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1

Sexual selection hinders adaptation in experimental populations of yeast  

PubMed Central

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

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

2013-01-01

2

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

3

Detecting sexually antagonistic coevolution with population crosses.  

PubMed Central

The result of population crosses on traits such as mating rate, oviposition rate and survivorship are increasingly used to distinguish between modes of coevolution between the sexes. Two key hypotheses, erected from a verbal theory of sexually antagonistic coevolution, have been the subject of several recent tests. First, statistical interactions arising in population crosses are suggested to be indicative of a complex signal/receiver system. In the case of oviposition rates, an interaction between populations (x, y and z) would be indicated by the rank order of female oviposition rates achieved by x, y and z males changing depending upon the female (x, y or z) with which they mated. Second, under sexually antagonistic coevolution females will do 'best' when mated with their own males, where best is defined by the weakest response to the signal and the highest fitness. We test these hypotheses by crossing strains generated from a formal model of sexually antagonistic coevolution. Strains differ in the strength of natural selection acting on male and female traits. In our model, we assume sexually antagonistic coevolution of a single male signal and female receptor. The female receptor is treated as a preference function where both the slope and intercept of the function can evolve. Our results suggest that neither prediction is consistently supported. Interactions are not diagnostic of complex signal-receiver systems, and even under sexually antagonistic coevolution, females may do better mating with males of strains other than their own. These results suggest a reinterpretation of several recent experiments and have important implications for developing theories of speciation when sexually antagonistic coevolution is involved. PMID:14561288

Rowe, Locke; Cameron, Erin; Day, Troy

2003-01-01

4

Sexual compulsivity scale: adaptation and validation in the spanish population.  

PubMed

Sexual compulsivity has been studied in relation to high-risk behavior for sexually transmitted infections. The aim of this study was the adaptation and validation of the Sexual Compulsivity Scale to a sample of Spanish young people. This scale was applied to 1,196 (891 female, 305 male) Spanish college students. The results of principal components factor analysis using a varimax rotation indicated a two-factor solution. The reliability of the Sexual Compulsivity Scale was found to be high. Moreover, the scale showed good temporal stability. External correlates were examined through Pearson correlations between the Sexual Compulsivity Scale and other constructs related with HIV prevention. The authors' results suggest that the Sexual Compulsivity Scale is an appropriate measure for assessing sexual compulsivity, showing adequate psychometric properties in the Spanish population. PMID:23631692

Ballester-Arnal, Rafael; Gómez-Martínez, Sandra; Llario, M Dolores-Gil; Salmerón-Sánchez, Pedro

2013-01-01

5

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

PubMed Central

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

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

2009-01-01

6

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

2013-11-01

7

Sexually-transmitted disease risk in a Micronesian atoll population.  

PubMed

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

Brewis, A A

1992-10-01

8

Mutator dynamics in sexual and asexual experimental populations of yeast  

Microsoft Academic Search

Background  In asexual populations, mutators may be expected to hitchhike with associated beneficial mutations. In sexual populations,\\u000a recombination is predicted to erode such associations, inhibiting mutator hitchhiking. To investigate the effect of recombination\\u000a on mutators experimentally, we compared the frequency dynamics of a mutator allele (msh2?) in sexual and asexual populations of Saccharomyces cerevisiae.\\u000a \\u000a \\u000a \\u000a \\u000a Results  Mutator strains increased in frequency at the

Yevgeniy Raynes; Matthew R Gazzara; Paul D Sniegowski

2011-01-01

9

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

2008-07-01

10

Simulation for Competition of Languages with AN Aging Sexual Population  

Microsoft Academic Search

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

Veit Schwämmle

2005-01-01

11

Are Eukaryotic Microorganisms Clonal or Sexual? A Population Genetics Vantage  

Microsoft Academic Search

We argue that the mode of reproduction of microorganisms in nature can only be decided by population genetic information. The evidence available indicates that many parasitic protozoa and unicellular fungi have clonal rather than sexual population structures, which has major consequences for medical research and practice. Plasmodium falciparum, the agent of malaria, is a special case: the scarce evidence available

Michel Tibayrenc; Finn Kjellberg; Jacques Arnaud; Bruno Oury; S. Frederique Breniere; Marle-Laure Darde; Francisco J. Ayala

1991-01-01

12

Population genetic structure of sexual and parthenogenetic damselflies inferred from mitochondrial and nuclear markers  

PubMed Central

It has been postulated that obligate asexual lineages may persist in the long term if they escape from negative interactions with either sexual lineages or biological enemies; and thus, parthenogenetic populations will be more likely to occur in places that are difficult for sexuals to colonize, or those in which biological interactions are rare, such as islands or island-like habitats. Ischnura hastata is the only known example of natural parthenogenesis within the insect order Odonata, and it represents also a typical example of geographic parthenogenesis, as sexual populations are widely distributed in North America, whereas parthenogenetic populations of this species have only been found at the Azores archipelago. In order to gain insight in the origin and distribution of parthenogenetic I. hastata lineages, we have used microsatellites, mitochondrial and nuclear DNA sequence data, to examine the population genetic structure of this species over a wide geographic area. Our results suggest that sexual populations of I. hastata in North America conform to a large subdivided population that has gone through a recent spatial expansion. A recent single long distance dispersal event, followed by a demographic expansion, is the most parsimonious hypothesis explaining the origin of the parthenogenetic population of this species in the Azores islands. PMID:21915148

Lorenzo-Carballa, M O; Hadrys, H; Cordero-Rivera, A; Andres, J A

2012-01-01

13

Population genetic structure of sexual and parthenogenetic damselflies inferred from mitochondrial and nuclear markers.  

PubMed

It has been postulated that obligate asexual lineages may persist in the long term if they escape from negative interactions with either sexual lineages or biological enemies; and thus, parthenogenetic populations will be more likely to occur in places that are difficult for sexuals to colonize, or those in which biological interactions are rare, such as islands or island-like habitats. Ischnura hastata is the only known example of natural parthenogenesis within the insect order Odonata, and it represents also a typical example of geographic parthenogenesis, as sexual populations are widely distributed in North America, whereas parthenogenetic populations of this species have only been found at the Azores archipelago. In order to gain insight in the origin and distribution of parthenogenetic I. hastata lineages, we have used microsatellites, mitochondrial and nuclear DNA sequence data, to examine the population genetic structure of this species over a wide geographic area. Our results suggest that sexual populations of I. hastata in North America conform to a large subdivided population that has gone through a recent spatial expansion. A recent single long distance dispersal event, followed by a demographic expansion, is the most parsimonious hypothesis explaining the origin of the parthenogenetic population of this species in the Azores islands. PMID:21915148

Lorenzo-Carballa, M O; Hadrys, H; Cordero-Rivera, A; Andrés, J A

2012-04-01

14

Population genetic consequences of extreme variation in sexual and clonal reproduction in an aquatic plant.  

PubMed

Most plants combine sexual reproduction with asexual clonal reproduction in varying degrees, yet the genetic consequences of reproductive variation remain poorly understood. The aquatic plant Butomus umbellatus exhibits striking reproductive variation related to ploidy. Diploids produce abundant viable seed whereas triploids are sexually sterile. Diploids also produce hundreds of tiny clonal bulbils, whereas triploids exhibit only limited clonal multiplication through rhizome fragmentation. We investigated whether this marked difference in reproductive strategy influences the diversity of genotypes within populations and their movement between populations by performing two large-scale population surveys (n = 58 populations) and assaying genotypic variation using random amplified polymorphic DNA (RAPDs). Contrary to expectations, sexually fertile populations did not exhibit higher genotypic diversity than sterile populations. For each cytotype, we detected one very common and widespread genotype. This would only occur with a very low probability (< 10-7) under regular sexual recombination. Compatibility analysis also indicated that the pattern of genotypic variation largely conformed to that expected with predominant clonal reproduction. The potential for recombination in diploids is not realized, possibly because seeds are outcompeted by bulbils for safe sites during establishment. We also failed to find evidence for more extensive movement of fertile than sterile genotypes. Aside from the few widespread genotypes, most were restricted to single populations. Genotypes in fertile populations were very strongly differentiated from those in sterile populations, suggesting that new triploids have not arisen during the colonization of North America. The colonization of North America involves two distinct forms of B. umbellatus that, despite striking reproductive differences, exhibit largely clonal population genetic structures. PMID:12535085

Eckert, Christopher G; Lui, Keiko; Bronson, Kelly; Corradini, Pierre; Bruneau, Anne

2003-02-01

15

Natural and sexual selection in a monogamous historical human population  

E-print Network

those applying evolutionary theory in humans, some scientists consider recent selective pressures weakNatural and sexual selection in a monogamous historical human population Alexandre Courtiola,b,c,1, Cambridge, MA, and approved March 28, 2012 (received for review November 4, 2011) Whether and how human

Lummaa, Virpi

16

Increasing access by priority populations to Australian sexual health clinics.  

PubMed

Data from a network of 35 Australian sexual health clinics, in geographically diverse locations, showed that the number and proportion of patients from priority populations (ie, young people, men who have sex with men, indigenous people, and female sex workers) increased significantly between 2004 and 2011. PMID:24275736

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

2013-10-01

17

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

18

Sexual behaviour and condom use as a protection against sexually transmitted infections in student population.  

PubMed

The aim of the study was to determine the differences in sexual behaviour and condom use as a protection against sexually transmitted infections (STI) between the first-year and the last-year students. Data were collected by filling anonymous and consented questionnaire in June of 2011 at University of Josip Juraj Strossmayer in Osijek, Croatia. Out of 857 students in the planned sample, 462 (53.9%) filled out the questionnaire, and 353/462 (76.4%) were sexually active. Data from sexually active students were processed and statistically significant results between first-year and the last-year students were presented. Studied sample consisted of 192/353 (54.4%) first-year students and 161/353 (45.6%) last-year students. Average age of sexual initiation for the first-year students was 17.28 +/- 1.29 years, a for the last-year students 18.45 +/- 2.14 years, and the difference is significant (Man-Whitney test = 10335.00, p < 0.01). First-year students have lower number of sexual partners (chi2 = 28.005, p < 0.01), during relationship they had lower number of intercourses with the third person (2 = 17.947, p < 0.01), and feel that lower number of their friends were already sexually active at the time of their own sexual initiation (chi2 = 18.350, p < 0.01). First-year students more often inform their partners about existing or previous STI (chi2 = 14.476, p < 0.01) and curiosity significantly influenced their decision regarding sexual initiation (chi2 = 8.689, p < 0.05). First-year students more often used condom at their first sexual intercourse (chi2 = 7.275, p < 0.01), and more rarely used withdrawal (chi2 = 6.380, p < 0.05). At their last sexual intercourse, first-year students more often used any kind of protection (chi2 = 3.853, p < 0.05),more often used condom (chi2 = 11.110, p < 0.01) and withdrawal (chi2 = 5.156, p < 0.05), and more rarely used contraceptive pills (chi2 = 4.405, p < 0.05). First-year students more often use condom in a permanent relationship (chi2 = 13.384, p < 0.05), and also plan to use it during following intercourse in the permanent relationship (chi2 = 17.575, p < 0.01). Growing condom use and decreasing risky sexual behaviour among students, as well as other adolescents and young adults needs to be maintained. Youth should learn before sexual initiation that only correct condom use at every sexual intercourse protects them against STI and human immunodeficiency virus (HIV). Sexual education and STI/HIV prevention programmes, positive role of media (television) and civil organisations that communicate with the youth can help that. Such changes among adolescents and young adults should have to be seen in student population as well. PMID:24851594

Dijani?, Tomislav; Kozul, Karlo; Miskulin, Maja; Medi?, Alan; Jurcev-Savicevi?, Anamarija; Burazin, Jelena

2014-03-01

19

Simulation for competition of languages with an ageing sexual population  

E-print Network

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 ageing 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

2005-01-01

20

Population variation in second metacarpal sexual size dimorphism.  

PubMed

This paper contrasts levels of sexual size dimorphism in second metacarpal osteometric and geometric morphology in two bioculturally distinctive populations: 19th century Euro-Canadian settlers, and proto/historic central Canadian Inuit. Significant within-group sexual size dimorphism is found for all variables, though few show significant interpopulation differences. However, in every case the Euro-Canadian sample is more dimorphic than the Inuit sample. Notably, differences reside in geometric measures (total area, Imax) sensitive to variation in functional strain, and thus are interpretable in light of proximate causal models, i.e., activity profiles distinct from generalized mode of subsistence. Other proximate factors, such as nutritional stress acting to diminish Inuit sexual size dimorphism, may also play a role. However, models often cited to explain dimorphism, such as marriage practice (e.g., polygyny) or division of labor situated in mode of subsistence, do not. The higher sexual size dimorphism in the 19th century settler sample belies the notion that technological progress inevitably leads to reduced dimorphism. PMID:12124917

Lazenby, Richard A

2002-08-01

21

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

ERIC Educational Resources Information Center

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

de la Vega, Ernesto

1990-01-01

22

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. PMID:23227145

Dmitriew, Caitlin; Blanckenhorn, Wolf U.

2012-01-01

23

Age at sexual initiation and number of sexual partners in the female Spanish population Results from the AFRODITA survey  

Microsoft Academic Search

Objectives: The AFRODITA study was designed to describe patterns relating to the number of lifetime sexual partners (SP) and age at first sexual intercourse (AFSI) by geographic region in a representative sample of Spanish women. Study design: A representative sample of the female Spanish population was obtained using the Access Panel Technique. Postal questionnaires were sent to 11,086 women aged

Silvia de Sanjose; Xavier Cortes; Cristina Mendez; Lluis Puig-Tintore; Aureli Torned; Esther Roura; F. Xavier Bosch; Xavier Castellsague

2008-01-01

24

Adolescent sexuality in Asia: new focus for population policy.  

PubMed

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

Robey, B

1989-09-01

25

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

2013-01-01

26

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

27

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

28

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

2011-01-01

29

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 Långström

2010-01-01

30

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

31

Population generation for large-scale simulation  

NASA Astrophysics Data System (ADS)

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

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

2005-05-01

32

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

PubMed Central

BACKGROUND This study examines the prevalence of vaginal, oral, and anal inter-course among a population of urban, public middle school students, the characteristics of early sexual initiators, and the sequence of sexual initiation. Such data are limited for early adolescents. METHODS A total of 1279 seventh-grade students (57.3% female, 43.6% black, and 41.8% Hispanic), mean age 12.5 years (SD = 0.63) from 10 middle schools in a large southeastern US public school district completed a cross-sectional survey using audio computer-assisted self-interviews. Main outcomes included lifetime and past 3-months’ experience of vaginal, oral, and anal sex; condom use; age of initiation; and number of lifetime partners. RESULTS Overall, 12.0% of students had engaged in vaginal sex, 7.9% in oral sex, and 6.5% in anal sex. Among students who had initiated intercourse, approximately two thirds were currently sexually active and one quarter reported ?4 lifetime partners. Six percent had engaged in 1 type of intercourse, 4% in 2 types of intercourse, and 4% in all 3 types of intercourse; vaginal sex was typically initiated at an earlier or at the same age as other types of intercourse. Only 2% had engaged in oral sex without engaging in vaginal sex. Although black students were significantly more likely to have initiated sex compared to other racial/ethnic groups, Hispanic students who had initiated each type of intercourse were more likely to be currently sexually active and to have engaged in recent unprotected sex. CONCLUSIONS A small percentage of early adolescents are engaging in multiple sexual behaviors. These findings have implications for early adolescent school-based sexual health education. PMID:19292852

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

2010-01-01

33

Sexual Reproduction in a Simple Growth Population Model  

NASA Astrophysics Data System (ADS)

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

Lemos, Carlos Gentil Oro; Santos, Marcio

2012-05-01

34

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. PMID:21512945

Frost, David M.; Meyer, Ilan H.

2011-01-01

35

A Lotka-Volterra Model of Coexistence between a Sexual Population and Multiple Asexual Clones  

Microsoft Academic Search

At carrying capacity, small advantages in competitive ability can compensate a sexual population for its two-fold disadvantage in growth capacity when facing invasion by asexual mutants. In this paper, we develop a generic analytical model to consider the ecology of a sexual population comprising equal numbers of males and females, competing for shared prey resources with multiple female-only clones. We

Graeme E. Poundw; C. Patrick Doncaster; Simon J. Coxw

2002-01-01

36

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

PubMed Central

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

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

2013-01-01

37

Infection dynamics in coexisting sexual and asexual host populations: support for the Red Queen hypothesis.  

PubMed

The persistence of sexual reproduction is a classic problem in evolutionary biology. The problem stems from the fact that, all else equal, asexual lineages should rapidly replace coexisting sexual individuals due to the cost of producing males in sexual populations. One possible countervailing advantage to sexual reproduction is that, on average, outcrossed offspring are more resistant than common clones to coevolving parasites, as predicted under the Red Queen hypothesis. In this study, we evaluated the prevalence of infection by a sterilizing trematode (Microphallus sp.) in a natural population of freshwater snails that was composed of both sexual and asexual individuals (Potamopyrgus antipodarum). More specifically, we compared the frequency of infection in sexual and asexual individuals over a 5-year period at four sites at a natural glacial lake (Lake Alexandrina, South Island, New Zealand). We found that at most sites and over most years, the sexual population was less infected than the coexisting asexual population. Moreover, the frequency of uninfected sexual females was periodically greater than two times the frequency of uninfected asexual females. These results give clear support for a fluctuating parasite-mediated advantage to sexual reproduction in a natural population. PMID:25061675

Vergara, Daniela; Jokela, Jukka; Lively, Curtis M

2014-08-01

38

The realized effect of postpollination sexual selection in a natural plant population.  

PubMed Central

The ultimate importance of postpollination sexual selection has remained elusive, largely because of the difficulty of assigning paternity in the field. Here I use a powerful new molecular marker (AFLP) for paternity analysis in a natural population of the outcrossing angiosperm Persoonia mollis (Proteaceae) to assess male reproductive success following equal pollination of 15 pollen donors on each of 6310 pistils. These results were contrasted with male reproductive success of these same plants following natural mating. Following equal pollination, there was a significant departure from equal siring success, indicating a potential for postpollination sexual selection. The most successful pollen donor sired more than twice the expected number of seeds, and this was largely consistent across recipient plants. However, siring success following natural mating was significantly different from siring success following artificial pollination and showed that the reproductive gains to be made from superior pollen performance did not translate into increased reproductive success following natural mating. As the ecological context for post-pollination sexual selection is strong in P. mollis, I suggest that pollen competition may ultimately have only a weak effect on non-random male mating success under natural conditions because the realized opportunities for pollen competition within pistils are limited. PMID:11075703

Krauss, S L

2000-01-01

39

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

2013-09-24

40

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. PMID:24019480

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

2013-01-01

41

Ingestion rate decrease as the stimulus for sexuality in populations of Moina macrocopa  

Microsoft Academic Search

The stimulus for the switch from asexual to sexual reproduction in populations of Moina macrocopa americana is an abrupt decrease in ingestion rate caused by a rapid reduction in the amount of available food. When nearly constant ingestion rates are maintained, through the addition of either nutritive or nonnutritive particles, asexual females do not produce any male or sexual female

LOUIS R. D'ABRAMO

1980-01-01

42

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

ERIC Educational Resources Information Center

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

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

2009-01-01

43

Sexual size dimorphism in bighorn sheep ( Ovis canadensis ): effects of population density  

Microsoft Academic Search

Sexual dimorphism is an important characteristic of many mammals, but little is known about how environ- mental variables may affect its phenotypic expression. The relationships between population size, body mass, seasonal mass changes, and sexual mass dimorphism were investigated using 22 years of data on individually marked bighorn sheep (Ovis canadensis) on Ram Mountain, Alberta. The number of adult ewes

Mylène LeBlanc; Marco Festa-Bianchet; Jon T. Jorgenson

2001-01-01

44

Food choice behaviour may promote habitat specificity in mixed populations of clonal and sexual Potamopyrgus antipodarum  

Microsoft Academic Search

Genetic polymorphism along an environmental gradient may be maintained if disruptive selection on habitat-specific traits leads to a correlated response in traits that reduce gene flow between habitats. We studied a short-distance cline in a population of freshwater snails Potamopyrgus antipodarum in which sexual and clonal snails coexist. Sexuals and clones show a life history cline by depth: snails reproduce

Sonja Negovetic; Jukka Jokela

2000-01-01

45

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

46

Epidemiology of sexual dysfunction in the male population.  

PubMed

Sexual dysfunctions have found an increasing attention in recent epidemiological studies of the ageing male. The purpose of this paper is to review the prevalence of sexual dysfunctions and risk factors based on community samples. Studies have not only demonstrated a strong age-related incline of erectile dysfunction (ED), but also of ejaculatory and orgasmic disorders (particularly a reduced or absent ejaculation). Despite a declining sexual desire, sexual interest remains present in old age. Lower urinary tract symptoms have been identified as strong risk factors for ED along with cardiovascular, metabolic, psychiatric disorders and lifestyle factors. The wide range of prevalence rate estimates is likely because of different definitions and criteria of sexual dysfunctions. More research is needed on other dysfunctions besides ED and on the partner relationship as a major determinant of sexual activity and satisfaction. The interrelationship between risk factors calls for interdisciplinary prevention and treatment approaches. As disability-free life expectancy keeps increasing, the need to identify, adequately assess and treat male sexual dysfunction as an important impediment to quality of life most likely will become even more pressing. PMID:16872462

Beutel, M E; Weidner, W; Brähler, E

2006-08-01

47

Pattern of sexually transmitted diseases in a Malagasy population.  

PubMed

Between November 1992 and April 1993, interviews were conducted with 400 patients (169 men, 231 women) aged 14-52 years at the sexually transmitted disease (STD) clinic of the Institut d'Hygiene Sociale in Antananarivo, Madagascar, to determine the pattern of STDs and to improve treatment of the leading STDs. The 400 patients presented with 434 syndromes. 124 men had urethral discharge. 210 women had cervicovaginal discharge. 43 men and 18 women had genital ulcers. Clinicians could not establish a diagnosis in 33 patients. 171 patients had more than one infection. Chlamydia infection was the most common infection associated with another STD (gonorrhea in 22% of men and 11% of women with discharge, trichomoniasis in 2.4% of men and 13% of women, candidiasis in 1.6% of men and 9% of women, and bacterial vaginosis in 15% of women with discharge). Gonorrhea was the most common etiology for male discharge (69%) while chlamydia infection was for female discharge (52%). Women with discharge were more likely than men with discharge to have chlamydia infection (52% vs. 42%), trichomoniasis (30% vs. 9%; p 0.00001), and candidiasis (32% vs. 12%; p 0.00001). 37% of women with discharge had bacterial vaginosis. Chlamydia infection was the most common STD in this population (45%). 32% of male and 71% of female gonorrhea cases also had chlamydia infection. 70 patients had syphilis. 36 of them had secondary stage syphilis. No one had HIV-1 or HIV-2 infection. The most efficacious antibiotics for gonorrhea were ampicillin, ciprofloxacin, and spectinomycin (100% susceptibility). 31% and 26% of isolates were susceptible to tetracycline and cotrimoxazole, respectively. Public facilities in Madagascar do not have the capabilities to diagnosis chlamydia, resulting in many untreated chlamydia cases. These findings stress the need to improve combined treatment of gonorrhea and chlamydia infection and for educational efforts to increase awareness of genital ulcer disease. PMID:7871444

Harms, G; Matull, R; Randrianasolo, D; Andriamiadana, J; Rasamindrakotroka, A; Kirsch, T; Hof, U; Rarivoharilala, E; Korte, R

1994-01-01

48

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

PubMed

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

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

2014-02-01

49

Trends in High-Risk Sexual Behaviors among General Population Groups in China: A Systematic Review  

PubMed Central

Background The objective of this review was to investigate whether Chinese population groups that do not belong to classical high risk groups show an increasing trend of engaging in high-risk sexual behaviors. Methods We systematically searched the English and Chinese literature on sexual risk behaviors published between January 1980 and March 2012 in PubMed and the China National Knowledge Infrastructure (CNKI). We included observational studies that focused on population groups other than commercial sex workers (CSWs) and their clients, and men who have sex with men (MSM) and quantitatively reported one of the following indicators of recent high-risk sexual behavior: premarital sex, commercial sex, multiple sex partners, condom use or sexually transmitted infections (STIs). We used generalized linear mixed model to examine the time trend in engaging in high-risk sexual behaviors. Results We included 174 observational studies involving 932,931 participants: 55 studies reported on floating populations, 73 on college students and 46 on other groups (i.e. out-of-school youth, rural residents, and subjects from gynecological or obstetric clinics and premarital check-up centers). From the generalized linear mixed model, no significant trends in engaging in high-risk sexual behaviors were identified in the three population groups. Discussion Sexual risk behaviors among certain general population groups have not increased substantially. These groups are therefore unlikely to incite a STI/HIV epidemic among the general Chinese population. Because the studied population groups are not necessarily representative of the general population, the outcomes found may not reflect those of the general population. PMID:24236121

Cai, Rui; Richardus, Jan Hendrik; Looman, Caspar W. N.; de Vlas, Sake J.

2013-01-01

50

Sexual selection on song and cuticular hydrocarbons in two distinct populations of Drosophila montana  

PubMed Central

Sexual selection has the potential to contribute to population divergence and speciation. Most studies of sexual selection in Drosophila have concentrated on a single signaling modality, usually either courtship song or cuticular hydrocarbons (CHCs), which can act as contact pheromones. We have examined the relationship between both signal types and reproductive success using F1–3 offspring of wild-collected flies, raised in the lab. We used two populations of the Holarctic species Drosophila montana that represent different phylogeographic clades that have been separate for ca. 0.5 million years (MY), and differ to some extent in both traits. Here, we characterize the nature and identify the targets of sexual selection on song, CHCs, and both traits combined within the populations. Three measures of courtship outcome were used as fitness proxies. They were the probability of mating, mating latency, and the production of rejection song by females, and showed patterns of association with different traits that included both linear and quadratic selection. Courtship song predicted courtship outcome better than CHCs and the signal modalities acted in an additive rather than synergistic manner. Selection was generally consistent in direction and strength between the two populations and favored males that sang more vigorously. Sexual selection differed in the extent, strength, and nature on some of the traits between populations. However, the differences in the directionality of selection detected were not a good predictor of population differences. In addition, a character previously shown to be important for species recognition, interpulse interval, was found to be under sexual selection. Our results highlight the complexity of understanding the relationship between within-population sexual selection and population differences. Sexual selection alone cannot predict differences between populations. PMID:22408728

Veltsos, Paris; Wicker-Thomas, Claude; Butlin, Roger K; Hoikkala, Anneli; Ritchie, Michael G

2012-01-01

51

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

2012-06-01

52

Evolution of increased phenotypic diversity enhances population performance by reducing sexual harassment in damselflies.  

PubMed

The effect of evolutionary changes in traits and phenotypic/genetic diversity on ecological dynamics has received much theoretical attention; however, the mechanisms and ecological consequences are usually unknown. Female-limited colour polymorphism in damselflies is a counter-adaptation to male mating harassment, and thus, is expected to alter population dynamics through relaxing sexual conflict. Here we show the side effect of the evolution of female morph diversity on population performance (for example, population productivity and sustainability) in damselflies. Our theoretical model incorporating key features of the sexual interaction predicts that the evolution of increased phenotypic diversity will reduce overall fitness costs to females from sexual conflict, which in turn will increase productivity, density and stability of a population. Field data and mesocosm experiments support these model predictions. Our study suggests that increased phenotypic diversity can enhance population performance that can potentially reduce extinction rates and thereby influence macroevolutionary processes. PMID:25034518

Takahashi, Yuma; Kagawa, Kotaro; Svensson, Erik I; Kawata, Masakado

2014-01-01

53

Sexual Practices and Sexual Satisfaction: A Population Based Study of Chinese Urban Adults  

Microsoft Academic Search

This study examined sexual satisfaction and its social and behavioral correlates among urbanites aged 20–64 in China, using\\u000a data from a nationally representative sample of 1,194 women and 1,217 men with a spouse or other long-term sexual partner\\u000a with whom they had sex during the last year. The results from structural equation models suggest a multiplex set of determinants\\u000a of

William L. Parish; Ye Luo; Ross Stolzenberg; Edward O. Laumann; Gracia Farrer; Suiming Pan

2007-01-01

54

Studying allozyme variation in sexual and apomictic Taraxacum and Pilosella (Asteraceae) populations  

Microsoft Academic Search

Allozyme spectra of peroxidase, esterase, superoxid dismutase, tyrosinase, alcohol dehydrogenase, lactate dehydrogenase, and acid phosphatase were examined in populations of sexual (Taraxacum serotinum and Pilosella echioides) and apomictic (T. officinale and P. officinarum) plant species. The heterozygosity in these populations (0.455–0.620) proved to be considerably higher than the average level characteristic of plant populations (0.058–0.185). The populations examined did not

A. S. Kashin; V. E. Anfalov; Yu. A. Demochko

2005-01-01

55

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. PMID:15315900

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

2004-01-01

56

Sexual reproduction and population dynamics: the role of polygyny and demographic sex differences.  

PubMed Central

Most models of population dynamics do not take sexual reproduction into account (i.e., they do not consider the role of males). However, assumptions behind this practice--that no demographic sex differences exist and males are always abundant enough to fertilize all the females--are usually not justified in natural populations. On the contrary, demographic sex differences are common, especially in polygynous species. Previous models that consider sexual reproduction report a stabilizing effect through mixing of different genotypes, thus suggesting a decrease in the propensity for complex of dynamics in sexually reproducing populations. Here we show that considering the direct role of males in reproduction and density dependence leads to the conclusion that a two-sex model is not necessarily more stable compared with the corresponding one-sex model. Although solutions exist where sexual reproduction has a stabilizing effect even when no genotypic variability is included (primarily when associated with monogamy), factors like polygyny, sex differences in survival or density dependence, and possible alterations of the primary sex ratio (the Trivers-Willard mechanism), may enlarge the parametric region of complex dynamics. Sexual reproduction therefore does not necessarily increase the stability of population dynamics and can have destabilizing effects, at least in species with complicated mating systems and sexual dimorphism. PMID:9606132

Lindström, J; Kokko, H

1998-01-01

57

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

PubMed

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

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

2014-03-01

58

Sexual size dimorphism in bighorn sheep (Ovis canadensis): effects of population density  

E-print Network

Sexual size dimorphism in bighorn sheep (Ovis canadensis): effects of population density Myl�ne Le dimorphism were investigated using 22 years of data on individually marked bighorn sheep (Ovis canadensis individuelle des Mouflons d'Am�rique (Ovis canadensis) de la population de Ram Mountain, Alberta. Le nombre de

Festa-Bianchet, Marco

59

Pheromonally Mediated Sexual Isolation Among Denning Populations of Red-Sided Garter Snakes, Thamnophis sirtalis parietalis  

Microsoft Academic Search

Utilizing behavioral experiments and chemical analyses, we examined whether pheromonally mediated sexual isolation exists between denning populations of red-sided garter snakes (Thamnophis sirtalis parietalis) in Manitoba, Canada. Simultaneous choice tests conducted during the breeding season revealed that adult males from a hibernaculum in central Manitoba displayed a strong courtship preference for females from their own population over females from a

Michael P. LeMaster; Robert T. Mason

2003-01-01

60

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

61

Prevalence of sexual violence and posttraumatic stress disorder in an urban african-american population.  

