Understanding the New Context of the Male Sex Work Industry

Science.gov (United States)

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…

'In different situations, in different ways': male sex work in St. Petersburg, Russia.

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Niccolai, Linda M; King, Elizabeth J; Eritsyan, Ksenia U; 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 and with male sex workers themselves. Male sex work involves a variety of exchanges, including expensive vacations, negotiated monetary amounts or simply access to food. Methods of finding 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 alcohol was 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.

Profile of male Brazilian injecting drug users who have sex with men

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Ferreira Aline Dayrell

2006-01-01

Full Text Available This study aims to characterize the profile of male injecting drug users who have sex with other men (MSM IDUs recruited through a cross-sectional multi-city survey (AjUDE-Brasil II Project in six Brazilian cities, in 2000-2001. MSM IDUs were compared to other male IDUs using bivariate and multivariate procedures (logistic regression and answer tree analysis with the CHAID algorithm. Among the 709 male IDUs, 187 (26.4% reported ever having had sex with other men, while only 37 reported sex with other men in the previous six months. MSM IDUs were more likely to be unemployed (OR = 2.3, to have injected tranquilizers (OR = 3.6, and to be HIV-seropositive (OR = 2.1, compared to other male IDUs. Male same-sex relations in this subgroup appear to be associated with strategies to finance drug consuming habits, including sex for drugs with occasional female partners or obtaining injection paraphernalia from occasional sex partners. Further studies should focus on this especially vulnerable subgroup of IDUs, due to the bidirectional and complex interrelationships between their drug injecting habits and sexual risk behaviors.

Sex steroid hormones matter for learning and memory: estrogenic regulation of hippocampal function in male and female rodents

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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

Sex roles and mutual mate choice matter during mate sampling.

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Myhre, Lise Cats; de Jong, Karen; Forsgren, Elisabet; Amundsen, Trond

2012-06-01

The roles of females and males in mating competition and mate choice have lately proven more variable, between and within species, than previously thought. In nature, mating competition occurs during mate search and is expected to be regulated by the numbers of potential mates and same-sex competitors. Here, we present the first study to test how a temporal change in sex roles affects mating competition and mate choice during mate sampling. Our model system (the marine fish Gobiusculus flavescens) is uniquely suitable because of its change in sex roles, from conventional to reversed, over the breeding season. As predicted from sex role theory, courtship was typically initiated by males and terminated by females early in the breeding season. The opposite pattern was observed late in the season, at which time several females often simultaneously courted the same male. Mate-searching females visited more males early than late in the breeding season. Our study shows that mutual mate choice and mating competition can have profound effects on female and male behavior. Future work needs to consider the dynamic nature of mating competition and mate choice if we aim to fully understand sexual selection in the wild.

'Inconstant males' and the maintenance of labile sex expression in subdioecious plants

DEFF Research Database (Denmark)

Ehlers, Bodil; Bataillon, Thomas

2007-01-01

. Depending on the genetics of sex determination, we found pure dioecy, stable subdioecy (trioecy), and situations where inconstant males coexisted with either pure females or pure males. Under selfing and pollen limitation, certain conditions selected for inconstant males which will drive populations......Here, we evaluate the role of pollen limitation and selfing in the maintenance of labile sex expression in subdioecious plant species. We used a literature survey to explore which factors correlated with a significant occurrence of hermaphrodites in dioecious species. We developed models to explore...... the selective maintenance of labile sex expression. The models had similar ecological assumptions but differed in the genetic basis of sex lability. We found that a significant frequency of hermaphrodites was associated with animal pollination, and that hermaphrodites were ‘inconstant' males with perfect...

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

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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.

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

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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. Copyright © 2016 Elsevier B.V. All rights reserved.

Chinmo prevents transformer alternative splicing to maintain male sex identity.

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Grmai, Lydia; Hudry, Bruno; Miguel-Aliaga, Irene; Bach, Erika A

2018-02-01

Reproduction in sexually dimorphic animals relies on successful gamete production, executed by the germline and aided by somatic support cells. Somatic sex identity in Drosophila is instructed by sex-specific isoforms of the DMRT1 ortholog Doublesex (Dsx). Female-specific expression of Sex-lethal (Sxl) causes alternative splicing of transformer (tra) to the female isoform traF. In turn, TraF alternatively splices dsx to the female isoform dsxF. Loss of the transcriptional repressor Chinmo in male somatic stem cells (CySCs) of the testis causes them to "feminize", resembling female somatic stem cells in the ovary. This somatic sex transformation causes a collapse of germline differentiation and male infertility. We demonstrate this feminization occurs by transcriptional and post-transcriptional regulation of traF. We find that chinmo-deficient CySCs upregulate tra mRNA as well as transcripts encoding tra-splice factors Virilizer (Vir) and Female lethal (2)d (Fl(2)d). traF splicing in chinmo-deficient CySCs leads to the production of DsxF at the expense of the male isoform DsxM, and both TraF and DsxF are required for CySC sex transformation. Surprisingly, CySC feminization upon loss of chinmo does not require Sxl but does require Vir and Fl(2)d. Consistent with this, we show that both Vir and Fl(2)d are required for tra alternative splicing in the female somatic gonad. Our work reveals the need for transcriptional regulation of tra in adult male stem cells and highlights a previously unobserved Sxl-independent mechanism of traF production in vivo. In sum, transcriptional control of the sex determination hierarchy by Chinmo is critical for sex maintenance in sexually dimorphic tissues and is vital in the preservation of fertility.

Chinmo prevents transformer alternative splicing to maintain male sex identity.

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Lydia Grmai

2018-02-01

Full Text Available Reproduction in sexually dimorphic animals relies on successful gamete production, executed by the germline and aided by somatic support cells. Somatic sex identity in Drosophila is instructed by sex-specific isoforms of the DMRT1 ortholog Doublesex (Dsx. Female-specific expression of Sex-lethal (Sxl causes alternative splicing of transformer (tra to the female isoform traF. In turn, TraF alternatively splices dsx to the female isoform dsxF. Loss of the transcriptional repressor Chinmo in male somatic stem cells (CySCs of the testis causes them to "feminize", resembling female somatic stem cells in the ovary. This somatic sex transformation causes a collapse of germline differentiation and male infertility. We demonstrate this feminization occurs by transcriptional and post-transcriptional regulation of traF. We find that chinmo-deficient CySCs upregulate tra mRNA as well as transcripts encoding tra-splice factors Virilizer (Vir and Female lethal (2d (Fl(2d. traF splicing in chinmo-deficient CySCs leads to the production of DsxF at the expense of the male isoform DsxM, and both TraF and DsxF are required for CySC sex transformation. Surprisingly, CySC feminization upon loss of chinmo does not require Sxl but does require Vir and Fl(2d. Consistent with this, we show that both Vir and Fl(2d are required for tra alternative splicing in the female somatic gonad. Our work reveals the need for transcriptional regulation of tra in adult male stem cells and highlights a previously unobserved Sxl-independent mechanism of traF production in vivo. In sum, transcriptional control of the sex determination hierarchy by Chinmo is critical for sex maintenance in sexually dimorphic tissues and is vital in the preservation of fertility.

Sex differences in socioemotional functioning, attentional bias, and gray matter volume in maltreated children: A multilevel investigation.

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Kelly, Philip A; Viding, Essi; Puetz, Vanessa B; Palmer, Amy L; Mechelli, Andrea; Pingault, Jean-Baptiste; Samuel, Sophie; McCrory, Eamon J

2015-11-01

While maltreatment is known to impact social and emotional functioning, threat processing, and neural structure, the potentially dimorphic influence of sex on these outcomes remains relatively understudied. We investigated sex differences across these domains in a large community sample of children aged 10 to 14 years (n = 122) comprising 62 children with verified maltreatment experience and 60 well-matched nonmaltreated peers. The maltreated group relative to the nonmaltreated comparison group exhibited poorer social and emotional functioning (more peer problems and heightened emotional reactivity). Cognitively, they displayed a pattern of attentional avoidance of threat in a visual dot-probe task. Similar patterns were observed in males and females in these domains. Reduced gray matter volume was found to characterize the maltreated group in the medial orbitofrontal cortex, bilateral middle temporal lobes, and bilateral supramarginal gyrus; sex differences were observed only in the supramarginal gyrus. In addition, a disordinal interaction between maltreatment exposure and sex was found in the postcentral gyrus. Finally, attentional avoidance to threat mediated the relationship between maltreatment and emotional reactivity, and medial orbitofrontal cortex gray matter volume mediated the relationship between maltreatment and peer functioning. Similar mediation patterns were observed across sexes. This study highlights the utility of combining multiple levels of analysis when studying the "latent vulnerability" engendered by childhood maltreatment and yields tentative findings regarding a neural basis of sex differences in long-term outcomes for maltreated children.

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

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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.

Behavioral and psychosocial correlates of anal sex among male clients of female sex workers in Tijuana, Mexico.

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Semple, Shirley J; Strathdee, Steffanie A; Pitpitan, Eileen V; Chavarin, Claudia; Patterson, Thomas L

2015-05-01

Most studies of heterosexual sex risk practices have focused on condomless vaginal sex despite evidence that condomless anal sex has a significantly higher risk of HIV transmission. The present study focused on male clients' anal sex practices with female sex workers (FSWs) in Tijuana, Mexico, where an HIV epidemic is growing among high-risk groups. Logistic regression analyses were used to identify psychosocial and behavioral correlates of anal sex among male clients. Our sample of HIV-negative men (N = 400) was predominantly Latino (87.5 %), born in Mexico (78.8 %), never married (36.8 %) or in a regular or common-law marriage (31.5 %), and employed (62.8 %), with an average age and education of 37.8 and 9.2 years, respectively. Eighty-nine percent identified as heterosexual and 11 % as bisexual. By design, 50 % of the sample resided in Tijuana and the other 50 % in San Diego County. Nearly half (49 %) reported at least one incident of anal sex with a FSW in Tijuana in the past 4 months; of those participants, 85 % reported that one or more of their anal sex acts with FSWs had been without a condom. In a multivariate model, anal sex with a FSW in the past 4 months was associated with bisexual identification, methamphetamine use with FSWs, repeat visits to the same FSW, higher scores on perceived stigma about being a client of FSWs, and sexual compulsivity. Prevention programs are needed that address the behavioral and psychosocial correlates of heterosexual anal sex in order to reduce HIV/STI transmission risk among male clients, FSWs, and their sexual network members.

The association between male-biased sex ratio and indicators of stress in red-spotted newts.

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Aspbury, Andrea S; Grayson, Kristine L; Fantaye, Selamawit; Nichols, Ian; Myers-Burton, Miranda; Ortiz-Mangual, Xavier; Gabor, Caitlin R

2017-05-01

In populations with a male-biased operational sex ratio, coercive mating by males can have fitness consequences for females. One component of reduced fitness for females in populations with a male-biased OSR may be greater activation of the stress response, resulting in higher corticosterone release rates (CORT; a glucocorticoid stress hormone in amphibians). We test the hypothesis that a male-biased sex ratio affects female activity and release rates of CORT and testosterone (T) in male and female red-spotted newts (Notophthalmus viridescens). First, we evaluated if chemical cues from a male-biased sex ratio affect activity and CORT release rates in females. We predicted that females exposed to chemical cues of three males would be less active and have higher CORT release rates than those exposed to chemical cues of one male. Second, we measured CORT release rates of red-spotted newts in field enclosures with either a male-biased or a female-biased sex ratio. We predicted that females in the male-biased treatment would have higher CORT and T release rates than those in a female-biased treatment, owing to higher levels of male harassment. We also predicted that males would have higher CORT and T release rates in male-biased treatments due to higher levels of male-male competition. Females were not less active in response to chemical cues from more males over fewer males, but there was a positive relationship between female activity and CORT when they were exposed to the cues of three males. We also found that females, but not males, in the male-biased sex ratio treatment had higher CORT and T release rates than those in the female-biased treatment. Our results support the hypothesis that a male-biased sex ratio leads to a higher stress response, which may underlie the observed decrease in immune function and body condition in previous work exposing female red-spotted newts to a male-biased sex ratio. This study furthers our understanding of the mechanistic basis

Perceptions About Sex Related Myths And Misconceptions: Difference In Male And Female

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Anupam Raizada

1997-04-01

Full Text Available Research problem: Perceptions about sex-re- iated myths and misconceptions. Objectives: To identify the difference in percep­tions of mates and females over sex-reiated myths and misconceptions. Study Design - Community based cross sectional study. Setting - Self-administered questionnaire study was un­dertaken in an urban area of Jhansi. Participants - Married couples with reproductive age wife. Sample size - 417 couples of the area. Study Variables-Sex-related myths and misconceptions. Outcome Variables - Masturbation, Penis-size and sexual performance, STD transmission. Intercourse with virgin and cure of STDs, Initiation of sexual act, Bleeding on first night. Statistical analysis - By chi - square test. Results: Response rate 63.8%. Only 8.6% females and 33.7% males knew correctly about masturbation. Males also knew better about route of STD infection (73.5% and about the fact that intercouse with a virgin cannot cure STDs (47.4%. Females, however, outnumber males on the question of relation between man's penis size and his sexual performance (70%, initiation of sexual act (58.6% and bleeding in females on first night of marriage (70%. Conclusion: Males and females had significantly different perceptions on sex related myths and misconceptions. Recommendations: Sex education campaigns should be designed and implemented to eliminate these age old sex related myths and misconceptions.

Perceptions About Sex Related Myths And Misconceptions: Difference In Male And Female

Directory of Open Access Journals (Sweden)

Anupam Raizada

1997-04-01

Full Text Available Research problem: Perceptions about sex-re- iated myths and misconceptions.Objectives: To identify the difference in percep­tions of mates and females over sex-reiated myths and misconceptions.Study Design - Community based cross sectional study.Setting - Self-administered questionnaire study was un­dertaken in an urban area of Jhansi.Participants - Married couples with reproductive age wife.Sample size - 417 couples of the area.Study Variables-Sex-related myths and misconceptionsOutcome Variables - Masturbation, Penis-size and sexual performance, STD transmission. Intercourse with virgin and cure of STDs, Initiation of sexual act, Bleeding on first night.Statistical analysis - By chi - square test.Results: Response rate 63.8%. Only 8.6% females and 33.7% males knew correctly about masturbation. Males also knew better about route of STD infection (73.5% and about the fact that intercouse with a virgin cannot cure STDs (47.4%. Females, however, outnumber males on the question of relation between man's penis size and his sexual performance (70%, initiation of sexual act (58.6% and bleeding in females on first night of marriage (70%.Conclusion: Males and females had significantly different perceptions on sex related myths and misconceptions.Recommendations: Sex education campaigns should be designed and implemented to eliminate these age old sex related myths and misconceptions.

Motivational influences on the safer sex behavior of agency-based male sex workers.

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Smith, Michael D; Seal, David W

2008-10-01

Although indoor male sex workers (MSWs) have been found to engage in lower rates of HIV risk behavior with clients than street-based MSWs, few studies have examined the motivations behind such practices. We interviewed 30 MSWs working for the same escort agency regarding their safer sex practices with clients and their reasons for these. As in other research, MSWs reported little risk behavior with clients. Five motivational themes related to safer sex on the job emerged: health concerns, emotional intimacy, client attractiveness, relationships, and structural work factors. Results suggest that participants engaged in rational decision-making relative to sex with clients, facilitated by reduced economic incentive for riskier behavior and a supportive social context. MSWs desired a safe sexual work place, personal integrity, and minimal negative consequences to personal relationships. Collaborating with sex work employers to study their role in encouraging a safer workplace may be important to future research.

White matter sexual dimorphism of the adult human brain

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Bourisly Ali K.

2017-05-01

Full Text Available Sex-biased psychophysiology, behavior, brain function, and conditions are extensive, yet underlying structural brain mechanisms remain unclear. There is contradicting evidence regarding sexual dimorphism when it comes to brain structure, and there is still no consensus on whether or not there exists such a dimorphism for brain white matter. Therefore, we conducted a voxel-based morphometry (VBM analysis along with global volume analysis for white matter across sex. We analyzed 384 T1-weighted MRI brain images (192 male, 192 female to investigate any differences in white matter (WM between males and females. In the VBM analysis, we found males to have larger WM, compared to females, in occipital, temporal, insular, parietal, and frontal brain regions. In contrast, females showed only one WM region to be significantly larger than males: the right postcentral gyrus in the parietal lobe region. Although, on average, males showed larger global WM volume, we did not find any significant difference in global WM volume between males and females.

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

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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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Exploring the interpersonal relationships in street-based male sex work: results from an Australian qualitative study.

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Leary, David; Minichiello, Victor

2007-01-01

While the literature on male sex work has increased significantly over the past decade, few studies examine the influence of relational dynamics in the lives of those engaged in male sex work. This qualitative study, conducted with a sample of male street sex workers in Sydney, Australia, explores how relationships color their involvement with sex work. The findings reveal the complexity of their relationships and how their interactions with others shape their engagement in sex work. The data also offer insight into how exit pathways are influenced by money and relationships that occur within this particular male sex work setting. Implications for health policy and intervention are considered.

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

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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

A Population-Based Comparison of Female and Male Same-Sex Parent and Different-Sex Parent Households.

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Bos, Henny M W; Kuyper, Lisette; Gartrell, Nanette K

2018-03-01

This investigation compared Dutch same-sex parent and different-sex parent households on children's psychological well-being, parenting stress, and support in child rearing. It was also assessed whether associations among children's well-being, parenting stress, and support in child rearing were different in the two household types. Data were based on a nationally representative survey (N = 25,250). Matching was used to enhance similarity in background characteristics between both types of families. Parental and child characteristics were matched for 43 female same-sex parent, 52 male same-sex parent, and 95 different-sex parent households with offspring between 5 and 18 years old. No significant differences were found on children's well-being, problems in the parent-child relationship, being worried about the child, or the use of formal and informal support between mothers in same-sex and different-sex parent households or for fathers in same-sex and different-sex parent households. Regarding perceived confidence in child rearing, fathers in same-sex parent households and mothers in different-sex parent households felt less competent than their counterparts. Neither the associations between children's well-being and the predictors (parenting stress variables) nor those between support and the predictors (parenting stress and children's well-being) differed along household type. In this population-based study, the similarity in child outcomes regardless of household type confirms the results of prior investigations based on convenience samples. These findings are pertinent to family therapists, practitioners, court officials, and policymakers who seek information on parenting experiences and child outcomes in female and male same-sex parent families. © 2017 Family Process Institute.

Sex Differences in Judgments of Male and Female Role Stereotypes.

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Getz, Sandra K.; Herman, Jeanne B.

This study tests whether or not there are sex differences in judgments of the success of various male and female lifestyles, and if so, what differential standards are applied to males and females. The most interesting result of this study is that college men and women use the same standards to judge the success of male lifestyles but different…

Sex Differences in Human and Animal Toxicology.

Science.gov (United States)

Gochfeld, Michael

2017-01-01

Sex, the states of being female or male, potentially interacts with all xenobiotic exposures, both inadvertent and deliberate, and influences their toxicokinetics (TK), toxicodynamics, and outcomes. Sex differences occur in behavior, exposure, anatomy, physiology, biochemistry, and genetics, accounting for female-male differences in responses to environmental chemicals, diet, and pharmaceuticals, including adverse drug reactions (ADRs). Often viewed as an annoying confounder, researchers have studied only one sex, adjusted for sex, or ignored it. Occupational epidemiology, the basis for understanding many toxic effects in humans, usually excluded women. Likewise, Food and Drug Administration rules excluded women of childbearing age from drug studies for many years. Aside from sex-specific organs, sex differences and sex × age interactions occur for a wide range of disease states as well as hormone-influenced conditions and drug distribution. Women have more ADRs than men; the classic sex hormone paradigm (gonadectomy and replacement) reveals significant interaction of sex and TK including absorption, distribution, metabolisms, and elimination. Studies should be designed to detect sex differences, describe the mechanisms, and interpret these in a broad social, clinical, and evolutionary context with phenomena that do not differ. Sex matters, but how much of a difference is needed to matter remains challenging.

High burden of STI and HIV in male sex workers working as internet escorts for men in an observational study: a hidden key population compared with female sex workers and other men who have sex with men.

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Verhaegh-Haasnoot, Amanja; Dukers-Muijrers, Nicole H T M; Hoebe, Christian J P A

2015-07-29

Male sex work in the western countries has changed, including now a subculture of male sex workers who have paid sex with men arranged for via the internet. The men involved in this subculture do not easily identify themselves as sex workers nor as homosexual, and are therefore missed by regular health care and public health interventions. These male sex workers may form a hidden key population for sexually transmitted infections (STIs) and HIV, bridging towards other persons outside this context. This clinic-based observational study included consultations by male sex workers (n = 212), female sex workers (n = 801) and in men having sex with men who did not report being paid for sexual contacts (MSM, n = 2703) who received STI and HIV testing and counselling at our clinic during the study period. In this study we compare the consultations in male sex workers to those in in female sex workers and MSM. Demographic characteristics and sexual behaviour of the male sex workers, female sex workers and MSM were compared using chi-square tests and non-parametric tests. Using univariate and multivariate regression analyses, determinants for STI positivity in male sex workers were evaluated. Male sex workers tested positive for STI (including HIV) in 40 % of the consultations; female sex workers and MSM respectively in 9 and 14 % of the consultations. A new HIV infection was found in 8 % of the consultations of male sex workers. Male sex workers were a young population of migrant sex workers from Eastern Europe. They reported more often to also have sex contacts with women and other sex workers. Male sex workers are at a higher risk for one or more new STI than female sex workers and other MSM, even after correction for age, ethnicity, known HIV positivity and behavioural variables. Male sex workers form a hidden key population that impacts the transmission of STI and HIV within the MSM population and, possibly, to the heterosexual population. They require specific targeted

The male sex pheromone of the butterfly Bicyclus anynana: towards an evolutionary analysis.

Directory of Open Access Journals (Sweden)

Caroline M Nieberding

Full Text Available BACKGROUND: Female sex pheromones attracting mating partners over long distances are a major determinant of reproductive isolation and speciation in Lepidoptera. Males can also produce sex pheromones but their study, particularly in butterflies, has received little attention. A detailed comparison of sex pheromones in male butterflies with those of female moths would reveal patterns of conservation versus novelty in the associated behaviours, biosynthetic pathways, compounds, scent-releasing structures and receiving systems. Here we assess whether the African butterfly Bicyclus anynana, for which genetic, genomic, phylogenetic, ecological and ethological tools are available, represents a relevant model to contribute to such comparative studies. METHODOLOGY/PRINCIPAL FINDINGS: Using a multidisciplinary approach, we determined the chemical composition of the male sex pheromone (MSP in the African butterfly B. anynana, and demonstrated its behavioural activity. First, we identified three compounds forming the presumptive MSP, namely (Z-9-tetradecenol (Z9-14:OH, hexadecanal (16:Ald and 6,10,14-trimethylpentadecan-2-ol (6,10,14-trime-15-2-ol, and produced by the male secondary sexual structures, the androconia. Second, we described the male courtship sequence and found that males with artificially reduced amounts of MSP have a reduced mating success in semi-field conditions. Finally, we could restore the mating success of these males by perfuming them with the synthetic MSP. CONCLUSIONS/SIGNIFICANCE: This study provides one of the first integrative analyses of a MSP in butterflies. The toolkit it has developed will enable the investigation of the type of information about male quality that is conveyed by the MSP in intraspecific communication. Interestingly, the chemical structure of B. anynana MSP is similar to some sex pheromones of female moths making a direct comparison of pheromone biosynthesis between male butterflies and female moths relevant

Converging Evidence of Ubiquitous Male Bias in Human Sex Perception.

Directory of Open Access Journals (Sweden)

Justin Gaetano

Full Text Available 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.

Controversies of Sex Re-assignment in Genetic Males with Congenital Inadequacy of the Penis.

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Raveenthiran, Venkatachalam

2017-09-01

Sex assignment in 46XY genetic male children with congenital inadequacy of the penis (CIP) is controversial. Traditionally, children with penile length less than 2 cm at birth are considered unsuitable to be raised as males. They are typically re-assigned to female-sex and feminizing genitoplasty is usually done in infancy. However, the concept of cerebral androgen imprinting has caused paradigm shift in the philosophy of sex re-assignment. Masculinization of the brain, rather than length of the penis, is the modern criterion of sex re-assignment in CIP. This review summarizes the current understanding of the complex issue. In 46XY children with CIP, male-sex assignment appears appropriate in non-hormonal conditions such as idiopathic micropenis, aphallia and exstrophy. Female-sex re-assignment appears acceptable in complete androgen insensitivity (CAIS), while partial androgen insensitivity syndrome (PAIS) patients are highly dissatisfied with the assignment of either sex. Children with 5-alpha reductase deficiency are likely to have spontaneous penile lengthening at puberty. Hence, they are better raised as males. Although female assignment is common in pure gonadal dysgenesis, long-term results are not known to justify the decision.

Sex-role identification of normal adolescent males and females as related to school achievement.

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Hock, R A; Curry, J F

1983-12-01

The historical view of masculinity/femininity posited essentially bipolar opposites, with the presence of one set of characteristics precluding the other. More recent studies of sex-role stereotypes have defined sexual orientation within clusters of socially desirable attributes which males and females perceive as differentiating males from females. This view negates the contention that psychological sex roles are composed of bipolar opposites, and concludes that the constructs of masculinity and femininity are independent dimensions rather than a single bipolar dimension. Little is known about the sex-role functioning of adolescents, yet it is during adolescence that qualitative shifts occur in interpersonal relationships and concurrent changes occur in cognitive functioning, with adolescents shifting toward hypothetical thinking and abstract ideal notions. In view of these changes, much can be learned about adult functioning by studying the sex-role perceptions of adolescents related to familial and social variables. This study examines the sex-role perceptions that adolescents hold of fathers, mothers, ideal males, ideal females, and selves. Differences exist between male and female adolescents, and significant linkages exist between sex-role identification and academic achievement.

Sex matters: females in proestrus show greater diazepam anxiolysis and brain-derived neurotrophin factor- and parvalbumin-positive neurons than males.

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Ravenelle, Rebecca; Berman, Ariel K; La, Jeffrey; Mason, Briana; Asumadu, Evans; Yelleswarapu, Chandra; Donaldson, S Tiffany

2018-04-01

In humans and animal models, sex differences are reported for anxiety-like behavior and response to anxiogenic stimuli. In the current work, we studied anxiety-like behavior and response to the prototypical anti-anxiety drug, diazepam. We used 6th generation outbred lines of adult Long Evans rats with high and low anxiety-like behavior phenotypes to investigate the impact of proestrus on the baseline and diazepam-induced behavior. At three doses of diazepam (0, 0.1, and 1.0 mg/kg, i.p.), we measured anxiogenic responses on the elevated plus maze of adult male and female rats. We assessed parvalbumin and brain-derived neurotrophin protein levels in forebrain and limbic structures implicated in anxiety/stress using immunohistochemistry. At baseline, we saw significant differences between anxiety lines, with high anxiety lines displaying less time on the open arms of the elevated plus maze, and less open arm entries, regardless of sex. During proestrus, high anxiety females showed less anxiety-like behavior at 0.1 mg/kg, while low anxiety females displayed less anxiety-like behavior at 0.1 and 1.0 doses, relative to males. Brain-derived neurotrophin protein was elevated in females in the medial prefrontal cortex and central amygdala, while parvalbumin-immunoreactive cells were greater in males in the medial prefrontal cortex. Parvalbumin-positive cells in high anxiety females were higher in CA2 and dentate gyrus relative to males from the same line. In sum, when tested in proestrus, females showed greater anxiolytic effects of diazepam relative to males, and this correlated with increases in neurotrophin and parvalbumin neuron density in corticolimbic structures. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

A novel male-associated marker for sex identification in Ussuri catfish Pseudobagrus ussuriensis

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Zhu, Chuankun; Pan, Zhengjun; Wang, Hui; Chang, Guoliang; Ding, Huaiyu

2017-08-01

The Ussuri catfish Pseudobagrus ussuriensis is a promising aquaculture fish with sexual dimorphism that males grow 2-3 times faster than females. Therefore, all-male breeding could increase production of this fish, and sex-linked markers would be useful during the breeding process. In this study, a male-associated marker named PuGT54 was isolated in P. ussuriensis from a previously constructed microsatellite library. A total of 185 P. ussuriensis individuals containing 95 females and 90 males were used to test the usage of this maker. And results showed that sexes of all individuals were successfully identified, indicating the high reliability and accuracy of this marker for sex identification. Furthermore, the male-specific fragment amplified by this maker was cloned and sequenced, which was 118 base pairs in length. As homologous genes of this fragment was not found through BLASTn, detailed information of the male-specific fragment is unknown presently. Nevertheless, this marker would be helpful in conservation, breeding and ecological study of P. ussuriensis.

