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1

The effect of sexual cannibalism on the evolution of large populations  

NASA Astrophysics Data System (ADS)

The notion of sexual cannibalism is introduced in a simple model of population growth derived from the Bernardes model (J. Phys. I 5 (1995) 1501). The effect of sexual cannibalism is studied at the level of a population of individuals. Even in presence of cannibalism, a population can survive and stabilize for a birth rate b > 2. Before reaching a stable situation, the evolution of the (sexual cannibalism) population presents an unexpected pattern which is not present in the non-cannibalism case.

Vandewalle, N.

1997-02-01

2

Genetic Draft and Quasi-Neutrality in Large Facultatively Sexual Populations  

PubMed Central

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 ?. 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/?. 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/?, but only weakly on population size N. In addition, the anomalous fluctuations due to draft change the spectrum of (quasi)-neutral alleles from f(?) ? ??1, corresponding to drift, to ? ??2. Finally, draft accelerates the rate of two-step adaptations through deleterious intermediates.

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

2011-01-01

3

Emergence of clones in sexual populations  

NASA Astrophysics Data System (ADS)

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.

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

2013-01-01

4

How can sexual selection promote population divergence?  

Microsoft Academic Search

Sexual selection is a competition between conspecific individuals to acquire mates and maximize their reproductive success. This can lead to the development of conspicuous secondary sexual traits under several possible mechanisms. Since these sexual characters can be used as potential discriminant features in species recognition, it seems legitimate to think of a potential role of sexual selection in population divergence.

Sophie Questiau

1999-01-01

5

Sexual networks: measuring sexual selection in structured, polyandrous populations.  

PubMed

Sexual selection is traditionally measured at the population level, assuming that populations lack structure. However, increasing evidence undermines this approach, indicating that intrasexual competition in natural populations often displays complex patterns of spatial and temporal structure. This complexity is due in part to the degree and mechanisms of polyandry within a population, which can influence the intensity and scale of both pre- and post-copulatory sexual competition. Attempts to measure selection at the local and global scale have been made through multi-level selection approaches. However, definitions of local scale are often based on physical proximity, providing a rather coarse measure of local competition, particularly in polyandrous populations where the local scale of pre- and post-copulatory competition may differ drastically from each other. These limitations can be solved by social network analysis, which allows us to define a unique sexual environment for each member of a population: 'local scale' competition, therefore, becomes an emergent property of a sexual network. Here, we first propose a novel quantitative approach to measure pre- and post-copulatory sexual selection, which integrates multi-level selection with information on local scale competition derived as an emergent property of networks of sexual interactions. We then use simple simulations to illustrate the ways in which polyandry can impact estimates of sexual selection. We show that for intermediate levels of polyandry, the proposed network-based approach provides substantially more accurate measures of sexual selection than the more traditional population-level approach. We argue that the increasing availability of fine-grained behavioural datasets provides exciting new opportunities to develop network approaches to study sexual selection in complex societies. PMID:23339246

McDonald, Grant C; James, Richard; Krause, Jens; Pizzari, Tommaso

2013-01-21

6

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

PubMed

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

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

2009-04-01

7

Spreading of sexually transmitted diseases in heterosexual populations  

Microsoft Academic Search

The spread of sexually transmitted diseases (e.g., chlamydia, syphilis, gonorrhea, HIV, etc.) across populations is a major concern for scientists and health agencies. In this context, both the data collection on sexual contact networks and the modeling of disease spreading are intensive contributions to the search for effective immunization policies. Here, the spreading of sexually transmitted diseases on bipartite scale-free

Jesús Gómez-Gardeńes; Vito Latora; Yamir Moreno; Elio V. Profumo

2008-01-01

8

population structure in large mammals  

Microsoft Academic Search

We simulated large mammal populations using an individual-based stochastic model under various sex-specific migration schemes and life history parameters from the blue whale and the Asian elephant. Our model predicts that genetic structure at nuclear loci is significantly more influenced by female than by male migration. We identified requisite comigration of mother and offspring during gravidity and lactation as the

RALPH TIEDEMANN; OLIVIER HARDY; XA V IER VEKEMANS; MICHEL C. MILINKOVITCH

9

Sexual Abuse in Childhood and Sexual Dysfunction in Adulthood: An Australian Population-Based Study  

Microsoft Academic Search

This study examined self-reported adult sexual functioning in individuals reporting a history of childhood sexual abuse (CSA) in a representative sample of the Australian population. A sample of 1793 persons, aged 18–59 years, were randomly selected from the electoral roll for Australian states and territories in April 2000. Respondents were interviewed about their health status and sexual experiences, including unwanted

Jake M. Najman; Michael P. Dunne; David M. Purdie; Francis M. Boyle; Peter D. Coxeter

2005-01-01

10

Natural Selection in Large Populations  

NASA Astrophysics Data System (ADS)

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.

Desai, Michael

2011-03-01

11

Metacarpal sexual determination in a Spanish population.  

PubMed

Anthropologists and forensic pathologist determine the sex of skeletons by analyzing quantitative and qualitative characters in the bone remains. Generally, the skull and os coxae are the elements most used, but they are not always preserved. In such cases, the investigator needs to have available other techniques based on different remains. The aim of the present work is to develop and describe discriminating functions for sex determination in a recent Spanish population using metacarpal morphology. A sample of bones corresponding to a contemporary Spanish population deposited at the Complutense University of Madrid (UCM) was analyzed. This sample comprised 697 metacarpals, corresponding to 79 adult individuals (37 men and 42 women). These allowed us to obtain 120 unifactorial discriminant functions. We selected the 10 equations, one for each metacarpal from both hands, that provided the best sexual discrimination. The correct sex classification rank progressed from 81%, for right (R) metacarpals IV and V, to 91%, for left (L) metacarpal II. The results suggest that metacarpals are structures that can be used for sex determination in paleoanthropological and forensic identifications. PMID:17018074

Barrio, Pedro A; Trancho, Gonzalo J; Sánchez, José A

2006-09-01

12

Mutator dynamics in sexual and asexual experimental populations of yeast  

PubMed Central

Background In asexual populations, mutators may be expected to hitchhike with associated beneficial mutations. In sexual populations, recombination is predicted to erode such associations, inhibiting mutator hitchhiking. To investigate the effect of recombination on mutators experimentally, we compared the frequency dynamics of a mutator allele (msh2?) in sexual and asexual populations of Saccharomyces cerevisiae. Results Mutator strains increased in frequency at the expense of wild-type strains in all asexual diploid populations, with some approaching fixation in 150 generations of propagation. Over the same period of time, mutators declined toward loss in all corresponding sexual diploid populations as well as in haploid populations propagated asexually. Conclusions We report the first experimental investigation of mutator dynamics in sexual populations. We show that a strong mutator quickly declines in sexual populations while hitchhiking to high frequency in asexual diploid populations, as predicted by theory. We also show that the msh2? mutator has a high and immediate realized cost that is alone sufficient to explain its decline in sexual populations. We postulate that this cost is indirect; namely, that it is due to a very high rate of recessive lethal or strongly deleterious mutation. However, we cannot rule out the possibility that msh2? also has unknown directly deleterious effects on fitness, and that these effects may differ between haploid asexual and sexual populations. Despite these reservations, our results prompt us to speculate that the short-term cost of highly deleterious recessive mutations can be as important as recombination in preventing mutator hitchhiking in sexual populations.

2011-01-01

13

The genetic structure of populations of sexual and asexual Taraxacum (dandelions)  

Microsoft Academic Search

The genetic structure, as assessed by isozymes, is described for three populations of outbreeding sexuals, three populations of obligate agamosperms, and six accessions of inbreeding sexual Taraxacum. Fifteen loci in 10 isozyme systems were identified, and isozyme bands were previously shown to be allelic in sexual × sexual and were confirmed as allelic in sexual × agamosperm crosses. Sexual ×

Jane Hughes; A J Richards

1988-01-01

14

Phase Transitions in Sexual Populations Subject to Stabilizing Selection  

NASA Astrophysics Data System (ADS)

We show that a simple model of an evolving sexual population, which dates back to some of the earliest work in theoretical population genetics, exhibits an unexpected and previously unobserved phase transition between ordered and disordered states. This behavior is not present in populations evolving asexually without recombination and is thus important in any comparison of sexual and asexual populations. In order to calculate the details of the phase transition, we use techniques from statistical physics. We introduce the correlation of the population as the order parameter of the system and use maximum entropy inference to find the state of the population at any time.

Rogers, A.

2003-04-01

15

Substance Abuse and Sexual Trauma in a Female Veteran Population  

Microsoft Academic Search

An increasing number of researchers have explored connections between substance abuse, posttraumatic stress disorder (PTSD), and sexual assault histories in civilian women. Despite literature suggesting the prevalence of substance abuse and sexual assault for female veterans, few studies have investigated these variables in a female veteran population. Thus, this paper was designed to provide preliminary information about this group of

Tania M. Davis; Peggy S. Wood

1999-01-01

16

A population study of the association between sexual function, sexual satisfaction and depressive symptoms in men  

Microsoft Academic Search

Background: Depression and erectile dysfunction (ED) have a complex and bi-directional relationship. We examined the relationships between erectile dysfunction and depressive symptoms or diagnosed depression, sexual activity and sexual satisfaction.Methods: A population survey of men aged 40–70 years was carried out in Brazil, Italy, Japan and Malaysia in 1997–1998. A questionnaire was used to collect life style, sexual behaviors and

Alfredo Nicolosi; Edson D. Moreira; Marco Villa; Dale B. Glasser

2004-01-01

17

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

|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…

Steel, Jennifer L.; Herlitz, Claes A.

2005-01-01

18

Cytological differentiation and sexual isolation between populations of Drosophila nigricruria.  

PubMed

Drosophila nigricruria has a distribution ranging from northern Mexico to Chile. It is a relatively rare species, primarily limited to cactus deserts or pine-oak associations at altitudes of 1200 to 2100 meters above sea level. The species comprises two cytological races with a zone of hybridization in the Oaxaca and Puebla regions of Mexico. Despite the zone of hybridization, gene flow for chromosome 4 genes is limited, or non-existent, between the two races. Sexual isolation tests were run using a population from the northern race, a hybrid population, and a population that is essentially southern. Sexual discrimination among these strains was on the same order of magnitude as that found between geographical populations of other species. There was no evidence to indicate that sexual isolation is any stronger between the cytological races of nigricruria than one might expect between any two geographical populations within a species. PMID:874304

Wasserman, M; Koepfer, H R

19

Are Australian sexual health clinics attracting priority populations?  

PubMed

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 ?(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

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

2013-10-01

20

Sexual isolation and mating propensity among allopatric Drosophila mettleri populations.  

PubMed

Drosophila mettleri is found in deserts of North America breeding in soil soaked by the juices of necrotic cacti. Saguaro (Carnegiea gigantea) and cardón (Pachycereus pringlei) are the usual host cacti in Mexico and Arizona, while prickly pear (Opuntia spp.) is used by an isolated population on Santa Catalina Island off the southern California Coast. Populations of D. mettleri show significant local genetic differentiation, especially when geographical isolation is coupled with host shifts. We tested for evidence of sexual isolation among allopatric populations of D. mettleri using a variety of choice and no-choice tests. Populations exhibited significant differences in mating propensity, which translated into significant deviations from random mating. While in some cases these deviations were consistent with sexual isolation, in others, negative assortative mating was observed. No relationship between degree of genetic differentiation and the appearance of sexual isolation was detected. PMID:18561017

Castrezana, Sergio J; Markow, Therese Ann

2008-06-17

21

Substance abuse and sexual trauma in a female veteran population.  

PubMed

An increasing number of researchers have explored connections between substance abuse, posttraumatic stress disorder (PTSD), and sexual assault histories in civilian women. Despite literature suggesting the prevalence of substance abuse and sexual assault for female veterans, few studies have investigated these variables in a female veteran population. Thus, this paper was designed to provide preliminary information about this group of women. The results of this preliminary study suggest a high incidence of PTSD related to sexual trauma in a substance-abusing population of female veterans and a high incidence of substance abuse among female veterans who presented requesting help for sexual trauma. Suggestions for future study include examination of comparison samples of female veterans with and without PTSD and substance abuse across a variety of dimensions, including psychiatric symptoms, substance use, treatment utilization, and impact of treatment. Implications for assessment are highlighted. PMID:10023609

Davis, T M; Wood, P S

1999-03-01

22

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

PubMed

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

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

2010-11-10

23

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

PubMed

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

Collier, S

1993-08-01

24

Genetic diversity in populations of asexual and sexual bag worm moths (Lepidoptera: Psychidae)  

PubMed Central

Background Despite the two-fold cost of sex, most of the higher animals reproduce sexually. The advantage of sex has been suggested to be its ability, through recombination, to generate greater genetic diversity than asexuality, thus enhancing adaptation in a changing environment. We studied the genetic diversity and the population structure of three closely related species of bag worm moths: two strictly sexual (Dahlica charlottae and Siederia rupicolella) and one strictly asexual (D. fennicella). These species compete for the same resources and share the same parasitoids. Results Allelic richness was comparable between the sexual species but it was higher than in the asexual species. All species showed high heterozygote deficiency and a large variation was observed among FIS values across loci and populations. Large genetic differentiation was observed between populations confirming the poor dispersal ability of these species. The asexual species showed lower genotype diversity than the sexual species. Nevertheless, genotype diversity was high in all asexual populations. Conclusion The three different species show a similar population structure characterised by high genetic differentiation among populations and low dispersal. Most of the populations showed high heterozygote deficiency likely due to the presence of null alleles at most of the loci and/or to the Wahlund effect. Although the parthenogenetic D. fennicella shows reduced genetic diversity compared to the sexual species, it still shows surprisingly high genotype diversity. While we can not totally rule out the presence of cryptic sex, would explain this high genotype diversity, we never observed sex in the parthenogenetic D. fennicella, nor was there any other evidence of this. Alternatively, a non-clonal parthenogenetic reproduction, such as automictic thelytoky, could explain the high genotypic diversity observed in D. fennicella.

Grapputo, Alessandro; Kumpulainen, Tomi; Mappes, Johanna; Parri, Silja

2005-01-01

25

The Female Sexual Function Index (FSFI) and the Female Sexual Distress Scale (FSDS): Psychometric Properties within a Dutch Population  

Microsoft Academic Search

The aim of the present study was to investigate the psychometric properties of the Female Sexual Function Index (FSFI; Rosen et al., 2000) and the Female Sexual Distress Scale (FSDS; Derogatis, Rosen, Leiblum, Burnett, & Heiman, 2002) within a Dutch population of approximately 350 women with and without sexual complaints. The main conclusions of this study are that the multidimensional

Moniek M. Ter Kuile; Marieke Brauer; Ellen Laan

2006-01-01

26

Child sexual abuse in southern Brazil and associated factors: a population-based study  

Microsoft Academic Search

BACKGROUND: The prevalence of child sexual abuse (CSA) in the population has been poorly described in developing countries. Population data on child sexual abuse in Brazil is very limited. This paper aims to estimate lifetime prevalence of child sexual abuse and associated factors in a representative sample of the population aged 14 and over in a city of southern Brazil.

Diego G Bassani; Lilian S Palazzo; Jorge U Béria; Luciana P Gigante; Andréia CL Figueiredo; Denise RGC Aerts; Beatriz CW Raymann

2009-01-01

27

Interactive genetic algorithms with large population size  

Microsoft Academic Search

Interactive genetic algorithms (IGAs) are effective methods to solve an optimization problem with implicit indices. Whereas it requires direct evaluation of user for each individual and the fact limits the population size for user fatigue problem. While, in general to solve many problems with genetic algorithm, it is desirable to maintain the population size as large as possible. To break

Dunwei Gong; Jie Yuan; Xiaoping Ma

2008-01-01

28

Population variation in sexual dimorphism in the human innominate  

Microsoft Academic Search

In the adult human innominate, pubis length and sciatic notch width are generally considered to offer the best prospect for\\u000a reliable sex identification. Population variation in the extent of sexual dimorphism in these features was examined in two\\u000a temporally distinct European skeletal collections of documented age and sex. (English and Dutch). A complex relationship was\\u000a found to exist between pubis

S. M. MacLaughlin; M. F. Bruce

1986-01-01

29

Simulation for Competition of Languages with AN Aging Sexual Population  

NASA Astrophysics Data System (ADS)

Recently, individual-based models originally used for biological purposes revealed interesting insights into processes of the competition of languages. Within this new field of population dynamics a model considering sexual populations with aging is presented. The agents are situated on a lattice and each one speaks one of two languages or both. The stability and quantitative structure of an interface between two regions, initially speaking different languages, is studied. We find that individuals speaking both languages do not prefer any of these regions and have a different age structure than individuals speaking only one language.

Schwämmle, V.

30

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

PubMed Central

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.

Dmitriew, Caitlin; Blanckenhorn, Wolf U.

2012-01-01

31

Natural and sexual selection in a monogamous historical human population.  

PubMed

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

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

2012-04-30

32

Rate of fixation of beneficial mutations in sexual populations  

NASA Astrophysics Data System (ADS)

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.

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

2009-06-01

33

On the Genealogy of Large Populations  

Microsoft Academic Search

A new Markov chain is introduced which can be used to describe the family relationships among n individuals drawn from a particular generation of a large haploid population. The properties of this process can be studied, simultaneously for all n, by coupling techniques. Recent results in neutral mutation theory are seen as consequences of the genealogy described by the chain.

J. F. C. KINGMAN

34

HIV, Sexual Violence and Special Populations: Adolescence and Pregnancy  

PubMed Central

The risk of male to female transmission of HIV is impacted by baseline inflammation in the female genital tract, semen viral load and seminal plasma’s ability to induce specific patterns of cervical cytokine signalling and influx of immune cell populations. Disruption of the epithelial barrier during non-consensual intercourse may trigger further inflammation and initiation of cell-signalling pathways, thus facilitating transmission of HIV and expansion of local infection. Adolescent and pregnant women are at high risk for sexual violence and may exhibit alterations of genital mucosal immunity that promote immune activation, making them uniquely vulnerable to HIV acquisition.

Madan, Rebecca Pellett; Herold, Betsy C.

2013-01-01

35

Divergence in androgen sensitivity contributes to population differences in sexual dimorphism of electrocommunication behavior.  

PubMed

Weakly-electric fish (Apteronotidae) produce highly diverse electrocommunication signals. Electric organ discharges (EODs) vary across species, sexes, and in the magnitude and direction of their sexual dimorphism. Gonadal steroid hormones can modulate EODs, and differences in androgen sensitivity are hypothesized to underlie variation in the degree of sexual dimorphism across species. In this study, we asked whether variation in androgen sensitivity explained variation in sexual dimorphism of EODs within species, at the population level. We examined two populations of black ghost knifefish (Apteronotus albifrons), one from the Orinoco and the other from the Amazon River Basin. EOD frequency (EODf) and chirp rates were measured to characterize diversity in sexual dimorphism across populations. The magnitude of sexual dimorphism in EODf differed significantly across populations, and was more pronounced in the Orinoco population than in the Amazon population. Chirp rates were sexually monomorphic in both populations. 11-Ketotestosterone (11-kT) was administered over a two-week period to assess population differences in sensitivity to androgens. 11-kT masculinized EODf significantly more in the population with the greater degree of sexual dimorphism. 11-kT had no effect on the sexually monomorphic chirping rates. We conclude that population divergence in androgen sensitivity contributes to variation in sexual dimorphism of EODf in A. albifrons. PMID:23142327

Ho, Winnie W; Rack, Jessie M; Smith, G Troy

2012-11-08

36

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

NASA Astrophysics Data System (ADS)

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.

Neher, Richard

2010-03-01

37

Molecular population divergence and sexual selection on morphology in the banded demoiselle (Calopteryx splendens)  

Microsoft Academic Search

The importance of sexual selection in population divergence is of much interest, mainly because it is thought to cause reproductive isolation and hence could lead to speciation. Sexually selected traits have been hypothesized to diverge faster between populations than other traits, presumably because of differences in the strength, mechanism or dynamics of selection. We investigated this by quantifying population divergence

E I Svensson; L Kristoffersen; K Oskarsson; S Bensch

2004-01-01

38

Adult Sexual Assault: Prevalence, Symptomatology, and Sex Differences in the General Population  

Microsoft Academic Search

The prevalence and impact of adult sexual assault (ASA) were examined in a stratified random sample of the general population. Among 941 participants, ASA was reported by 22% of women and 3.8% of men. Multivariate risk factors for ASA included a younger age, being female, having been divorced, sexual abuse in childhood, and physical assault in adulthood. Childhood sexual abuse

Diana M. Elliott; Doris S. Mok; John Brierel

2004-01-01

39

Sexual Body Image and Its Correlates: A Population-Based Study of Finnish Women and Men  

Microsoft Academic Search

Sexual body image was examined in a population-based sample of 9,532 Finnish men and women, age 18 to 49 years. More than one half of women and men were satisfied with their genitals, one half of the women were satisfied with their breasts. Higher levels of genital satisfaction were related to higher frequencies of sexual behavior and better sexual function

Monica Ĺlgars; Pekka Santtila; Patrick Jern; Ada Johansson; Minja Westerlund; N. Kenneth Sandnabba

2011-01-01

40

Detecting cell assemblies in large neuronal populations.  

PubMed

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

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

2013-04-29

41

Sexually Coercive Behavior in Male Youth: Population Survey of General and Specific Risk Factors  

Microsoft Academic Search

Little is known about risk\\/protective factors for sexually coercive behavior in general population youth. We used a Swedish\\u000a school-based population survey of sexual attitudes and experiences (response rate 77%) and investigated literature-based variables\\u000a across sexually coercive (SEX), non-sexual conduct problem (CP), and normal control (NC) participants to identify general\\u000a and specific risk\\/protective factors for sexual coercion. Among 1,933 male youth,

Cecilia Kjellgren; Gisela Priebe; Carl Göran Svedin; Niklas Lĺngström

2010-01-01

42

Evaluation of the Female Sexual Function Index in a Population Based Sample from Finland  

Microsoft Academic Search

The factor structure and reliability of the Female Sexual Function Index (FSFI) was evaluated in a Finnish population based\\u000a sample of 2,081 women, age 33–43 years. In addition, associations between female sexual function and age, psychological distress,\\u000a alcohol use, hormone based contraceptives, child sexual abuse (CSA), and adult sexual abuse were examined. The results supported\\u000a a six factor solution for the

Katarina Witting; Pekka Santtila; Patrick Jern; Markus Varjonen; Ingrid Wager; Maria Höglund; Ada Johansson; Nina Vikström; N. Kenneth Sandnabba

2008-01-01

43

Population density and the intensity of sexual selection on body length in spatially or temporally restricted natural populations of a seed bug  

Microsoft Academic Search

Summary Population density affects the dynamics of mate acquisition and the opportunity for sexual selection in natural populations of the seed bug, Neacoryphus bicrucis Say (Hemiptera : Lygaeidae). The opportunity for sexual selection and the intensity of directional sexual selection on body length increased as the population density declined within a season for a population in a small, disjunct patch

Denson Kelly McLain

1992-01-01

44

Measuring Community Connectedness among Diverse Sexual Minority Populations  

PubMed Central

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.

Frost, David M.; Meyer, Ilan H.

2011-01-01

45

Molecular hyperdiversity and evolution in very large populations.  

PubMed

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 noncrossover recombination in genomes and for determining the identity and micro-evolutionary selective pressures on noncoding regulatory elements. PMID:23506466

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

2013-03-18

46

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

PubMed

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

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

2009-11-04

47

Sexual recombination in the Botrytis cinerea populations in Hungarian vineyards.  

PubMed

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

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

48

Self-fertilization is the main sexual reproduction mechanism in native wine yeast populations.  

PubMed

Saccharomyces cerevisiae is a model eukaryotic organism for classical genetics and genomics, and yet its ecology is still largely unknown. In this work, a population genetic analysis was performed on five yeast populations isolated from wine-making areas with different enological practices using simple sequence repeats and restriction fragment length polymorphism of mitochondrial DNA as molecular markers on 292 strains. In accordance with other studies, genome size estimation suggests that native S. cerevisiae strains are mainly homothallic and diploids. Analysis of mtDNA data showed that yeast populations from nonindustrial areas have 40% higher genetic diversity than populations isolated from industrial areas, demonstrating that industrial enological practices are likely to affect native yeast populations negatively by reducing its biodiversity. On the other hand, genetic differentiation analysis based on their microsatellite showed no correlation between genetic and geographic distance and a nonsignificant value when a Mantel test was applied. Finally, in the five populations studied, positive inbreeding (F(is)) values from 0.4 to 0.75, a low but significant level of linkage disequilibrium and a high number of multilocus genotypes were detected. These results strongly advocate that sexual reproduction is frequent enough to erase clonal signature in natural populations and that self-fertilization is the main mating system. PMID:19016866

Cubillos, Francisco A; Vásquez, Claudia; Faugeron, Sylvain; Ganga, Angélica; Martínez, Claudio

2008-11-07

49

Coalescence and genetic diversity in sexual populations under selection  

PubMed Central

In sexual populations, selection operates neither on the whole genome, which is repeatedly taken apart and reassembled by recombination, nor on individual alleles that are tightly linked to the chromosomal neighborhood. The resulting interference between linked alleles reduces the efficiency of selection and distorts patterns of genetic diversity. Inference of evolutionary history from diversity shaped by linked selection requires an understanding of these patterns. Here, we present a simple but powerful scaling analysis identifying the unit of selection as the genomic “linkage block” with a characteristic length, , determined in a self-consistent manner by the condition that the rate of recombination within the block is comparable to the fitness differences between different alleles of the block. We find that an asexual model with the strength of selection tuned to that of the linkage block provides an excellent description of genetic diversity and the site frequency spectra compared with computer simulations. This linkage block approximation is accurate for the entire spectrum of strength of selection and is particularly powerful in scenarios with many weakly selected loci. The latter limit allows us to characterize coalescence, genetic diversity, and the speed of adaptation in the infinitesimal model of quantitative genetics.

Neher, Richard A.; Kessinger, Taylor A.; Shraiman, Boris I.

2013-01-01

50

Coalescence and genetic diversity in sexual populations under selection.  

PubMed

In sexual populations, selection operates neither on the whole genome, which is repeatedly taken apart and reassembled by recombination, nor on individual alleles that are tightly linked to the chromosomal neighborhood. The resulting interference between linked alleles reduces the efficiency of selection and distorts patterns of genetic diversity. Inference of evolutionary history from diversity shaped by linked selection requires an understanding of these patterns. Here, we present a simple but powerful scaling analysis identifying the unit of selection as the genomic "linkage block" with a characteristic length, , determined in a self-consistent manner by the condition that the rate of recombination within the block is comparable to the fitness differences between different alleles of the block. We find that an asexual model with the strength of selection tuned to that of the linkage block provides an excellent description of genetic diversity and the site frequency spectra compared with computer simulations. This linkage block approximation is accurate for the entire spectrum of strength of selection and is particularly powerful in scenarios with many weakly selected loci. The latter limit allows us to characterize coalescence, genetic diversity, and the speed of adaptation in the infinitesimal model of quantitative genetics. PMID:24019480

Neher, Richard A; Kessinger, Taylor A; Shraiman, Boris I

2013-09-09

51

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

ERIC Educational Resources Information Center

|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…

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

2008-01-01

52

Sexual Child Abuse in a Defined Swedish Area 1993–97: A Population-Based Survey  

Microsoft Academic Search

Attempting to avoid some of the most common methodological problems involved in research on sexual child abuse, we collected data on crimes, perpetrators, and sanctions in all convicted cases of sexual child abuse in a defined population during a 5-year period. This approach provided amply documented and ascertained cases with precise definitions and descriptions of the crimes involved, no clinical

Anita Carlstedt; Anders Forsman; Henrik Soderstrom

2001-01-01

53

Patterns of sexual behaviour in a rural population in north-western Tanzania  

Microsoft Academic Search

The HIV epidemic in sub-Saharan Africa has been characterised by the predominance of heterosexual transmission. Patterns of sexual behaviour have been implicated in the spread of the epidemic, but few quantitative data are available on sexual behaviour in rural populations in Africa. This paper reports data from a survey of 1117 adults aged 15–54 years selected randomly from twelve rural

Katua Munguti; Heiner Grosskurth; James Newell; Kesheni Senkoro; Frank Mosha; James Todd; Philippe Mayaud; Awena Gavyole; Maria Quigley; Richard Hayes

1997-01-01

54

The strength of postcopulatory sexual selection within natural populations of field crickets  

Microsoft Academic Search

Sperm competition and cryptic female choice are likely to exert strong postcopulatory sexual selection and may amplify or ameliorate selection acting via male mating success. However, relatively few studies have estimated the potential strength of postcopulatory sexual selection acting within natural populations. Field crickets in the genus Teleogryllus have been used extensively as laboratory models to study the evolution of

Leigh W. Simmons; Maxine Beveridge

2010-01-01

55

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

PubMed Central

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.

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

2012-01-01

56

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

PubMed Central

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.

Arnqvist, Goran; Tuda, Midori

2010-01-01

57

Sexual dimorphism is associated with population fitness in the seed beetle Callosobruchus maculatus.  

PubMed

The population consequences of sexual selection remain empirically unexplored. Comparative studies, involving extinction risk, have yielded different results as to the effect of sexual selection on population densities make contrasting predictions. Here, we investigate the relationship between sexual dimorphism (SD) and population productivity in the seed beetle Callosobruchus maculatus, using 13 populations that have evolved in isolation. Geometric morphometric methods and image analysis are employed to form integrative measures of sexual dimorphism, composed of variation in weight, size, body shape, and pigmentation. We found a positive relationship between SD and adult fitness (net adult offspring production) across our study populations, but failed to find any association between SD and juvenile fitness (egg-to-adult survival). Several mechanisms may have contributed to the pattern found, and variance in sexual selection regimes across populations, either in female choice for "good genes" or in the magnitude of direct benefits provided by their mates, would tend to produce the pattern seen. However, our results suggest that evolutionary constraints in the form of intralocus sexual conflict may have been the major generator of the relationship seen between SD and population fitness. PMID:18182072

Rankin, Daniel J; Arnqvist, Göran

2007-12-25

58

Large population size predicts the distribution of asexuality in scale insects.  

PubMed

Understanding why some organisms reproduce by sexual reproduction while others can reproduce asexually remains an important unsolved problem in evolutionary biology. Simple demography suggests that asexuals should outcompete sexually reproducing organisms, because of their higher intrinsic rate of increase. However, the majority of multicellular organisms have sexual reproduction. The widely accepted explanation for this apparent contradiction is that asexual lineages have a higher extinction rate. A number of models have indicated that population size might play a crucial role in the evolution of asexuality. The strength of processes that lead to extinction of asexual species is reduced when population sizes get very large, so that the long-term advantage of sexual over asexual reproduction may become negligible. Here, we use a comparative approach using scale insects (Coccoidea, Hemiptera) to show that asexuality is indeed more common in species with larger population density and geographic distribution and we also show that asexual species tend to be more polyphagous. We discuss the implication of our findings for previously observed patterns of asexuality in agricultural pests. PMID:23289572

Ross, Laura; Hardy, Nate B; Okusu, Akiko; Normark, Benjamin B

2012-10-10

59

Genetic differences among populations in sexual dimorphism: evidence for selection on males in a dioecious plant  

PubMed Central

Genetic variation among populations in the degree of sexual dimorphism may be a consequence of selection on one or both sexes. We analysed genetic parameters from crosses involving three populations of the dioecious plant Silene latifolia, which exhibits sexual dimorphism in flower size, to determine whether population differentiation was a result of selection on one or both sexes. We took the novel approach of comparing the ratio of population differentiation of a quantitative trait (QST) to that of neutral genetic markers (FST) for males vs. females. We attributed 72.6% of calyx width variation in males to differences among populations vs. only 6.9% in females. The QST/FST ratio was 4.2 for males vs. 0.4 for females, suggesting that selection on males is responsible for differentiation among populations in calyx width and its degree of sexual dimorphism. This selection may be indirect via genetic correlations with other morphological and physiological traits.

YU, Q.; ELLEN, E. D.; WADE, M. J.; DELPH, L. F.

2011-01-01

60

Sexually transmitted infections in tribal populations of central India  

Microsoft Academic Search

This community-based cross-sectional study was carried out in 17 tribal villages of the Kundam block of the Jabalpur district\\u000a of India. Individuals with sexually transmitted disease (STD) syndromes were enumerated and the specimens were collected for\\u000a the laboratory diagnosis of sexually transmitted infections (STIs). Trichomoniasis, gonorrhoea, bacterial vaginosis and syphilis\\u000a sero-reactivity were diagnosed by standard microbiological techniques. Chlamydia infection was

V. G. Rao; A. Anvikar; D. Savargaonkar; J. Bhat

2009-01-01

61

Characteristics of victims of sexual abuse by gender and race in a community corrections population.  

PubMed

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 women, African American men, and African American women) using univariate and logistic regression analyses, which were conducted separately for each group. White women were the most likely to report a history of sexual abuse (26.5%), followed by African American women (16.0%), White men (4.0%), and African American men (1.1%). For all groups, histories of suicidal ideation and suicide attempts were associated with a history of sexual abuse. Sexual abuse was associated with substance abuse problems for women but not the men. Cannabis dependence was associated with sexual abuse for the White women while cocaine dependence was associated with sexual abuse for the African American women. Several other variables were associated with sexual abuse for women but not men, including lower education (White women only), a history of violent offenses (White women only), and living in a shelter (African American women only). African American men tended to have higher levels of education; this was the only variable uniquely associated with either male group. Receiving psychiatric medications was associated with sexual abuse for all groups except African American men and a history of sex for drugs was associated with sexual abuse for all groups except White men. Consistent with national sample, women, particularly White women, were more likely to be victims of sexual abuse. The gender-race differences for the sociodemographic factors associated with sexual abuse, particularly the risk of substance abuse for women, suggest the need for tailored interventions for sexual abuse prevention and treatment. PMID:22203627

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

2011-12-26

62

Gender Differences in Sexual Attitudes and Behaviors: A Review of Meta-Analytic Results and Large Datasets  

Microsoft Academic Search

Gender differences in sexual attitudes and behaviors are typically believed to be large, yet recent evidence suggests that some gender differences in sexuality are much smaller than common knowledge would suggest. This article reviews gender differences in sexual attitudes and behaviors as reported by major meta-analyses and large datasets. In particular, this article reviews gender differences in heterosexual intercourse, masturbation,

Jennifer L. Petersen; Janet Shibley Hyde

2011-01-01

63

Decreased sexual signalling reveals reduced viability in small populations of the drumming wolf spider Hygrolycosa rubrofasciata.  

PubMed Central

One of the important goals in conservation biology is to determine reliable indicators of population viability. Sexual traits have been suggested to indicate population extinction risk, because they may be related to viability through condition dependence. Moreover, condition-dependent sexual traits may be more sensitive indicators of population viability than early life-history traits, because deleterious fitness effects of inbreeding tend to be expressed mainly at the end of the species' life history. However, empirical evidence of the significance of sexual behaviour for population viability is missing. In this study, we examined two male sexual traits and survival in 39 different-sized and isolated natural populations of the wolf spider, Hygrolycosa rubrofasciata. We also used several traits to estimate female reproductive success in 25 populations of H. rubrofasciata. According to previous studies, H. rubrofasciata males have a costly and condition-dependent acoustic signal, courtship drumming, which is the target of female choice. Males with a high drumming rate have considerably higher viability than males with a low drumming rate, and females that mate with the more actively drumming males gain genetic benefits in terms of increased offspring viability. Our results show that males in small populations had both lower survival and lower drumming rate than males in larger populations. However, we did not find any evidence for a decline in important early life-history traits (offspring number, hatching success or offspring body mass) or female body mass in small populations. Our results have two important messages for conservation biology. First, they show that sexual traits can be used as sensitive indicators of population viability. Second, the indirect benefits of female choice in terms of good genes might partially compensate for the reduction of viability in declining populations. Also, our results support the view that deleterious effects of small population size are expressed at the end of the species' life history.

Ahtiainen, Jari J; Alatalo, Rauno V; Mappes, Johanna; Vertainen, Laura

2004-01-01

64

Screening for Chlamydial Cervicitis in a Sexually Active University Population.  

