song variation within and among males indicated significantly higher repeatability along the canonical axis of greatest stabilizing selection than along the axis of greatest linear selection. These results are largely consistent with patterns of song divergence that characterize speciation and suggest that different song characters have the potential to indicate distinct information to females during courtship. PMID:23760640

  11. The Relationship between Parental Opinion of School-Based Sex Education, Parent-Child Communication about Sexuality, and Parenting Styles in a Diverse Urban Community College Population

    ERIC Educational Resources Information Center

    Heller, Janet

    2009-01-01

    One hundred and ninety-one parents attending an urban, community college were surveyed about what topics schools should teach their children about sexuality education, and how they communicate with their child about sexuality topics. The quantitative data was collected using a "School Sexuality Education Questionnaire" (SSEQ), and the "Parenting…

  12. The Relationship between Parental Opinion of School-Based Sex Education, Parent-Child Communication about Sexuality, and Parenting Styles in a Diverse Urban Community College Population

    ERIC Educational Resources Information Center

    Heller, Janet

    2009-01-01

    One hundred and ninety-one parents attending an urban, community college were surveyed about what topics schools should teach their children about sexuality education, and how they communicate with their child about sexuality topics. The quantitative data was collected using a "School Sexuality Education Questionnaire" (SSEQ), and the "Parenting

  13. Waterscape genetics of the yellow perch (Perca flavescens): patterns across large connected ecosystems and isolated relict populations.

    PubMed

    Sepulveda-Villet, Osvaldo J; Stepien, Carol A

    2012-12-01

    Comparisons of a species' genetic diversity and divergence patterns across large connected populations vs. isolated relict areas provide important data for understanding potential response to global warming, habitat alterations and other perturbations. Aquatic taxa offer ideal case studies for interpreting these patterns, because their dispersal and gene flow often are constrained through narrow connectivity channels that have changed over geological time and/or from contemporary anthropogenic perturbations. Our research objective is to better understand the interplay between historic influences and modern-day factors (fishery exploitation, stocking supplementation and habitat loss) in shaping population genetic patterns of the yellow perch Perca flavescens (Percidae: Teleostei) across its native North American range. We employ a modified landscape genetics approach, analysing sequences from the entire mitochondrial DNA control region and 15 nuclear DNA microsatellite loci of 664 spawning adults from 24 populations. Results support that perch from primary glacial refugium areas (Missourian, Mississippian and Atlantic) founded contemporary northern populations. Genetic diversity today is highest in southern (never glaciated) populations and also is appreciable in northern areas that were founded from multiple refugia. Divergence is greater among isolated populations, both north and south; the southern Gulf Coast relict populations are the most divergent, reflecting their long history of isolation. Understanding the influence of past and current waterway connections on the genetic structure of yellow perch populations may help us to assess the roles of ongoing climate change and habitat disruptions towards conserving aquatic biodiversity. PMID:23078285

  14. Population Genetics of Two Asexually and Sexually Reproducing Psocids Species Inferred by the Analysis of Mitochondrial and Nuclear DNA Sequences

    PubMed Central

    Wei, Dan-Dan; Yuan, Ming-Long; Wang, Bao-Jun; Zhou, An-Wei; Dou, Wei; Wang, Jin-Jun

    2012-01-01

    Background The psocids Liposcelis bostrychophila and L. entomophila (Psocoptera: Liposcelididae) are found throughout the world and are often associated with humans, food stores and habitations. These insects have developed high levels of resistance to various insecticides in grain storage systems. However, the population genetic structure and gene flow of psocids has not been well categorized, which is helpful to plan appropriate strategies for the control of these pests. Methodology/Principal Findings The two species were sampled from 15 localities in China and analyzed for polymorphisms at the mitochondrial DNA (Cytb) and ITS (ITS1-5.8S-ITS2) regions. In total, 177 individual L. bostrychophila and 272 individual L. entomophila were analysed. Both Cytb and ITS sequences showed high genetic diversity for the two species with haplotype diversities ranged from 0.154±0.126 to 1.000±0.045, and significant population differentiation (mean FST = 0.358 for L. bostrychophila; mean FST = 0.336 for L. entomophila) was also detected among populations investigated. A Mantel test indicated that for both species there was no evidence for isolation-by-distance (IBD). The neutrality test and mismatch distribution statistics revealed that the two species might have undergone population expansions in the past. Conclusion Both L. bostrychophila and L. entomophila displayed high genetic diversity and widespread population genetic differentiation within and between populations. The significant population differentiation detected for both psocids may be mainly due to other factors, such as genetic drift, inbreeding or control practices, and less by geographic distance since an IBD effect was not found. PMID:22479465

  15. A Large Plasmodium vivax Reservoir and Little Population Structure in the South Pacific

    PubMed Central

    Koepfli, Cristian; Timinao, Lincoln; Antao, Tiago; Barry, Alyssa E.; Siba, Peter; Mueller, Ivo; Felger, Ingrid

    2013-01-01

    Introduction The importance of Plasmodium vivax in malaria elimination is increasingly being recognized, yet little is known about its population size and population genetic structure in the South Pacific, an area that is the focus of intensified malaria control. Methods We have genotyped 13 microsatellite markers in 295 P. vivax isolates from four geographically distinct sites in Papua New Guinea (PNG) and one site from Solomon Islands, representing different transmission intensities. Results Diversity was very high with expected heterozygosity values ranging from 0.62 to 0.98 for the different markers. Effective population size was high (12′872 to 19′533 per site). In PNG population structuring was limited with moderate levels of genetic differentiation. FST values (adjusted for high diversity of markers) were 0.14–0.15. Slightly higher levels were observed between PNG populations and Solomon Islands (FST = 0.16). Conclusions Low levels of population structure despite geographical barriers to transmission are in sharp contrast to results from regions of low P. vivax endemicity. Prior to intensification of malaria control programs in the study area, parasite diversity and effective population size remained high. PMID:23823758

  16. Disentangling the effects of climate, density dependence, and harvest on an iconic large herbivore's population dynamics.

    PubMed

    Koons, David N; Colchero, Fernando; Hersey, Kent; Gimenez, Olivier

    2015-06-01

    Understanding the relative effects of climate, harvest, and density dependence on population dynamics is critical for guiding sound population management, especially for ungulates in arid and semiarid environments experiencing climate change. To address these issues for bison in southern Utah, USA, we applied a Bayesian state-space model to a 72-yr time series of abundance counts. While accounting for known harvest (as well as live removal) from the population, we found that the bison population in southern Utah exhibited a strong potential to grow from low density (β0 = 0.26; Bayesian credible interval based on 95% of the highest posterior density [BCI] = 0.19-0.33), and weak but statistically significant density dependence (β1 = -0.02, BCI = -0.04 to -0.004). Early spring temperatures also had strong positive effects on population growth (Pfat1 = 0.09, BCI = 0.04-0.14), much more so than precipitation and other temperature-related variables (model weight > three times more than that for other climate variables). Although we hypothesized that harvest is the primary driving force of bison population dynamics in southern Utah, our elasticity analysis indicated that changes in early spring temperature could have a greater relative effect on equilibrium abundance than either harvest or. the strength of density dependence. Our findings highlight the utility of incorporating elasticity analyses into state-space population models, and the need to include climatic processes in wildlife management policies and planning. PMID:26465036

  17. Phylogeography of competing sexual and parthenogenetic forms of a freshwater flatworm: patterns and explanations

    PubMed Central

    Pongratz, Norbert; Storhas, Martin; Carranza, Salvador; Michiels, Nicolaas K

    2003-01-01

    Background Models of the maintenance of sex predict that one reproductive strategy, sexual or parthenogenetic, should outcompete the other. Distribution patterns may reflect the outcome of this competition as well as the effect of chance and historical events. We review the distribution data of sexual and parthenogenetic biotypes of the planarian Schmidtea polychroa. Results S. polychroa lives in allopatry or sympatry across Europe except for Central and North-Western Europe, where sexual individuals have never been reported. A phylogenetic relationship between 36 populations based on a 385 bp fragment of the mitochondrial cytochrome oxidase I gene revealed that haplotypes were often similar over large geographic distances. In North Italian lakes, however, diversity was extreme, with sequence differences of up to 5% within the same lake in both sexuals and parthenogens. Mixed populations showed "endemic" parthenogenetic lineages that presumably originated from coexisting sexuals, and distantly related ones that probably result from colonization by parthenogens independent from sexuals. Conclusions Parthenogens originated repeatedly from sexuals, mainly in Italy, but the same may apply to other Mediterranean regions (Spain, Greece). The degree of divergence between populations suggests that S. polychroa survived the ice ages in separate ice-free areas in Central, Eastern and Southern Europe and re-colonised Europe after the retreat of the major glaciers. Combining these results with those based on nuclear markers, the data suggest that repeated hybridisation between sexuals and parthenogenetic lineages in mixed populations maintains high levels of genetic diversity in parthenogens. This can explain why parthenogens persist in populations that were originally sexual. Exclusive parthenogenesis in central and western populations suggests better colonisation capacity, possibly because of inbreeding costs as well as hybridisation of sexuals with parthenogens. PMID:14622447