Brain activation associated to olfactory conditioned same-sex partner preference in male rats.

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Coria-Avila, Genaro A; Cibrian-Llanderal, Tamara; Díaz-Estrada, Victor X; García, Luis I; Toledo-Cárdenas, Rebeca; Pfaus, James G; Manzo, Jorge

2018-03-01

Sexual preferences can be strongly modified by Pavlovian learning. For instance, olfactory conditioned same-sex partner preference can occur when a sexually naïve male cohabits with an scented male during repeated periods under the effects of enhanced D2-type activity. Preference is observed days later via social and sexual behaviors. Herein we explored brain activity related to learned same-sex preference (Fos-Immunoreactivity, IR) following exposure to a conditioned odor paired with same-sex preference. During conditioning trials males received either saline or the D2-type receptor agonist quinpirole (QNP) and cohabitated during 24 h with a stimulus male that bore almond scent on the back as conditioned stimulus. This was repeated every 4 days, for a total of three trials. In a drug-free final test we assessed socio/sexual partner preference between the scented male and a receptive female. The results indicated that QNP-conditioned males developed a same-sex preference observed via contact, time spent, olfactory investigations, and non-contact erections. By contrast, saline-conditioned and intact (non-exposed to conditioning) males expressed an unconditioned preference for the female. Four days later the males were exposed to almond scent and their brains were processed for Fos-IR. Results indicated that the QNP-conditioned group expressed more Fos-IR in the nucleus accumbens (AcbSh), medial preoptic area (MPA), piriform cortex (Pir) and ventromedial nucleus of the hypothalamus (VMH) as compared to saline-conditioned. Intact males expressed the lowest Fos-IR in AcbSh and VMH, but the highest in MPA and Pir. We discuss the role of these areas in the learning process of same-sex partner preferences and olfactory discrimination. Copyright © 2018 Elsevier Inc. All rights reserved.

Sex Hormones And Biochemical Profiles Of Male Gossypol Users In ...

African Journals Online (AJOL)

The present study was designed to evaluate the effects of gossypol administration on sex hormones and biochemical parameters of male subjects. Twelve male subjects receiving 20mg daily gossypol at the family planning clinic of University College Hospital, Ibadan were studied. Blood samples collected from the subjects ...

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

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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)

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

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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.

Prevalence and Correlates of Non-Disclosure of HIV Serostatus to Sex partners among HIV-Infected Female Sex Workers and HIV-infected Male Clients of Female Sex Workers in India

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Raj, Anita; Mahapatra, Bidhubhusan; Cheng, Debbie M.; Coleman, Sharon; Bridden, Carly; Battala, Madhusudana; Silverman, Jay G.; Pardeshi, Manoj H.; Samet, Jeffrey H.

2013-01-01

This study examines non-disclosure of HIV serostatus to sex partners among HIV-infected adults involved with transactional sex in Mumbai, India. Surveys were conducted with HIV-infected female sex workers (n = 211) and infected male clients (n = 205) regarding HIV knowledge, awareness of sex partners’ HIV serostatus, alcohol use, transactional sex involvement post-HIV diagnosis and non-disclosure of HIV serostatus. Gender-stratified multiple logistic regression models were used for analysis. Non-disclosure of one’s serostatus to all sex partners was reported by almost three-fifths of females and two-fifths of males. Predictors of non-disclosure included lack of correct knowledge about HIV and no knowledge of sex partners’ HIV serostatus. Among females, recent alcohol consumption also predicted non-disclosure. Among males, 10 + paid sexual partners in the year following HIV diagnosis predicted non-disclosure. Secondary HIV prevention efforts in India require greater focus on HIV disclosure communication and integrated alcohol and sexual risk reduction. PMID:22810892

Heterosexual experience prevents the development of conditioned same-sex partner preference in male rats.

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Ramírez-Rodríguez, Rodrigo; Tecamachaltzi-Silvaran, Miriam B; Díaz-Estrada, Victor X; Chena-Becerra, Florencia; Herrera-Covarrubias, Deissy; Paredes-Ramos, Pedro; Manzo, Jorge; Garcia, Luis I; Coria-Avila, Genaro A

2017-03-01

Sexual partner preferences can be strengthened, weakened or even drastically modified via Pavlovian conditioning. For example, conditioned same-sex partner preference develops in sexually-naïve male rats that undergo same-sex cohabitation under the effects of quinpirole (QNP, D2 agonist). Here, we assessed the effect of prior heterosexual experience on the probability to develop a conditioned same-sex preference. Naïve or Sexually-experienced males received either Saline or QNP and cohabited during 24h with a male partner that bore almond scent on the back as conditioned stimulus. This was repeated every 4days for a total of three trials and resulted in four groups (Saline-naïve, Saline-experienced, QNP-naïve, QNP-experienced). 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 Saline-naïve, Saline-experienced and QNP-experienced displayed a clear preference for the female (opposite-sex). By contrast, only QNP-naïve males displayed a same-sex preference. Accordingly, QNP-experienced males were not affected by the conditioning process and continued to prefer females. We discuss the effects of copulation and D2 agonists on the facilitation and/or disruption of conditioned partner preferences. Copyright © 2017 Elsevier B.V. All rights reserved.

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

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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.

Reversed sex change by widowed males in polygynous and protogynous fishes: female removal experiments in the field

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Kuwamura, Tetsuo; Suzuki, Shohei; Kadota, Tatsuru

2011-12-01

Sex change, either protogyny (female to male) or protandry (male to female), is well known among fishes, but evidence of bidirectional sex change or reversed sex change in natural populations is still very limited. This is the first report on female removal experiments for polygnous and protogynous fish species to induce reversed sex change in the widowed males in the field. We removed all of the females and juveniles from the territories of dominant males in the cleaner wrasse Labroides dimidiatus (Labridae) and the rusty angelfish Centropyge ferrugata (Pomacanthidae) on the coral reefs of Okinawa. In both species, if new females or juveniles did not immigrate into the territories of the widowed males, some of them emigrated to form male-male pairs. When a male-male pair formed, the smaller, subordinate partner began to perform female sexual behaviours ( n = 4 in L. dimidiatus; n = 2 in C. ferrugata) and, finally, released eggs ( n = 1, respectively). Thus, the reversed sex change occurred in the widowed males according to the change of their social status. These results suggest that such female removal experiments will contribute to the discovery of reversed sex change in the field also in other polygnous and protogynous species.

Biological sex affects the neurobiology of autism

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Lombardo, Michael V.; Suckling, John; Ruigrok, Amber N. V.; Chakrabarti, Bhismadev; Ecker, Christine; Deoni, Sean C. L.; Craig, Michael C.; Murphy, Declan G. M.; Bullmore, Edward T.; Baron-Cohen, Simon

2013-01-01

In autism, heterogeneity is the rule rather than the exception. One obvious source of heterogeneity is biological sex. Since autism was first recognized, males with autism have disproportionately skewed research. Females with autism have thus been relatively overlooked, and have generally been assumed to have the same underlying neurobiology as males with autism. Growing evidence, however, suggests that this is an oversimplification that risks obscuring the biological base of autism. This study seeks to answer two questions about how autism is modulated by biological sex at the level of the brain: (i) is the neuroanatomy of autism different in males and females? and (ii) does the neuroanatomy of autism fit predictions from the ‘extreme male brain’ theory of autism, in males and/or in females? Neuroanatomical features derived from voxel-based morphometry were compared in a sample of equal-sized high-functioning male and female adults with and without autism (n = 120, n = 30/group). The first question was investigated using a 2 × 2 factorial design, and by spatial overlap analyses of the neuroanatomy of autism in males and females. The second question was tested through spatial overlap analyses of specific patterns predicted by the extreme male brain theory. We found that the neuroanatomy of autism differed between adult males and females, evidenced by minimal spatial overlap (not different from that occurred under random condition) in both grey and white matter, and substantially large white matter regions showing significant sex × diagnosis interactions in the 2 × 2 factorial design. These suggest that autism manifests differently by biological sex. Furthermore, atypical brain areas in females with autism substantially and non-randomly (P males with autism. How differences in neuroanatomy relate to the similarities in cognition between males and females with autism remains to be understood. Future research should stratify by biological sex to reduce

Sex differences in gender characteristics of Australian nurses and male engineers: a comparative cross-sectional survey.

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J Fisher, Murray

2011-08-01

There continue to be assumptions within the nursing literature that nursing is synonymous with a feminine sex role identity. A comparative cross-sectional survey consisting of the Bem Sex Role Inventory and the Australian sex role scale was used to determine sex difference in gender characteristics of Australian nurses and with male engineers. A statistically significant difference in femininity was found between all the samples (F((2,908)) = 20.24, p orientation (t = 27.67) and self display (t = 12.42). Whilst differences in expressive characteristics were found between male and female nurses, a similar difference was found between male nurses and male engineers, supporting the notion that male nurses perceive themselves as having feminine characteristics essentially required for nursing.

Sex and Gender: How Being Male or Female Can Affect Your Health

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... Special Issues Subscribe May 2016 Print this issue Sex and Gender How Being Male or Female Can ... a major impact on your health. While both sexes are similar in many ways, researchers have found ...

Sex-specific Gray Matter Volume Differences in Females with Developmental Dyslexia

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Evans, Tanya M.; Flowers, D. Lynn; Napoliello, Eileen M.; Eden, Guinevere F.

2013-01-01

Developmental dyslexia, characterized by unexpected reading difficulty, is associated with anomalous brain anatomy and function. Previous structural neuroimaging studies have converged in reports of less gray matter volume (GMV) in dyslexics within left hemisphere regions known to subserve language. Due to the higher prevalence of dyslexia in males, these studies are heavily weighted towards males, raising the question whether studies of dyslexia in females only and using the same techniques, would generate the same findings. In a replication study of men we obtained the same findings of less GMV in dyslexics in left middle/inferior temporal gyri and right postcentral/supramarginal gyri as reported in the literature. However, comparisons in women with and without dyslexia did not yield left hemisphere differences and instead we found less GMV in right precuneus and paracentral lobule/medial frontal gyrus. In boys, we found less GMV in left inferior parietal cortex (supramarginal/angular gyri), again consistent with previous work, while in girls differences were within right central sulcus, spanning adjacent gyri, and left primary visual cortex. Our investigation into anatomical variants in dyslexia replicates existing studies in males, but at the same time shows that dyslexia in females is not characterized by involvement of left hemisphere language regions but rather early sensory and motor cortices (i.e. motor and premotor cortex, primary visual cortex). Our findings suggest that models on the brain basis of dyslexia, primarily developed through the study of males, may not be appropriate for females and suggest a need for more sex-specific investigations into dyslexia. PMID:23625146

Change in sex pheromone expression by nutritional shift in male cockroaches

DEFF Research Database (Denmark)

Jensen, Kim; Shearman, Melanie; Rapkin, James

2017-01-01

affected by dietary nutrient composition with higher values on carbohydrate-biased diet, and males had significantly higher and lower levels of consumption, lipid reserves, and sex pheromones when shifted to a carbohydrate-biased and a protein-biased diet, respectively, compared with males maintained...

Torque teno virus infection in male commercial sex workers in Surakarta Indonesia

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Prasetyo, Afiono Agung; Luvi, Sabrina Damara; Hartono, Sari, Yulia

2017-02-01

The molecular epidemiology data of torque teno virus (TTV) in Indonesia is very rare. This study evaluated the prevalence of TTV in male commercial sex workers, as one of the high risk community for blood borne viruses pathogens in Surakarta, Indonesia. All blood samples collected from male commercial sex workers in Surakarta in 2009-2013 were tested by nested polymerase chain reaction (PCR). The amplified PCR products were molecularly cloned and subjected to sequence analysis. TTV DNA was detected in 80.9% (72/89) samples. Furthermore, the molecular characterization revealed that the most prevalent was genogroup 3, followed by genogroup 2 and l, respectively. TTV was detected in male commercial sex workers in Surakarta with high infection rate. Further investigation about TTV circulation in Indonesian population is needed in order to provide additional information about the genetic variability and TTV epidemiology in Indonesia, especially in the high risk communities.

Postzygotic incompatibilities between the pupfishes, Cyprinodon elegans and Cyprinodon variegatus: hybrid male sterility and sex ratio bias.

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Tech, C

2006-11-01

I examined the intrinsic postzygotic incompatibilities between two pupfishes, Cyprinodon elegans and Cyprinodon variegatus. Laboratory hybridization experiments revealed evidence of strong postzygotic isolation. Male hybrids have very low fertility, and the survival of backcrosses into C. elegans was substantially reduced. In addition, several crosses produced female-biased sex ratios. Crosses involving C. elegans females and C. variegatus males produced only females, and in backcrosses involving hybrid females and C. elegans males, males made up approximately 25% of the offspring. All other crosses produced approximately 50% males. These sex ratios could be explained by genetic incompatibilities that occur, at least in part, on sex chromosomes. Thus, these results provide strong albeit indirect evidence that pupfish have XY chromosomal sex determination. The results of this study provide insight on the evolution of reproductive isolating mechanisms, particularly the role of Haldane's rule and the 'faster-male' theory in taxa lacking well-differentiated sex chromosomes.

Exploring the population implications of male preference when the sex probabilities at birth can be altered

Directory of Open Access Journals (Sweden)

Frank T Denton

2014-10-01

Full Text Available Objective: The paper explores the population effects of male preference stopping rules and of alternative combinations of fertility rates and male-biased birth sex ratios. Methods: The 'laboratory' is a closed, stable population with five age groups and a dynamic process represented by a compact Leslie matrix. The new element is sex-selective abortion. We consider nine stopping rules, one with no male preference, two with male preference but no abortion, and six with male preference and the availability of abortion to achieve a desired number of male births. We calculate the probability distribution over the number of births and number of male births for each rule and work out the effects at the population level if the rule is adopted by all women bearing children. We then assess the impact of alternative combinations of fertility rates and male-biased sex ratios on the population. Results: In the absence of sex-selective abortion, stopping rules generally have no effect on the male/female birth proportions in the population, although they can alter the fertility rate, age distribution, and rate of growth. When sex-selective abortion is introduced the effect on male/female proportions may be considerable, and other effects may also be quite different. The contribution of this paper is the quantification of effects that might have been predictable in general but which require model-based calculations to see how large they can be. As the paper shows, they can in fact be very large: a population in which sex-selective abortion is widely practised can look quite different from what it would otherwise be.

Male sex pheromone components in Heliconius butterflies released by the androconia affect female choice

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Kathy Darragh

2017-11-01

Full Text Available Sex-specific pheromones are known to play an important role in butterfly courtship, and may influence both individual reproductive success and reproductive isolation between species. Extensive ecological, behavioural and genetic studies of Heliconius butterflies have made a substantial contribution to our understanding of speciation. Male pheromones, although long suspected to play an important role, have received relatively little attention in this genus. Here, we combine morphological, chemical and behavioural analyses of male pheromones in the Neotropical butterfly Heliconius melpomene. First, we identify putative androconia that are specialized brush-like scales that lie within the shiny grey region of the male hindwing. We then describe putative male sex pheromone compounds, which are largely confined to the androconial region of the hindwing of mature males, but are absent in immature males and females. Finally, behavioural choice experiments reveal that females of H. melpomene, H. erato and H. timareta strongly discriminate against conspecific males which have their androconial region experimentally blocked. As well as demonstrating the importance of chemical signalling for female mate choice in Heliconius butterflies, the results describe structures involved in release of the pheromone and a list of potential male sex pheromone compounds.

46, XX male: a case study of clinical, hormonal and molecular cytogenetic evaluation of sex development disorder

International Nuclear Information System (INIS)

Ali, S.; Shahid, S.M.; Azhar, A.

2012-01-01

Disorders of sex development (DSD) create medical and social dilemma. Maleness with XX genotype is a rare genetic condition affecting one in 24,000 new-born males. The XX male syndrome is a varied condition characterized by a spectrum of clinical presentation. ranging from normal male genitalia to ambiguous sex. Chromosomal anomalies are important cause of lack of development in secondary sexual characteristics, delayed puberty, miscarriage, infertility and other associated problems. An individual having ambiguous sex may have lifelong impact on social, psychological and sexual functions. The present case study describes the hormonal, clinical and molecular cytogenetics data of sex development disorders in a patient who was phenotypically male but cytogenetic analysis revealed 46.XX. (author)

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

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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.

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

Directory of Open Access Journals (Sweden)

Elizabeth J Rideout

2015-12-01

Full Text Available 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.

Sex determination in beetles: Production of all male progeny by Parental RNAi knockdown of transformer

Science.gov (United States)

Shukla, Jayendra Nath; Palli, Subba Reddy

2012-01-01

Sex in insects is determined by a cascade of regulators ultimately controlling sex-specific splicing of a transcription factor, Doublesex (Dsx). We recently identified homolog of dsx in the red flour beetle, Tribolium castaneum (Tcdsx). Here, we report on the identification and characterization of a regulator of Tcdsx splicing in T. castaneum. Two male-specific and one female-specific isoforms of T. castaneum transformer (Tctra) were identified. RNA interference-aided knockdown of Tctra in pupa or adults caused a change in sex from females to males by diverting the splicing of Tcdsx pre-mRNA to male-specific isoform. All the pupa and adults developed from Tctra dsRNA injected final instar larvae showed male-specific sexually dimorphic structures. Tctra parental RNAi caused an elimination of females from the progeny resulting in production of all male progeny. Transformer parental RNAi could be used to produce all male population for use in pest control though sterile male release methods. PMID:22924109

Prevalence of consensual male-male sex and sexual violence, and associations with HIV in South Africa: a population-based cross-sectional study.

Directory of Open Access Journals (Sweden)

Kristin L Dunkle

Full Text Available In sub-Saharan Africa the population prevalence of men who have sex with men (MSM is unknown, as is the population prevalence of male-on-male sexual violence, and whether male-on-male sexual violence may relate to HIV risk. This paper describes lifetime prevalence of consensual male-male sexual behavior and male-on-male sexual violence (victimization and perpetration in two South African provinces, socio-demographic factors associated with these experiences, and associations with HIV serostatus.In a cross-sectional study conducted in 2008, men aged 18-49 y from randomly selected households in the Eastern Cape and KwaZulu-Natal provinces provided anonymous survey data and dried blood spots for HIV serostatus assessment. Interviews were completed in 1,737 of 2,298 (75.6% of enumerated and eligible households. From these households, 1,705 men (97.1% provided data on lifetime history of same-sex experiences, and 1,220 (70.2% also provided dried blood spots for HIV testing. 5.4% (n = 92 of participants reported a lifetime history of any consensual sexual activity with another man; 9.6% (n = 164 reported any sexual victimization by a man, and 3.0% (n = 51 reported perpetrating sexual violence against another man. 85.0% (n = 79 of men with a history of consensual sex with men reported having a current female partner, and 27.7% (n = 26 reported having a current male partner. Of the latter, 80.6% (n = 21/26 also reported having a female partner. Men reporting a history of consensual male-male sexual behavior are more likely to have been a victim of male-on-male sexual violence (adjusted odds ratio [aOR] = 7.24; 95% CI 4.26-12.3, and to have perpetrated sexual violence against another man (aOR = 3.10; 95% CI 1.22-7.90. Men reporting consensual oral/anal sex with a man were more likely to be HIV+ than men with no such history (aOR = 3.11; 95% CI 1.24-7.80. Men who had raped a man were more likely to be HIV+ than non

Diabetes and male sex are key risk factor correlates of the extent of coronary artery calcification

DEFF Research Database (Denmark)

Nicoll, Rachel; Zhao, Ying; Wiklund, Urban

2017-01-01

for CAC scoring. RESULTS: Among all patients, male sex (OR = 4.85, pdyslipidemia and smoking also showing a relationship. Among patients with CAC, age, diabetes, hypertension...... and dyslipidemia were associated with an increasing CAC score in males and females, with diabetes being the strongest dichotomous risk factor (p... males and females. To a lesser extent, hypertension and dyslipidemia were also associated in the high CAC quantiles and the low CAC quantiles respectively. CONCLUSION: In addition to age and male sex in the total population, diabetes is the most important correlate of CAC extent in both sexes....

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

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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. Copyright © 2013 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

XX male sex reversal with genital abnormalities associated with a de novo SOX3 gene duplication.

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Moalem, Sharon; Babul-Hirji, Riyana; Stavropolous, Dmitri J; Wherrett, Diane; Bägli, Darius J; Thomas, Paul; Chitayat, David

2012-07-01

Differentiation of the bipotential gonad into testis is initiated by the Y chromosome-linked gene SRY (Sex-determining Region Y) through upregulation of its autosomal direct target gene SOX9 (Sry-related HMG box-containing gene 9). Sequence and chromosome homology studies have shown that SRY most probably evolved from SOX3, which in humans is located at Xq27.1. Mutations causing SOX3 loss-of-function do not affect the sex determination in mice or humans. However, transgenic mouse studies have shown that ectopic expression of Sox3 in the bipotential gonad results in upregulation of Sox9, resulting in testicular induction and XX male sex reversal. However, the mechanism by which these rearrangements cause sex reversal and the frequency with which they are associated with disorders of sex development remains unclear. Rearrangements of the SOX3 locus were identified recently in three cases of human XX male sex reversal. We report on a case of XX male sex reversal associated with a novel de novo duplication of the SOX3 gene. These data provide additional evidence that SOX3 gain-of-function in the XX bipotential gonad causes XX male sex reversal and further support the hypothesis that SOX3 is the evolutionary antecedent of SRY. Copyright © 2012 Wiley Periodicals, Inc.

Identification of SOX3 as an XX male sex reversal gene in mice and humans.

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Sutton, Edwina; Hughes, James; White, Stefan; Sekido, Ryohei; Tan, Jacqueline; Arboleda, Valerie; Rogers, Nicholas; Knower, Kevin; Rowley, Lynn; Eyre, Helen; Rizzoti, Karine; McAninch, Dale; Goncalves, Joao; Slee, Jennie; Turbitt, Erin; Bruno, Damien; Bengtsson, Henrik; Harley, Vincent; Vilain, Eric; Sinclair, Andrew; Lovell-Badge, Robin; Thomas, Paul

2011-01-01

Sex in mammals is genetically determined and is defined at the cellular level by sex chromosome complement (XY males and XX females). The Y chromosome-linked gene sex-determining region Y (SRY) is believed to be the master initiator of male sex determination in almost all eutherian and metatherian mammals, functioning to upregulate expression of its direct target gene Sry-related HMG box-containing gene 9 (SOX9). Data suggest that SRY evolved from SOX3, although there is no direct functional evidence to support this hypothesis. Indeed, loss-of-function mutations in SOX3 do not affect sex determination in mice or humans. To further investigate Sox3 function in vivo, we generated transgenic mice overexpressing Sox3. Here, we report that in one of these transgenic lines, Sox3 was ectopically expressed in the bipotential gonad and that this led to frequent complete XX male sex reversal. Further analysis indicated that Sox3 induced testis differentiation in this particular line of mice by upregulating expression of Sox9 via a similar mechanism to Sry. Importantly, we also identified genomic rearrangements within the SOX3 regulatory region in three patients with XX male sex reversal. Together, these data suggest that SOX3 and SRY are functionally interchangeable in sex determination and support the notion that SRY evolved from SOX3 via a regulatory mutation that led to its de novo expression in the early gonad.

Identification of SOX3 as an XX male sex reversal gene in mice and humans

Science.gov (United States)

Sutton, Edwina; Hughes, James; White, Stefan; Sekido, Ryohei; Tan, Jacqueline; Arboleda, Valerie; Rogers, Nicholas; Knower, Kevin; Rowley, Lynn; Eyre, Helen; Rizzoti, Karine; McAninch, Dale; Goncalves, Joao; Slee, Jennie; Turbitt, Erin; Bruno, Damien; Bengtsson, Henrik; Harley, Vincent; Vilain, Eric; Sinclair, Andrew; Lovell-Badge, Robin; Thomas, Paul

2010-01-01

Sex in mammals is genetically determined and is defined at the cellular level by sex chromosome complement (XY males and XX females). The Y chromosome–linked gene sex-determining region Y (SRY) is believed to be the master initiator of male sex determination in almost all eutherian and metatherian mammals, functioning to upregulate expression of its direct target gene Sry-related HMG box–containing gene 9 (SOX9). Data suggest that SRY evolved from SOX3, although there is no direct functional evidence to support this hypothesis. Indeed, loss-of-function mutations in SOX3 do not affect sex determination in mice or humans. To further investigate Sox3 function in vivo, we generated transgenic mice overexpressing Sox3. Here, we report that in one of these transgenic lines, Sox3 was ectopically expressed in the bipotential gonad and that this led to frequent complete XX male sex reversal. Further analysis indicated that Sox3 induced testis differentiation in this particular line of mice by upregulating expression of Sox9 via a similar mechanism to Sry. Importantly, we also identified genomic rearrangements within the SOX3 regulatory region in three patients with XX male sex reversal. Together, these data suggest that SOX3 and SRY are functionally interchangeable in sex determination and support the notion that SRY evolved from SOX3 via a regulatory mutation that led to its de novo expression in the early gonad. PMID:21183788

HIV prevention interventions for young male commercial sex workers.

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Ballester-Arnal, R; Gil-Llario, M D; Salmeron-Sánchez, P; Giménez-García, C

2014-03-01

The sex industry, where men sell sexual services to other men or women, has grown in recent years. These men who offer sexual services are particularly vulnerable to HIV infection due to such factors as: frequency of risky sexual practices, number of sex partners, drug-taking, prevalence of sexually-transmitted infections (STI) and their specific situation of social exclusion which may hinder access to health services. These multi-faceted realities faced by sex workers explain the burgeoning interest in new avenues of scientific research. There are too few preventive programs however aimed at this population group and the studies that evaluate their effectiveness are fewer still. In this article we survey more recent studies on the difficulties of implementing programs for HIV prevention in male sex workers (MSW), as well as the studies that have gauged the impact of preventive programs in this group.

