Science.gov

Sample records for male sex organ

  1. Technology, normalisation and male sex work.

    PubMed

    MacPhail, Catherine; Scott, John; Minichiello, Victor

    2015-01-01

    Technological change, particularly the growth of the Internet and smart phones, has increased the visibility of male escorts, expanded their client base and diversified the range of venues in which male sex work can take place. Specifically, the Internet has relocated some forms of male sex work away from the street and thereby increased market reach, visibility and access and the scope of sex work advertising. Using the online profiles of 257 male sex workers drawn from six of the largest websites advertising male sexual services in Australia, the role of the Internet in facilitating the normalisation of male sex work is discussed. Specifically we examine how engagement with the sex industry has been reconstituted in term of better informed consumer-seller decisions for both clients and sex workers. Rather than being seen as a 'deviant' activity, understood in terms of pathology or criminal activity, male sex work is increasingly presented as an everyday commodity in the market place. In this context, the management of risks associated with sex work has shifted from formalised social control to more informal practices conducted among online communities of clients and sex workers. We discuss the implications for health, legal and welfare responses within an empowerment paradigm.

  2. Technology, normalisation and male sex work.

    PubMed

    MacPhail, Catherine; Scott, John; Minichiello, Victor

    2015-01-01

    Technological change, particularly the growth of the Internet and smart phones, has increased the visibility of male escorts, expanded their client base and diversified the range of venues in which male sex work can take place. Specifically, the Internet has relocated some forms of male sex work away from the street and thereby increased market reach, visibility and access and the scope of sex work advertising. Using the online profiles of 257 male sex workers drawn from six of the largest websites advertising male sexual services in Australia, the role of the Internet in facilitating the normalisation of male sex work is discussed. Specifically we examine how engagement with the sex industry has been reconstituted in term of better informed consumer-seller decisions for both clients and sex workers. Rather than being seen as a 'deviant' activity, understood in terms of pathology or criminal activity, male sex work is increasingly presented as an everyday commodity in the market place. In this context, the management of risks associated with sex work has shifted from formalised social control to more informal practices conducted among online communities of clients and sex workers. We discuss the implications for health, legal and welfare responses within an empowerment paradigm. PMID:25215634

  3. Sex mosaics in a male dimorphic ant Cardiocondyla kagutsuchi

    NASA Astrophysics Data System (ADS)

    Yoshizawa, Juri; Mimori, Kohei; Yamauchi, Katsusuke; Tsuchida, Koji

    2009-01-01

    Gynandromorphy, or the development of organisms with a combination of male and female morphological features, is common in Hymenoptera. The underlying mechanism is likely associated with the sex-determination system, and studying this phenomenon should lead to a deeper understanding of both embryonic development and sex determination. The reproductive capabilities of gynandromorphs (hereafter, sex mosaics) remain unclear. We studied gynandromorphy in the Malaysian ant Cardiocondyla kagutsuchi, which has sex mosaics of queens (gynandromorphs; mosaic of queens and winged male) and workers (ergatandromorphs; mosaic of worker and wingless ergatoid male). These sex mosaics were classified into seven morphological categories. Most individuals had more male than female body areas. Behavioral observations revealed that sex mosaics behave more in accordance with the “sex” of their brain than that of the reproductive organs (gaster). Relative DNA quantities showed that both female and male regions contained haploid and diploid nuclei, irrespective of their phenotypic appearance, indicating that external appearance did not reflect internal tissues. Nearly one third of the adults were sex mosaics and they were not infected with Wolbachia. Our results suggest that the production of sex mosaics in this species does not pose a substantial cost to colonies and that the underlying causes are therefore not strongly selected against.

  4. [Thr arteries of the male sex organs of Japanese quail (Coturnix coturnix japonica) and their development after hatching].

    PubMed

    Okamoto, T; Vollmerhaus, B; Roos, H; Waibl, H; König, H E

    1992-06-01

    A total of 83 male Japanese quails of the following age groups were used for this study: 11, 18, 25, 32, 35, 37, 39, 41, 43 days, and 7, 9, 17 weeks after hatching. Neoprene-Latex, Tensol-Cement, and the china ink were injected via the aortic arch. In most of male Japanese quails, the testes are supplied by the A. testicularis originated from the Aorta descendens through a common trunk with the A. renalis cranialis. But in only 3 quails had this artery originated directly from the Aorta descendens on either side. In 9 quails had the A. testicularis accessoria originating independently from the Aorta descendens and running cranially or caudally in short distance to the normal A. testicularis. The arteries for the Ductus deferens were divided into 3 categories. The Rami ureterodeferentiales craniales were spread out from A. testicularis or Rami epididymales. The Rami ureterodeferentiales medii came from the A. renalis media and the A. renalis caudalis. The Rami ureterodeferentiales caudales originated from the A. caudae lateralis and A. pudenda. The Receptaculum ductus deferentis, the Corpus vasculare paracloacalis and the Phallus nonprotrudens in the Cloaca were supplied from the thick Ramus cloacalis of the A. pudenda. The Ramus bursalis of this artery supplied the Glandula proctodaealis and the Bursa cloacalis, and was also thick. The arteries to the genital organs were observed in the 11 day old male quail. The A. pudenda began developing at about 30 days after hatching when the quail's body matured. While the A. testicularis began developing at about 40 days after hatching when the male Japanese quail was full of the spermatogenic activity. PMID:1497141

  5. Rogue Males: Sex Differences in Psychology Students

    ERIC Educational Resources Information Center

    Sander, Paul; Sanders, Lalage

    2006-01-01

    Introduction: This paper reports a preliminary study into the commitment and academic confidence of male students in undergraduate psychology, prompted by our own observations of the performance of male students and the literature on sex differences in education. Method: Using an analytical survey, level 1 psychology students at a new university…

  6. Male pygmy hippopotamus influence offspring sex ratio.

    PubMed

    Saragusty, Joseph; Hermes, Robert; Hofer, Heribert; Bouts, Tim; Göritz, Frank; Hildebrandt, Thomas B

    2012-01-01

    Pre-determining fetal sex is against the random and equal opportunity that both conceptus sexes have by nature. Yet, under a wide variety of circumstances, populations shift their birth sex ratio from the expected unity. Here we show, using fluorescence in situ hybridization, that in a population of pygmy hippopotamus (Choeropsis liberiensis) with 42.5% male offspring, males bias the ratio of X- and Y-chromosome-bearing spermatozoa in their ejaculates, resulting in a 0.4337±0.0094 (mean±s.d.) proportion of Y-chromosome-bearing spermatozoa. Three alternative hypotheses for the shifted population sex ratio were compared: female counteract male, female indifferent, or male and female in agreement. We conclude that there appears little or no antagonistic sexual conflict, unexpected by prevailing theories. Our results indicate that males possess a mechanism to adjust the ratio of X- and Y-chromosome-bearing spermatozoa in the ejaculate, thereby substantially expanding currently known male options in sexual conflict.

  7. Male pygmy hippopotamus influence offspring sex ratio.

    PubMed

    Saragusty, Joseph; Hermes, Robert; Hofer, Heribert; Bouts, Tim; Göritz, Frank; Hildebrandt, Thomas B

    2012-01-01

    Pre-determining fetal sex is against the random and equal opportunity that both conceptus sexes have by nature. Yet, under a wide variety of circumstances, populations shift their birth sex ratio from the expected unity. Here we show, using fluorescence in situ hybridization, that in a population of pygmy hippopotamus (Choeropsis liberiensis) with 42.5% male offspring, males bias the ratio of X- and Y-chromosome-bearing spermatozoa in their ejaculates, resulting in a 0.4337±0.0094 (mean±s.d.) proportion of Y-chromosome-bearing spermatozoa. Three alternative hypotheses for the shifted population sex ratio were compared: female counteract male, female indifferent, or male and female in agreement. We conclude that there appears little or no antagonistic sexual conflict, unexpected by prevailing theories. Our results indicate that males possess a mechanism to adjust the ratio of X- and Y-chromosome-bearing spermatozoa in the ejaculate, thereby substantially expanding currently known male options in sexual conflict. PMID:22426218

  8. Sex Steroid Actions in Male Bone

    PubMed Central

    Laurent, Michaël R.; Claessens, Frank; Gielen, Evelien; Lagerquist, Marie K.; Vandenput, Liesbeth; Börjesson, Anna E.; Ohlsson, Claes

    2014-01-01

    Sex steroids are chief regulators of gender differences in the skeleton, and male gender is one of the strongest protective factors against osteoporotic fractures. This advantage in bone strength relies mainly on greater cortical bone expansion during pubertal peak bone mass acquisition and superior skeletal maintenance during aging. During both these phases, estrogens acting via estrogen receptor-α in osteoblast lineage cells are crucial for male cortical and trabecular bone, as evident from conditional genetic mouse models, epidemiological studies, rare genetic conditions, genome-wide meta-analyses, and recent interventional trials. Genetic mouse models have also demonstrated a direct role for androgens independent of aromatization on trabecular bone via the androgen receptor in osteoblasts and osteocytes, although the target cell for their key effects on periosteal bone formation remains elusive. Low serum estradiol predicts incident fractures, but the highest risk occurs in men with additionally low T and high SHBG. Still, the possible clinical utility of serum sex steroids for fracture prediction is unknown. It is likely that sex steroid actions on male bone metabolism rely also on extraskeletal mechanisms and cross talk with other signaling pathways. We propose that estrogens influence fracture risk in aging men via direct effects on bone, whereas androgens exert an additional antifracture effect mainly via extraskeletal parameters such as muscle mass and propensity to fall. Given the demographic trends of increased longevity and consequent rise of osteoporosis, an increased understanding of how sex steroids influence male bone health remains a high research priority. PMID:25202834

  9. Gene Expression and Localization of NGF and Its Cognate Receptors NTRK1 and NGFR in the Sex Organs of Male Rabbits.

    PubMed

    Maranesi, M; Zerani, M; Leonardi, L; Pistilli, A; Arruda-Alencar, J; Stabile, A M; Rende, M; Castellini, C; Petrucci, L; Parillo, F; Moura, A; Boiti, C

    2015-12-01

    Experiments were devised to characterize the expression of nerve growth factor, beta polypeptide (NGF), and its cognate receptors neurotrophic tyrosine kinase receptor type 1 (NTRK1) and nerve growth factor receptor (NGFR) in rabbit male sex organs, as well as the concentrations of NGF in both seminal and blood plasma of sexually mature male rabbits. Immunoreactivity and gene expression for NGF and cognate receptors were detected in testis, prostate gland and seminal vesicle. The highest levels of NGF and NTRK1 transcripts were found in the prostate, while intermediate expressions were found in the testis. NGFR transcripts were expressed at the same levels in both testis and prostate and were more abundant than in seminal vesicles. The widespread distribution of NGF in all prostate glandular cells, together with its relative high mRNA abundance, confirms that the prostate of rabbits is the main source of this neurotrophin. In conclusion, the present data suggest that the NGF system is involved in the testicular development and spermatogenesis of rabbits and that NGF may act as a potential ovulation-inducing factor being abundantly present in the seminal plasma.

  10. Gene Expression and Localization of NGF and Its Cognate Receptors NTRK1 and NGFR in the Sex Organs of Male Rabbits.

    PubMed

    Maranesi, M; Zerani, M; Leonardi, L; Pistilli, A; Arruda-Alencar, J; Stabile, A M; Rende, M; Castellini, C; Petrucci, L; Parillo, F; Moura, A; Boiti, C

    2015-12-01

    Experiments were devised to characterize the expression of nerve growth factor, beta polypeptide (NGF), and its cognate receptors neurotrophic tyrosine kinase receptor type 1 (NTRK1) and nerve growth factor receptor (NGFR) in rabbit male sex organs, as well as the concentrations of NGF in both seminal and blood plasma of sexually mature male rabbits. Immunoreactivity and gene expression for NGF and cognate receptors were detected in testis, prostate gland and seminal vesicle. The highest levels of NGF and NTRK1 transcripts were found in the prostate, while intermediate expressions were found in the testis. NGFR transcripts were expressed at the same levels in both testis and prostate and were more abundant than in seminal vesicles. The widespread distribution of NGF in all prostate glandular cells, together with its relative high mRNA abundance, confirms that the prostate of rabbits is the main source of this neurotrophin. In conclusion, the present data suggest that the NGF system is involved in the testicular development and spermatogenesis of rabbits and that NGF may act as a potential ovulation-inducing factor being abundantly present in the seminal plasma. PMID:26392300

  11. Transgenerational sex determination: the embryonic environment experienced by a male affects offspring sex ratio

    PubMed Central

    Warner, Daniel A.; Uller, Tobias; Shine, Richard

    2013-01-01

    Conditions experienced during embryonic development can have lasting effects, even carrying across generations. Most evidence for transgenerational effects comes from studies of female mammals, with much less known about egg-laying organisms or paternally-mediated effects. Here we show that offspring sex can be affected by the incubation temperature its father experiences years earlier. We incubated eggs of an Australian lizard with temperature-dependent sex determination under three thermal regimes; some eggs were given an aromatase inhibitor to produce sons at temperatures that usually produce only daughters. Offspring were raised to maturity and freely interbred within field enclosures. After incubating eggs of the subsequent generation and assigning parentage, we found that the developmental temperature experienced by a male significantly influences the sex of his future progeny. This transgenerational effect on sex ratio may reflect an epigenetic influence on paternally-inherited DNA. Clearly, sex determination in reptiles is far more complex than is currently envisaged. PMID:24048344

  12. Male sex drive and the maintenance of sex: evidence from Drosophila.

    PubMed

    Singh, Rama S; Artieri, Carlo G

    2010-01-01

    The resolution of the paradoxes surrounding the evolutionary origins and maintenance of sexual reproduction has been a major focus in biology. The operation of sexual selection-which is very common among multicellular organisms-has been proposed as an important factor in the maintenance of sex, though in order for this hypothesis to hold, the strength of sexual selection must be stronger in males than in females. Sexual selection poses its own series of evolutionary questions, including how genetic variability is maintained in the face of sustained directional selection (known as the "paradox of the lek"). In this short review, we present evidence obtained from recent comparative genomics projects arguing that 1) the genomic consequences of sexual selection clearly show that its effect is stronger in males and 2) this sustained selection over evolutionary timescales also has an effect of capturing de novo genes and expression patterns influencing male fitness, thus providing a mechanism via which new genetic variation can be input into to male traits. Furthermore, we argue that this latter process of genomic "masculinization" has an additional effect of making males difficult to purge from populations, as evidence from Drosophila indicates that, for example, many male sexually selected seminal fluid factors are required to ensure maximally efficient reproduction. Newly arising parthenogenic mutations would suffer an immediate reproductive rate disadvantage were these proteins lost. We show that recent studies confirm that genomic masculinization, as a result of "male sex drive," has important consequences for the evolution of sexually dimorphic species.

  13. Understanding the New Context of the Male Sex Work Industry

    ERIC Educational Resources Information Center

    Scott, John; Minichiello, Victor; Marino, Rodrigo; Harvey, Glenn P.; Jamieson, Maggie; Browne, Jan

    2005-01-01

    The article reviews past and recent research on male sex work to offer a context to understand violence in the industry. It provides a critical review of research to show, first, the assumptions made about male sex workers and violence and, second, how such discourses have shaped thinking on the topic. The article presents a case study and…

  14. Sex-different response in growth traits to resource heterogeneity explains male-biased sex ratio

    NASA Astrophysics Data System (ADS)

    Matsushita, Michinari; Takao, Mikako; Makita, Akifumi

    2016-08-01

    In dioecious plants, differences in growth traits between sexes in a response to micro-environmental heterogeneity may affect sex ratio bias and spatial distributions. Here, we examined sex ratios, stem growth traits and spatial distribution patterns in the dioecious clonal shrub Aucuba japonica var. borealis, in stands with varying light intensities. We found that male stems were significantly more decumbent (lower height/length ratio) but female stems were upright (higher height/length ratio). Moreover, we found sex-different response in stem density (no. of stems per unit area) along a light intensity gradient; in males the stem density increased with increases in canopy openness, but not in females. The higher sensitivity of males in increasing stem density to light intensity correlated with male-biased sex ratio; fine-scale sex ratio was strongly male-biased as canopy openness increased. There were also differences between sexes in spatial distributions of stems. Spatial segregation of sexes and male patches occupying larger areas than female patches might result from vigorous growth of males under well-lit environments. In summary, females and males showed different growth responses to environmental variation, and this seemed to be one of possible causes for the sex-differential spatial distributions and locally biased sex ratios.

  15. Double-strand break repair on sex chromosomes: challenges during male meiotic prophase

    PubMed Central

    Lu, Lin-Yu; Yu, Xiaochun

    2015-01-01

    During meiotic prophase, DNA double-strand break (DSB) repair-mediated homologous recombination (HR) occurs for exchange of genetic information between homologous chromosomes. Unlike autosomes or female sex chromosomes, human male sex chromosomes X and Y share little homology. Although DSBs are generated throughout male sex chromosomes, homologous recombination does not occur for most regions and DSB repair process is significantly prolonged. As a result, male sex chromosomes are coated with many DNA damage response proteins and form a unique chromatin structure known as the XY body. Interestingly, associated with the prolonged DSB repair, transcription is repressed in the XY body but not in autosomes, a phenomenon known as meiotic sex chromosome inactivation (MSCI), which is critical for male meiosis. Here using mice as model organisms, we briefly summarize recent progress on DSB repair in meiotic prophase and focus on the mechanism and function of DNA damage response in the XY body. PMID:25565522

  16. Male sex drive and the masculinization of the genome.

    PubMed

    Singh, Rama S; Kulathinal, Rob J

    2005-05-01

    Charles Darwin remarked that "males, with their superior strength, pugnacity, armaments, unwieldly passion and love songs, are almost always the more active and most often, the initiators of sexual interactions". Here, we propose that such male sex drive directly impacts the genome by leading to its progressive masculinization--genes that possess sex-specific effects on male fitness accumulate to a much greater extent and are generally more diverged. The larger proportion of male versus female fitness modifiers in combination with stronger sexual selection may generate evolutionary signatures such as a greater sensitivity to male sterility and a paucity of X-linked male-specific genes. Male sex-drive theory complements the female-choice theory of sexual selection and allows for the genetic variation of costly sexual traits to be continuously replenished.

  17. Variably male-biased sex ratio in a marine bird with females larger than males.

    PubMed

    Torres, R; Drummond, H

    1999-01-01

    When the costs of rearing males and females differ progeny sex ratios are expected to be biased toward the less expensive sex. Blue-footed booby (Sula nebouxii) females are larger and roughly 32% heavier than males, thus presumably more costly to rear. We recorded hatching and fledging sex ratios in 1989, and fledging sex ratios during the next 5 years. In 1989, the sample of 751 chicks showed male bias at hatching (56%) and at fledging (57% at 90 days). Fledging sex ratios during the five subsequent reproductive seasons were at unity (1 year) or male-biased, varying from 56% to 70%. Male bias was greater during years when mean sea surface temperature was warmer and food was presumably in short supply. During two warm-water years (only) fledging sex ratio varied with hatching date. Proportions of male fledglings increased with date from 0.48 to 0.73 in 1994, and from 0.33 to 0.79 in 1995. Similar results were obtained when the analysis was repeated using only broods with no nestling mortality, suggesting that the overall increase in the proportion of males over the season was the result of sex ratio adjustments at hatching. The male-biased sex ratio, and the increased male bias during poor breeding conditions supports the idea that daughters may be more costly than sons, and that their relative cost increases in poor conditions. PMID:20135156

  18. Sex-Typed Attitudes, Sex-Typed Contingency Behaviors, and Personality Traits of Male Caregivers.

    ERIC Educational Resources Information Center

    Robinson, Bryan E.

    This study examined the contingency behaviors, attitudinal dispositions, and personality traits of male caregivers in day care settings. A random sample of 20 male caregivers was contrasted with 20 female caregivers and 20 male engineers on measures of sex-typed attitudes and personality traits. Male and female caregivers were also contrasted on…

  19. Refocusing HIV / AIDS interventions in Thailand: the case for male sex workers and other homosexually active men.

    PubMed

    Mccamish, M; Storer, G; Carl, G

    2000-01-01

    Although studies have shown that male sex workers in Thailand are at increased risk of HIV infection, no sustained strategy have so far been directed towards homosexually active men in the country. This paper brings together data from qualitative research carried out in Pattaya and Bangkok, with data generated during a bar-based intervention in Bangkok, to develop a taxonomy of sites in which the recruitment of male commercial sex can occur. The researchers also examined the sexual networks of Thai male sex workers and their clients in order to show the overlap of commercial and non-commercial male-male sex sites, and the intersection of male commercial sex with heterosexual sex. Previous efforts directed towards Thai male sex workers have been non-continuous; largely restricted to high-profile tourist areas; have not acknowledged the importance of recreational sex; and have not built up a capacity for ongoing intervention. With a change of focus, interventions targeted at sex workers could reduce the risks of HIV infection among organized and freelance sex workers as well as their commercial and male and female casual sex partners. Foremost, however, is the need to commit to well planned and long range interventions directed by and at male sex workers. PMID:12295881

  20. Male mutation rates and the cost of sex for females

    NASA Astrophysics Data System (ADS)

    Redfield, Rosemary J.

    1994-05-01

    ALTHOUGH we do not know why sex evolved, the twofold cost of meiosis for females provides a standard against which postulated benefits of sex can be evaluated1. The most reliable benefit is sex's ability to reduce the impact of deleterious mutations2,3. But deleterious mutations may themselves generate a large and previously overlooked female-specific cost of sex. DNA sequence comparisons have confirmed Haldane's suggestion that most mutations arise in the male germ line4,5; recent estimates of α, the ratio of male to female mutation rates, are ten, six and two in humans, primates and rodents, respectively6-8. Consequently, male gametes may give progeny more mutations than the associated sexual recombination eliminates. Here I describe computer simulations showing that the cost of male mutations can easily exceed the benefits of recombination, causing females to produce fitter progeny by parthenogenesis than by mating. The persistence of sexual reproduction by females thus becomes even more problematic.

  1. Group Work Practice with Transgendered Male to Female Sex Workers.

    ERIC Educational Resources Information Center

    Klein, Rebecca

    1999-01-01

    Examines group work with transgendered male-to-female adolescents who engage in sex work. Provides an overview of the role that sex work plays in the lives of some transgendered youth, using case examples, and offers guidance for those utilizing group work approaches with transgendered adolescents. Discusses homelessness and institutionalization,…

  2. Hands as sex cues: sensitivity measures, male bias measures, and implications for sex perception mechanisms.

    PubMed

    Gaetano, Justin; van der Zwan, Rick; Blair, Duncan; Brooks, Anna

    2014-01-01

    Sex perceptions, or more particularly, sex discriminations and sex categorisations, are high-value social behaviours. They mediate almost all inter-personal interactions. The two experiments reported here had the aim of exploring some of the basic characteristics of the processes giving rise to sex perceptions. Experiment 1 confirmed that human hands can be used as a cue to an individual's sex even when colour and texture cues are removed and presentations are brief. Experiment 1 also showed that when hands are sexually ambiguous observers tend to classify them as male more often than female. Experiment 2 showed that "male bias" arises not from sensitivity differences but from differences in response biases. Observers are conservative in their judgements of targets as female but liberal in their judgements of targets as male. These data, combined with earlier reports, suggest the existence of a sex-perception space that is cue-invariant.

  3. Musings on male sex work: a "virtual" discussion.

    PubMed

    Harriman, Rebecca L; Johnston, Barry; Kenny, Paula M

    2007-01-01

    Contributors and editors were asked to respond to a series of questions concerning male sex work in order to stimulate an informal "conversation." Some of the topics explored include: why people seek the services of prostitutes; is the term "sex work" favorable to "prostitution": is it right to pay for sex; and is exploitation a necessary part of the sex worker/client interchange'? Contributors' responses were compiled and listed in the order they were received. Common elements of their responses are summarized and the advantages of this informal approach are articulated. PMID:18019078

  4. What do isogamous organisms teach us about sex and the two sexes?

    PubMed

    Lehtonen, Jussi; Kokko, Hanna; Parker, Geoff A

    2016-10-19

    Isogamy is a reproductive system where all gametes are morphologically similar, especially in terms of size. Its importance goes beyond specific cases: to this day non-anisogamous systems are common outside of multicellular animals and plants, they can be found in all eukaryotic super-groups, and anisogamous organisms appear to have isogamous ancestors. Furthermore, because maleness is synonymous with the production of small gametes, an explanation for the initial origin of males and females is synonymous with understanding the transition from isogamy to anisogamy. As we show here, this transition may also be crucial for understanding why sex itself remains common even in taxa with high costs of male production (the twofold cost of sex). The transition to anisogamy implies the origin of male and female sexes, kickstarts the subsequent evolution of sex roles, and has a major impact on the costliness of sexual reproduction. Finally, we combine some of the consequences of isogamy and anisogamy in a thought experiment on the maintenance of sexual reproduction. We ask what happens if there is a less than twofold benefit to sex (not an unlikely scenario as large short-term benefits have proved difficult to find), and argue that this could lead to a situation where lineages that evolve anisogamy-and thus the highest costs of sex-end up being associated with constraints that make invasion by asexual reproduction unlikely (the 'anisogamy gateway' hypothesis).This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'. PMID:27619696

  5. What do isogamous organisms teach us about sex and the two sexes?

    PubMed

    Lehtonen, Jussi; Kokko, Hanna; Parker, Geoff A

    2016-10-19

    Isogamy is a reproductive system where all gametes are morphologically similar, especially in terms of size. Its importance goes beyond specific cases: to this day non-anisogamous systems are common outside of multicellular animals and plants, they can be found in all eukaryotic super-groups, and anisogamous organisms appear to have isogamous ancestors. Furthermore, because maleness is synonymous with the production of small gametes, an explanation for the initial origin of males and females is synonymous with understanding the transition from isogamy to anisogamy. As we show here, this transition may also be crucial for understanding why sex itself remains common even in taxa with high costs of male production (the twofold cost of sex). The transition to anisogamy implies the origin of male and female sexes, kickstarts the subsequent evolution of sex roles, and has a major impact on the costliness of sexual reproduction. Finally, we combine some of the consequences of isogamy and anisogamy in a thought experiment on the maintenance of sexual reproduction. We ask what happens if there is a less than twofold benefit to sex (not an unlikely scenario as large short-term benefits have proved difficult to find), and argue that this could lead to a situation where lineages that evolve anisogamy-and thus the highest costs of sex-end up being associated with constraints that make invasion by asexual reproduction unlikely (the 'anisogamy gateway' hypothesis).This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'.

  6. The evolution of sex chromosomes in organisms with separate haploid sexes.

    PubMed

    Immler, Simone; Otto, Sarah Perin

    2015-03-01

    The evolution of dimorphic sex chromosomes is driven largely by the evolution of reduced recombination and the subsequent accumulation of deleterious mutations. Although these processes are increasingly well understood in diploid organisms, the evolution of dimorphic sex chromosomes in haploid organisms (U/V) has been virtually unstudied theoretically. We analyze a model to investigate the evolution of linkage between fitness loci and the sex-determining region in U/V species. In a second step, we test how prone nonrecombining regions are to degeneration due to accumulation of deleterious mutations. Our modeling predicts that the decay of recombination on the sex chromosomes and the addition of strata via fusions will be just as much a part of the evolution of haploid sex chromosomes as in diploid sex chromosome systems. Reduced recombination is broadly favored, as long as there is some fitness difference between haploid males and females. The degeneration of the sex-determining region due to the accumulation of deleterious mutations is expected to be slower in haploid organisms because of the absence of masking. Nevertheless, balancing selection often drives greater differentiation between the U/V sex chromosomes than in X/Y and Z/W systems. We summarize empirical evidence for haploid sex chromosome evolution and discuss our predictions in light of these findings.

  7. Sexual systems and dwarf males in barnacles: integrating life history and sex allocation theories.

    PubMed

    Yamaguchi, Sachi; Yusa, Yoichi; Sawada, Kota; Takahashi, Satoshi

    2013-03-01

    Barnacles, which are sedentary marine crustaceans, have diverse sexual systems that include simultaneous hermaphroditism, androdioecy (coexistence of hermaphrodites and males) and dioecy (females and males). In dioecious and androdioecious species, the males are very small and are thus called dwarf males. These sexual systems are defined by two factors: sex allocation of non-dwarf individuals and the presence or absence of dwarf males. We constructed an ESS model treating sex allocation and life history simultaneously to explain sexual systems in barnacles. We analyzed the evolutionarily stable size-dependent resource allocation strategy to male reproductive function, female reproductive function and growth in non-dwarf barnacles, and the ESS proportion of dwarf males, under conditions of varying mortality and food availability. Sex allocation in non-dwarf individuals (hermaphrodites or females) is affected by mate availability and the proportion of dwarf males. When hermaphrodites appear, all hermaphrodites become protandric simultaneous hermaphrodites. Furthermore, high mortality and poor resource availability favor dwarf males because of their early maturation and weakened sperm competition. In conclusion, we showed that combining sex allocation and life history theories is a useful way to understand various sexual systems in barnacles and perhaps in other organisms as well.

  8. Female and Male Usage of Pragmatic Expressions in Same-Sex and Mixed-Sex Interaction.

    ERIC Educational Resources Information Center

    Erman, Britt

    1992-01-01

    A study investigated the use of three pragmatic expressions ("you know, you see, I mean") by female and male British English speakers to (1) establish actual differences in usage over a number of functions of the three expressions, and (2) discover any correlation of usage with same-sex vs. mixed-sex interaction. (Author/MSE)

  9. A comparison of sex offenders against female and male minors.

    PubMed

    Freund, K; Watson, R; Rienzo, D

    1987-01-01

    Male sex offenders against minors were grouped according to age and sex of victims, and according to whether they had offended against one or more than one minor. Cases of incest or courtship disorder were not included in the study. Among offenders against female children, the number of one-case offenders was substantially larger than that of multicase offenders. The opposite was true of offenders against male children, and there was no significant difference between one-case and multicase offenders against female or male early adolescents. If these counts reflect corresponding prevalences within sex offenders against minors in a Western cultural setting, some inferences can be made from these comparisons. PMID:3694689

  10. Risk of HIV infection among male sex workers in Spain

    PubMed Central

    Belza, M; t for

    2005-01-01

    Objective: To assess HIV prevalence and predictive factors for HIV among male sex workers in Spain. Methods: In this study we analysed all male sex workers who visited HIV testing clinics in 19 Spanish cities between 2000 and 2002. The information was obtained during examination by means of a brief questionnaire. For repeating testers, only the last confirmed result was taken into account. Results: 418 male sex workers were included in the analysis; 58% visited these clinics for the first time and 42% were repeating testers. 67% were of foreign origin, mostly from Latin America (91%). 96% had had sex with men, 18% were transvestites or transsexuals, and 3.3% had used injected drugs. HIV prevalence was 12.2% (95% CI, 9.3 to 15.8%), and rose to 16.9% among first time testers. No differences in HIV prevalence were found between injecting drug users, transvestites/transsexuals, and men from foreign countries. Conclusion: Because of the high risk of HIV infection, male sex workers should be the target of specific preventive activities. Preventive and healthcare strategies that are culturally adapted to migrants are required. PMID:15681730

  11. Converging Evidence of Ubiquitous Male Bias in Human Sex Perception.

    PubMed

    Gaetano, Justin; van der Zwan, Rick; Oxner, Matthew; Hayward, William G; Doring, Natalie; Blair, Duncan; Brooks, Anna

    2016-01-01

    Visually judging the sex of another can be achieved easily in most social encounters. When the signals that inform such judgements are weak (e.g. outdoors at night), observers tend to expect the presence of males-an expectation that may facilitate survival-critical decisions under uncertainty. The present aim was to examine whether this male bias depends on expertise. To that end, Caucasian and Asian observers targeted female and male hand images that were either the same or different to the observers' race (i.e. long term experience was varied) while concurrently, the proportion of targets changed across presentation blocks (i.e. short term experience change). It was thus found that: (i) observers of own-race stimuli were more likely to report the presence of males and absence of females, however (ii) observers of other-race stimuli--while still tending to accept stimuli as male--were not prone to rejecting female cues. Finally, (iii) male-biased measures did not track the relative frequency of targets or lures, disputing the notion that male bias derives from prior expectation about the number of male exemplars in a set. Findings are discussed in concert with the pan-stimulus model of human sex perception. PMID:26859570

  12. Converging Evidence of Ubiquitous Male Bias in Human Sex Perception.

    PubMed

    Gaetano, Justin; van der Zwan, Rick; Oxner, Matthew; Hayward, William G; Doring, Natalie; Blair, Duncan; Brooks, Anna

    2016-01-01

    Visually judging the sex of another can be achieved easily in most social encounters. When the signals that inform such judgements are weak (e.g. outdoors at night), observers tend to expect the presence of males-an expectation that may facilitate survival-critical decisions under uncertainty. The present aim was to examine whether this male bias depends on expertise. To that end, Caucasian and Asian observers targeted female and male hand images that were either the same or different to the observers' race (i.e. long term experience was varied) while concurrently, the proportion of targets changed across presentation blocks (i.e. short term experience change). It was thus found that: (i) observers of own-race stimuli were more likely to report the presence of males and absence of females, however (ii) observers of other-race stimuli--while still tending to accept stimuli as male--were not prone to rejecting female cues. Finally, (iii) male-biased measures did not track the relative frequency of targets or lures, disputing the notion that male bias derives from prior expectation about the number of male exemplars in a set. Findings are discussed in concert with the pan-stimulus model of human sex perception.

  13. The Male Sex Role: A Selected and Annotated Bibliography.

    ERIC Educational Resources Information Center

    Grady, Kathleen E.; And Others

    This bibliography, containing more than 250 entries, presents research and theoretical perspectives into the male sex role. Articles were chosen for their usefulness to researchers, with emphasis on scientific and data-based research literature. All the annotations use a standard format including subjects, method, findings and comments. Articles…

  14. Beyond the Bravado: Sex Roles and the Exploitive Male.

    ERIC Educational Resources Information Center

    Taubman, Stan

    1986-01-01

    Examines the tendency of men to engage in domestic violence and sexual exploitation and presents male sex-role acquisition as a process of psychosocial violence against young boys, which creates a sense of shame, powerlessness, self-alienation, isolation from others, and retaliatory rage and inhibits capacities for intimacy and mutuality.…

  15. Sex behaviour of male Japanese tourists in Bangkok, Thailand.

    PubMed

    Yokota, Fumihiko

    2006-01-01

    This paper explores why Japanese men engage in potentially risky commercial sexual behaviours while on holiday in Thailand. Semi-structured, in-depth interviews were conducted with 30 heterosexual male Japanese tourists, aged 19-36, who paid for sex with Thai women. Study participants were recruited at guesthouses in Bangkok. Analysis revealed eight main factors that encourage participation in commercial sex: a sense of freedom and anonymity during "time-out" spent travelling in a foreign country; a sense that there are permissive norms governing commercial sex in Thailand; the perceived sexual desirability of Thai women, a sense of economic and racial superiority relative to Thai women; a sense of loneliness or feeling in need of companionship; peer influence; the widespread availability of inexpensive sexual services in Thailand; and sexual desire or need. Findings indicate that Japanese male sexual conduct reflects individual drives while on holiday, in the context of interactions among Japanese peers, shaped by Thailand's socio-cultural environment.

  16. Males on demand: the environmental-neuro-endocrine control of male sex determination in daphnids.

    PubMed

    LeBlanc, Gerald A; Medlock, Elizabeth K

    2015-11-01

    Branchiopod crustaceans (e.g., Daphnia sp.) and some other taxa utilize both asexual and sexual reproduction to maximize population sustainability. The decision to switch from asexual to sexual reproduction is triggered by environmental cues that foretell a potentially detrimental change in environmental conditions. This review describes the cascade of events beginning with environmental cues and ending with changes in gene expression that dictate male sex determination in daphnids, the initial event in the switch to sexual reproduction. Several environmental cues have been identified which, either in isolation or in combination, stimulate male sex determination. These cues are typically associated with change of season, exhaustion of resources or loss of habitat. Maternal daphnids receive and respond to these cues, we propose, through the secretion of neuropeptides, which suppress (hyperglycemic hormone-like neuropeptides, allatostatin) or stimulate (allatotropin) the male sex differentiation program. In response, maternal daphnids produce the male sex-determining hormone, methyl farnesoate. Methyl farnesoate binds to a protein MET that dimerizes with the protein SRC forming an active transcription factor. This complex then regulates the expression of genes, primarily doublesex (dsx), involved in programming the single-celled embryo to develop into a male. In the absence of methyl farnesoate programming, the embryo develops into a female. Epigenetic modifications of the genome as a possible mode of methyl farnesoate action and the utility of this model to decipher the role of epigenetics in sex differentiation in other species are discussed. PMID:26237283

  17. Male sex hormones and systemic inflammation in Alzheimer disease.

    PubMed

    Butchart, Joe; Birch, Brian; Bassily, Ramy; Wolfe, Laura; Holmes, Clive

    2013-01-01

    Several studies have shown that the levels of sex hormones in men with Alzheimer disease (AD) differ from men without AD. Therefore, male sex hormones have been postulated as risk modifiers in AD, possibly through immunomodulatory effects on known inflammatory AD risk factors, such as tumor necrosis factor α (TNF-α). We conducted a cross-sectional study of sex hormones and TNF-α levels in 94 community-dwelling men with AD. Comparisons were made with normal values derived from the literature. Men with AD had lower free testosterone levels than non-AD men (1-sample t test: age <80, P=0.0002; age ≥80, P<0.0001), and higher luteinizing hormone (LH) levels (Wilcoxon signed rank test: age <80, P=0.001; age ≥80, P<0.0001). Within the cohort of men with AD, there was a positive correlation between LH and TNF-α (Spearman r=0.25, P=0.019), and this remained significant after correcting for age (partial r=0.21, P=0.05). These data support the hypothesis that sex hormones and the immune system influence each other in AD. Furthermore, modulatory effects between LH and TNF-α may provide a mechanism for an effect of male sex hormones on AD risk.

  18. Chemosterilization of male sea lampreys (Petromyzon marinus) does not affect sex pheromone release

    USGS Publications Warehouse

    Siefkes, Michael J.; Bergstedt, Roger A.; Twohey, Michael B.; Li, Weiming

    2003-01-01

    Release of males sterilized by injection with bisazir is an important experimental technique in management of sea lamprey (Petromyzon marinus), an invasive, nuisance species in the Laurentian Great Lakes. Sea lampreys are semelparous and sterilization can theoretically eliminate a male's reproductive capacity and, if the ability to obtain mates is not affected, waste the sex products of females spawning with him. It has been demonstrated that spermiating males release a sex pheromone that attracts ovulating females. We demonstrated that sterilized, spermiating males also released the pheromone and attracted ovulating females. In a two-choice maze, ovulating females increased searching behavior and spent more time in the side of the maze containing chemical stimuli from sterilized, spermiating males. This attraction response was also observed in spawning stream experiments. Also, electro-olfactograms showed that female olfactory organs were equally sensitive to chemical stimuli from sterilized and nonsterilized, spermiating males. Finally, fast atom bombardment mass spectrometry showed that extracts from water conditioned with sterilized and nonsterilized, spermiating males contained the same pheromonal molecule at similar levels. We concluded that injection of bisazir did not affect the efficacy of sex pheromone in sterilized males.

  19. Converging Evidence of Ubiquitous Male Bias in Human Sex Perception

    PubMed Central

    Gaetano, Justin; van der Zwan, Rick; Oxner, Matthew; Hayward, William G.; Doring, Natalie; Blair, Duncan; Brooks, Anna

    2016-01-01

    Visually judging the sex of another can be achieved easily in most social encounters. When the signals that inform such judgements are weak (e.g. outdoors at night), observers tend to expect the presence of males–an expectation that may facilitate survival-critical decisions under uncertainty. The present aim was to examine whether this male bias depends on expertise. To that end, Caucasian and Asian observers targeted female and male hand images that were either the same or different to the observers’ race (i.e. long term experience was varied) while concurrently, the proportion of targets changed across presentation blocks (i.e. short term experience change). It was thus found that: (i) observers of own-race stimuli were more likely to report the presence of males and absence of females, however (ii) observers of other-race stimuli–while still tending to accept stimuli as male–were not prone to rejecting female cues. Finally, (iii) male-biased measures did not track the relative frequency of targets or lures, disputing the notion that male bias derives from prior expectation about the number of male exemplars in a set. Findings are discussed in concert with the pan-stimulus model of human sex perception. PMID:26859570

  20. A sex-specific transcription factor controls male identity in a simultaneous hermaphrodite

    PubMed Central

    Chong, Tracy; Collins, James J.; Brubacher, John L.; Zarkower, David; Newmark, Phillip A.

    2013-01-01

    Evolutionary transitions between hermaphroditic and dioecious reproductive states are found in many groups of animals. To understand such transitions, it is important to characterize diverse modes of sex determination utilized by metazoans. Currently, little is known about how simultaneous hermaphrodites specify and maintain male and female organs in a single individual. Here we show that a sex-specific gene, Smed-dmd-1 encoding a predicted doublesex/male-abnormal-3 (DM) domain transcription factor, is required for specification of male germ cells in a simultaneous hermaphrodite, the planarian Schmidtea mediterranea. dmd-1 has a male-specific role in the maintenance and regeneration of the testes and male accessory reproductive organs. In addition, a homologue of dmd-1 exhibits male-specific expression in Schistosoma mansoni, a derived, dioecious flatworm. These results demonstrate conservation of the role of DM domain genes in sexual development in lophotrochozoans and suggest one means by which modulation of sex-specific pathways can drive the transition from hermaphroditism to dioecy. PMID:23652002

  1. The scent of inbreeding: a male sex pheromone betrays inbred males

    PubMed Central

    van Bergen, Erik; Brakefield, Paul M.; Heuskin, Stéphanie; Zwaan, Bas J.; Nieberding, Caroline M.

    2013-01-01

    Inbreeding depression results from mating among genetically related individuals and impairs reproductive success. The decrease in male mating success is usually attributed to an impact on multiple fitness-related traits that reduce the general condition of inbred males. Here, we find that the production of the male sex pheromone is reduced significantly by inbreeding in the butterfly Bicyclus anynana. Other traits indicative of the general condition, including flight performance, are also negatively affected in male butterflies by inbreeding. Yet, we unambiguously show that only the production of male pheromones affects mating success. Thus, this pheromone signal informs females about the inbreeding status of their mating partners. We also identify the specific chemical component (hexadecanal) probably responsible for the decrease in male mating success. Our results advocate giving increased attention to olfactory communication as a major causal factor of mate-choice decisions and sexual selection. PMID:23466986

  2. Correlates of unprotected sex with female sex workers among male clients in Tijuana, Mexico

    PubMed Central

    Goldenberg, Shira M; Cruz, Manuel Gallardo; Strathdee, Steffanie A; Nguyen, Lucie; Semple, Shirley J; Patterson, Thomas L

    2010-01-01

    Background Tijuana, situated adjacent to San Diego, CA on the US-Mexico border, is experiencing an emerging HIV epidemic, with prevalence among female sex workers (FSWs) having risen in recent years from <1% to 6%. Comparable data on FSWs’ clients are lacking. We explored correlates of unprotected sex with FSWs among male clients in Tijuana. Methods In 2008, males from San Diego (N=189) and Tijuana (N=211) aged 18 or older who had paid or traded for sex with a FSW in Tijuana during the past 4 months were recruited in Tijuana’s red light district. Participants underwent psychosocial interviews and were tested for HIV, syphilis (Treponema pallidum), gonorrhea (Neisseria gonorrhoeae), and Chlamydia (Chlamydia trachomatis). Results Of 394 men, median age was 36 years, 42.1% were married, and 39.3% were unemployed. Ethnic composition was 13.2% white, 79.4% Hispanic and 7.4% black or other. Half (50.3%) reported unprotected vaginal or anal sex with FSWs in Tijuana in the past 4 months. High proportions reported using drugs during sex (66%), and 36% reported frequenting the same FSW. Factors independently associated with unprotected sex with FSWs were using drugs during sex, visiting the same FSW, being married, and being unemployed. Conclusions FSWs’ clients represent an STI/HIV transmission “bridge” through unprotected sex with FSWs, wives and other partners. Tailored interventions to promote consistent condom use are needed for clients, especially within the context of drug use and ongoing relations with particular FSWs. PMID:20081558

  3. Sex behaviour of male Japanese tourists in Bangkok, Thailand.

    PubMed

    Yokota, Fumihiko

    2006-01-01

    This paper explores why Japanese men engage in potentially risky commercial sexual behaviours while on holiday in Thailand. Semi-structured, in-depth interviews were conducted with 30 heterosexual male Japanese tourists, aged 19-36, who paid for sex with Thai women. Study participants were recruited at guesthouses in Bangkok. Analysis revealed eight main factors that encourage participation in commercial sex: a sense of freedom and anonymity during "time-out" spent travelling in a foreign country; a sense that there are permissive norms governing commercial sex in Thailand; the perceived sexual desirability of Thai women, a sense of economic and racial superiority relative to Thai women; a sense of loneliness or feeling in need of companionship; peer influence; the widespread availability of inexpensive sexual services in Thailand; and sexual desire or need. Findings indicate that Japanese male sexual conduct reflects individual drives while on holiday, in the context of interactions among Japanese peers, shaped by Thailand's socio-cultural environment. PMID:16641061

  4. The social meanings behind male sex work: implications for sexual interactions.

    PubMed

    Browne, J; Minichiello, V

    1995-12-01

    This qualitative study explores the meanings of the commercial sexual encounter between male sex workers and their clients. The study highlights the various social meanings male sex workers attribute to having sex, their typologies of clients, the psychic contexts of male commercial sex, safer sex interactions, and how these issues inform sexual behaviour. The data shows that the meaning attached to the act of having sex is an important aspect of the way in which participants perceive their partners, conduct themselves during sexual encounters, and engage in safe sex practices. Clients are categorized by sex workers according to their perceptions of 'them', which include 'marrieds', 'easy trade', 'undesirables', 'sugar daddies' and 'heaven trade'. Different types of clients pose alternate levels of risk to the safe sex practices of sex workers. The sex worker's definition of commercial sex as work enables him to separate work and personal sex and define work sex as 'not real sex', in which safe sex practices symbolize both the degree of self that is shared and protective work equipment. It was also found that this sample of sex workers do not negotiate safe sex. Rather they use 'modes of interaction' which direct the encounter either towards safe sex, or they refuse to continue with the transaction. The interactive modes identified are 'natural', 'educative', 'challenge', 'other options' and 'walk-out'. These modes of interaction are effective strategies for ensuring safe sex, and can be used by the broader community to gain partner compliance in safe sex practices.

  5. Male sex workers: practices, contexts, and vulnerabilities for HIV acquisition and transmission.

    PubMed

    Baral, Stefan David; Friedman, M Reuel; Geibel, Scott; Rebe, Kevin; Bozhinov, Borche; Diouf, Daouda; Sabin, Keith; Holland, Claire E; Chan, Roy; Cáceres, Carlos F

    2015-01-17

    Male sex workers who sell or exchange sex for money or goods encompass a very diverse population across and within countries worldwide. Information characterising their practices, contexts where they live, and their needs is limited, because these individuals are generally included as a subset of larger studies focused on gay men and other men who have sex with men (MSM) or even female sex workers. Male sex workers, irrespective of their sexual orientation, mostly offer sex to men and rarely identify as sex workers, using local or international terms instead. Growing evidence indicates a sustained or increasing burden of HIV among some male sex workers within the context of the slowing global HIV pandemic. Several synergistic facilitators could be potentiating HIV acquisition and transmission among male sex workers, including biological, behavioural, and structural determinants. Criminalisation and intersectional stigmas of same-sex practices, commercial sex, and HIV all augment risk for HIV and sexually transmitted infections among male sex workers and reduce the likelihood of these people accessing essential services. These contexts, taken together with complex sexual networks among male sex workers, define this group as a key population underserved by current HIV prevention, treatment, and care services. Dedicated efforts are needed to make those services available for the sake of both public health and human rights. Evidence-based and human rights-affirming services dedicated specifically to male sex workers are needed to improve health outcomes for these men and the people within their sexual networks. PMID:25059939

  6. Sex-specific, male-line transgenerational responses in humans.

    PubMed

    Pembrey, Marcus E; Bygren, Lars Olov; Kaati, Gunnar; Edvinsson, Sören; Northstone, Kate; Sjöström, Michael; Golding, Jean

    2006-02-01

    Transgenerational effects of maternal nutrition or other environmental 'exposures' are well recognised, but the possibility of exposure in the male influencing development and health in the next generation(s) is rarely considered. However, historical associations of longevity with paternal ancestors' food supply in the slow growth period (SGP) in mid childhood have been reported. Using the Avon Longitudinal Study of Parents and Children (ALSPAC), we identified 166 fathers who reported starting smoking before age 11 years and compared the growth of their offspring with those with a later paternal onset of smoking, after correcting for confounders. We analysed food supply effects on offspring and grandchild mortality risk ratios (RR) using 303 probands and their 1818 parents and grandparents from the 1890, 1905 and 1920 Overkalix cohorts, northern Sweden. After appropriate adjustment, early paternal smoking is associated with greater body mass index (BMI) at 9 years in sons, but not daughters. Sex-specific effects were also shown in the Overkalix data; paternal grandfather's food supply was only linked to the mortality RR of grandsons, while paternal grandmother's food supply was only associated with the granddaughters' mortality RR. These transgenerational effects were observed with exposure during the SGP (both grandparents) or fetal/infant life (grandmothers) but not during either grandparent's puberty. We conclude that sex-specific, male-line transgenerational responses exist in humans and hypothesise that these transmissions are mediated by the sex chromosomes, X and Y. Such responses add an entirely new dimension to the study of gene-environment interactions in development and health.

  7. How to make a sexy snake: estrogen activation of female sex pheromone in male red-sided garter snakes.

    PubMed

    Parker, M Rockwell; Mason, Robert T

    2012-03-01

    Vertebrates indicate their genetic sex to conspecifics using secondary sexual signals, and signal expression is often activated by sex hormones. Among vertebrate signaling modalities, the least is known about how hormones influence chemical signaling. Our study species, the red-sided garter snake (Thamnophis sirtalis parietalis), is a model vertebrate for studying hormonal control of chemical signals because males completely rely on the female sex pheromone to identify potential mates among thousands of individuals. How sex hormones can influence the expression of this crucial sexual signal is largely unknown. We created two groups of experimental males for the first experiment: Sham (blank implants) and E2 (17β-estradiol implants). E2 males were vigorously courted by wild males in outdoor bioassays, and in a Y-maze E2 pheromone trails were chosen by wild males over those of small females and were indistinguishable from large female trails. Biochemically, the E2 pheromone blend was similar to that of large females, and it differed significantly from Shams. For the second experiment, we implanted males with 17β-estradiol in 2007 but removed the implants the following year (2008; Removal). That same year, we implanted a new group of males with estrogen implants (Implant). Removal males were courted by wild males in 2008 (implant intact) but not in 2009 (removed). Total pheromone quantity and quality increased following estrogen treatment, and estrogen removal re-established male-typical pheromone blends. Thus, we have shown that estrogen activates the production of female pheromone in adult red-sided garter snakes. This is the first known study to quantify both behavioral and biochemical responses in chemical signaling following sex steroid treatment of reptiles in the activation/organization context. We propose that the homogametic sex (ZZ, male) may possess the same targets for activation of sexual signal production, and the absence of the activator (17

  8. How to make a sexy snake: estrogen activation of female sex pheromone in male red-sided garter snakes.

    PubMed

    Parker, M Rockwell; Mason, Robert T

    2012-03-01

    Vertebrates indicate their genetic sex to conspecifics using secondary sexual signals, and signal expression is often activated by sex hormones. Among vertebrate signaling modalities, the least is known about how hormones influence chemical signaling. Our study species, the red-sided garter snake (Thamnophis sirtalis parietalis), is a model vertebrate for studying hormonal control of chemical signals because males completely rely on the female sex pheromone to identify potential mates among thousands of individuals. How sex hormones can influence the expression of this crucial sexual signal is largely unknown. We created two groups of experimental males for the first experiment: Sham (blank implants) and E2 (17β-estradiol implants). E2 males were vigorously courted by wild males in outdoor bioassays, and in a Y-maze E2 pheromone trails were chosen by wild males over those of small females and were indistinguishable from large female trails. Biochemically, the E2 pheromone blend was similar to that of large females, and it differed significantly from Shams. For the second experiment, we implanted males with 17β-estradiol in 2007 but removed the implants the following year (2008; Removal). That same year, we implanted a new group of males with estrogen implants (Implant). Removal males were courted by wild males in 2008 (implant intact) but not in 2009 (removed). Total pheromone quantity and quality increased following estrogen treatment, and estrogen removal re-established male-typical pheromone blends. Thus, we have shown that estrogen activates the production of female pheromone in adult red-sided garter snakes. This is the first known study to quantify both behavioral and biochemical responses in chemical signaling following sex steroid treatment of reptiles in the activation/organization context. We propose that the homogametic sex (ZZ, male) may possess the same targets for activation of sexual signal production, and the absence of the activator (17

  9. Sex steroid levels in XY males and sex-reversed XX males, of rainbow trout (Oncorhynchus mykiss), during the reproductive cycle.

    PubMed

    Espinosa, E; Josa, A; Gil, L; González, N

    2011-02-01

    In this study, the annual cycle of the gonadal steroids testosterone (T), 11-ketotestosterone (11-KT), 17β-oestradiol (E2) and 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) was determined using radioimmunoassay and then compared, for XY males (n=35) and sex-reversed XX males (n=27) rainbow trout, to establish possible endocrinology differences. Both in XY males and sex-reversed XX males, significant correlation was shown between body weight and T (r=0.5046 and 0.34078, respectively; p<0.0001) or KT (r=0.52494 and 0.43545, respectively; p<0.0001) concentrations. Plasma androgen levels in XY and sex-reversed XX males were similar and showed an intense seasonal variation. The highest levels for T and 11-KT were detected from December to April with a peak in January (51.67 ± 5.11 and 61.95 ± 4.25 ng/ml, for XY males and 57.1 ± 5.82 and 59.27 ± 4.84 ng/ml, respectively, for XX males). In addition, there was a positive correlation (p<0.0001) between T and 11-KT levels for XY males (r=0.7533) and sex-reversed XX males (r=0.6019). Concentrations of DHP in XY males also showed seasonal variation with a peak in February (25.18 ± 12.99 ng/ml). However, DHP levels in sex-reversed XX males were undetectable (<0.1 ng/ml) over the year. Levels of E2 were undetectable through the year in both groups of trout. In conclusion, the androgenic and oestrogenic profiles of sex-reversed XX males were similar to those observed in XY males. The only difference in the annual gonadal steroid cycle between XY and sex-reversed XX males was in the DHP profile.

  10. A psychosocial study of male-to-female transgendered and male hustler sex workers in São Paulo, Brazil.

    PubMed

    Prado Cortez, Fernanda Cestaro; Boer, Douglas Pieter; Baltieri, Danilo Antonio

    2011-12-01

    This study examined sociodemographic variables, personality characteristics, and alcohol and drug misuse among male sex workers in the city of Santo André, São Paulo, Brazil. A total of 45 male-to-female transgender sex workers and 41 male hustlers were evaluated in face-to-face interviews at their place of work from 2008 to 2010. A "snowball" sampling procedure was used to access this hard-to-reach population. Male-to-female transgender sex workers reported fewer conventional job opportunities, fewer school problems, and higher harm avoidance and depression levels than male hustlers. Also, transgender sex workers reported earning more money through sex work and more frequently living in hostels with peers than their counterparts. As biological male sex workers are a heterogeneous population, attempts to classify them into distinctive groups should be further carried out as a way to better understand and identify their behavior, design effective health interventions, and consequently minimize the likelihood of unintended adverse outcomes. Our study showed that gender performance can be an important variable to be considered by researchers and policy makers when working with sex workers and developing HIV/AIDS prevention and public health programs, given that transgender and male sex workers not only display distinctive behavior and physical appearance but also reveal differences on specific psychological measures, such as personality traits and depression levels. We recommend that counselors working with this population strike a balance between facilitating self-disclosure and establishing more evidence-based directive interventions. PMID:21667231

  11. Vitamin D metabolism, sex hormones, and male reproductive function.

    PubMed

    Blomberg Jensen, Martin

    2012-08-01

    The spectrum of vitamin D (VD)-mediated effects has expanded in recent years, and VD is now recognized as a versatile signaling molecule rather than being solely a regulator of bone health and calcium homeostasis. One of the recently identified target areas of VD is male reproductive function. The VD receptor (VDR) and the VD metabolizing enzyme expression studies documented the presence of this system in the testes, mature spermatozoa, and ejaculatory tract, suggesting that both systemic and local VD metabolism may influence male reproductive function. However, it is still debated which cell is the main VD target in the testis and to what extent VD is important for sex hormone production and function of spermatozoa. This review summarizes descriptive studies on testicular VD metabolism and spatial distribution of VDR and the VD metabolizing enzymes in the mammalian testes and discusses mechanistic and association studies conducted in animals and humans. The reviewed evidence suggests some effects of VD on estrogen and testosterone biosynthesis and implicates involvement of both systemic and local VD metabolism in the regulation of male fertility potential.

  12. Non-Mendelian segregation of sex chromosomes in heterospecific Drosophila males.

    PubMed Central

    Dermitzakis, E T; Masly, J P; Waldrip, H M; Clark, A G

    2000-01-01

    Interspecific hybrids and backcrossed organisms generally suffer from reduced viability and/or fertility. To identify and genetically map these defects, we introgressed regions of the Drosophila sechellia genome into the D. simulans genome. A female-biased sex ratio was observed in 24 of the 221 recombinant inbred lines, and subsequent tests attributed the skew to failure of Y-bearing sperm to fertilize the eggs. Apparently these introgressed lines fail to suppress a normally silent meiotic drive system. Using molecular markers we mapped two regions of the Drosophila genome that appear to exhibit differences between D. simulans and D. sechellia in their regulation of sex chromosome segregation distortion. The data indicate that the sex ratio phenotype results from an epistatic interaction between at least two factors. We discuss whether this observation is relevant to the meiotic drive theory of hybrid male sterility. PMID:10655222

  13. Sex, eyes, and vision: male/female distinctions in ophthalmic disorders.

    PubMed

    Eisner, Alvin

    2015-02-01

    There is growing recognition: (1) that sex (male and female) and sex hormones (androgens and estrogens) are important for physiologic functions outside those pertaining expressly to reproduction, and (2) that both classes of sex hormones are active in both sexes, and moreover are produced locally in non-gonadal tissues throughout the body. The visual system, in addition to being of tremendous inherent importance, is unique in a very distinctive way; it possesses an organ - the eye - having a window allowing its interior to be examined with exquisite precision and control in both laboratory and clinical settings. Plus, many diseases manifest in the eye or are exclusive to the eye. This special issue of Current Eye Research contains 12 review articles, each addressing a different topical area important for Sex, Eyes, and Vision: Male/Female Distinctions in Ophthalmic Disorders. Of course, the distinctions between topical areas are blurred, and the overlap between the various lines of knowledge and investigation likewise is substantial. Eye diseases can be both neurodegenerative and involve altered blood flow, for instance. In fact, the thematic overlap is greater yet, in that the articles for this special issue address matters of interest to clinicians and scientists who may identify more with women's health or sex & gender fields than with eye & vision fields. Nevertheless, because this special issue needs a home, the following 12 topical areas each have here their own dedicated review: age-related maculopathy, central nervous system function and cognition & perception, diabetic retinopathy, dry eye, glaucoma, inherited diseases, lens and cataract, neuro-ophthalmology, ocular blood flow, ocular inflammatory disorders, optical coherence tomography, and sex/gender eye care disparities. This overview article itself raises additional points expressly concerning: (1) the estrogen therapy timing hypothesis, and (2) breast cancer treatment with aromatase inhibitors.

  14. Sex and species recognition by wild male southern white rhinoceros using contact pant calls.

    PubMed

    Cinková, Ivana; Policht, Richard

    2016-03-01

    Recognition of information from acoustic signals is crucial in many animals, and individuals are under selection pressure to discriminate between the signals of conspecifics and heterospecifics or males and females. Here, we first report that rhinos use information encoded in their calls to assess conspecifics and individuals of closely related species. The southern (Ceratotherium simum) and critically endangered northern (C. cottoni) white rhinos are the most social out of all the rhinoceros species and use a contact call pant. We found that southern white rhino pant calls provide reliable information about the caller's sex, age class and social situation. Playback experiments on wild territorial southern white rhinoceros males revealed that they responded more strongly to the pant calls of conspecific females compared to the calls of other territorial males. This suggests that pant calls are more important form of communication between males and females than between territorial males. Territorial southern males also discriminated between female and territorial male calls of northern species and reacted more intensively to the calls of northern than southern males. This might be caused by a novelty effect since both species naturally live in allopatry. We conclude that white rhinos can directly benefit from assessing individuals at long distances using vocal cues especially because their eyesight is poor. Pant calls thus likely play a significant role in their social relationships and spatial organization. In addition, better understanding of vocal communication in white rhinos might be helpful in conservation management particularly because of their low reproduction in captivity. PMID:26577089

  15. Sex differences in DNA methylation and expression in zebrafish brain: a test of an extended 'male sex drive' hypothesis.

    PubMed

    Chatterjee, Aniruddha; Lagisz, Malgorzata; Rodger, Euan J; Zhen, Li; Stockwell, Peter A; Duncan, Elizabeth J; Horsfield, Julia A; Jeyakani, Justin; Mathavan, Sinnakaruppan; Ozaki, Yuichi; Nakagawa, Shinichi

    2016-09-30

    The sex drive hypothesis predicts that stronger selection on male traits has resulted in masculinization of the genome. Here we test whether such masculinizing effects can be detected at the level of the transcriptome and methylome in the adult zebrafish brain. Although methylation is globally similar, we identified 914 specific differentially methylated CpGs (DMCs) between males and females (435 were hypermethylated and 479 were hypomethylated in males compared to females). These DMCs were prevalent in gene body, intergenic regions and CpG island shores. We also discovered 15 distinct CpG clusters with striking sex-specific DNA methylation differences. In contrast, at transcriptome level, more female-biased genes than male-biased genes were expressed, giving little support for the male sex drive hypothesis. Our study provides genome-wide methylome and transcriptome assessment and sheds light on sex-specific epigenetic patterns and in zebrafish for the first time. PMID:27259666

  16. Female-to-male sex reversal in mice caused by transgenic overexpression of Dmrt1.

    PubMed

    Zhao, Liang; Svingen, Terje; Ng, Ee Ting; Koopman, Peter

    2015-03-15

    Genes related to Dmrt1, which encodes a DNA-binding DM domain transcription factor, act as triggers for primary sex determination in a broad range of metazoan species. However, this role is fulfilled in mammals by Sry, a newly evolved gene on the Y chromosome, such that Dmrt1 has become dispensable for primary sex determination and instead maintains Sertoli cell phenotype in postnatal testes. Here, we report that enforced expression of Dmrt1 in XX mouse fetal gonads using a Wt1-BAC transgene system is sufficient to drive testicular differentiation and male secondary sex development. XX transgenic fetal gonads showed typical testicular size and vasculature. Key ovarian markers, including Wnt4 and Foxl2, were repressed. Sertoli cells expressing the hallmark testis-determining gene Sox9 were formed, although they did not assemble into normal testis cords. Other bipotential lineages differentiated into testicular cell types, including steroidogenic fetal Leydig cells and non-meiotic germ cells. As a consequence, male internal and external reproductive organs developed postnatally, with an absence of female reproductive tissues. These results reveal that Dmrt1 has retained its ability to act as the primary testis-determining trigger in mammals, even though this function is no longer normally required. Thus, Dmrt1 provides a common thread in the evolution of sex determination mechanisms in metazoans. PMID:25725066

  17. Sex-peptides: seminal peptides of the Drosophila male.

    PubMed

    Kubli, E

    2003-08-01

    Mating affects the reproductive behaviour of insect females: the egg-laying rate increases and courting males are rejected. These post-mating responses are induced mainly by seminal fluid. In Drosophila melanogaster, males transfer two peptides (sex-peptides, = Sps) that reduce receptivity and elicit increased egg laying in their mating partners. Similarities in the open reading frames of the genes suggest that they have arisen by gene duplication. In females, Sps bind to specific sites in the central and peripheral nervous system, and to the genital tract. The binding proteins of the nervous system and genital tract are membrane proteins, but they differ molecularly. The former protein is proposed to be a receptor located at the top of a signalling cascade leading to the two post-mating responses, whereas the latter is a carrier protein moving Sps from the genital tract into the haemolymph. Sps bind to sperm. Together with sperm they are responsible for the persistence of the two post-mating responses. But Sps are the molecular basis of the sperm effect; sperm is merely the carrier. PMID:14504657

  18. Male sex work and HIV risk among young heroin users in Hanoi, Vietnam.

    PubMed

    Clatts, Michael C; Giang, Le M; Goldsamt, Lloyd A; Yi, Huso

    2007-12-01

    The present study describes complex drug and sexual risk in a group of male sex workers (n = 79) who were recruited in the context of a larger study of young heroin users in Hanoi, Vietnam (n = 1270). Male sex workers were significantly more likely than male non-sex workers to be migrants (P < 0.001) and to have unstable housing (P < 0.001), to have lifetime exposure to marijuana (P < 0.001), 3,4 methylenedioxymethamphetamine (MDMA, ecstasy) (P < 0.01), amphetamines (P < 0.05), cocaine (P < 0.01) and morphine (P < 0.001). Male sex workers are more likely to currently use MDMA (P < 0.05), amphetamines (P < 0.001), morphine (P < 0.05) and to 'smoke' as their most frequent mode of heroin administration (P < 0.01). Male sex workers are more likely to have both male and female concurrent sex partners (P < 0.001), to have a history of sexual victimisation (P < 0.001), to have had more than three different sex partners in the past 30 days (P < 0.001), and to have had partners who injected drugs before sex (P < 0.001) or who used drugs during sex (P < 0.01). In their last sexual encounter with a client partner, approximately one-third (31.1%) reported having had receptive anal sex. In nearly three-quarters of these exchanges (71.4%), no condom was used. Similarly, in their last sexual encounter with a client partner, 42.2% reported having had insertive anal sex and in nearly half (47.4%) of these encounters no condom was used. Consistent with recent data from elsewhere in the region, there is an urgent need for additional research on male sex work in South-east Asia in order to properly situate behavioural interventions for male sex workers in this region.

  19. Autosomal gsdf acts as a male sex initiator in the fish medaka

    PubMed Central

    Zhang, Xi; Guan, Guijun; Li, Mingyou; Zhu, Feng; Liu, Qizhi; Naruse, Kiyoshi; Herpin, Amaury; Nagahama, Yoshitaka; Li, Jiale; Hong, Yunhan

    2016-01-01

    Sex is pivotal for reproduction, healthcare and evolution. In the fish medaka, the Y-chromosomal dmy (also dmrt1bY) serves the sex determiner, which activates dmrt1 for male sex maintenance. However, how dmy makes the male decision via initiating testicular differentiation has remained unknown. Here we report that autosomal gsdf serves a male sex initiator. Gene addition and deletion revealed that gsdf was necessary and sufficient for maleness via initiating testicular differentiation. We show that gsdf transcription is activated directly by dmy. These results establish the autosomal gsdf as the first male sex initiator. We propose that dmy determines maleness through activating gsdf and dmrt1 without its own participation in developmental processes of sex initiation and maintenance. gsdf may easily become a sex determiner or other autosomal genes can be recruited as new sex determiners to initiate gsdf expression. Our findings offer new insights into molecular mechanisms underlying sex development and evolution of sex-controlling genes in vertebrates. PMID:26813267

  20. Personality, Sex-Role Orientation, and Psychological Health in Stereotypically Masculine Groups of Males.

    ERIC Educational Resources Information Center

    Mills, Carol J.; Bohannon, Wayne E.

    1983-01-01

    Sex role identity and personality characteristics were examined in 104 male college football players and police cadets by means of the Bem Sex Role Inventory and the California Psychological Inventory. No significant differences were found between these stereotypically "masculine" groups and normative samples of males. (CMG)

  1. Men's constructions of masculinity and male sexuality through talk of buying sex.

    PubMed

    Huysamen, Monique; Boonzaier, Floretta

    2015-01-01

    Commercial sex is an everyday occurrence across a range of contexts in South Africa. In this paper we turn our attention to the often-marginalised role of the buyers of sex by drawing on narrative interviews with male clients of female sex workers recruited through online advertisements in order to explore the ways in which heterosexual men construct, negotiate and perform their masculinity and sexuality through talking about their experiences of paying for sex. We highlight parallels between men's narratives of paying for sex and dominant discourses of gender and heterosexuality. We show how men draw on heteronormative sexual scripts in constructing and making sense of paid sexual encounters and how men are simultaneously able to construct and enact a particular idealised version of masculinity and male sexuality through their talk on paying for sex. Finally, we discuss how online resources could be used more extensively in future research with the male clients of sex workers.

  2. From Client to Pimp: Male Violence against Female Sex Workers

    ERIC Educational Resources Information Center

    Karandikar, Sharvari; Prospero, Moises

    2010-01-01

    The present study explores intimate partner violence (IPV) among female sex workers from the red-light area based in Mumbai, India. Using a grounded theory approach, in-depth interviews were conducted with ten sex workers to explore their experiences of IPV in the context of commercial sex work. Narratives were analyzed and themes constructed. A…

  3. An Investigation of Sex-Related Slang Vocabulary and Sex-Role Orientation Among Male and Female University Students

    ERIC Educational Resources Information Center

    Kutner, Nancy G.; Brogan, Donna

    1974-01-01

    Undergraduate males, undergraduate females, and graduate student nurses (female) were asked to list all the slang expressions they knew for 17 sex-related stimulus words. Males listed a significantly larger total number of slang expressions than either female group. (Author)

  4. Fluorochemicals used in food packaging inhibit male sex hormone synthesis

    SciTech Connect

    Rosenmai, A.K.; Nielsen, F.K.; Pedersen, M.; Hadrup, N.; Trier, X.; Christensen, J.H.; Vinggaard, A.M.

    2013-01-01

    synthesis of male sex hormones. ► Generally, levels of estrogens and cortisol stayed unaffected or increased. ► The effect on steroid synthesis was specific on gene expression of Bzrp and CYP19.

  5. Effects of sex of judge and sex of victim on recommended punishment of a male murderer in a mock scenario.

    PubMed

    McKelvie, Stuart J

    2002-10-01

    Two samples of undergraduates (36 women, 7 men; 44 women, 45 men) read a mock transcript in which a murderer's victim was a man or a woman, after which they made prison sentence and death penalty judgments. Female judges gave longer sentences for the female victim than for the male victim, whereas male judges gave longer sentences for the male victim than for the female victim. This same-sex bias suggests that extralegal factors can affect judgments about sentencing.

  6. Constrained sex allocation in a parasitoid due to variation in male quality.

    PubMed

    Henter, H J

    2004-07-01

    The theory of constrained sex allocation posits that when a fraction of females in a haplodiploid population go unmated and thus produce only male offspring, mated females will evolve to lay a female-biased sex ratio. I examined evidence for constrained sex ratio evolution in the parasitic hymenopteran Uscana semifumipennis. Mated females in the laboratory produced more female-biased sex ratios than the sex ratio of adults hatching from field-collected eggs, consistent with constrained sex allocation theory. However, the male with whom a female mated affected her offspring sex ratio, even when sperm was successfully transferred, suggesting that constrained sex ratios can occur even in populations where all females succeed in mating. A positive relationship between sex ratio and fecundity indicates that females may become sperm-limited. Variation among males occurred even at low fecundity, however, suggesting that other factors may also be involved. Further, a quantitative genetic experiment found significant additive genetic variance in the population for the sex ratio of offspring produced by females. This has only rarely been demonstrated in a natural population of parasitoids, but is a necessary condition for sex ratio evolution. Finally, matings with larger males produced more female-biased offspring sex-ratios, suggesting positive selection on male size. Because the great majority of parasitic hymenoptera are monandrous, the finding of natural variation among males in their capacity to fertilize offspring, even after mating successfully, suggests that females may often be constrained in the sex allocation by inadequate number or quality of sperm transferred.

  7. Perceived stigma of purchasing sex among Latino and non-Latino male clients of female sex workers in Tijuana, Mexico.

    PubMed

    Pitpitan, Eileen V; Strathdee, Steffanie A; Semple, Shirley J; Wagner, Karla D; Chavarin, Claudia V; Earnshaw, Valerie A; Patterson, Thomas L

    2015-02-01

    HIV prevention efforts must be comprehensive in their understanding of the factors involved in HIV risk. Male clients, who have received less research attention than female sex workers (FSWs), may experience stigma as a function of purchasing sex. Perceived stigma may be related to poor psychological outcomes, risky psychosexual characteristics, and higher drug and sexual risk behavior among male clients of FSWs. However, perceived stigma of purchasing sex may differ between clients of different ethnic groups. In the present study, we examine the correlates of perceived stigma of purchasing sex among Latino versus non-Latino male clients of FSWs in Tijuana, Mexico. Using time-location sampling, we recruited 375 male clients (323 Latino, 52 non-Latino) in Tijuana who completed a computerized survey on various measures. We measured perceived stigma of purchasing sex using three items we developed for this study. Using linear regression analyses we found that perceived stigma was associated with greater guilt, a greater feeling of escape from everyday life, and more negative condom attitudes among Latino clients. This was not found among non-Latino clients. Features of Latino culture, like machismo, and how they may relate to stigma of purchasing sex are discussed.