ERIC Educational Resources Information Center

Enzyme-linked immunoabsorbent assays to detect chlamydial cervicitis were performed on samples from 1,320 sexually active university women. Seventy-five had positive tests. Demographic, history, symptom, and physical examination variables were insufficient to predict infection accurately. Concludes that screening during routine visits with this…

Malotte, C. Kevin; And Others

1990-01-01

65

Clonality and sexual reproductive failure in remnant populations of Santalum lanceolatum (Santalaceae)  

Microsoft Academic Search

Habitat fragmentation can have important conservation consequences for clonal plant species that possess self-incompatibility mechanisms, as lack of genetic variability within remnant populations may result in sexual reproductive failure. Allozymes and RAPDs were used in this study to determine the extent of clonality in remnant Victorian populations of the northern sandalwood, Santalum lanceolatum (Santalaceae), a species that has been heavily

Cindy L Warburton; Elizabeth A James; Yvonne J Fripp; Stephen J Trueman; Helen M Wallace

2000-01-01

66

Sexual orientation and mental and physical health status: findings from a Dutch population survey  

Microsoft Academic Search

OBJECTIVES: We sought to determine whether sexual orientation is related to mental and physical health and health behaviors in the general population. METHODS: Data was derived from a health interview survey that was part of the second Dutch National Survey of General Practice, carried out in 2001 among an all-age random sample of the population. Of the 19685 persons invited

T. G. M. Sandfort; F. Bakker; F. G. Schellevis; I. Vanwesenbeeck

2006-01-01

67

Sexual Orientation and Mental and Physical Health Status: Findings From a Dutch Population Survey  

Microsoft Academic Search

Objectives. We sought to determine whether sexual orientation is related to mental and physical health and health behaviors in the general population. Methods. Data was derived from a health interview survey that was part of the second Dutch National Survey of General Practice, carried out in 2001 among an all-age random sample of the population. Of the 19685 persons invited

THEO G. M. SANDFORT; FLOOR BAKKER; FRANÇOIS G. SCHELLEVIS; INE VANWESENBEECK

68

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

PubMed Central

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.

Lambertucci, Sergio A.; Carrete, Martina; Donazar, Jose Antonio; Hiraldo, Fernando

2012-01-01

69

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

ERIC Educational Resources Information Center

|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…

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

2012-01-01

70

Sexual dysfunction after a first trimester induced abortion in a Chinese population  

Microsoft Academic Search

Objective: To evaluate the short-term effect of a first trimester induced abortion on sexuality in a Chinese population. Studydesign: Thisisacross-sectionalstudy.Onehundredand fourwomen attendingthepost-abortionclinic 3-4monthsafterafirsttrimester induced abortion were recruited. They completed a self-administered questionnaire anonymously. The associations of various factors with sexual behavior after abortion were analyzed by the Chi-square test. Results: More than 30% of thewomen reported a reduction in both

Wing Yee Fok; Shing-Shun Nelson Siu; Tze Kin Lau

71

A measure of sexual dimorphism in populations which are univariate normal mixtures  

Microsoft Academic Search

Measures of sexual dimorphism have been used extensively to predict the social organization and ecology of animal and human\\u000a populations. There is, however, no universally accepted measure of phenotypic differences between the sexes. Most indices\\u000a of sexual dimorphism fail to incorporate all of the information contained in a random data set. In an attempt to have a better\\u000a alternative, an

S. L. Ipińa; A. I. Durand

2000-01-01

72

Variation in sexual selection on male body size within and between populations of the soapberry bug  

Microsoft Academic Search

In spite of its evolutionary importance, little is known about intraspecific variation in sexual selection. In the soapberry bug, Jadera haematoloma, absolute adult sex ratio varies within and between populations because of differences in mortality rates, creating natural opportunities for variation in the intensity of sexual selection. Sex ratios in Oklahoma, U.S.A., are variably male biased, but approach 1:1 in

Scott P. Carroll; Michael H. Salamon

1995-01-01

73

Generalizing Classification Tables to Large Populations.  

ERIC Educational Resources Information Center

The technique of generalizing sample results in a classification study to large subpopulations of unequal sizes was examined. The usual output from the discriminant analysis routine in the Statistical Package for the Social Sciences was extended to handle the present statistical problems. Advantages of the technique were discussed. (Author/DWH)

Koslowsky, Meni

1985-01-01

74

Gender differences in sexual attitudes and behaviors: a review of meta-analytic results and large datasets.  

PubMed

Gender differences in sexual attitudes and behaviors are typically believed to be large, yet recent evidence suggests that some gender differences in sexuality are much smaller than common knowledge would suggest. This article reviews gender differences in sexual attitudes and behaviors as reported by major meta-analyses and large datasets. In particular, this article reviews gender differences in heterosexual intercourse, masturbation, pornography use, attitudes toward premarital sex, and gender differences in same-gender sexuality. Evolutionary psychology, social cognitive learning theory, and social structural theory are explored as possible explanations for gender differences in sexuality. PMID:21409712

Petersen, Jennifer L; Hyde, Janet Shibley

2011-03-01

75

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

PubMed

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

Lĺngström, Niklas; Hanson, R Karl

2006-02-01

76

Does Viewing Explain Doing? Assessing the Association Between Sexually Explicit Materials Use and Sexual Behaviors in a Large Sample of Dutch Adolescents and Young Adults.  

PubMed

INTRODUCTION: Concerns have been voiced that the use of sexually explicit materials (SEMs) may adversely affect sexual behaviors, particularly in young people. Previous studies have generally found significant associations between SEM consumption and the sexual behaviors investigated. However, most of these studies have focused on sexual behaviors related to sexually transmitted infections or sexual aggression and/or failed to adequately control for relevant covariates. Thus, research more thoroughly investigating the association between SEM consumption and a broader range of sexual behaviors is needed. AIMS: The study aims to investigate SEM consumption patterns of young people, and to assess the strength of the association between SEM consumption and a range of sexual behaviors, controlling for a comprehensive array of variables previously shown to affect these relationships. METHODS: Online cross-sectional survey study of 4,600 young people, 15-25 years of age, in The Netherlands was performed. MAIN OUTCOMES MEASURES: The main outcome measures were self-reported SEM consumption and sexual practices. RESULTS: The study found that 88% of men and 45% of women had consumed SEM in the past 12 months. Using hierarchical multiple regression analyses to control for other factors, the association between SEM consumption and a variety of sexual behaviors was found to be significant, accounting for between 0.3% and 4% of the total explained variance in investigated sexual behaviors. CONCLUSIONS: This study suggests that, when controlling for important other factors, SEM consumption influences sexual behaviors. The small to moderate associations that emerged between SEM consumption and sexual behavior after controlling for other variables suggest that SEM is just one factor among many that may influence youth sexual behaviors. These findings contribute novel information to the ongoing debates on the role of SEM consumption in sexual behaviors and risk, and provide appropriate guidance to policy makers and program developers concerned with sexual education and sexual health promotion for young people. Hald GM, Kuyper L, Adam PCG, and de Wit JBF. Does viewing explain doing? Assessing the association between sexually explicit materials use and sexual behaviors in a large sample of Dutch adolescents and young adults. J Sex Med **;**:**-**. PMID:23621804

Hald, Gert Martin; Kuyper, Lisette; Adam, Philippe C G; de Wit, John B F

2013-04-26

77

Populations with elevated mutation load do not benefit from the operation of sexual selection  

PubMed Central

Theory predicts that if most mutations are deleterious to both overall fitness and condition-dependent traits affecting mating success, sexual selection will purge mutation load and increase nonsexual fitness. We explored this possibility with populations of mutagenized Drosophila melanogaster exhibiting elevated levels of deleterious variation and evolving in the presence or absence of male-male competition and female choice. After 60 generations of experimental evolution, monogamous populations exhibited higher total reproductive output than polygamous populations. Parental environment also affected fitness measures—flies that evolved in the presence of sexual conflict showed reduced nonsexual fitness when their parents experienced a polygamous environment, indicating trans-generational effects of male harassment and highlighting the importance of a common garden design. This cost of parental promiscuity was nearly absent in monogamous lines, providing evidence for the evolution of reduced sexual antagonism. There was no overall difference in egg-to-adult viability between selection regimes. If mutation load was reduced by the action of sexual selection in this experiment, the resultant gain in fitness was not sufficient to overcome the costs of sexual antagonism.

Hollis, Brian; Houle, David

2011-01-01

78

Population structure influences sexual conflict in wild populations of water striders  

PubMed Central

Summary 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.

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

2013-01-01

79

Testing for sexually transmitted infections in a population-based sexual health survey: development of an acceptable ethical approach.  

PubMed

Population-based research is enhanced by biological measures, but biological sampling raises complex ethical issues. The third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3) will estimate the population prevalence of five sexually transmitted infections (STIs) (Chlamydia trachomatis, Neisseria gonorrhoeae, human papillomavirus (HPV), HIV and Mycoplasma genitalium) in a probability sample aged 16-44 years. The present work describes the development of an ethical approach to urine testing for STIs, including the process of reaching consensus on whether to return results. The following issues were considered: (1) testing for some STIs that are treatable and for which appropriate settings to obtain free testing and advice are widely available (Natsal-3 provides all respondents with STI and healthcare access information), (2) limits on test accuracy and timeliness imposed by survey conditions and sample type, (3) testing for some STIs with unknown clinical and public health implications, (4) how a uniform approach is easier to explain and understand, (5) practical difficulties in returning results and cost efficiency, such as enabling wider STI testing by not returning results. The agreed approach, to perform voluntary anonymous testing with specific consent for five STIs without returning results, was approved by stakeholders and a research ethics committee. Overall, this was acceptable to respondents in developmental piloting; 61% (68 of 111) of respondents agreed to provide a sample. The experiences reported here may inform the ethical decision making of researchers, research ethics committees and funders considering population-based biological sampling. PMID:22252417

Field, Nigel; Tanton, Clare; Mercer, Catherine H; Nicholson, Soazig; Soldan, Kate; Beddows, Simon; Ison, Catherine; Johnson, Anne M; Sonnenberg, Pam

2012-01-17

80

Testing for sexually transmitted infections in a population-based sexual health survey: development of an acceptable ethical approach  

PubMed Central

Population-based research is enhanced by biological measures, but biological sampling raises complex ethical issues. The third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3) will estimate the population prevalence of five sexually transmitted infections (STIs) (Chlamydia trachomatis, Neisseria gonorrhoeae, human papillomavirus (HPV), HIV and Mycoplasma genitalium) in a probability sample aged 16–44?years. The present work describes the development of an ethical approach to urine testing for STIs, including the process of reaching consensus on whether to return results. The following issues were considered: (1) testing for some STIs that are treatable and for which appropriate settings to obtain free testing and advice are widely available (Natsal-3 provides all respondents with STI and healthcare access information), (2) limits on test accuracy and timeliness imposed by survey conditions and sample type, (3) testing for some STIs with unknown clinical and public health implications, (4) how a uniform approach is easier to explain and understand, (5) practical difficulties in returning results and cost efficiency, such as enabling wider STI testing by not returning results. The agreed approach, to perform voluntary anonymous testing with specific consent for five STIs without returning results, was approved by stakeholders and a research ethics committee. Overall, this was acceptable to respondents in developmental piloting; 61% (68 of 111) of respondents agreed to provide a sample. The experiences reported here may inform the ethical decision making of researchers, research ethics committees and funders considering population-based biological sampling.

Tanton, Clare; Mercer, Catherine H; Nicholson, Soazig; Soldan, Kate; Beddows, Simon; Ison, Catherine; Johnson, Anne M; Sonnenberg, Pam

2012-01-01

81

The role of sexual harassment in cave and surface dwelling populations of the Atlantic molly, Poecilia mexicana (Poeciliidae, Teleostei)  

Microsoft Academic Search

Sexual coercion is a common behaviour for males trying to compensate for being inferior in male competition and\\/or female choice. We measured the cost of male sexual harassment for females as reduced feeding time in three populations of the Atlantic molly ( Poecilia mexicana). Of these populations, one originated from a typical river habitat, another from a lightless cave chamber

Martin Plath; Jakob Parzefall; Ingo Schlupp

2003-01-01

82

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

Microsoft Academic Search

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

K J Miller; D J Ayre

2004-01-01

83

Analysis of Aerobic Capacity in a Large United States Population.  

National Technical Information Service (NTIS)

This study presents a description of aerobic capacity in a large U.S. population comprised of 1,514 males and 375 females. such influencing factors as age, training state, occupation and body composition were evaluated. The population consisted of new rec...

J. A. Vogel J. F. Patton R. P. Mello W. L. Daniels

1985-01-01

84

Lifetime sexual assault prevalence rates and reporting practices in an emergency department population  

Microsoft Academic Search

Study Objective: Studies suggest significant rates of female sexual assault (SA); the majority of SAs remain unreported, and few victims receive medical care. The purpose of this study was to determine lifetime prevalence rates of SA in an emergency department population and to assess reporting patterns to police, physicians, and social service agencies. Methods: A verbally administered survey was given

Kim M. Feldhaus; Debra Houry; Robin Kaminsky

2000-01-01

85

Postcopulatory Sexual Selection Reduces Genetic Diversity in Experimental Populations of Caenorhabditis elegans  

Microsoft Academic Search

Postcopulatory sexual selection affects the evolution of numerous features ranging from mating behavior to seminal fluid toxicity to thesize of gametes. Inan earlier study of theeffect of sperm competitionrisk on spermsize evolution, experimental populations of the nematode Caenorhabditis elegans were maintained either by outcrossing (sperm competition present) or by selfing (no sperm competition), and after 60 generations, significantly larger sperm

CRAIG W. LAMUNYON; O USSAMA BOUBAN; ASHER D. CUTTER

2007-01-01

86

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

Microsoft Academic Search

Local adaptation to divergent environmental conditions can promote popu- lation 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

M. TOBLER; R. RIESCH; C. M. TOBLER; T. SCHULZ-MIRBACH

2009-01-01

87

Methodological considerations on the study of sexual dimorphism in past human populations  

Microsoft Academic Search

The degree of sexual dimorphism in human populations is influenced by stress, social role and by labour division. However,\\u000a studies on ethnographic populations provided contradictory results. Unfortunately, most of these studies were based on stature\\u000a only, which, as we could observe in a survey on pre-protohistoric circum-Medirerranean samples, is a poor indicator of functionally\\u000a related dimorphism.\\u000a \\u000a A number of skeletal

S. M. Borgognini Tarli; E. Repetto

1986-01-01

88

A Population-Based Study on Alcohol and High-Risk Sexual Behaviors in Botswana  

Microsoft Academic Search

BackgroundIn Botswana, an estimated 24% of adults ages 15–49 years are infected with HIV. While alcohol use is strongly associated with HIV infection in Africa, few population-based studies have characterized the association of alcohol use with specific high-risk sexual behaviors.Methods and FindingsWe conducted a cross-sectional, population-based study of 1,268 adults from five districts in Botswana using a stratified two-stage probability

Sheri D. Weiser; Karen Leiter; Michele Heisler; Willi McFarland; Fiona Percy-de Korte; Sonya M. DeMonner; Sheila Tlou; Nthabiseng Phaladze; Vincent Iacopino; David R. Bangsberg

2006-01-01

89

Evolutionary rescue of sexual and asexual populations in a deteriorating environment.  

PubMed

The environmental change experienced by many contemporary populations of organisms poses a serious risk to their survival. From the theory of evolutionary rescue, we predict that the combination of sex and genetic diversity should increase the probability of survival by increasing variation and thereby the probability of generating a type that can tolerate the stressful environment. We tested this prediction by comparing experimental populations of Chlamydomonas reinhardtii that differ in sexuality and in the initial amount of genetic diversity. The lines were serially propagated in an environment where the level of stress caused by salt increased over time from fresh water to the limits of marine conditions. In the long term, the combination of high diversity and obligate sexuality was most effective in supporting evolutionary rescue. Most of the adaptation to high-salt environments in the obligate sexual-high diversity lines had occurred by midway through the experiment, indicating that positive genetic correlations of adaptation to lethal stress with adaptation to sublethal stress greatly increased the probability of evolutionary rescue. The evolutionary rescue events observed in this study provide evidence that major shifts in ways of life can arise within short time frames through the action of natural selection in sexual populations. PMID:23106714

Lachapelle, Josianne; Bell, Graham

2012-06-11

90

Sexual Orientation and Mental and Physical Health Status: Findings From a Dutch Population Survey  

PubMed Central

Objectives. We sought to determine whether sexual orientation is related to mental and physical health and health behaviors in the general population. Methods. Data was derived from a health interview survey that was part of the second Dutch National Survey of General Practice, carried out in 2001 among an all-age random sample of the population. Of the 19685 persons invited to participate, 65% took part in the survey. Sexual orientation was assessed in persons aged 18 years and older and reported by 98.2% of 9684 participants. The respondents’ characteristics are comparable with those of the Dutch general population. Results. Gay/lesbian participants reported more acute mental health symptoms than heterosexual people and their general mental health also was poorer. Gay/lesbian people more frequently reported acute physical symptoms and chronic conditions than heterosexual people. Differences in smoking, alcohol use, and drug use were less prominent. Conclusions. We found that sexual orientation was associated with mental as well as physical health. The causal processes responsible for these differences by sexual orientation need further exploration.

Sandfort, Theo G.M.; Bakker, Floor; Schellevis, Francois G.; Vanwesenbeeck, Ine

2006-01-01

91

Special populations: Treatment concerns for gay male sexual addicts  

Microsoft Academic Search

Although the most basic tenets of addiction assessment and treatment are minimally affected by gender and cultural concerns, an empathic understanding of the social and psychological values and experiences of specific populations helps the addiction specialist provide effective appropriate care. Homosexual men, having experienced developmental and social challenges related to both the cultural repression and vilification of homosexuality and the

Robert Weiss

1997-01-01

92

Sexually-transmitted disease risk in a Micronesian atoll population  

Microsoft Academic Search

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

Alexandra A. Brewis

93

Evolution of Population with Sexual and Asexual Reproduction in Changing Environment  

NASA Astrophysics Data System (ADS)

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.

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

94

FFPopSim: an efficient forward simulation package for the evolution of large populations  

PubMed Central

Motivation: The analysis of the evolutionary dynamics of a population with many polymorphic loci is challenging, as a large number of possible genotypes needs to be tracked. In the absence of analytical solutions, forward computer simulations are an important tool in multi-locus population genetics. The run time of standard algorithms to simulate sexual populations increases as 8L with the number of loci L, or with the square of the population size N. Results: We have developed algorithms to simulate large populations with arbitrary genetic maps, including multiple crossovers, with a run time that scales as 3L. If the number of crossovers is restricted to at most one, the run time is reduced to L2L. The algorithm is based on an analogue of the Fast Fourier Transform (FFT) and allows for arbitrary fitness functions (i.e. any epistasis). In addition, we include a streamlined individual-based framework. The library is implemented as a collection of C++ classes and a Python interface. Availability: http://code.google.com/p/ffpopsim/. Contact: richard.neher@tuebingen.mpg.de Supplementary information: Supplementary data are available at Bioinformatics online.

Zanini, Fabio; Neher, Richard A.

2012-01-01

95

Large Shifts in Pathogen Virulence Relate to Host Population Structure  

Microsoft Academic Search

Theory on the evolution of virulence generally predicts selection for an optimal level of virulence determined by trade-offs with transmission and\\/or recovery. Here we consider the evolution of pathogen virulence in hosts who acquire long-lived immunity and live in a spatially structured population. We show theoretically that large shifts in virulence may occur in pathogen populations as a result of

M. Boots; P. J. Hudson; A. Sasaki

2004-01-01

96

Large-scale spatial population databases in infectious disease research.  

PubMed

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

Linard, Catherine; Tatem, Andrew J

2012-03-20

97

Sexual dimorphism in human skulls. A comparison of sexual dimorphism in different populations  

Microsoft Academic Search

Application and comparison of sex discriminant functions in different populations led to the conclusion that a certain combination\\u000a and weighting of a few sex dimorphism variables (in this study we only used craniometric variables) can give a good discrimination\\u000a between male and female individuals, independent of the racial group to which this function is applied.\\u000a \\u000a In our study, the sex-discriminatory

H. T. Uytterschaut

1986-01-01

98

Child sexual abuse in southern Brazil and associated factors: a population-based study  

PubMed Central

Background The prevalence of child sexual abuse (CSA) in the population has been poorly described in developing countries. Population data on child sexual abuse in Brazil is very limited. This paper aims to estimate lifetime prevalence of child sexual abuse and associated factors in a representative sample of the population aged 14 and over in a city of southern Brazil. Methods A two-stage sampling strategy was used and individuals were invited to respond to a confidential questionnaire in their households. CSA was defined as non-consensual oral-genital, genital-genital, genital-rectal, hand-genital, hand-rectal, or hand-breast contact/intercourse between ages 0 and 18. Associations between socio-demographic variables and CSA, before and after age 12, were estimated through multinomial regression. Results Complete data were available for 1936 respondents from 1040 households. Prevalence of CSA among girls (5.6% 95%CI [4.8;7.5]) was higher than among boys (1.6% 95%CI [0.9;2.6]). Boys experienced CSA at younger ages than girls and 60% of all reported CSA happened before age 12. Physical abuse was frequently associated with CSA at younger (OR 5.6 95%CI [2.5;12.3]) and older (OR 9.4 95%CI [4.5;18.7]) ages. CSA after age 12 was associated with an increased number of sexual partners in the last 2 months. Conclusion Results suggest that CSA takes place at young ages and is associated with physical violence, making it more likely to have serious health and developmental consequences. Except for gender, no other socio-demographic characteristic identified high-risk sub-populations.

Bassani, Diego G; Palazzo, Lilian S; Beria, Jorge U; Gigante, Luciana P; Figueiredo, Andreia CL; Aerts, Denise RGC; Raymann, Beatriz CW

2009-01-01

99

Prevalence of sexually transmitted disease syndromes in tribal population of central India  

Microsoft Academic Search

Background:A syndromic approach has been advocated for identification and management of sexually transmitted diseases (STDs) in countries where diagnostic laboratory tests are not consistently available. A community-based cross-sectional study was conducted to discover the prevalence of STD syndromes in tribal population of central India.Methods:All married men and women in the age group of 15–49 years from selected villages were enumerated

V G Rao; A Anvikar; D Savargaonkar; J Bhat; R Yadav; B K Tiwary; A Abbad

2009-01-01

100

The Group-Level Consequences of Sexual Conflict in Multigroup Populations  

PubMed Central

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.

Eldakar, Omar Tonsi; Gallup, Andrew C.

2011-01-01

101

Enzyme variability in large-lake Daphnia populations  

Microsoft Academic Search

Allozyme studies of two primarily parthenogenetic, large-lake Daphnia species, D. galeata mendotae and D. cucullata, revealed high clonal diversity and levels of enzyme polymorphism similar to those found in other groups of organisms. Temporal analyses showed moderate stability of genotypes. Hardy–Weinberg deviations were detected on some dates in D. cucullata, most often resulting from homozygote excesses. Thus, these populations show

Mona A Mort; Hans Georg Wolf

1985-01-01

102

Sexually dimorphic spatial learning varies seasonally in two populations of deer mice.  

PubMed

Spatial learning in photoperiodically induced breeding (reproductive) and non-breeding (non-reproductive) adult male and female deer mice (Peromyscus maniculatus) was examined in a Morris water-maze task. Sexually mature, adult male and female deer mice that were derived from either a mainland population (P. m. artemisiae) or an island population (P. m. angustus) were required to learn the spatial position of a hidden, submerged platform in a water maze. Deer mice were tested either during the breeding season (summer; long day photoperiod) or during the non-breeding season (winter; short day photoperiod) with a total of six blocks of four trials conducted in a single day. Retention was tested with two probe trials which occurred one and three days after acquisition. During the breeding season male spatial task acquisition was superior to female spatial task acquisition for both populations. In contrast, during the non-breeding season there were no significant sex differences in spatial acquisition for either population. This change in sexually dimorphic spatial learning was due to female spatial-performance decreasing from non-breeding season to the breeding season and male spatial-performance increasing over the same period. Both populations displayed similar seasonal variations in sexually dimorphic water-maze task performance. There were, however, overall population differences in water-maze task performance that were related to the ecology of the mice, with the insular mice displaying shorter latencies to reach the hidden platform than did the mainland deer mice.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8173954

Galea, L A; Kavaliers, M; Ossenkopp, K P; Innes, D; Hargreaves, E L

1994-01-28

103

The Impact of Aging on Sexual Function and Sexual Dysfunction in Women: A Review of Population-Based Studies  

Microsoft Academic Search

Introduction. Scientific interest in the impact of aging on women's sexual function and dysfunction has increased in the half century since Kinsey described age-related changes in women's sexual activities. However, a range of methodological issues limit the conclusions that can be drawn from many published studies in this area. Aim. To review community-based studies investigating changes in women's sexual function

Richard Hayes; Lorraine Dennerstein

2005-01-01

104

Neural population modes capture biologically realistic large scale network dynamics.  

PubMed

Large scale brain networks are understood nowadays to underlie the emergence of cognitive functions, though the detailed mechanisms are hitherto unknown. The challenges in the study of large scale brain networks are amongst others their high dimensionality requiring significant computational efforts, the complex connectivity across brain areas and the associated transmission delays, as well as the stochastic nature of neuronal processes. To decrease the computational effort, neurons are clustered into neural masses, which then are approximated by reduced descriptions of population dynamics. Here, we implement a neural population mode approach (Assisi et al. in Phys. Rev. Lett. 94(1):018106, 2005; Stefanescu and Jirsa in PLoS Comput. Biol. 4(11):e1000219, 2008), which parsimoniously captures various types of population behavior. We numerically demonstrate that the reduced population mode system favorably captures the high-dimensional dynamics of neuron networks with an architecture involving homogeneous local connectivity and a large-scale, fiber-like connection with time delay. PMID:20821061

Jirsa, Viktor K; Stefanescu, Roxana A

2010-09-04

105

Genetic rescue of an insular population of large mammals  

PubMed Central

Natural populations worldwide are increasingly fragmented by habitat loss. Isolation at small population size is thought to reduce individual and population fitness via inbreeding depression. However, little is known about the time-scale over which adverse genetic effects may develop in natural populations or the number and types of traits likely to be affected. The benefits of restoring gene flow to isolates are therefore also largely unknown. In contrast, the potential costs of migration (e.g. disease spread) are readily apparent. Management for ecological connectivity has therefore been controversial and sometimes avoided. Using pedigree and life-history data collected during 25 years of study, we evaluated genetic decline and rescue in a population of bighorn sheep founded by 12 individuals in 1922 and isolated at an average size of 42 animals for 10–12 generations. Immigration was restored experimentally, beginning in 1985. We detected marked improvements in reproduction, survival and five fitness-related traits among descendants of the 15 recent migrants. Trait values were increased by 23–257% in maximally outbred individuals. This is the first demonstration, to our knowledge, of increased male and female fitness attributable to outbreeding realized in a fully competitive natural setting. Our findings suggest that genetic principles deserve broader recognition as practical management tools with near-term consequences for large-mammal conservation.

Hogg, John T; Forbes, Stephen H; Steele, Brian M; Luikart, Gordon

2006-01-01

106

Does selection on floral odor promote differentiation among populations and species of the sexually deceptive orchid genus Ophrys?  

PubMed

Sexually deceptive orchids from the genus Ophrys attract their pollinators primarily through the chemical mimicry of female hymenopteran sex pheromones, thereby deceiving males into attempted matings with the orchid labellum. Floral odor traits are crucial for the reproductive success of these pollinator-limited orchids, as well as for maintaining reproductive isolation through the attraction of specific pollinators. We tested for the signature of pollinator-mediated selection on floral odor by comparing intra and interspecific differentiation in odor compounds with that found at microsatellite markers among natural populations. Three regions from southern Italy were sampled. We found strong floral odor differentiation among allopatric populations within species, among allopatric species and among sympatric species. Population differences in odor were also reflected in significant variation in the attractivity of floral extracts to the pollinator, Colletes cunicularius. Odor compounds that are electrophysiologically active in C. cunicularius males, especially alkenes, were more strongly differentiated among conspecific populations than nonactive compounds in the floral odor. In marked contrast to these odor patterns, there was limited population or species level differentiation in microsatellites (FST range 0.005 to 0.127, mean FST 0.075). We propose that the strong odor differentiation and lack of genetic differentiation among sympatric taxa indicates selection imposed by the distinct odor preferences of different pollinating species. Within species, low FST values are suggestive of large effective population sizes and indicate that divergent selection rather than genetic drift accounts for the strong population differentiation in odor. The higher differentiation in active versus non-active odor compounds suggests that divergent selection among orchid populations may be driven by local pollinator preferences for those particular compounds critical for pollinator attraction. PMID:16153031

Mant, Jim; Peakall, Rod; Schiestl, Florian P

2005-07-01

107

Epidemiology of sexually transmitted infections in global indigenous populations: data availability and gaps.  

PubMed

Socioeconomic and health disadvantage is widespread within and across indigenous communities in the world, leading to differentials in morbidity and mortality between indigenous and non-indigenous populations. Sexually transmitted infections (STIs), including HIV/AIDS, among indigenous populations are an emerging public health concern. The focus of this paper is on examining the STI epidemiology in indigenous communities in various parts of the world utilizing a range of data sources. Most of the STI research on global indigenous communities has concentrated on developed countries, neglecting more than half the world's indigenous people in the developing countries. This has resulted in major gaps in data at global level for STIs and HIV/AIDS among indigenous populations. Available data show that the prevalence of STIs is increasing among the indigenous communities and in several instances, the rates of these infections are higher than among non-indigenous populations. However, HIV still remains low when compared with the rates of other STIs. The paper argues that there is an urgent need to collect more comprehensive and reliable data at the global level across various indigenous communities. There is also an opportunity to reverse current trends in STIs through innovative, evidence-based and culturally appropriate targeted sexual health programmes. PMID:24052012

Minichiello, Victor; Rahman, Saifur; Hussain, Rafat

2013-08-29

108

High variation in clonal vs. sexual reproduction in populations of the wild strawberry, Fragaria virginiana (Rosaceae)  

PubMed Central

Background and Aims Many plants reproduce both clonally and sexually, and the balance between the two modes of reproduction will vary among populations. Clonal reproduction was characterized in three populations of the wild strawberry, Fragaria virginiana, to determine the extent that reproductive mode varied locally between sites. The study sites were fragmented woodlands in Cook County, Illinois, USA. Methods A total of 95 strawberry ramets were sampled from the three sites via transects. Ramets were mapped and genotyped at five variable microsatellite loci. The variability at these five loci was sufficient to assign plants to clones with high confidence, and the spatial pattern of genets was mapped at each site. Key Results A total of 27 distinct multilocus genotypes were identified. Of these, 18 genotypes were detected only once, with the remaining nine detected in multiple ramets. The largest clone was identified in 16 ramets. No genets were shared between sites, and each site exhibited markedly different clonal and sexual recruitment patterns, ranging from two non-overlapping and widespread genets to 19 distinct genets. Only one flowering genet was female; the remainder were hermaphrodites. Conclusions Local population history or fine-scale ecological differences can result in dramatically different reproductive patterns at small spatial scales. This finding may be fairly widespread among clonal plant species, and studies that aim to characterize reproductive modes in species capable of asexual reproduction need to evaluate reproductive modes in multiple populations and sites.

Wilk, John A.; Kramer, Andrea T.; Ashley, Mary V.

2009-01-01

109

Argentine Population Genetic Structure: Large Variance in Amerindian Contribution  

PubMed Central

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.

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; Guilleron, Carolina; Catoggio, Luis J.; Prigione, Cristina; Berbotto, Guillermo A.; Garcia, Mercedes A.; Perandones, Carlos E.; Pons-Estel, Bernardo A.; Alarcon-Riquelme, Marta E.

2011-01-01

110

Female sperm limitation in natural populations of a sexual/asexual mating complex (Poecilia latipinna, Poecilia formosa).  

PubMed

In sperm-dependent sexual/asexual mating systems, male mate choice is critical for understanding the mechanisms behind apparent stability observed in natural populations. The gynogenetic Amazon molly (Poecilia formosa) requires sperm from sexual males (e.g. Poecilia latipinna) to trigger embryogenesis, but inheritance is strictly maternal. Consequently, males should try to avoid or reduce the cost of mating with asexuals. We investigated male mate choice by documenting the presence of sperm in natural populations and found that a higher proportion of sexual females had sperm than asexuals. In addition, among those females that had sperm, sexuals had more sperm than asexuals. Our results hint at a role for male mate choice as a stabilizing factor in such systems. PMID:18319207

Riesch, Rüdiger; Schlupp, Ingo; Plath, Martin

2008-06-23

111

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

PubMed Central

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.

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

2006-01-01

112

Dimorphic male midshipman fish: reduced sexual selection or sexual selection for reduced characters?  

Microsoft Academic Search

In most taxa with male dimorphisms, some males are large in body size with exaggerated secondary sexual characters (exaggerated morph), whereas other males in the same population are small and have reduced secondary sexual characters (reduced morph). What selective pressures cause male dimorphisms? Reduced morphologies may result when a) some males develop a morphology that, in the absence of sexual

Jonathan S. F. Lee; Andrew H. Bass

2006-01-01

113

Changes and correlates in multiple sexual partnerships among Chinese adult women--population-based surveys in 2000 and 2006.  

PubMed

The sexual transmission of HIV and STI is becoming a major public health concern in China. However, studies on sexuality in China remain scant, particularly those that analyze female sexuality. This study is to investigate the prevalence of multiple sexual partnerships (MSP) among adult women, and to examine trends and correlates for having more than one lifetime sexual partner. MSP, coded as having one or none vs. two or more lifetime sexual partners, was the key binary outcome measure. The data were from two national probability surveys on sexual behaviors in China carried out in 2000 and 2006. The sample size of adult women was 1899 in 2000 (total sample n=3812), and 2626 in 2006 (n=5404). Overall prevalence of MSP increased from 8.1% in 2000 to 29.6% in 2006 (chi-square test, significance = 0.000). The most rapid changes took place among women with less education, those who worked in blue-collar jobs and lower social-status positions, and those living in rural areas or small towns. Women who were better educated, lived in big cities, and held management-level occupations exhibited less change but had a higher baselines prevalence of MSP, suggesting that changes in MSP behavior may occur initially among women of higher socioeconomic status. Based on the 2006 data-set, significant positive correlates of MSP included more years of education, being in a long-term relationship, being middle aged, having a lower-status job, going out dancing at entertainments venues, and being a state of overall health in the past 12 months. The significant recent increase in MSP among women reinforces the need to examine China's sexual revolution in the context of a rapidly transitioning society. Findings regarding female sexuality also raise new questions to be explored in further sexuality studies, in order to better understand population sexual behaviors and to inform future HIV-prevention efforts. PMID:21660755

Yingying, Huang; Smith, Kumi; Suiming, Pan

2011-06-01

114

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

PubMed

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 assess whether populations in northern United States have characteristics consistent with sexual reproduction, 1024 isolates collected over a 3-y period were analyzed for frequency and distribution of mating type genes. After clone correction, an approximately equal distribution of mating types was found for each sampling year. Mating type frequency was also assessed in individual lesions. Lesions always consisted of isolates with a single mating type and microsatellite haplotype, but both mating types and up to five microsatellite haplotypes could be found on an individual leaf. The MAT1-1-1 and MAT1-2-1 genes were sequenced from 28 MAT1-1 and 28 MAT1-2 isolates, respectively. Three MAT1-1-1 nucleotide haplotypes were identified that encoded a single amino acid sequence. For MAT1-2-1, five nucleotide haplotypes were identified that encoded four protein variants. MAT1-1-1 and MAT1-2-1 gene expression analyses were conducted on plants inoculated with either or both mating types. MAT1-1-1 expression remained low, but MAT1-2-1 spiked during late stages of colonization. A segment of the MAT1-2-1 coding sequence was also found in MAT1-1 isolates. Taken together, these results suggest that C. beticola has the potential for sexual reproduction. PMID:22483049

Bolton, Melvin D; Secor, Gary A; Rivera, Viviana; Weiland, John J; Rudolph, Kurt; Birla, Keshav; Rengifo, Judith; Campbell, Larry G

2012-02-14

115

Urologic characteristics and sexual behaviors associated with prostate cancer in an african-Caribbean population in barbados, west indies.  

PubMed

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

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

2013-02-25

116

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

PubMed Central

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.

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

2013-01-01

117

Large population speaker recognition using wideband and telephone speech  

NASA Astrophysics Data System (ADS)

The two largest factors affecting automatic speaker identification performance are the size of the population to be distinguished among and the degradations introduced by noisy communication channels (e.g., telephone transmission). To experimentally examine these two factors, this paper presents text-independent speaker identification results for varying speaker population sizes up to 630 speakers for both clean, wideband speech and telephone speech. A system based on Gaussian mixture speaker models is used for speaker identification and experiments are conducted on the TIMIT and NTIMIT databases. The aims of this study are to (1) establish how well text-independent speaker identification can perform under near ideal conditions for very large populations (using the TIMIT database), (2) gauge the performance loss incurred by transmitting the speech over the telephone network (using the NTIMIT database), and (3) examine the validity of current models of telephone degradations commonly used in developing compensation techniques (using the NTIMIT calibration signals). This is believed to be the first speaker identification experiments on the complete 630 speaker TIMIT and NTIMIT databases and the largest text-independent speaker identification task reported to date. Identification accuracies of 99.5% and 60.7% are achieved on the TIMIT and NTIMIT databases, respectively.

Reynolds, Douglas A.

1994-10-01

118

Mating-Type Distribution and Genetic Diversity of Cercospora sojina Populations on Soybean from Arkansas: Evidence for Potential Sexual Reproduction.  