Caenorhabditis elegans Male Copulation Circuitry Incorporates Sex-Shared Defecation Components To Promote Intromission and Sperm Transfer

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LeBoeuf, Brigitte; Garcia, L. Rene

2016-01-01

Sexual dimorphism can be achieved using a variety of mechanisms, including sex-specific circuits and sex-specific function of shared circuits, though how these work together to produce sexually dimorphic behaviors requires further investigation. Here, we explore how components of the sex-shared defecation circuitry are incorporated into the sex-specific male mating circuitry in Caenorhabditis elegans to produce successful copulation. Using behavioral studies, calcium imaging, and genetic manipulation, we show that aspects of the defecation system are coopted by the male copulatory circuitry to facilitate intromission and ejaculation. Similar to hermaphrodites, male defecation is initiated by an intestinal calcium wave, but circuit activity is coordinated differently during mating. In hermaphrodites, the tail neuron DVB promotes expulsion of gut contents through the release of the neurotransmitter GABA onto the anal depressor muscle. However, in the male, both neuron and muscle take on modified functions to promote successful copulation. Males require calcium-dependent activator protein for secretion (CAPS)/unc-31, a dense core vesicle exocytosis activator protein, in the DVB to regulate copulatory spicule insertion, while the anal depressor is remodeled to promote release of sperm into the hermaphrodite. This work shows how sex-shared circuitry is modified in multiple ways to contribute to sex-specific mating. PMID:28031243

Review: magnetic resonance imaging of male/female differences in human adolescent brain anatomy

Directory of Open Access Journals (Sweden)

Giedd Jay N

2012-08-01

Full Text Available Abstract Improvements in neuroimaging technologies, and greater access to their use, have generated a plethora of data regarding male/female differences in the developing brain. Examination of these differences may shed light on the pathophysiology of the many illnesses that differ between the sexes and ultimately lead to more effective interventions. In this review, we attempt to synthesize the anatomic magnetic resonance imaging (MRI literature of male/female brain differences with emphasis on studies encompassing adolescence – a time of divergence in physical and behavioral characteristics. Across all ages total brain size is consistently reported to be about 10% larger in males. Structures commonly reported to be different between sexes include the caudate nucleus, amygdala, hippocampus, and cerebellum – all noted to have a relatively high density of sex steroid receptors. The direction and magnitude of reported brain differences depends on the methodology of data acquisition and analysis, whether and how the subcomponents are adjusted for the total brain volume difference, and the age of the participants in the studies. Longitudinal studies indicate regional cortical gray matter volumes follow inverted U shaped developmental trajectories with peak size occurring one to three years earlier in females. Cortical gray matter differences are modulated by androgen receptor genotyope and by circulating levels of hormones. White matter volumes increase throughout childhood and adolescence in both sexes but more rapidly in adolescent males resulting in an expanding magnitude of sex differences from childhood to adulthood.

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

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

2010-05-01

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 Tijuana. 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). 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. FSWs' clients represent a sexually transmitted infections/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.

Epidemiology of male same-sex behaviour and associated sexual health indicators in low- and middle-income countries: 2003-2007 estimates.

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Cáceres, C F; Konda, K; Segura, E R; Lyerla, R

2008-08-01

To conduct a systematic review of published and unpublished data from research and public health information systems on the prevalence of male-to-male sex in the total male population; as well as among men who have sex with men (MSM), data on prevalence of heterosexual activity and heterosexual unions; prevalence of condom use with male and female partners; and prevalence of HIV infection and other sexually transmitted infections (STIs). Key indicators were defined (a) among men in the general population: prevalence of sex with a man ever and last year; (b) among MSM: prevalence of heterosexual experiences ever and last year; proportion of male-female transgenders; proportion of sex workers; prevalence of HIV and other STIs, condom use in last sexual encounter; consistent condom use with men last year; never used a condom with a man. With help from key informants, study searches were conducted in Pubmed, LILLACS, institutional databases, conference records and other sources. Methodology and quality of information were assessed, and the best data available for 2003-7 were selected. Indicator estimates from each study were used to propose regional estimate ranges. A total of 83 new entries were entered into the database in addition to the previous 561, totalling 644. Of these, 107 showing 2003-7 data were selected. Many new studies came from sub-Saharan Africa, portraying hidden HIV epidemics among MSM. The most frequently reported estimate was HIV infection, with high estimate ranges in most of the regions, except for Middle East and North Africa and Eastern Europe. The next most frequently reported was lifetime frequency of heterosexual sex, showing that roughly 50% of MSM ever had sex with a woman. The small number of newer studies reporting prevalence of "sex with a man in last 12 months" between 2003 and 2007, did not warrant enough new evidence to revise our 2005 size estimates for MSM populations. A considerable number of new studies with estimates of

Neurotoxic exposures and effects: gender and sex matter! Hänninen Lecture 2011.

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Mergler, Donna

2012-08-01

Although males and females differ both biologically and in their social and power relations throughout their life span, research in environmental and occupational neurotoxicology often ignore sex and/or gender as a characteristic that requires in-depth consideration. The neurotoxicology literature continues to confuse the terms sex (biological attributes) and gender (socially constructed roles and behavior) and the words are still used interchangeably. Throughout the lifespan, sex and gender are in interaction and both may play a role in influencing exposure and effect. Studies that have examined both males and females, provide evidence for sex differences in toxicokinetics and responses to neurotoxic assault as well as gender differences in exposure patterns, biomarkers of exposure, neurobehavioral performance and social consequences. Integrating sex and gender considerations into research in neurotoxicology would not only provide us with a better understanding of the mechanisms and pathways that lead to toxic assault, but also provide a means to improve preventive intervention strategies. Copyright © 2012 Elsevier Inc. All rights reserved.

Social factors and aromatase gene expression during adult male-to-female sex change in captive leopard grouper Mycteroperca rosacea.

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Romo-Mendoza, Daniel; Campos-Ramos, Rafael; Vázquez-Islas, Grecia; Burgos-Aceves, Mario A; Esquivel-Gutiérrez, Edgar R; Guerrero-Tortolero, Danitzia A

2018-01-25

Social factors and aromatase gene expression in the leopard grouper Mycteroperca rosacea was studied when captive fish were separated by sex during the reproductive (April-June) and post-reproductive (July-September) seasons. Monosex females, monosex males, and mixed-sex, held in social sextet units were analyzed for sex steroids throughout confinement. At the end of the experiment, the gonad-sex was defined by histology, and gonad and brain aromatase gene expressions were quantified. Only males held in the monosex social units changed sex. Histology showed one male remained unchanged, six were found in a transitional sexual stage, in which two had intersex-predominantly-testes, and four had a more defined intersex ovo-testes pattern, and 11 were immature de novo females (neofemales). Neofemales and most intersex fish did not survive. In spring, 11-ketosterone showed a specific male profile, which suggests that male-to-female sex change was not triggered during the reproductive season. The low steroid levels in summer made it impossible to associate the sex change to a gonad hormonal shift; in September, gonad aromatase gene expression was not significantly different among groups. However, brain aromatase expression in intersex fish was significantly higher than monosex females, mixed-sex females, and neofemale groups. These results suggest that in the absence of female hormonal compounds, and at a time when male gonad steroidogenesis was diminished, the brain mediated male-to-male social-behavioral interactions, including stress, by increasing aromatization, resulting in derived intersex-male, which triggered more aromatization, followed by a sex change. Copyright © 2018 Elsevier Inc. All rights reserved.

Sex differences in adults' relative visual interest in female and male faces, toys, and play styles.

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Alexander, Gerianne M; Charles, Nora

2009-06-01

An individual's reproductive potential appears to influence response to attractive faces of the opposite sex. Otherwise, relatively little is known about the characteristics of the adult observer that may influence his or her affective evaluation of male and female faces. An untested hypothesis (based on the proposed role of attractive faces in mate selection) is that most women would show greater interest in male faces whereas most men would show greater interest in female faces. Further, evidence from individuals with preferences for same-sex sexual partners suggests that response to attractive male and female faces may be influenced by gender-linked play preferences. To test these hypotheses, visual attention directed to sex-linked stimuli (faces, toys, play styles) was measured in 39 men and 44 women using eye tracking technology. Consistent with our predictions, men directed greater visual attention to all male-typical stimuli and visual attention to male and female faces was associated with visual attention to gender conforming or nonconforming stimuli in a manner consistent with previous research on sexual orientation. In contrast, women showed a visual preference for female-typical toys, but no visual preference for male faces or female-typical play styles. These findings indicate that sex differences in visual processing extend beyond stimuli associated with adult sexual behavior. We speculate that sex differences in visual processing are a component of the expression of gender phenotypes across the lifespan that may reflect sex differences in the motivational properties of gender-linked stimuli.

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

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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.

Using lod scores to detect sex differences in male-female recombination fractions.

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Feenstra, B; Greenberg, D A; Hodge, S E

2004-01-01

Human recombination fraction (RF) can differ between males and females, but investigators do not always know which disease genes are located in genomic areas of large RF sex differences. Knowledge of RF sex differences contributes to our understanding of basic biology and can increase the power of a linkage study, improve gene localization, and provide clues to possible imprinting. One way to detect these differences is to use lod scores. In this study we focused on detecting RF sex differences and answered the following questions, in both phase-known and phase-unknown matings: (1) How large a sample size is needed to detect a RF sex difference? (2) What are "optimal" proportions of paternally vs. maternally informative matings? (3) Does ascertaining nonoptimal proportions of paternally or maternally informative matings lead to ascertainment bias? Our results were as follows: (1) We calculated expected lod scores (ELODs) under two different conditions: "unconstrained," allowing sex-specific RF parameters (theta(female), theta(male)); and "constrained," requiring theta(female) = theta(male). We then examined the DeltaELOD (identical with difference between maximized constrained and unconstrained ELODs) and calculated minimum sample sizes required to achieve statistically significant DeltaELODs. For large RF sex differences, samples as small as 10 to 20 fully informative matings can achieve statistical significance. We give general sample size guidelines for detecting RF differences in informative phase-known and phase-unknown matings. (2) We defined p as the proportion of paternally informative matings in the dataset; and the optimal proportion p(circ) as that value of p that maximizes DeltaELOD. We determined that, surprisingly, p(circ) does not necessarily equal (1/2), although it does fall between approximately 0.4 and 0.6 in most situations. (3) We showed that if p in a sample deviates from its optimal value, no bias is introduced (asymptotically) to the maximum

High burden of STI and HIV in male sex workers working as internet escorts for men in an observational study: a hidden key population compared with female sex workers and other men who have sex with men

OpenAIRE

Verhaegh-Haasnoot, Amanja; Dukers-Muijrers, Nicole H. T. M.; Hoebe, Christian J. P. A.

2015-01-01

Background Male sex work in the western countries has changed, including now a subculture of male sex workers who have paid sex with men arranged for via the internet. The men involved in this subculture do not easily identify themselves as sex workers nor as homosexual, and are therefore missed by regular health care and public health interventions. These male sex workers may form a hidden key population for sexually transmitted infections (STIs) and HIV, bridging towards other persons outsi...

Wage differentials of males and females in same-sex and different-sex couples in Canada, 2006–2010

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Richard Mueller

2014-12-01

Full Text Available This paper utilizes five cycles of the General Social Survey in consecutive years from 2006 through 2010 to address the issue of differential wages amongst members of same-sex couples compared to their counterparts in different-sex couples. We find that men in gay couples have wages that are statistically indistinguishable from those of males in heterosexual relationships. By contrast, a sizeable and statistically significant earnings premium exists for lesbians in same-sex couples.

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

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Mélanie F Guigueno

Full Text Available 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.

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

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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

Heavy Alcohol Use Among Migrant and Non-Migrant Male Sex Workers in Thailand: A Neglected HIV/STI Vulnerability.

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Guadamuz, Thomas E; Clatts, Michael C; Goldsamt, Lloyd A

2018-02-20

There is scarce research on male sex workers in the context of alcohol use. While heavy alcohol use has been established as a risk factor for HIV and STI infections among men who have sex with men (MSM), men who engage in sex work with other men, particularly from the Global South, have not been included in these studies. Moreover, studies among male sex workers in Asia often do not explore migration contexts of these men. The objective of this exploratory study is to examine the prevalence and correlates of heavy alcohol use among migrant and non-migrant male sex workers in Bangkok and Pattaya, Central Thailand. Between August and October 2015, 18-24 year-old migrant and non-migrant male sex workers (n = 212) were recruited from various male sex work-identified venues (bars, clubs, massage parlors, and go-go bars) to take an interviewer-administered cross-sectional survey in Bangkok and Pattaya, Thailand. Measures were adapted from previous studies in similar populations and included structured questions across four domains, including demographic characteristics, alcohol use, stimulant use, and sexual behaviors. Multivariable logistic regression assessed the independent associations between heavy alcohol use (heavy versus not heavy) and demographic characteristics, stimulant use and sexual behavior. Heavy alcohol use was prevalent among one-third of participants. Heavy alcohol use was positively associated with male sex workers who were non-migrant and Thai, currently using stimulants, having 15 or more male clients in the past month and having first consumed alcohol at age 15 years or younger. Current HIV prevention efforts should consider subpopulations of MSM, including male sex workers and migrants, as well as other risk behaviors like alcohol, as important contexts for HIV and STI risks.

Sex-specific signaling in the blood-brain barrier is required for male courtship in Drosophila.

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Valbona Hoxha

Full Text Available Soluble circulating proteins play an important role in the regulation of mating behavior in Drosophila melanogaster. However, how these factors signal through the blood-brain barrier (bbb to interact with the sex-specific brain circuits that control courtship is unknown. Here we show that male identity of the blood-brain barrier is necessary and that male-specific factors in the bbb are physiologically required for normal male courtship behavior. Feminization of the bbb of adult males significantly reduces male courtship. We show that the bbb-specific G-protein coupled receptor moody and bbb-specific Go signaling in adult males are necessary for normal courtship. These data identify sex-specific factors and signaling processes in the bbb as important regulators of male mating behavior.

Gadd45g is essential for primary sex determination, male fertility and testis development.

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Heiko Johnen

Full Text Available In humans and most mammals, differentiation of the embryonic gonad into ovaries or testes is controlled by the Y-linked gene SRY. Here we show a role for the Gadd45g protein in this primary sex differentiation. We characterized mice deficient in Gadd45a, Gadd45b and Gadd45g, as well as double-knockout mice for Gadd45ab, Gadd45ag and Gadd45bg, and found a specific role for Gadd45g in male fertility and testis development. Gadd45g-deficient XY mice on a mixed 129/C57BL/6 background showed varying degrees of disorders of sexual development (DSD, ranging from male infertility to an intersex phenotype or complete gonadal dysgenesis (CGD. On a pure C57BL/6 (B6 background, all Gadd45g(-/- XY mice were born as completely sex-reversed XY-females, whereas lack of Gadd45a and/or Gadd45b did not affect primary sex determination or testis development. Gadd45g expression was similar in female and male embryonic gonads, and peaked around the time of sex differentiation at 11.5 days post-coitum (dpc. The molecular cause of the sex reversal was the failure of Gadd45g(-/- XY gonads to achieve the SRY expression threshold necessary for testes differentiation, resulting in ovary and Müllerian duct development. These results identify Gadd45g as a candidate gene for male infertility and 46,XY sex reversal in humans.

Beyond the Bravado: Sex Roles and the Exploitive Male.

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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.…

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

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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. © The Author(s) 2014.

Field dispersal ability and taxis to sex pheromone of irradiated F-1 male Asian corn borer

International Nuclear Information System (INIS)

Wang Huasong; Liu Qiongru; Lu Daguang; Wang Endong; Kang Wen; Li Yongjun; He Qiulan; Hu Jianguo

1998-01-01

The dispersal ability of F-1 male Asian corn borer, Ostrinia furnacalis (Guenee), irradiated with 100, 150 and 200 Gy Separately in parental generation were tested by marking (with Calco oil red or Sudan blue internally)-releasing-recapturing (with synthesized sex pheromone) method in the field where the farthest distance from release point to pheromone trap was 550 m. The results showed that, as compared with the normal male moths, despite of the fact that a part of the irradiated F-1 males had lost dispersal ability or taxis to sex pheromone, there was no significant difference between the captured rates of irradiated F-1 males and normal males in the trap 550 m from release point, indicated that the dispersal ability or taxis to sex pheromone of irradiated F-1 males arrived at 550 m from release point are still well matched with the normal ones

HIV behavioural risks and the role of work environment among Chinese male sex workers in Hong Kong.

Science.gov (United States)

Wong, William C W; Leung, Phil W S; Li, C W

2012-01-01

Male sex workers are a highly marginalised group in Hong Kong and it is increasingly so with an influx of them travelling from mainland China to work as "freelance" sex workers. This study aimed to measure important work environment variables that might affect the likelihood of condom use among male sex workers working in Hong Kong. A cross-sectional survey of 161 participants recruited by snowball and convenience sampling methods through outreach workers of a local non-governmental organization was conducted in 2007-2008. Only 27.4%, 54.7% and 42.6% reported consistent condom use when engaging in oral, anal and vaginal sex, respectively. Logistic regression shows unsafe sex was nearly four times (OR=3.41; 95%CI 1.51-7.69) as common in institutionalised male sex workers as among their independent counterparts. Lack of condoms provided at workplaces was a major barrier in this socio-legal context and was strongly associated with condom non-use amongst institutionalised sex workers (OR= 10.86; 95%CI 2.94-40.17). The present study finds that when compared with independent Male sex workers (MSWs), institutionalised MSWs were older, less educated, earned a higher income but more likely to engage in unsafe sex with their clients and their partners. Public health physicians must work with law-enforcing authorities to provide clear guidelines to remove these HIV prevention barriers.

Autism attenuates sex differences in brain structure: a combined voxel-based morphometry and diffusion tensor imaging study.

Science.gov (United States)

Beacher, F D; Minati, L; Baron-Cohen, S; Lombardo, M V; Lai, M-C; Gray, M A; Harrison, N A; Critchley, H D

2012-01-01

It has been proposed that autism spectrums condition may represent a form of extreme male brain (EMB), a notion supported by psychometric, behavioral, and endocrine evidence. Yet, limited data are presently available evaluating this hypothesis in terms of neuroanatomy. Here, we investigated sex-related anatomic features in adults with AS, a "pure" form of autism not involving major developmental delay. Males and females with AS and healthy controls (n = 28 and 30, respectively) were recruited. Structural MR imaging was performed to measure overall gray and white matter volume and to assess regional effects by means of VBM. DTI was used to investigate the integrity of the main white matter tracts. Significant interactions were found between sex and diagnosis in total white matter volume, regional gray matter volume in the right parietal operculum, and fractional anisotropy (FA) in the body of the CC, cingulum, and CR. Post hoc comparisons indicated that the typical sexual dimorphism found in controls, whereby males have larger FA and total white matter volume, was absent or attenuated in participants with AS. Our results point to a fundamental role of the factors that underlie sex-specific brain differentiation in the etiology of autism.

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

Science.gov (United States)

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.

Screening of Genes Specifically Expressed in Males of Fenneropenaeus chinensis and Their Potential as Sex Markers

Directory of Open Access Journals (Sweden)

Shihao Li

2013-01-01

Full Text Available The androgenic gland (AG, playing an important role in sex differentiation of male crustacean, is a target candidate to understand the mechanism of male development and to mine male-specific sex markers. An SSH library (designated as male reproduction-related tissues—SSH library, MRT-SSH library for short was constructed using cDNA from tissues located at the basal part of the 5th pereiopods, including AG and part of spermatophore sac, as tester, and the cDNA from the basal part of the 4th pereiopods of these male shrimp as driver. 402 ESTs from the SSH library were sequenced and assembled into 48 contigs and 104 singlets. Twelve contigs and 14 singlets were identified as known genes. The proteins encoded by the identified genes were categorized, according to their proposed functions, into neuropeptide hormone and hormone transporter, RNA posttranscriptional regulation, translation, cell growth and death, metabolism, genetic information processing, signal transduction/transport, or immunity-related proteins. Eleven highly expressed contigs in the SSH library were selected for validation of the MRT-SSH library and screening sex markers of shrimp. One contig, specifically expressed in male shrimp, had a potential to be developed as a transcriptomic sex marker in shrimp.

Myth Information and Bizarre Beliefs of Male Juvenile Sex Offenders.

Science.gov (United States)

Lakey, Joyce F.

1992-01-01

Describes mythical beliefs, thinking errors, and faulty attitudes collected from a group of 67 male juvenile sex offenders. Addresses four major thinking errors: pretentiousness, uniqueness, failure to assume responsibility, and distorted values. Notes that therapists need this information to develop effective treatment strategies for replacing…

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

Science.gov (United States)

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.

How does sex matter? Behavior, stress and animal models of neurobehavioral disorders.

Science.gov (United States)

Palanza, Paola; Parmigiani, Stefano

2017-05-01

Many aspects of brain functioning exhibit important sex differences that affect behavior, mental health and mental disorders. However, most translational neuroscience research related to animal models of neurobehavioral disorders are carried out in male animals only. Based on published data from our laboratory on the House mouse, we discuss the following issues: (1) sex differences in social behavior of wild-derived mice; (2) artificial selection of laboratory strains and its consequences on social and reproductive competition; (3) sex-dependent effects of common experimental procedures; (4) differential effects of developmental events: the case of endocrine disruption; (5) implications for female models of stress and neurobehavioral disorders. Altogether, this review of data outline the marked differences of male and female responses to different social challenges and evinces the current lack of a relevant female mouse model of social stress. Whilst animal modelling is an important approach towards understanding mechanisms of neurobehavioral disorders, it is evident that data obtained in males may be irrelevant for inferring psychopathology and efficacy of pharmacological treatments for females. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Sexual behavior and sources of information about sex among male adolescents: An 8-year follow-up].

Science.gov (United States)

Korkmaz Cetin, Saniye; Bildik, Tezan; Erermiş, Serpil; Demiral, Nagehan; Ozbaran, Burcu; Tamar, Müge; Aydin, Cahide

2008-01-01

This study aimed to determine the changes over time in sexual attitude and behavior among adolescents, and to measure the effect of sources information about sex on these changes. This study was conducted in 2 stages, the first in 1996 and the second in 2004. In all, 392 male tenth grade students (150 in the first stage and 242 in the second stage) were evaluated. A personal information questionnaire developed by the authors was used to collect sociodemographic data, including sexual behavior, sexual attitude, and sources of information about sex. The findings show that there was a significant increase in intercourse and flirting behavior from 1996 to 2004, although no significant difference in masturbation was observed. Additionally, the number of male adolescents that reported family and pornographic films as their sources of information about sex increased 1.6-fold and 2.9-fold, respectively. A significant relationship between watching pornographic films and engaging in sexual intercourse was noted. The number of male adolescents age mean 16, engaging in sexual intercourse increased between 1996 and 2004. Pornographic films were observed to be the most common source of information about sex and also predicted the probability of adolescents having sex. Findings that indicate the need for better and more accurate sources of information about sex. The availability of good quality information about sex is critical to the development of the sexual identity and mental health of male adolescents.

Sex beyond the genitalia: The human brain mosaic

Science.gov (United States)

Joel, Daphna; Berman, Zohar; Tavor, Ido; Wexler, Nadav; Gaber, Olga; Stein, Yaniv; Shefi, Nisan; Pool, Jared; Urchs, Sebastian; Margulies, Daniel S.; Liem, Franziskus; Hänggi, Jürgen; Jäncke, Lutz; Assaf, Yaniv

2015-01-01

Whereas a categorical difference in the genitals has always been acknowledged, the question of how far these categories extend into human biology is still not resolved. Documented sex/gender differences in the brain are often taken as support of a sexually dimorphic view of human brains (“female brain” or “male brain”). However, such a distinction would be possible only if sex/gender differences in brain features were highly dimorphic (i.e., little overlap between the forms of these features in males and females) and internally consistent (i.e., a brain has only “male” or only “female” features). Here, analysis of MRIs of more than 1,400 human brains from four datasets reveals extensive overlap between the distributions of females and males for all gray matter, white matter, and connections assessed. Moreover, analyses of internal consistency reveal that brains with features that are consistently at one end of the “maleness-femaleness” continuum are rare. Rather, most brains are comprised of unique “mosaics” of features, some more common in females compared with males, some more common in males compared with females, and some common in both females and males. Our findings are robust across sample, age, type of MRI, and method of analysis. These findings are corroborated by a similar analysis of personality traits, attitudes, interests, and behaviors of more than 5,500 individuals, which reveals that internal consistency is extremely rare. Our study demonstrates that, although there are sex/gender differences in the brain, human brains do not belong to one of two distinct categories: male brain/female brain. PMID:26621705

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

Science.gov (United States)

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.

Developmental Sex Differences in the Relation of Neuroanatomical Connectivity to Intelligence

Science.gov (United States)

Schmithorst, Vincent J.

2009-01-01

Recent neuroimaging research has shown sex-related differences in the relationship between brain structure and cognitive function. Anatomical studies have shown a greater reliance for cognitive function on white matter structure in adult females, and a greater reliance on gray matter structure in adult males. Functional neuroimaging studies have…

Regulation of antioxidant enzyme activities in male and female rat macrophages by sex steroids

Directory of Open Access Journals (Sweden)

Azevedo R.B.

2001-01-01

Full Text Available Human and animal immune functions present sex dimorphism that seems to be mainly regulated by sex hormones. In the present study, the activities of the antioxidant enzymes total superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GSH-Px were measured in intraperitoneal resident macrophages from adult male and female rats. In addition to comparing males and females, we also examined the regulation of these enzyme activities in macrophages by sex steroids. GSH-Px activity did not differ between male and female macrophages. However, both total SOD and CAT activities were markedly higher in females than in males (83 and 180%. Removal of the gonads in both males and females (comparison between castrated groups increased the difference in SOD activity from 83 to 138% and reduced the difference in CAT activity from 180 to 86%. Castration and testosterone administration did not significantly modify the activities of the antioxidant enzymes in male macrophages. Ovariectomy did not affect SOD or GSH-Px activity but markedly reduced (48% CAT activity. This latter change was fully reversed by estrogen administration, whereas progesterone had a smaller effect. These results led us to conclude that differences in the SOD and CAT activities may partially explain some of the differences in immune function reported for males and females. Also, estrogen is a potent regulator of CAT in macrophages and therefore this enzyme activity in macrophages may vary considerably during the menstrual cycle.

Older Male Clients of Female Sex Workers in the United States.

Science.gov (United States)

Milrod, Christine; Monto, Martin

2017-08-01

Recent research has provided increased information about the clients of sex workers; however, little is known about the population of older male customers who contract for heterosexual services online. Clients (N = 208) between 60 and 84 years of age were obtained through sex work review sites and online discussion forums. Participants completed a 129-item questionnaire focusing on physical health, sexual and non-sexual behaviors with sex providers, and the qualities sought in the same. More than half reported having visited sex providers between 13 and 24 times or more during the past 12 months. Participants' advancing age was positively associated with frequency of paid sex. Most frequent sexual activities with providers were fellatio without a condom, followed by penile-vaginal sex with a condom. Analyses also examine the relationship between aging and buying sex. Those with higher incomes and without spouses or partners were more likely to report non-sexual activities with providers, and many participants sought a "GFE" or girlfriend experience, in which paid sexual exchanges are part of a relationship that mirrors conventional non-remunerative relationships.

Interchromosomal insertional translocation at Xq26.3 alters SOX3 expression in an individual with XX male sex reversal.