PubMed

Sexual violence is prevalent nationally and contributes to psychopathology in the general population. Despite elevated traumatic event exposure among economically disadvantaged urban-dwelling African-Americans, there is insufficient information on lifetime sexual violence exposure and associated psychopathology in this population. In 2008-2009, 1,306 African-Americans from a Detroit household probability sample reported on lifetime rape and sexual assault and past-month and lifetime posttraumatic stress disorder (PTSD). Lifetime sexual violence prevalence was 26.3 % for women and 5.1 % for men. Relative to non-victims, sexual violence victims: reported more other traumatic events; had 4 times greater unadjusted odds of past-month and lifetime PTSD; had 1.6 times greater adjusted odds of lifetime PTSD only after controlling for other traumatic events. Sexual violence was associated with increased risk for lifetime PTSD and exposure to other traumas. Findings highlight a need to screen for sexual violence and PTSD among urban African-Americans. PMID:23686528

Walsh, Kate; Koenen, Karestan C; Aiello, Allison E; Uddin, Monica; Galea, Sandro

2014-12-01

62

Antagonism between sexual and natural selection in experimental populations of Saccharomyces cerevisiae.  

PubMed

Trade-offs between life-history components are a central concept of evolution and ecology. Sexual and natural selection seem particularly apt to impose antagonistic selective pressures. When sex is not integrated into reproduction, as in Saccharomyces cerevisiae, natural selection can impair or even eliminate it. In this study, a genetic trade-off between the sexual and asexual phases of the yeast life cycle was suggested by sharp declines in the mating and sporulation abilities of unrelated genotypes that were propagated asexually in minimal growth medium and in mice. When sexual selection was applied to populations that had previously evolved asexually, sexual fitness increased but asexual fitness declined. No such negative correlation was observed when sexual selection was applied to an ancestral strain: sexual and asexual fitness both increased. Thus, evolutionary history affected the evolution of genetic correlations, as fitness increases in a population already well adapted to the environment were more likely to come at the expense of sexual functions. PMID:16405156

Zeyl, Clifford; Curtin, Ciara; Karnap, Kristin; Beauchamp, Elspeth

2005-10-01

63

Sexual child abuse in a defined Swedish area 1993-97: a population-based survey.  

PubMed

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 referral bias, and minimal dependence on memory effects. The results are valid for the small proportion of cases that lead to conviction in the context of Swedish legislation. Structured data were collected from the court dossiers in all cases of sexual crimes against minors (less than 15 years of age) tried and sentenced at the courts in the Västra Götaland region of Sweden between 1993 and 1997. The total number of 496 sentences for sexual crimes during the study period included 203 cases of sexual child abuse (40.8%) with 283 victims and 196 perpetrators, all men. Girls were victims in 85% of the cases, boys in 12%, and boys as well as girls in 3%. Sexual penetration had occurred in 54.5% of cases and the total proportion of hands-on crimes was 83%. Most perpetrators, 72%, were well known to the child. The most severe offenses took place within the family. A wide range of acts were classified as sexual child abuse, but most common was sexual penetration of a female child by her biological father or a family friend. PMID:11501297

Carlstedt, A; Forsman, A; Soderstrom, H

2001-10-01

64

Allelic and genotypic diversity in long-term asexual populations of the pea aphid, Acyrthosiphon pisum in comparison with sexual populations.  

PubMed

Many aphid species exhibit geographical variation in the mode of reproduction that ranges from cyclical parthenogenesis with a sexual phase to obligate parthenogenesis (asexual reproduction). Theoretical studies predict that organisms reproducing asexually should maintain higher allelic diversity per locus but lower genotypic diversity than organisms reproducing sexually. To corroborate this hypothesis, we evaluated genotypic and allelic diversities in the sexual and asexual populations of the pea aphid, Acyrthosiphon pisum (Harris). Microsatellite analysis revealed that populations in central Japan are asexual, whereas populations in northern Japan are obligatorily sexual. No mixed populations were detected in our study sites. Phylogenetic analysis using microsatellite data and mitochondrial cytochrome oxidase subunit I (COI) gene sequences revealed a long history of asexuality in central Japan and negated the possibility of the recent origin of the asexual populations from the sexual populations. Asexual populations exhibited much lower genotypic diversity but higher allelic richness per locus than did sexual populations. Asexual populations consisted of a few predominant clones that were considerably differentiated from one another. Sexual populations on alfalfa, an exotic plant in Japan, were most closely related to asexual populations associated with Vicia sativa L. The alfalfa-associated sexual populations harboured one COI haplotype that was included in the haplotype clade of the asexual populations. Available evidence suggests that the sexuality of the alfalfa-associated populations has recently been restored through the northward migration and colonization of alfalfa by V. sativa-associated lineages. Therefore, our results support the theoretical predictions and provide a new perspective on the origin of sexual populations. PMID:19207245

Kanbe, Takashi; Akimoto, Shin-ichi

2009-03-01

65

The Importance of Sexual and Clonal Reproduction for Population Dynamics in the Understory Herb Calathea marantifolia (Marantaceae).  

E-print Network

??I addressed how light availability influences sexual and clonal offspring production, demographic performance and contribution to population dynamics by studying the Neotropical understory herb Calathea… (more)

Matlaga, David Packard

2008-01-01

66

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

PubMed

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

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

2005-02-01

67

Sexually transmitted infections clinics as strategic venues for targeting high risk populations for HIV research and sexual health interventions.  

PubMed

Puerto Rico has one of the highest incidence rates of HIV in the U.S. Concurrent with increases in sexually transmitted infections (STI), an increasing share of the new infections in PR are associated with sexual transmission. Much of the available research on sexual risk in PR derives from STI/HIV surveillance data. There is limited social and epidemiological research on sexual risk in PR, particularly in hidden and often hard-to-reach populations at high risk. Despite the absence of substantial resources that most epidemiological studies require, a research collaboration was initiated in 2007 between researchers in the School of Public Health at the University of Puerto Rico and the Centro Latinoamericano de Enfermedades de Transmisión Sexual (CLETS), one of the largest publicly funded centers for STI/HIV screening and treatment in the San Juan metropolitan area. Structured as a case study in the development of community-based research collaborations, this paper describes the early history and development of the project, including formative research, recruitment and training of students, and evolution in the study design that contributed to the current configuration of the ongoing "Core" study. Preliminary data are presented, highlighting data from a number of subpopulations that may contribute to our understanding of the role of behavioral risk in the STI/HIV epidemics in PR. More generally, the paper may guide the development of similar collaboration elsewhere in the Caribbean where HIV risk is increasing but where resources for research in high risk settings and groups are scarce. PMID:21932709

Clatts, Michael C; Rodríguez-Díaz, Carlos E; García, Hermes; Vargas-Molina, Ricardo L; Colón-López, Vivian; Pérez-Rios, Naydi; Goldsamt, Lloyd; Jovet-Toledo, Gerardo G

2011-09-01

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. PMID:23029488

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

2012-01-01

69

Computational Methods for Learning Population History from Large Scale Genetic  

E-print Network

Computational Methods for Learning Population History from Large Scale Genetic Variation Datasets of Philosophy. Copyright 2013 Ming-Chi Tsai #12;Keywords: Population Genetics, Minimum Description Length is a fundamental question in population genetics with numerous implications for basic and applied research

Matsuda, Noboru

70

Efficient Nash Computation in Large Population Games with Bounded Influence  

E-print Network

Efficient Nash Computation in Large Population Games with Bounded Influence Michael Kearns of provably efficient Nash computation and learning algorithms for broad classes of large-population games. 2 Department of Computer and Information Science University of Pennsylvania Philadelphia, Pennsylvania mkearns

Kearns, Michael

71

Efficient Nash Computation in Large Population Games with Bounded Influence  

E-print Network

Efficient Nash Computation in Large Population Games with Bounded Influence Michael Kearns of provably efficient Nash computation and learning algorithms for broad classes of large­population games. 2 Department of Computer and Information Science University of Pennsylvania Philadelphia, Pennsylvania mkearns

Kearns, Michael

72

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. PMID:24049189

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

2013-01-01

73

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

PubMed

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

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

2014-05-01

74

Pheromonally mediated sexual isolation among denning populations of red-sided garter snakes, Thamnophis sirtalis parietalis.  

PubMed

Utilizing behavioral experiments and chemical analyses, we examined whether pheromonally mediated sexual isolation exists between denning populations of red-sided garter snakes (Thamtnophis sirtalis parietalis) in Manitoba, Canada. Simultaneous choice tests conducted during the breeding season revealed that adult males from a hibernaculum in central Manitoba displayed a strong courtship preference for females from their own population over females from a hibernaculum in western Manitoba, whereas males from the western Manitoba hibernaculum showed no such preference. In addition. trailing experiments testing the response of males from the two hibernacula to familiar and unfamiliar female trails showed similar results, demonstrating that the observed male preference is mediated through chemical cues. Subsequent chemical analysis of the female sexual attractiveness pheromone. a homologous series of long-chain saturated and (omega-9 cis-unsaturated methyl ketones responsible for eliciting male courtship behavior and trailing behavior in garter snakes, showed significant variation in the composition of the pheromone between the two populations. Specifically, the two populations varied in the relative concentrations of individual unsaturated methyl ketones expressed by females. These results suggest that sexual isolation exists to a degree among denning populations of red-sided garter snakes due to variation in the expression of the female sexual attractiveness pheromone. PMID:12775159

Lemaster, Michael P; Mason, Robert T

2003-04-01

75

Long-term decline in a red-winged blackbird population: ecological causes and sexual selection consequences.  

PubMed

Habitat loss and large-scale climate phenomena are widely implicated as causing decline in animal populations. I examined how both factors contributed to a precipitous decline in an Ontario red-winged blackbird (Agelaius phoeniceus) population using 16 years of data collected between 1974 and 1995. The decline was manifested as an almost 50% reduction in mean harem size, which reduced the opportunity for sexual selection threefold. Regional hay production, which should affect recruitment into the study population, also declined substantially. Correlation between blackbirds and hay may be coincidental, however, because annual changes in harem size were not associated with annual changes in hay production. This study coincided with an unprecedented positive phase of the North Atlantic Oscillation (NAO). Changes in harem size were correlated with winter NAO index values, suggesting that winter mortality contributed to the population decline. Positive correlation between harem size change and male return rates also supported the winter mortality hypothesis. Continued declines will cause this blackbird population to change from socially polygynous to socially monogamous. Study of red-winged blackbird winter ecology is needed to identify the proximate causes of mortality, whereas breeding studies can explore the consequences of relaxed sexual selection. PMID:16191645

Weatherhead, Patrick J

2005-11-01

76

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

Microsoft Academic Search

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

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

2012-01-01

77

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

2012-06-01

78

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

PubMed Central

Objectives This study provides national estimates of the prevalence of childhood sexual contact and its association with sexual well-being and psychological distress among adults in China. Method A national stratified probability sample of 1,519 women and 1,475 men aged 20 to 64 years in urban China completed a computer-administered survey in 1999–2000. The data from this survey on both adult-to-child and peer-to-peer sexual contact before age 14 were subjected to descriptive and multivariate analyses that were adjusted for both sampling weights and sampling design. Results The overall prevalence of reported childhood sexual contact was 4.2%, with prevalence higher among men (5.1%) than among women (3.3%) and higher among those aged 20–29 years (8.3%). Childhood sexual contact was associated with multiplex consequences, including hyper-sexuality (high levels of masturbation, thoughts about sex, varieties of sexual practices, partner turnover), adult sexual victimization (unwanted sex, unwanted sexual acts, sexual harassment), sexual difficulties (genitor-urinary symptoms, sexually transmitted infections, sexual dysfunctions), and psychological distress. Psychological distress was largely mediated by adult sexual victimization, sexual difficulties, and hyper-sexuality. Conclusions Despite the relatively modest prevalence of childhood sexual contact among Chinese adults, the association with multiplex adult outcomes suggests that much as in the West early sexual contact is a significant issue. Practice Implications The findings underscore the importance of public education about childhood sexual contact and abuse in China. The findings suggest a need for public health campaigns that tackle the stigma associated with being abused and encourage victims to report abusive behavior to proper sources. The findings are also consistent with new efforts to alleviate the negative long-term impact of childhood sexual abuse. PMID:18614231

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

2008-01-01

79

Population genetics of French brown trout (Salmo trutta L): large geographical differentiation of wild populations  

E-print Network

Population genetics of French brown trout (Salmo trutta L): large geographical differentiation : Electrophoretic variation, population genetics, Salmo trutta L. Résumé Génétique des populations françaises de truite fario (Salmo trutta L.) : forte différenciation géographique des populations naturelles et

Paris-Sud XI, Université de

80

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

81

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

ERIC Educational Resources Information Center

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

Heller, Janet R.; Johnson, Helen L.

2013-01-01

82

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

83

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

E-print Network

to be the source of independently evolved and widely distributed asexual lineages, or clones. Either apomixis, but their existence in sexual populations is indicated by the presence of sperm in the reproductive tracts of queens- gests multiple independent origins of asexual reproduction, and a divergence-dating analysis indicates

Bi, Xin

84

Sexual violence among two populations of men at high risk of HIV infection  

Microsoft Academic Search

This study sought to compare the prevalence of, and relationship between, age at first experience of sexual violence and HIV and other health risk behaviors in two populations of men at high risk of HIV infection. Data were drawn from two cohorts: Vanguard, a prospective study of young men who have sex with men (MSM), and VIDUS, the Vancouver Injection

Paula Braitstein; Jérôme J. Asselin; Arn Schilder; Mary-Lou Miller; Nancy Laliberté; Martin T. Schechter; Robert S. Hogg

2006-01-01

85

Multiple sexual signals and behavioral reproductive isolation in a diverging population.  

PubMed

Sexual trait divergence has been shown to play a role in the evolution of reproductive isolation. While variation in multiple sexual signals is common among closely related species, little is known about the role of these different axes of phenotype variation with respect to the evolution of behavioral reproductive isolation. Here we study a unique population of barn swallows (Hirundo rustica transitiva) that can be distinguished phenotypically from its neighboring populations only on the basis of two features of male plumage: exaggerated expression of both long tail streamers and dark ventral coloration. Using phenotype manipulation experiments, we conducted a paternity study to examine whether both traits are sexually selected. Our results show that an exaggerated form of the local male phenotype (with both tail elongation and color darkening) is favored by local females, whereas males whose phenotypes were manipulated to look like males of neighboring subspecies suffered paternity losses from their social mates. These results confirm the multiple signaling role of the unique tail and color combination in our diverging population and suggest a novel possibility according to which multiple sexual signals may also be used to discriminate among males from nearby populations when prezygotic reproductive isolation is adaptive. PMID:24021403

Vortman, Yoni; Lotem, Arnon; Dor, Roi; Lovette, Irby; Safran, Rebecca J

2013-10-01

86

The evolution of sexual size dimorphism in the house finch. II. Population divergence in relation to local selection.  

PubMed

Recent colonization of ecologically distinct areas in North America by the house finch (Carpodacus mexicanus) was accompanied by strong population divergence in sexual size dimorphism. Here we examined whether this divergence was produced by population differences in local selection pressures acting on each sex. In a long-term study of recently established populations in Alabama, Michigan, and Montana, we examined three selection episodes for each sex: selection for pairing success, overwinter survival, and within-season fecundity. Populations varied in intensity of these selection episodes, the contribution of each episode to the net selection, and in the targets of selection. Direction and intensity of selection strongly differed between sexes, and different selection episodes often favored opposite changes in morphological traits. In each population, current net selection for sexual dimorphism was highly concordant with observed sexual dimorphism--in each population, selection for dimorphism was the strongest on the most dimorphic traits. Strong directional selection on sexually dimorphic traits, and similar intensities of selection in both sexes, suggest that in each of the recently established populations, both males and females are far from their local fitness optimum, and that sexual dimorphism has arisen from adaptive responses in both sexes. Population differences in patterns of selection on dimorphism, combined with both low levels of ontogenetic integration in heritable sexually dimorphic traits and sexual dimorphism in growth patterns, may account for the close correspondence between dimorphism in selection and observed dimorphism in morphology across house finch populations. PMID:11209788

Badyaev, A V; Hill, G E; Stoehr, A M; Nolan, P M; McGraw, K J

2000-12-01

87

Sexual violence and neonatal outcomes: a Norwegian population-based cohort study  

PubMed Central

Objective The objective of this study was to explore the association between sexual violence and neonatal outcomes. Design National cohort study. Setting Women were recruited to the Norwegian Mother and Child Cohort Study (MoBa) while attending routine ultrasound examinations from 1999 to 2008. Population A total of 76?870 pregnant women. Methods Sexual violence and maternal characteristics were self-reported in postal questionnaires during pregnancy. Neonatal outcomes were retrieved from the Medical Birth Registry of Norway (MBRN). Risk estimations were performed with linear and logistic regression analysis. Outcome measures: gestational age at birth, birth weight, preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA). Results Of 76?870 women, 18.4% reported a history of sexual violence. A total of 4.7% delivered prematurely, 2.7% had children with a birth weight <2500?g and 8.1% children were small for their gestational age. Women reporting moderate or severe sexual violence (rape) had a significantly reduced gestational length (2?days) when the birth was provider-initiated in an analysis adjusted for age, parity, education, smoking, body mass index and mental distress. Those exposed to severe sexual violence had a significantly reduced gestational length of 0.51?days with a spontaneous start of birth. Crude estimates showed that severe sexual violence was associated with PTB, LBW and SGA. When controlling for the aforementioned sociodemographic and behavioural factors, the association was no longer significant. Conclusions Sexual violence was not associated with adverse neonatal outcomes. Moderate and severe violence had a small but significant effect on gestational age; however, the clinical influence of this finding is most likely limited. Women exposed to sexual violence in this study reported more of the sociodemographic and behavioural factors associated with PTB, LBW and SGA compared with non-abused women.

Henriksen, Lena; Schei, Berit; Vangen, Siri; Lukasse, Mirjam

2014-01-01

88

Religiosity and Risky Sexual Behaviors among an African American Church-based Population  

PubMed Central

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

Hawes, Starlyn M.; Berkley-Patton, Jannette Y.

2014-01-01

89

Synchronization of animal population dynamics by large-scale climate  

Microsoft Academic Search

The hypothesis that animal population dynamics may be synchronized by climate is highly relevant in the context of climate change because it suggests that several populations might respond simultaneously to climatic trends if their dynamics are entrained by environmental correlation. The dynamics of many species throughout the Northern Hemisphere are influenced by a single large-scale climate system, the North Atlantic

Eric Post; Mads C. Forchhammer

2002-01-01

90

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

91

"Sexual" Population Structure and Genetics of the Malaria Agent P. falciparum  

PubMed Central

The population genetics and structure of P. falciparum determine the rate at which malaria evolves in response to interventions such as drugs and vaccines. This has been the source of considerable recent controversy, but here we demonstrate the organism to be essentially sexual, in an area of moderately high transmission in the Lower Shire Valley, Malawi. Seven thousand mosquitoes were collected and dissected, and genetic data were obtained on 190 oocysts from 56 infected midguts. The oocysts were genotyped at three microsatellite loci and the MSP1 locus. Selfing rate was estimated as 50% and there was significant genotypic linkage disequilibrium (LD) in the pooled oocysts. A more appropriate analysis searching for genotypic LD in outcrossed oocysts and/or haplotypic LD in the selfed oocysts found no evidence for LD, indicating that the population was effectively sexual. Inbreeding estimates at MSP1 were higher than at the microsatellites, possibly indicative of immune action against MSP1, but the effect was confounded by the probable presence of null mutations. Mating appeared to occur at random in mosquitoes and evidence regarding whether malaria clones in the same host were related (presumably through simultaneous inoculation in the same mosquito bite) was ambiguous. This is the most detailed genetic analysis yet of P. falciparum sexual stages, and shows P. falciparum to be a sexual organism whose genomes are in linkage equilibrium, which acts to slow the emergence of drug resistance and vaccine insensitivity, extending the likely useful therapeutic lifespan of drugs and vaccines. PMID:17637829

Mzilahowa, Themba; McCall, Philip J.; Hastings, Ian M.

2007-01-01

92

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. PMID:22039491

Eldakar, Omar Tonsi; Gallup, Andrew C.

2011-01-01

93

RECESSIVE MUTATIONS FROM NATURAL POPULATIONS OF NEUROSPORA CRASSA THAT ARE EXPRESSED IN THE SEXUAL DIPLOPHASE  

Microsoft Academic Search

Wild-collected isolates of Neurospora crassa Shear and Dodge were system- atically 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

JOHN F. LESLIE; B. RAJU

1985-01-01

94

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. PMID:19432975

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

2009-01-01

95

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

96

Large-scale spatial population databases in infectious disease research  

PubMed Central

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

2012-01-01

97

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

98

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

PubMed Central

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

2014-01-01

99

Stark sexual display divergence among jumping spider populations in the face of gene flow.  

PubMed

Gene flow can inhibit evolutionary divergence by eroding genetic differences between populations. A current aim in speciation research is to identify conditions in which selection overcomes this process. We focused on a state of limited differentiation, asking whether selection enables divergence with gene flow in a set of Habronattus americanus jumping spider populations that exhibit three distinct male sexual display morphs. We found that each population is at high frequency or fixed for a single morph. These strong phenotypic differences contrast with low divergence at 210 AFLP markers, suggesting selection has driven or maintains morph divergence. Coinciding patterns of isolation by distance and 'isolation by phenotype' (i.e. increased genetic divergence among phenotypically contrasting populations) across the study area support several alternative demographic hypotheses for display divergence, each of which entails gene flow. Display-associated structure appears broadly distributed across the genome and the markers producing this pattern do not stand out from background levels of differentiation. Overall, the results suggest selection can promote stark sexual display divergence in the face of gene flow among closely related populations. PMID:25266277

Blackburn, Gwylim S; Maddison, Wayne P

2014-11-01

100

Strong lensing statistics in large, z~galaxy population  

E-print Network

We calculate the expected lensing statistics of the galaxy population in large, low-redshift surveys. Galaxies are modeled using realistic, multiple components: a dark matter halo, a bulge component and disc. We use semi-analytic models of galaxies coupled with dark matter haloes in the Millennium Run to model the lens galaxy population. We predict that a fraction of 1.4+/-0.18*10^-3 of radio sources will be lensed by galaxies within a survey like the 2dF below zgalaxy population consists mainly of ellipticals (~80%) with an average lens velocity dispersion of 164+/-3 km/s, producing typical image separations of ~3 arcsec. The lens galaxy population lies on the fundamental plane but its velocity dispersion distribution is shifted to higher values compared to all early-type galaxies. Taking magnification bias into account, we predict that the ratio of 4:2 image systems is 30+/-5%, consistent with the observed ratio found in the Cosmic Lens All-Sky Survey. We also find that the population of 4-image lens galaxies is distinguishable from the population of lens galaxies in 2-image systems. Our key result is the explicit demonstration that the population of lens galaxies differs markedly from the galaxy population as a whole: lens galaxies have a higher average luminosity and reside in more massive haloes than the overall sample of ellipticals. This bias restricts our ability to infer galaxy evolution parameters from a sample of lensing galaxies. (abridged)

Ole Moeller; Manfred Kitzbichler; Priyamvada Natarajan

2006-07-03

101

The maintenance of sex, clonal dynamics, and host-parasite coevolution in a mixed population of sexual and asexual snails.  

PubMed

Sexual populations should be vulnerable to invasion and replacement by ecologically similar asexual females because asexual lineages have higher per capita growth rates. However, as asexual genotypes become common, they may also become disproportionately infected by parasites. The Red Queen hypothesis postulates that high infection rates in the common asexual clones could periodically favor the genetically diverse sexual individuals and promote the short-term coexistence of sexual and asexual populations. Testing this idea requires comparison of competing sexual and asexual lineages that are attacked by natural parasites. To date no such data have been available. Here, we report on long-term dynamics and parasite coevolution in a "mixed" (sexual and asexual) population of snails (Potamopyrgus antipodarum). We found that, within 7-10 years, the most common clones were almost completely replaced by initially rare clones in two different habitats, while sexuals persisted throughout the study period. The common clones, which were initially more resistant to infection, also became more susceptible to infection by sympatric (but not allopatric) parasites over the course of the study. These results are consistent with the Red Queen hypothesis and show that the coevolutionary dynamics predicted by the theory may also favor sexual reproduction in natural populations. PMID:19441961

Jokela, Jukka; Dybdahl, Mark F; Lively, Curtis M

2009-07-01

102

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

103

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

PubMed

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

Yeh, Pamela J

2004-01-01

104

Health and demographic characteristics of respondents in an Australian national sexuality survey: comparison with population norms  

PubMed Central

Study objective: To assess the representativeness of survey participants by systematically comparing volunteers in a national health and sexuality survey with the Australian population in terms of self reported health status (including the SF-36) and a wide range of demographic characteristics. Design: A cross sectional sample of Australian residents were compared with demographic data from the 1996 Australian census and health data from the 1995 National Health Survey. Setting: The Australian population. Participants: A stratified random sample of adults aged 18–59 years drawn from the Australian electoral roll, a compulsory register of voters. Interviews were completed with 1784 people, representing 40% of those initially selected (58% of those for whom a valid telephone number could be located). Main results: Participants were of similar age and sex to the national population. Consistent with prior research, respondents had higher socioeconomic status, more education, were more likely to be employed, and less likely to be immigrants. The prevalence estimates, means, and variances of self reported mental and physical health measures (for example, SF-36 subscales, women's health indicators, current smoking status) were similar to population norms. Conclusions: These findings considerably strengthen inferences about the representativeness of data on health status from volunteer samples used in health and sexuality surveys. PMID:12239200

Purdie, D; Dunne, M; Boyle, F; Cook, M; Najman, J

2002-01-01

105

Sexual systems and population genetic structure in an annual plant: testing the metapopulation model.  

PubMed

The need for reproductive assurance during dispersal, along with the pressure of local mate competition, means that the importance of frequent or repeated colonization is implicit in the literature on sexual system evolution. However, there have been few empirical tests of the association between colonization history and sexual system in plants, and none within a single species. Here we use patterns of genetic diversity to provide such a test in the Mercurialis annua species complex, which spans the range of systems from self-compatible monoecy through androdioecy to dioecy. This variation has been hypothesized to result from differing patterns of metapopulation turnover and recolonization. Because monoecy should be favored during colonization, androdioecy and dioecy will be maintained only in regions with low rates of local extinction and recolonization, and these differences should also be reflected in patterns of neutral genetic diversity. We show that monoecious populations of M. annua display lower within-population genetic diversity than androdioecious populations and higher genetic differentiation than dioecious and androdioecious populations, as predicted by metapopulation models. In contrast, regional diversity in M. annua appears to be primarily a product of postglacial range expansion from two refugia in the eastern and western Mediterranean Basin. PMID:16673344

Obbard, Darren J; Harris, Stephen A; Pannell, John R

2006-03-01

106

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

PubMed

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

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

2014-02-01

107

[Facilitating access to care for most-at-risk populations : The Bamako night sexual health clinic experience (Mali)].  

PubMed

The estimated prevalence of HIV in Mali is 1.3 % of the general population. The epidemic is concentrated in certain groups, particularly men who have sex with men (MSM) and sex workers (SW). Access to care is limited for these populations, notably because of structural obstacles (e.g. marked social rejection ; health care services poorly adapted to the real needs of these people). Innovative strategies must be envisaged to ensure access to care services and retention in care for these populations. As part of a health promotion process, ARCAD-SIDA, a Malian NGO involved in the fight against AIDS since 1995, set up a night sexual health clinic in 2010 as part of a strategy to more adequately respond to the health needs of these populations. This clinic adapts health service timetables to match the lifestyles of the targeted populations, brings services in closer physical proximity to the places in which these populations live, proposes patient-tailored consultations, works to improve the patients' psychosocial skills, and promotes community-based peer mobilization. In an environment which is generally hostile to MSM and SW, ARCAD-SIDA also works in advocacy, targeting political decision-makers, defense forces and journalists. The NGO has also played a key role in ensuring that these populations are taken into account in the national strategy for the fight against HIV. Since opening in 2010, the clinic has helped reach a large number of MSM and SW and has improved retention in care. This innovative strategy has also enabled the NGO to improve its professional practices in terms of an individual-based approach to prevention. Interventions that are better adapted to the needs and environment of the populations for whom they are intented to have a positive effect on access to and use of healthcare services. PMID:25380379

Coulibaly, Alou; Dembelé Keita, Bintou; Henry, Emilie; Trenado, Emmanuel

2014-09-01

108

Psychosocial variables associated with sexual risk behavior among an urban seventh grade population  

Microsoft Academic Search

This dissertation examines the psychosocial factors associated with sexual risk behavior among low socio-economic, minority middle school students in a large urban school district in Houston, Texas and is presented in the form of three articles. Article One examines the association between knowledge, perceived risk of HIV\\/STD, and self-reported lifetime engagement in vaginal sex among seventh grade students. The purpose

Toan H Ha

2008-01-01

109

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

PubMed Central

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

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

1995-01-01

110

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

PubMed

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

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

2013-08-01

111

Changes and Correlates in Multiple Sexual Partnerships among Chinese Adult Women----Population Based Surveys in 2000 and 2006  

PubMed Central

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 among adult women, and to examine trends and correlates for having more than one lifetime sexual partner. Multiple sexual partnership (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, sig.=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 dataset, 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

2011-01-01

112

Significance of temporal changes on sexual dimorphism of cranial measurements of Indian population.  

PubMed

Revision of discriminant function formulae has always been advocated by anthropologist to take into account the changing pattern of sexual dimorphism due to temporal/secular changes. The present study aims to track temporal changes in cranial measurements of temporally distinct North Indian population and providing updated sex discriminating formulae. A total of 483 adult (20-65 years) crania representing contemporary and sub-recent populations collected from two medical colleges in North India. A total of 11 variables were measured to observe the changes in cranial dimension over time. Analysis of data demonstrated significant sexual and population (contemporary vs sub-recent sample) variations over time. The contemporary males and females exhibited larger cranial dimensions but it expressed less dimorphism than their predecessors. A trend toward brachycephalization was also observed in contemporary females. Maximum cranial length (84%) and biauricular breadth (79%) represent the most dimorphic variables for contemporary and sub-recent sample, respectively. The possible causes of such variations are discussed. PMID:25043554

Saini, Vineeta

2014-09-01

113

Prevalence and predictors of concurrent sexual partnerships in a predominantly african american population in jackson, Mississippi.  