PubMed

ABSTRACT Cercospora sojina causes frogeye leaf spot of soybean, which can cause serious economic losses in the United States. In this study, 132 C. sojina isolates were collected from six fields (from two counties, Cross and Crawford) in Arkansas. To determine mating type, a multiplex polymerase chain reaction assay was developed with primers specific for C. sojina. Of the 132 isolates, 68 isolates had the MAT1-1-1 idiomorph and 64 isolates had the MAT1-2 idiomorph; no isolates possessed both idiomorphs. Both mating types were present in a variety of spatial scales, including separate lesions on individual leaves. Clone-corrected data from eight microsatellites indicated that mating-type loci were present in approximately equal proportions in all populations analyzed, which suggests that Arkansas populations of C. sojina are undergoing cryptic sexual reproduction. All six populations evaluated had high genotypic diversity of 26 to 79%. In addition, among strains isolated from a single leaf, multiple and distinct haplotypes were associated with both mating types, supporting the hypothesis that sexual reproduction occurs within the populations. Most populations showed significant gametic disequilibrium but levels of disequilibrium were relatively low, particularly in populations from Crawford County. A low differentiation index (GST) was observed for all simple-sequence repeat markers across all populations. Furthermore, the value of G statistics between populations suggests that significant genetic exchange exists among the populations. Taken together, these results demonstrate that C. sojina populations from Arkansas are genetically diverse and most likely undergoing sexual reproduction. PMID:23721180

Kim, Hun; Newell, Annakay D; Cota-Sieckmeyer, Robyn G; Rupe, John C; Fakhoury, Ahmad M; Bluhm, Burton H

2013-10-01

119

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

PubMed Central

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.

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

2011-01-01

120

Suicide Attempts Among Sexual-Minority Youths: Population and Measurement Issues  

Microsoft Academic Search

Two questions were addressed regarding suicide attempts among sexual-minority youths: Who should be classified as a sexual minority, and what constitutes a suicide attempt? Results from 2 studies indicated that sexual-minority youths, broadly defined in terms of sexual orientation and recruitment venue, were slightly more likely than heterosexual youths to report a suicide attempt. To afford a more accurate assessment

Ritch C. Savin-Williams

2001-01-01

121

Genetic and Environmental Effects on Same-sex Sexual Behavior: A Population Study of Twins in Sweden  

Microsoft Academic Search

There is still uncertainty about the relative importance of genes and environments on human sexual orientation. One reason\\u000a is that previous studies employed self-selected, opportunistic, or small population-based samples. We used data from a truly\\u000a population-based 2005–2006 survey of all adult twins (20–47 years) in Sweden to conduct the largest twin study of same-sex\\u000a sexual behavior attempted so far. We performed

Niklas Lĺngström; Qazi Rahman; Eva Carlström; Paul Lichtenstein

2010-01-01

122

Sexual determination of the femur using discriminant functions. Analysis of a Spanish population of known sex and age.  

PubMed

Until present, functions for sexual discrimination of a Spanish population from series of known sex and age were not available. In this work, we present a sample of 132 femora (72 females and 60 males) belonging to a Spanish population of adult individuals of known filiation deposited in the Complutense University of Madrid. The ten mathematical functions which yield a higher sexual discrimination in each part of the femur, were selected. The resulting percentages of correspondence varied between 84 and 97% when each variable was considered independently, and a 99% is obtained with two variables of the epiphyses combined. PMID:9068175

Trancho, G J; Robledo, B; López-Bueis, I; Sánchez, J A

1997-03-01

123

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

PubMed

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 (?) can be used to determine whether the clades are samples from different species (K/? ? 4) or the same species (K/?<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/? 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/? 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/? 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/? 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

Birky, C William

2013-01-04

124

Molecular computational elements encode large populations of small objects  

NASA Astrophysics Data System (ADS)

Since the introduction of molecular computation, experimental molecular computational elements have grown to encompass small-scale integration, arithmetic and games, among others. However, the need for a practical application has been pressing. Here we present molecular computational identification (MCID), a demonstration that molecular logic and computation can be applied to a widely relevant issue. Examples of populations that need encoding in the microscopic world are cells in diagnostics or beads in combinatorial chemistry (tags). Taking advantage of the small size (about 1nm) and large `on/off' output ratios of molecular logic gates and using the great variety of logic types, input chemical combinations, switching thresholds and even gate arrays in addition to colours, we produce unique identifiers for members of populations of small polymer beads (about 100?m) used for synthesis of combinatorial libraries. Many millions of distinguishable tags become available. This method should be extensible to far smaller objects, with the only requirement being a `wash and watch' protocol. Our focus on converting molecular science into technology concerning analog sensors, turns to digital logic devices in the present work.

Prasanna de Silva, A.; James, Mark R.; McKinney, Bernadine O. F.; Pears, David A.; Weir, Sheenagh M.

2006-10-01

125

Estimating the sexual mixing patterns in the general population from those in people acquiring gonorrhoea infection: theoretical foundation and empirical findings.  

PubMed Central

STUDY OBJECTIVES--To describe mathematically the relationship between patterns of sexual mixing in the general population and those of people with gonorrhoea infection, and hence to estimate the sexual mixing matrix for the general population. DESIGN--Integration of data describing sexual behaviour in the general population, with data describing sexual behaviour and mixing among individuals infected with gonorrhoea. Use of these data in a simple mathematical model of the transmission dynamics of gonorrhoea infection. SETTING--The general population of London and a genitourinary medicine (GUM) clinic in west London. PARTICIPANT--These comprised 1520 men and women living in London who were randomly selected for the national survey of sexual attitudes and lifestyles and 2414 heterosexual men and women who presented to the GUM clinic with gonorrhoea. MAIN RESULTS--The relationship between sexual mixing among people with gonorrhoea and sexual mixing in the general population is derived mathematically. An empirical estimate of the sexual mixing matrix for the general population is presented. The results provide tentative evidence that individuals with high rates of acquisition of sexual partners preferentially select other individuals with high rates as partners (assortative mixing). CONCLUSIONS--Reliable estimates of sexual mixing have been shown to be important for understanding the evolution of the epidemics of HIV infection and other sexually transmitted diseases. The possibility of estimating patterns of sexual mixing in the general population from information routinely collected in gonorrhoea contact tracing programmes is demonstrated. Furthermore, the approach we describe could, in principle, be used to estimate the same patterns of mixing, using contact tracing data for other sexually transmitted diseases, thus providing a way of validating our results.

Renton, A; Whitaker, L; Ison, C; Wadsworth, J; Harris, J R

1995-01-01

126

Silent night: adaptive disappearance of a sexual signal in a parasitized population of field crickets  

PubMed Central

Abstract Sexual signals are often critical for mate attraction and reproduction, although their conspicuousness exposes them to parasites and predators. We document the near-disappearance of song, the sexual signal of crickets, and its replacement with a novel silent morph, in a population subject to strong natural selection by a deadly acoustically orienting parasitoid fly. On the Hawaiian Island of Kauai, more than 90% of male field crickets (Teleogryllus oceanicus) shifted in less than 20 generations from a normal-wing morphology to a mutated wing that renders males unable to call (flatwing). Flatwing morphology protects male crickets from the parasitoid, which uses song to find hosts, but poses obstacles for mate attraction, since females also use the males' song to locate mates. Field experiments support the hypothesis that flatwings overcome the difficulty of attracting females without song by acting as ‘satellites’ to the few remaining callers, showing enhanced phonotaxis to the calling song that increases female encounter rate. Thus, variation in behaviour facilitated establishment of an otherwise maladaptive morphological mutation.

Zuk, Marlene; Rotenberry, John T; Tinghitella, Robin M

2006-01-01

127

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

PubMed Central

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.

2011-01-01

128

Stellar Populations in the Closest Large Low Surface Brightness Galaxy  

NASA Astrophysics Data System (ADS)

We propose to observe the closest known large low surface brightness {LSB} galaxy, UGC 2302, in order to resolve for the first time the massive stars and tip of the red giant branch in such a system. Large LSBs represent an extreme star formation environment, both locally within their disks, and on a larger scale, often residing in underdense regions of the universe. Resolving the underlying stellar component of such a galaxy can provide critical information on how stars form and evolve in low metallicity, yet gas-rich environments. The combination of this data with planned near-infrared, abundance and molecular gas studies, existing optical UBVRI and Halpha data, and a VLA HI map, will allow comparison between the abundance and distribution of stars, star formation, and neutral gas in unprecedented detail for disk LSBs. In addition, determination of the characteristics of even the brightest stars in this galaxy will provide a key calibration of the relative contribution o f the brightest main sequence, gia nt, and supergiant stars to the optical and near-infrared colors. This calibration can then be applied to determining the underlying stellar populations of other massive LSB galaxies using broad-band filters.

Knezek, Patricia

1999-07-01

129

Modeling mid-aged women's sexual functioning: a prospective, population-based study.  

PubMed

This article uses a prospectively, annually collected sexuality questionnaire from an 8-year study of 340 mid-aged Melbourne women. We modeled the interactions of sexuality domains, the effect of prior level of sexual functioning, and the effects of change in partner-related factors. We found that we were unable to separate items denoting sexual interest from those denoting responsiveness. Using the statistical technique of auto-correlation, we determined that the most important predictor of female sexual functioning is prior level of sexual functioning. Partner-related factors (change in partner status and feelings for partner) also had significant effects. PMID:15205073

Dennerstein, Lorraine; Lehert, Philippe

130

Recessive Mutations from Natural Populations of NEUROSPORA CRASSA That Are Expressed in the Sexual Diplophase  

PubMed Central

Wild-collected isolates of Neurospora crassa Shear and Dodge were systematically examined for recessive mutations affecting the sexual phase of the life cycle, which is essentially diploid. Seventy-four of 99 wild-collected isolates from 26 populations in the United States, India and Pakistan carried one or more recessive mutations that reduced fertility significantly when homozygous; mutations affecting spore morphology were also detected. Limited complementation tests indicate that most of the 106 recovered mutations are unique.—The recessive diplophase (= sexual phase) mutations were uncovered by crossing each wild-collected isolate to a marked two-chromosome double-reciprocal translocation strain as "balancer." Surviving progeny receive approximately 60% of their genome from the wild parent, but receive the mating-type allele from the "balancer" parent. These progeny were backcrossed to the wild parent and were also crossed with a standard laboratory strain (fl). Reduced fertility in the backcross vs. normal fertility in the cross with the laboratory standard signals the presence of a recessive mutation in the wild-collected isolate.—Most of the mutants (95 of 106) fall into two major classes: those producing barren perithecia with no or few viable ascospores (51) and those with spore maturation defects (44). Most of the recessive barrens result either from an early block in meiosis or ascus development (25) or from a late disturbance in postmeiotic ascus behavior (18).—These recessive mutations are formally equivalent to recessive lethals in higher eukaryotes and may be important in determining the breeding structure of natural Neurospora populations.

Leslie, John F.; Raju, Namboori B.

1985-01-01

131

Linkage disequilibrium and spatial aggregation of genotypes in sexually reproducing populations of Erysiphe necator.  

PubMed

Random mating and recombination in heterothallic ascomycetes should result in high genotypic diversity, 1:1 mating-type ratios, and random associations of alleles, or linkage equilibrium, at different loci. To test for random mating in populations of the grape powdery mildew fungus Erysiphe necator, we sampled isolates from vineyards of Vitis vinifera in Burdett, NY (NY09) and Winchester, VA (VA09) at the end of the epidemic in fall 2009. We also sampled isolates from the same Winchester, VA vineyard in spring 2010 at the onset of the next epidemic. Isolates were genotyped for mating type and 11 microsatellite markers. In the spring sample, which originated from ascospore infections, nearly every isolate had a unique genotype. In contrast, fall populations were less diverse. In all, 9 of 45 total genotypes in VA09 were represented by two or more isolates; 3 of 40 total genotypes in NY09 were represented by two or more isolates, with 1 genotype represented by 20 isolates. After clone correction, mating-type ratios in the three populations did not deviate from 1:1. However, even with clone correction, we detected significant linkage disequilibrium (LD) in all populations. Mantel tests detected positive correlations between genetic and physical distances within vineyards. Spatial autocorrelation showed aggregations up to 42 and 3 m in VA09 and NY09, respectively. Spatial autocorrelation most likely results from short dispersal distances. Overall, these results suggest that spatial genetic aggregation and clonal genotypes that arise during the asexual phase of the epidemic contribute to persistent LD even though populations undergo sexual reproduction annually. PMID:22755546

Brewer, Marin Talbot; Frenkel, Omer; Milgroom, Michael G

2012-10-01

132

Contrasting Life Histories in Neighbouring Populations of a Large Mammal  

PubMed Central

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.

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

2011-01-01

133

Sexual reproduction, clonal diversity and genetic differentiation in patchily distributed populations of the temperate forest herb Paris quadrifolia (Trilliaceae)  

Microsoft Academic Search

Clonal plant species have been shown to adopt different strategies to persist in heterogeneous environments by changing relative investments in sexual reproduction and clonal propagation. As a result, clonal diversity and genetic variation may be different along environmental gradients. We examined the regional and local population structure of the clonal rhizomatous forest herb Paris quadrifolia in a complex of forest

Hans Jacquemyn; Rein Brys; Olivier Honnay; Martin Hermy; Isabel Roldán-Ruiz

2006-01-01

134

Relationship of sexual orientation to substance use, suicidal ideation, suicide attempts, and other factors in a population of homeless adolescents  

Microsoft Academic Search

Purpose: To explore the relationship of sexual orientation and gender to four sets of factors: (a) family history, (b) incarceration, (c) substance use, and (d) depression and suicide, in a population of homeless adolescents.Methods: A sample of homeless adolescents was recruited in Portland, Oregon and assessed using semi-structured interviews at baseline, three months and six months. A total of 532

John W Noell; Linda M Ochs

2001-01-01

135

A LATE PLEISTOCENE HUMAN SKELETON FROM LIUJIANG, CHINA SUGGESTS REGIONAL POPULATION VARIATION IN SEXUAL DIMORPHISM IN THE HUMAN PELVIS  

Microsoft Academic Search

This paper provides a description and analysis of a late Pleistocene human from Liujiang, China. Although most scholars have interpreted the cranium as male, sexing of the pelvis has been more problematic. I argue that this ambiguity reflects variation in the pattern of sexual dimorphism in the pelvis between human populations in different regions. Although the direction of the differences

KAREN ROSENBERG

2002-01-01

136

Association of sexual problems with social, psychological, and physical problems in men and women: a cross sectional population survey  

Microsoft Academic Search

STUDY OBJECTIVE: To investigate the association of sexual problems with social, physical, and psychological problems. DESIGN: An anonymous postal questionnaire survey. SETTING: Four general practices in England. PARTICIPANTS: 789 men and 979 women responding to a questionnaire sent to a stratified random sample of the adult general population (n = 4000). MAIN RESULTS: Strong physical, social, and psychological associations were

K. M. Dunn; P. R. Croft; G. I. Hackett

1999-01-01

137

Modeling Mid-Aged Women's Sexual Functioning: A Prospective, Population-Based Study  

Microsoft Academic Search

This article uses a prospectively, annually collected sexuality questionnaire from an 8-year study of 340 mid-aged Melbourne women. We modeled the interactions of sexuality domains, the effect of prior level of sexual functioning, and the effects of change in partner-related factors. We found that we were unable to separate items denoting sexual interest from those denoting responsiveness. Using the statistical

LORRAINE DENNERSTEIN; PHILIPPE LEHERT

2004-01-01

138

Assessing Competency to Consent to Sexual Activity in the Cognitively Impaired Population  

Microsoft Academic Search

Sexuality is an integral factor when considering quality of life. Psychologists and mental health providers have a responsibility to promote patients' rights to sexual expression, but also to protect patients when impairments interfere with the ability to make informed decisions. Rehabilitation facilities struggle with this issue, especially the question of ability to consent. The Sexual Consent and Education Assessment (SCEA),

Carrie Hill Kennedy

1999-01-01

139

Assessment of Sexual Assault in Clinical Practice: Available Screening Tools for Use with Different Adult Populations  

Microsoft Academic Search

Clinicians agree that knowledge of clients' sexual victimization histories are invaluable in conceptualizing cases and choosing treatment interventions; however, the routine assessment of sexual assault in clinical practice is not standard (e.g., Hurst, MacDonald, Say, & Reed, 2003; Pruitt & Kappius, 1992). This article reviews recent research related to prevalence rates, short- and long-term consequences of sexual assault, available screening

Danielle R. Probst; Jessica A. Turchik; Eric H. Zimak; Jamie L. Huckins

2011-01-01

140

Determinants of female sexual dysfunction in type 2 diabetes  

Microsoft Academic Search

Studies assessing sexual dysfunction in type 2 diabetic women are scanty. This study was designed to evaluate the prevalence and correlates of female sexual function in a quite large population of diabetic women. A total of 595 women with type 2 diabetes completed a questionnaire of self-report measures of sexual dysfunction and were analyzed in this study. Their age was

K Esposito; M I Maiorino; G Bellastella; F Giugliano; M Romano; D Giugliano

2010-01-01

141

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

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.

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

2009-01-01

142

How Large was the Founding Population of Darwin's Finches?  

Microsoft Academic Search

A key assumption of many allopatric speciation models is that evolution in peripheral or isolated populations is facilitated by drastic reductions in population size. Population bottlenecks are believed to lead to rapid changes in gene frequencies through genetic drift, to facilitate rapid emergence of novel phenotypes, and to enhance reproductive isolation via genetic revolutions. For such effects to occur, founding

Vladimir Vincek; Colm O'Huigin; Yoko Satta; Naoyuki Takahata; Peter T. Boag; Peter R. Grant; B. Rosemary Grant; Jan Klein

1997-01-01

143

Large-scale MHC class II genotyping of a wild lemur population by next generation sequencing.  

PubMed

The critical role of major histocompatibility complex (MHC) genes in disease resistance, along with their putative function in sexual selection, reproduction and chemical ecology, make them an important genetic system in evolutionary ecology. Studying selective pressures acting on MHC genes in the wild nevertheless requires population-wide genotyping, which has long been challenging because of their extensive polymorphism. Here, we report on large-scale genotyping of the MHC class II loci of the grey mouse lemur (Microcebus murinus) from a wild population in western Madagascar. The second exons from MHC-DRB and -DQB of 772 and 672 individuals were sequenced, respectively, using a 454 sequencing platform, generating more than 800,000 reads. Sequence analysis, through a stepwise variant validation procedure, allowed reliable typing of more than 600 individuals. The quality of our genotyping was evaluated through three independent methods, namely genotyping the same individuals by both cloning and 454 sequencing, running duplicates, and comparing parent-offspring dyads; each displaying very high accuracy. A total of 61 (including 20 new) and 60 (including 53 new) alleles were detected at DRB and DQB genes, respectively. Both loci were non-duplicated, in tight linkage disequilibrium and in Hardy-Weinberg equilibrium, despite the fact that sequence analysis revealed clear evidence of historical selection. Our results highlight the potential of 454 sequencing technology in attempts to investigate patterns of selection shaping MHC variation in contemporary populations. The power of this approach will nevertheless be conditional upon strict quality control of the genotyping data. PMID:22948859

Huchard, Elise; Albrecht, Christina; Schliehe-Diecks, Susanne; Baniel, Alice; Roos, Christian; Peter, Peter M Kappeler; Brameier, Markus

2012-09-05

144

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

ERIC Educational Resources Information Center

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…

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

2004-01-01

145

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

ERIC Educational Resources Information Center

|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…

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

2010-01-01

146

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

ERIC Educational Resources Information Center

|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…

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

2004-01-01

147

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

ERIC Educational Resources Information Center

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…

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

2010-01-01

148

Sensation seeking and impulsivity: combined associations with risky sexual behavior in a large sample of young adults.  

PubMed

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

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

2012-03-28

149

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

PubMed

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

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

2011-07-18

150

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

PubMed Central

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.

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

2011-01-01

151

How large was the founding population of Darwin's finches?  

PubMed Central

A key assumption of many allopatric speciation models is that evolution in peripheral or isolated populations is facilitated by drastic reductions in population size. Population bottlenecks are believed to lead to rapid changes in gene frequencies through genetic drift, to facilitate rapid emergence of novel phenotypes, and to enhance reproductive isolation via genetic revolutions. For such effects to occur, founding populations must be very small, and remain small for some time after founding. This assumption has, however, rarely been tested in nature. One approach is to exploit the polymorphism of the major histocompatibility complex (Mhc) to obtain information about the founding population. Here, we use the Mhc polymorphism to estimate the size of the founding population of Darwin's finches in the Galápagos Archipelago. The results indicate that the population could not have been smaller than 30 individuals.

Vincek, V.; O'Huigin, C.; Satta, Y.; Takahata, Y.; Boag, P. T.; Grant, P. R.; Grant, B. R.; Klein, J.

1997-01-01

152

Knowledge of sexually transmissible infections: a comparison of prisoners and the general population.  

PubMed

The World Health Organization (WHO) has identified a failure to provide education for vulnerable populations such as prisoners as a contributing factor to the epidemic of sexually transmissible infections (STIs). Despite this recognition, little is known about prisoners' level of knowledge of STIs compared with the general population. Using computer-assisted telephone interviews, we compared a representative sample of 2289 Australian prisoners, aged 18-59 years from New South Wales and Queensland prisons with a representative community sample of 3536 participants from these two states. Prisoners had significantly better knowledge than the general community of chlamydia-related questions, while knowledge of herpes (genital and oral) was slightly better in the community sample. Prisoners who were aged over 25 years, not married, female, self-identified as either homosexual or bisexual and reported a history of STIs tended to have better STI knowledge levels. Despite their more disadvantaged backgrounds, prisoners demonstrated relatively good health literacy in relation to STIs. Ongoing education about the transmission risks of STIs for prisoners and the general community is needed. PMID:21729956

Malacova, E; Butler, T; Richters, J; Yap, L; Grant, L; Richards, A; Smith, A M A; Donovan, B

2011-07-01

153

Admixture and sexual bias in the population settlement of La Réunion Island (Indian Ocean).  

PubMed

La Réunion, one of the three Mascarene islands located in the Indian Ocean, remained devoid of inhabitants until it was first colonized by the French in the middle of the 17th century. The continuous flow of foreign-born slaves and immigrant workers from Africa, India, Southeast Asia, and China to work on coffee and sugar cane plantations led to the island becoming a melting pot of people of multiple ethnic origins. To establish the impact of the different incoming ethnic groups on the present Reunionese gene pool, we have sequenced both hypervariable regions I and II of the mitochondrial DNA molecule, the 9 bp COII/tRNA(Lys) deletion, and four SNPs located in the coding region in a total of 41 samples of the general population, and a further 18 STRs and 35 SNPs on the Y chromosome in 26 of these samples. Our results show that there was a strong sexual bias (asymmetrical gene flow) in the peopling of La Réunion, where admixture events were mainly between male settlers and females from the incoming slave groups. Most of the Y-chromosome gene pool is of European/Middle Eastern ancestry (85%), whereas the mtDNA gene pool is mainly of Indian and East Asian ancestry (70%). The absence of genetic diversity within these two major components of the mtDNA gene pool suggests these populations may have witnessed strong founder effects during the colonization process. PMID:18186507

Berniell-Lee, Gemma; Plaza, Stéphanie; Bosch, Elena; Calafell, Francesc; Jourdan, Eric; Césari, Maya; Lefranc, Gérard; Comas, David

2008-05-01

154

Adjustment among Mothers Reporting Same-Gender Sexual Partners: A Study of a Representative Population Sample from Quebec Province (Canada)  

Microsoft Academic Search

We examined the well-being of mothers and non-mothers reporting exclusive opposite-gender sexual partners (OG), same-gender\\u000a sexual partners (SG), or both (BI) in a representative sample of 20,773 participants (11,034 women) 15-years-old or older\\u000a from the population of Quebec province in Canada. Participants completed a self-administered questionnaire and SG and BI women\\u000a (n = 179) were matched to a sample of OG women

Danielle Julien; Emilie Jouvin; Emilie Jodoin; Alexandre l’Archevęque; Elise Chartrand

2008-01-01

155

Laboratory mating trials indicate incipient speciation by sexual selection among populations of the cichlid fish Pseudotropheus zebra from Lake Malawi.  

PubMed Central

It has been suggested that sexual selection may have played a major role in the rapid evolution of hundreds of species of cichlid fishes in Lake Malawi. We report the results of a laboratory test of assortative mating among Lake Malawi cichlid fishes from five closely related geographical populations differing in male courtship colour. Paternity of clutches was tested using microsatellite DNA typing of offspring. Out of 1955 offspring typed, 1296 (66.3%) were sired by the male from the same population as the female, which is more than three times the rate expected if females do not differentiate among males of the different populations (20%). This result indicates that mate preferences of geographical races are strongly differentiated, consistent with the races representing incipient geographical species diverging under sexual selection exerted by female preferences for different male courtship colours.

Knight, Mairi E; Turner, George F

2004-01-01

156

Getting the timing right: antler growth phenology and sexual selection in a wild red deer population.  

PubMed

There has been growing interest in the determinants of the annual timing of biological phenomena, or phenology, in wild populations, but research on vertebrate taxa has primarily focused on the phenology of reproduction. We present here analyses of the phenology of the annual growth of a secondary sexual characteristic, antlers in red deer (Cervus elaphus) males. The long-term individual-based data from a wild population of red deer on the Isle of Rum, Scotland allow us to consider ecological factors influencing variation in the phenology of growth of antlers, and the implications of variation in antler growth phenology with respect to the phenotype of antler grown (antler mass) and annual breeding success. The phenology of antler growth was influenced by local environmental conditions: higher population density delayed both the start date (during spring) and the relative end date (in late summer) of antler growth, and warmer temperatures in the September and April prior to growth advanced start and end dates, respectively. Furthermore, there was variation between individuals in this phenotypic plasticity of start date, although not in that of end date of growth. The phenology of antler growth impacted on the morphology of antlers grown, with individuals who started and ended growth earliest having the heaviest antlers. The timing of antler growth phenology was associated with breeding success in the following mating season, independently of the mass of antlers grown: an earlier start of antler growth was associated with siring a higher number of the calves born the following spring. Our results suggest that the phenology of traits that are not directly correlated with offspring survival may also regularly show correlations with fitness. PMID:20480184

Clements, Michelle N; Clutton-Brock, Tim H; Albon, Steve D; Pemberton, Josephine M; Kruuk, Loeske E B

2010-05-18

157

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

PubMed

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

Gutiérrez-Redomero, Esperanza; Alonso-Rodríguez, Concepción

2013-04-17

158

Sexual abuse and suicidality: gender differences in a large community sample of adolescents  

Microsoft Academic Search

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 depression (Centre for Epidemiological Studies Depression Scale), hopelessness (Beck Hopelessness Scale), and family

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

2004-01-01

159

Pre and post-mating sexual selection both favor large males in a rainbowfish  

Microsoft Academic Search

Sexual selection can act through female choice and male–male competition. Although both processes can act simultaneously,\\u000a they are typically studied independently. Here, we adopt a more integrated approach to studying sexual selection by incorporating\\u000a measures of both processes using the western rainbowfish Melanotaenia australis, a freshwater fish endemic to northwestern Australia. We assessed male–male competition and female choice separately while

Michael J. Young; Leigh W. Simmons; Jonathan P. Evans

2010-01-01

160

Female sexual dysfunction in a population-based study in Iran: prevalence and associated risk factors  

Microsoft Academic Search

To explore the prevalence and risk factors of female sexual dysfunction (FSD) in Iran. A total of 2626 women aged 20–60 years old were interviewed by 41 female general practitioners and answered a self-administered questionnaire on several aspects of FSD including desire, arousal, pain and orgasmic disorders (OD). Criteria of sexual dysfunction followed classification by DSM-IV. The sexual function was

M R Safarinejad; Safarinejad

2006-01-01

161

Degree of pelvic sexual dimorphism in human populations. A greene t-test application  

Microsoft Academic Search

The knowledge of sexual dimorphisms is important in many aspects of paleodemography and paleobiology. One major problem lies\\u000a in a correct sexual diagnosis. However, due to the different methodologies employed to estimate the degree of sexual dimorphism,\\u000a the comparison of the results remains difficult. The Greene t-test (1989) is accurate for a comparative analysis of raw data.\\u000a On the basis

J. Bruzek

1996-01-01

162

Complex Multivariate Sexual Selection on Male Acoustic Signaling in a Wild Population of Teleogryllus commodus  

Microsoft Academic Search

Mate choice may impose both linear (i.e., directional) and nonlinear (i.e., quadratic and correlational) sexual selection on advertisement traits. Traditionally, mate recognition and sensory tun- ing have been thought to impose stabilizing (i.e., negative quadratic) sexual selection, whereas adaptive mate choice effects directional se- lection. It has been suggested that adaptive choice may exert positive quadratic and\\/or correlational sexual selection.

John Hunt; Robert Brooks

2006-01-01

163

Large Population Speaker Identification Using Clean and Telephone Speech.  

National Technical Information Service (NTIS)

This paper presents text-independent speaker identification results for varying speaker population sizes up to 630 speakers for both clean, wideband speech, and telephone speech. A system based on Gaussian mixture speaker models is used for speaker identi...

D. A. Reynolds

1994-01-01

164

Population Dynamics of Large Walleye in Big Sand Lake.  

National Technical Information Service (NTIS)

Walleye population parameters in Big Sand Lake, Hubbard County were estimated from 3 years of tagging and creel surveys. Estimated walleye biomass and annual yield were midrange of other North American walleye lakes. Although growth of Big Sand Lake walle...

P. C. Jacobson

1994-01-01

165

The Speed of Evolution in Large Asexual Populations  

Microsoft Academic Search

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\\u000a to computing the speed of logarithmic fitness

Su-Chan Park; Damien Simon; Joachim Krug

2010-01-01

166

Relation between Psychiatric Syndromes and Behaviorally Defined Sexual Orientation in a Sample of the US Population  

PubMed Central

Most surveys of the prevalence of psychiatric disorders among lesbians and gay men find no increased risk in comparison with heterosexuals. However, the majority of this work has relied on convenience samples drawn from the visible lesbian and gay community. The authors examined differences in 1-year prevalence of six psychiatric syndromes among sexually active individuals in the 1996 National Household Survey of Drug Abuse who reported either exclusive heterosexuality (n = 9,714) or having any same-gender sex partners (n = 194) in the prior year. Although nearly three quarters of homosexually active individuals did not meet criteria for any of the six syndromes assessed, in multivariate logistic regression analyses, homosexually active men were more likely than other men to evidence major depression and panic attack syndromes. In contrast, homosexually active women were more likely than other women to be classified with alcohol or drug dependency syndromes. Both men and women reporting any same-gender sex partners were more likely than others to have used mental health services in the year prior to interview. These findings suggest a small increased risk among homosexually active populations in 1-year psychiatric morbidity and use of mental health care services.

Cochran, Susan D.; Mays, Vickie M.

2013-01-01

167

Variation in Fitness-Related Characters among Small and Large Populations of Salvia-Pratensis  

Microsoft Academic Search

1 The threatened perennial Salvia pratensis is restricted to a few isolated populations in the Netherlands, which vary in size from 10 to 1500 flowering individuals. Small populations are known to have significantly lower allozyme diversity than the large populations, probably as a consequence of genetic erosion. We test the prediction that small populations of this species will have lower

N. J. Ouborg; R. Van Treuren

1995-01-01

168

Sexual selection and non-random mating for shell colour in a natural population of the marine snailLittorina mariae (Gastropoda: Prosobranchia)  

Microsoft Academic Search

In order to estimate the three independent components of mating behaviour, sexual selection in females, sexual selection in males and mating pattern, we studied the distribution of shell colour morphs among mating pairs and between copulating and non-copulating snails in four subsamples of a natural population ofL. mariae. The colour of the shell, the sex and a qualitative estimate of

Emilio Rolán-Alvarez; Anette Ekendahl

1996-01-01

169

Sexual Pharmacology: Love Potions, Pills, and Poisons  

Microsoft Academic Search

The human population is increasingly exposed to chemicals that affect sexual function, from industrial pollutants to life-saving pharmaceuticals. First, the products that can cause dysfunction, including endocrine disruptors, drugs of abuse, and prescription medications, are reviewed. A systemic perspective proves helpful in explaining the large variability in effects and side effects of medications. Secondly, the biological treatments of sexual dysfunction

Johan Verhulst; Jonathan K. Reynolds

2009-01-01

170

Sexual satisfaction in the elderly female population: A special focus on women with gynecologic pathology.  

PubMed

SEXUAL FUNCTION IN AGING WOMEN: Sexuality is an integral part of human expressions. Mental health plays a major role in sexuality. Several psychological interventions are proposed to increase the sexual quality of life in older women with diverse gynecologic pathology. A biopsychosocial approach utilizing brief strategies can be easily implemented in clinics to help women of all ages increase their sexual quality of life. THE IMPACT OF FEMALE PELVIC FLOOR DISORDERS ON SEXUAL FUNCTION IN OLDER WOMEN: Female pelvic floor disorders include urinary incontinence, pelvic organ prolapse, and fecal incontinence. These disorders increase dramatically with increasing age. Urinary incontinence has been demonstrated to have a negative impact on a woman's sexual function. Among sexually active older women with urinary incontinence, 22% report being moderately or extremely worried that sexual activity would cause urine loss. An increased prevalence of sexual distress [9% (6/76) vs. 1.3% (2/216), p=0.005] has been reported in sexually active women over 40 years old with urinary incontinence. Treatment of urinary incontinence can improve sexual function in older women. Among sexually active women (N=53) who underwent midurethral slings procedures for the correction of urinary incontinence, increased coital frequency, decrease fear of incontinence with coitus, decreased embarrassment due to incontinence was reported six months after surgery. Pelvic organ prolapse, a hernia of the vagina resulting in a visible vaginal bulge, has also been associated with a negative impact on sexual function. Women with advanced pelvic organ prolapse (POP-Q stage III or IV) have been demonstrated to have decreased body image reporting that they are more self-conscious about their appearance [adjusted odds ratio (AOR) 4.7; 95% confidence interval (CI) 2.9, 51], feel less feminine (AOR 4.0; 95% CI 1.2, 15) and less sexually attractive (AOR 4.6; 95% CI 1.4, 17) compared with women who have normal pelvic support. Both vaginal and abdominal approaches to surgical correction of pelvic organ prolapse have been demonstrated to improve sexual function. MENTAL HEALTH: Mental health plays a major role in older woman's sexuality. Sexual interest and satisfaction is tied to emotional expressivity, women's self-worth, feelings of depression and loneliness as well as cognitive function. Research has shown that both general practitioners and specialists lack training in sexual assessments. Behavioral health specialists, such as a psychologist, can play an integral role in helping to facilitate communication between the patient and the provider. A main focus of communication training is to facilitate open and genuine conversation between the provider and the patient. Providers are encouraged to ask open ended questions while patients are encouraged to discuss symptoms while coping with an internal state of anxiety. Despite the known prevalence of sexual dysfunction among older women, few studied empirically based interventions have been published with these women. This speaks to the general assumption among medical professionals that having the "sex talk" in older women with gynecological pathology is not important or relevant. A biopsychosocial approach utilizing some of the aforementioned brief strategies can be easily implemented in comprehensive gynecology clinics in order to help women of all ages increase their sexual quality of life. PMID:21943557

Ratner, Elena S; Erekson, Elisabeth A; Minkin, Mary Jane; Foran-Tuller, Kelly A

2011-09-22

171

Prevalence of Childhood Sexual Abuse and Related Sequelae in a Lesbian Population  

Microsoft Academic Search

Purpose: This paper reports on the prevalence of a history of childhood sexual abuse from a national community-based sample of 1633 adult lesbians. Design: The descriptive analysis includes a comparison of mental and physical health variables commonly reported in adult survivors of childhood abuse in two subsamples, one who reported a history of childhood sexual abuse and one who did

Susan J. Roberts; Lena Sorensen

1999-01-01

172

Female mate choice copying affects sexual selection in wild populations of the ocellated wrasse  

Microsoft Academic Search

Explaining the factors that determine the distribution of mating success among males is essential to our understanding of sexual selection. Classic theory has focused on how competition among males and female choice for traits of the male or his territory drive sexual selection. Recent theory has also shown that female mate choice copying can alter the strength and direction of

Suzanne H. Alonzo

2008-01-01

173

Predictors of Clinically Significant Sexual Concerns in a Child Welfare Population  

Microsoft Academic Search

This study employed a risk and resilience paradigm to examine the correlates of youth with and without clinically significant sexual concerns (Trauma Symptom Checklist for Children) in a child welfare sample. Participants were 158 youth in substitute care with sexual behavior problems, as well as their caregivers. A multivariate classification tree analysis yielded an overall classification rate of 88%. Youth

Amy M. Lyons; Scott C. Leon; Christopher Zaddach; Erica J. Luboyeski; Maryse Richards

2009-01-01

174

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

Microsoft Academic Search

The ability of clinical and actuarial variables to predict criminal behavior was investigated in a sample of 342 sexual offenders that was previously used in a study by Hall and Proctor (1987). Discriminant analyses suggested that a linear combination of actuarial variables was significantly predictive of sexual reoffenses against adults and of nonsexual violent and nonviolent reoffending. However, clinical judgment

Gordon C. Nagayama Hall

1988-01-01

175

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

ERIC Educational Resources Information Center

|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)|

Bryan, Janice Westlund; Freed, Florence Wallach

1993-01-01

176

Sexual Orientation and Suicide Attempt: A Longitudinal Study of the General Norwegian Adolescent Population  

Microsoft Academic Search

Past and future suicide attempt rates among gay, lesbian, and bisexual (GLB) young people were compared with those of heterosexual young people. A sample of Norwegian students (N = 2,924; grades 7–12) was followed in 3 data collection waves. Risk factors included previous suicide attempt, depressed mood, eating problems, conduct problems, early sexual debut, number of sexual partners, pubertal timing,

Lars Wichstrřm; Kristinn Hegna

2003-01-01

177

Molecular Characterization of Sexual Diversity in a Population of Serpula lacrymans, a Tetrapolar Basidiomycete  

PubMed Central

Different mating systems have evolved in the fungal kingdom, including a tetrapolar multiallelic mating system in many basidiomycetes. In tetrapolar species, the presence of different alleles at two mating loci (MAT A and MAT B) is necessary for mating to occur. The tetrapolar fungus Serpula lacrymans causes wood-decay in buildings in temperate regions worldwide and is present in Europe with a genetically homogeneous founder population. Using genome sequence data, we annotated the two mating type loci for S. lacrymans and found the expected synteny with other basidiomycetes, except for a retrotransposon being present in one locus (MAT A). We developed markers linked to the MAT A and MAT B regions and used these to investigate the mating type diversity in the European population. Moreover, we found a good match between the genetic markers and functional mating types as revealed by segregation and mating studies. A low diversity of mating types is present in the European S. lacrymans population caused by the founder event where a limited number of genotypes were introduced. This finding contrasts the situation in natural fungal populations where a high diversity of mating types is normally present. Although S. lacrymans has a large and viable population in Europe, we argue that the low mating type diversity restrains the dispersal and establishment of the fungus.