Science.gov (United States)

Haines, Bryan; Hughes, James; Corbett, Mark; Shaw, Marie; Innes, Josie; Patel, Leena; Gecz, Jozef; Clayton-Smith, Jill; Thomas, Paul

2015-05-01

46,XX male sex reversal occurs in approximately 1: 20 000 live births and is most commonly caused by interchromosomal translocations of the Y-linked sex-determining gene, SRY. Rearrangements of the closely related SOX3 gene on the X chromosome are also associated with 46,XX male sex reversal. It has been hypothesized that sex reversal in the latter is caused by ectopic expression of SOX3 in the developing urogenital ridge where it triggers male development by acting as an analog of SRY. However, altered regulation of SOX3 in individuals with XX male sex reversal has not been demonstrated. Here we report a boy with SRY-negative XX male sex reversal who was diagnosed at birth with a small phallus, mixed gonads, and borderline-normal T. Molecular characterization of the affected individual was performed using array comparative genomic hybridization, fluorescent in situ hybridization of metaphase chromosomes, whole-genome sequencing, and RT-PCR expression analysis of lymphoblast cell lines. The affected male carries ∼774-kb insertion translocation from chromosome 1 into a human-specific palindromic sequence 82 kb distal to SOX3. Importantly, robust SOX3 expression was identified in cells derived from the affected individual but not from control XX or XY cells, indicating that the translocation has a direct effect on SOX3 regulation. This is the first demonstration of altered SOX3 expression in an individual with XX male sex reversal and suggests that SOX3 can substitute for SRY to initiate male development in humans.

Gender variation, partial male sterility and labile sex expression in gynodioecious Plantago coronopus

NARCIS (Netherlands)

Koelewijn, HP; VanDamme, JMM

Gynodioecy is a breeding system consisting of male steriles (MS, females) and hermaphrodites (H). There is however within such sq stems a third, often neglected, class of partially male sterile plants (PMS), i.e. plants with an intermediate sex expression. In natural populations of Plantago

Gender variation, partial male sterility and labile sex expression in gynodioecious Plantago coronopus

NARCIS (Netherlands)

Koelewijn, H.P.; Van Damme, J.M.M.

1996-01-01

Gynodioecy is a breeding system consisting of male steriles (MS, females) and hermaphrodites (H). There is however within such sq stems a third, often neglected, class of partially male sterile plants (PMS), i.e. plants with an intermediate sex expression. In natural populations of Plantago

Synergistic Disruption of External Male Sex Organ Development by a Mixture of Four Antiandrogens

DEFF Research Database (Denmark)

Christiansen, Sofie; Scholze, Martin; Dalgaard, Majken

2009-01-01

: Strikingly, the effect of combined exposure to the selected chemicals on malformations of external sex organs was synergistic, and the observed responses were greater than would be predicted from the toxicities of the individual chemicals. In relation to other hallmarks of disrupted male sexual development......, and a pharmaceutical, finasteride, on landmarks of male sexual development in the rat, including changes in anogenital distance, retained nipples, sex organ weights and malformations of genitalia. These chemicals were chosen because they disrupt androgen action according to differing mechanisms of action. Results...... in male offspring. Conclusions: Since unhindered androgen action is essential for human male development in foetal life, these findings are highly relevant to human risk assessment. Evaluations that ignore the possibility of combination effects may lead to considerable underestimations of risks associated...

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

Science.gov (United States)

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�

Male sex workers in Córdoba, Argentina: sociodemographic characteristics and sex work experiences

Directory of Open Access Journals (Sweden)

Mariño Rodrigo

2003-01-01

Full Text Available OBJECTIVE: To report on the sociodemographic characteristics and work experiences of 31 male sex workers (MSWs in the city of Córdoba, Argentina. METHODS: Information on each of the MSWs was collected using a questionnaire that covered his personal characteristics and his work background, self-assessed general health status, and use of health and social services. Scales were included in order to assess attitudes towards condom use, knowledge about safe sex, perceptions about the risk of getting HIV, individual self-efficacy, and locus of control. The questionnaire also asked each respondent to rank his level of agreement with interactive strategies for gaining client compliance with safe sex practices. RESULTS: In terms of their self-identity, out of the 30 MSWs who answered the question, 10 of them (33.3% self-identified as heterosexual and 9 (30% as bisexual. Alcohol and drug consumption and unsafe sexual practices were relatively low among the MSWs. Of the 31 MSWs responding, 21 of them (67.7% reported that they had been tested for HIV, but only 13 of them (41.9% said they had been vaccinated for either hepatitis A or hepatitis B. A variety of differences were found between the study's 17 street sex workers (sex workers who offer their services in public places such as streets and parks and the 14 independent sex workers (sex workers who are self-employed, advertise and manage their own business, and have an exclusive location for their commercial sex work. The street MSWs were younger and had less formal education. Independent MSWs were economically more settled, had been working longer in the sex industry, and were more comfortable about having sex with men. Independent MSWs were also more likely to report a gay sexual orientation and less likely to report using alcohol, marijuana, or other substances. CONCLUSIONS: The differences between street MSWs and independent MSWs are important since they could influence the negotiating of safer sex

Anonymous sex and HIV risk practices among men using the Internet specifically to find male partners for unprotected sex.

Science.gov (United States)

Klein, H

2012-06-01

To examine the popularity of anonymous sex practices among men using the Internet to find male partners for unprotected sex, and how anonymous sex relates to involvement in other HIV-related risk behaviours, and to investigate the factors associated with engaging in anonymous sex. Structured telephone interviews were conducted with men who used the Internet specifically to find male partners for unprotected sex. Random sampling from 16 websites was used to obtain a national sample. The data reported in this paper were based on quantitative interviews collected with a cross-sectional study design. Between January 2008 and May 2009, confidential telephone interviews lasting approximately 1-2 h were completed with 332 men. Participants were paid $35 for their participation. Most of the men (67.4%) liked anonymous sex, and slightly more than half (51.2%) had engaged in the behaviour during the month prior to interview. Involvement in anonymous sex was associated with greater involvement in a variety of human immunodeficiency virus (HIV)-related risk practices, such as illegal drug use, number of sex partners, and amount of unprotected sex. Four factors were associated with having vs not having anonymous sex: (1) being HIV positive; (2) answering all of the HIV-related knowledge questions correctly; (3) deriving greater enjoyment from having sex in public places, such as parks, public toilets, or adult book shops; and (4) greater impulsivity. Seven factors were associated with greater vs lesser involvement in anonymous sex among those practising the behaviour: (1) being involved in a relationship with a long-term partner; (2) liking to have sex in public places; (3) using bareback-oriented websites to identify sex partners; (4) greater impulsivity; (5) low level of condom use self-efficacy; (6) greater knowledge about HIV/acquired immunodeficiency syndrome; and either (7a) severe childhood maltreatment or (7b) Caucasian race. Men in this population often sought

Preparation of slowly released male sex hormone drug by radiation polymerization technique and its evaluation in vivo

International Nuclear Information System (INIS)

Liu Rueizhi; Lei Shaoqiong; Li Ximing

1992-01-01

The radiation polymerization technique was used for immobilization testosterone propionate into crosslinked network of poly hydroxyethyl methacrylate to prepare slowly released male sex hormone drug which is used for testicular prosthesis. The testicular prosthesis was transplanted into the scrotum of male rabbit whose testes was excised 2 months before the transplantation. Then the level of male sex hormone in serum was measured by radioimmunoassay once a week after transplantation. The results of measurement in a period of 6 months were shown that the testicular prosthesis has a stable release of male sex hormone. The testosterone level in serum of the castrated male rabbits rises markedly and finally stabilizes at the level of 429 ± 36 ng/100 ml after transplantation. Macroscopic examination of biopsies taken from the tissues around the testicular prosthesis showed that tissue compatibility was revealed well

Cold-induced alteration in the global structure of the male sex ...

Indian Academy of Sciences (India)

Cold-induced alteration in the global structure of the male sex ... dar et al. 1978). Chromosome preparated from a single pair of salivary glands show extremely puffy and diffuse ..... Akhtar A. 2003 Dosage compensation: an intertwined world of.

Correlates of self-efficacy for condom use among male clients of female sex workers in Tijuana, Mexico.

Science.gov (United States)

Volkmann, Tyson; Wagner, Karla D; Strathdee, Steffanie A; Semple, Shirley J; Ompad, Danielle C; Chavarin, Claudia V; Patterson, Thomas L

2014-05-01

Male clients of female sex workers (FSWs) in Tijuana, Mexico engage in high levels of unprotected sex. While behavioral change theories posit that self-efficacy predicts condom use, correlates of self-efficacy for condom use remain largely unstudied. We examined these correlates among male clients of FSWs in Tijuana. Eligible male clients were at least 18 years of age, HIV-negative, lived in Tijuana or San Diego, reported unprotected sex with a Tijuana FSW at least once in the past 4 months, and agreed to be treated for sexually transmitted infections (STIs). Participants completed an interviewer-administered questionnaire including demographics, substance use, psychosocial and psychosexual characteristics (e.g., outcome expectancies for negotiation of safer sex, social support, and sexual sensation seeking), and sexual behaviors. Participants also underwent HIV/STI testing. A stepwise hierarchical multiple regression analysis identified correlates of self-efficacy for condom use. Of 393 male clients, median age was 37 years. Participants were mostly Spanish-speaking and employed. Factors independently associated with higher self-efficacy for condom use were higher positive outcome expectancies for negotiation of safer sex, lower sexual sensation seeking scores, and higher social support scores. Both psychosocial and psychosexual factors may influence self-efficacy for condom use among male clients of FSWs. These factors represent central constructs in sociocognitive models that explain behavioral change and could be intervention targets for improving self-efficacy for condom use and, ultimately, safer sex behavior.

Job Orientation of Males and Females: Are Sex Differences Declining?

Science.gov (United States)

Brenner, O. C.; Tomkiewicz, Joseph

1979-01-01

Sex differences in job orientation found by Manhardt (1972) were explored to determine if they still exist, or if a trend toward similarity as found in studies on traits and behaviors prevails. Implications for personnel managers in handling differences on job orientation of males and females are discussed. (Author/KC)

Transactional sex and the challenges to safer sexual behaviors: a study among male sex workers in Chennai, India.

Science.gov (United States)

Biello, Katie B; Thomas, Beena E; Johnson, Blake E; Closson, Elizabeth F; Navakodi, Pandiaraja; Dhanalakshmi, A; Menon, Sunil; Mayer, Kenneth H; Safren, Steven A; Mimiaga, Matthew J

2017-02-01

Male sex workers (MSW) are a significant but invisible population in India who are at risk for HIV/sexually transmitted infections (STIs). Few studies from India have documented HIV risk factors and motivations for sex work in this population. Between 2013 and 2014, a community-based convenience sample of 100 MSW in Chennai (south India) completed a baseline risk assessment as part of a behavioral intervention. Participants were ≥18 years, and reported current sex work. We report medians and proportions, and Wilcoxon-Mann-Whitney and chi-square tests are used to examine differences between sex work and sexual behavior measures by income source. Participants were engaged in sex work for 5.0 years (IQR = 2.3-10.0), and earned 3000 (IQR = 2000-8000) Rupees (India engage in high levels of sexual risk for HIV/STIs. Money appears to be a driving factor for engaging in sex work and condomless sex with clients. HIV prevention interventions with MSW should focus on facilitating skills that will support their ability to negotiate sexual safety in the context of monetary disincentives.

Influence of electromagnetic pulse on the offspring sex ratio of male BALB/c mice.

Science.gov (United States)

Li, Jin-Hui; Jiang, Da-Peng; Wang, Ya-Feng; Yan, Jia-Jia; Guo, Qi-Yan; Miao, Xia; Lang, Hai-Yang; Xu, Sheng-Long; Liu, Jun-Ye; Guo, Guo-Zhen

2017-09-01

Public concern is growing about the exposure to electromagnetic fields (EMF) and its effect on male reproductive health. Detrimental effect of EMF exposure on sex hormones, reproductive performance and sex-ratio was reported. The present study was designed to clarify whether paternal exposure to electromagnetic pulse (EMP) affects offspring sex ratio in mice. 50 male BALB/c mice aged 5-6 weeks were exposed to EMP daily for 2 weeks before mated with non-exposed females at 0d, 7d, 14d, 21d and 28d after exposure. Sex hormones including total testosterone, LH, FSH, and GnRH were detected using radioimmunoassay. The sex ratio was examined by PCR and agarose gel electrophoresis. The results of D0, D21 and D28 showed significant increases compared with sham-exposed groups. The serum testosterone increased significantly in D0, D14, D21, and D28 compared with sham-exposed groups (p<0.05). Overall, this study suggested that EMP exposure may lead to the disturbance of reproductive hormone levels and affect the offspring sex ratio. Copyright © 2017. Published by Elsevier B.V.

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

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Linbin Zhang

2015-03-01

Full Text Available 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.

Molecular diagnostic testing for Klinefelter syndrome and other male sex chromosome aneuploidies

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Hager Karl

2012-04-01

Full Text Available Abstract Background Male sex chromosome aneuploidies are underdiagnosed despite concomitant physical and behavioral manifestations. Objective To develop a non-invasive, rapid and high-throughput molecular diagnostic assay for detection of male sex chromosome aneuploidies, including 47,XXY (Klinefelter, 47,XYY, 48,XXYY and 48,XXXY syndromes. Methods The assay utilizes three XYM and four XA markers to interrogate Y:X and X:autosome ratios, respectively. The seven markers were PCR amplified using genomic DNA isolated from a cohort of 323 males with aneuploid (n = 117 and 46,XY (n = 206 karyotypes. The resulting PCR products were subjected to Pyrosequencing, a quantitative DNA sequencing method. Results Receiver operator characteristic (ROC curves were used to establish thresholds for the discrimination of aneuploid from normal samples. The XYM markers permitted the identification of 47,XXY, 48,XXXY and 47,XYY syndromes with 100% sensitivity and specificity in both purified DNA and buccal swab samples. The 48,XXYY karyotype was delineated by XA marker data from 46,XY; an X allele threshold of 43% also permitted detection of 48,XXYY with 100% sensitivity and specificity. Analysis of X chromosome-specific biallelic SNPs demonstrated that 43 of 45 individuals (96% with 48,XXYY karyotype had two distinct X chromosomes, while 2 (4% had a duplicate X, providing evidence that 48,XXYY may result from nondisjunction during early mitotic divisions of a 46,XY embryo. Conclusions Quantitative Pyrosequencing, with high-throughput potential, can detect male sex chromosome aneuploidies with 100% sensitivity.

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

DEFF Research Database (Denmark)

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

2015-01-01

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...... 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...

Associations Between Sex Education and Contraceptive Use Among Heterosexually Active, Adolescent Males in the United States.

Science.gov (United States)

Jaramillo, Nicole; Buhi, Eric R; Elder, John P; Corliss, Heather L

2017-05-01

This study examined associations between reports of receiving education on topics commonly included in sex education (e.g., abstinence only, comprehensive) prior to age 18 years and contraceptive use at the last sex among heterosexually active, 15- to 20-year-old males in the United States. Cross-sectional data from 539 males participating in the 2011-2013 National Survey of Family Growth were analyzed. Bivariate and multinomial logistic regression analyses adjusting for confounding estimated associations between receipt of seven sex education topics (e.g., information on HIV/AIDS, how to say no to sex) and contraceptive use at the last sex (i.e., dual barrier and female-controlled effective methods, female-controlled effective method only, barrier method only, and no method). Nearly, all participants (99%) reported receiving sex education on at least one topic. Education on sexually transmitted diseases (94.7%) and HIV/AIDS (92.0%) were the most commonly reported topics received; education on where to get birth control was the least common (41.6%). Instruction about birth control methods (adjusted odds ratio [AOR] = 3.01; 95% confidence interval [CI] = 1.32-6.87) and how to say no to sex (AOR = 3.39; CI = 1.33-8.64) were positively associated with dual contraception compared to no use. For each additional sex education topic respondents were exposed to, their odds of using dual methods compared to no method was 47% greater (AOR = 1.47; CI = 1.16-1.86). Exposure to a larger number of sex education topics is associated with young men's report of dual contraception use at the last sex. Comprehensive sex education, focusing on a range of topics, may be most effective at promoting safer sex among adolescent males. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

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

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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.

Associations of lead and cadmium with sex hormones in adult males

Energy Technology Data Exchange (ETDEWEB)

Kresovich, Jacob K., E-mail: jkreso2@uic.edu; Argos, Maria; Turyk, Mary E.

2015-10-15

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. - Highlights: • We used a nationally representative dataset (NHANES) and employed sample weighting. • We examined associations between lead and cadmium with sex-hormone levels. • Blood lead level was positively associated with serum testosterone and SHBG levels. • Blood cadmium level was positively associated with SHBG levels, modified by lead. • Diabetes, smoking and cadmium modified lead and testosterone association.

Associations of lead and cadmium with sex hormones in adult males

International Nuclear Information System (INIS)

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

2015-01-01

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. - Highlights: • We used a nationally representative dataset (NHANES) and employed sample weighting. • We examined associations between lead and cadmium with sex-hormone levels. • Blood lead level was positively associated with serum testosterone and SHBG levels. • Blood cadmium level was positively associated with SHBG levels, modified by lead. • Diabetes, smoking and cadmium modified lead and testosterone association.

A Reasoned Action Model of Male Client Involvement in Commercial Sex Work in Kibera, A Large Informal Settlement in Nairobi, Kenya.

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Roth, Eric Abella; Ngugi, Elizabeth; Benoit, Cecilia; Jansson, Mikael; Hallgrimsdottir, Helga

2014-01-01

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.

Fibroblast growth factor receptor 2 regulates proliferation and Sertoli differentiation during male sex determination

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Kim, Yuna; Bingham, Nathan; Sekido, Ryohei; Parker, Keith L.; Lovell-Badge, Robin; Capel, Blanche

2007-01-01

Targeted mutagenesis of Fgf9 in mice causes male-to-female sex reversal. Among the four FGF receptors, FGFR2 showed two highly specific patterns based on antibody staining, suggesting that it might be the receptor-mediating FGF9 signaling in the gonad. FGFR2 was detected at the plasma membrane in proliferating coelomic epithelial cells and in the nucleus in Sertoli progenitor cells. This expression pattern suggested that Fgfr2 might play more than one role in testis development. To test the hypothesis that Fgfr2 is required for male sex determination, we crossed mice carrying a floxed allele of Fgfr2 with two different Cre lines to induce a temporal or cell-specific deletion of this receptor. Results show that deletion of Fgfr2 in embryonic gonads phenocopies deletion of Fgf9 and leads to male-to-female sex reversal. Using these two Cre lines, we provide the first genetic evidence that Fgfr2 plays distinct roles in proliferation and Sertoli cell differentiation during testis development. PMID:17940049

Male circumcision and penis enhancement in Southeast Asia: matters of pain and pleasure.

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Hull, T H; Budiharsana, M

2001-11-01

This paper reviews some uniquely male sexual health concerns in Southeast Asia, with particular attention to Indonesia. These include various forms of male circumcision, different types of 'penis enhancement' carried out across the region and the use of dry sex by women. These practices appear to be motivated by specific notions of sexual pleasure, based on indigenous gender constructs. Although they may or may not pose a serious public health problem, as markers of misguided or exploitative gender relations they do reveal important aspects of social psychology related to sexuality and sexual health. Male circumcision provides an ideal opportunity to consider male reproductive health needs and risks in Indonesia, Malaysia and the Philippines. Practices that involve cutting the male genitals need to be addressed in ways that stress the importance of sexual relationships based on mutual respect and open communication. Penis implants and inserts and other penis augmentation devices, as well as dry sex practices, are potentially dangerous to both men and women, and of questionable value in bringing pleasure to either, and should be discouraged.

Commercial sex behaviours among involuntary male bachelors: findings from a survey of migrants in Xi'an, China.

Science.gov (United States)

Yang, Xueyan; Li, Shuzhuo; Attané, Isabelle; Feldman, Marcus W

2015-06-01

The highly male-biased sex ratio at birth has produced a severe male 'marriage squeeze' in China. However, with an imbalanced sex ratio, the marriage-squeezed or involuntary bachelors can meet their sexual needs only through ways other than marriage. To investigate the commercial sex behaviours of involuntary bachelors, we conducted a survey on reproductive health and family living among male migrant bachelors in Xi'an City, the capital of Shaanxi Province, from December 2009 to January 2010. The prevalence of commercial sex use was 37.2% among unmarried men, 30.1% among married but separated men and 17.2% among married and cohabitating men (χ(2) = 31.33; P = 0.000; df = 2). Marital status, knowledge about acquired immunodeficiency syndrome (AIDS), age and income were associated with the prevalence and frequency of commercial sex behaviours. Condom use was less frequent among involuntary bachelors and was significantly associated with knowledge about AIDS and other sexually transmitted diseases, the frequency of commercial sex behaviours, marital status and age. The higher prevalence of commercial sex behaviours and the lower frequency of condom use indicate a higher risk of disease from commercial sex among involuntary bachelors, implicating both individual and public health. © The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Sex-related difference in human white matter volumes studied: Inspection of the corpus callosum and other white matter by VBM

Science.gov (United States)

Shiino, Akihiko; Chen, Yen-Wei; Tanigaki, Kenji; Yamada, Atsushi; Vigers, Piers; Watanabe, Toshiyuki; Tooyama, Ikuo; Akiguchi, Ichiro

2017-01-01

It has been contended that any observed difference of the corpus callosum (CC) size between men and women is not sex-related but brain-size-related. A recent report, however, showed that the midsagittal CC area was significantly larger in women in 37 brain-size-matched pairs of normal young adults. Since this constituted strong evidence of sexual dimorphism and was obtained from publicly available data in OASIS, we examined volume differences within the CC and in other white matter using voxel-based morphometry (VBM). We created a three-dimensional region of interest of the CC and measured its volume. The VBM statistics were analyzed by permutation test and threshold-free cluster enhancement (TFCE) with the significance levels at FWER women in the same 37 brain-size-matched pairs. We found that the CC genu was the subregion showing the most significant sex-related difference. We also found that white matter in the bilateral anterior frontal regions and the left lateral white matter near to Broca’s area were larger in women, whereas there were no significant larger regions in men. Since we used brain-size-matched subjects, our results gave strong volumetric evidence of localized sexual dimorphism of white matter.

Activation of PPAR by Rosiglitazone Does Not Negatively Impact Male Sex Steroid Hormones in Diabetic Rats

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Mahmoud Mansour

2009-01-01

Full Text Available Peroxisome proliferator-activated receptor gamma (PPAR activation decreased serum testosterone (T in women with hyperthecosis and/or polycystic ovary syndrome and reduced the conversion of androgens to estradiol (E2 in female rats. This implies modulation of female sex steroid hormones by PPAR. It is not clear if PPAR modulates sex steroid hormones in diabetic males. Because PPAR activation by thiazolidinedione increased insulin sensitivity in type 2 diabetes, understanding the long term impact of PPAR activation on steroid sex hormones in males is critical. Our objective was to determine the effect of PPAR activation on serum and intratesticular T, luteinizing hormone (LH, follicle stimulating hormone (FSH and E2 concentrations in male Zucker diabetic fatty (ZDF rats treated with the PPAR agonist rosiglitazone (a thiazolidinedione. Treatment for eight weeks increased PPAR mRNA and protein in the testis and elevated serum adiponectin, an adipokine marker for PPAR activation. PPAR activation did not alter serum or intratesticular T concentrations. In contrast, serum T level but not intratesticular T was reduced by diabetes. Neither diabetes nor PPAR activation altered serum E2 or gonadotropins FSH and LH concentrations. The results suggest that activation of PPAR by rosiglitazone has no negative impact on sex hormones in male ZDF rats.

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

Science.gov (United States)

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.

A NEW HYPOTHESIS ON THE EVOLUTION OF SEX DETERMINATION IN VERTEBRATES - BIG FEMALES ZW, BIG MALES XY

NARCIS (Netherlands)

KRAAK, SBM; DELOOZE, EMA

1993-01-01

Why are there two chromosomal sex-determining mechanisms in vertebrates; ZW/ZZ, meaning female heterogamety, and XX/XY, meaning male heterogamety? We propose an evolutionary explanation. Transition from environmental sex determination to genetic sex determination can result when an allele that

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

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Sinchan Adhikari

2014-01-01

Full Text Available 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.

Polymorphic male color morphs visualized with steroids in monomorphic females: a tool for designing analysis of sex-limited trait inheritance.

Science.gov (United States)

Olsson, Mats; Healey, Mo; Wilson, Mark; Tobler, Michael

2012-02-15

In diploid animals, males and females share most of the genome (except sex-specific elements, such as sex chromosome genes), yet despite sharing the underlying genes that hard-wire traits, males and females may differ in their phenotypes when traits are controlled by proximate mechanisms, such as hormones. In color polymorphic species where coloration is only expressed in one sex, the design of studies of the inheritance of color and coevolved morph-specific traits (e.g. territorial vs sneaker strategies, skewed energetic investment in territorial defense vs sperm production, etc.) is compromised as the expression of morph-coding genes is only visualized in one sex. Here, we circumvented this problem by first characterizing oxidative stress traits in both sexes and then using testosterone implants in females to expose their otherwise 'silent' coloration. Males of our model species are highly territorial and exhibit morph-specific levels of aggression, whereas females are non-territorial and display very low levels of aggression. Interestingly, reactive oxygen species levels were found to be morph specific regardless of sex, despite considerable differences in lifestyle. Males and females did differ remarkably, however, in superoxide levels depending on whether they sported a colored throat bib or not, a trait also used in male sexual signaling. Females with throat bibs had significantly lower levels of superoxide than females without a bib, which was not the case for males.

The 'male escape hypothesis': sex-biased metamorphosis in response to climatic drivers in a facultatively paedomorphic amphibian.

Science.gov (United States)

Mathiron, Anthony G E; Lena, Jean-Paul; Baouch, Sarah; Denoël, Mathieu

2017-04-26

Paedomorphosis is a major evolutionary process that bypasses metamorphosis and allows reproduction in larvae. In newts and salamanders, it can be facultative with paedomorphs retaining gills and metamorphs dispersing. The evolution of these developmental processes is thought to have been driven by the costs and benefits of inhabiting aquatic versus terrestrial habitats. In this context, we aimed at testing the hypothesis that climatic drivers affect phenotypic transition and the difference across sexes because sex-ratio is biased in natural populations. Through a replicated laboratory experiment, we showed that paedomorphic palmate newts ( Lissotriton helveticus ) metamorphosed at a higher frequency when water availability decreased and metamorphosed earlier when temperature increased in these conditions. All responses were sex-biased, and males were more prone to change phenotype than females. Our work shows how climatic variables can affect facultative paedomorphosis and support theoretical models predicting life on land instead of in water. Moreover, because males metamorphose and leave water more often and earlier than females, these results, for the first time, give an experimental explanation for the rarity of male paedomorphosis (the 'male escape hypothesis') and suggest the importance of sex in the evolution of paedomorphosis versus metamorphosis. © 2017 The Author(s).

Aging and sex hormones in males

Science.gov (United States)

Decaroli, Maria Chiara

2017-01-01

ABSTRACT Several large cohort studies have disclosed the trajectories of sex steroids changes overtime in men and their clinical significance. In men the slow, physiological decline of serum testosterone (T) with advancing age overlaps with the clinical condition of overt, pathological hypogonadism. In addition, the increasing number of comorbidities, together with the high prevalence of chronic diseases, all further contribute to the decrease of serum T concentrations in the aging male. For all these reasons both the diagnosis of late-onset hypogonadism (LOH) in men and the decision about starting or not T replacement treatment remain challenging. At present, the biochemical finding of T deficiency alone is not sufficient for diagnosing hypogonadism in older men. Coupling hypogonadal symptoms with documented low serum T represents the best strategy to refine the diagnosis of hypogonadism in older men and to avoid unnecessary treatments. PMID:27831823

Changes in radiosensitivity of male sex hormones in rats maintained on kelthane contaminated feed

International Nuclear Information System (INIS)

Abughadeer, A.R.M.