  18. Delayed sleep phase syndrome in adolescents: prevalence and correlates in a large population based study

    PubMed Central

    2013-01-01

    Background The aims of this study were to estimate the prevalence of Delayed Sleep Phase Syndrome (DSPS) in adolescence, and to examine the association to insomnia and school non-attendance. Methods Data stem from a large population based study in Hordaland County in Norway conducted in 2012, the ung@hordaland study. In all, 10,220 adolescents aged 16–18 years (54% girls) provided self-reported data on a range of sleep parameters: DSPS was defined according to the International Classification of Sleep Disorders, Revised (ICSD-R) criteria, while insomnia was defined according to the Quantitative Criteria for Insomnia. Other sleep parameters included time in bed, sleep duration, sleep efficiency, oversleeping, sleep onset latency, wake after sleep onset, subjective sleep need, sleep deficiency, sleepiness and tiredness. Sleep data were calculated separately for weekdays and weekends. Data on school non-attendance were provided by official registers. Results The prevalence of DSPS was 3.3%, and significantly higher among girls (3.7%) than boys (2.7%). There was a strong overlap between DSPS and insomnia, with more than half of the adolescents with DSPS also meeting the criteria for insomnia (53.8% for boys and 57.1% for girls). Adolescents with DSPS had significantly higher odds ratios (OR) of non-attendance at school. After adjusting for sociodeographical factors, insomnia and depression, the adjusted ORs for days of non-attendance were OR = 3.22 (95% CI: 1.94-5.34) for boys and OR = 1.87 (95% CI: 1.25-2.80) for girls. A similar effect was found for hours of non-attendance for boys, with an adjusted OR = 3.05 (95% CI: 1.89-4.92). The effect for girls was no longer significant after full adjustment (OR =1.48 [95% CI: 0.94-2.32]). Conclusions This is one of the first studies to estimate the prevalence of DSPS in adolescents. The high prevalence of DSPS, and overlap with insomnia, in combination with the odds of school non-attendance, suggest that a broad and thorough clinical approach is warranted when adolescents present with symptoms of DSPS. PMID:24330358

  19. Diurnal fluctuations in brain volume: Statistical analyses of MRI from large populations.

    PubMed

    Nakamura, Kunio; Brown, Robert A; Narayanan, Sridar; Collins, D Louis; Arnold, Douglas L

    2015-09-01

    We investigated fluctuations in brain volume throughout the day using statistical modeling of magnetic resonance imaging (MRI) from large populations. We applied fully automated image analysis software to measure the brain parenchymal fraction (BPF), defined as the ratio of the brain parenchymal volume and intracranial volume, thus accounting for variations in head size. The MRI data came from serial scans of multiple sclerosis (MS) patients in clinical trials (n=755, 3269 scans) and from subjects participating in the Alzheimer's Disease Neuroimaging Initiative (ADNI, n=834, 6114 scans). The percent change in BPF was modeled with a linear mixed effect (LME) model, and the model was applied separately to the MS and ADNI datasets. The LME model for the MS datasets included random subject effects (intercept and slope over time) and fixed effects for the time-of-day, time from the baseline scan, and trial, which accounted for trial-related effects (for example, different inclusion criteria and imaging protocol). The model for ADNI additionally included the demographics (baseline age, sex, subject type [normal, mild cognitive impairment, or Alzheimer's disease], and interaction between subject type and time from baseline). There was a statistically significant effect of time-of-day on the BPF change in MS clinical trial datasets (-0.180 per day, that is, 0.180% of intracranial volume, p=0.019) as well as the ADNI dataset (-0.438 per day, that is, 0.438% of intracranial volume, p<0.0001), showing that the brain volume is greater in the morning. Linearly correcting the BPF values with the time-of-day reduced the required sample size to detect a 25% treatment effect (80% power and 0.05 significance level) on change in brain volume from 2 time-points over a period of 1year by 2.6%. Our results have significant implications for future brain volumetric studies, suggesting that there is a potential acquisition time bias that should be randomized or statistically controlled to account for the day-to-day brain volume fluctuations. PMID:26049148

  20. Injecting drug use, sexual risk, HIV knowledge and harm reduction uptake in a large prison in Bali, Indonesia.

    PubMed

    Sawitri, Anak Agung Sagung; Hartawan, Anak Agung Gede; Craine, Noel; Sari, Ayu Kartika; Septarini, Ni Wayan; Wirawan, Dewa Nyoman

    2016-03-14

    Purpose - The purpose of this paper is to describe HIV-related risk behavior and knowledge of HIV among inmates of Kerobokan prison Bali, Indonesia. Design/methodology/approach - A cross-sectional survey of inmates of using a structured questionnaire and sample framework to reflect narcotic use among inmates and the prison gender mix. Findings - Among 230 inmates recruited to the study self-reported prevalence of injecting drug use was 7.4 percent (95 percent CI 4.0-10.8percent). Respondents who participated in a prison based methadone treatment program were all still injecting drugs, these made up 13/17 of the IDU. In total, 47 percent (95 percent CIs 45-55 percent) of respondents who reported injecting also reported sharing needles within the last week. Sexual intercourse while in prison was reported by 3.0 percent (95 percent CI 0.82-5.26 percent) of study respondents. One-third of non-injectors were unaware of the preventative role of condom use. This study suggests that despite harm reduction initiatives within Kerobokan prison HIV risk behavior continues and there is a considerable lack of awareness of the importance of condom use in preventing HIV. Research limitations/implications - The authors relied on self-reported risk behavior that may be subject to reporting bias. The sampling strategy may not reflect the true ratio inmates using or not using narcotics. Practical implications - The current harm reduction approach, including methadone substitution treatment should be optimized within the Indonesian prison setting. Originality/value - This is the first study reporting HIV-related risk behavior from an Indonesian prison with an established methadone substitution program. PMID:26933990

  1. Self-reported and agency-notified child sexual abuse in a population-based birth cohort.

    PubMed

    Mills, Ryan; Kisely, Steve; Alati, Rosa; Strathearn, Lane; Najman, Jake

    2016-03-01

    Child sexual abuse (CSA) has been associated with many adverse psychiatric outcomes. However, most studies have relied on retrospective self-report of exposure to CSA. We set out to investigate the incidence of CSA in the same birth cohort using both retrospective self-report and prospective government agency notification, and examine the psychological outcomes in young adulthood. The primary outcomes were measures of DSM-IV diagnoses (CIDI-Auto) at age 21. The 21-year retrospective CSA questions were completed by 3739 participants. CSA was self-reported by 19.3% of males and 30.6% of females. After adjustment for potential confounders, both self-reported and agency-notified CSA were associated with increased odds of lifetime major depressive disorder (MDD), anxiety disorders, and posttraumatic stress disorder (PTSD). For the first time in a birth cohort, this study has shown the disparity between the incidence of CSA when measured by self-report and government agency notification. Despite this discrepancy, adverse psychiatric outcomes are seen when CSA is defined using either method. PMID:26774419

  2. Dynamics of an emerging disease drive large-scale amphibian population extinctions.

    PubMed

    Vredenburg, Vance T; Knapp, Roland A; Tunstall, Tate S; Briggs, Cheryl J

    2010-05-25

    Epidemiological theory generally suggests that pathogens will not cause host extinctions because the pathogen should fade out when the host population is driven below some threshold density. An emerging infectious disease, chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is directly linked to the recent extinction or serious decline of hundreds of amphibian species. Despite continued spread of this pathogen into uninfected areas, the dynamics of the host-pathogen interaction remain unknown. We use fine-scale spatiotemporal data to describe (i) the invasion and spread of Bd through three lake basins, each containing multiple populations of the mountain yellow-legged frog, and (ii) the accompanying host-pathogen dynamics. Despite intensive sampling, Bd was not detected on frogs in study basins until just before epidemics began. Following Bd arrival in a basin, the disease spread to neighboring populations at approximately 700 m/yr in a wave-like pattern until all populations were infected. Within a population, infection prevalence rapidly reached 100% and infection intensity on individual frogs increased in parallel. Frog mass mortality began only when infection intensity reached a critical threshold and repeatedly led to extinction of populations. Our results indicate that the high growth rate and virulence of Bd allow the near-simultaneous infection and buildup of high infection intensities in all host individuals; subsequent host population crashes therefore occur before Bd is limited by density-dependent factors. Preventing infection intensities in host populations from reaching this threshold could provide an effective strategy to avoid the extinction of susceptible amphibian species in the wild. PMID:20457913

  3. Population.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    In an effort to help meet the growing interest and concern about the problems created by the rapid growth of population, The International Planned Parenthood Federation has prepared this booklet with the aim of assisting the study of the history and future trends of population growth and its impact on individual and family welfare, national,…

  4. NASA Orbital Debris Large-Object Baseline Population in ORDEM 3.0

    NASA Technical Reports Server (NTRS)

    Krisco, Paula H.; Vavrin, A. B.; Anz-Meador, P. D.

    2013-01-01

    The NASA Orbital Debris Program Office (ODPO) has created and validated high fidelity populations of the debris environment for the latest Orbital Debris Engineering Model (ORDEM 3.0). Though the model includes fluxes of objects 10 um and larger, this paper considers particle fluxes for 1 cm and larger debris objects from low Earth orbit (LEO) through Geosynchronous Transfer Orbit (GTO). These are validated by several reliable radar observations through the Space Surveillance Network (SSN), Haystack, and HAX radars. ORDEM 3.0 populations were designed for the purpose of assisting, debris researchers and sensor developers in planning and testing. This environment includes a background derived from the LEO-to-GEO ENvironment Debris evolutionary model (LEGEND) with a Bayesian rescaling as well as specific events such as the FY-1C anti-satellite test, the Iridium 33/Cosmos 2251 accidental collision, and the Soviet/Russian Radar Ocean Reconnaissance Satellite (RORSAT) sodium-potassium droplet releases. The environment described in this paper is the most realistic orbital debris population larger than 1 cm, to date. We describe derivations of the background population and added specific populations. We present sample validation charts of our 1 cm and larger LEO population against Space Surveillance Network (SSN), Haystack, and HAX radar measurements.