Skrede, Inger; Maurice, Sundy; Kauserud, Havard

2013-01-01

178

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

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.

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

2012-01-01

179

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

Microsoft Academic Search

BackgroundTrichomonas 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

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

2012-01-01

180

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

PubMed Central

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.

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

181

Adjustment among mothers reporting same-gender sexual partners: a study of a representative population sample from Quebec Province (Canada).  

PubMed

We examined the well-being of mothers and non-mothers reporting exclusive opposite-gender sexual partners (OG), same-gender sexual partners (SG), or both (BI) in a representative sample of 20,773 participants (11,034 women) 15-years-old or older from the population of Quebec province in Canada. Participants completed a self-administered questionnaire and SG and BI women (n = 179) were matched to a sample of OG women (n = 179) based on age, income, geographical area, and children (having at least one 18-year-old or younger biological or adopted child at home). We assessed social milieu variables, risk factors for health disorders, mental health, and quality of mothers' relationship with children. The findings indicated a sexual orientation main effect: Mothers and non-mothers in the SG and BI group, as compared to their OG controls, were significantly less likely to live in a couple relationship, had significantly lower levels of social support, higher prevalence of early negative life events, substance abuse, suicide ideation, and higher levels of psychological distress. There were no Sexual Orientation X Parenthood status effects. The results further indicated that sexual orientation did not account for unique variance in women's psychological distress beyond that afforded by their social milieu, health risk factors, and parenthood status. No significant differences were found for the quality of mothers' relationship with children. SG-BI and OG mothers with low levels of social integration were significantly more likely to report problems with children than parents with high levels of social integration. We need to understand how marginal sexualities and their associated social stigma, as risk indicators for mothers, interact with other factors to impact family life, parenting skills, and children's adjustment. PMID:17665300

Julien, Danielle; Jouvin, Emilie; Jodoin, Emilie; L'archevęque, Alexandre; Chartrand, Elise

2007-07-31

182

Large-scale manipulation of mayfly recruitment affects population size.  

PubMed

Recruitment establishes the initial size of populations and may influence subsequent population dynamics. Although strong inference can be made from empirical relationships between recruitment and population sizes, a definitive test of recruitment limitation requires manipulating recruitment at relevant spatial and temporal scales. We manipulated oviposition of the mayfly Baetis bicaudatus in multiple streams and measured the abundance of late-stage larvae at the end of the cohort. Based on fundamental knowledge of mayfly behavior, we increased, eliminated, or left unmodified preferred mayfly oviposition sites in 45-m reaches of streams (N = 4) of one high-altitude drainage basin in western Colorado, USA. We compared egg densities before (2001) and after the manipulation (2002) using paired t tests and compared larval densities before and after the manipulation among treatments using repeated measures analysis of variance. This manipulation altered not only egg densities, but also larval abundances 1 year later. Compared to the previous year, we experimentally increased egg densities at the addition sites by approximately fourfold, reduced egg densities to zero in the subtraction sites, and maintained egg densities in the control sites. After the manipulation, larval densities increased significantly by a factor of approximately 2.0 in the addition sites and decreased by a factor of approximately 2.5 in the subtraction sites. This outcome demonstrates that dramatic changes in recruitment can limit larval population size at the scale of a stream reach, potentially masking previously observed post-recruitment processes explaining the patterns of variation in abundance of a stream insect. Furthermore, our results emphasize the importance of preferred oviposition habitats to population sizes of organisms. PMID:22015569

Encalada, Andrea C; Peckarsky, Barbara L

2011-10-21

183

Attitudes and beliefs about anti-retroviral therapy are associated with high risk sexual behaviors among the general population of Kisumu, Kenya  

Microsoft Academic Search

Attitudes and beliefs about antiretroviral therapy (ART) may affect sexual risk behaviors among the general population in sub-Saharan Africa. We performed a cross-sectional population-based study in Kisumu, Kenya to test this hypothesis in October 2006. A total of 1655 participants were interviewed regarding attitudes and beliefs about ART and their sexual risk behaviors. The majority of participants, (71%) men and

Rachel M. Smith; Adam W. Carrico; Michele Montandon; Zachary Kwena; Robert Bailey; Elizabeth A. Bukusi; Craig R. Cohen

2011-01-01

184

Evidence for a large population of shocked interstellar clouds  

Microsoft Academic Search

A 21 cm absorption measurement over a long path length free of the effects of differential galactic rotation indicates the\\u000a existence of two distinct cloud populations in the plane. One of them consisting of cold, dense clouds has been well studied\\u000a before. The newly found hot clouds appear to be at least five times more numerous. They have a spin

V. Radhakrishnan; G. Srinivasan

1980-01-01

185

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

USGS Publications Warehouse

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.

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

1997-01-01

186

Sexual Victimization: Incidence, Knowledge and Resource Use among a Population of College Women  

Microsoft Academic Search

Study ObjectiveTo assess the incidence of sexual victimization among a convenience sample of college women and evaluate both victims and non-victims' knowledge and use of available on and off campus resources.

Aarti Nasta; Brijen Shah; Shoma Brahmanandam; Katherine Richman; Kathleen Wittels; Jenifer Allsworth; Lori Boardman

2005-01-01

187

[Characteristics of a population of sex workers and their association with the presence of sexually transmitted diseases].  

PubMed

The objectives of this study were to describe a population of sex workers considering their sociodemographic characteristics, gyneco-obstetric history and behavioral factors, and to verify the association of these characteristics with the presence of sexually transmitted diseases. This epidemiological cross-sectional study was performed with 102 female sex workers. Data were collected using structured interviews and gold-standard exams for diagnosis of the diseases of interest. The women's mean age was 26.1 years. Most of them had attended school for nine years or more, were single and reported becoming sexually active before 15 years of age. Performing oral sex on partners was cited by 90.2% of women, and 99% reported the use of condoms at work; only 26.3% used condoms with permanent partners, and 42.2% used illicit drugs. No association was observed between sociodemographic factors, gyneco-obstetric history or behavioral factors and sexually transmitted diseases, which may have been due to their educational status and the fact that the population had very similar characteristics, thus making it difficult to determine such associations. PMID:23018397

Dal Pogetto, Maíra Rodrigues Baldin; Marcelino, Larissa Doddi; Carvalhaes, Maria Antonieta de Barros Leite; Rall, Vera Lúcia Mores; da Silva, Márcia Guimarăes; Parada, Cristina Maria Garcia de Lima

2012-08-01

188

A Population-Based Study of Sexual Orientation Identity and Gender Differences in Adult Health  

PubMed Central

Objectives. We provide estimates of several leading US adult health indicators by sexual orientation identity and gender to fill gaps in the current literature. Methods. We aggregated data from the 2001–2008 Massachusetts Behavioral Risk Factor Surveillance surveys (N = 67 359) to examine patterns in self-reported health by sexual orientation identity and gender, using multivariable logistic regression. Results. Compared with heterosexuals, sexual minorities (i.e., gays/lesbians, 2% of sample; bisexuals, 1%) were more likely to report activity limitation, tension or worry, smoking, drug use, asthma, lifetime sexual victimization, and HIV testing, but did not differ on 3-year Papanicolaou tests, lifetime mammography, diabetes, or heart disease. Compared with heterosexuals, bisexuals reported more barriers to health care, current sadness, past-year suicidal ideation, and cardiovascular disease risk. Gay men were less likely to be overweight or obese and to obtain prostate-specific antigen tests, and lesbians were more likely to be obese and to report multiple risks for cardiovascular disease. Binge drinking and lifetime physical intimate partner victimization were more common among bisexual women. Conclusions. Sexual orientation disparities in chronic disease risk, victimization, health care access, mental health, and smoking merit increased attention. More research on heterogeneity in health and health determinants among sexual minorities is needed.

Mimiaga, Matthew J.; Landers, Stewart J.

2010-01-01

189

Capturing the social demographics of hidden sexual minorities: An internet study of the transgender population in the United States  

Microsoft Academic Search

As part of a larger study, we investigated the feasibility of using Internet research to capture the demographic characteristics\\u000a of a largely closeted sexual minority and to report such characteristics in the first national study of transgender persons\\u000a ever attempted in the United States. To achieve a nonclinical national sample, online convenience sampling was used. Of 1,373\\u000a surveys received, 1,229

B. R. Simon Rosser; J. Michael Oakes; Walter O. Bockting; Michael Miner

2007-01-01

190

Some Estimators of a Population Total from Simple Random Samples Containing Large Units  

Microsoft Academic Search

The problem considered is the estimation of the population total of some characteristic from a simple random sample containing a few large or extreme observations. The effect of these large units in the sample is to distort the estimate of the population total. It is therefore important to correct the weights for such units or deflate their values at the

Michael A. Hidiroglou; Kadaba P. Srinath

1981-01-01

191

Magnaporthe oryzae populations adapted to finger millet and rice exhibit distinctive patterns of genetic diversity, sexuality and host interaction.  

PubMed

In this study, host-specific forms of the blast pathogen Magnaporthe oryzae in sub-Saharan Africa (SSA) were characterised from distinct cropping locations using a combination of molecular and biological assays. Finger millet blast populations in East Africa revealed a continuous genetic variation pattern and lack of clonal lineages, with a wide range of haplotypes. M. oryzae populations lacked the grasshopper (grh) element (96%) and appeared distinct to those in Asia. An overall near equal distribution (47-53%) of the mating types MAT1-1 and MAT1-2, high fertility status (84-89%) and the dominance of hermaphrodites (64%) suggest a strong sexual reproductive potential. Differences in pathogen aggressiveness and lack of cultivar incompatibility suggest the importance of quantitative resistance. Rice blast populations in West Africa showed a typical lineage-based structure. Among the nine lineages identified, three comprised ~90% of the isolates. Skewed distribution of the mating types MAT1-1 (29%) and MAT1-2 (71%) was accompanied by low fertility. Clear differences in cultivar compatibility within and between lineages suggest R gene-mediated interactions. Distinctive patterns of genetic diversity, sexual reproductive potential and pathogenicity suggest adaptive divergence of host-specific forms of M. oryzae populations linked to crop domestication and agricultural intensification. PMID:21701860

Takan, J P; Chipili, J; Muthumeenakshi, S; Talbot, N J; Manyasa, E O; Bandyopadhyay, R; Sere, Y; Nutsugah, S K; Talhinhas, P; Hossain, M; Brown, A E; Sreenivasaprasad, S

2012-02-01

192

Collective Response of Human Populations to Large-Scale Emergencies  

PubMed Central

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.

Barabasi, Albert-Laszlo

2011-01-01

193

Sexual fantasies and sexual arousal in women with a history of childhood sexual abuse  

Microsoft Academic Search

Treatments of female sexual arousal dysfunction for childhood sexual abuse (CSA) survivors could greatly benefit from more information on mechanisms to the sexual arousal problems specific to this population. In this study, 60 CSA survivors and 120 women with no history of CSA (NCSA) participated in an Internet-based survey on sexual arousal and sexual fantasies. Self-reported sexual arousal was measured

Julia Camuso; Alessandra H. Rellini

2010-01-01

194

Plasma lipid profiling in a large population-based cohort.  

PubMed

We have performed plasma lipid profiling using liquid chromatography electrospray ionization tandem mass spectrometry on a population cohort of more than 1,000 individuals. From 10 ?l of plasma we were able to acquire comparative measures of 312 lipids across 23 lipid classes and subclasses including sphingolipids, phospholipids, glycerolipids, and cholesterol esters (CEs) in 20 min. Using linear and logistic regression, we identified statistically significant associations of lipid classes, subclasses, and individual lipid species with anthropometric and physiological measures. In addition to the expected associations of CEs and triacylglycerol with age, sex, and body mass index (BMI), ceramide was significantly higher in males and was independently associated with age and BMI. Associations were also observed for sphingomyelin with age but this lipid subclass was lower in males. Lysophospholipids were associated with age and higher in males, but showed a strong negative association with BMI. Many of these lipids have previously been associated with chronic diseases including cardiovascular disease and may mediate the interactions of age, sex, and obesity with disease risk. PMID:23868910

Weir, Jacquelyn M; Wong, Gerard; Barlow, Christopher K; Greeve, Melissa A; Kowalczyk, Adam; Almasy, Laura; Comuzzie, Anthony G; Mahaney, Michael C; Jowett, Jeremy B M; Shaw, Jonathan; Curran, Joanne E; Blangero, John; Meikle, Peter J

2013-07-18

195

Hydrodynamic stretching of single cells for large population mechanical phenotyping.  

PubMed

Cell state is often assayed through measurement of biochemical and biophysical markers. Although biochemical markers have been widely used, intrinsic biophysical markers, such as the ability to mechanically deform under a load, are advantageous in that they do not require costly labeling or sample preparation. However, current techniques that assay cell mechanical properties have had limited adoption in clinical and cell biology research applications. Here, we demonstrate an automated microfluidic technology capable of probing single-cell deformability at approximately 2,000 cells/s. The method uses inertial focusing to uniformly deliver cells to a stretching extensional flow where cells are deformed at high strain rates, imaged with a high-speed camera, and computationally analyzed to extract quantitative parameters. This approach allows us to analyze cells at throughputs orders of magnitude faster than previously reported biophysical flow cytometers and single-cell mechanics tools, while creating easily observable larger strains and limiting user time commitment and bias through automation. Using this approach we rapidly assay the deformability of native populations of leukocytes and malignant cells in pleural effusions and accurately predict disease state in patients with cancer and immune activation with a sensitivity of 91% and a specificity of 86%. As a tool for biological research, we show the deformability we measure is an early biomarker for pluripotent stem cell differentiation and is likely linked to nuclear structural changes. Microfluidic deformability cytometry brings the statistical accuracy of traditional flow cytometric techniques to label-free biophysical biomarkers, enabling applications in clinical diagnostics, stem cell characterization, and single-cell biophysics. PMID:22547795

Gossett, Daniel R; Tse, Henry T K; Lee, Serena A; Ying, Yong; Lindgren, Anne G; Yang, Otto O; Rao, Jianyu; Clark, Amander T; Di Carlo, Dino

2012-04-30

196

The Molecular Cloud Population of the Large Magellanic Cloud  

NASA Astrophysics Data System (ADS)

We have mapped an extensive sample of molecular clouds in the Large Magellanic Cloud (LMC) at 11 pc resolution in the CO(1-0) line as part of the Magellanic Mopra Assessment (MAGMA). We identify clouds as regions of connected CO emission and determine their sizes, line widths, and fluxes. We find that GMCs are not preferentially located in regions of high Hi line width or velocity gradient, and that there is no clear Hi column density threshold for CO detection. The luminosity function of CO clouds is steeper than dN/dL ? L -2, suggesting a substantial fraction of mass in low-mass clouds. The correlation between size and linewidth, while apparent for the largest emission structures, breaks down when those structures are decomposed into smaller structures. The virial parameter (the ratio of a cloud's kinetic to gravitational energy) shows a wide range of values and exhibits no clear trends with the likelihood of hosting young stellar object (YSO) candidates, suggesting that this parameter is a poor reflection of the evolutionary state of a cloud. More massive GMCs are more likely to harbor a YSO candidate, and more luminous YSOs are more likely to be coincident with detectable CO emission, confirming GMCs as the principal sites of massive star formation.

Wong, Tony; Hughes, Annie; Ott, Jürgen; Pineda, Jorge L.; Muller, Erik; MAGMA Collaboration

2013-03-01

197

Changes and correlates in multiple sexual partnerships among Chinese adult women – population-based surveys in 2000 and 2006  

Microsoft Academic Search

The sexual transmission of HIV and STI is becoming a major public health concern in China. However, studies on sexuality in China remain scant, particularly those that analyze female sexuality. This study is to investigate the prevalence of multiple sexual partnerships (MSP) among adult women, and to examine trends and correlates for having more than one lifetime sexual partner.MSP, coded

Huang Yingying; Kumi Smith; Pan Suiming

2011-01-01

198

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

PubMed Central

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.

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

2013-01-01

199

Partner violence and sexual jealousy in China: a population-based survey.  

PubMed

Using data from a nationally representative survey in China, this article examines the prevalence and risk factors for partner violence with a special focus on the important role of sexual jealousy. Among women aged 20 to 49, 7.2% reported that they were hit by their partners in the past 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

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

2009-05-18

200

A population-based study investigating the association between sexual and relationship satisfaction and psychological distress among heterosexuals.  

PubMed

This study examined whether sexual/relationship satisfaction are differentially associated with mental health issues. Using data from a population-based computer-assisted telephone survey, the authors included in this study 3,800 respondents who had a regular heterosexual partner. The authors used 2 methods of scoring the K6 to produce measures of moderate psychological distress and serious psychological distress. Overall, 8.8% of men and 12.1% of women were classified as having moderate psychological distress, whereas 1.6% of men and 3.2% of women were classified as currently experiencing serious psychological distress. The association between satisfaction and mental health was influenced by sex and the severity of the mental health issue but not by type of satisfaction. After adjusting for demographic differences in mental health, low ratings of sexual/relationship satisfaction were both consistently associated with higher levels of moderate psychological distress in men and women and higher proportions of serious psychological distress in men. Although women may be able to resolve their satisfaction issues during less severe stages of psychological distress, for men there was a strong association between low sexual/relationship satisfaction and serious psychological distress. PMID:23152969

Patrick, Kent; Heywood, Wendy; Smith, Anthony M A; Simpson, Judy M; Shelley, Julia M; Richters, Juliet; Pitts, Marian K

2013-01-01

201

Sexual Conflict as a Consequence of Ecology: Evidence from Guppy, Poecilia reticulata, Populations in Trinidad  

Microsoft Academic Search

An investigation of the behaviour of guppies, Poecilia reticulata, in the wild reveals that sexual conflict varies markedly in different habitats. Males from high-predation sites in Trinidad (where the pike cichlid Crenicichla alta occurs) engage in less antipredator behaviour than females, have lower foraging rates than males from low-risk sites and are able to devote a greater proportion of their

Anne E. Magurran; Benoni H. Seghers

1994-01-01

202

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

ERIC Educational Resources Information Center

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…

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

2011-01-01

203

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

ERIC Educational Resources Information Center

|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…

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

2012-01-01

204

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

ERIC Educational Resources Information Center

|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…

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

2011-01-01

205

Sexual dimorphism of the human sternum in a Maharashtrian population of India: A morphometric analysis  

Microsoft Academic Search

Determination of sex from human skeletal remains is an imperative element of any medicolegal investigation. Length of manubrium, length of mesosternum, and combined length of manubrium and mesosternum were measured in 115 sternums of confirmed sex (75 male and 40 female) for sexual dimorphism. Application of “the 50 rule” for the manubrium confirmed sex in 77.3% male and 77.5% female

Shahin A. Hunnargi; Ritesh G. Menezes; Tanuj Kanchan; Stany W. Lobo; V. S. Binu; Selma Uysal; Hareesh R. S. Kumar; Prakash Baral; N. G. Herekar; R. K. Garg

2008-01-01

206

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

Microsoft Academic Search

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

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

2010-01-01

207

MORTALITY COSTS OF SEXUAL SELECTION AND PARENTAL CARE IN NATURAL POPULATIONS OF BIRDS  

Microsoft Academic Search

Is the cost of reproduction different between males and females? On the one hand, males typically compete intensely for mates, thus sexual selection theory predicts higher cost of reproduction for males in species with intense male-male competition. On the other hand, care provisioning such as incubating the eggs and raising young may also be costly, thus parental care theory predicts

András Liker; Tamás Székely

2005-01-01

208

Divide or broadcast: Interrelation of asexual and sexual reproduction in a population of the fissiparous hermaphroditic seastar Nepanthia belcheri (Asteroidea: Asterinidae)  

Microsoft Academic Search

Asexual and sexual reproduction were studied in an intertidal population of Nepanthia belcheri (Perrier) at Townsville, Queensland, Australia, by regular sampling over a year (March 1976-March 1977) and by histological analysis of gonads. Fission reached a peak in early winter (April–June), when about 45% of the population showed evidence of recent fission. Propensity for fission was unrelated to longest arm

P. O. Ottesen; J. S. Lucas

1982-01-01

209

Knowledge of Sexually Transmitted Diseases and Attitudes Towards them in Populations at Risk in Djibouti. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

Sexually transmitted diseases (STDs) are an increasing public health problem in Djibouti. The authors have attempted to obtain basic information on the level of knowledge concerning STDs and on the sexual behavior of highly sexually promiscuous individual...

H. H. Wassef E. Fox E. A. Abbatte J.-F. Toledo G. Rodier

1989-01-01

210

The evolution of the female sexual response concept: treatment implications.  

PubMed

Sexual dysfunctions have been the most prevalent group of sexual disorders and include a large number of populations of both sexes.The research of sexual behavior and treatment of women with sexual distress arises many questions related to differences in sexual response of men and women. The conceptualization of this response in modern sexology has changed over time.The objective of our paper was to present the changes and evolution of the female's sexual response concept in a summarized and integrated way, to analyze the expanded and revised definitions of the female sexual response as well as implications and recommendations of new approaches to diagnostics and treatment according to the established changes.The lack of adequate empirical basis of the female sexual response model is a critical question in the literature dealing with this issue. Some articles report that linear models demonstrate more correctly and precisely the sexual response of women with normal sexual functions in relation to women with sexual dysfunction. Modification of this model later resulted in a circular model which more adequately presented the sexual response of women with sexual function disorder than of women with normal sexual function.The nonlinear model of female sexual response constructed by Basson incorporates the value of emotional intimacy, sexual stimulus and satisfaction with the relationship. Female functioning is significantly affected by multiple psychosocial factors such as satisfaction with the relationship, self-image, earlier negative sexual experience, etc. Newly revised, expanded definitions of female sexual dysfunction try to contribute to new knowledge about a highly contextual nature of woman's sexuality so as to enhance clinical treatment of dysfunctions.The definitions emphasize the evaluation of the context of women's problematic sexual experiences. PMID:23745356

Damjanovi?, Aleksandar; Duisin, Dragana; Barisi?, Jasmina

211

Attitudes and beliefs about anti-retroviral therapy are associated with high risk sexual behaviors among the general population of Kisumu, Kenya  

PubMed Central

Attitudes and beliefs about antiretroviral therapy (ART) may affect sexual risk behaviors among the general population in sub-Saharan Africa. We performed a cross-sectional population-based study in Kisumu, Kenya to test this hypothesis in October 2006. A total of 1655 participants were interviewed regarding attitudes and beliefs about ART and their sexual risk behaviors. The majority of participants, (71%) men and (70%) women, had heard of ART. Of these, 20% of men and 29% of women believed ART cures HIV. Among women, an attitude that “HIV is more controllable now that ART is available” was associated with sex with a non-spousal partner, increased lifetime number of sexual partners as well as a younger age at sexual debut. No significant associations with this factor were found among men. The belief that “ART cures HIV” was associated with younger age of sexual debut among women. The same belief was associated with an increased likelihood of exchanging sex for money/gifts and decreased likelihood of condom use at last sex among men. These findings were most significant for people aged 15–29 years. In high HIV seroprevalence populations with expanding access to ART, prevention programs must ensure their content counteracts misconceptions of ART in order to reduce high risk sexual behaviors, especially among youth.

Smith, Rachel M.; Carrico, Adam W.; Montandon, Michele; Kwena, Zachary; Bailey, Robert; Bukusi, Elizabeth A.; Cohen, Craig R.

2013-01-01

212

Sleep Patterns and Predictors of Disturbed Sleep in a Large Population of College Students  

Microsoft Academic Search

PurposeTo characterize sleep patterns and predictors of poor sleep quality in a large population of college students. This study extends the 2006 National Sleep Foundation examination of sleep in early adolescence by examining sleep in older adolescents.

Hannah G. Lund; Brian D. Reider; Annie B. Whiting; J. Roxanne Prichard

2010-01-01

213

Maximum body size among insular Komodo dragon populations covaries with large prey density  

Microsoft Academic Search

ABSTRACT This study documents,variation in maximum,body size of Komodo dragons (Varanus Komodoensis) among the 4 extant island populations, and compares an indirect measure of deer density, the major prey item for large dragons, to differences in

Tim S. Jessop; Thomas Madsen; Joanna Sumner; Heru Rudiharto; John A. Phillips; Claudio Ciofi

2006-01-01

214

Exploring knowledge and healthseeking behaviour related to sexually transmitted infections among the tribal population of Madhya Pradesh, central India.  

PubMed

This community-based cross-sectional study was carried out in the tribal population of randomly selected villages of Jabalpur district, Madhya Pradesh, central India. A total of 200 married men and women aged 15–49 years were interviewed to explore their knowledge, experience and health-seeking behaviour related to sexually transmitted infections (STIs). Though 91% of respondents were aware of STIs, the sexual route was mentioned by only 19%as the route of transmission. Around 18% reported a need for social isolation from persons with STIs. Though 88% of the respondents felt modern medicine was the best remedy for STIs, only a few of them used medical treatment while suffering from an STI. Twenty-seven per cent of respondents resorted to traditional healers, and 30% utilized home remedies for STI treatment. The study highlights a need for generating STI awareness amongst the tribal population of the region through a needs-based behaviour change communication (BCC)strategy. PMID:23016157

Rao, V G; Saha, K B; Bhat, J; Tiwary, B K; Abbad, A

2012-09-01

215

Population dynamics of large herbivores: variable recruitment with constant adult survival  

Microsoft Academic Search

Recent long-term studies of population ecology of large herbivorous mammals suggest that survival of prime-aged females varies little from year to year and across populations. Juvenile survival, on the other hand, varies considerably from year to year. The pattern of high and stable adult survival and variable juvenile survival is observed in contrasting environments, independently of the main proximal sources

Jean-Michel Gaillard; Marco Festa-Bianchet; Nigel Gilles Yoccoz

1998-01-01

216

A population of gamma-ray emitting globular clusters seen with the Fermi Large Area Telescope  

Microsoft Academic Search

Context. Globular clusters with their large populations of millisecond pulsars (MSPs) are believed to be potential emitters of high-energy gamma-ray emission. The observation of this emission provides a powerful tool to assess the millisecond pulsar population of a cluster, is essential for understanding the importance of binary systems for the evolution of globular clusters, and provides complementary insights into magnetospheric

Aous Abdo; M. Ackermann; M. Ajello; L. Baldini; J. Ballet; G. Barbiellini; D. Bastieri; R. Bellazzini; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; A. Bouvier; T. J. Brandt; J. Bregeon; M. Brigida; P. Bruel; R. Buehler; S. Buson; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; S. Carrigan; J. M. Casandjian; E. Charles; S. Chaty; A. Chekhtman; C. C. Cheung; J. Chiang; S. Ciprini; R. Claus; J. Cohen-Tanugi; J. Conrad; M. E. Decesar; C. D. Dermer; F. de Palma; S. W. Digel; E. Do Couto E. Silva; P. S. Drell; R. Dubois; D. Dumora; C. Favuzzi; P. Fortin; M. Frailis; Y. Fukazawa; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; N. Giglietto; F. Giordano; T. Glanzman; G. Godfrey; I. Grenier; M.-H. Grondin; J. E. Grove; L. Guillemot; S. Guiriec; D. Hadasch; A. K. Harding; E. Hays; P. Jean; G. Jóhannesson; T. J. Johnson; W. N. Johnson; T. Kamae; H. Katagiri; J. Kataoka; M. Kerr; J. Knödlseder; M. Kuss; J. Lande; L. Latronico; S.-H. Lee; M. Lemoine-Goumard; M. Llena Garde; F. Longo; F. Loparco; M. N. Lovellette; P. Lubrano; A. Makeev; M. N. Mazziotta; P. F. Michelson; W. Mitthumsiri; T. Mizuno; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; M. Naumann-Godo; P. L. Nolan; J. P. Norris; E. Nuss; T. Ohsugi; N. Omodei; E. Orlando; J. F. Ormes; B. Pancrazi; D. Parent; M. Pepe; M. Pesce-Rollins; F. Piron; T. A. Porter; S. Rainň; R. Rando; A. Reimer; O. Reimer; T. Reposeur; J. Ripken; R. W. Romani; M. Roth; H. F.-W. Sadrozinski; P. M. Saz Parkinson; C. Sgrň; E. J. Siskind; D. A. Smith; P. Spinelli; M. S. Strickman; D. J. Suson; H. Takahashi; T. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; L. Tibaldo; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. L. Usher; V. Vasileiou; C. Venter; N. Vilchez; V. Vitale; A. P. Waite; P. Wang; N. Webb; B. L. Winer; Z. Yang; T. Ylinen; M. Ziegler

2010-01-01

217

High genetic variation in leopards indicates large and long-term stable effective population size  

Microsoft Academic Search

In this paper we employ recently developed statistical and molecular tools to analyse the population history of the Tanzanian leopard ( Panthera pardus ), a large solitary felid. Because of their solitary lifestyle little is known of their past or present population dynamics. Eighty-one individuals were scored at 18 microsatellite loci. Overall, levels of hetero- zygosity were high (0.77 ?

G. Spong; M. Johansson; M. Björklund

2000-01-01

218

Sexual activity, sexual dysfunction and associated help-seeking behaviours in middle-aged and older adults in Spain: a population survey  

Microsoft Academic Search

To study sexual activity, the prevalence of sexual dysfunction and related help-seeking behaviours among mature adults in\\u000a Spain, a telephone survey was conducted in Spain in 2001–2002. This was completed by 750 men and 750 women aged 40–80 years.\\u000a Eighty-eight percent of men and 66% of women had engaged in sexual intercourse during the 12 months preceding the interview.\\u000a Early ejaculation (31%)

Edson D. Moreira; Dale B. Glasser; Clive Gingell

2005-01-01

219

Sexually transmitted infections, bacterial vaginosis, and candidiasis in women of reproductive age in rural Northeast Brazil: a population-based study  

Microsoft Academic Search

Population-based data on sexually transmitted infections (STI), bacterial vaginosis (BV), and candidiasis reflect the epidemiological situation more accurately than studies performed in specific populations, but such data are scarce. To determine the prevalence of STI, BV, and candidiasis among women of reproductive age from a resource-poor community in Northeast Brazil, a population-based cross sectional study was undertaken. All women from

Fabíola Araújo Oliveira; Viola Pfleger; Katrin Lang; Jörg Heukelbach; Iracema Miralles; Francisco Fraga; Anastácio Queiroz Sousa; Marina Stoffler-Meilicke; Ralf Ignatius; Ligia Franco Sansigolo Kerr; Hermann Feldmeier

2007-01-01

220

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

PubMed

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

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

2010-11-02

221

Large-scale copy number variants (CNVs) detected in different ethnic human populations  

Microsoft Academic Search

The large-scale copy-number variations (CNVs) in the human genome are associated with developmental disorders and susceptibility to diseases. More importantly, CNVs may represent a major genetic component of our phenotypic diversity. Following the development of methodologies and introduction of new research platforms, accumulation of the nature and pattern of CNVs from normal populations has progressed. The examination of relatively large

N. Takahashi; Y. Satoh; M. Kodaira; H. Katayama

2008-01-01

222

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

PubMed Central

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. See research article http://www.biomedcentral.com/1471-2148/10/104

2010-01-01

223

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

PubMed Central

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.

2012-01-01

224

Sexual Abuse and Sexual Functioning in a Chronic Pelvic Pain Sample  

ERIC Educational Resources Information Center

|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…

Randolph, Mary E.; Reddy, Diane M.

2006-01-01

225

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

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.

2010-01-01

226

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

PubMed Central

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

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

2013-01-01

227

Minireview: Hormones and Human Sexual Orientation  

PubMed Central

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.

2011-01-01

228

Sexual Reproduction Plays a Major Role in the Genetic Structure of Populations of the Fungus Mycosphaerella Graminicola  

PubMed Central

The relative contributions of sexual and asexual reproduction to the genetic structure of populations can be difficult to determine for fungi that use a mixture of both types of propagation. Nuclear RFLPs and DNA fingerprints were used to make indirect and direct measures of departures from random mating in a population of the plant pathogenic fungus Mycosphaerella graminicola during the course of an epidemic cycle. DNA fingerprints resolved 617 different genotypes among 673 isolates sampled from a single field over a 3-month period. Only 7% of the isolates represented asexual clones that were found more than once in the sample. The most common clone was found four times. Genotypic diversity averaged 85% of its maximum possible value during the course of the epidemic. Analyses of multilocus structure showed that allelic distributions among RFLP loci were independent. Pairwise comparisons between individual RFLP loci showed that the majority of alleles at these loci were in gametic equilibrium. Though this fungus has the capacity for a significant level of asexual reproduction, each analysis suggested that M. graminicola populations maintain a genetic structure more consistent with random-mating over the course of an epidemic cycle.

Chen, R. S.; McDonald, B. A.

1996-01-01

229

Deformation measurement of individual cells in large populations using a single-cell microchamber array chip  

NASA Astrophysics Data System (ADS)

We analyze the deformability of individual red blood cells (RBCs) using SiCMA technology. Our approach is adequate to quickly measure large numbers of individual cells in heterogeneous populations. Individual cells are trapped in a large-scale array of micro-wells, and dielectrophoretic (DEP) force is applied to deform the cells. The simple structures of micro-wells and DEP electrodes facilitate the analysis of thousands of RBCs in parallel. This unique method allows the correlation of red cell deformation with cell surface and cytosolic characteristics to define the distribution of individual cellular characteristics in heterogeneous populations.

Doh, I.; Lee, W. C.; Cho, Y.-H.; Pisano, A. P.; Kuypers, F. A.

2012-04-01

230

Deformation measurement of individual cells in large populations using a single-cell microchamber array chip  

PubMed Central

We analyze the deformability of individual red blood cells (RBCs) using SiCMA technology. Our approach is adequate to quickly measure large numbers of individual cells in heterogeneous populations. Individual cells are trapped in a large-scale array of micro-wells, and dielectrophoretic (DEP) force is applied to deform the cells. The simple structures of micro-wells and DEP electrodes facilitate the analysis of thousands of RBCs in parallel. This unique method allows the correlation of red cell deformation with cell surface and cytosolic characteristics to define the distribution of individual cellular characteristics in heterogeneous populations.

Doh, I.; Lee, W. C.; Cho, Y.-H.; Pisano, A. P.; Kuypers, F. A.

2012-01-01

231

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

NASA Astrophysics Data System (ADS)

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.

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

2012-03-01

232

The Multidimensional Scale of Sexuality.  