PubMed

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

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

2014-12-01

114

Intragenomic conflict in populations infected by Parthenogenesis Inducing Wolbachia ends with irreversible loss of sexual reproduction  

PubMed Central

Background The maternally inherited, bacterial symbiont, parthenogenesis inducing (PI) Wolbachia, causes females in some haplodiploid insects to produce daughters from both fertilized and unfertilized eggs. The symbionts, with their maternal inheritance, benefit from inducing the production of exclusively daughters, however the optimal sex ratio for the nuclear genome is more male-biased. Here we examine through models how an infection with PI-Wolbachia in a previously uninfected population leads to a genomic conflict between PI-Wolbachia and the nuclear genome. In most natural populations infected with PI-Wolbachia the infection has gone to fixation and sexual reproduction is impossible, specifically because the females have lost their ability to fertilize eggs, even when mated with functional males. Results The PI Wolbachia infection by itself does not interfere with the fertilization process in infected eggs, fertilized infected eggs develop into biparental infected females. Because of the increasingly female-biased sex ratio in the population during a spreading PI-Wolbachia infection, sex allocation alleles in the host that cause the production of more sons are rapidly selected. In haplodiploid species a reduced fertilization rate leads to the production of more sons. Selection for the reduced fertilization rate leads to a spread of these alleles through both the infected and uninfected population, eventually resulting in the population becoming fixed for both the PI-Wolbachia infection and the reduced fertilization rate. Fertilization rate alleles that completely interfere with fertilization ("virginity alleles") will be selected over alleles that still allow for some fertilization. This drives the final resolution of the conflict: the irreversible loss of sexual reproduction and the complete dependence of the host on its symbiont. Conclusions This study shows that dependence among organisms can evolve rapidly due to the resolution of the conflicts between cytoplasmic and nuclear genes, and without requiring a mutualism between the partners. PMID:20667099

2010-01-01

115

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

Microsoft Academic Search

One of the most important factors that determine the evolutionary trajectory of a suite of traits in a population is the structure of the genetic variance–covariance matrix (G). We studied the cyclically parthenogenetic aphid Rhopalosiphum padi, whose populations exhibit two types of reproductive lineages respectively specialized in sexuality (that is, cyclically parthenogenetic lineages) and in asexuality (that is, obligate parthenogenetic

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

2008-01-01

116

Demography of the demosponge Amphimedon compressa: Evaluation of the importance of sexual versus asexual recruitment to its population dynamics  

Microsoft Academic Search

We used size-based population matrix models to describe the demography of the demosponge Amphimedon compressa. The relative importance of growth, survivorship, and recruitment to population growth (?) was assessed by performing elasticity and life table response experiment (LTRE) analyses. We also evaluated the relative contribution of sexual and asexual recruitment to ? by analyzing four different scenarios: (1) the combined

Alex E. Mercado-Molina; Alberto M. Sabat; Paul M. Yoshioka

2011-01-01

117

Differences in Chemical Sexual Signals May Promote Reproductive Isolation and Cryptic Speciation between Iberian Wall Lizard Populations  

PubMed Central

Interpopulational variation in sexual signals may lead to premating reproductive isolation and speciation. Genetic and morphological studies suggest that the Iberian wall lizard, Podarcis hispanica, forms part of a “species complex” with several cryptic species. We explored the role of chemical sexual signals in interpopulational recognition between five distinct populations of Iberian wall lizards in Central Spain. Results showed that these populations differed in morphology and in composition and proportion of chemical compounds in femoral gland secretions of males. Tongue-flick experiments indicated that male and female lizards discriminated and were more interested in scents of lizards from their own area (i.e., Northern versus Southern populations), but did not discriminate between all populations. Moreover, only males from the populations that are geographically located more far away preferred scent of females from their own population. These data suggest that, at least between some populations, there may be reproductive isolation mediated by chemical signals and cryptic speciation. PMID:22288019

Gabirot, Marianne; Lopez, Pilar; Martin, Jose

2012-01-01

118

A Population-Based and Longitudinal Study of Sexual Behavior and Multidrug-Resistant HIV Among Patients in Clinical Care  

PubMed Central

Background Population-based and longitudinal information regarding sexual risk behavior among patients with multidrug resistant (MDR) HIV and their sexual partners is of great public health and clinical importance. Objective To characterize the HIV sexual risk behaviors of patients with and without drug-resistant HIV in the clinical care setting over time. Measurements 393 HIV-positive patients completed questionnaires of self-reported sexual risk behaviors at approximate 6-month intervals extending over 24 months. HIV viral load and genotypic drug resistance obtained during the same time points were matched to the behavioral data. Multidrug resistance was defined as having resistance to 2 or 3 antiretroviral (ARV) drug classes. Results In serial cross-sectional analyses, 393 patients (44% female and 79% heterosexual) contributed 919 matched behavioral and virologic results over the 24 months of data collection. Of these, 250 patients (64%) reported having sex during at least 1 survey period resulting in greater than 10,000 sexual events with more than 1000 partners. Unprotected sexual behavior was reported by 45% of sexually active patients, resulting in 34% of all sex events that exposed 29% of all partners. Of these patients with unprotected sexual events, 31% had HIV drug resistance 11.6% with resistance to 2 classes of ARVs (2-class), and 1.8% with 3-class ARV resistance at the time of a sexual risk event. Close to 1000 or 28% of all unprotected sexual events involved resistant strains (11% of these with resistance to 2 classes and 0.2% with 3-class resistance, exposing 20% of unprotected sexual partners to resistant HIV (8% to 2-class and 0.6% to 3-class resistance). In longitudinal analysis among the 78 patients who reported a cumulative total of 12 months of sexual history and had resistance testing, 38% reported engaging in unprotected sexual behavior. There was substantial and complex variation in the distribution of unprotected sexual events and in the detection of resistance over time. Conclusion In this study of HIV sexual risk and resistance over time among HIV-infected patients in clinical care, a substantial proportion engaged in unprotected sex and had drug-resistant HIV, frequently exposing partners to 1- or 2-class resistant HIV strains. However, relatively few exposures involved 3-class resistance. The dynamics of sexual risk behavior and HIV drug resistance are complex and vary over time and urgently require both general and targeted interventions to reduce transmission of resistant HIV.

2006-01-01

119

A Population-Based and Longitudinal Study of Sexual Behavior and Multidrug-Resistant HIV Among Patients in Clinical Care  

PubMed Central

Background Population-based and longitudinal information regarding sexual risk behavior among patients with multidrug resistant (MDR) HIV and their sexual partners is of great public health and clinical importance. Objective To characterize the HIV sexual risk behaviors of patients with and without drug-resistant HIV in the clinical care setting over time. Measurements 393 HIV-positive patients completed questionnaires of self-reported sexual risk behaviors at approximate 6-month intervals extending over 24 months. HIV viral load and genotypic drug resistance obtained during the same time points were matched to the behavioral data. Multidrug resistance was defined as having resistance to 2 or 3 antiretroviral (ARV) drug classes. Results In serial cross-sectional analyses, 393 patients (44% female and 79% heterosexual) contributed 919 matched behavioral and virologic results over the 24 months of data collection. Of these, 250 patients (64%) reported having sex during at least 1 survey period resulting in greater than 10,000 sexual events with more than 1000 partners. Unprotected sexual behavior was reported by 45% of sexually active patients, resulting in 34% of all sex events that exposed 29% of all partners. Of these patients with unprotected sexual events, 31% had HIV drug resistance – 11.6% with resistance to 2 classes of ARVs (2-class), and 1.8% with 3-class ARV resistance at the time of a sexual risk event. Close to 1000 or 28% of all unprotected sexual events involved resistant strains (11% of these with resistance to 2 classes and 0.2% with 3-class resistance, exposing 20% of unprotected sexual partners to resistant HIV (8% to 2-class and 0.6% to 3-class resistance). In longitudinal analysis among the 78 patients who reported a cumulative total of 12 months of sexual history and had resistance testing, 38% reported engaging in unprotected sexual behavior. There was substantial and complex variation in the distribution of unprotected sexual events and in the detection of resistance over time. Conclusion In this study of HIV sexual risk and resistance over time among HIV-infected patients in clinical care, a substantial proportion engaged in unprotected sex and had drug-resistant HIV, frequently exposing partners to 1- or 2-class resistant HIV strains. However, relatively few exposures involved 3-class resistance. The dynamics of sexual risk behavior and HIV drug resistance are complex and vary over time and urgently require both general and targeted interventions to reduce transmission of resistant HIV. PMID:16926811

Kozal, Michael J.; Amico, K. Rivet; Chiarella, Jennifer; Cornman, Deborah; Fisher, William; Fisher, Jeffrey; Friedland, Gerald

2006-01-01

120

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

121

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

Microsoft Academic Search

Research addressing relationships between alcohol and human sexuality has proliferated, due in part to efforts to characterize\\u000a alcohol’s role in HIV risk behavior. This study provides a descriptive review of the alcohol–sexuality literature, using abstracts\\u000a from 264 identified studies to estimate changes in publication activity, target populations, and the prevalence of HIV-related\\u000a studies over time. We also examine methodological trends

Christian S. Hendershot; William H. George

2007-01-01

122

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

PubMed

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

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

2010-01-01

123

Mating-type distribution and genetic diversity of Cercospora sojina populations on soybean from Arkansas: evidence for potential sexual reproduction.  

PubMed

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

124

Moroccan women with a history of child sexual abuse and its long-term repercussions: A population-based epidemiological study  

Microsoft Academic Search

Summary. Childhood sexual abuse is defined as sexual contact imposed on a child whose development is still, from the emotional, cognitive and maturity point of view, lacking. The objective of this epidemiological study, conducted among a representative sample of the female population aged 20 and over in Casablanca, Morocco, is to determine the prevalence of the childhood sexual abuse and

K. Mchichi Alami; N. Kadri

2004-01-01

125

Response of human populations to large-scale emergencies  

NASA Astrophysics Data System (ADS)

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

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

2010-03-01

126

Comparison of sexual compatibility in crosses between the southern and northern populations of the cabbage beetle Colaphellus bowringi.  

PubMed

It is widely accepted that the genetic divergence and reproductive incompatibility between closely related species and/or populations is often viewed as an important step toward speciation. In this study, sexual compatibility in crosses between the southern XS population and the northern TA population of the polyandrous cabbage beetle Colaphellus bowringi was investigated by testing their mating preferences, mating latency, copulation duration, and reproductive performances of post-mating. In choice mating experiments, the percentages of matings were significantly higher in intra-population crosses than in inter-population crosses. Both isolation index (I) and index of pair sexual isolation (IPSI ) indicated partial mating incompatibility or assortative mating in crosses between the two different geographical populations. In single pair mating experiments, XS females in inter-population crosses mated significantly later and copulated significantly shorter than those in intra-population crosses. However, TA females in inter-population crosses mated significantly earlier and copulated longer than those in intra-population crosses, suggesting that larger XS males may enhance heterotypic mating. The lifetime fecundity was highest in XS homotypic matings, lowest in TA homotypic matings, and intermediate in heterotypic matings between their parents. The inter-population crosses resulted in significantly lower egg hatching rate and shorter female longevity than intra-population crosses. These results demonstrated that there exist some incompatibilities in premating, postmating-prezygotic, and postzygotic stages between the southern XS population and northern TA population of the cabbage beetle Colaphellus bowringi. PMID:24339338

Liu, Xing-Ping; Tu, Xiao-Yun; He, Hai-Min; Chen, Chao; Xue, Fang-Sen

2014-12-01

127

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

PubMed Central

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

2013-01-01

128

Prevalence of sexual problems in Portugal: results of a population-based study using a stratified sample of men aged 18 to 70 years.  

PubMed

Despite the use of different methodologies, target populations, and clinical definitions of sexual problems, recent epidemiological studies have shown that the occurrence of sexual difficulties is a very common experience among men from the general population regardless of their age. The objective of this study was to present epidemiological data on the prevalence of sexual difficulties in a community sample of 650 sexually active Portuguese men, stratified by age, marital status, and educational level. Participants completed a self-reported questionnaire assessing sexual function in the previous four weeks (International Index of Erectile Function). Results showed that sexual difficulties were relatively common among this sample. Rapid ejaculation was the most frequently reported sexual difficulty (23.2%), followed by erectile difficulties (10.2%), orgasm problems (8.2%), and low desire (2.9%) in the previous four weeks. With the exception of rapid ejaculation, all categories showed age-specific prevalence rates, with sexual difficulties increasing gradually in men above age 45. Age was a significant predictor of all sexual difficulties except rapid ejaculation, and lower educational levels were related to orgasm difficulties. Findings are consistent with the majority of epidemiological studies indicating a high prevalence of sexual difficulties among men in the general population and highlight the importance and the need to implement sexual health promotion programs in the target population. PMID:23573897

Quinta Gomes, Ana Luísa; Nobre, Pedro J

2014-01-01

129

Enriching Ploidy Level Diversity: the Role of Apomictic and Sexual Biotypes of Hieracium subgen. Pilosella (Asteraceae) that Coexist in Polyploid Populations  

Microsoft Academic Search

The capacity to generate variation in ploidy and reproductive mode was compared in facultatively apomictic versus sexual maternal\\u000a plants that coexist in two model populations. The population structure was studied in polyploid hybrid swarms comprised of\\u000a Hieracium pilosella (usually sexual, less commonly apomictic), H. bauhini (apomictic), and their hybrids (sexual, apomictic, or sterile). Relationships among established biotypes were proposed on

Anna Krahulcová; Olga Rotreklová; František Krahulec; Radka Rosenbaumová; Ivana Pla?ková

2009-01-01

130

Adaptive divergence and speciation among sexual and pseudoviviparous populations of Festuca  

PubMed Central

Pseudovivipary is an environmentally induced flowering abnormality in which vegetative shoots replace seminiferous (sexual) inflorescences. Pseudovivipary is usually retained in transplantation experiments, indicating that the trait is not solely induced by the growing environment. Pseudovivipary is the defining characteristic of Festuca vivipara, and arguably the only feature separating this species from its closest seminiferous relative, Festuca ovina. We performed phylogenetic and population genetic analysis on sympatric F. ovina and F. vivipara samples to establish whether pseudovivipary is an adaptive trait that accurately defines the separation of genetically distinct Festuca species. Chloroplast and nuclear marker-based analyses revealed that variation at a geographical level can exceed that between F. vivipara and F. ovina. We deduced that F. vivipara is a recent species that frequently arises independently within F. ovina populations and has not accumulated significant genetic differentiation from its progenitor. We inferred local gene flow between the species. We identified one amplified fragment length polymorphism marker that may be linked to a pseudovivipary-related region of the genome, and several other markers provide evidence of regional local adaptation in Festuca populations. We conclude that F. vivipara can only be appropriately recognized as a morphologically and ecologically distinct species; it lacks genetic differentiation from its relatives. This is the first report of a ‘failure in normal flowering development' that repeatedly appears to be adaptive, such that the trait responsible for species recognition constantly reappears on a local basis. PMID:20959864

Chiurugwi, T; Beaumont, M A; Wilkinson, M J; Battey, N H

2011-01-01

131

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. PMID:2933298

Leslie, John F.; Raju, Namboori B.

1985-01-01

132

The Power to Detect Quantitative Trait Loci Using Resequenced, Experimentally Evolved Populations of Diploid, Sexual Organisms  

PubMed Central

A novel approach for dissecting complex traits is to experimentally evolve laboratory populations under a controlled environment shift, resequence the resulting populations, and identify single nucleotide polymorphisms (SNPs) and/or genomic regions highly diverged in allele frequency. To better understand the power and localization ability of such an evolve and resequence (E&R) approach, we carried out forward-in-time population genetics simulations of 1 Mb genomic regions under a large combination of experimental conditions, then attempted to detect significantly diverged SNPs. Our analysis indicates that the ability to detect differentiation between populations is primarily affected by selection coefficient, population size, number of replicate populations, and number of founding haplotypes. We estimate that E&R studies can detect and localize causative sites with 80% success or greater when the number of founder haplotypes is over 500, experimental populations are replicated at least 25-fold, population size is at least 1,000 diploid individuals, and the selection coefficient on the locus of interest is at least 0.1. More achievable experimental designs (less replicated, fewer founder haplotypes, smaller effective population size, and smaller selection coefficients) can have power of greater than 50% to identify a handful of SNPs of which one is likely causative. Similarly, in cases where s ? 0.2, less demanding experimental designs can yield high power. PMID:24441104

Baldwin-Brown, James G.; Long, Anthony D.; Thornton, Kevin R.

2014-01-01

133

Behavioural surveillance of sexually-related risk behaviours of the Chinese male general population in Hong Kong: A benchmark study  

Microsoft Academic Search

The objective of the study was to establish a behavioural surveillance system (BSS) for sexually-related risk behaviours of the Hong Kong adult male general population. Benchmark data were obtained by interviewing 1,020 male respondents, age 18 to 60. The results showed that: (1) 14% of the respondents had engaged in commercial sex in the past six months, (2) 27% of

J. T. F. Lau; P. C. Siah

2001-01-01

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

Microsoft Academic Search

This study examined if sexual and relationship satisfaction are differentially associated with mental health issues. Using data from a population-based computer assisted telephone survey, a total of 3800 respondents with a regular heterosexual partner were included in the current analyses. Two methods of scoring the K6 were used to produce measures of moderate psychological distress and serious psychological distress. Overall,

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

2012-01-01

136

Among-population variation in adipose fin size parallels the expression of other secondary sexual characteristics in  

E-print Network

secondary sexual characteristics in sockeye salmon (Oncorhynchus nerka) Peter A. H. Westley Ã? Stephanie M size of mature male sockeye salmon, Oncorhynchus nerka, among five popu- lations. Populations differed. Reimchen and Temple (2004) experimentally removed adipose fins from juvenile steelhead trout, Oncorhynchus

Carlson, Stephanie

137

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

Microsoft Academic Search

BackgroundSexual cannibalism may be a form of extreme sexual conflict in which females benefit more from feeding on males than mating with them, and males avoid aggressive, cannibalistic females in order to increase net fitness. A thorough understanding of the adaptive significance of sexual cannibalism is hindered by our ignorance of its prevalence in nature. Furthermore, there are serious doubts

Rubén Rabaneda-Bueno; Miguel Á. Rodríguez-Gironés; Carmen Fernández-Montraveta; Eva de Mas; David H. Wise; Jordi Moya-Laraño; Robert Brooks

2008-01-01

138

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. PMID:21768368

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

2011-01-01

139

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. PMID:22125651

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

2011-01-01

140

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. PMID:15209099

Knight, Mairi E.; Turner, George F.

2004-01-01

141

Prevalence and sociodemographic predictors of sexual problems in portugal: a population-based study with women aged 18 to 79 years.  

PubMed

Studies on epidemiology of female sexual problems consistently indicate high prevalence rates worldwide, suggesting that this clinical presentation should be considered as a public health concern. However, there are no published studies on prevalence of sexual problems in Portugal. The present study investigated the prevalence, severity, and comorbidity of female sexual problems in a Portuguese community sample. In addition, the authors assessed the role of sociodemographic predictors of women's sexual difficulties. The authors recruited 500 women using quota methods to resemble the Portuguese population according to its demographic characteristics. Participants answered to the Female Sexual Function Index and to a sociodemographic questionnaire. Findings indicated that 37.9% of the Portuguese women reported symptoms of sexual problems. Symptoms of lack of sexual desire was the most frequent sexual difficulty with 25.4% of the women reporting low desire most times or always, followed by symptoms of orgasmic (16.8%), sexual arousal (15.1%), and lubrication difficulties (12.9%), dyspareunia (9.8%), and vaginismus (6.6%). Results indicated that age was a significant predictor of female sexual problems. Results also indicated that symptoms of female sexual problems are a significant health concern in Portugal, suggesting that public policies should be developed to promote sexual health. PMID:24364817

Peixoto, Maria Manuela; Nobre, Pedro

2015-01-01

142

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

2013-06-10

143

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

PubMed

Precopulatory sexual selection is the association between fitness and traits associated with mate acquisition. Although sexual selection is generally recognized to be a powerful evolutionary force, most investigations are limited to characters belonging to individuals. A broader multilevel perspective acknowledges that individual fitness can be affected by aspects of mating success that are characters of groups, such as families. Parental mating success in polygynous or polyandrous human societies may exemplify traits under group-level sexual selection. Using fitness measures that account for age-structure, I measure multilevel selection for mate number over 55 years in a human population with declining rates of polygyny. Sexual selection had three components: individual-level selection for ever-mating (whether an individual mated) and individual- and family-level selection for polyandry and polygyny. Family- and individual-level selection for polygyny was equally strong, three times stronger than family-level selection for polyandry and more than an order of magnitude stronger than individual-level selection for polyandry. However, individual-level selection for polyandry and polygyny was more effective at explaining relative fitness variance than family-level selection. Selection for ever-mating was the most important source of sexual selection for fitness; variation for ever-mating explained 23% of relative fitness variance. PMID:23730758

Moorad, Jacob A

2013-06-01

144

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

PubMed Central

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

Moorad, Jacob

2013-01-01

145

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

PubMed Central

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

Tabima, Javier F.; Grunwald, Niklaus J.

2014-01-01

146

Could the predation risk hypothesis explain large-scale spatial sexual segregation in fallow deer ( Dama dama )?  

Microsoft Academic Search

Large-scale spatial segregation was assessed by means of radio-telemetry in 48 fallow deer studied for 4 years. Three hypotheses have traditionally been used to explain sexual segregation: (1) the predation risk hypothesis, (2) the forage selection hypothesis, (3) the activity budget hypothesis. The first of these seems to be a valid explanation of large-scale segregation in fallow deer at San Rossore,

Simone Ciuti; Sara Davini; Siriano Luccarini; Marco Apollonio

2004-01-01

147

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

148

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

149

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

PubMed

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

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

2014-08-01

150

Alcohol and sexuality research in the AIDS era: trends in publication activity, target populations and research design.  

PubMed

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

Hendershot, Christian S; George, William H

2007-03-01

151

Morphometric analysis of pelvic sexual dimorphism in a contemporary Western Australian population.  

PubMed

Requisite to routine casework involving unidentified skeletal remains is the formulation of an accurate biological profile, including sex estimation. Choice of method(s) is invariably related to preservation and by association, available bones. It is vital that the method applied affords statistical quantification of accuracy rates and predictive confidence so that evidentiary requirements for legal submission are satisfied. Achieving the latter necessitates the application of contemporary population-specific standards. This study examines skeletal pelvic dimorphism in contemporary Western Australian individuals to quantify the accuracy of using pelvic measurements to estimate sex and to formulate a series of morphometric standards. The sample comprises pelvic multi-slice computer tomography (MSCT) scans from 200 male and 200 female adults. Following 3D rendering, the 3D coordinates of 24 landmarks are acquired using OsiriX® (v.4.1.1) with 12 inter-landmark linear measurements and two angles acquired using MorphDb. Measurements are analysed using basic descriptive statistics and discriminant functions analyses employing jackknife validation of classification results. All except two linear measurements are dimorphic with sex differences explaining up to 65 % of sample variance. Transverse pelvic outlet and subpubic angle contribute most significantly to sex discrimination with accuracy rates between 100 % (complete pelvis-10 variables) and 81.2 % (ischial length). This study represents the initial forensic research into pelvic sexual dimorphism in a Western Australian population. Given these methods, we conclude that this highly dimorphic bone can be used to classify sex with a high degree of expected accuracy. PMID:24789357

Franklin, Daniel; Cardini, Andrea; Flavel, Ambika; Marks, Murray K

2014-09-01

152

Sexuality Education.  

ERIC Educational Resources Information Center

Explores the state of sexuality education in the United States. After concerted efforts in the 1960s to stop sex education, interest in sexuality education resurged in the 1980s, largely as a result of AIDS fears. There is now a broad-based consensus on the necessity of sexuality education, but there are still few effective programs. (SLD)

Haffner, Debra W.

1998-01-01

153

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

2011-11-01

154

Molecular characterization of sexual diversity in a population of Serpula lacrymans, a tetrapolar basidiomycete.  

PubMed

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. PMID:23390592

Skrede, Inger; Maurice, Sundy; Kauserud, Håvard

2013-02-01

155

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. PMID:23390592

Skrede, Inger; Maurice, Sundy; Kauserud, Havard

2013-01-01

156

Runaway Youths and Sexual Victimization: Gender Differences in an Adolescent Runaway Population.  

ERIC Educational Resources Information Center

Data collected from 149 runaways (15-20 years old) revealed that 38% of the males and 73% of the females reported having been sexually abused. Sexually abused females were significantly more likely than nonabused females to engage in delinquent/criminal activities. (CL)

McCormack, Arlene; And Others

1986-01-01

157

Bridging Populations—Sexual Risk Behaviors and HIV Prevalence in Clients and Partners of Female Sex Workers, Bangkok, Thailand 2007  

Microsoft Academic Search

The aim of this study is to estimate HIV prevalence and assess sexual behaviors in a high-risk and difficult-to-reach population\\u000a of clients of female sex workers (FSWs). A modified variation of respondent-driven sampling was conducted among FSWs in Bangkok,\\u000a where FSWs recruited 3 FSW peers, 1 client, and 1 nonpaying partner. After informed consent was obtained, participants completed\\u000a a questionnaire,

Neha S. Shah; Ray W. Shiraishi; Wonchart Subhachaturas; Abhijeet Anand; Sara J. Whitehead; Suvimon Tanpradech; Chomnad Manopaiboon; Keith M. Sabin; Kimberley K. Fox; Andrea Y. Kim

158

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

159

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. PMID:22479659

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

160

Golombok Rust Inventory of Sexual Satisfaction for the presence of sexual dysfunction within a Ghanaian urological population.  

PubMed

Sexual dysfunction (SD) is devastating to a man's ego and its presence could defeat his purpose of masculinity. A number of studies have explored and reported on existing comorbidities between SD and medical conditions for which urological problems are no exception. However, in Ghana there is paucity of data exploring the epidemiological, etiological and health associations of medical conditions with SD. This study was therefore conducted to determine the prevalence, types and determinants of SD in a sample of Ghanaian men with urological conditions. This descriptive cross-sectional study was carried out between December 2012 and April 2013 at the Urology clinic of the Tamale Teaching Hospital in the Northern Region of Ghana. A total of 200 participants were enrolled in the study. All participants were evaluated by using a semistructured questionnaire and the Golombok Rust Inventory of Sexual Satisfaction questionnaire. An overall response rate of 47.5% was estimated after 69 patients refused to partake in the study; 6 patients found the questionnaire too sensitive and refused to participate and 30 participants returned incomplete questionnaire. The mean age of the participants was 36.5±13.8 years and ranged from 18 to 70 years. The estimated prevalence of SD was 71.6%. The prevalence of the various SD domains was as follows: non-sensuality (71.6%), premature ejaculation (70.5%), non-communication (69.5%), impotence and infrequency (68.4%), dissatisfaction (61.1%) and avoidance (57.9%). Participants who were married, consumed alcoholic beverages, smoked cigarettes and aging males who had children were at a greater risk of developing SD. Urologic patients have a high prevalence of SD that is dependent on marital status, alcohol consumption, smoking status and aged patients with children. PMID:24430277

Amidu, N; Quaye, L; Afoko, A A; Karikari, P; Gandau, B B N; Amoah, E O; Nuwoku, E

2014-01-01

161

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

162

Sexual dimorphism in human cranial trait scores: effects of population, age, and body size.  

PubMed

Sex estimation from the skull is commonly performed by physical and forensic anthropologists using a five-trait scoring system developed by Walker. Despite the popularity of this method, validation studies evaluating its accuracy across a variety of samples are lacking. Furthermore, it remains unclear what other intrinsic or extrinsic variables are related to the expression of these traits. In this study, cranial trait scores and postcranial measurements were collected from four diverse population groups (U.S. Whites, U.S. Blacks, medieval Nubians, and Arikara Native Americans) following Walker's protocols (total n?=?499). Univariate and multivariate analyses were utilized to evaluate the accuracy of these traits in sex estimation, and to test for the effects of population, age, and body size on trait expressions. Results revealed significant effects of population on all trait scores. Sample-specific correct sex classification rates ranged from 74% to 94%, with an overall accuracy of 85% for the pooled sample. Classification performance varied among the traits (best for glabella and mastoid scores and worst for nuchal scores). Furthermore, correlations between traits were weak or nonsignificant, suggesting that different factors may influence individual traits. Some traits displayed correlations with age and/or postcranial size that were significant but weak, and within-population analyses did not reveal any consistent relationships between these traits across all groups. These results indicate that neither age nor body size plays a large role in trait expression, and thus does not need to be incorporated into sex estimation methods. PMID:24595622

Garvin, Heather M; Sholts, Sabrina B; Mosca, Laurel A

2014-06-01

163

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

PubMed Central

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

Rabaneda-Bueno, Ruben; Rodriguez-Girones, Miguel A.; Aguado-de-la-Paz, Sara; Fernandez-Montraveta, Carmen; De Mas, Eva; Wise, David H.; Moya-Larano, Jordi

2008-01-01

164

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

SciTech Connect

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

Mols, Floortje [CoRPS-Center of Research on Psychology in Somatic Diseases, Tilburg University, Tilburg (Netherlands); Comprehensive Cancer Centre South (CCCS), Eindhoven Cancer Registry, Eindhoven (Netherlands)], E-mail: F.Mols@uvt.nl; Korfage, Ida J. [Department of Public Health, Erasmus MC-University Medical Center, Rotterdam (Netherlands); Vingerhoets, Ad J.J.M. [Clinical Psychology Section, Tilburg University, Tilburg (Netherlands); Kil, Paul J.M. [Department of Urology, Sint Elisabeth Hospital, Tilburg (Netherlands); Coebergh, Jan Willem W. [Comprehensive Cancer Centre South (CCCS), Eindhoven Cancer Registry, Eindhoven (Netherlands); Department of Public Health, Erasmus MC-University Medical Center, Rotterdam (Netherlands); Essink-Bot, Marie-Louise [Department of Public Health, Erasmus MC-University Medical Center, Rotterdam (Netherlands); Department of Social Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam (Netherlands); Poll-Franse, Lonneke V. van de [CoRPS-Center of Research on Psychology in Somatic Diseases, Tilburg University, Tilburg (Netherlands); Comprehensive Cancer Centre South (CCCS), Eindhoven Cancer Registry, Eindhoven (Netherlands)

2009-01-01

165

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

Microsoft Academic Search

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

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

2009-01-01

166

Student understanding in mechanics: A large population survey  

NSDL National Science Digital Library

There has recently been a considerable growth in research probing student understanding in mechanics. Questions based on four such research probes were included in the end-of-high-school physics examination undertaken by some 5500 students. The results obtained give an indication of the extent to which various interpretations of some physical situations are held in a whole population. The possibilities of using research probes as a basis for assessment questions are also illustrated.

Gunstone, Richard

2005-10-20

167

Prevalence and Predictors of Self-Reported Sexual Abuse in Severely Obese Patients in a Population-Based Bariatric Program  

PubMed Central

Background. Sexual abuse may be associated with poorer weight loss outcomes following bariatric treatment. Identifying predictors of abuse would enable focused screening and may increase weight management success. Methods. We analyzed data from 500 consecutively recruited obese subjects from a population-based, regional bariatric program. The prevalence of self-reported sexual abuse was ascertained using a single interview question. Health status was measured using a visual analogue scale (VAS). Multivariable logistic regression was performed to identify sexual abuse predictors. Results. The mean age was 43.7?y (SD 9.6), 441 (88.2%) were females, 458 (91.8%) were white, and the mean body mass index (BMI) was 47.9?kg/m2 (SD 8.1). The self-reported prevalence of past abuse was 21.8% (95% CI 18.4–25.4%). Abused subjects had worse health status (VAS score 53.1 (SD 21.2) versus 58.0 (SD 20.1), P = 0.03). BMI was not associated with abuse (P > 0.5). Age, sex, BMI, and covariate-adjusted independent predictors of abuse included alcohol addiction (adjusted odds ratio 15.8; 95% CI 4.0–62.8), posttraumatic stress disorder (4.9; 2.5–9.5), borderline personality (3.8; 1.0–13.8), depression (2.4; 1.3–4.3), and lower household income (3.4; 1.6–7.0). Conclusions. Abuse was common amongst obese patients managed in a population-based bariatric program; alcohol addiction, psychiatric comorbidities, and low-income status were highly associated with sexual abuse. PMID:23864941

Gabert, Danielle L.; Majumdar, Sumit R.; Sharma, Arya M.; Rueda-Clausen, Christian F.; Klarenbach, Scott W.; Birch, Daniel W.; Karmali, Shahzeer; McCargar, Linda; Fassbender, Konrad; Padwal, Raj S.

2013-01-01

168

Sexual harassment victimization and perpetration among high school students.  