  8. Perceived stigma of purchasing sex among Latino and non-Latino male clients of female sex workers in Tijuana, Mexico

    PubMed Central

    Pitpitan, Eileen V.; Strathdee, Steffanie A.; Semple, Shirley J.; Wagner, Karla D.; Chavarin, Claudia V.; Earnshaw, Valerie A.; Patterson, Thomas L.

    2013-01-01

    HIV prevention efforts must be comprehensive in their understanding of the factors involved in HIV risk. Male clients, who have received less research attention than female sex workers (FSWs), may experience stigma as a function of purchasing sex. Perceived stigma may be related to poor psychological outcomes, risky psychosexual characteristics, and higher drug and sexual risk behavior among male clients of FSWs. However, perceived stigma of purchasing sex may differ between clients of different ethnic groups. In the present study, we examine the correlates of perceived stigma of purchasing sex among Latino vs. non-Latino male clients of FSWs in Tijuana, Mexico. Using time-location sampling, we recruited 375 male clients (323 Latino, 52 non-Latino) in Tijuana who completed a computerized survey on various measures. We measured perceived stigma of purchasing sex using three items we developed for this study. Using linear regression analyses we found that perceived stigma was associated with greater guilt, a greater feeling of escape from everyday life, and more negative condom attitudes among Latino clients. This was not found among non-Latino clients. Features of Latino culture, like machismo, and how they may relate to stigma of purchasing sex are discussed. PMID:23979714

  9. Sex-Biased Temporal Gene Expression in Male and Female Floral Buds of Seabuckthorn (Hippophae rhamnoides)

    PubMed Central

    Chawla, Aseem; Stobdan, Tsering; Srivastava, Ravi B.; Jaiswal, Varun; Chauhan, Rajinder S.; Kant, Anil

    2015-01-01

    Seabuckthorn is an economically important dioecious plant in which mechanism of sex determination is unknown. The study was conducted to identify seabuckthorn homologous genes involved in floral development which may have role in sex determination. Forty four putative Genes involved in sex determination (GISD) reported in model plants were shortlisted from literature survey, and twenty nine seabuckthorn homologous sequences were identified from available seabuckthorn genomic resources. Of these, 21 genes were found to differentially express in either male or female flower bud stages. HrCRY2 was significantly expressed in female flower buds only while HrCO had significant expression in male flowers only. Among the three male and female floral development stages (FDS), male stage II had significant expression of most of the GISD. Information on these sex-specific expressed genes will help in elucidating sex determination mechanism in seabuckthorn. PMID:25915052

  10. “In different situations, in different ways”: Male sex work in St. Petersburg, Russia

    PubMed Central

    Niccolai, Linda M; King, Elizabeth J; Eritsyan, Ksenia; Safiullina, Liliya; Rusakova, Maia M

    2013-01-01

    We conducted a qualitative study of male sex work in St. Petersburg Russia with a focus on social vulnerabilities, HIV risk perception, and HIV-related behaviours. In-depth interviews were conducted with individuals knowledgeable about male sex work through their profession (n=8) and with male sex workers themselves (n=12). Male sex work involves a variety of exchanges including expensive vacations, negotiated monetary amounts, or simply access to food. Methods to find clients included the Internet, social venues (e.g. gay clubs and bars), and public places (e.g. parks). Use of the Internet greatly facilitated male sex work in a variety of ways. It was used by both individuals and agencies to find clients, and appeared to be increasing. Men often reported not being professionally connected to other male sex workers and limited disclosure about their work. Many were aware of the work-related risks to personal safety including violence and robbery by clients. Perceived risk for HIV was mostly abstract, and several exceptions to condom use with clients were noted. Alcohol use was reported as moderate but consumed frequently in association with work. These data suggest that the most salient risks for male sex workers include professional isolation, threats to personal safety, limited perceived HIV risk, and sub-optimal levels of condom use. PMID:23464743

  11. Shadow of domestic violence and extramarital sex cohesive with spousal communication among males in Nepal

    PubMed Central

    2014-01-01

    Background Public health and human right issues are challenging in low and middle income countries. The main objectives of this paper were to determine the prevalence and factors associated with domestic violence, extramarital sex, and spousal communication among male. Methods A cross-sectional study among 2466 married males in Kathmandu, Nepal was conducted using random sampling method. Adjusted odds ratios (AORs) and 95% confidence intervals (CI) of associated factors were estimated by stepwise backward likelihood ratio method. Results Prevalence of domestic violence was 63.14% (95% CI 61.20-65.05), extramarital sex was 32.12% (95% CI 30.27-34.00), and spousal communication was 48.87% (95% CI 46.85-50.90). Nearly one in five male (18.20%) had not used condom during extramarital sex. Interestingly, male who had more than three or equal children were less likely to have perpetrated domestic violence compared with those who had less children. Older male aged 25 and above were more likely (AORs = 1.55, 95% CI 1.19-2.03) to have extramarital sex compared with male aged 24 or below. Those male who had studied secondary or higher level of education were less likely to have extramarital sex compared to those who had primary level or no education. Male who had higher income were more likely to have spousal communication compared to those who had less income. Surprisingly, those male who had extramarital sex were less likely to have spousal communication compared with those was not involved in extramarital sex. Conclusion Practice of domestic violence and extramarital sex is quite common among married male in Nepal, where spousal communication is sparse. These findings can be used to advocate for immediate attention and activities needs to be endorsed by policymakers and programmers. PMID:24924872

  12. Review: Male systemic lupus erythematosus: a review of sex disparities in this disease.

    PubMed

    Lu, L-J; Wallace, D J; Ishimori, M L; Scofield, R H; Weisman, M H

    2010-02-01

    Although males with systemic lupus erythematosus (SLE) represent 4-22% of all SLE patients, it may not be appropriate that these cases should be subordinated to females with SLE in terms of most health-related issues. Over the past few decades, some distinctive features of male lupus have been observed with regard to genetic and environmental aspects of sex differences, clinical features, and outcome. In addition, recent insights into sex disparities in this disease have brought forth a few plausible and novel pathogenetic hypotheses. This review discusses these findings and sex disparities in SLE that appear to be especially noteworthy and pertinent to our understanding of male SLE.

  13. Sexual hazards, life experiences and social circumstances among male sex workers in Nigeria.

    PubMed

    Okanlawon, Kehinde; Adebowale, Ayo Stephen; Titilayo, Ayotunde

    2013-01-01

    The sexual health and rights needs of male sex workers in Nigeria remain poorly understood and served. Men who sell sex are at high risk of discrimination and violation because of laws criminalising same-sex activity and sex work. This paper examines the experiences, social circumstances, vulnerabilities and sexual hazards experienced by male sex workers in Nigeria. In-depth interviews were used to explore the experiences of six male sex workers who were selected by means of convenience sampling from among those who came for counselling. Findings reveal that economic disadvantage drives some men to engage in sex work and risky sexual behaviour. Subsequently, sex work may put their lives and health at risk as a result of violation by the police and clients, including ritual murder. Men's extreme vulnerability points to the need for appropriate interventions to improve well-being. Sexual health and rights programmes must identify ways of making male sex workers less vulnerable to abuse, and devise strategies for protecting their health and human rights, while empowering them economically to reduce their dependency on often risky sexual behaviour for livelihoods. PMID:23252939

  14. Sex recognition and mate choice by male western toads, Bufo boreas.

    PubMed

    Marco; Kiesecker; Chivers; Blaustein

    1998-06-01

    In field-based choice experiments, we examined sex recognition and mate choice in male western toads, Bufo boreas. When given a simultaneous choice between a male and a female of equal size, males did not discriminate between the sexes and attempted to amplex a male or a female with equal frequency. When a test male clasped a stimulus male, the stimulus male uttered a release call that caused the test male to release the stimulus male. Male-male amplexus never lasted more than 3 s, but male-female amplexus was tenacious and prolonged. Furthermore, males discriminated between gravid females that differed in body size, choosing larger gravid females over smaller ones, but they did not discriminate between gravid females or non-gravid females of equal size. In choice tests that excluded chemical cues, males jumped more frequently towards large females than small ones. Given that females are significantly larger than males, selecting larger individuals as potential mates increases the probability that males amplex with a female. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9642006

  15. Trait compensation and sex-specific aging of performance in male and female professional basketball players.

    PubMed

    Lailvaux, Simon P; Wilson, Robbie; Kasumovic, Michael M

    2014-05-01

    Phenotypic traits are often influenced by dynamic resource allocation trade-offs which, when occurring over the course of individual lifespan, may manifest as trait aging. Although aging is studied for a variety of traits that are closely tied to reproduction or reproductive effort, the aging of multiple traits related to fitness in other ways are less well understood. We took advantage of almost 30 years of data on human whole-organism performance in the National Basketball Association (USA) to examine trends of aging in performance traits associated with scoring. Given that patterns of aging differ between sexes in other animal species, we also analyzed a smaller dataset on players in the Women's National Basketball Association to test for potential sex differences in the aging of comparable traits. We tested the hypothesis that age-related changes in a specific aspect of overall performance can be compensated for by elevated expression of another, related aspect. Our analyses suggest that the aging of performance traits used in basketball is generally characterized by senescence in males, whereas age-related changes in basketball performance are less evident in females. Our data also indicate a different rate of senescence of different performance traits associated with scoring over a male's lifetime.

  16. Effects of vomeronasal organ removal on olfactory sex discrimination and odor preferences of female ferrets.

    PubMed

    Woodley, S K; Cloe, A L; Waters, P; Baum, M J

    2004-10-01

    Previous research suggests that body odorants, including anal scents and urinary odors, contribute to sex discrimination and mate identification in European ferrets of both sexes. We assessed the possible role of the vomeronasal organ (VNO) in these functions by surgically removing the organ bilaterally in sexually experienced female ferrets. Lesioned (VNOx) and sham-operated control (VNOi) females reliably discriminated between male- and female-derived anal scent gland as well as fresh urinary odors in habituation/dishabituation tests. However, VNOi females spent significantly more time than VNOx subjects investigating male urinary odors in these tests. Also, VNOi females, but not VNOx subjects, preferred to investigate day-old male versus female urine spots as well as wooden blocks that had previously been soiled by male versus female ferrets. Both groups of female ferrets preferred to approach volatile odors from a breeding male instead of an estrous female in Y-maze tests and both groups showed similar levels of receptive sexual behavior in response to a male's neck grip. The VNO is apparently not required for olfactory sex discrimination or mate recognition in this carnivore, but instead may play a role in promoting continued contact with nonvolatile body odors previously deposited by opposite-sex conspecifics during territorial scent marking. PMID:15466811

  17. Sex ratio and spatial distribution of male and female Antennaria dioica (Asteraceae) plants

    NASA Astrophysics Data System (ADS)

    Varga, Sandra; Kytöviita, Minna-Maarit

    2011-09-01

    Sex ratio, sex spatial distribution and sexual dimorphism in reproduction and arbuscular mycorrhizal colonisation were investigated in the dioecious clonal plant Antennaria dioica (Asteraceae). Plants were monitored for five consecutive years in six study plots in Oulanka, northern Finland. Sex ratio, spatial distribution of sexes, flowering frequency, number of floral shoots and the number and weight of inflorescences were recorded. In addition, intensity of mycorrhizal fungi in the roots was assessed. Both sexes flowered each year with a similar frequency, but the overall genet sex ratio was strongly female-biased. The bivariate Ripley's analysis of the sex distribution showed that within most plots sexes were randomly distributed except for one plot. Sexual dimorphism was expressed as larger floral and inflorescence production and heavier inflorescences in males. In addition, the roots of both sexes were colonised to a similar extent by arbuscular mycorrhizal fungi. The female sex-biased flowering ratios reported are not consistent among years and cannot be explained in terms of spatial segregation of the sexes or sex lability. The possible reasons for the female-biased sex ratio are discussed.

  18. Male and Female Pathways through Four-Year Colleges: Disruption and Sex Stratification in Higher Education

    ERIC Educational Resources Information Center

    Ewert, Stephanie

    2010-01-01

    Pathways through college vary by sex in ways that may contribute to the contemporary male-female gap in college graduation that favors women. Although past research has documented sex differences in college pathways, little research has investigated the underlying causes of this variation. Using data from the National Education Longitudinal Study,…

  19. Prevalence and correlates of sexual risk among male and female sex workers in Tijuana, Mexico.

    PubMed

    Katsulis, Yasmina; Durfee, Alesha

    2012-01-01

    We investigated prevalence and correlates of sexual risk behaviours among male and female sex workers in Tijuana, Mexico, the busiest border crossing area on the US - Mexico border, analysing survey data from a purposive, cross-sectional sample of male and female sex workers who worked in a range of indoor and outdoor settings. Logistic regression was used to determine factors that were associated with sexual risk-taking, defined as failing to use a condom with last client. In bivariate regression models, gender, work setting (e.g., indoor vs. outdoor), poverty, engaging in survival sex, marital status and perceived drug addiction were correlated with sexual risk. When controlling for work location, housing insecurity, poverty, survival sex, marital status and perceived drug addiction, male sex workers were still 10 times more likely than female sex workers (FSW) to engage in sex without a condom during their last encounter with a client. And, although FSW were significantly more likely than males to have used a condom with a client, they were significantly less likely than males to have used a condom with their regular partner. Future research should further examine how gender shapes sexual risk activities in both commercial and non-commercial relationships. PMID:22304493

  20. Cloning of Taiwan water buffalo male-specific DNA sequence for sexing.

    PubMed

    Horng, Yan-Ming; Chen, Yi-Ting; Wu, Chean-Ping; Jea, Yu-Shine; Huang, Mu-Chiou

    2004-11-01

    Random amplified polymorphic DNA (RAPD) fingerprinting was carried out to investigate the sex-specific DNA sequence for sexing in Taiwan water buffalos. One hundred and forty random primers were used for RAPD-PCR (polymerase chain reaction). One of these primers, OPC-16, produced a 321 bp fragment found only in tested males. This male-specific fragment was isolated and constructed into plasmids for nucleotide sequencing, a novel male-specific sequence was obtained. Two primers (BuSexOPC16-F and -R) were designed according to the cloned male-specific sequence to amplify the male-specific fragment using PCR for sexing. Sex-specific bands in the gel were represented in the males but none were found in the females when the Taiwan water buffalo genomic DNA samples were amplified with these two primers using PCR. The same results were also obtained from Taiwan yellow, Holstein, Angus, and Hereford cattle samples. This showed that the sex of these five breeds could be easily and effectively determined using the PCR technique.

  1. Identification of a sex pheromone from male yellow mealworm beetles, Tenebrio molitor.

    PubMed

    Bryning, Gareth P; Chambers, John; Wakefield, Maureen E

    2005-11-01

    The sex pheromone released by the adult female Tenebrio molitor, 4-methyl-1-nonanol, is well known. In addition, there is evidence that adult males release a pheromone that attracts females. The purpose of the present study was to isolate and identify male-released pheromone(s). Emissions from virgin adult males and females were collected on filter paper and extracted with pentane. Extracts were analyzed by gas chromatography-mass spectrometry. One male-specific compound was detected and identified as (Z)-3-dodecenyl acetate (Z3-12:Ac). In arena bioassays, E3-12:Ac was attractive to females only, at 1 and 10 microg doses. E3-12:Ac was also attractive to females at a 10-microg dose. The presence of both male and female pheromones, each attracting the opposite sex, may contribute to maintaining a high-density population of both sexes. PMID:16273437

  2. Women's motivations to have sex in casual and committed relationships with male and female partners.

    PubMed

    Armstrong, Heather L; Reissing, Elke D

    2015-05-01

    Women report a wide variety of reasons to have sex (e.g., Meston & Buss, 2010), and while it is reasonable to assume that those reasons may vary based on the context of the relationship, this assumption has not yet been tested. The purpose of this study was to explore how relationship type, sexual attraction, and the gender of one's partner interact and affect the sexual motivations of women. A total of 510 women (361 who reported exclusively other-sex attraction and 149 who reported same-sex/bisexual attraction) completed the YSEX? questionnaire. Participants rated their sexual motivations for casual sex and sex in a committed relationship with male and/or female partners, depending on reported sexual attraction. Results showed that relationship type affected reported motivation for sex: physical motivations were more strongly endorsed for casual sex, whereas emotional motivations were more strongly endorsed for sex in committed relationships. No significant differences in motivation were reported between women who reported same-sex attraction and those who did not. Women who reported bisexual attraction and identified as being lesbian, bisexual, or another sexual minority reported no significant differences in motivation for sex with male or female partners. The results of this study highlight the importance of relationship context when discussing sexual motivation and suggest a high degree of similarity in motivation for women, regardless of sexual orientation or gender of partner.

  3. Differences in Gay Male Couples' Use of Drugs and Alcohol With Sex by Relationship HIV Status.

    PubMed

    Mitchell, Jason W

    2016-07-01

    Prior studies with men who have sex with men have documented a strong association between substance use with sex and risk for acquisition of HIV. However, few studies have been conducted about gay male couples' use of substances with sex, despite the fact that between one third and two thirds of men who have sex with men acquire HIV from their relationship partners. The present study sought to (1) describe whether one or both partners in the male couple uses substances with sex-by substance type-within and/or outside of their relationship, and (2) assess whether differences exist in those who use substances with sex within and outside the relationship by the couples' HIV status. Dyadic data for this analysis were collected in the United States from a nation-wide cross-sectional Internet study about male couples' relationships and behaviors. Couple-level descriptive and comparative analyses were employed with 361 male couples. Except for alcohol, most couples did not use substances with sex. Of those who did, rates of who used it with sex and substance type within the relationship varied; most couples only had one partner who used substances with sex outside the relationship. Significantly higher proportions of concordantly HIV-negative and HIV-positive couples had both partners who used substances (all types) with sex within their relationship over discordant couples. Most couples had one partner who used outside the relationship; only marijuana and erectile dysfunction medication use with sex significantly differed by couples' HIV status. Findings indicate the need to conduct additional research for prevention development.

  4. Tribolium castaneum Transformer-2 regulates sex determination and development in both males and females.

    PubMed

    Shukla, Jayendra Nath; Palli, Subba Reddy

    2013-12-01

    Tribolium castaneum Transformer (TcTra) is essential for female sex determination and maintenance through the regulation of sex-specific splicing of doublesex (dsx) pre-mRNA. In females, TcTra also regulates the sex-specific splicing of its own pre-mRNA to ensure continuous production of functional Tra protein. Transformer protein is absent in males and hence dsx pre-mRNA is spliced in a default mode. The mechanisms by which males inhibit the production of functional Tra protein are not known. Here, we report on functional characterization of transformer-2 (tra-2) gene (an ortholog of Drosophila transformer-2) in T. castaneum. RNA interference-mediated knockdown in the expression of gene coding for tra-2 in female pupae or adults resulted in the production of male-specific isoform of dsx and both female and male isoforms of tra suggesting that Tra-2 is essential for the female-specific splicing of tra and dsx pre-mRNAs. Interestingly, knockdown of tra-2 in males did not affect the splicing of dsx but resulted in the production of both female and male isoforms of tra suggesting that Tra-2 suppresses female-specific splicing of tra pre-mRNA in males. This dual regulation of sex-specific splicing of tra pre-mRNA ensures a tight regulation of sex determination and maintenance. These data suggest a critical role for Tra-2 in suppression of female sex determination cascade in males. In addition, RNAi studies showed that Tra-2 is also required for successful embryonic and larval development in both sexes.

  5. Exploring the desires and sexual culture of men who have sex with male-to-female transgender women.

    PubMed

    Mauk, Daniel; Perry, Ashley; Muñoz-Laboy, Miguel

    2013-07-01

    Men who have sex with transgender women (MSTW) currently constitute a gap in the research community's understanding of male sexuality and sexual desire. In an effort to address this lack of knowledge, an ethnographic study of MSTW in New York City was conducted between December 2005 and May 2007, including in-depth interviews with MSTW (n = 15), key informant interviews (n = 13), and ethnographic observation of semi-private "tranny" parties held at various venues throughout New York City. The specific objectives were to: (1) describe the sex marketplaces and the sexual experiences of an ethnographic sample of MSTW in New York City and (2) describe the ways MSTW construct their sexual partnering practices and the meanings attributed to those practices in relation to varying social contexts (in and outside the sex marketplace). In this analysis, we described the MSTW sex market landscape in New York and identified three major recurrent themes in the ways that MSTW organized their sexual desire for TW transitioning from sex marketplaces to social spaces in their lives: (1) phallus-centric trade sex market focus; (2) relational-companionship market focus; and (3) specialized market focus. Although the findings from the study are not representative of the broader MSTW population, they represent an important step in amassing a body of knowledge about an understudied and underserved sex market upon which future research is needed.

  6. Differential Response of Males and Females to Work Situations Which Evoke Sex Role Stereotypes.

    ERIC Educational Resources Information Center

    Gutek, Barbara A.; Stevens, Denise A.

    The hypothesis in the present study is that in work situations which evoke sex role stereotypes, women will respond less stereotypically than males since it is in their best interest to do so. The method comes from the Rosen et al. (1975) study of male managers. In the present study, 293 introductory psychology students were asked to role play an…

  7. Hepatic injury induces contrasting response in liver and kidney to chemicals that are metabolically activated: Role of male sex hormone

    SciTech Connect

    Kim, Young C. Yim, Hye K.; Jung, Young S.; Park, Jae H.; Kim, Sung Y.

    2007-08-15

    Injury to liver, resulting in loss of its normal physiological/biochemical functions, may adversely affect a secondary organ. We examined the response of the liver and kidney to chemical substances that require metabolic activation for their toxicities in mice with a preceding liver injury. Carbon tetrachloride treatment 24 h prior to a challenging dose of carbon tetrachloride or acetaminophen decreased the resulting hepatotoxicity both in male and female mice as determined by histopathological examination and increases in serum enzyme activities. In contrast, the renal toxicity of the challenging toxicants was elevated markedly in male, but not in female mice. Partial hepatectomy also induced similar changes in the hepatotoxicity and nephrotoxicity of a challenging toxicant, suggesting that the contrasting response of male liver and kidney was associated with the reduction of the hepatic metabolizing capacity. Carbon tetrachloride pretreatment or partial hepatectomy decreased the hepatic xenobiotic-metabolizing enzyme activities in both sexes but elevated the renal p-nitrophenol hydroxylase, p-nitroanisole O-demethylase and aminopyrine N-demethylase activities significantly only in male mice. Increases in Cyp2e1 and Cyp2b expression were also evident in male kidney. Castration of males or testosterone administration to females diminished the sex-related differences in the renal response to an acute liver injury. The results indicate that reduction of the hepatic metabolizing capacity induced by liver injury may render secondary target organs susceptible to chemical substances activated in these organs. This effect may be sex-specific. It is also suggested that an integrated approach should be taken for proper assessment of chemical hazards.

  8. The Sicker Sex: Understanding Male Biases in Parasitic Infection, Resource Allocation and Fitness

    PubMed Central

    Córdoba-Aguilar, Alex; Munguía-Steyer, Roberto

    2013-01-01

    The “sicker sex” idea summarizes our knowledge of sex biases in parasite burden and immune ability whereby males fare worse than females. The theoretical basis of this is that because males invest more on mating effort than females, the former pay the costs by having a weaker immune system and thus being more susceptible to parasites. Females, conversely, have a greater parental investment. Here we tested the following: a) whether both sexes differ in their ability to defend against parasites using a natural host-parasite system; b) the differences in resource allocation conflict between mating effort and parental investment traits between sexes; and, c) effect of parasitism on survival for both sexes. We used a number of insect damselfly species as study subjects. For (a), we quantified gregarine and mite parasites, and experimentally manipulated gregarine levels in both sexes during adult ontogeny. For (b), first, we manipulated food during adult ontogeny and recorded thoracic fat gain (a proxy of mating effort) and abdominal weight (a proxy of parental investment) in both sexes. Secondly for (b), we manipulated food and gregarine levels in both sexes when adults were about to become sexually mature, and recorded gregarine number. For (c), we infected male and female adults of different ages and measured their survival. Males consistently showed more parasites than females apparently due to an increased resource allocation to fat production in males. Conversely, females invested more on abdominal weight. These differences were independent of how much food/infecting parasites were provided. The cost of this was that males had more parasites and reduced survival than females. Our results provide a resource allocation mechanism for understanding sexual differences in parasite defense as well as survival consequences for each sex. PMID:24194830

  9. Stabilization of beta-catenin in XY gonads causes male-to-female sex-reversal.

    PubMed

    Maatouk, Danielle M; DiNapoli, Leo; Alvers, Ashley; Parker, Keith L; Taketo, Makoto M; Capel, Blanche

    2008-10-01

    During mammalian sex determination, expression of the Y-linked gene Sry shifts the bipotential gonad toward a testicular fate by upregulating a feed-forward loop between FGF9 and SOX9 to establish SOX9 expression in somatic cells. We previously proposed that these signals are mutually antagonistic with counteracting signals in XX gonads and that a shift in the balance of these factors leads to either male or female development. Evidence in mice and humans suggests that the male pathway is opposed by the expression of two signals, WNT4 and R-SPONDIN-1 (RSPO1), that promote the ovarian fate and block testis development. Both of these ligands can activate the canonical Wnt signaling pathway. Duplication of the distal portion of chromosome 1p, which includes both WNT4 and RSPO1, overrides the male program and causes male-to-female sex reversal in XY patients. To determine whether activation of beta-catenin is sufficient to block the testis pathway, we have ectopically expressed a stabilized form of beta-catenin in the somatic cells of XY gonads. Our results show that activation of beta-catenin in otherwise normal XY mice effectively disrupts the male program and results in male-to-female sex-reversal. The identification of beta-catenin as a key pro-ovarian and anti-testis signaling molecule will further our understanding of the mechanisms controlling sex determination and the molecular mechanisms that lead to sex-reversal. PMID:18617533

  10. Female Choice or Male Sex Drive? The Advantages of Male Body Size during Mating in Drosophila Melanogaster.

    PubMed

    Jagadeeshan, Santosh; Shah, Ushma; Chakrabarti, Debarti; Singh, Rama S

    2015-01-01

    The mating success of larger male Drosophila melanogaster in the laboratory and the wild has been traditionally been explained by female choice, even though the reasons are generally hard to reconcile. Female choice can explain this success by virtue of females taking less time to mate with preferred males, but so can the more aggressive or persistent courtships efforts of large males. Since mating is a negotiation between the two sexes, the behaviors of both are likely to interact and influence mating outcomes. Using a series of assays, we explored these negotiations by testing for the relative influence of male behaviors and its effect on influencing female courtship arousal threshold, which is the time taken for females to accept copulation. Our results show that large males indeed have higher copulation success compared to smaller males. Competition between two males or an increasing number of males had no influence on female sexual arousal threshold;-females therefore may have a relatively fixed 'arousal threshold' that must be reached before they are ready to mate, and larger males appear to be able to manipulate this threshold sooner. On the other hand, the females' physiological and behavioral state drastically influences mating; once females have crossed the courtship arousal threshold they take less time to mate and mate indiscriminately with large and small males. Mating quicker with larger males may be misconstrued to be due to female choice; our results suggest that the mating advantage of larger males may be more a result of heightened male activity and relatively less of female choice. Body size per se may not be a trait under selection by female choice, but size likely amplifies male activity and signal outputs in courtship, allowing them to influence female arousal threshold faster.

  11. Female Choice or Male Sex Drive? The Advantages of Male Body Size during Mating in Drosophila Melanogaster

    PubMed Central

    Jagadeeshan, Santosh; Shah, Ushma; Chakrabarti, Debarti; Singh, Rama S.

    2015-01-01

    The mating success of larger male Drosophila melanogaster in the laboratory and the wild has been traditionally been explained by female choice, even though the reasons are generally hard to reconcile. Female choice can explain this success by virtue of females taking less time to mate with preferred males, but so can the more aggressive or persistent courtships efforts of large males. Since mating is a negotiation between the two sexes, the behaviors of both are likely to interact and influence mating outcomes. Using a series of assays, we explored these negotiations by testing for the relative influence of male behaviors and its effect on influencing female courtship arousal threshold, which is the time taken for females to accept copulation. Our results show that large males indeed have higher copulation success compared to smaller males. Competition between two males or an increasing number of males had no influence on female sexual arousal threshold;—females therefore may have a relatively fixed ‘arousal threshold’ that must be reached before they are ready to mate, and larger males appear to be able to manipulate this threshold sooner. On the other hand, the females’ physiological and behavioral state drastically influences mating; once females have crossed the courtship arousal threshold they take less time to mate and mate indiscriminately with large and small males. Mating quicker with larger males may be misconstrued to be due to female choice; our results suggest that the mating advantage of larger males may be more a result of heightened male activity and relatively less of female choice. Body size per se may not be a trait under selection by female choice, but size likely amplifies male activity and signal outputs in courtship, allowing them to influence female arousal threshold faster. PMID:26658421

  12. Japan's progressive sex: male homosexuality, national competition, and the cinema.

    PubMed

    Hall, J M

    2000-01-01

    This essay serves as a broad investigation of the origins of what came to be called the "gay boom" in 1990's Japanese cinema: a culmination of print media, television, and especially films which made the gay male not merely a visible (political) subject but also the site of displaced contestations of gendered (female) desire. The most visible transnational signifier of the "gay boom" was the 1992 film Okoge, a film which, in keeping with a Japanese trend which relocates the gay male as a safe displacement of female desire, posits the heterosexual female as the audience's point of identification in a film about the lives of gay Japanese men. Using this as a starting point, this essay seeks to explore how male homosexuality and gender construction operate within both Japanese nationalism and the transnational discourse of Japanese cinema's dissemination.

  13. Japan's progressive sex: male homosexuality, national competition, and the cinema.

    PubMed

    Hall, J M

    2000-01-01

    This essay serves as a broad investigation of the origins of what came to be called the "gay boom" in 1990's Japanese cinema: a culmination of print media, television, and especially films which made the gay male not merely a visible (political) subject but also the site of displaced contestations of gendered (female) desire. The most visible transnational signifier of the "gay boom" was the 1992 film Okoge, a film which, in keeping with a Japanese trend which relocates the gay male as a safe displacement of female desire, posits the heterosexual female as the audience's point of identification in a film about the lives of gay Japanese men. Using this as a starting point, this essay seeks to explore how male homosexuality and gender construction operate within both Japanese nationalism and the transnational discourse of Japanese cinema's dissemination. PMID:11133140

  14. Differential Growth of the Reproductive Organs during the Peripubertal Period in Male Rats.

    PubMed

    Han, Seung Hee; Lee, Sung-Ho

    2013-12-01

    In mammals, puberty is a process of acquiring reproductive competence, triggering by activation of hypothalamic kisspeptin (KiSS)-gonadotropin releasing hormone (GnRH) neuronal circuit. During peripubertal period, not only the external genitalia but the internal reproductive organs have to be matured in response to the hormonal signals from hypothalamic-pituitary-gonadal (H-P-G) axis. In the present study, we evaluated the maturation of male rat accessory sex organs during the peripubertal period using tissue weight measurement, histological analysis and RT-PCR assay. Male rats were sacrificed at 25, 30, 35, 40, 45, 50, and 70 postnatal days (PND). The rat accessory sex organs exhibited differential growth patterns compared to those of non-reproductive organs. The growth rate of the accessory sex organs were much higher than the those of non-reproductive organs. Also, the growth spurts occurred differentially even among the accessory sex organs; the order of prepubertal organ growth spurts is testis = epididymis > seminal vesicle = prostate. Histological study revealed that the presence of sperms in seminiferous tubules and epididymal ducts at day 50, indicating the puberty onset. The number of duct and the volume of duct in epididymis and prostate were inversely correlated during the experimental period. Our RT-PCR revealed that the levels of hypothalamic GnRH transcript were increased significantly on PND 40, suggesting the activation of hypothalamic GnRH pulse-generator before puberty onset. Studies on the peripubertal male accessory sex organs will provide useful references on the growth regulation mechanism which is differentially regulated during the period in andevrepogen-sensitive organs. The detailed references will render easier development of endocrine disruption assay.

  15. Male facial attractiveness and masculinity may provide sex- and culture-independent cues to semen quality.

    PubMed

    Soler, C; Kekäläinen, J; Núñez, M; Sancho, M; Álvarez, J G; Núñez, J; Yaber, I; Gutiérrez, R

    2014-09-01

    Phenotype-linked fertility hypothesis (PLFH) predicts that male secondary sexual traits reveal honest information about male fertilization ability. However, PLFH has rarely been studied in humans. The aim of the present study was to test PLFH in humans and to investigate whether potential ability to select fertile partners is independent of sex or cultural background. We found that on the contrary to the hypothesis, facial masculinity was negatively associated with semen quality. As increased levels of testosterone have been demonstrated to impair sperm production, this finding may indicate a trade-off between investments in secondary sexual signalling (i.e. facial masculinity) and fertility or status-dependent differences in investments in semen quality. In both sexes and nationalities (Spanish and Colombian), ranked male facial attractiveness predicted male semen quality. However, Spanish males and females estimated facial images generally more attractive (gave higher ranks) than Colombian raters, and in both nationalities, males gave higher ranks than females. This suggests that male facial cues may provide culture- and sex-independent information about male fertility. However, our results also indicate that humans may be more sensitive to facial attractiveness cues within their own populations and also that males may generally overestimate the attractiveness of other men to females.

  16. Effect of Withania somnifera (L.) Dunal on Sex Hormone and Gonadotropin Levels in Addicted Male Rats

    PubMed Central

    Rahmati, Batool; Ghosian Moghaddam, Mohammad Hassan; Khalili, Mohsen; Enayati, Ehsan; Maleki, Maryam; Rezaeei, Saeedeh

    2016-01-01

    Background Opioid consumption has been widely increasing across the globe; how- ever, it can cause adverse effects on the body. Morphine, an opioid, can reduce sex hor- mones and fertility. Withania somnifera (WS) is a traditional herb used to improve sexual activities. This study strives to investigate the effect of WS on sex hormones and gonado- tropins in addicted male rats. Materials and Methods In this experimental study, forty-eight male National Maritime Research Institute (NMRI) rats were randomly divided into four groups: i. Control group, ii. WS-treated control group, iii. Addicted group, and iv. WS-treated addicted group. Wa- ter-soluble morphine was given to rats for 21 days to induce addiction, concurrently the treated groups (2 and 4) also received WS plant-mixed pelleted food (6.25%). At the end of the treatment, the sex hormone and gonadotropin levels of the rats’ sera were deter- mined in all the groups. Results Except for follicle-stimulating hormone (FSH), morphine reduced most of the gonadotropin and sex hormone levels. Whereas WS caused a considerable increase in the hormones in the treated addicted group, there was only a slight increase in the treated control group. Conclusion WS increased sex hormones and gonadotropins-especially testosterone, es- trogen, and luteinizing hormone-in the addicted male rats and even increased the proges- terone level, a stimulant of most sex hormones in addicted male rats. PMID:27441058

  17. Alcohol Use Among Female Sex Workers and Male Clients: An Integrative Review of Global Literature

    PubMed Central

    Li, Qing; Li, Xiaoming; Stanton, Bonita

    2010-01-01

    Aims: To review the patterns, contexts and impacts of alcohol use associated with commercial sex reported in the global literature. Methods: We identified peer-reviewed English-language articles from 1980 to 2008 reporting alcohol consumption among female sex workers (FSWs) or male clients. We retrieved 70 articles describing 76 studies, in which 64 were quantitative (52 for FSWs, 12 for male clients) and 12 qualitative. Results: Studies increased over the past three decades, with geographic concentration of the research in Asia and North America. Alcohol use was prevalent among FSWs and clients. Integrating quantitative and qualitative studies, multilevel contexts of alcohol use in the sex work environment were identified, including workplace and occupation-related use, the use of alcohol to facilitate the transition into and practice of commercial sex among both FSWs and male clients, and self-medication among FSWs. Alcohol use was associated with adverse physical health, illicit drug use, mental health problems, and victimization of sexual violence, although its associations with HIV/sexually transmitted infections and unprotected sex among FSWs were inconclusive. Conclusions: Alcohol use in the context of commercial sex is prevalent, harmful among FSWs and male clients, but under-researched. Research in this area in more diverse settings and with standardized measures is required. The review underscores the importance of integrated intervention for alcohol use and related problems in multilevel contexts and with multiple components in order to effectively reduce alcohol use and its harmful effects among FSWs and their clients. PMID:20089544

  18. METHODS OF PROMOTING SAFER SEX BEHAVIORS UTILIZED BY MEN WHO HAVE SEX WITH MALE CASUAL SEX PARTNERS

    PubMed Central

    Serovich, Julianne M.; Craft, Shonda M.; McDowell, Tiffany L.; Grafsky, Erika L.; Andrist, David

    2009-01-01

    The purpose of this article is to report results of a qualitative investigation into the methods that HIV-positive men who have sex with men (MSM) use to initiate safer sex with casual sexual partners. In-depth, qualitative interviews were conducted with 57 HIV-positive adult MSM living in a large midwestern city. Using an inductive approach to data analysis, participants revealed a typology of safer sex strategies that can be placed into four primary categorizations: having a nonnegotiable sexual behavior policy, behaviorally controlling the interaction, being verbally direct, and being verbally indirect. Strategies varied by degree of explicitness and partner involvement. Men in this study often employed multiple strategies if their partner was not initially receptive to engaging in safer sex behaviors. The strategies described can be especially beneficial to those working in the area of HIV prevention. Providing MSM a variety of options to initiate safer sex may enhance current prevention efforts. PMID:19243227

  19. Sex recognition and mate choice by male Bufo gargarizans in central China.

    PubMed

    Yu, Tong Lei; Sharma, Manmohan D

    2012-06-01

    Mate choice is important for successful reproduction, and consequently species have evolved various ways to choose potential high-quality mates. Anuran mate choice and underlying processes have been the subject of several recent investigations, however we are far from a complete understanding of mate choice in this system. In the present study, when given a simultaneous choice between a male and a female of identical size, males did not discriminate between the sexes, and attempted to clasp a male or a female with equal frequency. Test males only released the stimulus toad when a release call was emitted by the stimulus male. When two males with distinct size differences were provided with a male, the male chose the larger one. Moreover, males discriminated between gravid females that differed in body size, choosing larger gravid females over smaller ones. These results suggest that male Bufo gargarizans can discriminate between the sexes, probably based on male release calls, and prefer to mate with larger individual using visual cues. PMID:22639803

  20. Sex steroids and the male skeleton: a tale of two hormones.

    PubMed

    Callewaert, Filip; Boonen, Steven; Vanderschueren, Dirk

    2010-02-01

    Traditionally, the stronger male skeleton was considered to result from higher androgen levels in men compared to women. However, the regulation of male bone growth by sex steroids appears more complex than originally anticipated. Based on clinical observations and studies in animal models, not only androgens and androgen receptor (AR), but also estrogens and estrogen receptor-alpha (not ERbeta) are required for optimal bone mineral acquisition during male growth. In addition, both sex steroids are involved in the maintenance of male skeletal health. In fact, bone loss and fracture risk have been associated with estrogen exposure in elderly men. Overall, a compelling body of evidence suggests that both androgens and estrogens are crucial for male skeletal growth and maintenance.

  1. Sex Reassignment Surgery in the Female-to-Male Transsexual.

    PubMed

    Monstrey, Stan J; Ceulemans, Peter; Hoebeke, Piet

    2011-08-01

    In female-to-male transsexuals, the operative procedures are usually performed in different stages: first the subcutaneous mastectomy which is often combined with a hysterectomy-ovarectomy (endoscopically assisted). The next operative procedure consists of the genital transformation and includes a vaginectomy, a reconstruction of the horizontal part of the urethra, a scrotoplasty and a penile reconstruction usually with a radial forearm flap (or an alternative). After about one year, penile (erection) prosthesis and testicular prostheses can be implanted when sensation has returned to the tip of the penis. The authors provide a state-of-the-art overview of the different gender reassignment surgery procedures that can be performed in a female-to-male transsexual.

  2. Dysregulation of male sex hormones in chronic hepatitis C patients.

    PubMed

    El-Serafi, A T; Osama, S; El-Zalat, H; EL-Deen, I M

    2016-02-01

    Chronic hepatitis C (HCV) infection is a serious problem all over the world and has a special importance in Egypt, where the prevalence of infection is 14.7% of population. In males, HCV is associated with sexual dysfunction and changes in the semen parameters. This study aimed at estimation of a panel of the most important related hormones in the serum of patients and illustration of their correlation to the routine laboratory investigations. The four studied hormones showed alteration in the patients in comparison with the controls. While androstenedione, prolactin and testosterone were significantly increased in patients, dehydroepiandrosterone sulphate was decreased. These changes in the hormones were not related to the liver functions, pathological grade or even viral load. We hypothesised a model of how HCV can induce these hormonal changes and recommended to add these hormones to the follow-up panel of male patients with HCV.

  3. The Weaker Sex? The Propensity for Male-Biased Piglet Mortality

    PubMed Central

    Baxter, Emma M.; Jarvis, Susan; Palarea-Albaladejo, Javier; Edwards, Sandra A.

    2012-01-01

    For the most part solutions to farm animal welfare issues, such as piglet mortality, are likely to lie within the scientific disciplines of environmental design and genetic selection, however understanding the ecological basis of some of the complex dynamics observed between parent and offspring could make a valuable contribution. One interesting, and often discussed, aspect of mortality is the propensity for it to be sex-biased. This study investigated whether known physiological and behavioural indicators of piglet survival differed between the sexes and whether life history strategies (often reported in wild or feral populations) relating to parental investment were being displayed in a domestic population of pigs. Sex ratio (proportion of males (males/males+females)) at birth was 0.54 and sex allocation (maternal investment measured as piglet birth weight/litter weight) was statistically significantly male-biased at 0.55 (t35 = 2.51 P = 0.017), suggesting that sows invested more in sons than daughters during gestation. Despite this investment in birth weight, a known survival indicator, total pre-weaning male mortality was statistically significantly higher than female mortality (12% vs. 7% respectively z = 2.06 P = 0.040). Males tended to suffer from crushing by the sow more than females and statistically significantly more males died from disease-related causes. Although males were born on average heavier, with higher body mass index and ponderal index, these differences were not sustained. In addition male piglets showed impaired thermoregulation compared to females. These results suggest male-biased mortality exists despite greater initial maternal investment, and therefore reflects the greater susceptibility of this sex to causal mortality factors. Life history strategies are being displayed by a domestic population of pigs with sows in this study displaying a form of parental optimism by allocating greater resources at birth to males and

  4. Male-killing symbiont damages host's dosage-compensated sex chromosome to induce embryonic apoptosis

    PubMed Central

    Harumoto, Toshiyuki; Anbutsu, Hisashi; Lemaitre, Bruno; Fukatsu, Takema

    2016-01-01

    Some symbiotic bacteria are capable of interfering with host reproduction in selfish ways. How such bacteria can manipulate host's sex-related mechanisms is of fundamental interest encompassing cell, developmental and evolutionary biology. Here, we uncover the molecular and cellular mechanisms underlying Spiroplasma-induced embryonic male lethality in Drosophila melanogaster. Transcriptomic analysis reveals that many genes related to DNA damage and apoptosis are up-regulated specifically in infected male embryos. Detailed genetic and cytological analyses demonstrate that male-killing Spiroplasma causes DNA damage on the male X chromosome interacting with the male-specific lethal (MSL) complex. The damaged male X chromosome exhibits a chromatin bridge during mitosis, and bridge breakage triggers sex-specific abnormal apoptosis via p53-dependent pathways. Notably, the MSL complex is not only necessary but also sufficient for this cytotoxic process. These results highlight symbiont's sophisticated strategy to target host's sex chromosome and recruit host's molecular cascades toward massive apoptosis in a sex-specific manner. PMID:27650264

  5. Male-killing symbiont damages host's dosage-compensated sex chromosome to induce embryonic apoptosis.

    PubMed

    Harumoto, Toshiyuki; Anbutsu, Hisashi; Lemaitre, Bruno; Fukatsu, Takema

    2016-01-01

    Some symbiotic bacteria are capable of interfering with host reproduction in selfish ways. How such bacteria can manipulate host's sex-related mechanisms is of fundamental interest encompassing cell, developmental and evolutionary biology. Here, we uncover the molecular and cellular mechanisms underlying Spiroplasma-induced embryonic male lethality in Drosophila melanogaster. Transcriptomic analysis reveals that many genes related to DNA damage and apoptosis are up-regulated specifically in infected male embryos. Detailed genetic and cytological analyses demonstrate that male-killing Spiroplasma causes DNA damage on the male X chromosome interacting with the male-specific lethal (MSL) complex. The damaged male X chromosome exhibits a chromatin bridge during mitosis, and bridge breakage triggers sex-specific abnormal apoptosis via p53-dependent pathways. Notably, the MSL complex is not only necessary but also sufficient for this cytotoxic process. These results highlight symbiont's sophisticated strategy to target host's sex chromosome and recruit host's molecular cascades toward massive apoptosis in a sex-specific manner. PMID:27650264

  6. Clover root exudate produces male-biased sex ratios and accelerates male metamorphic timing in wood frogs.

    PubMed

    Lambert, Max R

    2015-12-01

    In amphibians, abnormal metamorph sex ratios and sexual development have almost exclusively been considered in response to synthetic compounds like pesticides or pharmaceuticals. However, endocrine-active plant chemicals (i.e. phytoestrogens) are commonly found in agricultural and urban waterways hosting frog populations with deviant sexual development. Yet the effects of these compounds on amphibian development remain predominantly unexplored. Legumes, like clover, are common in agricultural fields and urban yards and exude phytoestrogen mixtures from their roots. These root exudates serve important ecological functions and may also be a source of phytoestrogens in waterways. I show that clover root exudate produces male-biased sex ratios and accelerates male metamorphosis relative to females in low and intermediate doses of root exudate. My results indicate that root exudates are a potential source of contaminants impacting vertebrate development and that humans may be cultivating sexual abnormalities in wildlife by actively managing certain plant species.

  7. Clover root exudate produces male-biased sex ratios and accelerates male metamorphic timing in wood frogs.

    PubMed

    Lambert, Max R

    2015-12-01

    In amphibians, abnormal metamorph sex ratios and sexual development have almost exclusively been considered in response to synthetic compounds like pesticides or pharmaceuticals. However, endocrine-active plant chemicals (i.e. phytoestrogens) are commonly found in agricultural and urban waterways hosting frog populations with deviant sexual development. Yet the effects of these compounds on amphibian development remain predominantly unexplored. Legumes, like clover, are common in agricultural fields and urban yards and exude phytoestrogen mixtures from their roots. These root exudates serve important ecological functions and may also be a source of phytoestrogens in waterways. I show that clover root exudate produces male-biased sex ratios and accelerates male metamorphosis relative to females in low and intermediate doses of root exudate. My results indicate that root exudates are a potential source of contaminants impacting vertebrate development and that humans may be cultivating sexual abnormalities in wildlife by actively managing certain plant species. PMID:27019728

  8. Clover root exudate produces male-biased sex ratios and accelerates male metamorphic timing in wood frogs

    PubMed Central

    Lambert, Max R.

    2015-01-01

    In amphibians, abnormal metamorph sex ratios and sexual development have almost exclusively been considered in response to synthetic compounds like pesticides or pharmaceuticals. However, endocrine-active plant chemicals (i.e. phytoestrogens) are commonly found in agricultural and urban waterways hosting frog populations with deviant sexual development. Yet the effects of these compounds on amphibian development remain predominantly unexplored. Legumes, like clover, are common in agricultural fields and urban yards and exude phytoestrogen mixtures from their roots. These root exudates serve important ecological functions and may also be a source of phytoestrogens in waterways. I show that clover root exudate produces male-biased sex ratios and accelerates male metamorphosis relative to females in low and intermediate doses of root exudate. My results indicate that root exudates are a potential source of contaminants impacting vertebrate development and that humans may be cultivating sexual abnormalities in wildlife by actively managing certain plant species. PMID:27019728

  9. Transactional sex risk and STI among HIV-infected female sex workers and HIV-infected male clients of FSWs in India.

    PubMed

    Raj, Anita; Saggurti, N; Cheng, Debbie M; Dasgupta, Anindita; Bridden, Carly; Pradeshi, Manojkumar; Samet, J H

    2011-11-01

    To describe sex risk behaviors of HIV-infected female sex workers (FSWs) and HIV-infected male clients of FSWs, to evaluate associations between risky transactional sex and number of unprotected transactional sex episodes, and to assess the association between unprotected transactional sex and self-reported sexually transmitted infection (STI). Adult HIV-infected FSWs (n = 211) and HIV-infected male clients (n = 205) were surveyed in Mumbai about demographics, STI, and past 90-day and past year sex and substance use histories. Gender-stratified Poisson regression models were used to evaluate associations between four risky transactional sex behaviors (number of transactional sex partners; alcohol use before transactional sex; anal transactional sex; and transactional sex with a known HIV-infected partner) and number of unprotected transactional sex episodes; logistic regression was used to assess the association between unprotected transactional sex and self-reported STI. Twenty-nine percent of females and 7% of males reported any unprotected transactional sex episodes in the past 90 days. Thirty-nine percent of females and 12% of males reported past year STI. Among males, a greater number of transactional sex partners was associated with more unprotected transactional sex episodes (adjusted incidence rate ratio [IRR] = 8.2, 95% confidence interval [CI] = 1.8-38.4 highest vs. lowest tertile), and any unprotected transactional sex was associated with a higher odds of self-reported STI in the past year (adjusted odds ratio [AOR] = 5.6, 95% CI = 1.4-22.4). For women, risky transactional sex behaviors were not associated with condom non-use, and unprotected sex was negatively associated with STI (AOR = 0.4, 95% CI = 0.2-0.9). Reports of condom use during transactional sex were high for these samples. However, standard predictors of unprotected transactional sex (i.e., greater number of partners) and STI (i.e., unprotected sex) only held true for males. Further research

  10. Low concentrations of dihydrotestosterone induce female-to-male sex reversal in the frog Pelophylax nigromaculatus.

    PubMed

    Xu, Wei; Li, Yuan-Yuan; Lou, Qin-Qin; Chen, Xiao-Ran; Qin, Zhan-Fen; Wie, Wu-Ji

    2015-10-01

    Previous studies have demonstrated that some amphibian species can be sex-reversed by high concentrations of androgens. Little attention has focused on the effects of androgenic endocrine-disrupting chemicals (EDCs) on amphibians. The present study aimed to investigate the effects of lower concentrations of the androgenic EDC 5α-dihydrotestosterone (DHT) on gonadal differentiation and development in Pelophylax nigromaculatus, a true frog distributed widely in East Asia. Tadpoles at Gosner stage 24/25 were exposed to nominal concentrations of 40 ng/L, 400 ng/L, and 4000 ng/L DHT to complete metamorphosis. In all DHT treatment groups, males and ambiguous sexes were identified based on gonadal morphology, whereas no females were found; thus, all treatment groups exhibited male-skewed ratios compared with the control group. Gonadal histological examination revealed that ambiguous sexes displayed overall testicular structure with certain ovarian characteristics, demonstrating that DHT-induced sex-ambiguous gonads were incomplete ovary-to-testis reversals (IOTTRs). The expression levels of some ovary-biased genes in the IOTTRs were significantly higher than in the control testes but lower than in the control ovaries. These results show that low concentrations of DHT induced complete or incomplete female-to-male sex reversal in P. nigromaculatus, and incomplete sex reversal retained certain ovarian characteristics not only at gonadal morphological and histological levels but also at the molecular level. They present study highlights potential risks of DHT and other androgenic EDCs for P. nigromaculatus. PMID:26226837

  11. Low concentrations of dihydrotestosterone induce female-to-male sex reversal in the frog Pelophylax nigromaculatus.

    PubMed

    Xu, Wei; Li, Yuan-Yuan; Lou, Qin-Qin; Chen, Xiao-Ran; Qin, Zhan-Fen; Wie, Wu-Ji

    2015-10-01

    Previous studies have demonstrated that some amphibian species can be sex-reversed by high concentrations of androgens. Little attention has focused on the effects of androgenic endocrine-disrupting chemicals (EDCs) on amphibians. The present study aimed to investigate the effects of lower concentrations of the androgenic EDC 5α-dihydrotestosterone (DHT) on gonadal differentiation and development in Pelophylax nigromaculatus, a true frog distributed widely in East Asia. Tadpoles at Gosner stage 24/25 were exposed to nominal concentrations of 40 ng/L, 400 ng/L, and 4000 ng/L DHT to complete metamorphosis. In all DHT treatment groups, males and ambiguous sexes were identified based on gonadal morphology, whereas no females were found; thus, all treatment groups exhibited male-skewed ratios compared with the control group. Gonadal histological examination revealed that ambiguous sexes displayed overall testicular structure with certain ovarian characteristics, demonstrating that DHT-induced sex-ambiguous gonads were incomplete ovary-to-testis reversals (IOTTRs). The expression levels of some ovary-biased genes in the IOTTRs were significantly higher than in the control testes but lower than in the control ovaries. These results show that low concentrations of DHT induced complete or incomplete female-to-male sex reversal in P. nigromaculatus, and incomplete sex reversal retained certain ovarian characteristics not only at gonadal morphological and histological levels but also at the molecular level. They present study highlights potential risks of DHT and other androgenic EDCs for P. nigromaculatus.

  12. Male and female mate choice affects offspring quality in a sex-role-reversed pipefish.

    PubMed

    Sandvik, M; Rosenqvist, G; Berglund, A

    2000-11-01

    Where both sexes invest substantially in offspring, both females and males should discriminate between potential partners when choosing mates. The degree of choosiness should relate to the costs of choice and to the potential benefits to be gained. We measured offspring quality from experimentally staged matings with preferred and non-preferred partners in a sex-role-reversed pipefish, Syngnathus typhle L. Here, a substantial male investment in offspring results in a lower potential reproductive rate in males than in females, and access to males limits female reproductive success rather than vice versa. Thus, males are choosier than females and females compete more intensely over mates than do males. Broods from preferred matings were superior at escaping predation, when either males or females were allowed to choose a partner. However, only 'choosing' females benefited in terms of faster-growing offspring. Our results have important implications for mate-choice research: here we show that even the more competitive and less choosy sex may contribute significantly to sexual selection through mate choice. PMID:11413626

  13. Alcohol and drug use in Australian male sex workers: its relationship to the safety outcome of the sex encounter.

    PubMed

    Minichiello, V; Mariño, R; Khan, M A; Browne, J

    2003-08-01

    This paper describes the self-reporting patterns of alcohol and drug consumption among male sex workers (MSWs) in three Australian cities during commercial sex encounters, and examines to what extent alcohol and drugs are used and whether this is related to the safe/unsafe outcome of the commercial sex encounter. One hundred and eighty-six MSWs from Brisbane, Sydney and Melbourne completed a diary following each commercial sex encounter over a two-week period. MSWs reported 2,087 commercial sex encounters during the study period. Alcohol or drug consumption was reported in 50.5% of the encounters. There were 488 instances of marijuana use reported before or during a commercial sex encounter, 210 instances of volatile inhalants use, 149 instances of heroine use and 151 of other drug use, including benzodiasepines, ecstasy, speed and cocaine. These substances were consumed either alone or combined. Marijuana consumption was associated with the commercial sex encounter occurring at the MSWs' place of residence and consumption of alcohol, marijuana and nitrites with the client's place. The results also reveal that consumption of drugs and alcohol was statistically related to length of the encounter, and that clients obtained through escort agencies or brothels were significantly associated with marijuana, other drug consumption and heroine use. Interestingly, a multivariate analysis indicated that encounters where the MSW consumed marijuana or did not consume any substance were less likely to have an unsafe outcome. The paper argues that it is necessary to identify and target risk groups and behaviours that are usually not included in broad based health education messages.

  14. Comparisons of female and male early adolescent sex role attitude and behavior development.

    PubMed

    Nelson, C; Keith, J

    1990-01-01

    This study contrasted female and male early adolescent sex role attitude and behavior development in an ecological context as defined by Bronfenbrenner. Data were the results of a state-wide survey of early adolescents and their parents. Hierarchical multiple regression was used to test both sex role attitude development and behavior development models. Only the models for attitude development were significant. The level of traditionalism of female sex role attitude development was significantly influenced by maternal employment, the level of traditionalism of the father's sex role attitudes in interaction with the amount of time he spent with his daughter, and chronological age. In contrast, the level of traditionalism of male sex role attitude development was significantly influenced by the level of traditionalism of the mother's sex role attitudes in interaction with the level of closeness to the mother that was reported by the son, and both mother's and father's perception of pubertal age. The implications of the findings for human development theory, early adolescence as a stage of development, and sex role theory and research are discussed.

  15. The trap of sex in social insects: from the female to the male perspective.

    PubMed

    Beani, Laura; Dessì-Fulgheri, Francesco; Cappa, Federico; Toth, Amy

    2014-10-01

    The phenotype of male Hymenoptera and the peculiar role of males has been neglected and greatly understudied, given the spectacular cooperative behavior of female social insects. In social insects there has been considerable progress in understanding the molecular mechanisms behind haplodiploid sex determination but, beyond that, very little is known concerning the neural, endocrine, and genetic correlates of sexual selection in males. An opportunity is being missed: the male phenotype in Hymenoptera is a natural experiment to compare the drives of natural versus sexual selection. In contrast to females, males do not work, they usually display far from the nest to gain mates, compete among rivals in nuptial flights or for a symbolic territory at leks, and engage in direct or ritualized conflicts. By comparing the available data on male paper wasps with studies on other social Hymenoptera, we summarize what we currently know about the physical, hormonal, neural and behavioral traits in a model system appropriate to examine current paradigms on sexual selection. Here we review male behavior in social Hymenoptera beyond sex stereotypes: the subtle role of "drones" in the colony, the lack of armaments and ornaments, the explosive mating crowds, the "endurance" race, the cognitive bases of the "choosy" male and his immune defense. Social insect males are not just simple-minded mating machines, they are shaped, constrained and perhaps trapped by sexual selection. PMID:25280909

  16. The trap of sex in social insects: from the female to the male perspective.

    PubMed

    Beani, Laura; Dessì-Fulgheri, Francesco; Cappa, Federico; Toth, Amy

    2014-10-01

    The phenotype of male Hymenoptera and the peculiar role of males has been neglected and greatly understudied, given the spectacular cooperative behavior of female social insects. In social insects there has been considerable progress in understanding the molecular mechanisms behind haplodiploid sex determination but, beyond that, very little is known concerning the neural, endocrine, and genetic correlates of sexual selection in males. An opportunity is being missed: the male phenotype in Hymenoptera is a natural experiment to compare the drives of natural versus sexual selection. In contrast to females, males do not work, they usually display far from the nest to gain mates, compete among rivals in nuptial flights or for a symbolic territory at leks, and engage in direct or ritualized conflicts. By comparing the available data on male paper wasps with studies on other social Hymenoptera, we summarize what we currently know about the physical, hormonal, neural and behavioral traits in a model system appropriate to examine current paradigms on sexual selection. Here we review male behavior in social Hymenoptera beyond sex stereotypes: the subtle role of "drones" in the colony, the lack of armaments and ornaments, the explosive mating crowds, the "endurance" race, the cognitive bases of the "choosy" male and his immune defense. Social insect males are not just simple-minded mating machines, they are shaped, constrained and perhaps trapped by sexual selection.

  17. [MALE, FEMALE, NEUTRUM. SEXUAL IDENTITY, UNCERTAIN SEX AND BIOLOGY].

    PubMed

    Famularo, Simone

    2014-01-01

    For almost 2000 years, human beings have been discussing about gender. New scientific evidences give interesting new points of view, partially subverting the normal dichotomy described by the "two-gender" theory. In this article, we are going to critically review the history of the approach towards people born with a Sexual-Differentiation-Disorder, passing through the analysis of the Italian National Ethics Committee's opinion, describing the modern scientific evidences on the gender-identity development, furthermore ruling out the new approach borned from the femminist philosophies, and the new biogiuridical experiments borned in Australia and Germany. Would it be possible a world where a person could be more then a male or a female?

  18. HIV Prevention Needs Among Street-Based Male Sex Workers in Providence, Rhode Island

    PubMed Central

    Closson, Elizabeth F.; Oldenburg, Catherine E.; Holcomb, Richard; Spurlock, Shannon; Mimiaga, Matthew J.

    2014-01-01

    We examined data derived from a needs assessment of the personal and social characteristics and HIV risk behavior of street-based male sex workers, in Providence, Rhode Island, who engage in transactional sexual intercourse with other men. Substance use, injected drugs, needle sharing, and psychosocial distress were highly prevalent among the sample. History of physical, sexual, and emotional abuse was associated with increased risk of condomless anal sexual intercourse with paying male clients. PMID:25211761

  19. SEX-DETector: A Probabilistic Approach to Study Sex Chromosomes in Non-Model Organisms.

    PubMed

    Muyle, Aline; Käfer, Jos; Zemp, Niklaus; Mousset, Sylvain; Picard, Franck; Marais, Gabriel Ab

    2016-01-01

    We propose a probabilistic framework to infer autosomal and sex-linked genes from RNA-seq data of a cross for any sex chromosome type (XY, ZW, and UV). Sex chromosomes (especially the non-recombining and repeat-dense Y, W, U, and V) are notoriously difficult to sequence. Strategies have been developed to obtain partially assembled sex chromosome sequences. Most of them remain difficult to apply to numerous non-model organisms, either because they require a reference genome, or because they are designed for evolutionarily old systems. Sequencing a cross (parents and progeny) by RNA-seq to study the segregation of alleles and infer sex-linked genes is a cost-efficient strategy, which also provides expression level estimates. However, the lack of a proper statistical framework has limited a broader application of this approach. Tests on empirical Silene data show that our method identifies 20-35% more sex-linked genes than existing pipelines, while making reliable inferences for downstream analyses. Approximately 12 individuals are needed for optimal results based on simulations. For species with an unknown sex-determination system, the method can assess the presence and type (XY vs. ZW) of sex chromosomes through a model comparison strategy. The method is particularly well optimized for sex chromosomes of young or intermediate age, which are expected in thousands of yet unstudied lineages. Any organisms, including non-model ones for which nothing is known a priori, that can be bred in the lab, are suitable for our method. SEX-DETector and its implementation in a Galaxy workflow are made freely available. PMID:27492231

  20. SEX-DETector: A Probabilistic Approach to Study Sex Chromosomes in Non-Model Organisms

    PubMed Central

    Muyle, Aline; Käfer, Jos; Zemp, Niklaus; Mousset, Sylvain; Picard, Franck; Marais, Gabriel AB

    2016-01-01

    We propose a probabilistic framework to infer autosomal and sex-linked genes from RNA-seq data of a cross for any sex chromosome type (XY, ZW, and UV). Sex chromosomes (especially the non-recombining and repeat-dense Y, W, U, and V) are notoriously difficult to sequence. Strategies have been developed to obtain partially assembled sex chromosome sequences. Most of them remain difficult to apply to numerous non-model organisms, either because they require a reference genome, or because they are designed for evolutionarily old systems. Sequencing a cross (parents and progeny) by RNA-seq to study the segregation of alleles and infer sex-linked genes is a cost-efficient strategy, which also provides expression level estimates. However, the lack of a proper statistical framework has limited a broader application of this approach. Tests on empirical Silene data show that our method identifies 20–35% more sex-linked genes than existing pipelines, while making reliable inferences for downstream analyses. Approximately 12 individuals are needed for optimal results based on simulations. For species with an unknown sex-determination system, the method can assess the presence and type (XY vs. ZW) of sex chromosomes through a model comparison strategy. The method is particularly well optimized for sex chromosomes of young or intermediate age, which are expected in thousands of yet unstudied lineages. Any organisms, including non-model ones for which nothing is known a priori, that can be bred in the lab, are suitable for our method. SEX-DETector and its implementation in a Galaxy workflow are made freely available. PMID:27492231

  1. SEX-DETector: A Probabilistic Approach to Study Sex Chromosomes in Non-Model Organisms.

    PubMed

    Muyle, Aline; Käfer, Jos; Zemp, Niklaus; Mousset, Sylvain; Picard, Franck; Marais, Gabriel Ab

    2016-01-01

    We propose a probabilistic framework to infer autosomal and sex-linked genes from RNA-seq data of a cross for any sex chromosome type (XY, ZW, and UV). Sex chromosomes (especially the non-recombining and repeat-dense Y, W, U, and V) are notoriously difficult to sequence. Strategies have been developed to obtain partially assembled sex chromosome sequences. Most of them remain difficult to apply to numerous non-model organisms, either because they require a reference genome, or because they are designed for evolutionarily old systems. Sequencing a cross (parents and progeny) by RNA-seq to study the segregation of alleles and infer sex-linked genes is a cost-efficient strategy, which also provides expression level estimates. However, the lack of a proper statistical framework has limited a broader application of this approach. Tests on empirical Silene data show that our method identifies 20-35% more sex-linked genes than existing pipelines, while making reliable inferences for downstream analyses. Approximately 12 individuals are needed for optimal results based on simulations. For species with an unknown sex-determination system, the method can assess the presence and type (XY vs. ZW) of sex chromosomes through a model comparison strategy. The method is particularly well optimized for sex chromosomes of young or intermediate age, which are expected in thousands of yet unstudied lineages. Any organisms, including non-model ones for which nothing is known a priori, that can be bred in the lab, are suitable for our method. SEX-DETector and its implementation in a Galaxy workflow are made freely available.

  2. Operational sex ratio and density do not affect directional selection on male sexual ornaments and behavior.

    PubMed

    Head, Megan L; Lindholm, Anna K; Brooks, Robert

    2008-01-01

    Demographic parameters including operational sex ratio (OSR) and population density may influence the opportunity for, and strength of sexual selection. Traditionally, male-biased OSRs and high population densities have been thought to increase the opportunity for sexual selection on male sexual traits due to increased male competition for mates. Recent experimental evidence, however, suggests that male-biased OSRs might reduce the opportunity for sexual selection due to increased sexual coercion experienced by females. How OSR, density, and any resultant changes in the opportunity for sexual selection actually affect selection on male sexual traits is unclear. In this study, we independently manipulated OSR and density in the guppy (Poecilia reticulata) without altering the number of males present. We recorded male and female behavior and used DNA microsatellite data to assign paternity to offspring and estimate male reproductive success. We then used linear selection analyses to examine the effects of OSR and density on directional sexual selection on male behavioral and morphological traits. We found that females were pursued more by males in male-biased treatments, despite no change in individual male behavior. There were no differences in sexual behavior experienced by females or performed by males in relation to density. Neither OSR nor density significantly altered the opportunity for sexual selection. Also, Although there was significant multivariate linear selection operating on males, neither OSR nor density altered the pattern of sexual selection on male traits. Our results suggest that differences in either OSR or density (independent of the number of males present) are unlikely to alter directional evolutionary change in male sexual traits.

  3. Operational sex ratio and density do not affect directional selection on male sexual ornaments and behavior.

    PubMed

    Head, Megan L; Lindholm, Anna K; Brooks, Robert

    2008-01-01

    Demographic parameters including operational sex ratio (OSR) and population density may influence the opportunity for, and strength of sexual selection. Traditionally, male-biased OSRs and high population densities have been thought to increase the opportunity for sexual selection on male sexual traits due to increased male competition for mates. Recent experimental evidence, however, suggests that male-biased OSRs might reduce the opportunity for sexual selection due to increased sexual coercion experienced by females. How OSR, density, and any resultant changes in the opportunity for sexual selection actually affect selection on male sexual traits is unclear. In this study, we independently manipulated OSR and density in the guppy (Poecilia reticulata) without altering the number of males present. We recorded male and female behavior and used DNA microsatellite data to assign paternity to offspring and estimate male reproductive success. We then used linear selection analyses to examine the effects of OSR and density on directional sexual selection on male behavioral and morphological traits. We found that females were pursued more by males in male-biased treatments, despite no change in individual male behavior. There were no differences in sexual behavior experienced by females or performed by males in relation to density. Neither OSR nor density significantly altered the opportunity for sexual selection. Also, Although there was significant multivariate linear selection operating on males, neither OSR nor density altered the pattern of sexual selection on male traits. Our results suggest that differences in either OSR or density (independent of the number of males present) are unlikely to alter directional evolutionary change in male sexual traits. PMID:18067568

  4. Behavioral evidence for the presence of a sex pheromone in male Phlebotomus papatasi scopoli (Diptera: Psychodidae).

    PubMed

    Chelbi, I; Zhioua, E; Hamilton, J G C

    2011-05-01

    Phlebotomus papatasi (Diptera: Psychodidae) is the Old World sand fly vector of zoonotic cutaneous leishmaniasis caused by Leishmania major (Trypanosomatidae: Kinetoplastida), a debilitating and disfiguring protist parasitic disease prevalent throughout southern Mediterranean countries, the Middle East, as well as southern and eastern European countries, where it is regarded as a serious public health problem. Little is known of the mating ecology of P. papatasi, and, in particular, the role (if any) of pheromones is not known. In this laboratory- and field-based study, we have shown that a male-produced sex pheromone exists in P. papatasi. Young female P. papatasi are attracted to the headspace volatiles of small groups of males, males and females together, but not females alone. Males were not attracted to males, females, or mixed groups of males and females in the laboratory. Larger groups of males or males and females together were repellent in the laboratory study. Field experiments showed that Centers for Disease Control (CDC) light traps baited with small groups of males and females together were attractive to females, but not males. CDC traps baited with large groups of males and females together caught significantly fewer females and males than the control traps; however, the proportion of females caught compared with males overall was much higher than with CDC traps baited with small numbers of males and females. These results suggest that females may be attracted in preference to males to the vicinity of the baited traps and are highly sensitive to the concentration of male pheromone. It also suggests that P. papatasi mating behavior is fundamentally different from that of Lutzomyia longipalpis, where large mating aggregations of males and females occur. PMID:21661311

  5. Male Sex Workers: Practices, Contexts, and Vulnerabilities for HIV acquisition and transmission

    PubMed Central

    Baral, Stefan David; Friedman, M. Reuel; Geibel, Scott; Rebe, Kevin; Bozhinov, Borche; Diouf, Daouda; Sabin, Keith; Holland, Claire E.; Chan, Roy; Caceres, Carlos

    2015-01-01

    Summary Male sex workers (MSW) who sell/exchange sex for money or goods comprise an extremely diverse population across and within countries worldwide. Information characterizing their practices, contexts where they live, and their needs is very limited, as these men are generally included as subsets of larger studies focused on gay men and other men who have sex with men (MSM) or even female sex workers. MSW, regardless of their sexual orientation, mostly offer sex to men, and rarely identify as sex workers, using local or international terms instead. There is growing evidence of a sustained or increasing burden of HIV among some MSW in the context of the slowing global HIV pandemic. There are several synergistic facilitator spotentiating HIV acquisition and transmission among MSW, including biological, behavioural, and structural determinants. The criminalization and intersectional stigmas of same-sex practices, commercial sex, and HIV all increase HIV and STI risk for MSW and decrease their likelihood of accessing essential services. These contexts, taken together with complex sexual networks among MSW, define them as a key population underserved by current HIV prevention, treatment, and care services. Dedicated efforts are needed to make those services available for the sake of both public health and human rights. PMID:25059939

  6. Strategies for recruiting steady male partners of female sex workers for HIV research

    PubMed Central

    Fleming, Paul J.; Barrington, Clare; Perez, Martha; Donastorg, Yeycy; Kerrigan, Deanna

    2014-01-01

    Steady male partners of female sex workers (FSW) are a key population for HIV prevention, but researchers face challenges finding and recruiting this population. We conducted forty in-depth interviews with FSW and steady male partners of FSW in Santo Domingo, Dominican Republic about how to engage steady male partners in HIV research. Participants cautioned that male partners might be unwilling to participate because of discomfort disclosing intimate information and cultural norms of masculinity. They recommended inviting male partners to research offices, instead of venue-based recruitment, because it was more private and trust-promoting. Most participants suggested that FSW could refer their partners or men could refer their friends who have FSW partners. Participants emphasized that referrals could break down trust-related barriers that prevent male partners from participating. Establishing an environment of respect and trust in the research setting can aid referral processes as individuals who participate communicate their positive experiences to their networks. PMID:25192901

  7. The Sex Determination Gene transformer Regulates Male-Female Differences in Drosophila Body Size.

    PubMed

    Rideout, Elizabeth J; Narsaiya, Marcus S; Grewal, Savraj S

    2015-12-01

    Almost all animals show sex differences in body size. For example, in Drosophila, females are larger than males. Although Drosophila is widely used as a model to study growth, the mechanisms underlying this male-female difference in size remain unclear. Here, we describe a novel role for the sex determination gene transformer (tra) in promoting female body growth. Normally, Tra is expressed only in females. We find that loss of Tra in female larvae decreases body size, while ectopic Tra expression in males increases body size. Although we find that Tra exerts autonomous effects on cell size, we also discovered that Tra expression in the fat body augments female body size in a non cell-autonomous manner. These effects of Tra do not require its only known targets doublesex and fruitless. Instead, Tra expression in the female fat body promotes growth by stimulating the secretion of insulin-like peptides from insulin producing cells in the brain. Our data suggest a model of sex-specific growth in which body size is regulated by a previously unrecognized branch of the sex determination pathway, and identify Tra as a novel link between sex and the conserved insulin signaling pathway.