PubMed

Research on the assessment of sexual orientation has been limited, and what does exist is often conflicting and confusing. This is largely due to the lack of any agreed upon definition of bisexuality. The Multidimensional Scale of Sexuality (MSS) was developed to validate and to contrast six proposed categories of bisexuality, as well as categories related to heterosexuality, homosexuality, and asexuality. This instrument includes ratings of the behavioral and cognitive/affective components of sexuality. The MSS was completed by 148 subjects, the majority of whom were from identified homosexual and bisexual populations. Although subjects' self-descriptions on the MSS were consistent with their self-descriptions on the Kinsey Heterosexual-Homosexual Scale, the MSS provided a more varied description of sexual orientation. Subject's self-described sexual orientation on the MSS was more consistent with their cognitive/affective ratings than with their behavioral ratings. With the exception of self-described heterosexuals, the frequency of cognitive/affective sexuality was greater than that of behavioral sexuality. PMID:2230111

Berkey, B R; Perelman-Hall, T; Kurdek, L A

1990-01-01

233

A population-based study of syphilis and sexually transmitted disease syndromes in north-western Tanzania. 2. Risk factors and health seeking behaviour  

Microsoft Academic Search

OBJECTIVE--To determine risk factors for syphilis and sexually transmitted disease (STD) syndromes, and to study health seeking behaviour among those with STD syndromes, in the population of Mwanza Region, North-Western Tanzania. METHODS--A population-based random cluster sample survey, stratified by rural, roadside or urban residence, of 4173 individuals aged 15-54 years was performed in 1990-91. The seroprevalence of syphilis and the

J Newell; K Senkoro; F Mosha; H Grosskurth; A Nicoll; L Barongo; M Borgdorff; A Klokke; J Changalucha; J Killewo

1993-01-01

234

Mating system change reduces the strength of sexual selection in an American frontier population of the 19th century  

Microsoft Academic Search

Sexual selection, or competition among members of one sex for reproductive access to the other, is one of the strongest and fastest evolutionary processes. Comparative studies support the prediction that sexual selection is stronger in polygamous than in monogamous species. We report the first study of the effect on sexual selection of a change in mating system, from polygyny to

Jacob A. Moorad; Daniel E. L. Promislow; Ken R. Smith; Michael J. Wade

2011-01-01

235

Models for an arenavirus infection in a rodent population: consequences of horizontal, vertical and sexual transmission.  

PubMed

Arenaviruses are associated with rodent-transmitted diseases in humans. Five arenaviruses are known to cause human illness: Lassa virus, Junin virus, Machupo virus, Guanarito virus and Sabia virus. In this investigation, we model the spread of Machupo virus in its rodent host Calomys callosus. Machupo virus infection in humans is known as Bolivian hemorrhagic fever (BHF) which has a mortality rate of approximately 5-30% [31]. Machupo virus is transmitted among rodents through horizontal (direct contact), vertical (infected mother to offspring) and sexual transmission. The immune response differs among rodents infected with Machupo virus. Either rodents develop immunity and recover (immunocompetent) or they do not develop immunity and remain infected (immunotolerant). We formulate a general deterministic model for male and female rodents consisting of eight differential equations, four for females and four for males. The four states represent susceptible, immunocompetent, immunotolerant and recovered rodents, denoted as S, I( t), I( c)and R, respectively. A unique disease-free equilibrium (DFE) is shown to exist and a basic reproduction number R( 0)is computed using the next generation matrix approach. The DFE is shown to be locally asymptotically stable if R(0) < 1and unstable if R( 0) > 1. Special cases of the general model are studied, where there is only one immune stage, either I(t) or I(c). In the first model, SI(c)R( c), it is assumed that all infected rodents are immunocompetent and recover. In the second model, SI(t), it is assumed that all infected rodents are immunotolerant. For each of these models, the basic reproduction numbers are computed and their relationship to the basic reproduction number of the general model determined. For the SI( t)model, it is shown that bistability may occur, the DFE and an enzootic equilibrium, with all rodents infectious, are locally asymptotically stable for the same set of parameter values. A simplification of the SI( t)model yields a third model, where the sexes are not differentiated, and therefore, there is no sexual transmission. For this third simplified model, the dynamics are completely analyzed. It is shown that there exists a DFE and possibly two additional equilibria, one of which is globally asymptotically stable for any given set of parameter values; bistability does not occur. Numerical examples illustrate the dynamics of the models. The biological implications of the results and future research goals are discussed in the conclusion. PMID:19278272

Banerjee, Chandrani; Allen, Linda J S; Salazar-Bravo, Jorge

2008-10-01

236

Assessing the use of global land cover data for guiding large area population distribution modelling.  

PubMed

Gridded population distribution data are finding increasing use in a wide range of fields, including resource allocation, disease burden estimation and climate change impact assessment. Land cover information can be used in combination with detailed settlement extents to redistribute aggregated census counts to improve the accuracy of national-scale gridded population data. In East Africa, such analyses have been done using regional land cover data, thus restricting application of the approach to this region. If gridded population data are to be improved across Africa, an alternative, consistent and comparable source of land cover data is required. Here these analyses were repeated for Kenya using four continent-wide land cover datasets combined with detailed settlement extents and accuracies were assessed against detailed census data. The aim was to identify the large area land cover dataset that, combined with detailed settlement extents, produce the most accurate population distribution data. The effectiveness of the population distribution modelling procedures in the absence of high resolution census data was evaluated, as was the extrapolation ability of population densities between different regions. Results showed that the use of the GlobCover dataset refined with detailed settlement extents provided significantly more accurate gridded population data compared to the use of refined AVHRR-derived, MODIS-derived and GLC2000 land cover datasets. This study supports the hypothesis that land cover information is important for improving population distribution model accuracies, particularly in countries where only coarse resolution census data are available. Obtaining high resolution census data must however remain the priority. With its higher spatial resolution and its more recent data acquisition, the GlobCover dataset was found as the most valuable resource to use in combination with detailed settlement extents for the production of gridded population datasets across large areas. PMID:23576839

Linard, Catherine; Gilbert, Marius; Tatem, Andrew J

2010-05-25

237

Large time behavior in a nonlinear age-dependent population dynamics problem with spatial diffusion  

Microsoft Academic Search

In this work we analyze the large time behavior in a nonlinear model of population dynamics with age-dependence and spatial diffusion. We show that when t?+8 either the solution of our problem goes to 0 or it stabilizes to a nontrivial stationary solution. We give two typical examples where the stationary solutions can be evaluated upon solving very simple partial

Michel Langlais

1988-01-01

238

Multimodal Biometric Identification for Large User Population Using Fingerprint, Face and Iris Recognition  

Microsoft Academic Search

Biometric systems based solely on one-modal biometrics are often not able to meet the desired performance requirements for large user population applications, due to problems such as noisy data, intra-class variations, restricted degrees of freedom, nonuniversity, spoof attacks, and unacceptable error rates. Multimodal biometrics refers to the use of a combination of two or more biometric modalities in a single

Teddy Ko

2005-01-01

239

Speaker Model Clustering for Efficient Speaker Identification in Large Population Applications  

Microsoft Academic Search

In large population speaker identification (SI) sys- tems, likelihood computations between an unknown speaker's feature vectors and the registered speaker models can be very time-consuming and impose a bottleneck. For applications re- quiring fast SI, this is a recognized problem and improvements in efficiency would be beneficial. In this paper, we propose a method whereby GMM-based speaker models are clustered

Vijendra Raj Apsingekar; Phillip L. De Leon

2009-01-01

240

Suicidality and sexual orientation: differences between men and women in a general population-based sample from the Netherlands.  

PubMed

Homosexuality has been shown to be associated with suicidality and mental disorders. It is unclear whether homosexuality is related to suicidality, independently of mental disorders. This study assessed differences in lifetime symptoms of suicidality (death ideation, death wishes, suicide contemplation, and deliberate self-harm) between homosexual and heterosexual men and women, controlling for lifetime psychiatric morbidity. Interaction effects of age and the role of perceived discrimination were also examined. Data were collected on a representative sample of the Dutch population aged 18-64 years. Classification as heterosexual or homosexual was based upon reported sexual behavior in the preceding year. Of those sexually active, 2.8% of 2,878 men and 1.4% of 3,120 women had had same-sex partners. Homosexual men differed from their heterosexual counterparts on all four suicide symptoms (OR ranging from 2.58 to 10.23, with higher ORs for more severe symptoms), and on the sum total of the four symptoms; homosexual women only differed from heterosexual women on suicide contemplation (OR=2.12). Controlling for psychiatric morbidity decreased the ORs, but among men all associations were still significant; the significance for suicide contemplation among women disappeared. Younger homosexuals were not at lower risk for suicidality than older homosexuals in comparison with their heterosexual counterparts. Among homosexual men, perceived discrimination was associated with suicidality. This study suggests that even in a country with a comparatively tolerant climate regarding homosexuality, homosexual men were at much higher risk for suicidality than heterosexual men. This relationship could not only be attributed to their higher psychiatric morbidity. In women, there was no such clear relationship. PMID:16799841

de Graaf, Ron; Sandfort, Theo G M; ten Have, Margreet

2006-06-24

241

Population structure of two beetle-associated yeasts: comparison of a New World asexual and an endemic Nearctic sexual species in the Metschnikowia clade.  

PubMed

The genetic structure of two related yeast species, one sexual and one asexual, was compared using polymorphic DNA markers. Although both yeasts propagate by asexual budding of haploid cells, Metschnikowia borealis reproduces sexually when compatible strains come in contact. To what extent this has occurred in nature was not known. As Candida ipomoeae is a closely related, asexual species, the two yeasts provide an excellent model system to assess the role of sexual reproduction in a biogeographic context. Natural isolates of the two species were characterized using several polymorphic DNA markers. As predicted for an organism whose reproduction is strictly clonal, C. ipomoeae exhibited low haplotype diversity, high linkage disequilibrium, and high population differentiation. In contrast, M. borealis had unique haplotypes in most isolates, lower population differentiation, and little linkage disequilibrium, demonstrating that sexual recombination is prevalent. Geographic gradients were identified in both species, indicating that historical and climatic factors both play a role in shaping the populations. The spatial structure is also thought to be influenced by the ecology of the small floricolous beetles (family Nitidulidae) that vector the yeasts. For example, Hawaiian strains of C. ipomoeae show evidence of having undergone a genetic bottleneck, most likely when the vector was introduced to the islands. The two haplotypes found in Hawaii were nearly identical and were also found in North and Central America. M. borealis had a more continuous distribution where the genetic markers follow latitudinal and longitudinal gradients. PMID:19319659

Wardlaw, Alison M; Berkers, Tanya E; Man, Karen C; Lachance, Marc-André

2009-03-25

242

Effects of genotoxicity and its consequences at the population level in sexual and asexual Artemia assessed by analysis of inter-simple sequence repeats (ISSR).  

PubMed

There is considerable evidence that genetic damage in organisms occurs in the environment as a result of exposure to genotoxins and ionising radiation, but we have limited understanding of the extent to which this results in adverse consequences at a population level. We used inter-simple sequence repeat (ISSR) markers to quantify genotoxic effects of the mutagen ethylmethane sulfonate (EMS) on a sexual (Artemia franciscana) and an asexual (Artemia parthenogenetica) species of brine shrimp. The method provides information similar to that obtained with assessment of RAPD (random amplification of polymorphic DNA) but is more robust. Genetic damage was transmitted to the F1 generation in both Artemia species, but the sexual species showed a greater degree of recovery, as shown by higher values of genomic template stability. There was a strong correlation between DNA damage and effects on individual fitness parameters: size, survival, reproduction and population growth. These effects persisted into the F2 generation in A. parthenogenetica, but in the sexual A. franciscana only effects on fecundity continued beyond the exposed generation, even though there were substantial alterations in ISSR patterns in the F1 generation. Genetic biomarkers can thus be indicative of effects at the population level, but sexually reproducing species have a considerable assimilative capacity for the effects of genotoxins. PMID:23872504

Sukumaran, Sandhya; Grant, Alastair

2013-07-16

243

People with Disabilities as a Health Disparities Population: The Case of Sexual and Reproductive Health Disparities  

Microsoft Academic Search

Disability has yet to achieve its proper place in the discussion of health disparities. Several major Federal initiatives to remove health disparities have only addressed disability as a consequence of poverty, low education levels, lack of access to health care, and other disparity factors, but fail to acknowledge people with disabilities as a health disparity population. Whereas policymakers and health

Margaret A. Nosek; Darrell K. Simmons

2007-01-01

244

Identifi cation of individuals with gonorrhoea within sexual networks: a population-based study  

Microsoft Academic Search

Findings We identifi ed 21 prevalent strains in this diverse gonococcal population, each infecting between 20 and 124 individuals. Seven of these strains were predominantly from men who have sex with men; the remaining 14 were predominantly from heterosexual people. No diff erences were recorded between the strains associated with men who have sex with men in the demographic or

Bhudipa Choudhury; Claire L Risley; Azra C Ghani; Cynthia J Bishop; Helen Ward; Kevin A Fenton; Catherine A Ison; Brian G Spratt; C L Risley DPhil

245

Sexual Health  

MedlinePLUS

... Exams Polycystic Ovary Syndrome Sexual Attraction and Orientation Sexual Harassment and Sexual Bullying Talking to Your Partner About ... Normal? Male Reproductive System Sexual Attraction and Orientation Sexual Harassment and Sexual Bullying Talking to Your Partner About ...

246

[Population aspects of sexual dimorphism in guild of the Mustelidae: Mustela lutreola, Neovison vison, Mustela putorius, Martes martes as an example].  

PubMed

Size sexual dimorphism was investigated on 695 skulls of four Mustelidae species. By extent of increasing of differences between sexes the species are placed in following order: European pine marten (Martes martes), European mink (Mustela lutreola), American mink (Neovison vison), and European polecat (Mustela putorius). Extent of the dimorphism characterizes ecological plasticity of the species and is population characteristic. It is shown that M. martes takes specific and relatively narrow ecological niche of forest ecosystems, entering into weak competitive relationships with smaller Mustelidae species. The level of sexual dimorphism of M. lutreola, N. vison and M. putorius reflects intensity of its interspecific relationships within study area. High level of sexual dimorphism of M. putorius is determined by further divergence of ecological niches of males and females, and also appears to be compensatory mechanism reducing consequences of hardened environmental requirements. PMID:23662464

Korablev, M P; Korablev, N P; Korablev, P N

247

Sexual dimorphism in the Turkmenian population in two types of dermatoglyphic traits: discriminant analysis.  

PubMed

The aim of this study is to compare the pattern of sex differences between two different sets of dermatoglyphic traits (22 quantitative and 42 indices of diversity and asymmetry). Finger and palmar prints of Turkmenian population (547 individuals) were used for Multivariate analyses includes Cluster, Discriminant and Mantel test of matrix correlations. All variables (two groups) scattered into a number of small clusters those are markedly similar between males and females. These results were confirmed by Discriminant analysis--the two groups of variables are almost similar, the percentages of correctly classified individuals are 64.14% (22 traits) and 65.45% (42 traits); and Mantel statistics--the Z values are within the level of non-significance, very good similarities in 22 (0.95) and good similarities in 42 (0.87) traits. Sex dimorphism is similar between two categories of dermatoglyphic variables may be used for sex-discrimination in different populations. PMID:20102042

Karmakar, Bibha; Kobyliansky, Eugene

2009-12-01

248

Disease-mediated inbreeding depression in a large, open population of cooperative crows.  

PubMed

Disease-mediated inbreeding depression is a potential cost of living in groups with kin, but its general magnitude in wild populations is unclear. We examined the relationships between inbreeding, survival and disease for 312 offspring, produced by 35 parental pairs, in a large, open population of cooperatively breeding American crows (Corvus brachyrhynchos). Genetic analyses of parentage, parental relatedness coefficients and pedigree information suggested that 23 per cent of parental dyads were first- or second-order kin. Heterozygosity-heterozygosity correlations suggested that a microsatellite-based index of individual heterozygosity predicted individual genome-wide heterozygosity in this population. After excluding birds that died traumatically, survival probability was lower for relatively inbred birds during the 2-50 months after banding: the hazard rate for the most inbred birds was 170 per cent higher than that for the least inbred birds across the range of inbreeding index values. Birds that died with disease symptoms had higher inbreeding indices than birds with other fates. Our results suggest that avoidance of close inbreeding and the absence of inbreeding depression in large, open populations should not be assumed in taxa with kin-based social systems, and that microsatellite-based indices of individual heterozygosity can be an appropriate tool for examining the inbreeding depression in populations where incest and close inbreeding occur. PMID:19324784

Townsend, Andrea K; Clark, Anne B; McGowan, Kevin J; Buckles, Elizabeth L; Miller, Andrew D; Lovette, Irby J

2009-03-04

249

Disease-mediated inbreeding depression in a large, open population of cooperative crows  

PubMed Central

Disease-mediated inbreeding depression is a potential cost of living in groups with kin, but its general magnitude in wild populations is unclear. We examined the relationships between inbreeding, survival and disease for 312 offspring, produced by 35 parental pairs, in a large, open population of cooperatively breeding American crows (Corvus brachyrhynchos). Genetic analyses of parentage, parental relatedness coefficients and pedigree information suggested that 23 per cent of parental dyads were first- or second-order kin. Heterozygosity–heterozygosity correlations suggested that a microsatellite-based index of individual heterozygosity predicted individual genome-wide heterozygosity in this population. After excluding birds that died traumatically, survival probability was lower for relatively inbred birds during the 2–50 months after banding: the hazard rate for the most inbred birds was 170 per cent higher than that for the least inbred birds across the range of inbreeding index values. Birds that died with disease symptoms had higher inbreeding indices than birds with other fates. Our results suggest that avoidance of close inbreeding and the absence of inbreeding depression in large, open populations should not be assumed in taxa with kin-based social systems, and that microsatellite-based indices of individual heterozygosity can be an appropriate tool for examining the inbreeding depression in populations where incest and close inbreeding occur.

Townsend, Andrea K.; Clark, Anne B.; McGowan, Kevin J.; Buckles, Elizabeth L.; Miller, Andrew D.; Lovette, Irby J.

2009-01-01

250

Changes in human immunodeficiency virus and sexually transmitted infections-related sexual risk taking among young Croatian adults: findings from the 2005 and 2010 population-based surveys  

PubMed Central

Aim To determine changes in sexual behaviors and other relevant characteristics related to human immunodeficiency virus (HIV) and sexually transmitted infection (STI) risks among young Croatian adults. Method We surveyed adults aged 18-24 in 2005 (n?=?1092) and 18-25 in 2010 (n?=?1005). Both samples were probabilistic and stratified by county, settlement size, age, and gender. The samples were non-matched. Trained interviewers conducted structured face-to-face interviews in participants’ households. The part of the questionnaire assessing sensitive information was self-administered. Results A majority of participants at both survey points (85.2%-86.2%) were sexually active. Median age at sexual debut (17 years) remained unchanged. Lifetime number of sexual partners was also stable. More women than men reported only one lifetime sexual partner. The prevalence of condom use at first intercourse increased (from 62.6 to 70%, P?=?0.002), while the prevalence of condom use at most recent sexual intercourse remained stable (54% in 2005 and 54.7% in 2010). Consistent condom use also remained unchanged. About one fifth of participants (19.2% in 2005 and 20% in 2010) reported consistent condom use in the past year. At both survey points for both genders, consistent condom use was associated with age (odds ratio [OR] Women2005?=?0.74, P?=?0.004; ORWomen2010?=?0.72, P?sexual practices remain common among young Croatian adults. Given the recently reported STI prevalence rates in this age cohort, introduction of school-based sex education that would focus on protective behavioral and communication skills seems to be of crucial epidemiological importance.

Landripet, Ivan; Stulhofer, Aleksandar; Bacak, Valerio

2011-01-01

251

Sexuality education groups in juvenile detention.  

PubMed

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

Farrow, J A; Schroeder, E

1984-01-01

252

Human Papillomavirus Infection in a Male Population Attending a Sexually Transmitted Infection Service  

PubMed Central

Objective Human Papillomavirus (HPV) infection in men may produce cancer and other major disorders. Men play an important role in the transmission of the virus and act as a reservoir. The aim of this study was to determine the HPV-genotypes and their prevalence in a group of men attending a Sexually Transmitted Infection service. Patients and Samples Between July 2002 and June 2011, 1392 balanopreputial, 435 urethral, 123 anal, and 67 condyloma lesions from 1551 men with a mean age of 35.8±11.3 years old (range: 17–87) were collected for HPV-DNA testing. Methods A fragment of the L1-gene and a fragment of the E6/E7-genes were amplified by PCR. Positive samples were typed by hybridization. Results The HPV genome was detected in 36.9% (486/1318) balanopreputial and in 24.9% (101/405) urethral (p<0.0001) swabs from 38.1% (538) of 1469 men. Co-infections were present in 5.4% (80/1469) of cases. HPV was found in 43.9% (373/850) of men younger than 35 vs. 31.7% (187/589) of men aged >35. HPV was found in 59.4% (104) of 165 men with lesions (macroscopic or positive peniscopy), and in 22.8% (61/267) without clinical alterations. HPV was also detected in 71.4% (40/56) men with condylomata and in 58.7% (64/109) of men with positive peniscopy. Conclusions HPV prevalence in men was high and decreased with age. HPV was found more frequently in balanopreputial than in urethral swabs. There was a low rate of co-infections. Low-risk HPV vaccine genotypes were the most recurrent especially in younger. Although HPV has been associated with clinical alterations, it was also found in men without any clinical presentation. Inclusion of men in the national HPV vaccination program may reduce their burden of HPV-related disease and reduce transmission of the virus to non-vaccinated women.

Alvarez-Arguelles, Marta Elena; Melon, Santiago; Junquera, Maria Luisa; Boga, Jose Antonio; Villa, Laura; Perez-Castro, Sonia; de Ona, Maria

2013-01-01

253

Adolescents' Exposure to Sexually Explicit Internet Material, Sexual Uncertainty, and Attitudes Toward Uncommitted Sexual ExplorationIs There a Link?  

Microsoft Academic Search

The link between adolescents' exposure to sexual media content and their sexual socialization has hardly been approached from an identity development framework. Moreover, existing research has largely ignored the role of adolescents' exposure to sexually explicit Internet material in that association. This study introduces two characteristics of adolescents' sexual self—sexual uncertainty and attitudes toward sexual exploration—and investigates these characteristics as

Jochen Peter; Patti M. Valkenburg

2008-01-01

254

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

PubMed

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

Crothers, Laura R; Cummings, Molly E

2013-02-25

255

Rising Incidence of Hospital reported Drug-facilitated Sexual Assault in a Large Urban Community in Canada  

Microsoft Academic Search

Background: Drug-facilitated sexual assault (DFSA) occurs when an individual has been sexually assaulted due to the surreptitious administration of drug(s) thereby rendering her\\/him unable to give consent. Our study aim was to calculate the age- and sex-specific annual incidence of hospital-reported DFSA and to determine whether a one-year increase in DFSA observed in 1999 in a pilot study on the

Margaret J. McGregor; Patricia A. Janssen; Janet Ericksen; Anneke Van Vliet; Lisa A. Ronald; Michael Schulzer

256

California hospitals serving large minority populations were more likely than others to employ ambulance diversion.  

PubMed

It is well documented that racial and ethnic minority populations disproportionately use hospital emergency departments for safety-net care. But what is not known is whether emergency department crowding is disproportionately affecting minority populations and potentially aggravating existing health care disparities, including poorer outcomes for minorities. We examined ambulance diversion, a proxy measure for crowding, at 202 California hospitals. We found that hospitals serving large minority populations were more likely to divert ambulances than were hospitals with a lower proportion of minorities, even when controlling for hospital ownership, emergency department capacity, and other hospital demographic and structural factors. These findings suggest that establishing more-uniform criteria to regulate diversion may help reduce disparities in access to emergency care. PMID:22869655

Hsia, Renee Yuen-Jan; Asch, Steven M; Weiss, Robert E; Zingmond, David; Liang, Li-Jung; Han, Weijuan; McCreath, Heather; Sun, Benjamin C

2012-08-01

257

Estimating demographic parameters from large-scale population genomic data using Approximate Bayesian Computation  

PubMed Central

Background The Approximate Bayesian Computation (ABC) approach has been used to infer demographic parameters for numerous species, including humans. However, most applications of ABC still use limited amounts of data, from a small number of loci, compared to the large amount of genome-wide population-genetic data which have become available in the last few years. Results We evaluated the performance of the ABC approach for three 'population divergence' models - similar to the 'isolation with migration' model - when the data consists of several hundred thousand SNPs typed for multiple individuals by simulating data from known demographic models. The ABC approach was used to infer demographic parameters of interest and we compared the inferred values to the true parameter values that was used to generate hypothetical "observed" data. For all three case models, the ABC approach inferred most demographic parameters quite well with narrow credible intervals, for example, population divergence times and past population sizes, but some parameters were more difficult to infer, such as population sizes at present and migration rates. We compared the ability of different summary statistics to infer demographic parameters, including haplotype and LD based statistics, and found that the accuracy of the parameter estimates can be improved by combining summary statistics that capture different parts of information in the data. Furthermore, our results suggest that poor choices of prior distributions can in some circumstances be detected using ABC. Finally, increasing the amount of data beyond some hundred loci will substantially improve the accuracy of many parameter estimates using ABC. Conclusions We conclude that the ABC approach can accommodate realistic genome-wide population genetic data, which may be difficult to analyze with full likelihood approaches, and that the ABC can provide accurate and precise inference of demographic parameters from these data, suggesting that the ABC approach will be a useful tool for analyzing large genome-wide datasets.

2012-01-01

258

Insulin sensitivity and regular alcohol consumption: large, prospective, cross sectional population study (Bruneck study)  

Microsoft Academic Search

AbstractObjectives: To assess the relation between regular alcohol consumption and insulin sensitivity, and to estimate the importance of insulin in the association of alcohol with multiple vascular risk factors and cardiovascular disease.Design: Prospective and cross sectional study of a large randomly selected population sample.Setting: Part of the Bruneck study 1990–5 (Bolzano province, Italy).Subjects: 820 healthy non-diabetic women and men aged

Stefan Kiechl; Johann Willeit; Werner Poewe; Georg Egger; Friedrich Oberhollenzer; Michele Muggeo; Enzo Bonora

1996-01-01

259

Sexually transmitted viral infections in various population groups in Mogadishu, Somalia.  

PubMed Central

The prevalence of serum antibodies to human immunodeficiency virus (HIV), herpes simplex virus (HSV), and cytomegalovirus (CMV) and of hepatitis B virus (HBV) markers was investigated in different population groups, including prostitutes, in Mogadishu, Somalia. Hepatitis B surface antigen (HBsAg) was detected in 37% of pregnant women, 4% of neonates, 22% of educated women, and 20% of prostitutes. No significant difference between the groups was observed for HBV. In contrast to figures reported from South East Asia, the prevalence of hepatitis Be antigen (HBeAg) was 18% in prostitutes and only 3% in all other HBsAg positive subjects. The prevalence of antibodies to HSV (100%) and CMV (90%) was very high, but antibodies against HIV were not detected in any of 471 sera. As the routes of transmission for HBV and HIV infections are considered to be similar, HIV will probably spread rapidly in Somalia once this virus has been introduced into the country.

Jama, H; Grillner, L; Biberfeld, G; Osman, S; Isse, A; Abdirahman, M; Bygdeman, S

1987-01-01

260

Montane refugia predict population genetic structure in the Large-blotched Ensatina salamander.  

PubMed

Understanding the biotic consequences of Pleistocene range shifts and fragmentation remains a fundamental goal in historical biogeography and evolutionary biology. Here, we combine species distribution models (SDM) from the present and two late Quaternary time periods with multilocus genetic data (mitochondrial DNA and microsatellites) to evaluate the effect of climate-induced habitat shifts on population genetic structure in the Large-blotched Ensatina (Ensatina eschscholtzii klauberi), a plethodontid salamander endemic to middle and high-elevation conifer forest in the Transverse and Peninsular Ranges of southern California and northern Baja California. A composite SDM representing the range through time predicts two disjunct refugia, one in southern California encompassing the core of the species range and the other in the Sierra San Pedro Mártir of northern Baja California at the southern limit of the species range. Based on our spatial model, we would expect a pattern of high connectivity among populations within the northern refugium and, conversely, a pattern of isolation due to long-term persistence of the Sierra San Pedro Mártir population. Our genetic results are consistent with these predictions based on the hypothetical refugia in that (i) historical measures of population connectivity among stable areas are correlated with gene flow estimates; and (ii) there is strong geographical structure between separate refugia. These results provide evidence for the role of recent climatic change in shaping patterns of population persistence and connectivity within the Transverse and Peninsular Ranges, an evolutionary hotspot. PMID:23379992

Devitt, Thomas J; Devitt, Susan E Cameron; Hollingsworth, Bradford D; McGuire, Jimmy A; Moritz, Craig

2013-02-04

261

Correction of Population Stratification in Large Multi-Ethnic Association Studies  

PubMed Central

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

Serre, David; Montpetit, Alexandre; Pare, Guillaume; Engert, James C.; Yusuf, Salim; Keavney, Bernard; Hudson, Thomas J.; Anand, Sonia

2008-01-01

262

Shame and adult sexual assault: a study with a group of female survivors recruited from an East London population  

Microsoft Academic Search

This study assessed feelings of shame in a group of 25 female survivors of adult sexual assault by using a series of self-rating scales. Women were recruited from a sexual health service and via media advertisement within East London. Findings demonstrated how shame was a noteworthy psychological response for this group of women (up to 75% of women reported feeling

Maria Elena Vidal Chartered Clinical Psychologist

2007-01-01

263

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

ERIC Educational Resources Information Center

|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…

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

1996-01-01

264

Rapid assessment of drug use and sexual HIV risk patterns among vulnerable drugusing populations in Cape Town, Durban and Pretoria, South Africa  

Microsoft Academic Search

This exploratory study examines the links between drug use and high-risk sexual practices and HIV in vulnerable drug-using populations in South Africa, including commercial sex workers (CSWs), men who have sex with men (MSM), injecting drug users (IDUs) and non-injecting drug users who are not CSWs or MSM (NIDUs). A rapid assessment ethnographic study was undertaken using observation, mapping, key

Charles Parry; Petal Petersen; Tara Carney; Sarah Dewing; Richard Needle

2008-01-01

265

CONSTRAINTS ON THE EVOLUTION OF MALES AND SEXUAL DIMORPHISM: FIELD ESTIMATES OF GENETIC ARCHITECTURE OF REPRODUCTIVE TRAITS IN THREE POPULATIONS OF GYNODIOECIOUS FRAGARIA VIRGINIANA  

Microsoft Academic Search

To understand how genetic constraints may limit the evolution of males and sexual dimorphism in a gynodioecious species, I conducted a quantitative genetic experiment in a gynodioecious wild strawberry, Fragaria virginiana. I estimated and compared genetic parameters (narrow-sense heritabilities, between-trait and between-sex genetic correlations, as well as phenotypic and genetic variance-covariance matrices) in the two sex morphs from three populations

Tia-Lynn Ashman

2003-01-01

266

Prevalence and psychological sequelae of self-reported childhood physical and sexual abuse in a general population sample of men and women  

Microsoft Academic Search

Objective: This study examined the prevalence and psychological sequelae of childhood sexual and physical abuse in adults from the general population.Method: A national sampling service generated a geographically stratified, random sample of 1,442 subjects from the United States. Subjects were mailed a questionnaire that included the Traumatic Events Survey (TES) [Traumatic Events Survey, Unpublished Psychological Test, Harbor-UCLA Medical Center, Los

John Briere; Diana M. Elliott

2003-01-01

267

Constraining the Galactic millisecond pulsar population using Fermi Large Area Telescope  

NASA Astrophysics Data System (ADS)

Context. The Fermi Large Area Telescope (Fermi-LAT) has recently revealed a large population of gamma-ray emitting millisecond pulsars (MSPs) in our Galaxy. Aims: We aim to infer the properties of the Galactic population of gamma-ray emitting MSPs from the samples detected by the Fermi-LAT. Methods: We developed a Monte Carlo model to predict the spatial and gamma-ray luminosity distribution of the Galactic MSP population. Based on the estimated detection sensitivity of Fermi-LAT, we split the model population into detectable and undetectable samples of MSPs. Using a maximum likelihood method, we compared the detectable sample to a set of 36 MSPs detected by Fermi-LAT, and we derived the parameters of the spatial distribution and the total number of gamma-ray emitting MSPs in the Galaxy. The corresponding undetectable sample provided us with an estimate for the expected diffuse emission from unresolved MSPs in the Milky Way. We also applied our method to an extended sample of 66 MSPs that combines firmly detected MSPs and ?-ray sources that show characteristics reminiscent of MSPs. Results: Using the sample of 36 MSPs detected by Fermi-LAT, our analysis suggests the existence of 9000-11 000 ?-ray emitting MSPs in the Galaxy. The maximum likelihood analysis suggests an exponential radial scale length of ~4 kpc and an exponential vertical scale height of ~1 kpc for the underlying MSP population. The unresolved population of Galactic ?-ray emitting MSPs is predicted to contribute a flux of ~2 × 10-6 ph cm-2 s-1 sr-1 to the Galactic diffuse emission observed from the central radian above 100 MeV. This value corresponds to ~1% of the total observed ?-ray flux from that region. For latitudes |b| ? 40° the expected average intensity amounts to ~2 × 10-8 ph cm-2 s-1 sr-1 above 100 MeV, which corresponds to 0.2% of the high-latitude background intensity. Using the extended sample increases the estimated number of ?-ray emitting MSPs in the Galaxy to ~22 000 and slightly reduces the scale parameters of the spatial distribution. The results are robust with respect to systematic uncertainties in the estimated Fermi-LAT detection sensitivity. Conclusions: For the first time our analysis provides ?-ray based constraints on the Galactic population of MSPs. The radial scale length and vertical scale height of the population is consistent with estimates based on radio data. Our analysis suggests that MSPs do not provide any significant contribution to the isotropic diffuse ?-ray background emission.

Grégoire, T.; Knödlseder, J.

2013-06-01

268

Comparison of the 99th percentiles of three troponin I assays in a large reference population.  

PubMed

Abstract Background: The IFCC Task Force on Clinical Applications of Cardiac Biomarkers suggests comparing several contemporary sensitive troponin assays in the same, sufficiently large reference population. Methods: Three contemporary sensitive assays were used to measure troponin I concentration in samples from a uniquely large healthy population (2404 individuals) and in a sub-group with tighter inclusion criteria of 908 individuals. The 99th percentiles were calculated using quantile regression which takes the entire population into account. Results: The 99th percentile for the ARCHITECT STAT Troponin I assay was 21 ng/L, 31 ng/L for the ADVIA Centaur Troponin I-Ultra assay and 28 ng/L for the Dimension Vista cTnI assay. Significantly higher values were found in males than in women only in the Dimension Vista cTnI assay and in the subgroup for the ARCHITECT STAT Troponin I assay. Conclusions: Quantile regression provides a tool to accurately estimate the 99th percentile and establish a continuous function of the relation between the 99th percentile and the age and gender. There was no age dependency demonstrated. A gender difference was found in one assay but inconclusive in another and not demonstrated in a third. PMID:23846150

Petersmann, Astrid; Ittermann, Till; Fries, Cornelia; Lubenow, Norbert; Kohlmann, Thomas; Kallner, Anders; Greinacher, Andreas; Nauck, Matthias

2013-11-01

269

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

SciTech Connect

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.

Perumalla, Kalyan S [ORNL; Schryver, Jack C [ORNL

2009-01-01

270

Validation of Screening Questions for Limited Health Literacy in a Large VA Outpatient Population  

Microsoft Academic Search

Objectives  Previous studies have shown that a single question may identify individuals with inadequate health literacy. We evaluated\\u000a and compared the performance of 3 health literacy screening questions for detecting patients with inadequate or marginal health\\u000a literacy in a large VA population.\\u000a \\u000a \\u000a \\u000a Methods  We conducted in-person interviews among a random sample of patients from 4 VA medical centers that included 3 health

Lisa D. Chew; Joan M. Griffin; Melissa R. Partin; Siamak Noorbaloochi; Joseph P. Grill; Annamay Snyder; Katharine A. Bradley; Sean M. Nugent; Alisha D. Baines; Michelle VanRyn

2008-01-01

271

Interpersonal Mistreatment in the Workplace: The Interface and Impact of General Incivility and Sexual Harassment  

Microsoft Academic Search

This article examined the relationships and outcomes of behaviors falling at the interface of general and sexual forms of interpersonal mistreatment in the workplace. Data were collected with surveys of two different female populations (Ns = 833 and 1,425) working within a large public-sector organization. Findings revealed that general incivility and sexual harassment were related constructs, with gender harassment bridging

Sandy Lim; Lilia M. Cortina

2005-01-01

272

The Association Between Body Esteem and Sexual Desire Among College Women  

Microsoft Academic Search

Relationships between body image variables and sexuality have been found among several groups of women. However, research\\u000a has largely focused on generalized experiences of sexuality. With the exception of two studies which focused on specific medical\\u000a populations, to our knowledge there has been no investigation of the relationship between body image and acute measures of\\u000a sexual response. In the current

Brooke N. Seal; Andrea Bradford; Cindy M. Meston

2009-01-01

273

Sexual competitiveness and compatibility between mass-reared sterile flies and wild populations of Anastrepha Ludens (Diptera: Tephritidae) from different regions in Mexico  

SciTech Connect

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 determi

Orozco-Davila, D.; Hernandez, R.; Meza, S.; Dominguez, J. [Programa Moscamed Moscafrut-Desarrollo de Metodos, Central Poniente No. 14 altos-Esq. 2a Avenida Sur. CP 30700 Tapachula, Chiapas (Mexico)

2007-03-15

274

Detection of recombination events in bacterial genomes from large population samples  

PubMed Central

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.

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

2012-01-01

275

Amyloid beta precursor protein regulates male sexual behavior.  