  5. Prime time sexual harrassment.

    PubMed

    Grauerholz, E; King, A

    1997-04-01

    This study explores the explicit and implicit messages of sexual harassment that viewers receive when viewing prime-time television in the US. A content analysis of 48 hours of prime-time television reveals that sexual harassment on television is both highly visible and invisible. Sexual harassment is rendered visible simply by its prominence in these programs. Incidents involving quid-pro-quo harassment and environmental harassment occur with regularity on television. Furthermore, about 84% of the shows studied contained at least one incident of sexual harassment; yet these acts of sexual harassment remained largely invisible because none of the behaviors were labeled as sexual harassment. These incidents are presented in humorous ways, and victims are generally unharmed and very effective at ending the harassment. Although such programs may actually reflect the reality of many women's lives in terms of prevalence of sexual harassment, they perpetuate several myths about sexual harassment, such as that sexual harassment is not serious and that victims should be able to handle the situations themselves. PMID:12294811

  6. Determinants of young people's sexual behaviour concerning HIV and AIDS in the practice population of a university health centre in Lagos, Nigeria

    PubMed Central

    Odusote, Kofo; Omoegun, Mopelola O.; Ofoha, Victoria; Adedokun, Ayoade; Abiola, Kehinde O.

    2011-01-01

    Abstract Background AIDS has been a scourge of universities in Africa for a long time. This study was launched at ground-level to fight the dreaded disease by concentrating on young people and to counter the ignorance that surrounds the disease even in numerous African universities. This study of the student community was carried out by family doctors at the University Health Department to determine the prevalence of the determinants of young people's reproductive health behaviour. Objectives This study is aimed at determining young people's sexual behaviour concerning HIV and AIDS in the practice population of a university in Lagos, Nigeria. Method Self-administered 63-item questionnaires were distributed amongst 2000 randomly selected students of the University of Lagos, Lagos, Nigeria in September 2005, using a semi-structured form of the Comprehensive Youth Survey questionnaire, developed by FOCUS (led by Pathfinder International, Futures Group International and Tulane University School of Public Health). Results The age distribution of the respondents was designated in the age groups of 15–19 years (15.8%), 20–24 years (60.1%), 25–29 years (19.6%), 30–34 years (2.8%). Demographics of note were that 88.3% of the fathers of the respondents were literate and that 94.5% of the fathers earned more than one US $ per day. The majority of the respondents (99.1%) indicated adherence to one religious faith or the other and 58.8% believed definitely that religion shaped their attitudes about sexual intercourse and sexuality. More than half (64.0%) denied having had sex at all in the three months preceding the study. Furthermore, 68.8% affirmed that it was common amongst friends of their age to use condoms. A significant number of respondents (65.5%) thought that their friends have drunken alcohol. Almost all of the respondents (94.3%) had a positive perception of their family. Conclusion The Programming for HIV and AIDS Reduction on university campuses in Africa should be conducted comprehensively rather than monothematically and should, take into consideration the five thematic areas of behaviour change communication amongst young people concerning their reproductive health.

  7. Evolution and human sexuality.

    PubMed

    Gray, Peter B

    2013-12-01

    The aim of this review is to put core features of human sexuality in an evolutionary light. Toward that end, I address five topics concerning the evolution of human sexuality. First, I address theoretical foundations, including recent critiques and developments. While much traces back to Darwin and his view of sexual selection, more recent work helps refine the theoretical bases to sex differences and life history allocations to mating effort. Second, I consider central models attempting to specify the phylogenetic details regarding how hominin sexuality might have changed, with most of those models honing in on transitions from a possible chimpanzee-like ancestor to the slightly polygynous and long-term bonded sociosexual partnerships observed among most recently studied hunter-gatherers. Third, I address recent genetic and physiological data contributing to a refined understanding of human sexuality. As examples, the availability of rapidly increasing genomic information aids comparative approaches to discern signals of selection in sexuality-related phenotypes, and neuroendocrine studies of human responses to sexual stimuli provide insight into homologous and derived mechanisms. Fourth, I consider some of the most recent, large, and rigorous studies of human sexuality. These provide insights into sexual behavior across other national samples and on the Internet. Fifth, I discuss the relevance of a life course perspective to understanding the evolution of human sexuality. Most research on the evolution of human sexuality focuses on young adults. Yet humans are sexual beings from gestation to death, albeit in different ways across the life course, and in ways that can be theoretically couched within life history theory. PMID:24151100

  8. The impact of climate change on the bottom up regulation of density dependence in large herbivore populations

    NASA Astrophysics Data System (ADS)

    Ahrestani, F.; Smith, W. A.; Hebblewhite, M.; Running, S. W.; Post, E.

    2013-12-01

    Population dynamics are regulated by either density dependent or, independent (environmental) factors, and climate change may influence populations through either pathway. One key factor in the population dynamics of large herbivores is the dynamics of vegetation nutrient content, which although being an environmental factor, has the potential to impact the degree of density dependence that regulates population dynamics. To understand this bottom up regulatory mechanism and how climate interacts with vegetation, we will estimate the influence of vegetation dynamics on annual abundance estimates of multiple vertebrate populations using time-series analysis. We will test the hypothesis that the strength of density dependence is expected to vary inversely with changes in vegetation availability, i.e., in areas with higher forage abundance and quality, density dependence is expected to be stronger. Extended to climate change, this hypothesis predicts that climate impacts will be stronger in areas of low vegetation availability, such as the arctic and alpine regions. We will analyze a combined dataset of 55 globally distributed Cervus (elk/red deer) and Rangifer (caribou/reindeer) populations that inhabit areas >100km2. These population time-series we will be analyzed using Markov Chain Monte Carlo Bayesian state-space models, and to represent annual vegetation dynamics we will use Global Inventory Monitoring and Modeling System (GIMMS) normalized difference vegetation index (NDVI) data (i.e., third generation GIMMS NDVI from AVHRR sensors).

  9. Shell productivity of the large benthic foraminifer Baculogypsina sphaerulata, based on the population dynamics in a tropical reef environment

    NASA Astrophysics Data System (ADS)

    Fujita, Kazuhiko; Otomaru, Maki; Lopati, Paeniu; Hosono, Takashi; Kayanne, Hajime

    2016-03-01

    Carbonate production by large benthic foraminifers is sometimes comparable to that of corals and coralline algae, and contributes to sedimentation on reef islands and beaches in the tropical Pacific. Population dynamic data, such as population density and size structure (size-frequency distribution), are vital for an accurate estimation of shell production of foraminifers. However, previous production estimates in tropical environments were based on a limited sampling period with no consideration of seasonality. In addition, no comparisons were made of various estimation methods to determine more accurate estimates. Here we present the annual gross shell production rate of Baculogypsina sphaerulata, estimated based on population dynamics studied over a 2-yr period on an ocean reef flat of Funafuti Atoll (Tuvalu, tropical South Pacific). The population density of B. sphaerulata increased from January to March, when northwest winds predominated and the study site was on the leeward side of reef islands, compared to other seasons when southeast trade winds predominated and the study site was on the windward side. This result suggested that wind-driven flows controlled the population density at the study site. The B. sphaerulata population had a relatively stationary size-frequency distribution throughout the study period, indicating no definite intensive reproductive period in the tropical population. Four methods were applied to estimate the annual gross shell production rates of B. sphaerulata. The production rates estimated by three of the four methods (using monthly biomass, life tables and growth increment rates) were in the order of hundreds of g CaCO3 m-2 yr-1 or cm-3 m-2 yr-1, and the simple method using turnover rates overestimated the values. This study suggests that seasonal surveys should be undertaken of population density and size structure as these can produce more accurate estimates of shell productivity of large benthic foraminifers.

  10. Large-scale structure of brown rat (Rattus norvegicus) populations in England: effects on rodenticide resistance

    PubMed Central

    Haniza, Mohd Z.H.; Adams, Sally; Jones, Eleanor P.; MacNicoll, Alan; Mallon, Eamonn B.; Smith, Robert H.

    2015-01-01

    The brown rat (Rattus norvegicus) is a relatively recent (<300 years) addition to the British fauna, but by association with negative impacts on public health, animal health and agriculture, it is regarded as one of the most important vertebrate pest species. Anticoagulant rodenticides were introduced for brown rat control in the 1950s and are widely used for rat control in the UK, but long-standing resistance has been linked to control failures in some regions. One thus far ignored aspect of resistance biology is the population structure of the brown rat. This paper investigates the role population structure has on the development of anticoagulant resistance. Using mitochondrial and microsatellite DNA, we examined 186 individuals (from 15 counties in England and one location in Wales near the Wales–England border) to investigate the population structure of rural brown rat populations. We also examined individual rats for variations of the VKORC1 gene previously associated with resistance to anticoagulant rodenticides. We show that the populations were structured to some degree, but that this was only apparent in the microsatellite data and not the mtDNA data. We discuss various reasons why this is the case. We show that the population as a whole appears not to be at equilibrium. The relative lack of diversity in the mtDNA sequences examined can be explained by founder effects and a subsequent spatial expansion of a species introduced to the UK relatively recently. We found there was a geographical distribution of resistance mutations, and relatively low rate of gene flow between populations, which has implications for the development and management of anticoagulant resistance. PMID:26664802

  11. Large-scale structure of brown rat (Rattus norvegicus) populations in England: effects on rodenticide resistance.

    PubMed

    Haniza, Mohd Z H; Adams, Sally; Jones, Eleanor P; MacNicoll, Alan; Mallon, Eamonn B; Smith, Robert H; Lambert, Mark S