1995-01-01

Alteration of sex hormones levels in male rats after whole body gamma irradiation (6.5 Gy) has been studied. The hormonal response of irradiated rats fed on experimental feed contaminated with organo chlorine insecticide 'kelthane' (200 mg/kg body weight) for different time intervals (3,6 and 12 weeks), has been also investigated. Investigations included measurements of testes/body weight ratio; Testosterone; Follicle Stimulating Hormone (FSH); luteinizing hormone (LH) and prolactin levels in serum and testes homogenate of treated rats. The data indicate that whole body gamma irradiation causes significant alteration in all tested parameters except for the testosterone level. Normal rats fed on 'kelthane' contaminated feed, showed significant alteration in all tested parameters, which increased with the prolongation of 'kelthane' exposure period. Double treatment of 'kelthane' and irradiation resulted in more pronounced alterations. It can be concluded that the male sex hormones in rats fed on 'kelthane', were more sensitive to whole body gamma irradiation. Moreover, male sex hormones have shown reliable reliable dose/effect relationship for either radiation or pesticide internal contamination. This suggests their possible use as markers in early diagnosis of radiation exposure and pesticides toxication syndromes. 3 tabs

Genetic-gonadal-genitals sex (3G-sex) and the misconception of brain and gender, or, why 3G-males and 3G-females have intersex brain and intersex gender.

Science.gov (United States)

Joel, Daphna

2012-12-17

The categorization of individuals as "male" or "female" is based on chromosome complement and gonadal and genital phenotype. This combined genetic-gonadal-genitals sex, here referred to as 3G-sex, is internally consistent in ~99% of humans (i.e., one has either the "female" form at all levels, or the "male" form at all levels). About 1% of the human population is identified as "intersex" because of either having an intermediate form at one or more levels, or having the "male" form at some levels and the "female" form at other levels. These two types of "intersex" reflect the facts, respectively, that the different levels of 3G-sex are not completely dimorphic nor perfectly consistent. Using 3G-sex as a model to understand sex differences in other domains (e.g., brain, behavior) leads to the erroneous assumption that sex differences in these other domains are also highly dimorphic and highly consistent. But parallel lines of research have led to the conclusion that sex differences in the brain and in behavior, cognition, personality, and other gender characteristics are for the most part not dimorphic and not internally consistent (i.e., having one brain/gender characteristic with the "male" form is not a reliable predictor for the form of other brain/gender characteristics). Therefore although only ~1% percent of humans are 3G-"intersex", when it comes to brain and gender, we all have an intersex gender (i.e., an array of masculine and feminine traits) and an intersex brain (a mosaic of "male" and "female" brain characteristics).

Sleep spindling and fluid intelligence across adolescent development: sex matters

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Róbert eBódizs

2014-11-01

Full Text Available Evidence supports the intricate relationship between sleep electroencephalogram (EEG spindling and cognitive abilities in children and adults. Although sleep EEG changes during adolescence index fundamental brain reorganization, a detailed analysis of sleep spindling and the spindle-intelligence relationship was not yet provided for adolescents. Therefore, adolescent development of sleep spindle oscillations were studied in a home polysomnographic study focusing on the effects of chronological age and developmentally acquired overall mental efficiency (fluid IQ with sex as a potential modulating factor. Subjects were 24 healthy adolescents (12 males with an age range of 15–22 years (mean: 18 years and fluid IQ of 91-126 (mean: 104.12, Raven Progressive Matrices Test. Slow spindles (SSs and fast spindles (FSs were analyzed in 21 EEG derivations by using the individual adjustment method. A significant age-dependent increase in average FS density (r = .57; p = .005 was found. Moreover, fluid IQ correlated with FS density (r = .43; p = .04 and amplitude (r = .41; p = .049. The latter effects were entirely driven by particularly reliable FS-IQ correlations in females [r = .80 (p = .002 and r = .67 (p = .012, for density and amplitude, respectively]. Region-specific analyses revealed that these correlations peak in the fronto-central regions. The control of the age-dependence of FS measures and IQ scores did not considerably reduce the spindle-IQ correlations with respect to FS density. The only positive spindle-index of fluid IQ in males turned out to be the frequency of FSs (r = .60, p = .04. Increases in FS density during adolescence may index reshaped structural connectivity related to white matter maturation in the late developing human brain. The continued development over this age range of cognitive functions is indexed by specific measures of sleep spindling unravelling gender differences in adolescent brain maturation and perhaps cognitive

Age, sex, and telomere dynamics in a long-lived seabird with male-biased parental care.

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Rebecca C Young

Full Text Available The examination of telomere dynamics is a recent technique in ecology for assessing physiological state and age-related traits from individuals of unknown age. Telomeres shorten with age in most species and are expected to reflect physiological state, reproductive investment, and chronological age. Loss of telomere length is used as an indicator of biological aging, as this detrimental deterioration is associated with lowered survival. Lifespan dimorphism and more rapid senescence in the larger, shorter-lived sex are predicted in species with sexual size dimorphism, however, little is known about the effects of behavioral dimorphism on senescence and life history traits in species with sexual monomorphism. Here we compare telomere dynamics of thick-billed murres (Urialomvia, a species with male-biased parental care, in two ways: 1 cross-sectionally in birds of known-age (0-28 years from one colony and 2 longitudinally in birds from four colonies. Telomere dynamics are compared using three measures: the telomere restriction fragment (TRF, a lower window of TRF (TOE, and qPCR. All showed age-related shortening of telomeres, but the TRF measure also indicated that adult female murres have shorter telomere length than adult males, consistent with sex-specific patterns of ageing. Adult males had longer telomeres than adult females on all colonies examined, but chick telomere length did not differ by sex. Additionally, inter-annual telomere changes may be related to environmental conditions; birds from a potentially low quality colony lost telomeres, while those at more hospitable colonies maintained telomere length. We conclude that sex-specific patterns of telomere loss exist in the sexually monomorphic thick-billed murre but are likely to occur between fledging and recruitment. Longer telomeres in males may be related to their homogamous sex chromosomes (ZZ or to selection for longer life in the care-giving sex. Environmental conditions appeared to

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

Science.gov (United States)

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

Obstructive sleep apnea and cortical thickness in females and males.

Science.gov (United States)

Macey, Paul M; Haris, Natasha; Kumar, Rajesh; Thomas, M Albert; Woo, Mary A; Harper, Ronald M

2018-01-01

Obstructive sleep apnea (OSA) affects approximately 10% of adults, and alters brain gray and white matter. Psychological and physiological symptoms of the disorder are sex-specific, perhaps related to greater injury occurs in female than male patients in white matter. Our objective was to identify influences of OSA separated by sex on cortical gray matter. We assessed cortical thickness in 48 mild-severe OSA patients (mean age±std[range] = 46.5±9.0[30.8-62.7] years; apnea-hypopnea index = 32.6±21.1[6-102] events/hour; 12 female, 36 male; OSA severity: 5 mild, 18 moderate, 25 severe) and 62 controls (mean age = 47.7±8.9[30.9-65.8] years; 22 female, 40 male). All OSA patients were recently-diagnosed via polysomnography, and control subjects screened and a subset assessed with sleep studies. We used high-resolution magnetic resonance imaging to identify OSA-related cortical thinning, based on a model with condition and sex as independent variables. OSA and OSA-by-sex interaction effects were assessed (Pfrontal lobe in female OSA vs. all other groups. Significant thinning within the pre- and post-central gyri and the superior temporal gyrus, extending into the insula, appeared between the general OSA populations vs. control subjects. No areas showed increased thickness in OSA vs. controls or positive female OSA interaction effects. Reduced cortical thickness likely represents tissue atrophy from long term injury, including death of neurons and supporting glia from repeated intermittent hypoxic exposure in OSA, although disease comordities may also contribute to thinning. Lack of polysomnography in all control subjects means results may be confounded by undiagnosed OSA. The greater cortical injury in cognitive areas of female OSA patients may underlie enhanced symptoms in that group. The thinning associated with OSA in male and females OSA patients may contribute to autonomic dysregulation and impaired upper airway sensori-motor function.

Nice guys finish last: same-sex sexual behavior and pairing success in male budgerigars

OpenAIRE

Puya Abbassi; Nancy Tyler Burley

2012-01-01

In budgerigars (Melopsittacus undulatus), a social parrot in which females are socially dominant, males of all ages engage in a set of behaviors with other males that closely resembles the repertoire used in heterosexual courtship. One adaptive hypothesis for this tendency, the "courtship practice hypothesis," posits that males with greater experience in same-sex activities develop superior skills that increase their courtship success with females. To test this hypothesis, we measured individ...

Gray and white matter density changes in monozygotic and same-sex dizygotic twins discordant for schizophrenia using voxel-based morphometry

DEFF Research Database (Denmark)

Hulshoff Pol, HE; Schnack, HG; Mandl, RC

2006-01-01

Global gray matter brain tissue volume decreases in schizophrenia have been associated to disease-related (possibly nongenetic) factors. Global white matter brain tissue volume decreases were related to genetic risk factors for the disease. However, which focal gray and white matter brain regions...... best reflect the genetic and environmental risk factors in the brains of patients with schizophrenia remains unresolved. 1.5-T MRI brain scans of 11 monozygotic and 11 same-sex dizygotic twin-pairs discordant for schizophrenia were compared to 11 monozygotic and 11 same-sex dizygotic healthy control...... twin-pairs using voxel-based morphometry. Linear regression analysis was done in each voxel for the average and difference in gray and white matter density separately, in each twin-pair, with group (discordant, healthy) and zygosity (monozygotic, dizygotic) as between subject variables, and age, sex...

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

Science.gov (United States)

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.

Evolving knowledge of sex differences in brain structure, function, and chemistry.

Science.gov (United States)

Cosgrove, Kelly P; Mazure, Carolyn M; Staley, Julie K

2007-10-15

Clinical and epidemiologic evidence demonstrates sex differences in the prevalence and course of various psychiatric disorders. Understanding sex-specific brain differences in healthy individuals is a critical first step toward understanding sex-specific expression of psychiatric disorders. Here, we evaluate evidence on sex differences in brain structure, chemistry, and function using imaging methodologies, including functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), and structural magnetic resonance imaging (MRI) in mentally healthy individuals. MEDLINE searches of English-language literature (1980-November 2006) using the terms sex, gender, PET, SPECT, MRI, fMRI, morphometry, neurochemistry, and neurotransmission were performed to extract relevant sources. The literature suggests that while there are many similarities in brain structure, function, and neurotransmission in healthy men and women, there are important differences that distinguish the male from the female brain. Overall, brain volume is greater in men than women; yet, when controlling for total volume, women have a higher percentage of gray matter and men a higher percentage of white matter. Regional volume differences are less consistent. Global cerebral blood flow is higher in women than in men. Sex-specific differences in dopaminergic, serotonergic, and gamma-aminobutyric acid (GABA)ergic markers indicate that male and female brains are neurochemically distinct. Insight into the etiology of sex differences in the normal living human brain provides an important foundation to delineate the pathophysiological mechanisms underlying sex differences in neuropsychiatric disorders and to guide the development of sex-specific treatments for these devastating brain disorders.

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

Science.gov (United States)

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.

Conditioned same-sex partner preference in male rats is facilitated by oxytocin and dopamine: effect on sexually dimorphic brain nuclei.

Science.gov (United States)

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Complementarity of Sex Differences in Brain and Behavior: From Laterality to Multi-Modal Neuroimaging

Science.gov (United States)

Gur, Ruben C.; Gur, Raquel E.

2016-01-01

While overwhelmingly behavior is similar in males and females, and correspondingly the brains are similar, sex differences permeate both brain and behavioral measures and these differences have been the focus of increasing scrutiny by neuroscientists. Here we describe milestones of over three decades of research in brain and behavior. This research was necessarily bound by available methodology, and we began by indirect behavioral indicators of brain function such as handedness. We proceeded to using neuropsychological batteries and then to structural and functional neuroimaging that provided the foundations of a cognitive neuroscience based computerized neurocognitive battery. Sex differences were apparent and consistent in neurocognitive measures, with females performing better on memory and social cognition tasks and males on spatial processing and motor speed. Sex differences were also prominent on all major brain parameters, including higher rates of cerebral blood flow, higher percent of gray matter tissue and higher inter-hemispheric connectivity in females compared to higher percent of white matter and greater intra-hemispheric connectivity, as well as higher glucose metabolism in limbic regions in males. Many of these differences are present in childhood but they become more prominent with adolescence, perhaps linked to puberty. Together they indicate complementarity between the sexes that would result in higher adaptive diversity. PMID:27870413

The ‘male escape hypothesis’: sex-biased metamorphosis in response to climatic drivers in a facultatively paedomorphic amphibian

Science.gov (United States)

Mathiron, Anthony G. E.; Lena, Jean-Paul; Baouch, Sarah

2017-01-01

Paedomorphosis is a major evolutionary process that bypasses metamorphosis and allows reproduction in larvae. In newts and salamanders, it can be facultative with paedomorphs retaining gills and metamorphs dispersing. The evolution of these developmental processes is thought to have been driven by the costs and benefits of inhabiting aquatic versus terrestrial habitats. In this context, we aimed at testing the hypothesis that climatic drivers affect phenotypic transition and the difference across sexes because sex-ratio is biased in natural populations. Through a replicated laboratory experiment, we showed that paedomorphic palmate newts (Lissotriton helveticus) metamorphosed at a higher frequency when water availability decreased and metamorphosed earlier when temperature increased in these conditions. All responses were sex-biased, and males were more prone to change phenotype than females. Our work shows how climatic variables can affect facultative paedomorphosis and support theoretical models predicting life on land instead of in water. Moreover, because males metamorphose and leave water more often and earlier than females, these results, for the first time, give an experimental explanation for the rarity of male paedomorphosis (the ‘male escape hypothesis’) and suggest the importance of sex in the evolution of paedomorphosis versus metamorphosis. PMID:28424346

Condition dependence and the nature of genetic variation for male sex comb bristle number in Drosophila melanogaster.

Science.gov (United States)

Ahuja, Abha; De Vito, Scott; Singh, Rama S

2011-04-01

Genetic architecture of variation underlying male sex comb bristle number, a rapidly evolving secondary sexual character of Drosophila, was examined. First, in order to test for condition dependence, diet was manipulated in a set of ten Drosophila melanogaster full-sib families. We confirmed heightened condition dependent expression of sex comb bristle number and its female homologue (distal transverse row bristles) as compared to non-sex sternopleural bristles. Significant genotype by environment effects were detected for the sex traits indicating a genetic basis for condition dependence. Next we measured sex comb bristle number and sternopleural bristle number, as well as residual mass, a commonly used condition index, in a set of thirty half-sib families. Sire effect was not significant for sex comb and sternopleural bristle number, and we detected a strong dominance and/or maternal effect or X chromosome effect for both traits. A strong sire effect was detected for condition and its heritability was the highest as compared to sex comb and sternopleural bristles. We discuss our results in light of the rapid response to divergent artificial selection for sex comb bristle number reported previously. The nature of genetic variation for male sex traits continues to be an important unresolved issue in evolutionary biology.

Myths of Male Same-Sex Love in the Art of the Italian Renaissance

Directory of Open Access Journals (Sweden)

Ann Haughton

2015-09-01

Full Text Available Visual culture has much to contribute to an understanding of the history of sexuality. Yet, to date, the depiction of pederasty in the art of the Renaissance has not been covered adequately by dominant theoretical paradigms. Moreover, the interpretive approach of traditional art historical discourse has been both limited and limiting in its timidity toward matters concerning the representation of sexual proclivity between males. This article will address the ways in which Italian Renaissance artistic depictions of some mythological narratives were enmeshed with the period’s attitudes toward sexual and social relationships between men. Particular attention is paid here to the manner in which, under the veneer of a mythological narrative, certain works of art embodied a complex set of messages that encoded issues of masculine behaviour and performance in the context of intergenerational same-sex erotic relationships.  The primary case studies under investigation for these concerns of gender and sexuality in this particular context are Benvenuto Cellini’s marble Apollo and Hyacinth (1545, and Giulio Romano’s drawing of Apollo and Cyparissus (1524. By incorporating pictorial analysis, social history, and gender and sexuality studies, new possibilities will be offered for evaluating these artworks as visual chronicles of particular sexual and cultural mores of the period. Furthermore, this article will consider how visual representation of these mythic narratives of erotic behaviour between males conformed to the culturally defined sexual and social roles relating to the articulation of power that permeated one of the greatest milestones in art history.

Changes in the Plasma Sex Hormone Profile in Males with Severe Concomitant Injury

Directory of Open Access Journals (Sweden)

K. N Yezhova

2009-01-01

Full Text Available Objective: to perform a complex study of typical plasma sex hormone changes and their functional significance in males with severe concomitant injury (SCI. Subjects and methods. Fifty-nine males aged 18—49 years who had SCI were enrolled in the study. The admission severity was an APACHE II score of 18.6±2.4. According to the outcome of the disease, all the patients were divided into 2 groups: A survivors; B deceased persons. A control comprised 12 healthy male donors aged 19-36 years, in whom the levels of 8 sex steroids were measured. The standard procedures were used to comparatively analyze the concentrations of pituitary reproductive hormones and aldosterone. Hormonal concentrations were studied over time on posttraumatic days 1, 3, 5, 7, 10, and 15. The plasma hormone profile was examined by test kits (BSL, USA on a Stat Fax 2100 device (Awareness Technology Inc., USA for enzyme immunoassay. Prolactin, luteinizing hormone (LH, follicle-stimulating hormone (FSH, progesterone (P, 17-hydroxyprogesterone (17-OH-P, dehydroepiandrosterone sulfate (DHEA-S, androstendione (A, testosterone (T, dihydrotestosterone (DHT, estrone (E1, estradiol (E2, and aldosterone were determined. Results. The complex study of phasic changes in the profile of 11 plasma sex hormones was first conducted in males in the posttraumatic period. Moreover, the typical plasma hormonal changes were elevated prolactin levels and their phasic variations, normal LH and FSH levels with a tendency for further phasic LH changes and FSH reduction. After the injury, the plasma concentration of P was increased and that of 17-OH-P was decreased. The levels of A and DHEA-S varied in the normal range with a tendency for DHEA-S to be lower during the process. In the posttraumatic period, the plasma content of T and DHT was substantially reduced and that of E1 and E2 was increased. The deceased patients generally showed higher levels of A, DHEA-S, and estrogens as a reflection of

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

Science.gov (United States)

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

Cerebral sex dimorphism and sexual orientation.

Science.gov (United States)

Manzouri, Amirhossein; Savic, Ivanka

2018-03-01

The neurobiology of sexual orientation is frequently discussed in terms of cerebral sex dimorphism (defining both functional and structural sex differences). Yet, the information about possible cerebral differences between sex-matched homo and heterosexual persons is limited, particularly among women. In this multimodal MRI study, we addressed these issues by investigating possible cerebral differences between homo and heterosexual persons, and by asking whether there is any sex difference in this aspect. Measurements of cortical thickness (Cth), subcortical volumes, and functional and structural resting-state connections among 40 heterosexual males (HeM) and 40 heterosexual females (HeF) were compared with those of 30 homosexual males (HoM) and 30 homosexual females (HoF). Congruent with previous reports, sex differences were detected in heterosexual controls with regard to fractional anisotropy (FA), Cth, and several subcortical volumes. Homosexual groups did not display any sex differences in FA values. Furthermore, their functional connectivity was significantly less pronounced in the mesial prefrontal and precuneus regions. In these two particular regions, HoM also displayed thicker cerebral cortex than other groups, whereas HoF did not differ from HeF. In addition, in HoM the parietal Cth showed "sex-reversed" values, not observed in HoF. Homosexual orientation seems associated with a less pronounced sexual differentiation of white matter tracts and a less pronounced functional connectivity of the self-referential networks compared to heterosexual orientation. Analyses of Cth suggest that male and female homosexuality are not simple analogues of each other and that differences from heterosexual controls are more pronounced in HoM. © 2017 Wiley Periodicals, Inc.

Variation in sex pheromone emission does not reflect immunocompetence but affects attractiveness of male burying beetles-a combination of laboratory and field experiments.

Science.gov (United States)

Chemnitz, Johanna; Bagrii, Nadiia; Ayasse, Manfred; Steiger, Sandra

2017-08-01

Life history theory predicts a trade-off between male sexual trait expression and immunocompetence. Using burying beetles, Nicrophorus vespilloides, as a model, we investigated the relationship between male immune function, sex pheromone emission, and attractiveness under field conditions. In the first experiment, we tested whether there is a positive correlation between immune capacity, sex pheromone characteristics (quantity, relative composition, and time invested in pheromone emission), and male attractiveness. As a measurement of immune capacity, we used an individual's encapsulation ability against a novel antigen. In the second experiment, we specifically examined whether a trade-off between chemical trait expression and immune function existed. To this end, we challenged the immune system and measured the subsequent investment in sex pheromone emission and the attractiveness of the male under field conditions. We found that a male's immunocompetence was neither related to the emission of the male's sex pheromone nor to its attractiveness in the field. Furthermore, none of the immune-challenge treatments affected the subsequent investment in pheromone emission or number of females attracted. However, we showed that the same males that emitted a high quantity of their sex pheromone in the laboratory were able to attract more females in the field. Our data suggest that the chemical signal is not a reliable predictor of a male's immunocompetence but rather is a general important fitness-related trait, with a higher emission of the sex pheromone measured in the laboratory directly affecting the attractiveness of a male under field conditions.

Variation in sex pheromone emission does not reflect immunocompetence but affects attractiveness of male burying beetles—a combination of laboratory and field experiments

Science.gov (United States)

Chemnitz, Johanna; Bagrii, Nadiia; Ayasse, Manfred; Steiger, Sandra

2017-08-01

Life history theory predicts a trade-off between male sexual trait expression and immunocompetence. Using burying beetles, Nicrophorus vespilloides, as a model, we investigated the relationship between male immune function, sex pheromone emission, and attractiveness under field conditions. In the first experiment, we tested whether there is a positive correlation between immune capacity, sex pheromone characteristics (quantity, relative composition, and time invested in pheromone emission), and male attractiveness. As a measurement of immune capacity, we used an individual's encapsulation ability against a novel antigen. In the second experiment, we specifically examined whether a trade-off between chemical trait expression and immune function existed. To this end, we challenged the immune system and measured the subsequent investment in sex pheromone emission and the attractiveness of the male under field conditions. We found that a male's immunocompetence was neither related to the emission of the male's sex pheromone nor to its attractiveness in the field. Furthermore, none of the immune-challenge treatments affected the subsequent investment in pheromone emission or number of females attracted. However, we showed that the same males that emitted a high quantity of their sex pheromone in the laboratory were able to attract more females in the field. Our data suggest that the chemical signal is not a reliable predictor of a male's immunocompetence but rather is a general important fitness-related trait, with a higher emission of the sex pheromone measured in the laboratory directly affecting the attractiveness of a male under field conditions.

Complementarity of sex differences in brain and behavior: From laterality to multimodal neuroimaging.

Science.gov (United States)

Gur, Ruben C; Gur, Raquel E

2017-01-02

Although, overwhelmingly, behavior is similar in males and females, and, correspondingly, the brains are similar, sex differences permeate both brain and behavioral measures, and these differences have been the focus of increasing scrutiny by neuroscientists. This Review describes milestones from more than 3 decades of research in brain and behavior. This research was necessarily bound by available methodology, and we began with indirect behavioral indicators of brain function such as handedness. We proceeded to the use of neuropsychological batteries and then to structural and functional neuroimaging that provided the foundations of a cognitive neuroscience-based computerized neurocognitive battery. Sex differences were apparent and consistent in neurocognitive measures, with females performing better on memory and social cognition tasks and males on spatial processing and motor speed. Sex differences were also prominent in all major brain parameters, including higher rates of cerebral blood flow, higher percentage of gray matter tissue, and higher interhemispheric connectivity in females, compared with higher percentage of white matter and greater intrahemispheric connectivity as well as higher glucose metabolism in limbic regions in males. Many of these differences are present in childhood, but they become more prominent with adolescence, perhaps linked to puberty. Overall, they indicate complementarity between the sexes that would result in greater adaptive diversity. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Sex Hormone-Related Functions in Regenerating Male Rat Liver

Science.gov (United States)

FRANCAVILLA, ANTONIO; EAGON, PATRICIA K.; DiLEO, ALFREDO; POLIMENO, LORENZO; PANELLA, CARMINE; AQUILINO, A. MARIA; INGROSSO, MARCELLO; Van THIEL, DAVID H.; STARZL, THOMAS E.

2011-01-01

Sex hormone receptors were quantitated in normal male rat liver and in regenerating liver at several different times after partial (70%) hepatectomy. Both estrogen and androgen receptor content were altered dramatically by partial hepatectomy. Total hepatic content and nuclear retention of estrogen receptors increased, with the zenith evident 2 days after partial hepatectomy, corresponding to the zenith of mitotic index. Serum estradiol increased after 1 day, and reached a maximum at 3 days after surgery. In contrast, total and nuclear androgen receptor content demonstrated a massive decline at 1, 2, and 3 days after resection. Serum testosterone displayed a parallel decline. In addition, hepatic content of two androgen-responsive proteins was reduced to 15% and 13% of normal values during this period. The activity of these various proteins during regeneration of male rat liver is comparable to that observed in the liver of normal female rats. Taken together, these results indicate that partial hepatectomy induces a feminization of certain sexually dimorphic aspects of liver function in male rats. Furthermore, these data provide evidence that estrogens, but not androgens, may have an important role in the process of liver regeneration. PMID:3758617

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

Science.gov (United States)

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.

Behavioural and cognitive sex/gender differences in autism spectrum condition and typically developing males and females.

Science.gov (United States)

Hull, Laura; Mandy, William; Petrides, K V

2017-08-01

Studies assessing sex/gender differences in autism spectrum conditions often fail to include typically developing control groups. It is, therefore, unclear whether observed sex/gender differences reflect those found in the general population or are particular to autism spectrum conditions. A systematic search identified articles comparing behavioural and cognitive characteristics in males and females with and without an autism spectrum condition diagnosis. A total of 13 studies were included in meta-analyses of sex/gender differences in core autism spectrum condition symptoms (social/communication impairments and restricted/repetitive behaviours and interests) and intelligence quotient. A total of 20 studies were included in a qualitative review of sex/gender differences in additional autism spectrum condition symptoms. For core traits and intelligence quotient, sex/gender differences were comparable in autism spectrum conditions and typical samples. Some additional autism spectrum condition symptoms displayed different patterns of sex/gender differences in autism spectrum conditions and typically developing groups, including measures of executive function, empathising and systemising traits, internalising and externalising problems and play behaviours. Individuals with autism spectrum conditions display typical sex/gender differences in core autism spectrum condition traits, suggesting that diagnostic criteria based on these symptoms should take into account typical sex/gender differences. However, awareness of associated autism spectrum condition symptoms should include the possibility of different male and female phenotypes, to ensure those who do not fit the 'typical' autism spectrum condition presentation are not missed.

Sex and aggregation pheromone transport after methyl eugenol consumption in male Bactrocera papayae

International Nuclear Information System (INIS)

Hee, Alvin K.W.; Tan, K.H.