PubMed

Sexual behavior is variable between individuals, ranging from celibacy to sexual addictions. Within normal populations of individual men, ranging from young to middle aged, testosterone levels do not correlate with libido. To study the genetic mechanisms that contribute to individual differences in male sexual behavior, we used hybrid B6D2F1 male mice, which are a cross between two common inbred strains (C57BL/6J and DBA/2J). Unlike most laboratory rodent species in which male sexual behavior is highly dependent upon gonadal steroids, sexual behavior in a large proportion of these hybrid male mice after castration is independent of gonadal steroid hormones and their receptors; thus, we have the ability to discover novel genes involved in this behavior. Gene expression arrays, validation of gene candidates, and transgenic mice that overexpress one of the genes of interest were used to reveal genes involved in maintenance of male sexual behavior. Several genes related to neuroprotection and neurodegeneration were differentially expressed in the hypothalamus of males that continued to mate after castration. Male mice overexpressing the human form of one of these candidate genes, amyloid beta precursor protein (APP), displayed enhanced sexual behavior before castration and maintained sexual activity for a longer duration after castration compared with controls. Our results reveal a novel and unexpected relationship between APP and male sexual behavior. We speculate that declining APP during normal aging in males may contribute to the loss of sexual function. PMID:20668181

Park, Jin Ho; Bonthius, Paul J; Tsai, Houng-Wei; Bekiranov, Stefan; Rissman, Emilie F

2010-07-28

276

A population of gamma-ray emitting globular clusters seen with the Fermi Large Area Telescope  

NASA Astrophysics Data System (ADS)

Context. Globular clusters with their large populations of millisecond pulsars (MSPs) are believed to be potential emitters of high-energy gamma-ray emission. The observation of this emission provides a powerful tool to assess the millisecond pulsar population of a cluster, is essential for understanding the importance of binary systems for the evolution of globular clusters, and provides complementary insights into magnetospheric emission processes. Aims: Our goal is to constrain the millisecond pulsar populations in globular clusters from analysis of gamma-ray observations. Methods: We use 546 days of continuous sky-survey observations obtained with the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope to study the gamma-ray emission towards 13 globular clusters. Results: Steady point-like high-energy gamma-ray emission has been significantly detected towards 8 globular clusters. Five of them (47 Tucanae, Omega Cen, NGC 6388, Terzan 5, and M 28) show hard spectral power indices (0.7 < ? <1.4) and clear evidence for an exponential cut-off in the range 1.0-2.6 GeV, which is the characteristic signature of magnetospheric emission from MSPs. Three of them (M 62, NGC 6440 and NGC 6652) also show hard spectral indices (1.0 < ? < 1.7), however the presence of an exponential cut-off can not be unambiguously established. Three of them (Omega Cen, NGC 6388, NGC 6652) have no known radio or X-ray MSPs yet still exhibit MSP spectral properties. From the observed gamma-ray luminosities, we estimate the total number of MSPs that is expected to be present in these globular clusters. We show that our estimates of the MSP population correlate with the stellar encounter rate and we estimate 2600-4700 MSPs in Galactic globular clusters, commensurate with previous estimates. Conclusions: The observation of high-energy gamma-ray emission from globular clusters thus provides a reliable independent method to assess their millisecond pulsar populations.

Abdo, A. A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Carrigan, S.; Casandjian, J. M.; Charles, E.; Chaty, S.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Decesar, M. E.; Dermer, C. D.; de Palma, F.; Digel, S. W.; Silva, E. Do Couto E.; Drell, P. S.; Dubois, R.; Dumora, D.; Favuzzi, C.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giordano, F.; Glanzman, T.; Godfrey, G.; Grenier, I.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Harding, A. K.; Hays, E.; Jean, P.; Jóhannesson, G.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kerr, M.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S.-H.; Lemoine-Goumard, M.; Llena Garde, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Makeev, A.; Mazziotta, M. N.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Pancrazi, B.; Parent, D.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainň, S.; Rando, R.; Reimer, A.; Reimer, O.; Reposeur, T.; Ripken, J.; Romani, R. W.; Roth, M.; Sadrozinski, H. F.-W.; Saz Parkinson, P. M.; Sgrň, C.; Siskind, E. J.; Smith, D. A.; Spinelli, P.; Strickman, M. S.; Suson, D. J.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vasileiou, V.; Venter, C.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Webb, N.; Winer, B. L.; Yang, Z.; Ylinen, T.; Ziegler, M.; Fermi LAT Collaboration

2010-12-01

277

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

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.

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

2010-01-01

278

Wavefront corrector requirements for compensation of ocular aberrations in two large populations of normal human eyes  

NASA Astrophysics Data System (ADS)

Numerous types of wavefront correctors have been employed in adaptive optics (AO) systems for correcting the wave aberrations of the eye. While each has been shown to reduce the degrading impact of the ocular aberrations, none have shown sufficient correction to yield diffraction-limited imaging for large pupils (>=6 mm), where the aberrations are most severe and the benefit of AO is largest. As the wavefront corrector appears to be the limiting AO component, it raises a fundamental concern as to what characteristics of this device, in particular actuator stroke and number, are required to achieve diffraction-limited imaging, and to optimally match corrector performance and cost to that required of a particular imaging task in the eye. In this paper, we model the performance of discrete actuator deformable mirrors, piston-only segmented mirrors, and piston/tip/tilt segmented mirrors in conjunction with wavefront aberrations measured on human eyes in two large population datasets (University of Rochester and Indiana University). The actuator stroke and number required to achieve diffraction-limited imaging for a 7.5 mm pupil were found to be highly dependent on the level of 2nd order aberrations and the population considered. Specifically, the required stroke for encompassing 95% of the population ranged from 12-53 (Rochester) and 7-11 (Indiana) microns. The wide range resulted from whether 2nd order aberrations were corrected or set to zero prior to correction. To achieve a Strehl > 0.8, the actuator number across the pupil diameter ranged from >14 (Rochester) and 11-14 (Indiana) for discrete actuator deformable mirrors, >95 (Rochester) and 50-90 (Indiana) for piston-only segmented mirrors, and finally 12-19 (Rochester) and 9-10 (Indiana) for piston/tip/tilt segmented mirrors.

Doble, Nathan; Miller, Donald T.; Yoon, Geunyoung; Helmbrecht, Michael A.; Williams, David R.

2006-03-01

279

Early sexual behaviour and Chlamydia trachomatis infection - a population based cross-sectional study on gender differences among adolescents in Norway  

PubMed Central

Background Early sexual behaviour has been shown to differ significantly between genders, but few studies have addressed this topic to explain the commonly observed differences in chlamydia rates between adolescent girls and boys. Our study aimed to determine chlamydia prevalence in adolescents aged 15–20 years in a high-incidence area in Norway, and to identify gender-specific early sexual behaviours associated with infection. Methods A population based cross-sectional study was conducted among all high school students in five towns in Finnmark county in 2009, using a web-based questionnaire and real-time Chlamydia trachomatis PCR in first-void urine samples (participation rate 85%, 800 girls/818 boys, mean age 17.2 years). Crude and multivariable logistic regression models were applied with chlamydia test result as dependent variable. Results Prevalence of chlamydia infection was 5.7% (95% confidence interval, CI, 4.4–7.3%). Girls were twice as likely to be infected as boys (7.3%, 5.3–9.7 vs 3.9%, 2.3–6.0). Girls reported earlier sexual debut, older partners, higher lifetime number of partners, and were poorer condom users. In girls, higher maternal education (odds ratio, OR, 2.2, 95% CI 1.1–4.4), ?2 sexual partners past 6 months (OR 3.6, 1.8–7.3), and partner meeting venue at a private party, bar or disco (OR 5.0, 1.1–22.7) increased the odds of infection in the multivariable model. In boys, condom use at first intercourse (OR 0.06, 0.01–0.42) decreased the odds of infection, while having an older last sexual partner (OR 3.7, 1.3–11.0) increased the odds. In all participants, the risk of infection increased if residence outside the family home during school year (OR 2.0, 1.2–3.6), and decreased if condom was used at last intercourse (OR 0.2, 0.1–0.8). Conclusions We detected significant gender differences in chlamydia prevalence and sexual behaviours, and accordingly differing independent risk factors for chlamydia infection. We suggest that accumulation of essentially different experiences in the early sexually active years contribute to gender disparities in chlamydia risk in individuals this age. Gender-specific approaches may be the best alternative to control chlamydia infection in age group 15–20 years.

2012-01-01

280

Reproductive and resource benefits to large female body size in a mammal with female-biased sexual size dimorphism  

SciTech Connect

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.

Fokidis, H.B., T.S. Risch and T.C. Glenn

2007-01-01

281

Sexual dysfunctions among people living with AIDS in Brazil  

PubMed Central

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.

de Tubino Scanavino, Marco; Abdo, Carmita Helena Najjar

2010-01-01

282

Sexual recombination in Colletotrichum lindemuthianum occurs on a fine scale.  

PubMed

Glomerella cingulata f. sp phaseoli is the sexual phase of the fungus Colletotrichum lindemuthianum, the causal agent of common bean anthracnose. This fungus is of great concern, because it causes large economic losses in common bean crops. RAPD markers of five populations of G. cingulata f. sp phaseoli from two Brazilian states were analyzed to determine if this population possesses the sexual reproductive potential to generate the genetic variation that is observed in this phytopathogen. We identified 128 polymorphic bands, amplified by 28 random primers. The estimates of genetic similarity in this analysis ranged from 0.43 to 1.00, and the dendrogram generated from analysis of all genotypes displayed five principal groups, coinciding with the five populations. Genetic differentiation was observed between the populations (GST=0.6455); 69% of the overall observed genetic variation was between individual populations and 31% of the variance was within the sub-populations. We identified significant levels of linkage disequilibrium in all populations. However, the values of the disequilibrium ranged from low to moderate, indicating that this pathogen maintains a genetic structure consistent with sexual reproduction. The mean contribution of sexual reproduction was determined by comparison of the amplitudes of genetic similarity of isolates from sexual and asexual phases. These results support the hypothesis that recombination plays an important role in determining the amplitude of variability in this pathogen population and that this determination occurs on a fine scale. PMID:20830667

Souza, E A; Camargo, O A; Pinto, J M A

2010-09-08

283

Trends in chlamydia and gonorrhea positivity among heterosexual men and men who have sex with men attending a large urban sexual health service in Australia, 2002-2009  

Microsoft Academic Search

Background  To determine whether chlamydia positivity among heterosexual men (MSW) and chlamydia and gonorrhea positivity among men who\\u000a have sex with men (MSM), are changing.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Computerized records for men attending a large sexual health clinic between 2002 and 2009 were analyzed. Chlamydia and gonorrhea\\u000a positivity were calculated and logistic regression used to assess changes over time.\\u000a \\u000a \\u000a \\u000a \\u000a Results  17769 MSW and 8328 MSM

Lenka A Vodstrcil; Christopher K Fairley; Glenda Fehler; David Leslie; Jennifer Walker; Catriona S Bradshaw; Jane S Hocking

2011-01-01

284

Sexual size dimorphism in anurans.  

PubMed Central

Several hypotheses have been proposed to explain the direction and extent of sexual size dimorphism in anurans (in which males are usually smaller than females) as a result of sexual selection. Here, we present an analysis to test the hypothesis that sexual dimorphism in anurans is largely a function of differences between the sexes in life-history strategies. Morphological and demographic data for anurans were collected from the literature, and the mean size and age in each sex were calculated for 51 populations, across 30 species and eight genera. Comparisons across 14 Rana species, eight Bufo species and across the genera showed a highly significant relationship between size dimorphism, measured using the female-male size ratio, and mean female-male age difference. A comparison of a subset of 17 of these species for which phylogenetic information was available, using the method of independent contrasts, yielded a similar result. These results indicate that most of the variation in size dimorphism in the anura can be explained in terms of differences in the age structure between the sexes in breeding populations. If sexual selection has an effect on size dimorphism in anurans, it is likely to be only a secondary one.

Monnet, Jean-Matthieu; Cherry, Michael I

2002-01-01

285

A WASHINGTON PHOTOMETRIC SURVEY OF THE LARGE MAGELLANIC CLOUD FIELD STAR POPULATION  

SciTech Connect

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.

Piatti, Andres E. [Instituto de Astronomia y Fisica del Espacio, CC 67, Suc. 28, 1428, Ciudad de Buenos Aires (Argentina); Geisler, Doug; Mateluna, Renee, E-mail: andres@iafe.uba.ar [Departamento de Astronomia, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile)

2012-10-01

286

Atrial fibrillation in a multiethnic inpatient population of a large public hospital.  

PubMed Central

INTRODUCTION: Atrial fibrillation (AF) has not been well-studied in minority and underserved populations. We report a one-year inpatient experience of AF among 80,021 total ECG records in a multiethnic population of a large public hospital. METHODS: ECG parameters, demographic data, discharge diagnoses, and discharge status were compiled for the first 1,999 hospitalizations associated with AF among 80,021 total ECG records and compared among the population subgroups. RESULTS: Of 3,935 records of patients with AF, 737 matched first hospitalizations. Mean age was 62.3 years; 56% were male. Hispanics comprised 59.2%, Caucasians 16.4%, Asians 11.1%, African Americans 10.3%; unclassified 3%; 30.6% were uninsured. Compared to Caucasians, Left ventricular hypertrophy was more common in African-American [9.9% vs. 21.1%, odds ratio (OR)=2.3] and Asians (9.9% vs. 15.3%, OR=2.76). At discharge, Caucasians more frequently had coronary artery disease, compared to Hispanics (26.4% vs. 17.7%, OR=0.62), African Americans (26.4% vs. 10.5%, OR=0.36), and Asians (26.4% vs. 8.5%, OR=0.25); cardiomyopathy was less common in Caucasians as compared to African Americans (2.5% vs. 10.5%, OR=4.2), Hispanics (2.5% vs. 3.9%, OR=1.5) and Asians (2.5% vs. 4.9%, OR=1.96). Mortality was 16%; nonsurvivors compared to survivors were older, 64.9 years vs. 61.8 years, p<0.05, more frequently had myocardial infarction (20.4% vs. 6.2%, p=0.000) and stroke (16.5% vs. 5.0%, p=0.000). CONCLUSIONS: This AF population, particularly African Americans, was younger than previously reported. ECG and discharge parameters had differential frequencies among race/ethnic subgroups. Nonsurvivors were older and more commonly had myocardial infarction and stroke. Further study is warranted of AF occurrence, management, and outcomes in lower-socioeconomic, multiethnic populations. Images Figure 2

Dang, David; Patel, Rajan; Haywood, L. Julian

2004-01-01

287

Sexual Health  

MedlinePLUS

... experiences, free of coercion, discrimination and violence. [1] Sexual Health News & Information HHS Statement on LGBT Health Awareness ... infectious diseases, reproductive health and sexual violence prevention. Sexual Health Topics Sexually Transmitted Diseases Up-to-date information ...

288

Mass-loss From Evolved Stellar Populations In The Large Magellanic Cloud  

NASA Astrophysics Data System (ADS)

I have conducted a study of a sample of 30,000 evolved stars in the Large Magellanic Cloud (LMC) and 6,000 in the Small Magellanic Cloud (SMC), covering their variability, mass-loss properties, and chemistry. The initial stages of of my thesis work focused on the infrared variability of Asymptotic Giant Branch (AGB) stars in the LMC. I determined the period-luminosity (P-L) relations for 6 separate sequences of 30,000 evolved star candidates at 8 wavelengths, as a function of photometrically assigned chemistry, and showed that the P-L relations are different for different chemical populations (O-rich or C-rich). I also present results from the Grid of Red supergiant and Asymptotic giant branch star ModelS (GRAMS) radiative transfer (RT) model grid applied to the evolved stellar population of the LMC. GRAMS is a pre-computed grid of RT models of RSG and AGB stars and surrounding circumstellar dust. Best-fit models are determined based on 12 bands of photometry from the optical to the mid-infrared. Using a pre-computed grid, I can present the first reasonably detailed radiative transfer modeling for tens of thousands of stars, allowing me to make statistically accurate estimations of the carbon-star luminosity function and the global dust mass return to the interstellar medium from AGB stars, both key parameters for stellar population synthesis models to reproduce. In the SAGE-Var program, I used the warm Spitzer mission to take 4 additional epochs of observations of 7500 AGB stars in the LMC and SMC. These epochs, combined with existing data, enable me to derive mean fluxes at 3.6 and 4.5 microns, that will be used for tighter constraints for GRAMS, which is currently limited by the variability induced error on the photometry. This work is support by NASA NAG5-12595 and Spitzer contract 1415784.

Riebel, David

2012-01-01

289

Fundamental form of a population TCP model in the limit of large heterogeneity  

SciTech Connect

A population tumor control probability (TCP) model for fractionated external beam radiotherapy, based on Poisson statistics and in the limit of large parameter heterogeneity, is studied. A reduction of a general eight-parameter TCP equation, which incorporates heterogeneity in parameters characterizing linear-quadratic radiosensitivity, repopulation, and clonogen number, to an equation with four parameters is obtained. The four parameters represent the mean and standard deviation for both clonogen number and a generalized radiosensitivity that includes linear-quadratic and repopulation descriptors. Further, owing to parameter inter-relationship, it is possible to express these four parameters as three ratios of parameters in the large heterogeneity limit. These ratios can be directly linked to two defining features of the TCP dose response: D{sub 50} and {gamma}{sub 50}. In the general case, the TCP model can be written in terms of D{sub 50}, {gamma}{sub 50} and a third parameter indicating the ratio of the levels of heterogeneity in clonogen number and generalized radiosensitivity; however, the third parameter is unnecessary when either of these two sources of heterogeneity is dominant. It is shown that heterogeneity in clonogen number will have little impact on the TCP formula for clinical scenarios, and thus it will generally be the case that the fundamental form of the Poisson-based population TCP model can be specified completely in terms of D{sub 50} and {gamma}{sub 50}: TCP=(1/2) erfc[{radical}({pi}){gamma}{sub 50}(D{sub 50}/D-1)]. This implies that limited radiobiological information can be determined by the analysis of dose response data: information about parameter ratios can be ascertained, but knowledge of absolute values for the fundamental radiobiological parameters will require independent auxiliary measurements.

Carlone, Marco C.; Warkentin, Brad; Stavrev, Pavel; Fallone, B. Gino [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton (Canada); Department of Medical Physics, Cross Cancer Institute and Department of Oncology, University of Alberta, 11560 University Avenue, Edmonton (Canada)

2006-06-15

290

Exploratory factor analysis of self-reported symptoms in a large, population-based military cohort  

PubMed Central

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.

2010-01-01

291

Large-Scale Distribution of the Young Stellar Population in Perseus  

NASA Astrophysics Data System (ADS)

We present NEWFIRM observations of the Perseus molecular cloud covering nearly 7 square degrees obtained using the KPNO Mayall 4-meter telescope. Our J, H, and K (1.2, 1.6, and 2.2 ?m, respectively) observations are complete to 18.0-18.5 magnitudes, depending on the region, which are 2.5-3.0 magnitudes deeper than 2MASS. We construct a source catalog of near-infrared fluxes, bandmerged with mid-infrared fluxes from Spitzer and WISE observations, to provide fluxes spanning the spectral range 1-24 ?m. The spectral energy distributions are then analyzed to identify (1) young stellar objects (YSOs) associated with Perseus, and (2) extincted stars behind the cloud. The background stars are used to create a high angular resolution extinction map covering the diffuse, extended regions of Perseus as well as the densest regions. We characterize the YSO population and distribution as a function of cloud extinction and environment in order to study associations between the YSO population and large-scale cloud structure. With the extended coverage of our deep near-infrared observations and the WISE mid-infrared observations, our survey enables a more complete census of star formation in Perseus than provided by previous surveys.

Bittle, Lauren E.; Huard, T. L.; Mundy, L. G.

2013-01-01

292

Sexual dimorphism in a dioecious population of the wind-pollinated herb Mercurialis annua: the interactive effects of resource availability and competition  

PubMed Central

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.

Hesse, Elze; Pannell, John R.

2011-01-01

293

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

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

Larsen, Christina Viskum Lytken; Curtis, Tine; Bjerregaard, Peter

2012-10-12

294

Variation in mating systems and sexual size dimorphism between populations of the Australian python Morelia spilota (Serpentes: Pythonidae)  

Microsoft Academic Search

Although adaptationist hypotheses predict a functional relationship between mating systems and sexual size dimorphism, such predictions are difficult to test because of the high degree of phylogenetic conservatism in both of these traits. Taxa that show intraspecific variation in mating systems hence offer valuable opportunities for more direct tests of evolutionary-ecological hypotheses. Based on a collation of published and unpublished

R. Shine; M. Fitzgerald

1995-01-01

295

Sexual behaviors relevant to HIV transmission in a rural African population : How much can a KAP survey tell us?  

Microsoft Academic Search

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

Doris Schopper; Serge Doussantousse; John Orav

1993-01-01

296

Heritability of metabolic syndrome traits in a large population-based sample[S  

PubMed Central

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 = 2,792–27,021, 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, ?18–98 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.

van Dongen, Jenny; Willemsen, Gonneke; Chen, Wei-Min; de Geus, Eco J. C.; Boomsma, Dorret I.

2013-01-01

297

The influence of population dynamics and environmental conditions on salmon re-colonization after large-scale distrubance  

NASA Astrophysics Data System (ADS)

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.

Pess, G. R.; Hilborn, R.; Kloehn, K.; Quinn, T.

2010-12-01

298

Galactic Stellar Populations in the Era of the Sloan Digital Sky Survey and Other Large Surveys  

NASA Astrophysics Data System (ADS)

Studies of stellar populations, understood to mean collections of stars with common spatial, kinematic, chemical, and/or age distributions, have been reinvigorated during the past decade by the advent of large-area sky surveys such as the Sloan Digital Sky Survey, the Two-Micron All Sky Survey, the Radial Velocity Experiment, and others. We review recent analyses of these data that, together with theoretical and modeling advances, are revolutionizing our understanding of the nature of the Milky Way and galaxy formation and evolution in general. The formation of galaxies like the Milky Way was long thought to be a steady process leading to a smooth distribution of stars. However, the abundance of substructure in the multidimensional space of various observables, such as position, kinematics, and metallicity, is now proven beyond doubt and demonstrates the importance of mergers in the growth of galaxies. Unlike smooth models that involve simple components, the new data reviewed here clearly exhibit many irregular structures, such as the Sagittarius dwarf tidal stream and the Virgo and Pisces overdensities in the halo and the Monoceros stream closer to the Galactic plane. These recent developments have made it clear that the Milky Way is a complex and dynamic structure, one that is still being shaped by the merging of neighboring smaller galaxies. We also briefly discuss the next generation of wide-field sky surveys, such as SkyMapper, Panoramic Survey Telescope & Rapid Response System, Global Astrometric Interferometer for Astrophysics, and the Large Synoptic Survey Telescope, which will improve measurement precision manyfold and include billions of individual stars. The ultimate goal, development of a coherent and detailed story of the assembly and evolutionary history of the Milky Way and other large spirals like it, now appears well within reach.

Ivezi?, Željko; Beers, Timothy C.; Juri?, Mario

2012-09-01

299

Influence of the spatial pattern of conserved lands on the persistence of a large population of red-cockaded woodpeckers  

Microsoft Academic Search

Spatial configuration of habitats can affect chances of survival for many rare species, especially those with low dispersal rates or large area requirements. The red-cockaded woodpecker (Picoides borealis) disperses relatively short distances and also requires large blocks of habitat — characteristics that make its populations especially sensitive to the distribution of its habitat across a region. We created conservation scenarios for

James Cox; R. Todd Engstrom

2001-01-01

300

Behavioral treatment approaches for methamphetamine dependence and HIV-related sexual risk behaviors among urban gay and bisexual men  

Microsoft Academic Search

Background:Methamphetamine-dependent gay and bisexual men (GBM) are at high risk for HIV transmission, largely due to drug-associated sexual risk behaviors. This project evaluated the efficacy of four behavioral drug abuse treatments for reducing methamphetamine use and sexual risk behaviors among this population.

Steven Shoptaw; Cathy J. Reback; James A. Peck; Xiaowei Yang; Erin Rotheram-Fuller; Sherry Larkins; Rosemary C. Veniegas; Thomas E. Freese; Christopher Hucks-Ortiz

2005-01-01

301

Awareness of osteoporosis and its relationship with calcaneus quantitative ultrasound in a large Chinese community population  

PubMed Central

Background The People’s Republic of China has the largest population affected by osteoporosis in the world. However, no population-based survey of osteoporosis awareness in People’s Republic of China has been reported. This study investigated the level of basic awareness of osteoporosis in a large community in People’s Republic of China. The relationship between level of awareness and quantitative ultrasound (US) measurements at the calcaneus was also assessed. Methods A questionnaire was completed by 9983 men and women aged 40 years or older in Nanjing, People’s Republic of China, between June and December 2011. During this time, the study participants underwent quantitative US measurement. Data from 9049 of the subjects were included in the final analysis. Results The proportion of subjects who were aware of osteoporosis was very low. Only 30.7% had heard of osteoporosis, and only 18.5% had heard of osteoporotic fracture. In total, 52.9% of the subjects drank milk, 16.0% took calcium, 7.1% took vitamin D, and 47.2% were performing regular physical activity. Logistic regression showed that more highly educated older women had significantly better awareness of osteoporosis (P < 0.05). Subjects with a history of a previous osteoporotic fracture also had better awareness (P < 0.05) than subjects without such a history, except for those who drank milk. Similar to previous reports, female sex, old age, a low education level, and a personal history of osteoporotic fracture were significantly associated with a low quantitative US measurement (P < 0.001). Further, drinking milk and having not heard of osteoporosis were significantly associated with a higher quantitative US measurement (P < 0.05), while other indicators of osteoporosis awareness were not associated with quantitative US values (P > 0.05). Conclusion Awareness of osteoporosis in People’s Republic of China is very low. National awareness strategies should be implemented, especially for poorly educated young men.

Xu, Jingjing; Sun, Min; Wang, Zhixiao; Fu, Qi; Cao, Mengdei; Zhu, Zhenxin; Meng, Chuchen; Yan, Yan; Mao, Jia; Tao, Hua; Huang, Xiaoping; Lin, Zheng; Yang, Tao; He, Wei

2013-01-01

302

The massive stellar population in the young association LH 95 in the Large Magellanic Cloud  

NASA Astrophysics Data System (ADS)

We present a spectroscopic study of the most massive stars in the young (4 Myr old) stellar cluster LH 95 in the Large Magellanic Cloud. This analysis allows us to complete the census of the stellar population of the system, previously investigated by us down to 0.4 M? with deep Hubble Space Telescope Advanced Camera for Surveys photometry. We perform spectral classification of the five stars in our sample, based on high-resolution optical spectroscopy obtained with the 2.2-m MPG/ESO Fibre-fed Extended Range Optical Spectrograph. We use complementary ground-based photometry, previously performed by us, to place these stars in the Hertzsprung-Russell diagram. We derive their masses and ages by interpolation from evolutionary models. The average ages and age spread of the most massive stars are found to be in general comparable with those previously derived for the cluster from its low-mass pre-main-sequence stars. We use the masses of the five sample stars to extend to the high-mass end the stellar initial mass function of LH 95 previously established by us. We find that the initial mass function follows a Salpeter relation down to the intermediate-mass regime at 2 M?. The second most massive star in LH 95 shows broad Balmer line emission and infrared excess, which are compatible with a classical Be star. The existence of such a star in the system adds a constrain to the age of the cluster, which is well covered by our age and age spread determinations. The most massive star, a 60-70 M? O2 giant, is found to be younger (<1 Myr) than the rest of the population. Its mass in relation to the total mass of the system does not follow the empirical relation of the maximum stellar mass versus the hosting cluster mass, making LH 95 an exception to the average trend.

Da Rio, N.; Gouliermis, D. A.; Rochau, B.; Pasquali, A.; Setiawan, J.; De Marchi, G.

2012-06-01

303

Effects of a large northern European no-take zone on flatfish populations(a.).  

PubMed

In March 2006, a 360?km(2) 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

Florin, A-B; Bergström, U; Ustups, D; Lundström, K; Jonsson, P R

2013-05-31

304

Childhood sexual abuse, adolescent sexual coercion and sexually transmitted infection acquisition among homeless female adolescents  

Microsoft Academic Search

Objective: To examine the relationship between childhood experiences of sexual abuse, sexual coercion during adolescence, and the acquisition of sexually transmitted infections (STIs) in a population of homeless adolescents.Method: Homeless adolescent females (N = 216) from a northwestern United States city were recruited by street outreach workers for a longitudinal study of STI epidemiology. Baseline data on childhood abuse and

John Noell; Paul Rohde; John Seeley; Linda Ochs

2001-01-01

305

Superoxide Dismutase 3 Polymorphism Associated with Reduced Lung Function in Two Large Populations  

PubMed Central

Rationale: Superoxide dismutase (SOD) 3 inhibits oxidative fragmentation of lung matrix components collagen I, hyaluronan, and heparan sulfate. Inherited change in SOD3 expression or function could affect lung matrix homeostasis and influence pulmonary function. Objectives: To identify novel SOD3 polymorphisms that are associated with lung function or chronic obstructive pulmonary disease (COPD). Methods: Resequencing of 182 individuals identified two novel polymorphisms, E1 (rs8192287) and I1 (rs8192288), in a conserved region of the SOD3 gene of potential relationship to lung function. We next genotyped 9,093 individuals from the Copenhagen City Heart Study for the polymorphisms and recorded spirometry, and admissions and deaths due to COPD during 26-year follow-up. Finally, we validated our findings in a cross-sectional analysis of 35,635 individuals from the Copenhagen General Population Study. Measurements and Main Results: Genotyping the Copenhagen City Heart Study identified 35 E1/I1 homozygotes, 1,050 heterozygotes, and 8,008 noncarriers (Hardy-Weinberg equilibrium: P = 0.93). Using quadruple lung function measurements, we found that E1/I1 homozygotes had 7% lower FVC % predicted (P = 0.006) and 4% lower FEV1 % predicted (P = 0.12) compared with noncarriers. In the Copenhagen General Population Study, E1/I1 homozygotes also had lower FVC % predicted than noncarriers (P = 0.03), confirming an association between E1/I1 genotype and reduced lung function. E1/I1 homozygotes had adjusted hazard ratios for COPD hospitalization and COPD mortality of 2.5 (95% confidence interval, 1.0–5.9) and 3.7 (95% confidence interval, 0.9–15), respectively; the results were independent of influence from the R213G allele of the SOD3 gene. Conclusions: We identified two novel polymorphisms in a conserved region of the SOD3 gene and show that individuals that are homozygous for these polymorphisms have reduced FVC % predicted in two large, population-based studies.

Dahl, Morten; Bowler, Russell P.; Juul, Klaus; Crapo, James D.; Levy, Samuel; Nordestgaard, B?rge G.

2008-01-01

306

Sex-linked heritability of a sexually selected character in a natural population of Poecilia reticulata (Pisces: Poeciliidae) (guppies)  

Microsoft Academic Search

The relative extent of orange-pigmented spots in the colour patterns of male guppies, Poecilia reticulata, has previously been shown to be a basis for female choice. Parent–offspring and half-sib breeding experiments and selection experiments were conducted to determine if heritability of this character is maintained in the face of apparent sexual selection. The results demonstrate strong heritability of orange area.

Anne E Houde

1992-01-01

307

ORIGIN OF THE UNUSUALLY LOW NITROGEN ABUNDANCES IN YOUNG POPULATIONS OF THE LARGE MAGELLANIC CLOUD  

SciTech Connect

It is a longstanding problem that H II regions and very young stellar populations in the Large Magellanic Cloud (LMC) have nitrogen abundances ([N/H]) that are a factor of {approx}7 lower than the solar value. We here discuss a new scenario in which the observed unusually low nitrogen abundances can be closely associated with recent collisions and subsequent accretion of H I high velocity clouds (HVCs) that surround the Galaxy and have low nitrogen abundances. We show that if the observed low [N/H] is limited to very young stars with ages less than {approx}10{sup 7} yr, then the collision/accretion rate of the HVCs onto the LMC needs to be {approx}0.2 M{sub sun} yr{sup -1} (corresponding to the total HVC mass of 10{sup 6}-10{sup 7} M{sub sun}) to dilute the original interstellar medium (ISM) before star formation. The required accretion rate means that even if the typical mass of HVCs accreted onto the LMC is {approx}10{sup 7} M{sub sun}, the Galaxy needs to have {approx}2500 massive HVCs within the LMC's orbital radius with respect to the Galactic center. The rather large number of required massive HVCs drives us to suggest that the HVCs are not likely to efficiently dilute the ISM of the LMC and consequently lower the [N/H]. We thus suggest the transfer of gas with low [N/H] from the Small Magellanic Cloud to the LMC as a promising scenario that can explain the observed low [N/H].

Bekki, Kenji [ICRAR, M468, University of Western Australia, 35 Stirling Highway, Crawley Western Australia 6009 (Australia); Tsujimoto, Takuji [National Astronomical Observatory, Mitaka-shi, Tokyo 181-8588 (Japan)

2010-10-01

308

Preferential enrichment of large-sized very low density lipoprotein populations with transferred cholesteryl esters  

SciTech Connect

The effect of lipid transfer proteins on the exchange and transfer of cholesteryl esters from rat plasma HDL2 to human very low (VLDL) and low density (LDL) lipoprotein populations was studied. The use of a combination of radiochemical and chemical methods allowed separate assessment of (/sup 3/H)cholesteryl ester exchange and of cholesteryl ester transfer. VLDL-I was the preferred acceptor for transferred cholesteryl esters, followed by VLDL-II and VLDL-III. LDL did not acquire cholesteryl esters. The contribution of exchange of (/sup 3/H)cholesteryl esters to total transfer was highest for LDL and decreased in reverse order along the VLDL density range. Inactivation of lecithin: cholesterol acyltransferase (LCAT) and heating the HDL2 for 60 min at 56 degrees C accelerated transfer and exchange of (/sup 3/H)cholesteryl esters. Addition of lipid transfer proteins increased cholesterol esterification in all systems. The data demonstrate that large-sized, triglyceride-rich VLDL particles are preferred acceptors for transferred cholesteryl esters. It is suggested that enrichment of very low density lipoproteins with cholesteryl esters reflects the triglyceride content of the particles.

Eisenberg, S.

1985-04-01

309

Challenges of Measuring Diurnal Cortisol Concentrations in a Large Population-Based Field Study  

PubMed Central

Objectives Longitudinal examinations of associations between daily stress, diurnal cortisol concentrations, and physiological parameters in population-based studies are needed. This study evaluates issues related to consent, collection, and protocol adherence for a low-burden saliva collection protocol. Methods In the 2007 pretest (N = 193) for Wave IV of the National Longitudinal Study of Adolescent Health (Add Health) a three-sample, one-day, unsupervised saliva collection protocol was pilot tested. Embedded experiments allowed for examination of adherence and effects of monetary incentives. Results Although most (97%) study participants consented to collection, only about 80% actually mailed back samples. Use of a time-stamping TrackCap allowed comparison of self-reported and stamp-recorded collection times. Of returned samples, self-report of collection time was missing for about a quarter, and only about one in three respondents (of those for whom adherence was calculable) fully adhered to the collection protocol, indicating significant potential for bias. Consent, return, and protocol adherence were unrelated to key sociodemographic characteristics, and did not improve with higher monetary incentives or knowledge of being monitored. Conclusions Despite the relatively low-burden collection protocol and use of multiple strategies thought to improve collection and protocol adherence, response and adherence were poor, leading to a decision to drop cortisol measurement from the Wave IV Add Health protocol. Large field studies should carefully evaluate the feasibility of collection and protocol adherence for unsupervised collection protocols before implementing costly, and potentially unusable, biological measurements.

Halpern, Carolyn Tucker; Whitsel, Eric A.; Wagner, Brandon; Harris, Kathleen Mullan

2011-01-01

310

Reducing NIR prediction errors with nonlinear methods and large populations of intact compound feedstuffs  

NASA Astrophysics Data System (ADS)

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.

Fernández-Ahumada, E.; Fearn, T.; Gómez, A.; Vallesquino, P.; Guerrero, J. E.; Pérez-Marín, D.; Garrido-Varo, A.

2008-08-01

311

A Deployable In Vivo EPR Tooth Dosimeter for Triage After a Radiation Event Involving Large Populations  

PubMed Central

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.

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

312

Dynamic large-scale chromosomal rearrangements fuel rapid adaptation in yeast populations.  

PubMed

Large-scale genome rearrangements have been observed in cells adapting to various selective conditions during laboratory evolution experiments. However, it remains unclear whether these types of mutations can be stably maintained in populations and how they impact the evolutionary trajectories. Here we show that chromosomal rearrangements contribute to extremely high copper tolerance in a set of natural yeast strains isolated from Evolution Canyon (EC), Israel. The chromosomal rearrangements in EC strains result in segmental duplications in chromosomes 7 and 8, which increase the copy number of genes involved in copper regulation, including the crucial transcriptional activator CUP2 and the metallothionein CUP1. The copy number of CUP2 is correlated with the level of copper tolerance, indicating that increasing dosages of a single transcriptional activator by chromosomal rearrangements has a profound effect on a regulatory pathway. By gene expression analysis and functional assays, we identified three previously unknown downstream targets of CUP2: PHO84, SCM4, and CIN2, all of which contributed to copper tolerance in EC strains. Finally, we conducted an evolution experiment to examine how cells maintained these changes in a fluctuating environment. Interestingly, the rearranged chromosomes were reverted back to the wild-type configuration at a high frequency and the recovered chromosome became fixed in less selective conditions. Our results suggest that transposon-mediated chromosomal rearrangements can be highly dynamic and can serve as a reversible mechanism during early stages of adaptive evolution. PMID:23358723

Chang, Shang-Lin; Lai, Huei-Yi; Tung, Shu-Yun; Leu, Jun-Yi

2013-01-24

313

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

|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…

Priebe, Gisela; Svedin, Carl Goran

2009-01-01

314

Conserving large populations of lions - the argument for fences has holes.  