    2015-01-01

    The brown rat (Rattus norvegicus) is a relatively recent (<300 years) addition to the British fauna, but by association with negative impacts on public health, animal health and agriculture, it is regarded as one of the most important vertebrate pest species. Anticoagulant rodenticides were introduced for brown rat control in the 1950s and are widely used for rat control in the UK, but long-standing resistance has been linked to control failures in some regions. One thus far ignored aspect of resistance biology is the population structure of the brown rat. This paper investigates the role population structure has on the development of anticoagulant resistance. Using mitochondrial and microsatellite DNA, we examined 186 individuals (from 15 counties in England and one location in Wales near the Wales-England border) to investigate the population structure of rural brown rat populations. We also examined individual rats for variations of the VKORC1 gene previously associated with resistance to anticoagulant rodenticides. We show that the populations were structured to some degree, but that this was only apparent in the microsatellite data and not the mtDNA data. We discuss various reasons why this is the case. We show that the population as a whole appears not to be at equilibrium. The relative lack of diversity in the mtDNA sequences examined can be explained by founder effects and a subsequent spatial expansion of a species introduced to the UK relatively recently. We found there was a geographical distribution of resistance mutations, and relatively low rate of gene flow between populations, which has implications for the development and management of anticoagulant resistance. PMID:26664802

  12. Polymorphism analysis of 15 STR loci in a large sample of Guangdong (Southern China) Han population.

    PubMed

    Chen, Ling; Lu, Huijie; Qiu, Pingming; Yang, Xingyi; Liu, Chao

    2015-11-01

    AmpFℓSTR Sinofiler PCR Amplification Kit is specially developed for Chinese forensic laboratories, but there are little population-genetic data about this kit for Southern China. This kit contains 15 STR loci: D8S1179, D21S11, D7S820, CSF1PO, D3S1358, D13S317, D16S539, D2S1338, D19S433, vWA, D18S51, D6S1043, D12S391, D5S818 and FGA. We have conducted genotyping experiments on the 15 STR loci in 5234 unrelated individuals from Guangdong (Southern China). We observed a total of 243 alleles in the group with the allelic frequency values ranging from less than 0.0001 to 0.3686. Our statistic analysis indicates that the 15 STR loci conform to the Hardy-Weinberg's equilibrium (p>0.05). The highest polymorphism was found at D6S1043 locus and the lowest was found at D3S1358. The combined power of discrimination reached 0.99999999999999999977431 and the combined probability of paternity exclusion reached 0.999999721 for 15 STR loci. Guangdong Han population had significant differences compared with Shaanxi, Shandong and Henan province of Northern China. A Neighbor-joining tree indicates that the Guangdong Han has a close genetic relationship with the Yunnan population. Significant differences were found between Guangdong Han population and other reported populations (Japanese, Philippine, African American, Caucasian, Hispanic and Western Romanian) at 2-11 STR loci. The results may provide useful information for forensic sciences and population genetics studies. The present findings indicate that all the 15 STR loci are highly genetically polymorphic in the Han population of Guangdong. PMID:26593995

  13. Sexual coercion and the misperception of sexual intent☆

    PubMed Central

    Farris, Coreen; Treat, Teresa A.; Viken, Richard J.; McFall, Richard M.

    2010-01-01

    Misperceiving a woman’s platonic interest as sexual interest has been implicated in a sexual bargaining process that leads to sexual coercion. This paper provides a comprehensive review of sexual misperception, including gender differences in perception of women’s sexual intent, the relationship between sexual coercion and misperception, and situational factors that increase the risk that sexual misperception will occur. Compared to women, men consistently perceive a greater degree of sexual intent in women’s behavior. However, there is evidence to suggest that this gender effect may be driven largely by a sub-group of men who are particularly prone to perceive sexual intent in women’s behavior, such as sexually coercive men and men who endorse sex-role stereotypes. Situational factors, such as alcohol use by the man or woman, provocative clothing, and dating behaviors (e.g., initiating the date or making eye contact), are all associated with increased estimates of women’s sexual interest. We also critique the current measurement strategies and introduce a model of perception that more closely maps on to important theoretical questions in this area. A clearer understanding of sexual perception errors and the etiology of these errors may serve to guide sexual-assault prevention programs toward more effective strategies. PMID:17462798

  14. Does developmental timing of exposure to child maltreatment predict memory performance in adulthood? Results from a large, population-based sample.

    PubMed

    Dunn, Erin C; Busso, Daniel S; Raffeld, Miriam R; Smoller, Jordan W; Nelson, Charles A; Doyle, Alysa E; Luk, Gigi

    2016-01-01

    Although maltreatment is a known risk factor for multiple adverse outcomes across the lifespan, its effects on cognitive development, especially memory, are poorly understood. Using data from a large, nationally representative sample of young adults (Add Health), we examined the effects of physical and sexual abuse on working and short-term memory in adulthood. We examined the association between exposure to maltreatment as well as its timing of first onset after adjusting for covariates. Of our sample, 16.50% of respondents were exposed to physical abuse and 4.36% to sexual abuse by age 17. An analysis comparing unexposed respondents to those exposed to physical or sexual abuse did not yield any significant differences in adult memory performance. However, two developmental time periods emerged as important for shaping memory following exposure to sexual abuse, but in opposite ways. Relative to non-exposed respondents, those exposed to sexual abuse during early childhood (ages 3-5), had better number recall and those first exposed during adolescence (ages 14-17) had worse number recall. However, other variables, including socioeconomic status, played a larger role (than maltreatment) on working and short-term memory. We conclude that a simple examination of "exposed" versus "unexposed" respondents may obscure potentially important within-group differences that are revealed by examining the effects of age at onset to maltreatment. PMID:26585216

  15. AIDS and human sexuality.

    PubMed

    Smith, L L; Lathrop, L M

    1993-01-01

    The sexual behaviours placing an individual at risk for HIV infection are those also placing him/her at risk for gonorrhoea, syphilis, hepatitis B, chlamydia and unplanned pregnancy. This article proposes that approaches to HIV prevention must be included within a broad context of human sexuality. To address disease prevention in the absence of including people's relationships, social, behavioural and emotional needs is futile. Compartmentalization, denial of risk by various populations, and societal barriers are all factors to be overcome in the fight against HIV transmission. Specific strategies involved in a comprehensive approach are outlined under the categories of predisposing, enabling and reinforcing factors contributing to healthy sexual behaviour. PMID:8481861

  16. Genetic population structure of Gyrodactylus thymalli (Monogenea) in a large Norwegian river system.

    PubMed

    Pettersen, Ruben Alexander; Mo, Tor Atle; Hansen, Haakon; Vøllestad, Leif Asbjørn

    2015-12-01

    The extent of geographic genetic variation is the result of several processes such as mutation, gene flow, selection and drift. Processes that structure the populations of parasite species are often directly linked to the processes that influence the host. Here, we investigate the genetic population structure of the ectoparasite Gyrodactylus thymalli Žitňan, 1960 (Monogenea) collected from grayling (Thymallus thymallus L.) throughout the river Glomma, the largest watercourse in Norway. Parts of the mitochondrial dehydrogenase subunit 5 (NADH 5) and cytochrome oxidase I (COI) genes from 309 G. thymalli were analysed to study the genetic variation and investigated the geographical distribution of parasite haplotypes. Three main clusters of haplotypes dominated the three distinct geographic parts of the river system; one cluster dominated in the western main stem of the river, one in the eastern and one in the lower part. There was a positive correlation between pairwise genetic distance and hydrographic distance. The results indicate restricted gene flow between sub-populations of G. thymalli, most likely due to barriers that limit upstream migration of infected grayling. More than 80% of the populations had private haplotypes, also indicating long-time isolation of sub-populations. According to a molecular clock calibration, much of the haplotype diversity of G. thymalli in the river Glomma has developed after the last glaciation. PMID:26463886

  17. A Comparison by Sexual Orientation of Sexual Health and Sexual Behaviors among Hispanic Men

    PubMed Central

    De Santis, Joseph P.; Valdes, Beatriz; Provencio-Vasquez, Elias; Gattamorta, Karina A.