  8. Aggressive behavior of the male parent predicts brood sex ratio in a songbird

    NASA Astrophysics Data System (ADS)

    Szász, Eszter; Garamszegi, László Zsolt; Hegyi, Gergely; Szöllősi, Eszter; Markó, Gábor; Török, János; Rosivall, Balázs

    2014-08-01

    Brood sex ratio is often affected by parental or environmental quality, presumably in an adaptive manner that is the sex that confers higher fitness benefits to the mother is overproduced. So far, studies on the role of parental quality have focused on parental morphology and attractiveness. However, another aspect, the partner's behavioral characteristics, may also be expected to play a role in brood sex ratio adjustment. To test this hypothesis, we investigated whether the proportion of sons in the brood is predicted by the level of territorial aggression displayed by the father, in the collared flycatcher ( Ficedula albicollis). The proportion of sons in the brood was higher in early broods and increased with paternal tarsus length. When controlling for breeding date and body size, we found a higher proportion of sons in the brood of less aggressive fathers. Male nestlings are more sensitive to the rearing environment, and the behavior of courting males may often be used by females to assess their future parental activity. Therefore, adjusting brood sex ratio to the level of male aggression could be adaptive. Our results indicate that the behavior of the partner could indeed be a significant determinant in brood sex ratio adjustment, which should not be overlooked in future studies.

  9. Male-specific suppression of hepatic microsomal UDP-glucuronosyl transferase activities toward sex hormones in the adult male rat administered bisphenol A.

    PubMed Central

    Shibata, Noriaki; Matsumoto, Junya; Nakada, Ken; Yuasa, Akira; Yokota, Hiroshi

    2002-01-01

    Various adverse effects of endocrine disruptors on the reproductive organs of male animals have been reported. We found that UDP-glucuronosyltransferase (UGT) activities towards bisphenol A, testosterone and oestradiol were significantly decreased in liver microsomes prepared from adult male Wistar rats administered with the endocrine disruptor bisphenol A (1 mg/2 days for 2 or 4 weeks). However, suppression of the transferase activities was not observed in female rats, even after bisphenol A treatment for 4 weeks. Diethylstilbestrol, which is well known as an endocrine disruptor, had the same effects, but p -cumylphenol had no effect on UGT activities towards sex hormones. Co-administration of an anti-oestrogen, tamoxifen, inhibited the suppression of the transferase activities by bisphenol A. Western blotting analysis showed that the amount of UGT2B1, an isoform of UGT which glucuronidates bisphenol A, was decreased in the rat liver microsomes by the treatment. Northern blotting analysis also indicated that UGT2B1 mRNA in the liver was decreased by bisphenol A treatment. The suppression of UGT activities, UGT2B1 protein and UGT2B1 mRNA expression did not occur in female rats. The results indicate that bisphenol A treatment reduces the mRNA expression of UGT2B1 and other UGT isoforms that mediate the glucuronidation of sex hormones in adult male rats, and this suggests that the endocrine balance may be disrupted by suppression of glucuronidation. PMID:12230427

  10. Genetic variation in male effects on female reproduction and the genetic covariance between the sexes.

    PubMed

    Czesak, Mary Ellen; Fox, Charles W

    2003-06-01

    Males of many insect species increase the fecundity and/or egg size of their mates through the amount or composition of their nuptial gifts or ejaculate. The genetic bases of such male effects on fecundity or egg size are generally unknown, and thus their ability to evolve remains speculative. Likewise, the genetic relationship between male and female investment into reproduction in dioecious species, which is expected to be positive if effects on fecundity are controlled by at least some of the same genes in males and females, is also unknown. Males of the seed beetle Stator limbatus contribute large ejaculates to females during mating, and the amount of donated ejaculate is positively correlated with male body mass. Females mated to large males lay more eggs in their lifetime than females mated to small males. We describe an experiment in which we quantify genetic variation in the number of eggs sired by males (mated to a single female) and found that a significant proportion of the phenotypic variance in the number of eggs sired by males was explained by their genotype. Additionally, the number of eggs sired by a male was highly positively genetically correlated with his body mass. The between-sex genetic correlation, that is, the genetic correlation between the number of eggs sired by males and the number of eggs laid by females, was highly positive when eggs were laid on Acacia greggii seeds. This indicates that males that sire many eggs have sisters that lay many eggs. Thus, some of the genes that control male ejaculate size (or some other fecundity-enhancing factor) when expressed in males appear to control fecundity when expressed in females. We found no significant interaction between male and female genotype on fecundity.

  11. Social context, sexual risk perceptions and stigma: HIV vulnerability among male sex workers in Mombasa, Kenya.

    PubMed

    Okal, Jerry; Luchters, Stanley; Geibel, Scott; Chersich, Matthew F; Lango, Daniel; Temmerman, Marleen

    2009-11-01

    Knowledge about sexual practices and life experiences of men having sex with men in Kenya, and indeed in East Africa, is limited. Although the impact of male same-sex HIV transmission in Africa is increasingly acknowledged, HIV prevention initiatives remain focused largely on heterosexual and mother-to-child transmission. Using data from ten in-depth interviews and three focus group discussions (36 men), this analysis explores social and behavioural determinants of sexual risks among men who sell sex to men in Mombasa, Kenya. Analysis showed a range and variation of men by age and social class. First male same-sex experiences occurred for diverse reasons, including love and pleasure, as part of sexual exploration, economic exchange and coercion. Condom use is erratic and subject to common constraints, including notions of sexual interference and motivations of clients. Low knowledge compounds sexual risk taking, with a widespread belief that the risk of HIV transmission through anal sex is lower than vaginal sex. Traditional family values, stereotypes of abnormality, gender norms and cultural and religious influences underlie intense stigma and discrimination. This information is guiding development of peer education programmes and sensitisation of health providers, addressing unmet HIV prevention needs. Such changes are required throughout Eastern Africa.

  12. Social context, sexual risk perceptions and stigma: HIV vulnerability among male sex workers in Mombasa, Kenya.

    PubMed

    Okal, Jerry; Luchters, Stanley; Geibel, Scott; Chersich, Matthew F; Lango, Daniel; Temmerman, Marleen

    2009-11-01

    Knowledge about sexual practices and life experiences of men having sex with men in Kenya, and indeed in East Africa, is limited. Although the impact of male same-sex HIV transmission in Africa is increasingly acknowledged, HIV prevention initiatives remain focused largely on heterosexual and mother-to-child transmission. Using data from ten in-depth interviews and three focus group discussions (36 men), this analysis explores social and behavioural determinants of sexual risks among men who sell sex to men in Mombasa, Kenya. Analysis showed a range and variation of men by age and social class. First male same-sex experiences occurred for diverse reasons, including love and pleasure, as part of sexual exploration, economic exchange and coercion. Condom use is erratic and subject to common constraints, including notions of sexual interference and motivations of clients. Low knowledge compounds sexual risk taking, with a widespread belief that the risk of HIV transmission through anal sex is lower than vaginal sex. Traditional family values, stereotypes of abnormality, gender norms and cultural and religious influences underlie intense stigma and discrimination. This information is guiding development of peer education programmes and sensitisation of health providers, addressing unmet HIV prevention needs. Such changes are required throughout Eastern Africa. PMID:19484638

  13. Male Sex Roles and Epithets for Ethnic Women in American Slang.

    ERIC Educational Resources Information Center

    Allen, Irving Lewis

    1984-01-01

    Research shows that derogatory names used for women of ethnic outgroups (1) are aimed disproportionately at women of racial minorities; (2) stereotype physical differences between ethnic groups; (3) make derogatory sexual allusions, often using food and animal metaphors; and (4) display the strains of traditional male sex roles in ethnic and…

  14. Adolescent and Young Adult Male Sex Offenders: Understanding the Role of Recidivism

    ERIC Educational Resources Information Center

    Riser, Diana K.; Pegram, Sheri E.; Farley, Julee P.

    2013-01-01

    The current review explores the complex paths that can lead to adolescent and young adult males becoming sexually abusive. Because sexual abuse is an ongoing issue in our society that is often oversimplified, this article distinguishes between the various risk factors that predict sexually abusive behavior and types of sex offenders, particularly…

  15. An Examination of the Male Sex Role Model in Prime Time Television Commercials.

    ERIC Educational Resources Information Center

    Meyers, Renee

    Noting that previous research has shown that television content influences attitudes and behavior, a content analysis of 269 television commercials broadcast during prime time was conducted to examine whether male sex role stereotyping existed in the commercials and, if it did, to determine the characteristics of that stereotyping and whether the…

  16. Does Sex (Female versus Male) Influence the Impact of Class Attendance on Examination Performance?

    ERIC Educational Resources Information Center

    Cortright, Ronald N.; Lujan, Heidi L.; Cox, Julie H.; DiCarlo, Stephen E.

    2011-01-01

    The "conventional wisdom" is that grades are related to class attendance, i.e., students who attend classes more frequently obtain better grades and class attendance dramatically contributes to enhanced learning. However, the influence of sex (female vs. male) on this relationship is understudied. Furthermore, there have been several studies…

  17. Assisted reproduction in a cohort of same-sex male couples and single men.

    PubMed

    Grover, Stephanie A; Shmorgun, Ziva; Moskovtsev, Sergey I; Baratz, Ari; Librach, Clifford L

    2013-08-01

    To date, there is limited published data on same-sex male couples and single men using assisted reproduction treatment to build their families. The objective of this retrospective study was to better understand treatment considerations and outcomes for this population when using assisted reproduction treatment. A total of 37 same-sex male couples and eight single men (seven homosexual and one heterosexual) who attended the CReATe Fertility Centre for assisted reproduction services were studied. There was a 21-fold increase in the number of same-sex male couples and single men undergoing assisted reproduction treatment since 2003. The mean age was 46years (24-58). Twenty-eight couples (76%) chose to use spermatozoa from both partners to fertilize their donated oocytes. Most men (32 same-sex male couples and seven single men; 87%) obtained oocytes from an anonymous donor, whereas five couples and one single man (13%) had a known donor. Anonymous donors who were open to be contacted by the child after the age of 18 were selected by 67% of patients. Of all 25 deliveries, eight (32%) were sets of twins. All of the twins were half genetic siblings. PMID:23768615

  18. When Sex Work Becomes Your Everything: The Complex Linkages Between Economy and Affection Among Male Sex Workers in Peru.

    PubMed

    Bayer, Angela M; Garvich, Mijail; Díaz, David A; Sánchez, Hugo; García, Patricia J; Coates, Thomas J

    2014-09-01

    In Peru, there are few studies on male sex workers (MSWs), and existing studies explore limited subgroups or offer limited information about MSWs' perspectives. This study provides in-depth perspectives from 40 MSWs who work in downtown Lima (Cercado) and in surrounding urban neighborhoods (non-Cercado) through interviews on their identities, lives, and HIV/STI (sexually transmitted infection) risks and vulnerabilities. Findings are that entry into sex work links economy and affection, particularly among Cercado MSWs. Continued sex work cements this link, making it difficult to exit sex work and establish goals. Ties between economics and affections influence MSWs' perceived HIV/STI risks, vulnerabilities, and prevention practices. Although Cercado MSWs report higher HIV/STI risks and vulnerabilities than non-Cercado peers, they report fewer prevention practices given inability to buy condoms and acceptance of client offers of higher payment, especially clients they feel affection for. MSWs need support to strengthen their self-perceptions and define and pursue their goals in order to improve their HIV/STI prevention practices, health, and well-being.

  19. When sex work becomes your everything: The complex linkages between economy and affection among male sex workers in Peru

    PubMed Central

    Bayer, Angela M.; Garvich, Mijail; Díaz, David A.; Sánchez, Hugo; García, Patricia J.; Coates, Thomas J.

    2014-01-01

    In Peru, there are few studies on male sex workers (MSWs) and existing studies explore limited sub-groups or offer limited information about MSWs’ perspectives. This study provides in-depth perspectives from 40 MSWs who work in downtown Lima (Cercado) and in surrounding urban neighborhoods (non-Cercado) through interviews on their identities, lives and HIV/STI risks and vulnerabilities. Findings are that entry into sex work links economy and affection, particularly among Cercado MSWs. Continued sex work cements this link, making it difficult to exit sex work and establish goals. Ties between economics and affections influence MSWs’ perceived HIV/STI risks, vulnerabilities and prevention practices. Although Cercado MSWs report higher HIV/STI risks and vulnerabilities than non-Cercado peers, they report fewer prevention practices given inability to buy condoms and acceptance of client offers of higher payment, especially clients they feel affection for. MSWs need support to strengthen their self-perceptions and define and pursue their goals in order to improve their HIV/STI prevention practices, health and well-being. PMID:24368712

  20. The role of sexually explicit material in the sexual development of same-sex-attracted Black adolescent males.

    PubMed

    Arrington-Sanders, Renata; Harper, Gary W; Morgan, Anthony; Ogunbajo, Adedotun; Trent, Maria; Fortenberry, J Dennis

    2015-04-01

    Sexually explicit material (SEM) (including Internet, video, and print) may play a key role in the lives of Black same-sex sexually active youth by providing the only information to learn about sexual development. There is limited school- and/or family-based sex education to serve as models for sexual behaviors for Black youth. We describe the role SEM plays in the sexual development of a sample of Black same-sex attracted (SSA) young adolescent males ages 15-19. Adolescents recruited from clinics, social networking sites, and through snowball sampling were invited to participate in a 90-min, semi-structured qualitative interview. Most participants described using SEM prior to their first same-sex sexual experience. Participants described using SEM primarily for sexual development, including learning about sexual organs and function, the mechanics of same-gender sex, and to negotiate one's sexual identity. Secondary functions were to determine readiness for sex; to learn about sexual performance, including understanding sexual roles and responsibilities (e.g., "top" or "bottom"); to introduce sexual performance scripts; and to develop models for how sex should feel (e.g., pleasure and pain). Youth also described engaging in sexual behaviors (including condom non-use and/or swallowing ejaculate) that were modeled on SEM. Comprehensive sexuality education programs should be designed to address the unmet needs of young, Black SSA men, with explicit focus on sexual roles and behaviors that may be inaccurately portrayed and/or involve sexual risk-taking (such as unprotected anal intercourse and swallowing ejaculate) in SEM. This work also calls for development of Internet-based HIV/STI prevention strategies targeting young Black SSA men who may be accessing SEM.

  1. The role of sexually explicit material in the sexual development of same-sex-attracted Black adolescent males.

    PubMed

    Arrington-Sanders, Renata; Harper, Gary W; Morgan, Anthony; Ogunbajo, Adedotun; Trent, Maria; Fortenberry, J Dennis

    2015-04-01

    Sexually explicit material (SEM) (including Internet, video, and print) may play a key role in the lives of Black same-sex sexually active youth by providing the only information to learn about sexual development. There is limited school- and/or family-based sex education to serve as models for sexual behaviors for Black youth. We describe the role SEM plays in the sexual development of a sample of Black same-sex attracted (SSA) young adolescent males ages 15-19. Adolescents recruited from clinics, social networking sites, and through snowball sampling were invited to participate in a 90-min, semi-structured qualitative interview. Most participants described using SEM prior to their first same-sex sexual experience. Participants described using SEM primarily for sexual development, including learning about sexual organs and function, the mechanics of same-gender sex, and to negotiate one's sexual identity. Secondary functions were to determine readiness for sex; to learn about sexual performance, including understanding sexual roles and responsibilities (e.g., "top" or "bottom"); to introduce sexual performance scripts; and to develop models for how sex should feel (e.g., pleasure and pain). Youth also described engaging in sexual behaviors (including condom non-use and/or swallowing ejaculate) that were modeled on SEM. Comprehensive sexuality education programs should be designed to address the unmet needs of young, Black SSA men, with explicit focus on sexual roles and behaviors that may be inaccurately portrayed and/or involve sexual risk-taking (such as unprotected anal intercourse and swallowing ejaculate) in SEM. This work also calls for development of Internet-based HIV/STI prevention strategies targeting young Black SSA men who may be accessing SEM. PMID:25677334

  2. Sex ratio shift in offspring of male fixed-wing naval aviation officers.

    PubMed

    Baczuk, Rebecca; Biascan, Anthony; Grossgold, Erik; Isaacson, Ari; Spencer, Joel; Wisotzky, Eric

    2009-05-01

    The concept that aviators father more daughters than sons is a persistent rumor within aviation circles. This study was designed to determine the sex ratio among offspring of male fixed-wing naval aviation officers and to look for associations between sex ratio, flight hours, and mission. Through an online questionnaire, we asked for gender and date of birth of the child, monthly flying hours during the 4 months before conception, and the type of aircraft flown. Analysis revealed that the sex ratio of offspring from all participants in our study was not statistically significantly different from the general population. However, a significant sex ratio shift favoring daughters existed as the officer flew more hours during the 11th month before birth. As the implications of this are unknown, officers should be counseled that their chance of having a son or daughter is no different than the general population.

  3. The dermatoglyphic characteristics of transsexuals: is there evidence for an organizing effect of sex hormones.

    PubMed

    Slabbekoorn, D; van Goozen, S H; Sanders, G; Gooren, L J; Cohen-Kettenis, P T

    2000-05-01

    It has been proposed that gender identity and sexual orientation are influenced by the prenatal sex steroid milieu. Human dermatoglyphics and brain asymmetry have also been ascribed to prenatal hormone levels. This study investigated dermatoglyphics (total ridge count and finger ridge asymmetry) in 184 male-to-female transsexuals and 110 female-to-male transsexuals. In a subgroup, the relationship between dermatoglyphic asymmetry and spatial ability was tested. All investigations included controls. For all subjects hand preference and sexual orientation were noted. We hypothesized that the dermatoglyphics of male-to-female transsexuals would show similarities with control women and those of female-to-male transsexuals with control men. Our results showed a trend for a sex difference in total ridge count (P<.1) between genetic males and females, but no difference in directional asymmetry was found. Contrary to our expectations, the total ridge count and finger ridge asymmetry of transsexuals were similar to their genetic sex controls. Additionally, directional asymmetry was neither related to sexual orientation, nor to different aspects of spatial ability. In conclusion, we were unable to demonstrate that our chosen dermatoglyphic variables, total ridge count and finger ridge asymmetry are related to gender identity and sexual orientation in adult transsexuals. Hence, we found no support for a prenatal hormonal influence on these characteristics, at least insofar as dermatoglyphics may be regarded as a biological marker of organizing hormonal effects.

  4. Stigma, social inequality, and HIV risk disclosure among Dominican male sex workers☆

    PubMed Central

    Padilla, Mark; Castellanos, Daniel; Guilamo-Ramos, Vincent; Reyes, Armando Matiz; Sánchez Marte, Leonardo E.; Soriano, Martha Arredondo

    2010-01-01

    Some quantitative behavioral studies in the USA have concluded that bisexually behaving Latino men are less likely than White men to disclose to their female partners that they have engaged in same-sex risk behavior and/or are HIV-positive, presumably exposing female partners to elevated risk for HIV infection. Nevertheless, very little theoretical or empirical research has been conducted to understand the social factors that promote or inhibit sexual risk disclosure among Latino men who have sex with men (MSM), and much of the existing literature has neglected to contextualize disclosure patterns within broader experiences of stigma and social inequality. This paper examines decisions about disclosure of sex work, same-sex behavior, and sexual risk for HIV among male sex workers in two cities in the Dominican Republic. Data derive from long-term ethnography and qualitative in-depth interviews with 72 male sex workers were used to analyze the relationships among experiences of stigma, social inequality, and patterns of sexual risk disclosure. Thematic analysis of interviews and ethnographic evidence revealed a wide range of stigma management techniques utilized by sex workers to minimize the effects of marginality due to their engagement in homosexuality and sex work. These techniques imposed severe constraints on men’s sexual risk disclosure, and potentially elevated their own and their female partners’ vulnerability to HIV infection. Based on the study’s findings, we conclude that future studies of sexual risk disclosure among ethnic minority MSM should avoid analyzing disclosure as a decontextualized variable, and should seek to examine sexual risk communication as a dynamic social process constrained by hierarchical systems of power and inequality. PMID:18410986

  5. Developmental effects of an environmental antiandrogen: the fungicide vinclozolin alters sex differentiation of the male rat.

    PubMed

    Gray, L E; Ostby, J S; Kelce, W R

    1994-11-01

    In humans and rodents, exposure to hormonally active chemicals during sex differentiation can produce a wide range of abnormal sexual phenotypes including masculinized and defeminized females and feminized and demasculinized males. Although numerous "environmental estrogens," including pesticides, toxic substances (PCBs), and plant and fungal estrogens, have been shown to alter mammalian sex differentiation, similar information on environmental androgens is lacking. Recently, the fungicide vinclozolin (V) was found to inhibit sexual differentiation in male rats in an antiandrogenic manner. In the present study, V was administered to pregnant rats (p.o.) at 0, 100, or 200 mg/kg/day in corn oil during the period of sex differentiation (Gestational Day 14 to Postnatal Day 3) to examine the demasculinizing effect of this fungicide more closely. In both groups of V-treated male offspring, anogenital distance was female like at birth, and nipple development was prominent at 2 weeks of age. After puberty, most of the V-treated male offspring were unable to attain intromission even though they all mounted sexually receptive females. The V-treated male offspring that appeared to achieve intromission, failed to ejaculate normally, as no sperm were found in the uterus after overnight matings. A factor in the abnormal ejaculation was that all V-treated male offspring had cleft phallus with hypospadias. In addition, a number of unusual reproductive malformations were noted when the males were necropsied at 1 year. Many V-treated male offspring had suprainguinal ectopic scrota/testes, a vaginal pouch, epididymal granulomas, and small to absent sex accessory glands. During the study, about 25% of the V-treated males died as a result of bladder stones, hydroureter, or hydronephrosis, while other males displayed these lesions at necropsy. While some of the above malformations in male offspring can also be produced by perinatal administration of a potent estrogen, like DES, V

  6. The Influence of the Status and Sex Composition of Occupations on the Male-Female Earnings Gap

    ERIC Educational Resources Information Center

    Gunderson, Morley

    1978-01-01

    Reports a study of alternative theories of sex discrimination which imply ambiguous predictions about the relation between the male/female earnings ratio and the status and sex composition of the occupation. Notes that about one-half of the earnings gap between the sexes can be attributed to direct discrimination in the labor market, with…

  7. Androgens regulate sex differences in signaling but are not associated with male variation in morphology in the weakly electric fish Parapteronotus hasemani.

    PubMed

    Petzold, Jacquelyn M; Smith, G Troy

    2016-02-01

    Sexually dimorphic signaling is widespread among animals and can act as an honest indicator of mate quality. Additionally, differences in signaling and morphology within a sex can be associated with different strategies for acquiring mates. Weakly electric fish communicate via self-generated electrical fields that transmit information about sex, reproductive state, and social status. The weakly electric knifefish Parapteronotus hasemani exhibits sexual dimorphism in body size as well as substantial within-male variation in body size and jaw length. We asked whether P. hasemani exhibits hormonally mediated sexual dimorphism in electrocommunication behavior. We also asked whether males with short versus long jaws differed significantly from each other in morphology, behavior, hormone levels, or reproductive maturity. Males produced longer chirps than females, but other signal parameters (electric organ discharge frequency; chirp rate and frequency modulation) were sexually monomorphic. Pharmacologically blocking androgen receptors in males reduced chirp duration, suggesting that this sexually dimorphic trait is regulated at least in part by the activational effects of androgens. Males sorted into two distinct morphological categories but did not differ in circulating 11-ketotestosterone or testosterone. Short-jawed males and long-jawed males also did not differ in any aspects of signaling. Thus, chirping and high levels of 11-ketotestosterone were reliably associated with reproductively active males but do not necessarily indicate male type or quality. This contrasts with other alternative male morph systems in which males that differ in morphology also differ in androgen profiles and signaling behavior.

  8. Androgens regulate sex differences in signaling but are not associated with male variation in morphology in the weakly electric fish Parapteronotus hasemani.

    PubMed

    Petzold, Jacquelyn M; Smith, G Troy

    2016-02-01

    Sexually dimorphic signaling is widespread among animals and can act as an honest indicator of mate quality. Additionally, differences in signaling and morphology within a sex can be associated with different strategies for acquiring mates. Weakly electric fish communicate via self-generated electrical fields that transmit information about sex, reproductive state, and social status. The weakly electric knifefish Parapteronotus hasemani exhibits sexual dimorphism in body size as well as substantial within-male variation in body size and jaw length. We asked whether P. hasemani exhibits hormonally mediated sexual dimorphism in electrocommunication behavior. We also asked whether males with short versus long jaws differed significantly from each other in morphology, behavior, hormone levels, or reproductive maturity. Males produced longer chirps than females, but other signal parameters (electric organ discharge frequency; chirp rate and frequency modulation) were sexually monomorphic. Pharmacologically blocking androgen receptors in males reduced chirp duration, suggesting that this sexually dimorphic trait is regulated at least in part by the activational effects of androgens. Males sorted into two distinct morphological categories but did not differ in circulating 11-ketotestosterone or testosterone. Short-jawed males and long-jawed males also did not differ in any aspects of signaling. Thus, chirping and high levels of 11-ketotestosterone were reliably associated with reproductively active males but do not necessarily indicate male type or quality. This contrasts with other alternative male morph systems in which males that differ in morphology also differ in androgen profiles and signaling behavior. PMID:26518663

  9. SEX DETERMINATION. A male-determining factor in the mosquito Aedes aegypti.

    PubMed

    Hall, Andrew Brantley; Basu, Sanjay; Jiang, Xiaofang; Qi, Yumin; Timoshevskiy, Vladimir A; Biedler, James K; Sharakhova, Maria V; Elahi, Rubayet; Anderson, Michelle A E; Chen, Xiao-Guang; Sharakhov, Igor V; Adelman, Zach N; Tu, Zhijian

    2015-06-12

    Sex determination in the mosquito Aedes aegypti is governed by a dominant male-determining factor (M factor) located within a Y chromosome-like region called the M locus. Here, we show that an M-locus gene, Nix, functions as an M factor in A. aegypti. Nix exhibits persistent M linkage and early embryonic expression, two characteristics required of an M factor. Nix knockout with clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 resulted in largely feminized genetic males and the production of female isoforms of two key regulators of sexual differentiation: doublesex and fruitless. Ectopic expression of Nix resulted in genetic females with nearly complete male genitalia. Thus, Nix is both required and sufficient to initiate male development. This study provides a foundation for mosquito control strategies that convert female mosquitoes into harmless males. PMID:25999371

  10. Stigma in Male Depression and Suicide: A Canadian Sex Comparison Study.

    PubMed

    Oliffe, John L; Ogrodniczuk, John S; Gordon, Susan J; Creighton, Genevieve; Kelly, Mary T; Black, Nick; Mackenzie, Corey

    2016-04-01

    Stigma in men's depression and suicide can restrict help-seeking, reduce treatment compliance and deter individuals from confiding in friends and family. In this article we report sex comparison findings from a national survey of English-speaking adult Canadians about stigmatized beliefs concerning male depression and suicide. Among respondents without direct experience of depression or suicide (n = 541) more than a third endorsed the view that men with depression are unpredictable. Overall, a greater proportion of males endorsed stigmatizing views about male depression compared to female respondents. A greater proportion of female respondents endorsed items indicating that men who suicide are disconnected, lost and lonely. Male and female respondents with direct personal experience of depression or suicide (n = 360) strongly endorsed stigmatizing attitudes toward themselves and a greater proportion of male respondents indicated that they would be embarrassed about seeking help for depression. PMID:26733336

  11. Male-to-female transsexuals show sex-atypical hypothalamus activation when smelling odorous steroids.

    PubMed

    Berglund, H; Lindström, P; Dhejne-Helmy, C; Savic, I

    2008-08-01

    One working hypothesis behind transsexuality is that the normal sex differentiation of certain hypothalamic networks is altered. We tested this hypothesis by investigating the pattern of cerebral activation in 12 nonhomosexual male-to-female transsexuals (MFTRs) when smelling 4,16-androstadien-3-one (AND) and estra-1,3,5(10),16-tetraen-3-ol (EST). These steroids are reported to activate the hypothalamic networks in a sex-differentiated way. Like in female controls the hypothalamus in MFTRs activated with AND, whereas smelling of EST engaged the amygdala and piriform cortex. Male controls, on the other hand, activated the hypothalamus with EST. However, when restricting the volume of interest to the hypothalamus activation was detected in MFTR also with EST, and explorative conjunctional analysis revealed that MFTR shared a hypothalamic cluster with women when smelling AND, and with men when smelling EST. Because the EST effect was limited, MFTR differed significantly only from male controls, and only for EST-AIR and EST-AND. These data suggest a pattern of activation away from the biological sex, occupying an intermediate position with predominantly female-like features. Because our MFTRs were nonhomosexual, the results are unlikely to be an effect of sexual practice. Instead, the data implicate that transsexuality may be associated with sex-atypical physiological responses in specific hypothalamic circuits, possibly as a consequence of a variant neuronal differentiation.

  12. Do acoustic features of lion, Panthera leo, roars reflect sex and male condition?

    PubMed

    Pfefferle, Dana; West, Peyton M; Grinnell, Jon; Packer, Craig; Fischer, Julia

    2007-06-01

    Long distance calls function to regulate intergroup spacing, attract mating partners, and/or repel competitors. Therefore, they may not only provide information about the sex (if both sexes are calling) but also about the condition of the caller. This paper provides a description of the acoustic features of roars recorded from 18 male and 6 female lions (Panthera leo) living in the Serengeti National park, Tanzania. After analyzing whether these roars differ between the sexes, tests whether male roars may function as indicators of their fighting ability or condition were conducted. Therefore, call characteristics were tested for relation to anatomical features as size, mane color, or mane length. Call characteristics included acoustic parameters that previously had been implied as indicators of size and fighting ability, e.g., call length, fundamental frequency, and peak frequency. The analysis revealed differences in relation to sex, which were entirely explained by variation in body size. No evidence that acoustic variables were related to male condition was found, indicating that sexual selection might only be a weak force modulating the lion's roar. Instead, lion roars may have mainly been selected to effectively advertise territorial boundaries.

  13. Effects of male sex hormones on gender identity, sexual behavior, and cognitive function.

    PubMed

    Zhu, Yuan-shan; Cai, Li-qun

    2006-04-01

    Androgens, the male sex hormones, play an essential role in male sexual differentiation and development. However, the influence of these sex hormones extends beyond their roles in sexual differentiation and development. In many animal species, sex hormones have been shown to be essential for sexual differentiation of the brain during development and for maintaining sexually dimorphic behavior throughout life. The principals of sex determination in humans have been demonstrated to be similar to other mammals. However, the hormonal influence on sexual dimorphic differences in the nervous system in humans, sex differences in behaviors, and its correlations with those of other mammals is still an emerging field. In this review, the roles of androgens in gender and cognitive function are discussed with the emphasis on subjects with androgen action defects including complete androgen insensitivity due to androgen receptor mutations and 5alpha-reductase-2 deficiency syndromes due to 5alpha-reductase-2 gene mutations. The issue of the complex interaction of nature versus nurture is addressed. PMID:16706106

  14. [Electrophysiological and behavioral responses of male Apamea apameoides (Draudt) (Lepidoptera: Noctuidae) to sex pheromone components].

    PubMed

    Zhang, Ai-Liang; Zhou, Zhang-Ting; Zhang, Ya-Bo; Zhou, Zhi-Feng; Shen, Zhi-Lian; Wang, Hao-Jie; Shu, Jin-Ping

    2014-10-01

    The sex pheromone gland extracts collected from calling females of Apamea apameoides (Lepidoptera: Noctuidae) were analyzed with GC-MS, the electrophysiological and behavioral responses of the male adults to serial dilutions of sex pheromone components and their synthetic blends were investigated with Y-tube olfactometer in laboratory and in bamboo forest field. The results indicated that (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol were the functional components in the sex pheromone gland extracts. Electroantennogram (EAG) recordings showed that sex pheromone gland extracts, (Z)-11-hexadecenyl acetate, (Z)-11-hexadecen-1-ol and the mixture of (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol all could elicit strong EAG responses, and the average EAG values increased with the increasing concentration of the sex pheromone. The blends of (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol at the ratio of 57:43 elicited a higher EAG value than each singular component did. The results of behavioral assay by Y-tube olfactometer accorded with those of EAG responses on the whole, and the mixture of (Z)-11-hexadecenyl acetate and (Z)-11-hexadecen-1-ol at the ratio of 57:43 was more attractive than each component alone. In field tests with silicone rubber as pheromone dispensers (concentration = 10(4) ng · uL(-1)), the average number of male adults captured per trap by the mixture was (48.5 ± 6.7). PMID:25796914

  15. Sex disparity in colonic adenomagenesis involves promotion by male hormones, not protection by female hormones

    PubMed Central

    Amos-Landgraf, James M.; Heijmans, Jarom; Wielenga, Mattheus C. B.; Dunkin, Elisa; Krentz, Kathy J.; Clipson, Linda; Ederveen, Antwan G.; Groothuis, Patrick G.; Mosselman, Sietse; Muncan, Vanesa; Hommes, Daniel W.; Shedlovsky, Alexandra; Dove, William F.; van den Brink, Gijs R.

    2014-01-01

    It recently has been recognized that men develop colonic adenomas and carcinomas at an earlier age and at a higher rate than women. In the ApcPirc/+ (Pirc) rat model of early colonic cancer, this sex susceptibility was recapitulated, with male Pirc rats developing twice as many adenomas as females. Analysis of large datasets revealed that the ApcMin/+ mouse also shows enhanced male susceptibility to adenomagenesis, but only in the colon. In addition, WT mice treated with injections of the carcinogen azoxymethane (AOM) showed increased numbers of colonic adenomas in males. The mechanism underlying these observations was investigated by manipulation of hormonal status. The preponderance of colonic adenomas in the Pirc rat model allowed a statistically significant investigation in vivo of the mechanism of sex hormone action on the development of colonic adenomas. Females depleted of endogenous hormones by ovariectomy did not exhibit a change in prevalence of adenomas, nor was any effect observed with replacement of one or a combination of female hormones. In contrast, depletion of male hormones by orchidectomy (castration) markedly protected the Pirc rat from adenoma development, whereas supplementation with testosterone reversed that effect. These observations were recapitulated in the AOM mouse model. Androgen receptor was undetectable in the colon or adenomas, making it likely that testosterone acts indirectly on the tumor lineage. Our findings suggest that indirect tumor-promoting effects of testosterone likely explain the disparity between the sexes in the development of colonic adenomas. PMID:25368192

  16. Experience-independent sex differences in newborn macaques: Females are more social than males

    PubMed Central

    Simpson, Elizabeth A.; Nicolini, Ylenia; Shetler, Melissa; Suomi, Stephen J.; Ferrari, Pier F.; Paukner, Annika

    2016-01-01

    Human females exhibit greater social interest and skills relative to males, appearing in infancy, suggesting biological roots; however, male and female infants may be treated differently, potentially causing or amplifying sex differences. Here, we tested whether sex differences in social motivation emerge in infant monkeys (n = 48) reared in a controlled postnatal environment. Compared to males, females at 2–3 weeks looked more at conspecifics’ faces (d = 0.65), especially the eyes (d = 1.09), and at 4–5 weeks exhibited more affiliative behaviors (d = 0.64), including gesturing, looking, and proximity to familiar and unfamiliar human caretakers. In sum, converging evidence from humans and monkeys suggests that female infants are more social than males in the first weeks of life, and that such differences may arise independent of postnatal experience. Individual differences in social interest have wide-ranging developmental consequences, impacting infants’ social interaction quality and opportunities for learning. Understanding the evolution of sex differences and their developmental emergence is necessary to best support infants with varying levels of sociality. PMID:26794858

  17. Hombre Seguro (Safe Men): a sexual risk reduction intervention for male clients of female sex workers

    PubMed Central

    2014-01-01

    Background Male clients of female sex workers (FSWs) are at risk of HIV and other sexually transmitted infections (STIs). We conducted a two-arm randomized controlled trial to test the efficacy of a sexual risk reduction intervention for male clients of FSWs in Tijuana, Mexico. Methods/Design Male clients of FSWs who were at least 18, were HIV-negative at baseline, and reported recent unprotected sex with FSWs were randomized to the Hombre Seguro sexual risk reduction intervention, or a time-attention didactic control condition. Each condition lasted approximately one hour. Participants underwent interviewer-administered surveys and testing for HIV and other STIs at baseline, and at 4, 8, and 12 month follow-ups. Combined HIV/STI incidence and unprotected vaginal and anal sex acts with FSWs were the primary outcomes. Discussion A total of 400 participants were randomized to one of the two conditions. Analyses indicated that randomization was successful; there were no significant differences between the participants in the two conditions at baseline. Average follow-up was 84% across both conditions. This is the first study to test the efficacy of a sexual risk reduction intervention for male clients of FSWs using the rigor of a randomized controlled trial. Trial registration NCT01280838, Date of registration: January 19, 2011. PMID:24885949

  18. Risk factors for HIV and syphilis infection among male sex workers who have sex with men: a cross-sectional study in Hangzhou, China, 2011

    PubMed Central

    Luo, Yan; Zhu, Chunyan; Chen, Shuchang; Geng, Qingshan; Fu, Rong; Li, Xiting; Xu, Ke; Cheng, Jie; Ding, Jianming

    2015-01-01

    Objective To investigate the prevalence and risk factors of HIV and syphilis infection among men who have sex with men (MSM) in male sex workers (MSW). Design Cross-sectional survey. Setting Hangzhou, China. Participants 259 MSW in MSM were recruited by respondent-driven sampling from May 2011 to December 2011.The inclusion criteria were: (1) age ≥18 years; (2) engaging in sex with men in the previous year and (3) willing to cooperate in the implementation of the study. Outcome measures HIV-related knowledge, high-risk behaviour and condom use. Results Among these MSW in MSM, 23.2% were infected with HIV and/or syphilis, 8.9% were infected only with HIV, 12.7% only with syphilis and 1.5% with HIV/syphilis co-infection; 96.6% sold sex to males, 8.9% bought sex from males and 15.4% sold sex to females; 49.0% had non-commercial sex behaviours with males and 24.3% with females. The rate of condom use while having commercial sex with clients was 86.9% and 53.3% (selling anal and oral sex to males, respectively), 95.5% (buying sex from males) and 77.5% (selling sex to females), respectively. Regarding their non-commercial sex behaviour, the rate of condom use was 77.2% (with males) and 49.2% (with females), respectively. Multivariate analysis showed that age >30 years (OR 1.055; 95% CIs 1.015 to 1.095) and having ≥10 non-commercial male sex partners (OR, 1.573; 95% CI 1.018 to 2.452) were significantly associated with HIV/syphilis infection, while heterosexuality (OR, 0.238; 95% CI 0.066 to 0.855) was significantly associated with a low HIV/syphilis infection rate. Conclusions The MSW in MSM population in Hangzhou has a high prevalence of HIV/syphilis infection, poor perceived risks of HIV and more engagement in unsafe sex with its clients and partners, in addition to a low rate of condom use. These risk factors may account for their relatively high infection rate of HIV/syphilis. PMID:25922096

  19. HIV and STI Prevalence and Risk Factors Among Male Sex Workers and Other Men Who Have Sex With Men in Nairobi, Kenya

    PubMed Central

    Muraguri, Nicholas; Tun, Waimar; Okal, Jerry; Broz, Dita; Raymond, H. Fisher; Kellogg, Timothy; Dadabhai, Sufia; Musyoki, Helgar; Sheehy, Meredith; Kuria, David; Kaiser, Reinhard; Geibel, Scott

    2016-01-01

    Previous surveys of men who have sex with men (MSM) in Africa have not adequately profiled HIV status and risk factors by sex work status. MSM in Nairobi, Kenya, were recruited using respondent-driven sampling, completed a behavioral interview, and were tested for HIV and sexually transmitted infections. Overlapping recruitment among 273 male sex workers and 290 other MSM was common. Sex workers were more likely to report receptive anal sex with multiple partners (65.7% versus 18.0%, P < 0.001) and unprotected receptive anal intercourse (40.0% versus 22.8%, P = 0.005). Male sex workers were also more likely to be HIV infected (26.3% versus 12.2%, P = 0.007). PMID:25501346

  20. Cisgender male and transgender female sex workers in South Africa: gender variant identities and narratives of exclusion.

    PubMed

    Samudzi, Zoe; Mannell, Jenevieve

    2016-01-01

    Sex workers are often perceived as possessing 'deviant' identities, contributing to their exclusion from health services. The literature on sex worker identities in relation to health has focused primarily on cisgender female sex workers as the 'carriers of disease', obscuring the experiences of cisgender male and transgender sex workers and the complexities their gender identities bring to understandings of stigma and exclusion. To address this gap, this study draws on 21 interviews with cisgender male and transgender female sex workers receiving services from the Sex Workers Education and Advocacy Taskforce in Cape Town, South Africa. Our findings suggest that the social identities imposed upon sex workers contribute to their exclusion from public, private, discursive and geographic spaces. While many transgender female sex workers described their identities using positive and empowered language, cisgender male sex workers frequently expressed shame and internalised stigma related to identities, which could be described as 'less than masculine'. While many of those interviewed felt empowered by positive identities as transgender women, sex workers and sex worker-advocates, disempowerment and vulnerability were also linked to inappropriately masculinised and feminised identities. Understanding the links between gender identities and social exclusion is crucial to creating effective health interventions for both cisgender men and transgender women in sex work. PMID:26242843

  1. Cisgender male and transgender female sex workers in South Africa: gender variant identities and narratives of exclusion.

    PubMed

    Samudzi, Zoe; Mannell, Jenevieve

    2016-01-01

    Sex workers are often perceived as possessing 'deviant' identities, contributing to their exclusion from health services. The literature on sex worker identities in relation to health has focused primarily on cisgender female sex workers as the 'carriers of disease', obscuring the experiences of cisgender male and transgender sex workers and the complexities their gender identities bring to understandings of stigma and exclusion. To address this gap, this study draws on 21 interviews with cisgender male and transgender female sex workers receiving services from the Sex Workers Education and Advocacy Taskforce in Cape Town, South Africa. Our findings suggest that the social identities imposed upon sex workers contribute to their exclusion from public, private, discursive and geographic spaces. While many transgender female sex workers described their identities using positive and empowered language, cisgender male sex workers frequently expressed shame and internalised stigma related to identities, which could be described as 'less than masculine'. While many of those interviewed felt empowered by positive identities as transgender women, sex workers and sex worker-advocates, disempowerment and vulnerability were also linked to inappropriately masculinised and feminised identities. Understanding the links between gender identities and social exclusion is crucial to creating effective health interventions for both cisgender men and transgender women in sex work.

  2. Quantitative Trait Locus Analysis of Mating Behavior and Male Sex Pheromones in Nasonia Wasps

    PubMed Central

    Diao, Wenwen; Mousset, Mathilde; Horsburgh, Gavin J.; Vermeulen, Cornelis J.; Johannes, Frank; van de Zande, Louis; Ritchie, Michael G.; Schmitt, Thomas; Beukeboom, Leo W.

    2016-01-01

    A major focus in speciation genetics is to identify the chromosomal regions and genes that reduce hybridization and gene flow. We investigated the genetic architecture of mating behavior in the parasitoid wasp species pair Nasonia giraulti and Nasonia oneida that exhibit strong prezygotic isolation. Behavioral analysis showed that N. oneida females had consistently higher latency times, and broke off the mating sequence more often in the mounting stage when confronted with N. giraulti males compared with males of their own species. N. oneida males produce a lower quantity of the long-range male sex pheromone (4R,5S)-5-hydroxy-4-decanolide (RS-HDL). Crosses between the two species yielded hybrid males with various pheromone quantities, and these males were used in mating trials with females of either species to measure female mate discrimination rates. A quantitative trait locus (QTL) analysis involving 475 recombinant hybrid males (F2), 2148 reciprocally backcrossed females (F3), and a linkage map of 52 equally spaced neutral single nucleotide polymorphism (SNP) markers plus SNPs in 40 candidate mating behavior genes revealed four QTL for male pheromone amount, depending on partner species. Our results demonstrate that the RS-HDL pheromone plays a role in the mating system of N. giraulti and N. oneida, but also that additional communication cues are involved in mate choice. No QTL were found for female mate discrimination, which points at a polygenic architecture of female choice with strong environmental influences. PMID:27172207

  3. Quantitative Trait Locus Analysis of Mating Behavior and Male Sex Pheromones in Nasonia Wasps.

    PubMed

    Diao, Wenwen; Mousset, Mathilde; Horsburgh, Gavin J; Vermeulen, Cornelis J; Johannes, Frank; van de Zande, Louis; Ritchie, Michael G; Schmitt, Thomas; Beukeboom, Leo W

    2016-01-01

    A major focus in speciation genetics is to identify the chromosomal regions and genes that reduce hybridization and gene flow. We investigated the genetic architecture of mating behavior in the parasitoid wasp species pair Nasonia giraulti and Nasonia oneida that exhibit strong prezygotic isolation. Behavioral analysis showed that N. oneida females had consistently higher latency times, and broke off the mating sequence more often in the mounting stage when confronted with N. giraulti males compared with males of their own species. N. oneida males produce a lower quantity of the long-range male sex pheromone (4R,5S)-5-hydroxy-4-decanolide (RS-HDL). Crosses between the two species yielded hybrid males with various pheromone quantities, and these males were used in mating trials with females of either species to measure female mate discrimination rates. A quantitative trait locus (QTL) analysis involving 475 recombinant hybrid males (F2), 2148 reciprocally backcrossed females (F3), and a linkage map of 52 equally spaced neutral single nucleotide polymorphism (SNP) markers plus SNPs in 40 candidate mating behavior genes revealed four QTL for male pheromone amount, depending on partner species. Our results demonstrate that the RS-HDL pheromone plays a role in the mating system of N. giraulti and N. oneida, but also that additional communication cues are involved in mate choice. No QTL were found for female mate discrimination, which points at a polygenic architecture of female choice with strong environmental influences. PMID:27172207

  4. Sex differences in orbitofrontal connectivity in male and female veterans with TBI.

    PubMed

    McGlade, Erin; Rogowska, Jadwiga; Yurgelun-Todd, Deborah

    2015-09-01

    More female soldiers are now serving in combat theaters than at any other time. However, little is known about possible sex differences underlying the neuropathology and manifestation of one of modern war's signature injuries, traumatic brain injury (TBI). The paucity of information regarding sex differences in TBI is particularly evident when examining changes in executive function and emotion regulation associated with post concussive events. The current study objective was to observe whether patterns of orbitofrontal (OFC) functional connectivity would differ between female veterans with TBI and their male counterparts. The study further sought to determine whether OFC connectivity might be differentially associated with clinical measures of aggression and hostility. Seventeen female veterans and 24 male veterans, age 18 to 25, who met criteria for TBI completed resting state magnetic resonance imaging (MRI) and clinical assessment measures. Imaging data were analyzed using left and right seed regions of the OFC, and regression analyses were conducted to observe the relationship between resting state connectivity and self-reported aggression. Females and males in this study differed in OFC connectivity, with females demonstrating greater connectivity between left and right OFC and parietal and occipital regions and males demonstrating greater connectivity between left and right OFC and frontal and temporal regions. Significant associations between resting state connectivity and clinical measures were found only in male veterans. These findings suggest that TBI may interact with sex-specific patterns of brain connectivity in male and female veterans and exert divergent effects on clinical profiles of aggression post-injury. PMID:25864195

  5. Agency-Based Male Sex Work: A Descriptive Focus on Physical, Personal, and Social Space

    PubMed Central

    Smith, Michael D.; Grov, Christian; Seal, David W.

    2009-01-01

    Thirty male sex workers (MSWs) from a single agency participated in a qualitative interview about social and occupational aspects of their lives. MSWs established physical (defined areas where clients were not invited) and psychological (limitations of relationship with clients, other escorts, and the agency manager) boundaries to construct personal and professional space regarding sex work. Physical and psychological boundaries often were blended (e.g., bringing friends/family to the agency, utilizing the agency as a “drop-in community center”). The agency further mitigated negative aspects of sex work by providing job training, social support, stigma management, and dual-use space. Actors co-created a context wherein business could be conducted while meeting MSWs' psychosocial needs. PMID:19779572

  6. Two males with SRY-positive 46,XX testicular disorder of sex development.

    PubMed

    Gunes, Sezgin; Asci, Ramazan; Okten, Gülsen; Atac, Fatih; Onat, Onur E; Ogur, Gonul; Aydin, Oguz; Ozcelik, Tayfun; Bagci, Hasan

    2013-02-01

    The 46,XX testicular disorder of sex development (46,XX testicular DSD) is a rare phenotype associated with disorder of the sex chromosomes. We describe the clinical, molecular, and cytogenetic findings of a 16- and a 30-year-old male patient with sex-determining region Y (SRY)-positive 46,XX testicular DSD. Chromosomal analysis revealed 46,XX karyotype. Fluorescence in situ hybridization (FISH) showed the SRY region translocated to the short arm of the X chromosome. The presence of the SRY gene was also confirmed by polymerase chain reaction (PCR). The X chromosome inactivation (XCI) assay showed that both patients have a random pattern of X chromosome inactivation. This report compares the symptoms and features of the SRY-positive 46,XX testicular DSD patients.

  7. Male-biased genes are overrepresented among novel Drosophila pseudoobscura sex-biased genes

    PubMed Central

    2008-01-01

    Background The origin of functional innovation is among the key questions in biology. Recently, it has been shown that new genes could arise from non-coding DNA and that such novel genes are often involved in male reproduction. Results With the aim of identifying novel genes, we used the technique "generation of longer cDNA fragments from serial analysis of gene expression (SAGE) tags for gene identification (GLGI)" to extend 84 sex-biased 3'end SAGE tags that previously could not be mapped to the D. pseudoobscura transcriptome. Eleven male-biased and 33 female-biased GLGI fragments were obtained, of which 5 male-biased and 3 female-biased tags corresponded to putatively novel genes. This excess of novel genes with a male-biased gene expression pattern is consistent with previous results, which found novel genes to be primarily expressed in male reproductive tissues. 5' RACE analysis indicated that these novel transcripts are very short in length and could contain introns. Interspecies comparisons revealed that most novel transcripts show evidence for purifying selection. Conclusion Overall, our data indicate that among sex-biased genes a considerable number of novel genes (~2–4%) exist in D. pseudoobscura, which could not be predicted based on D. melanogaster gene models. PMID:18577217

  8. Selection on male sex pheromone composition contributes to butterfly reproductive isolation

    PubMed Central

    Bacquet, P. M. B.; Brattström, O.; Wang, H.-L.; Allen, C. E.; Löfstedt, C.; Brakefield, P. M.; Nieberding, C. M.

    2015-01-01

    Selection can facilitate diversification by inducing character displacement in mate choice traits that reduce the probability of maladaptive mating between lineages. Although reproductive character displacement (RCD) has been demonstrated in two-taxa case studies, the frequency of this process in nature is still debated. Moreover, studies have focused primarily on visual and acoustic traits, despite the fact that chemical communication is probably the most common means of species recognition. Here, we showed in a large, mostly sympatric, butterfly genus, a strong pattern of recurrent RCD for predicted male sex pheromone composition, but not for visual mate choice traits. Our results suggest that RCD is not anecdotal, and that selection for divergence in male sex pheromone composition contributed to reproductive isolation within the Bicyclus genus. We propose that selection may target olfactory mate choice traits as a more common sensory modality to ensure reproductive isolation among diverging lineages than previously envisaged. PMID:25740889

  9. Female-to-male transsexualism and sex roles: self and spouse ratings on the PAQ.

    PubMed

    Fleming, M Z; MacGowan, B R; Salt, P

    1984-02-01

    The sex-role-based perceptions of self and spouse in a group of female-to-male transsexuals, their wives, and a matched control group were studied. Each participant was given four copies of the Personal Attributes Questionnaire and asked to rate self, spouse, ideal self, and ideal spouse. The transsexual group rated themselves significantly higher than the control male group on the F scale, while there were no significant differences between the two groups on the M and M-F scales. The transsexuals' wives rated their spouses higher than did the control women on the F scale, and this difference approached significance. There were no significant differences between the spouse ratings of these two groups on the M and M-F scales. These results are discussed in terms of the relationship between sex role and gender identity and in terms of the theories that propose role strain as the cause of transsexualism.

  10. Sex steroid and prolactin profiles in male American black bears (Ursus americanus) during denning.

    PubMed

    Tsubota, T; Garshelis, D L; Nelson, R A; Bahr, J M

    1999-01-01

    Serum sex steroid and prolactin profiles were examined in the male American black bear, Ursus americanus during denning. Sera collected in December and the following March from 8 denning male black bears in Minnesota, U.S.A. were assayed for testosterone, estradiol-17 beta and prolactin. Eight bears were confirmed to be the denning mode based on a serum urea to creatinine ratio less than 10. Serum testosterone concentrations tended to increase from December to the subsequent March whereas serum estradiol-17 beta concentrations tended to decrease during this period. There were few changes in serum prolactin concentrations between December and March. These findings suggest that spermatogenesis and testicular steroidogenesis initiated during denning may be influenced by changes in serum sex steroid concentrations in the American black bear. PMID:10027172

  11. Sex Chromatin Positive Metastatic Melanoma in a Male with a Favourable Prognosis

    PubMed Central

    Atkin, N. B.

    1971-01-01

    The presence of sex chromatin in a metastatic malignant melanoma from a male patient aged 26 who showed no evidence of any constitutional chromosome anomaly is described. A possible association between the apparently “female” origin of the tumour and the good response to therapy is considered. ImagesFig. 2p488-5-aFig. 4Fig. 3Fig. 1p488-9-a PMID:5144523

  12. In the company of friends: peer influence on Thai male extramarital sex.

    PubMed

    Vanlandingham, M; Knodel, J; Saengtienchai, C; Pramualratana, A

    1998-12-01

    We explore some of the key social dynamics underlying patterns of male extramarital heterosexual behavior in Thailand. We analyze transcripts of focus group discussions and focused individual interviews conducted during 1993 and 1994 with married men and women living in both urban and rural areas of central Thailand. We discern several pathways of peer influence on extramarital commercial sex patronage that are common across our sites and interpret these peer effects in light of contemporary theories of social influence and sexual behavior.

  13. Spatial bridging in a network of drug-using male sex workers.

    PubMed

    Williams, Mark L; Atkinson, John; Klovdahl, Alden; Ross, Michael W; Timpson, Sandra

    2005-03-01

    This study sought to determine whether drug-using male sex workers (MSWs) spatially bridge sexual networks across cities and to determine whether the behaviors of MSWs who bridge differ from the behaviors of those who do not. Data were collected from 42 MSWs in Houston, Texas, between May 2003 and February 2004. Spatial bridging was defined as having traded sex for money in another city before traveling to and trading in Houston. Cities bridged by MSWs were geographically plotted and were primarily located in the Gulf Coast and in Florida. Slightly less than half of MSWs were identified as spatially bridging from one city to another. A significantly higher proportion of MSWs who bridged cities were homosexual (55% vs. 23%) and HIV positive (31% vs. 5%). Those who bridged cities used marijuana and injected drugs more frequently and had significantly more male sex partners than MSWs who did not bridge cities. Despite the small sample size, this study found that many drug-using MSWs spatially bridge sexual networks in cities where they trade sex for money. PMID:15738322

  14. Relationship dynamics and sexual risk behaviour of male partners of female sex workers in Kampala, Uganda.

    PubMed

    Mbonye, Martin; Siu, Godfrey E; Kiwanuka, Thadeus; Seeley, Janet

    2016-07-01

    Regular male partners of female sex workers (FSWs) represent an important population to reach with HIV-prevention interventions. This paper discusses the relationship dynamics and HIV/sexually transmitted infection risk behaviour of men involved with self-identified FSWs in Kampala. Between 2011 and 2014 we conducted repeat in-depth interviews with 42 male partners of FSWs attending a clinic for women at high risk of HIV-infection in Kampala. Men publicly struggled with the stigma of dating women who are considered to be engaged in a shamed profession, but privately saw meaning in these relationships. In coping with the stigma, some described the work of their partners in terms that distanced them from sex work, while others struggled to have the control that "being a man" demanded since they could not monitor all movements of their partners. Dealing with HIV disclosure was hard and seeking support was difficult for some of the men, leading to missed opportunities and guilt. Despite challenges, relationships with sex workers offered men some benefits such as access to much needed care and treatment. A few men also admitted to being motivated by material and financial benefits from sex workers who they perceived as being rich and this was one factor that helped them sustain the relationships. These findings offer insights into the complex relationship dynamics within high risk sexual partnerships. However, the findings suggest that effective interventions that are couple centred can be established to promote better health. PMID:27399044

  15. Relationship dynamics and sexual risk behaviour of male partners of female sex workers in Kampala, Uganda.

    PubMed

    Mbonye, Martin; Siu, Godfrey E; Kiwanuka, Thadeus; Seeley, Janet

    2016-07-01

    Regular male partners of female sex workers (FSWs) represent an important population to reach with HIV-prevention interventions. This paper discusses the relationship dynamics and HIV/sexually transmitted infection risk behaviour of men involved with self-identified FSWs in Kampala. Between 2011 and 2014 we conducted repeat in-depth interviews with 42 male partners of FSWs attending a clinic for women at high risk of HIV-infection in Kampala. Men publicly struggled with the stigma of dating women who are considered to be engaged in a shamed profession, but privately saw meaning in these relationships. In coping with the stigma, some described the work of their partners in terms that distanced them from sex work, while others struggled to have the control that "being a man" demanded since they could not monitor all movements of their partners. Dealing with HIV disclosure was hard and seeking support was difficult for some of the men, leading to missed opportunities and guilt. Despite challenges, relationships with sex workers offered men some benefits such as access to much needed care and treatment. A few men also admitted to being motivated by material and financial benefits from sex workers who they perceived as being rich and this was one factor that helped them sustain the relationships. These findings offer insights into the complex relationship dynamics within high risk sexual partnerships. However, the findings suggest that effective interventions that are couple centred can be established to promote better health.

  16. [Inappropriate sexual differentiation of sex reversal type in 16-year-old boy with male phenotype].

    PubMed

    Starzyk, Jerzy; Górska, Aleksandra; Januś, Dominika

    2005-01-01

    We present a case of a 16-year-old boy with gynecomastia and symptoms of delayed puberty (relatively small testes and penis), who attended the Endocrinology Clinic. Pubic hair development was normal. Basic hormonal blood tests showed a primary testicular lesion (hypergonadotropic hypogonadism). The result of karyotype examination showed female karyotype 46, XX. Based on those results the boy was diagnosed to be 46, XX male. A replacement testosterone therapy was administered. He stays in follow-up for gonad observation. The authors emphasize the possibility of establishing the diagnosis of a severe disorder belonging to the group of inappropriate sex differentiation of sex reversal type not earlier than in teenage adolescents, who present symptoms of delayed puberty. In such cases the main rule in establishing a final diagnosis is played by a physical examination with evaluation of sex development, as well as basic hormonal blood tests and karyotype result. Their correct interpretation is possible only by a physician who has reliable knowledge of the physiology of male sex determination.

  17. Associations of lead and cadmium with sex hormones in adult males.

    PubMed

    Kresovich, Jacob K; Argos, Maria; Turyk, Mary E

    2015-10-01

    Heavy metal exposures are ubiquitous in the environment and their relation to sex hormones is not well understood. This paper investigates the associations between selected heavy metals (lead and cadmium) and sex hormones (testosterone, free testosterone, estradiol, free estradiol) as well as other major molecules in the steroid biosynthesis pathway (androstanedione glucuronide and sex-hormone binding globulin (SHBG)). Blood lead and cadmium were selected as biomarkers of exposure, and tested for associations in males using National Health and Nutritional Examination Survey (NHANES) data from 1999-2004. After adjustment for age, race, body mass index, smoking status, diabetes and alcohol intake, blood lead was positively associated with testosterone and SHBG while blood cadmium was positively associated with SHBG. After controlling for additional heavy metal exposure, the associations between lead and testosterone as well as cadmium and SHBG remained significant. Furthermore, the association between blood lead and testosterone was modified by smoking status (P for interaction=0.011), diabetes (P for interaction=0.021) and blood cadmium (P for interaction=0.029). The association between blood cadmium and SHBG levels was modified by blood lead (P for interaction=0.004). This study is the most comprehensive investigation to date regarding the association between heavy metals and sex hormones in males.

  18. Awareness of Human Papillomavirus Vaccine Among Adolescent African American Males Who Have Sex with Males: a Pilot Study.

    PubMed

    Onyeabor, Onyekachi S; Martin, Nicolle; Orish, Verner N; Sanyaolu, Adekunle O; Iriemenam, Nnaemeka C

    2015-09-01

    African American adolescent males who have sex with males (MSMs) have a high prevalence of sexually transmitted diseases (STDs) that has been directly linked to lack of access to primary care providers and reluctance to disclose their sexuality. The human papillomavirus (HPV) is the most common STD with more than 40 different serotypes and can lead to anal/genital warts as well as oral and genital cancers. The HPV vaccine if taken prior to an adolescent becoming sexually active serves a prophylactic function. The HPV vaccine is approved by the Food and Drug Administration (FDA) for girls and boys; however, HPV vaccination rates among adolescents within different minority and underserved communities have been disappointing even though these groups are disproportionately infected with the HPV virus and certain male-specific cancers. Little is known about the uptake of the vaccine among African American MSMs and thus the aim of this study. This qualitative study is based on the health belief model and assessed participants' level of awareness of HPV, the HPV vaccine, and HPV-related illnesses among 24 African American male adolescents between 16 and 18 years old who self identify as MSMs. As part of a larger study, two focus groups were conducted for African American MSMs. Participants failed to understand their potential risk for HPV given the higher rates of STD infection experienced by MSMs. They expressed very little knowledge of the HPV vaccine and are also not aware of the complications of HPV virus infection. However, they were very eager to know more about the virus and the vaccine. This study demonstrates the need for the development of health communication intervention and more research targeting African American MSMs and also the need for policy change towards making the HPV vaccine routine for males especially adolescents at no cost.

  19. Preventing HIV Transmission among Partners of HIV-Positive Male Sex Workers in Mexico City: A Modeling Study

    PubMed Central

    Monteiro, João Filipe G.; Marshall, Brandon D.L.; Escudero, Daniel; Sosa-Rubí, Sandra G.; González, Andrea; Flanigan, Timothy; Operario, Don; Mayer, Kenneth H.; Lurie, Mark N.; Galárraga, Omar

    2015-01-01

    Mexico has a concentrated HIV epidemic, with male sex workers constituting a key affected population. We estimated annual HIV cumulative incidence among male sex workers’ partners, and then compared incidence under three hypothetical intervention scenarios: improving condom use; and scaling up HIV treatment as prevention, considering current viral suppression rates (CVS, 60.7%) or full viral suppression among those treated (FVS, 100%). Clinical and behavioral data to inform model parameterization were derived from a sample (n=79) of male sex workers recruited from street locations and Clínica Condesa, an HIV clinic in Mexico City. We estimated annual HIV incidence among male sex workers’ partners to be 8.0% (95% CI: 7.3–8.7). Simulation models demonstrated that increasing condom use by 10%, and scaling up HIV treatment initiation by 50% (from baseline values) would decrease the male sex workers-attributable annual incidence to 5.2%, 4.4% (CVS) and 3.2% (FVS), respectively. Scaling up the number of male sex workers on ART and implementing interventions to ensure adherence is urgently required to decrease HIV incidence among male sex workers’ partners in Mexico City. PMID:25307025

  20. Preventing HIV Transmission Among Partners of HIV-Positive Male Sex Workers in Mexico City: A Modeling Study.

    PubMed

    Monteiro, João Filipe G; Marshall, Brandon D L; Escudero, Daniel; Sosa-Rubí, Sandra G; González, Andrea; Flanigan, Timothy; Operario, Don; Mayer, Kenneth H; Lurie, Mark N; Galárraga, Omar

    2015-09-01

    Mexico has a concentrated HIV epidemic, with male sex workers constituting a key affected population. We estimated annual HIV cumulative incidence among male sex workers' partners, and then compared incidence under three hypothetical intervention scenarios: improving condom use; and scaling up HIV treatment as prevention, considering current viral suppression rates (CVS, 60.7 %) or full viral suppression among those treated (FVS, 100 %). Clinical and behavioral data to inform model parameterization were derived from a sample (n = 79) of male sex workers recruited from street locations and Clínica Condesa, an HIV clinic in Mexico City. We estimated annual HIV incidence among male sex workers' partners to be 8.0 % (95 % CI: 7.3-8.7). Simulation models demonstrated that increasing condom use by 10 %, and scaling up HIV treatment initiation by 50 % (from baseline values) would decrease the male sex workers-attributable annual incidence to 5.2, 4.4 % (CVS) and 3.2 % (FVS), respectively. Scaling up the number of male sex workers on ART and implementing interventions to ensure adherence is urgently required to decrease HIV incidence among male sex workers' partners in Mexico City.

  1. Sex ratio meiotic drive as a plausible evolutionary mechanism for hybrid male sterility.

    PubMed

    Zhang, Linbin; Sun, Tianai; Woldesellassie, Fitsum; Xiao, Hailian; Tao, Yun

    2015-03-01

    Biological diversity on Earth depends on the multiplication of species or speciation, which is the evolution of reproductive isolation such as hybrid sterility between two new species. An unsolved puzzle is the exact mechanism(s) that causes two genomes to diverge from their common ancestor so that some divergent genes no longer function properly in the hybrids. Here we report genetic analyses of divergent genes controlling male fertility and sex ratio in two very young fruitfly species, Drosophila albomicans and D. nasuta. A majority of the genetic divergence for both traits is mapped to the same regions by quantitative trait loci mappings. With introgressions, six major loci are found to contribute to both traits. This genetic colocalization implicates that genes for hybrid male sterility have evolved primarily for controlling sex ratio. We propose that genetic conflicts over sex ratio may operate as a perpetual dynamo for genome divergence. This particular evolutionary mechanism may largely contribute to the rapid evolution of hybrid male sterility and the disproportionate enrichment of its underlying genes on the X chromosome--two patterns widely observed across animals.

  2. The impact of sirolimus on sex hormones in male adolescent kidney recipients.

    PubMed

    Cavanaugh, Teresa M; Schoenemen, Heather; Goebel, Jens

    2012-05-01

    While it is known that sirolimus affects sex hormones in adult kidney transplant patients, there is a scarcity of data on its effects on sex hormone levels in adolescent kidney recipients. The objective of this study is to describe the impact of sirolimus on the sex hormones in this patient population. This is a retrospective review of male adolescent renal transplant patients transitioned to sirolimus. Baseline and subsequent annual testosterone levels were collected. Linear regression was undertaken to determine the predictors of testosterone levels. Four African Americans and 11 Caucasians, median age of 15 yr (11-18) in 2008, were included. Mean time post-transplant was 81 ± 37 months. Mean testosterone values were the following: 336 ± 135 ng/dL (n = 8) at baseline, 349 ± 130 ng/dL (n = 15) one yr later, and 360 ± 132 ng/dL (n = 13) two yr later (normal range for adult males: 350-970 ng/dL). Seven (47%) patients experienced a decrease in testosterone levels. Time on sirolimus was associated with decreased testosterone (r = 0.643, p = 0.010). Testosterone levels in pubertal male kidney transplant recipients on sirolimus may be suppressed, especially if they have been treated with sirolimus for several years. These data need to be confirmed in a larger study.

  3. Gene organization of the liverwort Y chromosome reveals distinct sex chromosome evolution in a haploid system

    PubMed Central

    Yamato, Katsuyuki T.; Ishizaki, Kimitsune; Fujisawa, Masaki; Okada, Sachiko; Nakayama, Shigeki; Fujishita, Mariko; Bando, Hiroki; Yodoya, Kohei; Hayashi, Kiwako; Bando, Tomoyuki; Hasumi, Akiko; Nishio, Tomohisa; Sakata, Ryoko; Yamamoto, Masayuki; Yamaki, Arata; Kajikawa, Masataka; Yamano, Takashi; Nishide, Taku; Choi, Seung-Hyuk; Shimizu-Ueda, Yuu; Hanajiri, Tsutomu; Sakaida, Megumi; Kono, Kaoru; Takenaka, Mizuki; Yamaoka, Shohei; Kuriyama, Chiaki; Kohzu, Yoshito; Nishida, Hiroyuki; Brennicke, Axel; Shin-i, Tadasu; Kohara, Yuji; Kohchi, Takayuki; Fukuzawa, Hideya; Ohyama, Kanji

    2007-01-01

    Y chromosomes are different from other chromosomes because of a lack of recombination. Until now, complete sequence information of Y chromosomes has been available only for some primates, although considerable information is available for other organisms, e.g., several species of Drosophila. Here, we report the gene organization of the Y chromosome in the dioecious liverwort Marchantia polymorpha and provide a detailed view of a Y chromosome in a haploid organism. On the 10-Mb Y chromosome, 64 genes are identified, 14 of which are detected only in the male genome and are expressed in reproductive organs but not in vegetative thalli, suggesting their participation in male reproductive functions. Another 40 genes on the Y chromosome are expressed in thalli and male sexual organs. At least six of these genes have diverged X-linked counterparts that are in turn expressed in thalli and sexual organs in female plants, suggesting that these X- and Y-linked genes have essential cellular functions. These findings indicate that the Y and X chromosomes share the same ancestral autosome and support the prediction that in a haploid organism essential genes on sex chromosomes are more likely to persist than in a diploid organism. PMID:17395720

  4. Male Prison Inmates With Gender Dysphoria: When Is Sex Reassignment Surgery Appropriate?

    PubMed

    Osborne, Cynthia S; Lawrence, Anne A

    2016-10-01

    Gender dysphoria (GD), a feeling of persistent discomfort with one's biologic sex or assigned gender, is estimated to be more prevalent in male prison inmates than in nonincarcerated males; there may be 3000-4000 male inmates with GD in prisons in the United States. An increasing number of U.S. prison systems now offer gender dysphoric inmates diagnostic evaluation, psychotherapy, cross-sex hormone therapy, and opportunities, albeit limited, to enact their preferred gender role. Sex reassignment surgery (SRS), however, has not been offered to inmates except in response to litigation. In the first case of its kind, the California Department of Corrections and Rehabilitation recently agreed to provide SRS to an inmate and developed policy guidelines for its future provision. In other recent cases, U.S. courts have ruled that male inmates with GD are entitled to SRS when it is medically necessary. Although these decisions may facilitate the provision of SRS to inmates in the future, many U.S. prison systems will probably remain reluctant to offer SRS unless legally compelled to do so. In this review, we address the medical necessity of SRS for male inmates with GD. We also discuss eligibility criteria and the practical considerations involved in providing SRS to inmates. We conclude by offering recommendations for physicians, mental health professionals, and prison administrators, designed to facilitate provision of SRS to inmates with GD in a manner that provides humane treatment, maximizes the likelihood of successful outcomes, minimizes risk of regret, and generates data that can help inform future decisions.

  5. Persistence of an extreme male-biased adult sex ratio in a natural population of polyandrous bird.

    PubMed

    Kosztolányi, A; Barta, Z; Küpper, C; Székely, T

    2011-08-01

    In a number of insects, fishes and birds, the conventional sex roles are reversed: males are the main care provider, whereas females focus on matings. The reversal of typical sex roles is an evolutionary puzzle, because it challenges the foundations of sex roles, sexual selection and parental investment theory. Recent theoretical models predict that biased parental care may be a response to biased adult sex ratios (ASRs). However, estimating ASR is challenging in natural populations, because males and females often have different detectabilities. Here, we use demographic modelling with field data from 2101 individuals, including 579 molecularly sexed offspring, to provide evidence that ASR is strongly male biased in a polyandrous bird with male-biased care. The model predicts 6.1 times more adult males than females (ASR=0.860, proportion of males) in the Kentish plover Charadrius alexandrinus. The extreme male bias is consistent between years and concordant with experimental results showing strongly biased mating opportunity towards females. Based on these results, we conjecture that parental sex-role reversal may occur in populations that exhibit extreme male-biased ASR.

  6. Sex-Linked Chromosome Heterozygosity in Males of Tityus confluens (Buthidae): A Clue about the Presence of Sex Chromosomes in Scorpions

    PubMed Central

    Adilardi, Renzo Sebastián; Ojanguren-Affilastro, Andrés Alejandro; Mola, Liliana María

    2016-01-01

    Scorpions of the genus Tityus show holokinetic chromosomes, achiasmatic male meiosis and an absence of heteromorphic sex chromosomes, like all Buthidae. In this work, we analysed the meiotic behaviour and chromosome rearrangements of a population of the scorpion Tityus confluens, characterising the cytotypes of males, females and embryos with different cytogenetic techniques. This revealed that all the females were structural homozygotes, while all the males were structural heterozygotes for different chromosome rearrangements. Four different cytotypes were described in males, which differed in chromosome number (2n = 5 and 2n = 6) and meiotic multivalent configurations (chains of four, five and six chromosomes). Based on a detailed mitotic and meiotic analysis, we propose a sequence of chromosome rearrangements that could give rise to each cytotype and in which fusions have played a major role. Based on the comparison of males, females and a brood of embryos, we also propose that the presence of multivalents in males and homologous pairs in females could be associated with the presence of cryptic sex chromosomes, with the male being the heterogametic sex. We propose that the ancestral karyotype of this species could have had homomorphic XY/XX (male/female) sex chromosomes and a fusion could have occurred between the Y chromosome and an autosome. PMID:27783630

  7. Transgenerational epigenetic imprinting of the male germline by endocrine disruptor exposure during gonadal sex determination.