PubMed

Packer et al. reported that fenced lion populations attain densities closer to carrying capacity than unfenced populations. However, fenced populations are often maintained above carrying capacity, and most are small. Many more lions are conserved per dollar invested in unfenced ecosystems, which avoid the ecological and economic costs of fencing. PMID:23837659

Creel, S; Becker, M S; Durant, S M; M'soka, J; Matandiko, W; Dickman, A J; Christianson, D; Dröge, E; Mweetwa, T; Pettorelli, N; Rosenblatt, E; Schuette, P; Woodroffe, R; Bashir, S; Beudels-Jamar, R C; Blake, S; Borner, M; Breitenmoser, C; Broekhuis, F; Cozzi, G; Davenport, T R B; Deutsch, J; Dollar, L; Dolrenry, S; Douglas-Hamilton, I; Fitzherbert, E; Foley, C; Hazzah, L; Henschel, P; Hilborn, R; Hopcraft, J G C; Ikanda, D; Jacobson, A; Joubert, B; Joubert, D; Kelly, M S; Lichtenfeld, L; Mace, G M; Milanzi, J; Mitchell, N; Msuha, M; Muir, R; Nyahongo, J; Pimm, S; Purchase, G; Schenck, C; Sillero-Zubiri, C; Sinclair, A R E; Songorwa, A N; Stanley-Price, M; Tehou, C A; Trout, C; Wall, J; Wittemyer, G; Zimmermann, A

2013-07-09

315

The Impact of Sexual Orientation on Sexuality and Sexual Practices in North American Medical Students  

PubMed Central

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.

Breyer, Benjamin N.; Smith, James F.; Eisenberg, Michael L.; Ando, Kathryn A.; Rowen, Tami S.; Shindel, Alan W.

2013-01-01

316

The Effective Population Size of Malaria Mosquitoes: Large Impact of Vector Control  

PubMed Central

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.

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

317

Prevalence of arrhythmias and conduction disturbances in large population-based samples of children.  

PubMed

The aim of our study is to provide data on the prevalence of disturbances of rhythm in the general population of children. Accurate estimates of true prevalence of such disturbances of rhythm from large samples are mandatory if we are to interpret properly electrocardiographic abnormalities. We analysed prevalence of disturbances of rhythm in a population of 152,322, comprised of 71,855 elementary school students, 36,692 males and 35,163 females, aged from 5 to 6 years, and 80,467 students of junior high school, 41,842 males and 38,625 females, aged from 12 to 13 years. We analysed the prevalence of premature atrial and ventricular contractions, first, second and third degree atrioventricular block, incomplete and complete right bundle branch block, Wolff-Parkinson-White syndrome, and prolongation of the QT interval. The prevalence of disturbances of rhythm in total rose with age, being found in 1.25% of elementary school students and 2.32% of junior high school students, and was higher in males than females, at 2.00% as opposed to 1.38%, both values being statistically significant at a level of less than 0.0001. Prevalences of all types of rhythmic disturbances were higher in junior high school students than elementary school students (p < 0.0001). Premature atrial and ventricular contractions and prolongation of the QT interval were higher in female than male students, at percentages of 0.089, 0.497, and 0.02 for males, and 0.123, 0.534 and 0.027 in females (p < 0.0001). In contrast, incomplete and complete right bundle branch blocks were higher in males than females, at 0.983% and 0.083% in males versus 0.410% and 0.161% in females (p < 0.0001). Disturbances of rhythm increased with age, and conduction disturbances were higher in male students than female, although premature atrial and ventricular contractions and prolongation of the QT interval were more frequent in female. These data may be useful for future comparative studies of disturbance of rhythm in children. PMID:15237674

Niwa, Koichiro; Warita, Naomi; Sunami, Yuko; Shimura, Akimitsu; Tateno, Shigeru; Sugita, Katsuo

2004-02-01

318

Arsenic Exposure and Impaired Lung Function. Findings from a Large Population-based Prospective Cohort Study.  

PubMed

Rationale: Exposure to arsenic through drinking water has been linked to respiratory symptoms, obstructive lung diseases, and mortality from respiratory diseases. Limited evidence for the deleterious effects on lung function exists among individuals exposed to a high dose of arsenic. Objectives: To determine the deleterious effects on lung function that exist among individuals exposed to a high dose of arsenic. Methods: In 950 individuals who presented with any respiratory symptom among a population-based cohort of 20,033 adults, we evaluated the association between arsenic exposure, measured by well water and urinary arsenic concentrations measured at baseline, and post-bronchodilator-administered pulmonary function assessed during follow-up. Measurements and Main Results: For every one SD increase in baseline water arsenic exposure, we observed a lower level of FEV1 (-46.5 ml; P < 0.0005) and FVC (-53.1 ml; P < 0.01) in regression models adjusted for age, sex, body mass index, smoking, socioeconomic status, betel nut use, and arsenical skin lesions status. Similar inverse relationships were observed between baseline urinary arsenic and FEV1 (-48.3 ml; P < 0.005) and FVC (-55.2 ml; P < 0.01) in adjusted models. Our analyses also demonstrated a dose-related decrease in lung function with increasing levels of baseline water and urinary arsenic. This association remained significant in never-smokers and individuals without skin lesions, and was stronger in male smokers. Among male smokers and individuals with skin lesions, every one SD increase in water arsenic was related to a significant reduction of FEV1 (-74.4 ml, P < 0.01; and -116.1 ml, P < 0.05) and FVC (-72.8 ml, P = 0.02; and -146.9 ml, P = 0.004), respectively. Conclusions: This large population-based study confirms that arsenic exposure is associated with impaired lung function and the deleterious effect is evident at low- to moderate-dose range. PMID:23848239

Parvez, Faruque; Chen, Yu; Yunus, Mahbub; Olopade, Christopher; Segers, Stephanie; Slavkovich, Vesna; Argos, Maria; Hasan, Rabiul; Ahmed, Alauddin; Islam, Tariqul; Akter, Mahmud M; Graziano, Joseph H; Ahsan, Habibul

2013-10-01

319

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)

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.

Tannenbaum, Emmanuel

2008-01-01

320

Sexual behaviour after antiretroviral therapy initiation in female sex workers and HIV-positive patients from the general population, Cotonou, Benin.  

PubMed

From September 2008 to December 2011, we enrolled and followed-up 247 HIV-negative, 88 untreated and 32 treated HIV-positive female sex workers (FSWs), as well as 238 untreated and 115 treated HIV-positive patients from the general population (GP) of Cotonou, Benin. We wanted to assess the effect of antiretroviral therapy (ART) on sexual risk-taking in FSWs and patients from the GP. We used multivariate log binomial regression models for repeated measures to compare risky behaviours reported during pre-ART and post-ART visits and we performed linear time-trend analyses to assess changes in condom use in all five groups. At 58.8% of pre-ART and 45.3% of post-ART visits (adjusted p-value=0.293), treated FSWs have reported ?16 clients during the last week of work. Inconsistent condom use with clients over the same period decreased by more than 50% (from 20.7 to 10.0%, adjusted p-value=0.082). In treated patients from the GP, inconsistent condom use with regular partners during the last four months was reported at 52.8% of pre-ART and 53.5% of post-ART visits (p=0.778). Reported casual sex was stable (36.8% versus 38.7%, adjusted p-value=0.924). In linear time-trend analyses, there was a significant downward trend in inconsistent condom use at the early stage of the study and stability thereafter in all HIV-negative and HIV-positive FSWs. There was no negative alteration in sexual behaviour following ART initiation either inpatients from the GP or in FSWs. The results underscore the key role of concomitant sexual risk-reduction strategies. PMID:23438011

Diabaté, Souleymane; Chamberland, Annie; Zannou, Djimon M; Geraldo, Nassirou; Azon-Kouanou, Angčle; Massinga-Loembé, Marguérite; Ahomadégbé, Christelle; Labbé, Annie-Claude; Tremblay, Cécile; Alary, Michel

2013-02-25

321

Population structure and dispersal patterns within and between Atlantic and Mediterranean populations of a large-range pelagic seabird.  

PubMed

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

Genovart, Meritxell; Thibault, Jean-Claude; Igual, José Manuel; Bauzŕ-Ribot, Maria del Mar; Rabouam, Corinne; Bretagnolle, Vincent

2013-08-12

322

Population genetics of 17 Y-STR loci in a large Chinese Han population from Zhejiang Province, Eastern China.  

PubMed

Seventeen Y-STRs (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385a, DYS385b, DYS438, DYS439, DYS437, DYS448, DYS456, DYS458, DYS635 and YGATAH4) were analyzed for 4451 Chinese Han unrelated males from Zhejiang Province, Eastern China, with the AmpFlSTR Yfiler™ PCR Amplification kit. A total of 3389 different haplotypes was identified, of which 2877 were unique and 512 repeatedly found among different individuals. The overall haplotype diversity (HD) and discrimination capacity (DC) were 0.999696 and 0.761402, respectively. Analysis of molecular variance (AMOVA) tests demonstrated that genetic distance between Zhejiang Han and most Chinese Han populations is closer than that between Zhejiang Han and non-Han populations. This study provides information for the application of Y-chromosomal STRs to forensic identification, indicating that the extended genotyping of Y-STRs is needed for forensic practice. PMID:20457064

Wu, Weiwei; Pan, Lipeng; Hao, Honglei; Zheng, Xiaoting; Lin, Jinfeng; Lu, Dejian

2010-01-19

323

Ten-Year Detection Rate of Brain Arteriovenous Malformations in a Large, Multiethnic, Defined Population  

PubMed Central

Background To evaluate whether increased neuroimaging use is associated with increased brain arteriovenous malformation (BAVM) detection, we examined detection rates in Kaiser Permanente Medical Care Program (KPMCP) of Northern California between 1995 and 2004. Methods We reviewed medical records, radiology reports and administrative databases to identify BAVM, intracranial aneurysms (IA: subarachnoid hemorrhage, SAH, and unruptured aneurysms) and other vascular malformations (OVM: dural fistulas, cavernous malformation, Vein of Galen malformation, venous malformation). Poisson regression (with robust standard errors) was used to test for trend. Random effects meta-analysis generated a pooled measure of BAVM detection rate from six studies. Results We identified 401 BAVMs (197 ruptured, 204 unruptured), 570 OVMs, and 2,892 IAs (2,079 SAH, 813 unruptured IA). Detection rates per 100,000 person-years were 1.4 (95% CI=1.3-1.6) for BAVM, 2.0 (1.8-2.3) for OVM, and 10.3 (9.9-10.7) for IA. Neuroimaging utilization increased 12% per year during the time period (P<0.001). Overall, rates increased for IAs (P<0.001), remained stable for OVMs (P=0.858), and decreased for BAVMs (P=0.001). Detection rates increased 15% per year for unruptured IA (P<0.001), with no change in SAH (P=0.903). However, rates decreased 7% per year for unruptured BAVM (P=0.016) and 3% per year for ruptured BAVM (P=0.005). Meta-analysis yielded a pooled BAVM detection rate of 1.3 (1.2-1.4) per 100,000, without heterogeneity between studies (P=0.25). Conclusions Rates for BAVM, OVM and IA in this large, multiethnic population were similar to other series. During 1995-2004, a period of increasing neuroimaging utilization, we did not observe an increased rate of detection of unruptured BAVM, despite increased detection of unruptured IA.

Gabriel, Rodney A.; Kim, Helen; Sidney, Stephen; McCulloch, Charles E.; Singh, Vineeta; Claiborne Johnston, S.; Ko, Nerissa U.; Achrol, Achal S.; Zaroff, Jonathan G.; Young, William L.

2010-01-01

324

Large delay in flowering in continental versus coastal populations of a Mediterranean shrub, Globularia alypum  

Microsoft Academic Search

Globularia alypum is a perennial shrub typical of western Mediterranean thermophilous shrublands. Nine populations of G. alypum located in different localities of Catalonia (NE Spain) were surveyed for flowering phenology. Flower-head buds were present\\u000a in all the populations in July. Flowering time in the area spans from the late summer–early autumn to the next spring depending\\u000a on the populations; there

Marc Estiarte; Gloria Puig; Josep Peńuelas

325

Does large volatility help?—stochastic population forecasting technology in explaining real estate price process  

Microsoft Academic Search

This paper investigates the association between real estate demand and the volatility of population changes. In a financial\\u000a liberalized housing market, the housing mortgage loan implies insurance function to homeowners through the default option.\\u000a Larger expected volatilities in the population imply a higher value of the default option. When analyzing the impact of the\\u000a long-term population development on housing prices,

Yuan Cheng; Xuehui Han

326

Sexual Assault of Adult Males  

Microsoft Academic Search

The circumstances and characteristics of sexual assaults against adult males presenting to a crisis unit in a large metropolitan area were examined. Twenty-nine men, ranging in age from 18 to 65, who were victims of sexual assaults or attempted sexual assaults, were seen over a 16-month period. Information extracted from the unit database included client demographics and personal history, assault

LANA STERMAC; PETER M. SHERIDAN; ALISON DAVIDSON; SHEILA DUNN

1996-01-01

327

The feasibility of using mobile phone technology for sexual behaviour research in a population vulnerable to HIV: a prospective survey with female sex workers in South India.  

PubMed

Sexual behaviour studies are often challenged by sampling, participation and measurement biases, and may be unacceptable to participants. We invited 293 randomly selected female sex workers (FSWs) in Bangalore, India, to participate in a telephone survey, with condom breakage as the main outcome. Free cell phones were supplied and trained interviewers telephoned FSWs daily to ask about all sex acts the previous day. Later, we undertook focus groups to discuss the methodology with the participants. We evaluated technical and operational feasibility; data reliability and measurement error; emotional and fatigue effects; interviewer bias; survey reactivity effects; and user acceptability. Response rates were high, with 84% of invited participants complying fully with the protocol. The study ran smoothly, with little evidence of biases. The methodology was highly acceptable; the respondents enjoyed using a new telephone and being interviewed at times convenient to them. Other reasons for the success of the method were that the study was sanctioned and supported by the sex worker collective, and the interviewers were well trained and developed a strong rapport with the participants. The success of this methodology, and the wealth of data produced, indicates that it can be an important tool for conducting sexual behaviour research in low literacy, high sex volume populations. PMID:22292915

Bradley, Janet; Ramesh, B M; Rajaram, S; Lobo, Anil; Gurav, Kaveri; Isac, Shajy; Chandra Shekhar Gowda, G; Pushpalatha, R; Moses, Stephen; Sunil, Kumar D R; Alary, Michel

2012-01-31

328

Population genetics of complex life-cycle parasites: an illustration with trematodes  

Microsoft Academic Search

Accurate inferences on population genetics data require a sound underlying theoretical null model. Organisms alternating sexual and asexual reproduction during their life-cycle have been largely neglected in theoretical population genetic models, thus limiting the biological interpretation of population genetics parameters measured in natural populations. In this article, we derive the expectations of those parameters for the life-cycle of monoecious trematodes,

Franck Prugnolle; Hua Liu; Thierry de Meeűs; François Balloux

2005-01-01

329

Epidemiology of Hypertrophic Cardiomyopathy-Related Death Revisited in a Large Non-Referral-Based Patient Population  

Microsoft Academic Search

Background—Death resulting from hypertrophic cardiomyopathy (HCM), particularly when sudden, has been reported to be largely confined to young persons. These data emanated from tertiary HCM centers with highly selected referral patterns skewed toward high-risk patients. Methods and Results—The present analysis was undertaken in an international population of 744 consecutively enrolled and largely unselected patients more representative of the overall HCM

Barry J. Maron; Iacopo Olivotto; Paolo Spirito; Susan A. Casey; Pietro Bellone; Thomas E. Gohman; Kevin J. Graham; David A. Burton; Franco Cecchi

330

Population III Star Formation in Large Cosmological Volumes. I. Halo Temporal and Physical Environment  

NASA Astrophysics Data System (ADS)

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 ~ 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 × 105 M ? to 1.2 × 1010 M ?. 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 ~ 10.

Crosby, Brian D.; O'Shea, Brian W.; Smith, Britton D.; Turk, Matthew J.; Hahn, Oliver

2013-08-01

331

Modeling population dynamics and conservation of arapaima in the Amazon  

Microsoft Academic Search

To promote understanding of fish population dynamics in tropical river-floodplains, we have synthesized existing information\\u000a by developing a largely empirical population model for arapaima (Arapaima sp.). Arapaima are characterized by very large bodies, relatively late sexual maturity, small clutches, and large parental\\u000a investment per offspring, and their populations are overexploited and even declining due to overfishing. We used unparalleled\\u000a time

L. CastelloD; D. J. Stewart; C. C. Arantes

332

Correlates of Sexual Abuse and Smoking among French Adults  

ERIC Educational Resources Information Center

|Objective: The goal of this study was to examine the association between sexual abuse (SA) and initiation, cessation, and current cigarette smoking among a large representative adult population in France. Method: A random sample size of 12,256 adults (18-75 years of age) was interviewed by telephone concerning demographic variables, health…

King, Gary; Guilbert, Philippe; Ward, D. Gant; Arwidson, Pierre; Noubary, Farzad

2006-01-01

333

A Cost of Sexual Harassment in the Guppy, Poecilia reticulata  

Microsoft Academic Search

Male guppies in wild Trinidadian populations devote a large proportion of their time to pursuing females, and females, as a result, are frequent targets of sneaky mating attempts. In this paper we demonstrate a cost, in terms of lost feeding opportunities, to these female recipients of sexual harassment. An experiment in pools of a Trinidadian stream manipulated sex ratio and

Anne E. Magurran; Benoni H. Seghers

1994-01-01

334

Sexual harassment of university faculty by colleagues and students  

Microsoft Academic Search

The focus of this research was on faculty members as victims of sexual harassment by colleagues (peer harassment) and students (contrapower harassment). A self-administered, mailed questionnaire was sent to a probability sample of faculty at a large, public Midwestern university and to the whole population of faculty at a small, public institution in the Western Mountain region. Several hypotheses were

Kathleen McKinney

1990-01-01

335

Multivariate sexual selection in a rapidly evolving speciation phenotype.  

PubMed

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 (?) 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

Oh, Kevin P; Shaw, Kerry L

2013-05-01

336

Sex differences, sexual selection, and ageing: an experimental evolution approach.  

PubMed

Life-history (LH) theory predicts that selection will optimize the trade-off between reproduction and somatic maintenance. Reproductive ageing and finite life span are direct consequences of such optimization. Sexual selection and conflict profoundly affect the reproductive strategies of the sexes and thus can play an important role in the evolution of life span and ageing. In theory, sexual selection can favor the evolution of either faster or slower ageing, but the evidence is equivocal. We used a novel selection experiment to investigate the potential of sexual selection to influence the adaptive evolution of age-specific LH traits. We selected replicate populations of the seed beetle Callosobruchus maculatus for age at reproduction ("Young" and "Old") either with or without sexual selection. We found that LH selection resulted in the evolution of age-specific reproduction and mortality but these changes were largely unaffected by sexual selection. Sexual selection depressed net reproductive performance and failed to promote adaptation. Nonetheless, the evolution of several traits differed between males and females. These data challenge the importance of current sexual selection in promoting rapid adaptation to environmental change but support the hypothesis that sex differences in LH-a historical signature of sexual selection-are key in shaping trait responses to novel selection. PMID:19519633

Maklakov, Alexei A; Bonduriansky, Russell; Brooks, Robert C

2009-06-10

337

Second-Order Selection for Evolvability in a Large Escherichia coli Population  

Microsoft Academic Search

In theory, competition between asexual lineages can lead to second-order selection for greater evolutionary potential. To test this hypothesis, we revived a frozen population of Escherichia coli from a long-term evolution experiment and compared the fitness and ultimate fates of four genetically distinct clones. Surprisingly, two clones with beneficial mutations that would eventually take over the population had significantly lower

Robert J. Woods; Jeffrey E. Barrick; Tim F. Cooper; Utpala Shrestha; Mark R. Kauth; Richard E. Lenski

2011-01-01

338

Surprising similarity of sneaking rates and genetic mating patterns in two populations of sand goby experiencing disparate sexual selection regimes  

Microsoft Academic Search

Molecular markers have proved extremely useful in resolving mating patterns within indi- vidual populations of a number of species, but little is known about how genetic mating systems might vary geographically within a species. Here we use microsatellite markers to compare patterns of sneaked fertilization and mating success in two populations of sand goby ( Pomatoschistus minutus ) that differ

Adam G. Jones; Deette Walker; Kai Lindstrom; Charlotta Kvarnemo; John C. Avise

2001-01-01

339

Population Dynamics of Phytophthora infestans in the Netherlands Reveals Expansion and Spread of Dominant Clonal Lineages and Virulence in Sexual Offspring  

PubMed Central

For a comprehensive survey of the structure and dynamics of the Dutch Phytophthora infestans population, 652 P. infestans isolates were collected from commercial potato fields in the Netherlands during the 10-year period 2000–2009. Genotyping was performed using 12 highly informative microsatellite markers and mitochondrial haplotypes. In addition, for each isolate, the mating type was determined. STRUCTURE analysis grouped the 322 identified genotypes in three clusters. Cluster 1 consists of a single clonal lineage NL-001, known as “Blue_13”; all isolates in this cluster have the A2 mating type and the Ia mitochondrial haplotype. Clusters 2 and 3 display a more elaborate substructure containing many unique genotypes. In Cluster 3, several distinct clonal lineages were also identified. This survey witnesses that the Dutch population underwent dramatic changes in the 10 years under study. The most notable change was the emergence and spread of A2 mating type strain NL-001 (or “Blue_13”). The results emphasize the importance of the sexual cycle in generating genetic diversity and the importance of the asexual cycle as the propagation and dispersal mechanism for successful genotypes. Isolates were also screened for absence of the Avrblb1/ipiO class I gene, which is indicative for virulence on Rpi-blb1. This is also the first report of Rpi-blb1 breakers in the Netherlands. Superimposing the virulence screening on the SSR genetic backbone indicates that lack the Avrblb1/ipiO class I gene only occurred in sexual progeny. So far, the asexual spread of the virulent isolates identified has been limited.

Li, Y.; van der Lee, T. A. J.; Evenhuis, A.; van den Bosch, G. B. M.; van Bekkum, P. J.; Forch, M. G.; van Gent-Pelzer, M. P. E; van Raaij, H. M. G.; Jacobsen, E.; Huang, S. W.; Govers, F.; Vleeshouwers, V. G. A. A.; Kessel, G. J. T.

2012-01-01

340

Population dynamics of Phytophthora infestans in the Netherlands reveals expansion and spread of dominant clonal lineages and virulence in sexual offspring.  

PubMed

For a comprehensive survey of the structure and dynamics of the Dutch Phytophthora infestans population, 652 P. infestans isolates were collected from commercial potato fields in the Netherlands during the 10-year period 2000-2009. Genotyping was performed using 12 highly informative microsatellite markers and mitochondrial haplotypes. In addition, for each isolate, the mating type was determined. STRUCTURE analysis grouped the 322 identified genotypes in three clusters. Cluster 1 consists of a single clonal lineage NL-001, known as "Blue_13"; all isolates in this cluster have the A2 mating type and the Ia mitochondrial haplotype. Clusters 2 and 3 display a more elaborate substructure containing many unique genotypes. In Cluster 3, several distinct clonal lineages were also identified. This survey witnesses that the Dutch population underwent dramatic changes in the 10 years under study. The most notable change was the emergence and spread of A2 mating type strain NL-001 (or "Blue_13"). The results emphasize the importance of the sexual cycle in generating genetic diversity and the importance of the asexual cycle as the propagation and dispersal mechanism for successful genotypes. Isolates were also screened for absence of the Avrblb1/ipiO class I gene, which is indicative for virulence on Rpi-blb1. This is also the first report of Rpi-blb1 breakers in the Netherlands. Superimposing the virulence screening on the SSR genetic backbone indicates that lack the Avrblb1/ipiO class I gene only occurred in sexual progeny. So far, the asexual spread of the virulent isolates identified has been limited. PMID:23275876

Li, Y; van der Lee, T A J; Evenhuis, A; van den Bosch, G B M; van Bekkum, P J; Förch, M G; van Gent-Pelzer, M P E; van Raaij, H M G; Jacobsen, E; Huang, S W; Govers, F; Vleeshouwers, V G A A; Kessel, G J T

2012-12-01

341

Two Test Items to Explore High School Students' Beliefs of Sample Size When Sampling from Large Populations  

ERIC Educational Resources Information Center

|Two test items that examined high school students' beliefs of sample size for large populations using the context of opinion polls conducted prior to national and state elections were developed. A trial of the two items with 21 male and 33 female Year 9 students examined their naive understanding of sample size: over half of students chose a…

Bill, Anthony; Henderson, Sally; Penman, John

2010-01-01

342

Confirmation of association of the macrophage migration inhibitory factor gene with systemic sclerosis in a large European population  

Microsoft Academic Search

Objectives. The aim of this study was to confirm the implication of macrophage migration inhibitory factor (MIF) gene in SSc susceptibility or clinical phenotypes in a large European population. Methods. A total of 3800 SSc patients and 4282 healthy controls of white Caucasian ancestry from eight different European countries were included in the study. The MIF -173 single nucleotide polymorphism

L. Bossini-Castillo; C. P. Simeon; L. Beretta; M. C. Vonk; J. L. Callejas-Rubio; G. Espinosa; P. Carreira; M. T. Camps; L. Rodriguez-Rodriguez; M. Rodriguez-Carballeira; F. J. Garcia-Hernandez; F. J. Lopez-Longo; V. Hernandez-Hernandez; L. Saez-Comet; M. V. Egurbide; R. Hesselstrand; A. Nordin; A. M. Hoffmann-Vold; M. Vanthuyne; V. Smith; E. De Langhe; A. Kreuter; G. Riemekasten; T. J. M. de Witte; N. Hunzelmann; A. E. Voskuyl; A. J. Schuerwegh; C. Lunardi; P. Airo; R. Scorza; P. Shiels; J. M. van Laar; C. Fonseca; C. Denton; A. Herrick; J. Worthington; B. P. Koeleman; B. Rueda; T. R. D. J. Radstake; J. Martin

2011-01-01

343

The Nature of Social Work Services in a Large Public Medical Center Serving an Impoverished Multicultural Population  

Microsoft Academic Search

The purpose of this paper is to describe the nature of social work services in a large public medical center serving an impoverished multicultural population. This monitoring evaluation was developed and conducted within the context of a research collaboration between a School of Social Work and a team of clinical workers, supervisors, and administrators from the social work department of

Karen Subramanian

2000-01-01

344

Applicability of a filter paper method to measure blood lead levels in large populations of Chinese children  

Microsoft Academic Search

Background: Capillary filter paper can be useful for screening blood lead concentrations in large populations of geographically dispersed Chinese children. Methods: A total of 159 at 0–6 years of age were enrolled in the study when they came for routine pediatric care. Paired venous and capillary filter paper samples were collected from all subjects. Graphite furnace atomic absorption spectrophotometry was

Xiao-Ming Shen; Yi-Wen Zhang; Sheng-Hu Wu; Chong-Huai Yan; Jie-Min Ying; Ren-Qiu Li

2003-01-01

345

The utility of relative afferent pupillary defect as a screening tool for glaucoma: prospective examination of a large population-based study in a south Indian population  

Microsoft Academic Search

BackgroundPrevious authors have suggested that an afferent pupillary defect (APD) may serve as an effective screening tool for some specific eye diseases, especially glaucomatous optic neuropathy, since the disease usually presents asymmetrically. Its success as a screening tool for glaucoma has never been previously prospectively evaluated in a large population.MethodsIn this study, the authors carry out assessments for the presence

Amy L Hennessy; Joanne Katz; Rengappa Ramakrishnan; Ramasamy Krishnadas; Ravilla D Thulasiraj; James M Tielsch; Alan L Robin

2011-01-01

346

Quasi-stationarity in populations that are subject to large-scale mortality or emigration.  

PubMed

We shall examine a model, first studied by Brockwell et al., which can be used to describe the long-term behaviour of populations that are subject to catastrophic mortality or emigration events. Populations can suffer dramatic declines when disease, such as an introduced virus, affects the population, or when food shortages occur, due to overgrazing or fluctuations in rainfall. However, perhaps surprisingly, such populations can survive for long periods and, although they may eventually become extinct, they can exhibit an apparently stationary regime. It is useful to be able to model this behaviour. This is particularly true of the ecological examples that motivated the present study, since, in order to properly manage these populations, it is necessary to be able to predict persistence times and to estimate the conditional probability distribution of population size. We shall see that although our model predicts eventual extinction, the time till extinction can be long and the stationary exhibited by these populations over any reasonable time scale can be explained using a quasi-stationary distribution. PMID:11697675

Pollett, P K

2001-09-01

347

Accumulation of factors influencing children's middle ear disease: risk factor modelling on a large population cohort  

Microsoft Academic Search

STUDY OBJECTIVES: Data were analysed from a large national birth cohort to examine cumulative and interactive prediction from various risk factors for childhood middle ear disease, and to resolve conflicting evidence arising from small and incompletely controlled studies. The large sample size permitted appropriate covariate adjustment to give generality, and permit demographic breakdown of the risk factors. SETTING: A large

K. E. Bennett; M. P. Haggard

1998-01-01

348

Female sexual dysfunction  

MedlinePLUS

... women was thought to be largely due to psychological problems. Recent research is beginning to uncover many ... women. While many sexual problems have an underlying psychological component, possible physical causes must be ruled out ...

349

Stem cells from innate sexual but not acquired sexual planarians have the capability to form a sexual individual.  

PubMed

Planarian species may harbor as many as three populations with different reproductive strategies. Animals from innate asexual (AS) and innate sexual (InS) populations reproduce only by fission and cross-fertilization, respectively, whereas the third population switches seasonally between the two reproductive modes. AS worms can be experimentally sexualized by feeding them with minced InS worms; we termed the resulting animals "acquired sexual" (AqS) worms. Both AqS and InS worms exhibit sexualizing activity when used as feed, suggesting that they maintain their sexual state via endogenous sexualizing substances, although the mechanisms underlying determination of reproductive strategy and sexual switching in these metazoans remain enigmatic. Therefore, we compared the endogenous sexualizing activity of InS worms and AqS worms. First, we amputated mature worms and assessed if they could re-enter a sexual state. Regenerants of InS worms, but not AqS worms, were only sexual, indicating that sexual state regulation comprises two steps: (1) autonomous initiation of sexualizing substance production and (2) maintenance of the sexual state by continuous production of sexualizing substances. Next, InS neoblasts were characterized by transplantation, finding that they successfully engrafted, proliferated, and replaced all recipient cells. Under such conditions, the AS recipients of InS worm neoblasts, but not those of AqS worms, became sexual. These results clearly show that there is a neoblast-autonomous determination of reproductive strategy in planarians. PMID:22968921

Nodono, Hanae; Ishino, Yugo; Hoshi, Motonori; Matsumoto, Midori

2012-09-25

350

The characteristics of epilepsy in a largely untreated population in rural Ecuador  

Microsoft Academic Search

A house-to-house survey of epileptic seizures covering a population of 72,121 persons was carried out in a rural area of northern Ecuador. A cascade system of diagnosis was used to identify all cases of epileptic seizures in this population. 1029 cases were found, of whom 881 were considered to be definite cases and 148 were possible cases. Of the 1029

M Placencia; J W Sander; M Roman; A Madera; F Crespo; S Cascante; S D Shorvon

1994-01-01

351

LifeGene—a large prospective population-based study of global relevance  

Microsoft Academic Search

Studying gene-environment interactions requires that the amount and quality of the lifestyle data is comparable to what is\\u000a available for the corresponding genomic data. Sweden has several crucial prerequisites for comprehensive longitudinal biomedical\\u000a research, such as the personal identity number, the universally available national health care system, continuously updated\\u000a population and health registries and a scientifically motivated population. LifeGene builds

Catarina Almqvist; Hans-Olov Adami; Paul W. Franks; Leif Groop; Erik Ingelsson; Juha Kere; Lauren Lissner; Jan-Eric Litton; Markus Maeurer; Karl Michaëlsson; Juni Palmgren; Göran Pershagen; Alexander Ploner; Patrick F. Sullivan; Gunnel Tybring; Nancy L. Pedersen

2011-01-01

352

Dynamics of an emerging disease drive large-scale amphibian population extinctions.  

PubMed

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

Vredenburg, Vance T; Knapp, Roland A; Tunstall, Tate S; Briggs, Cheryl J

2010-05-10

353

Premarital sexual behavior and postmarital adjustment  

Microsoft Academic Search

Data from a large sample survey of sexual attitudes and behavior were examined for correlations between various premarital sexual experiences and postmarital sexual behavior. Hypotheses concerning the effects of intervening and extraneous variables on the relationships between premarital chastity and postmarital adjustment did not receive support. In general, a relationship between pre- and postmarital sexual activity exists in these data

Robert Athanasiou; Richard Sarkin

1974-01-01

354

The Natsal-SF: a validated measure of sexual function for use in community surveys.  

PubMed

Sexual dysfunction often features as an outcome variable in community health surveys and epidemiological surveys. Key design imperatives for measures included in large scale, population-based surveys are acceptability, brevity and relevance to diverse sexual lifestyles. None of the available measures of sexual dysfunction are entirely suited to this task. We developed a new measure of sexual function for the third British National Survey of Sexual Attitudes and Lifestyles (Natsal 3). Items for the measure were derived from qualitative work from patients and community members. The draft measure was developed and validated using a general population sample (internet panel survey (n = 1,262)) and a clinical sample (patients attending sexual problems clinics (n = 100). Confirmatory factor analysis established that a 'general-specific model' had the best fit and was equivalent between general population and clinical samples (Comparative Fit Index = 0.963 Tucker Lewis Index = 0.951; Root Mean Square Error of Approximation = 0.064). The 17-item Natsal-SF is positively associated with the Female Sexual Function Index-6 (B = 0.572) and Brief Sexual Function Questionnaire for men (B = 0.705); it can discriminate between clinical and general population groups (OR = 2.667); and it has good test-retest reliability (r = 0.72). The Natsal-SF provides an estimate of the level of sexual function in the last year. By including items on distress about sex and sexual relationships, and by being relevant to all regardless of sexual lifestyle, it addresses some of the gaps in current measurement design. PMID:22711585

Mitchell, Kirstin R; Ploubidis, George B; Datta, Jessica; Wellings, Kaye

2012-06-19

355

Sexual Health  

MedlinePLUS

Sexual health Basics In-Depth Multimedia Expert Answers Resources What's New Sexual health By Mayo Clinic staff Original Article: http://www. ... not share your e-mail address Sign up Sexual health basics Sexuality is part of being human. Love, ...

356

Sexual Harassment.  

ERIC Educational Resources Information Center

|This paper sets out the legal grounds for sexual harassment claims in education settings, and notes a number of pertinent cases that are illustrative of common legal and factual issues. Sexual harassment, including sexual abuse, is prohibited by federal and state statutes. Sexual harassment in the context of employment constitutes employment…

Uerling, Donald F.

357

Sexual coercion and the misperception of sexual intent?  

PubMed Central

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.

Farris, Coreen; Treat, Teresa A.; Viken, Richard J.; McFall, Richard M.

2010-01-01

358

Sexual coercion and the misperception of sexual intent.  

PubMed

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

Farris, Coreen; Treat, Teresa A; Viken, Richard J; McFall, Richard M

2007-03-15

359

Population Genetics of Two Asexually and Sexually Reproducing Psocids Species Inferred by the Analysis of Mitochondrial and Nuclear DNA Sequences  

PubMed Central

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.

Wei, Dan-Dan; Yuan, Ming-Long; Wang, Bao-Jun; Zhou, An-Wei; Dou, Wei; Wang, Jin-Jun

2012-01-01

360

Prevalence and phenotype consequence of FRAXA and FRAXE alleles in a large, ethnically diverse, special education-needs population.  