2000-01-01

Amongst at least 52 sibling species complexes in the Oriental fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae), B. papayae (formerly Mal B) Drew and Hancock (Drew and Hancock 1994) is beginning to emerge as an economically important insect pest which poses a severe threat to the fruit cultivation in both subtropical and tropical countries. In Malaysia, B. papayae is one of the most damaging pests which infests many commercially grown fruits (Tan and Lee 1982). Like the Oriental fruit fly and its sibling species complex, B. carambolae Drew and Hancock, B. papayae is also strongly attracted to, and compulsively feeds on, methyl eugenol (ME) (Tan 1993). Chemical analyses revealed that in B. papayae males, ME is converted to phenylpropanoids which are then selectively accumulated in the rectal gland. Of the three major volatile substances, 2-allyl-4,5-dimethoyphenol (allyl-DMP) was detected in higher quantities relative to the trans-coniferyl alcohol (4-(3-hydroxy-E-propenyl)-2-methoxyphenol) (CF) and cis-3,4-dimethoxycinnamyl alcohol (cis-DMC) (Nishida et al. 1988a, 1988b). Behavioural studies have also shown that allyl-DMP and CF function as male sex and aggregation pheromone in B. papayae (Tan and Nishida 1996, Hee and Tan 1998). Allyl-DMP was found to be the most attractive compound and cis-DMC the least attractive to the males (Tan 1996). Consumption of ME enhances the mating competitiveness of males. This is demonstrated by the strong attraction of females to conspecific ME-fed males in wind tunnel experiments (Hee and Tan 1998). In male-male mating competition for virgin females, males that fed on ME performed significantly better (Shelly and Dewire 1994, Tan and Nishida 1996). Thus it appears that ME-fed males produced signals that were more attractive. However, the characterisation and understanding of the functions of these phenylpropanoids have not been accompanied by studies of their physiological mode of transport in male flies. The current

Parent-adolescent sex communication in China.

Science.gov (United States)

Zhang, Liying; Li, Xiaoming; Shah, Iqbal H; Baldwin, Wendy; Stanton, Bonita

2007-06-01

Communication concerning sexual matters between parents and their adolescent children serve as a protective factor and exerts a favourable influence on adolescents' sexual behaviours. As limited data regarding parent-adolescent sex communication are available in China, this study was undertaken with the aim of exploring the patterns and related factors of such communication and its relationship with adolescent sexual behaviour. Community-based data were collected in 2001 in Changchun, China. Unmarried adolescents 15-19 years of age (322 young men and 360 young women) were included in a survey using self-administered questionnaires. Overall, sex communication with parents was relatively infrequent. There was a significant gender difference in the pattern of sex communication, with male adolescents being more likely to talk with fathers and female adolescents with mothers. Logistic regression analysis revealed that gender of adolescents, quality of communication with mothers on general topics, and adolescent's perception of mother being the main source of sex knowledge were predictive of the level of sex communication between mother and her adolescent children. This study reveals that communication regarding sexual matters between parents and adolescents was limited in China. The quality of communication on general topics between parents and their adolescent children is one of the important factors related to sex communication between them. It is essential that Chinese parents are better informed and skilled to be involved, in addition to school and community, in the sex education of their adolescent children. They should be able to communicate appropriately on sex-related issues with them.

Sex differences in the association between gray matter volume and verbal creativity.

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Shi, Baoguo; Xu, Li; Chen, Qunlin; Qiu, Jiang

2017-08-02

The explanation for why significant sex differences are found in creativity has become an increasingly important topic. The current study applied a cognitive neuroscience perspective and voxel-based morphometry to investigate the sex differences for the association between verbal creativity and gray matter volume (GMV) in a large sample of healthy adults from the Chinese Mainland (163 men and 193 women). Furthermore, we sought to determine which brain regions are responsible for these differences. Our behavioral results showed a significant sex difference. Specifically, women scored higher than men on originality. The voxel-based morphometry results indicated that the relationship between originality and GMV differed between men and women in the left temporo-occipital junction. Higher originality scores in women were associated with more GMV. In contrast, higher originality scores in men were related to less GMV. These findings suggest the left temporo-occipital junction GMV plays a unique role in the sex differences in verbal creativity because women usually surpass men in semantic processing, which is the major function of the left temporal region.

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

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Jin-Ying Zhuang

Full Text Available 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.

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

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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.

Sex differences in the relationship between white matter connectivity and creativity.

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Ryman, Sephira G; van den Heuvel, Martijn P; Yeo, Ronald A; Caprihan, Arvind; Carrasco, Jessica; Vakhtin, Andrei A; Flores, Ranee A; Wertz, Christopher; Jung, Rex E

2014-11-01

Creative cognition emerges from a complex network of interacting brain regions. This study investigated the relationship between the structural organization of the human brain and aspects of creative cognition tapped by divergent thinking tasks. Diffusion weighted imaging (DWI) was used to obtain fiber tracts from 83 segmented cortical regions. This information was represented as a network and metrics of connectivity organization, including connectivity strength, clustering and communication efficiency were computed, and their relationship to individual levels of creativity was examined. Permutation testing identified significant sex differences in the relationship between global connectivity and creativity as measured by divergent thinking tests. Females demonstrated significant inverse relationships between global connectivity and creative cognition, whereas there were no significant relationships observed in males. Node specific analyses revealed inverse relationships across measures of connectivity, efficiency, clustering and creative cognition in widespread regions in females. Our findings suggest that females involve more regions of the brain in processing to produce novel ideas to solutions, perhaps at the expense of efficiency (greater path lengths). Males, in contrast, exhibited few, relatively weak positive relationships across these measures. Extending recent observations of sex differences in connectome structure, our findings of sexually dimorphic relationships suggest a unique topological organization of connectivity underlying the generation of novel ideas in males and females. Published by Elsevier Inc.

Vitamin D metabolism, sex hormones, and male reproductive function

DEFF Research Database (Denmark)

Blomberg Jensen, Martin

2012-01-01

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...... 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...

Occipital Lobe Gray Matter Volume in Male Patients with Chronic Schizophrenia: A Quantitative MRI Study

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Onitsuka, Toshiaki; McCarley, Robert W.; Kuroki, Noriomi; Dickey, Chandlee C.; Kubicki, Marek; Demeo, Susan S.; Frumin, Melissa; Kikinis, Ron; Jolesz, Ferenc A.; Shenton, Martha E.

2008-01-01

Schizophrenia is characterized by deficits in cognition as well as visual perception. There have, however, been few magnetic resonance imaging (MRI) studies of the occipital lobe as an anatomically defined region of interest in schizophrenia. To examine whether or not patients with chronic schizophrenia show occipital lobe volume abnormalities, we measured gray matter volumes for both the primary visual area (PVA) and the visual association areas (VAA) using MRI based neuroanatomical landmarks and three-dimensional information. PVA and VAA gray matter volumes were measured using high-spatial resolution MRI in 25 male patients diagnosed with chronic schizophrenia and in 28 male normal controls. Chronic schizophrenia patients showed reduced bilateral VAA gray matter volume (11%), compared with normal controls, whereas patients showed no group difference in PVA gray matter volume. These results suggest that reduced bilateral VAA may be a neurobiological substrate of some of the deficits observed in early visual processing in schizophrenia. PMID:17350226

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.

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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.

Sleep spindling and fluid intelligence across adolescent development: sex matters.

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Bódizs, Róbert; Gombos, Ferenc; Ujma, Péter P; Kovács, Ilona

2014-01-01

Evidence supports the intricate relationship between sleep electroencephalogram (EEG) spindling and cognitive abilities in children and adults. Although sleep EEG changes during adolescence index fundamental brain reorganization, a detailed analysis of sleep spindling and the spindle-intelligence relationship was not yet provided for adolescents. Therefore, adolescent development of sleep spindle oscillations were studied in a home polysomnographic study focusing on the effects of chronological age and developmentally acquired overall mental efficiency (fluid IQ) with sex as a potential modulating factor. Subjects were 24 healthy adolescents (12 males) with an age range of 15-22 years (mean: 18 years) and fluid IQ of 91-126 (mean: 104.12, Raven Progressive Matrices Test). Slow spindles (SSs) and fast spindles (FSs) were analyzed in 21 EEG derivations by using the individual adjustment method (IAM). A significant age-dependent increase in average FS density (r = 0.57; p = 0.005) was found. Moreover, fluid IQ correlated with FS density (r = 0.43; p = 0.04) and amplitude (r = 0.41; p = 0.049). The latter effects were entirely driven by particularly reliable FS-IQ correlations in females [r = 0.80 (p = 0.002) and r = 0.67 (p = 0.012), for density and amplitude, respectively]. Region-specific analyses revealed that these correlations peak in the fronto-central regions. The control of the age-dependence of FS measures and IQ scores did not considerably reduce the spindle-IQ correlations with respect to FS density. The only positive spindle-index of fluid IQ in males turned out to be the frequency of FSs (r = 0.60, p = 0.04). Increases in FS density during adolescence may index reshaped structural connectivity related to white matter maturation in the late developing human brain. The continued development over this age range of cognitive functions is indexed by specific measures of sleep spindling unraveling gender differences in adolescent brain maturation and perhaps

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

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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. © The Author(s) 2013.

Incidence, prevalence, diagnostic delay, morbidity, mortality and socioeconomic status in males with 46,XX disorders of sex development

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Berglund, A.; Johannsen, T. H.; Stochholm, K.

2017-01-01

STUDY QUESTION What is the epidemiology and trajectory of health and socioeconomic status in males with 46,XX disorders of sex development (DSD)? SUMMARY ANSWER 46,XX DSD males had an increased overall morbidity compared to male background population controls, and the socioeconomic status was inf...

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

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João Fabrício Mota Rodrigues

Full Text Available 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.

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

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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.

Contact networks structured by sex underpin sex-specific epidemiology of infection.

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Silk, Matthew J; Weber, Nicola L; Steward, Lucy C; Hodgson, David J; Boots, Mike; Croft, Darren P; Delahay, Richard J; McDonald, Robbie A

2018-02-01

Contact networks are fundamental to the transmission of infection and host sex often affects the acquisition and progression of infection. However, the epidemiological impacts of sex-related variation in animal contact networks have rarely been investigated. We test the hypothesis that sex-biases in infection are related to variation in multilayer contact networks structured by sex in a population of European badgers Meles meles naturally infected with Mycobacterium bovis. Our key results are that male-male and between-sex networks are structured at broader spatial scales than female-female networks and that in male-male and between-sex contact networks, but not female-female networks, there is a significant relationship between infection and contacts with individuals in other groups. These sex differences in social behaviour may underpin male-biased acquisition of infection and may result in males being responsible for more between-group transmission. This highlights the importance of sex-related variation in host behaviour when managing animal diseases. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Risk factors for HIV infection in Males who have Sex with Males (MSM in Bangladesh

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Khan Omar A

2007-07-01

Full Text Available Abstract Background Recent surveillance data from Bangladesh indicate rising HIV infection among intravenous drug users (IDU in the country. We suggest a likely association between HIV risk factors in this group and other groups, such as males who have sex with males (MSM. Methods Data on MSM in Bangladesh was collected and analyzed from numerous primary and secondary sources, including government ministries, non-profit health organizations, and personal communications. Results The overall prevalence of HIV in Bangladesh is relatively low, but surveillance data indicate that infection has reached significant proportions in certain high-risk groups and may soon spread to other groups, specifically MSM. Conclusion The epidemiology of HIV infection in other countries suggests that increasing rates of HIV in higher-risk populations can precede an epidemic in the general population. We review the data concerning MSM, IDU and HIV in Bangladesh from a variety of sources and propose ways to prevent HIV transmission.

Burden of HIV and Syphilis: A Comparative Evaluation between Male Sex Workers and Non-Sex-Worker Men Who Have Sex with Men in Urban China.

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Weiming Tang

Full Text Available The increasing burden of sexually transmitted infections (STIs including HIV and syphilis among male sex workers (MSWs is a major global concern. The aim of our study was to evaluate the difference between MSWs and non-commercial MSMs in China.During 2008-09, in a cross-sectional study, 2618 adult MSM were recruited through respondent-driven and snowball sampling from seven cities of China. Information regarding socio-demographics, risk behaviors, HIV-related knowledge and STI-related symptoms were collected and participants were tested for HIV and syphilis.Among 2618 participating MSM, 9.97% sold sex to males. HIV prevalence was 7.45% (6.13% among MSWs and 7.59% among non-MSW MSM and syphilis prevalence was 14.32% (10.73% for MSWs and 14.72% for non-MSW MSM. Compared to non-MSW MSM, MSWs were more likely to be younger (adjusted odds ratio: aOR = 0.91, 95% confidence interval: 95%CI=0.88-0.93, never married (aOR = 4.38, 95% CI = 2.38-6.80, less educated, heterosexual (aOR = 13.04, 95% CI = 6.08-27.95, less knowledgeable regarding HIV (aOR = 0.70, 95% CI=0.51-0.96, experiencing symptoms of STI (aOR = 2.16, 95% CI = 1.47-3.19, engaging in condomless vaginal intercourse (aOR = 2.16, 95% CI = 1.47-3.19 and less likely to engage in condomless anal intercourse (aOR = 0.62, 95% CI = 0.46-0.85.High HIV and syphilis prevalence warranted urgent intervention targeting MSWs as a separate sentinel group for efficient surveillance owing to their different distribution from non-MSW MSM. Although male sex workers and non-commercial homosexuals have similar rates of HIV and syphilis, MSWs have different characteristics which should be considered in designing intervention programs targeting them.

Presence of Putative Male-Produced Sex Pheromone in Lutzomyia cruciata (Diptera: Psychodidae), Vector of Leishmania mexicana.

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Serrano, A K; Rojas, J C; Cruz-López, L C; Malo, Edi A; Mikery, O F; Castillo, A

2016-11-01

Lutzomyia cruciata (Coquillet) is a vector of cutaneous leishmaniasis in Mexico and Central America. However, several aspects of its ecology and behavior are unknown, including whether a male pheromone partially mediates the sexual behavior of this sand fly. In this study, we evaluated the behavioral response of females to male abdominal extracts in a Y-tube olfactometer. The volatile compounds from male abdominal extracts were identified by gas chromatography-mass spectrometry and compared with those of female abdominal extracts. Finally, the disseminating structures of the putative sex pheromone were examined by scanning electron microscopy in the male abdomen. Females were more attracted to male abdominal extract than to the hexane control, suggesting the presence of male-produced sex pheromone. The male abdominal extracts were characterized by the presence of 12 sesquiterpene compounds. The major component, an unknown sesquiterpene with an abundance of 60%, had a mass spectrum with molecular ion of m/z 262. In contrast, the abdominal female extracts contained saturated fatty acids. Finally, we detected the presence of small "papules" with a mammiform morphology distributed on the abdominal surface of tergites IV-VII of male Lu. cruciata These structures are not present in females. We conclude that Lu. cruciata males likely produce a pheromone involved in attracting or courting females. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Hazardous drinking and HIV-risk-related behavior among male clients of female sex workers in Tijuana, Mexico.

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Goodman-Meza, David; Pitpitan, Eileen V; Semple, Shirley J; Wagner, Karla D; Chavarin, Claudia V; Strathdee, Steffanie A; Patterson, Thomas L

2014-01-01

Male clients of female sex workers (FSWs) are at high risk for HIV. Whereas the HIV risks of alcohol use are well understood, less is known about hazardous alcohol use among male clients of FSWs, particularly in Mexico. We sought to identify risk factors for hazardous alcohol use and test associations between hazardous alcohol use and HIV risk behavior among male clients in Tijuana. Male clients of FSWs in Tijuana (n = 400) completed a quantitative interview in 2008. The AUDIT was used to characterize hazardous alcohol use. Multivariate logistic regression was used to determine independent associations of demographic and HIV risk variables with hazardous alcohol use (vs. non-hazardous). Forty percent of our sample met criteria for hazardous alcohol use. Variables independently associated with hazardous drinking were reporting any sexually transmitted infection (STI), having sex with a FSW while under the influence of alcohol, being younger than 36 years of age, living in Tijuana, and ever having been jailed. Hazardous drinkers were less likely ever to have been deported or to have shared injection drugs. Hazardous alcohol use is associated with HIV risk, including engaging in sex with FSWs while intoxicated and having an STI among male clients of FSWs in Tijuana. We systematically described patterns and correlates of hazardous alcohol use among male clients of FSWs in Tijuana, Mexico. The results suggest that HIV/STI risk reduction interventions must target hazardous alcohol users, and be tailored to address alcohol use. © American Academy of Addiction Psychiatry.

Etiological Diagnosis of Undervirilized Male / XY Disorder of Sex Development

International Nuclear Information System (INIS)

Atta, I.; Ibrahim, M.; Parkash, A.; Lone, S. W.; Khan, Y. N.; Raza, J.

2014-01-01

Objective: To do clinical, hormonal and chromosomal analysis in undervirilized male / XY disorder of sex development and to make presumptive etiological diagnosis according to the new Disorder of Sex Development (DSD) classification system. Study Design: Case series. Place and Duration of Study: Endocrine Unit at National Institute of Child Health, Karachi, Pakistan, from January 2007 to December 2012. Methodology: Patients of suspected XY DSD / undervirilized male visiting endocrine clinic were enrolled in the study. Criteria suggested XY DSD include overt genital ambiguity, apparent female/male genitalia with inguinal/labial mass, apparent male genitalia with unilateral or bilateral non-palpable testes, micropenis and isolated hypospadias or with undescended testis. The older children who had delayed puberty were also evaluated with respect to DSD. As a part of evaluation of XY DSD, abdominopelvic ultrasound, karyotype, hormone measurement (testosterone, FSH, LH), FISH analysis with SRY probing, genitogram, laparoscopy, gonadal biopsy and HCG stimulation test were performed. Frequencies and percentages applied on categorical data whereas mean, median, standard deviation were calculated for continuous data. Results: A total of 187 patients met the criteria of XY DSD. Age ranged from 1 month to 15 years, 55 (29.4%) presented in infancy, 104 (55.6%) between 1 and 10 years and 28 (15%) older than 10 years. Twenty five (13.4%) were raised as female and 162 as (86.6%) male. The main complaints were ambiguous genitalia, unilateral cryptorchidism, bilateral cryptorchidism, micropenis, delayed puberty, hypospadias, female like genitalia with gonads, inguinal mass. The karyotype was 46 XY in 183 (97.9%), 46 XX in 2 (1.1%), 47 XXY in 1 (0.5%), 45 X/46 XY in 1 (0.5%) patient. HCG stimulation test showed low testosterone response in 43 (23 %), high testosterone response in 62 (33.2%), partial testosterone response in 32 (17.1%) and normal testosterone response in 50 (26

Testosterone regulation of sex steroid-related mRNAs and dopamine-related mRNAs in adolescent male rat substantia nigra

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Purves-Tyson Tertia D

2012-08-01

Full Text Available Abstract Background Increased risk of schizophrenia in adolescent males indicates that a link between the development of dopamine-related psychopathology and testosterone-driven brain changes may exist. However, contradictions as to whether testosterone increases or decreases dopamine neurotransmission are found and most studies address this in adult animals. Testosterone-dependent actions in neurons are direct via activation of androgen receptors (AR or indirect by conversion to 17β-estradiol and activation of estrogen receptors (ER. How midbrain dopamine neurons respond to sex steroids depends on the presence of sex steroid receptor(s and the level of steroid conversion enzymes (aromatase and 5α-reductase. We investigated whether gonadectomy and sex steroid replacement could influence dopamine levels by changing tyrosine hydroxylase (TH protein and mRNA and/or dopamine breakdown enzyme mRNA levels [catechol-O-methyl transferase (COMT and monoamine oxygenase (MAO A and B] in the adolescent male rat substantia nigra. We hypothesized that adolescent testosterone would regulate sex steroid signaling through regulation of ER and AR mRNAs and through modulation of aromatase and 5α-reductase mRNA levels. Results We find ERα and AR in midbrain dopamine neurons in adolescent male rats, indicating that dopamine neurons are poised to respond to circulating sex steroids. We report that androgens (T and DHT increase TH protein and increase COMT, MAOA and MAOB mRNAs in the adolescent male rat substantia nigra. We report that all three sex steroids increase AR mRNA. Differential action on ER pathways, with ERα mRNA down-regulation and ERβ mRNA up-regulation by testosterone was found. 5α reductase-1 mRNA was increased by AR activation, and aromatase mRNA was decreased by gonadectomy. Conclusions We conclude that increased testosterone at adolescence can shift the balance of sex steroid signaling to favor androgenic responses through promoting

The male-female health-survival paradox and sex differences in cohort life expectancy in Utah, Denmark, and Sweden 1850-1910

DEFF Research Database (Denmark)

Lindahl-Jacobsen, Rune; Hanson, Heidi A; Oksuzyan, Anna

2013-01-01

PURPOSE: In Utah, the prevalence of unhealthy male risk behaviors are lower than in most other male populations, whereas women experience higher mortality risk because of higher fertility rates. Therefore, we hypothesize that the Utah sex differential in mortality would be small and less than...... in the sex differences in cohort life expectancy was approximately 2 years smaller for active Mormons in Utah than for other groups suggesting lifestyle as an important component for the overall change seen in cohort life expectancy. Sex differences in cohort life expectancy at the age of 50 years were...

The Tyranny of Surveillance: Male Teachers and the Policing of Masculinities in a Single Sex School

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Martino, Wayne; Frank, Blye

2006-01-01

This paper draws on research into male teachers in one single sex high school in the Australian context to highlight how issues of masculinity impact on their pedagogical practices and relationships with boys. The study is situated within the broader international field of research on male teachers, masculinities and schooling in Australia, the UK…

Changes in HIV Seroprevalence and Related Behaviors Among Male Injection Drug Users Who Do and Do Not Have Sex With Men: New York City, 1990–1999

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Maslow, Carey B.; Friedman, Samuel R.; Perlis, Theresa E.; Rockwell, Russell; Des Jarlais, Don C.

2002-01-01

Objectives. This study examined HIV prevalence and risk behaviors among male injection drug users (IDUs) who have sex with men and among other male IDUs. Methods. Male IDUs were interviewed and tested for HIV at a detoxification clinic during 1990 to 1994 and 1995 to 1999. Analyses compared male IDUs who do and do not have sex with men within and between periods. Results. Initially, HIV seroprevalence and risk behaviors were higher among IDUs who have sex with men. Seroprevalence (initially 60.5% vs 48.3%) declined approximately 15% in both groups, remaining higher among those who have sex with men. Generally, injection prevalence, but not sexual risk behaviors, declined. Conclusions. Male IDUs who have sex with men are more likely to engage in higher-risk behaviors and to be HIV infected. Improved intervention approaches for male IDUs who have sex with men are needed. (Am J Public Health. 2002;92:382–384) PMID:11867315

Epigenetics and sex-specific fitness: an experimental test using male-limited evolution in Drosophila melanogaster.

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Abbott, Jessica K; Innocenti, Paolo; Chippindale, Adam K; Morrow, Edward H

2013-01-01

When males and females have different fitness optima for the same trait but share loci, intralocus sexual conflict is likely to occur. Epigenetic mechanisms such as genomic imprinting (in which expression is altered according to parent-of-origin) and sex-specific maternal effects have been suggested as ways by which this conflict can be resolved. However these ideas have not yet been empirically tested. We designed an experimental evolution protocol in Drosophila melanogaster that enabled us to look for epigenetic effects on the X-chromosome-a hotspot for sexually antagonistic loci. We used special compound-X females to enforce father-to-son transmission of the X-chromosome for many generations, and compared fitness and gene expression levels between Control males, males with a Control X-chromosome that had undergone one generation of father-son transmission, and males with an X-chromosome that had undergone many generations of father-son transmission. Fitness differences were dramatic, with experimentally-evolved males approximately 20% greater than controls, and with males inheriting a non-evolved X from their father about 20% lower than controls. These data are consistent with both strong intralocus sexual conflict and misimprinting of the X-chromosome under paternal inheritance. However, expression differences suggested that reduced fitness under paternal X inheritance was largely due to deleterious maternal effects. Our data confirm the sexually-antagonistic nature of Drosophila's X-chromosome and suggest that the response to male-limited X-chromosome evolution entails compensatory evolution for maternal effects, and perhaps modification of other epigenetic effects via coevolution of the sex chromosomes.

EVALUATION OF MALE SEX HORMONES AND TRACE ELEMENTS IN MALE TYPE 2 DIABETIC PATIENTS ATTENDING NNAMDI AZIKIWE UNIVERSITY TEACHING HOSPITAL DIABETIC CLINICS.

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Ubajaka, C F; Meludu, S C; Dioka, C E; Onah, C E; Osuji, C U; Modebe, I A; Ifeadike, G C; Okwara, J E; Amah, U K; Nnebue, C C

2015-01-01

There is accumulating evidence that the metabolism of male sex hormones and several trace elements are altered in type 2 diabetic mellitus and may have specific role in the pathogenesis and progression of the disease. To assess the levels of male sex hormones and trace elements in type 2 diabetic patients and to ascertain an association between male sex hormones and trace elements among diabetic subjects. A descriptive cross sectional study was conducted among 125 diabetic and 50 non diabetic subjects. Venous blood samples were collected from all respondents and estimated for fasting blood glucose, male sex hormones and trace elements. The results were subjected to statistical analysis and comparison using Students' test and Pearson correlation analysis. The mean testosterone level was significantly lower in diabetics than in controls (3.9 ± 1.9ng/ml) in comparison with (5.1 ± 1.7ng/ml; P < 0.05). The mean value of Zinc, Manganese, Selenium and Chromium were significantly lower among the diabetics when compared with the controls (Zn;898.7 ± 131.0 μg/l; Mn:0.30 ± 0.06 μg/l;Se:51.3 ± 11.1 μg/l; Cr: 0.04 ± 0.03 μg/I) in comparison with (Zn: 1007.3 ± 85.2 μg/l; Mn: 0.05 ± 0.07μg/l; Se: 62.1 ± 11.1 μg/l; Cr: 0.06 ± 0.01 μg/l; P < 0.05).The mean Fasting Blood Glucose in diabetic subjects was significantly higher when compared with the controls (7.9 ± 3.7 mmol/l) in comparison with (4.6 ± 0.4 mmol/l; P < 0.05).The trace elements showed a positive correlation with testosterone in diabetic subjects (Zn r = 0.359, Ser = 0.443, Mn r = 0.350, P < 0.05). This study observed decreased levels of testosterone and trace elements in type 2 diabetics and a positive correlation between low testosterone and low trace elements levels in diabetic subjects. These trace elements are antioxidants and their low levels in diabetic patients may further increase the severity of the disease.

Promoting female condoms in the sex industry in 4 towns of Southern China: context matters.

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Nie, Li; Liao, Susu; Weeks, Margaret R; Wang, Yanhong; Jiang, Jingmei; Zhang, Qingning; Zhou, Yuejiao; He, Bin; Li, Jianghong; Dunn, Jennifer

2013-03-01

The female condom (FC) is an effective tool for dual protection, but it remains underused. Individual and contextual reasons need to be explored. The aim of this study was to compare individual and contextual characteristics of FC multitime users, 1-time users, and nonusers among women in the sex industry of 4 study sites in China. A standardized 1-year FC intervention along with male condoms was implemented through outreach to sex establishments. Three serial cross-sectional surveys were conducted at baseline and after each of two 6-month intervention phases. A total of 445, 437, and 290 eligible women were interviewed at 3 cross-sectional surveys, respectively. At the first and second postintervention surveys, 83.3% and 81.7% of women reported knowing about FC, and 28.8% and 36.6% had used FC at least once. Women who used FC multiple times reported less unprotected sex than nonusers in the last 30 days (3.0% vs. 17.2% at first and 3.2% vs. 16.8% at second postintervention survey, P 4.0) and working in boarding houses (adjusted odds ratio, 3.4) were associated with FC use. Adding FC into male-condom-only intervention may reduce unprotected sex among women in sex establishments in rural and small urban areas of China. Adoption of FC may be related not only to intervention exposure but also to contextual factors associated with study site and type of sex establishments.