    PubMed

    Chang, Hung-Shu; Anway, Matthew D; Rekow, Stephen S; Skinner, Michael K

    2006-12-01

    Embryonic exposure to the endocrine disruptor vinclozolin at the time of gonadal sex determination was previously found to promote transgenerational disease states. The actions of vinclozolin appear to be due to epigenetic alterations in the male germline that are transmitted to subsequent generations. Analysis of the transgenerational epigenetic effects on the male germline (i.e. sperm) identified 25 candidate DNA sequences with altered methylation patterns in the vinclozolin generation sperm. These sequences were identified and mapped to specific genes and noncoding DNA regions. Bisulfite sequencing was used to confirm the altered methylation pattern of 15 of the candidate DNA sequences. Alterations in the epigenetic pattern (i.e. methylation) of these genes/DNA sequences were found in the F2 and F3 generation germline. Therefore, the reprogramming of the male germline involves the induction of new imprinted-like genes/DNA sequences that acquire an apparent permanent DNA methylation pattern that is passed at least through the paternal allele. The expression pattern of several of the genes during embryonic development were found to be altered in the vinclozolin F1 and F2 generation testis. A number of the imprinted-like genes/DNA sequences identified are associated with epigenetic linked diseases. In summary, an endocrine disruptor exposure during embryonic gonadal sex determination was found to promote an alteration in the epigenetic (i.e. induction of imprinted-like genes/DNA sequences) programming of the male germline, and this is associated with the development of transgenerational disease states.

  8. Condom Use During Commercial Sex Among Male Clients of Female Sex Workers in Sichuan China: A Social Cognitive Theory Analysis.

    PubMed

    Yang, Yi; Yang, Cui; Latkin, Carl A; Luan, Rongsheng; Nelson, Kenrad E

    2016-10-01

    There has been little theory-based research focusing on condom use among male clients of female sex workers (CFSW) in China. The current study applied social cognitive theory to condom use behaviors of CFSW in China. Face-to-face structured interviews were conducted among 584 CFSW recruited through snowball sampling. Bivariate and multivariate logistic regression models were applied to examine factors associated with consistent condom use. A minority (30.65 %) of respondents reported using condoms consistently with FSW, and 7 of 12 social cognitive dimensions/subdimensions were found to be significantly influential. The most significant factors were self-efficacy [adjusted prevalence ratio (APR) = 2.11, 95 %, CI = 1.74-2.43] and personal pleasure reduction (APR = 0.3, 95 % CI = 0.15-0.6). HIV-related knowledge, perceived HIV susceptibility, condom cost, condom efficacy, and embarrassment of carrying condoms were not associated with consistent condom uses with FSW. Findings from the current study suggest future prevention programs should target sex venues, and condom access should ensure both quantity and quality. Peer education should focus on knowledge education and peer norms, and knowledge education should include information on HIV infection severity and how to increase pleasure with condom use.

  9. The costs of risky male behaviour: sex differences in seasonal survival in a small sexually monomorphic primate

    PubMed Central

    Kraus, Cornelia; Eberle, Manfred; Kappeler, Peter M

    2008-01-01

    Male excess mortality is widespread among mammals and frequently interpreted as a cost of sexually selected traits that enhance male reproductive success. Sex differences in the propensity to engage in risky behaviours are often invoked to explain the sex gap in survival. Here, we aim to isolate and quantify the survival consequences of two potentially risky male behavioural strategies in a small sexually monomorphic primate, the grey mouse lemur Microcebus murinus: (i) most females hibernate during a large part of the austral winter, whereas most males remain active and (ii) during the brief annual mating season males roam widely in search of receptive females. Using a 10-year capture–mark–recapture dataset from a population of M. murinus in Kirindy Forest, western Madagascar, we statistically modelled sex-specific seasonal survival probabilities. Surprisingly, we did not find any evidence for direct survival benefits of hibernation—winter survival did not differ between males and females. By contrast, during the breeding season males survived less well than females (sex gap: 16%). Consistent with the ‘risky male behaviour’ hypothesis, the period for lowered male survival was restricted to the short mating season. Thus, sex differences in survival in a promiscuous mammal can be substantial even in the absence of sexual dimorphism. PMID:18426751

  10. Genetic manipulation of sex ratio for the large-scale breeding of YY super-male and XY all-male yellow catfish (Pelteobagrus fulvidraco (Richardson)).

    PubMed

    Liu, Hanqin; Guan, Bo; Xu, Jiang; Hou, Changchun; Tian, Hua; Chen, Hongxi

    2013-06-01

    Yellow catfish has become one of the most important freshwater aquaculture species in China. The mono-sex male yellow catfish has important application value in aquaculture because the male grows generally faster than the sibling females under the same conditions. This study has screened YY super-male and YY physiological female yellow catfish by sex reversal, gynogenesis, and progeny testing, which can help to achieve the large-scale production of YY super-male and XY all-male. From 2008 to 2010, about 123,000 YY super-male were produced, and about 81 million XY all-male fry were produced with 100% male rate by random sampling. Therefore, these results indicate that YY super-male and YY physiological female yellow catfish can be viable and fertile. We conclude that the mono-sex breeding technique by YY super-male yellow catfish is stable and reliable, which has great potential for application in yellow catfish aquaculture.

  11. The value of outside support for male and female politicians involved in a political sex scandal.

    PubMed

    Stewart, Dennis D; Rose, Roger P; Rosales, Felixia M; Rudney, Philip D; Lehner, Tasha A; Miltich, Gemma; Snyder, Cassie; Sadecki, Brianna

    2013-01-01

    This research examined how third party statements impact the evaluation of male and female politicians caught in a scandal (i.e., extramarital affair). Governor's sex was crossed with three types of support statements: third party supportive (TPS), third party non-supportive (TPNS), and governor self-supportive (GSS). In Experiment 1, a female politician was evaluated more positively than a male politician. The TPS and the GSS conditions were both evaluated more positively than the TPNS condition. Experiment 2's design was similar to Experiment l's, except it involved multiple affairs. In Experiment 2, participants used the third party's statements as an information source and thus reduced their use of gender stereotypes in the TPS and TPNS conditions compared to the GSS condition. We also found that male respondents gave more negative evaluations of the female governor than female respondents. Implications for the gender stereotype and social influence literatures are discussed.

  12. Influence of sex and age on morphological organ damage after hemorrhagic shock.

    PubMed

    Mees, Soeren Torge; Gwinner, Maike; Marx, Kerstin; Faendrich, Fred; Schroeder, Joerg; Haier, Joerg; Kahlke, Volker

    2008-06-01

    Immune function after hemorrhagic shock (shock) and subsequent sepsis is proofed to be sex- and age-related, showing an enhanced immune function and better survival of young females and a deteriorating immune response in advanced age. However, it remains unclear if the observed sex- and age-related effects observed on the immune function mirror the histomorphological changes of the affected organs. To scrutinize a possible association, male and female CBA/J mice (young, 2-3 months; aged 18-19 months) were subjected to shock (35 + 5 mmHg for 90 min and fluid resuscitation) or sham operation. At 48 h after shock, histological specimen at definite sites were harvested (lung, small bowel, liver, and kidney) and immediately stored in 10% formalin. After paraffin embedding, hematoxylin-eosin stain and immunohistochemical stains (vascular cell adhesion molecule 1 [VCAM-1], cluster of differentiation 44 [CD44], signal transducers and activators of transcription 3 [STAT-3]) were performed. In both sexes, aged animals developed significantly increased (P < 0.05) tissue damage in all analyzed organs compared with young mice. Sex differences were noticed in the lungs of young mice, showing a significantly (P < 0.05) lower organ damage score in female animals. Sex-related differences were found for VCAM-1 and cluster of differentiation 44 expression, whereas age-related changes were observed for STAT-3. These results demonstrate that the severity of tissue damage caused by hemorrhagic shock is influenced by sex- and age-related effects. Variances in the VCAM-1 and STAT-3 expression suggest that improved immune function in female and young subjects may be responsible for less shock-induced tissue damage.

  13. High-Resolution Sex-Specific Linkage Maps of the Mouse Reveal Polarized Distribution of Crossovers in Male Germline

    PubMed Central

    Liu, Eric Yi; Morgan, Andrew P.; Chesler, Elissa J.; Wang, Wei; Churchill, Gary A.; Pardo-Manuel de Villena, Fernando

    2014-01-01

    Since the publication of the first comprehensive linkage map for the laboratory mouse, the architecture of recombination as a basic biological process has become amenable to investigation in mammalian model organisms. Here we take advantage of high-density genotyping and the unique pedigree structure of the incipient Collaborative Cross to investigate the roles of sex and genetic background in mammalian recombination. Our results confirm the observation that map length is longer when measured through female meiosis than through male meiosis, but we find that this difference is modified by genotype at loci on both the X chromosome and the autosomes. In addition, we report a striking concentration of crossovers in the distal ends of autosomes in male meiosis that is absent in female meiosis. The presence of this pattern in both single- and double-recombinant chromosomes, combined with the absence of a corresponding asymmetry in the distribution of double-strand breaks, indicates a regulated sequence of events specific to male meiosis that is anchored by chromosome ends. This pattern is consistent with the timing of chromosome pairing and evolutionary constraints on male recombination. Finally, we identify large regions of reduced crossover frequency that together encompass 5% of the genome. Many of these “cold regions” are enriched for segmental duplications, suggesting an inverse local correlation between recombination rate and mutation rate for large copy number variants. PMID:24578350

  14. Same-sex sexual behaviors among male migrants in a context of male "marriage squeeze": results from an exploratory survey in urban Xi'an, China.

    PubMed

    Yang, Xueyan; Attané, Isabelle; Li, Shuzhuo; Yang, Bo

    2012-11-01

    The male marriage squeeze in China may increase the prevalence of male same-sex sexual behaviors among unmarried male migrants who lack stable female sexual partners. The same-sex sexual behaviors among unmarried male migrants appear to be at high risk of transmission of human immunodeficiency virus (HIV) and sexually transmitted infections (STIs), mainly because of a lack of knowledge of these diseases. Using data from the "Survey on Reproductive Health and Family Life of Migrant Male Bachelors in Urban Areas" conducted in Xi'an City, Shaanxi Province, in December 2009 and January 2010, this study compares same-sex sexual behaviors of unmarried with that of married male migrants (including married but separated men who are migrating without their spouse or partner and cohabitating men who are migrating with their spouse or partner). It is reported that the prevalence of same-sex sexual behaviors among unmarried males reaches 11%, more than twice the 5.1% reported by married but separated men and thrice the 3.8% reported by cohabitating men. It also appears that the same-sex sexual behaviors is significantly associated with men's attitudes toward same-sex sexual behaviors (odds ratio = 1.59, p < .001), toward life-long bachelorhood (odds ratio = 1.35, p < .01), and with marital status (odds ratio = 0.37, p < .01). The frequency of condom use appears to be higher among unmarried men than among men who are married, whether or not they migrated with their wives, and is significantly associated with scores on knowledge about HIV/AIDS (estimated coefficient = .12, p < .001) and STIs (estimated coefficient = .22, p < .01). It is also associated with the likelihood of same-sex sexual behaviors (estimated coefficients = .83, p < .01) and marital status (estimated coefficients for married but separated = -.50, p < .05; estimated coefficients for cohabitating = -.77, p < .001).

  15. Androstenedione may organize or activate sex-reversed traits in female spotted hyenas.

    PubMed

    Glickman, S E; Frank, L G; Davidson, J M; Smith, E R; Siiteri, P K

    1987-05-01

    Spotted hyenas (Crocuta crocuta Erxleben) present a unique syndrome of reversal in behavioral and anatomical distinction between the sexes: females are heavier and more aggressive than males and dominant over them. The female's external genitalia include a false scrotum and a fully erectile pseudopenis through which mating and birth take place. Results of studies of circulating testosterone levels in wild spotted hyenas do not account for the "male-like" characteristics of the female. Androstenedione, however, is consistently higher in females than in males, particularly during early infancy. Experiments on rodents show that androstenedione can be a potent organizer of anatomical and behavioral differentiation. This study suggests that it may also produce the profound virilization of female spotted hyenas.

  16. Sex differences in recovery from PTSD in male and female interpersonal assault survivors.

    PubMed

    Galovski, Tara E; Blain, Leah M; Chappuis, Courtney; Fletcher, Thomas

    2013-06-01

    Men and women differ in exposure to trauma and the development of posttraumatic stress disorder (PTSD); however, research regarding sex differences in recovery from PTSD has been sparse. This study evaluated the treatment response trajectory for 69 male and female interpersonal assault survivors, using a modified Cognitive Processing Therapy (CPT) protocol that allowed survivors to receive up to18 sessions of CPT, with treatment end determined by therapy progress. Few sex differences were observed in trauma history, baseline PTSD and depressive severity, Axis I comorbidity, anger, guilt and dissociation. Women did report more sexual assault in adulthood and elevated baseline guilt cognitions, whereas men reported more baseline anger directed inward. Attrition and total number of sessions did not differ by sex. Over the course of treatment and follow-up, men and women demonstrated similar rates of change in PTSD and depressive symptoms. However, medium effect sizes on both of these primary outcomes at the 3-month follow-up assessment favored women. Several differences in the slope of change emerged on secondary outcomes such that women evidenced more rapid gains on global guilt, guilt cognitions, anger/irritability, and dissociation. Results suggest that male survivors may warrant additional attention to address these important clinical correlates. PMID:23510841

  17. Self-Organization in the Battle of the Sexes

    NASA Astrophysics Data System (ADS)

    Alonso-Sanz, Ramón

    This paper presents a spatial version of the iterated battle of the sexes game in which every one individual plays with his nearest partners and imitates the optimal strategy of his nearest mate neighbors. It is concluded that the spatial structure enables the emergence of clusters of coincident choices, leading to the mean payoff per encounter to values that are accessible only in the cooperative two-person game scenario, which constitutes a notable case of self-organization.

  18. Drug-using male clients of female sex workers who report being paid for sex: HIV/STI, demographic and drug use correlates

    PubMed Central

    Wagner, Karla D.; Pitpitan, Eileen V.; Chavarin, Claudia V.; Magis-Rodriguez, Carlos; Patterson, Thomas L.

    2013-01-01

    Background Research has focused on male clients of female sex workers (FSWs) and their risk for HIV/STIs. Yet, it is unclear whether the commercial sex behaviors of these men are limited to paying for sex, or whether they may also be paid for sex themselves. Methods We analyzed interview data and HIV/STI test results from 170 drug-using male clients of FSWs in Tijuana, Mexico, to determine the extent to which these men report being paid for sex and the association with positive HIV/STI results. Results Over one-quarter of men reported having been paid for sex in the past four months. In a multivariate logistic regression model, reporting having been paid for sex was significantly associated with testing positive for any HIV/STI (Adjusted Odds Ratio [AdjOR] 3.53, 95% C.I. 1.33–9.35), being bisexual (AdjOR 15.59, 95% C.I. 4.81–50.53), injection drug use in the past four months (AdjOR 2.65, 95% C.I. 1.16–6.03), and cocaine use in the past four months (AdjOR 2.93, 95% C.I. 1.22–7.01). Conclusions Findings suggest that drug-using male clients of FSWs may be characterized by unique risk profiles that require tailored HIV prevention interventions. PMID:23863514

  19. Dgcr8 and Dicer are essential for sex chromosome integrity during meiosis in males

    PubMed Central

    Modzelewski, Andrew J.; Hilz, Stephanie; Crate, Elizabeth A.; Schweidenback, Caterina T. H.; Fogarty, Elizabeth A.; Grenier, Jennifer K.; Freire, Raimundo; Cohen, Paula E.; Grimson, Andrew

    2015-01-01

    ABSTRACT Small RNAs play crucial roles in regulating gene expression during mammalian meiosis. To investigate the function of microRNAs (miRNAs) and small interfering RNAs (siRNAs) during meiosis in males, we generated germ-cell-specific conditional deletions of Dgcr8 and Dicer in mice. Analysis of spermatocytes from both conditional knockout lines revealed that there were frequent chromosomal fusions during meiosis, always involving one or both sex chromosomes. RNA sequencing indicates upregulation of Atm in spermatocytes from miRNA-deficient mice, and immunofluorescence imaging demonstrates an increased abundance of activated ATM kinase and mislocalization of phosphorylated MDC1, an ATM phosphorylation substrate. The Atm 3′UTR contains many potential microRNA target sites, and, notably, target sites for several miRNAs depleted in both conditional knockout mice were highly effective at promoting repression. RNF8, a telomere-associated protein whose localization is controlled by the MDC1–ATM kinase cascade, normally associates with the sex chromosomes during pachytene, but in both conditional knockouts redistributed to the autosomes. Taken together, these results suggest that Atm dysregulation in microRNA-deficient germ lines contributes to the redistribution of proteins involved in chromosomal stability from the sex chromosomes to the autosomes, resulting in sex chromosome fusions during meiotic prophase I. PMID:25934699

  20. Diversity of commercial sex among men and male-born trans people in three Peruvian cities.

    PubMed

    Nureña, César R; Zúñiga, Mario; Zunt, Joseph; Mejía, Carolina; Montano, Silvia; Sánchez, Jorge L

    2011-11-01

    In Peru, commercial sex involving men and male-born travestis, transgenders and transsexuals (CSMT) is usually represented as a dangerous practice carried out on the streets by people experiencing economic hardship and social exclusion. However, in reality little is known about the complexities of this practice in Peru. This paper presents findings from an ethnographic study of the characteristics, patterns and sociocultural aspects of CSMT in three Peruvian cities. The study included participant observation in sex work venues and interviews with 42 sex workers and 25 key informants. We found that CSMT in Peru takes many forms (some not previously described in the country) and is practised in different places by people from various socioeconomic levels. In many cases, the practice appears linked to ideals of social mobility, migratory experiences and other economic activities. In addition, the increasing use of the Internet and mobile phones has changed patterns of sex work in Peru. We review the implications of these findings for future research and public health interventions.

  1. Diversity of commercial sex among men and male-born trans people in three Peruvian cities

    PubMed Central

    Zúñiga, Mario; Zunt, Joseph; Mejía, Carolina; Montano, Silvia; Sánchez, Jorge L.

    2011-01-01

    In Peru, commercial sex involving men and male-born travestis, transgenders and transsexuals (CSMT) is usually represented as a dangerous practice carried out on the streets by people experiencing economic hardship and social exclusion. However, in reality little is known about the complexities of this practice in Peru. This paper presents findings from an ethnographic study of the characteristics, patterns and socio-cultural aspects of CSMT in three Peruvian cities. The study included participant observation in sex work venues and interviews with 42 sex workers and 25 key informants. We found that CSMT in Peru takes many forms (some not previously described in the country) and is practised in different places by people from various socioeconomic levels. In many cases, the practice appears linked to ideals of social mobility, migratory experiences and other economic activities. In addition, the increasing use of the internet and mobile phones has changed patterns of sex work in Peru. We review the implications of these findings for future research and public health interventions. PMID:21936651

  2. Dgcr8 and Dicer are essential for sex chromosome integrity during meiosis in males.

    PubMed

    Modzelewski, Andrew J; Hilz, Stephanie; Crate, Elizabeth A; Schweidenback, Caterina T H; Fogarty, Elizabeth A; Grenier, Jennifer K; Freire, Raimundo; Cohen, Paula E; Grimson, Andrew

    2015-06-15

    Small RNAs play crucial roles in regulating gene expression during mammalian meiosis. To investigate the function of microRNAs (miRNAs) and small interfering RNAs (siRNAs) during meiosis in males, we generated germ-cell-specific conditional deletions of Dgcr8 and Dicer in mice. Analysis of spermatocytes from both conditional knockout lines revealed that there were frequent chromosomal fusions during meiosis, always involving one or both sex chromosomes. RNA sequencing indicates upregulation of Atm in spermatocytes from miRNA-deficient mice, and immunofluorescence imaging demonstrates an increased abundance of activated ATM kinase and mislocalization of phosphorylated MDC1, an ATM phosphorylation substrate. The Atm 3'UTR contains many potential microRNA target sites, and, notably, target sites for several miRNAs depleted in both conditional knockout mice were highly effective at promoting repression. RNF8, a telomere-associated protein whose localization is controlled by the MDC1-ATM kinase cascade, normally associates with the sex chromosomes during pachytene, but in both conditional knockouts redistributed to the autosomes. Taken together, these results suggest that Atm dysregulation in microRNA-deficient germ lines contributes to the redistribution of proteins involved in chromosomal stability from the sex chromosomes to the autosomes, resulting in sex chromosome fusions during meiotic prophase I.

  3. Sex hormone influence on hepatitis in young male A/JCr mice infected with Helicobacter hepaticus.

    PubMed

    Theve, Elizabeth J; Feng, Yan; Taghizadeh, Koli; Cormier, Kathleen S; Bell, David R; Fox, James G; Rogers, Arlin B

    2008-09-01

    Hepatitis B virus (HBV), the leading cause of human hepatocellular carcinoma, is especially virulent in males infected at an early age. Likewise, the murine liver carcinogen Helicobacter hepaticus is most pathogenic in male mice infected before puberty. We used this model to investigate the influence of male sex hormone signaling on infectious hepatitis. Male A/JCr mice were infected with H. hepaticus or vehicle at 4 weeks and randomized into surgical and pharmacologic treatment groups. Interruption of androgen pathways was confirmed by hormone measurements, histopathology, and liver gene and Cyp4a protein expression. Castrated males and those receiving the competitive androgen receptor antagonist flutamide had significantly less severe hepatitis as determined by histologic activity index than intact controls at 4 months. Importantly, the powerful androgen receptor agonist dihydrotestosterone did not promote hepatitis. No effect on hepatitis was evident in males treated with the 5alpha-reductase inhibitor dutasteride, the peroxisome proliferator-activated receptor-alpha agonist bezafibrate, or the nonsteroidal anti-inflammatory drug flufenamic acid. Consistent with previous observations of hepatitis-associated liver-gender disruption, transcriptional alterations involved both feminine (cytochrome P450 4a14) and masculine (cytochrome P450 4a12 and trefoil factor 3) genes, as well gender-neutral (H19 fetal liver mRNA, lipocalin 2, and ubiquitin D) genes. Hepatitis was associated with increased unsaturated C(18) long-chain fatty acids (oleic acid and linoleic acid) relative to saturated stearic acid. Our results indicate that certain forms of androgen interruption can inhibit H. hepaticus-induced hepatitis in young male mice, whereas androgen receptor agonism does not worsen disease. This raises the possibility of targeted hormonal therapy in young male patients with childhood-acquired HBV.

  4. Where have all the females gone? Male biased sex-ratio in Arctodiaptomus alpinus (Imhof, 1885) in alpine lakes

    NASA Astrophysics Data System (ADS)

    Žibrat, U.; Brancelj, A.

    2009-04-01

    In populations with both males and females sex-ratio is one of the driving forces of population dynamics. It influences fecundity, inbreeding and social interactions. Sex-ratio is affected by several biotic and abiotic factors, either by selective killing of one sex or by inducing migrations. In alpine lakes of Triglav National Park, Slovenia, an extremely male biased sex-ratio in Arctodiaptomus alpinus (Imhof, 1885) was regularly observed since 1992. We analysed population dynamics and sex-ratio of A. alpinus in three alpine lakes (Jezero v Ledvicah, Rjavo jezero and Zgornje Kriško jezero) from Triglav National Park in Slovenia. In addition to seasonal dynamics we also researched long-term changes in sex-ratio (in a period of 11 years from autumn samples) as a result of increased air-temperature, and zooplankton diurnal vertical migrations. Adults of both sexes were found to appear at the same time in the water collumn with males prevailing throughout the season. A similar trend was found in copepodites CV. The percent of adult females began increasing in late summer, when there were no more copepodites and recrutation from copepodites CV to adults stopped, while male mortality increased. All cohorts of A. alpinus were found to perform diurnal vertical migrations. Both adult and CV females remained close to the bottom during the day and migrated vertically during the night. Results of the long-term study show no changes in sex-ratio in autumn.

  5. Induction of Female-to-Male Sex Change in Adult Zebrafish by Aromatase Inhibitor Treatment

    NASA Astrophysics Data System (ADS)

    Takatsu, Kanae; Miyaoku, Kaori; Roy, Shimi Rani; Murono, Yuki; Sago, Tomohiro; Itagaki, Hideyuki; Nakamura, Masaru; Tokumoto, Toshinobu

    2013-12-01

    This study investigated whether undifferentiated germ and/or somatic stem cells remain in the differentiated ovary of a species that does not undergo sex changes under natural conditions and retain their sexual plasticity. The effect of aromatase inhibitor (AI)-treatment on sexually mature female zebrafish was examined. A 5-month AI treatment caused retraction of the ovaries after which testes-like organs appeared, and cyst structures filled with spermatozoa-like cells were observed in sections of these tissues. Electron microscopic observations revealed that these cells appeared as large sperm heads without tails. Sperm formation was re-examined after changing the diet to an AI-free food. A large number of normal sperm were obtained after eight weeks, and no formation of ovarian tissue was observed. Artificial fertilization using sperm from the sex-changed females was successful. These results demonstrated that sex plasticity remains in the mature ovaries of this species.

  6. Induction of Female-to-Male Sex Change in Adult Zebrafish by Aromatase Inhibitor Treatment

    PubMed Central

    Takatsu, Kanae; Miyaoku, Kaori; Roy, Shimi Rani; Murono, Yuki; Sago, Tomohiro; Itagaki, Hideyuki; Nakamura, Masaru; Tokumoto, Toshinobu

    2013-01-01

    This study investigated whether undifferentiated germ and/or somatic stem cells remain in the differentiated ovary of a species that does not undergo sex changes under natural conditions and retain their sexual plasticity. The effect of aromatase inhibitor (AI)-treatment on sexually mature female zebrafish was examined. A 5-month AI treatment caused retraction of the ovaries after which testes-like organs appeared, and cyst structures filled with spermatozoa-like cells were observed in sections of these tissues. Electron microscopic observations revealed that these cells appeared as large sperm heads without tails. Sperm formation was re-examined after changing the diet to an AI-free food. A large number of normal sperm were obtained after eight weeks, and no formation of ovarian tissue was observed. Artificial fertilization using sperm from the sex-changed females was successful. These results demonstrated that sex plasticity remains in the mature ovaries of this species. PMID:24292399

  7. Sex differences in scent-marking in sifaka: Mating conflict or male services?

    PubMed

    Lewis, Rebecca J

    2005-10-01

    Male and female interests can either be in conflict or serve as a basis for exchange. Communication is thus an important aspect of intersexual relationships. Verreaux's sifaka (Propithecus verreauxi verreauxi), like many prosimians, uses chemical signals as one form of communication. The goals of this study were to determine 1) if males and females exhibit sex differences in their scent-marking behavior, and 2) if scent-marking is an example of mating conflict or cooperation. All occurrences of scent-marks, scent-mark context, and scent-mark style were collected on 23 sifaka in the Kirindy Forest of western Madagascar for 7 months (September 2001-March 2002). Scent-mark rates were collected using continuous focal animal sampling from November 2000-March 2002. Home-range data were collected using monthly censuses and instantaneous focal sampling throughout those 17 months. The pressures of behavioral ecology seem to have shaped scent-marking in sifaka: the sexes exhibited significantly different scent-marking behavior. Results from this study are consistent with the hypotheses that 1) females scent-mark to advertise their presence and mark their resources, 2) clean-chested males use scent-marks as between-group communication to advertise their presence, and 3) stained-chested males use scent-marks as a form of olfactory mate-guarding. Scent-marking does not appear to be a "service" that males provide to females, because overmarking limits female communication rather than adding to the overall number of scent-marks. Scent-marking behavior is a crucial aspect of the mating conflict and for understanding intersexual relationships in sifaka.

  8. Effects of sex role attitudes and similarity on men's rejection of male homosexuals.

    PubMed

    Krulewitz, J E; Nash, J E

    1980-01-01

    The present study investigated reactions to homosexuals as a function of perceived attitude similarity and subjects' sex role attitudes. Male subjects, preselected on the basis of their profeminist, moderate, or antifeminist scores on the Attitude Toward Feminism Scale were assigned at random to one of the four experimental conditions. Using a standard attraction paradigm design, subjects rated a bogus "partner," who was represented as either homosexual or heterosexual and as having attitudes either similar or dissimilar to theirs. Consistent with predictions, similar partners were liked more than dissimilar partners, and heterosexual partners were liked more than homosexuals. Homosexuals were seen as more dissimilar to the subjects in all conditions. Further, liberals were more accepting of homosexuals and dissimilar partners than were traditionals. The results are discussed in terms of the relationship between sex role attitudes and tolerance of dissimilarity. PMID:7373510

  9. Effects of sex role attitudes and similarity on men's rejection of male homosexuals.

    PubMed

    Krulewitz, J E; Nash, J E

    1980-01-01

    The present study investigated reactions to homosexuals as a function of perceived attitude similarity and subjects' sex role attitudes. Male subjects, preselected on the basis of their profeminist, moderate, or antifeminist scores on the Attitude Toward Feminism Scale were assigned at random to one of the four experimental conditions. Using a standard attraction paradigm design, subjects rated a bogus "partner," who was represented as either homosexual or heterosexual and as having attitudes either similar or dissimilar to theirs. Consistent with predictions, similar partners were liked more than dissimilar partners, and heterosexual partners were liked more than homosexuals. Homosexuals were seen as more dissimilar to the subjects in all conditions. Further, liberals were more accepting of homosexuals and dissimilar partners than were traditionals. The results are discussed in terms of the relationship between sex role attitudes and tolerance of dissimilarity.

  10. Identification and Synthesis of the Male-produced Sex Pheromone of the Stink Bug, Pellaea stictica.

    PubMed

    Fávaro, Carla F; Millar, Jocelyn G; Zarbin, Paulo H G

    2015-09-01

    Stink bugs are major pests of a wide variety of agricultural crops worldwide. The species Pellaea stictica is a Neotropical stink bug found in several South American countries. Chromatographic analyses of volatiles released by adults of this species showed that males produce a sex-specific compound, and bioassays with a Y-tube olfactometer showed that the compound was attractive only to females, confirming that it is a sex pheromone. Gas chromatography coupled to mass spectrometry and Fourier transform infrared analyses of the natural compound and several derivatives suggested that the structure was an alcohol with a saturated carbon chain and several methyl branches. After synthesis of two proposed structures, the pheromone of P. stictica was identified as a novel compound, 2,4,8,13-tetramethyltetradecan-1-ol. Laboratory bioassays showed that the synthesized mixture of stereoisomers of 2,4,8,13-tetramethyltetradecan-1-ol was as attractive to P. stictica females as the natural pheromone. PMID:26318441

  11. Sex typing of forensic DNA samples using male- and female-specific probes.

    PubMed

    Naito, E; Dewa, K; Yamanouchi, H; Kominami, R

    1994-07-01

    Forensic DNA samples have been examined to ascertain the feasibility of a sex-typing procedure that we have recently developed. This uses two sets of primers complementary to the DXZ4 and SRY genes for polymerase chain reaction (PCR). PCR target in the DXZ4, an 80-bp sequence within the 130-bp fragment specific to females, is generated from inactive chromosome X by the DNA digestion with a methylation-sensitive restriction enzyme, HpaII. Therefore, the DXZ4 amplification and subsequent agarose gel electrophoresis detect the 80-bp fragment from female DNA. On the other hand, the SRY probe identifies a male-specific sequence on chromosome Y. Testing DNAs from fresh Turner's blood and from postmortem tissues exhibited band-signals confirming the sex identification. Degraded DNAs isolated from severely decomposed specimens were also identifiable when high-molecular-weight DNA was isolated before the assay. This demonstrates the usefulness of this method in forensic identification.

  12. Modeling the suppression of sea lamprey populations by use of the male sex pheromone

    USGS Publications Warehouse

    Klassen, Waldemar; Adams, Jean V.; Twohey, Michael B.

    2005-01-01

    The suppression of sea lamprey populations, Petromyzon marinus (Linnaeus), was modeled using four different applications of the male sex pheromone: (1) pheromone-baited traps that remove females from the spawning population, (2) pheromone-baited decoys that exhaust females before they are able to spawn, (3) pheromone-enhanced sterile males that increase the proportion of non-fertile matings, and (4) camouflaging of the pheromone emitted by calling males to make it difficult for females to find a mate. The models indicated that thousands of traps or hundreds of thousands of decoys would be required to suppress a population of 100,000 animals. The potential efficacy of pheromone camouflages is largely unknown, and additional research is required to estimate how much pheromone is needed to camouflage the pheromone plumes of calling males. Pheromone-enhanced sterile males appear to be a promising application in the Great Lakes. Using this technique for three generations each of ca. 7 years duration could reduce sea lamprey populations by 90% for Lakes Huron and Ontario and by 98% for Lake Michigan, based on current trapping operations that capture 20 to 30% of the population each year.

  13. Male harassment drives females to alter habitat use and leads to segregation of the sexes.

    PubMed

    Darden, Safi K; Croft, Darren P

    2008-10-23

    Sexual conflict is ubiquitous across taxa. It often results in male harassment of females for mating opportunities that are costly for females, in some cases reducing reproductive success and increasing mortality. One strategy that females may employ to avoid sexual harassment is to segregate spatially from males. In fact, we do find sexual segregation in habitat use in species that have high levels of sexual conflict; however, the role of sexual harassment in driving such segregation remains poorly understood. Here, we demonstrate experimentally in a population of wild Trinidadian guppies Poecilia reticulata that male sexual harassment drives females into habitats that they otherwise do not prefer to occupy. In support of the social factors hypothesis for sexual segregation, which states that social factors such as harassment drive sexual segregation, this female behaviour leads to segregation of the sexes. In the presence of males, females actively select areas of high predation risk, but low male presence, and thus trade off increased predation risk against reduced sexual harassment.

  14. Relationship characteristics and HIV transmission risk in same-sex male couples in HIV serodiscordant relationships.

    PubMed

    Starks, Tyrel J; Gamarel, Kristi E; Johnson, Mallory O

    2014-01-01

    Unprotected anal intercourse (UAI) remains a main risk factor for HIV among men who have sex with men (MSM) and this is of particular concern for partners of HIV serodiscordant status. However, HIV transmission risk has been demonstrated to vary by the sexual position adopted among partners. Guided by interdependence theory, this study examined how relational factors were differentially associated with risk taking (HIV-positive/insertive and HIV-negative/receptive) and strategic positioning (HIV-positive/receptive and HIV-negative/insertive) UAI within serodiscordant same-sex male couples. HIV-positive men and their HIV-negative partners (n couples = 91; n individuals = 182) simultaneously but independently completed computerized questionnaires and HIV-positive men had blood drawn for viral load. A minority of couples (30 %) engaged in risk taking and/or strategic positioning unprotected anal sex. Results of multinomial logistic regression indicated that HIV-negative partners' levels of relationship commitment were positively associated with the odds of engaging in strategic positioning sexual behaviors. For HIV-negative partners, reports of relationship intimacy, and sexual satisfaction were negatively associated with odds of reporting risk taking behavior. In contrast, HIV-positive partners' reported sexual satisfaction was positively associated with odds of engaging in risk taking behavior. Findings suggested that aspects of relational quality may be differentially associated with sexual decision making for same-sex male couples in serodiscordant relationships. Study findings lend support for the incorporation of discussions of HIV risk reduction strategies, enhancing communication between partners, and support for general relationship functioning in HIV care.

  15. The impact of sex hormone concentrations on decision-making in females and males

    PubMed Central

    Derntl, Birgit; Pintzinger, Nina; Kryspin-Exner, Ilse; Schöpf, Veronika

    2014-01-01

    Human decision-making has been frequently studied and sex differences have been reported. Interestingly, previous results of hormone concentration on decision-making are somewhat inconsistent, regarding the impact of menstrual cycle phase in women or the influence of testosterone concentration on decision-making in women and men. However, the influence of the female sex hormone concentration (estradiol, progesterone) and the impact of oral contraceptive intake have rarely been examined and data regarding the effect of daytime variations of male testosterone are lacking. Moreover if personality factors such as sensation seeking, impulsivity, and anxiety influence decision-making, sex-specific effects, act as modulators is unclear. In the present study 71 women and 45 men were enrolled. All participants performed an evaluated decision-making task measuring risk-taking behavior on the basis of contingencies (Haegler et al., 2010), which can be carried out several times without a learning effect. Saliva samples were collected to obtain estradiol, progesterone, and testosterone levels. Additionally, all participants completed questionnaires measuring various personality factors. Data analysis revealed no sex differences in decision-making and no significant impact of testosterone concentration on behavioral performance in women or men. However, a significant negative correlation between progesterone concentration of women in the luteal phase and their performance in the risk-averse condition was obtained. Interestingly, a significant correlation between trait anxiety and decision-making occurred in females and males. Despite similar risky decision-making of women and men and no influence of testosterone concentration, menstrual cycle phase showed an effect on risk taking in women. In contrary to other studies, our findings provide rather subtle evidence for hormonal influences in decision-making, which may be primarily explained by task factors. PMID:25414632

  16. The effects of adult sex ratio on mating competition in male and female guppies (Poecilia reticulata) in two wild populations.

    PubMed

    Chuard, Pierre J C; Brown, Grant E; Grant, James W A

    2016-08-01

    When competing for mates, males typically exhibit higher rates of intrasexual aggression and courtship than females. Operational sex ratio, represented here by adult sex ratio (ASR) as a proxy, is likely the best predictor of this competition, which typically increases between members of one sex as members of the opposite sex become rarer. Moreover, in populations subject to high predation, males often decrease mating competitive behaviour due to predation risk. We explored the combined effects of ASR and population of origin (low vs. high ambient predation risk) on mating competition in male and female wild-caught Trinidadian guppies. Both male and female aggression rates increased with ASR, but the increase for males was only significant in the low-predation population. In regard to male mating tactics, courtship propensity was unaffected by ASR, while the propensity to sneak increased at male-biased ASRs. Guppies from a high predation population had lower aggression rates than their low predation counterpart, but male courtship and sneaking attempts did not differ between populations. Surprisingly, females were just as aggressive as males when competing for mates. These results highlight the trade-offs between antipredator and agonistic behaviour, which may affect sexual selection pressures in wild populations.

  17. Sex Differences in Spatial Memory in Brown-Headed Cowbirds: Males Outperform Females on a Touchscreen Task

    PubMed Central

    Guigueno, Mélanie F.; MacDougall-Shackleton, Scott A.; Sherry, David F.

    2015-01-01

    Spatial cognition in females and males can differ in species in which there are sex-specific patterns in the use of space. Brown-headed cowbirds are brood parasites that show a reversal of sex-typical space use often seen in mammals. Female cowbirds, search for, revisit and parasitize hosts nests, have a larger hippocampus than males and have better memory than males for a rewarded location in an open spatial environment. In the current study, we tested female and male cowbirds in breeding and non-breeding conditions on a touchscreen delayed-match-to-sample task using both spatial and colour stimuli. Our goal was to determine whether sex differences in spatial memory in cowbirds generalizes to all spatial tasks or is task-dependant. Both sexes performed better on the spatial than on the colour touchscreen task. On the spatial task, breeding males outperformed breeding females. On the colour task, females and males did not differ, but females performed better in breeding condition than in non-breeding condition. Although female cowbirds were observed to outperform males on a previous larger-scale spatial task, males performed better than females on a task testing spatial memory in the cowbirds’ immediate visual field. Spatial abilities in cowbirds can favour males or females depending on the type of spatial task, as has been observed in mammals, including humans. PMID:26083573

  18. The effects of adult sex ratio on mating competition in male and female guppies (Poecilia reticulata) in two wild populations.

    PubMed

    Chuard, Pierre J C; Brown, Grant E; Grant, James W A

    2016-08-01

    When competing for mates, males typically exhibit higher rates of intrasexual aggression and courtship than females. Operational sex ratio, represented here by adult sex ratio (ASR) as a proxy, is likely the best predictor of this competition, which typically increases between members of one sex as members of the opposite sex become rarer. Moreover, in populations subject to high predation, males often decrease mating competitive behaviour due to predation risk. We explored the combined effects of ASR and population of origin (low vs. high ambient predation risk) on mating competition in male and female wild-caught Trinidadian guppies. Both male and female aggression rates increased with ASR, but the increase for males was only significant in the low-predation population. In regard to male mating tactics, courtship propensity was unaffected by ASR, while the propensity to sneak increased at male-biased ASRs. Guppies from a high predation population had lower aggression rates than their low predation counterpart, but male courtship and sneaking attempts did not differ between populations. Surprisingly, females were just as aggressive as males when competing for mates. These results highlight the trade-offs between antipredator and agonistic behaviour, which may affect sexual selection pressures in wild populations. PMID:27208810

  19. Plant odorants interfere with detection of sex pheromone signals by male Heliothis virescens

    PubMed Central

    Pregitzer, Pablo; Schubert, Marco; Breer, Heinz; Hansson, Bill S.; Sachse, Silke; Krieger, Jürgen

    2012-01-01

    In many insects, mate finding relies on female-released sex pheromones, which have to be deciphered by the male olfactory system within an odorous background of plant volatiles present in the environment of a calling female. With respect to pheromone-mediated mate localization, plant odorants may be neutral, favorable, or disturbing. Here we examined the impact of plant odorants on detection and coding of the major sex pheromone component, (Z)-11-hexadecenal (Z11-16:Ald) in the noctuid moth Heliothis virescens. By in vivo imaging the activity in the male antennal lobe (AL), we monitored the interference at the level of olfactory sensory neurons (OSN) to illuminate mixture interactions. The results show that stimulating the male antenna with Z11-16:Ald and distinct plant-related odorants simultaneously suppressed pheromone-evoked activity in the region of the macroglomerular complex (MGC), where Z11-16:Ald-specific OSNs terminate. Based on our previous findings that antennal detection of Z11-16:Ald involves an interplay of the pheromone binding protein (PBP) HvirPBP2 and the pheromone receptor (PR) HR13, we asked if the plant odorants may interfere with any of the elements involved in pheromone detection. Using a competitive fluorescence binding assay, we found that the plant odorants neither bind to HvirPBP2 nor affect the binding of Z11-16:Ald to the protein. However, imaging experiments analyzing a cell line that expressed the receptor HR13 revealed that plant odorants significantly inhibited the Z11-16:Ald-evoked calcium responses. Together the results indicate that plant odorants can interfere with the signaling process of the major sex pheromone component at the receptor level. Consequently, it can be assumed that plant odorants in the environment may reduce the firing activity of pheromone-specific OSNs in H. virescens and thus affect mate localization. PMID:23060749

  20. Neonatal sex hormones have 'organizational' effects on the hypothalamic-pituitary-adrenal axis of male rats.

    PubMed

    McCormick, C M; Furey, B F; Child, M; Sawyer, M J; Donohue, S M

    1998-02-10

    Sex hormones have activational effects on the hypothalamic-pituitary-adrenal (HPA) axis in adulthood: For example, corticosterone release is influenced by gonadal status. These experiments investigated whether sex hormones have organizational effects on the HPA axis of male rats: Do sex hormones have relatively permanent effects on its development? In adults, both neonatal (neoGDX) and adult gonadectomy (adult GDX) resulted in elevated corticosterone (CORT) levels in response to stress compared to intact rats. Five days of testosterone propionate (TP) replacement was not as effective at attenuating CORT levels in neoGDX rats as in adult GDX rats. Neonatal GDX elevated corticosterone binding globulin (CBG) levels, whereas adult GDX was without effect. In Experiment 2 the effects of neonatal gonadectomy and neonatal treatment with either TP, estradiol benzoate (EB), or oil vehicle was examined. Despite 14 days of hormone replacement, neoGDX showed elevated CORT levels in response to stress compared to all other groups. A single neonatal dose of TP or EB in neoGDX rats eliminated the increased responsiveness. Neonatal TP and EB were without effect in sham-operated rats. Plasma CBG levels were elevated in neoGDX groups regardless of neonatal hormone treatment. Corticosteroid receptor binding levels were examined in various brain areas and the pituitary in two groups most different in their androgen experience: NeoGDX and shams that did not receive treatments as adults. NeoGDX had lower levels of glucocorticoid receptor, and higher levels of mineralocorticoid receptor binding in the pituitary. No other receptor differences were found. These experiments suggest that neonatal sex hormones influence the sensitivity of the HPA axis to sex hormones in adulthood and, thus, that they have organizational effects in addition to activational effects on HPA function.

  1. Evolutionary Consequences of Male Driven Sexual Selection and Sex-Biased Fitness Modifications in Drosophila melanogaster and Members of the simulans Clade

    PubMed Central

    Jagadeeshan, Santosh; Haerty, Wilfried; Moglinicka, Monika; Ahuja, Abha; De Vito, Scot; Singh, Rama S.

    2015-01-01

    Males have evolved a variety of behavioral, morphological, and physiological traits to manipulate their mates in order to maximize their chances of success. These traits are bound to influence how females respond to male behaviors and influence the nature of sexual selection/conflict. A common consequence of aggressive male mating strategies in Drosophila melanogaster is the reduction of female lifespan. Our study shows that this is common across members of the simulans clade. Reduced life expectancy of females implies that female contribution to a population is less than that of males per generation. Fitness differences between the sexes in every generation will invariably affect overall population fitness. How natural selection responds to the female deaths and thereby the unequal fitness of the sexes has rarely been addressed. We shed light on this issue and provide evidence, which suggests that additional gains of fitness by males due to their longevity and continued mating may provide one explanation as to why the loss of female fitness may be “invisible” (effectively neutral) to natural selection. Male driven sexual selection and additional, transgenerational gains of male fitness can be an important force of evolutionary change and need to be tested with other organisms. PMID:26421208

  2. The Size Advantage Model of Sex Allocation in the Protandrous Sex-Changer Crepidula fornicata: Role of the Mating System, Sperm Storage, and Male Mobility.

    PubMed

    Broquet, Thomas; Barranger, Audrey; Billard, Emmanuelle; Bestin, Anastasia; Berger, Rémy; Honnaert, Gaelle; Viard, Frédérique

    2015-09-01

    Sequential hermaphroditism is adaptive when the reproductive value of an individual varies with size or age, and this relationship differs between males and females. In this case, theory shows that the lifetime reproductive output of an individual is increased by changing sex (a hypothesis referred to as the size-advantage model). Sex-linked differences in size-fitness curves can stem from differential costs of reproduction, the mating system, and differences in growth and mortality between sexes. Detailed empirical data is required to disentangle the relative roles of each of these factors within the theory. Quantitative data are also needed to explore the role of sperm storage, which has not yet been considered with sequential hermaphrodites. Using experimental rearing and paternity assignment, we report relationships between size and reproductive success of Crepidula fornicata, a protandrous (male-first) gastropod. Male reproductive success increased with size due to the polygamous system and stacking behavior of the species, but females nonetheless had greater reproductive success than males of the same size, in agreement with the size-advantage theory. Sperm storage appeared to be a critical determinant of success for both sexes, and modeling the effect of sperm storage showed that it could potentially accelerate sex change in protandrous species. PMID:26655357

  3. The Size Advantage Model of Sex Allocation in the Protandrous Sex-Changer Crepidula fornicata: Role of the Mating System, Sperm Storage, and Male Mobility.

    PubMed

    Broquet, Thomas; Barranger, Audrey; Billard, Emmanuelle; Bestin, Anastasia; Berger, Rémy; Honnaert, Gaelle; Viard, Frédérique

    2015-09-01

    Sequential hermaphroditism is adaptive when the reproductive value of an individual varies with size or age, and this relationship differs between males and females. In this case, theory shows that the lifetime reproductive output of an individual is increased by changing sex (a hypothesis referred to as the size-advantage model). Sex-linked differences in size-fitness curves can stem from differential costs of reproduction, the mating system, and differences in growth and mortality between sexes. Detailed empirical data is required to disentangle the relative roles of each of these factors within the theory. Quantitative data are also needed to explore the role of sperm storage, which has not yet been considered with sequential hermaphrodites. Using experimental rearing and paternity assignment, we report relationships between size and reproductive success of Crepidula fornicata, a protandrous (male-first) gastropod. Male reproductive success increased with size due to the polygamous system and stacking behavior of the species, but females nonetheless had greater reproductive success than males of the same size, in agreement with the size-advantage theory. Sperm storage appeared to be a critical determinant of success for both sexes, and modeling the effect of sperm storage showed that it could potentially accelerate sex change in protandrous species.

  4. Androgenic control of male-typical behavior, morphology and sex recognition is independent of the mode of sex determination: A case study on Lichtenfelder's gecko (Eublepharidae: Goniurosaurus lichtenfelderi).

    PubMed

    Golinski, Alison; Kubička, Lukáš; John-Alder, Henry; Kratochvíl, Lukáš

    2015-06-01

    Previous work on lizards has shown that many sexually dimorphic traits depend on testosterone (T), but the details of this control can vary among species. Here, we tested the role of T on the expression of morphological, physiological, and behavioral traits in Lichtenfelder's gecko (Goniurosaurus lichtenfelderi), from the lizard family Eublepharidae notable for interspecific variation in sexually dimorphic traits and the mode of sex determination. Experiments included three groups of males (intact control, surgically castrated, castrated with T replacement) and two groups of females (intact control, T supplemented). In males, castration caused reductions in 1) the size of hemipenes, 2) offensive aggression, 3) male sexual behavior in a neutral arena, 4) activity of precloacal glands, and 5) loss of male chemical cues for sex recognition. These reductions were not observed in castrated males with T replacement. Interestingly, castrated males performed sexual behavior in their home cages, which shows that the effect of T depends on the environmental context. Notably, tail vibration, previously reported as a courtship behavior in other eublepharids, is displayed by males of G. lichtenfelderi during interactions with conspecifics of both sexes, suggesting an evolutionary shift in the meaning of this signal. In females, T induced growth of hemipenes and male-typical courtship but did not induce precloacal pore activity, aggression, or mounting. In comparison to previous reports on Eublepharis macularius, our results indicate that effects of T do not depend on the mode of sex determination. Further, our results extend our understanding of the complexity of control of male traits and illustrate how lability in the effects of T can be a general mechanism causing evolutionary changes in the components of suites of functionally correlated traits.

  5. Sex and Condom Use in a Large Jail Unit for Men Who Have Sex with Men (MSM) and Male-to-Female Transgenders

    PubMed Central

    Harawa, Nina T.; Sweat, Jeffery; George, Sheba; Sylla, Mary

    2013-01-01

    Few data are available on factors contributing to sexual activity and condom use in custody settings, particularly among self-identified sexual minority prisoners. To address this gap, we undertook a study of sexual behavior and condom use of 101 randomly-selected men who have sex with men (MSM) and male-to-female transgender inmates in a segregated Los Angeles jail unit that has weekly condom access. Most survey participants (53%) reported anal sex during custody. Although 65% of these reported using condoms, 75% also reported having sex without condoms. Qualitative interviews (n=17) indicate a wide range of reasons for participating in protected and unprotected sex during custody, the use of cues within the custody environment to assess potential partners’ HIV status, and support for increased condom availability. Findings also indicate that high-risk sex occurs frequently in this unit and that condom distribution likely prevents a substantial amount of related HIV/STD risk. PMID:20693745

  6. Social Deficits in Male Children and Adolescents with Sex Chromosome Aneuploidy: A Comparison of XXY, XYY, and XXYY Syndromes

    ERIC Educational Resources Information Center

    Cordeiro, Lisa; Tartaglia, Nicole; Roeltgen, David; Ross, Judith

    2012-01-01

    We compare social skills in three groups of males with sex chromosome aneuploidies (SCAs) using the Social Responsiveness Scale (SRS). Participants included males with XXY (N = 102, M = 10.08 years), XYY (N = 40, M = 9.93 years), and XXYY (N = 32, M = 11.57 years). XXY had lower (better) SRS scores compared to XYY and XXYY. Scores were not…

  7. Sex Differentials in Unemployment Rates in Male-dominated Occupations and Industries during Periods of Economic Downturn.

    ERIC Educational Resources Information Center

    Monk-Turner, Elizabeth

    A study examined the ways in which cyclical changes in the business cycle affect unemployment rates by sex in male-dominated occupations and industries. Using data from the monthly reports on employment and earnings issued by the U.S. Bureau of Labor Statistics (1969-1982), the report examined employment rates in selected male-dominated and…

  8. Determinants of recent HIV testing among male sex workers and other men who have sex with men in Shenzhen, China: a cross-sectional study.

    PubMed

    Cai, Rui; Cai, Wende; Zhao, Jin; Chen, Lin; Yang, Zhengrong; Tan, Wei; Zhang, Chenli; Gan, Yongxia; Zhang, Yan; Tan, Jingguang; Richards, Jan Hendrik; De Vlas, Sake J

    2015-11-01

    We recruited 510 male sex workers (also referred as 'money boys' (MBs) and 533 other men who have sex with men (MSM) to investigate determinants of recent (last year) HIV testing in Shenzhen, China. Overall, 43% of MBs and 48% of other MSM reported having been tested for HIV in the last year. The most important determinant of testing among MBs was having multiple anal sex partners; among other MSM, the most important determinants were having a homosexual orientation and having a history of sexually transmissible infection. For MBs, education programs are needed to increase their awareness of actual HIV risk. For other MSM, destigmatising programs are needed. PMID:26364154

  9. Identification and validation of a new male sex-specific ISSR marker in pointed gourd (Trichosanthes dioica Roxb.).

    PubMed

    Adhikari, Sinchan; Saha, Soumen; Bandyopadhyay, Tapas Kumar; Ghosh, Parthadeb

    2014-01-01

    The aim of the present study was to develop a genetic sex marker for the pointed gourd (Trichosanthes dioica Roxb.) to allow gender determination at any stage in the life cycle. Screening of genomic DNA with intersimple sequence repeat (ISSR) primers was used to discover sex-specific touch-down polymerase chain reaction (Td-PCR) amplification products. Using pooled DNA from male and female genotypes and 42 ISSR primers, a putative male specific marker (~550 bp) was identified. DNA marker specific to male is an indication of existence of nonepigenetic factors involved in gender development in pointed gourd. The ISSR technique has proved to be a reliable technique in gender determination of pointed gourd genotypes at the seedling phenophase. The sex marker developed here could also be used as a starting material towards sequence characterization of sex linked genes for better understanding the developmental as well as evolutionary pathways in sexual dimorphism. PMID:25538949

  10. The syndemic condition of psychosocial problems and HIV risk among male sex workers in Ho Chi Minh City, Vietnam.

    PubMed

    Biello, Katie B; Colby, Donn; Closson, Elizabeth; Mimiaga, Matthew J

    2014-07-01

    In Vietnam, the co-occurrence (i.e., "syndemic") of psychosocial factors (e.g., depression and substance use) may disproportionately burden male sex workers and increase their HIV risk. A comprehensive survey was conducted among 300 male sex workers in Ho Chi Minh City, Vietnam in 2010. We performed logistic regression to examine the association between the syndemic variable-a count score of the number of five psychosocial conditions endorsed-and unprotected anal sex (UAS) in the past. One-third of participants reported any UAS, and 42 % reported ≥2 psychosocial health problems. In multivariable models, experiencing ≥4 psychosocial health problems was significantly associated with UAS. Every unit increase in number of psychosocial health problems was associated with a 25-30 % increase in odds of UAS. Understanding the syndemic condition and its association with HIV risk among male sex workers in Vietnam may lead to the development of more effective, comprehensive interventions.

  11. Identification and Validation of a New Male Sex-Specific ISSR Marker in Pointed Gourd (Trichosanthes dioica Roxb.)

    PubMed Central

    Adhikari, Sinchan; Saha, Soumen; Bandyopadhyay, Tapas Kumar

    2014-01-01

    The aim of the present study was to develop a genetic sex marker for the pointed gourd (Trichosanthes dioica Roxb.) to allow gender determination at any stage in the life cycle. Screening of genomic DNA with intersimple sequence repeat (ISSR) primers was used to discover sex-specific touch-down polymerase chain reaction (Td-PCR) amplification products. Using pooled DNA from male and female genotypes and 42 ISSR primers, a putative male specific marker (~550 bp) was identified. DNA marker specific to male is an indication of existence of nonepigenetic factors involved in gender development in pointed gourd. The ISSR technique has proved to be a reliable technique in gender determination of pointed gourd genotypes at the seedling phenophase. The sex marker developed here could also be used as a starting material towards sequence characterization of sex linked genes for better understanding the developmental as well as evolutionary pathways in sexual dimorphism. PMID:25538949

  12. The Sex Attractant Pheromone of Male Brown Rats: Identification and Field Experiment.

    PubMed

    Takács, Stephen; Gries, Regine; Zhai, Huimin; Gries, Gerhard

    2016-05-10

    Trapping brown rats is challenging because they avoid newly placed traps in their habitat. Herein, we report the identification of the sex pheromone produced by male brown rats and its effect on trap captures of wild female brown rats. Collecting urine- and feces-soiled bedding material of laboratory-kept rats and comparing the soiled-bedding odorants of juvenile and adult males, as well as of adult males and females, we found nine compounds that were specific to, or most prevalent in, the odor profiles of sexually mature adult males. When we added a synthetic blend of six of these compounds (2-heptanone, 4-heptanone, 3-ethyl-2-heptanone, 2-octanone, 2-nonanone, 4-nonanone) to one of two paired food-baited trap boxes, these boxes attracted significantly more laboratory-strain female rats in laboratory experiments, and captured ten times more wild female rats in a field experiment than the corresponding control boxes. Our data show that the pheromone facilitates captures of wild female brown rats. PMID:27060700

  13. Meiotic sex chromosome inactivation is disrupted in sterile hybrid male house mice.

    PubMed

    Campbell, Polly; Good, Jeffrey M; Nachman, Michael W

    2013-03-01

    In male mammals, the X and Y chromosomes are transcriptionally silenced in primary spermatocytes by meiotic sex chromosome inactivation (MSCI) and remain repressed for the duration of spermatogenesis. Here, we test the longstanding hypothesis that disrupted MSCI might contribute to the preferential sterility of heterogametic hybrid males. We studied a cross between wild-derived inbred strains of Mus musculus musculus and M. m. domesticus in which sterility is asymmetric: F1 males with a M. m. musculus mother are sterile or nearly so while F1 males with a M. m. domesticus mother are normal. In previous work, we discovered widespread overexpression of X-linked genes in the testes of sterile but not fertile F1 males. Here, we ask whether this overexpression is specifically a result of disrupted MSCI. To do this, we isolated cells from different stages of spermatogenesis and measured the expression of several genes using quantitative PCR. We found that X overexpression in sterile F1 primary spermatocytes is coincident with the onset of MSCI and persists in postmeiotic spermatids. Using a series of recombinant X genotypes, we then asked whether X overexpression in hybrids is controlled by cis-acting loci across the X chromosome. We found that it is not. Instead, one large interval in the proximal portion of the M. m. musculus X chromosome is associated with both overexpression and the severity of sterility phenotypes in hybrids. These results demonstrate a strong association between X-linked hybrid male sterility and disruption of MSCI and suggest that trans-acting loci on the X are important for the transcriptional regulation of the X chromosome during spermatogenesis.

  14. Sex differences in impaling behaviour of Great Grey Shrike Lanius excubitor: do males have better impaling skills than females?

    PubMed

    Antczak, Marcin; Hromada, Martin; Tryjanowski, Piotr

    2012-09-01

    Prey impaling in shrikes Laniidae is considered to be a feeding adaptation to dismember and consume large prey and is unique among food-storing animals. However, other exaptations of this behaviour were recorded, including signals in mate choice, where cache size is a sign of male quality. Thus, due to a strong sexual selection, male and female birds might differ in their behavioural patterns of impaling behaviour. We examined sex differences in impaling behaviour of the Great Grey Shrike Lanius excubitor - one of the species where caches are known to be sexual signals. Data were collected in western Poland during breeding seasons in the years 2006-2010. In the studied population, we recorded several sex-specific differences in impaling behaviour. Males impaled prey, invertebrates as well as vertebrates, faster and with fewer attempts per impaling event than females. Sexes differed in the location of impaled prey; males selected more visible places, especially during the mating and courtship phase, whereas females impaled prey in concealed locations. Males also had slightly better impaling success compared to females. We suggest that sex differences in impaling behaviour may be due to different uses of impaled prey, and the better impaling skills of males may be the result of better experience in impaling which is forced by sexual selection in this species. We also discuss other factors which might trigger sex-specific differences in food caching by shrikes.

  15. The Role of Clitoral Anatomy in Female to Male Sex Reassignment Surgery

    PubMed Central

    2014-01-01

    Introduction. Controversies on clitoral anatomy and its role in female sexual function still make clitoral reconstructive surgery very challenging. We evaluated the role of clitoral anatomic features in female to male sex reassignment surgery. Material and Methods. The study included 97 female transsexuals, aged from 18 to 41 years, who underwent single stage metoidioplasty between March 2008 and January 2013. The operative technique involved vaginectomy, the release of clitoral ligaments and urethral plate, urethroplasty by combining buccal mucosa graft and genital flaps, and scrotoplasty with insertion of testicle prostheses. Postoperative questionnaire was used to evaluate aesthetic, functional, and sexual outcome. Results. The mean followup was 30 months. The mean length of the neophallus was 7 cm, compared to mean preoperative length of the hypertrophied clitoris of 3.3 cm. Complications occurred in 27.84% of all patients, related mostly to urethroplasty. Voiding while standing was achieved in all cases. None of the patients had problems in sexual arousal, masturbation, or orgasms. Conclusion. Accurate knowledge of the clitoral anatomy, physiology, and neurovascular supply is crucial for a successful outcome of female to male sex reassignment surgery. Our approach appears to ensure overall satisfaction and high quality of sexual life. PMID:24982953

  16. Gentamicin Induced Nephrotoxicity: The Role of Sex Hormones in Gonadectomized Male and Female Rats

    PubMed Central

    Eshraghi-Jazi, Fatemeh; Talebi, Ardeshir; Moslemi, Fatemeh

    2016-01-01

    Background. Gentamicin (GM) induced nephrotoxicity may be sex hormones related. The effects of sex hormones on GM induced nephrotoxicity in gonadectomized rats were investigated. Methods. Ovariectomized rats received 0.25, 0.5, or 1 mg/kg/week of estradiol (ES) alone or accompanied with 10 mg/kg/week of progesterone (Pro) for two weeks followed by GM (100 mg/kg/day) for 9 days. Castrated rats were also treated with 10, 50, or 100 mg/kg/week of testosterone (TS) for two weeks and then received GM. In addition, a single castrated group received 0.25 mg/kg/week of ES plus GM. Results. GM increased the serum levels of blood urea nitrogen (BUN) and creatinine (Cr) and kidney tissue damage score (KTDS) (P < 0.05). TS had no effect on the serum levels of BUN and Cr and KTDS, while low dose of ES intensified these parameters in male (P < 0.05). ES (0.5 mg/kg) without Pro ameliorated KTDS in female (P < 0.05) while ES (1 mg/kg) with or without Pro exacerbated the BUN values and Cr values, KTDS, and body weight loss (P < 0.05). Conclusion. ES (0.5 mg/kg) without Pro ameliorated kidney damage induced by GM in female while neither TS nor ES had beneficial effect on nephrotoxicity induced by GM in male, although ES aggravated it. PMID:27213082

  17. The balancing act: exploring stigma, economic need and disclosure among male sex workers in Ho Chi Minh City, Vietnam.

    PubMed

    Closson, Elizabeth F; Colby, Donn J; Nguyen, Thi; Cohen, Samuel S; Biello, Katie; Mimiaga, Matthew J

    2015-01-01

    In Vietnam, there is an emerging HIV epidemic among men who have sex with men (MSM). Male sex workers engage in high-risk sexual behaviours that make them particularly vulnerable to HIV infection. In 2010, 23 MSM in Ho Chi Minh City (HCMC) who recently received payment for sex with another man completed in-depth qualitative interviews exploring motivations for sex work, patterns of sex work disclosure and experiences of social stigma. Interviews were recorded, transcribed and translated into English and analysed using a qualitative descriptive approach. Low wages, unstable employment and family remittances were motivating factors for MSM in HCMC to sell sex. Participants described experiences of enacted and felt social stigma related to their involvement in sex work. In response, they utilised stigma management techniques aimed at concealment of involvement in sex work. Such strategies restricted sexual communication with non-paying sex partners and potentially limited their ability to seek social support from family and friends. Departing from decontextualized depictions of sex work disclosure, our findings describe how decisions to reveal involvement in sex work are shaped by social and structural factors such as social stigma, techniques to minimise exposure to stigma, economic imperatives and familial responsibilities.

  18. Expression analysis of sex-determining pathway genes during development in male and female Atlantic salmon (Salmo salar).

    PubMed

    Lubieniecki, Krzysztof P; Botwright, Natasha A; Taylor, Richard S; Evans, Brad S; Cook, Mathew T; Davidson, William S

    2015-12-01

    We studied the expression of 28 genes that are involved in vertebrate sex-determination or sex-differentiation pathways, in male and female Atlantic salmon (Salmo salar) in 11 stages of development from fertilization to after first feeding. Gene expression was measured in half-sibs that shared the same dam. The sire of family 1 was a sex-reversed female (i.e., genetically female but phenotypically male), and so the progeny of this family are all female. The sire of family 2 was a true male, and so the offspring were 50% male and 50% female. Gene expression levels were compared among three groups: 20 female offspring of the cross between a regular female and the sex-reversed female (family 1, first group), ∼ 10 females from the cross between a regular female and a regular male (family 2, second group) and ∼ 10 males from this same family (family 2, third group). Statistically significant differences in expression levels between males and the two groups of females were observed for two genes, gsdf and amh/mis, in the last four developmental stages examined. SdY, the sex-determining gene in rainbow trout, appeared to be expressed in males from 58 days postfertilization (dpf). Starting at 83 dpf, ovarian aromatase, cyp19a, expression appeared to be greater in both groups of females compared with males, but this difference was not statistically significant. The time course of expression suggests that sdY may be involved in the upregulation of gsdf and amh/mis and the subsequent repression of cyp19a in males via the effect of amh/mis.

  19. Breeding periodicity for male sea turtles, operational sex ratios, and implications in the face of climate change.

    PubMed

    Hays, Graeme C; Fossette, Sabrina; Katselidis, Kostas A; Schofield, Gail; Gravenor, Mike B

    2010-12-01

    Species that have temperature-dependent sex determination (TSD) often produce highly skewed offspring sex ratios contrary to long-standing theoretical predictions. This ecological enigma has provoked concern that climate change may induce the production of single-sex generations and hence lead to population extirpation. All species of sea turtles exhibit TSD, many are already endangered, and most already produce sex ratios skewed to the sex produced at warmer temperatures (females). We tracked male loggerhead turtles (Caretta caretta) from Zakynthos, Greece, throughout the entire interval between successive breeding seasons and identified individuals on their breeding grounds, using photoidentification, to determine breeding periodicity and operational sex ratios. Males returned to breed at least twice as frequently as females. We estimated that the hatchling sex ratio of 70:30 female to male for this rookery will translate into an overall operational sex ratio (OSR) (i.e., ratio of total number of males vs females breeding each year) of close to 50:50 female to male. We followed three male turtles for between 10 and 12 months during which time they all traveled back to the breeding grounds. Flipper tagging revealed the proportion of females returning to nest after intervals of 1, 2, 3, and 4 years were 0.21, 0.38, 0.29, and 0.12, respectively (mean interval 2.3 years). A further nine male turtles were tracked for short periods to determine their departure date from the breeding grounds. These departure dates were combined with a photoidentification data set of 165 individuals identified on in-water transect surveys at the start of the breeding season to develop a statistical model of the population dynamics. This model produced a maximum likelihood estimate that males visit the breeding site 2.6 times more often than females (95%CI 2.1, 3.1), which was consistent with the data from satellite tracking and flipper tagging. Increased frequency of male breeding will

  20. The brain organization of the lichen moth Eilema japonica, which secretes an alkenyl sex pheromone.

    PubMed

    Namiki, Shigehiro; Fujii, Takeshi; Ishikawa, Yukio; Kanzaki, Ryohei

    2012-10-01

    The neuroanatomy of the brain is important for the functional analysis of sex pheromone recognition in moths. Most moths use either of two types of compounds, aliphatic or alkenyl compounds, as sex pheromones. As previous studies on the neuroanatomy of moths have mostly been carried out using moths that use aliphatic compounds, information on the brain of moths that use alkenyl compounds is scarce. Here, we describe the brain anatomy of the male lichen-feeding moth Eilema japonica (Lepidoptera: Arctiidae), which uses a mixture of alkenyl compounds as a sex pheromone. We reconstructed the major neuropils in the midbrain of E. japonica and compared them with those of the silkmoth, which uses an aliphatic derivative as a sex pheromone. The brain organization of the two species was basically similar, except for the size of the macroglomerular complex, where pheromone information is processed. The macroglomerular complex in E. japonica consisted of four large glomeruli, which were positioned along dorsoventral and anterior-posterior axes. The glomerulus at the site of entry of the antennal nerve was shown to have the largest volume. The number of glomeruli was equal to the number of pheromone components that are crucial for orientation behavior in E. japonica.

  1. Male Sex is Associated with a Reduced Alveolar Epithelial Sodium Transport

    PubMed Central

    Kaltofen, Till; Haase, Melanie; Thome, Ulrich H.; Laube, Mandy

    2015-01-01

    Respiratory distress syndrome (RDS) is the most frequent pulmonary complication in preterm infants. RDS incidence differs between genders, which has been called the male disadvantage. Besides maturation of the surfactant system, Na+ transport driven alveolar fluid clearance is crucial for the prevention of RDS. Na+ transport is mediated by the epithelial Na+ channel (ENaC) and the Na,K-ATPase, therefore potential differences in their expression or activity possibly contribute to the gender imbalance observed in RDS. Fetal distal lung epithelial (FDLE) cells of rat fetuses were separated by sex and analyzed regarding expression and activity of the Na+ transporters. Ussing chamber experiments showed a higher baseline short-circuit current (ISC) and amiloride-sensitive ΔISC in FDLE cells of female origin. In addition, maximal amiloride-sensitive ΔISC and maximal ouabain-sensitive ΔISC of female cells were higher when measured in the presence of a permeabilized basolateral or apical membrane, respectively. The number of FDLE cells per fetus recoverable during cell isolation was also significantly higher in females. In addition, lung wet-to-dry weight ratio was lower in fetal and newborn female pups. Female derived FDLE cells had higher mRNA levels of the ENaC- and Na,K-ATPase subunits. Furthermore, estrogen (ER) and progesterone receptor (PR) mRNA levels were higher in female cells, which might render female cells more responsive, while concentrations of placenta-derived sex steroids do not differ between both genders during fetal life. Inhibition of ER-β abolished the sex differences in Na+ transport and female cells were more responsive to estradiol stimulation. In conclusion, a higher alveolar Na+ transport, possibly attributable to a higher expression of hormone receptors in female FDLE cells, provides an explanation for the well known sex-related difference in RDS occurrence and outcome. PMID:26291531

  2. Male Sex is Associated with a Reduced Alveolar Epithelial Sodium Transport.

    PubMed

    Kaltofen, Till; Haase, Melanie; Thome, Ulrich H; Laube, Mandy

    2015-01-01

    Respiratory distress syndrome (RDS) is the most frequent pulmonary complication in preterm infants. RDS incidence differs between genders, which has been called the male disadvantage. Besides maturation of the surfactant system, Na+ transport driven alveolar fluid clearance is crucial for the prevention of RDS. Na+ transport is mediated by the epithelial Na+ channel (ENaC) and the Na,K-ATPase, therefore potential differences in their expression or activity possibly contribute to the gender imbalance observed in RDS. Fetal distal lung epithelial (FDLE) cells of rat fetuses were separated by sex and analyzed regarding expression and activity of the Na+ transporters. Ussing chamber experiments showed a higher baseline short-circuit current (ISC) and amiloride-sensitive ΔISC in FDLE cells of female origin. In addition, maximal amiloride-sensitive ΔISC and maximal ouabain-sensitive ΔISC of female cells were higher when measured in the presence of a permeabilized basolateral or apical membrane, respectively. The number of FDLE cells per fetus recoverable during cell isolation was also significantly higher in females. In addition, lung wet-to-dry weight ratio was lower in fetal and newborn female pups. Female derived FDLE cells had higher mRNA levels of the ENaC- and Na,K-ATPase subunits. Furthermore, estrogen (ER) and progesterone receptor (PR) mRNA levels were higher in female cells, which might render female cells more responsive, while concentrations of placenta-derived sex steroids do not differ between both genders during fetal life. Inhibition of ER-β abolished the sex differences in Na+ transport and female cells were more responsive to estradiol stimulation. In conclusion, a higher alveolar Na+ transport, possibly attributable to a higher expression of hormone receptors in female FDLE cells, provides an explanation for the well known sex-related difference in RDS occurrence and outcome.

  3. Effects of zinc on male sex hormones and semen quality in rats.

    PubMed

    Egwurugwu, J N; Ifedi, C U; Uchefuna, R C; Ezeokafor, E N; Alagwu, E A

    2013-01-01

    This study assessed the effects of zinc on male sex hormones and semen quality in male albino wistar rats. Forty rats weighing between 150- 210g, grouped into 5 of 8 rats each, were used for the research that lasted for six weeks. Group I, the control group, received normal rat chow and water ad libitum. The four test groups II-V, received 20g, 40g, 60g and 80g of zinc sulphate mixed with their rat chow respectively in addition to water for six weeks. Blood samples were collected and assayed for Luteinizing hormone (LH), follicle stimulating hormone (FSH), Prolactin (PL), testosterone (T), progesterone and oestradiol. Semen was also analysed for sperm motility, sperm count and morphology. Results showed statistically significant decrease in serum levels of follicle stimulating hormone (FSH) (p< 0.05) in groups II and IV with mean values of 0.10±0.00 and 1.20±0.00 respectively when compared with the control (1.10±0.10). The results also revealed statistically significant increase in the serum levels of testosterone in groups II, III and IV with mean values of 3.60±1.40, 4.5±0.30 and 0.80±0.70 respectively when compared with the control with a value of 0.35±0.15. The increase in testosterone levels were dose dependent as there were consistent increment in groups II and III after which the levels decreased with increasing zinc concentrations. There was statistically significant dose dependent decrease in sperm motility and morphology in the test groups compared with the control (p<0.05). In conclusion, zinc sulphate has some significant positive effects on male sex hormones and sperm quality at doses within physiological levels but harmful at higher doses.