    2014-01-01

    Background/Significance High rates of HIV infection and other sexually transmitted infections (STIs) related to high risk sexual behaviors are a public health problem in the U.S. Hispanics have the second highest rates of HIV infection among racial/ethnic minorities. Previous research with Hispanic men has identified a number of factors that influence sexual risk and render Hispanic men at risk for HIV/STIs. These factors vary by sexual orientation. Despite these differences in sexual risk by sexual orientation, no study to date has compared the sexual behaviors of Hispanic men by sexual orientation. Objective The purpose of this study was to compare the sexual behaviors of a sample of Hispanic men by sexual orientation. Method A descriptive, cross-sectional design was used to collect data from 163 Hispanic men in South Florida, 80 heterosexual and 83 MSM. Participants completed measures of sexual health, sexual behaviors, and demographics. Results No statistically significant differences were found between the two groups of men in terms of age of sexual debut, number of sexual partners during the previous 3 months, condom usage during the previous 3 months, HIV testing history, and substance use during sex. Statistically significant differences were found between the two groups of men in terms of certain STIs. Implications Hispanic men as a population may engage in high risk sexual behaviors that place them at risk for HIV/STIs. More research is needed to develop both culturally tailored and sexual orientation appropriate interventions to assist Hispanic men reduce high risk sexual behaviors. PMID:25663832

  18. Behavioral convergence: implications for mathematical models of sexually transmitted infection transmission.

    PubMed

    Aral, Sevgi O; Ward, Helen

    2014-12-01

    Recent trends in the behaviors of some groups with high sexual activity and of the general population in some countries suggest that sexual behavior profiles of high and low sexual activity categories may be converging and may call into question the assumptions around sexual mixing that are built into theoretical models of sexually transmitted infections (STIs)/human immunodeficiency virus (HIV) transmission dynamics. One category of high sexual activity, sex work, has been undergoing modification in many societies, becoming more acceptable, more dispersed, and larger in volume in some societies and shrinking in others. Concurrent with changes in the characteristics of sex work, the accumulating data on the sexual behaviors of the general population suggest a shift toward those of sex workers, including large numbers of sex partners and short-duration partnerships. The closing of the gap between behaviors associated with high and low sexual activity may have important implications for theories of sexual structure and models of transmission dynamics for STIs, including HIV infection. PMID:25381381

  19. Behavioral Convergence: Implications for Mathematical Models of Sexually Transmitted Infection Transmission

    PubMed Central

    Aral, Sevgi O.; Ward, Helen

    2014-01-01

    Recent trends in the behaviors of some groups with high sexual activity and of the general population in some countries suggest that sexual behavior profiles of high and low sexual activity categories may be converging and may call into question the assumptions around sexual mixing that are built into theoretical models of sexually transmitted infections (STIs)/human immunodeficiency virus (HIV) transmission dynamics. One category of high sexual activity, sex work, has been undergoing modification in many societies, becoming more acceptable, more dispersed, and larger in volume in some societies and shrinking in others. Concurrent with changes in the characteristics of sex work, the accumulating data on the sexual behaviors of the general population suggest a shift toward those of sex workers, including large numbers of sex partners and short-duration partnerships. The closing of the gap between behaviors associated with high and low sexual activity may have important implications for theories of sexual structure and models of transmission dynamics for STIs, including HIV infection. PMID:25381381

  20. Masters Swimmers Use More Dietary Supplements Than a Large National Comparison Population in the United States.

    PubMed

    Guthrie, Sally K; Erickson, Steven R

    2016-04-01

    The use of dietary supplements was compared between a cohort of committed exercisers, U.S. Masters Swimming (USMS) members (n = 1,042), and the general U.S. population, exemplified by respondents to the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2010 (n = 6,209). USMS swimmers were significantly more likely to take dietary supplements (62%) than the general U.S. adult population, as represented by the NHANES population (37%). Those taking dietary supplements were older, more likely to be female and Caucasian, and more highly educated and affluent than those not taking supplements (p < .001 for all). When adjusted for age, race, gender, annual income, and education, masters swimmers were still more likely (p < .001) to use dietary supplements than the NHANES cohort. In addition, masters swimmers were significantly more likely (p < .001) to use either creatine or dehydroepiandrosterone or testosterone than those in the NHANES cohort. PMID:26322803

  1. Sexual reproduction in the white pine weevil (Pissodes strobi [Peck] [Coleoptera: Curculionidae]): implications for population genetic diversity.

    PubMed

    Lewis, K G; Liewlaksaneeyanawin, C; Alfaro, R I; Ritland, C; Ritland, K; El-Kassaby, Y A

    2002-01-01

    Controlled mating experiments in the white pine weevil (Pissodes strobi [Peck]) indicated that female weevils either stored sperm or fertilized eggs from one season to the next, and were able to colonize Sitka spruce (Picea sitchensis [Bong.] Carr.) trees without additional mating events. This was interpreted as being beneficial for the insect, in that population establishment in a new habitat could be initiated by dispersing previously mated females without participation of the male. This makes colonization and population/outbreak development more likely as it reduces the need for mate searching in the second season. Paternity identification, based on microsatellite molecular markers, established that the progeny produced in year 2 by females mated only in year 1, were often fathered by more than one male. Multiple paternity, coupled with a lack of parthenogenesis, which was also demonstrated herein, may help to account for the high degree of genetic diversity evidenced in this species. PMID:12195030

  2. Large fluctuations in the effective population size of the malaria mosquito Anopheles gambiae s.s. during vector control cycle

    PubMed Central

    Hodges, Theresa K; Athrey, Giridhar; Deitz, Kevin C; Overgaard, Hans J; Matias, Abrahan; Caccone, Adalgisa; Slotman, Michel A

    2013-01-01

    On Bioko Island, Equatorial Guinea, indoor residual spraying (IRS) has been part of the Bioko Island Malaria Control Project since early 2004. Despite success in reducing childhood infections, areas of high transmission remain on the island. We therefore examined fluctuations in the effective population size (Ne) of the malaria vector Anopheles gambiae in an area of persistent high transmission over two spray rounds. We analyzed data for 13 microsatellite loci from 791 An.gambiae specimens collected at six time points in 2009 and 2010 and reconstructed the demographic history of the population during this period using approximate Bayesian computation (ABC). Our analysis shows that IRS rounds have a large impact on Ne, reducing it by 65%92% from prespray round Ne. More importantly, our analysis shows that after 35months, the An.gambiae population rebounded by 2818% compared shortly following the spray round. Our study underscores the importance of adequate spray round frequency to provide continuous suppression of mosquito populations and that increased spray round frequency should substantially improve the efficacy of IRS campaigns. It also demonstrates the ability of ABC to reconstruct a detailed demographic history across only a few tens of generations in a large population. PMID:24478799

  3. Large fluctuations in the effective population size of the malaria mosquito Anopheles gambiae s.s. during vector control cycle.

    PubMed

    Hodges, Theresa K; Athrey, Giridhar; Deitz, Kevin C; Overgaard, Hans J; Matias, Abrahan; Caccone, Adalgisa; Slotman, Michel A

    2013-12-01

    On Bioko Island, Equatorial Guinea, indoor residual spraying (IRS) has been part of the Bioko Island Malaria Control Project since early 2004. Despite success in reducing childhood infections, areas of high transmission remain on the island. We therefore examined fluctuations in the effective population size (N e ) of the malaria vector Anopheles gambiae in an area of persistent high transmission over two spray rounds. We analyzed data for 13 microsatellite loci from 791 An. gambiae specimens collected at six time points in 2009 and 2010 and reconstructed the demographic history of the population during this period using approximate Bayesian computation (ABC). Our analysis shows that IRS rounds have a large impact on N e , reducing it by 65%-92% from prespray round N e . More importantly, our analysis shows that after 3-5 months, the An. gambiae population rebounded by 2818% compared shortly following the spray round. Our study underscores the importance of adequate spray round frequency to provide continuous suppression of mosquito populations and that increased spray round frequency should substantially improve the efficacy of IRS campaigns. It also demonstrates the ability of ABC to reconstruct a detailed demographic history across only a few tens of generations in a large population. PMID:24478799

  4. Sexuality and affection among elderly German men and women in long-term relationships: results of a prospective population-based study.

    PubMed

    Müller, Britta; Nienaber, Christoph A; Reis, Olaf; Kropp, Peter; Meyer, Wolfgang

    2014-01-01

    Satisfaction with sexual activity i.e. sexual satisfaction and the importance of sexuality and affection were analysed using data from the German "Interdisciplinary Longitudinal Study of Adult Development" (ILSE). At three measurement points, 1993-1995, 1997-1998, and 2004-2006 i.e. subjects' ages of 63, 67, and 74 years, participants' reports about their affection and sexual activity were collected. The sample of completed records used for this study consisted of 194 urban non-institutionalised participants, 68% male, all living with partners. Median levels of sexual satisfaction were reported, fluctuating between the measurement points of ages 63 to 74. Between baseline, first and second follow-up no differences were found in levels of sexual satisfaction, though at measurement points age 63 and 67 women were more satisfied than men. When measured at age 74, affection was given a higher priority than sexual activity. Although men and women reported similar priorities, sexual activity and affection were more important for men than for women. Satisfaction within the relationship can be predicted by the importance of affection, but not by that of sexual activity. Our results confirm the thesis of the 'second language of sexuality': for humans in their later years affection seems to be more important than for younger individuals. PMID:25369193

  5. The relationship between sexual selection and sexual conflict.

    PubMed

    Kokko, Hanna; Jennions, Michael D

    2014-09-01

    Evolutionary conflicts of interest arise whenever genetically different individuals interact and their routes to fitness maximization differ. Sexual selection favors traits that increase an individual's competitiveness to acquire mates and fertilizations. Sexual conflict occurs if an individual of sex A's relative fitness would increase if it had a "tool" that could alter what an individual of sex B does (including the parental genes transferred), at a cost to B's fitness. This definition clarifies several issues: Conflict is very common and, although it extends outside traits under sexual selection, sexual selection is a ready source of sexual conflict. Sexual conflict and sexual selection should not be presented as alternative explanations for trait evolution. Conflict is closely linked to the concept of a lag load, which is context-dependent and sex-specific. This makes it possible to ask if one sex can "win." We expect higher population fitness if females win. PMID:25038050

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

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  7. Large-scale selective sweep among Segregation Distorter chromosomes in African populations of Drosophila melanogaster.