PubMed

We conducted a large population-based survey of fragile X (FRAXA) syndrome in ethnically diverse metropolitan Atlanta. The eligible study population consisted of public school children, aged 7-10 years, in special education-needs (SEN) classes. The purpose of the study was to estimate the prevalence among whites and, for the first time, African Americans, among a non-clinically referred population. At present, 5 males with FRAXA syndrome (4 whites and 1 African American), among 1,979 tested males, and no females, among 872 tested females, were identified. All males with FRAXA syndrome were mentally retarded and had been diagnosed previously. The prevalence for FRAXA syndrome was estimated to be 1/3,460 (confidence interval [CI] 1/7,143-1/1,742) for the general white male population and 1/4, 048 (CI 1/16,260-1/1,244) for the general African American male population. We also compared the frequency of intermediate and premutation FRAXA alleles (41-199 repeats) and fragile XE syndrome alleles (31-199 repeats) in the SEN population with that in a control population, to determine if there was a possible phenotype consequence of such high-repeat alleles, as has been reported previously. No difference was observed between our case and control populations, and no difference was observed between populations when the probands were grouped by a rough estimate of IQ based on class placement. These results suggest that there is no phenotype consequence of larger alleles that would cause carriers to be placed in an SEN class. PMID:9973286

Crawford, D C; Meadows, K L; Newman, J L; Taft, L F; Pettay, D L; Gold, L B; Hersey, S J; Hinkle, E F; Stanfield, M L; Holmgreen, P; Yeargin-Allsopp, M; Boyle, C; Sherman, S L

1999-02-01

361

Differential responses of sexual and asexual Artemia to genotoxicity by a reference mutagen: Is the comet assay a reliable predictor of population level responses?  

PubMed

The impact of chronic genotoxicity to natural populations is always questioned due to their reproductive surplus. We used a comet assay to quantify primary DNA damage after exposure to a reference mutagen ethyl methane sulfonate in two species of crustacean with different reproductive strategies (sexual Artemia franciscana and asexual Artemia parthenogenetica). We then assessed whether this predicted individual performance and population growth rate over three generations. Artemia were exposed to different chronic concentrations (0.78mM, 1.01mM, 1.24mM and 1.48mM) of ethyl methane sulfonate from instar 1 onwards for 3 h, 24 h, 7 days, 14 days and 21 days and percentage tail DNA values were used for comparisons between species. The percentage tail DNA values showed consistently elevated values up to 7 days and showed a reduction from 14 days onwards in A. franciscana. Whilst in A. parthenogenetica such a reduction was evident on 21 days assessment. The values of percentage tail DNA after 21 days were compared with population level fitness parameters, growth, survival, fecundity and population growth rate to know whether primary DNA damage as measured by comet assay is a reliable biomarker. Substantial increase in tail DNA values was associated with substantial reductions in all the fitness parameters in the parental generation of A. franciscana and parental, F1 and F2 generations of A. parthenogenetica. So comet results were more predictive in asexual species over generations. These results pointed to the importance of predicting biomarker responses from multigenerational consequences considering life history traits and reproductive strategies in ecological risk assessments. PMID:23414719

Sukumaran, Sandhya; Grant, Alastair

2013-02-13

362

AIDS and human sexuality.  

PubMed

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

Smith, L L; Lathrop, L M

363

A Framework for Comparative Evaluation of Dosimetric Methods to Triage a Large Population Following a Radiological Event  

PubMed Central

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

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

2011-01-01

364

Sexual dimorphism in two types of dermatoglyphic traits in the Turkmenian population of Russia: principal component analysis.  

PubMed

Summary: Objective of this study is to explore the nature of sex differences between two different sets of dermatoglyphic traits based on principal components in the Turkmenian population. Two categories of dermatoglyphic traits--22 usually studied quantitative traits and 42 variables of diversity and asymmetry were analysed among 745 individuals (309 males and 436 females). The three principal components are very prominent in both sexes--"digital pattern size factor" indicates the degree of universality, as found in earlier studies among different ethnic populations; "intra individual diversity factor" and "bilateral asymmetry factor" are also similar with the earlier studies, which suggest the genetic factor has more influence on these variables than environmental factors. These results strongly indicate that there is a common biological validity exists of the underlying principal component structures between two different sets of dermatoglyphic characters and thus dermatoglyphic factors between two groups of variables can be used for sex-discrimination in different populations. PMID:20405699

Karmakar, Bibha; Kobyliansky, Eugene

2009-09-01

365

Self-reported history of sexually transmissible infections (STIs) and STI-related utilization of the German health care system by men who have sex with men: data from a large convenience sample  

Microsoft Academic Search

Background  In Germany, testing and treatment of sexually transmissible infections (STIs) services are not provided by one medical discipline,\\u000a but rather dispersed among many different providers. Common STIs like gonorrhoea or Chlamydia infection are not routinely\\u000a reported. Although men who have sex with men (MSM) are particularly vulnerable to STIs, respective health care utilization\\u000a among MSM is largely unknown.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  A sexual

Axel J Schmidt; Ulrich Marcus

2011-01-01

366

Bride price and sexual risk taking in Uganda.  

PubMed

This study assessed the relationship of bride price to sexual risk taking based on a large, population-based survey. Data were collected on bride prices for 592 married women in 12 districts in Uganda in 2001. Controlling for covariates, we found that having had a bride price significantly lowered the wife's odds of sexual intercourse with a partner other than the spouse (OR= 0.222; 95% CI= 0.067, 0.737). Controlling for covariates, bride price increased the husband's odds of non-spousal sexual intercourse (OR=1.489; 95% CI= 0.746, 2.972), although this finding is not statistically significant. Bride price payment is statistically significantly associated with lower rates of non-spousal sexual contact in women, but is not statistically significantly associated with higher rates in men. PMID:20687272

Bishai, David; Falb, Kathryn L; Pariyo, George; Hindin, Michelle J

2009-03-01

367

High sexual reproduction and limited contemporary dispersal in the ectomycorrhizal fungus Tricholoma scalpturatum: new insights from population genetics and spatial autocorrelation analysis.  

PubMed

Dispersal and establishment are fundamental processes influencing the response of species to environmental changes, and the long-term persistence of populations. A previous study on the symbiotic ectomycorrhizal fungus Tricholoma scalpturatum revealed strong genetic differentiations between populations in Western Europe, suggesting restricted dispersal for this wind-dispersed cosmopolitan fungus. Two distinct genetic groups (genetic groups 1 and 2), co-occurring in some locations, were also identified and could correspond to cryptic species. In the present work, we examine the reproductive strategy and dispersal biology of the two T. scalpturatum's genetic groups. Variable molecular markers (intersimple sequence repeats and intergenic spacer 2-restriction fragment length polymorphisms) and spatial autocorrelation analyses were used to examine fine-scale patterns (< 140 m) of genetic structure, in an effort to determine the physical scale at which genetic structure exists. A total of 473 fruit bodies were mapped and collected over 3 years from two plots located in the south of France, including 219 and 254 samples from group 1 and group 2, respectively. High genetic diversity and the presence of numerous small genets were observed in both groups. Autocorrelation analyses revealed significant positive spatial genetic structures of genets at close distances (up to few metres for both groups). Mantel tests confirmed this isolation-by-distance pattern. These results clearly demonstrate high sexual reproduction and spatial structuring of genets at very small geographical scales in this wind-dispersed ectomycorrhizal fungal species, a pattern consistent with restricted contemporary dispersal of spores. PMID:18986492

Carriconde, Fabian; Gryta, Hervé; Jargeat, Patricia; Mouhamadou, Bello; Gardes, Monique

2008-10-01

368

Large-Scale Selective Sweep among Segregation Distorter Chromosomes in African Populations of Drosophila melanogaster  

PubMed Central

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 (?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.

Presgraves, Daven C.; Gerard, Pierre R.; Cherukuri, Anjuli; Lyttle, Terrence W.

2009-01-01

369

Antihypertensive treatment and control in a large primary care population of 21 167 patients  

Microsoft Academic Search

The efficacy of antihypertensive drug therapy is undisputed, but observational studies show that few patients reach a target blood pressure <140\\/90 mm Hg. However, there is limited data on the drug prescribing patterns and their effectiveness in real practice. This retrospective observational survey of electronic patient records extracted data from 24 Swedish primary health-care centres, with a combined registered population

M Qvarnström; B Wettermark; C Ljungman; R Zarrinkoub; J Hasselström; K Manhem; A Sundström; T Kahan

2011-01-01

370

Census of Population: 1970. Low-Income Neighborhoods in Large Cities: 1970. Newark, N.J.  

National Technical Information Service (NTIS)

The report summarizes information on population and housing characteristics of low-income neighborhoods in Newark. Low-income neighborhoods are subdivisions of low-income areas, which include all census tracts in which 20 percent or more of all persons we...

1974-01-01

371

Determinants of Cluster Size in Large, Population-Based Molecular Epidemiology Study of Tuberculosis, Northern Malawi  

Microsoft Academic Search

Tuberculosis patients with identical strains of Mycobacterium tuberculosis are described as clustered. Cluster size may depend on patient or strain characteristics. In a 7-year population-based study of tuberculosis in Karonga District, Malawi, clusters were defined by using IS6110 restriction fragment length polymorphism, excluding patterns with <5 bands. Spoligotyping was used to compare strains with an international database. Among 682 clustered

Judith R. Glynn; Amelia C. Crampin; Hamidou Traore; Steve Chaguluka; Donex T. Mwafulirwa; Saad Alghamdi; Bagrey M. M. Ngwira; Malcolm D. Yates; Francis D. Drobniewski; Paul E. M. Fine

2008-01-01

372

Incidence, significance, and subtypes of hemophilia B M in a large population of hemophilia B patients  

Microsoft Academic Search

Eleven patients with hemophilia BM were found out of a population of 66 patients with hemophilia B. Factor IX activity in the hemophilia BM varied between less than 1% and 1.6% of normal but factor IX antigen was normal or only slightly reduced in each instance. Thrombotest clotting time was variably prolonged and was not corrected by the addition of

A. Girolami; R. Bo Zanon; P. Saltarin; V. Quaino; G. Altinier; T. Ripa; A. Marchetti; D. Stocco

1982-01-01

373

Gender differences in colorectal cancer screening and incidence in large nationwide, population-based cohorts  

Microsoft Academic Search

Background. A few studies have reported gender differences along the colorectal cancer (CRC) continuum but none has done so longitudinally to compare a cancer and a non-cancer populations.^ Objectives and Methods. To examine gender differences in colorectal cancer screening (CRCS); to examine trends in gender differences in CRC screening among two groups of patients (Medicare beneficiaries with and without cancer);

Peter Nathaniel Abotchie

2010-01-01

374

Clients of Female Sex Workers in Lima, Peru A Bridge Population for Sexually Transmitted Disease\\/HIV Transmission?  

Microsoft Academic Search

Objectives: The objectives of this study were to determine the prev- alence of risk behaviors, gonorrhea, and chlamydia in clients of female sex workers, and to compare them with men selected from the general population. Study Design: We conducted a cross-sectional study of men re- cruited from commercial sex venues in Lima, Peru from January to February 2002. Subjects answered

GREGG A. MILLER; WALTER MENDOZA; MELISSA R. KRONE; RENA MEZA; CARLOS F. CACERES; THOMAS J. COATES; JEFFREY D. KLAUSNER

375

Predicted Exposures to Steroid Estrogens in U.K. Rivers Correlate with Widespread Sexual Disruption in Wild Fish Populations  

Microsoft Academic Search

Steroidal estrogens, originating principally from human excretion, are likely to play a major role in causing widespread endocrine disruption in wild populations of the roach (Rutilus rutilus), a com- mon cyprinid fish, in rivers contaminated by treated sewage effluents. Given the extent of this problem, risk assessment models are needed to predict the location and severity of endocrine dis- ruption

Susan Jobling; Richard Williams; Andrew Johnson; Ayesha Taylor; Melanie Gross-Sorokin; Monique Nolan; Charles R. Tyler; Ronny van Aerle; Eduarda Santos; Geoff Brighty

2005-01-01

376

Five-year Follow-up Study of Tooth Extraction After Nonsurgical Endodontic Treatment in a Large Population in Taiwan  

Microsoft Academic Search

Background\\/Purpose: Nonsurgical retreatment, apical surgery and tooth extraction are three major unto- ward events following nonsurgical root canal treatment (NSRCT). The purpose of this study was to assess untoward events and total tooth extraction after NSRCT in a large population of dental patients in Taiwan. Methods: A total of 1,588,217 teeth treated with NSRCT in Taiwan in 2000 were analyzed

Shih-Chung Chen; Ling-Huey Chueh; Hsin-Ping Wu; Chuhsing Kate Hsiao

377

Sexuality, rights and personhood: tensions in a transnational world  

PubMed Central

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 aim was to generate a conceptual and analytical framework around sexuality and rights rather than to undertake an empirical survey of any one population. Results As descriptors, globalized identity categories such as Men who have Sex with Men (MSM), used by public health providers, the state and donors; and gay/lesbian, invoked by human rights activists and transnational NGOs, are too narrow to capture the fluid and highly context-specific ways in which gender and sexually nonconforming persons understand themselves in Bangladesh. Further, class position mediates to a significant degree the reception, appropriation or rejection of transnational categories such as MSM and Lesbian, Gay, Bisexual, Transgender (LGBT). The tension is reflected in the sometimes fraught relations between service providers to MSM, the people they serve and an emerging group who identify as LGBT. Conclusion A simple politics of recognition will be inadequate to the task of promoting health and human rights for all; such a strategy would effectively exclude individuals who do not necessarily connect their sexual practices with a specific sexual or social identity.

2011-01-01

378

Big Data: Large-Scale Historical Infrastructure from the Minnesota Population Center.  

PubMed

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

Sobek, Matthew; Cleveland, Lara; Flood, Sarah; Hall, Patricia Kelly; King, Miriam L; Ruggles, Steven; Schroeder, Matthew

2011-01-01

379

Fleet health monitoring of large populations: aged concrete T-beam bridges in Pennsylvania  

NASA Astrophysics Data System (ADS)

The importance of rational decision-making for optimum resource distribution of civil infrastructure systems management is well recognized. Bridges, serving as node points of the highway transportation system, are critical components of the nation's infrastructure. As the nation's bridge population is aging, management decisions must be based on an objective, complete, accurate and compatible information for maximum reliable bridge lifecycle. For bridges sharing common materials, similar geometric design attributes and behavior mechanisms, fleet-strategies for health monitoring would offer significant advantages. Improvements from fleet health monitoring would lead to objective engineering knowledge for optimal decision making. This paper provides an overview of fleet health monitoring concept, then summarizes an on-going research on re- qualification of reinforced concrete T-beam bridge population in Pennsylvania.

Catbas, Fikret N.; Ciloglu, Korhan; Celebioglu, Arda; Popovics, John S.; Aktan, A. Emin

2001-08-01

380

Population-based laboratory surveillance for Serratia species isolates in a large Canadian health region  

Microsoft Academic Search

A population-based laboratory surveillance was conducted during a six-year period to define the incidence, demographic risk\\u000a factors for acquisition, and anti-microbial susceptibilities of Serratia species isolates. A total of 715 incident Serratia species isolates were identified for an annual incidence of 10.8 per 100,000 residents; bacteremic disease occurred in 0.9\\u000a per 100,000 residents annually. The incidence increased with advancing age

K. B. Laupland; M. D. Parkins; D. B. Gregson; D. L. Church; T. Ross; J. D. D. Pitout

2008-01-01

381

Potential role for the PDE5 inhibitor sildenafil in the treatment of female sexual dysfunction  

Microsoft Academic Search

\\u000a Although female sexual dysfunction has been recognized as a health problem that affects the well-being of a large population\\u000a of both pre-and post-menopausal women, organic underlying causes that could be susceptible to pharmacologic or surgical treatment\\u000a have only recently been considered [1]. In the last decade significant discoveries in the biochemistry, physiology and pharmacology of male sexual function have\\u000a led

Jennifer T. Anger; Jennifer R. Berman

382

Sexuality in nursing homes: practice and policy.  

PubMed

Older adults' sexuality and sexual expression are often overlooked in nursing home and residential care settings. Despite cultural beliefs that this population is asexual, sexual activity occurs frequently among residents in long-term care. This study, using written survey instrumentation, examines the scope of resident sexuality, staff reactions to sexual behavior, and the policies and guidelines used in 91 nursing homes to address residents' sexual activity. Eighty-five percent of respondents reported that sexual activity had occurred in their homes, and staff reactions to sexual activity were based on general guidelines. Many responses indicated that sexual expression of residents was considered non-normative. Issues of consent, especially concerning residents with dementia, and residents' right to privacy were addressed using existing general policies. Survey results demonstrate a need for specific policies and staff training regarding sexual expression to be developed with the input of nurses, family members, and residents. PMID:23614386

Doll, Gayle M

2013-04-26

383

Sexual selection and the differential effect of polyandry.  

PubMed

In principle, widespread polyandry (female promiscuity) creates potential for sexual selection in males both before and after copulation. However, the way polyandry affects pre- and postcopulatory episodes of sexual selection remains little understood. Resolving this fundamental question has been difficult because it requires extensive information on mating behavior as well as paternity for the whole male population. Here we show that in replicate seminatural groups of red junglefowl, Gallus gallus, polyandry eroded variance in male mating success, which simultaneously weakened the overall intensity of sexual selection but increased the relative strength of postcopulatory episodes. We further illustrate the differential effect of polyandry on pre- and postcopulatory sexual selection by considering the case of male social status, a key determinant of male reproductive success in this species. In low-polyandry groups, however, status was strongly sexually selected before copulation because dominants mated with more females. In high-polyandry groups, sexual selection for status was weakened and largely restricted after copulation because dominants defended paternity by mating repeatedly with the same female. These results reveal polyandry as a potent and dynamic modulator of sexual selection episodes. PMID:22592795

Collet, Julie; Richardson, David S; Worley, Kirsty; Pizzari, Tommaso

2012-05-16

384

Sexual selection and the differential effect of polyandry  

PubMed Central

In principle, widespread polyandry (female promiscuity) creates potential for sexual selection in males both before and after copulation. However, the way polyandry affects pre- and postcopulatory episodes of sexual selection remains little understood. Resolving this fundamental question has been difficult because it requires extensive information on mating behavior as well as paternity for the whole male population. Here we show that in replicate seminatural groups of red junglefowl, Gallus gallus, polyandry eroded variance in male mating success, which simultaneously weakened the overall intensity of sexual selection but increased the relative strength of postcopulatory episodes. We further illustrate the differential effect of polyandry on pre- and postcopulatory sexual selection by considering the case of male social status, a key determinant of male reproductive success in this species. In low-polyandry groups, however, status was strongly sexually selected before copulation because dominants mated with more females. In high-polyandry groups, sexual selection for status was weakened and largely restricted after copulation because dominants defended paternity by mating repeatedly with the same female. These results reveal polyandry as a potent and dynamic modulator of sexual selection episodes.

Collet, Julie; Richardson, David S.; Worley, Kirsty; Pizzari, Tommaso

2012-01-01

385

[Pharmacological treatment of female sexual disfunction: chimera or reality?].  

PubMed

Sexual dysfunction is defined as a disturbance in the sexual response cycle or as a pain with sexual intercourse. The prevalence of sexual dysfunctions is approximately 40% in the female population. The disorders affecting sexual desire are the most common sexual dysfunctions encountered in women. Whereas recent studies have demonstrated clear influences of hormones on sexual dysfunctions, no pharmacological treatment has been approved for that indication. We will review here several pharmacological treatment strategies proposed in case of sexual dysfunction, underlying the fact that they are effective only to treat specific cases of sexual disorders but cannot replace the sex therapies. PMID:15856845

Bianchi-Demicheli, Francesco; De Ziegler, Dominique

2005-03-16

386

Investigating the effects of topography and clonality on genetic structuring within a large Norwegian population of Arabidopsis lyrata  

PubMed Central

Background and Aims The gene flow through pollen or seeds governs the extent of spatial genetic structure in plant populations. Another factor that can contribute to this pattern is clonal growth. The perennial species Arabidopsis lyrata ssp. petraea (Brassicaceae) is a self-incompatible, clonal species found in disjunctive populations in central and northern Europe. Methods Fourteen microsatellite markers were employed to study the level of kinship and clonality in a high-altitude mountain valley at Spiterstulen, Norway. The population has a continuous distribution along the banks of the River Visa for about 1·5 km. A total of 17 (10 m × 10 m) squares were laid out in a north–south transect following the river on both sides. Key Results It is shown that clonal growth is far more common than previously shown in this species, although the overall size of the genets is small (mean diameter = 6·4 cm). Across the whole population there is no indication of isolation by distance, and spatial genetic structure is only visible on fine spatial scales. In addition, no effect of the river on the spatial distribution of genotypes was found. Conclusions Unexpectedly, the data show that populations of small perennials like A. lyrata can behave like panmictic units across relatively large areas at local sites, as opposed to earlier findings in central Europe.

Lundemo, Sverre; Sten?ien, Hans K.; Savolainen, Outi

2010-01-01

387

Internet Sexualities  

NASA Astrophysics Data System (ADS)

The term “internet sexuality” (or OSA, online sexual activities) refers to sexual-related content and activities observable on the internet (cf. Adams, Oye, & Parker, 2003; Cooper, McLoughlin, & Campbell, 2000; Leiblum & Döring, 2002). It designates a variety of sexual phenomena (e.g., pornography, sex education, sexual contacts) related to a wide spectrum of online services and applications (e.g., websites, online chat rooms, peer-to-peer networks). If an even broader range of computer networks - such as the Usenet or bulletin board systems - is included in this extensional definition, one speaks of “online sexuality” or “cybersexuality.”

Döring, Nicola

388

Climatically driven synchrony of gerbil populations allows large-scale plague outbreaks.  

PubMed

In central Asia, the great gerbil (Rhombomys opimus) is the main host for the bacterium Yersinia pestis, the cause of bubonic plague. In order to prevent plague outbreaks, monitoring of the great gerbil has been carried out in Kazakhstan since the late 1940s. We use the resulting data to demonstrate that climate forcing synchronizes the dynamics of gerbils over large geographical areas. As it is known that gerbil densities need to exceed a threshold level for plague to persist, synchrony in gerbil abundance across large geographical areas is likely to be a condition for plague outbreaks at similar large scales. Here, we substantiate this proposition through autoregressive modelling involving the normalized differentiated vegetation index as a forcing covariate. Based upon predicted climate changes, our study suggests that during the next century, plague epizootics may become more frequent in central Asia. PMID:17550884

Kausrud, Kyrre Linné; Viljugrein, Hildegunn; Frigessi, Arnoldo; Begon, Mike; Davis, Stephen; Leirs, Herwig; Dubyanskiy, Vladimir; Stenseth, Nils Chr

2007-08-22

389

Population.  

ERIC Educational Resources Information Center

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,…

International Planned Parenthood Federation, London (England).

390

Private sexual behavior, public opinion, and public health policy related to sexually transmitted diseases: a US-British comparison.  

PubMed Central

OBJECTIVES: The purpose of this study was to characterize sexual behavior and opinions about sex in the United States and Britain; implications are discussed for effective public health policy regarding sexually transmitted diseases (STDs) in the United States. METHODS: Large-scale national probability surveys conducted in the 2 countries detailed sexual behavior, opinions, and the prevalence of STDs. RESULTS: In comparison with that of Britain, the US population has greater variability in sexual behavior, less tolerant opinions about sexual behavior, and a higher STD prevalence and lower condom usage among men. CONCLUSIONS: The survey data show compelling evidence from both countries of a strong association between number of sex partners and STD risk. In the United States relative to Britain, there is both greater dispersion in sexual behavior and a greater incidence of unconditional opposition to certain sexual practices. The former implies a need for strong public health policy to address the risks of STDs, but the latter implies strong opposition to that policy. This disjuncture between public health need and feasibility may contribute to the high US rate of STDs.

Michael, R T; Wadsworth, J; Feinleib, J; Johnson, A M; Laumann, E O; Wellings, K

1998-01-01

391

Large-scale aerial images capture details of invasive plant populations  

Technology Transfer Automated Retrieval System (TEKTRAN)

Satellite and aerial remote sensing have been successfully used to measure invasive weed infestations over very large areas, but have limited resolution. Ground-based methods have provided detailed measurements of invasive weeds, but can measure only limited areas. Here we test a novel approach th...

392

A Population of Gamma-Ray Millisecond Pulsars Seen with the Fermi Large Area Telescope  

Microsoft Academic Search

Pulsars are born with subsecond spin periods and slow by electromagnetic braking for several tens of millions of years, when detectable radiation ceases. A second life can occur for neutron stars in binary systems. They can acquire mass and angular momentum from their companions, to be spun up to millisecond periods and begin radiating again. We searched Fermi Large Area

A. A. Abdo; M. Ackermann; M. Ajello; W. B. Atwood; M. Axelsson; L. Baldini; J. Ballet; G. Barbiellini; M. G. Baring; D. Bastieri; B. M. Baughman; K. Bechtol; R. Bellazzini; B. Berenji; G. F. Bignami; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; J. Bregeon; A. Brez; M. Brigida; P. Bruel; T. H. Burnett; G. A. Caliandro; R. A. Cameron; F. Camilo; P. A. Caraveo; P. Carlson; J. M. Casandjian; C. Cecchi; Ö. Çelik; E. Charles; A. Chekhtman; C. C. Cheung; J. Chiang; S. Ciprini; R. Claus; I. Cognard; J. Cohen-Tanugi; L. R. Cominsky; J. Conrad; R. Corbet; S. Cutini; C. D. Dermer; G. Desvignes; A. de Angelis; A. de Luca; F. de Palma; S. W. Digel; M. Dormody; E. do Couto e Silva; P. S. Drell; R. Dubois; D. Dumora; Y. Edmonds; C. Farnier; C. Favuzzi; S. J. Fegan; W. B. Focke; M. Frailis; P. C. C. Freire; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; B. Giebels; N. Giglietto; F. Giordano; T. Glanzman; G. Godfrey; I. A. Grenier; M. H. Grondin; J. E. Grove; L. Guillemot; S. Guiriec; Y. Hanabata; A. K. Harding; M. Hayashida; E. Hays; G. Hobbs; R. E. Hughes; G. Jóhannesson; A. S. Johnson; R. P. Johnson; T. J. Johnson; W. N. Johnson; S. Johnston; T. Kamae; H. Katagiri; J. Kataoka; N. Kawai; M. Kerr; J. Knödlseder; M. L. Kocian; M. Kramer; M. Kuss; J. Lande; L. Latronico; M. Lemoine-Goumard; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; G. M. Madejski; A. Makeev; R. N. Manchester; M. N. Mazziotta; W. McConville; J. E. McEnery; M. A. McLaughlin; C. Meurer; P. F. Michelson; W. Mitthumsiri; T. Mizuno; A. A. Moiseev; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; P. L. Nolan; J. P. Norris; E. Nuss; T. Ohsugi; N. Omodei; E. Orlando; J. F. Ormes; D. Paneque; J. H. Panetta; D. Parent; V. Pelassa; M. Pesce-Rollins; F. Piron; T. A. Porter; S. Rainň; R. Rando; S. M. Ransom; P. S. Ray; M. Razzano; N. Rea; A. Reimer; O. Reimer; T. Reposeur; S. Ritz; L. S. Rochester; A. Y. Rodriguez; R. W. Romani; M. Roth; F. Ryde; H. F. W. Sadrozinski; D. Sanchez; A. Sander; P. M. Saz Parkinson; J. D. Scargle; T. L. Schalk; C. Sgrň; E. J. Siskind; D. A. Smith; P. D. Smith; G. Spandre; P. Spinelli; B. W. Stappers; J. L. Starck; E. Striani; M. S. Strickman; D. J. Suson; H. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; G. Theureau; D. J. Thompson; S. E. Thorsett; L. Tibaldo; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. L. Usher; A. Van Etten; V. Vasileiou; C. Venter; N. Vilchez; V. Vitale; A. P. Waite; E. Wallace; P. Wang; K. Watters; N. Webb; P. Weltevrede; B. L. Winer; K. S. Wood; T. Ylinen; M. Ziegler

2009-01-01

393

Development of large engineered cartilage constructs from a small population of cells.  

PubMed

Confronted with articular cartilage's limited capacity for self-repair, joint resurfacing techniques offer an attractive treatment for damaged or diseased tissue. Although tissue engineered cartilage constructs can be created, a substantial number of cells are required to generate sufficient quantities of tissue for the repair of large defects. As routine cell expansion methods tend to elicit negative effects on chondrocyte function, we have developed an approach to generate phenotypically stable, large-sized engineered constructs (?3 cm(2) ) directly from a small amount of donor tissue or cells (as little as 20,000 cells to generate a 3 cm(2) tissue construct). Using rabbit donor tissue, the bioreactor-cultivated constructs were hyaline-like in appearance and possessed a biochemical composition similar to native articular cartilage. Longer bioreactor cultivation times resulted in increased matrix deposition and improved mechanical properties determined over a 4 week period. Additionally, as the anatomy of the joint will need to be taken in account to effectively resurface large affected areas, we have also explored the possibility of generating constructs matched to the shape and surface geometry of a defect site through the use of rapid-prototyped defect tissue culture molds. Similar hyaline-like tissue constructs were developed that also possessed a high degree of shape correlation to the original defect mold. Future studies will be aimed at determining the effectiveness of this approach to the repair of cartilage defects in an animal model and the creation of large-sized osteochondral constructs. PMID:23197468

Brenner, Jillian M; Kunz, Manuela; Tse, Man Yat; Winterborn, Andrew; Bardana, Davide D; Pang, Stephen C; Waldman, Stephen D

2013-01-17

394

Holocene artiodactyl population histories and large game hunting in the Wyoming Basin, USA  

Microsoft Academic Search

Regional paleoenvironmental reconstructions and data on artiodactyl response to climate change suggest that large game densities would have expanded during the late Holocene in the Wyoming Basin. Within this context, we use the prey model of foraging theory to predict a late Holocene increase in the hunting of artiodactyls, relative to lagomorphs and rodents. This prediction is then tested against

David A. Byers; Craig S. Smith; Jack M. Broughton

2005-01-01

395

Large-scale Aerial Images Capture Details of Invasive Plant Populations  

Microsoft Academic Search

Satellite and high-altitude aerial remote sensing have been used to measure dense infestations of invasive weeds over very large areas but have limited resolution and cannot be used to detect sparsely distributed weeds. Ground-based methods have provided detailed measurements of invasive weeds but can measure only limited areas. Here we test a novel approach that uses a lightweight airplane, flying

Dana Blumenthal; D. Terrence Booth; Samuel E. Cox; Cara E. Ferrier

2007-01-01

396

Mechanisms that control bacterial populations in continuous-flow culture models of mouse large intestinal flora.  

PubMed

A previous study had established that anaerobic continuous-flow (CF) cultures of conventional mouse cecal flora were able to maintain the in vivo ecological balance among the indigenous bacterial species tested. This paper describes experiments designed to determine the mechanisms which control the population sizes of these species in such CF cultures. One strain each of Escherichia coli, Fusobacterium sp., and Eubacterium sp. were studied. Growth of these strains in filtrates of CF cultures was considerably more rapid than in the CF cultures themselves, indicating that the inhibitory activity had been lost in the process of filtration. Growth rates to match those in CF cultures could be obtained, however, by restoring the original levels of H(2)S in the culture filtrates. The inhibitory effect of H(2)S in filtrates and in dialysates of CF cultures could be abolished by adding glucose or pyruvate, but not formate or lactate. The fatty acids present in CF cultures matched those in the cecum of conventional mice in both quality and concentration. These acids could not account for the slow rates of growth of the tested strains in CF cultures, but they did cause a marked increase in the initial lag phase of E. coli growth. The results obtained are compatible with the hypothesis that the populations of most indigenous intestinal bacteria are controlled by one or a few nutritional substrates which a given strain can utilize most efficiently in the presence of H(2)S and at the prevailing conditions of pH and anaerobiosis. This hypothesis consequently implies that the populations of enterobacteria, such as the E. coli strain tested, and those of the predominant anaerobes are controlled by analogous mechanisms. PMID:6339388

Freter, R; Brickner, H; Botney, M; Cleven, D; Aranki, A

1983-02-01

397

Sexual diversity in urban Norwegians.  

PubMed

The purpose of this study is to describe homosexual and heterosexual experiences in terms of sexual fantasies, sexual attraction, sexual conduct, and falling in love in an urban Norwegian population. In 1997, a random sample of 5,000 persons (18-49 years) was drawn from the population register in Oslo to participate in a sexual behavior survey. Data collection was carried out by means of postal questionnaires and 45% responded. The results indicated that exclusive homosexuality was rare in the population. One exception was the prevalence of homosexual fantasies in women. Compared to respondents who had had exclusively heterosexual contact, respondents reporting bisexual contacts had a significantly higher number of lifetime sex partners, higher frequency of anal and oral sex and masturbation, and lower age at orgasm and masturbation debut. What significantly separated the groups of exclusive heterosexuals, bisexuals, and exclusive homosexuals were attitudes towards various expressions of sexuality and number of lifetime sex partners. PMID:12545407

Traeen, Bente; Stigum, Hein; Sřorensen, Dagfinn

2002-11-01

398

Determining the role of correlated firing in large populations of neurons using white noise and natural scene stimuli.  

PubMed

The role of correlated firing in representing information has been a subject of much discussion. Several studies in retina, visual cortex, somatosensory cortex, and motor cortex, have suggested that it plays only a minor role, carrying <10% of the total information carried by the neurons (Gawne & Richmond, 1993; Nirenberg et al., 2001; Oram et al., 2001; Petersen, Panzeri, & Diamond, 2001; Rolls et al., 2003). A limiting factor of these studies, however, is that they were carried out using pairs of neurons; how the results extend to large populations was not clear. Recently, new methods for modeling network firing patterns have been developed (Nirenberg & Pandarinath, 2012; Pillow et al., 2008), opening the door to answering this question for more complete populations. One study, Pillow et al. (2008), showed that including correlations increased information by a modest amount, ~20%; however, this work used only a single retina (primate) and a white noise stimulus. Here we performed the analysis using several retinas (mouse) and both white noise and natural scene stimuli. The results showed that correlations added little information when white noise stimuli were used (~13%), similar to Pillow et al.'s findings, and essentially no information when natural scene stimuli were used. Further, the results showed that ignoring correlations did not change the quality of the information carried by the population (as measured by comparing the full pattern of decoding errors). These results suggest generalization: the pairwise analysis in several species show that correlations account for very little of the total information. Now, the analysis with large populations in two species show a similar result, that correlations still account for only a small fraction of the total information, and, most significantly, the amount is not statistically significant when natural stimuli are used, making rapid advances in the study of population coding possible. PMID:22885035

Meytlis, Marsha; Nichols, Zachary; Nirenberg, Sheila

2012-08-03

399

Serum levels of the hepcidin-20 isoform in a large general population: The Val Borbera study?  

PubMed Central

Hepcidin, a 25 amino-acid liver hormone, has recently emerged as the key regulator of iron homeostasis. Proteomic studies in limited number of subjects have shown that biological fluids can also contain truncated isoforms, whose role remains to be elucidated. We report, for the first time, data about serum levels of the hepcidin-20 isoform (hep-20) in a general population, taking advantage of the Val Borbera (VB) study where hepcidin-25 (hep-25) was measured by SELDI-TOF-MS. Detectable amount of hep-20 were found in sera from 854 out of 1577 subjects (54.2%), and its levels were about 14% of hep-25 levels. A small fraction of subjects (n = 30, 1.9%) had detectable hep-20 but undetectable hep-25. In multivariate regression models, significant predictors of hep-20 were hep-25 and age in males, and hep-25, age, serum ferritin and body mass index in females. Of note, the hep-25:hep-20 ratio was not constant in the VB population, but increased progressively with increasing ferritin levels. This is not consistent with the simplistic view of hep-20 as a mere catabolic byproduct of hep-25. Although a possible active regulation of hep-20 production needs further confirmation, our results may also have implications for immunoassays for serum hepcidin based on antibodies lacking specificity for hep-25. This article is part of a Special Issue entitled: Integrated omics.

Campostrini, Natascia; Traglia, Michela; Martinelli, Nicola; Corbella, Michela; Cocca, Massimiliano; Manna, Daniele; Castagna, Annalisa; Masciullo, Corrado; Silvestri, Laura; Olivieri, Oliviero; Toniolo, Daniela; Camaschella, Clara; Girelli, Domenico

2012-01-01

400

Associations of Psoriatic Arthritis and Cardiovascular Conditions in a Large Population  

PubMed Central

Purpose: We studied the hypothesis that possibly via shared inflammatory mechanisms, psoriatic arthritis (PsA) is associated with increased prevalence of cardiovascular (CV) conditions. Methods: Among a multiethnic population of 76,465 men and women with known demographics, we studied all persons (n = 99) with confirmed outpatient diagnoses of PsA. Associations of PsA with CV diagnoses were studied in the entire population by logistic regression with six covariates. With two matched control study subjects for each study subject with PsA, selected risk traits for CV conditions at time of PsA diagnosis were compared with findings on t-tests. Results: Study subjects with PsA did not exhibit more atherothrombotic disease (coronary and cerebrovascular) or diabetes mellitus but had increased prevalence of systemic hypertension and heart failure compared with study control subjects. In the case-control analysis, study subjects with PsA had a lower mean blood cholesterol, a higher mean body mass index, and a higher mean blood pressure compared with study control subjects; mean blood glucose was similar in both groups. Conclusions: In this analysis the associations of PsA with CV risk factors and CV conditions are mixed. Except for increased systemic hypertension, it is unclear whether PsA is related to higher prevalence of CV disease.

Kondratiouk, Svetlana; Udaltsova, Natalia; Klatsky, Arthur L

2008-01-01