  4. Prevalence and associated factors of condomless receptive anal intercourse with male clients among transgender women sex workers in Shenyang, China

    PubMed Central

    Cai, Yong; Wang, Zixin; Lau, Joseph TF; Li, Jinghua; Ma, Tiecheng; Liu, Yan

    2016-01-01

    Introduction Globally, transgender women sex workers have a high prevalence of HIV and condomless receptive anal intercourse with male clients (CRAIMC). We investigated the prevalence of CRAIMC and factors associated with CRAIMC among transgender women sex workers in China. Methods In 2014, we anonymously interviewed 220 transgender women sex workers face to face in Shenyang, China. Those who self-reported as HIV negative or as having unknown HIV serostatus were invited to take up free, anonymous HIV rapid testing (n=183); 90 did so. Using CRAIMC in the last month as the dependent variable, three types of associated factors were investigated, in addition to background factors: feminizing medical interventions, sex work and perceptions related to condom use. Univariate and multiple logistic regression models were fitted. Results Of the participants, 16.8% self-reported as HIV positive and 9.1% were detected to be HIV positive through free HIV testing; 26.8% had had CRAIMC in the last month, 45.5% had performed sex work in other Chinese cities (last year), and 23.2% had had condomless anal intercourse with men who were non-clients. In the adjusted analysis, significant factors associated with CRAIMC (last month) included the following: 1) any feminizing medical intervention performed (adjusted odds ratio, AOR: 2.22); 2) sex-work-related factors, including recruitment of male clients most often at hotels (AOR: 5.02) and charge per episode of transactional sex (201 to 400 RMB, AOR: 0.27; reference group: ≤100 RMB); and 3) perceptions related to condom use, including perceived transgender identity's impact on condomless sex such as wearing feminine attire, concern about exposing their status as a transgender woman to male clients (AOR: 1.20) and perceived self-efficacy of consistent condom use with male clients (AOR: 0.56). Perceived self-efficacy of consistent condom use with male clients fully mediated the association between perceived transgender identity's impact

  5. MicroRNAs Influence Reproductive Responses by Females to Male Sex Peptide in Drosophila melanogaster

    PubMed Central

    Fricke, Claudia; Green, Darrell; Smith, Damian; Dalmay, Tamas; Chapman, Tracey

    2014-01-01

    Across taxa, female behavior and physiology change significantly following the receipt of ejaculate molecules during mating. For example, receipt of sex peptide (SP) in female Drosophila melanogaster significantly alters female receptivity, egg production, lifespan, hormone levels, immunity, sleep, and feeding patterns. These changes are underpinned by distinct tissue- and time-specific changes in diverse sets of mRNAs. However, little is yet known about the regulation of these gene expression changes, and hence the potential role of microRNAs (miRNAs), in female postmating responses. A preliminary screen of genomic responses in females to receipt of SP suggested that there were changes in the expression of several miRNAs. Here we tested directly whether females lacking four of the candidate miRNAs highlighted (miR-279, miR-317, miR-278, and miR-184) showed altered fecundity, receptivity, and lifespan responses to receipt of SP, when mated once or continually to SP null or control males. The results showed that miRNA-lacking females mated to SP null males exhibited altered receptivity, but not reproductive output, in comparison to controls. However, these effects interacted significantly with the genetic background of the miRNA-lacking females. No significant survival effects were observed in miRNA-lacking females housed continually with SP null or control males. However, continual exposure to control males that transferred SP resulted in significantly higher variation in miRNA-lacking female lifespan than did continual exposure to SP null males. The results provide the first insight into the effects and importance of miRNAs in regulating postmating responses in females. PMID:25245794

  6. Unique sex chromosome systems in Ellobius: How do male XX chromosomes recombine and undergo pachytene chromatin inactivation?

    PubMed Central

    Matveevsky, Sergey; Bakloushinskaya, Irina; Kolomiets, Oxana

    2016-01-01

    Most mammalian species have heteromorphic sex chromosomes in males, except for a few enigmatic groups such as the mole voles Ellobius, which do not have the Y chromosome and Sry gene. The Ellobius (XX ♀♂) system of sex chromosomes has no analogues among other animals. The structure and meiotic behaviour of the two X chromosomes were investigated for males of the sibling species Ellobius talpinus and Ellobius tancrei. Their sex chromosomes, despite their identical G-structure, demonstrate short synaptic fragments and crossover-associated MLH1 foci in both telomeric regions only. The chromatin undergoes modifications in the meiotic sex chromosomes. SUMO-1 marks a small nucleolus-like body of the meiotic XX. ATR and ubiH2A are localized in the asynaptic area and the histone γH2AFX covers the entire XX bivalent. The distribution of some markers of chromatin inactivation differentiates sex chromosomes of mole voles from those of other mammals. Sex chromosomes of both studied species have identical recombination and meiotic inactivation patterns. In Ellobius, similar chromosome morphology masks the functional heteromorphism of the male sex chromosomes, which can be seen at meiosis. PMID:27425629

  7. Unique sex chromosome systems in Ellobius: How do male XX chromosomes recombine and undergo pachytene chromatin inactivation?

    PubMed

    Matveevsky, Sergey; Bakloushinskaya, Irina; Kolomiets, Oxana

    2016-07-18

    Most mammalian species have heteromorphic sex chromosomes in males, except for a few enigmatic groups such as the mole voles Ellobius, which do not have the Y chromosome and Sry gene. The Ellobius (XX ♀♂) system of sex chromosomes has no analogues among other animals. The structure and meiotic behaviour of the two X chromosomes were investigated for males of the sibling species Ellobius talpinus and Ellobius tancrei. Their sex chromosomes, despite their identical G-structure, demonstrate short synaptic fragments and crossover-associated MLH1 foci in both telomeric regions only. The chromatin undergoes modifications in the meiotic sex chromosomes. SUMO-1 marks a small nucleolus-like body of the meiotic XX. ATR and ubiH2A are localized in the asynaptic area and the histone γH2AFX covers the entire XX bivalent. The distribution of some markers of chromatin inactivation differentiates sex chromosomes of mole voles from those of other mammals. Sex chromosomes of both studied species have identical recombination and meiotic inactivation patterns. In Ellobius, similar chromosome morphology masks the functional heteromorphism of the male sex chromosomes, which can be seen at meiosis.

  8. Structural vulnerability and access to medical care among migrant street-based male sex workers in Germany.

    PubMed

    Castañeda, Heide

    2013-05-01

    This article discusses health concerns of migrant street-based male sex workers (SMSW) in Germany, a population that remains underexplored by health and social scientists. It is based on five months of ethnographic research in 2011/2012, including 46 semi-structured interviews with physicians, social workers, health department staff, and SMSW from Romania and Bulgaria. This is supplemented with annual reports by organizations providing assistance to this population in eight cities. The article contributes, first, an analysis of the increase in migrant SMSW as a response to economic opportunities (freedom of movement across European Union borders) and constraints (transitional measures restricting access to the labor market). It seeks to move beyond the myopic association between sex work and HIV to contextualize health risks as resultant of macro-level processes associated with migration. Second, the article contributes a summary of primary health concerns for this population. Especially troubling is their lack of access to regular medical services, reflecting a socio-legal position that often resembles that of unauthorized migrants rather than European Union citizens.

  9. Structural vulnerability and access to medical care among migrant street-based male sex workers in Germany.

    PubMed

    Castañeda, Heide

    2013-05-01

    This article discusses health concerns of migrant street-based male sex workers (SMSW) in Germany, a population that remains underexplored by health and social scientists. It is based on five months of ethnographic research in 2011/2012, including 46 semi-structured interviews with physicians, social workers, health department staff, and SMSW from Romania and Bulgaria. This is supplemented with annual reports by organizations providing assistance to this population in eight cities. The article contributes, first, an analysis of the increase in migrant SMSW as a response to economic opportunities (freedom of movement across European Union borders) and constraints (transitional measures restricting access to the labor market). It seeks to move beyond the myopic association between sex work and HIV to contextualize health risks as resultant of macro-level processes associated with migration. Second, the article contributes a summary of primary health concerns for this population. Especially troubling is their lack of access to regular medical services, reflecting a socio-legal position that often resembles that of unauthorized migrants rather than European Union citizens. PMID:23455375

  10. Sex Education for Male Adolescent Sex Offenders in a Group Setting Led by General Psychiatry Residents: A Literature Review and Example in Practice

    ERIC Educational Resources Information Center

    Dwyer, R. Gregg; Boyd, Mary S.

    2009-01-01

    Male adolescents have been credited with a significant percentage of sex crimes in recent years. They are a heterogeneous population with offenses spanning the same range found among adult offenders. A lack of interpersonal social skills relevant to intimate relationships and inaccurate knowledge regarding appropriate sexual behaviors contribute…

  11. 1-Tridecene—male-produced sex pheromone of the tenebrionid beetle Parastizopus transgariepinus

    NASA Astrophysics Data System (ADS)

    Geiselhardt, Sven; Ockenfels, Peter; Peschke, Klaus

    2008-03-01

    Males of the genus Parastizopus (Coleoptera: Tenebrionidae) exhibit a special pheromone-emitting behaviour. They do a headstand, expose the aedeagus and remain in this posture for a few seconds. The pheromone emitted by P. transgariepinus was collected by solid-phase micro-extraction (100 μm polydimethylsiloxane fibre) and identified as 1-tridecene by gas chromatography/mass spectrometry. Presumably, this compound originates from the aedeagal gland, a special feature in Parastizopus, as 1-tridecene is the main compound in the gland reservoirs (23.6 ± 3.8%), accompanied by various less volatile fatty acid esters (25.2 ± 2.0%) and hydrocarbons (51.2 ± 5.7%). 1-Tridecene is also part of the pygidial defensive secretion of both sexes, together with other 1-alkenes, monoterpene hydrocarbons and 1,4-benzoquinones, but as none of these other compounds was detected during calling, the pygidial gland could be ruled out as pheromone source. Extracts of the aedeagal gland reservoirs and the pygidial defensive secretion contained comparable amounts of 1-tridecene, 1.24 ± 0.41 and 1.88 ± 0.54 μg/male, respectively. Chemo-orientation experiments using a servosphere showed that 1 μg of 1-tridecene was attractive to females but not to males.

  12. Eysenck's personality dimensions and sex steroids in male abstinent alcoholics and nonalcoholics: an exploratory study.

    PubMed

    King, A C; Errico, A L; Parsons, O A

    1995-02-01

    This study investigated the relationship between alcoholics' personality characteristics [as indexed by the Eysenck Personality Questionnaire (EPQ)] and sex steroid levels. Three serum samples were drawn over a 90-min period in 58 inpatient male alcoholics (mean 33 days sober) and 33 non-alcoholic controls. The EPQ was administered at approximately the same point in the treatment process. Replicating previous work, we found alcoholics scored significantly higher on the Neuroticism and Psychoticism scales of the EPQ than controls. Alcoholics also had higher levels of estradiol and total testosterone than controls, which may be reflective of a biological rebound or characteristic premorbid levels. A significant positive correlation was found between testosterone and extroversion in controls, but not in alcoholics. Alcoholics showed a positive correlation between estradiol and neuroticism and a negative relationship between estradiol and extroversion. The results suggest that (a) 'normal' hormone-personality relationships are disrupted in male alcoholics, and b) personality and psychological changes consistent with the physical feminization syndrome may occur in male alcoholics.

  13. Male-biased sex allocation in ageing parents; a longitudinal study in a long-lived seabird.

    PubMed

    Vedder, Oscar; Bouwhuis, Sandra; Benito, María M; Becker, Peter H

    2016-08-01

    Optimal sex allocation is frequency-dependent, but senescence may cause behaviour at old age to be suboptimal. We investigated whether sex allocation changes with parental age, using 16 years of data comprising more than 2500 molecularly sexed offspring of more than 600 known-age parents in common terns (Sterna hirundo), slightly sexually size-dimorphic seabirds. We decomposed parental age effects into within-individual change and sex allocation-associated selective (dis)appearance. Individual parents did not differ consistently in sex allocation, but offspring sex ratios at fledging changed from female- to male-biased as parents aged. Sex ratios at hatching were not related to parental age, suggesting sons to outperform daughters after hatching in broods of old parents. Our results call for the integration of sex allocation theory with theory on ageing and demography, as a change in sex allocation with age per se will cause the age structure of a population to affect the frequency-dependent benefits and the age-specific strength of selection on sex allocation. PMID:27484643

  14. Male-biased sex allocation in ageing parents; a longitudinal study in a long-lived seabird.

    PubMed

    Vedder, Oscar; Bouwhuis, Sandra; Benito, María M; Becker, Peter H

    2016-08-01

    Optimal sex allocation is frequency-dependent, but senescence may cause behaviour at old age to be suboptimal. We investigated whether sex allocation changes with parental age, using 16 years of data comprising more than 2500 molecularly sexed offspring of more than 600 known-age parents in common terns (Sterna hirundo), slightly sexually size-dimorphic seabirds. We decomposed parental age effects into within-individual change and sex allocation-associated selective (dis)appearance. Individual parents did not differ consistently in sex allocation, but offspring sex ratios at fledging changed from female- to male-biased as parents aged. Sex ratios at hatching were not related to parental age, suggesting sons to outperform daughters after hatching in broods of old parents. Our results call for the integration of sex allocation theory with theory on ageing and demography, as a change in sex allocation with age per se will cause the age structure of a population to affect the frequency-dependent benefits and the age-specific strength of selection on sex allocation.

  15. Sex-specific antennal sensory system in the ant Camponotus japonicus: glomerular organizations of antennal lobes.

    PubMed

    Nakanishi, Aki; Nishino, Hiroshi; Watanabe, Hidehiro; Yokohari, Fumio; Nishikawa, Michiko

    2010-06-15

    Ants have well-developed chemosensory systems for social lives. The goal of our study is to understand the functional organization of the ant chemosensory system based on caste- and sex-specific differences. Here we describe the common and sex-specific glomerular organizations in the primary olfactory center, the antennal lobe of the carpenter ant Camponotus japonicus. Differential labeling of the two antennal nerves revealed distinct glomerular clusters innervated by seven sensory tracts (T1-T7 from ventral to dorsal) in the antennal lobe. T7 innervated 10 glomeruli, nine of which received thick axon terminals almost exclusively from the ventral antennal nerve. Coelocapitular (hygro-/thermoreceptive), coeloconic (thermoreceptive), and ampullaceal (CO2-receptive) sensilla, closely appositioned in the flagellum, housed one or three large sensory neurons supplying thick axons exclusively to the ventral antennal nerve. These axons, therefore, were thought to project into T7 glomeruli in all three castes. Workers and virgin females had about 140 T6 glomeruli, whereas males completely lacked these glomeruli. Female-specific basiconic sensilla (cuticular hydrocarbon-receptive) contained over 130 sensory neurons and were completely lacking in males' antennae. These sensory neurons may project into T6 glomeruli in the antennal lobe of workers and virgin females. Serotonin-immunopositive neurons innervated T1-T5 and T7 glomeruli but not T6 glomeruli in workers and virgin females. Because males had no equivalents to T6 glomeruli, serotonin-immunopositive neurons appeared to innervate all glomeruli in the male's antennal lobe. T6 glomeruli in workers and virgin females are therefore female-specific and may have functions related to female-specific tasks in the colony rather than sexual behaviors.

  16. Sex-specific antennal sensory system in the ant Camponotus japonicus: glomerular organizations of antennal lobes.

    PubMed

    Nakanishi, Aki; Nishino, Hiroshi; Watanabe, Hidehiro; Yokohari, Fumio; Nishikawa, Michiko

    2010-06-15

    Ants have well-developed chemosensory systems for social lives. The goal of our study is to understand the functional organization of the ant chemosensory system based on caste- and sex-specific differences. Here we describe the common and sex-specific glomerular organizations in the primary olfactory center, the antennal lobe of the carpenter ant Camponotus japonicus. Differential labeling of the two antennal nerves revealed distinct glomerular clusters innervated by seven sensory tracts (T1-T7 from ventral to dorsal) in the antennal lobe. T7 innervated 10 glomeruli, nine of which received thick axon terminals almost exclusively from the ventral antennal nerve. Coelocapitular (hygro-/thermoreceptive), coeloconic (thermoreceptive), and ampullaceal (CO2-receptive) sensilla, closely appositioned in the flagellum, housed one or three large sensory neurons supplying thick axons exclusively to the ventral antennal nerve. These axons, therefore, were thought to project into T7 glomeruli in all three castes. Workers and virgin females had about 140 T6 glomeruli, whereas males completely lacked these glomeruli. Female-specific basiconic sensilla (cuticular hydrocarbon-receptive) contained over 130 sensory neurons and were completely lacking in males' antennae. These sensory neurons may project into T6 glomeruli in the antennal lobe of workers and virgin females. Serotonin-immunopositive neurons innervated T1-T5 and T7 glomeruli but not T6 glomeruli in workers and virgin females. Because males had no equivalents to T6 glomeruli, serotonin-immunopositive neurons appeared to innervate all glomeruli in the male's antennal lobe. T6 glomeruli in workers and virgin females are therefore female-specific and may have functions related to female-specific tasks in the colony rather than sexual behaviors. PMID:20437523

  17. Male-biased sex ratio does not promote increased sperm competitiveness in the seed beetle, Callosobruchus maculatus

    PubMed Central

    McNamara, Kathryn B.; Robinson, Stephen P.; Rosa, Márta E.; Sloan, Nadia S.; van Lieshout, Emile; Simmons, Leigh W.

    2016-01-01

    Sperm competition risk and intensity can select for adaptations that increase male fertilisation success. Evolutionary responses are examined typically by generating increased strength of sexual selection via direct manipulation of female mating rates (by enforcing monandry or polyandry) or by alteration of adult sex ratios. Despite being a model species for sexual selection research, the effect of sexual selection intensity via adult sex-ratio manipulation on male investment strategies has not been investigated in the seed beetle, Callosobruchus maculatus. We imposed 32 generations of experimental evolution on 10 populations of beetles by manipulating adult sex ratio. Contrary to predictions, males evolving in male-biased populations did not increase their testes and accessory gland size. This absence of divergence in ejaculate investment was also reflected in the fact that males from male-biased populations were not more successful in either preventing females from remating, or in competing directly for fertilisations. These populations already demonstrate divergence in mating behaviour and immunity, suggesting sufficient generations have passed to allow divergence in physiological and behavioural traits. We propose several explanations for the absence of divergence in sperm competitiveness among our populations and the pitfalls of using sex ratio manipulation to assess evolutionary responses to sexual selection intensity. PMID:27306351

  18. Male-biased sex ratio does not promote increased sperm competitiveness in the seed beetle, Callosobruchus maculatus.

    PubMed

    McNamara, Kathryn B; Robinson, Stephen P; Rosa, Márta E; Sloan, Nadia S; van Lieshout, Emile; Simmons, Leigh W

    2016-01-01

    Sperm competition risk and intensity can select for adaptations that increase male fertilisation success. Evolutionary responses are examined typically by generating increased strength of sexual selection via direct manipulation of female mating rates (by enforcing monandry or polyandry) or by alteration of adult sex ratios. Despite being a model species for sexual selection research, the effect of sexual selection intensity via adult sex-ratio manipulation on male investment strategies has not been investigated in the seed beetle, Callosobruchus maculatus. We imposed 32 generations of experimental evolution on 10 populations of beetles by manipulating adult sex ratio. Contrary to predictions, males evolving in male-biased populations did not increase their testes and accessory gland size. This absence of divergence in ejaculate investment was also reflected in the fact that males from male-biased populations were not more successful in either preventing females from remating, or in competing directly for fertilisations. These populations already demonstrate divergence in mating behaviour and immunity, suggesting sufficient generations have passed to allow divergence in physiological and behavioural traits. We propose several explanations for the absence of divergence in sperm competitiveness among our populations and the pitfalls of using sex ratio manipulation to assess evolutionary responses to sexual selection intensity. PMID:27306351

  19. Sex Chromosome-wide Transcriptional Suppression and Compensatory Cis-Regulatory Evolution Mediate Gene Expression in the Drosophila Male Germline

    PubMed Central

    Landeen, Emily L.; Muirhead, Christina A.; Meiklejohn, Colin D.; Presgraves, Daven C.

    2016-01-01

    The evolution of heteromorphic sex chromosomes has repeatedly resulted in the evolution of sex chromosome-specific forms of regulation, including sex chromosome dosage compensation in the soma and meiotic sex chromosome inactivation in the germline. In the male germline of Drosophila melanogaster, a novel but poorly understood form of sex chromosome-specific transcriptional regulation occurs that is distinct from canonical sex chromosome dosage compensation or meiotic inactivation. Previous work shows that expression of reporter genes driven by testis-specific promoters is considerably lower—approximately 3-fold or more—for transgenes inserted into X chromosome versus autosome locations. Here we characterize this transcriptional suppression of X-linked genes in the male germline and its evolutionary consequences. Using transgenes and transpositions, we show that most endogenous X-linked genes, not just testis-specific ones, are transcriptionally suppressed several-fold specifically in the Drosophila male germline. In wild-type testes, this sex chromosome-wide transcriptional suppression is generally undetectable, being effectively compensated by the gene-by-gene evolutionary recruitment of strong promoters on the X chromosome. We identify and experimentally validate a promoter element sequence motif that is enriched upstream of the transcription start sites of hundreds of testis-expressed genes; evolutionarily conserved across species; associated with strong gene expression levels in testes; and overrepresented on the X chromosome. These findings show that the expression of X-linked genes in the Drosophila testes reflects a balance between chromosome-wide epigenetic transcriptional suppression and long-term compensatory adaptation by sex-linked genes. Our results have broad implications for the evolution of gene expression in the Drosophila male germline and for genome evolution. PMID:27404402

  20. Sex Chromosome-wide Transcriptional Suppression and Compensatory Cis-Regulatory Evolution Mediate Gene Expression in the Drosophila Male Germline.

    PubMed

    Landeen, Emily L; Muirhead, Christina A; Wright, Lori; Meiklejohn, Colin D; Presgraves, Daven C

    2016-07-01

    The evolution of heteromorphic sex chromosomes has repeatedly resulted in the evolution of sex chromosome-specific forms of regulation, including sex chromosome dosage compensation in the soma and meiotic sex chromosome inactivation in the germline. In the male germline of Drosophila melanogaster, a novel but poorly understood form of sex chromosome-specific transcriptional regulation occurs that is distinct from canonical sex chromosome dosage compensation or meiotic inactivation. Previous work shows that expression of reporter genes driven by testis-specific promoters is considerably lower-approximately 3-fold or more-for transgenes inserted into X chromosome versus autosome locations. Here we characterize this transcriptional suppression of X-linked genes in the male germline and its evolutionary consequences. Using transgenes and transpositions, we show that most endogenous X-linked genes, not just testis-specific ones, are transcriptionally suppressed several-fold specifically in the Drosophila male germline. In wild-type testes, this sex chromosome-wide transcriptional suppression is generally undetectable, being effectively compensated by the gene-by-gene evolutionary recruitment of strong promoters on the X chromosome. We identify and experimentally validate a promoter element sequence motif that is enriched upstream of the transcription start sites of hundreds of testis-expressed genes; evolutionarily conserved across species; associated with strong gene expression levels in testes; and overrepresented on the X chromosome. These findings show that the expression of X-linked genes in the Drosophila testes reflects a balance between chromosome-wide epigenetic transcriptional suppression and long-term compensatory adaptation by sex-linked genes. Our results have broad implications for the evolution of gene expression in the Drosophila male germline and for genome evolution. PMID:27404402

  1. Sexual practices, partner concurrency and high rates of sexually transmissible infections among male sex workers in three cities in Vietnam

    PubMed Central

    Clatts, Michael C.; Goldsamt, Lloyd A.; Giang, Le Minh; Yu, Gary

    2015-01-01

    Background This paper examines sexual practices, partner concurrency and sexually transmissible infections (STI)/HIV infection among male sex workers (MSWs) in Vietnam. Methods Six hundred and fifty-four MSWs, aged 16–35 years, were recruited in Hanoi, Nha Trang and Ho Chi Minh City between 2009 and 2011. Survey measures included demographic characteristics, drug use, types of sexual partners and sexual practices. Subjects were screened for STIs, including HIV. Results MSWs in Ho Chi Minh City (33%) were more likely than those from the other two sites to be current users of one or more types of illegal drugs (P < 0.001). MSWs with both male and female elective partners (compared with other partnership types) were more likely to have anal sex with male client partners (P < 0.001), elective male partners (P = 0.045) and elective female partners (P = 0.025). At last sex with a male client partner, only 30% used a condom during anal intercourse. At last sex with an elective female partner, only 31% used a condom during vaginal sex and only 3% during anal sex. Although rates of HIV are low (4%), other STIs are high, including chlamydia (17%), gonorrhoea (29%) and human papillomavirus (33%). Most (57.3%) have never been tested for HIV and only 17% have ever disclosed to a healthcare provider that they have sex with men. Conclusions Complex patterns of sexual concurrency, coupled with high rates of STIs, signal the urgent need for health services interventions among MSWs, both to improve individual health outcomes and to reduce secondary STI/HIV transmission among sexual partner networks. PMID:25622225

  2. Behavioral treatment of deviant sex-role behaviors in a male child1

    PubMed Central

    Rekers, George A.; Lovaas, O. Ivar

    1974-01-01

    This study demonstrated reinforcement control over pronounced feminine behaviors in a male child who had been psychologically evaluated as manifesting “childhood cross-gender identity”. The clinical history of the subject paralleled the retrospective reports of adult transsexuals, including (a) cross-gender clothing preferences, (b) actual or imaginal use of cosmetic articles, (c) feminine behavior mannerisms, (d) aversion to masculine activities, coupled with preference for girl playmates and feminine activities, (e) preference for female role, (f) feminine voice inflection and predominantly feminine content in speech, and (g) verbal statements about the desire or preference to be a girl. The subject was treated sequentially in the clinic and home environments by his mother, trained to be his therapist. The mother was taught to reinforce masculine behaviors and to extinguish feminine behaviors, by using social reinforcement in the clinic and a token reinforcement procedure in the home. During this treatment, his feminine behaviors sharply decreased and masculine behavior increased. The treatment effects were found to be largely response-specific and stimulus-specific; consequently, it was necessary to strengthen more than one masculine behavior and weaken several feminine behaviors, in both clinic and home settings. A multiple-baseline intrasubject design was used to ensure both replication and identification of relevant treatment variables. Follow-up data three years after the treatment began suggests that the boy's sex-typed behaviors have become normalized. This study suggests a preliminary step toward correcting pathological sex-role development in boys, which may provide a basis for the primary prevention of adult transsexualism or similar adult sex-role deviation. PMID:4436165

  3. The embodiment of tourism among bisexually-behaving Dominican male sex workers.

    PubMed

    Padilla, Mark B

    2008-10-01

    While theories of "structure" and social inequality have increasingly informed global health efforts for HIV prevention--with growing recognition of the linkages between large-scale political and economic factors in the distribution and impact of the HIV/AIDS epidemic--there is still little theorization of precisely how structural factors shape the very bodies and sexualities of specific populations and groups. In order to extend the theoretical understanding of these macro-micro linkages, this article examines how the growth of the tourism industry in the Dominican Republic has produced sexual practices and identities that reflect both the influence of large-scale structural processes and the resistant responses of local individuals. Drawing on social science theories of political economy, embodiment, and authenticity, I argue that an understanding of patterns of sexuality and HIV risk in the region requires analysis of how political-economic transformations related to tourism intersect with the individual experiences and practices of sexuality on the ground. The analysis draws on long-term ethnographic research with bisexually behaving male sex workers in two cities in the Dominican Republic, including participant observation, in-depth interviews, focus groups, and surveys. By examining the global and local values placed on these men's bodies and the ways sex workers use their bodies to broker tourists' pleasure, we may better understand how the large-scale structures of the tourism industry are linked to the specific meanings and practices of sexuality.

  4. Love, Trust, and HIV Risk Among Female Sex Workers and Their Intimate Male Partners

    PubMed Central

    Bazzi, Angela Robertson; Martinez, Gustavo; Rangel, M. Gudelia; Ulibarri, Monica D.; Fergus, Kirkpatrick B.; Amaro, Hortensia; Strathdee, Steffanie A.

    2015-01-01

    Objectives. We examined correlates of love and trust among female sex workers and their noncommercial male partners along the Mexico–US border. Methods. From 2011 to 2012, 322 partners in Tijuana and Ciudad Juárez, Mexico, completed assessments of love and trust. Cross-sectional dyadic regression analyses identified associations of relationship characteristics and HIV risk behaviors with love and trust. Results. Within 161 couples, love and trust scores were moderately high (median 70/95 and 29/40 points, respectively) and correlated with relationship satisfaction. In regression analyses of HIV risk factors, men and women who used methamphetamine reported lower love scores, whereas women who used heroin reported slightly higher love. In an alternate model, men with concurrent sexual partners had lower love scores. For both partners, relationship conflict was associated with lower trust. Conclusions. Love and trust are associated with relationship quality, sexual risk, and drug use patterns that shape intimate partners’ HIV risk. HIV interventions should consider the emotional quality of sex workers’ intimate relationships. PMID:26066947

  5. The embodiment of tourism among bisexually-behaving Dominican male sex workers.

    PubMed

    Padilla, Mark B

    2008-10-01

    While theories of "structure" and social inequality have increasingly informed global health efforts for HIV prevention--with growing recognition of the linkages between large-scale political and economic factors in the distribution and impact of the HIV/AIDS epidemic--there is still little theorization of precisely how structural factors shape the very bodies and sexualities of specific populations and groups. In order to extend the theoretical understanding of these macro-micro linkages, this article examines how the growth of the tourism industry in the Dominican Republic has produced sexual practices and identities that reflect both the influence of large-scale structural processes and the resistant responses of local individuals. Drawing on social science theories of political economy, embodiment, and authenticity, I argue that an understanding of patterns of sexuality and HIV risk in the region requires analysis of how political-economic transformations related to tourism intersect with the individual experiences and practices of sexuality on the ground. The analysis draws on long-term ethnographic research with bisexually behaving male sex workers in two cities in the Dominican Republic, including participant observation, in-depth interviews, focus groups, and surveys. By examining the global and local values placed on these men's bodies and the ways sex workers use their bodies to broker tourists' pleasure, we may better understand how the large-scale structures of the tourism industry are linked to the specific meanings and practices of sexuality. PMID:18506615

  6. Peripheral and central sex steroids have differential effects on the HPA axis of male and female rats.

    PubMed

    McCormick, Cheryl M; Linkroum, William; Sallinen, Bethany J; Miller, Nicholas W

    2002-12-01

    Sex differences in hypothalamic-pituitary-adrenal (HPA) function were examined in gonadectomized male and female rats given equivalent sex hormone replacement regimens either using subcutaneous silastic implants (Experiment 1) or cannula implants in the medial preoptic area (MPOA) (Experiment 2) containing either dihydrotestosterone (DHT), testosterone propionate (TP), estradiol benzoate (EB), or left empty (control). Plasma was obtained before and after 20 min of restraint stress to determine plasma ACTH, corticosterone, and CBG levels as measures of HPA function. Consistent with the literature, androgens decreased, and estrogen increased these measures of HPA function, although peripheral implants were more effective than MPOA implants. Gonadectomy and sex hormone treatment did not eliminate sex differences; overall, females had higher levels than males on measures of HPA function. Analyses of variance (ANOVA) indicated interactions of sex and sex hormone treatment on CBG levels and post-stress corticosterone levels in Expt. 1. The results suggest that sexual dimorphisms influence HPA function even when males and females are given equivalent physiological doses of gonadal steroids, and that the relevant sexual dimorphisms involve both the periphery and the CNS.

  7. Venue-Mediated Weak Ties in Multiplex HIV Transmission Risk Networks Among Drug-Using Male Sex Workers and Associates

    PubMed Central

    Wang, Peng; Ross, Michael W.; Williams, Mark L.

    2015-01-01

    Objectives. We investigated the structural characteristics of a multiplex HIV transmission risk network of drug-using male sex workers and their associates. Methods. Using a sample of 387 drug-using male sex workers and their male and female associates in Houston, Texas, we estimated an exponential random graph model to examine the venue-mediated relationships between individuals, the structural characteristics of relationships not linked to social venues, and homophily. We collected data in 2003 to 2004. The network comprised social, sexual, and drug-using relationships and affiliations with social venues. Results. Individuals affiliated with the same social venues, bars, or street intersections were more likely to have nonreciprocated (weak) ties with others. Sex workers were less likely than were other associates to have reciprocated (strong) ties to other sex workers with the same venues. Individuals tended to have reciprocated ties not linked to venues. Partner choice tended to be predicated on homophily. Conclusions. Social venues may provide a milieu for forming weak ties in HIV transmission risk networks centered on male sex workers, which may foster the efficient diffusion of prevention messages as diverse information is obtained and information redundancy is avoided. PMID:25880956

  8. Sex-linkage of sexually antagonistic genes is predicted by female, but not male, effects in birds.

    PubMed

    Mank, Judith E; Ellegren, Hans

    2009-06-01

    Evolutionary theory predicts that sexually antagonistic loci will be preferentially sex-linked, and this association can be empirically testes with data on sex-biased gene expression with the assumption that sex-biased gene expression represents the resolution of past sexual antagonism. However, incomplete dosage compensating mechanisms and meiotic sex chromosome inactivation have hampered efforts to connect expression data to theoretical predictions regarding the genomic distribution of sexually antagonistic loci in a variety of animals. Here we use data on the underlying regulatory mechanism that produce expression sex-bias to test the genomic distribution of sexually antagonistic genes in chicken. Using this approach, which is free from problems associated with the lack of dosage compensation in birds, we show that female-detriment genes are significantly overrepresented on the Z chromosome, and female-benefit genes underrepresented. By contrast, male-effect genes show no over- or underrepresentation on the Z chromosome. These data are consistent with a dominant mode of inheritance for sexually antagonistic genes, in which male-benefit coding mutations are more likely to be fixed on the Z due to stronger male-specific selective pressures. After fixation of male-benefit alleles, regulatory changes in females evolve to minimize antagonism by reducing female expression.

  9. Differences in Movement Pattern and Detectability between Males and Females Influence How Common Sampling Methods Estimate Sex Ratio

    PubMed Central

    Rodrigues, João Fabrício Mota; Coelho, Marco Túlio Pacheco

    2016-01-01

    Sampling the biodiversity is an essential step for conservation, and understanding the efficiency of sampling methods allows us to estimate the quality of our biodiversity data. Sex ratio is an important population characteristic, but until now, no study has evaluated how efficient are the sampling methods commonly used in biodiversity surveys in estimating the sex ratio of populations. We used a virtual ecologist approach to investigate whether active and passive capture methods are able to accurately sample a population’s sex ratio and whether differences in movement pattern and detectability between males and females produce biased estimates of sex-ratios when using these methods. Our simulation allowed the recognition of individuals, similar to mark-recapture studies. We found that differences in both movement patterns and detectability between males and females produce biased estimates of sex ratios. However, increasing the sampling effort or the number of sampling days improves the ability of passive or active capture methods to properly sample sex ratio. Thus, prior knowledge regarding movement patterns and detectability for species is important information to guide field studies aiming to understand sex ratio related patterns. PMID:27441554

  10. Sex-determining mechanism in Buergeria buergeri (Anura, Rhacophoridae). III. Does the ZZW triploid frog become female or male?

    PubMed

    Ohta, S; Sumida, M; Nishioka, M

    1999-02-15

    Both triploids and gynogenetic diploids (GDs) were produced to clarify the relationship between the sex-chromosome constitution and the expression of sex in the common bell-ring frog, Buergeria buergeri. The sex differentiation of triploids in B. buergeri is quite remarkable. Triploid frogs consisted of three sex genotypes, ZZZ, ZWW and ZZW. All ZZZ triploids were males, and all ZWW triploids were females. It is very interesting that half of the ZZW triploids became female, and the other half became male. The GD frogs consisted of two sex genotypes, ZW and ZZ, which did not differ from the controls in sex differentiation. Since the ratios of ZZ and ZW eggs were significantly different among female parents, it is assumed that most (approximately 80-90%) of the eggs made pre-reductional division in some females and post-reductional division in others during meiosis. It seems that ZW eggs were produced by the occurrence of recombination between the centromere and the sex-determining genes in B. buergeri. It was also found that the number of Z chromosomes in each cell of these triploids and GDs agreed with that of the nucleoli in each cell. PMID:9933938

  11. Behavioural evidence of male volatile pheromones in the sex-role reversed wolf spiders Allocosa brasiliensis and Allocosa alticeps.

    PubMed

    Aisenberg, Anita; Baruffaldi, Luciana; González, Macarena

    2010-01-01

    The use of chemical signals in a sexual context is widespread in the animal kingdom. Most studies in spiders report the use of female pheromones that attract potential sexual partners. Allocosa brasiliensis and Allocosa alticeps are two burrowing wolf spiders that show sex-role reversal. Females locate male burrows and initiate courtship before males perform any detectable visual or vibratory signal. So, females of these species would be detecting chemical or mechanical cues left by males. Our objective was to explore the potential for male pheromones to play a role in mate detection in A. brasiliensis and A. alticeps. We designed two experiments. In Experiment 1, we tested the occurrence of male contact pheromones by evaluating female courtship when exposed to empty burrows constructed by males or females (control). In Experiment 2, we tested the existence of male volatile pheromones by evaluating female behaviour when exposed to artificial burrows connected to tubes containing males, females or empty tubes (control). Our results suggest the occurrence of male volatile pheromones that trigger female courtship in both Allocosa species. The sex-role reversal postulated for these wolf spiders could be driving the consequent reversal in typical pheromone-emitter and detector roles expected for spiders.

  12. Behavioural evidence of male volatile pheromones in the sex-role reversed wolf spiders Allocosa brasiliensis and Allocosa alticeps

    NASA Astrophysics Data System (ADS)

    Aisenberg, Anita; Baruffaldi, Luciana; González, Macarena

    2010-01-01

    The use of chemical signals in a sexual context is widespread in the animal kingdom. Most studies in spiders report the use of female pheromones that attract potential sexual partners. Allocosa brasiliensis and Allocosa alticeps are two burrowing wolf spiders that show sex-role reversal. Females locate male burrows and initiate courtship before males perform any detectable visual or vibratory signal. So, females of these species would be detecting chemical or mechanical cues left by males. Our objective was to explore the potential for male pheromones to play a role in mate detection in A. brasiliensis and A. alticeps. We designed two experiments. In Experiment 1, we tested the occurrence of male contact pheromones by evaluating female courtship when exposed to empty burrows constructed by males or females (control). In Experiment 2, we tested the existence of male volatile pheromones by evaluating female behaviour when exposed to artificial burrows connected to tubes containing males, females or empty tubes (control). Our results suggest the occurrence of male volatile pheromones that trigger female courtship in both Allocosa species. The sex-role reversal postulated for these wolf spiders could be driving the consequent reversal in typical pheromone-emitter and detector roles expected for spiders.

  13. Intervention of D-glucose ameliorates the toxicity of streptozotocin in accessory sex organs of rat

    SciTech Connect

    Vikram, A.; Tripathi, D.N.; Ramarao, P.; Jena, G.B.

    2008-01-01

    Streptozotocin (STZ) is a naturally occurring compound isolated from Streptomyces achromogens. It is used extensively for inducing diabetes in experimental animals. Diabetes mellitus is known to have proven adverse effects on male sexual organs and their reproductive functions. The atrophy of prostate gland and other organs of the genitourinary tract were observed in experimental diabetic animals. STZ exhibits a structural resemblance to D-glucose due to the presence of sugar moiety in its structure. Pancreatic {beta}-cells mainly contain GLUT1 and GLUT2 glucose transporters. Possibly due to structural resemblance, STZ and D-glucose, share a common recognition site for entry into the {beta}-cells. The objective of the present study is to evaluate the effect of D-glucose on STZ-induced toxicity in accessory sex organs of male rats. Animals were kept on overnight fasting. One group received vehicle and served as negative control, while all other groups were given STZ (45 mg/kg). Animals that received only STZ served as positive control. The effect of D-glucose was studied on STZ treated animals with different dosage of D-glucose (250, 500, 1000 and 2000 mg/kg). Restoration of body weight, plasma glucose and plasma insulin was evident only at 1000 and 2000 mg/kg of D-glucose. The protective effect of D-glucose is evident only when it is administered simultaneously with STZ. In the present investigation, we report that simultaneous administration of D-glucose along with STZ ameliorates STZ-induced toxicity. This is evident from the restoration of accessory sex organ's weight, cellular morphology as well as insulin level.

  14. Green light synergistally enhances male sweetpotato weevil response to sex pheromone.

    PubMed

    McQuate, Grant T

    2014-01-01

    Sweetpotato, commercially grown in over 100 countries, is one of the ten most important staple crops in the world. Sweetpotato weevil is a major pest of sweetpotato in most areas of cultivation, the feeding of which induces production in the sweetpotato root of extremely bitter tasting and toxic sesquiterpenes which can render the sweetpotato unfit for consumption. A significant step towards improved management of this weevil species was the identification of a female-produced sex pheromone [(Z)-3-dodecenyl (E)-2-butenoate] to which males are highly attracted. Reported here are results of research that documents a nearly 5-fold increase in male sweetpotato weevil catch in traps baited with this pheromone and a green light provided by a solar-powered, light-emitting diode (LED). The combination of olfactory and night-visible visual cues significantly enhanced trap effectiveness for this nighttime-active insect species. These results provide promise for improved sweetpotato weevil detection and suppression in mass trapping programs. PMID:24675727

  15. Green Light Synergistally Enhances Male Sweetpotato Weevil Response to Sex Pheromone

    PubMed Central

    McQuate, Grant T.

    2014-01-01

    Sweetpotato, commercially grown in over 100 countries, is one of the ten most important staple crops in the world. Sweetpotato weevil is a major pest of sweetpotato in most areas of cultivation, the feeding of which induces production in the sweetpotato root of extremely bitter tasting and toxic sesquiterpenes which can render the sweetpotato unfit for consumption. A significant step towards improved management of this weevil species was the identification of a female-produced sex pheromone [(Z)-3-dodecenyl (E)-2-butenoate] to which males are highly attracted. Reported here are results of research that documents a nearly 5-fold increase in male sweetpotato weevil catch in traps baited with this pheromone and a green light provided by a solar-powered, light-emitting diode (LED). The combination of olfactory and night-visible visual cues significantly enhanced trap effectiveness for this nighttime-active insect species. These results provide promise for improved sweetpotato weevil detection and suppression in mass trapping programs. PMID:24675727

  16. Application of condoms on male clients by female sex workers in Yerevan, Armenia: prevalence and correlates.

    PubMed

    Darbinyan, Nelli; Lang, Delia L; Diclemente, Ralph J; Joseph, Jesse B; Markosyan, Karine

    2011-09-01

    This study sought to assess the prevalence of consistent condom application on male clients by female sex workers (FSWs) in Armenia and its association with demographic, psychosocial and behavioural factors. In this cross-sectional study, 120 street-based FSWs aged 20-52 completed an interviewer-administered questionnaire. The primary outcome measure was consistent application of condoms by FSWs on their male clients. A total of 21.7% of participants reported consistently applying condoms on clients. Logistic regression analysis demonstrated that higher condom use self-efficacy (Adjusted Odds Ratio, AOR=1.1; p=0.01), lower perceived condom use barriers (AOR=0.9; p=0.04) and not using douching as a method to prevent STI/HIV (AOR=4.8; p=0.04) significantly predicted consistent condom application. Higher HIV/AIDS knowledge was a marginally significant predictor of condom application (AOR=1.3; p=0.05). Future interventions should address these modifiable factors to encourage FSWs to apply condoms on clients themselves, which may reduce condom failure and exposure to HIV transmission.

  17. Useless Hearing in Male Emblemasoma auditrix (Diptera, Sarcophagidae) – A Case of Intralocus Sexual Conflict during Evolution of a Complex Sense Organ?

    PubMed Central

    Lakes-Harlan, Reinhard; deVries, Thomas; Stölting, Heiko; Stumpner, Andreas

    2014-01-01

    Sensory modalities typically are important for both sexes, although sex-specific functional adaptations may occur frequently. This is true for hearing as well. Consequently, distinct behavioural functions were identified for the different insect hearing systems. Here we describe a first case, where a trait of an evolutionary novelty and a highly specialized hearing organ is adaptive in only one sex. The main function of hearing of the parasitoid fly Emblemasoma auditrix is to locate the host, males of the cicada species Okanagana rimosa, by their calling song. This task is performed by female flies, which deposit larvae into the host. We show that male E. auditrix possess a hearing sense as well. The morphology of the tympanal organ of male E. auditrix is rather similar to the female ear, which is 8% broader than the male ear. In both sexes the physiological hearing threshold is tuned to 5 kHz. Behavioural tests show that males are able to orient towards the host calling song, although phonotaxis often is incomplete. However, despite extensive observations in the field and substantial knowledge of the biology of E. auditrix, no potentially adaptive function of the male auditory sense has been identified. This unique hearing system might represent an intralocus sexual conflict, as the complex sense organ and the behavioural relevant neuronal network is adaptive for only one sex. The correlated evolution of the sense organ in both sexes might impose substantial constraints on the sensory properties of the ear. Similar constraints, although hidden, might also apply to other sensory systems in which behavioural functions differ between sexes. PMID:24489872

  18. Useless hearing in male Emblemasoma auditrix (Diptera, Sarcophagidae)--a case of intralocus sexual conflict during evolution of a complex sense organ?

    PubMed

    Lakes-Harlan, Reinhard; Devries, Thomas; Stölting, Heiko; Stumpner, Andreas

    2014-01-01

    Sensory modalities typically are important for both sexes, although sex-specific functional adaptations may occur frequently. This is true for hearing as well. Consequently, distinct behavioural functions were identified for the different insect hearing systems. Here we describe a first case, where a trait of an evolutionary novelty and a highly specialized hearing organ is adaptive in only one sex. The main function of hearing of the parasitoid fly Emblemasoma auditrix is to locate the host, males of the cicada species Okanagana rimosa, by their calling song. This task is performed by female flies, which deposit larvae into the host. We show that male E. auditrix possess a hearing sense as well. The morphology of the tympanal organ of male E. auditrix is rather similar to the female ear, which is 8% broader than the male ear. In both sexes the physiological hearing threshold is tuned to 5 kHz. Behavioural tests show that males are able to orient towards the host calling song, although phonotaxis often is incomplete. However, despite extensive observations in the field and substantial knowledge of the biology of E. auditrix, no potentially adaptive function of the male auditory sense has been identified. This unique hearing system might represent an intralocus sexual conflict, as the complex sense organ and the behavioural relevant neuronal network is adaptive for only one sex. The correlated evolution of the sense organ in both sexes might impose substantial constraints on the sensory properties of the ear. Similar constraints, although hidden, might also apply to other sensory systems in which behavioural functions differ between sexes.

  19. Prenatal exposure to dexamethasone disturbs sex-determining gene expression and fetal testosterone production in male embryos.

    PubMed

    Yun, Hyo Jung; Lee, Ji-Yeon; Kim, Myoung Hee

    2016-02-26

    Prenatal stress is known to cause intrauterine fetal growth retardation, and is also associated with various long-term effects in the form of metabolic and neurodevelopmental diseases in adults. Many of the diseases associated with prenatal stress exhibit a sex bias. Perturbations and vulnerability to prenatal stress are often more profound in males, but the mechanisms responsible for this relationship are not clear. We have previously shown that administration of the synthetic glucocorticoid, dexamethasone (Dex), at embryonic days 7.5, 8.5, and 9.5, induces embryonic growth restriction in a sex-dependent manner in a mouse model. Here we examined the effect of prenatal exposure to Dex on gonadal development. During male gonadal development, sex-determining genes, such as Sry, Sox9, and other downstream genes, were found to be dysregulated in response to prenatal Dex, whereas the genes for the ovarian pathway were affected to a lesser degree in females. In addition, fetal testosterone concentrations were decreased by prenatal exposure to Dex, in parallel with reduced numbers of 3β-hydroxysteroid dehydrogenase (3β-HSD)-positive cells in the embryonic testis. These results show that prenatal exposure to Dex differentially influences male versus female on the gene expression and hormone production during sex determination. We believe these studies provide valuable insights into possible mechanisms responsible for sex-specific responses to prenatal stress.

  20. Prenatal exposure to dexamethasone disturbs sex-determining gene expression and fetal testosterone production in male embryos.

    PubMed

    Yun, Hyo Jung; Lee, Ji-Yeon; Kim, Myoung Hee

    2016-02-26

    Prenatal stress is known to cause intrauterine fetal growth retardation, and is also associated with various long-term effects in the form of metabolic and neurodevelopmental diseases in adults. Many of the diseases associated with prenatal stress exhibit a sex bias. Perturbations and vulnerability to prenatal stress are often more profound in males, but the mechanisms responsible for this relationship are not clear. We have previously shown that administration of the synthetic glucocorticoid, dexamethasone (Dex), at embryonic days 7.5, 8.5, and 9.5, induces embryonic growth restriction in a sex-dependent manner in a mouse model. Here we examined the effect of prenatal exposure to Dex on gonadal development. During male gonadal development, sex-determining genes, such as Sry, Sox9, and other downstream genes, were found to be dysregulated in response to prenatal Dex, whereas the genes for the ovarian pathway were affected to a lesser degree in females. In addition, fetal testosterone concentrations were decreased by prenatal exposure to Dex, in parallel with reduced numbers of 3β-hydroxysteroid dehydrogenase (3β-HSD)-positive cells in the embryonic testis. These results show that prenatal exposure to Dex differentially influences male versus female on the gene expression and hormone production during sex determination. We believe these studies provide valuable insights into possible mechanisms responsible for sex-specific responses to prenatal stress. PMID:26827828

  1. Partners met via sex parties present significantly greater odds for condomless anal sex among MSM: An event-level analysis of venues where male partners are met

    PubMed Central

    Grov, Christian; Rendina, H. Jonathon; Ventuneac, Ana; Parsons, Jeffrey T.

    2014-01-01

    N=147 MSM completed time-line follow-back interviews about the venues where they met their male partners (n=1,180 sexual events with first-time partners, < 30 days). We ran multivariate models to determine the association between venues and condomless anal sex (CAS). After adjusting for known correlates of CAS, partners met at sex parties presented significantly greater odds for CAS, compared to meeting a partner at a gay bar/club (AOR=.44), online (AOR=.42), bathhouse (AOR=.35), or via “other” venues (AOR=.35), all p < .01. These findings highlight the need to develop innovative HIV/STI prevention initiatives for men who attend sex parties. PMID:25226209

  2. Sex and age differences in hibernation patterns of common hamsters: adult females hibernate for shorter periods than males.

    PubMed

    Siutz, Carina; Franceschini, Claudia; Millesi, Eva

    2016-08-01

    In this study, we investigated the timing and duration of hibernation as well as body temperature patterns in free-ranging common hamsters (Cricetus cricetus) with regard to sex and age differences. Body temperature was recorded using subcutaneously implanted data loggers. The results demonstrate that although immergence and vernal emergence sequences of sex and age groups resembled those of most hibernators, particularly adult females delayed hibernation onset until up to early January. Thus, in contrast to other hibernators, female common hamsters hibernated for shorter periods than males and correspondingly spent less time in torpor. These sex differences were absent in juvenile hamsters. The period between the termination of hibernation and vernal emergence varied among individuals but did not differ between the sex and age groups. This period of preemergence euthermy was related to emergence body mass: individuals that terminated hibernation earlier in spring and had longer euthermic phases prior to emergence started the active season in a better condition. In addition, males with longer periods of preemergence euthermy had larger testes at emergence. In conclusion, females have to rely on sufficient food stores but may adjust the use of torpor in relation to the available external energy reserves, whereas males show a more pronounced energy-saving strategy by hibernating for longer periods. Nonetheless, food caches seem to be important for both males and females as indicated by the euthermic preemergence phase and the fact that some individuals, mainly yearlings, emerged with a higher body mass than shortly before immergence in autumn.

  3. Have Sex Differences in Spatial Ability Evolved from Male Competition for Mating and Female Concern for Survival?

    ERIC Educational Resources Information Center

    Ecuyer-Dab, Isabelle; Robert, Michele

    2004-01-01

    Drawing on the theoretical and empirical foundations of two evolutionary models, we argue that, among humans and other mammals, a twofold selection process would parsimoniously account for sex-linked advantages in spatial contexts. In males, a superiority for both solving navigation-related spatial problems and understanding physical principles…

  4. “Working together to reach a goal”: MSM's Perceptions of Dyadic HIV Care for Same-Sex Male Couples

    PubMed Central

    Goldenberg, Tamar; Clarke, Donato; Stephenson, Rob

    2014-01-01

    Introduction Same-sex serodiscordant male dyads represent a high priority risk group, with approximately one to two-thirds of new HIV infections among MSM attributable to main partnerships. Early initiation and adherence to highly active antiretroviral treatment (HAART) is a key factor in HIV prevention and treatment; however, adherence to HAART in the U.S. is low, with poor retention throughout the continuum of care. This study examines MSM's perceptions of dyadic HIV treatment across the continuum of care to understand preferences for how care may be sought with a partner. Methods We conducted five focus group discussions (FGDs) in Atlanta, GA with 35 men who report being in same-sex male partnerships. Participants discussed perceptions of care using scenarios of a hypothetical same-sex male couple who recently received serodiscordant or seroconcordant positive HIV results. Verbatim transcripts were segmented thematically and systematically analyzed to examine patterns in responses within and between participants and FGDs. Results Participants identified the need for comprehensive dyadic care and differences in care for seroconcordant positive versus serodiscordant couples. Participants described a reciprocal relationship between comprehensive dyadic care and positive relationship dynamics. This combination was described as reinforcing commitment, ultimately leading to increased accountability and treatment adherence. Discussion Results indicate that the act of same-sex male couples “working together to reach a goal” may increase retention to HIV care across the continuum if care is comprehensive, focuses on both individual and dyadic needs, and promotes positive relationship dynamics. PMID:24126448

  5. Perceptions about HIV and Condoms and Consistent Condom Use among Male Clients of Commercial Sex Workers in the Philippines

    ERIC Educational Resources Information Center

    Regan, Rotrease; Morisky, Donald E.

    2013-01-01

    Because consistent condom use is an effective strategy in the prevention of sexually transmitted infections and HIV transmission, it is important to examine social cognitive influences of consistent condom use not only among female sex workers (FSWs) but also among their male clients, for whom less is known. Because little is known about how HIV…

  6. A Case Study of the Academic Achievement of African American Males in Single-Sex Classrooms in Rural South Carolina

    ERIC Educational Resources Information Center

    Pannell, Lynette Martin

    2013-01-01

    The purpose of this study was to investigate the differences of Measures of Academic Progress (MAP) scores between fourth-grade African American male students who were enrolled in single-sex classrooms and their counterparts who were enrolled in coeducational classrooms. The research provided descriptive data concerning one Title I school in rural…

  7. Sex and age differences in hibernation patterns of common hamsters: adult females hibernate for shorter periods than males.

    PubMed

    Siutz, Carina; Franceschini, Claudia; Millesi, Eva

    2016-08-01

    In this study, we investigated the timing and duration of hibernation as well as body temperature patterns in free-ranging common hamsters (Cricetus cricetus) with regard to sex and age differences. Body temperature was recorded using subcutaneously implanted data loggers. The results demonstrate that although immergence and vernal emergence sequences of sex and age groups resembled those of most hibernators, particularly adult females delayed hibernation onset until up to early January. Thus, in contrast to other hibernators, female common hamsters hibernated for shorter periods than males and correspondingly spent less time in torpor. These sex differences were absent in juvenile hamsters. The period between the termination of hibernation and vernal emergence varied among individuals but did not differ between the sex and age groups. This period of preemergence euthermy was related to emergence body mass: individuals that terminated hibernation earlier in spring and had longer euthermic phases prior to emergence started the active season in a better condition. In addition, males with longer periods of preemergence euthermy had larger testes at emergence. In conclusion, females have to rely on sufficient food stores but may adjust the use of torpor in relation to the available external energy reserves, whereas males show a more pronounced energy-saving strategy by hibernating for longer periods. Nonetheless, food caches seem to be important for both males and females as indicated by the euthermic preemergence phase and the fact that some individuals, mainly yearlings, emerged with a higher body mass than shortly before immergence in autumn. PMID:27138337

  8. Prevalence of needle sharing, commercial sex behaviors and associated factors in Chinese male and female injecting drug user populations.

    PubMed

    Gu, Jing; Wang, Renfan; Chen, Hongyao; Lau, Joseph T F; Zhang, Linglin; Hu, Xianyou; Lei, Zhangquan; Li, Zhenglin; Cai, Hua; Wang, Tao; Tsui, Hiyi

    2009-01-01

    The objective of this study is to investigate prevalence and associated factors of commercial sex behaviors and condom use at commercial sex, as well as prevalence of needle sharing among injecting drug users (IDUs) in China. In this study, 162 IDUs were recruited by peer workers in Dazhou, Sichuan and were anonymously interviewed by using a structured questionnaire. Univariate and multivariate logistic regression analyses were performed and interaction between gender and the studied independent variables were tested for significance. The results of this study showed that the male and female respondents, respectively 11.7 and 16.9% were HIV positive; 34.0 and 40.7% engaged in commercial sex and 23.3 and 11.9% shared needles with others in the last six months. Percent using a condom in the last episode of commercial sex was 30.3% for males and 76.2% for females. The multivariate analyses showed that higher drug dosage (OR=0.3, 95% CI: 0.1-0.9) and reduced sexual drive (OR=0.3, 95% CI: 0.1-0.9) were associated with lower likelihood for commercial sex among male IDUs while higher drug dosage (OR=9.1, 95% CI: 1.0-86.0), perceived difficulty in finding a job (OR=5.1, 95% CI: 1.3-20.1) and lack of family support (OR=4.0, 95% CI: 1.1-15.4) were associated with commercial sex among female IDUs. Similarly, unknown HIV status (OR=8.2, 95% CI: 1.7-9.2) and having a regular sex partner (OR=3.7, 95% CI: 1.3-10.9) was associated with needle sharing. It is concluded that male and female IDUs were sexually active and often engaged in commercial sex. Drug dosage and reduced sexual drive were relevant but did not stop commercial sex behaviors. More supportive social environment is required to prevent female IDUs to enter sex work. PMID:19085218

  9. Frequency and inheritance of non-male producing clones in Daphnia magna: evolution towards sex specialization in a cyclical parthenogen?

    PubMed

    Galimov, Y; Walser, B; Haag, C R

    2011-07-01

    In Daphnia (Cladocera, Crustacea), parthenogenetic reproduction alternates with sexual reproduction. Individuals of both sexes that belong to the same parthenogenetic line are genetically identical, and their sex is determined by the environment. Previously, non-male producing (NMP) genotypes have been described in species of the Daphnia pulex group. Such genotypes can only persist through phases of sexual reproduction if they co-occur with normal (MP) genotypes that produce both males and females, and thus the breeding system polymorphism is similar to gynodioecy (coexistence of females with hermaphrodites), which is well known in plants. Here we show that the same breeding system polymorphism also occurs in Daphnia magna, a species that has diverged from D. pulex more than 100 MY ago. Depending on the population, between 0% and 40% of D. magna females do not produce males when experimentally exposed to a concentration of the putative sex hormone methyl farnesoate that normally leads to male-only clutches. Natural broods of these NMP females never contained males, contrasting with high proportions of male offspring in MP females from the same populations. The results from a series of crossing experiments suggest that NMP is determined by a dominant allele at a single nuclear locus (or a several closely linked loci): NMP × MP crosses always yielded 50% NMP and 50% MP offspring, whereas MP × MP crosses always yielded 100% MP offspring. Based on cytochrome c oxidase subunit I-sequences, we found that NMP genotypes from different populations belong to three highly divergent mitochondrial lineages, potentially representing three independent evolutionary origins of NMP in D. magna. Thus, the evolution of NMP genotypes in cyclical parthenogens may be more common than previously thought. Moreover, MP genotypes that coexist with NMP genotypes may have responded to the presence of the latter by partially specializing on male production. Hence, these populations of D

  10. Discriminating males and unpredictable females: males differentiate self-similar facial cues more than females in the judgment of opposite-sex attractiveness.

    PubMed

    Zhuang, Jin-Ying; Zhang, Sen; Xu, Jing; Hu, Die

    2014-01-01

    Attractiveness judgment in the context of mate preferences is thought to reflect an assessment of mate quality in relation to an absolute scale of genetic fitness and a relative scale of self-similarity. In this study, subjects judged the attractiveness and trustworthiness of faces in composite images that were manipulated to produce self-similar (self-resemblance) and dissimilar (other-resemblance) images. Males differentiated between self- and other-resemblance as well as among different degrees of self-resemblance in their attractiveness ratings; females did not. Specifically, in Experiment 1, using a morphing technique, we created previously unseen face images possessing different degrees (0%, 30%, 40%, or 50%) of incorporation of the subject's images (different degrees of self-resemblance) and found that males preferred images that were closer to average (0%) rather than more self-similar, whereas females showed no preference for any degree of self-similarity. In Experiment 2, we added a pro-social question about trustworthiness. We replicated the Experiment 1 attractiveness rating results and further found that males differentiated between self- and other-resemblance for the same degree of composites; women did not. Both males and females showed a similar preference for self-resemblances when judging trustworthiness. In conclusion, only males factored self-resemblance into their attractiveness ratings of opposite-sex individuals in a manner consistent with cues of reproductive fitness, although both sexes favored self-resemblance when judging trustworthiness.

  11. Discriminating Males and Unpredictable Females: Males Differentiate Self-Similar Facial Cues More than Females in the Judgment of Opposite-Sex Attractiveness

    PubMed Central

    Zhuang, Jin-Ying; Zhang, Sen; Xu, Jing; Hu, Die

    2014-01-01

    Attractiveness judgment in the context of mate preferences is thought to reflect an assessment of mate quality in relation to an absolute scale of genetic fitness and a relative scale of self-similarity. In this study, subjects judged the attractiveness and trustworthiness of faces in composite images that were manipulated to produce self-similar (self-resemblance) and dissimilar (other-resemblance) images. Males differentiated between self- and other-resemblance as well as among different degrees of self-resemblance in their attractiveness ratings; females did not. Specifically, in Experiment 1, using a morphing technique, we created previously unseen face images possessing different degrees (0%, 30%, 40%, or 50%) of incorporation of the subject's images (different degrees of self-resemblance) and found that males preferred images that were closer to average (0%) rather than more self-similar, whereas females showed no preference for any degree of self-similarity. In Experiment 2, we added a pro-social question about trustworthiness. We replicated the Experiment 1 attractiveness rating results and further found that males differentiated between self- and other-resemblance for the same degree of composites; women did not. Both males and females showed a similar preference for self-resemblances when judging trustworthiness. In conclusion, only males factored self-resemblance into their attractiveness ratings of opposite-sex individuals in a manner consistent with cues of reproductive fitness, although both sexes favored self-resemblance when judging trustworthiness. PMID:24594644

  12. Discriminating males and unpredictable females: males differentiate self-similar facial cues more than females in the judgment of opposite-sex attractiveness.

    PubMed

    Zhuang, Jin-Ying; Zhang, Sen; Xu, Jing; Hu, Die

    2014-01-01

    Attractiveness judgment in the context of mate preferences is thought to reflect an assessment of mate quality in relation to an absolute scale of genetic fitness and a relative scale of self-similarity. In this study, subjects judged the attractiveness and trustworthiness of faces in composite images that were manipulated to produce self-similar (self-resemblance) and dissimilar (other-resemblance) images. Males differentiated between self- and other-resemblance as well as among different degrees of self-resemblance in their attractiveness ratings; females did not. Specifically, in Experiment 1, using a morphing technique, we created previously unseen face images possessing different degrees (0%, 30%, 40%, or 50%) of incorporation of the subject's images (different degrees of self-resemblance) and found that males preferred images that were closer to average (0%) rather than more self-similar, whereas females showed no preference for any degree of self-similarity. In Experiment 2, we added a pro-social question about trustworthiness. We replicated the Experiment 1 attractiveness rating results and further found that males differentiated between self- and other-resemblance for the same degree of composites; women did not. Both males and females showed a similar preference for self-resemblances when judging trustworthiness. In conclusion, only males factored self-resemblance into their attractiveness ratings of opposite-sex individuals in a manner consistent with cues of reproductive fitness, although both sexes favored self-resemblance when judging trustworthiness. PMID:24594644

  13. Wolbachia is not all about sex: male-feminizing Wolbachia alters the leafhopper Zyginidia pullula transcriptome in a mainly sex-independent manner

    PubMed Central

    Asgharian, Hosseinali; Chang, Peter L.; Mazzoglio, Peter J.; Negri, Ilaria

    2014-01-01

    Wolbachia causes the feminization of chromosomally male embryos in several species of crustaceans and insects, including the leafhopper Zyginidia pullula. In contrast to the relatively well-established ecological aspects of male feminization (e.g., sex ratio distortion and its consequences), the underlying molecular mechanisms remain understudied and unclear. We embarked on an exploratory study to investigate the extent and nature of Wolbachia's effect on gene expression pattern in Z. pullula. We sequenced whole transcriptomes from Wolbachia-infected and uninfected adults. 18147 loci were assembled de novo, including homologs of several Drosophila sex determination genes. A number of transcripts were flagged as candidate Wolbachia sequences. Despite the resemblance of Wolbachia-infected chromosomal males to uninfected and infected chromosomal females in terms of sexual morphology and behavior, principal component analysis revealed that gene expression patterns did not follow these sexual phenotype categories. The principal components generated by differentially expressed genes specified a strong sex-independent Wolbachia effect, followed by a weaker Wolbachia-sexual karyotype interaction effect. Approaches to further examine the molecular mechanism of Wolbachia-host interactions have been suggested based on the presented findings. PMID:25225494

  14. Changing seasonality and phenological responses of free-living male arctic ground squirrels: the importance of sex.

    PubMed

    Sheriff, Michael J; Richter, Melanie M; Buck, C Loren; Barnes, Brian M

    2013-08-19

    Many studies have addressed the effects of climate change on species as a whole; however, few have examined the possibility of sex-specific differences. To understand better the impact that changing patterns of snow-cover have on an important resident Arctic mammal, we investigated the long-term (13 years) phenology of hibernating male arctic ground squirrels living at two nearby sites in northern Alaska that experience significantly different snow-cover regimes. Previously, we demonstrated that snow-cover influences the timing of phenological events in females. Our results here suggest that the end of heterothermy in males is influenced by soil temperature and an endogenous circannual clock, but timing of male emergence from hibernation is influenced by the timing of female emergence. Males at both sites, Atigun and Toolik, end heterothermy on the same date in spring, but remain in their burrows while undergoing reproductive maturation. However, at Atigun, where snowmelt and female emergence occur relatively early, males emerge 8 days earlier than those at Toolik, maintaining a 12-day period between male and female emergence found at each site, but reducing the pre-emergence euthermic period that is critical for reproductive maturation. This sensitivity in timing of male emergence to female emergence will need to be matched by phase shifts in the circannual clock and responsiveness to environmental factors that time the end of heterothermy, if synchrony in reproductive readiness between the sexes is to be preserved in a rapidly changing climate. PMID:23836786

  15. Vascular wall function in insulin-resistant JCR:LA-cp rats: role of male and female sex.

    PubMed

    O'Brien, S F; Russell, J C; Dolphin, P J; Davidge, S T

    2000-08-01

    Vascular wall function was assessed in obese insulin-resistant (cp/cp) and lean normal (+/?), male and female, JCR:LA-cp rats. Both male and female cp/cp rats showed enhanced maximum contractility in response to norepinephrine; impaired smooth muscle in response to sodium nitroprusside, a nitric oxide (NO) donor; and impaired relaxation in response to acetylcholine (ACh), compared with their lean counterparts. The abnormalities were similar in male and female cp/cp rats. The NO synthase inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME), inhibited ACh-mediated relaxation significantly in male rats, both cp/cp and +/?. The inhibition of ACh-mediated relaxation by L-NAME in +/? females was less, with no reduction in maximal relaxation, and was absent in cp/cp females. These effects suggest that the relative importance of NO in the endothelial modulation of smooth muscle contractility is greater in male rats. The results are consistent with a decreased role for endothelial NO in the cp/cp rats of both sexes and a reduction in NO-independent cholinergic relaxation in the male cp/cp rat. This NO-independent mechanism is not affected in the female cp/cp rats. The relatively small differences between males and females in smooth muscle cell and vascular function may contribute to sex-related differences in the atherogenesis, vasospasm, and ischemic damage associated with the obese insulin-resistant state.

  16. Effect of dietary protein levels on sex hormones in growing male rats kept under constant darkness.

    PubMed

    Hanai, Miho; Esashi, Takatoshi

    2012-01-01

    The purpose of this experiment was to clarify the effects of dietary protein levels on the gonadal development and sex hormones in male rats kept under constant darkness as a model of disturbed daily rhythm. Four-week-old male rats (Fischer 344 strain) were kept under constant darkness or normal lighting (12-h light/dark cycle). Two kinds of experimental diet were prepared, one with low dietary protein levels (9% casein) and one with normal levels (18% casein). Harper mineral mixture and Panvitan were used as mineral and vitamin sources, respectively. After 4 weeks, gonadal weight, serum testosterone, and other hormone contents were evaluated. The gonadal weight in the constant darkness groups (D-groups) was lower than that in the normal lighting groups (N-groups). Although the low-protein diet in the D-groups significantly reduced gonadal weight, the normal-protein diet mitigated the reduction of gonadal weight in rats kept under constant darkness. Serum testosterone and androstenedione concentrations were lower in D-group rats fed the low-protein diet. There were no effects of lighting condition or protein levels on serum luteinizing hormone (LH), follicle- stimulating hormone (FSH), or progesterone concentrations. These results indicate that the suppression of gonadal development in D-group rats fed the low-protein diet was caused by low testosterone, which we attribute to the inhibition of synthesized androstenedione, a precursor of testosterone. The present study showed that constant darkness and the low- protein diet inhibited the synthetic pathway from progesterone to androstenedione.

  17. Effect of dietary protein levels on sex hormones in growing male rats kept under constant darkness.

    PubMed

    Hanai, Miho; Esashi, Takatoshi

    2012-01-01

    The purpose of this experiment was to clarify the effects of dietary protein levels on the gonadal development and sex hormones in male rats kept under constant darkness as a model of disturbed daily rhythm. Four-week-old male rats (Fischer 344 strain) were kept under constant darkness or normal lighting (12-h light/dark cycle). Two kinds of experimental diet were prepared, one with low dietary protein levels (9% casein) and one with normal levels (18% casein). Harper mineral mixture and Panvitan were used as mineral and vitamin sources, respectively. After 4 weeks, gonadal weight, serum testosterone, and other hormone contents were evaluated. The gonadal weight in the constant darkness groups (D-groups) was lower than that in the normal lighting groups (N-groups). Although the low-protein diet in the D-groups significantly reduced gonadal weight, the normal-protein diet mitigated the reduction of gonadal weight in rats kept under constant darkness. Serum testosterone and androstenedione concentrations were lower in D-group rats fed the low-protein diet. There were no effects of lighting condition or protein levels on serum luteinizing hormone (LH), follicle- stimulating hormone (FSH), or progesterone concentrations. These results indicate that the suppression of gonadal development in D-group rats fed the low-protein diet was caused by low testosterone, which we attribute to the inhibition of synthesized androstenedione, a precursor of testosterone. The present study showed that constant darkness and the low- protein diet inhibited the synthetic pathway from progesterone to androstenedione. PMID:23095819

  18. Haploinsufficiency of SF-1 Causes Female to Male Sex Reversal in Nile Tilapia, Oreochromis niloticus.

    PubMed

    Xie, Qing-Ping; He, Xue; Sui, Yi-Ning; Chen, Li-Li; Sun, Li-Na; Wang, De-Shou

    2016-06-01

    Steroidogenic factor-1 (Sf-1) (officially designated nuclear receptor subfamily 5 group A member 1 [NR5A1]) is a master regulator of steroidogenesis and reproduction in mammals. However, its function remains unclear in nonmammalian vertebrates. In the present study, we used immunohistochemistry to detect expression of Sf-1 in the steroidogenic cells, the interstitial, granulosa, and theca cells of the ovary, and the Leydig cells of the testis, in Nile tilapia. Clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9 (Cas9) cleavage of sf-1 resulted in a high mutation rate in the F0 generation and a phenotype of gonadal dysgenesis and reduced steroidogenic cells in XX and XY fish. Sf-1 deficiency also resulted in decreased cytochrome P450, family 19, subfamily A, polypeptide 1a, forkhead box L2 expression, and serum estradiol-17β in XX fish. In XY fish, Sf-1 deficiency increased cytochrome P450, family 19, subfamily A, polypeptide 1a and forkhead box L2 expression but decreased cytochrome P450, family 11, subfamily B, polypeptide 2 expression and serum 11-ketotestosterone levels. 17α-methyltestosterone treatment successfully rescued the gonadal phenotype of Sf-1-deficient XY fish, as demonstrated by normal spermatogenesis and production of F1 mutants. In contrast, estradiol-17β treatment only partially rescued the gonadal phenotype of Sf-1-deficient XX fish, as demonstrated by the appearance of phase II oocytes. Furthermore, both sf-1(+/-) F1 XX and XY mutants developed as fertile males, although spermatogenesis was delayed and efferent duct formation was disordered. Our data suggest that Sf-1 is a major regulator of steroidogenesis and reproduction in fish, as it is in mammals. Sf-1 deficiency resulted in gonadal dysgenesis and feminization of XY gonads. However, unlike in mammals, Sf-1 deficiency also resulted in female to male sex reversal in 8.1% of F0 and 92.1% of sf-1(+/-) F1 in XX fish. PMID:27046435

  19. Sex hormone receptors in the hypothalamus and their role in sexual differentiation of the male rat brain

    SciTech Connect

    Shishkina, I.V.; Babichev, V.N.; Ozol', L.Yu.