    PubMed

    Presgraves, Daven C; Gérard, Pierre R; Cherukuri, Anjuli; Lyttle, Terrence W

    2009-05-01

    Segregation Distorter (SD) is a selfish, coadapted gene complex on chromosome 2 of Drosophila melanogaster that strongly distorts Mendelian transmission; heterozygous SD/SD(+) males sire almost exclusively SD-bearing progeny. Fifty years of genetic, molecular, and theory work have made SD one of the best-characterized meiotic drive systems, but surprisingly the details of its evolutionary origins and population dynamics remain unclear. Earlier analyses suggested that the SD system arose recently in the Mediterranean basin and then spread to a low, stable equilibrium frequency (1-5%) in most natural populations worldwide. In this report, we show, first, that SD chromosomes occur in populations in sub-Saharan Africa, the ancestral range of D. melanogaster, at a similarly low frequency (approximately 2%), providing evidence for the robustness of its equilibrium frequency but raising doubts about the Mediterranean-origins hypothesis. Second, our genetic analyses reveal two kinds of SD chromosomes in Africa: inversion-free SD chromosomes with little or no transmission advantage; and an African-endemic inversion-bearing SD chromosome, SD-Mal, with a perfect transmission advantage. Third, our population genetic analyses show that SD-Mal chromosomes swept across the African continent very recently, causing linkage disequilibrium and an absence of variability over 39% of the length of the second chromosome. Thus, despite a seemingly stable equilibrium frequency, SD chromosomes continue to evolve, to compete with one another, or evade suppressors in the genome. PMID:19412335

  8. Density dependence in marine fish populations revealed at small and large spatial scales.

    PubMed

    Johnson, Darren W

    2006-02-01

    Experimental manipulation of population density has frequently been used to demonstrate demographic density dependence. However, such studies are usually small scale and typically provide evidence of spatial (within-generation) density dependence. It is often unclear whether small-scale, experimental tests of spatial density dependence will accurately describe temporal (between-generation) density dependence required for population regulation. Understanding the mechanisms generating density dependence may provide a link between spatial experiments and temporal regulation of populations. In this study, I manipulated the density of recently settled kelp rockfish (Sebastes atrovirens) in both the presence and absence of predators to test for density-dependent mortality and whether predation was the mechanism responsible. I also examined mortality of rockfish cohorts within kelp beds throughout central California to evaluate temporal (between-generation) density dependence in mortality. Experiments suggested that short-term behavioral responses of predators and/or a shortage of prey refuges caused spatial density dependence. Temporal density dependence in mortality was also detected at larger spatial scales for several species of rockfish. It is likely that short-term responses of predators generated both spatial and temporal density dependence in mortality. Spatial experiments that describe the causal mechanisms generating density dependence may therefore be valuable in describing temporal density dependence and population regulation. PMID:16637357

  9. Language Shift and the Inclusion of Indigenous Populations in Large-Scale Assessment Programs

    ERIC Educational Resources Information Center

    Solano-Flores, Guillermo; Backhoff, Eduardo; Contreras-Niño, Luis A.; Vázquez-Muñoz, Mariana

    2015-01-01

    Indicators of academic achievement for bilingual students can be inaccurate due to linguistic heterogeneity. For indigenous populations, language shift (the gradual replacement of one language by another) is a factor that can increase this heterogeneity and poses an additional challenge for valid testing. We investigated whether and how indigenous…

  10. Large-scale distribution of microbial and viral populations in the South Atlantic Ocean.

    PubMed

    De Corte, Daniele; Sintes, Eva; Yokokawa, Taichi; Lekunberri, Itziar; Herndl, Gerhard J

    2016-04-01

    Viruses are abundant, diverse and dynamic components of the marine environments and play a significant role in the ocean biogeochemical cycles. To assess potential variations in the relation between viruses and microbes in different geographic regions and depths, viral and microbial abundance and production were determined throughout the water column along a latitudinal transect in the South Atlantic Ocean. Path analysis was used to examine the relationships between several abiotic and biotic parameters and the different microbial and viral populations distinguished by flow cytometry. The depth-integrated contribution of microbial and viral abundance to the total microbial and viral biomass differed significantly among the different provinces. Additionally, the virus-to-microbe ratio increased with depth and decreased laterally towards the more productive regions. Our data revealed that the abundance of phytoplankton and microbes is the main controlling factor of the viral populations in the euphotic and mesopelagic layers, whereas in the bathypelagic realm, viral abundance was only weakly related to the biotic and abiotic variables. The relative contribution of the three viral populations distinguished by flow cytometry showed a clear geographical pattern throughout the water column, suggesting that these populations are composed of distinct taxa able to infect specific hosts. Overall, our data indicate the presence of distinct microbial patterns along the latitudinal transect. This variability is not limited to the euphotic layer but also detectable in the meso- and bathypelagic layers. PMID:26765966

  11. Language Shift and the Inclusion of Indigenous Populations in Large-Scale Assessment Programs

    ERIC Educational Resources Information Center

    Solano-Flores, Guillermo; Backhoff, Eduardo; Contreras-Nio, Luis A.; Vzquez-Muoz, Mariana

    2015-01-01

    Indicators of academic achievement for bilingual students can be inaccurate due to linguistic heterogeneity. For indigenous populations, language shift (the gradual replacement of one language by another) is a factor that can increase this heterogeneity and poses an additional challenge for valid testing. We investigated whether and how indigenous

  12. Household economy and population survey on a large agriculture-oriented county.

    PubMed

    He, C; Chen, C

    1995-01-01

    In this article household socioeconomic characteristics and standard of living are described for agricultural workers in Renshou County of Sichuan Province in western rural China. Data are obtained for the population in the county, and more detailed data are available among a sample of 215 households (743 persons) in 1993 in Anlin Village in Jinshun Township of Longzheng District. Anlin village is one of 1103 villages in the county. Family size declined during 1990-93 by 0.4 persons. 25.1% of households in Anlin Village had elderly members. 6.68% of elderly lived alone, and 8.22% lived in 2-person families. Over 60% lived in 3 or more generation households, and 27.4% lived in nuclear households. There were no homes for the aged in Anlin Village. All households were family, rather than collective, households. 8.04% of household heads were women. Total village population was 1110 persons. The sex ratio was normal. The village population aged under 15 years was lower, and the working age population was higher than the respective township populations. Marriages were stable and early marriage was not a problem. During 1990-93 the proportion with a junior high or more education increased as did the proportion illiterate or semi-literate. The working age population from rural statistics reports numbered 477 persons, of whom 92.9% were engaged in farming, animal farming, and fishing. 5.9% worked in non-agricultural jobs. 4.8% worked outside the area. The survey found a higher number of working age population than the 1993 annual report of rural statistics. Each person averaged 6.67 acres of arable land, and one in seven households owned cattle. Most households had electricity and bicycles. 56% had television sets. The average income was 1089.47 RMB yuan per person. In 1993, most women had one child and hoped to have a second one. Although regulations permitted only one child, most desired two and still relied on family support for the elderly. Renshou County is shifting from a subsistence economy to a diversified economy. It is expected that this shift eventually will create options for reducing family size. PMID:12291088

  13. Large-Scale Modelling of the Environmentally-Driven Population Dynamics of Temperate Aedes albopictus (Skuse)

    PubMed Central

    Erguler, Kamil; Smith-Unna, Stephanie E.; Waldock, Joanna; Proestos, Yiannis; Christophides, George K.; Lelieveld, Jos; Parham, Paul E.

    2016-01-01

    The Asian tiger mosquito, Aedes albopictus, is a highly invasive vector species. It is a proven vector of dengue and chikungunya viruses, with the potential to host a further 24 arboviruses. It has recently expanded its geographical range, threatening many countries in the Middle East, Mediterranean, Europe and North America. Here, we investigate the theoretical limitations of its range expansion by developing an environmentally-driven mathematical model of its population dynamics. We focus on the temperate strain of Ae. albopictus and compile a comprehensive literature-based database of physiological parameters. As a novel approach, we link its population dynamics to globally-available environmental datasets by performing inference on all parameters. We adopt a Bayesian approach using experimental data as prior knowledge and the surveillance dataset of Emilia-Romagna, Italy, as evidence. The model accounts for temperature, precipitation, human population density and photoperiod as the main environmental drivers, and, in addition, incorporates the mechanism of diapause and a simple breeding site model. The model demonstrates high predictive skill over the reference region and beyond, confirming most of the current reports of vector presence in Europe. One of the main hypotheses derived from the model is the survival of Ae. albopictus populations through harsh winter conditions. The model, constrained by the environmental datasets, requires that either diapausing eggs or adult vectors have increased cold resistance. The model also suggests that temperature and photoperiod control diapause initiation and termination differentially. We demonstrate that it is possible to account for unobserved properties and constraints, such as differences between laboratory and field conditions, to derive reliable inferences on the environmental dependence of Ae. albopictus populations. PMID:26871447

  14. Large-Scale Modelling of the Environmentally-Driven Population Dynamics of Temperate Aedes albopictus (Skuse).

    PubMed

    Erguler, Kamil; Smith-Unna, Stephanie E; Waldock, Joanna; Proestos, Yiannis; Christophides, George K; Lelieveld, Jos; Parham, Paul E

    2016-01-01

    The Asian tiger mosquito, Aedes albopictus, is a highly invasive vector species. It is a proven vector of dengue and chikungunya viruses, with the potential to host a further 24 arboviruses. It has recently expanded its geographical range, threatening many countries in the Middle East, Mediterranean, Europe and North America. Here, we investigate the theoretical limitations of its range expansion by developing an environmentally-driven mathematical model of its population dynamics. We focus on the temperate strain of Ae. albopictus and compile a comprehensive literature-based database of physiological parameters. As a novel approach, we link its population dynamics to globally-available environmental datasets by performing inference on all parameters. We adopt a Bayesian approach using experimental data as prior knowledge and the surveillance dataset of Emilia-Romagna, Italy, as evidence. The model accounts for temperature, precipitation, human population density and photoperiod as the main environmental drivers, and, in addition, incorporates the mechanism of diapause and a simple breeding site model. The model demonstrates high predictive skill over the reference region and beyond, confirming most of the current reports of vector presence in Europe. One of the main hypotheses derived from the model is the survival of Ae. albopictus populations through harsh winter conditions. The model, constrained by the environmental datasets, requires that either diapausing eggs or adult vectors have increased cold resistance. The model also suggests that temperature and photoperiod control diapause initiation and termination differentially. We demonstrate that it is possible to account for unobserved properties and constraints, such as differences between laboratory and field conditions, to derive reliable inferences on the environmental dependence of Ae. albopictus populations. PMID:26871447