PubMed

This large, population-based study is one of the few to examine prevalence rates of sexual harassment occurring during the past 12 months by victimization and perpetration among adolescents. In this large, cross-sectional survey of students attending 26 high schools, sexual harassment was defined using three questions from the Sexual Experiences Questionnaire. Among 18,090 students completing the survey, 30% disclosed sexual harassment victimization (37% of females, 21% of males) and 8.5% reported perpetration (5% of females, 12% of males). Sexual harassment perpetration was highly correlated with male sex, minority race/ethnicity, same-sex attraction, bullying, alcohol binge drinking, and intraparental partner violence. PMID:25288593

Clear, Emily R; Coker, Ann L; Cook-Craig, Patricia G; Bush, Heather M; Garcia, Lisandra S; Williams, Corrine M; Lewis, Alysha M; Fisher, Bonnie S

2014-10-01

169

A Population-Based Study of Cardiovascular Disease Risk in Sexual-Minority Women  

PubMed Central

Objectives. We sought to determine if sexual-minority women were at greater risk for cardiovascular disease (CVD) than their heterosexual counterparts. Methods. We aggregated data from the 2001–2008 National Health and Nutrition Examination Surveys to examine differences in CVD risk between heterosexual and sexual-minority women by using the Framingham General CVD Risk Score to calculate a ratio of vascular and chronological age. We also examined differences in the prevalence of various CVD risk factors. Results. Sexual-minority women were more likely to be current or former smokers, to report a history of drug use, to report risky drinking, and to report a family history of CVD. On average, sexual-minority women were 13.9% (95% confidence interval [CI]?=?8.5%, 19.3%) older in vascular terms than their chronological age, which was 5.7% (95% CI?=?1.5%, 9.8%) greater than that of their heterosexual counterparts. Family history of CVD and history of drug use were unrelated to increased CVD risk, and this risk was not fully explained by either risky drinking or smoking. Conclusions. Sexual-minority women are at increased risk for CVD compared with heterosexual women. PMID:23948018

Jabson, Jennifer M.; Bucholz, Kathleen K.; Bowen, Deborah J.

2013-01-01

170

Population structure of lake trout (Salvelinus namaycush) in a large glacial-fed lake inferred  

E-print Network

Population structure of lake trout (Salvelinus namaycush) in a large glacial-fed lake inferred from Columbia, Canada, and contains relatively pristine populations of lake trout (Salvelinus namaycush, et il contient des populations de touladis (Salvelinus namaycush) encore relativement dans leur e

Taylor, Eric B. "Rick"

171

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. PMID:19451317

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

2013-01-01

172

Large Populations Are Not Always The Best Choice In Genetic Programming  

E-print Network

Large Populations Are Not Always The Best Choice In Genetic Programming Matthias Fuchs Automated@arp.anu.edu.au, URL: http://arp.anu.edu.au:80/~fuchs Abstract In genetic programming a general consensus is that the population should be as large as practically possible or sensible. In this pa­ per we examine a batch

Fernandez, Thomas

173

Dust and Stellar Populations in the Large Magellanic Cloud  

Microsoft Academic Search

We present an analysis of line-of-sight extinction measurements obtained using data from the Magellanic Clouds Photometric Survey (Zaritsky, Harris, & Thompson), which provides four-filter photometry for millions of stars in the Large Magellanic Cloud. We find that visual extinctions are typically larger by several tenths of a magnitude for stars with effective temperatures greater than 12,000 K than for stars

Dennis Zaritsky

1999-01-01

174

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. PMID:21479206

Barabasi, Albert-Laszlo

2011-01-01

175

Collective response of human populations to large-scale emergencies  

E-print Network

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.

Bagrow, James P; Barabási, Albert-László; 10.1371/journal.pone.0017680

2011-01-01

176

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

Microsoft Academic Search

The World Health Organization estimates that 340 million new cases of curable sexually transmitted infections (STIs) occur every year, while 33 million individuals are estimated to be living with HIV. The AIDS and STI epidemics are not independent with untreated STIs increasing HIV acquisition and transmission. Female sex workers have increased prevalence of untreated STIs and have been hypothesized to

Rachel Rosenheck; David Ngilangwa; Rachael Manongi; Saidi Kapiga

2010-01-01

177

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

178

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

E-print Network

that reproductive mode varied locally between sites. The study sites were fragmented woodlands in Cook County, and studies that aim to characterize reproductive modes in species capable of asexual reproduction need are capable of both sexual and asexual reproduction. How such plants partition their reproductive effort

Ashley, Mary V.

179

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

180

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

PubMed Central

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

McElroy, Jane A.; Everett, Kevin D.

2014-01-01

181

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

182

Determining asymptotically large population sizes in insect swarms.  

PubMed

Social animals commonly form aggregates that exhibit emergent collective behaviour, with group dynamics that are distinct from the behaviour of individuals. Simple models can qualitatively reproduce such behaviour, but only with large numbers of individuals. But how rapidly do the collective properties of animal aggregations in nature emerge with group size? Here, we study swarms of Chironomus riparius midges and measure how their statistical properties change as a function of the number of participating individuals. Once the swarms contain order 10 individuals, we find that all statistics saturate and the swarms enter an asymptotic regime. The influence of environmental cues on the swarm morphology decays on a similar scale. Our results provide a strong constraint on how rapidly swarm models must produce collective states. But our findings support the feasibility of using swarms as a design template for multi-agent systems, because self-organized states are possible even with few agents. PMID:25121646

Puckett, James G; Ouellette, Nicholas T

2014-10-01

183

Sexual behaviour  

PubMed Central

Sexual health is not merely the absence of disease, but the ability to have informed, consensual, safe, respectful, and pleasurable sexual relationships. The majority of the population are sexually active, most with someone of the opposite sex. The frequency and range of sexual practices that people engage in declines with age, but for many, sexual activity continues well into later life. Different aspects of sexual health affect people at different times throughout their lives. As people in the UK tend to first have sex around the age of 16, but do not start living with a partner until much later, the avoidance of sexually transmitted infections and unplanned pregnancy is necessary for many for a number of years. As people get older, their sexual health needs change and they become more concerned with the impact of their general health on their ability to have sex. Some people experience non-volitional sex (sex against their will); although this occurs typically in late teenage it may affect women and men at any age and so requires consideration throughout life. As many people find it difficult to talk about sex and sexual health matters, health professionals should make sexual health enquiry a component of their holistic healthcare. PMID:24966786

Mercer, Catherine H.

2014-01-01

184

Comparing Female and Male Perpetrators' Modus OperandiVictims' Reports of Sexual Abuse  

Microsoft Academic Search

Although a sizable percentage of all sexual abuse in the United States is perpetrated by females, until recently the subject of sexual offending by this population has been largely overlooked. In this study, reports of child sexual abuse by 53 victims of female perpetrators were compared with reports by a group of 53 victims of male perpetrators. Victims were matched

KEITH L. KAUFMAN; ANNE M. WALLACE; CHARLES FELZEN JOHNSON; MARK LESLEY REEDER

1995-01-01

185

DNA fingerprinting uncovers a new sexually reproducing population of Phytophthora infestans in the Netherlands  

Microsoft Academic Search

The oomycetous fungusPhytophthora infestans (Mont.) de Bary, which causes late blight disease in potatoes, is heterothallic with two known mating types, A1 and A2. From 1845 until 1980 only A1 mating type isolates were found in Europe. In 1980, the A2 mating type appeared permitting sexual reproduction. Here we show that virulence properties and DNA fingerprint patterns of isolates collected

André Drenth; Inge C. Q. Tas; Francine Govers

1994-01-01

186

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

PubMed

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

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

2014-01-01

187

A population-based survey of sexual activity, sexual problems and associated help-seeking behavior patterns in mature adults in the United States of America  

Microsoft Academic Search

To study sexual activity, the prevalence of sexual dysfunction and related help-seeking behaviors among mature adults in the United States of America, a telephone survey was conducted in 2001–2002. A total of 1491 individuals (742 men\\/749 women) aged 40–80 years completed the survey. Overall, 79.4% of men and 69.3% of women had engaged in sexual intercourse during the 12 months

E O Laumann; D B Glasser; R C S Neves; E D Moreira; ED Moreira Jr

2009-01-01

188

The Relationship Between Child Sexual Abuse and Alexithymic Symptoms in a Population of Recovering Adult Substance Abusers  

Microsoft Academic Search

Recovering substance abusers with a history of childhood sexual abuse (n = 69) or no history of childhood sexual abuse (n = 68) completed the Toronto Alexithymia Scale (TAS) and a background survey assessing demographic data and (In the case of sexually abused respondents) parameters of the childhood abuse experienced. The sexually abused group scored significantly higher than the non-abused

Dean Scher; James A. Twaite

1999-01-01

189

Large-Scale Comparative Analysis of Pertussis Population Dynamics: Periodicity, Synchrony, and Impact of Vaccination  

E-print Network

Large-Scale Comparative Analysis of Pertussis Population Dynamics: Periodicity, Synchrony, 2004; accepted for publication February 9, 2005. Pertussis is a worldwide infectious disease which view of pertussis dynamics and the impact of vaccination, the authors performed, using the wavelet

Roche, Benjamin

190

COMMENT Conserving large populations of lions the argument for fences has holes  

E-print Network

fences around protected areas is the best method to conserve African lions. Their deterministic populaTECHNICAL COMMENT Conserving large populations of lions ­ the argument for fences has holes S G. Wittemyer38 and A. Zimmermann6,21 Abstract Packer et al. reported that fenced lion populations

Creel, Scott

191

A large percentage of the population in Bangladesh is highly exposed to arsenic and  

E-print Network

A large percentage of the population in Bangladesh is highly exposed to arsenic and manganese are even higher in portions of Araihazar, Bangladesh (the location of the current study), where 80 population in Araihazar, Bangladesh (Wasserman et al. 2006). Although the impact of manganese expo- sures

van Geen, Alexander

192

Adolescent Sexual Behavior and Sexual Education in the United States  

Microsoft Academic Search

This review of sexual education in the United States broadly defines the two most common approaches in sexual education seen in this country today. I cover the status of certain sexual behaviors and risks amongst the teenage population in the U.S. and specifically cover reported sexual activity in high school students and overall data on teen pregnancies and sexually transmitted

Therese B Orbea

2010-01-01

193

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

PubMed Central

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

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

2012-01-01

194

Osteometric analysis of sexual dimorphism in the sternal end of the rib in a west African population.  

PubMed

This study, and others, are being carried out in order to establish a Forensic Anthropology databank on age estimation and sex determination of skeletonized remains in Ghana. An osteometric study of sexual dimorphism in the sternal end of the right fourth rib on 346 consecutive coroner's autopsy cases (221 males, 125 females) of known age, sex, and race was conducted. The height and width of the sternal end of the rib were measured in each case. The sample was analyzed in three groups: young (< 30 years), old (> or = 30 years), and total sample (total group). Stepwise discriminant function analysis showed that the accuracy of sex determination varied from 80% in the young and 74% in the old groups to 78% for the total group. Statistical analysis of the results obtained when the functions derived from the study were tested using another batch of ribs showed the functions to be effective and reliable in determining sex. When functions derived from a previous study of American Whites were used to determine sex in our study sample, the vast majority of males were misclassified as females. This is the first time, to our knowledge, that a Black African population has been studied osteometrically to evaluate sexual dimorphism in the sternal end of the fourth rib. PMID:10486942

Wiredu, E K; Kumoji, R; Seshadri, R; Biritwum, R B

1999-09-01

195

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

PubMed Central

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

2014-01-01

196

Genetic Diversity in Relation to Sexual and Asexual Reproduction in Populations of Melampsora larici-epitea  

Microsoft Academic Search

Genetic diversity of Melampsora larici-epitea leaf rust from three cultivated stands of the willow Salix viminalis was studied using AFLP polymorphisms at 60 loci. One population was located in Northern Ireland and two in Sweden. Analysis of molecular variance (AMOVA) showed that most of the genetic variation was distributed on a fine scale within the field in all populations. Both

Berit Samils; Valérie Stepien; Ulf Lagercrantz; Martin Lascoux; Urban Gullberg

2001-01-01

197

Asexual and sexual reproductive strategies in clonal plants  

Microsoft Academic Search

Most plants can reproduce both sexually and asexually (or vegetatively), and the balance between the two reproductive modes\\u000a may vary widely between and within species. Extensive clonal growth may affect the evolution of life history traits in many\\u000a ways. First, in some clonal species, sexual reproduction and sex ratio vary largely among populations. Variation in sexual\\u000a reproduction may strongly affect

Yufen Zhang; Dayong Zhang

2007-01-01

198

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

PubMed

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

Havens, J A; Etges, W J

2013-03-01

199

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

200

Long-term decline in a red-winged blackbird population: ecological causes and sexual  

E-print Network

in an Ontario red-winged blackbird (Agelaius phoeniceus) population using 16 years of data collected between-winged blackbirds (Agelaius phoeniceus) in eastern Ontario. I assess the relative importance of habitat change

Weatherhead, Patrick J.

201

Copyright 0 1996 by the Genetics Society of America Sexual Reproduction Playsa Major Role in the Genetic Structure of Populations  

E-print Network

Copyright 0 1996 by the Genetics Society of America Sexual Reproduction Playsa Major Role% of the isolates represented asexual clones that were found morethanonceinthesample than sexual reproduction because a limited number of clones or clonal lineages are widespread

McDonald, Bruce

202

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. PMID:22413838

2012-01-01

203

Effects of Large Woody Debris Addition on Stream Habitat and Brook Trout Populations in Appalachian Streams  

Microsoft Academic Search

Large woody debris (LWD) was added to eight streams in the central Appalachians of West Virginia to determine if stream habitat\\u000a could be enhanced and brook trout (Salvelinus fontinalis) populations increased. Brook trout populations were assessed one year prior to habitat manipulation and 3 years post-habitat\\u000a manipulation. LWD was added by felling approximately 15 trees per 300 m stream reach. Four of

John A. Sweka; Kyle J. Hartman

2006-01-01

204

Dynamical Quorum Sensing and Synchronization in Large Populations of Chemical Oscillators  

Microsoft Academic Search

Populations of certain unicellular organisms, such as suspensions of yeast in nutrient solutions, undergo transitions to coordinated activity with increasing cell density. The collective behavior is believed to arise through communication by chemical signaling via the extracellular solution. We studied large, heterogeneous populations of discrete chemical oscillators (~100,000) with well-defined kinetics to characterize two different types of density-dependent transitions to

Annette F. Taylor; Mark R. Tinsley; Fang Wang; Zhaoyang Huang; Kenneth Showalter

2009-01-01

205

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

PubMed Central

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

Pachankis, John E.; Wolff, Joshua

2012-01-01

206

Sexually transmitted diseases and enteric infections in the male homosexual population.  

PubMed

There are certain special considerations in the management of sexually transmitted diseases (STDs) in homosexual men, with the impact of human immunodeficiency virus (HIV) infection on the presentation, diagnosis, and management of certain STDs just becoming apparent recently. Rectal and pharyngeal gonorrhea are usually asymptomatic and also more difficult to treat. The serological diagnosis of syphillis may be unreliable in acquired immunodeficiency syndrome (AIDS) patients, and HIV-seropositive homosexual men may be at risk of accelerated progression to neurosyphilis, despite treatment with benzathine penicillin. Chlamydia trachomatis is infrequently detected in patients with proctitis so therapy should be directed only at culture-positive cases. Herpes simplex is usually severe and persistent in immunosuppressed patients and may be further complicated by the development of acyclovir-resistance. Concurrent HIV infection may be associated with increased infectivity of homosexual chronic hepatitis B carriers, but milder hepatic injury and reduced efficacy of hepatitis B vaccines and immodulatory or antiviral agents. Although there is some concern regarding the possibility of increased risk of anal cancer in homosexual men, conservative management of human papilloma-virus-associated conditions is advised. The carriage of Entamoeba histolytica in this group is rarely associated with any deleterious effects and treatment should be directed only at symptomatic patients in whom other enteric pathogens have been excluded. PMID:2202414

Law, C

1990-06-01

207

Sexual dimorphism of acetabulum–pubis index in South-Indian population  

Microsoft Academic Search

Accurate sexing of skeletal remains is a vital part of any medicolegal investigation and a challenge to physical anthropologists. Hipbone is considered as the most reliable sex indicator in the human skeleton. Standards of morphological and morphometric sex differences in the skeleton may differ with the population sample involved and thus cannot be applied universally. The acetabulum–pubis index (A–P index)

K. R. Nagesh; Tanuj Kanchan; Binay K. Bastia

2007-01-01

208

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

209

Can simple population genetic models reconcile partial match frequencies observed in large forensic databases?  

Microsoft Academic Search

A recent study of partial matches in the Arizona offender database of DNA profiles has revealed a large number of nine and\\u000a ten locus matches. I use simple models that incorporate the product rule, population substructure, and relatedness to predict\\u000a the expected number of matches in large databases. I find that there is a relatively narrow window of parameter values

Laurence D. Mueller

2008-01-01

210

The prevalence of diffuse idiopathic skeletal hyperostosis (DISH) in two large American Midwest metropolitan hospital populations  

Microsoft Academic Search

Objective. There are no published large-scale studies of the overall prevalence of diffuse idiopathic skeletal hyperostosis (DISH) and\\u000a it has been proposed that the prevalence is greater than previously reported. We thus decided to review chest radiographs\\u000a in a population of patients over 50 years of age seen at two large but differing metropolitan hospitals in a major American\\u000a Midwest

R. M. Weinfeld; Paul N. Olson; Daniel D. Maki; H. J. Griffiths

1997-01-01

211

[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

2013-01-01

212

HIV populations are large and accumulate high genetic diversity in a nonlinear fashion.  

PubMed

HIV infection is characterized by rapid and error-prone viral replication resulting in genetically diverse virus populations. The rate of accumulation of diversity and the mechanisms involved are under intense study to provide useful information to understand immune evasion and the development of drug resistance. To characterize the development of viral diversity after infection, we carried out an in-depth analysis of single genome sequences of HIV pro-pol to assess diversity and divergence and to estimate replicating population sizes in a group of treatment-naive HIV-infected individuals sampled at single (n = 22) or multiple, longitudinal (n = 11) time points. Analysis of single genome sequences revealed nonlinear accumulation of sequence diversity during the course of infection. Diversity accumulated in recently infected individuals at rates 30-fold higher than in patients with chronic infection. Accumulation of synonymous changes accounted for most of the diversity during chronic infection. Accumulation of diversity resulted in population shifts, but the rates of change were low relative to estimated replication cycle times, consistent with relatively large population sizes. Analysis of changes in allele frequencies revealed effective population sizes that are substantially higher than previous estimates of approximately 1,000 infectious particles/infected individual. Taken together, these observations indicate that HIV populations are large, diverse, and slow to change in chronic infection and that the emergence of new mutations, including drug resistance mutations, is governed by both selection forces and drift. PMID:23678164

Maldarelli, Frank; Kearney, Mary; Palmer, Sarah; Stephens, Robert; Mican, JoAnn; Polis, Michael A; Davey, Richard T; Kovacs, Joseph; Shao, Wei; Rock-Kress, Diane; Metcalf, Julia A; Rehm, Catherine; Greer, Sarah E; Lucey, Daniel L; Danley, Kristen; Alter, Harvey; Mellors, John W; Coffin, John M

2013-09-01

213

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. PMID:21853540

Landripet, Ivan; Stulhofer, Aleksandar; Bacak, Valerio

2011-01-01

214

Nash Certainty Equivalence in Large Population Stochastic Dynamic Games: Connections with the  

E-print Network

/33 #12;Brief Historic Background: John Nash John Nash (1950) Equilibrium points in N-Person Games, PNASNash Certainty Equivalence in Large Population Stochastic Dynamic Games: Connections and Morgenstern Following the publication of Theory of Games and Economic Behavior by John von Neumann and Oskar

Huang, Minyi

215

Population age structure and growth in four syntopic amphibian species inhabiting a large river floodplain  

Microsoft Academic Search

River floodplains are disturbance-dominated landscapes where floods are major regulators of both aquatic and nearby terrestrial communities. Amphibians are common inhabitants of floodplains and their life cycle depends on both aquatic and terrestrial habitats. We focused on how different syntopic species of amphibians reacted to the environmental conditions of a large river floodplain. We examined life-history traits such as population

Dan Cogalniceanu; Claude Miaud

2003-01-01

216

Prevalences of ECG findings in large population based samples of men and women  

Microsoft Academic Search

OBJECTIVETo obtain accurate estimates of the prevalence of ECG abnormalities in the general population and to describe them in relation to age, sex, and some lifestyle related factors.DESIGNThe results were obtained from the records of 47 358 men and women participating in four large Belgian epidemiological studies during the past 30 years. All tracings were read and coded by two

D De Bacquer; G De Backer; M Kornitzer

2000-01-01

217

Birth seasonality and calf mortality in a large population of Asian elephants  

E-print Network

Birth seasonality and calf mortality in a large population of Asian elephants Hannah S. Mumby1, Germany Keywords Birth season, climate, conservation, Elephas maximus, offspring mortality, working Ecology and Evolution 2013; 3(11): 3794­ 3803 doi: 10.1002/ece3.746 Abstract In seasonal environments

Lummaa, Virpi

218

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

219

Sexual Assault  

MedlinePLUS

... assault fact sheet Sexual assault fact sheet ePublications Sexual assault fact sheet Print this fact sheet Sexual assault ... assaulted? More information on sexual assault What is sexual assault? Sexual assault and abuse is any type of ...

220

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

PubMed Central

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

2013-01-01

221

Disruptive sexual selection on male nuptial coloration in an experimental hybrid population of cichlid fish.  

PubMed

Theory suggests that genetic polymorphisms in female mating preferences may cause disruptive selection on male traits, facilitating phenotypic differentiation despite gene flow, as in reinforcement or other models of speciation with gene flow. Very little experimental data have been published to test the assumptions regarding the genetics of mate choice that such theory relies on. We generated a population segregating for female mating preferences and male colour dissociated from other species differences by breeding hybrids between species of the cichlid fish genus Pundamilia. We measured male mating success as a function of male colour. First, we demonstrate that non-hybrid females of both species use male nuptial coloration for choosing mates, but with inversed preferences. Second, we show that variation in female mating preferences in an F2 hybrid population generates a quadratic fitness function for male coloration suggestive of disruptive selection: intermediate males obtained fewer matings than males at either extreme of the colour range. If the genetics of female mate choice in Pundamilia are representative for those in other species of Lake Victoria cichlid fish, it may help explain the origin and maintenance of phenotypic diversity despite some gene flow. PMID:18522918

Stelkens, Rike B; Pierotti, Michele E R; Joyce, Domino A; Smith, Alan M; van der Sluijs, Inke; Seehausen, Ole

2008-09-12

222

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

2009-06-01

223

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

SciTech Connect

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

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

2009-07-15

224

fastSTRUCTURE: Variational Inference of Population Structure in Large SNP Data Sets  

PubMed Central

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

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

2014-01-01

225

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

226

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

ERIC Educational Resources Information Center

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

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

2008-01-01

227

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

228

The Genetic Structure of Natural Populations of DROSOPHILA MELANOGASTER. Xii. Linkage Disequilibrium in a Large Local Population  

PubMed Central

Seven hundred and three second chromosomes were extracted from a Raleigh, North Carolina population of Drosophila melanogaster in 1970. Additionally, four hundred and eighty-nine third chromosomes were extracted from a large cage population founded from the flies in the 1970 Raleigh collection. The ? glycerol-3-phosphate dehydrogenase-1, malate dehydrogenase-1, alcohol dehydrogenase, and ? amylase loci were studied from the second chromosomes, and the esterase-6, esterase-C, and octanol dehydrogenase loci were analyzed from the third chromosomes. Inversions, relative viability and fecundity were studied for both classes of chromosomes. The following significant findings were obtained: (1) All loci examined were polymorphic or had at least two alleles at appreciable frequencies. Analysis of the combined data from this experiment with that of Mukai, Mettler and Chigusa (1971) revealed that the frequencies of the genes in the second chromosomes collected in early August were approximately the same over three years. (2) Linkage disequilibria between and among isozyme genes inter se were not detected except in a few cases which can be considered due to non-random sampling. (3) Linkage disequilibria between isozyme genes and polymorphic inversions were detected when the recombination values between the breakage points of the inversions and the genes in question were small. In only a few cases, were second and third order linkage disequilibria including polymorphic inversions detected. (4) Evidence for either variation among genotypes within loci or cumulative effects of heterozygosity was found for viability and fecundity. As a result of these findings, it was tentatively concluded that although selection might be perceptibly operating on some polymorphic isozyme loci, most of the polymorphic isozyme genes are selectively neutral or near-neutral in the populations studied. PMID:4213910

Muki, Terumi; Watanabe, Takao K.; Yamaguchi, Osamu

1974-01-01

229

The use of odds ratio in the large population-based studies: Warning to readers  

PubMed Central

Summary When researchers conduct large prospective studies, they provide results generating statistical analysis; therefore readers need considerable familiarity with descriptive and inferential statistics. If quantitative judgments are based on interpreting odds ratios as though they were relative risks, they are unlikely to be seriously in error. Because of the calculating method, the OR is often less precise than the RR in estimating the strength of an association, and this should definitely be kept in mind by anyone who reads and interprets the results of a large population based-study. PMID:24932454

Di Lorenzo, Luigi; Coco, Valeria; Forte, Francesco; Trinchese, Giovanni Felice; Forte, Alfonso Maria; Pappagallo, Marco

2014-01-01

230

Familial aggregation of melanoma risks in a large population-based sample of melanoma cases  

Microsoft Academic Search

ObjectiveMelanoma has been shown in numerous studies to be associated with sun exposure, and with host phenotypic factors of genetic origin. In this study we use information from a large series of incident cases of melanoma from an international population-based study to examine the patterns of incidence of melanoma in the first-degree relatives of these cases. Methods: A total of

Colin B. Begg; Amanda Hummer; Urvi Mujumdar; Bruce K. Armstrong; Anne Kricker; Loraine D. Marrett; Robert C. Millikan; Stephen B. Gruber; Hoda Anton-Culver; Judith B. Klotz; Roberto Zanetti; Richard P. Gallagher; Terence Dwyer; Timothy R. Rebbeck; Marrianne R. Berwick

2004-01-01

231

Large Scale Variability Survey of Orion II: mapping the young, low-mass stellar populations  

Microsoft Academic Search

We present further results of our ongoing large scale variability survey of the Orion OB1 Association, carried out with the 8k x 8k CCD Mosaic Camera on the 1m Schmidt telescope at the Venezuela National Observatory. In an area of over 60 square degrees we have unveiled new populations of low-mass young stars over a range of environments, from the

C. Briceño; N. Calvet; L. W. Hartmann; A. K. Vivas

2000-01-01

232

Germ-line DNA copy number variation frequencies in a large North American population  

Microsoft Academic Search

Genomic copy number variation (CNV) is a recently identified form of global genetic variation in the human genome. The Affymetrix\\u000a GeneChip 100 and 500 K SNP genotyping platforms were used to perform a large-scale population-based study of CNV frequency.\\u000a We constructed a genomic map of 578 CNV regions, covering approximately 220 Mb (7.3%) of the human genome, identifying 183\\u000a previously unknown intervals.

George Zogopoulos; Kevin C. H. Ha; Faisal Naqib; Sara Moore; Hyeja Kim; Alexandre Montpetit; Frederick Robidoux; Philippe Laflamme; Michelle Cotterchio; Celia Greenwood; Stephen W. Scherer; Brent Zanke; Thomas J. Hudson; Gary D. Bader; Steven Gallinger

2007-01-01

233

sexual Assault sexual Assault  

E-print Network

sexual Assault sexual Assault if You Are a Victim of a sexual Assault 1. Get to a safe place. 2. Call out for help. 3. DiAl 6111 or ask someone to ring for you and state "sEXUAl AssAUlT" giving exact. if You Witness a sexual Assault 1. Everyone is asked to assist in making the campus a safe place by being

Hickman, Mark

234

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

2013-03-01

235

Strong lensing statistics in large, z <~ 0.2, surveys: bias in the lens galaxy population  

NASA Astrophysics Data System (ADS)

Large current and future surveys, like the Two-degree Field Survey (2dF), the Sloan Digital Sky Survey (SDSS) and the proposed Kilo-Degree Survey (KIDS), are likely to provide us with many new strong gravitational lenses. Taking cosmological parameters as known, we calculate the expected lensing statistics of the galaxy population in large, low-redshift surveys. Galaxies are modelled using realistic, multiple components: a dark matter halo, a bulge component and disc. We use semi-analytic models of galaxies coupled with dark matter haloes in the Millennium Run to model the lens galaxy population. Replicating the selection criteria of the 2dF, we create a mock galaxy catalogue. We predict that a fraction of 7.5 +/- 0.2 × 10-5 of radio sources will be lensed by galaxies within a survey like the 2dF below z < 0.2. We find that proper inclusion of the baryonic component is crucial for calculating lensing statistics - pure dark matter haloes produce lensing cross-sections several orders of magnitude lower. With a simulated sample of lensed radio sources, the predicted lensing galaxy population consists mainly of ellipticals (~ 80 per cent) with an average lens velocity dispersion of 191 +/- 3kms-1, producing typical image separations of ~1.5 arcsec. The lens galaxy population lies on the fundamental plane but its velocity dispersion distribution is shifted to higher values compared to all early-type galaxies. We show that magnification bias affects lens statistics very strongly and increases the 4:2 image ratio drastically. Taking this effect into account, we predict that the ratio of 4:2 image systems is 18 +/- 5 per cent, marginally consistent with the observed ratio found in the Cosmic Lens All-Sky Survey (CLASS). We also find that the population of four-image lens galaxies differs markedly from the population of lens galaxies in two-image systems. We find that while most lenses tend to be ellipticals, galaxies that produce four-image systems preferentially tend to be lower velocity dispersion systems with more pronounced disc components. Our key result is the explicit demonstration that the population of lens galaxies differs markedly from the galaxy population as a whole: lens galaxies have a higher average luminosity and, for a given luminosity, they reside in more massive haloes than the overall sample of ellipticals. This bias restricts our ability to infer galaxy evolution parameters from a sample of lensing galaxies.

Möller, Ole; Kitzbichler, Manfred; Natarajan, Priyamvada

2007-08-01

236

Populations and partnerships: insights from metapopulation and pair models into the epidemiology of gonorrhoea and other sexually transmitted infections  

Microsoft Academic Search

BackgroundModels of sexually transmitted infection (STI) transmission can offer insights as to why gonorrhoea and other STIs are disproportionately concentrated in epidemiologically distinct subpopulations.MethodsWe highlight two different constructs for modelling STIs by drawing on previously published work on pair and metapopulation models, and reanalysed partnership data from the National Survey of Sexual Attitudes and Lifestyles II (NATSAL II) in the

Mark I Chen; Azra C Ghani

2010-01-01

237

Intensive management fails to promote recruitment in the last large population of Juniperus communis (L.) in Flanders (Belgium)  

Microsoft Academic Search

In this study, the effectiveness of management measures aimed at promoting recruitment in the last large Flemish juniper population at Heiderbos is evaluated. We resurveyed demographic plots 23 years after their establishment in 1980 and linked the population changes with detailed records of the intensive management during the same period. Between 1980 and 2003 the population size has decreased by

Kris Verheyen; Koen Schreurs; Bert Vanholen; Martin Hermy

2005-01-01

238

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

PubMed

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

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

2003-08-01

239

Hospitalization for lifestyle related diseases in long haul drivers compared with other truck drivers and the working population at large  

Microsoft Academic Search

Personal lifestyle and working conditions are closely linked for long haul truck drivers. We compare lifestyle related diseases in long haul drivers with other drivers of goods and the working population at large. Standardized hospital treatment ratios (SHR) for lifestyle related diseases were compared for long haul truck drivers and other truck drivers to the working population at large. The

Søren Dahl; Linda Kaerlev; Anker Jensen; Finn T; Harald Hannerz; Sabro Nielsen

2009-01-01

240

A deep survey of the Coma cluster: Is there a large population of star- forming dwarfs?  