    1986-09-01

    In this investigation, changes in the level of receptors for sex hormones in the hypothalamus and cerebral cortex of male rats were studied on the first through fifth days of postnatal life, and the results obtained were compared with the levels of luteinizing hormone and sex hormones in the peripheral blood in order to discover any correlation between these parameters. 2,4,6,7,-/sup 3/H-estradiol-17..beta.. and 1,2,6,7-/sup 3/H-testosterone were used as labeled hormones. The values of the association constant and concentration of specific binding sites for estradiol and testosterone in hypothalamus and cerebral cortex of male rats during neonatal development is shown. It is found that in male rats on the first day after birth, receptors for estradiol and testosterone are present and they enable the action both of the testicular hormone and that of estradiol to be realized.

  20. Selection by mating competitiveness improves the performance of Anastrepha ludens males of the genetic sexing strain Tapachula-7.

    PubMed

    Quintero-Fong, L; Toledo, J; Ruiz, L; Rendón, P; Orozco-Dávila, D; Cruz, L; Liedo, P

    2016-10-01

    The sexual performance of Anastrepha ludens males of the Tapachula-7 genetic sexing strain, produced via selection based on mating success, was compared with that of males produced without selection in competition with wild males. Mating competition, development time, survival, mass-rearing quality parameters and pheromone production were compared. The results showed that selection based on mating competitiveness significantly improved the sexual performance of offspring. Development time, survival of larvae, pupae and adults, and weights of larvae and pupae increased with each selection cycle. Differences in the relative quantity of the pheromone compounds (Z)-3-nonenol and anastrephin were observed when comparing the parental males with the F4 and wild males. The implications of this colony management method on the sterile insect technique are discussed.

  1. Selection by mating competitiveness improves the performance of Anastrepha ludens males of the genetic sexing strain Tapachula-7.

    PubMed

    Quintero-Fong, L; Toledo, J; Ruiz, L; Rendón, P; Orozco-Dávila, D; Cruz, L; Liedo, P

    2016-10-01

    The sexual performance of Anastrepha ludens males of the Tapachula-7 genetic sexing strain, produced via selection based on mating success, was compared with that of males produced without selection in competition with wild males. Mating competition, development time, survival, mass-rearing quality parameters and pheromone production were compared. The results showed that selection based on mating competitiveness significantly improved the sexual performance of offspring. Development time, survival of larvae, pupae and adults, and weights of larvae and pupae increased with each selection cycle. Differences in the relative quantity of the pheromone compounds (Z)-3-nonenol and anastrephin were observed when comparing the parental males with the F4 and wild males. The implications of this colony management method on the sterile insect technique are discussed. PMID:27215583

  2. The Impact of Sex of Psychological Examiner on Sexually Abused Girls' Preference for and Anticipated Comfort with Male versus Female Counselors.

    ERIC Educational Resources Information Center

    Fowler, William E.; And Others

    1992-01-01

    As part of a psychological evaluation, 35 sexually abused girls were asked to indicate their preference for a male or female counselor. Girls evaluated by male examiners were less likely to have a clear preference for a female counselor. The sex of the examiner was related to participants' anticipated comfort with a counselor of a particular sex.…

  3. Testosterone, sex hormone-binding globulin, calculated free testosterone, and oestradiol in male vegans and omnivores.

    PubMed

    Key, T J; Roe, L; Thorogood, M; Moore, J W; Clark, G M; Wang, D Y

    1990-07-01

    Total testosterone (T), total oestradiol (E2) and sex hormone-binding globulin (SHBG) concentrations were measured in plasma samples from fifty-one male vegans and fifty-seven omnivores of similar age. Free T concentration was estimated by calculation. In comparison with the omnivores, the vegans had 7% higher total T (P = 0.250), 23% higher SHBG (P = 0.001), 3% lower free T (P = 0.580), and 11% higher E2 (P = 0.194). In a subset of eighteen vegans and twenty-two omnivores for whom 4 d diet records were available, there were statistically significant correlations between T and polyunsaturated fatty acids (r 0.37), SHBG and fat (r 0.43 for total fat, 0.46 for saturated fatty acids and 0.33 for polyunsaturated fatty acids), and SHBG and alcohol (r-0.39). It is concluded that a vegan diet causes a substantial increase in SHBG but has little effect on total or free T or on E2.

  4. Sex-Role Development and Parental Expectations among Disturbed Adolescent Males

    ERIC Educational Resources Information Center

    Small, Arnold; And Others

    1975-01-01

    This study was designed to examine the sex-linked personality traits of adolescents referred to out-patient clinics for a variety of psychological problems, the sex-linked personality traits of their parents, and the sex-linked personality characteristics that the parents of these adolescents would ideally like for their sons. (Author/RK)

  5. CHALLENGES IN BIODEGRADATION OF TRACE ORGANIC CONTAMINANTS-GASOLINE OXYGENATES AND SEX HORMONES

    EPA Science Inventory

    Advances in analytical methods have led to the identification of several classes of organic chemicals that are associated with adverse environmental impacts. Two such classes of organic chemicals, gasoline oxygenates and sex hormones, are used to illustrate challenges associated ...

  6. Sex differences in liver toxicity-do female and male human primary hepatocytes react differently to toxicants in vitro?

    PubMed

    Mennecozzi, Milena; Landesmann, Brigitte; Palosaari, Taina; Harris, Georgina; Whelan, Maurice

    2015-01-01

    There is increasing amount of evidence for sex variation in drug efficiency and toxicity profiles. Women are more susceptible than men to acute liver injury from xenobiotics. In general, this is attributed to sex differences at a physiological level as well as differences in pharmacokinetics and pharmacodynamics, but neither of these can give a sufficient explanation for the diverse responses to xenobiotics. Existing data are mainly based on animal models and limited data exist on in vitro sex differences relevant to humans. To date, male and female human hepatocytes have not yet been compared in terms of their responses to hepatotoxic drugs. We investigated whether sex-specific differences in acute hepatotoxicity can be observed in vitro by comparing hepatotoxic drug effects in male and female primary human hepatocytes. Significant sex-related differences were found for certain parameters and individual drugs, showing an overall higher sensitivity of female primary hepatocytes to hepatotoxicants. Moreover, our work demonstrated that high content screening is feasible with pooled primary human hepatocytes in suspension. PMID:25849576

  7. Prevalence of Same-Sex Sexual Behavior and Associated Characteristics among Low-Income Urban Males in Peru

    PubMed Central

    Clark, Jesse L.; Caceres, Carlos F.; Lescano, Andres G.; Konda, Kelika A.; Leon, Segundo R.; Jones, Franca R.; Kegeles, Susan M.; Klausner, Jeffrey D.; Coates, Thomas J.

    2007-01-01

    Background Peru has a concentrated HIV epidemic in which men who have sex with men are particularly vulnerable. We describe the lifetime prevalence of same-sex sexual contact and associated risk behaviors of men in Peru's general population, regardless of their sexual identity. Methods and Results A probability sample of males from low-income households in three Peruvian cities completed an epidemiologic survey addressing their sexual risk behavior, including sex with other men. Serum was tested for HSV-2, HIV, and syphilis. Urine was tested for chlamydia and gonorrhea. A total of 2,271 18–30 year old men and women were contacted, of whom 1,645 (72.4%) agreed to participate in the study. Among the sexually experienced men surveyed, 15.2% (85/558, 95% CI: 12.2%–18.2%) reported a history of sex with other men. Men ever reporting sex with men (MESM) had a lower educational level, had greater numbers of sex partners, and were more likely to engage in risk behaviors including unprotected sex with casual partners, paying for or providing compensated sex, and using illegal drugs. MESM were also more likely to have had previous STI symptoms or a prior STI diagnosis, and had a greater prevalence of HSV-2 seropositivity. Conclusions Many low-income Peruvian men have engaged in same-sex sexual contact and maintain greater behavioral and biological risk factors for HIV/STI transmission than non-MESM. Improved surveillance strategies for HIV and STIs among MESM are necessary to better understand the epidemiology of HIV in Latin America and to prevent its further spread. PMID:17712426

  8. The patient's motivation during bicycle stress ECG test is dependent on the investigator's sex in male patients.

    PubMed

    Jung, Christian; Ferrari, Markus; Goebel, Bjoern; Figulla, Hans R

    2009-08-21

    The exercise electrocardiogram is a commonly used non-invasive method for detection of electrocardiogram (ECG) changes secondary to myocardial ischemia. Studies showed the importance of the patient's motivation to reach the estimated submaximal heart rate. The purpose of this study was to test whether the patient's motivation is dependent on the investigator's sex. We included 1170 patients (in-hospital patients and out-clinic patients; 63.5% male, 36.5% female) in this study. Stress test data (stationary bicycle with gradually increasing intensity) were collected retrospectively: patient's age, sex, maximal power stage, ECG-abnormalities, angina pectoris, and attending physician's sex. Male patients achieved a higher power stage than their female counterparts (126.5+/-47.7 W vs. 89.7+/-30.4 W). When male patients were supervised by a female doctor they reached higher maximum power stages (136.6+/-53.5 W vs. 121.6+/-43.3 W; p=0,001), more often the submaximal heart rate (47.9% vs. 38.3%; p=0.02) but complained less frequent about angina pectoris (5.6% vs. 17.3%). In contrast, none of these parameters was dependent on the attending physician's sex in female patients. The attending physician's sex influences the maximum exercise ability and the incidence of complaints during bicycle stress in male patients but not in females. We would speculate that men try to impress women with physical strength and try to dissimulate physical discomfort or pain. This could possibly influence the validity of such non-invasive methods with exercise dependent detection of myocardial ischemia.

  9. Sensilla on different organs of female and male Telenomus dendrolimusi Chu (Hymenoptera: Scelionidae).

    PubMed

    Zhang, Sufang; Zhang, Zhen; Kong, Xiangbo; Wang, Hongbin; Luo, Jitong; Yang, Zhongwu

    2015-11-01

    Telenomus dendrolimusi Chu is a dominant egg parasitoid of Dendrolimus, which is the most serious conifer defoliator in China. However, the host locating mechanism of T. dendrolimusi is unclear. To take better advantage of this kind of parasitoid, it is necessary to clarify the basic knowledge of the organization of the wasp's sensory system. In this study, the external morphologies of the sensilla on the entire female and male T. dendrolimusi body were described using scanning electron microscopy. Antennae shape and sensilla types were sexually dimorphic. Ten segments and nine types of sensilla were found on the female antenna, including basiconic sensillum (BS), chaeticum sensillum (ChS), trichoid sensillum type 1 (TS1), trichoid sensillum type 2 (TS2), trichoid curvata sensillum (TCS), sickle-shaped sensillum (SSS), multiporous gustatory sensillum (MGS), campaniform sensillum (CS), and styloconica sensillum (STS). The distribution of the sensilla was directional on female antenna. The male antenna consisted of 12 segments, and 1-3 segments were similar to those of the female. Five types of sensilla were found on male antenna, including BS, ChS, TS1, TCS, and STS. The mouthparts, thoracic legs, eyes, mesonotum, and wings were all covered with longitudinally fluted TSs without hole. A tympana structure appeared on the thoracic legs. Special crevice-shaped structures were found on the abdomens of both T. dendrolimusi sexes. Possible sensilla functions are discussed according to their morphology. These results provide a solid basis for further researches about the parasitic mechanisms of T. dendrolimusi.

  10. Prenatal Testosterone Induces Sex-Specific Dysfunction in Endothelium-Dependent Relaxation Pathways in Adult Male and Female Rats1

    PubMed Central

    Chinnathambi, Vijayakumar; Yallampalli, Chandrasekhar; Sathishkumar, Kunju

    2013-01-01

    ABSTRACT Prenatal testosterone (T) exposure impacts postnatal cardiovascular function, leading to increases in blood pressure with associated decreased endothelium-dependent vascular relaxation in adult females. Endothelial function in males is not known. Furthermore, which of the endothelial pathways contributes to endothelial dysfunction and if there exists sex differences are not known. The objective of this study was to characterize the relative contribution of nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF) to the impaired endothelium-dependent vasodilation in prenatal T-exposed adult males and females. Offspring of pregnant rats treated with T propionate or its vehicle were examined. Telemetric blood pressure levels and endothelium-dependent vascular reactivity were assessed with wire myography. Levels of nitric oxide synthase (NOS3) and Kcnn3 and Kcnn4 channel expression were examined in mesenteric arteries. Mean arterial pressure was significantly higher in T males and females than in controls. Endothelium-dependent acetylcholine relaxation was significantly lower in both T males and females. EDHF-mediated relaxation was specifically blunted in T males (Emax = 48.64% ± 3.73%) compared to that in control males (Emax = 81.71% ± 3.18%); however, NO-mediated relaxation was specifically impaired in T females (Emax = 36.01% ± 4.29%) compared with that in control females (Emax = 54.56% ± 6.37%). Relaxation to sodium nitroprusside and levcromakalim were unaffected with T-treatment. NOS3 protein was decreased in T females but not in T males. Kcnn3 expression was decreased in both T males and females compared to controls. These findings suggest that prenatal T leads to an increase in blood pressure in the adult offspring, associated with blunting of endothelial cell-associated relaxation and that the effects are sex-specific: EDHF-related in males and NO-related in females. PMID:23966325

  11. Sex pheromone blend discrimination by male moths fromE andZ strains of European corn borer.

    PubMed

    Glover, T J; Tang, X H; Roelofs, W L

    1987-01-01

    Sex pheromone behavioral responses were analyzed in a flight tunnel with European corn borer,Ostrinia nubilalis (Hübner), males from three distinct populations. Males from a bivoltine and a univoltine biotype using a 97.8∶2.2 blend (Z strains) of (Z)- and (E)-11-tetradecenyl acetate were assayed with treatments containing 0, 0.5, 1, and 3% of theE isomer. Males from neither population oriented in the plume to the 100%Z treatment, but bivoltine males oriented and flew to the source to the other three treatments, whereas univoltine males oriented and flew to the source only to the 1 % and 3 %E treatments. Males from a bivoltine biotype using a 1∶99 blend ofZ/E isomers (E strain) were assayed with sources containing 0, 0.5, 1, and 3% of theZ isomer. Males did not orient to the 0%Z source, but oriented and flew to the source to the other three treatments. In addition to using opposite geometric isomers for the main pheromone component, the bivoltineE strain differed from the bivoltineZ strain by producing and responding better to 1 % of the minor component and by storing 3 times more pheromone in the female glands. Contrary to previous reports, the blend of two pheromone components is significantly better than the main component alone in eliciting oriented flight and close-range behavior with males from all three populations of European corn borer. PMID:24301366

  12. A Qualitative Study of Medical Mistrust, Perceived Discrimination, and Risk Behavior Disclosure to Clinicians by U.S. Male Sex Workers and Other Men Who Have Sex with Men: Implications for Biomedical HIV Prevention.

    PubMed

    Underhill, Kristen; Morrow, Kathleen M; Colleran, Christopher; Holcomb, Richard; Calabrese, Sarah K; Operario, Don; Galárraga, Omar; Mayer, Kenneth H

    2015-08-01

    Access to biomedical HIV prevention technologies such as pre-exposure prophylaxis (PrEP) requires individuals to disclose risk behavior to clinicians, but experiences of discrimination and medical mistrust may limit disclosure among male sex workers and other MSM. We explored experiences of perceived discrimination, medical mistrust, and behavior disclosure among male sex workers compared to other men who have sex with men (MSM). We conducted 56 interviews with MSM and compared findings about medical mistrust, discrimination, and disclosure for 31 men who engaged in sex work vs. 25 men who did not. MSM who engaged in sex work reported more medical mistrust and healthcare discrimination due to issues beyond MSM behavior/identity (e.g., homelessness, substance use, poverty). MSM who did not report sex work described disclosing sex with men to clinicians more often. Both subgroups reported low PrEP awareness, but willingness to disclose behavior to obtain PrEP. Medical mistrust and perceived discrimination create barriers for sexual behavior disclosure to clinicians, potentially impeding access to PrEP and other forms of biomedical HIV prevention. These barriers may be higher among male sex workers compared to other MSM, given overlapping stigmas including sex work, substance use, homelessness, and poverty. An intersectionality framework for understanding multiple stigmas can help to identify how these dynamics may limit access to biomedical HIV prevention among male sex workers, as well as suggesting strategies for addressing stigmas to improve the delivery of PrEP and other HIV prevention approaches in this population.

  13. Short-term treatment of adult male zebrafish (Danio Rerio) with 17α-ethinyl estradiol affects the transcription of genes involved in development and male sex differentiation.

    PubMed

    Reyhanian Caspillo, Nasim; Volkova, Kristina; Hallgren, Stefan; Olsson, Per-Erik; Porsch-Hällström, Inger

    2014-08-01

    The synthetic estrogen 17α-ethinyl estradiol (EE2) disturbs reproduction and causes gonadal malformation in fish. Effects on the transcription of genes involved in gonad development and function that could serve as sensitive biomarkers of reproductive effects in the field is, however, not well known. We have studied mRNA expression in testes and liver of adult zebrafish (Danio rerio) males treated with 0, 5 or 25 ng/L EE2for 14 days. qPCR analysis showed that the mRNA expression of four genes linked to zebrafish male sex determination and differentiation, Anti-Mullerian Hormone, Double sex and mab-related protein, Sry-related HMG box-9a and Nuclear receptor subfamily 5 group number 1b were significantly decreased by 25 ng/L, but not 5 ng/L EE2 compared with the levels in untreated fish. The decreased transcription was correlated with a previously shown spawning failure in these males (Reyhanian et al., 2011. Aquat Toxicol 105, 41-48), suggesting that decreased mRNA expression of genes regulating male sexual function could be involved in the functional sterility. The mRNA level of Cytochrome P-45019a, involved in female reproductive development, was unaffected by hormone treatment. The transcription of the female-specific Vitellogenin was significantly induced in testes. While testicular Androgen Receptor and the Estrogen Receptor-alpha mRNA levels were unchanged, Estrogen receptor-beta was significantly decreased by 25 ng/L EE2. Hepatic Estrogen Receptor-alpha mRNA was significantly increased by both exposure concentrations, while Estrogen Receptor-beta transcription was unaltered. The decreased transcription of male-predominant genes supports a demasculinization of testes by EE2 and might reflect reproductive disturbances in the environment. PMID:24747828

  14. Severe impairment of male reproductive organ development in a low SMN expressing mouse model of spinal muscular atrophy

    PubMed Central

    Ottesen, Eric W.; Howell, Matthew D.; Singh, Natalia N.; Seo, Joonbae; Whitley, Elizabeth M.; Singh, Ravindra N.

    2016-01-01

    Spinal muscular atrophy (SMA) is caused by low levels of survival motor neuron (SMN), a multifunctional protein essential for higher eukaryotes. While SMN is one of the most scrutinized proteins associated with neurodegeneration, its gender-specific role in vertebrates remains unknown. We utilized a mild SMA model (C/C model) to examine the impact of low SMN on growth and development of mammalian sex organs. We show impaired testis development, degenerated seminiferous tubules, reduced sperm count and low fertility in C/C males, but no overt sex organ phenotype in C/C females. Underscoring an increased requirement for SMN expression, wild type testis showed extremely high levels of SMN protein compared to other tissues. Our results revealed severe perturbations in pathways critical to C/C male reproductive organ development and function, including steroid biosynthesis, apoptosis, and spermatogenesis. Consistent with enhanced apoptosis in seminiferous tubules of C/C testes, we recorded a drastic increase in cells with DNA fragmentation. SMN was expressed at high levels in adult C/C testis due to an adult-specific splicing switch, but could not compensate for low levels during early testicular development. Our findings uncover novel hallmarks of SMA disease progression and link SMN to general male infertility. PMID:26830971

  15. Understanding the diversity of male clients of sex workers in China and the implications for HIV prevention programmes.

    PubMed

    Huang, Yingying; Maman, Suzanne; Pan, Suiming

    2012-01-01

    Male clients of sex workers have been overlooked in China's HIV prevention efforts. This study aims to examine men's practices and attitudes toward extramarital sexual relationships, motivations for visiting female sex workers (FSWs), perceptions of sexually transmitted infection (STI)/HIV risk and risk prevention strategies used. One hundred and eighty-six clients of FSWs with varying socio-economic statuses were interviewed in different sex work settings. Men described no conflict between their role as a client and a responsible family provider. They described social pressure from peers and business partners to visit FSWs, sexual pleasure and companionship as motivators to seek commercial sex. While some men reported no risks associated with visiting FSWs, others identified risks such as being arrested by the police, robbed by gangs and threatening the health of their families by contracting a STI. This study underscores the diversity of FSW clients and the need to understand the beliefs and behaviours of different client types to develop appropriate HIV prevention programmes. It also demonstrates the feasibility of recruiting different types of male clients, a hard-to-reach population for Chinese HIV prevention efforts.

  16. Understanding the diversity of male clients of sex workers in China and the implications for HIV prevention programmes.

    PubMed

    Huang, Yingying; Maman, Suzanne; Pan, Suiming

    2012-01-01

    Male clients of sex workers have been overlooked in China's HIV prevention efforts. This study aims to examine men's practices and attitudes toward extramarital sexual relationships, motivations for visiting female sex workers (FSWs), perceptions of sexually transmitted infection (STI)/HIV risk and risk prevention strategies used. One hundred and eighty-six clients of FSWs with varying socio-economic statuses were interviewed in different sex work settings. Men described no conflict between their role as a client and a responsible family provider. They described social pressure from peers and business partners to visit FSWs, sexual pleasure and companionship as motivators to seek commercial sex. While some men reported no risks associated with visiting FSWs, others identified risks such as being arrested by the police, robbed by gangs and threatening the health of their families by contracting a STI. This study underscores the diversity of FSW clients and the need to understand the beliefs and behaviours of different client types to develop appropriate HIV prevention programmes. It also demonstrates the feasibility of recruiting different types of male clients, a hard-to-reach population for Chinese HIV prevention efforts. PMID:22313090

  17. A prospective study on sexual function and mood in female-to-male transsexuals during testosterone administration and after sex reassignment surgery.

    PubMed

    Costantino, Antonietta; Cerpolini, Silvia; Alvisi, Stefania; Morselli, Paolo Giovanni; Venturoli, Stefano; Meriggiola, Maria Cristina

    2013-01-01

    Testosterone administration in female-to-male transsexual subjects aims to develop and maintain the characteristics of the desired sex. Very little data exists on its effects on sexuality of female-to-male transsexuals. The aim of this study was to evaluate sexual function and mood of female-to-male transsexuals from their first visit, throughout testosterone administration and after sex reassignment surgery. Participants were 50 female-to-male transsexual subjects who completed questionnaires assessing sexual parameters and mood. The authors measured reproductive hormones and hematological parameters. The results suggest a positive effect of testosterone treatment on sexual function and mood in female-to-male transsexual subjects.

  18. Male only progeny in Anastrepha suspensa by RNAi-induced sex reversion of chromosomal females

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Tephritidae sex determination is established by orthologs to the Drosophila melanogaster transformer and transformer-2 genes. In contrast, primary signals for sex determination are different in these species corresponding to the number of X chromosomes (XSE) in Drosophilidae species and to the pr...

  19. AIDS/other STIs prevention in China: the effect of sex worker migration and the organization of the sex industry.

    PubMed

    Zhuang, Kongshao; McQuaide, Shiling

    2013-04-01

    HIV/AIDS prevention projects that pay special attention to the socio-cultural context of a community have been implemented in a number of Asian and African countries recently. Such projects integrate scientific approaches, such as condom promotion, with cultural approaches that focus on regional social norms. This paper explores effective intervention strategies in the context of sex workers' mobility patterns, and the sex industry's internal organization in China. It argues that a social network based on quasi-familial relations and regional ties recruits young women into the business, helps them move vertically as well as horizontally within the business, and facilitates the smooth operation of the business. A sound understanding of the specific characteristics of sex work in China, therefore, is instrumental in formulating effective intervention tactics.

  20. Opposite-sex attraction in male mice requires testosterone-dependent regulation of adult olfactory bulb neurogenesis

    PubMed Central

    Schellino, Roberta; Trova, Sara; Cimino, Irene; Farinetti, Alice; Jongbloets, Bart C.; Pasterkamp, R. Jeroen; Panzica, Giancarlo; Giacobini, Paolo; De Marchis, Silvia; Peretto, Paolo

    2016-01-01

    Opposite-sex attraction in most mammals depends on the fine-tuned integration of pheromonal stimuli with gonadal hormones in the brain circuits underlying sexual behaviour. Neural activity in these circuits is regulated by sensory processing in the accessory olfactory bulb (AOB), the first central station of the vomeronasal system. Recent evidence indicates adult neurogenesis in the AOB is involved in sex behaviour; however, the mechanisms underlying this function are unknown. By using Semaphorin 7A knockout (Sema7A ko) mice, which show a reduced number of gonadotropin-releasing-hormone neurons, small testicles and subfertility, and wild-type males castrated during adulthood, we demonstrate that the level of circulating testosterone regulates the sex-specific control of AOB neurogenesis and the vomeronasal system activation, which influences opposite-sex cue preference/attraction in mice. Overall, these data highlight adult neurogenesis as a hub for the integration of pheromonal and hormonal cues that control sex-specific responses in brain circuits. PMID:27782186

  1. Cigarette smoking and male sex are independent and age concomitant risk factors for the development of ocular sarcoidosis in a new orleans sarcoidosis population

    PubMed Central

    Janot, Adam C.; Huscher, Dörte; Walker, McCall; Grewal, Harmanjot K.; Yu, Mary; Lammi, Matthew R.; Saketkoo, Lesley Ann

    2016-01-01

    Introduction Sarcoidosis is a multi-organ system granulomatous disease of unknown origin with an incidence of 1–40/100,000. Though pulmonary manifestations are predominant, ocular sarcoidosis (OS) affects 25–50% of patients with sarcoidosis and can lead to blindness. Methods A retrospective, single-center chart review of sarcoidosis cases investigated variables associated with the development of OS. Inclusion criteria were biopsy-proven sarcoidosis, disease duration greater than 1 year, documented smoking status on chart review and documentation of sarcoid-related eye disease. Multivariate analysis identified independent risk factors for OS. Results Of 269 charts reviewed, 109 patients met inclusion criteria. The OS group had a significantly higher proportion of smokers (71.4%) than without OS (42.0%, p=0.027) with no difference (p=0.61) in median number of pack years. Male sex was significantly higher in the OS group (57.1% versus 26.1%, p=0.009). Median duration of sarcoidosis was higher in the OS group (10 versus 4 years, p=0.031). Multivariate regression identified tobacco exposure (OR=5.25, p=0.007, 95% CI 1.58–17.41), male sex (OR=7.48, p=0.002, 95% CI 2.15–26.01), and age (OR=1.114, p=0.002, 95% CI 1.04–1.19) as concomitant risk factors for the development of OS. Conclusion To date, there are few dedicated investigations of risk factors for OS, especially smoking. This investigation identified male sex, age, and tobacco exposure as independent risk factors for OS. Though disease duration did not withstand regression analysis in this moderately sized group, age at chart review suggests screening for OS should not remit but rather intensify in aging patients with sarcoidosis. PMID:26278693

  2. Adaptations for rapid and forceful contraction in wing muscles of the male golden-collared manakin: sex and species comparisons.

    PubMed

    Schultz, J D; Hertel, F; Bauch, M; Schlinger, B A

    2001-11-01

    The courtship display of the male golden-collared manakin (Manacus vitellinus) of Panamanian rainforests is noteworthy for several types of whip-crack-like sounds created by a rapid overhead flip of the wings. We have hypothesized that this courtship behavior. which is not performed by females, is associated with steroid-sensitive and sexually dimorphic neuromuscular systems. Presumably, muscles creating the motion of the wingsnap in males are specialized for greater force generation and speed of contraction. We tested this hypothesis by examining mass, fiber diameter, metabolic enzyme activity, and myosin isoform expression in several muscles of male and female manakins and in both sexes of a non-wingsnapping bird, the zebra finch (Taenopygia guttata). We have identified three wing muscles, the scapulohumeralis caudalis, the supracoracoideus, and the pectoralis major, that differ in one or more of these characteristics across sex and species, suggesting they are specialized for faster contraction and greater force production in male manakins. These muscles normally function to raise and lower the wings during flight. As this movement is the principal motion of the wingsnap, these adaptations presumably underlie the performance of the wingsnap display. PMID:11778830

  3. The Sertoli Cell Only Syndrome and Glaucoma in a Sex - Determining Region Y (SRY) Positive XX Infertile Male.

    PubMed

    Jain, Manish; V, Veeramohan; Chaudhary, Isha; Halder, Ashutosh

    2013-07-01

    The XX male syndrome is a rare genetic disorder. The phenotype is variable; it ranges from a severe impairment of the external genitalia to a normal male phenotype with infertility. It generally results from an unequal crossing over between the short arms of the sex chromosomes (X and Y). We are reporting a case of a 38-year-old man who presented with infertility and the features of hypogonadism and glaucoma. The examinations revealed normal external male genitalia, soft small testes, gynaecomastia and glaucoma. The semen analysis showed azoospermia. The serum gonadotropins were high, with low Anti Mullerian Hormone (AMH) and Inhibin B levels. The chromosomal analysis demonstrated a 46, XX karyotype. Fluorescent In-Situ Hybridization (FISH) and Polymerase Chain Reaction (PCR) revealed the presence of a Sex-determining Region Y (SRY). Testicular Fine Needle Aspiration Cytology (FNAC) revealed the Sertoli Cell Only Syndrome (SCOS). The presence of only Sertoli Cells in the testes, with glaucoma in the XX male syndrome, to our knowledge, has not been reported in the literature.

  4. Concurrent modulation of neuronal and behavioural olfactory responses to sex and host plant cues in a male moth.

    PubMed

    Kromann, Sophie H; Saveer, Ahmed M; Binyameen, Muhammad; Bengtsson, Marie; Birgersson, Göran; Hansson, Bill S; Schlyter, Fredrik; Witzgall, Peter; Ignell, Rickard; Becher, Paul G

    2015-01-22

    Mating has profound effects on animal physiology and behaviour, not only in females but also in males, which we show here for olfactory responses. In cotton leafworm moths, Spodoptera littoralis, odour-mediated attraction to sex pheromone and plant volatiles are modulated after mating, producing a behavioural response that matches the physiological condition of the male insect. Unmated males are attracted by upwind flight to sex pheromone released by calling females, as well as to volatiles of lilac flowers and green leaves of the host plant cotton, signalling adult food and mating sites, respectively. Mating temporarily abolishes male attraction to females and host plant odour, but does not diminish attraction to flowers. This behavioural modulation is correlated with a response modulation in the olfactory system, as shown by electro-physiological recordings from antennae and by functional imaging of the antennal lobe, using natural odours and synthetic compounds. An effect of mating on the olfactory responses to pheromone and cotton plant volatiles but not to lilac flowers indicates the presence of functionally independent neural circuits within the olfactory system. Our results indicate that these circuits interconnect and weigh perception of social and habitat odour signals to generate appropriate behavioural responses according to mating state.

  5. Sex difference in the size of the neural song control regions in a dueting songbird with similar song repertoire size of males and females.

    PubMed

    Gahr, M; Sonnenschein, E; Wickler, W

    1998-02-01

    Previous studies have suggested a causal relation between sex differences in behavior such as singing and sex differences in the size of brain areas such as the forebrain song control areas of songbirds. In the present study we show that the size of the forebrain vocal control areas nucleus hyperstriatalis ventrale pars caudale (HVC) and nucleus robustus archistriatalis (RA) and its neuron numbers are about twice as large in males as in females of the African dueting bush shrike Laniarius funebris. However, song types are of similar complexity (number of elements per song type, physical properties of elements) in both sexes, and repertoire size does not differ between males and females. Furthermore, in captivity male and female shrikes are able to learn the same song types. This demonstrates for the shrike that sex differences in the size of vocal control areas and in its neuron numbers do not predict the type of sex-typical vocal behavior. This result is supported by a statistical comparison of the sex differences in HVC size, RA size, and song repertoire size of all songbird species studied to date. Sex differences in species in which only the males sing are indeed larger than in species in which the females also sing; in songbird species with singing females, however, the sex differences in HVC and RA volume appear to be independent of the vocal repertoire size of females. The songbird model therefore does not support the notion that sex differences in area size and neuron number explain sex differences in a behavior that occurs in both sexes. Furthermore, in the shrike, neuron soma size is similar in males and females in the song motonucleus hypoglossus pars tracheosyringealis (nXIIts) and in the premotor nucleus RA, but is sexually dimorphic in the higher vocal center HVC. Thus, male and female shrikes produce songs of similar complexity with different neuron phenotypes.

  6. Individuality and Transgenerational Inheritance of Social Dominance and Sex Pheromones in Isogenic Male Mice.

    PubMed

    Fang, Qi; Zhang, Yao-Hua; Shi, Yao-Long; Zhang, Jin-Hua; Zhang, Jian-Xu

    2016-06-01

    Phenotypic variation and its epigenetic regulations within the inbred isogenic mice have long intrigued biologists. Here, we used inbred C57BL/6 mice to examine the individual differences and the inheritance of social dominance and male pheromones, expecting to create a model for studying the underlying epigenetic mechanisms for the evolution of these traits. We used a repeated male-male contest paradigm to form stable dominance-submission relationships between paired males and make superior or inferior quality manifest. Females showed olfactory preferences for the urine of dominant males to that of subordinate opponents. Gas chromatography-mass spectrometer analysis revealed that dominance-related or superior quality related pheromones were actually exaggerated male pheromone components (e.g., E-β-farnesene, hexadecanol, and 1-hexadecanol acetate) of preputial gland origin. Although the socially naïve sons of both dominant and subordinate males elicited the same female attraction when reaching adulthood, the former could dominated over the latter during undergoing the male-male competition and then gained more attraction of females. Our results demonstrated that social dominance or superior quality and the related pheromones were heritable and could be expressed through the interaction between aggression-related epigenotypes and male-male contests. It suggested that the evolution of sexually selected traits could be epigenetically determined and promoted through female mate choice. The epigenetic mechanisms driving the individual differences in behavior and male pheromones deserve further studies.

  7. Transgression and the Situated Body: Gender, Sex, and the Gay Male Teacher.

    ERIC Educational Resources Information Center

    Rofes, Eric

    This paper begins by examining representations of gay male school teachers in discourses produced by gay men, illustrating the ways gay men represent themselves in public discourse. The literature is reviewed for answers to questions about the role of the gay male teacher in education and the responsibility of the gay male teacher to gay…

  8. Individuality and Transgenerational Inheritance of Social Dominance and Sex Pheromones in Isogenic Male Mice.

    PubMed

    Fang, Qi; Zhang, Yao-Hua; Shi, Yao-Long; Zhang, Jin-Hua; Zhang, Jian-Xu

    2016-06-01

    Phenotypic variation and its epigenetic regulations within the inbred isogenic mice have long intrigued biologists. Here, we used inbred C57BL/6 mice to examine the individual differences and the inheritance of social dominance and male pheromones, expecting to create a model for studying the underlying epigenetic mechanisms for the evolution of these traits. We used a repeated male-male contest paradigm to form stable dominance-submission relationships between paired males and make superior or inferior quality manifest. Females showed olfactory preferences for the urine of dominant males to that of subordinate opponents. Gas chromatography-mass spectrometer analysis revealed that dominance-related or superior quality related pheromones were actually exaggerated male pheromone components (e.g., E-β-farnesene, hexadecanol, and 1-hexadecanol acetate) of preputial gland origin. Although the socially naïve sons of both dominant and subordinate males elicited the same female attraction when reaching adulthood, the former could dominated over the latter during undergoing the male-male competition and then gained more attraction of females. Our results demonstrated that social dominance or superior quality and the related pheromones were heritable and could be expressed through the interaction between aggression-related epigenotypes and male-male contests. It suggested that the evolution of sexually selected traits could be epigenetically determined and promoted through female mate choice. The epigenetic mechanisms driving the individual differences in behavior and male pheromones deserve further studies. PMID:27283352

  9. Sex Differences in Processing Speed: Developmental Effects in Males and Females

    ERIC Educational Resources Information Center

    Camarata, Stephen; Woodcock, Richard

    2006-01-01

    The purpose of this study was to compare the cognitive abilities and selected achievement performance of females and males across the lifespan on standardization samples of broad cognitive abilities in 1987 participants (1102 females, 885 males) from the WJ III, 4253 participants (2014 males, 2239 females) from the WJ-R, and 4225 participants…

  10. Towards 'reflexive epidemiology': Conflation of cisgender male and transgender women sex workers and implications for global understandings of HIV prevalence.

    PubMed

    Perez-Brumer, Amaya G; Oldenburg, Catherine E; Reisner, Sari L; Clark, Jesse L; Parker, Richard G

    2016-01-01

    The HIV epidemic has had a widespread impact on global scientific and cultural discourses related to gender, sexuality, and identity. 'Male sex workers' have been identified as a 'key population' in the global HIV epidemic; however, there are methodological and conceptual challenges for defining inclusion and exclusion of transgender women within this group. To assess these potential implications, this study employs self-critique and reflection to grapple with the empiric and conceptual implications of shifting understandings of sexuality and gender within the externally re-created etic category of 'MSM' and 'transgender women' in epidemiologic HIV research. We conducted a sensitivity analysis of our previously published meta-analysis which aimed to identify the scope of peer-reviewed articles assessing HIV prevalence among male sex workers globally between 2004 and 2013. The inclusion of four studies previously excluded due to non-differentiation of cisgender male from transgender women participants (studies from Spain, Thailand, India, and Brazil: 421 total participants) increased the overall estimate of global HIV prevalence among 'men' who engage in sex work from 10.5% (95% CI 9.4-11.5%) to 10.8% (95% CI 9.8-11.8%). The combination of social science critique with empiric epidemiologic analysis represents a first step in defining and operationalising 'reflexive epidemiology'. Grounded in the context of sex work and HIV prevention, this paper highlights the multiplicity of genders and sexualities across a range of social and cultural settings, limitations of existing categories (i.e. 'MSM', 'transgender'), and their global implications for epidemiologic estimates of HIV prevalence. PMID:27173599

  11. Social deficits in male children and adolescents with sex chromosome aneuploidy: a comparison of XXY, XYY, and XXYY syndromes.

    PubMed

    Cordeiro, Lisa; Tartaglia, Nicole; Roeltgen, David; Ross, Judith

    2012-01-01

    We compare social skills in three groups of males with sex chromosome aneuploidies (SCAs) using the Social Responsiveness Scale (SRS). Participants included males with XXY (N=102, M=10.08 years), XYY (N=40, M=9.93 years), and XXYY (N=32, M=11.57 years). XXY had lower (better) SRS scores compared to XYY and XXYY. Scores were not significantly different between XYY and XXYY. In all groups, there were significantly more with SRS scores in the severe range compared to the SRS normative sample. All groups scored lowest (better) on Social Motivation. Relationships between SRS scores and demographic and clinical variables were examined. Results describe the social skills in males with SCA, and suggest that an additional Y chromosome may contribute to increased risk of autistic behaviors.

  12. Cross-sex hormone treatment in male-to-female transsexual persons reduces serum brain-derived neurotrophic factor (BDNF).

    PubMed

    Fuss, Johannes; Hellweg, Rainer; Van Caenegem, Eva; Briken, Peer; Stalla, Günter K; T'Sjoen, Guy; Auer, Matthias K

    2015-01-01

    Serum levels of brain-derived neurotrophic factor (BDNF) are reduced in male-to-female transsexual persons (MtF) compared to male controls. It was hypothesized before that this might reflect either an involvement of BDNF in a biomechanism of transsexualism or to be the result of persistent social stress due to the condition. Here, we demonstrate that 12 month of cross-sex hormone treatment reduces serum BDNF levels in male-to-female transsexual persons independent of anthropometric measures. Participants were acquired through the European Network for the Investigation of Gender Incongruence (ENIGI). Reduced serum BDNF in MtF thus seems to be a result of hormonal treatment rather than a consequence or risk factor of transsexualism.

  13. Changes in Condom Use Over Time Among Female Sex Workers and Their Male Noncommercial Partners and Clients.

    PubMed

    Tracas, Ashley; Bazzi, Angela Robertson; Artamonova, Irina; Rangel, M Gudelia; Staines, Hugo; Ulibarri, Monica D

    2016-08-01

    Female sex workers (FSWs) often report inconsistent condom use with clients and noncommercial male partners, yet changes in condom use with various partner types during participation in observation studies remains underexplored. This longitudinal study of 214 FSWs and their male, noncommercial partners in the Mexico-U.S. border region, where HIV prevalence among FSWs continues to be high, utilized negative binomial regressions to examine changes in condom use with intimate partners and clients (regular and nonregular) over 24 months. Condom use decreased over time among couples in Ciudad Juarez, but there was no change in condom use among couples in Tijuana. FSWs' condom use with regular and nonregular clients significantly increased over time, which is consistent with previous research finding behavioral changes when participating in observational studies. Findings suggest the need for continued efforts to promote condom use among FSWs and their noncommercial male partners in addition to clients. PMID:27427926

  14. Sex steroid hormones matter for learning and memory: estrogenic regulation of hippocampal function in male and female rodents

    PubMed Central

    Kim, Jaekyoon; Tuscher, Jennifer J.; Fortress, Ashley M.

    2015-01-01

    Ample evidence has demonstrated that sex steroid hormones, such as the potent estrogen 17β-estradiol (E2), affect hippocampal morphology, plasticity, and memory in male and female rodents. Yet relatively few investigators who work with male subjects consider the effects of these hormones on learning and memory. This review describes the effects of E2 on hippocampal spinogenesis, neurogenesis, physiology, and memory, with particular attention paid to the effects of E2 in male rodents. The estrogen receptors, cell-signaling pathways, and epigenetic processes necessary for E2 to enhance memory in female rodents are also discussed in detail. Finally, practical considerations for working with female rodents are described for those investigators thinking of adding females to their experimental designs. PMID:26286657

  15. Role of sex hormones in hypercapnia-induced activation of the locus coeruleus in female and male rats.

    PubMed

    de Carvalho, D; Marques, D A; Bernuci, M P; Leite, C M; Araújo-Lopes, R; Anselmo-Franci, J; Bícego, K C; Szawka, R E; Gargaglioni, L H

    2016-01-28

    The locus coeruleus (LC) has been suggested as a CO2 chemoreceptor site in mammals. Most of the studies involving the role of the LC in hypercapnic ventilatory responses have been performed in males. Since ovarian steroids modulate the activity of LC neurons and females have a different respiratory response to CO2 than males, we evaluated the activity of LC noradrenergic neurons during normocapnia and hypercapnia in female and male rats with distinct sex hormone levels. Ovariectomized (OVX), estradiol (E2)-treated ovariectomized (OVX+E2) and female rats on the diestrous day of the estrous cycle were evaluated. Concurrently, males were investigated as gonad-intact, orchidectomized (ORX), testosterone (T)-treated ORX (ORX+T), and E2-treated ORX (ORX+E2). Activation of LC neurons was determined by double-label immunohistochemistry to c-Fos and tyrosine hydroxylase (TH). Hypercapnia induced by 7% CO2 increased the number of c-Fos/TH-immunoreactive (ir) neurons in the LC of all groups when compared to air exposure. Hypercapnia-induced c-Fos expression did not differ between diestrous females and intact male rats. In the OVX+E2 group, there was attenuation in the c-Fos expression during normocapnia compared with OVX rats, but CO2 responsiveness was not altered. Moreover, in ORX rats, neither T nor E2 treatments changed c-Fos expression in LC noradrenergic neurons. Thus, in female rats, E2 reduces activation of LC noradrenergic neurons, whereas in males, sex hormones do not influence the LC activity.

  16. Male and female stem cells and sex reversal in Hydra polyps.

    PubMed

    Bosch, T C; David, C N

    1986-12-01

    Single interstitial stem cells of male polyps of Hydra magnipapillata give rise to clones that differentiate either male or female gametes. To test the sexual stability of these clones, stem cells were recloned. The results indicate that stem cells from female clones are stable in their sexual differentiation capacity; male stem cells, by comparison, switch sexual phenotype at the rate of 10(-2) per cell per generation. As a result, female polyps contain only female stem cells; male polyps contain a mixture of male and female stem cells. A model is presented in which the sexual phenotype of Hydra polyps is controlled by (i) the switching rate of male and female stem cells and (ii) the repression of female differentiation by male stem cells.

  17. A Reasoned Action Model of Male Client Involvement in Commercial Sex Work in Kibera, A Large Informal Settlement in Nairobi, Kenya

    PubMed Central

    Roth, Eric Abella; Ngugi, Elizabeth; Benoit, Cecilia; Jansson, Mikael; Hallgrimsdottir, Helga

    2015-01-01

    Male clients of female sex workers (FSWs) are epidemiologically important because they can form bridge groups linking high- and low-risk subpopulations. However, because male clients are hard to locate, they are not frequently studied. Recent research emphasizes searching for high-risk behavior groups in locales where new sexual partnerships form and the threat of HIV transmission is high. Sub-Saharan Africa public drinking venues satisfy these criteria. Accordingly, this study developed and implemented a rapid assessment methodology to survey men in bars throughout the large informal settlement of Kibera, Nairobi, Kenya, with the goal of delineating cultural and economic rationales associated with male participation in commercial sex. The study sample consisted of 220 male patrons of 110 bars located throughout Kibera’s 11 communities. Logistic regression analysis incorporating a modified Reasoned Action Model indicated that a social norm condoning commercial sex among male peers and the cultural belief that men should practice sex before marriage support commercial sex involvement. Conversely, lacking money to drink and/or pay for sexual services were barriers to male commercial sex involvement. Results are interpreted in light of possible harm reduction programs focusing on FSWs’ male clients. PMID:26778847

  18. Description of the pre-reductional sex chromosome during male meiosis of Pachylis laticornis (Heteroptera: Coreidae).

    PubMed

    Banho, C A; Alevi, K C C; Pereira, L L V; Souza-Firmino, T S; Itoyama, M M

    2016-04-28

    In Heteroptera, the division of sex chromosomes is well defined as post-reductional for most of species, i.e., the first meiotic division is equational and the second is reductional. However, in some species pre-reductional division has been observed, whereby the first meiotic division is reductional and the second is equational. These include Anisops fieberi (Notonectidae), Ectrychotes disparate (Reduviidae), Dictyonota tricornis (Tingidae), and Archimerus alternatus (Coreidae), as well as other species of the genus Pachylis, in the family Coreidae. Thus, this study aimed to characterize the meiotic behavior of Pachylis laticornis, in order to consider whether this species also undergoes pre-reduction division for the sex chromosomes. Cytogenetic analysis of meiosis in P. laticornis made it possible to characterize the holocentric nature of the chromosomes, the chromosome number of this species [2n = 15 (2m + 12A + X0)], the chromosomal system of sex X0 type, and the presence of m-chromosomes. Furthermore, the analysis of anaphase I, telophase I and II allowed pre-reductional meiotic behavior to be observed for this sex chromosome. Thus, this meiotic behavior was confirmed for another species of Heteroptera, stressing the importance of more cytogenetic studies of meiosis to increase our understanding of variation in the behavior of sex chromosomes during spermatogenesis in heteropterans. Therefore, the present study describes the chromosomal number, the system of sex determination, and meiotic behavior of P. laticornis, corroborating the relationship of this species with others of the same genus.

  19. Male rats with same sex preference show high experimental anxiety and lack of anxiogenic-like effect of fluoxetine in the plus maze test.

    PubMed

    García-Cárdenas, Nallely; Olvera-Hernández, Sandra; Gómez-Quintanar, Blanca Nelly; Fernández-Guasti, Alonso

    2015-08-01

    Homosexual men show a 2-4 higher risk to suffer anxiety in comparison with heterosexuals. It is unknown if biological factors collaborate to increase such incidence. Fluoxetine produces differential brain activation in homosexuals as compared with heterosexuals, suggesting that it may produce a divergent behavioral effect dependant on sex-preference. The first aim was to evaluate experimental anxiety in male rats that show same-sex preference in the elevated plus maze (EPM). The second goal explored the putative differential effect of fluoxetine (10mg/kg) in male rats with female and same-sex preference in the EPM. To induce same-sex preference males were prenatally treated with letrozole (0.56μg/kg, 10-20 gestation days), while controls were males prenatally treated with letrozole that retain female-preference or which mothers received oil. In both groups we found animals with male preference, but the proportion was higher in males that prenatally received letrozole (10 vs. 27%). Males with same-sex preference spent less time and showed lower number of entries to the open arms of the EPM than males that prefer females, regardless of the prenatal treatment. In males with female preference, fluoxetine reduced the time spent and number of entries to the open arms that was absent in males with same-sex preference. These data suggest that biological factors contribute to the high levels of anxiety in subjects with same-sex preference and that fluoxetine in men may produce a divergent action depending on sexual orientation.

  20. On same-sex sexual behaviors among male bachelors in rural China: evidence from a female shortage context.

    PubMed

    Yang, Xueyan; Attané, Isabelle; Li, Shuzhuo; Zhang, Qunlin

    2012-03-01

    Using data from a survey conducted in the rural areas of Anhui Province, this study adopted the crosstabs and logistic regression model to analyze the same-sex sexual behaviors of forced male bachelors and the determinants when compared with married men with same ages. The prevalence of same-sex sexual behaviors among the unmarried men was reported as 17.2%, significantly higher than 8.9% among married men with same ages, indicating that same-sex sexual behaviors could be as a compensation for the absence of female sexual partners to some extent for those marriage squeezed or forced male bachelors. Among all groups, the occurrence of unprotected sexual behaviors were reported above 60%, regardless of marital status and the genders of sexual partners; the scores obtained on knowledge of acquired immune deficiency syndrome (AIDS) and sexually transmitted diseases (STDs) among bachelors (AIDS knowledge = 2.85; STDs knowledge = 2.38) are much poorer than those of married men (AIDS knowledge = 3.45; STDs knowledge = 2.79), which might exert potential negative impacts on men's health.

  1. High-glucose diets have sex-specific effects on aging in C. elegans: toxic to hermaphrodites but beneficial to males.

    PubMed

    Liggett, Marjorie R; Hoy, Michael J; Mastroianni, Michael; Mondoux, Michelle A

    2015-06-01

    Diet and sex are important determinants of lifespan. In humans, high sugar diets, obesity, and type 2 diabetes correlate with decreased lifespan, and females generally live longer than males. The nematode Caenorhabditis elegans is a classical model for aging studies, and has also proven useful for characterizing the response to high-glucose diets. However, studies on male animals are lacking. We found a surprising dichotomy: glucose regulates lifespan and aging in a sex-specific manner, with beneficial effects on males compared to toxic effects on hermaphrodites. High-glucose diet resulted in greater mobility with age for males, along with a modest increase in median lifespan. In contrast, high-glucose diets decrease both lifespan and mobility for hermaphrodites. Understanding sex-specific responses to high-glucose diets will be important for determining which evolutionarily conserved glucose-responsive pathways that regulate aging are "universal" and which are likely to be cell-type or sex-specific.

  2. Are Sex Drive and Hypersexuality Associated with Pedophilic Interest and Child Sexual Abuse in a Male Community Sample?

    PubMed

    Klein, Verena; Schmidt, Alexander F; Turner, Daniel; Briken, Peer

    2015-01-01

    Although much is currently known about hypersexuality (in the form of excessive sexual behavior) among sexual offenders, the degree to which hypersexual behavior is linked to paraphilic and especially pedophilic interests in non-forensic populations has not been established.The purpose of the present study was to elucidate the associations between total sexual outlets(TSO) and other sex drive indicators, antisocial behavior, pedophilic interests, and sexual offending behavior in a large population-based community sample of males. The sample included 8,718 German men who participated in an online study. Hypersexual behavior as measured by self-reported TSO, self-reported sex drive, criminal history, and pedophilic interests were assessed. In moderated hierarchical logistic regression analyses self-reported contact sexual offending against children was linked to sexual fantasizing about children and anti sociality.There was no association between aggregated sex drive, and sexual abusive behaviour in the multivariate analyses. In contrast, self-reported child pornography consumption was associated with sex drive, sexual fantasies involving children, and anti sociality. Nevertheless, in convicted sexual offenders anti sociality, sexual preoccupation (like hypersexuality), and pedophilic interest are important predictors of sexual reoffending against prepubescent children.Therefore, in clinical practice an assessment of criminal history and pedophilic interests in hypersexual individuals and vice versa hypersexuality in antisocial or pedophilic men should be considered [corrected]. PMID:26147099

  3. Are Sex Drive and Hypersexuality Associated with Pedophilic Interest and Child Sexual Abuse in a Male Community Sample?

    PubMed Central

    Klein, Verena; Schmidt, Alexander F.; Turner, Daniel; Briken, Peer

    2015-01-01

    Although much is currently known about hypersexuality (in the form of excessive sexual behavior) among sexual offenders, the degree to which hypersexual behavior is linked to paraphilic and especially pedophilic interests in non-forensic populations has not been established. The purpose of the present study was to elucidate the associations between total sexual outlets (TSO) and other sex drive indicators, antisocial behavior, pedophilic interests, and sexual offending behavior in a large population-based community sample of males. The sample included 8,718 German men who participated in an online study. Hypersexual behavior as measured by self-reported TSO, self-reported sex drive, criminal history, and pedophilic interests were assessed. In moderated hierarchical logistic regression analyses self-reported contact sexual offending against children was linked to sexual fantasizing about children and antisociality. There was no association between aggregated sex drive, and sexual abusive behaviour in the multivariate analyses. In contrast, self-reported child pornography consumption was associated with sex drive, sexual fantasies involving children, and antisociality. Nevertheless, in clinical practice an assessment of criminal history and pedophilic interests in hypersexual individuals and vice versa hypersexuality in antisocial or pedophilic men should be considered as particularly antisociality and pedophilic interest are important predictors of sexual offending against prepubescent children. PMID:26147099

  4. Are Sex Drive and Hypersexuality Associated with Pedophilic Interest and Child Sexual Abuse in a Male Community Sample?

    PubMed

    Klein, Verena; Schmidt, Alexander F; Turner, Daniel; Briken, Peer

    2015-01-01

    Although much is currently known about hypersexuality (in the form of excessive sexual behavior) among sexual offenders, the degree to which hypersexual behavior is linked to paraphilic and especially pedophilic interests in non-forensic populations has not been established.The purpose of the present study was to elucidate the associations between total sexual outlets(TSO) and other sex drive indicators, antisocial behavior, pedophilic interests, and sexual offending behavior in a large population-based community sample of males. The sample included 8,718 German men who participated in an online study. Hypersexual behavior as measured by self-reported TSO, self-reported sex drive, criminal history, and pedophilic interests were assessed. In moderated hierarchical logistic regression analyses self-reported contact sexual offending against children was linked to sexual fantasizing about children and anti sociality.There was no association between aggregated sex drive, and sexual abusive behaviour in the multivariate analyses. In contrast, self-reported child pornography consumption was associated with sex drive, sexual fantasies involving children, and anti sociality. Nevertheless, in convicted sexual offenders anti sociality, sexual preoccupation (like hypersexuality), and pedophilic interest are important predictors of sexual reoffending against prepubescent children.Therefore, in clinical practice an assessment of criminal history and pedophilic interests in hypersexual individuals and vice versa hypersexuality in antisocial or pedophilic men should be considered [corrected].

  5. Genetic method of combating the cabbage root fly. Part II. Localization of factor determining male sex in the cabbage root fly Delia brassicae bouche

    SciTech Connect

    Samoilov, Yu.B.

    1986-05-01

    Cytogenetic analysis was conducted of 15 lines of the cabbage root fly with hereditary semisterility in the form of late embryonic lethals (LEL). In 14 lines (93%), the presence of translocations was noted. A high yield of translocations linked with the male sex was obtained, which was caused by the fact that determination of male sex in this species is apparently associated with the largest chromosome 6, and not with chromosome 1, as was believed previously.

  6. Sex, stress and social status: patterns in fecal testosterone and glucocorticoid metabolites in male Ethiopian wolves.

    PubMed

    van Kesteren, Freya; Sillero-Zubiri, Claudio; Millar, Robert; Argaw, Kifle; Macdonald, David W; Paris, Monique

    2012-10-01

    Ethiopian wolves, Canis simensis, live in large multi-male family packs, where males are philopatric and do not disperse. Within a pack, mating and breeding is largely monopolized by the dominant male and female, although extra-pack copulations are common, and subordinate males may sire pups in neighboring packs. Regardless of paternity, all males in a pack help rear the pups. We non-invasively studied patterns in fecal testosterone and glucocorticoid metabolite concentrations using radioimmunoassays of fecal samples collected from nine wild male Ethiopian wolves between August 2007 and February 2008. We tested the predictions of the Challenge Hypothesis, namely that fecal testosterone metabolite concentrations would be higher during the annual mating season, which is the portion of the reproductive cycle when mating and increased aggression typically occur, and lower when there were pups in the pack for which to care. Contrary to the predictions of the Challenge Hypothesis, we did not detect patterns in fecal testosterone metabolite concentrations associated with reproductive stage during our study period. Similarly, we found no patterns associated with reproductive stage in male fecal glucocorticoid metabolite concentrations. Dominant males had higher average fecal testosterone and glucocorticoid metabolite concentrations than did subordinates, which may be related to higher rates of aggression and mate guarding in dominant males of group-living canids, a pattern also reported in African wild dogs, Lycaon pictus. PMID:22841807

  7. The Impact of Single-Sex Education on Male and Female Gains in Mathematics and Reading at the Elementary Level in a Selected School in North Carolina

    ERIC Educational Resources Information Center

    O'Neill, Lisa

    2011-01-01

    The gender gap in achievement and the increasing awareness of differences between male and female cognitive development have ignited a growing interest in single-sex education. No Child Left Behind legislation and amendments to Title IX legislation have increased the number of schools in America offering single-sex education. This 2-year…

  8. Acceptability of Three Novel HIV Prevention Methods Among Young Male and Transgender Female Sex Workers in Puerto Rico.

    PubMed

    Giguere, Rebecca; Frasca, Timothy; Dolezal, Curtis; Febo, Irma; Cranston, Ross D; Mayer, Kenneth; McGowan, Ian; Carballo-Diéguez, Alex

    2016-10-01

    Sex workers need HIV-prevention methods they can control and incorporate easily in their work. We studied the acceptability of three methods: HIV self-test use with clients, oral pre-exposure prophylaxis (PrEP), and rectal microbicide gel. Four male and eight transgender female (TGF) sex workers in Puerto Rico completed a baseline survey with a quantitative measure of likelihood of use. From them, one male and four TGF also completed a 12-week study of rectal microbicide placebo gel use prior to receptive anal intercourse with male clients and evaluated via qualitative in-depth interviews and follow-up quantitative assessments how each method could be incorporated into their work. Most were interested in a rectal microbicide gel and able to use it covertly with clients. Challenges to using the HIV self-test with clients included the potential for both breach of confidentiality and confronting violent situations. Participants also expressed interest in oral PrEP, but raised concerns about side effects.

  9. Diagnosis of prolactinoma in two male-to-female transsexual subjects following high-dose cross-sex hormone therapy.

    PubMed

    Cunha, F S; Domenice, S; Câmara, V L; Sircili, M H P; Gooren, L J G; Mendonça, B B; Costa, E M F

    2015-08-01

    Male-to-female transsexual persons use oestrogens + antiandrogens to adapt their physical bodies to the female sex. Doses are usually somewhat higher than those used by hypogonadal women receiving oestrogen replacement. Particularly in cases of self-administration of cross-sex hormones, doses may be very high. Oestrogens are powerful stimulators of synthesis and release of prolactin and serum prolactin levels are usually somewhat increased following oestrogen treatment. Prolactinomas have been reported in male-to-female transsexual persons, both after use of high and conventional doses of oestrogens but remain rare events. We report two new cases of prolactinomas in male-to-female transsexual persons, one in a 41-year-old subject who had used nonsupervised high-dose oestrogen treatment since the age of 23 years and another one in a 42 year old who had initiated oestrogen treatment at the age of 17 years. Their serum prolactin levels were strongly increased, and the diagnosis of a pituitary tumour was confirmed by imaging techniques. Both cases responded well to treatment with cabergoline treatment whereupon serum prolactin normalised. Our two cases are added to the three cases of prolactinomas in the literature in persons who had used supraphysiological doses of oestrogens.

  10. Acceptability of Three Novel HIV Prevention Methods Among Young Male and Transgender Female Sex Workers in Puerto Rico.

    PubMed

    Giguere, Rebecca; Frasca, Timothy; Dolezal, Curtis; Febo, Irma; Cranston, Ross D; Mayer, Kenneth; McGowan, Ian; Carballo-Diéguez, Alex

    2016-10-01

    Sex workers need HIV-prevention methods they can control and incorporate easily in their work. We studied the acceptability of three methods: HIV self-test use with clients, oral pre-exposure prophylaxis (PrEP), and rectal microbicide gel. Four male and eight transgender female (TGF) sex workers in Puerto Rico completed a baseline survey with a quantitative measure of likelihood of use. From them, one male and four TGF also completed a 12-week study of rectal microbicide placebo gel use prior to receptive anal intercourse with male clients and evaluated via qualitative in-depth interviews and follow-up quantitative assessments how each method could be incorporated into their work. Most were interested in a rectal microbicide gel and able to use it covertly with clients. Challenges to using the HIV self-test with clients included the potential for both breach of confidentiality and confronting violent situations. Participants also expressed interest in oral PrEP, but raised concerns about side effects. PMID:27048236

  11. Effects of portal vein ligation on sex hormone metabolism in male rats: relationship to lowered hepatic cytochrome P450 levels.

    PubMed

    Farrell, G C; Koltai, A; Zaluzny, L; Murray, M

    1986-02-01

    Hepatic cytochrome P450 levels in male rats fall after portal vein ligation, a procedure that produces total hepatic bypass of portal blood. The present study was undertaken to examine whether changes in sex hormone metabolism could account for these lowered cytochrome P450 levels. Portal vein ligation resulted in testicular atrophy and low serum testosterone concentrations. Serum luteinizing hormone levels were also reduced, suggesting that testicular atrophy was secondary to suppression of the hypothalamic-pituitary-gonadal axis. Serum estrone and estradiol concentrations were significantly increased after portal vein ligation, while the magnitude and delayed onset of increases in urinary total estrogen excretion suggested that this was due largely to increased estrogen production. In male rats, both castration (at 12 wk) and exogenous estrogen administration resulted in changes in hepatic cytochrome P450 levels and ethylmorphine N-demethylase activity that were qualitatively similar to those seen after portal vein ligation. In female and castrated male rats, however, cytochrome P450 was not affected by portal vein ligation. Testosterone supplementation corrected the changes of cytochrome P450 levels in castrated male rats but did not have this effect in portal vein-ligated male rats. It is concluded that changes in sex hormone metabolism do occur after portal vein ligation and may contribute to alterations in cytochrome P450 and drug-metabolizing enzyme activity. Decreased levels of serum testosterone, however, do not alone account for the changes in hepatic drug metabolism in this model, and suppression of a hypothalamic-pituitary factor appears to be important.

  12. Mating system of the European hornet Vespa crabro: male seeking strategies and evidence for the involvement of a sex pheromone.

    PubMed

    Spiewok, S; Schmolz, E; Ruther, J

    2006-12-01

    We describe details of the mate finding strategy of drones of the European hornet, Vespa crabro, and present evidence for the involvement of sex pheromones. Tests were carried out with free flying drones in natural habitats. Males patrolled the nest site itself, as well as nearby nonresource-based sites, without showing territorial behavior. Patrolling was restricted to sunny spots in the vegetation, and thus, the locations changed throughout the day. Drones were attracted to both caged gynes and to dead workers treated with gyne extracts, indicating the presence of a female-produced sex attractant. Treated workers also elicited copulation attempts by the attracted drones. Extracts from gynes, workers, and drones contained exclusively cuticular lipids, and the profile from gynes was much more diverse than that of workers and drones. The most striking differences observed related to the alkenes, monomethyl- and dimethylalkanes. The results provide a lead for potential attracting and copulation-releasing semiochemicals in V. crabro.

  13. Context matters: The moderating role of bar context in the association between substance use during sex and condom use among male clients of female sex workers in Tijuana, Mexico

    PubMed Central

    Pitpitan, Eileen V.; Wagner, Karla D.; Goodman, David; Semple, Shirley J.; Chavarin, Claudia; Strathdee, Steffanie A.; Patterson, Thomas L.

    2013-01-01

    Tijuana is situated on Mexico’s northern border with the U.S., where sex work is quasi-legal. Whereas previous work has focused on the risk behaviors of female sex workers (FSWs), less is known about the risk behaviors of their male clients. Further, research has not examined structural factors as moderators of the association between substance use and condom use, including the contexts in which sex takes place. The purpose of the current study is to examine whether having sex with FSWs in a bar moderates the link between alcohol intoxication during sex and condom use. We recruited 375 male clients of FSWs in Tijuana, Mexico from San Diego, California and Tijuana. Using computer assisted interviewing, we surveyed participants on their alcohol use, condom use, and physical contexts of sex with FSWs in the past four months. Results showed that more frequent intoxication during sex with FSWs is associated with more unprotected sex, but only among clients having sex with FSWs in a bar context. Results point to potential reasons for inconsistent condom use with FSWs in this context, including lower risk perceptions of sex with FSWs in bars. Future research should examine structural factors that underlie clients’ risk behavior in bars in order to inform structural-level HIV prevention interventions. PMID:23640653

  14. The attraction of virgin female hide beetles (Dermestes maculatus) to cadavers by a combination of decomposition odour and male sex pheromones

    PubMed Central

    2012-01-01

    Introduction The hide beetle Dermestes maculatus (Coleoptera: Dermestidae) feeds as an adult and larva on decomposing animal remains and can also be found on human corpses. Therefore, forensic entomological questions with regard to when and how the first receptive females appear on carcasses are important, as the developmental stages of their larvae can be used to calculate the post-mortem interval. To date, we know that freshly emerged males respond to the cadaver odour of post-bloated carcasses (approximately 9 days after death at Tmean = 27°C), being attracted by benzyl butyrate. This component occurs at its highest concentration at this stage of decay. The aim of our study was to determine the principle of attraction of virgin females to the feeding and breeding substrate. For this purpose, we tested the response of these females to headspace samples of piglet cadavers and male sex pheromones [(Z9)-unsaturated fatty acid isopropyl esters] in a Y-olfactometer. Because we expected that such an odour combination is of importance for virgin female attraction, we tested the following two questions: 1) Are virgin female hide beetles attracted by a combination of cadaver odour and male sex pheromones? 2) During which decomposition stage do the first virgin females respond to cadaver odour when combined with male sex pheromones? Results We found that young virgin females were attracted to the cadaver by a combination of cadaver odour and male sex pheromones. Neither cadaver odour alone nor male sex pheromones alone was significantly more attractive than a solvent control. Our results also gave a weak indication that the first young virgin females respond as early as the post-bloating stage to its associated decomposition odour when combined with male sex pheromones. Conclusions Our results indicate that freshly emerged males possibly respond to cadaver odour and visit carcasses before virgin females. Being attracted to cadavers when male sex pheromone is perceived as

  15. ["Prostatic" kallikreins, sex hormones and insulin-like growth factors: complex of male and female regulatory elements in health and carcinogenesis].

    PubMed

    Zezerov, E G; Severin, E S

    1999-01-01

    Publications (up to the year 1997) on the interactions of "prostatic" kallikreins (prostatic specific antigen-PSA, etc.), sex hormones, insulin-like growth factors (IGF) and proteins binding them (IGFBP) in physiological processes (ageing, menstrual cycle, pregnancy) and oncogenesis (prostatic and mammary cancer) are reviewed. The concentrations of PSA, IGF, and IGFBP in organs and liquid media of men and women are presented. A concept of similarity in the mechanisms of interactions of sex hormones (dihydrotestosterone in men and progesterone in women), PSA, IGFBP, and IGF during activation of anabolic and proliferative processes in health and carcinogenesis is presented as a scheme. The diagnostic and prognostic value of PSA as a cancer marker should not be confined to male tumors (prostatic cancer and benign prostatic hyperplasia). Our data permits us to regard PSA as an oncofetal marker for men and women, indicating normal and neoplastic proliferative processes in the prostatic, mammary, salivary, and other glands and in the lungs and endometrium. Diagnostic and prognostic significance of PSA in breast cancer is shown. The traditional name "PSA" does not reflect its physiological and pathogenetic role as a member of the kallikrein family with chymotrypsin-like activity. PSA is not absolutely specific towards the producer organ and sex. Its relative specificity for the prostate is undoubted, because the content of PSA in prostatic tissue and seminal plasma is 10(6)-10(8) times higher than in the serum and other organs of men and women. Therefore, although the terms "prostatic, "specific", and "antigen" now became trivial and it is difficult to refuse from them, they can be used only in quotation marks.

  16. Birth Order and Sibling Sex Ratio in Homosexual Male Adolescents and Probably Prehomosexual Feminine Boys.

    ERIC Educational Resources Information Center

    Blanchard, Ray; And Others

    1995-01-01

    Examined the hypothesis that male homosexuals have a greater than average proportion of male siblings and a later than average birth order, by comparing a group of prehomosexual boys (individuals exhibiting cross-gender behaviors) and homosexual adolescents with a control group. Both predicted results were confirmed. (MDM)

  17. Sex Differences in Political Communication: A Study of Female and Male State Legislators.

    ERIC Educational Resources Information Center

    Leenhouts, Thelma K.

    In an investigation of the communication similarities and differences between male and female legislators, the nine female representatives in the Michigan House of Representatives were matched with nine male representatives on four variables: political party, length of legislative service, district represented, and race. The representatives were…

  18. Familiarity and Sex Based Stereotypes on Instant Impressions of Male and Female Faculty

    ERIC Educational Resources Information Center

    Nadler, Joel T.; Berry, Seth A.; Stockdale, Margaret S.

    2013-01-01

    To address the stranger-to-stranger critique of stereotyping research, psychology students (n = 139) and law students (n = 58) rated photographs of familiar or unfamiliar male or female professors on competence. Results from Study 1 indicated that familiar male psychology faculty were rated as more competent than were familiar female faculty,…

  19. Same-sex cohabitation under the effects of quinpirole induces a conditioned socio-sexual partner preference in males, but not in female rats.

    PubMed

    Triana-Del Rio, Rodrigo; Montero-Domínguez, Felix; Cibrian-Llanderal, Tamara; Tecamachaltzi-Silvaran, Miriam B; Garcia, Luis I; Manzo, Jorge; Hernandez, María Elena; Coria-Avila, Genaro A

    2011-10-01

    The effects of the dopamine D2-type receptor agonist quinpirole (QNP) were examined on the development of conditioned same-sex partner preference induced by cohabitation in rats. In Experiment 1, males received either saline or QNP (1.25mg/kg) and cohabited during three trials with almond-scented stimulus males that were sexually naïve. In Experiment 2, males received six trials, and in Experiment 3 received three trials with sexually expert stimulus males. During a final drug-free preference test, males chose between the familiar or a novel male partner. In Experiments 1, 2 and 3 only QNP-treated males displayed a social preference for the familiar male, observed with more time spent together. In Experiment 3 males also displayed a sexual preference observed with more non-contact erections when were exposed to their male partner. In Experiment 4 we tested the effects on OVX, E+P primed females that received 1 systemic injection of either saline or QNP during three conditioning trials. In Experiment 5, females received 2 injections 12-h apart during each trial. Results indicated that both saline and QNP-treated females failed to develop partner preference. These data demonstrate that enhanced D2-type receptor activity during cohabitation facilitates the development of conditioned same-sex partner preference in males, but not in female rats. We discuss the implications for same-sex partner preferences.

  20. Birth Order and Sibling Sex Ratio in a Population with High Fertility: Are Turkish Male to Female Transsexuals Different?