  15. Grouping of large populations into few CTL immune ‘response-types' from influenza H1N1 genome analysis

    PubMed Central

    Mukherjee, Sumanta; Chandra, Nagasuma

    2014-01-01

    Despite extensive work on influenza, a number of questions still remain open about why individuals are differently susceptible to the disease and why only some strains lead to epidemics. Here we study the effect of human leukocyte antigen (HLA) genotype heterogeneity on possible cytotoxic T-lymphocyte (CTL) response to 186 influenza H1N1 genomes. To enable such analysis, we reconstruct HLA genotypes in different populations using a probabilistic method. We find that epidemic strains in general correlate with poor CTL response in populations. Our analysis shows that large populations can be classified into a small number of groups called response-types, specific to a given viral strain. Individuals of a response-type are expected to exhibit similar CTL responses. Extent of CTL responses varies significantly across different populations and increases with increase in genetic heterogeneity. Overall, our analysis presents a conceptual advance towards understanding how genetic heterogeneity influences disease susceptibility in individuals and in populations. We also obtain lists of top-ranking epitopes and proteins, ranked on the basis of conservation, antigenic cross-reactivity and population coverage, which provide ready short-lists for rational vaccine design. Our method is fairly generic and has the potential to be applied for studying other viruses. PMID:25505972

  16. Testing the sexually abused-sexual abuser hypothesis: A prospective longitudinal birth cohort study.

    PubMed

    Leach, Chelsea; Stewart, Anna; Smallbone, Stephen

    2016-01-01

    The sexually abused-sexual abuser hypothesis posits that persons, especially males, who are sexually abused as children are at particular risk of sexually abusing others later in life. We tested this hypothesis by prospectively examining associations between maltreatment and offending in a birth cohort of 38,282 males with a maltreatment history and/or at least one finalized offense. We examined these associations within the context of the wider birth population. Proportionally few boys were the subject of official notifications for sexual abuse (14.8% of maltreated boys, and 1.4% of the birth population); proportionally very few of these sexually abused boys (3%) went on to become sexual offenders; and, contrary to findings typically reported in retrospective clinical studies, proportionally few sexual offenders (4%) had a confirmed history of sexual abuse. Poly-victimization (exposure to multiple types of maltreatment) was significantly associated with sexual offending, violent offending, and general (nonsexual, nonviolent) offending. We found no specific association between sexual abuse and sexual offending, and nor did we find any association between sexual abuse and sexual offending specifically within the poly-victimized group. The total number of sexual abuse notifications did make a small unique contribution to the variance in sexual offending compared to other offending. Implications concerning maltreated boys and male sexual offenders are discussed. PMID:26615777

  17. Big Data: Large-Scale Historical Infrastructure from the Minnesota Population Center.

    PubMed

    Sobek, Matthew; Cleveland, Lara; Flood, Sarah; Hall, Patricia Kelly; King, Miriam L; Ruggles, Steven; Schroeder, Matthew

    2011-01-01

    The Minnesota Population Center (MPC) provides aggregate data and microdata that have been integrated and harmonized to maximize crosstemporal and cross-spatial comparability. All MPC data products are distributed free of charge through an interactive Web interface that enables users to limit the data and metadata being analyzed to samples and variables of interest to their research. In this article, the authors describe the integrated databases available from the MPC, report on recent additions and enhancements to these data sets, and summarize new online tools and resources that help users to analyze the data over time. They conclude with a description of the MPC's newest and largest infrastructure project to date: a global population and environment data network. PMID:21949459

  18. Breath methane and large bowel cancer risk in contrasting African populations.

    PubMed Central

    Segal, I; Walker, A R; Lord, S; Cummings, J H

    1988-01-01

    Breath methane has been measured in 1016 people from four populations resident in Southern Africa which experience widely different risks of bowel cancer and other colonic diseases. Highly significant differences in the proportion of subjects with detectable methane in breath were found; % producers--rural black 84, urban black 72, white 52, Indian 41 (chi 2 121 p less than 0.001 3 df). There was a slight preponderance of female producers over male (female producers 63%, males 57%) and an age trend with fewer producers in the older age groups in the urban blacks and Indians, these comparisons being significant when tested by stepwise logistic regression analysis. Bowel cancer risk, determined from a variety of sources, was lowest in rural blacks, greatest in whites, with intermediate rates for urban blacks and Indians. Methane production in the human colon shows significant interethnic differences but which bear no relation to bowel cancer risk in these populations. PMID:3396948

  19. Exploring the acceptability and feasibility of conducting a large longitudinal population-based study in Canada.

    PubMed

    Kirkland, Susan A; Raina, Parminder S; Wolfson, Christina; Strople, Geoff; Kits, Olga; Dukeshire, Steven; Angus, Camille L; Szala-Meneok, Karen; Uniat, Jennifer; Keshavarz, Homa; Furlini, Linda; Pelletier, Amélie

    2009-09-01

    ABSTRACTSuccessful recruitment and retention for population-based longitudinal studies requires understanding facilitators and barriers to participation. This study explored Canadians' views regarding one such study, the proposed Canadian Longitudinal Study on Aging (CLSA). Focus groups of participants > or =40 years of age were held in six proposed CLSA data collection sites (Halifax, Montreal, Hamilton, Winnipeg, Calgary, and Vancouver) to discuss participating in a long-term study of healthy aging. There was fundamental support for longitudinal research on health and aging. Altruism was a key motivation to participation, and universities were viewed as credible parties to conduct such studies. Participants had few worries about providing biological samples but expressed concern about potential misuse of genetic materials, commercialization of participant data, and privacy issues. These findings have already informed current, and will inform future, work on the CLSA, and will also provide useful information to researchers who undertake other population-based longitudinal studies. PMID:19860978

  20. Sexuality and Affection among Elderly German Men and Women in Long-Term Relationships: Results of a Prospective Population-Based Study

    PubMed Central

    Müller, Britta; Nienaber, Christoph A.; Reis, Olaf; Kropp, Peter; Meyer, Wolfgang

    2014-01-01

    Satisfaction with sexual activity i.e. sexual satisfaction and the importance of sexuality and affection were analysed using data from the German “Interdisciplinary Longitudinal Study of Adult Development” (ILSE). At three measurement points, 1993–1995, 1997–1998, and 2004–2006 i.e. subjects' ages of 63, 67, and 74 years, participants' reports about their affection and sexual activity were collected. The sample of completed records used for this study consisted of 194 urban non-institutionalised participants, 68% male, all living with partners. Median levels of sexual satisfaction were reported, fluctuating between the measurement points of ages 63 to 74. Between baseline, first and second follow-up no differences were found in levels of sexual satisfaction, though at measurement points age 63 and 67 women were more satisfied than men. When measured at age 74, affection was given a higher priority than sexual activity. Although men and women reported similar priorities, sexual activity and affection were more important for men than for women. Satisfaction within the relationship can be predicted by the importance of affection, but not by that of sexual activity. Our results confirm the thesis of the ‘second language of sexuality’: for humans in their later years affection seems to be more important than for younger individuals. PMID:25369193

  1. Disentangling the cause of a catastrophic population decline in a large marine mammal.

    PubMed

    Baylis, Alastair M M; Orben, Rachael A; Arnould, John P Y; Christiansen, Fredrik; Hays, Graeme C; Staniland, Iain J

    2015-10-01

    Considerable uncertainties often surround the causes of long-term changes in population abundance. One striking example is the precipitous decline of southern sea lions (SSL; Otariaflavescens) at the Falkland Islands, from 80 555 pups in the mid 1930s to just 5506 pups in 1965. Despite an increase in SSL abundance over the past two decades, the population has not recovered, with the number of pups born in 2014 (minimum 4443 pups) less than 6% of the 1930s estimate. The order-of-magnitude decline is primarily attributed to commercial sealing in Argentina. Here, we test this established paradigm and alternative hypotheses by assessing (1) commercial sealing at the Falkland Islands, (2) winter migration of SSL from the Falkland Islands to Argentina, (3) whether the number of SSL in Argentina could have sustained the reported level of exploitation, and (4) environmental change. The most parsimonious hypothesis explaining the SSL population decline was environmental change. Specifically, analysis of 160 years of winter sea surface temperatures revealed marked changes, including a period of warming between 1930 and 1950 that was consistent with the period of SSL decline. Sea surface temperature changes likely influenced the distribution or availability of SSL prey and impacted its population dynamics. We suggest that historical harvesting may not always be the "smoking gun" as is often purported. Rather, our conclusions support the growing evidence for bottom-up forcing on the abundance of species at lower trophic levels (e.g., plankton and fish) and resulting impacts on higher trophic levels across a broad range of ecosystems. PMID:26649403