NASA Astrophysics Data System (ADS)

We request 2 nights with the 8K Mosaic Camera on the KPNO 4-meter to obtain medium-band imaging of a 2.88sq° strip in the Coma cluster. These filters, for the cluster redshift of z=0.0231, are appropriately tuned to isolate the rest-frame wavelength of key spectral features in star-forming and dwarf spheroidal Coma galaxies. These observations will allow us to efficiently isolate thousands of cluster members relative to the background field galaxy population, a job that would be very expensive using spectroscopic followup. Recent ground- and HST-based studies indicate that star-forming dwarf populations may be a fundamental component in clusters. Such a population is believed to produce a steep upturn in some cluster luminosity functions, however a lack of deep cluster redshift surveys prevents firm confirmation of this dwarf component. We seek to isolate candidate galaxies in Coma which represent the most likely source of the steep faint-end LF reputed to exist by others: star- forming dwarfs with strong emission lines and early-type dwarf spheroidals with 4000 an breaks. There is mounting evidence that such star-bursting components may form structural sub-units in clusters and may be manifestations of the Butcher-Oemler effect seen at high redshift. The large number of high-probability cluster members expected from this medium-band survey will enable us to address these important recent findings concerning cluster populations.

Odewahn, Stephen; Windhorst, Rogier; Geller, Margaret; Kurtz, Michael

2001-02-01

241

Sexual network position and risk of sexually transmitted infections  

Microsoft Academic Search

Objectives:A population-based sexual network study was used to identify sexual network structures associated with sexually transmitted infection (STI) risk, and to evaluate the degree to which the use of network-level data furthers the understanding of STI risk.Methods:Participants (n = 655) were from the baseline and 12-month follow-up waves of a 2001–2 population-based longitudinal study of sexual networks among urban African–American

C M Fichtenberg; S Q Muth; B Brown; N S Padian; T A Glass; J M Ellen

2009-01-01

242

SEXUALLY TRANSMITTED DISEASES SURVEILLANCE SYSTEM  

EPA Science Inventory

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

243

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. PMID:20228091

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

2010-01-01

244

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. PMID:23174009

2012-01-01

245

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

246

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

PubMed

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

Stanghellini; Shaw; Balick; Blades

2000-05-10

247

Epidemiological features of amyotrophic lateral sclerosis in a large clinic-based African American population.  

PubMed

Our objective was to identify the main clinical and epidemiological features of ALS in a large cohort of African American (AA) patients and compare them to Caucasian (CA) patients in a clinic-based population. We retrospectively identified 207 patients who were diagnosed with ALS based on the revised El Escorial criteria (60 AA and 147 CA subjects). Patients were seen in the Neuromuscular Division at the University Medical Center. We compared epidemiological and clinical features of these two groups, focusing on age of onset and diagnosis, clinical presentation and survival. Results showed that AA patients had a significantly younger age of disease onset (55 years vs. 61 years for CA, p = 0.011) and were diagnosed at an earlier age (56 years vs. 62 years, p = 0.012). In younger ALS patients (< 45 years of age), there was a significant difference in gender frequency, with females predominating in the AA population and males in the CA population (p = 0.025). In a multivariable Cox proportional hazard model, survival rates were not different between the groups. In both groups, survival significantly increased with younger age. In conclusion, AA patients presented at an earlier age, but there was no difference in survival compared to CA patients. A gender reversal occurred in younger ALS patients, with AA patients more likely to be female and CA patients more likely to be male. PMID:23458155

Kazamel, Mohamed; Cutter, Gary; Claussen, Gwendolyn; Alsharabati, Mohammad; Oh, Shin J; Lu, Liang; King, Peter H

2013-09-01

248

Acculturation, Health Protective Sexual Communication, and HIV/AIDS Risk Behavior among Hispanic Women in a Large Midwestern City  

ERIC Educational Resources Information Center

The relationships among acculturation, health protective sexual communication, and HIV/AIDS risk behaviors of Hispanic women are examined. Respondents represented 14 Latin American countries, a mean age of 29.5 years, and relatively low education and income levels. A significant correlation was found between higher non-Hispanic acculturation level…

Rojas-Guyler, Liliana; Ellis, Nancy; Sanders, Stephanie

2005-01-01

249

Characterization of mitochondrial haplogroups in a large population-based sample from the United States.  

PubMed

Mitochondrial DNA (mtDNA) haplogroups are valuable for investigations in forensic science, molecular anthropology, and human genetics. In this study, we developed a custom panel of 61 mtDNA markers for high-throughput classification of European, African, and Native American/Asian mitochondrial haplogroup lineages. Using these mtDNA markers, we constructed a mitochondrial haplogroup classification tree and classified 18,832 participants from the National Health and Nutrition Examination Surveys (NHANES). To our knowledge, this is the largest study to date characterizing mitochondrial haplogroups in a population-based sample from the United States, and the first study characterizing mitochondrial haplogroup distributions in self-identified Mexican Americans separately from Hispanic Americans of other descent. We observed clear differences in the distribution of maternal genetic ancestry consistent with proposed admixture models for these subpopulations, underscoring the genetic heterogeneity of the United States Hispanic population. The mitochondrial haplogroup distributions in the other self-identified racial/ethnic groups within NHANES were largely comparable to previous studies. Mitochondrial haplogroup classification was highly concordant with self-identified race/ethnicity (SIRE) in non-Hispanic whites (94.8 %), but was considerably lower in admixed populations including non-Hispanic blacks (88.3 %), Mexican Americans (81.8 %), and other Hispanics (61.6 %), suggesting SIRE does not accurately reflect maternal genetic ancestry, particularly in populations with greater proportions of admixture. Thus, it is important to consider inconsistencies between SIRE and genetic ancestry when performing genetic association studies. The mitochondrial haplogroup data that we have generated, coupled with the epidemiologic variables in NHANES, is a valuable resource for future studies investigating the contribution of mtDNA variation to human health and disease. PMID:24488180

Mitchell, Sabrina L; Goodloe, Robert; Brown-Gentry, Kristin; Pendergrass, Sarah A; Murdock, Deborah G; Crawford, Dana C

2014-07-01

250

Health benefits of legal services for criminalized populations: the case of people who use drugs, sex workers and sexual and gender minorities.  

PubMed

Social exclusion and legal marginalization are important determinants of health outcomes for people who use illicit drugs, sex workers, and persons who face criminal penalties because of homosexuality or transgenderism. Incarceration may add to the health risks associated with police repression and discrimination for these persons. Access to legal services may be essential to positive health outcomes in these populations. Through concrete examples, this paper explores types of legal problems and legal services linked to health outcomes for drug users, sex workers, and sexual minorities and makes recommendations for donors, legal service providers, and civil society organizations. PMID:21105945

Csete, Joanne; Cohen, Jonathan

2010-01-01

251

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. PMID:21385775

Hesse, Elze; Pannell, John R.

2011-01-01

252

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

2010-01-01

253

Impaired Sexual Function  

Microsoft Academic Search

The incidence of impaired sexual function in adults with Parkinson’s disease (PD) is greater than in the general population.\\u000a Studies have examined different aspects of sexual function among adults with PD and their partners. Comparison groups have\\u000a included healthy adults matched for age and gender, as well as age-matched controls with chronic, non-neurological disease\\u000a with motor impairment. Impaired sexual function

Cheryl Waters; Janice Smolowitz

254

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. PMID:12495496

Monnet, Jean-Matthieu; Cherry, Michael I

2002-01-01

255

Populations, pathogens, and epidemic phases: closing the gap between theory and practice in the prevention of sexually transmitted diseases  

Microsoft Academic Search

The phase specific model for the prevention and control of sexually transmitted infections (STI) offers new insights into the strategic planning of programmes. The model illustrates the importance of modifying the focus of prevention and control activities to different subpopulations as the epidemic evolves over time. However, the practical application of phase specific approaches will depend on an understanding of

J F Blanchard

2002-01-01

256

Poppr 1.0.5: An R package for genetic analysis of populations with mixed (clonal/sexual) reproduction  

E-print Network

/sexual) reproduction Zhian N. Kamvar1 and Niklaus J. Gr¨unwald1,2 1) Department of Botany and Plant Pathology, Oregon with mixed reproductive modes. Poppr's main advantage is the ease of use and integration with other packages such as adegenet and vegan, including support for novel methods such as clone correction, multilocus genotype

Grünwald, Niklaus J.

257

Is religiosity a barrier to sexual and reproductive health? Results from a population-based study of young Croatian adults.  

PubMed

Following the demise of socialism in 1989, religious identification substantially increased in most countries of Central, East, and Southeast Europe. Considering that there is evidence that religiosity is associated with reduced sexual risk taking among young people, this study explored associations between religiosity--assessed at three different levels (religious upbringing, personal religiosity, and social network religiosity)--and sexual risks among young Croatian adults. In addition, we examined whether religiosity predicted chlamydial infection among women and men aged 18-25. The data were collected in a national probability survey carried out in 2010 (n = 1,005). Overall, the effects of religiosity were sporadic, present primarily among women, and of small size. This lack of a sizeable impact of religiosity on young adults' sexuality was likely related to a particular type of religiosity, characterized by individualized morality, found among young people in the country. Although Croatia seems to be one of the most religious countries in Europe, our findings suggest that promoting religious morality--as recently attempted by an abstinence-based educational program--may not be an efficient tool in reducing sexual risks. PMID:22441770

Puzek, Ivan; Stulhofer, Aleksandar; Boži?evi?, Ivana

2012-12-01

258

Sexual selection and natural selection in bird speciation  

PubMed Central

The role of sexual selection in speciation is investigated, addressing two main issues. First, how do sexually selected traits become species recognition traits? Theory and empirical evidence suggest that female preferences often do not evolve as a correlated response to evolution of male traits. This implies that, contrary to runaway (Fisherian) models of sexual selection, premating isolation will not arise as an automatic side effect of divergence between populations in sexually selected traits. I evaluate premating isolating mechanisms in one group, the birds. In this group premating isolation is often a consequence of sexual imprinting, whereby young birds learn features of their parents and use these features in mate choice. Song, morphology and plumage are known recognition cues. I conclude that perhaps the main role for sexual selection in speciation is in generating differences between populations in traits. Sexual imprinting then leads to these traits being used as species recognition mechanisms. The second issue addressed in this paper is the role of sexual selection in adaptive radiation, again concentrating on birds. Ecological differences between species include large differences in size, which may in themselves be sufficient for species recognition, and differences in habitat, which seem to evolve frequently and at all stages of an adaptive radiation. Differences in habitat often cause song and plumage patterns to evolve as a result of sexual selection for efficient communication. Therefore sexual selection is likely to have an important role in generating premating isolating mechanisms throughout an adaptive radiation. It is also possible that sexual selection, by creating more allopatric species, creates more opportunity for ecological divergence to occur. The limited available evidence does not support this idea. A role for sexual selection in accelerating ecological diversification has yet to be demonstrated.

Price, T.

1998-01-01

259

Sexual Assault  

MedlinePLUS

... for Patients Share This Page: Sexual Assault Resources Sexual Assault Sexual assault is a significant problem affecting American ... National Network at 1-800-656-HOPE (4673). Sexual Assault Examinations It is important to know that a ...

260

Canadian fishery closures provide a large-scale test of the impact of gillnet bycatch on seabird populations  

PubMed Central

In 1992, the eastern Canadian gillnet fisheries for northern cod and Atlantic salmon were largely closed. These large-scale fishery closures resulted in the removal of tens of thousands of gillnets known to inflict high levels of seabird mortality. We used this unprecedented opportunity to test the effects of gillnet removal on seabird populations. Consistent with predictions, we show that the breeding populations of divers (auks, gannets; susceptible to gillnet bycatch) have increased from pre-closure levels, whereas the populations of scavenging surface-feeders (gulls; low vulnerability to gillnet bycatch but susceptible to removal of fisheries discards) have decreased. Using the most complete series of seabird census data for the species most vulnerable to bycatch, we demonstrate a positive population response of common murres to reduction in gillnet fishing within its foraging range. These findings support the widespread but seldom documented contention that fisheries bycatch negatively impacts populations of non-target large vertebrates. PMID:23720519

Regular, Paul; Montevecchi, William; Hedd, April; Robertson, Gregory; Wilhelm, Sabina

2013-01-01

261

Canadian fishery closures provide a large-scale test of the impact of gillnet bycatch on seabird populations.  

PubMed

In 1992, the eastern Canadian gillnet fisheries for northern cod and Atlantic salmon were largely closed. These large-scale fishery closures resulted in the removal of tens of thousands of gillnets known to inflict high levels of seabird mortality. We used this unprecedented opportunity to test the effects of gillnet removal on seabird populations. Consistent with predictions, we show that the breeding populations of divers (auks, gannets; susceptible to gillnet bycatch) have increased from pre-closure levels, whereas the populations of scavenging surface-feeders (gulls; low vulnerability to gillnet bycatch but susceptible to removal of fisheries discards) have decreased. Using the most complete series of seabird census data for the species most vulnerable to bycatch, we demonstrate a positive population response of common murres to reduction in gillnet fishing within its foraging range. These findings support the widespread but seldom documented contention that fisheries bycatch negatively impacts populations of non-target large vertebrates. PMID:23720519

Regular, Paul; Montevecchi, William; Hedd, April; Robertson, Gregory; Wilhelm, Sabina

2013-08-23

262

Five novel mutations and two large deletions in a population analysis of the phenylalanine hydroxylase gene.  

PubMed

Mutational spectrum of the phenylalanine hydroxylase (PAH) deficiency was investigated in 107 families (90% of the Slovene PKU population). The entire coding region of the PAH gene was analyzed with dHPLC to select the samples where subsequently the automated sequencing analysis was performed. MLPA analysis was performed to identify large deletions, which were later confirmed with long-range PCR. Correlations with patients' phenotypes and genotype-based predictions of BH(4)-responsiveness were assessed. Altogether, disease-causing mutations were identified on 209 alleles (detection rate 97.7%). A spectrum of 36 different disease-causing mutations was identified: 20 missense mutations (80% of the alleles), eight splicing mutations (13% of the alleles), one nonsense mutation (0.5% of the alleles), four small deletions with frame shift (6% of the alleles), one small insertion with frame shift (0.5% of the alleles), and two large deletions (2% of the alleles). The most frequent mutation was p.R408W in exon 12, representing 29% of the alleles, which is in concordance with other neighboring and/or Slavic PKU populations. Other common mutations were: p.R158Q, p.A403V, p.P281L and p.E390G, accounting for 9%, 7%, 7% and 7% of the alleles respectively. Five novel mutations were detected: c.43_44insAG, c.56_59+1delACAGG, p.V45A, p.L62P and p.R157S. Large deletion of exon 5 (EX5del955) was found in three patients and a deletion of exon 3 (EX3del4765) in one patient. A spectrum of 64 different genotypes was found, seven of them accounting for over than a third of all families. Among thirteen families with homozygous mutation (13% of the PKU population), 10 had p.R408W, two had p.R158Q and one had p.E390G. Among 107 families, 58 were classified as classic PKU (54.2%), 28 as mild PKU (25.9%) and 21 as MHP (19.6%). Twenty-six different genotypes (40.6%) were predicted to be BH(4)-responsive, represented by 38 different families (35.5%). PMID:22513348

Groselj, Urh; Tansek, Mojca Zerjav; Kovac, Jernej; Hovnik, Tinka; Podkrajsek, Katarina Trebusak; Battelino, Tadej

2012-06-01

263

A Washington Photometric Survey of the Large Magellanic Cloud Field Star Population  

NASA Astrophysics Data System (ADS)

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 deg2, obtained from Washington CT 1 T 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 1(MS TO) mags are on average ~0.5 mag brighter than the T 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 ~1 and 13 Gyr and ~-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 (~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 ~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, Andrés E.; Geisler, Doug; Mateluna, Renee

2012-10-01

264

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

265

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

E-print Network

We investigate the evolution of stellar population gradients from $z=2$ to $z=0$ in massive galaxies at large radii ($r > 2R_{\\mathrm{eff}}$) using ten cosmological zoom simulations of halos with $6 \\times 10^{12} M_{\\odot} cooling and enrichment from SNII, SNIa and AGB winds. We explore the differential impact of an empirical model for galactic winds that reproduces the mass-metallicity relation and its evolution with redshift. At larger radii the galaxies, for both models, become more dominated by stars accreted from satellite galaxies in major and minor mergers. In the wind model, fewer stars are accreted, but they are significantly more metal poor resulting in steep global metallicity ($\\langle \

Hirschmann, Michaela; Ostriker, Jeremiah P; Forbes, Duncan A; Duc, Pierre-Alain; Davé, Romeel; Oser, Ludwig; Karabal, Emin

2014-01-01

266

Estimating inbreeding in large, semi-isolated populations: effects of varying generation lengths and of migration.  

PubMed

The purpose of the study reported here was to investigate two important assumptions used in a recently reported new method of estimating inbreeding in large, relatively isolated populations over historic times. The method, based on modeling the genealogical "paradox," produces values of Pearl's coefficients, Z, a measure of inbreeding or genealogical coalescence, as a function of time. In this study, the effects on inbreeding of two important assumptions made in earlier studies, namely those of using a constant generation length and of ignoring migration, have been investigated for the population of Britain. First, by relating the median age of women at childbirth to the development level of various societies, the variation of the generation lengths for different periods in historic Britain were estimated. Values of Z for two types of varying generation lengths were then calculated and compared with the case of constant generation length. Second, the population curve for Britain used in earlier studies was modified to obtain the subpopulation at any time during the past two millennia that was descended from the pre-Roman British Celts. Values of Z for the case with migration were then calculated and compared with the case for no migration. It is shown that these two assumptions may be taken into account if and when required. Both the effect of a varying generation length and the effect of migration on Z were found to be 20-40%, when no known value of inbreeding was used, and 2-5%, when a known value of inbreeding was used. PMID:17546611

Pattison, J E

2007-01-01

267

FRET Imaging by Laser Scanning Cytometry on Large Populations of Adherent Cells.  

PubMed

The application of FRET (fluorescence resonance energy transfer) sensors for monitoring protein-protein interactions under vital conditions is attracting increasing attention in molecular and cell biology. Laser-scanning cytometry (LSC), a slide-based sister procedure to flow cytometry, provides an opportunity to analyze large populations of adherent cells or 2-D solid tissues in their undisturbed physiological settings. Here we provide an LSC-based three-laser protocol for high-throughput ratiometric FRET measurements utilizing cyan and yellow fluorescent proteins as a FRET pair. Membrane labeling with Cy5 dye is used for cell identification and contouring. Pixel-by-pixel and single-cell FRET efficiencies are calculated to estimate the extent of the molecular interactions and their distribution in the cell populations examined. We also present a non-high-throughput donor photobleaching FRET application, for obtaining the required instrument parameters for ratiometric FRET. In the biological model presented, HeLa cells are transfected with the ECFP- or EYFP-tagged Fos and Jun nuclear proteins, which heterodimerize to form active AP1 transcription factor. Curr. Protoc. Cytom. 70:2.23.1-2.23.29. © 2014 by John Wiley & Sons, Inc. PMID:25271960

Doan-Xuan, Quang-Minh; Szalóki, Nikoletta; Tóth, Katalin; Szöll?si, János; Bacso, Zsolt; Vámosi, György

2014-01-01

268

Large Scale Variability Survey of Orion II: mapping the young, low-mass stellar populations  

NASA Astrophysics Data System (ADS)

We present further results of our ongoing large scale variability survey of the Orion OB1 Association, carried out with the 8k x 8k CCD Mosaic Camera on the 1m Schmidt telescope at the Venezuela National Observatory. In an area of over 60 square degrees we have unveiled new populations of low-mass young stars over a range of environments, from the dense molecular clouds of the Orion belt region, Ori OB 1b, to areas devoid of gas in Orion OB 1a. These new young stars span ages from 1-2 Myr in Ori OB 1b to roughly 10 Myr in Ori OB 1a, a likely scenario of sequential star formation triggered by the first generation of massive stars. Proxy indicators like H? emission and near-IR excesses show that accretion from circumstellar disks in the 10 Myr stars of Ori OB 1a has mostly stopped. This population is a numerous analog of groups like TW Hya, making it an excellent laboratory to look for debris disks and study the epoch of planet formation in sparse, non-clustered environments. Research reported herein funded by NSF grant No. 9987367, and by CONICIT and Ministerio de Ciencia y Tecnología, Venezuela.

Briceño, C.; Calvet, N.; Hartmann, L. W.; Vivas, A. K.

2000-12-01

269

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

270

New X-ray lights on the supernova remnant population of the Large Magellanic Cloud  

NASA Astrophysics Data System (ADS)

Supernova remnants (SNRs) mark the end point of stellar evolution. They return nucleosynthesis products to the interstellar medium (ISM), enriching and mixing it with freshly-produced heavy elements. Studying SNRs in general, and their X-ray emission in particular, is crucial to advance our understanding of many important astrophysical processes. With an XMM-Newton Very Large Programme (PI: F. Haberl), we conducted an X-ray survey of the Large Magellanic Cloud (LMC). As opposed to the Milky Way, the LMC offers an ideal target, at a well-constrained distance with small absorption column densities. Thus, X-ray properties of the evolved end of the SNR population of a galaxy can be studied. I will present the characteristics of the newly X-ray-discovered SNRs, with emphasis on the discovery of several iron-rich SNRs, which are the most evolved remnants of type Ia (i.e. thermonuclear) supernovae. I will take advantage of the high level of completeness of our sample of SNRs to i) present the X-ray luminosity function (XLF) of LMC SNRs, extended towards lower-luminosity objects, comparing it to the XLF of SNRs in other galaxies; and ii) compare the spatial distribution of SNRs and star formation histories in the LMC.

Maggi, P.; Haberl, F.; Sasaki, M.; Kavanagh, P.; Filipovi?, M.; Bozzetto, L.; Points, S.; Chu, Y.; Gruendl, R.; Dickel, J.

2014-07-01

271

Sexual health and stigma in urban newspaper coverage of methamphetamine.  

PubMed

The epidemic use of methamphetamine in the United States is a growing public health problem. Recently its use has increased among gay men who live in urban areas, with accompanying increases in sexually transmitted diseases. This study examined how methamphetamine and sexual health are framed. It investigated the stigma associated with heterosexuals and gay men. Stories from 13 urban newspapers in cities with large populations of gay men published from 2000 to 2006 were analyzed. Results indicated that methamphetamine and sexual health were framed primarily as an individual, present problem. Stories framed methamphetamine as a health problem slightly more often than as a crime problem, but health was the dominant frame in stories mentioning gay men. Crime was the dominant frame in stories with heterosexuals. Articles tied gay men to sexual health issues. Findings indicate gay men and heterosexuals are stigmatized in news coverage of sexual issues and methamphetamine but in different ways. PMID:19477770

Schwartz, Joseph; Andsager, Julie L

2008-03-01

272

Trends and Milestones: Continuing Reduction in Populations of Large State Residential Facilities for Persons with Intellectual and Developmental Disabilities.  

ERIC Educational Resources Information Center

This article discusses the continuing trend of downsizing and closure of large state institutions for persons with mental retardation. Between 1987 and 2001, nine states closed all of their large state residential facilities, reducing the total national population of such facilities by 2,414 residents. A chart illustrates state reductions. (CR)

Coucouvanis, Kathie; Polister, Barbara; Prouty, Robert; Lakin, K. Charlie

2003-01-01

273

Workplace bullying and sleep disturbances: findings from a large scale cross-sectional survey in the French working population  

E-print Network

1 Workplace bullying and sleep disturbances: findings from a large scale cross-sectional survey between workplace bullying, and its characteristics, and sleep disturbances in a large sample of employees of the French working population. Design: Workplace bullying, evaluated using the validated instrument developed

Paris-Sud XI, Université de

274

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

275

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

276

Large population survey: strengths and limits. Methodology of the EDIFICE survey.  

PubMed

In France, mass screening for breast and colon cancer issupported by the French National Cancer Institute (INCa). In these nationwide screening campaigns, individuals aged between 50 and 74 years receive a personalized letter inviting them for a screening examination every 2 years. Prostate cancer screening is, however, still controversial and has not been included in the INCa recommendations so far. Research organizations are particularly interested in screening and indeed, several studies have been conducted in France and other countries to examine the different aspects of the subject. To provide actual benefits, screening should be undertaken on a regular scheduled basis. Therefore, several studies have assessed the factors influencing the participation rate of women in breast cancer screening in France (). The Institut National de Prévention et d'Education pour la Santé conducted one of these in 2005: the Baromètre Cancer (including 4046 individuals aged 15 years or older, interviewed by telephone) analysed beliefs and perceptions about cancer screening and studied attendance rates for breast, colon and prostate cancer (including scheduled screening). No previous survey has ever been conducted simultaneously among the general population and physicians with regard to individual and scheduled screening for breast cancer and colorectal cancer (CRC) or individual screening for prostate cancer. EDIFICE is thus the first large-scale survey to assess screening practices in France by analysing the targeted population on the one hand and the clinical practice of French general practitioners (GPs) on the other hand, using the 'mirror study' method to compare results. Two national surveys were conducted in 2005 and 2008. In 2005, only 22 geographical regions were included in the screening programme for CRC. PMID:21245682

Roussel, Claire; Touboul, Chantal

2011-01-01

277

Prevalences of and risk factors for biliary stones and gallbladder polyps in a large Chinese population  

PubMed Central

Objectives This study aimed to identify the prevalences of and risk factors associated with the development of gallbladder stones and polyps in a large Chinese population. Methods Prevalences of and risk factors for biliary stones and gallbladder polyps were retrospectively investigated among subjects who underwent a general check-up at the Health Screening Centres of Peking Union Medical College Hospital and Beijing Charity Hospital between January 2007 and June 2010. Results A total of 60 064 people were enrolled in the study. Overall prevalences of biliary stones and gallbladder polyps were 4.2% (n = 2527) and 6.9% (n = 4119), respectively. Risk factors associated with increased odds ratios (ORs) for the development of biliary stones were female gender (OR = 1.51), age ?50 years (OR = 2.09), history of hypertension (OR = 1.37), thickened gallbladder wall (cholecystitis) (OR = 1.98), fasting blood glucose ?6.10 mmol/l (OR = 1.27), body mass index ?25 kg/m2 (OR = 1.25), systolic blood pressure ?140 mmHg (OR = 1.31) and diastolic blood pressure ?90 mmHg (OR = 1.44). Factors associated with gallbladder polyps were female gender (OR = 0.66), thickened gallbladder wall (OR = 2.09), negativity for hepatitis B surface antigen (HBsAg) and positivity for hepatitis B core antibody (anti-HBc) (OR = 2.61), and positivity for both HBsAg and anti-HBc (OR = 3.21). Conclusions Prevalences of biliary stones and gallbladder polyps among Chinese people are similar to those reported for other populations. Biliary stones appear to be associated with female gender, age, obesity, blood glucose, blood pressure and cholecystitis. Male gender, hepatitis B virus infection and cholecystitis were strong risk factors for the formation of gallbladder polyps. PMID:22568413

Xu, Qing; Tao, Lian-yuan; Wu, Qiao; Gao, Fei; Zhang, Feng-liang; Yuan, Li; He, Xiao-dong

2012-01-01

278

Population Genetic Structure of Titanotrichum oldhamii (Gesneriaceae), a Subtropical Bulbiliferous Plant with Mixed Sexual and Asexual Reproduction  

PubMed Central

• Background and Aims Titanotrichum oldhamii is a monotypic genus distributed in Taiwan, adjacent regions of China and the Ryukyu Isands of Japan. Its conservation status is vulnerable as most populations are small and widely scattered. Titanotrichum has a mixed system of reproduction with vegetative bulbils and seeds. The aim of this study was to understand the population genetic structure of Titanotrichum in relation to its specific reproductive behaviour and to determine possible implications for conservation strategies. • Methods After an extensive inventory of most wild populations of Titanotrichum in East Asia, samples from 25 populations within its major distribution were carried out utilizing RAPD and inter?SSR molecular fingerprinting analysis. • Key Results The findings support the conclusion that many populations reproduce predominantly asexually but that some genetic variation still exists within populations. However, significant amounts of variation exist between populations, perhaps reflecting population differentiation by drift. This partitioning of genetic diversity indicates that the level of inter?population gene exchange is extremely low. These findings are consistent with field observations of very limited seed production. The Chinese populations are similar to those of Northern Taiwan, while the Ryukyu populations fall within the range of variation of the north?central Taiwan populations. The Taiwanese populations are relatively variable and differentiation between north, east and south Taiwan is evident. • Conclusions The distribution of Titanotrichum seems to be consistent with a former land connection between China, Taiwan and the Ryukyu Islands at a glacial maximum during the Quaternary, followed by progressive fragmentation of the populations. North?central Taiwan is the centre of genetic diversity, possibly due to the proximity of the former land bridge between the regions, together with the variety of suitable habitats in north Taiwan. The significance of these findings for conservation is discussed. PMID:14707003

WANG, CHUN?NENG; MÖLLER, MICHAEL; CRONK, QUENTIN C. B.

2004-01-01

279

Evaluación de comportamientos sexuales de riesgo en una población universitaria de la Provincia de Buenos Aires Sexual risk behaviors assessment in a university-based population of Buenos Aires Province  

Microsoft Academic Search

Objectives: estimate prevalence of sexual risk behaviors, immunization against B Hepatitis, and to appraise the knowledge about Sexually Transmitted Diseases (STD) and contraceptives methods, among students of Universidad Tecnológica Nacional. Materials and methods: cross sectional descriptive study to assess sociodemographic data, sexual behavior history and knowledge about STD and contraceptives methods, through an anonymous questionnaire, with Likert-like scale answers. Results:

Coppolillo FE

280

Sexual reproduction of human fungal pathogens.  

PubMed

We review here recent advances in our understanding of sexual reproduction in fungal pathogens that commonly infect humans, including Candida albicans, Cryptococcus neoformans/gattii, and Aspergillus fumigatus. Where appropriate or relevant, we introduce findings on other species associated with human infections. In particular, we focus on rapid advances involving genetic, genomic, and population genetic approaches that have reshaped our view of how fungal pathogens evolve. Rather than being asexual, mitotic, and largely clonal, as was thought to be prevalent as recently as a decade ago, we now appreciate that the vast majority of pathogenic fungi have retained extant sexual, or parasexual, cycles. In some examples, sexual and parasexual unions of pathogenic fungi involve closely related individuals, generating diversity in the population but with more restricted recombination than expected from fertile, sexual, outcrossing and recombining populations. In other cases, species and isolates participate in global outcrossing populations with the capacity for considerable levels of gene flow. These findings illustrate general principles of eukaryotic pathogen emergence with relevance for other fungi, parasitic eukaryotic pathogens, and both unicellular and multicellular eukaryotic organisms. PMID:25085958

Heitman, Joseph; Carter, Dee A; Dyer, Paul S; Soll, David R

2014-08-01

281

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

282

Large Herbivore Impacts on Demographic Characteristics and Population Dynamics of an Endangered Orchid (Spiranthes parksii Correll)  

E-print Network

Spiranthes Parksii Correll is an endangered orchid of Texas. Populations of S. parksii are threatened by habitat loss and degradation resulting from human population growth and attendant development and resource extraction. Conservation easements...