    PubMed

    Bozkurt, Ali; Bozkurt, Ozlem Hekim; Sonmez, Ipek

    2015-07-01

    Western studies have consistently found that androphilic (sexually attracted to men) male-to-female transsexuals have a later birth order and a relative excess of brothers compared with appropriate control participants. However, non-Western studies on birth order and sibling sex ratio in androphilic males (transsexual or non-transsexual) are rare. The objective of the study was to test the hypothesis that androphilic male-to-female transsexuals have a late birth order and a relative excess of brothers in a non-Western culture with a higher fertility rate. The participants were 60 androphilic male-to-female transsexuals and 61 male heterosexual controls. The transsexual participants had significantly more older brothers than the control participants, but the groups did not differ in their numbers of older sisters, younger brothers, or younger sisters. The foregoing pattern is usually referred to as the "fraternal birth order effect." Slater's and Berglin's Indexes both showed that the mean birth order of the control participants was very close to that expected from a random sample drawn from a demographically stable population whereas the mean birth order of the transsexual participants was later. A measure of sibship composition, brothers/all siblings, showed that the transsexual group had a higher proportion of male siblings compared with the control group. In conclusion, the present study found that Turkish androphilic male-to-female transsexuals show the same high fraternal birth order that has been found in comparable androphilic samples in Western Europe, North America, and the South Pacific, which suggests a common underlying biological causal mechanism.

  1. Enhaced D2-type receptor activity facilitates the development of conditioned same-sex partner preference in male rats.

    PubMed

    Cibrian-Llanderal, Tamara; Rosas-Aguilar, Viridiana; Triana-Del Rio, Rodrigo; Perez, Cesar A; Manzo, Jorge; Garcia, Luis I; Coria-Avila, Genaro A

    2012-08-01

    Animal models have shown that the neural bases of social attachment, sexual preference and pair bonds, depend on dopamine D2-type receptor and oxytocin activity. In addition, studies have demonstrated that cohabitation can shape partner preference via conditioning. Herein, we used rats to explore the development of learned same-sex partner preferences in adulthood as a result of cohabitation during enhanced D2 activity. Experimental Wistar males (N=20), received saline or the D2 agonist (quinpirole) and were allowed to cohabitate during 24 h, with a stimulus male partner that bore almond scent on the back as conditioned stimulus. This was repeated every 4 days, for a total of three trials. Four days later they were drug-free tested for partner preference between the scented male partner and a sexually receptive female. Sexual partner preference was analyzed by measuring frequency and latency for appetitive and consummatory sexual behaviors, as well as non-contact erections. Social preference was also analyzed by measuring the frequency and latency of visits, body contacts and time spent together. Results indicated that only quinpirole-treated males displayed sexual and social preference for the scented male over the sexually receptive female. They spent more time together, displayed more body contacts, more female-like proceptive behaviors, and more non-contact erections. Accordingly, conditioned males appeared to be more sexually aroused and motivated by the known male than by a receptive female. We discuss the implications of this animal model on the formation of learned homosexual partner preferences.

  2. Serum sex hormone levels in different severity of male adult obstructive sleep apnea-hypopnea syndrome in East Asians.

    PubMed

    Dong, Jia-Qi; Chen, Xiong; Xiao, Ying; Zhang, Rui; Niu, Xun; Kong, Wei-Jia

    2015-08-01

    Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a serious health issue, which can impact the hormone secretion. The aim of this study is to analyze the relationship between serum sex hormone concentrations and different severity degree of OSAHS, and to evaluate the influence of OSAHS on sex hormone levels. We enrolled 116 subjects who were subjected to polysomnography (PSG). They were divided into three groups: control group (n=10) [apnea hypopnea index (AHI) <5/h], mild-moderate OSAHS group (n=15) (5≤AHI<30/h), and severe OSAHS group (n=91) (AHI≥30/h). The patients in OSAHS group were subdivided into obesity and non-obesity subgroups. The parameters such as AHI, body mass index (BMI), lowest oxygen saturation (LSaO2), and mean oxygen saturation (MSaO2) were recorded. Serum levels of testosterone, polactin, estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) were determined in the morning immediately after waking up. Mean levels of hormones were compared among groups. The correlation between hormone levels and sleep-breathing parameters was analyzed. No significant differences in serum sex hormone levels were found among control, mild-moderate OSAHS, and severe OSAHS groups (P>0.05). There was no correlation between AHI and sex hormone levels (P>0.05). Testosterone was significantly negatively correlated with BMI (P<0.05). These results suggested that BMI might have a direct effect on testosterone level, and it might be an important factor affecting testosterone level in male OSAHS patients, and there may be no correlation between severity of OSAHS and sex hormones levels. PMID:26223926

  3. Boredom Proneness, Social Connectedness, and Sexual Addiction among Men Who Have Sex with Male Internet Users

    ERIC Educational Resources Information Center

    Chaney, Michael P.; Blalock, Andrew C.

    2006-01-01

    The authors collected surveys from 517 men who have sex with men (MSM) recruited from Internet chat rooms to examine the relationships among boredom, social connectedness, and sexual addiction. The results provide addictions professionals psychosocial factors to assess when working with sexually addicted MSM. (Contains 3 tables.)

  4. Performance, Rewards, and Perceptions of Sex Discrimination among Male and Female Faculty

    ERIC Educational Resources Information Center

    Ferber, Marianne A.; Loab, Jane W.

    1973-01-01

    Married women with or without children appear to experience less success in academic life. Marital and, for men, parental status may enter reward decisions as a possible indicator of perceived financial need. Perception of sex discrimination appears to be more accurate among women than men. (Author/JB)

  5. Sex and the public: Social eavesdropping, sperm competition risk and male mate choice.

    PubMed

    Plath, Martin; Bierbach, David

    2011-05-01

    Mate choice can be sensitive to social cues from neighboring individuals, e.g., animals can copy mate choice decisions. Males that are at risk of being copied by others may respond to this with reduced preference expression ("audience effects"). We review the various pathways by which sperm competition risk affects (1) male mate copying behavior and (2) audience effects. For example, a recent study suggests that males gather complex social information on rivals' sexual competitiveness (sexual activity and attractiveness to females) and respond with reduced expression of mating preferences only "when it matters," i.e., when a sexually competitive rival is present.

  6. Annual changes in plasma levels of cortisol and sex steroid hormones in male rainbow trout, Oncorhynchus mykiss

    NASA Astrophysics Data System (ADS)

    Hou, Ya-Yi; Han, Xiao-Dong; Suzuki, Yuzuru

    2001-09-01

    The profiles of cortisol, testosterone, 11-ketotestosterone and 17α, 20β-dihydroxy-4-pregnene-3-one in male rainbow trout reared under constant water temperature and natural photoperiod were determined by radioimmunoassay. Gonads of male rainbow trout reached maturity when the fish were two years old. Changes in the plasma levels of both sex steroid hormones and cortisol were closely related to the GSI. Plasma levels of testosterone, 11-ketotestosterone and 17α; 20β-dihydroxy 4-pregnene-3-one showed a clear peak in the annual breeding season, when the GSI reached their maxima. Plasma cortisol levels also showed clearly seasonal changes in both two- and three-year-old fish. The results suggest that the elevated plasma levels of cortisol may not just be due to stresses during the breeding season but have certain physiological functions in the reproduction of rainbow trout.

  7. Assisting gay men to maintain safer sex: an evaluation of an AIDS service organization's safer sex maintenance program.

    PubMed

    Miller, R L

    1995-01-01

    As the second decade of the AIDS crisis unfolds, increasing concern has been raised that the widespread adoption of condom use that occurred among gay men in the 1980s is not being maintained. Most interventions to promote condom use among gay men are delivered by community-based organizations via programs that are virtually undocumented; little is known about their effectiveness, or the processes by which they may work. This study describes safer sex practices among self-identified gay men following their participation in an intervention developed and implemented by a community-based organization. The intervention was designed to enhance men's attitudes, beliefs, and self-efficacy expectations to maintain safer sex. Among 150 men with complete data at both assessments, self-reported condom use was low. Men reported using condoms more consistently for anal sexual behavior than oral sexual behavior, but there were men who reported consistent unprotected anal sexual intercourse. The intervention had little impact on patterns of behavior over time, although desired changes in attitudes, beliefs, and self-efficacy expectations were evidenced following the intervention. The results suggest the importance of assisting community-based organizations to document program models. Findings also suggest that community-based organizations can develop interventions to successfully enhance factors that theoretically support maintenance of safer sexual behaviors.

  8. Opposite-sex housing reactivates the declining GnRH system in aged transgenic male mice with FGF signaling deficiency

    PubMed Central

    Chung, Wilson C. J.; Hayes, Tyrone B.; Tsai, Pei-San

    2012-01-01

    The continued presence of gonadotropin-releasing hormone (GnRH) neurons is required for a healthy reproductive lifespan, but factors that maintain postnatal GnRH neurons have not been identified. To begin to understand these factors, we investigated whether 1) fibroblast growth factor (FGF) signaling and 2) interactions with the opposite sex are involved in the maintenance of the postnatal GnRH system. A transgenic mouse model (dnFGFR mouse) with the targeted expression of a dominant-negative FGF receptor (dnFGFR) in GnRH neurons was used to examine the consequence of FGF signaling deficiency on postnatal GnRH neurons. Male dnFGFR mice suffered a significant loss of postnatal GnRH neurons within the first 100 days of life. Interestingly, this loss was reversed after cohabitation with female, but not male, mice for 300–550 days. Along with a rescue in GnRH neuron numbers, opposite-sex housing in dnFGFR males also increased hypothalamic GnRH peptide levels, promoted a more mature GnRH neuronal morphology, facilitated litter production, and enhanced testicular morphology. Last, mice hypomorphic for FGFR3 exhibited a similar pattern of postnatal GnRH neuronal loss as dnFGFR males, suggesting FGF signaling acts, in part, through FGFR3 to enhance the maintenance of the postnatal GnRH system. In summary, we have shown that FGF signaling is required for the continued presence of postnatal GnRH neurons. However, this requirement is not absolute, since sexual interactions can compensate for defects in FGFR signaling, thereby rescuing the declining GnRH system. This suggests the postnatal GnRH system is highly plastic and capable of responding to environmental stimuli throughout adult life. PMID:23047985

  9. Male-driven grooming bouts in mixed-sex dyads of Kinda baboons (Papio kindae).

    PubMed

    Weyher, Anna H; Phillips-Conroy, Jane E; Fourrier, Marc S; Jolly, Clifford J

    2014-01-01

    The behavior of the Central African Kinda baboon (Papio kindae) is not well documented. Having previously noted distinctive grooming behavior in several Kinda baboon populations, we investigated the topic more systematically in the Kafue National Park, Zambia. We recorded the duration and details of male-female dyadic interactions (approaches, withdrawals and time spent grooming) in the early morning and late afternoon. Such interactions were more often initiated by the male and terminated by the female partner. The male groomed the female more often, and longer, than she groomed him, regardless of the female's reproductive state or the presence of an infant. The bias towards male grooming was stronger in morning than evening interactions. These behaviors, whose function is not immediately obvious, and which are unlike those previously reported in baboons, further exemplify the distinctiveness of the taxon.

  10. Synchronous firing of antennal-lobe projection neurons encodes the behaviorally effective ratio of sex-pheromone components in male Manduca sexta

    PubMed Central

    Martin, Joshua P.; Lei, Hong; Riffell, Jeffrey A.; Hildebrand, John G.

    2013-01-01

    Olfactory stimuli that are essential to an animal's survival and reproduction are often complex mixtures of volatile organic compounds in characteristic proportions. Here, we investigated how these proportions are encoded in the primary olfactory processing center, the antennal lobe (AL), of male Manduca sexta moths. Two key components of the female's sex pheromone, present in an approximately 2:1 ratio, are processed in each of two neighboring glomeruli in the macroglomerular complex (MGC) of males of this species. In wind-tunnel flight experiments, males exhibited behavioral selectivity for ratios approximating the ratio released by conspecific females. The ratio between components was poorly represented, however, in the firing-rate output of uniglomerular MGC projection neurons (PNs). PN firing rate was mostly insensitive to the ratio between components, and individual PNs did not exhibit a preference for a particular ratio. Recording simultaneously from pairs of PNs in the same glomerulus, we found that the natural ratio between components elicited the most synchronous spikes, and altering the proportion of either component decreased the proportion of synchronous spikes. The degree of synchronous firing between PNs in the same glomerulus thus selectively encodes the natural ratio that most effectively evokes the natural behavioral response to pheromone. PMID:24002682

  11. [Pattern of plasma sex steroid hormone levels during the breeding season of male and female skink: Eumeces chinensis].

    PubMed

    Hu, Jian Rao; Du, Ji Zeng; Ji, Xiang

    2004-12-01

    Changes in gonadal activity and plasma sex steroid hormone levels in male and female Eumece chinensis during the breeding season were described. The results showed that: The vitellogensis of follicles of female Eumeces chinensis needed the stimulation of 17beta-estradiol (E2). As ovary masses reached peak values between late April and mid-May, E2 levels rose to the top value by late March, and then sharply declined but went up again before preovulation; The physiological functions of plasma progesterone (P) consisted in its oviductal egg retention, embryo development, and eggshell formation. P levels fluctuated near the basic value between mid-March and late April. In mid-May, with the onset of ovulation, plasma P levels rose rapidly, reached peak value by late May and declined sharply after ovulation. Plasma E2 levels declined as plasma P levels rose, showing an inverse relationship between them; In males, plasma Testosterone (T) levels were closely correlated with the maintenance of spermatogenesis activities, male and male combat, sexual display, and mating. Plasma T levels tended to rise after the termination of hibernation, and reached peak value by mid-April. After mid-May, with the testis aggressing, plasma T levels gradually went down and reached bottom value by late June.

  12. Perceptions about HIV and condoms and consistent condom use among male clients of commercial sex workers in the Philippines.

    PubMed

    Regan, Rotrease; Morisky, Donald E

    2013-04-01

    Because consistent condom use is an effective strategy in the prevention of sexually transmitted infections and HIV transmission, it is important to examine social cognitive influences of consistent condom use not only among female sex workers (FSWs) but also among their male clients, for whom less is known. Because little is known about how HIV knowledge and condom attitudes affect condom use among male clients of FSWs in the Philippines, the main objective was to determine what characteristics (age, education, HIV knowledge, marital status) as well as attributes taken from protection motivation theory (perceived vulnerability, perceived severity, response efficacy) are significantly associated with consistent condom use among male clients of FSWs. Logistic regression analyses showed that the odds of using condoms consistently with an FSW are 13% higher for those with more years of education (adjusted odds ratio [AOR] = 1.13; 95% confidence interval [CI] = 1.03, 1.23), higher versus lower perception of severity of HIV/AIDS (AOR = 1.97; 95% CI = 1.04, 3.73), and had a higher score for response efficacy of condoms (AOR = 1.14; 95% CI = 1.03, 1.27). Future HIV/AIDS prevention interventions that address condom use among male clients should promote educational attainment and focus on awareness of the enduring negative health consequences of acquiring HIV/AIDS, as well as cultivate positive attitudes toward the efficacy of condom use, using creative social marketing strategies. PMID:22773598

  13. Implications of Sex Hormone Receptor Gene Expression in the Predominance of Hepatocellular Carcinoma in Males: Role of Natural Products.

    PubMed

    Ahmed, Hanaa H; Shousha, Wafaa Gh; Shalby, Aziza B; El-Mezayen, Hatem A; Ismaiel, Nora N; Mahmoud, Nadia S

    2015-01-01

    The present study was planned to investigate the role of sex hormone receptor gene expression in the pathogenesis of hepatocellular carcinoma (HCC). Adult male Wistar rats were divided into seven groups. Group (1) was negative control. Groups (2), (5), (6), and (7) were orally administered with N-nitrosodiethylamine for the induction of HCC, then group (2) was left untreated, group (5) was orally treated with curcumin, group (6) was orally treated with carvacrol, and group (7) was intraperitoneally injected with doxorubicin, whereas groups (3) and (4) were orally administered only curcumin and carvacrol, respectively. The HCC group showed significant upregulation in the androgen receptor (AR) and the estrogen receptor-alpha (ERα) gene expression levels in the liver tissue. On the contrary, HCC groups treated with either curcumin or carvacrol showed significant downregulation in AR and ERα gene expression levels in the liver tissue. In conclusion, the obtained data highlight that both AR and ERα but not estrogen receptor-beta (ERβ) gene expression may contribute to the male prevalence of HCC induced in male rats. Interestingly, both curcumin and carvacrol were found to have a promising potency in alleviating the male predominating HCC.

  14. A Sex-Linked Gene Controlling the Onset of Sexual Maturity in Female and Male Platyfish (XIPHOPHORUS MACULATUS), Fecundity in Females and Adult Size in Males

    PubMed Central

    Kallman, Klaus D.; Borkoski, Valerie

    1978-01-01

    A sex-linked gene, P, controls the onset of sexual maturity in the platyfish, Xiphophorus maculatus. The activity of this gene is correlated with the age and size at which the gonadotropic zone of the adenohypophysis differentiates and becomes physiologically active. Immature fish of all genotypes grow at the same rate; however, as adults, males with "early" genotypes are significantly smaller than males of "late" genotypes, since growth rate declines strongly under the influence of androgenic hormone. Five alleles, P1... P5, have been identified from natural populations that under controlled conditions cause gonad maturation between eight and 73 weeks. P1P1 males become mature at eight weeks and 21 mm, P2P2 and P3P3 males between eleven and 13.5 weeks and 25 to 29 mm, and P4P4 males at 25 weeks and 37 mm. Since P5 is X-linked, no males homozygous for P5 could be produced. The difference between P2 and P3 is largely based upon their interaction with P5. P3P5 males mature at 17.5 weeks and 33.5 mm and P2P5 males at 28 weeks and 38 mm. The rate of transformation of the unmodified anal fin into a gonopodium, which is under androgenic control, is directly related to the age at initiation of sexual maturity, ranging from 3.2 weeks in P1P1 males to seven weeks in P2P 5 males. These differences may reflect different levels of circulating gonadotropic and androgenic hormones.—In two genotypes of females, initiation of vitellogenesis was closely correlated with size and this critical size was independent of age (e.g., 21 mm for P1P1 ). In a third genotype (P1P5) the minimum size for vitellogenesis decreased with increasing age, so that females would mature as early as eleven weeks, provided they had attained at least 29 mm, but at 25 weeks even females as small as 23 mm possessed ripe gonads. For P5P5 females, which become mature between 34 and 73 weeks of age, there is no correlation between size and initiation of vitellogenesis. In all four genotypes of females examined

  15. Is the rate of insertion and deletion mutation male biased?: Molecular evolutionary analysis of avian and primate sex chromosome sequences.

    PubMed Central

    Sundström, Hannah; Webster, Matthew T; Ellegren, Hans

    2003-01-01

    The rate of mutation for nucleotide substitution is generally higher among males than among females, likely owing to the larger number of DNA replications in spermatogenesis than in oogenesis. For insertion and deletion (indel) mutations, data from a few human genetic disease loci indicate that the two sexes may mutate at similar rates, possibly because such mutations arise in connection with meiotic crossing over. To address origin- and sex-specific rates of indel mutation we have conducted the first large-scale molecular evolutionary analysis of indels in noncoding DNA sequences from sex chromosomes. The rates are similar on the X and Y chromosomes of primates but about twice as high on the avian Z chromosome as on the W chromosome. The fact that indels are not uncommon on the nonrecombining Y and W chromosomes excludes meiotic crossing over as the main cause of indel mutation. On the other hand, the similar rates on X and Y indicate that the number of DNA replications (higher for Y than for X) is also not the main factor. Our observations are therefore consistent with a role of both DNA replication and recombination in the generation of short insertion and deletion mutations. A significant excess of deletion compared to insertion events is observed on the avian W chromosome, consistent with gradual DNA loss on a nonrecombining chromosome. PMID:12750337

  16. Driving a hard bargain: sex ratio and male marriage success in a historical US population.

    PubMed

    Pollet, Thomas V; Nettle, Daniel

    2008-02-23

    Evolutionary psychologists have documented a widespread female preference for men of high status and resources, and evidence from several populations suggests that this preference has real effects on marriage success. Here, we show that in the US population of 1910, socioeconomic status (SES) had a positive effect on men's chances of marrying. We also test a further prediction from the biological markets theory, namely that where the local sex ratio produces an oversupply of men, women will be able to drive a harder bargain. As the sex ratio of the states increases, the effect of SES on marriage success becomes stronger, indicating increased competition between men and an increased ability to choose on the part of women.

  17. Effects of sex hormones on the metabolism of tryptophan to niacin and to serotonin in male rats.

    PubMed

    Shibata, K; Toda, S

    1997-07-01

    It is known that deaths attributable to pellagra, which is considered to be a disease caused by the disturbance of tryptophan metabolism, have been approximately two-fold higher in women than in men. We investigated the effects of the administration of female and male sex hormones on the contents of tryptophan and such metabolites as serotonin, nicotinamide, N1-methylnicotinamide, N1-methyl-2-pyridone-5-carboxamide, and N1-methyl-4-pyridone-3-carboxamide, and on the conversion ratio of tryptophan to niacin in male rats. Feeding a diet containing estrone or testosterone had no effect on the concentrations of tryptophan and serotonin in the blood and brain, or on the concentration of 5-hydroxyindole-3-acetic acid in the brain. On the contrary, feeding a diet containing estrone caused to a decrease in the urinary excretion of nicotinamide, N1-methylnicotinamide, N1-methyl-2-pyridone-5-carboxamide, and N1-methyl-4-pyridone-3-carboxamide, and of the conversion ratio of tryptophan to niacin when compared with the control rats. Feeding a diet containing testosterone had no effect on any parameter. We postulate from these findings that the cause of higher pellagra deaths in women than in men is attributable to the decrease in the formation of niacin from tryptophan, but not in the formation of serotonin by the female hormone. It seems likely that female sex hormones inhibit the synthesis of niacin from tryptophan, and that women, especially during pregnancy, will be more at risk to pellagra than are men.

  18. Isolation of a Female-Emitted Sex Pheromone Component of the Fungus Gnat, Lycoriella ingenua, Attractive to Males.

    PubMed

    Andreadis, Stefanos S; Cloonan, Kevin R; Myrick, Andrew J; Chen, Haibin; Baker, Thomas C

    2015-12-01

    Lycoriella ingenua Dufour (Diptera: Sciaridae) is acknowledged as the major pest species of the white button mushroom, Agaricus bisporus, throughout the world. Components of the female-produced sex pheromone of this species were identified previously as C15-C18 n-alkanes, with the major component n-heptadecane, and shown to be attractive to L. mali. However, a subsequent report could not repeat this work. We reinvestigated the sex pheromone of this species by confirming that virgin females were attractive to males in a Y-tube bioassay and by collection of extracts from virgin females. Extracts were analyzed by gas chromatography coupled to electroantennographic detection, and by the less widely-used technique of gas chromatography coupled to a behavioral bioassay to detect compounds causing wing-fanning and copulatory abdomen curling in males. A single, behaviorally-active pheromone component was isolated and characterized by gas chromatography coupled to mass spectrometry. This component was definitively not n-heptadecane or any of the other C15-C19 n-alkanes reported previously, but is proposed to be a sesquiterpene alcohol having analytical characteristics that closely matched those of reference germacradienols. PMID:26585193

  19. Stumbling into sexual crime: the passive perpetrator in accounts by male internet sex offenders.

    PubMed

    Winder, Belinda; Gough, Brendan; Seymour-Smith, Sarah

    2015-01-01

    Public reactions to internet child offending remain ambivalent in that, while there is vocal condemnation of contact child sex offending, there is less indignation about internet child abuse. This is potentially due to a lack of recognition of this type of offence as sexual offending per se. This ambiguity is reflected by internet sex offenders themselves in their verbalizations of their offending. This article presents a qualitative analysis of the accounts offered by seven individuals convicted of internet-based sexual offences involving the downloading and viewing of images of children. In particular, this article presents an analysis of the explanations of offenders for the commencement of internet activity and the progression to more illicit online materials. The data were collected through semi-structured interviews and analyzed using discursive methods, paying close attention to language use and function. The analysis documented the practices that internet child abusers employed in order to manage their identities, distance themselves from the label of sex offender, and/or reduce their personal agency and accountability. Implications of this analysis are discussed with reference to the current minimization of the downloading of sexually explicit images of children as a sexual crime per se by the public and offenders alike and the risk assessment and treatment of individuals convicted of these offences.

  20. BRCA1, histone H2AX phosphorylation, and male meiotic sex chromosome inactivation.

    PubMed

    Turner, James M A; Aprelikova, Olga; Xu, Xiaoling; Wang, Ruihong; Kim, Sangsoo; Chandramouli, Gadisetti V R; Barrett, J Carl; Burgoyne, Paul S; Deng, Chu-Xia

    2004-12-14

    In mammalian spermatogenesis, the X and Y chromosomes are transcriptionally silenced during the pachytene stage of meiotic prophase (meiotic sex chromosome inactivation, MSCI), forming a condensed chromatin domain termed the sex or XY body. The nucleosomal core histone H2AX is phosphorylated within the XY chromatin domain just prior to MSCI, and it has been hypothesized that this triggers the chromatin condensation and transcriptional repression. Here, we show that the kinase ATR localizes to XY chromatin at the onset of MSCI and that this localization is disrupted in mice with a mutant form of the tumor suppressor protein BRCA1. In the mutant pachytene cells, ATR is usually present at nonsex chromosomal sites, where it colocalizes with aberrant sites of H2AX phosphorylation; in these cells, there is MSCI failure. In rare pachytene cells, ATR does locate to XY chromatin, H2AX is then phosphorylated, a sex body forms, and MSCI ensues. These observations highlight an important role for BRCA1 in recruiting the kinase ATR to XY chromatin at the onset of MSCI and provide compelling evidence that it is ATR that phosphorylates H2AX and triggers MSCI.

  1. Preferred and actual relative height among homosexual male partners vary with preferred dominance and sex role.

    PubMed

    Valentova, Jaroslava Varella; Stulp, Gert; Třebický, Vít; Havlíček, Jan

    2014-01-01

    Previous research has shown repeatedly that human stature influences mate preferences and mate choice in heterosexuals. In general, it has been shown that tall men and average height women are most preferred by the opposite sex, and that both sexes prefer to be in a relationship where the man is taller than the woman. However, little is known about such partner preferences in homosexual individuals. Based on an online survey of a large sample of non-heterosexual men (N = 541), we found that the majority of men prefer a partner slightly taller than themselves. However, these preferences were dependent on the participant's own height, such that taller men preferred shorter partners, whereas shorter men preferred taller partners. We also examined whether height preferences predicted the preference for dominance and the adoption of particular sexual roles within a couple. Although a large proportion of men preferred to be in an egalitarian relationship with respect to preferred dominance (although not with respect to preferred sexual role), men that preferred a more dominant and more "active" sexual role preferred shorter partners, whereas those that preferred a more submissive and more "passive" sexual role preferred taller partners. Our results indicate that preferences for relative height in homosexual men are modulated by own height, preferred dominance and sex role, and do not simply resemble those of heterosexual women or men.

  2. Stumbling into sexual crime: the passive perpetrator in accounts by male internet sex offenders.

    PubMed

    Winder, Belinda; Gough, Brendan; Seymour-Smith, Sarah

    2015-01-01

    Public reactions to internet child offending remain ambivalent in that, while there is vocal condemnation of contact child sex offending, there is less indignation about internet child abuse. This is potentially due to a lack of recognition of this type of offence as sexual offending per se. This ambiguity is reflected by internet sex offenders themselves in their verbalizations of their offending. This article presents a qualitative analysis of the accounts offered by seven individuals convicted of internet-based sexual offences involving the downloading and viewing of images of children. In particular, this article presents an analysis of the explanations of offenders for the commencement of internet activity and the progression to more illicit online materials. The data were collected through semi-structured interviews and analyzed using discursive methods, paying close attention to language use and function. The analysis documented the practices that internet child abusers employed in order to manage their identities, distance themselves from the label of sex offender, and/or reduce their personal agency and accountability. Implications of this analysis are discussed with reference to the current minimization of the downloading of sexually explicit images of children as a sexual crime per se by the public and offenders alike and the risk assessment and treatment of individuals convicted of these offences. PMID:24917484

  3. Differential utilization of pyrrolizidine alkaloids by males of a danaid butterfly, Parantica sita, for the production of danaidone in the alar scent organ.

    PubMed

    Honda, Keiichi; Honda, Yasuyuki; Yamamoto, Satoshi; Omura, Hisashi

    2005-04-01

    Males of the chestnut tiger butterfly, Parantica sita, secrete danaidone as a major component from the alar androconial organ (sex brand). Since danaidone has been postulated to be derived from various pyrrolizidine alkaloids (PAs), which males ingest as adults from PA-containing plants, we conducted oral administration tests of several PAs to examine their availability for danaidone production by P. sita males. Males fed with a mixture of intermedine (80%) and lycopsamine (20%) produced danaidone at an average of 25.7 microg per individual, which was comparable to that found in field-caught males. In contrast, a smaller amount of danaidone (5.7 to 7.0 microg/ male) was formed when males ingested retronecine or heliotrine, and those fed with an HCI salt of monocrotaline or retrorsine produced only traces of danaidone (<0.5 microg/male). In addition, males showed a strong feeding response to intermedine/lycopsamine, whereas the other PAs elicited no positive feeding behavior. These results indicate that, unlike the arctiid moths, P. sita males can only successfully convert limited chemical types of PAs into danaidone, and further suggest that in the field, males selectively ingest particular PAs that are readily transformable into danaidone.

  4. The costs of being male: are there sex-specific effects of uniparental mitochondrial inheritance?

    PubMed Central

    Beekman, Madeleine; Dowling, Damian K.; Aanen, Duur K.

    2014-01-01

    Eukaryotic cells typically contain numerous mitochondria, each with multiple copies of their own genome, the mtDNA. Uniparental transmission of mitochondria, usually via the mother, prevents the mixing of mtDNA from different individuals. While on the one hand, this should resolve the potential for selection for fast-replicating mtDNA variants that reduce organismal fitness, maternal inheritance will, in theory, come with another set of problems that are specifically relevant to males. Maternal inheritance implies that the mitochondrial genome is never transmitted through males, and thus selection can target only the mtDNA sequence when carried by females. A consequence is that mtDNA mutations that confer male-biased phenotypic expression will be prone to evade selection, and accumulate. Here, we review the evidence from the ecological, evolutionary and medical literature for male specificity of mtDNA mutations affecting fertility, health and ageing. While such effects have been discovered experimentally in the laboratory, their relevance to natural populations—including the human population—remains unclear. We suggest that the existence of male expression-biased mtDNA mutations is likely to be a broad phenomenon, but that these mutations remain cryptic owing to the presence of counter-adapted nuclear compensatory modifier mutations, which offset their deleterious effects. PMID:24864311

  5. The costs of being male: are there sex-specific effects of uniparental mitochondrial inheritance?

    PubMed

    Beekman, Madeleine; Dowling, Damian K; Aanen, Duur K

    2014-07-01

    Eukaryotic cells typically contain numerous mitochondria, each with multiple copies of their own genome, the mtDNA. Uniparental transmission of mitochondria, usually via the mother, prevents the mixing of mtDNA from different individuals. While on the one hand, this should resolve the potential for selection for fast-replicating mtDNA variants that reduce organismal fitness, maternal inheritance will, in theory, come with another set of problems that are specifically relevant to males. Maternal inheritance implies that the mitochondrial genome is never transmitted through males, and thus selection can target only the mtDNA sequence when carried by females. A consequence is that mtDNA mutations that confer male-biased phenotypic expression will be prone to evade selection, and accumulate. Here, we review the evidence from the ecological, evolutionary and medical literature for male specificity of mtDNA mutations affecting fertility, health and ageing. While such effects have been discovered experimentally in the laboratory, their relevance to natural populations--including the human population--remains unclear. We suggest that the existence of male expression-biased mtDNA mutations is likely to be a broad phenomenon, but that these mutations remain cryptic owing to the presence of counter-adapted nuclear compensatory modifier mutations, which offset their deleterious effects.

  6. The influence of sex difference on self-reference effects in a male-dominated culture.

    PubMed

    Song, Xuan; Shang, Rui; Bi, Qi; Zhang, Xin; Wu, Yanhong

    2012-10-01

    52 secondary school students from the Chaoshan, China, area, where males are highly valued, were examined for self-reference, mother-reference, and father-reference effects. Because the father is the primary role model in Chaoshan culture, it was predicted that male participants would demonstrate a father-reference effect while females would show a mother-reference effect. The results confirmed that females showed significant self-, mother-, and father-reference effects in terms of memory performance, while males showed only a significant father-reference effect and a marginally significant self-reference effect. This study highlights the importance of researching subcultures such as the Chaoshan subculture to gain a comprehensive understanding of self-construct.

  7. Analysis of male pheromones that accelerate female reproductive organ development.

    PubMed

    Flanagan, Kelly A; Webb, William; Stowers, Lisa

    2011-01-01

    Male odors can influence a female's reproductive physiology. In the mouse, the odor of male urine results in an early onset of female puberty. Several volatile and protein pheromones have previously been reported to each account for this bioactivity. Here we bioassay inbred BALB/cJ females to study pheromone-accelerated uterine growth, a developmental hallmark of puberty. We evaluate the response of wild-type and mutant mice lacking a specialized sensory transduction channel, TrpC2, and find TrpC2 function to be necessary for pheromone-mediated uterine growth. We analyze the relative effectiveness of pheromones previously identified to accelerate puberty through direct bioassay and find none to significantly accelerate uterine growth in BALB/cJ females. Complementary to this analysis, we have devised a strategy of partial purification of the uterine growth bioactivity from male urine and applied it to purify bioactivity from three different laboratory strains. The biochemical characteristics of the active fraction of all three strains are inconsistent with that of previously known pheromones. When directly analyzed, we are unable to detect previously known pheromones in urine fractions that generate uterine growth. Our analysis indicates that pheromones emitted by males to advance female puberty remain to be identified.

  8. Sex differences in intergroup competition, aggression, and warfare: the male warrior hypothesis.

    PubMed

    Van Vugt, Mark

    2009-06-01

    The social science literature abounds with examples of human tribalism, the tendency to categorize individuals on the basis of their group membership and treat in-group members benevolently and out-group members malevolently. I argue that this tribal inclination is an evolved response to the threat of intergroup violence and warfare that was endemic in ancestral human environments (and is still common today). Here I hypothesize that intergroup conflict has profoundly affected the social psychology of human males in particular--the male warrior hypothesis--and present evidence consistent with this claim. I also discuss implications of this hypothesis for managing intergroup relations in our society.

  9. Birth order, sibling sex ratio, handedness, and sexual orientation of male and female participants in a BBC internet research project.

    PubMed

    Blanchard, Ray; Lippa, Richard A

    2007-04-01

    This study investigated the relations among sexual orientation, fraternal birth order (number of older brothers), and hand-preference. The participants were 87,798 men and 71,981 women who took part in a Web-based research project sponsored by the British Broadcasting Corporation (BBC). The results yielded some evidence confirming prior findings that non-right-handedness is associated with homosexuality in men and women, that older brothers increase the odds of homosexuality in men, and that the effect of older brothers on sexual orientation is limited to right-handed men. The evidence was weaker than in previous studies, however, probably because the usual relations among the variables of interest were partially obscured by the effects of other factors. Thus, the homosexual men and women had higher rates of non-right-handedness than their heterosexual counterparts, but the strongest handedness finding for both sexes was a marked tendency for participants who described themselves as ambidextrous also to describe themselves as bisexual. The birth order data were strongly affected by a tendency for the male participants to report an excess of older sisters, and the female participants to report an excess of older brothers. Statistical analyses confirmed that this was an artifact of the parental stopping rule, "Continue having children until you have offspring of both sexes." In subsequent analyses, participants were divided into those who did and did not have younger siblings, on the grounds that the data of the former would be less contaminated by the stopping rule. In the former subsample, the right-handed homo/bisexual males showed the typical high ratio of older brothers to older sisters, whereas the non-right-handed homo/bisexual males did not.

  10. Psoralen and Isopsoralen Ameliorate Sex Hormone Deficiency-Induced Osteoporosis in Female and Male Mice

    PubMed Central

    Yuan, Xiaomei; Bi, Yanan; Yan, Zeman; Pu, Weiling; Li, Yuhong; Zhou, Kun

    2016-01-01

    Osteoporosis is a systemic skeletal disease, which is characterized by a systemic destruction of bone mass and microarchitecture. With life standard improved, the treatment of osteoporosis attracted more attention. The aim of this study is to verify the osteoprotective effect of psoralen and isopsoralen in females and males. Female and male mice were divided into 7 groups in this study: control group (sham-operation), model group (by ovariectomy or orchidectomy), positive control group (females given estradiol valerate; males given alendronate sodium), psoralen groups (10 mg/kg and 20 mg/kg), and isopsoralen groups (10 mg/kg and 20 mg/kg). After administration of psoralen and isopsoralen for 8 weeks, osteoporosis was ameliorated with increasing bone strength and improving trabecular bone microstructure as indicated by CT scan and pathology. Serum alkaline phosphatase (ALP), tartrate resistant acid phosphatase (TRACP), osteocalcin (OC), and C-terminal cross-linking telopeptides of type I collagen (CTX-1) were examined. Decreased TRACP and increased ALP/TRACP suggested restoring from bone destruction. These results suggest that psoralen and isopsoralen may be used as good natural compounds for the treatment of osteoporosis in males, as well as females. PMID:27239473

  11. The Stigmatized Woman: The Professional Woman in a Male Sex-Typed Career.

    ERIC Educational Resources Information Center

    Marshall, Catherine

    1985-01-01

    Applies Erving Goffman's stigma theory to impressions of 25 women in educational administration careers. Analyzes data from an earlier study to show how women administrators, confronted with male leadership norms, deviate, acquire stigma, and become marginal. Concludes with suggestions for change, citing 32 references. (MLH)

  12. Opinion: Sex, Gender and the Diagnosis of Autism--A Biosocial View of the Male Preponderance

    ERIC Educational Resources Information Center

    Goldman, Sylvie

    2013-01-01

    Autism Spectrum Disorders (ASD) are behaviorally defined neurodevelopmental disorders. The best known yet less understood characteristic of autism is its unexplained male preponderance. Using a biosocial perspective, the goal of this article is to draw attention to the role of gender-based socialization practices and behavioral expectations during…

  13. The Effects of Single-Sex Mathematics Classrooms on African American Males in the Ninth Grade

    ERIC Educational Resources Information Center

    Faulkner-Simmons, Denise

    2012-01-01

    Research indicated that educators must consider socio-ecological accommodations because not all students learn in cooperative groups. Students must be taught how to discover the process of learning and to apply knowledge to real life situations. Gurian and Ballew (2003) identified differences in the male and female brain and the differences in how…

  14. Inherited human sex reversal due to impaired nucleocytoplasmic trafficking of SRY defines a male transcriptional threshold.

    PubMed

    Chen, Yen-Shan; Racca, Joseph D; Phillips, Nelson B; Weiss, Michael A

    2013-09-17

    Human testis determination is initiated by SRY (sex determining region on Y chromosome). Mutations in SRY cause gonadal dysgenesis with female somatic phenotype. Two subtle variants (V60L and I90M in the high-mobility group box) define inherited alleles shared by an XY sterile daughter and fertile father. Whereas specific DNA binding and bending are unaffected in a rat embryonic pre-Sertoli cell line, the variants exhibited selective defects in nucleocytoplasmic shuttling due to impaired nuclear import (V60L; mediated by Exportin-4) or export (I90M; mediated by chromosome region maintenance 1). Decreased shuttling limits nuclear accumulation of phosphorylated (activated) SRY, in turn reducing occupancy of DNA sites regulating Sertoli-cell differentiation [the testis-specific SRY-box 9 (Sox9) enhancer]. Despite distinct patterns of biochemical and cell-biological perturbations, V60L and I90M each attenuated Sox9 expression in transient transfection assays by twofold. Such attenuation was also observed in studies of V60A, a clinical variant associated with ovotestes and hence ambiguity between divergent cell fates. This shared twofold threshold is reminiscent of autosomal syndromes of transcription-factor haploinsufficiency, including XY sex reversal associated with mutations in SOX9. Our results demonstrate that nucleocytoplasmic shuttling of SRY is necessary for robust initiation of testicular development. Although also characteristic of ungulate orthologs, such shuttling is not conserved among rodents wherein impaired nuclear export of the high-mobility group box and import-dependent phosphorylation are compensated by a microsatellite-associated transcriptional activation domain. Human sex reversal due to subtle defects in the nucleocytoplasmic shuttling of SRY suggests that its transcriptional activity lies near the edge of developmental ambiguity. PMID:24003159

  15. [Male-to-female transsexualism. Sex reassignment surgery from a biopsychosocial perspective].

    PubMed

    Baranyi, Andreas; Piber, Dominique; Rothenhäusler, Hans-Bernd

    2009-01-01

    Many man-to-female-transsexuals prefer sex reassignment surgery. Surgical complications are common, most frequently a stenosis of the vagina as well as the urethral ostium. In up to 24% of patients secondary corrective surgery is necessary. Regret and feelings of doubt can occur in up to 8% of the cases. In the setting of an interdisciplinary team the postoperative somatic, psychological and socio-economic situation can be improved. This review is based on a Medline literature search and summarizes the pertinent literature of the last 22 years.

  16. nr0b1 (DAX1) mutation in zebrafish causes female-to-male sex reversal through abnormal gonadal proliferation and differentiation.

    PubMed

    Chen, Sijie; Zhang, Hefei; Wang, Fenghua; Zhang, Wei; Peng, Gang

    2016-09-15

    Sex determinations are diverse in vertebrates. Although many sex-determining genes and pathways are conserved, the mechanistic roles of these genes and pathways in the genetic sex determination are not well understood. DAX1 (encoded by the NR0B1 gene) is a vertebrate specific orphan nuclear receptor that regulates gonadal development and sexual determination. In human, duplication of the NR0B1 gene leads to male-to-female sex reversal. In mice, Nr0b1 shows both pro-testis and anti-testis functions. We generated inheritable nr0b1 mutation in the zebrafish and found the nr0b1 mutation caused homozygous mutants to develop as fertile males due to female-to-male sex reversal. The nr0b1 mutation did not increase Caspase-3 labeling nor tp53 expression in the developing gonads. Introduction of a tp53 mutation into the nr0b1 mutant did not rescue the sex-reversal phenotype. Further examination revealed reduction in cell proliferation and abnormal somatic cell differentiation in the nr0b1 mutant gonads at the undifferentiated and bi-potential ovary stages. Together, our results suggest nr0b1 regulates somatic cell differentiation and cell proliferation to ensure normal sex development in the zebrafish. PMID:27267667

  17. nr0b1 (DAX1) mutation in zebrafish causes female-to-male sex reversal through abnormal gonadal proliferation and differentiation.

    PubMed

    Chen, Sijie; Zhang, Hefei; Wang, Fenghua; Zhang, Wei; Peng, Gang

    2016-09-15

    Sex determinations are diverse in vertebrates. Although many sex-determining genes and pathways are conserved, the mechanistic roles of these genes and pathways in the genetic sex determination are not well understood. DAX1 (encoded by the NR0B1 gene) is a vertebrate specific orphan nuclear receptor that regulates gonadal development and sexual determination. In human, duplication of the NR0B1 gene leads to male-to-female sex reversal. In mice, Nr0b1 shows both pro-testis and anti-testis functions. We generated inheritable nr0b1 mutation in the zebrafish and found the nr0b1 mutation caused homozygous mutants to develop as fertile males due to female-to-male sex reversal. The nr0b1 mutation did not increase Caspase-3 labeling nor tp53 expression in the developing gonads. Introduction of a tp53 mutation into the nr0b1 mutant did not rescue the sex-reversal phenotype. Further examination revealed reduction in cell proliferation and abnormal somatic cell differentiation in the nr0b1 mutant gonads at the undifferentiated and bi-potential ovary stages. Together, our results suggest nr0b1 regulates somatic cell differentiation and cell proliferation to ensure normal sex development in the zebrafish.

  18. Annual cycle of plasma luteinizing hormone and sex hormones in male and female mallards (Anas platyrhynchos)

    USGS Publications Warehouse

    Donham, R.S.

    1979-01-01

    Comparisons between 'wild'and 'game farm' mallards (Anas platyrhynchos) were made to assess the differences in the temporal changes of plasma hormones. Seasonal variation in the levels of immunoreactive luteinizing hormone (LH), testosterone, 5 -dihydrotestosterone (DHT), estrone, estradiol-17i?? and progesterone were measured in male and female mallards. In all birds there was a vernal increase in the concentrations of LH and testosterone in plasma which were correlated with the development of the testes and ovaries prior to and during the nesting season. The concentrations of estrogens in the plasma of the females were, in general, slightly higher during the nesting season but were much lower than the levels of testosterone. The highest levels of LH and testosterone in the females coincided precisely with the period of egg laying which occurred approximately one month earlier in game farm females than in wild females. The concentrations of LH and testosterone in the plasma of females decreased rapidly during incubation. In wild males, the decline in levels of these hormones temporally coincided with that of females. In contrast, plasma levels of LH and testosterone of males of the game farm stock remained elevated after the beginning of incubation in females to which they were paired. On the basis of these results and an examination of the literature, it appears that domestication results in: 1) increased reproductive potential through earlier initiation of nesting and by delay of the termination of reproduction until later in the summer; and 2) a decrease in the synchronization of the hormonal events supporting reproduction between the male and female of a pair. Testicular weights and plasma levels of testosterone become higher in game farm and domestic males than in the wild stock but levels of LH are similar.

  19. Conditioned same-sex partner preference in male rats is facilitated by oxytocin and dopamine: effect on sexually dimorphic brain nuclei.

    PubMed

    Triana-Del Rio, Rodrigo; Tecamachaltzi-Silvarán, Miriam B; Díaz-Estrada, Victor X; Herrera-Covarrubias, Deissy; Corona-Morales, Aleph A; Pfaus, James G; Coria-Avila, Genaro A

    2015-04-15

    Conditioned same-sex partner preference can develop in male rats that undergo cohabitation under the effects of quinpirole (QNP, D2 agonist). Herein, we assessed the development of conditioned same-sex social/sexual preference in males that received either nothing, saline, QNP, oxytocin (OT), or QNP+OT during cohabitation with another male (+) or single-caged (-). This resulted in the following groups: (1) Intact-, (2) Saline+, (3) QNP-, (4) OT-, (5) QNP+, (6) OT+ and (7) QNP/OT+. Cohabitation occurred during 24h in a clean cage with a male partner that bore almond scent on the back as conditioned stimulus. This was repeated every 4 days for a total of three trials. Social and sexual preference were assessed four days after the last conditioning trial in a drug-free test in which experimental males chose between the scented familiar male and a novel sexually receptive female. Results showed that males from groups Intact-, Saline+, QNP- and OT- displayed a clear preference for the female (opposite-sex), whereas groups QNP+, OT+ and QNP/OT+ displayed socio/sexual preference for the male partner (same-sex). In Experiment 2, the brains were processed for Nissl dye and the area size of two sexually dimorphic nuclei (SDN-POA and SON) was compared between groups. Males from groups OT-, OT+ and QNP/OT+ expressed a smaller SDN-POA and groups QNP+ and QNP/OT+ expressed a larger SON. Accordingly, conditioned same-sex social/sexual partner preference can develop during cohabitation under enhanced D2 or OT activity but such preference does not depend on the area size of those sexually dimorphic nuclei.

  20. Effect of glyphosate on reproductive organs in male rat.

    PubMed

    Dai, Pengyuan; Hu, Ping; Tang, Juan; Li, Yansen; Li, Chunmei

    2016-06-01

    Glyphosate as an active ingredient of Roundup(®) which is thought to be one of the most popular herbicide was used worldwide. Many studies have focused on reproductive toxicity on glyphosate-based herbicide, but few evidence exists to imply the male reproductive toxicity of glyphosate alone in vivo. In this study SD rats were Lavaged with glyphosate at doses of 5, 50, 500mg/kg to detect the toxicity of glyphosate on rat testis. Glyphosate significantly decreased the average daily feed intake at dose of 50mg/kg, and the weight of seminal vesicle gland, coagulating gland as well as the total sperm count at dose of 500mg/kg. Immunohistochemistry of androgen receptor (AR) has no difference among all groups. As to testosterone, estradiol, progesterone and oxidative stress parameters, the level of them has no differences amidst all doses. Taken together, we conclude that glyphosate alone has low toxicity on male rats reproductive system.

  1. Effect of glyphosate on reproductive organs in male rat.

    PubMed

    Dai, Pengyuan; Hu, Ping; Tang, Juan; Li, Yansen; Li, Chunmei

    2016-06-01

    Glyphosate as an active ingredient of Roundup(®) which is thought to be one of the most popular herbicide was used worldwide. Many studies have focused on reproductive toxicity on glyphosate-based herbicide, but few evidence exists to imply the male reproductive toxicity of glyphosate alone in vivo. In this study SD rats were Lavaged with glyphosate at doses of 5, 50, 500mg/kg to detect the toxicity of glyphosate on rat testis. Glyphosate significantly decreased the average daily feed intake at dose of 50mg/kg, and the weight of seminal vesicle gland, coagulating gland as well as the total sperm count at dose of 500mg/kg. Immunohistochemistry of androgen receptor (AR) has no difference among all groups. As to testosterone, estradiol, progesterone and oxidative stress parameters, the level of them has no differences amidst all doses. Taken together, we conclude that glyphosate alone has low toxicity on male rats reproductive system. PMID:27286640

  2. Age, sex, reproduction, and spatial organization of lynxes colonizing northeastern Minnesota

    USGS Publications Warehouse

    Mech, L.D.

    1980-01-01

    From 1972 through 1978, lynxes (Felis lynx) emigrating from Canada were studied in northeastern Minnesota. Fourteen individuals were radio-tracked, 8 wefe ear-tagged, and 49 carcasses were examined. Sex ratios of the samples were equal during the first years of the study, but females predominated later. At least half of the radiotagged lynxes were killed by humans; no natural mortality was detected. Home range sizes ranged from 51 to 122 km2 for females and 145 to 243 km2 for males, up to 10 times the sizes of those reported by other workers. Ranges of females tended to overlap. Males and females appeared to be segregated in the population.

  3. RNAi-Mediated Gene Silencing in a Gonad Organ Culture to Study Sex Determination Mechanisms in Sea Turtle

    PubMed Central

    Sifuentes-Romero, Itzel; Merchant-Larios, Horacio; Milton, Sarah L.; Moreno-Mendoza, Norma; Díaz-Hernández, Verónica; García-Gasca, Alejandra

    2013-01-01

    The autosomal Sry-related gene, Sox9, encodes a transcription factor, which performs an important role in testis differentiation in mammals. In several reptiles, Sox9 is differentially expressed in gonads, showing a significant upregulation during the thermo-sensitive period (TSP) at the male-promoting temperature, consistent with the idea that SOX9 plays a central role in the male pathway. However, in spite of numerous studies, it remains unclear how SOX9 functions during this event. In the present work, we developed an RNAi-based method for silencing Sox9 in an in vitro gonad culture system for the sea turtle, Lepidochelys olivacea. Gonads were dissected as soon as the embryos entered the TSP and were maintained in organ culture. Transfection of siRNA resulted in the decrease of both Sox9 mRNA and protein. Furthermore, we found coordinated expression patterns for Sox9 and the anti-Müllerian hormone gene, Amh, suggesting that SOX9 could directly or indirectly regulate Amh expression, as it occurs in mammals. These results demonstrate an in vitro method to knockdown endogenous genes in gonads from a sea turtle, which represents a novel approach to investigate the roles of important genes involved in sex determination or differentiation pathways in species with temperature-dependent sex determination. PMID:24705165

  4. Sex hormone-binding globulin response to human chorionic gonadotropin stimulation in children with cryptorchidism, anorchia, male pseudohermaphroditism, and micropenis.

    PubMed

    Belgorosky, A; Rivarola, M A

    1982-04-01

    Sex hormone-binding globulin serum concentrations (SHBG) were measured before and after a 5-day hCG stimulation test in 11 prepubertal boys with cryptorchidism, 6 with anorchia, 5 with male pseudohermaphroditism, and 5 with micropenis. Cryptorchid boys had decreased SHBG levels after hCG, by 55 +/- 17% (mean +/- SE) of the basal concentration. Patients with anorchia, who did not show an elevation in serum androgens, did not have decreased SHBG concentrations. Four of the 5 patients with male pseudohermaphroditism had an adequate elevation of serum androgens, did not have decreased SHBG concentrations. Four of the 5 patients with male pseudohermaphroditism had an adequate elevation of serum androgens after hCG, but in only 3 of them did SHBG decrease. None of the 5 patients with micropenis had decreased serum SHBG levels despite normal increments in serum androgens. The administration of a long-acting preparation of testosterone to sexually infantile subjects produce a similar decrease in the SHBG concentration. This change in SHBG concentration after hCG or testosterone in prepubertal boys could be used as a convenient test of biological response to androgens.

  5. Organization of the sex-ratio Meiotic Drive Region in Drosophila simulans

    PubMed Central

    Montchamp-Moreau, Catherine; Ogereau, David; Chaminade, Nicole; Colard, Alexandre; Aulard, Sylvie

    2006-01-01

    Sex-ratio meiotic drive is the preferential transmission of the X chromosome by XY males, which occurs in several Drosophila species and results in female-biased progeny. Although the trait has long been known to exist, its molecular basis remains completely unknown. Here we report a fine-mapping experiment designed to characterize the major drive locus on a sex-ratio X chromosome of Drosophila simulans originating from the Seychelles (XSR6). This primary locus was found to contain two interacting elements at least, both of which are required for drive expression. One of them was genetically tracked to a tandem duplication containing six annotated genes (Trf2, CG32712, CG12125, CG1440, CG12123, org-1), and the other to a candidate region located ∼110 kb away and spanning seven annotated genes. RT–PCR showed that all but two of these genes were expressed in the testis of both sex-ratio and standard males. In situ hybridization to polytene chromosomes revealed a complete association of the duplication with the sex-ratio trait in random samples of X chromosomes from Madagascar and Reunion. PMID:16387875

  6. Prediagnostic Sex Steroid Hormones in Relation to Male Breast Cancer Risk

    PubMed Central

    Brinton, Louise A.; Key, Tim J.; Kolonel, Laurence N.; Michels, Karin B.; Sesso, Howard D.; Ursin, Giske; Van Den Eeden, Stephen K.; Wood, Shannon N.; Falk, Roni T.; Parisi, Dominick; Guillemette, Chantal; Caron, Patrick; Turcotte, Véronique; Habel, Laurel A.; Isaacs, Claudine J.; Riboli, Elio; Weiderpass, Elisabete; Cook, Michael B.

    2015-01-01

    Purpose Although previous studies have implicated a variety of hormone-related risk factors in the etiology of male breast cancers, no previous studies have examined the effects of endogenous hormones. Patients and Methods Within the Male Breast Cancer Pooling Project, an international consortium comprising 21 case-control and cohort investigations, a subset of seven prospective cohort studies were able to contribute prediagnostic serum or plasma samples for hormone quantitation. Using a nested case-control design, multivariable unconditional logistic regression analyses estimated odds ratios and 95% CIs for associations between male breast cancer risk and 11 individual estrogens and androgens, as well as selected ratios of these analytes. Results Data from 101 cases and 217 matched controls were analyzed. After adjustment for age and date of blood draw, race, and body mass index, androgens were found to be largely unrelated to risk, but circulating estradiol levels showed a significant association. Men in the highest quartile had an odds ratio of 2.47 (95% CI, 1.10 to 5.58) compared with those in the lowest quartile (trend P = .06). Assessment of estradiol as a ratio to various individual androgens or sum of androgens showed no further enhancement of risk. These relations were not significantly modified by either age or body mass index, although estradiol was slightly more strongly related to breast cancers occurring among younger (age < 67 years) than older men. Conclusion Our results support the notion of an important role for estradiol in the etiology of male breast cancers, similar to female breast cancers. PMID:25964249

  7. Female sex pheromone and male behavioral responses of the bombycid moth Trilocha varians: comparison with those of the domesticated silkmoth Bombyx mori

    NASA Astrophysics Data System (ADS)

    Daimon, Takaaki; Fujii, Takeshi; Yago, Masaya; Hsu, Yu-Feng; Nakajima, Yumiko; Fujii, Tsuguru; Katsuma, Susumu; Ishikawa, Yukio; Shimada, Toru

    2012-03-01

    Analysis of female sex pheromone components and subsequent field trap experiments demonstrated that the bombycid moth Trilocha varians uses a mixture of ( E, Z)-10,12-hexadecadienal (bombykal) and ( E,Z)-10,12-hexadecadienyl acetate (bombykyl acetate) as a sex pheromone. Both of these components are derivatives of ( E,Z)-10,12-hexadecadienol (bombykol), the sex pheromone of the domesticated silkmoth Bombyx mori. This finding prompted us to compare the antennal and behavioral responses of T. varians and B. mori to bombykol, bombykal, and bombykyl acetate in detail. The antennae of T. varians males responded to bombykal and bombykyl acetate but not to bombykol, and males were attracted only when lures contained both bombykal and bombykyl acetate. In contrast, the antennae of B. mori males responded to all the three components. Behavioral analysis showed that B. mori males responded to neither bombykal nor bombykyl acetate. Meanwhile, the wing fluttering response of B. mori males to bombykol was strongly inhibited by bombykal and bombykyl acetate, thereby indicating that bombykal and bombykyl acetate act as behavioral antagonists for B. mori males. T. varians would serve as a reference species for B. mori in future investigations into the molecular mechanisms underlying the evolution of sex pheromone communication systems in bombycid moths.

  8. Sex and Self-Organization on Rugged Landscapes

    NASA Astrophysics Data System (ADS)

    Finjord, Jan

    The two-parent reproduction model of Derrida and Peliti is simulated on a rugged fitness landscape. Fixed fitness values for each possible genotype are assigned randomly, with all fit individuals having the same probability of reproduction. The previously observed transition to a self-organized state of the population with less recombinational load, implies an abrupt change of genetic overlap distributions, showing up characteristics of a phase transition. A crossover variant of the model has a smoother transition to the adapted regime, with a residual collective adaptation for small values of the threshold in fitness. When a geographical constraint (shortest possible distance) on pairwise reproduction in a population arranged one-dimensionally is imposed, a poised state results, suggestive of self-organized criticality.

  9. Dominance as a Function of Sex-Role Expectation or Personality Type in Female-Male Interactions.

    ERIC Educational Resources Information Center

    Alter, Robin C.

    This study investigates the power of the sex-role social norm in determining dominance: is dominance determined by personality "type" (from Myers-Briggs) or by the sex-role expectation? Thinking (T) and feeling (F) types were paired, including all possible combinations of sex and T-F. Thirty-two dyads, 16 opposite sex and 16 same sex, discussed a…

  10. Sex differences on use of associative and dissociative cognitive strategies among male and female athletes.

    PubMed

    Philippe, Roberta Antonini; Seiler, Roland

    2005-10-01

    This study assessed whether men and women differed in using associative and dissociative cognitive strategies during athletic performance. Athletes (31 men, M age = 23.2 yr., SD = 3.9 and 29 women, M age = 22.9 yr., SD = 4.3) who practiced endurance activities (running, swimming, and cycling) were considered high-level performers because they participated in national or international competition. The athletes were interviewed, and Schomer's 1986 method of measurement was used to evaluate and quantify two cognitive strategies. Most specifically, categories of association concerned the way the athlete paid close attention to bodily signals, and categories of dissociation described how the athlete shunned sensory inputs. Analysis of variance and the t test showed that women tend to be more dissociative than men and men more associative than women. The results suggest that pain perception in these sports may be a function of sex. PMID:16383077

  11. gsdf is a downstream gene of dmrt1 that functions in the male sex determination pathway of the Nile tilapia.

    PubMed

    Jiang, Dong-Neng; Yang, Hui-Hui; Li, Ming-Hui; Shi, Hong-Juan; Zhang, Xian-Bo; Wang, De-Shou

    2016-06-01

    Gonadal soma-derived factor (gsdf) is critical for testicular differentiation in teleosts, yet detailed analysis of Gsdf on testicular differentiation is lacking. In the present study, we knocked out tilapia gsdf using CRISPR/Cas9. F0 gsdf-deficient XY fish with high mutation rate (≥58%) developed as intersex, with ovotestes 90 days after hatching (dah), and become completely sex-reversed with ovaries at 180 and 240 dah. Those individuals with a low mutation rate (<58%) and XY gsdf(+/-) fish developed as males with normal testes. In F2 XY gsdf(-/-) fish, the gonads first expressed Dmrt1, which initiated the male pathway at 10 dah, then both male and female pathways were activated, as reflected by the simultaneous expression of Dmrt1 and Cyp19a1a in different cell populations at 18 dah, shifted to the female pathway expressing only Cyp19a1a at 36 dah, and finally developed into functional ovaries as adults. The male pathway and Dmrt1 expression was initiated, but failed to be maintained, in the absence of Gsdf. Aromatase-inhibitor treatment from 10 to 35 dah, however, rescued the phenotype, resulting in XY gsdf(-/-) with normal testes that expressed Dmrt1 and Cyp11b2. In vitro promoter analyses demonstrated that Dmrt1 activated gsdf expression in a dose-dependent manner in the presence of Sf1, even though Dmrt1 alone could not. Taken together, our results demonstrated that gsdf is a downstream gene of dmrt1. Gsdf probably inhibits estrogen production to trigger testicular differentiation. Mol. Reprod. Dev. 83: 497-508, 2016. © 2016 Wiley Periodicals, Inc.

  12. Sentencing Male Sex Offenders Under the Age of 14: A Law Reform Advocacy Journey in Hong Kong.

    PubMed

    Ng, Wai-Ching Irene; Cheung, Monit; Ma, Anny Kit-Ying

    2015-01-01

    The common law presumption that a boy under the age of 14 is incapable of sexual intercourse has provoked controversial debates in Hong Kong. This article describes a 6-step advocacy journey to examine how community efforts have helped modify this law so that juvenile male sexual offenders under the age of 14 who have committed the crime of having sexual intercourse with underage females can be sentenced to receive appropriate treatment. Seven court cases provided by the magistrates' courts in Hong Kong were used in this advocacy effort for the removal of the presumption in July 2012. Although this effort has yet to reveal signs of effectiveness, it represents greater public awareness about providing rehabilitation appropriate for juvenile sex offenders through a formal sentence. Restorative justice, as opposed to retributive or punitive justice, places an emphasis on rehabilitation of the offender and restoration of victims to a place of wholeness.

  13. Can Male Circumcision Have an Impact on the HIV Epidemic in Men Who Have Sex with Men?

    PubMed Central

    Goodreau, Steven M.; Carnegie, Nicole B.; Vittinghoff, Eric; Lama, Javier R.; Fuchs, Jonathan D.; Sanchez, Jorge; Buchbinder, Susan P.

    2014-01-01

    Background Three trials have demonstrated the prophylactic effect of male circumcision (MC) for HIV acquisition among heterosexuals, and MC interventions are underway throughout sub-Saharan Africa. Similar efforts for men who have sex with men (MSM) are stymied by the potential for circumcised MSM to acquire HIV easily through receptive sex and transmit easily through insertive sex. Existing work suggests that MC for MSM should reach its maximum potential in settings where sexual role segregation is historically high and relatively stable across the lifecourse; HIV incidence among MSM is high; reported willingness for prophylactic circumcision is high; and pre-existing circumcision rates are low. We aim to identify the likely public health impact that MC interventions among MSM would have in one setting that fulfills these conditions—Peru—as a theoretical upper bound for their effectiveness among MSM generally. Methods and Findings We use a dynamic, stochastic sexual network model based in exponential-family random graph modeling and parameterized from multiple behavioral surveys of Peruvian MSM. We consider three enrollment criteria (insertive during 100%, >80% or >60% of UAI) and two levels of uptake (25% and 50% of eligible men); we explore sexual role proportions from two studies and different frequencies of switching among role categories. Each scenario is simulated 10 times. We estimate that efficiency could reach one case averted per 6 circumcisions. However, the population-level impact of an optimistic MSM-MC intervention in this setting would likely be at most ∼5–10% incidence and prevalence reductions over 25 years. Conclusions Roll-out of MC for MSM in Peru would not result in a substantial reduction in new HIV infections, despite characteristics in this population that could maximize such effects. Additional studies are needed to confirm these results for other MSM populations, and providers may consider the individual health benefits of

  14. Serum sex hormone and growth arrest-specific protein 6 levels in male patients with coronary heart disease

    PubMed Central

    Zhao, Rui; Li, Yan; Dai, Wen

    2016-01-01

    Epidemiological studies have shown a high prevalence of low serum testosterone levels in men with cardiovascular disease. Moreover, the tyrosine kinase receptor Axl, the ligand of which is growth arrest-specific protein 6 (GAS6), is expressed in the vasculature, and serum GAS6 levels are associated with endothelial dysfunction and cardiovascular events. Testosterone regulates GAS6 gene transcription directly, which inhibits calcification of vascular smooth muscle cells and provides a mechanistic insight into the cardioprotective action of androgens. This study was designed to determine the correlation between serum GAS6 and testosterone levels in male patients with coronary heart disease (CHD). We recruited 225 patients with CHD and 102 apparently healthy controls. Serum concentrations of GAS6 and soluble Axl were quantified by an enzyme-linked immunosorbent assay. Levels of high-sensitivity C-reactive protein, testosterone, estradiol, and other routine biochemical markers were also measured. Testosterone decreased from 432.69 ± 14.40 to 300.76 ± 6.23 ng dl−1 (P < 0.001) and GAS6 decreased from 16.20 ± 0.31 to 12.51 ± 0.19 ng ml−1 (P < 0.001) in patients with CHD, compared with control subjects. Multiple linear regression analysis showed that serum testosterone and GAS6 levels were positively associated in male patients with CHD. Alterations in GAS6 levels may influence the development of CHD. Downregulation of GAS6/Axl signaling in the presence of low sex hormone levels during disease progression is a potential mechanism by which GAS6 affects CHD. This study provides novel results regarding the influence of sex hormones on serum GAS6 levels in patients with CHD. PMID:26924277

  15. Interventions among male clients of female sex workers in Benin, West Africa: an essential component of targeted HIV preventive interventions

    PubMed Central

    Lowndes, C M; Alary, M; Labbé, A‐C; Gnintoungbè, C; Belleau, M; Mukenge, L; Meda, H; Ndour, M; Anagonou, S; Gbaguidi, A

    2007-01-01

    Objectives To assess the impact of interventions targeted towards female sex workers (FSWs) and their male clients on client HIV/STI prevalence and sexual behaviour. Methods From 1993 to 2006, an HIV/STI preventive intervention focusing on condom promotion and STI care was implemented among FSWs in Cotonou, Benin, and then expanded to cover their male sexual partners in 2000. The interventions were scaled up to five other cities of Benin in 2001–2002. Serial cross‐sectional surveys of HIV/STI prevalence and sexual behaviour were carried out among clients in Cotonou in 1998, 2002 and 2005; and in the five other cities (O/Cotonou) in 2002 and 2005. Results Significant declines in gonorrhoea prevalence among clients of FSWs: Cotonou, from 5.4% in 1998 to 1.6% in 2005; O/Cotonou: from 3.5% in 2002 to 0.59% in 2005. Chlamydia prevalence also declined O/Cotonou, from 4.8% to 1.8%, while HIV prevalence remained stable. Reported condom use by clients with both FSWs and casual non‐FSW partners, but not regular partners, increased significantly. While condom use at last sex with an FSW was similar in Cotonou to O/Cotonou around the time of implementation of the interventions (56% in 1998 vs 49% in 2002, respectively), it had risen to similar levels by 2005 (95% and 96%, respectively). Conclusions These results demonstrate that it is possible to implement preventive and clinical services for clients of FSWs, and suggest that such interventions, integrated with those targeted towards FSWs, can have a significant effect on sexual behaviour and STI prevalence (particularly gonorrhoea) among this population. PMID:17942573

  16. Associations between Male Anogenital Human Papillomavirus Infection and Circumcision by Anatomic Site Sampled and Lifetime Number of Female Sex Partners

    PubMed Central

    Nielson, Carrie M.; Schiaffino, Melody K.; Dunne, Eileen F.; Salemi, Jason L.; Giuliano, Anna R.

    2016-01-01

    Background Male circumcision may lower men’s risk of human papillomavirus (HPV) infection and reduce transmission to sex partners. Reported associations between circumcision and HPV infection in men have been inconsistent. Methods Four hundred sixty-three men in 2 US cities were tested at 6 anogenital sites and in semen for 37 types of HPV. Men were eligible if they reported sex with a woman within the past year, no history of genital warts or penile or anal cancer, and no current diagnosis of a sexually transmitted infection. Participants completed a self-administered questionnaire. Circumcision status was assessed by the study clinician. Logistic regression was used to examine associations between circumcision and HPV detection at each site and in semen, with adjustment for potential confounders. Results Seventy-four men (16.0%) were uncircumcised. Adjusted odds ratios (AORs) for any HPV genotype and circumcision were 0.53 (95% confidence interval [CI], 0.28–0.99) for any anatomic site/specimen, 0.17 (95% CI, 0.05–0.56) for the urethra, 0.44 (95% CI, 0.23–0.82) for the glans/corona, and 0.53 (95% CI, 0.28–0.99) for the penile shaft. AORs were <1.0 but not statistically significant for the scrotum, semen, anal canal, and perianal area. Conclusions Circumcision may be protective against HPV infection of the urethra, glans/corona, and penile shaft. PMID:19086813

  17. Female Sex Workers, Male Circumcision and HIV: A Qualitative Study of Their Understanding, Experience, and HIV Risk in Zambia

    PubMed Central

    Abbott, Sharon A.; Haberland, Nicole A.; Mulenga, Drosin M.; Hewett, Paul C.

    2013-01-01

    Several sub-Saharan African countries, including Zambia, have initiated national voluntary medical male circumcision (MC) programs to reduce HIV incidence. In-depth interviews were conducted with twenty female sex workers (FSWs) in Lusaka to examine their understanding of MC and experiences with circumcised clients. Knowledge of MC was derived primarily through informal sources, with very few FSWs reporting exposure to MC educational campaigns. MC was not widely believed to be protective against HIV, however it was viewed by some as protective against STIs. Three FSWs reported having sex with recently circumcised clients, and most reported that men often used their MC status to try to convince FSWs to forego condoms. Findings suggest that FSWs, already at high risk for HIV infection, may face additional pressure toward higher risk behavior as a result of MC. As MC services are expanded, programs should support FSWs' efforts to protect themselves by providing information about what MC can - and cannot - offer for HIV/STI infection prevention. PMID:23349745

  18. Annual changes in serum sex steroids in male and female black (Ursus americanus) and polar (Ursus maritimus) bears.

    PubMed

    Palmer, S S; Nelson, R A; Ramsay, M A; Stirling, I; Bahr, J M

    1988-06-01

    The adaptation of black and polar bears to their environments is proportional to the severity of climate and food restriction. Both black and polar bears mate during the spring, despite differences in their recent metabolic state. Reproductive activity in black bears follows 4 mo of torpor, whereas reproduction in polar bears occurs prior to torpor. The goals of this study were to measure the annual changes in serum sex steroids in male and female black and polar bears, and to determine if changes in serum levels of these steroids were associated with metabolic condition or photoperiod. Serum testosterone (T) concentrations were elevated during spring in black and polar bears. Moreover, this increase in serum T in polar bears during spring was correlated with age and testis size. Serum progesterone (P4) concentrations increased in pregnant polar bears in fall coincident with the time of expected implantation. No increases in serum P4 were observed in nonpregnant black and polar bears. Serum estradiol (E2) was elevated in nonpregnant and pregnant polar bears 2 mo prior to the time of expected implantation. We found that serum sex steroids measured in black and polar bears change independent of torpor. Therefore, our results suggest that photoperiod may be a more important regulator of serum steroid levels and reproduction than metabolic condition. PMID:3408772

  19. Testicular disorder of sex development in four cats with a male karyotype (38,XY; SRY-positive).

    PubMed

    Nowacka-Woszuk, Joanna; Szczerbal, Izabela; Salamon, Sylwia; Kociucka, Beata; Jackowiak, Hanna; Prozorowska, Ewelina; Slaska, Brygida; Rozanska, Dorota; Orzelski, Maciej; Ochota, Malgorzata; Dzimira, Stanislaw; Lipiec, Magdalena; Nizanski, Wojciech; Switonski, Marek

    2014-12-10

    The molecular background of disorders of sex development (DSD) in cats is poorly recognized. In this study we present cytogenetic, molecular and histological analyses of four cats subjected for the analysis due to ambiguous external genitalia. Three cases, with rudimentary penises and an abnormal position of the urethral orifice, represented different types of hypospadias. The fourth case had a normal penis, a blind vulva and spermatogenetically active testes. Histological studies showed structures typical of testes, but spermatogenic activity was observed in two cats only. All the cats had a normal male chromosome complement (38,XY) and the Y-chromosome linked genes (SRY and ZFY) were also detected. Fluorescent in situ hybridization (FISH), with the use of the feline BAC probe harboring the SRY gene, excluded the possibility of chromosome translocation of the Y chromosome fragment carrying the SRY gene onto another chromosome. Sequencing of four candidate genes (SRY--sex determining region Y; AR--androgen receptor; SRD5A2--steroid-5-alfa reductase 2 and MAMLD1--mastermind-like domain containing (1) revealed one SNP in the SRY gene, one common polymorphism in exon 1 of the AR gene (tandem repeat of a tri-nucleotide motif--CAG), six polymorphisms (5 SNPs and 1 indel) in the SRD5A2 gene and one SNP in the MAMLD1 gene. Molecular studies of the candidate genes showed no association with the identified polymorphisms, thus molecular background of the studied DSD phenotypes remains unknown. PMID:25455261

  20. Annual changes in serum sex steroids in male and female black (Ursus americanus) and polar (Ursus maritimus) bears.

    PubMed

    Palmer, S S; Nelson, R A; Ramsay, M A; Stirling, I; Bahr, J M

    1988-06-01

    The adaptation of black and polar bears to their environments is proportional to the severity of climate and food restriction. Both black and polar bears mate during the spring, despite differences in their recent metabolic state. Reproductive activity in black bears follows 4 mo of torpor, whereas reproduction in polar bears occurs prior to torpor. The goals of this study were to measure the annual changes in serum sex steroids in male and female black and polar bears, and to determine if changes in serum levels of these steroids were associated with metabolic condition or photoperiod. Serum testosterone (T) concentrations were elevated during spring in black and polar bears. Moreover, this increase in serum T in polar bears during spring was correlated with age and testis size. Serum progesterone (P4) concentrations increased in pregnant polar bears in fall coincident with the time of expected implantation. No increases in serum P4 were observed in nonpregnant black and polar bears. Serum estradiol (E2) was elevated in nonpregnant and pregnant polar bears 2 mo prior to the time of expected implantation. We found that serum sex steroids measured in black and polar bears change independent of torpor. Therefore, our results suggest that photoperiod may be a more important regulator of serum steroid levels and reproduction than metabolic condition.