Different male versus female breeding periodicity helps mitigate offspring sex ratio skews in sea turtles

Directory of Open Access Journals (Sweden)

Graeme Clive Hays

2014-09-01

Full Text Available The implications of climate change for global biodiversity may be profound with those species with little capacity for adaptation being thought to be particularly vulnerable to warming. A classic case of groups for concern are those animals exhibiting temperature-dependent sex-determination (TSD, such as sea turtles, where climate warming may produce single sex populations and hence extinction. We show that, globally, female biased hatchling sex ratios dominate sea turtle populations (exceeding 3:1 in >50% records, which, at-a-glance, reiterates concerns for extinction. However, we also demonstrate that more frequent breeding by males, empirically shown by satellite tracking 23 individuals and supported by a generalized bio-energetic life history model, generates more balanced operational sex ratios (OSRs. Hence, concerns of increasingly skewed hatchling sex ratios and reduced population viability are less acute than previously thought for sea turtles. In fact, in some scenarios skewed hatchling sex ratios in groups with TSD may be adaptive to ensure optimum OSRs.

Otolith morphology varies between populations, sexes and male alternative reproductive tactics in a vocal toadfish Porichthys notatus.

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Bose, A P H; Adragna, J B; Balshine, S

2017-01-01

In this study, the morphology of sagittal otoliths of the plainfin midshipman fish Porichthys notatus was compared between populations, sexes and male alternative reproductive phenotypes (known as 'type I males or guarders' and 'type II males or sneakers'). Sagitta size increased with P. notatus size and changes in shape were also detected with increasing body size. Porichthys notatus sagittae begin as simple rounded structures, but then elongate as they grow and take on a more triangular and complex shape with several prominent notches and indentations along the dorsal and caudal edges. Moreover, the sagittae of the two geographically and genetically distinct populations of P. notatus (northern and southern) differed in shape. Porichthys notatus from the north possessed taller sagittae with deeper caudal indentations compared to P. notatus from the south. Sagitta shape also differed between females and males of the conventional guarder tactic. Furthermore, guarder males had smaller sagittae for their body size than did sneaker males or females. These differences in sagittal otolith morphology are discussed in relation to ecological and life history differences between the sexes and male tactics of this species. This is the first study to investigate teleost otolith morphology from the perspective of alternative reproductive tactics. © 2016 The Fisheries Society of the British Isles.

Alternative Splicing Profile and Sex-Preferential Gene Expression in the Female and Male Pacific Abalone Haliotis discus hannai.

Science.gov (United States)

Kim, Mi Ae; Rhee, Jae-Sung; Kim, Tae Ha; Lee, Jung Sick; Choi, Ah-Young; Choi, Beom-Soon; Choi, Ik-Young; Sohn, Young Chang

2017-03-09

In order to characterize the female or male transcriptome of the Pacific abalone and further increase genomic resources, we sequenced the mRNA of full-length complementary DNA (cDNA) libraries derived from pooled tissues of female and male Haliotis discus hannai by employing the Iso-Seq protocol of the PacBio RSII platform. We successfully assembled whole full-length cDNA sequences and constructed a transcriptome database that included isoform information. After clustering, a total of 15,110 and 12,145 genes that coded for proteins were identified in female and male abalones, respectively. A total of 13,057 putative orthologs were retained from each transcriptome in abalones. Overall Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analyzed in each database showed a similar composition between sexes. In addition, a total of 519 and 391 isoforms were genome-widely identified with at least two isoforms from female and male transcriptome databases. We found that the number of isoforms and their alternatively spliced patterns are variable and sex-dependent. This information represents the first significant contribution to sex-preferential genomic resources of the Pacific abalone. The availability of whole female and male transcriptome database and their isoform information will be useful to improve our understanding of molecular responses and also for the analysis of population dynamics in the Pacific abalone.

Alternative Splicing Profile and Sex-Preferential Gene Expression in the Female and Male Pacific Abalone Haliotis discus hannai

Directory of Open Access Journals (Sweden)

Mi Ae Kim

2017-03-01

Full Text Available In order to characterize the female or male transcriptome of the Pacific abalone and further increase genomic resources, we sequenced the mRNA of full-length complementary DNA (cDNA libraries derived from pooled tissues of female and male Haliotis discus hannai by employing the Iso-Seq protocol of the PacBio RSII platform. We successfully assembled whole full-length cDNA sequences and constructed a transcriptome database that included isoform information. After clustering, a total of 15,110 and 12,145 genes that coded for proteins were identified in female and male abalones, respectively. A total of 13,057 putative orthologs were retained from each transcriptome in abalones. Overall Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes (KEGG pathways analyzed in each database showed a similar composition between sexes. In addition, a total of 519 and 391 isoforms were genome-widely identified with at least two isoforms from female and male transcriptome databases. We found that the number of isoforms and their alternatively spliced patterns are variable and sex-dependent. This information represents the first significant contribution to sex-preferential genomic resources of the Pacific abalone. The availability of whole female and male transcriptome database and their isoform information will be useful to improve our understanding of molecular responses and also for the analysis of population dynamics in the Pacific abalone.

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

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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.

Boys and girls on the playground: sex differences in social development are not stable across early childhood

OpenAIRE

Barbu , Stéphanie; Cabanes , Guénaël; Le Maner-Idrissi , Gaïd

2011-01-01

International audience; Sex differences in human social behaviors and abilities have long been a question of public and scientific interest. Females are usually assumed to be more socially oriented and skillful than males. However, despite an extensive literature, the very existence of sex differences remains a matter of discussion while some studies found no sex differences whereas others reported differences that were either congruent or not with gender stereotypes. Moreover, the magnitude,...

Female sex pheromone and male behavioral responses of the bombycid moth Trilocha varians: comparison with those of the domesticated silkmoth Bombyx mori

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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.

Concurrent sexual partnerships among female sex workers and their non-commercial male partners in Tijuana and Ciudad Juarez, Mexico.

Science.gov (United States)

Robertson, Angela Marie; Syvertsen, Jennifer L; Rangel, M Gudelia; Staines, Hugo S; Morris, Martina; Patterson, Thomas L; Ulibarri, Monica D; Strathdee, Steffanie A

2013-06-01

To investigate the prevalence and correlates of concurrent (overlapping) sexual partnerships among female sex workers (FSWs) and their non-commercial male partners in two Mexico-US border cities. A cross-sectional survey of FSWs and their non-commercial male partners was conducted in Tijuana and Ciudad Juárez, Mexico (2010-2011). Eligible FSWs and verified non-commercial partners were aged ≥18 years; FSWs had ever used hard drugs (lifetime) and recently exchanged sex for money, drugs or other goods (past month). Participants underwent baseline questionnaires obtaining dates of sex and condom use with ≤5 other recurring partners, including FSWs' regular clients. These dates were compared with dates of sex with enrolled study partners to determine overlap (ie, 'recurring' concurrency). Bivariate probit regression identified recurring concurrency correlates. Among 428 individuals (214 couples), past-year recurring concurrency prevalence was 16% and was higher among women than their non-commercial male partners (26% vs 6%). In 10 couples (5%), both partners reported recurring concurrency. The majority of couples (64%) always had unprotected sex, and most of the individuals (70%) with recurring concurrency 'sometimes' or 'never' used condoms with their concurrent partners. Recurring concurrency was positively associated with FSWs' income, men's caballerismo (a form of traditional masculinity) and men's belief that their FSW partners had sexually transmitted infections (STIs). Recurring concurrency, representing sustained periods of overlapping partnerships in which unprotected sex was common, should be addressed by couple-based STI prevention interventions.

Performance, power and condom use: reconceptualised masculinities amongst Western male sex tourists to Thailand.

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Bishop, Simon; Limmer, Mark

2018-03-01

Each year large numbers of Western men travel to Thailand for sex tourism. Although many will use condoms during their sexual encounters, others will not, potentially exposing themselves to the risk of acquiring sexually transmitted infections, including HIV. Although sex tourism in Thailand has been well documented, the social drivers underpinning voluntary sexual risk-taking through the avoidance of condoms remain poorly understood. Engaging with R.W. Connell's concept of hegemonic masculinity and drawing on data collected from 1237 online discussion board posts and 14 face-to-face interviews, this study considers the ways in which understandings and performances of masculinities may inform the sexual risk-taking behaviours of Western male sex tourists. It argues that for some of these men, unprotected sex is viewed not as a reckless behaviour but, instead, as a safe and appropriate masculine practice, supported by relationships that are often framed as romantic and within a setting where HIV is still largely considered a homosexual disease. With sex workers often disempowered to request safer sexual practices, and some men's attitudes towards unprotected sex resistant to external health promotion advice, the paper concludes by considering what this might mean for policy and practice.

Sexual dimorphism of Broca's region: More gray matter in female brains in Brodmann areas 44 and 45.

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Kurth, Florian; Jancke, Lutz; Luders, Eileen

2017-01-02

Although a sexual dimorphism in brain structure is generally well established, evidence for sex differences in Brodmann areas (BA) 44 and 45 is inconclusive. This may be due to the difficulty of accurately defining BA 44 and BA 45 in magnetic resonance images, given that these regions are variable in their location and extent and that they do not match well with macroanatomic landmarks. Here we set out to test for possible sex differences in the local gray matter of BA 44/45 by integrating imaging-based signal intensities with cytoarchitectonically defined tissue probabilities in a sample of 50 male and 50 female subjects. In addition to testing for sex differences with respect to left- and right-hemispheric measures of BA 44/45, we also assessed possible sex differences in BA 44/45 asymmetry. Our analyses revealed significantly larger gray matter volumes in females compared with males for BA 44 and BA 45 bilaterally. However, there was a lack of significant sex differences in BA 44/45 asymmetry. These results corroborate reports of a language-related female superiority, particularly with respect to verbal fluency and verbal memory tasks. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Low reproductive skew despite high male-biased operational sex ratio in a glass frog with paternal care.

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Mangold, Alexandra; Trenkwalder, Katharina; Ringler, Max; Hödl, Walter; Ringler, Eva

2015-09-03

Reproductive skew, the uneven distribution of reproductive success among individuals, is a common feature of many animal populations. Several scenarios have been proposed to favour either high or low levels of reproductive skew. Particularly a male-biased operational sex ratio and the asynchronous arrival of females is expected to cause high variation in reproductive success among males. Recently it has been suggested that the type of benefits provided by males (fixed vs. dilutable) could also strongly impact individual mating patterns, and thereby affecting reproductive skew. We tested this hypothesis in Hyalinobatrachium valerioi, a Neotropical glass frog with prolonged breeding and paternal care. We monitored and genetically sampled a natural population in southwestern Costa Rica during the breeding season in 2012 and performed parentage analysis of adult frogs and tadpoles to investigate individual mating frequencies, possible mating preferences, and estimate reproductive skew in males and females. We identified a polygamous mating system, where high proportions of males (69 %) and females (94 %) reproduced successfully. The variance in male mating success could largely be attributed to differences in time spent calling at the reproductive site, but not to body size or relatedness. Female H. valerioi were not choosy and mated indiscriminately with available males. Our findings support the hypothesis that dilutable male benefits - such as parental care - can favour female polyandry and maintain low levels of reproductive skew among males within a population, even in the presence of direct male-male competition and a highly male-biased operational sex ratio. We hypothesize that low male reproductive skew might be a general characteristic in prolonged breeders with paternal care.

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

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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.

Females scan more than males: a potential mechanism for sex differences in recognition memory.

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Heisz, Jennifer J; Pottruff, Molly M; Shore, David I

2013-07-01

Recognition-memory tests reveal individual differences in episodic memory; however, by themselves, these tests provide little information regarding the stage (or stages) in memory processing at which differences are manifested. We used eye-tracking technology, together with a recognition paradigm, to achieve a more detailed analysis of visual processing during encoding and retrieval. Although this approach may be useful for assessing differences in memory across many different populations, we focused on sex differences in face memory. Females outperformed males on recognition-memory tests, and this advantage was directly related to females' scanning behavior at encoding. Moreover, additional exposures to the faces reduced sex differences in face recognition, which suggests that males may be able to improve their recognition memory by extracting more information at encoding through increased scanning. A strategy of increased scanning at encoding may prove to be a simple way to enhance memory performance in other populations with memory impairment.

Behavioral and Psychosocial Correlates of HIV Testing Among Male Clients of Female Sex Workers in Tijuana, Mexico.

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Fleming, Paul J; Patterson, Thomas L; Chavarin, Claudia V; Semple, Shirley J; Magis-Rodriguez, Carlos; Pitpitan, Eileen V

2017-08-01

We use data collected from a sample of 400 male clients of female sex workers (FSW) to examine their HIV testing behavior. We present frequencies of HIV testing and used bivariate and multivariable analyses to assess its socio-demographic, behavioral, and psychosocial correlates. We found that the majority (55 %) of male clients of FSW in Tijuana, Mexico had never had an HIV test and the prevalence of HIV testing within the past year was low (9 %). In multivariable analyses, significant correlates of having ever tested for HIV were higher age, higher HIV knowledge score, lower sexual compulsiveness score, lower misogynistic attitudes score, having a condom break during sex with a FSW, and higher frequency of sex with a FSW while she was high. Our findings represent an important starting point for developing effective interventions to address the need to promote HIV testing among this population.

Behavioural and cognitive sex/gender differences in autism spectrum condition and typically developing males and females

OpenAIRE

Hull, L.; Mandy, W.; Petrides, K.

2017-01-01

Studies assessing sex/gender differences in autism spectrum conditions often fail to include typically developing control groups. It is, therefore, unclear whether observed sex/gender differences reflect those found in the general population or are particular to autism spectrum conditions. A systematic search identified articles comparing behavioural and cognitive characteristics in males and females with and without an autism spectrum condition diagnosis. A total of 13 studies were included ...

nr0b1 (DAX1) mutation in zebrafish causes female-to-male sex reversal through abnormal gonadal proliferation and differentiation.

Science.gov (United States)

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. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Putative sex differences in verbal abilities and language cortex: A critical review

DEFF Research Database (Denmark)

Wallentin, Mikkel

2009-01-01

  This review brings together evidence from a diverse field of methods for investigating sex differences in language processing. Differences are found in certain language-related deficits, such as stuttering, dyslexia, autism and schizophrenia. Common to these is that language problems may follow...... studies on regional grey matter distribution using voxel-based morphometry, indicate no consistent differences between males and females in language related cortical regions. Language function in Wada-tests, aphasia, and in normal aging also fails to show sex differentiation.  ...

Sex Differences in the Relationship Between Conduct Disorder and Cortical Structure in Adolescents.

Science.gov (United States)

Smaragdi, Areti; Cornwell, Harriet; Toschi, Nicola; Riccelli, Roberta; Gonzalez-Madruga, Karen; Wells, Amy; Clanton, Roberta; Baker, Rosalind; Rogers, Jack; Martin-Key, Nayra; Puzzo, Ignazio; Batchelor, Molly; Sidlauskaite, Justina; Bernhard, Anka; Martinelli, Anne; Kohls, Gregor; Konrad, Kerstin; Baumann, Sarah; Raschle, Nora; Stadler, Christina; Freitag, Christine; Sonuga-Barke, Edmund J S; De Brito, Stephane; Fairchild, Graeme

2017-08-01

Previous studies have reported reduced cortical thickness and surface area and altered gyrification in frontal and temporal regions in adolescents with conduct disorder (CD). Although there is evidence that the clinical phenotype of CD differs between males and females, no studies have examined whether such sex differences extend to cortical and subcortical structure. As part of a European multisite study (FemNAT-CD), structural magnetic resonance imaging (MRI) data were collected from 48 female and 48 male participants with CD and from 104 sex-, age-, and pubertal-status-matched controls (14-18 years of age). Data were analyzed using surface-based morphometry, testing for effects of sex, diagnosis, and sex-by-diagnosis interactions, while controlling for age, IQ, scan site, and total gray matter volume. CD was associated with cortical thinning and higher gyrification in ventromedial prefrontal cortex in both sexes. Males with CD showed lower, and females with CD showed higher, supramarginal gyrus cortical thickness compared with controls. Relative to controls, males with CD showed higher gyrification and surface area in superior frontal gyrus, whereas the opposite pattern was seen in females. There were no effects of diagnosis or sex-by-diagnosis interactions on subcortical volumes. Results are discussed with regard to attention-deficit/hyperactivity disorder, depression, and substance abuse comorbidity, medication use, handedness, and CD age of onset. We found both similarities and differences between males and females in CD-cortical structure associations. This initial evidence that the pathophysiological basis of CD may be partly sex-specific highlights the need to consider sex in future neuroimaging studies and suggests that males and females may require different treatments. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Donor/recipient sex mismatch and survival after heart transplantation: only an issue in male recipients? An analysis of the Spanish Heart Transplantation Registry.

Science.gov (United States)

Martinez-Selles, Manuel; Almenar, Luis; Paniagua-Martin, Maria J; Segovia, Javier; Delgado, Juan F; Arizón, Jose M; Ayesta, Ana; Lage, Ernesto; Brossa, Vicens; Manito, Nicolás; Pérez-Villa, Félix; Diaz-Molina, Beatriz; Rábago, Gregorio; Blasco-Peiró, Teresa; De La Fuente Galán, Luis; Pascual-Figal, Domingo; Gonzalez-Vilchez, Francisco

2015-03-01

The results of studies on the association between sex mismatch and survival after heart transplantation are conflicting. Data from the Spanish Heart Transplantation Registry. From 4625 recipients, 3707 (80%) were men. The donor was female in 943 male recipients (25%) and male in 481 female recipients (52%). Recipients of male hearts had a higher body mass index (25.9 ± 4.1 vs. 24.3 ± 3.7; P gender (P = 0.02). In the multivariate analysis, sex mismatch was associated with long-term mortality (HR, 1.14; 95% CI 1.01-1.29; P = 0.04), and there was a tendency toward significance for the interaction between sex mismatch and recipient gender (P = 0.08). In male recipients, mismatch increased mortality mainly during the first month and in patients with pulmonary gradient >13 mmHg. Sex mismatch seems to be associated with mortality after heart transplantation in men but not in women. © 2014 Steunstichting ESOT.

Distinct sperm nucleus behaviors between genotypic and temperature-dependent sex determination males are associated with replication and expression-related pathways in a gynogenetic fish.

Science.gov (United States)

Zhu, Yao-Jun; Li, Xi-Yin; Zhang, Jun; Li, Zhi; Ding, Miao; Zhang, Xiao-Juan; Zhou, Li; Gui, Jian-Fang

2018-06-05

Coexistence and transition of diverse sex determination strategies have been revealed in some ectothermic species, but the variation between males caused by different sex determination strategies and the underlying mechanism remain unclear. Here, we used the gynogenetic gibel carp (Carassius gibelio) with both genotypic sex determination (GSD) and temperature-dependent sex determination (TSD) strategies to illustrate this issue. We found out that males of GSD and TSD in gibel carp had similar morphology, testicular histology, sperm structure and sperm vitality. However, when maternal individuals were mated with males of GSD, sperm nucleus swelling and fusing with the female pronucleus were observed in the fertilized eggs. On the contrary, when maternal individuals were mated with males of TSD, sperm nucleus remained in the condensed status throughout the whole process. Subsequently, semen proteomics analysis unveiled that DNA replication and gene expression-related pathways were inhibited in the sperm from males of TSD compared to males of GSD, and most differentially expressed proteins associated with DNA replication, transcription and translation were down-regulated. Moreover, via BrdU incorporation and immunofluorescence detection, male nucleus replication was revealed to be present in the fertilized eggs by the sperm from males of GSD, but absent in the fertilized eggs by the sperm from males of TSD. These findings indicate that DNA replication and gene expression-related pathways are associated with the distinct sperm nucleus development behaviors in fertilized eggs in response to the sperm from males of GSD and TSD. And this study is the first attempt to screen the differences between males determined via GSD and TSD in gynogenetic species, which might give a hint for understanding evolutionary adaption of diverse sex determination mechanisms in unisexual vertebrates.

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

Directory of Open Access Journals (Sweden)

Vojkan Vukadinovic

2014-01-01

Full Text Available 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.

A Phenomenological Study of Middle Grade Female and Male Students' Single-Sex Mathematical Experiences

Science.gov (United States)

Simpson, Amber; Che, S. Megan

2016-01-01

Utilizing a descriptive phenomenological design, this study examines the lived experiences of seven middle grade students, four females and three males, enrolled in a single-sex mathematics classroom within a coeducational school setting. The intent of the study is to understand, from students themselves, about the experience of single-sex…

The relationship between female brooding and male nestling provisioning: does climate underlie geographic variation in sex roles?

Science.gov (United States)

Yoon, Jongmin; Sofaer, Helen R.; Sillett, T. Scott; Morrison, Scott A.; Ghalambor, Cameron K.

2017-01-01

Comparative studies of populations occupying different environments can provide insights into the ecological conditions affecting differences in parental strategies, including the relative contributions of males and females. Male and female parental strategies reflect the interplay between ecological conditions, the contributions of the social mate, and the needs of offspring. Climate is expected to underlie geographic variation in incubation and brooding behavior, and can thereby affect both the absolute and relative contributions of each sex to other aspects of parental care such as offspring provisioning. However, geographic variation in brooding behavior has received much less attention than variation in incubation attentiveness or provisioning rates. We compared parental behavior during the nestling period in populations of orange-crowned warblers Oreothlypis celata near the northern (64°N) and southern (33°N) boundaries of the breeding range. In Alaska, we found that males were responsible for the majority of food delivery whereas the sexes contributed equally to provisioning in California. Higher male provisioning in Alaska appeared to facilitate a higher proportion of time females spent brooding the nestlings. Surprisingly, differences in brooding between populations could not be explained by variation in ambient temperature, which was similar between populations during the nestling period. While these results represent a single population contrast, they suggest additional hypotheses for the ecological correlates and evolutionary drivers of geographic variation in brooding behavior, and the factors that shape the contributions of each sex.

Male sex workers: Are we ignoring a risk group in Mumbai, India?

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Shinde Santosh

2009-01-01

Full Text Available Background: Male sex workers (MSWs have recently been recognized as an important risk group for sexually transmitted infections (STIs including human immunodeficiency virus (HIV infection. Although there are global studies on MSWs, few such studies describe the behavioral patterns and STIs among this population in India. Methods: MSWs were evaluated at the Humsafar trust, a community based organization situated in suburban Mumbai, India. We report on the demographics, sexual behaviors, and STIs including HIV of these sex workers. Results: Of the 75 MSWs, 24 were men and 51 were transgenders. The mean age of the group was 23.3 (+ 4.9 years. About 15% were married or lived with a permanent partner. Of these individuals, 85% reported sex work as a main source of income and 15% as an additional source. All the individuals reported anal sex (87% anal receptive sex and 13% anal insertive sex. About 13% of MSWs had never used a condom. The HIV prevalence was 33% (17% in men vs 41% in transgenders, P = 0.04. The STI prevalence was 60% (58% in men vs 61% in transgenders, P = 0.8. Syphilis was the most common STI (28% in these MSWs. HIV was associated with being a transgender (41 vs 17%, P = 0.04, age > 26 years (57 vs 28%, P = 0.04, more than one year of sex work (38 vs 8%, P = 0.05, and income < Rs. 2000 per month (62 vs 27%, P = 0.02. Conclusions: The MSWs have high-risk behaviors, low consistent condom use, and high STI/HIV infections. These groups should be the focus of intensive public health interventions aimed at reduction of risky sexual practices, and STI/HIV prevention and care.

The dynamics of male brooding, mating patterns, and sex roles in pipefishes and seahorses (family Syngnathidae).

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Wilson, Anthony B; Ahnesjö, Ingrid; Vincent, Amanda C J; Meyer, Axel

2003-06-01

Modern theory predicts that relative parental investment of the sexes in their young is a key factor responsible for sexual selection. Seahorses and pipefishes (family Syngnathidae) are extraordinary among fishes in their remarkable adaptations for paternal care and frequent occurrences of sex-role reversals (i.e., female-female competition for mates), offering exceptional opportunities to test predictions of sexual selection theory. During mating, the female transfers eggs into or onto specialized egg-brooding structures that are located on either the male's abdomen or its tail, where they are osmoregulated, aerated, and nourished by specially adapted structures. All syngnathid males exhibit this form of parental care but the brooding structures vary, ranging from the simple ventral gluing areas of some pipefishes to the completely enclosed pouches found in seahorses. We present a molecular phylogeny that indicates that the diversification of pouch types is positively correlated with the major evolutionary radiation of the group, suggesting that this extreme development and diversification of paternal care may have been an important evolutionary innovation of the Syngnathidae. Based on recent studies that show that the complexity of brooding structures reflects the degree of paternal investment in several syngnathid species, we predicted sex-role reversals to be more common among species with more complex brooding structures. In contrast to this prediction, however, both parsimony- and likelihood-based reconstructions of the evolution of sex-role reversal in pipefishes and seahorses suggest multiple shifts in sex roles in the group, independent from the degree of brood pouch development. At the same time, our data demonstrate that sex-role reversal is positively associated with polygamous mating patterns, whereas most nonreversed species mate monogamously, suggesting that selection for polygamy or monogamy in pipefishes and seahorses may strongly influence sex

Perinatal testosterone contributes to mid-to-post pubertal sex differences in risk for binge eating in male and female rats.

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Culbert, Kristen M; Sinclair, Elaine B; Hildebrandt, Britny A; Klump, Kelly L; Sisk, Cheryl L

2018-02-01

Exposure to testosterone early in life may contribute to sex differences and pubertal changes in risk for eating pathology (i.e., females > males, after pubertal onset). Specifically, perinatal testosterone permanently alters brain structure/function and drives the masculinization of several sex-differentiated behaviors. However, the effects of perinatal testosterone are often not evident until puberty when increases in gonadal hormones activate the expression of sex typical behavior, including eating behaviors (e.g., chow intake; saccharin preference) in rodents. Despite perinatal testosterone's masculinizing effects on general feeding behavior, it remains unknown if perinatal testosterone exposure contributes to sex differences in pathological eating. The current study addressed this gap by examining whether perinatal testosterone exposure decreases risk for binge eating proneness after pubertal onset in male and female rats. Sprague-Dawley rats (n = 40 oil-treated control females; n = 39 testosterone-treated females; n = 40 oil-treated control males) were followed longitudinally across pre-to-early puberty, mid-to-late puberty, and adulthood. The binge eating prone (BEP)/binge eating resistant (BER) rodent model was used to identify individual differences in binge eating proneness across the dimensional spectrum. As expected, testosterone-treated females and control males showed masculinized (i.e., lower) risk for binge eating as compared to control females, but only after midpuberty. These animal data are significant in suggesting that perinatal testosterone exposure may protect against binge eating and underlie sex differences in binge eating prevalence during and after puberty. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

(Patho)physiology of cross-sex hormone administration to transsexual people: the potential impact of male-female genetic differences

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Gooren, L.J.; Kreukels, B.P.C.; Lapauw, B.; Giltay, E.J.

2015-01-01

There is a limited body of knowledge of desired and undesired effects of cross-sex hormones in transsexual people. Little attention has been given to the fact that chromosomal configurations, 46,XY in male-to-female transsexuals subjects (MtoF) and 46,XX in female-to-male transsexual subjects

The evolution of sex roles in birds is related to adult sex ratio.