Wonkka, Carissa Lyn

2012-02-14

283

On the Etiology of Sexual Dysfunction  

ERIC Educational Resources Information Center

Lack of consideration of the sexually functional population has led to misconceptions about causes of sexual dysfunction functioning. Automatic functioning can mask effects of pathogenic influences on sexuality, making these effects appear random, confounding etiological issues and creating the belief that causes of sexual dysfunction and disorder…

Apfelbaum, Bernard

1977-01-01

284

After breast cancer: sexual functioning of sexual minority survivors.  

PubMed

Research on sexual difficulties after cancer has neglected sexual minority women (SMW); for example, lesbian and bisexual women. Clinicians treating these women are therefore at a disadvantage as they lack information about sexual problems in this population. This study tested the hypothesis that SMW with breast cancer have poorer sexual function than SMW without breast cancer, distinguishing partnered from unpartnered women. Using convenience sample recruitment, we conducted a case-control study to compare survivors of breast cancers who are SMW, in other words, cases to controls, that is, SMW without cancer. Anonymous survey data were collected from 85 cases after they had completed active cancer treatment and 85 age- and partner-status matched controls with no history of any cancer. Participants' self-reported sexual frequency and sexual function measured by the Female Sexual Function Index were evaluated. Cases and controls did not differ in risk of sexual dysfunction or the level of overall sexual functioning; however, cases had lower sexual frequency and scored lower on desire and ability to reach orgasm, and higher on pain compared to controls. Results inform clinicians about sexual minority survivors' sexual domains affected by cancer. When discussing sexual problems and therapeutic options, sexual orientation should be ascertained. PMID:23730713

Boehmer, Ulrike; Ozonoff, Al; Timm, Alison; Winter, Michael; Potter, Jennifer

2014-01-01

285

Dynamic Large-Scale Chromosomal Rearrangements Fuel Rapid Adaptation in Yeast Populations  

PubMed Central

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

2013-01-01

286

Concurrence of Multiple Human Papillomavirus Infections in a Large US Population-based Cohort.  

PubMed

We examined the concurrence of multiple human papillomavirus (HPV) infections in 47,617 women who underwent cervical screening in New Mexico between December 2007 and April 2009 using the LINEAR ARRAY HPV Genotyping Test (Roche Diagnostics, Indianapolis, Indiana), which detects 37 different types of HPV. Our primary goal was to examine the distributions of multiple HPV types with a special interest in negative interactions, which could signal the possibility of type replacement associated with a common niche if some HPV types were prevented by vaccination. Multiple infections were found to be more common than expected under independence, but this could largely be accounted for by a woman-specific latent heterogeneity parameter which was found to be dependent on age and cytological grade. While multiple infections were more common in young women and in those with abnormal cytology, greater heterogeneity was seen in older women and in those with normal cytology, possibly reflecting greater variability in exposure due to current or past HPV exposure or due to heterogeneity in related HPV reactivation or in immune responses to HPV infection or persistence. A negative interaction was found between HPV 16 and several other HPV types for women with abnormal cytology but not for those with normal cytology, suggesting that type replacement in women vaccinated against HPV 16 is unlikely to be an issue for the general population. PMID:25355446

Yang, Zihua; Cuzick, Jack; Hunt, William C; Wheeler, Cosette M

2014-12-01

287

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. PMID:20384941

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

2013-01-01

288

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

2012-01-01

289

Understanding sexual harassment using aggregate construct models.  

PubMed

Sexual harassment has received a substantial amount of empirical attention over the past few decades, and this research has consistently shown that experiencing these behaviors has a detrimental effect on employees' well-being, job attitudes, and behaviors at work. However, these findings, and the conclusions that are drawn from them, make the implicit assumption that the empirical models used to examine sexual harassment are properly specified. This article presents evidence that properly specified aggregate construct models are more consistent with theoretical structures and definitions of sexual harassment and can result in different conclusions about the nomological network of harassment. Results from 3 large samples, 2 military and 1 from a civilian population, are used to illustrate the differences between aggregate construct and reflective indicator models of sexual harassment. These analyses suggested that the factor structure and the nomological network of sexual harassment differ when modeling harassment as an aggregate construct. The implications of these results for the continued study of sexual harassment are discussed. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:25265486

Nye, Christopher D; Brummel, Bradley J; Drasgow, Fritz

2014-11-01

290

Populations  

NSDL National Science Digital Library

This chapter introduces population as a group of the same kind of organisms in a given space at a given time. The activities in this section will provide students with the opportunity to define population, estimate populations in a community, and count and compare populations within a community. Students will gain the knowledge in describing plant and animal populations living in a community. They will also experiment with plant populations to control growth and development, not to mention discuss the effects of abiotic conditions on a community.

Galle, Janet R.; Warren, Patricia A.

2005-01-01

291

Population Genetic Structure of Titanotrichum oldhamii (Gesneriaceae), a Subtropical Bulbiliferous Plant with Mixed Sexual and Asexual Reproduction  

Microsoft Academic Search

d Background and Aims Titanotrichum oldhamii is a monotypic genus distributed in Taiwan, adjacent regions of China and the Ryukyu Isands of Japan. Its conservation status is vulnerable as most populations are small and widely scattered. Titanotrichum has a mixed system of reproduction with vegetative bulbils and seeds. The aim of this study was to understand the population genetic structure

CHUN-NENG W ANG; M ICHAEL M OLLER; C. B. C RONK

2004-01-01

292

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

293

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. PMID:23271973

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

294

Parents' Supportive Reactions to Sexual Orientation Disclosure Associated With Better Health: Results From a Population-Based Survey of LGB Adults in Massachusetts  

PubMed Central

This study investigated associations between coming out to parents, experiences of parental support, and self-reported health behaviors and conditions among a population-based sample of LGB individuals using data collected via the 2002 Massachusetts Behavioral Risk Factor Surveillance System (BRFSS) (N=177). We explored the following two hypotheses: (1) LGB individuals who had never disclosed their sexual orientation to a parent would report higher levels of risk behaviors and poorer health conditions than those who had come out; and (2) among LGB respondents who had come out to their parents, the individuals whose parents had reacted unsupportively would report higher levels of risk behaviors and poorer health conditions than those who had come out to parents who were supportive. Approximately two-thirds of GB males and LB females reported receiving adequate social and emotional support from the parent to whom they first disclosed their sexual orientation. Among LB females, no disclosure of sexual orientation to a parent was associated with significantly elevated levels of past month illict drug use (AOR 12.16, 95% CI 2.87–51.54), fair or poor self-reported health status (AOR 5.71, 95% CI 1.45–22.51), and >15 days of depression in the past month (AOR 5.95, 95% CI 1.78–19.90), controlling for potential confounders. However, non-disclosure to a parent by GB males was not associated with greater odds of any of the health indicators assessed. Among GB males, those with unsupportive parents were significantly more likely to report current binge drinking (AOR 6.94, 95% CI 1.70–28.35) and >15 days depression in the past month (AOR 6.08, 95% CI 1.15–32.15), and among LB females, those with unsupportive parents were significantly more likely to report lifetime illicit drug use (AOR 11.43, 95% CI 2.50–52.30), and >15 days depression in the past month (AOR 5.51, 95% CI 1.36–22.36). We conclude that coming out may be associated with better health for LB women, and that parents who react non-supportively when their children disclose LGB sexual orientation may contribute to children’s increased odds of depression and hazardous substance use. PMID:22335417

Rothman, Emily F.; Sullivan, Mairead; Keyes, Susan; Boehmer, Ulrike

2012-01-01

295

Parents' supportive reactions to sexual orientation disclosure associated with better health: results from a population-based survey of LGB adults in Massachusetts.  

PubMed

This study investigated associations between coming out to parents, experiences of parental support, and self-reported health behaviors and conditions among a population-based sample of LGB individuals using data collected via the 2002 Massachusetts Behavioral Risk Factor Surveillance System (BRFSS; N = 177). We explored the following two hypotheses: 1) Lesbian, gay, and bisexual (LGB) individuals who had never disclosed their sexual orientation to a parent would report higher levels of risk behaviors and poorer health conditions than those who had come out; and 2) among LGB respondents who had come out to their parents, the individuals whose parents had reacted unsupportively would report higher levels of risk behaviors and poorer health conditions than those who had come out to parents who were supportive. Approximately two thirds of gay and bisexual (GB) males and lesbian and bisexual (LB) females reported receiving adequate social and emotional support from the parent to whom they first disclosed their sexual orientation. Among LB females, no disclosure of sexual orientation to a parent was associated with significantly elevated levels of past-month illicit drug use (AOR 12.16, 95% CI 2.87-51.54), fair or poor self-reported health status (AOR 5.71, 95% CI 1.45-22.51), and >15 days of depression in the past month (AOR 5.95, 95% CI 1.78-19.90), controlling for potential confounders. However, nondisclosure to a parent by GB males was not associated with greater odds of any of the health indicators assessed. Among GB males, those with unsupportive parents were significantly more likely to report current binge drinking (AOR 6.94, 95% CI 1.70-28.35) and >15 days depression in the past month (AOR 6.08, 95% CI 1.15-32.15), and among LB females, those with unsupportive parents were significantly more likely to report lifetime illicit drug use (AOR 11.43, 95% CI 2.50-52.30), and >15 days depression in the past month (AOR 5.51, 95% CI 1.36-22.36). We conclude that coming out may be associated with better health for LB women, and that parents who react nonsupportively when their children disclose LGB sexual orientation may contribute to children's increased odds of depression and hazardous substance use. PMID:22335417

Rothman, Emily F; Sullivan, Mairead; Keyes, Susan; Boehmer, Ulrike

2012-01-01

296

Prevalence and risk factors of sleep disturbances in a large HIV-infected adult population  

PubMed Central

Introduction Sleep disturbances are frequently reported in HIV-infected patients but there is a lack of large studies on prevalence and risk factors, particularly in the context of current improved immuno-clinical status and use of the newest antiretrovirals (ARV). Method Cross-sectional study to evaluate the prevalence and factors associated with sleep disturbance in adult HIV-infected patients in six French centres of the region “Pays de la Loire”. Patients filled a self-administered questionnaire on their health behaviour, sleep attitudes (Pittsburgh Sleep Quality Index PSQI), quality of life (WHO QOL HIV BREF questionnaire) and depression (Beck depression Inventory (BDI)-II questionnaire). Socio-demographic and immunovirologic data, medical history, ARVs were collected. Results From November 2012 to May 2013, 1354 consecutive non-selected patients were enrolled. Patients’ characteristics were: 73.5% male, median age 47 years, active employment 56.7%, France-native 83% and Africa-native 14.7%, CDC stage C 21%, hepatitis co-infection 13%, lipodystrophy 11.8%, dyslipidemia 20%, high BP 15.1%, diabetes 3%, tobacco smokers 39%, marijuana and cocaine users, 11.7% and 1.7% respectively, and excessive alcohol drinkers 9%. Median (med) duration of HIV infection was 12.4 years, med CD4 count was 604/mm3; 94% of Patients were on ARVs, 87% had undetectable viral load. Median sleeping time was 7 hours. Sleep disturbances (defined as PSQI score >5) were observed in 47% of the patients, more frequently in female (56.4%) than in male (43.9%) (p<0.05) and moderate to serious depressive symptoms (BDI score>19) in 19.7% of the patients. In multivariate analysis, factors associated with sleep disturbances (p<0.05) were depression (odds ratio [OR] 4.6; 95% confidence interval [CI] 3.2–6.8), male gender (OR 0.7; CI 0.5–0.9), active employment (OR 0.7; CI 0.5–0.9), living single (OR 1.5; CI 1.2–2.0), tobacco-smoking (OR 1.3; CI 1.0–1.8), duration of HIV infection (>10 vs. <10 y.) (OR 1.5; CI 1.1–2.0), ARV regimen containing nevirapine (OR 0.7; CI 0.5–0.9) or efavirenz (OR 0.5; CI 0.3–0.7). Conclusions Prevalence of sleep disturbances is high in this HIV population and roughly similar to the French population. Associated factors are rather related to social and psychological status than HIV infection. Depression is frequent and should be taken in care to improve sleep quality. PMID:25394083

Allavena, Clotilde; Guimard, Thomas; Billaud, Eric; de la Tullaye, Sylvie; Reliquet, Véronique; Pineau, Solène; Hüe, Hervé; Supiot, Christelle; Marie Chennebault, Jean; Michau, Christophe; Hitoto, Hikombo; Vatan, Rémi; Raffi, François

2014-01-01

297

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

PubMed Central

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.

2013-01-01

298

Sexual Problems  

MedlinePLUS Videos and Cool Tools

... or constant. Sexual disorders can affect men and women and are classified into four categories: desire disorders, ... the time. Sexual disorders affect both men and women and are classified into 4 main categories: sexual ...

299

Healthy Sexuality  

MedlinePLUS Videos and Cool Tools

... or her sexuality. Let’s talk about how a woman’s body responds to sexual stimulation. During sexual arousal, blood flow increases to a woman’s genitals. Her vagina is lubricated by secretions from ...

300

Sexual Assault  

MedlinePLUS

Sexual assault is any sexual activity to which you haven't freely given your consent. This includes completed ... trust, a friend, an acquaintance, or a stranger. Sexual assault can affect your health in many ways. It ...

301

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. PMID:23275876

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

302

Modeling population exposure to community noise and air pollution in a large metropolitan area.  

PubMed

Epidemiologic studies have shown that both air pollution and community noise are associated with cardiovascular disease mortality. Because road traffic is a major contributor to these environmental pollutants in metropolitan areas, it is plausible that the observed associations may be confounded by coexistent pollutants. As part of a large population-based cohort study to address this concern, we used a noise prediction model to assess annual average community noise levels from transportation sources in metropolitan Vancouver, Canada. The modeled annual average noise level was 64 (inter quartile range 60-68) dB(A) for the region. This model was evaluated by comparing modeled annual daytime A-weighted equivalent continuous noise levels (L(day)) with measured 5-min daytime A-weighted equivalent continuous noise levels (L(eq,day,5 min)) at 103 selected roadside sites in the study region. On average, L(day) was 6.2 (95% CI, 6.0-7.9) dB(A) higher than, but highly correlated (r=0.62; 95% CI, 0.48-0.72) with, L(eq,day,5 min). These results suggest that our model-based noise exposure assessment could approximately reflect actual noise exposure in the study region. Overall, modeled noise levels were not strongly correlated with land use regression estimates of traffic-related air pollutants including black carbon, particulate matter with aerodynamic diameter ?2.5 ?m (PM(2.5)), NO(2) and NO; the highest correlation was with black carbon (r=0.48), whereas the lowest correlation was with PM(2.5) (r=0.18). There was no consistent effect of traffic proximity on the correlations between community noise levels and traffic-related air pollutant concentrations. These results, consistent with previous studies, suggest that it is possible to assess potential adverse cardiovascular effects from long-term exposures to community noise and traffic-related air pollution in prospective epidemiologic studies. PMID:22520824

Gan, Wen Qi; McLean, Kathleen; Brauer, Michael; Chiarello, Sarah A; Davies, Hugh W

2012-07-01

303

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

PubMed

In order to meet the potential need for emergency large-scale retrospective radiation biodosimetry following an accident or attack, we have developed instrumentation and methodology for in vivo electron paramagnetic resonance spectroscopy to quantify concentrations of radiation-induced radicals within intact teeth. This technique has several very desirable characteristics for triage, including independence from confounding biologic factors, a non-invasive measurement procedure, the capability to make measurements at any time after the event, suitability for use by non-expert operators at the site of an event, and the ability to provide immediate estimates of individual doses. Throughout development there has been a particular focus on the need for a deployable system, including instrumental requirements for transport and field use, the need for high throughput, and use by minimally trained operators.Numerous measurements have been performed using this system in clinical and other non-laboratory settings, including in vivo measurements with unexposed populations as well as patients undergoing radiation therapies. The collection and analyses of sets of three serially-acquired spectra with independent placements of the resonator, in a data collection process lasting approximately five minutes, provides dose estimates with standard errors of prediction of approximately 1 Gy. As an example, measurements were performed on incisor teeth of subjects who had either received no irradiation or 2 Gy total body irradiation for prior bone marrow transplantation; this exercise provided a direct and challenging test of our capability to identify subjects who would be in need of acute medical care. PMID:21966241

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

2011-09-01

304

Testing reported associations of genetic risk factors for oral clefts in a large Irish study population  

PubMed Central

BACKGROUND Suggestive, but not conclusive, studies implicate many genetic variants in oral cleft etiology. We used a large, ethnically homogenous study population to test whether reported associations between nonsyndromic oral clefts and 12 genes (CLPTM1, CRISPLD2, FGFR2, GABRB3, GLI2, IRF6, PTCH1, RARA, RYK, SATB2, SUMO1, TGFA) could be confirmed. METHODS Thirty-one single nucleotide polymorphisms (SNPs) in exons, splice sites, and conserved non-coding regions were studied in 509 patients with cleft lip with or without cleft palate (CLP), 383 with cleft palate only (CP), 838 mothers and 719 fathers of patients with oral clefts, and 902 controls from Ireland. Case-control and family-based statistical tests were performed using isolated oral clefts for the main analyses. RESULTS In case-control comparisons, the minor allele of PTCH1 A562A (rs2066836) was associated with reduced odds of CLP (OR: 0.29, 95% CI: 0.13–0.64 for homozygotes) whereas the minor allele of PTCH1 L1315P (rs357564) was associated with increased odds of CLP (OR: 1.36, 95% CI: 1.07–1.74 for heterozygotes and OR: 1.56, 95% CI: 1.09–2.24 for homozygotes). The minor allele of one SUMO1 SNP, rs3769817 located in intron 2, was associated with increased odds of CP (OR: 1.45, 95% CI: 1.06–1.99 for heterozygotes). Transmission disequilibrium was observed for the minor allele of TGFA V159V (rs2166975) which was over-transmitted to CP cases (P=0.041). CONCLUSIONS For 10 of the 12 genes, this is the largest candidate gene study of nonsyndromic oral clefts to date. The findings provide further evidence that PTCH1, SUMO1, and TGFA contribute to nonsyndromic oral clefts. PMID:19937600

Carter, Tonia C.; Molloy, Anne M.; Pangilinan, Faith; Troendle, James F.; Kirke, Peadar N.; Conley, Mary R.; Orr, David J. A.; Earley, Michael; McKiernan, Eamon; Lynn, Ena C.; Doyle, Anne; Scott, John M.; Brody, Lawrence C.; Mills, James L.

2012-01-01

305

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

306

POPULATION III STAR FORMATION IN LARGE COSMOLOGICAL VOLUMES. I. HALO TEMPORAL AND PHYSICAL ENVIRONMENT  

SciTech Connect

We present a semi-analytic, computationally inexpensive model to identify halos capable of forming a Population III star in cosmological simulations across a wide range of times and environments. This allows for a much more complete and representative set of Population III star forming halos to be constructed, which will lead to Population III star formation simulations that more accurately reflect the diversity of Population III stars, both in time and halo mass. This model shows that Population III and chemically enriched stars coexist beyond the formation of the first generation of stars in a cosmological simulation until at least z {approx} 10, and likely beyond, though Population III stars form at rates that are 4-6 orders of magnitude lower than chemically enriched stars by z = 10. A catalog of more than 40,000 candidate Population III forming halos were identified, with formation times temporally ranging from z = 30 to z = 10, and ranging in mass from 2.3 Multiplication-Sign 10{sup 5} M{sub Sun} to 1.2 Multiplication-Sign 10{sup 10} M{sub Sun }. At early times, the environment that Population III stars form in is very similar to that of halos hosting chemically enriched star formation. At later times Population III stars are found to form in low-density regions that are not yet chemically polluted due to a lack of previous star formation in the area. Population III star forming halos become increasingly spatially isolated from one another at later times, and are generally closer to halos hosting chemically enriched star formation than to another halo hosting Population III star formation by z {approx} 10.

Crosby, Brian D.; O'Shea, Brian W.; Smith, Britton D. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Turk, Matthew J. [Department of Astronomy, Columbia University, New York, NY 10025 (United States); Hahn, Oliver, E-mail: crosbyb1@msu.edu [Institute for Astronomy, ETH Zurich, CH-8093 Zuerich (Switzerland)

2013-08-20

307

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

2013-06-22

308

Waterscape genetics of the yellow perch (Perca flavescens): patterns across large connected ecosystems and isolated relict populations.  

PubMed

Comparisons of a species' genetic diversity and divergence patterns across large connected populations vs. isolated relict areas provide important data for understanding potential response to global warming, habitat alterations and other perturbations. Aquatic taxa offer ideal case studies for interpreting these patterns, because their dispersal and gene flow often are constrained through narrow connectivity channels that have changed over geological time and/or from contemporary anthropogenic perturbations. Our research objective is to better understand the interplay between historic influences and modern-day factors (fishery exploitation, stocking supplementation and habitat loss) in shaping population genetic patterns of the yellow perch Perca flavescens (Percidae: Teleostei) across its native North American range. We employ a modified landscape genetics approach, analysing sequences from the entire mitochondrial DNA control region and 15 nuclear DNA microsatellite loci of 664 spawning adults from 24 populations. Results support that perch from primary glacial refugium areas (Missourian, Mississippian and Atlantic) founded contemporary northern populations. Genetic diversity today is highest in southern (never glaciated) populations and also is appreciable in northern areas that were founded from multiple refugia. Divergence is greater among isolated populations, both north and south; the southern Gulf Coast relict populations are the most divergent, reflecting their long history of isolation. Understanding the influence of past and current waterway connections on the genetic structure of yellow perch populations may help us to assess the roles of ongoing climate change and habitat disruptions towards conserving aquatic biodiversity. PMID:23078285

Sepulveda-Villet, Osvaldo J; Stepien, Carol A

2012-12-01

309

Use of epidemiological data and direct bioassay for prioritization of affected populations in a large-scale radiation emergency.  

PubMed

Following a radiation emergency, evacuated, sheltered or other members of the public would require monitoring for external and/or internal contamination and, if indicated, decontamination. In addition, the potentially-impacted population would be identified for biodosimetry/bioassay or needed medical treatment (chelation therapy, cytokine treatment, etc.) and prioritized for follow-up. Expeditious implementation of these activities presents many challenges, especially when a large population is affected. Furthermore, experience from previous radiation incidents has demonstrated that the number of people seeking monitoring for radioactive contamination (both external and internal) could be much higher than the actual number of contaminated individuals. In the United States, the Department of Health and Human Services is the lead agency to coordinate federal support for population monitoring activities. Population monitoring includes (1) monitoring people for external contamination; (2) monitoring people for internal contamination; (3) population decontamination; (4) collecting epidemiologic data regarding potentially exposed and/or contaminated individuals to prioritize the affected population for limited medical resources; (5) administering available pharmaceuticals for internal decontamination as deemed necessary by appropriate health officials; (6) performing dose reconstruction; and (7) establishing a registry to conduct long-term monitoring of this population for potential long-term health effects. This paper will focus on screening for internal contamination and will describe the use of early epidemiologic data as well as direct bioassay techniques to rapidly identify and prioritize the affected population for further analysis and medical attention. PMID:21709510

Miller, Charles W; Ansari, Armin; Martin, Colleen; Chang, Art; Buzzell, Jennifer; Whitcomb, Robert C

2011-08-01

310

LARGE NONLETHAL EFFECTS OF AN INVASIVE INVERTEBRATE PREDATOR ON ZOOPLANKTON POPULATION GROWTH RATE  

Microsoft Academic Search

We conducted a study to determine the contribution of lethal and nonlethal effects to a predator's net effect on a prey's population growth rate in a natural setting. We focused on the effects of an invasive invertebrate predator, Bythotrephes longimanus ,o n zooplankton prey populations in Lakes Michigan and Erie. Field data taken at multiple dates and locations in both

Kevin L. Pangle; Scott D. Peacor; Ora E. Johannsson

2007-01-01

311

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. PMID:22479465

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

2012-01-01

312

Foraging costs of a tail ornament: Experimental evidence from two populations of barn swallows Hirundo rustica with different degrees of sexual size dimorphism  

Microsoft Academic Search

Secondary sexual characters are assumed to be costly to produce or maintain. A test of this assumption was performed using the sexually exaggerated outermost tail feathers of male barn swallows Hirundo rustica, a trait currently subject of a directional female mate preference. A possible cost of sexual signalling in male barn swallows arises from increased flight cost during foraging in

A. P. Moller; F. Lope; J. M. López Caballero

1995-01-01

313

Institutions serving a large population of Asian American and Native American Pacific Islander-Serving Institutions (AANAPISIs) have also  

E-print Network

Institutions serving a large population of Asian American and Native American Pacific Islander and Native American Pacific Islander-serving institution' means an institution of higher education of undergraduate students that is not less than 10 percent stu- dents who are Asian American or Native American

Hemmers, Oliver

314

1374 VOLUME 114 | NUMBER 9 | September 2006 Environmental Health Perspectives Large-scale, population-based epidemiologic  

E-print Network

-scale, population-based epidemiologic investigations of the health effects of ambient air pollution often rely in the large majority of locations, spatial estimation methods using geographic information systems (GIS methods. Important methodologic and practical issues still need to be resolved, however. This study

Short, Daniel

315

Population biology of eyeflukes in fish from a large fluvial ecosystem: the importance of gulls and habitat characteristics  

Microsoft Academic Search

Spottail shiners (Notropis hudsonius) were monitored for eyeflukes monthly at four sites in the St. Lawrence River, Quebec, from spring through autumn in 1997 and 1998. In general, mean abundance of Diplostomum spp. in the lens of spottail shiners was highest at sites near large ring-billed gull ( Larus delawarensis) colonies and was higher in 1998 than in 1997. Population

D. J. Marcogliese; S. Compagna; E. Bergeron; J. D. McLaughlin

2001-01-01

316

Growth of geologic fractures into large-strain populations: review of nomenclature, subcritical crack growth, and some implications  

E-print Network

Growth of geologic fractures into large-strain populations: review of nomenclature, subcritical crack growth, and some implications for rock engineering R.A. Schultz* Geomechanics-Rock Fracture Group of Nevada, Reno, NV 89557, USA Accepted 7 October 1999 Abstract Several aspects of fracture arrays

317

ORIGINAL RESEARCH New Morphologic Variants of the Hand Motor Cortex as Seen with MR Imaging in a Large Study Population  

Microsoft Academic Search

BACKGROUND AND PURPOSE: The hand motor cortex (HMC) has been classically described as having an omega or epsilon shape in axial-plane images obtained with CT and MR imaging. The aim of this study was to use MR imaging and Talairach normalization in a large sample population that was homogeneous for age and handedness to evaluate in a sex model a

M. Caulo; C. Briganti; P. A. Mattei; B. Perfetti; A. Ferretti; G. L. Romani; A. Tartaro; C. Colosimo

318

The Carina dwarf spheroidal - an old galaxy with a large intermediate age population  

NASA Astrophysics Data System (ADS)

Deep V R CCD photometry of the Carina dwarf spheroidal galaxy is presented. The resulting C-M diagram reaches V = 25.0 mag and clearly shows the existence of an old stellar population whose existence was predicted by the presence of RR Lyraes in the galaxy. Mould and Aaronson's (1983) finding that most of the stars in Carina belong to an intermediate-age (7.5 + or - 1.5 Gyr) population is confirmed. The old population is 17 + or - 4 percent of the total stellar population. The old population is 13.1 + or - 2.2 Gyr old. The ancient population of the Carina dwarf spheroidal galaxy probably formed in a short burst of star formation about 13-16 Gyr ago. The rate of star formation then probably became negligibly small for the next 6-8 Gyr. About 6-9 Gyr ago, the rate of star formation dramatically increased, and almost all of the remaining protostellar material was converted into stars in the burst of star formation that created the dominant intermediate-age population.

Mighell, K. J.

1990-01-01

319

Delayed sleep phase syndrome in adolescents: prevalence and correlates in a large population based study  

PubMed Central

Background The aims of this study were to estimate the prevalence of Delayed Sleep Phase Syndrome (DSPS) in adolescence, and to examine the association to insomnia and school non-attendance. Methods Data stem from a large population based study in Hordaland County in Norway conducted in 2012, the ung@hordaland study. In all, 10,220 adolescents aged 16–18 years (54% girls) provided self-reported data on a range of sleep parameters: DSPS was defined according to the International Classification of Sleep Disorders, Revised (ICSD-R) criteria, while insomnia was defined according to the Quantitative Criteria for Insomnia. Other sleep parameters included time in bed, sleep duration, sleep efficiency, oversleeping, sleep onset latency, wake after sleep onset, subjective sleep need, sleep deficiency, sleepiness and tiredness. Sleep data were calculated separately for weekdays and weekends. Data on school non-attendance were provided by official registers. Results The prevalence of DSPS was 3.3%, and significantly higher among girls (3.7%) than boys (2.7%). There was a strong overlap between DSPS and insomnia, with more than half of the adolescents with DSPS also meeting the criteria for insomnia (53.8% for boys and 57.1% for girls). Adolescents with DSPS had significantly higher odds ratios (OR) of non-attendance at school. After adjusting for sociodeographical factors, insomnia and depression, the adjusted ORs for days of non-attendance were OR?=?3.22 (95% CI: 1.94-5.34) for boys and OR?=?1.87 (95% CI: 1.25-2.80) for girls. A similar effect was found for hours of non-attendance for boys, with an adjusted OR?=?3.05 (95% CI: 1.89-4.92). The effect for girls was no longer significant after full adjustment (OR =1.48 [95% CI: 0.94-2.32]). Conclusions This is one of the first studies to estimate the prevalence of DSPS in adolescents. The high prevalence of DSPS, and overlap with insomnia, in combination with the odds of school non-attendance, suggest that a broad and thorough clinical approach is warranted when adolescents present with symptoms of DSPS. PMID:24330358

2013-01-01

320

Genetic variation in Fc? receptor IIa and risk of coronary heart disease: negative results from two large independent populations  

PubMed Central

Background The role of the Fc? receptor IIa (Fc?RIIa), a receptor for C-reactive protein (CRP), the classical acute phase protein, in atherosclerosis is not yet clear. We sought to investigate the association of Fc?RIIa genotype with risk of coronary heart disease (CHD) in two large population-based samples. Methods Fc?RIIa-R/H131 polymorphisms were determined in a population of 527 patients with a history of myocardial infarction and 527 age and gender matched controls drawn from a population-based MONICA- Augsburg survey. In the LURIC population, 2227 patients with angiographically proven CHD, defined as having at least one stenosis ? 50%, were compared with 1032 individuals with stenosis <50%. Results In both populations genotype frequencies of the Fc?RIIa gene did not show a significant departure from the Hardy-Weinberg equilibrium. Fc?RIIa R(-131) ? H genotype was not independently associated with lower risk of CHD after multivariable adjustments, neither in the MONICA population (odds ratio (OR) 1.08; 95% confidence interval (CI) 0.81 to 1.44), nor in LURIC (OR 0.96; 95% CI 0.81 to 1.14). Conclusion Our results do not confirm an independent relationship between Fc?RIIa genotypes and risk of CHD in these populations. PMID:19480687

Karakas, Mahir; Hoffmann, Michael M; Vollmert, Caren; Rothenbacher, Dietrich; Meisinger, Christa; Winkelmann, Bernhard; Khuseyinova, Natalie; Bohm, Bernhard O; Illig, Thomas; Marz, Winfried; Koenig, Wolfgang

2009-01-01

321

Efficacy of methods for manipulating earthworm populations in large-scale field experiments in agroecosystems  

Microsoft Academic Search

We established a long-term field experiment in 1991 to investigate the influence of earthworms on C and N cycling processes in agroecosystems. In a replicated field experiment we decreased earthworm populations using electroshocking, increased them by adding field-collected worms or left them unmanipulated. Population manipulations and sampling were done twice per year in 20 m2 field enclosures that were made

P. J. Bohlen; R. W. Parmelee; J. M. Blair; C. A. Edwards; B. R. Stinner

1995-01-01

322

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

PubMed Central

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 ?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.