  1. Sex-specific estimates of dispersal show female philopatry and male dispersal in a promiscuous amphibian, the alpine salamander (Salamandra atra).

    PubMed

    Helfer, V; Broquet, T; Fumagalli, L

    2012-10-01

    Amphibians display wide variations in life-history traits and life cycles that should prove useful to explore the evolution of sex-biased dispersal, but quantitative data on sex-specific dispersal patterns are scarce. Here, we focused on Salamandra atra, an endemic alpine species showing peculiar life-history traits. Strictly terrestrial and viviparous, the species has a promiscuous mating system, and females reproduce only every 3 to 4 years. In the present study, we provide quantitative estimates of asymmetries in male vs. female dispersal using both field-based (mark-recapture) and genetic approaches (detection of sex-biased dispersal and estimates of migration rates based on the contrast in genetic structure across sexes and age classes). Our results revealed a high level of gene flow among populations, which stems exclusively from male dispersal. We hypothesize that philopatric females benefit from being familiar with their natal area for the acquisition and defence of an appropriate shelter, while male dispersal has been secondarily favoured by inbreeding avoidance. Together with other studies on amphibians, our results indicate that a species' mating system alone is a poor predictor of sex-linked differences in dispersal, in particular for promiscuous species. Further studies should focus more directly on the proximate forces that favour or limit dispersal to refine our understanding of the evolution of sex-biased dispersal in animals.

  2. Seeking Male Sexual Partners via Internet and Traditional Venues among Chinese Men Who Have Sex with Men: Implications for HIV Risk Reduction Interventions.

    PubMed

    Liu, Yu; Wang, Juan; Qian, Han-Zhu; Liu, Hongjie; Yin, Lu; Lu, Hongyan; Zhang, Chen; Ruan, Yuhua; Shao, Yiming; Vermund, Sten H

    2016-10-01

    The dynamic nature of finding male sexual partners (sex-finding) among Chinese men who have sex with men (MSM) may play a substantial role in the HIV epidemic. We compared characteristics and behaviors of MSM who mostly sought sex via the Internet versus traditional venues in a cross-sectional survey among 3588 Chinese MSM. We assessed the sociodemographic predictors and compared high-risk behaviors of using Internet versus traditional venues for sex-finding. Compared to non-Internet MSM, Internet-user MSM were more likely to have been: younger, currently single, better educated, health-insured, with higher income, with Beijing residency ('Hukou'), living longer in the city, HIV-positive, ever using drug and engaging in condomless receptive anal sex. Internet sex-finding users were less likely to be sexually active for longer duration, drink alcohol, drink alcohol before sex, or ever have sex with women. Knowledge of differential characteristics of various sex-finding MSM can help design targeted interventions.

  3. Prenatal exposure to a low-frequency electromagnetic field demasculinizes adult scent marking behavior and increases accessory sex organ weights in rats

    SciTech Connect

    McGivern, R.F.; Sokol, R.Z.; Adey, W.R.

    1990-01-01

    Pregnant Sprague-Dawley dams were exposed to a low-level, low-frequency pulsed electromagnetic (EM) field (15 Hz, 0.3 msec duration, peak intensity 8 gauss) for 15 min twice a day from day 15 through day 20 of gestation, a period in development that is critical for sexual differentiation of the male rat brain. No differences in litter size, number of stillborns, or body weight were observed in offspring from field-exposed dams. At 120 days of age, field-exposed male offspring exhibited significantly less scent marking behavior than controls. Accessory sex organ weights, including epididymis, seminal vesicles, and prostate, were significantly higher in field-exposed subjects at this age. However, circulating levels of testosterone, luteinizing hormone, and follicle-stimulating hormone, as well as epididymal sperm counts, were normal. These data indicate that brief, intermittent exposure to low-frequency EM fields during the critical prenatal period for neurobehavioral sex differentiation can demasculinize male scent marking behavior and increase accessory sex organ weights in adulthood.

  4. Sex recognition and neuronal coding of electric organ discharge waveform in the pulse-type weakly electric fish, Hypopomus occidentalis.

    PubMed

    Shumway, C A; Zelick, R D

    1988-08-01

    1. Hypopomus occidentalis, a weakly electric gymnotiform fish with a pulse-type discharge, has a sexually dimorphic electric organ discharge (Hagedorn 1983). The electric organ discharges (EODs) of males in the breeding season are longer in duration and have a lower peak-power frequency than the EODs of females. We tested reproductively mature fish in the field by presenting electronically generated stimuli in which the only cue for sex recognition was the waveshape of individual EOD-like pulses in a train. We found that gravid females could readily discriminate male-like from female-like EOD waveshapes, and we conclude that this feature of the electric signal is sufficient for sex recognition. 2. To understand the possible neural bases for discrimination of male and female EODs by H . occidentalis, we conducted a neurophysiological examination of both peripheral and central neurons. Our studies show that there are sets of neurons in this species which can discriminate male or female EODs by coding either temporal or spectral features of the EOD. 3. Temporal encoding of stimulus duration was observed in evoked field potential recordings from the magnocellular nucleus of the midbrain torus semicircularis. This nucleus indirectly receives pulse marker electroreceptor information. The field potentials suggest that comparison is possible between pulse marker activity on opposite sides of the body. 4. From standard frequency-threshold curves, spectral encoding of stimulus peak-power frequency was measured in burst duration coder electroreceptor afferents. In both male and female fish, the best frequencies of the narrow-band population of electroreceptors were lower than the peak-power frequency of the EOD. Based on this observation, and the presence of a population of wide-band receptors which can serve as a frequency-independent amplitude reference, a slope-detection model of frequency discrimination is advanced. 5. Spectral discrimination of EOD peak-power frequency

  5. "Come on Baby. You Know I Love You": African American Women's Experiences of Communication with Male Partners and Disclosure in the Context of Unwanted Sex.

    PubMed

    Gutzmer, Kyle; Ludwig-Barron, Natasha T; Wyatt, Gail E; Hamilton, Alison B; Stockman, Jamila K

    2016-05-01

    We examined African American women's experiences of communication with their male intimate partners a couple of hours before and after an incident of unwanted sex. We also examined women's experiences of disclosure following an incident of unwanted sex. Semi-structured qualitative interviews were conducted with a community-based sample of sexually active African American women (n = 19) reporting at least one incident of sexual coercion (i.e., being pressured into unwanted sex without consent) by an intimate male partner since the age of 18. Our analysis was guided by "the sexual division of power" from Connell's (1987) theory of gender and power. Data were analyzed inductively by examining the interviews for common themes in the following domains: communication before the unwanted sex, communication after the unwanted sex, and disclosure to others. Men pressured partners for unwanted sex through verbal and non-verbal tactics, ranging from pestering and blunt requests for sex to verbal bullying and violence. Many women responded by clearly saying no. However, many women also described eventually ceasing to resist their partners and engaging in unwanted sex. After the unwanted sex, men actively and passively avoided discussing the incident. Although many women discussed the unwanted sex with family and friends, less women disclosed to trained professionals. In some cases, women did not discuss the incident with anyone at all. These findings indicate that, when addressing sexual violence against women, there is a need to target men as well as the norms of masculinity that underpin physical and sexual violence against women. PMID:26892099

  6. "Come on Baby. You Know I Love You": African American Women's Experiences of Communication with Male Partners and Disclosure in the Context of Unwanted Sex.

    PubMed

    Gutzmer, Kyle; Ludwig-Barron, Natasha T; Wyatt, Gail E; Hamilton, Alison B; Stockman, Jamila K

    2016-05-01

    We examined African American women's experiences of communication with their male intimate partners a couple of hours before and after an incident of unwanted sex. We also examined women's experiences of disclosure following an incident of unwanted sex. Semi-structured qualitative interviews were conducted with a community-based sample of sexually active African American women (n = 19) reporting at least one incident of sexual coercion (i.e., being pressured into unwanted sex without consent) by an intimate male partner since the age of 18. Our analysis was guided by "the sexual division of power" from Connell's (1987) theory of gender and power. Data were analyzed inductively by examining the interviews for common themes in the following domains: communication before the unwanted sex, communication after the unwanted sex, and disclosure to others. Men pressured partners for unwanted sex through verbal and non-verbal tactics, ranging from pestering and blunt requests for sex to verbal bullying and violence. Many women responded by clearly saying no. However, many women also described eventually ceasing to resist their partners and engaging in unwanted sex. After the unwanted sex, men actively and passively avoided discussing the incident. Although many women discussed the unwanted sex with family and friends, less women disclosed to trained professionals. In some cases, women did not discuss the incident with anyone at all. These findings indicate that, when addressing sexual violence against women, there is a need to target men as well as the norms of masculinity that underpin physical and sexual violence against women.

  7. Experiments with digital organisms on the origin and maintenance of sex in changing environments.

    PubMed

    Misevic, Dusan; Ofria, Charles; Lenski, Richard E

    2010-01-01

    Many theories have been proposed to explain the evolution of sex, but the question remains unsettled owing to a paucity of compelling empirical tests. The crux of the problem is to understand the prevalence of sexual reproduction in the natural world, despite obvious costs relative to asexual reproduction. Here we perform experiments with digital organisms (evolving computer programs) to test the hypothesis that sexual reproduction is advantageous in changing environments. We varied the frequency and magnitude of environmental change, while the digital organisms could evolve their mode of reproduction as well as the traits affecting their fitness (reproductive rate) under the various conditions. Sex became the dominant mode of reproduction only when the environment changed rapidly and substantially (with particular functions changing from maladaptive to adaptive and vice versa). Even under these conditions, it was easier to maintain sexual reproduction than for sex to invade a formerly asexual population, although sometimes sex did invade and spread despite the obstacles to becoming established. Several diverse properties of the ancestral genomes, including epistasis and modularity, had no effect on the subsequent evolution of reproductive mode. Our study provides some limited support for the importance of changing environments to the evolution of sex, while also reinforcing the difficulty of evolving and maintaining sexual reproduction.

  8. Evidence of female sex pheromones and characterization of the cuticular lipids of unfed, adult male versus female blacklegged ticks, Ixodes scapularis.

    PubMed

    Carr, Ann L; Sonenshine, Daniel E; Strider, John B; Roe, R Michael

    2016-04-01

    Copulation in Ixodes scapularis involves physical contact between the male and female (on or off the host), male mounting of the female, insertion/maintenance of the male chelicerae in the female genital pore (initiates spermatophore production), and the transfer of the spermatophore by the male into the female genital pore. Bioassays determined that male mounting behavior/chelicerae insertion required direct contact with the female likely requiring non-volatile chemical cues with no evidence of a female volatile sex pheromone to attract males. Unfed virgin adult females and replete mated adult females elicited the highest rates of male chelicerae insertion with part fed virgin adult females exhibiting a much lower response. Whole body surface hexane extracts of unfed virgin adult females and males, separately analyzed by GC-MS, identified a number of novel tick surface associated compounds: fatty alcohols (1-hexadecanol and 1-heptanol), a fatty amide (erucylamid), aromatic hydrocarbons, a short chain alkene (1-heptene), and a carboxylic acid ester (5β-androstane). These compounds are discussed in terms of their potential role in female-male communication. The two most abundant fatty acid esters found were butyl palmitate and butyl stearate present in ratios that were sex specific. Only 6 n-saturated hydrocarbons were identified in I. scapularis ranging from 10 to 18 carbons. PMID:26864785

  9. The effects of mesterolone, a male sex hormone in depressed patients (a double blind controlled study).

    PubMed

    Itil, T M; Michael, S T; Shapiro, D M; Itil, K Z

    1984-06-01

    Based on computer EEG (CEEG) profiles, in high doses, antidepressant properties of mesterolone, a synthetic androgen, were predicted. In a double-blind placebo controlled study, the clinical effects of 300-450 mg daily mesterolone were investigated in 52 relatively young (age range 26-53 years, mean 42.7 years) male depressed outpatients. During 6 weeks of mesterolone treatment, there was a significant improvement of depressive symptomatology. However, since an improvement was also established during the placebo treatment, no statistically appreciable difference in the therapeutic effects of mesterolone was established compared to placebo. Mesterolone treatment significantly decreased both plasma testosterone and protein bound testosterone levels. Patients with high testosterone levels prior to treatment seem to have had more benefit from mesterolone treatment than patients with low testosterone levels. The degree of improvement weakly correlated to the decrease of testosterone levels during mesterolone treatment. PMID:6431212

  10. The effects of mesterolone, a male sex hormone in depressed patients (a double blind controlled study).

    PubMed

    Itil, T M; Michael, S T; Shapiro, D M; Itil, K Z

    1984-06-01

    Based on computer EEG (CEEG) profiles, in high doses, antidepressant properties of mesterolone, a synthetic androgen, were predicted. In a double-blind placebo controlled study, the clinical effects of 300-450 mg daily mesterolone were investigated in 52 relatively young (age range 26-53 years, mean 42.7 years) male depressed outpatients. During 6 weeks of mesterolone treatment, there was a significant improvement of depressive symptomatology. However, since an improvement was also established during the placebo treatment, no statistically appreciable difference in the therapeutic effects of mesterolone was established compared to placebo. Mesterolone treatment significantly decreased both plasma testosterone and protein bound testosterone levels. Patients with high testosterone levels prior to treatment seem to have had more benefit from mesterolone treatment than patients with low testosterone levels. The degree of improvement weakly correlated to the decrease of testosterone levels during mesterolone treatment.

  11. Sex Pheromones of C. elegans Males Prime the Female Reproductive System and Ameliorate the Effects of Heat Stress.

    PubMed

    Aprison, Erin Z; Ruvinsky, Ilya

    2015-12-01

    Pheromones are secreted molecules that mediate animal communications. These olfactory signals can have substantial effects on physiology and likely play important roles in organismal survival in natural habitats. Here we show that a blend of two ascaroside pheromones produced by C. elegans males primes the female reproductive system in part by improving sperm guidance toward oocytes. Worms have different physiological responses to different ratios of the same two molecules, revealing an efficient mechanism for increasing coding potential of a limited repertoire of molecular signals. The endogenous function of the male sex pheromones has an important side benefit. It substantially ameliorates the detrimental effects of prolonged heat stress on hermaphrodite reproduction because it increases the effectiveness with which surviving gametes are used following stress. Hermaphroditic species are expected to lose female-specific traits in the course of evolution. Our results suggest that some of these traits could have serendipitous utility due to their ability to counter the effects of stress. We propose that this is a general mechanism by which some mating-related functions could be retained in hermaphroditic species, despite their expected decay.

  12. Sex Pheromones of C. elegans Males Prime the Female Reproductive System and Ameliorate the Effects of Heat Stress

    PubMed Central

    Aprison, Erin Z.; Ruvinsky, Ilya

    2015-01-01

    Pheromones are secreted molecules that mediate animal communications. These olfactory signals can have substantial effects on physiology and likely play important roles in organismal survival in natural habitats. Here we show that a blend of two ascaroside pheromones produced by C. elegans males primes the female reproductive system in part by improving sperm guidance toward oocytes. Worms have different physiological responses to different ratios of the same two molecules, revealing an efficient mechanism for increasing coding potential of a limited repertoire of molecular signals. The endogenous function of the male sex pheromones has an important side benefit. It substantially ameliorates the detrimental effects of prolonged heat stress on hermaphrodite reproduction because it increases the effectiveness with which surviving gametes are used following stress. Hermaphroditic species are expected to lose female-specific traits in the course of evolution. Our results suggest that some of these traits could have serendipitous utility due to their ability to counter the effects of stress. We propose that this is a general mechanism by which some mating-related functions could be retained in hermaphroditic species, despite their expected decay. PMID:26645097

  13. Regret after sex reassignment surgery in a male-to-female transsexual: a long-term follow-up.

    PubMed

    Olsson, Stig-Eric; Möller, Anders

    2006-08-01

    This case report describes a four-decade presentation of a non-homosexual gender dysphoric male patient. The case material was collected from two main sources. One of the authors had weekly therapy sessions with the patient over a period of 2 years almost 15 years after sex reassignment surgery. Information was also gained from the patient's medical records covering the period from the early 1960s to the early 1990s. Over the years, the patient fulfilled the criteria for different diagnoses: overanxious reaction of childhood, fetishism and transvestism during adolescence, and transsexualism during adolescence and early adulthood. The purpose of this report was to shed light on aspects of regret, its manifestation in a male-to-female transsexual with psychiatric co-morbidity, and to show the complexity of the process of adjustment when regret is involved. The present case is an argument for a strict interpretation of the Standards of Care provided by the Harry Benjamin International Gender Dysphoria Association in terms of evaluating patients' mental health, apart from the evaluation of the gender identity disorder, and the patients' subsequent need for treatment interventions. PMID:16900416

  14. Turning the tables of sex distinction in craniofacial identification: Why females possess thicker facial soft tissues than males, not vice versa.

    PubMed

    Stephan, Carl N; Preisler, Rory; Bulut, Ozgur; Bennett, Mike

    2016-10-01

    Males are universally reported to possess larger facial soft-tissue thickness (FSTT) than females, however, this observation oversimplifies the raw data yielding an underpowered assessment of FSTT sex-patterning where: differences are small (η(2)  < 5%) and inconsistent (females are routinely larger than males at the cheeks). Here we investigate body-size normalized data to assess whether more general and improved understanding of FSTT sex-variation in humans is possible. FSTTs were measured in 52 healthy living Australians aged 18 to 30 years using B-mode ultrasound. Participants' stature and body mass were also measured. Sex differences were calculated before and after normalization by the aforementioned body-composition variables. Methods were repeated in three other independent samples to evaluate reproducibility: 100 American Whites and 60 American Blacks measured by B-mode ultrasound; and 50 Turkish residents measured by regular supine CT. Compared to raw mean differences (F < M, by -6%), females displayed much thicker FSTTs than males when normalized for body mass (F > M, by +16%). Consequently, while the sexes share similar raw values, females possess much larger FSTTs for their relatively lighter bodies. The relative FSTT difference was 2.7× larger than the raw mean difference. Sex differences in FSTT are of larger magnitude and reversed direction in mass normalized data. Contrary to popular thought, females possess much larger FSTTs than males owing to their generically lighter bodies (-18 kg). These data patterns help explain why the pooling of sex-categorized FSTT does not jeopardize the sex-difference-it is encoded more strongly in terms relative to body mass. PMID:27324815

  15. Prenatal letrozole produces a subpopulation of male rats with same-sex preference and arousal as well as female sexual behavior.

    PubMed

    Olvera-Hernández, Sandra; Chavira, Roberto; Fernández-Guasti, Alonso

    2015-02-01

    Disruption of the sexual differentiation process during critical periods in male rodents produces changes in partner preference and sexual behavior. In this study we used prenatal (gestation days 10-22) letrozole (0.31 and 0.56 μg/kg) to inhibit aromatase and alter normal sexual differentiation of males. These animals and control rats (injected with vehicle) were used when adults to study: a) sexual preference (where the experimental male could choose to interact with a receptive female or a sexually experienced male); b) masculine and feminine sexual behaviors (tested in cylindrical arenas); c) non-contact erections when exposed to a female or a male and, d) serum sex steroids and gonadotropin levels. The results showed that 30% of the males treated with letrozole (0.56 μg/kg) had same-sex preference, 33% displayed lordosis and 63% showed non-contact erections in the presence of a sexually experienced male. However, 44% of these males also exhibited complete masculine sexual behavior towards receptive females. None of the control males displayed lordosis when mounted by another male and very few (12%) showed non-contact erections when exposed to a sexually experienced male. Similar low percentages were found in those males prenatally treated with the low letrozole dose (0.31 μg/kg). No difference was found in the serum levels of testosterone, estradiol, LH and FSH between control and letrozole-treated males regardless of their sexual preference. These results indicate that prenatal selective inhibition of aromatization produces feminization of sexual partner preference, arousal and sexual behavior but does not affect masculine sexual behavior.

  16. The role of the sex-determining region Y gene in the etiology of 46,XX maleness

    SciTech Connect

    Fechner, P.Y.; Marcantonio, S.M.; Jaswaney, V.; Stetten, G.; Migeon, C.J.; Smith, K.D.; Berkovitz, G.D. ); Goodfellow, P.N. ); Amrhein, J.A. ); Bard, P.A. ); Lee, P.A. ); Reid, C. ); Tsalikian, E. ); Urban, M.D. )

    1993-03-01

    The condition of 46,XX maleness is characterized by testicular development in subjects who have two X chromosomes but who lack a normal Y chromosome. Several etiologies have been proposed to explain 46,XX maleness: (1) translocation of the testis-determining factor from the Y to the X chromosome, (2) mutation in an autosomal or X chromosome gene which permits testicular determination in the absence of TDF, and (3) undetected mosaicism with a Y-bearing cell line. The authors evaluated 10 affected subjects who were ascertained for different reasons and who had several distinct phenotypes. Six subjects had inherited sequences from the short arm of the Y chromosome including the sex-determining region Y gene (SRY). Five of the subjects were pubertal at the time of evaluation and had a phenotype similar to that of Klinefelter syndrome with evidence of Sertoli cell and Leydig cell dysfunction. One subject had evidence from Southern blot analysis and in situ hybridization for the presence of an intact Y chromosome in approximately 1% of cells. Three subjects lacked Y sequences by Southern blot analysis and by polymerase chain reaction amplification of SRY. These subjects were ascertained in the newborn period because of congenital anomalies. One had multiple anomalies including cardiac abnormalities; one had cardiac anomalies alone; and one had ambiguous genitalia. The data confirm the genetic heterogeneity of 46,XX maleness, in which some subjects have SRY while other subjects lack it. In addition, there is phenotypic heterogeneity among subjects who lack SRY suggesting that there is also genetic heterogeneity within this subgroup. 43 refs., 3 figs., 4 tabs.

  17. First Record of the Scarab Beetle, Phyllophaga lissopyge from South America, with Descriptions of Adult Seasonal Activity and Male Response to Sex Attractants

    PubMed Central

    Morales-Rodriguez, Anuar; Peck, Daniel C.; Robbins, Paul S.

    2011-01-01

    Phyllophaga lissopyge (Bates) (Coleoptera: Scarabaeidae: Melolonthinae) is reported for the first time from South America. Male sex pheromone response is described for P. lissopyge and two other co-occurring Phyllophaga species. Adults of P. lissopyge and P. menetriesi (Blanchard) flew to traps baited with methyl 2-(methylthio) benzoate whereas adults of P. obsoleta (Blanchard) flew irregularly to four different pheromone compounds. Adult seasonal activity is described from males captures in Rionegro, Antioquia, Colombia. PMID:21529153

  18. Male circumcision, alcohol use and unprotected sex among patrons of bars and taverns in rural areas of North-West province, South Africa.

    PubMed

    Nkosi, Sebenzile; Sikweyiya, Yandisa; Kekwaletswe, Connie T; Morojele, Neo K

    2015-01-01

    Strong research evidence has shown that medical male circumcision significantly reduces heterosexual HIV acquisition among men. However, its effectiveness is enhanced by behavioural factors such as condom use. Currently, little is known of unprotected sex associated with male circumcision (MC) among alcohol-drinking tavern-going men, or whether engagement in unprotected sex may differ between men who have been traditionally circumcised and those who have been medically circumcised. The study sought to determine the relative importance of alcohol consumption and MC as correlates of unprotected sex and to compare the risk of engaging in unprotected sex between traditionally circumcised and medically circumcised tavern-going men from two rural villages in North-West province, South Africa. Data from 314 adult men (≥18 years) were analysed. The men were recruited from four bars/taverns using systematic sampling. They responded to questions regarding their demographic characteristics, alcohol consumption, circumcision status and method (where applicable), and engagement in unprotected sex. Descriptive analyses and bivariate and multivariate logistic regression analyses were conducted. Age, education, relationship status, alcohol consumption and traditional male circumcision (TMC) were independently and significantly associated with unprotected sex. Specifically, probable alcohol dependence and traditional circumcision were independent risk factors for engaging in unprotected sex among tavern-going men. Traditionally circumcised men had a higher risk of engaging in unprotected sex than medically circumcised men. Interventions aimed at reducing alcohol consumption, encouraging protective behaviour among men who have undergone TMC, and increasing condom use are needed in bar/tavern settings. HIV prevention education must be urgently incorporated into TMC programmes.

  19. Male-dependent doubly uniparental inheritance of mitochondrial DNA and female-dependent sex-ratio in the mussel Mytilus galloprovincialis.

    PubMed

    Saavedra, C; Reyero, M I; Zouros, E

    1997-04-01

    We have investigated sex ratio and mitochondrial DNA inheritance in pair-matings involving five female and five male individuals of the Mediterranean mussel Mytilus galloprovincialis. The percentage of male progeny varied widely among families and was found to be a characteristic of the female parent and independent of the male to which it was mated. Thus sex-ratio in Mytilus appears to be independent of the nuclear genotype of the sperm. With a few exceptions, doubly uniparental inheritance (DUI) of mtDNA was observed in all families fathered by four of the five males: female and male progeny contained the mother's mtDNA (the F genome), but males contained also the father's paternal mtDNA (the M genome). Two hermaphrodite individuals found among the progeny of these crosses contained the F mitochondrial genome in the female gonad and both the F and M genomes in the male gonad. All four families fathered by the fifth male showed the standard maternal inheritance (SMI) of animal mtDNA: both female and male progeny contained only the maternal mtDNA. These observations illustrate the intimate linkage between sex and mtDNA inheritance in species with DUI and suggest different major roles for each gender. We propose a model according to which development of a male gonad requires the presence in the early germ cells of an agent associated with sperm-derived mitochondria, these mitochondria are endowed with a paternally encoded replicative advantage through which they overcome their original minority in the fertilized egg and this advantage (and, therefore, the chance of an early entrance into the germ line) is countered by a maternally encoded egg factor.

  20. Male-Dependent Doubly Uniparental Inheritance of Mitochondrial DNA and Female-Dependent Sex-Ratio in the Mussel Mytilus Galloprovincialis

    PubMed Central

    Saavedra, C.; Reyero, M. I.; Zouros, E.

    1997-01-01

    We have investigated sex ratio and mitochondrial DNA inheritance in pair-matings involving five female and five male individuals of the Mediterranean mussel Mytilus galloprovincialis. The percentage of male progeny varied widely among families and was found to be a characteristic of the female parent and independent of the male to which it was mated. Thus sex-ratio in Mytilus appears to be independent of the nuclear genotype of the sperm. With a few exceptions, doubly uniparental inheritance (DUI) of mtDNA was observed in all families fathered by four of the five males: female and male progeny contained the mother's mtDNA (the F genome), but males contained also the father's paternal mtDNA (the M genome). Two hermaphrodite individuals found among the progeny of these crosses contained the F mitochondrial genome in the female gonad and both the F and M genomes in the male gonad. All four families fathered by the fifth male showed the standard maternal inheritance (SMI) of animal mtDNA: both female and male progeny contained only the maternal mtDNA. These observations illustrate the intimate linkage between sex and mtDNA inheritance in species with DUI and suggest different major roles for each gender. We propose a model according to which development of a male gonad requires the presence in the early germ cells of an agent associated with sperm-derived mitochondria, these mitochondria are endowed with a paternally encoded replicative advantage through which they overcome their original minority in the fertilized egg and this advantage (and, therefore, the chance of an early entrance into the germ line) is countered by a maternally encoded egg factor. PMID:9093859

  1. Organization of Needs in Male and Female Drug and Alcohol Users

    ERIC Educational Resources Information Center

    Huba, George J.; And Others

    1977-01-01

    The Personality Research Form (PRF) was administered to 1,095 college students. Students were divided into groups of nonusers of drugs and alcohol and users of a variety of drug combinations. Results suggest organization of motivational tendencies is the same for both sexes and for different types of substance users. (Author)

  2. Sex, contraception and childbearing among high-risk youth: do different factors influence males and females?

    PubMed

    Kowaleski-Jones, L; Mott, F L

    1998-01-01

    The correlates of high-risk adolescent sexual behaviors were investigated through use of data from the 1979-92 waves of the US National Longitudinal Survey of Youth and the linked 1994 young adult data file on their children. The sample was comprised of 959 youth, most of whom were 14-18 years old at the time of the 1994 survey, who were the oldest child of the original female respondents. The analysis of risk behaviors was restricted to the 483 youth known to be sexually active. Compared to their non-sexually-active counterparts, sexually active youth had lower family incomes, mothers with lower educational attainment, and mothers who themselves became sexually active at a young age (mean, 15.5 years). Sexual activity at an early age was further associated with substance abuse, a view of oneself as a risk taker, and a history of running away from home. Early age at first coitus, nonuse of contraception, and adolescent childbearing were significantly linked with depression, feeling like a failure, and little sense of control over one's life in female respondents. In contrast, sexually active teen males reported low levels of depression and felt in control of their lives. After parenthood, tentative evidence of maturity emerged for both genders. Young mothers reduced their alcohol consumption and spent less time with peers who drank; young fathers exhibited lower levels of willingness to take risks, higher depression, and greater involvement in socially productive activities. PMID:9711453

  3. Olfactory protocerebral pathways processing sex pheromone and plant odor information in the male moth Agrotis segetum.

    PubMed

    Lei, H; Anton, S; Hansson, B S

    2001-04-01

    We investigated protocerebral processing of behaviorally relevant signals in the turnip moth, Agrotis segetum. Single neurons were studied both physiologically and morphologically using intracellular recording techniques. In moth pheromone communication systems, the presence of the complete, female-produced pheromone blend is necessary for male attraction. We predicted that more protocerebral neurons, compared with AL, would display blend interactions. However, only a few protocerebral neurons responded differently to the blend than could be deduced from the response to single components. The majority of the pheromone-sensitive protocerebral neurons identified in this study responded to the major pheromone component. In coding time, most AL neurons can follow a 5-Hz odor stimulus, whereas most protocerebral neurons failed at higher frequencies than 1 Hz. The majority of neurons that responded to the odorants tested innervated one or both of the protocerebral lateral accessory lobes. If only one of these was innervated, then the innervation always displayed a varicose appearance, suggesting a presynaptic function. Thus, information seems to be transferred from other protocerebral areas to the lateral accessory lobes. Into these, descending neurons sent smooth, postsynaptic branches. A majority of the neurons innervating the superior medial protocerebrum were found to display single-component specificity. Few additional correlations between odor specificity and structural characteristics were apparent.

  4. The XX sex chromosome complement is required in male and female mice for enhancement of immunity induced by exposure to 3,4-dichloropropionanilide

    PubMed Central

    Holásková, Ida; Franko, Jennifer; Goodman, Robert L.; Arnold, Arthur P.; Schafer, Rosana

    2015-01-01

    Problem The chemical propanil enhances antibody responses to a heat killed-Streptococcus pneumoniae (HKSP) vaccine. The enhanced response is dependent on gonads in females, but independent of gonads in males. The sex differences in the immune response may be due to sexual differentiation of the immune system or sex chromosome complement. Method of Study To test the hypothesis that the immune system is sexually differentiated, newborn C57BL/6 pups were treated with testosterone propionate (TP) or placebo. The role of sex chromosome complement was investigated using the 4-core genotypes (FCG) model of XXF and XYF gonadal females (ovaries), and XXM and XYM gonadal males (testes). For some experiments mice were gonadectomized or sham gonadectomized. All mice were vaccinated with HKSP, treated with propanil, and the antibody response determined at day seven. Results. Neonatal TP did not alter the response to HKSP. In FCG mice propanil significantly enhanced the immune response in XXF females and XXM males, but not in XYF females or XYM males. Conclusion The immune system of females was not masculinized by neonatal TP treatment. Sex chromosome complement significantly contributes to the sexually dimorphic immune response after propanil exposure. PMID:25765220

  5. Trends in Infectious Diseases and the Male to Female Ratio: Possible Clues to Changes in Behavior among Men Who Have Sex with Men

    ERIC Educational Resources Information Center

    Beltrami, John F.; Shouse, R. Luke; Blake, Paul A.

    2005-01-01

    Men who have sex with men (MSM) are a priority population for HIV care and prevention programs. This report describes HIV and other sexually transmitted disease (STD) trends among MSM in metropolitan Atlanta by analyzing nine databases. We describe the use of the male-to-female (M:F) ratio, a surrogate marker for MSM in databases without…

  6. Sexual Initiation and Complex Recent Polydrug Use Patterns Among Male Sex Workers in Vietnam: A Preliminary Epidemiological Trajectory.

    PubMed

    Yu, Gary; Goldsamt, Lloyd A; Clatts, Michael C; Giang, Lê Minh

    2016-05-01

    Little is known about the age of onset of sexual and drug risk and their association with complex patterns of recent drug use among male sex workers (MSW) in a developing country, such as Vietnam. The aim of this study was to determine whether latent class analysis (LCA) would aid in the detection of current individual and polydrug use combinations to predict how different trajectories of sexual and drug initiation contribute to different patterns of current illicit drug use. Data were collected from a cross-sectional survey administered to young MSWs between 2010 and 2011 in Vietnam (N = 710). LCA clustered participants into recent drug use groups, incorporating both the specific types and overall count of different drugs used. Men reported drug use within a 1 month period from an 11-item drug use list. LCA identified three distinct drug use classes: (1) alcohol use, (2) alcohol and tobacco use, and (3) high polydrug use. The current drug use classes are associated with sex worker status, housing stability, income level, educational attainment, marital status, sexual identity, and sexual preferences. High levels of drug use are strongly associated with being a recent sex worker, not having recent stable housing, higher than median income, more than a high school education, less likely to be currently in school and more likely to have non-homosexual preferences and heterosexual partners. An event history analysis approach (time-event displays) examined the timing of the age of onset of drug and sexual risks. Early ages of drug and sexual initiation are seen for all three classes. High current drug users show earlier onset of these risks, which are significantly delayed for moderate and low current drug users. LCA incorporating an overall count of different drugs detected three distinct current drug use classes. The data illustrates that the complexity of drug factors that must be accounted for, both in advancing our epidemiological understanding of the complexity

  7. Sexual Initiation and Complex Recent Polydrug Use Patterns Among Male Sex Workers in Vietnam: A Preliminary Epidemiological Trajectory.

    PubMed

    Yu, Gary; Goldsamt, Lloyd A; Clatts, Michael C; Giang, Lê Minh

    2016-05-01

    Little is known about the age of onset of sexual and drug risk and their association with complex patterns of recent drug use among male sex workers (MSW) in a developing country, such as Vietnam. The aim of this study was to determine whether latent class analysis (LCA) would aid in the detection of current individual and polydrug use combinations to predict how different trajectories of sexual and drug initiation contribute to different patterns of current illicit drug use. Data were collected from a cross-sectional survey administered to young MSWs between 2010 and 2011 in Vietnam (N = 710). LCA clustered participants into recent drug use groups, incorporating both the specific types and overall count of different drugs used. Men reported drug use within a 1 month period from an 11-item drug use list. LCA identified three distinct drug use classes: (1) alcohol use, (2) alcohol and tobacco use, and (3) high polydrug use. The current drug use classes are associated with sex worker status, housing stability, income level, educational attainment, marital status, sexual identity, and sexual preferences. High levels of drug use are strongly associated with being a recent sex worker, not having recent stable housing, higher than median income, more than a high school education, less likely to be currently in school and more likely to have non-homosexual preferences and heterosexual partners. An event history analysis approach (time-event displays) examined the timing of the age of onset of drug and sexual risks. Early ages of drug and sexual initiation are seen for all three classes. High current drug users show earlier onset of these risks, which are significantly delayed for moderate and low current drug users. LCA incorporating an overall count of different drugs detected three distinct current drug use classes. The data illustrates that the complexity of drug factors that must be accounted for, both in advancing our epidemiological understanding of the complexity

  8. Examining the Sociocultural Context of HIV-related Risk Behaviors Among Kathoey (Male-to-female Transgender Women) Sex Workers in Bangkok, Thailand.

    PubMed

    Nemoto, Tooru; Cruz, Taylor; Iwamoto, Mariko; Trocki, Karen; Perngparn, Usaneya; Areesantichai, Chitlada; Suzuki, Sachiko; Roberts, Colin

    2016-01-01

    Kathoey (male-to-female transgender) sex workers (KSW) in Thailand are at high risk for sexually transmitted infections; however, few qualitative studies have been conducted to understand the sociocultural context of engaging in HIV risk behaviors. A total of 24 participants were purposively sampled in Bangkok based on KSW work venues and substance use. Results revealed the importance of participants' understanding of the self in relation to establishing economic independence through sex work, which could then be used to re-establish support from family, who often have not accepted a son's gender transition. Participants linked being kathoey to a belief in fate but did not view engagement in sex work in the same way. Different sex work venues exposed KSW to different risky situations. HIV prevention programs for kathoey must address the importance of economic security and its relation to social support and gender transition within a cultural- and work-environment-specific framework. PMID:26856798

  9. Examining the Sociocultural Context of HIV-related Risk Behaviors Among Kathoey (Male-to-female Transgender Women) Sex Workers in Bangkok, Thailand.

    PubMed

    Nemoto, Tooru; Cruz, Taylor; Iwamoto, Mariko; Trocki, Karen; Perngparn, Usaneya; Areesantichai, Chitlada; Suzuki, Sachiko; Roberts, Colin

    2016-01-01

    Kathoey (male-to-female transgender) sex workers (KSW) in Thailand are at high risk for sexually transmitted infections; however, few qualitative studies have been conducted to understand the sociocultural context of engaging in HIV risk behaviors. A total of 24 participants were purposively sampled in Bangkok based on KSW work venues and substance use. Results revealed the importance of participants' understanding of the self in relation to establishing economic independence through sex work, which could then be used to re-establish support from family, who often have not accepted a son's gender transition. Participants linked being kathoey to a belief in fate but did not view engagement in sex work in the same way. Different sex work venues exposed KSW to different risky situations. HIV prevention programs for kathoey must address the importance of economic security and its relation to social support and gender transition within a cultural- and work-environment-specific framework.

  10. Sexual shape dimorphism accelerated by male–male competition, but not prevented by sex-indiscriminate parental care in dung beetles (Scarabaeidae)

    PubMed Central

    Kishi, Shigeki; Takakura, Koh-Ichi; Nishida, Takayoshi

    2015-01-01

    Dimorphic sexual differences in shape and body size are called sexual dimorphism and sexual size dimorphism, respectively. The degrees of both dimorphisms are considered to increase with sexual selection, represented by male–male competition. However, the degrees of the two dimorphisms often differ within a species. In some dung beetles, typical sexual shape dimorphisms are seen in male horns and other exaggerated traits, although sexual size dimorphism looks rare. We hypothesized that the evolution of this sexual shape dimorphism without sexual size dimorphism is caused by male–male competition and their crucial and sex-indiscriminate provisioning behaviors, in which parents provide the equivalent size of brood ball with each of both sons and daughters indiscriminately. As a result of individual-based model simulations, we show that parents evolve to provide each of sons and daughters with the optimal amount of resource for a son when parents do not distinguish the sex of offspring and males compete for mates. This result explains why crucial and sex-indiscriminate parental provisioning does not prevent the evolution of sexual shape dimorphism. The model result was supported by empirical data of Scarabaeidae beetles. In some dung beetles, sexual size dimorphism is absent, compared with significant sexual size dimorphism in other horned beetles, although both groups exhibit similar degrees of sexual shape dimorphism in male horns and other exaggerated traits. PMID:26306164

  11. Sex determination in cattle based on simultaneous amplification of a new male-specific DNA sequence and an autosomal locus using the same primers.

    PubMed

    Weikard, R; Kühn, C; Brunner, R M; Roschlau, D; Pitra, C; Laurent, P; Schwerin, M

    2001-09-01

    A PCR-based method for sex determination of bovine DNA samples and embryo biopsies is presented. Using only one primer pair both the male-specific sequence FBNY (127 bp) and a sex-independent control PCR-fragment, the microsatellite marker FBN17 (136-140 bp) are generated in the same PCR reaction. Synteny mapping assigned the male-specific sequence to bovine chromosome Y (BTA Y), whereas FBN17 was mapped to bovine chromosome 2. Localisation of FBNY on BTA Y was confirmed by fluorescence in hybridisation of two BAC clones containing the male-specific sequence. There was no amplification of the male-specific target sequence FBNY in sheep, pig, goat, mice, man, and several wild species of the tribe Bovini. The bovine male-specific fragment was detected in dilutions containing as little as 10 pg genomic DNA and in blastomeres from embryo biopsies. The PCR assay presented here does require neither restriction endonuclease digestion of the PCR product nor additional nested PCR steps. Owing to the advantage of parallel amplification of the autosomal locus FBN17 no additional control fragment is necessary to detect PCR failure. The results of sex determination in embryo biopsies using FBNY were in agreement with the outcome from a reference assay used in commercial breeding programs. PMID:11550263

  12. Sex-Role Stereotyping and Male-Female Character Distribution in Popular, Prestigious, and Sex-Role Defining Children's Literature from 1959 to 1972.

    ERIC Educational Resources Information Center

    Fraad, Harriet

    This dissertation explored the extent and kind of sex-role stereotyping in popular, prestigious, and sex-role defining children's picture books printed between 1959 and 1972. The sample consisted of two categories of popular children's picture books, best-selling golden books and "New York Times" children's best-sellers, one category of Caldecott…

  13. Expression of sex-specific molecular markers in clones of bipartite allophenic nemertines produced by somatic embryogenesis from Lineus sanguineus male/female chimera fragments.

    PubMed

    Tarpin, M; Bierne, J

    1995-04-01

    SDS-PAGE electrophoresis showed major sex-specific proteins in sexually maturing and mature Lineus sanguineus. These "egg-specific" (145, 78 and 40 kDa) and "sperm-specific" (55,52 and 28 kDa) proteins are useful for studying sex differentiation in bilaterally allophenic worms produced by asexual reproduction of bipartite male/female chimeric worms. This study was carried out on 2 symmetrical clones of bilaterally allophenic worms, derived by somatic embryogenesis from fragments transected from chimeras obtained by exchange-grafting lateral body halves of male and female specimens, and from their asexually-derived progeny. The electrophoretic patterns of proteins extracted from sexually immature, maturing and mature allophenic animals from the 5th to the 19th year of cloning, showed the presence of all female-specific markers and the absence of male-specific markers. There was also complete biochemical feminization of the male halves. The synthesis of the only egg-specific molecules in initially male lateral body halves means that the long-term cloning results in the total repression of genes encoding sperm-specific proteins, since genetically male determinant-bearing cells can randomly re-express the testis characteristic as fertile but rudimentary male gonads.

  14. The effects of sex steroids on thyroid C cells and trabecular bone structure in the rat model of male osteoporosis

    PubMed Central

    Filipović, Branko; Šošić-Jurjević, Branka; Ajdžanović, Vladimir; Pantelić, Jasmina; Nestorović, Nataša; Milošević, Verica; Sekulić, Milka

    2013-01-01

    Androgen deficiency is one of the major factors leading to the development of osteoporosis in men. Since calcitonin (CT) is a potent antiresorptive agent, in the present study we investigated the effects of androgen deficiency and subsequent testosterone and estradiol treatment on CT-producing thyroid C cells, skeletal and hormonal changes in middle-aged orchidectomized (Orx) rats. Fifteen-month-old male Wistar rats were either Orx or sham-operated (SO). One group of Orx rats received 5 mg kg−1 b.w. testosterone propionate (TP) subcutaneously, while another group was injected with 0.06 mg kg−1 b.w. estradiol dipropionate (EDP) once a day for 3 weeks. A peroxidase–antiperoxidase method was applied for localization of CT in the C cells. The studies included ultrastructural microscopic observation of these cells. The metaphyseal region of the proximal tibia was measured histomorphometrically using an imagej public domain image processing program. TP or EDP treatment significantly increased C cell volume (Vc), volume densities (Vv) and serum CT concentration compared with the Orx animals. Administration of both TP and EDP significantly enhanced cancellous bone area (B.Ar), trabecular thickness (Tb.Th) and trabecular number (Tb.N) and reduced trabecular separation (Tb.Sp). Serum osteocalcin (OC) and urinary Ca concentrations were significantly lower after these treatments in comparison with Orx rats. These data suggest that testosterone and estradiol treatment in Orx middle-aged rats affect calcitonin-producing thyroid C cells, which may contribute to the bone protective effects of sex hormones in the rat model of male osteoporosis. PMID:23171170

  15. First evidence of neurons in the male copulatory organ of a spider (Arachnida, Araneae)

    PubMed Central

    Lipke, Elisabeth; Hammel, Jörg U.; Michalik, Peter

    2015-01-01

    Spider males have evolved a remarkable way of transferring sperm by using a modified part of their pedipalps, the so-called palpal organ. The palpal organ is ontogenetically derived from tarsal claws; however, no nerves, sensory organs or muscles have been detected in the palpal bulb so far, suggesting that the spider male copulatory organ is numb and sensorily blind. Here, we document the presence of neurons and a nerve inside the male palpal organ of a spider for the first time. Several neurons that are located in the embolus are attached to the surrounding cuticle where stresses and strains lead to a deformation (stretching) of the palpal cuticle on a local scale, suggesting a putative proprioreceptive function. Consequently, the male copulatory organ of this species is not just a numb structure but likely able to directly perceive sensory input during sperm transfer. In addition, we identified two glands in the palpal organ, one of which is located in the embolus (embolus gland). The embolus gland appears to be directly innervated, which could allow for rapid modulation of secretory activity. Thus, we hypothesize that the transferred seminal fluid can be modulated to influence female processes. PMID:26156131

  16. A Tandem Duplicate of Anti-Müllerian Hormone with a Missense SNP on the Y Chromosome Is Essential for Male Sex Determination in Nile Tilapia, Oreochromis niloticus

    PubMed Central

    Li, Minghui; Sun, Yunlv; Zhao, Jiue; Shi, Hongjuan; Zeng, Sheng; Ye, Kai; Jiang, Dongneng; Zhou, Linyan; Sun, Lina; Tao, Wenjing; Nagahama, Yoshitaka; Kocher, Thomas D.; Wang, Deshou

    2015-01-01

    Variation in the TGF-β signaling pathway is emerging as an important mechanism by which gonadal sex determination is controlled in teleosts. Here we show that amhy, a Y-specific duplicate of the anti-Müllerian hormone (amh) gene, induces male sex determination in Nile tilapia. amhy is a tandem duplicate located immediately downstream of amhΔ-y on the Y chromosome. The coding sequence of amhy was identical to the X-linked amh (amh) except a missense SNP (C/T) which changes an amino acid (Ser/Leu92) in the N-terminal region. amhy lacks 5608 bp of promoter sequence that is found in the X-linked amh homolog. The amhΔ-y contains several insertions and deletions in the promoter region, and even a 5 bp insertion in exonVI that results in a premature stop codon and thus a truncated protein product lacking the TGF-β binding domain. Both amhy and amhΔ-y expression is restricted to XY gonads from 5 days after hatching (dah) onwards. CRISPR/Cas9 knockout of amhy in XY fish resulted in male to female sex reversal, while mutation of amhΔ-y alone could not. In contrast, overexpression of Amhy in XX fish, using a fosmid transgene that carries the amhy/amhΔ-y haplotype or a vector containing amhy ORF under the control of CMV promoter, resulted in female to male sex reversal, while overexpression of AmhΔ-y alone in XX fish could not. Knockout of the anti-Müllerian hormone receptor type II (amhrII) in XY fish also resulted in 100% complete male to female sex reversal. Taken together, these results strongly suggest that the duplicated amhy with a missense SNP is the candidate sex determining gene and amhy/amhrII signal is essential for male sex determination in Nile tilapia. These findings highlight the conserved roles of TGF-β signaling pathway in fish sex determination. PMID:26588702

  17. A Tandem Duplicate of Anti-Müllerian Hormone with a Missense SNP on the Y Chromosome Is Essential for Male Sex Determination in Nile Tilapia, Oreochromis niloticus.

    PubMed

    Li, Minghui; Sun, Yunlv; Zhao, Jiue; Shi, Hongjuan; Zeng, Sheng; Ye, Kai; Jiang, Dongneng; Zhou, Linyan; Sun, Lina; Tao, Wenjing; Nagahama, Yoshitaka; Kocher, Thomas D; Wang, Deshou

    2015-11-01

    Variation in the TGF-β signaling pathway is emerging as an important mechanism by which gonadal sex determination is controlled in teleosts. Here we show that amhy, a Y-specific duplicate of the anti-Müllerian hormone (amh) gene, induces male sex determination in Nile tilapia. amhy is a tandem duplicate located immediately downstream of amhΔ-y on the Y chromosome. The coding sequence of amhy was identical to the X-linked amh (amh) except a missense SNP (C/T) which changes an amino acid (Ser/Leu92) in the N-terminal region. amhy lacks 5608 bp of promoter sequence that is found in the X-linked amh homolog. The amhΔ-y contains several insertions and deletions in the promoter region, and even a 5 bp insertion in exonVI that results in a premature stop codon and thus a truncated protein product lacking the TGF-β binding domain. Both amhy and amhΔ-y expression is restricted to XY gonads from 5 days after hatching (dah) onwards. CRISPR/Cas9 knockout of amhy in XY fish resulted in male to female sex reversal, while mutation of amhΔ-y alone could not. In contrast, overexpression of Amhy in XX fish, using a fosmid transgene that carries the amhy/amhΔ-y haplotype or a vector containing amhy ORF under the control of CMV promoter, resulted in female to male sex reversal, while overexpression of AmhΔ-y alone in XX fish could not. Knockout of the anti-Müllerian hormone receptor type II (amhrII) in XY fish also resulted in 100% complete male to female sex reversal. Taken together, these results strongly suggest that the duplicated amhy with a missense SNP is the candidate sex determining gene and amhy/amhrII signal is essential for male sex determination in Nile tilapia. These findings highlight the conserved roles of TGF-β signaling pathway in fish sex determination. PMID:26588702

  18. Reactions to male and female success and failure in sex-linked occupations: impressions of personality, causal attributions, and perceived likelihood of different consequences.

    PubMed

    Feather, N T; Simon, J G

    1975-01-01

    Female subjects responded to three short verbal cues in which either a male or female character succeeded or failed in an examination qualifying the male (or female) for entry into an occupation. Three occupations were involved varying in masculine dominance (medicine, teaching, and nursing). In responding to each cue, subjects first rated the character in the cue on semantic differential scales to provide impressions of personality, then rated the importance of different possible causes of the outcome (causal attribution), and finally rated the likelihood that each of a set of possible consequences might follow the outcome. Results indicated a fairly pervasive tendency for the female subjects to upgrade successful males in relation to unsuccessful males but to downgrade successful females in relation to unsuccessful females. Results were discussed in relation to sex roles in society as they relate to permissible achievements for males and females.

  19. HIV, Hepatitis C, and Other Sexually Transmitted Infections Among Male Sex Workers in Ho Chi Minh City, Vietnam.

    PubMed

    Colby, Donn J; Oldenburg, Catherine E; Nguyen, Thi; Closson, Elizabeth F; Biello, Katie B; Mayer, Kenneth H; Mimiaga, Matthew J

    2016-04-01

    There is little data on the burden of HIV and other infections that affect male sex workers (MSW) in Vietnam. We conducted behavioral and biological sexual health surveys with 300 MSW in Ho Chi Minh City. Generalized estimating equation models were built to assess factors associated with HIV, hepatitis C, and other sexually transmitted infections (STI). Of 300 MSW, 19 (6.3 %) were diagnosed seropositive for HIV, 11 (3.7 %) had hepatitis C, and 26 (8.7 %) had at least one prevalent STI. In a multivariable model, opiate use was significantly associated with HIV infection (aOR 6.46, 95 % CI 1.28-32.7) and hepatitis C (aOR = 19.6, 95 % CI 2.35-163.6). Alcohol dependency was associated with increased odds of hepatitis C (aOR = 4.79, 95 % CI 1.02-22.5) and decreased odds of other STI (aOR = 0.30, 95 % CI 0.10-0.97). These findings suggest that MSW in Vietnam would benefit from regular HIV and STI testing, as well as linkage to care and substance use rehabilitation services.

  20. Radiological evaluation by magnetic resonance of the 'new anatomy' of transsexual patients undergoing male to female sex reassignment surgery.

    PubMed

    Brunocilla, E; Soli, M; Franceschelli, A; Schiavina, R; Borghesi, M; Gentile, G; Pultrone, C V; Martorana, G; Orrei, M G; Colombo, F

    2012-09-01

    Magnetic resonance (MR) is the best way to assess the new anatomy of the pelvis after male to female (MtF) sex reassignment surgery. The aim of the study was to evaluate the radiological appearance of the small pelvis after MtF surgery and to compare it with the normal women's anatomy. Fifteen patients who underwent MtF surgery were subjected to pelvic MR at least 6 months after surgery. The anthropometric parameters of the small pelvis were measured and compared with those of ten healthy women (control group). Our personal technique (creation of the mons Veneris under the pubic skin) was performed in all patients. In patients who underwent MtF surgery, the mean neovaginal depth was slightly superior than in women (P=0.009). The length of the inferior pelvic aperture and of the inlet of pelvis was higher in the control group (P<0.005). The inclination between the axis of the neovagina and the inferior pelvis aperture, the thickness of the mons Veneris and the thickness of the rectovaginal septum were comparable between the two study groups. MR consents a detailed assessment of the new pelvic anatomy after MtF surgery. The anthropometric parameters measured in our patients were comparable with those of women.

  1. Personal or relational? Examining sexual health in the context of HIV serodiscordant same-sex male couples

    PubMed Central

    Gamarel, K.E.; Starks, T.J; Dilworth, S.E.; Neilands, T.B.; Taylor, J.M.; Johnson, M.O.

    2014-01-01

    Couples’ ability to adopt a “we” orientation has been associated with optimal health outcomes. This study examined how personal and relational motivations are uniquely associated with unprotected anal intercourse (UAI), protected anal intercourse (PAI), and the absence of sexual activity within HIV-serodiscordant same-sex male couples. HIV-positive men and their HIV-negative partners (n = 116 couples, 232 men) completed questionnaires and HIV-positive men had blood drawn for viral load. Results of a multinomial logistic regression illustrated that sexual satisfaction was positively associated with PAI among HIV-negative partners and negatively associated with PAI among HIV-positive partners. Endorsing a “we” orientation was positively associated with PAI among HIV-positive partners. Findings suggest that HIV-positive partners who espouse a “we” orientation may be willing to forgo their personal interests to protect their HIV-negative partners from HIV transmission. Couples-based interventions are warranted to help strengthen relationship dynamics to enhance the sexual health of serodiscordant couples. PMID:23636681

  2. Is Intimate Partner and Client Violence Associated with Condomless Anal Intercourse and HIV Among Male Sex Workers in Lima, Peru?

    PubMed

    George, Paul E; Bayer, Angela M; Garcia, Patricia J; Perez-Lu, Jose E; Burke, Jessica G; Coates, Thomas J; Gorbach, Pamina M

    2016-09-01

    Violence experience can increase HIV risk behaviors; however, literature is scarce on violence among male sex workers (MSWs) globally. In 2014, 210 Peruvian MSWs (median age 24.9) were interviewed about their experience of physical, emotional, and sexual violence and condom use with non-paying intimate partners and clients and were tested for HIV. Multivariable models examined relationships between violence in the past 6 months, condomless anal intercourse (CLAI) in the past 3 months and HIV infection. HIV infection (24 %), CLAI (43 %), being a violence victim (42 %) and perpetrator (39 %) were common. In separate multivariable models, being a violence victim [adjusted prevalence ratio aPR = 1.49 (95 % CI 1.09-2.03)] and perpetrator [aPR = 1.39 (1.03-1.87)] were associated with CLAI. Further, being a victim [aPR = 1.65 (1.04-2.62)] was associated with HIV infection. Violence, which was significantly associated with CLAI and HIV infection, is common among Peruvian MSWs, reinforcing the importance of violence awareness and prevention as HIV risk-reduction strategies. PMID:26880321

  3. Experimental reduction of intromittent organ length reduces male reproductive success in a bug.

    PubMed

    Dougherty, Liam R; Rahman, Imran A; Burdfield-Steel, Emily R; Greenway, E V Ginny; Shuker, David M

    2015-06-01

    It is now clear in many species that male and female genital evolution has been shaped by sexual selection. However, it has historically been difficult to confirm correlations between morphology and fitness, as genital traits are complex and manipulation tends to impair function significantly. In this study, we investigate the functional morphology of the elongate male intromittent organ (or processus) of the seed bug Lygaeus simulans, in two ways. We first use micro-computed tomography (micro-CT) and flash-freezing to reconstruct in high resolution the interaction between the male intromittent organ and the female internal reproductive anatomy during mating. We successfully trace the path of the male processus inside the female reproductive tract. We then confirm that male processus length influences sperm transfer by experimental ablation and show that males with shortened processi have significantly reduced post-copulatory reproductive success. Importantly, male insemination function is not affected by this manipulation per se. We thus present rare, direct experimental evidence that an internal genital trait functions to increase reproductive success and show that, with appropriate staining, micro-CT is an excellent tool for investigating the functional morphology of insect genitalia during copulation. PMID:25972470

  4. Sex Differences in the Choice of a Male or Female Career Line. An Analysis of Background Characteristics and Work Values.

    ERIC Educational Resources Information Center

    Lyson, Thomas A.

    1984-01-01

    Using data from the National Longitudinal Study of the High School Class of 1972, this article identifies similarities and differences in social background characteristics, academic ability, and work values among men and women in sex-typical and sex-atypical curricula. Results show that men and women in sex-atypical majors are more like their sex…

  5. The effects of scale on the costs of targeted HIV prevention interventions among female and male sex workers, men who have sex with men and transgenders in India

    PubMed Central

    Guinness, L; Kumaranayake, L; Reddy, Bhaskar; Govindraj, Y; Vickerman, P; Alary, M

    2010-01-01

    Background The India AIDS Initiative (Avahan) project is involved in rapid scale-up of HIV-prevention interventions in high-risk populations. This study examines the cost variation of 107 non-governmental organisations (NGOs) implementing targeted interventions, over the start up (defined as period from project inception until services to the key population commenced) and first 2 years of intervention. Methods The Avahan interventions for female and male sex workers and their clients, in 62 districts of four southern states were costed for the financial years 2004/2005 and 2005/2006 using standard costing techniques. Data sources include financial and economic costs from the lead implementing partners (LPs) and subcontracted local implementing NGOs retrospectively and prospectively collected from a provider perspective. Ingredients and step-down allocation processes were used. Outcomes were measured using routinely collected project data. The average costs were estimated and a regression analysis carried out to explore causes of cost variation. Costs were calculated in US$ 2006. Results The total number of registered people was 134 391 at the end of 2 years, and 124 669 had used STI services during that period. The median average cost of Avahan programme for this period was $76 per person registered with the project. Sixty-one per cent of the cost variation could be explained by scale (positive association), number of NGOs per district (negative), number of LPs in the state (negative) and project maturity (positive) (p<0.0001). Conclusions During rapid scale-up in the initial phase of the Avahan programme, a significant reduction in average costs was observed. As full scale-up had not yet been achieved, the average cost at scale is yet to be realised and the extent of the impact of scale on costs yet to be captured. Scale effects are important to quantify for planning resource requirements of large-scale interventions. The average cost after 2 years is

  6. Attraction of spathius agrili yang (Hymenoptera: eulophidae) to male-produced "aggregation-sex pheromone:" differences between the sexes and mating status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Male and female Spathius agrili Yang were tested for attraction to the synthetic male pheromone. Lures consisting of a 3-component pheromone blend were placed in the center of a white filter paper target used to activate upwind flight in the wind tunnel. When virgin males and females were tested for...

  7. Sex Workers, Fem Queens, and Cross-Dressers: Differential Marginalizations and HIV Vulnerabilities Among Three Ethnocultural Male-to-Female Transgender Communities in New York City

    PubMed Central

    Hwahng, Sel Julian; Nuttbrock, Larry

    2008-01-01

    This article describes 3 distinct ethnocultural male-to-female transgender communities in New York City: the low-income African American/Black1 and Latina(o) House Ball community; low-income, often undocumented immigrant Asian sex workers; and middle-class White cross-dressers. These communities are highly socially isolated from each other and are more connected to their ethnocultural contexts than to an abstract and shared transgender identity. Whereas previous research either has viewed male-to-female transgender people as one monolithic group or has separated them into abstract racial categories unconnected to their communities and lifestyles, this article positions them within specific social networks, cultures, neighborhoods, and lifestyles. With regard to HIV vulnerabilities, violence, and rape, House Ball community members seemed to engage in the riskiest form of survival sex work, whereas Asian sex workers seemed to engage in moderate-risk survival sex work. White cross-dressers seemed to engage in very low-risk recreational sex work.2 PMID:19079558

  8. The Earliest Case of Extreme Sexual Display with Exaggerated Male Organs by Two Middle Jurassic Mecopterans

    PubMed Central

    Wang, Qi; Shih, Chungkun; Ren, Dong

    2013-01-01

    Background Many extant male animals exhibit exaggerated body parts for display, defense or offence in sexual selection, such as male birds of paradise showing off colorful and elegant feathers and male moose and reindeers bearing large structured antlers. For insects, male rhinoceros and stag beetles have huge horn-like structure for fighting and competition and some male Leptopanorpa scorpionflies have very long abdominal terminal segments for sexual display and competition. Fossil records of insects having exaggerated body parts for sexual display are fairly rare. One example is two male holcorpids with elongate abdominal segments from sixth (A6) to eighth (A8) and enlarged male genitalia from Eocene, suggesting evolution of these characters occurred fairly late. Principal Findings We document two mecopterans with exaggerated male body parts from the late Middle Jurassic Jiulongshan Formation in northeastern China. Both have extremely extended abdominal segments from A6 to A8 and enlarged genitalia, which might have been used for sexual display and, to less extent, for fighting with other males in the competition for mates. Although Fortiholcorpa paradoxa gen. et sp. nov. and Miriholcorpa forcipata gen. et sp. nov. seem to have affinities with Holcorpidae, we deem both as Family Incertae sedis mainly due to significant differences in branching pattern of Media (M) veins and relative length of A8 for F. paradoxa, and indiscernible preservation of 5-branched M veins in hind wing for M. forcipata. Conclusions/Significance These two new taxa have extended the records of exaggerated male body parts of mecopterans for sexual display and/or selection from the Early Eocene to the late Middle Jurassic. The similar character present in some Leptopanorpa of Panorpidae suggests that the sexual display and/or sexual selection due to extremely elongated male abdominal and sexual organs outweigh the negative impact of bulky body and poor mobility in the evolutionary process

  9. Identification of a Male-Specific RNA Binding Protein That Regulates Sex-Specific Splicing of Bmdsx by Increasing RNA Binding Activity of BmPSI▿ §

    PubMed Central

    Suzuki, Masataka G.; Imanishi, Shigeo; Dohmae, Naoshi; Asanuma, Miwako; Matsumoto, Shogo

    2010-01-01

    Bmdsx is a sex-determining gene in the silkworm and is alternatively spliced in males and females. CE1 is a splicing silencer element responsible for the sex-specific splicing of Bmdsx. To identify sex-specific factors implicated in the sex-specific splicing of Bmdsx, we performed RNA affinity chromatography using CE1 RNA as a ligand. We have identified BmIMP, a Bombyx homolog of IGF-II mRNA binding protein (IMP), as a male-specific factor that specifically binds to CE1. The gene encoding BmIMP is localized on the Z chromosome and is male-specifically expressed in various tissues. Antisense inhibition of BmIMP expression increased female-specific splicing of Bmdsx pre-mRNA. Coimmunoprecipitation and glutathione S-transferase (GST) pulldown analyses demonstrated that BmIMP physically interacts with BmPSI, which has been identified as a factor implicated in the sex-specific splicing of Bmdsx, through the KH domains of BmIMP. The functional consequence of this interaction was examined using RNA mobility shift analysis. BmIMP increased BmPSI-CE1 RNA binding activity by decreasing the rate of BmPSI dissociation from CE1 RNA. Truncation analysis of BmIMP suggested that the KH domains are responsible for enhancing BmPSI-CE1 RNA binding activity. These results suggest that BmIMP may enhance the male-specific splicing of Bmdsx pre-mRNA by increasing RNA binding activity of BmPSI. PMID:20956562

  10. The chastity of amoebae: re-evaluating evidence for sex in amoeboid organisms

    PubMed Central

    Lahr, Daniel J. G.; Parfrey, Laura Wegener; Mitchell, Edward A. D.; Katz, Laura A.; Lara, Enrique

    2011-01-01

    Amoebae are generally assumed to be asexual. We argue that this view is a relict of early classification schemes that lumped all amoebae together inside the ‘lower’ protozoa, separated from the ‘higher’ plants, animals and fungi. This artificial classification allowed microbial eukaryotes, including amoebae, to be dismissed as primitive, and implied that the biological rules and theories developed for macro-organisms need not apply to microbes. Eukaryotic diversity is made up of 70+ lineages, most of which are microbial. Plants, animals and fungi are nested among these microbial lineages. Thus, theories on the prevalence and maintenance of sex developed for macro-organisms should in fact apply to microbial eukaryotes, though the theories may need to be refined and generalized (e.g. to account for the variation in sexual strategies and prevalence of facultative sex in natural populations of many microbial eukaryotes). We use a revised phylogenetic framework to assess evidence for sex in several amoeboid lineages that are traditionally considered asexual, and we interpret this evidence in light of theories on the evolution of sex developed for macro-organisms. We emphasize that the limited data available for many lineages coupled with natural variation in microbial life cycles overestimate the extent of asexuality. Mapping sexuality onto the eukaryotic tree of life demonstrates that the majority of amoeboid lineages are, contrary to popular belief, anciently sexual, and that most asexual groups have probably arisen recently and independently. Additionally, several unusual genomic traits are prevalent in amoeboid lineages, including cyclic polyploidy, which may serve as alternative mechanisms to minimize the deleterious effects of asexuality. PMID:21429931

  11. You’ve got male: Internet use, rural residence, and risky sex in men who have sex with men recruited in 12 U.S. cities

    PubMed Central

    Kakietek, Jakub; Sullivan, Patrick S.; Heffelfinger, James D.

    2013-01-01

    Objective To assess whether the relationship between using the Internet to meet sex partners and unprotected anal intercourse (UAI) differs for men who have sex with men (MSM) living in rural and urban areas. Methods Data on Internet use, residence and UAI were collected from MSM attending Gay Pride events in 12 U.S. cities. Results Rural MSM who used the Internet to meet sex partners were more likely to report any UAI (aOR: 1.89 (1.12-3.19)) and insertive UAI (aOR: 2.16 (1.13- 4.10)) with the last sex partner than those who did not use the Internet. For urban MSM, UAI was not more commonly reported by men who used the Internet to meet sex partners. Conclusions The association between using the Internet to meet sex partners and UAI depended on whether MSM resided in rural or urban areas. Rural MSM may have different patterns of risk behavior from urban MSM. The Internet may offer new prevention opportunities for rural MSM. PMID:21517661

  12. Effects of dibutyl phthalate as an environmental endocrine disruptor on gonadal sex differentiation of genetic males of the frog Rana rugosa.

    PubMed Central

    Ohtani, H; Miura, I; Ichikawa, Y

    2000-01-01

    To examine the effects of dibutyl phthalate (DBP) on gonadal sex differentiation, genetically male tadpoles of Rana rugosa were exposed to dilute solutions of DBP at concentrations of 0.1, 1, or 10 microM during days 19-23 after fertilization, which is the critical period of gonadal sex differentiation in R. rugosa. Tadpoles were necropsied on day 40. The genetically male tadpoles were produced from crossings between males (ZZ) of one local population, in which females are the heterogametic sex, and females (XX) of another local population, in which males are the heterogametic sex. As positive control groups, tadpoles were exposed to dilute solutions of 17beta-estradiol (E(2)) at concentrations of 0. 01, 0.1, or 1 microM during the same period. The internal structure of the gonads was histologically examined in a total of 30 control tadpoles, 86 E(2)-treated tadpoles, and 90 DBP-treated tadpoles. The gonads of the control tadpoles all showed the typical structure of testes. In contrast, 0.01, 0.1, and 1 microM E(2) treatments caused the undifferentiated gonads of 18, 63, and 100% of the tadpoles, respectively, to develop into gonads of complete or partial ovarian structure. After 0.1, 1, and 10 microM DBP treatment, 0, 7, and 17% of tadpoles, respectively, were similarly affected. These findings suggest that DBP was about 1,000-fold less potent than E(2). Nevertheless, DBP is an environmentally dangerous hormone that disrupts the pathways of testicular differentiation in genetically male animals. PMID:11133400

  13. Sex differences in the brain-an interplay of sex steroid hormones and sex chromosomes.

    PubMed

    Grgurevic, Neza; Majdic, Gregor

    2016-09-01

    Although considerable progress has been made in our understanding of brain function, many questions remain unanswered. The ultimate goal of studying the brain is to understand the connection between brain structure and function and behavioural outcomes. Since sex differences in brain morphology were first observed, subsequent studies suggest different functional organization of the male and female brains in humans. Sex and gender have been identified as being a significant factor in understanding human physiology, health and disease, and the biological differences between the sexes is not limited to the gonads and secondary sexual characteristics, but also affects the structure and, more crucially, the function of the brain and other organs. Significant variability in brain structures between individuals, in addition to between the sexes, is factor that complicates the study of sex differences in the brain. In this review, we explore the current understanding of sex differences in the brain, mostly focusing on preclinical animal studies. PMID:27433022

  14. Sex differences in the brain-an interplay of sex steroid hormones and sex chromosomes.

    PubMed

    Grgurevic, Neza; Majdic, Gregor

    2016-09-01

    Although considerable progress has been made in our understanding of brain function, many questions remain unanswered. The ultimate goal of studying the brain is to understand the connection between brain structure and function and behavioural outcomes. Since sex differences in brain morphology were first observed, subsequent studies suggest different functional organization of the male and female brains in humans. Sex and gender have been identified as being a significant factor in understanding human physiology, health and disease, and the biological differences between the sexes is not limited to the gonads and secondary sexual characteristics, but also affects the structure and, more crucially, the function of the brain and other organs. Significant variability in brain structures between individuals, in addition to between the sexes, is factor that complicates the study of sex differences in the brain. In this review, we explore the current understanding of sex differences in the brain, mostly focusing on preclinical animal studies.

  15. Human vocal organ: visible-human-male-based three-dimensional visualization

    NASA Astrophysics Data System (ADS)

    Kim, Jae-woo; Lee, Donghun; Han, Jong H.; Kim, Bohyung; Kim, Dongsung; Kang, Heung Sik

    2002-05-01

    The Visible Human Project planned and promoted by National Library of Medicine (NLM) provides cryosection images of the normal male and female human bodies. The anatomy of human vocal organ is difficult to understand and to imagine due to its complexity. The purpose of this study is to develop the three-dimensionally computerized atlas of the human vocal organ using Visible Human male dataset. A self-developed program with C language and a recent personal computer can show specific organs and structures separately or together, rotate them at three axes, cross-section them transparently at any angles, and zoom them in and out. As a result, our own PC-based program will be a more interactive, more detailed, and more realistic three-dimensional computerized atlas of a human vocal organ including larygopharynx.

  16. Misidentification by wild rabbits,Oryctolagus cuniculus, of group members carrying the odor of foreign inguinal gland secretion : III. Experiments with mixed sex groups and analysis of further data from all-male and all-female groups.

    PubMed

    Hesterman, E R; Malafant, K; Mykytowycz, R

    1984-03-01

    The experiments described in this paper are part of a series designed to clarify the behavioral function of the odor of the secretion from the inguinal glands of rabbits,Oryctolagus cuniculus. Results are presented of tests carried out on 48 mixed-sex groups consisting of 162 adult wild-type rabbits, 48 males and 114 females. The subordinate females of the groups were smeared with various odorous materials and the reactions of their pen-mates towards them recorded. Eight sources of natural rabbit odors and a commercial perfume were used in 198 tests. A high proportion (60%) of the subordinate females smeared with the inguinal gland secretions from unfamiliar males were attacked, mainly by the males, which were generally the most dominant individuals within the groups. The paper also presents statistical analyses of behavioral data collected during two earlier related experiments with single-sex groups involving 258 rabbits in 300 tests which have not previously been evaluated. The results throughout the whole study indicate clearly that the odor of the inguinal gland secretion of rabbits carries information which affects the acceptance of individuals by their companions in organized groups. Other sources of unfamiliar rabbit odor did not influence the attitude of groupmates toward the individuals smeared with them, or if they did, their effects were only marginal.