  2. Birth seasonality and calf mortality in a large population of Asian elephants

    PubMed Central

    Mumby, Hannah S; Courtiol, Alexandre; Mar, Khyne U; Lummaa, Virpi

    2013-01-01

    In seasonal environments, many species concentrate their reproduction in the time of year most likely to maximize offspring survival. Asian elephants (Elephas maximus) inhabit regions with seasonal climate, but females can still experience 16-week reproductive cycles throughout the year. Whether female elephants nevertheless concentrate births on periods with maximum offspring survival prospects remains unknown. We investigated the seasonal timing of births, and effects of birth month on short- and long-term mortality of Asian elephants, using a unique demographic data set of 2350 semicaptive, longitudinally monitored logging elephants from Myanmar experiencing seasonal variation in both workload and environmental conditions. Our results show variation in birth rate across the year, with 41% of births occurring between December and March. This corresponds to the cool, dry period and the beginning of the hot season, and to conceptions occurring during the resting, nonlogging period between February and June. Giving birth during the peak December to March period improves offspring survival, as the odds for survival between age 1 and 5 years are 44% higher for individuals born during the high birth rate period than those conceived during working months. Our results suggest that seasonal conditions, most likely maternal workload and/or climate, limit conception rate and calf survival in this population through effects on maternal stress, estrus cycles, or access to mates. This has implications for improving the birth rate and infant survival in captive populations by limiting workload of females of reproductive age. As working populations are currently unsustainable and supplemented through the capture of wild elephants, it is imperative to the conservation of Asian elephants to understand and alleviate the effects of seasonal conditions on vital rates in the working population in order to reduce the pressure for further capture from the wild. PMID:24198940

  3. Improving Blood Pressure Control in a Large Multiethnic California Population Through Changes in Health Care Delivery, 2004–2012

    PubMed Central

    Handler, Joel; Wall, Hilary K.; Kanter, Michael H.

    2014-01-01

    The Kaiser Permanente Southern California (Kaiser) health care system succeeded in improving hypertension control in a multiethnic population by adopting a series of changes in health care delivery. Data from the Healthcare Effectiveness Data and Information Set (HEDIS) was used to assess blood pressure control from 2004 through 2012. Hypertension control increased overall from 54% to 86% during that period, and 80% or more in every subgroup, regardless of race/ethnicity, preferred language, or type of health insurance plan. Health care delivery changes improved hypertension control across a large multiethnic population, which indicates that health care systems can achieve a clinical target goal of 70% for hypertension control in their populations. PMID:25357259

  4. Improving blood pressure control in a large multiethnic California population through changes in health care delivery, 2004-2012.

    PubMed

    Shaw, Kate M; Handler, Joel; Wall, Hilary K; Kanter, Michael H

    2014-01-01

    The Kaiser Permanente Southern California (Kaiser) health care system succeeded in improving hypertension control in a multiethnic population by adopting a series of changes in health care delivery. Data from the Healthcare Effectiveness Data and Information Set (HEDIS) was used to assess blood pressure control from 2004 through 2012. Hypertension control increased overall from 54% to 86% during that period, and 80% or more in every subgroup, regardless of race/ethnicity, preferred language, or type of health insurance plan. Health care delivery changes improved hypertension control across a large multiethnic population, which indicates that health care systems can achieve a clinical target goal of 70% for hypertension control in their populations. PMID:25357259

  5. Scaling Solution in the Large Population Limit of the General Asymmetric Stochastic Luria-Delbrück Evolution Process

    NASA Astrophysics Data System (ADS)

    Kessler, David A.; Levine, Herbert

    2015-02-01

    One of the most popular models for quantitatively understanding the emergence of drug resistance both in bacterial colonies and in malignant tumors was introduced long ago by Luria and Delbrück. Here, individual resistant mutants emerge randomly during the birth events of an exponentially growing sensitive population. A most interesting limit of this process occurs when the population size is large and mutation rates are low, but not necessarily small compared to . Here we provide a scaling solution valid in this limit, making contact with the theory of Levy -stable distributions, in particular one discussed long ago by Landau. One consequence of this association is that moments of the distribution are highly misleading as far as characterizing typical behavior. A key insight that enables our solution is that working in the fixed population size ensemble is not the same as working in a fixed time ensemble. Some of our results have been presented previously in abbreviated form [12].

  6. Large nonlethal effects of an invasive invertebrate predator on zooplankton population growth rate.

    PubMed

    Pangle, Kevin L; Peacor, Scott D; Johannsson, Ora E

    2007-02-01

    We conducted a study to determine the contribution of lethal and nonlethal effects to a predator's net effect on a prey's population growth rate in a natural setting. We focused on the effects of an invasive invertebrate predator, Bythotrephes longimanus, on zooplankton prey populations in Lakes Michigan and Erie. Field data taken at multiple dates and locations in both systems indicated that the prey species Daphnia mendotae, Daphnia retrocurva, and Bosmina longirostris inhabited deeper portions of the water column as Bythotrephes biomass increased, possibly as an avoidance response to predation. This induced migration reduces predation risk but also can reduce birth rate due to exposure to cooler temperatures. We estimated the nonlethal (i.e., resulting from reduced birth rate) and lethal (i.e., consumptive) effects of Bythotrephes on D. mendotae and Bosmina longirostris. These estimates used diel field survey data of the vertical gradient of zooplankton prey density, Bythotrephes density, light intensity, and temperature with growth and predation rate models derived from laboratory studies. Results indicate that nonlethal effects played a substantial role in the net effect of Bythotrephes on several prey population growth rates in the field, with nonlethal effects on the same order of magnitude as or greater (up to 10-fold) than lethal effects. Our results further indicate that invasive species can have strong nonlethal, behaviorally based effects, despite short evolutionary coexistence with prey species. PMID:17479758

  7. Large-scale mitogenomics enables insights into Schizophora (Diptera) radiation and population diversity.

    PubMed

    Junqueira, Ana Carolina M; Azeredo-Espin, Ana Maria L; Paulo, Daniel F; Marinho, Marco Antonio T; Tomsho, Lynn P; Drautz-Moses, Daniela I; Purbojati, Rikky W; Ratan, Aakrosh; Schuster, Stephan C

    2016-01-01

    True flies are insects of the order Diptera and encompass one of the most diverse groups of animals on Earth. Within dipterans, Schizophora represents a recent radiation of insects that was used as a model to develop a pipeline for generating complete mitogenomes using various sequencing platforms and strategies. 91 mitogenomes from 32 different species were sequenced and assembled with high fidelity, using amplicon, whole genome shotgun or single molecule sequencing approaches. Based on the novel mitogenomes, we estimate the origin of Schizophora within the Cretaceous-Paleogene (K-Pg) boundary, about 68.3 Ma. Detailed analyses of the blowfly family (Calliphoridae) place its origin at 22 Ma, concomitant with the radiation of grazing mammals. The emergence of ectoparasitism within calliphorids was dated 6.95 Ma for the screwworm fly and 2.3 Ma for the Australian sheep blowfly. Varying population histories were observed for the blowfly Chrysomya megacephala and the housefly Musca domestica samples in our dataset. Whereas blowflies (n = 50) appear to have undergone selective sweeps and/or severe bottlenecks in the New World, houseflies (n = 14) display variation among populations from different zoogeographical zones and low levels of gene flow. The reported high-throughput mitogenomics approach for insects enables new insights into schizophoran diversity and population history of flies. PMID:26912394

  8. Large-scale mitogenomics enables insights into Schizophora (Diptera) radiation and population diversity

    PubMed Central

    Junqueira, Ana Carolina M.; Azeredo-Espin, Ana Maria L.; Paulo, Daniel F.; Marinho, Marco Antonio T.; Tomsho, Lynn P.; Drautz-Moses, Daniela I.; Purbojati, Rikky W.; Ratan, Aakrosh; Schuster, Stephan C.

    2016-01-01

    True flies are insects of the order Diptera and encompass one of the most diverse groups of animals on Earth. Within dipterans, Schizophora represents a recent radiation of insects that was used as a model to develop a pipeline for generating complete mitogenomes using various sequencing platforms and strategies. 91 mitogenomes from 32 different species were sequenced and assembled with high fidelity, using amplicon, whole genome shotgun or single molecule sequencing approaches. Based on the novel mitogenomes, we estimate the origin of Schizophora within the Cretaceous-Paleogene (K-Pg) boundary, about 68.3 Ma. Detailed analyses of the blowfly family (Calliphoridae) place its origin at 22 Ma, concomitant with the radiation of grazing mammals. The emergence of ectoparasitism within calliphorids was dated 6.95 Ma for the screwworm fly and 2.3 Ma for the Australian sheep blowfly. Varying population histories were observed for the blowfly Chrysomya megacephala and the housefly Musca domestica samples in our dataset. Whereas blowflies (n = 50) appear to have undergone selective sweeps and/or severe bottlenecks in the New World, houseflies (n = 14) display variation among populations from different zoogeographical zones and low levels of gene flow. The reported high-throughput mitogenomics approach for insects enables new insights into schizophoran diversity and population history of flies. PMID:26912394

  9. Sexuality, rights and personhood: tensions in a transnational world

    PubMed Central

    2011-01-01

    Background This article discusses what happens when normative ‘global’ discourses of rights and individuated sexual identity confront the messiness of ‘local’ realities. It considers the tensions that emerge when the relationship between sexual and social identities is not obvious and the implications of such tensions for public health and sexual rights activism. These questions are addressed through debates over the naming of male-to-male sexualities and desires in the context of globalization and the growth of a large NGO (non-governmental organization) sector in urban Bangladesh. Methods The material in the paper draws on a research project undertaken in 2008-9 in Dhaka, Bangladesh. A fundamental objective was to produce a contextualized understanding of sexuality in Dhaka city. Methods used included structured interviews, focus group discussions and informal conversations with a range of participants (students, factory workers, public health professionals and sexual minorities). The