2010-01-01

323

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

324

Prime time sexual harrassment.  

PubMed

This study explores the explicit and implicit messages of sexual harassment that viewers receive when viewing prime-time television in the US. A content analysis of 48 hours of prime-time television reveals that sexual harassment on television is both highly visible and invisible. Sexual harassment is rendered visible simply by its prominence in these programs. Incidents involving quid-pro-quo harassment and environmental harassment occur with regularity on television. Furthermore, about 84% of the shows studied contained at least one incident of sexual harassment; yet these acts of sexual harassment remained largely invisible because none of the behaviors were labeled as sexual harassment. These incidents are presented in humorous ways, and victims are generally unharmed and very effective at ending the harassment. Although such programs may actually reflect the reality of many women's lives in terms of prevalence of sexual harassment, they perpetuate several myths about sexual harassment, such as that sexual harassment is not serious and that victims should be able to handle the situations themselves. PMID:12294811

Grauerholz, E; King, A

1997-04-01

325

NASA Orbital Debris Large-Object Baseline Population in ORDEM 3.0  

NASA Technical Reports Server (NTRS)

The NASA Orbital Debris Program Office (ODPO) has created and validated high fidelity populations of the debris environment for the latest Orbital Debris Engineering Model (ORDEM 3.0). Though the model includes fluxes of objects 10 um and larger, this paper considers particle fluxes for 1 cm and larger debris objects from low Earth orbit (LEO) through Geosynchronous Transfer Orbit (GTO). These are validated by several reliable radar observations through the Space Surveillance Network (SSN), Haystack, and HAX radars. ORDEM 3.0 populations were designed for the purpose of assisting, debris researchers and sensor developers in planning and testing. This environment includes a background derived from the LEO-to-GEO ENvironment Debris evolutionary model (LEGEND) with a Bayesian rescaling as well as specific events such as the FY-1C anti-satellite test, the Iridium 33/Cosmos 2251 accidental collision, and the Soviet/Russian Radar Ocean Reconnaissance Satellite (RORSAT) sodium-potassium droplet releases. The environment described in this paper is the most realistic orbital debris population larger than 1 cm, to date. We describe derivations of the background population and added specific populations. We present sample validation charts of our 1 cm and larger LEO population against Space Surveillance Network (SSN), Haystack, and HAX radar measurements.

Krisco, Paula H.; Vavrin, A. B.; Anz-Meador, P. D.

2013-01-01

326

Evolution and human sexuality.  

PubMed

The aim of this review is to put core features of human sexuality in an evolutionary light. Toward that end, I address five topics concerning the evolution of human sexuality. First, I address theoretical foundations, including recent critiques and developments. While much traces back to Darwin and his view of sexual selection, more recent work helps refine the theoretical bases to sex differences and life history allocations to mating effort. Second, I consider central models attempting to specify the phylogenetic details regarding how hominin sexuality might have changed, with most of those models honing in on transitions from a possible chimpanzee-like ancestor to the slightly polygynous and long-term bonded sociosexual partnerships observed among most recently studied hunter-gatherers. Third, I address recent genetic and physiological data contributing to a refined understanding of human sexuality. As examples, the availability of rapidly increasing genomic information aids comparative approaches to discern signals of selection in sexuality-related phenotypes, and neuroendocrine studies of human responses to sexual stimuli provide insight into homologous and derived mechanisms. Fourth, I consider some of the most recent, large, and rigorous studies of human sexuality. These provide insights into sexual behavior across other national samples and on the Internet. Fifth, I discuss the relevance of a life course perspective to understanding the evolution of human sexuality. Most research on the evolution of human sexuality focuses on young adults. Yet humans are sexual beings from gestation to death, albeit in different ways across the life course, and in ways that can be theoretically couched within life history theory. PMID:24151100

Gray, Peter B

2013-12-01

327

Behavioral Convergence: Implications for Mathematical Models of Sexually Transmitted Infection Transmission  

PubMed Central

Recent trends in the behaviors of some groups with high sexual activity and of the general population in some countries suggest that sexual behavior profiles of high and low sexual activity categories may be converging and may call into question the assumptions around sexual mixing that are built into theoretical models of sexually transmitted infections (STIs)/human immunodeficiency virus (HIV) transmission dynamics. One category of high sexual activity, sex work, has been undergoing modification in many societies, becoming more acceptable, more dispersed, and larger in volume in some societies and shrinking in others. Concurrent with changes in the characteristics of sex work, the accumulating data on the sexual behaviors of the general population suggest a shift toward those of sex workers, including large numbers of sex partners and short-duration partnerships. The closing of the gap between behaviors associated with high and low sexual activity may have important implications for theories of sexual structure and models of transmission dynamics for STIs, including HIV infection. PMID:25381381

Aral, Sevgi O.; Ward, Helen

2014-01-01

328

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. PMID:17462798

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

2010-01-01

329

Internet Sexualities  

Microsoft Academic Search

\\u000a The term “internet sexuality” (or OSA, online sexual activities) refers to sexual-related content and activities observable\\u000a on the internet (cf. Adams, Oye, & Parker, 2003; Cooper, McLoughlin, & Campbell, 2000; Leiblum & Döring, 2002). It designates\\u000a a variety of sexual phenomena (e.g., pornography, sex education, sexual contacts) related to a wide spectrum of online services\\u000a and applications (e.g., websites, online

Nicola Döring

2010-01-01

330

Large fluctuations in the effective population size of the malaria mosquito Anopheles gambiae s.s. during vector control cycle.  

PubMed

On Bioko Island, Equatorial Guinea, indoor residual spraying (IRS) has been part of the Bioko Island Malaria Control Project since early 2004. Despite success in reducing childhood infections, areas of high transmission remain on the island. We therefore examined fluctuations in the effective population size (N e ) of the malaria vector Anopheles gambiae in an area of persistent high transmission over two spray rounds. We analyzed data for 13 microsatellite loci from 791 An. gambiae specimens collected at six time points in 2009 and 2010 and reconstructed the demographic history of the population during this period using approximate Bayesian computation (ABC). Our analysis shows that IRS rounds have a large impact on N e , reducing it by 65%-92% from prespray round N e . More importantly, our analysis shows that after 3-5 months, the An. gambiae population rebounded by 2818% compared shortly following the spray round. Our study underscores the importance of adequate spray round frequency to provide continuous suppression of mosquito populations and that increased spray round frequency should substantially improve the efficacy of IRS campaigns. It also demonstrates the ability of ABC to reconstruct a detailed demographic history across only a few tens of generations in a large population. PMID:24478799

Hodges, Theresa K; Athrey, Giridhar; Deitz, Kevin C; Overgaard, Hans J; Matias, Abrahan; Caccone, Adalgisa; Slotman, Michel A

2013-12-01

331

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

PubMed Central

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

1999-01-01

332

Male mating behavior and costs of sexual harassment for females in cavernicolous and extremophile populations of Atlantic mollies ( Poecilia mexicana )  

Microsoft Academic Search

Summary The Atlantic molly Poecilia mexicana inhabits a variety of different habitat types, some of which are characterized by physicochemical stressors, such as toxic hydrogen sulfide (H2S), or the fish occur in lightless subterranean (cave) habitats. Using five different populations from surface habitats with or without H2S, and from a sulfidic and a non-sulfidic cave, I asked how extreme environmental

Martin Plath; Maulbeerallee Potsdam

2008-01-01

333

The relationship between sexual selection and sexual conflict.  

PubMed

Evolutionary conflicts of interest arise whenever genetically different individuals interact and their routes to fitness maximization differ. Sexual selection favors traits that increase an individual's competitiveness to acquire mates and fertilizations. Sexual conflict occurs if an individual of sex A's relative fitness would increase if it had a "tool" that could alter what an individual of sex B does (including the parental genes transferred), at a cost to B's fitness. This definition clarifies several issues: Conflict is very common and, although it extends outside traits under sexual selection, sexual selection is a ready source of sexual conflict. Sexual conflict and sexual selection should not be presented as alternative explanations for trait evolution. Conflict is closely linked to the concept of a lag load, which is context-dependent and sex-specific. This makes it possible to ask if one sex can "win." We expect higher population fitness if females win. PMID:25038050

Kokko, Hanna; Jennions, Michael D

2014-09-01

334

Sexuality and Affection among Elderly German Men and Women in Long-Term Relationships: Results of a Prospective Population-Based Study  

PubMed Central

Satisfaction with sexual activity i.e. sexual satisfaction and the importance of sexuality and affection were analysed using data from the German “Interdisciplinary Longitudinal Study of Adult Development” (ILSE). At three measurement points, 1993–1995, 1997–1998, and 2004–2006 i.e. subjects' ages of 63, 67, and 74 years, participants' reports about their affection and sexual activity were collected. The sample of completed records used for this study consisted of 194 urban non-institutionalised participants, 68% male, all living with partners. Median levels of sexual satisfaction were reported, fluctuating between the measurement points of ages 63 to 74. Between baseline, first and second follow-up no differences were found in levels of sexual satisfaction, though at measurement points age 63 and 67 women were more satisfied than men. When measured at age 74, affection was given a higher priority than sexual activity. Although men and women reported similar priorities, sexual activity and affection were more important for men than for women. Satisfaction within the relationship can be predicted by the importance of affection, but not by that of sexual activity. Our results confirm the thesis of the ‘second language of sexuality’: for humans in their later years affection seems to be more important than for younger individuals. PMID:25369193

Muller, Britta; Nienaber, Christoph A.; Reis, Olaf; Kropp, Peter; Meyer, Wolfgang

2014-01-01

335

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

PubMed

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. PMID:21949481

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

2011-09-01

336

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. PMID:21949481

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

2011-01-01

337

Chronic Physical Illness and Mental Health in Children. Results from a Large-Scale Population Study  

ERIC Educational Resources Information Center

Background: The aim of the present study was to evaluate the sensitivity and specificity of the Strengths and Difficulties Questionnaire (SDQ) in detecting emotional and behavioural problems among children with chronic illness (CI). Methods: Parents and teachers of a population of primary school children in Norway (n = 9430) completed a…

Hysing, Mari; Elgen, Irene; Gillberg, Christopher; Lie, Stein Atle; Lundervold, Astri J.

2007-01-01

338

A Metapopulation Model for Chikungunya Including Populations Mobility on a Large-Scale Network  

E-print Network

In this work we study the influence of populations mobility on the spread of a vector-borne disease. We focus on the chikungunya epidemic event that occurred in 2005-2006 on the R\\'eunion Island, Indian Ocean, France, and validate our models with real epidemic data from the event. We propose a metapopulation model to represent both a high-resolution patch model of the island with realistic population densities and also mobility models for humans (based on real-motion data) and mosquitoes. In this metapopulation network, two models are coupled: one for the dynamics of the mosquito population and one for the transmission of the disease. A high-resolution numerical model is created out from real geographical, demographical and mobility data. The Island is modeled with an 18 000-nodes metapopulation network. Numerical results show the impact of the geographical environment and populations' mobility on the spread of the disease. The model is finally validated against real epidemic data from the R\\'eunion event.

Moulay, Djamila

2012-01-01

339

APOE Genotype and Cognitive Functioning in a Large Age-Stratified Population Sample  

Microsoft Academic Search

There is evidence that the cognitive effects of Alzheimer's disease can be seen decades before disease diagnosis. If this is the case, then the apolipoprotein E (APOE)*E4 allele might be expected to have effects on cognitive functioning earlier in the life span. To assess such effects, the authors examined data on the *E4 allele and cognitive functioning from a population

Anthony F. Jorm; Karen A. Mather; Peter Butterworth; Kaarin J. Anstey; Helen Christensen; Simon Easteal

2007-01-01

340

TRANSGENIC PLANTS AND INSECTS A Multiyear, Large-Scale Comparison of Arthropod Populations on  

E-print Network

Ã?cant adverse impacts on the nontarget arthropod populations studied and, compared with insecticide-treated non-Bt studies conducted with Cry1Ac protein and Bt cotton indicate that Bt cotton only has direct toxic effects-scale, multilocation studies have been published on the nontarget impacts of Bt c

Behmer, Spencer T.

341

Quasistationarity in populations that are subject to large-scale mortality or emigration  

E-print Network

describe, called the birth-death and catastro- phe process, is particularly effective in modelling the present study, since, in order to properly manage these populations, it is necessary to be able to predict- tial reductions in numbers owing to overbrowsing combined with effects of severe winters; the moose

Pollett, Phil

342

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

Microsoft Academic Search

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

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

2011-01-01

343

Improving Blood Pressure Control in a Large Multiethnic California Population Through Changes in Health Care Delivery, 2004–2012  

PubMed Central

The Kaiser Permanente Southern California (Kaiser) health care system succeeded in improving hypertension control in a multiethnic population by adopting a series of changes in health care delivery. Data from the Healthcare Effectiveness Data and Information Set (HEDIS) was used to assess blood pressure control from 2004 through 2012. Hypertension control increased overall from 54% to 86% during that period, and 80% or more in every subgroup, regardless of race/ethnicity, preferred language, or type of health insurance plan. Health care delivery changes improved hypertension control across a large multiethnic population, which indicates that health care systems can achieve a clinical target goal of 70% for hypertension control in their populations. PMID:25357259

Handler, Joel; Wall, Hilary K.; Kanter, Michael H.

2014-01-01

344

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

345

Initial population of large-l Rydberg states for the radiative deexcitation in the beam-foil geometry  

NASA Astrophysics Data System (ADS)

In the recent beam-foil experiment, resonances have been observed in decay of the beam-foil excited 2p and 2s states of H-like Fe ions at very large times. Qualitatively, the resonances were explained as a consequence of cascading down from the Rydberg states (n?1,l=n-1) to 2p state. Full explanation requires the theoretical values of the population probabilities P of the large-l Rydberg states of multiply charged ions of core charges Z?1 a.u. escaping the solid surfaces at velocities v?1 a.u. The resonances observed in the time dependent photon intensity indicate the existence of resonances (pronounced maxima at several n=nres) in the P distributions. Considering the population process within the framework of the time-symmetrized two-state vector model, with dynamically generalized interaction Hamiltonian, we found that the nonresonant electron pick up from the foil conduction band into the field of ionic core when the ion leaves the surface represents an important population mechanism. The obtained population distributions have the resonance-like structure like the ones simulated from the experimental signal, and the overlap shape and magnitude in accordance with the wake field model estimations.

Nedeljkovi?, N. N.; Galijaš, S. M. D.; Mirkovi?, M. A.

2014-02-01

346

Breath methane and large bowel cancer risk in contrasting African populations.  

PubMed Central

Breath methane has been measured in 1016 people from four populations resident in Southern Africa which experience widely different risks of bowel cancer and other colonic diseases. Highly significant differences in the proportion of subjects with detectable methane in breath were found; % producers--rural black 84, urban black 72, white 52, Indian 41 (chi 2 121 p less than 0.001 3 df). There was a slight preponderance of female producers over male (female producers 63%, males 57%) and an age trend with fewer producers in the older age groups in the urban blacks and Indians, these comparisons being significant when tested by stepwise logistic regression analysis. Bowel cancer risk, determined from a variety of sources, was lowest in rural blacks, greatest in whites, with intermediate rates for urban blacks and Indians. Methane production in the human colon shows significant interethnic differences but which bear no relation to bowel cancer risk in these populations. PMID:3396948

Segal, I; Walker, A R; Lord, S; Cummings, J H

1988-01-01

347

Birth seasonality and calf mortality in a large population of Asian elephants  

PubMed Central

In seasonal environments, many species concentrate their reproduction in the time of year most likely to maximize offspring survival. Asian elephants (Elephas maximus) inhabit regions with seasonal climate, but females can still experience 16-week reproductive cycles throughout the year. Whether female elephants nevertheless concentrate births on periods with maximum offspring survival prospects remains unknown. We investigated the seasonal timing of births, and effects of birth month on short- and long-term mortality of Asian elephants, using a unique demographic data set of 2350 semicaptive, longitudinally monitored logging elephants from Myanmar experiencing seasonal variation in both workload and environmental conditions. Our results show variation in birth rate across the year, with 41% of births occurring between December and March. This corresponds to the cool, dry period and the beginning of the hot season, and to conceptions occurring during the resting, nonlogging period between February and June. Giving birth during the peak December to March period improves offspring survival, as the odds for survival between age 1 and 5 years are 44% higher for individuals born during the high birth rate period than those conceived during working months. Our results suggest that seasonal conditions, most likely maternal workload and/or climate, limit conception rate and calf survival in this population through effects on maternal stress, estrus cycles, or access to mates. This has implications for improving the birth rate and infant survival in captive populations by limiting workload of females of reproductive age. As working populations are currently unsustainable and supplemented through the capture of wild elephants, it is imperative to the conservation of Asian elephants to understand and alleviate the effects of seasonal conditions on vital rates in the working population in order to reduce the pressure for further capture from the wild. PMID:24198940

Mumby, Hannah S; Courtiol, Alexandre; Mar, Khyne U; Lummaa, Virpi

2013-01-01

348

Large nonlethal effects of an invasive invertebrate predator on zooplankton population growth rate.  

PubMed

We conducted a study to determine the contribution of lethal and nonlethal effects to a predator's net effect on a prey's population growth rate in a natural setting. We focused on the effects of an invasive invertebrate predator, Bythotrephes longimanus, on zooplankton prey populations in Lakes Michigan and Erie. Field data taken at multiple dates and locations in both systems indicated that the prey species Daphnia mendotae, Daphnia retrocurva, and Bosmina longirostris inhabited deeper portions of the water column as Bythotrephes biomass increased, possibly as an avoidance response to predation. This induced migration reduces predation risk but also can reduce birth rate due to exposure to cooler temperatures. We estimated the nonlethal (i.e., resulting from reduced birth rate) and lethal (i.e., consumptive) effects of Bythotrephes on D. mendotae and Bosmina longirostris. These estimates used diel field survey data of the vertical gradient of zooplankton prey density, Bythotrephes density, light intensity, and temperature with growth and predation rate models derived from laboratory studies. Results indicate that nonlethal effects played a substantial role in the net effect of Bythotrephes on several prey population growth rates in the field, with nonlethal effects on the same order of magnitude as or greater (up to 10-fold) than lethal effects. Our results further indicate that invasive species can have strong nonlethal, behaviorally based effects, despite short evolutionary coexistence with prey species. PMID:17479758

Pangle, Kevin L; Peacor, Scott D; Johannsson, Ora E

2007-02-01

349

The unusually large population of Blazhko variables in the globular cluster NGC 5024 (M53)  

NASA Astrophysics Data System (ADS)

We report the discovery of amplitude and phase modulations typical of the Blazhko effect in 22 RRc and nine RRab type RR Lyrae stars in NGC 5024 (M53). This brings the confirmed Blazhko variables in this cluster to 23 RRc and 11 RRab stars, which represent 66 and 37 per cent of the total population of RRc and RRab stars in the cluster, respectively, making NGC 5024 the globular cluster with the largest presently known population of Blazhko RRc stars. We place a lower limit of 52 per cent on the overall incidence rate of the Blazhko effect among the RR Lyrae population in this cluster. New data have allowed us to refine the pulsation periods. The limitations imposed by the time span and sampling of our data prevent reliable estimations of the modulation periods. The amplitudes of the modulations range between 0.02 and 0.39 mag. The RRab and RRc are neatly separated in the colour-magnitude diagram, and the RRc Blazhko variables are on average redder than their stable counterparts; these two facts may support the hypothesis that the horizontal branch (HB) evolution in this cluster is towards the red and that the Blazhko modulations in the RRc stars are connected with the pulsation mode switch. Based on observations collected at the Indian Astrophysical Observatory, Hanle, India.

Arellano Ferro, A.; Bramich, D. M.; Figuera Jaimes, R.; Giridhar, Sunetra; Kuppuswamy, K.

2012-02-01

350

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. PMID:20519240

Lundemo, Sverre; Sten?ien, Hans K.; Savolainen, Outi

2010-01-01

351

HLA-A, HLA-B, and HLA-DRB1 allele distribution in a large Armenian population sample.  

PubMed

Human leukocyte antigen (HLA)-A, HLA-B, and HLA-DRB1 gene frequencies were investigated in 4279 unrelated Armenian bone marrow donors. HLA alleles were defined by using PCR amplification with sequence specific primers (PCR-SSP) high- and low-resolution kits. The aim of this study was to examine the HLA diversity at the high-resolution level in a large Armenian population sample, and to compare HLA allele group distribution in Armenian subpopulations. The most frequently observed alleles in the HLA class I were HLA-A*0201, A*0101, A*2402, A*0301, HLA-B*5101, HLA-B*3501, and B*4901. Among DRB1 alleles, high frequencies of DRB1*1104 and DRB1*1501 were observed, followed by DRB1*1101 and DRB1*1401. The most common three-locus haplotype found in the Armenian population was A*33-B*14-DRB1*01, followed by A*03-B*35-DRB1*01. Our results show a similar distribution of alleles in Armenian subpopulations from different countries, and from different regions of the Republics of Armenia and Karabagh. The low level of genetic distances between subpopulations indicates a high level of population homogeneity, and the genetic distances between Armenians and other populations show Armenians as a distinct ethnic group relative to others, reflecting the fact that Armenians have been an 'isolated population' throughout centuries. This study is the first comprehensive investigation of HLA-allele group distribution in a subset of Armenian populations, and the first to provide HLA-allele and haplotype frequencies at a high-resolution level. It is a valuable reference for organ transplantation and for future studies of HLA-associated diseases in Armenian populations. PMID:21501120

Matevosyan, L; Chattopadhyay, S; Madelian, V; Avagyan, S; Nazaretyan, M; Hyussian, A; Vardapetyan, E; Arutunyan, R; Jordan, F

2011-07-01

352

A Large Stellar Evolution Database for Population Synthesis Studies. III. Inclusion of the full Asymptotic Giant Branch phase and Web tools for stellar population analyses  

E-print Network

Stellar evolution tracks and isochrones are key inputs for a wide range of astrophysical studies; in particular, they are essential to the interpretation of photometric and spectroscopic observations of resolved and unresolved stellar populations. We have made available to the astrophysical community a large, homogenous database of up-to-date stellar tracks and isochrones, and a set of programs useful in population synthesis studies. In this paper we first summarize the main properties of our stellar model database (BaSTI) already introduced in Pietrinferni et al. (2004) and Pietrinferni et al. (2006). We then discuss an important update of the database, i.e., the extension of all stellar models and isochrones until the end of the thermal pulses along the Asymptotic Giant Branch. This extension of the library is particularly relevant for stellar population analyses in the near-infrared, or longer wavelengths, where the contribution to the integrated photometric properties by cool and bright Asymptotic Giant Branch stars is significant. A few comparisons with empirical data are also presentend and briefly discussed. We then present three web-tools that allow an interactive access to the database, and make possible to compute user-specified evolutionary tracks, isochrones, stellar luminosity functions, plus synthetic Color-Magnitude-Diagrams and integrated magnitudes for arbitrary Star Formation Histories. All these web tools are available at the BaSTI database official site: http://www.oa-teramo.inaf.it/BASTI.

Daniel Cordier; Adriano Pietrinferni; Santi Cassisi; Maurizio Salaris

2006-12-21

353

Assessment of Sexual Behavior, Sexual Attitudes, and Sexual Risk in Sweden (1989–2003)  

Microsoft Academic Search

To assess changes in sexual behavior, sexual attitudes, and sexual risk related to HIV, we conducted mailed questionnaire surveys in random samples of the Swedish general population in 1989, 1994, 1997, 2000, and 2003 (total N = 13,762). Each sample consisted of 4,000–6,000 subjects aged 16–44 years, stratified by age: 16–17, 18–19, 20–24, 25–34, and 35–44 years. The overall participation

Claes Herlitz; Kristina Ramstedt

2005-01-01

354

Sexual Health  

MedlinePLUS

... them do, even if interest in sex and sexual activity declines to some extent with increasing age. This ... and a quarter report no pleasure from their sexual activity. About one out of 10 older women have ...

355

Sexual Abuse  

MedlinePLUS

... form of non-consensual physical contact. It includes rape, molestation, or any sexual conduct with a person ... more? "Speaking the unspeakable: An interview about elder sexual assault with Holly Ramsey-Klawsnik, Ph.D" in nexus , ...

356

Arterial stiffness, fatty liver and the presence of coronary artery calcium in a large population cohort  

PubMed Central

Background We tested whether fatty liver, brachial-ankle pulse wave velocity (baPWV) and conventional cardiovascular risk factors were associated with a coronary artery calcium (CAC) score?>?0 (as a marker of the presence of early atherosclerosis) in a cohort of healthy Korean adults. Method The study population consisted of individuals who underwent a comprehensive health examination in 2010 at Kangbuk Samsung Hospital, College of Medicine, Sungkyunkwan University in South Korea. The 6009 subjects of total 7371 participants who had an assigned CAC score following coronary computed tomography (CT) scanning and baPWV were analyzed. Results Among the study subjects, 39.2% of the population had evidence of fatty liver by ultrasound and 4.6% of the population had evidence of CAC score?>?0. Among individuals with a CAC score?=?0, 38% of the individuals had fatty liver compared with 58% of the individuals with a CAC score?>?0. The individuals with a CAC score?>?0 also had higher blood pressure and had more metabolic abnormalities. The prevalence of CAC score?>?0 was increased according to baPWV quartiles and was higher in the fatty liver group in comparison with those without fatty liver. The odds ratio for CAC score?>?0, after adjusting for clinical risk factors, showed a significant elevation with increasing quartiles of baPWV and the presence of fatty liver. Conclusion We showed that both fatty liver and baPWV are independently associated with the presence of CAC, a marker of preclinical atherosclerosis. These associations are independent of conventional risk factors and medical history. PMID:24191863

2013-01-01

357

Sexual orientation and labour supply  

Microsoft Academic Search

This is the first study of the effects of sexual orientation on labour supply. After discussing various reasons to expect that labour supply could differ by sexual orientation, the 2001 Current Population Survey is used to test for differences in both labour supply and labour market status (part-time, full-time, and not employed). It is found that gay men supply less

Edinaldo Tebaldi; Bruce Elmslie

2006-01-01

358

Workplace Bullying and Sleep Disturbances: Findings from a Large Scale Cross-Sectional Survey in the French Working Population  

PubMed Central

Study Objectives: The purpose of this study was to explore the associations between workplace bullying, the characteristics of workplace bullying, and sleep disturbances in a large sample of employees of the French working population. Design: Workplace bullying, evaluated using the validated instrument developed by Leymann, and sleep disturbances, as well as covariates, were measured using a self-administered questionnaire. Covariates included age, marital status, presence of children, education, occupation, working hours, night work, physical and chemical exposures at work, self-reported health, and depressive symptoms. Statistical analysis was performed using logistic regression analysis and was carried out separately for men and women. Setting: General working population. Participants: The study population consisted of a random sample of 3132 men and 4562 women of the working population in the southeast of France. Results: Workplace bullying was strongly associated with sleep disturbances. Past exposure to bullying also increased the risk for this outcome. The more frequent the exposure to bullying, the higher the risk of experiencing sleep disturbances. Observing someone else being bullied in the workplace was also associated with the outcome. Adjustment for covariates did not modify the results. Additional adjustment for self-reported health and depressive symptoms diminished the magnitude of the associations that remained significant. Conclusions: The prevalence of workplace bullying (around 10%) was found to be high in this study as well was the impact of this major job-related stressor on sleep disturbances. Although no conclusion about causality could be drawn from this cross-sectional study, the findings suggest that the contribution of workplace bullying to the burden of sleep disturbances may be substantial. Citation: Niedhammer I; David S; Degioanni S; Drummond A; Philip P. Workplace bullying and sleep disturbances: findings from a large scale cross-sectional survey in the French working population. SLEEP 2009;32(9):1211-1219. PMID:19750926

Niedhammer, Isabelle; David, Simone; Degioanni, Stephanie; Drummond, Anne; Philip, Pierre

2009-01-01

359

Genetic variation reveals large-scale population expansion and migration during the expansion of Bantu-speaking peoples  

PubMed Central

The majority of sub-Saharan Africans today speak a number of closely related languages collectively referred to as ‘Bantu’ languages. The current distribution of Bantu-speaking populations has been found to largely be a consequence of the movement of people rather than a diffusion of language alone. Linguistic and single marker genetic studies have generated various hypotheses regarding the timing and the routes of the Bantu expansion, but these hypotheses have not been thoroughly investigated. In this study, we re-analysed microsatellite markers typed for large number of African populations that—owing to their fast mutation rates—capture signatures of recent population history. We confirm the spread of west African people across most of sub-Saharan Africa and estimated the expansion of Bantu-speaking groups, using a Bayesian approach, to around 5600 years ago. We tested four different divergence models for Bantu-speaking populations with a distribution comprising three geographical regions in Africa. We found that the most likely model for the movement of the eastern branch of Bantu-speakers involves migration of Bantu-speaking groups to the east followed by migration to the south. This model, however, is only marginally more likely than other models, which might indicate direct movement from the west and/or significant gene flow with the western Branch of Bantu-speakers. Our study use multi-loci genetic data to explicitly investigate the timing and mode of the Bantu expansion and it demonstrates that west African groups rapidly expanded both in numbers and over a large geographical area, affirming the fact that the Bantu expansion was one of the most dramatic demographic events in human history. PMID:25209939

Li, Sen; Schlebusch, Carina; Jakobsson, Mattias

2014-01-01

360

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

361

NASH EQUILIBRIA FOR LARGE-POPULATION LINEAR STOCHASTIC SYSTEMS OF WEAKLY  

E-print Network

.malhame@polymtl.ca Peter E. Caines Department of Electrical and Computer Engineering, McGill University 3480 University Street, Montreal, QC H3A 2A7, Canada peterc@cim.mcgill.ca Abstract We consider dynamic games in large property of the mass behaviour is established. The method- ology and the results contained in this paper

Huang, Minyi

362

Early Childhood Experiences and Kindergarten Success: A Population-Based Study of a Large Urban Setting  

Microsoft Academic Search

This study examined the unique protective influence of center-based early care and education experiences on kindergarten outcomes for children entering public school kindergarten. The 3,969 participants were geographically and de- mographically representative of an entire kindergarten cohort in a large urban school district. Child age, gender, ethnicity, family poverty, low maternal education, and neighborhood were found to be risks for

John W. Fantuzzo; Heather L. Rouse; Paul A. McDermott; Yumiko Sekino; Stephanie Childs; Andrea Weiss

2005-01-01

363

surprisingly large majority of the UK population are unaware of the  

E-print Network

bumblebees (genus Bombus) and honeybees (Apis mel- lifera). Bumblebees are the large, furry and often hairless. Still fewer people are aware that there are lots of different species of bumblebee (with 27 known in 2 Biologist Volume 53 Number 1, February 2006 The demise of the bumblebee in Britain The last 60

364

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

Microsoft Academic Search

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

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

2006-01-01

365

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. PMID:22951294

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

366

Seasonal change in the opportunity for sexual selection.  

PubMed

Environmental and population parameters that influence the strength of sexual selection may vary considerably over the course of the reproductive season. However, the potential for sexual selection frequently fails to translate into variation in reproductive success among individuals. We investigated seasonal changes in variation in reproductive success, measured as the opportunity for sexual selection, using parentage analysis in 20 experimental populations of the European bitterling (Rhodeus amarus, Cyprinidae), a small freshwater fish with a promiscuous, resource-based mating system. We showed that although the largest males sired most offspring over the entire reproductive season, variation in reproductive success and hence the opportunity for sexual selection was low at the start of the season but increased significantly at its end. This seasonal difference probably arose from the superior competitive endurance of large males and from a higher temporal clustering of reproductively active females at the start of the breeding season than later in the season. The spatial distribution of oviposition sites had a negligible effect on the variation in reproductive success. We discuss the potential implications of our results for the importance and strength of sexual selection in natural populations. PMID:18179434

Reichard, M; Smith, C; Bryja, J

2008-01-01

367

Sexual conflict  

Microsoft Academic Search

Sexual conflict occurs when the genetic interests of males and females diverge. Recent evidence supporting the view that male and female genomes are in conflict has now revolutionized the way in which we interpret interactions between the sexes, and suggests that sexual conflict is a potent force in male–female coevolution. Here, we consider the nature of sexual conflict and what

Tracey Chapman; Göran Arnqvist; Jenny Bangham; Locke Rowe

2003-01-01

368

Mental health of victims of sexual violence in eastern Congo: associations with daily stressors, stigma, and labeling  

PubMed Central

Background The conflict-ridden context of eastern Congo has set the scene for grueling human rights violations, with sexual violence as one of the ‘weapons of war’. Currently, sexual violence continues, with a considerable increase in civilian perpetrators. However, little is known regarding the particular impact of different experiences of sexual violence on adolescents’ mental health. This study therefore investigates the impact of sexual violence on eastern Congolese adolescents’ mental health and its differing associations with daily stressors, stigma, and the labeling of sexual violence (as ‘rape’ or ‘non-consensual sexual experience’). Methods A cross-sectional, population-based survey design was implemented in 22 secondary schools, randomly selected from a stratified sample, in Bunia, eastern Congo, a region extensively affected by war. A total of 1,305 school-going adolescent girls aged 11 to 23 participated. Self-report measures of mental health symptoms, war-related traumatic events, experiences of sexual violence, daily stressors, and stigmatization were administered. Differences in sociodemographic characteristics, traumatic experiences and daily and social stressors between types of sexual violence (rape, non-consensual sexual violence, no sexual violence) were explored through statistical analysis. ANCOVA analyses investigated associations between those risk factors and adolescents’ mental health. Results More than one third of eastern Congolese adolescent girls reported experiences of sexual violence. Elevated levels of daily stressors, experiences of stigmatization, and stressful war-related events were found amongst girl victims of sexual violence, with the highest levels for girls who labeled the sexual violence as rape. Daily stressors, stigmatization, and war-related events showed a large impact on the girls’ mental health. Last, girls who labeled the sexual violence as non-consensual sexual experiences reported more post-traumatic hyper-arousal and intrusion symptoms compared to those labeling the sexual violence as rape. Conclusions These findings point to the important association between how war-affected adolescent girls label sexual violence (rape or non-consensual sexual experiences) and their mental health. This study also documents the large impact of sexual violence on other stressors (daily stressors, stigmatization, and stressful war events) and the impact of these stressors on girl victims’ mental health. It discusses important implications for addressing sexual violence and its consequences in war-affected contexts. PMID:25195041

2014-01-01

369

Sexuality in Perimenopausal and Postmenopausal Women.  

ERIC Educational Resources Information Center

Reviews psychological and biological aspects of effects of menopause on sexuality. Discusses population studies revealing that postmenopausal status is associated with decline in some components of sexual functioning. Notes that little research has examined psychological response to menopause and its effect on sexual functioning. Research on…

Morokoff, Patricia J.

1988-01-01

370

The Leo II Dwarf Spheroidal --- an Old Galaxy With A Large Intermediate-Age Population  

NASA Astrophysics Data System (ADS)

Deep F555W (broad-band V) and F814W (broad-band I) observations have been obtained of the Leo II dwarf spheroidal galaxy with the {Hubble Space Telescope} Wide Field Planetary Camera 2 instrument. The resulting color-magnitude diagrams reach V=27.4 mag and I=26.6 mag. The fiducial sequence has a main-sequence turnoff at V=25.1 mag. A metallicity of [Fe/H]=-1.6+/-0.25 dex and reddening E(V-I) = 0.035+/-0.019 were determined simultaneously using the technique of Sarajedini (1994, AJ, 107, 618). A well-defined horizontal branch is seen at V_HB = 22.18+/-0.08 mag and the true distance modulus is (m-M)_0 = 21.55+/-0.18 mag. The apparent distance moduli in V and I are (m-M)_V=21.63+/-0.19 mag and (m-M)_I=21.60+/-0.19 mag, respectively. Using a variety of age indicators, we have determined that the the main stellar population of Leo II is probably 8--10 Gyr old. By analyzing the distribution of stars near the base of the red giant branch, we have determined that half of the stars in Leo II probably formed during a period of star formation lasting about 4 Gyr. The Leo II dwarf spheroidal galaxy started forming stars about 13--15 Gyr ago and formed most of its stellar population during the succeeding 6--8 Gyr with the typical star having been formed about 8--10 Gyr ago. The rate of star formation has been negligibly small for the last 6--7 Gyr. Full details of this research project will be published in the Astronomical Journal in 1996.

Mighell, Kenneth J.; Rich, R. Michael

1996-04-01

371

The Leo II Dwarf Spheroidal - an Old Galaxy With a Large Intermediate-age Population  

NASA Astrophysics Data System (ADS)

Deep F555W (broadband V) and F814W (broadband I) observations have been obtained of the Leo II dwarf spheroidal galaxy with the Hubble Space Telescope Wide Field Planetary Camera 2 instrument. The resulting color- magnitude diagrams reach V = 27.4 mag and I = 26.6 mag, and the fiducial sequence has a main-sequence turnoff at V = 25.1 mag. A metallicity of [Fe/H] = -1.60+/-0.25 dex and reddening E (V - I) = 0.035+/-0.019 were determined simultaneously using the technique of Sarajedini [AJ, 107,618 (1994)]. A well-defined horizontal branch is seen at V_HB_ = 22.18+/-0.08 mag and the true distance modulus is (m - M)_0_ = 21.55+/-0.18 mag. The apparent distance moduli in V and I are (m - M)_V_=21.63+/-0.18 mag and (m - M)_I__ = 21.60+/-0.18 mag, respectively. Using a variety of age indicators, we have determined that the main stellar population of Leo II has an age of 9+/-1 Gyr. By analyzing the distribution of stars near the base of the red giant branch, we have determined that half of the stars in Leo II probably formed during a period of star formation lasting about 4 Gyr. The Leo II dwarf spheroidal galaxy started forming stars about 14+/-1 Gyr ago and formed most of its stellar population during the succeeding 7 +/- 1 Gyr with the typical star having been formed about 9+/-1 Gyr ago. The rate of star formation has been negligibly small for the last ~7 Gyr.

Mighell, Kenneth J.; Rich, R. Michael

1996-02-01

372

[Sexual orientations].  

PubMed

In this paper we study the concept of sexual orientation and its components by comparing the common orientations of hetero-, homo-, and bisexuality with alternative concepts suitable for describing persons with psychosexual and somatosexual divergencies (e.g., transgender or intersex developments). An assessment of these divergencies as well as their prevalence and societal influences are presented. Empirical findings on the relationship between sexual orientation and mental health are examined against the background of the sexual minority stress model, looking especially at the risks and the opportunities associated with belonging to a sexual minority. The paper also focuses on the normative power of a monosexual model. Finally, sexual orientation is conceptualized as an umbrella term encompassing both conscious and unconscious elements, including the aspects of sexual behavior, sexual identity, fantasies, and attraction. PMID:23361208

Schweizer, K; Brunner, F

2013-02-01

373

Selective exploitation of large pike Esox lucius--effects on mercury concentrations in fish populations.  

PubMed

The present study outlines two main trends of mercury transfer patterns through the fish community: 1) the Hg concentrations increase with increase in the trophic level, with top predators having the highest concentrations, and 2) a fast growth rate may dilute the concentrations of Hg in fish muscle tissue (growth biodilution). In 2004, an extensive reduction in number of large pike (Esox lucius L.), was initiated by selective gillnet fishing in Lake Arungen, Norway, in order to increase the pike recruitment due to an expected reduction in cannibalism. In this connection, total mercury (THg) concentrations in the fish community were studied both before (2003) and after (2005) the removal of large pike. The delta(15)N signatures and stomach content analyses indicated that pike and perch (Perca fluviatilis L.) occupied the highest trophic position, while roach (Rutilus rutilus (L.)) was at the lower level, and rudd (Scardinius erythrophthalmus L.) at the lowest. The piscivores, pike and perch, had the highest concentrations of THg. The biomagnification rate of THg through the food web in the fish community was 0.163 (per thousand delta(15)N), with the highest uptake rate (0.232) in perch. A significant decrease in THg concentrations was found in all fish species in 2005 compared to 2003. Removal of the top predators in an Hg contaminated lake might thus be an important management tool for reducing Hg levels in fish, thereby reducing health risk to humans. PMID:18485450

Sharma, Chhatra Mani; Borgstrøm, Reidar; Huitfeldt, Jørgen Sinkaberg; Rosseland, Bjørn Olav

2008-07-25

374

Plasma lipid profiling in a large population-based cohort[S  

PubMed Central

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.

2013-01-01

375

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  

PubMed Central

Background In Germany, testing and treatment of sexually transmissible infections (STIs) services are not provided by one medical discipline, but rather dispersed among many different providers. Common STIs like gonorrhoea or Chlamydia infection are not routinely reported. Although men who have sex with men (MSM) are particularly vulnerable to STIs, respective health care utilization among MSM is largely unknown. Methods A sexual behaviour survey among MSM was conducted in 2006. Questions on self-reported sexual behaviour, STI-related health care consultation and barriers to access, coverage of vaccination against hepatitis, screening for asymptomatic STIs, self-reported history of STIs, and partner notification were analysed. Analysis was stratified by HIV-serostatus (3,511 HIV-negative/unknown versus 874 positive). Results General Practitioners, particularly gay doctors, were preferred for STI-related health care. Low threshold testing in sex-associated venues was acceptable for most respondents. Shame and fear of homophobic reactions were the main barriers for STI-testing. More than half of the respondents reported vaccination against hepatitis A/B. HIV-positive MSM reported screening offers for STIs three to seven times more often than HIV-negative or untested MSM. Unlike testing for syphilis or hepatitis C, screening for asymptomatic pharyngeal and rectal infections was rarely offered. STIs in the previous twelve months were reported by 7.1% of HIV-negative/untested, and 34.7% of HIV-positive respondents. Conclusions Self-reported histories of STIs in MSM convenience samples differ significantly by HIV-serostatus. Higher rates of STIs among HIV-positive MSM may partly be explained by more testing. Communication between health care providers and their clients about sexuality, sexual practices, and sexual risks should be improved. A comprehensive STI screening policy for MSM is needed. PMID:21592342

2011-01-01

376

A Genetic Analysis of Bald Eagles in the Pacific Northwest: Retained Genetic Diversity Following a Large-Scale Population Bottleneck.  

E-print Network

??Bald eagle (Haliaeetus leucocephalus) populations in the continental United States experienced a dramatic population decline during the twentieth century. Populations across the species’ range have… (more)

Nadeau, Andrew Joseph

2012-01-01

377

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

PubMed Central

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 multi-purpose longitudinal birth cohort study of all births in the UK in one week in 1970, with multiple questionnaire sweeps. PARTICIPANTS: Over 13,000 children were entered into the original cohort. Data on over 12,000 children were available at the five year follow up. MAIN OUTCOME MEASURES: For children at 5 years, parent reported data were available on health and social factors including data on two markers for middle ear disease: the occurrence of purulent (nonwax) ear discharge and suspected or confirmed hearing difficulty. MAIN RESULTS: In those children who had ever had reported hearing difficulty (suspected or confirmed), after control for socioeconomic status, three of the classic factors (male sex, mother's smoking habits since birth, and attending day care) were significantly more frequent. In those who had ever had ear discharge reported, only mother's smoking habit since birth was significantly more frequent. However, it showed an orderly dose response relation. In addition, a derived general child health score was found to be significantly associated with both the middle ear disease markers. Control for this variable in the analysis of those having reported hearing difficulty reduced the effect size of mother's smoking habit, but it remained statistically significant. For reported ear discharge, even after control for the general health score and social index, mother's smoking habits and day care attendance were both significant predictors. Mother's (but not father's) smoking habits and day care attendance were found to be significant risk factors for middle ear disease. Breast feeding effects were weak and did not generally survive statistical control. CONCLUSIONS: A child having all three risk factors (attends day care, a mother who smokes, and male sex) is 3.4 times more likely to have problems with hearing than a child who has none, based on cumulative risk. Further studies should focus on preventative risk modification and well specified intervention.   PMID:10396519

Bennett, K. E.; Haggard, M. P.

1998-01-01

378

Agro-ecosystems impact malaria prevalence: large-scale irrigation drives vector population in western Ethiopia  

PubMed Central

Background Development strategies in Ethiopia have largely focused on the expansion of irrigated agriculture in the last decade to reduce poverty and promote economic growth. However, such irrigation schemes can worsen the socio-economic state by aggravating the problem of mosquito-borne diseases. In this study, the effect of agro-ecosystem practices on malaria prevalence and the risk of malaria transmission by the primary vector mosquito, Anopheles arabiensis, in Ethiopia were investigated. Methods In three villages in western Ethiopia practising large-scale sugarcane irrigation, traditional smallholder irrigation and non-irrigated farming, cross-sectional parasitological surveys were conducted during the short rains, after the long rains and during the dry season. Entomological surveys were undertaken monthly (February 2010-January 2011) in each village using light traps, pyrethrum spray collections and artificial pit shelters. Results Malaria prevalence and the risk of transmission by An. arabiensis assessed by the average human biting rate, mean sporozoite rate and estimated annual entomological inoculation rate were significantly higher in the irrigated sugarcane agro-ecosystem compared to the traditionally irrigated and non-irrigated agro-ecosystems. The average human biting rate was significantly elevated by two-fold, while the mean sporozoite rate was 2.5-fold higher, and the annual entomological inoculation rate was 4.6 to 5.7-fold higher in the irrigated sugarcane compared to the traditional and non-irrigated agro-ecosystems. Active irrigation clearly affected malaria prevalence by increasing the abundance of host seeking Anopheles mosquitoes year-round and thus increasing the risk of infective bites. The year-round presence of sporozoite-infected vectors due to irrigation practices was found to strengthen the coupling between rainfall and risk of malaria transmission, both on- and off-season. Conclusion This study demonstrates the negative impact of large-scale irrigation expansion on malaria transmission by increasing the abundance of mosquito vectors and indicates the need for effective vector monitoring and control strategies in the implementation of irrigation projects. PMID:24083353

2013-01-01

379

A large population of king crabs in Palmer Deep on the west Antarctic Peninsula shelf and potential invasive impacts  

PubMed Central

Lithodid crabs (and other skeleton-crushing predators) may have been excluded from cold Antarctic continental shelf waters for more than 14 Myr. The west Antarctic Peninsula shelf is warming rapidly and has been hypothesized to be soon invaded by lithodids. A remotely operated vehicle survey in Palmer Deep, a basin 120 km onto the Antarctic shelf, revealed a large, reproductive population of lithodids, providing the first evidence that king crabs have crossed the Antarctic shelf. DNA sequencing and morphology indicate the lithodid is Neolithodes yaldwyni Ahyong & Dawson, previously reported only from Ross Sea waters. We estimate a N. yaldwyni population density of 10 600 km?2 and a population size of 1.55 × 106 in Palmer Deep, a density similar to lithodid populations of commercial interest around Alaska and South Georgia. The lithodid occurred at depths of more than 850 m and temperatures of more than 1.4°C in Palmer Deep, and was not found in extensive surveys of the colder shelf at depths of 430–725 m. Where N. yaldwyni occurred, crab traces were abundant, megafaunal diversity reduced and echinoderms absent, suggesting that the crabs have major ecological impacts. Antarctic Peninsula shelf waters are warming at approximately 0.01°C yr?1; if N. yaldwyni is currently limited by cold temperatures, it could spread up onto the shelf (400–600 m depths) within 1–2 decades. The Palmer Deep N. yaldwyni population provides an important model for the potential invasive impacts of crushing predators on vulnerable Antarctic shelf ecosystems. PMID:21900324

Smith, Craig R.; Grange, Laura J.; Honig, David L.; Naudts, Lieven; Huber, Bruce; Guidi, Lionel; Domack, Eugene

2012-01-01

380

A large population of king crabs in Palmer Deep on the west Antarctic Peninsula shelf and potential invasive impacts.  

PubMed

Lithodid crabs (and other skeleton-crushing predators) may have been excluded from cold Antarctic continental shelf waters for more than 14 Myr. The west Antarctic Peninsula shelf is warming rapidly and has been hypothesized to be soon invaded by lithodids. A remotely operated vehicle survey in Palmer Deep, a basin 120 km onto the Antarctic shelf, revealed a large, reproductive population of lithodids, providing the first evidence that king crabs have crossed the Antarctic shelf. DNA sequencing and morphology indicate the lithodid is Neolithodes yaldwyni Ahyong & Dawson, previously reported only from Ross Sea waters. We estimate a N. yaldwyni population density of 10 600 km(-2) and a population size of 1.55 × 10(6) in Palmer Deep, a density similar to lithodid populations of commercial interest around Alaska and South Georgia. The lithodid occurred at depths of more than 850 m and temperatures of more than 1.4°C in Palmer Deep, and was not found in extensive surveys of the colder shelf at depths of 430-725 m. Where N. yaldwyni occurred, crab traces were abundant, megafaunal diversity reduced and echinoderms absent, suggesting that the crabs have major ecological impacts. Antarctic Peninsula shelf waters are warming at approximately 0.01°C yr(-1); if N. yaldwyni is currently limited by cold temperatures, it could spread up onto the shelf (400-600 m depths) within 1-2 decades. The Palmer Deep N. yaldwyni population provides an important model for the potential invasive impacts of crushing predators on vulnerable Antarctic shelf ecosystems. PMID:21900324

Smith, Craig R; Grange, Laura J; Honig, David L; Naudts, Lieven; Huber, Bruce; Guidi, Lionel; Domack, Eugene

2012-03-01

381

SEXUAL ASSAULT AND SEXUAL HARASSMENT QUICK REFERENCE  

E-print Network

SEXUAL ASSAULT AND SEXUAL HARASSMENT QUICK REFERENCE Sexual Assault Definition ­ any form of sexual contact without both parties' voluntary consent. Contrary to what most people think, sexual assault. ­ Zvulony & Company ­ The Law of Sexual Assault in Canada. Sexual Harassment Definition ­ is comment

Thompson, Michael

382

Variability in mutational fitness effects prevents full lethal transitions in large quasispecies populations  

NASA Astrophysics Data System (ADS)

The distribution of mutational fitness effects (DMFE) is crucial to the evolutionary fate of quasispecies. In this article we analyze the effect of the DMFE on the dynamics of a large quasispecies by means of a phenotypic version of the classic Eigen's model that incorporates beneficial, neutral, deleterious, and lethal mutations. By parameterizing the model with available experimental data on the DMFE of Vesicular stomatitis virus (VSV) and Tobacco etch virus (TEV), we found that increasing mutation does not totally push the entire viral quasispecies towards deleterious or lethal regions of the phenotypic sequence space. The probability of finding regions in the parameter space of the general model that results in a quasispecies only composed by lethal phenotypes is extremely small at equilibrium and in transient times. The implications of our findings can be extended to other scenarios, such as lethal mutagenesis or genomically unstable cancer, where increased mutagenesis has been suggested as a potential therapy.

Sardanyés, Josep; Simó, Carles; Martínez, Regina; Solé, Ricard V.; Elena, Santiago F.

2014-04-01

383

Effect of Occupant and Impact Factors on Forces within Neck: I. Overview of Large Population  

NASA Astrophysics Data System (ADS)

Scientific and medical data have been gathered for nearly 500 motor-vehicle occupants, whose dynamic response[1-2] was calculated to determine the forces generated at all potential injury sites. Particular attention was paid to the load within the cervical spine to examine the influence of certain variables relating to the occupant (height, weight, sex), the impact (magnitude, direction), and the neck itself (local vector, anatomical level). Exhaustive efforts were made to match the force with each variable using linear and logarithmic fits, but correlation coefficients were generally not high. These results might be influenced by the emphasis in this research to obtain the best statistics with large groupings of patients. Hence, a separate study with more detail is proposed as a significant continuation of this effort. 1. Proper Treatment of Complex Human Structures, Announcer 27 (4), 100 (1997); 2. Physics as a Key Element in the Complete Description of Dichotomies in Injury Distribution, Bull. Am. Phys. Soc. 44, 274 (1999).

Shaibani, Saami J.

2000-03-01

384

Anti-MDA5 Antibodies in a Large Mediterranean Population of Adults with Dermatomyositis  

PubMed Central

A new myositis-specific autoantibody directed against melanoma differentiation-associated gene 5 (anti-MDA5) has been described in patients with dermatomyositis (DM). We report the clinical characteristics of patients with anti-MDA5 in a large Mediterranean cohort of DM patients from a single center, and analyze the feasibility of detecting this autoantibody in patient sera using new assays with commercially available recombinant MDA5. The study included 117 white adult patients with DM, 15 (13%) of them classified as clinically amyopathic dermatomyositis (CADM). Clinical manifestations were analyzed, with special focus on interstitial lung disease and its severity. Determination of anti-MDA5 antibodies was performed by a new ELISA and immunoblot technique. In sera, from 14 (12%) DM patients (8 CADM), MDA5 was recognized by ELISA, and confirmed by immunoblot. Eight of the 14 anti-MDA5-positive patients (57.14%) presented rapidly-progressive interstitial lung disease (RP-ILD) versus 3 of 103 anti-MDA5-negative patients (2.91%) (P < 0.05; OR: 44.4, 95% CI 9.3–212). The cumulative survival rate was significantly lower in anti-MDA5-positive patients than in the remainder of the series (P < 0.05). Patients with anti-MDA5-associated ILD presented significantly lower 70-month cumulative survival than antisynthetase-associated ILD patients. Among the cutaneous manifestations, only panniculitis was significantly associated with the presence of anti-MDA5 antibodies (P < 0.05; OR: 3.85, 95% CI 1.11–13.27). These findings support the reliability of using commercially available recombinant MDA5 for detecting anti-MDA5 antibodies and confirm the association of these antibodies with RP-ILD in a large series of Mediterranean patients with DM. PMID:24741583

Martinez, Maria Angeles; Trallero-Araguas, Ernesto; Balada, Eva; Vilardell-Tarres, Miquel; Juarez, Candido

2014-01-01

385

A large population genetic study of 15 autosomal short tandem repeat loci for establishment of Korean DNA profile database.  

PubMed

Genotyping of highly polymorphic short tandem repeat (STR) markers is widely used for the genetic identification of individuals in forensic DNA analyses and in paternity disputes. The National DNA Profile Databank recently established by the DNA Identification Act in Korea contains the computerized STR DNA profiles of individuals convicted of crimes. For the establishment of a large autosomal STR loci population database, 1805 samples were obtained at random from Korean individuals and 15 autosomal STR markers were analyzed using the AmpFlSTR Identifiler PCR Amplification kit. For the 15 autosomal STR markers, no deviations from the Hardy-Weinberg equilibrium were observed. The most informative locus in our data set was the D2S1338 with a discrimination power of 0.9699. The combined matching probability was 1.521 × 10(-17). This large STR profile dataset including atypical alleles will be important for the establishment of the Korean DNA database and for forensic applications. PMID:21597912

Yoo, Seong Yeon; Cho, Nam Soo; Park, Myung Jin; Seong, Ki Min; Hwang, Jung Ho; Song, Seok Bean; Han, Myun Soo; Lee, Won Tae; Chung, Ki Wha

2011-07-01

386

A LARGE STELLAR EVOLUTION DATABASE FOR POPULATION SYNTHESIS STUDIES. VI. WHITE DWARF COOLING SEQUENCES  

SciTech Connect

We present a new set of cooling models and isochrones for both H- and He-atmosphere white dwarfs (WDs), incorporating accurate boundary conditions from detailed model atmosphere calculations, and carbon-oxygen chemical abundance profiles based on updated stellar evolution calculations from the BaSTI stellar evolution archive-a theoretical data center for the Virtual Observatory. We discuss and quantify the uncertainties in the cooling times predicted by the models, arising from the treatment of mixing during the central H- and He-burning phases, the number of thermal pulses experienced by the progenitors, progenitor metallicity, and the {sup 12}C({alpha}, {gamma}){sup 16}O reaction rate. The largest sources of uncertainty turn out to be related to the treatment of convection during the last stages of the progenitor central He-burning phase and the {sup 12}C({alpha}, {gamma}){sup 16}O reaction rate. We compare our new models to previous calculations performed with the same stellar evolution code, and discuss their application to the estimate of the age of the solar neighborhood and the interpretation of the observed number ratios between H- and He-atmosphere WDs. The new WD sequences and an extensive set of WD isochrones that cover a large range of ages and progenitor metallicities are made publicly available at the official BaSTI Web site.

Salaris, M. [Astrophysics Research Institute, Liverpool John Moores University, 12 Quays House, Birkenhead, CH41 1LD (United Kingdom); Cassisi, S.; Pietrinferni, A. [INAF-Osservatorio Astronomico di Collurania, via M. Maggini, 64100 Teramo (Italy); Kowalski, P. M. [Helmholtz-Centre Potsdam-GFZ German Research Centre for Geosciences, Section 3.3, D-14473, Potsdam (Germany); Isern, J., E-mail: ms@astro.livjm.ac.u, E-mail: cassisi@oa-teramo.inaf.i, E-mail: adriano@oa-teramo.inaf.i [Institut de Ciencies de l'Espai (CSIC), Facultat de Ciencies, Campus UAB, 08193 Bellaterra (Spain)

2010-06-20

387

Perceptions of sexuality by African American patients on hemodialysis  

Microsoft Academic Search

Sexuality is central to who we are as sentient beings and transcends physical sex acts. Sexuality concerns are reported as common for individuals receiving hemodialysis; yet, sexuality-related research for this population has been limited to a focus on altered physical sexuality. Little is known about the effects of hemodialysis on perceptions of personal identity, family-social roles as men or women,

Merry Stewart

2010-01-01

388

Prevalence and factors of sexual problems in Chinese males and females having sex with the same-sex partner in Hong Kong: a population-based study  

Microsoft Academic Search

A cross-sectional, anonymous telephone survey was conducted to examine sexual problem (SP) among sexually active, Chinese homosexual adults in Hong Kong. Of the homosexual respondents, 49.1% of males and 75.6% of females reported at least one SP, of whom 36.0 and 65.7% of the males and females, respectively, felt very bothered by the SP. The prevalence of SP ranged from

J T F Lau; J H Kim; H-Y Tsui; JTF Lau

2006-01-01

389

Republished paper: Populations and partnerships: insights from metapopulation and pair models into the epidemiology of gonorrhoea and other sexually transmitted infections  

Microsoft Academic Search

BackgroundModels of sexually transmitted infection (STI) transmission can offer insights as to why gonorrhoea and other STIs are disproportionately concentrated in epidemiologically distinct subpopulations.MethodsWe highlight two different constructs for modelling STIs by drawing on previously published work on pair and metapopulation models, and reanalysed partnership data from the National Survey of Sexual Attitudes and Lifestyles II (NATSAL II) in the

Mark I Chen; Azra C Ghani

2010-01-01

390

Sexual Dysfunction in Male Iraq and Afghanistan War Veterans: Association with Posttraumatic Stress Disorder and Other Combat-Related Mental Health Disorders: A Population-Based Cohort Study  

PubMed Central

Introduction Mental health disorders are prevalent in the United States, Iraq, and Afghanistan war veterans. Mental illness, including posttraumatic stress disorder (PTSD) with or without psychiatric medications, can increase the risk for male sexual dysfunction, threatening quality of life. Aims We sought to determine the prevalence and correlates of sexual dysfunction among male Iraq and Afghanistan veterans. Methods We performed a retrospective cohort study of 405,275 male Iraq and Afghanistan veterans who were new users of U.S. Department of Veterans Affairs healthcare from October 7, 2001 to September 30, 2009 and had 2-year follow-up. Main Outcome Measures We determined the independent association of mental health diagnoses and sexual dysfunction after adjusting for sociodemographic and military service characteristics, comorbidities, and medications. Results Veterans with PTSD were more likely to have a sexual dysfunction diagnosis, be prescribed medications for sexual dysfunction, or both (10.6%), compared with veterans having a mental diagnosis other than PTSD (7.2%), or no mental health diagnosis (2.3%). In a fully adjusted model, PTSD increased the risk of sexual dysfunction by more than threefold (adjusted risk ratio = 3.61, 95% CI = 3.48–3.75). Veterans with mental health disorders, particularly PTSD, were at the highest risk of sexual dysfunction when prescribed psychiatric medications (adjusted risk ratio = 4.59, 95% CI = 4.41–4.77). Conclusions Among U.S. combat veterans, mental health disorders, particularly PTSD, increased the risk of sexual dysfunction independent of the use of psychiatric medications. PMID:23679562

Breyer, Benjamin N.; Cohen, Beth E.; Bertenthal, Daniel; Rosen, Raymond C.; Neylan, Thomas C.; Seal, Karen H.

2014-01-01

391

New limits on the population of normal and millisecond pulsars in the Large and Small Magellanic Clouds  

E-print Network

We model the potentially observable populations of normal and millisecond radio pulsars in the Large and Small Magellanic Clouds (LMC and SMC) where the known population currently stands at 19 normal radio pulsars. Taking into account the detection thresholds of previous surveys, and assuming optimal period and luminosity distributions based on studies of Galactic pulsars, we estimate there are (1.79 +/- 0.20) x 10^4 and (1.09 +/- 0.16) x 10^4 normal pulsars in the LMC and SMC respectively. When we attempt to correct for beaming effects, and the fraction of high-velocity pulsars which escape the clouds, we estimate birth rates in both the LMC and SMC to be comparable and in the range 0.5--1 pulsar per century. Although higher than estimates for the rate of core-collapse supernovae in the clouds, these pulsar birth rates are consistent with historical supernova observations in the past 300 yr. A substantial population of active radio pulsars (of order a few hundred thousand) have escaped the LMC and SMC and po...

Ridley, J P

2010-01-01

392

Initial guess by improved population-based intelligent algorithms for large inter-frame deformation measurement using digital image correlation  

NASA Astrophysics Data System (ADS)

Digital image correlation (DIC) has received a widespread research and application in experimental mechanics. In DIC, the performance of subpixel registration algorithm (e.g., Newton-Raphson method, quasi-Newton method) relies heavily on the initial guess of deformation. In the case of small inter-frame deformation, the initial guess could be found by simple search scheme, the coarse-fine search for instance. While for large inter-frame deformation, it is difficult for simple search scheme to robustly estimate displacement parameters and deformation parameters simultaneously with low computational cost. In this paper, we proposed three improving strategies, i.e. Q-stage evolutionary strategy (T), parameter control strategy (C) and space expanding strategy (E), and then combined them into three population-based intelligent algorithms (PIAs), i.e. genetic algorithm (GA), differential evolution (DE) and particle swarm optimization (PSO), and finally derived eighteen different algorithms to calculate the initial guess for qN. The eighteen algorithms were compared in three sets of experiments including large rigid body translation, finite uniaxial strain and large rigid body rotation, and the results showed the effectiveness of proposed improving strategies. Among all compared algorithms, DE-TCE is the best which is robust, convenient and efficient for large inter-frame deformation measurement.

Zhao, Jia-qing; Zeng, Pan; Lei, Li-ping; Ma, Yuan

2012-03-01

393