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Liker, András; Freckleton, Robert P; Székely, Tamás

2013-01-01

Sex-role reversal represents a formidable challenge for evolutionary biologists, since it is not clear which ecological, life-history or social factors facilitated conventional sex roles (female care and male-male competition for mates) to be reversed (male care and female-female competition). Classic theories suggested ecological or life-history predictors of role reversal, but most studies failed to support these hypotheses. Recent theory however predicts that sex-role reversal should be driven by male-biased adult sex ratio (ASR). Here we test this prediction for the first time using phylogenetic comparative analyses. Consistent with theory, both mating system and parental care are strongly related to ASR in shorebirds: conventional sex roles are exhibited by species with female-biased ASR, whereas sex-role reversal is associated with male-biased ASR. These results suggest that social environment has a strong influence on breeding systems and therefore revealing the causes of ASR variation in wild populations is essential for understanding sex role evolution.

Dwarf males, large hermaphrodites and females in marine species: a dynamic optimization model of sex allocation and growth.

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Yamaguchi, Sachi; Sawada, Kota; Yusa, Yoichi; Iwasa, Yoh

2013-05-01

In this study, we investigate the evolutionarily stable schedule of growth and sex allocation for marine benthic species that contain dwarf males. We consider a population in an ephemeral microhabitat that receives a constant supply of larvae. Small individuals can immediately reproduce as a dwarf male or remain immature and grow. Large individuals allocate reproductive resources between male and female functions. The fraction c of newly settled individuals who remain immature and the sex allocation of large individuals m are quantities to evolve. In the stationary ESS, if the relative reproductive success of dwarf males is greater than the survivorship of immature individuals until they reach a mature size, then the population is a mixture of females and dwarf males. If the opposite inequality holds, the population is dominated by hermaphrodites and lacks dwarf males. There is no case in which a mixture of hermaphrodites and dwarf males to be the ESS in the stationary solution. The ESS can be solved by dynamic programming when the strategies depend on the age of the microhabitat (c(t) and m(t)). Typically, the ESS schedule begins with a population composed only of hermaphrodites, which is replaced by a mixture of dwarf males and hermaphrodites and then by a mixture of dwarf males and pure females. The relative importance of these three phases depends on multiple parameters. Copyright © 2013 Elsevier Inc. All rights reserved.

Study on the correlationship between serum levels of sex hormones and Th1/Th2 cytokines in male patients with graves' disease

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Liu Li; Su Shengou; Zhang Xuekun; Wang Hongfen

2009-01-01

Objective: To explore the effect of sex hormones on the balance of Th1/Th2 in male patients with GD through investigation of changes of serum levels of sex hormones and cytokines (IFN-γ and IL-4) after treatment. Methods: Serum levels of E 2 , testosterone, FSH, LH (with RIA) and IFN-γ, IL-4 (with ELISA) were determined in 42 male patients with Graves' disease (both before and after 12 weeks of successful antithyroid therapy) and 40 controls. Results: The levels of E 2 , T, LH, FSH in the patients before treatment were significantly higher than those in the controls (P 2 was an independent fator affecting the levels of IL-4, and showed positive correlationship. The level of T was an independent factor affecting the levels of IFN-γ, also showed positive correlationship. The levels of IL-4 and IFN-γ were independent factors to each other, and there was negative correlationship between them. Conclusion: There were changes in levels of sex hormones and imbalance of Th1/Th2 in male patients with Graves' disease. The sex hormones might have some effect on Th1/Th2 balance in male patients with GD. (authors)

Sexing a sex-role-reversed species based on plumage: potential challenges in the red phalarope

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Marie-Andrée Giroux

2016-05-01

Full Text Available Sex-role reversal, in which males care for offspring, can occur when mate competition is stronger between females than males. Secondary sex traits and mate attracting displays in sex-role-reversed species are usually more pronounced in females than in males. The red phalarope (Phalaropus fulicarius is a textbook example of a sex-role-reversed species. It is generally agreed that males are responsible for all incubation and parental care duties, whereas females typically desert males after having completed a clutch and may pair with new males to lay additional clutches. The breeding plumage of female red phalaropes is usually more brightly colored than male plumage, a reversed sexual dichromatism usually associated with sex-role reversal. Here, we confirm with PCR-based sexing that male red phalaropes can exhibit both the red body plumage typical of a female and the incubation behavior typical of a male. Our result, combined with previous observations of brightly colored red phalaropes incubating nests at the same arctic location (Igloolik Island, Nunavut, Canada, suggests that plumage dichromatism alone may not be sufficient to distinguish males from females in this breeding population of red phalaropes. This stresses the need for more systematic genetic sexing combined with standardized description of intersexual differences in red phalarope plumages. Determining whether such female-like plumage on males is a result of phenotypic plasticity or genetic variation could contribute to further understanding sex-role reversal strategies in the short Arctic summer.

To fight or mate? Hormonal control of sex recognition, male sexual behavior and aggression in the gecko lizard.

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Schořálková, Tereza; Kratochvíl, Lukáš; Kubička, Lukáš

2018-01-01

Squamate reptiles are a highly diversified vertebrate group with extensive variability in social behavior and sexual dimorphism. However, hormonal control of these traits has not previously been investigated in sufficient depth in many squamate lineages. Here, we studied the hormonal control of male sexual behavior, aggressiveness, copulatory organ (hemipenis) size and sex recognition in the gecko Paroedura picta, comparing ovariectomized females, ovariectomized females treated with exogenous dihydrotestosterone (DHT), ovariectomized females treated with exogenous testosterone (T), control females and males. The administration of both T and DHT led to the expression of male-typical sexual behavior in females. However, in contrast to T, increased circulating levels of DHT alone were not enough to initiate the full expression of male-typical offensive aggressive behavior and development of hemipenes in females. Ovariectomized females were as sexually attractive as control females, which does not support the need for the demasculinization of the cues used for sex recognition by ovarian hormones as suggested in other sauropsids. On the other hand, our results point to the masculinization of the sex recognition cues by male gonadal androgens. Previously, we also demonstrated that sexually dimorphic growth is controlled by ovarian hormones in P. picta. Overall, it appears that individual behavioral and morphological sexually-dimorphic traits are controlled by multiple endogenous pathways in this species. Variability in the endogenous control of particular traits could have permitted their disentangling during evolution and the occurrence of (semi)independent changes across squamate phylogeny. Copyright © 2017 Elsevier Inc. All rights reserved.

The Associations of Perceived Social Support with Key HIV Risk and Protective Factors Among Young Males Who Have Sex with Males in Bangkok and Chiang Mai, Thailand.

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Johnston, Lisa; Steinhaus, Mara; Sass, Justine; Benjarattanaporn, Patchara; Sirinirund, Petchsri; Siraprapasiri, Taweesap; Gass, Robert

2018-06-01

This study used respondent-driven sampling to explore the effects of social support on HIV risk and protective factors among young males who have sex with males (YMSM) in Bangkok (N = 273) and Chiang Mai (N = 243), Thailand. It compared different measures of social support, including living situation, the proportion of family and friends to whom the respondent had disclosed their same-sex attraction, and scores on the multi-dimensional scale of perceived social support as predictors of two outcomes of interest-coerced first sex and HIV knowledge. Social support from family played a mediating role in both outcomes among YMSM in Bangkok but not those from Chiang Mai. Though social support from friends was also studied, it was less strongly associated with the outcomes of interest. The findings support interventions designed to leverage social support networks to increase HIV knowledge and decrease coerced first sex among YMSM. At the same time, they demonstrate that there is not a single risk or demographic profile encompassing all YMSM. Successful programs and policies will need to consider the specific attributes and social environment of YMSM in particular locations in order to effectively address HIV risks.

The male-female health-survival paradox and sex differences in cohort life expectancy in Utah, Denmark, and Sweden 1850-1910.

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Lindahl-Jacobsen, Rune; Hanson, Heidi A; Oksuzyan, Anna; Mineau, Geraldine P; Christensen, Kaare; Smith, Ken R

2013-04-01

In Utah, the prevalence of unhealthy male risk behaviors are lower than in most other male populations, whereas women experience higher mortality risk because of higher fertility rates. Therefore, we hypothesize that the Utah sex differential in mortality would be small and less than in Sweden and Denmark. Life tables from Utah, Denmark, and Sweden were used to calculate cohort life expectancies for men and women born in 1850-1910. The sex difference in cohort life expectancy was similar or larger in Utah when compared with Denmark and Sweden. The change over time in the sex differences in cohort life expectancy was approximately 2 years smaller for active Mormons in Utah than for other groups suggesting lifestyle as an important component for the overall change seen in cohort life expectancy. Sex differences in cohort life expectancy at the age of 50 years were similar for individuals actively affiliated with the Church of Jesus Christ of Latter-day Saints and for Denmark and Sweden. The hypothesis that a smaller sex difference in cohort life expectancies in Utah would be detected in relation to Denmark and Sweden was not supported. In Utah, the male-female differences in life expectancy remain substantial pointing toward biological mechanisms or other unmeasured risk factors. Copyright © 2013 Elsevier Inc. All rights reserved.

Let’s Talk About Sex: Parental Communication and Sexual Behavior of Male Filipino Youth

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Goldilyn D. Gumban

2016-05-01

Full Text Available Understanding the sexual behavior of young people is important in pursuing health development in our society. In the Philippines, current data shows that there is a drastic increase in sex related activities concerning our youths. According to past studies, strong familial relationship and parent-child connectedness decrease the likelihood of a child to engage in risky sex. Furthermore, families with strong communication and are open to sexual topics became closer, and more comfortable with each other. This quantitative, correlational study was designed to describe the level of parental communication in terms of sexual health issues and its relationship to the sexual behaviorsof male Filipino youths in Metro Manila. A total of 143 male respondents ages 18-25 from Metro Manila participated in the study through an online survey. Results suggest that that majority of the respondents reported low level of parental communication in terms of sexual health issues and a large number reported risky sexual behaviors. The results of this study suggested no significant relationship between the respondent‟s level of parental communication and their sexual behavior.

Sex Steroid Hormones Matter for Learning and Memory: Estrogenic Regulation of Hippocampal Function Inmale and Female Rodents

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Frick, Karyn M.; Kim, Jaekyoon; Tuscher, Jennifer J.; Fortress, Ashley M.

2015-01-01

Ample evidence has demonstrated that sex steroid hormones, such as the potent estrogen 17ß-estradiol (E[subscript 2]), 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…

Correlates of unprotected sex with male clients among female sex workers in 13 Mexican cities.

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Semple, Shirley J; Pitpitan, Eileen V; Chavarin, Claudia V; Strathdee, Steffanie A; Mendoza, Doroteo V; Aarons, Gregory A; Patterson, Thomas L

2017-12-01

This study examined correlates of unprotected vaginal and anal sex (UVA) with male clients among female sex workers (FSWs). Baseline data were gathered from 1089 FSWs recruited from 13 cities across Mexico enrolled in an evidence-based sexual risk reduction intervention. We used generalised estimating equations (GEE) to predict total UVA while controlling for the nested structure of the data. Total UVA with clients in the past month was examined in relation to selected sociodemographic, substance-use, and micro- and macro-environmental factors. A greater number of UVA acts was associated with three micro-level environmental factors (i.e. never getting condoms for free, unaffordability of condoms, greater number of clients per month), and three macro-level environmental factors (i.e. lower health and higher education indices, greater population size of city). These findings suggest the development of social and structural approaches to HIV prevention for FSWs in Mexico, including modification of venue-based policies that pressure FSWs to maximise client volume, changes to the work environment that promote availability and affordability of condoms, and improved population health. Moreover, our findings call for the development of context-specific HIV interventions that take into account variations in the sexual risk behaviours and HIV risk environments of FSWs throughout Mexico.

Why size matters: differences in brain volume account for apparent sex differences in callosal anatomy: the sexual dimorphism of the corpus callosum.

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Luders, Eileen; Toga, Arthur W; Thompson, Paul M

2014-01-01

Numerous studies have demonstrated a sexual dimorphism of the human corpus callosum. However, the question remains if sex differences in brain size, which typically is larger in men than in women, or biological sex per se account for the apparent sex differences in callosal morphology. Comparing callosal dimensions between men and women matched for overall brain size may clarify the true contribution of biological sex, as any observed group difference should indicate pure sex effects. We thus examined callosal morphology in 24 male and 24 female brains carefully matched for overall size. In addition, we selected 24 extremely large male brains and 24 extremely small female brains to explore if observed sex effects might vary depending on the degree to which male and female groups differed in brain size. Using the individual T1-weighted brain images (n=96), we delineated the corpus callosum at midline and applied a well-validated surface-based mesh-modeling approach to compare callosal thickness at 100 equidistant points between groups determined by brain size and sex. The corpus callosum was always thicker in men than in women. However, this callosal sex difference was strongly determined by the cerebral sex difference overall. That is, the larger the discrepancy in brain size between men and women, the more pronounced the sex difference in callosal thickness, with hardly any callosal differences remaining between brain-size matched men and women. Altogether, these findings suggest that individual differences in brain size account for apparent sex differences in the anatomy of the corpus callosum. © 2013.

Helping Behavior: Effects of Sex and Sex-Typing.

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Basow, Susan A.; Crawley, Donna M.

1982-01-01

Male and female experimenters requested adult shoppers (N=178) to fill out a questionnaire. Refusal data showed shoppers helping other-sex more than same-sex experimenters. Other results showed a significant three-way interaction among helper and helpee sex and sex-typing and situation sex-typing and that helper sex-typing did not have significant…

How to be a dioecious fig: Chemical mimicry between sexes matters only when both sexes flower synchronously

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Hossaert-McKey, M.; Proffit, M.; Soler, C. C. L.; Chen, C.; Bessière, J.-M.; Schatz, B.; Borges, R. M.

2016-01-01

In nursery pollination mutualisms, which are usually obligate interactions, olfactory attraction of pollinators by floral volatile organic compounds (VOCs) is the main step in guaranteeing partner encounter. However, mechanisms ensuring the evolutionary stability of dioecious fig–pollinator mutualisms, in which female fig trees engage in pollination by deceit resulting in zero reproductive success of pollinators that visit them, are poorly understood. In dioecious figs, individuals of each sex should be selected to produce odours that their pollinating wasps cannot distinguish, especially since pollinators have usually only one choice of a nursery during their lifetime. To test the hypothesis of intersexual chemical mimicry, VOCs emitted by pollen-receptive figs of seven dioecious species were compared using headspace collection and gas chromatography-mass spectrometry analysis. First, fig-flower scents varied significantly among species, allowing host-species recognition. Second, in species in which male and female figs are synchronous, intersexual VOC variation was not significant. However, in species where figs of both sexes flower asynchronously, intersexual variation of VOCs was detectable. Finally, with one exception, there was no sexual dimorphism in scent quantity. We show that there are two ways to use scent to be a dioecious fig based on differences in flowering synchrony between the sexes. PMID:26888579

The Sertoli Cell Only Syndrome and Glaucoma in a Sex - Determining Region Y (SRY) Positive XX Infertile Male.

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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.

Factors associated with sex hormones and erectile dysfunction in male Taiwanese participants with obesity.

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Shi, Ming-Der; Chao, Jian-Kang; Ma, Mi-Chia; Hao, Lyh-Jyh; Chao, I-Chen

2014-01-01

Obesity has been receiving an increasing amount of attention recently, but investigations regarding the potential impact of obesity, sexual behaviors, and sex hormones on erectile dysfunction (ED) in men have not completely clarified the association. To identify the relationship between ED, sexual behavior, sexual satisfaction, sex hormones, and obesity in older adult males in Taiwan. Data were obtained from a baseline survey of 476 older adult males (≧40 years old). Their demographic data, body mass index (BMI), sex hormones, sexual desire, sexual satisfaction, and ED status were assessed. The International Index of Erectile Function-5 (IIEF-5), Sexual Desire Inventory (SDI), and Sexual Satisfaction Scale (SSS) were used to assess ED, sexual desire, and sexual satisfaction. In all, 476 men were available for analysis. The mean age of the sample was 51.34 ± 7.84 years (range 40 to 70 years). The IIEF total score had a mean of 19.44 ± 4.98; 264 (55.5%) subjects had ED, 250 (52.9%) were currently obese (BMI ≧27), and 297 (62.4%) had metabolic syndrome. The results showed an increased risk of ED among obese men and subjects with lower levels of sex hormones and lower sexual desire. Testosterone levels were lower in subjects with obesity (P < 0.001). Among the predictors of ED, obesity (odds ratio [OR] = 1.62, 95% CI = 1.07-2.44, P = 0.021), abnormal high sensitivity C-reactive protein (hs-CRP) (OR = 10.59, 95% CI = 4.70-23.87, P < 0.001), and lower serum full testosterone (OR = 3.27, 95% CI = 2.16-4.93, P < 0.001) were significantly independent factors. This study supports the idea of a close relationship between low levels of sex hormones, sexual desire, sexual satisfaction, obesity, and ED, and also shows that low free testosterone and hs-CRP may predict ED, even in obese populations. © 2013 International Society for Sexual Medicine.

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

NARCIS (Netherlands)

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 Apc(Pirc/+) (Pirc) rat model of early colonic cancer, this sex susceptibility was recapitulated, with male Pirc rats developing twice as many adenomas as

Negotiating the Edge: The Rationalization of Sexual Risk Taking Among Western Male Sex Tourists to Thailand.

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Bishop, Simon; Limmer, Mark

2017-09-08

Every year thousands of Western men travel to Thailand as sex tourists to participate in paid-for sex. Although many of these men will use condoms to protect themselves against sexually transmitted infections (STIs), others will not, despite the risks. By applying Steven Lyng's (1990) concept of edgework to data collected from 14 face-to-face interviews with male sex tourists in Pattaya, Thailand, and 1,237 online discussion board posts, this article explores the ways in which these men understood and sought to rationalize the sexual risks they took. We argue that notions of likelihood of infection and significance of consequence underpin these behaviors, and we identify the existence of understandings of sexual risk that reject mainstream safer-sex messages and frame condomless sex as a broadly safe activity for heterosexual men. The article concludes by summarizing the difficulties inherent in driving behavior change among this group of men, for whom sexual risks appear to be easily rationalized away as either inconsequential or irrelevant.

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

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

2013-01-01

Background In sub-Saharan Africa the population prevalence of men who have sex with men (MSM) is unknown, as is the population prevalence of male-on-male sexual violence, and whether male-on-male sexual violence may relate to HIV risk. This paper describes lifetime prevalence of consensual male–male sexual behavior and male-on-male sexual violence (victimization and perpetration) in two South African provinces, socio-demographic factors associated with these experiences, and associations with HIV serostatus. Methods and Findings In a cross-sectional study conducted in 2008, men aged 18–49 y from randomly selected households in the Eastern Cape and KwaZulu-Natal provinces provided anonymous survey data and dried blood spots for HIV serostatus assessment. Interviews were completed in 1,737 of 2,298 (75.6%) of enumerated and eligible households. From these households, 1,705 men (97.1%) provided data on lifetime history of same-sex experiences, and 1,220 (70.2%) also provided dried blood spots for HIV testing. 5.4% (n = 92) of participants reported a lifetime history of any consensual sexual activity with another man; 9.6% (n = 164) reported any sexual victimization by a man, and 3.0% (n = 51) reported perpetrating sexual violence against another man. 85.0% (n = 79) of men with a history of consensual sex with men reported having a current female partner, and 27.7% (n = 26) reported having a current male partner. Of the latter, 80.6% (n = 21/26) also reported having a female partner. Men reporting a history of consensual male–male sexual behavior are more likely to have been a victim of male-on-male sexual violence (adjusted odds ratio [aOR] = 7.24; 95% CI 4.26–12.3), and to have perpetrated sexual violence against another man (aOR = 3.10; 95% CI 1.22–7.90). Men reporting consensual oral/anal sex with a man were more likely to be HIV+ than men with no such history (aOR = 3.11; 95% CI 1.24–7.80). Men who had raped a man

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

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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.

Developing Online Recruitment and Retention Methods for HIV Prevention Research Among Adolescent Males Who Are Interested in Sex with Males: Interviews with Adolescent Males.

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Nelson, Kimberly M; Ramirez, Jaime J; Carey, Michael P

2017-12-21

Adolescent males interested in sex with males (AMSM) are an important audience for HIV prevention interventions, but they are difficult to reach due to their age and social stigma. We aim to identify efficient methods to recruit and retain AMSM in online research. Interviews with 14-to-18-year-old AMSM (N=16) were conducted at 2017 Pride events in Boston, MA and Providence, RI. Participants reported that (1) social media platforms are viable recruitment venues; (2) recruitment advertisements should describe the study using colorful/bright pictures, familiar words, and information about compensation; (3) surveys should be recruitment and retention procedures to increase the efficiency of HIV prevention research for this at-risk group. ©Kimberly M Nelson, Jaime J Ramirez, Michael P Carey. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 21.12.2017.

The CLOSER (CLarifying Vaginal Atrophy's Impact On SEx and Relationships) survey: implications of vaginal discomfort in postmenopausal women and in male partners.

Science.gov (United States)

Nappi, Rossella E; Kingsberg, Sheryl; Maamari, Ricardo; Simon, James

2013-09-01

Postmenopausal vaginal atrophy (VA) is a chronic condition with symptoms that include vaginal dryness, soreness, itching, burning, and dyspareunia. The CLarifying Vaginal Atrophy's Impact On SEx and Relationships survey evaluated the impact of VA on the physical and emotional aspects of sexual relationships between postmenopausal women and their male partners. Four thousand one hundred females and 4,100 males representing the United Kingdom, Finland, Norway, Sweden, Denmark, Italy, France, Canada, and the United States were surveyed. Assessments included: (i) talking about VA and its symptoms; (ii) the impact of VA on intimacy, relationships, and women's self-esteem; (iii) talking about VA and erectile dysfunction (ED); and (iv) the impact of local estrogen therapy (LET) on intimacy and relationships. Descriptive data on the impact of VA. Twenty-eight percent of women did not tell their partners when they first encountered vaginal discomfort, mainly because they felt "it was just a natural part of growing older" (52%) or because of "embarrassment" (21%). Eighty-two percent of males wanted their partner to share their experiences with VA; males were also more comfortable discussing VA than females (68% vs. 58%, respectively). Having sex less often (women: 58%, men: 61%), less satisfying sex (women: 49%, men: 28%), and putting off having sex (women: 35%, men: 14%) were the main effects of VA. Intimacy avoidance was attributed to painful sex (women: 55%, men: 61%) and women's reduced sexual desire (women: 46%, men: 43%). Discussions about vaginal discomfort and ED were generally limited to partners and healthcare providers (HCPs). LET use resulted in less painful sex (women: 62%, men: 59%) and more satisfying sex (women: 47%, men: 49%). VA has an adverse emotional and physical impact on postmenopausal women and their partners. These findings may encourage more open communication about VA between couples and their HCPs. © 2013 International Society for Sexual Medicine.

Associations between maternal phenolic exposure and cord sex hormones in male newborns.

Science.gov (United States)

Liu, Chunhua; Xu, Xijin; Zhang, Yuling; Li, Weiqiu; Huo, Xia

2016-03-01

Are maternal urinary phenol concentrations associated with cord steroid hormone levels and anogenital distance (AGD) in male newborns? High maternal urinary Bisphenol A (BPA) levels are associated with decreases in cord testosterone levels and the ratio of testosterone to estradiol in male newborns, but there was no significant association with AGD. Early life exposure to phenolic endocrine disrupting compounds (EDCs) is known to disrupt hormonal activities and affect reproductive development in males. However, studies on the health effects of prenatal human exposure are scarce. This was a cross-sectional study to investigate the association between maternal phenolic exposure and cord sex steroid hormones and AGD in male newborns. We recruited 100 mother-infant pairs from each of two hospitals, one in a polluted town (Guiyu) and the other in a cleaner town (Haojiang), from September 2010 to September 2011. One hundred and seventy eight maternal urine samples and 137 cord blood samples were available for quantification, thus 137 complete records entered into the final analysis. Of them, 77 pairs were from Guiyu, and 60 were from Haojiang. The chemical concentrations were determined by solid phase extraction and gas chromatography-mass spectrometry (SPE-GC-MS), and cord sex hormones were detected by radioimmunoassay (RIA). Neonatal anthropometric parameters including AGD were measured. Log2-transformed maternal urinary BPA concentration was negatively correlated with testosterone level and the ratio of testosterone to estradiol (T/E2) in male fetal cord blood after adjustment for potential confounders in linear regression models (βadjusted = -31.09 (95% CI, -53.07 to -9.11) and βadjusted = -0.08 (95% CI, -0.13 to -0.01), respectively). Moreover, compared with the lowest quartile group of BPA level, the highest group showed a significant decrease in testosterone level and T/E2 (βadjusted = -179.84 (95% CI, -333.45 to -26.24) and βadjusted = -0.37 (95% CI, -0.81 to

Radiation therapy induced changes in male sex hormone levels in rectal cancer patients

International Nuclear Information System (INIS)

Dueland, Svein; Groenlie Guren, Marianne; Rune Olsen, Dag; Poulsen, Jan Peter; Magne Tveit, Kjell

2003-01-01

Background and purpose:To determine the effect of curative radiation therapy (46-50 Gy) on the sex hormone levels in male rectal cancer patients. Materials and methods:Twenty-five male rectal cancer patients (mean age 65 years), receiving pelvic radiation therapy (2 Gyx23-25 fractions in 5 weeks) were included. Serum testosterone, FSH and LH were determined before start of treatment, at the 10th and 25th fractions, and 4-6 weeks after completed radiotherapy. The testicular dose was determined by thermoluminescent dosimetry. Results:Five weeks of radiation therapy (46-50 Gy) resulted in a 100% increase in serum FSH, a 70% increase in LH, and a 25% reduction in testosterone levels. After treatment, 35% of the patients had serum testosterone levels below lower limit of reference. The mean radiation dose to the testicles was 8.4 Gy. A reduction in testosterone values was observed already after a mean dose of 3.3 Gy (10th fraction). Conclusion:Radiation therapy (46-50 Gy) for rectal cancer resulted in a significant increase in serum FSH and LH and a significant decrease in testosterone levels, indicating that sex hormone production is sensitive to radiation exposure in patients with a mean age of 65 years

Molecular status of Human Immunodeficiency Virus, Hepatitis B virus, and Hepatitis C virus among injecting drug male commercial sex workers in Surakarta, Indonesia

Science.gov (United States)

Agung Prasetyo, Afiono; Marwoto; Arifin Adnan, Zainal; Hartono

2018-05-01

Male commercial sex workers are one of the high-risk community for blood-borne viruses. However, there are no data concerning the molecular status of Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV), and Hepatitis C Virus (HCV) circulated among male commercial sex workers with injecting drug habits in Surakarta, Indonesia. Blood samples obtained from injecting drug male commercial sex workers in Surakarta were examined for HIV antibodies, HBsAg, and HCV antibodies, respectively, by immunological assays. Blood samples were also subjected to viral nucleic acid extraction and molecular detection of HIV, HBV, and HCV by nested (RT) PCRs. The PCR products were purified from agarose gels, and the nucleotide sequences were retrieved and molecular analyzed. HIV, HBV, and HCV were detected in 29.4% (10/34), 17.6% (6/34), and 52.9% (18/34), respectively. HIV CRF01_AE and B were found to be circulating in the community. HBV genotype B3 was predominated, followed by C1. HCV genotype 1a was predominated, followed by 1c, 3a, 1b, and 4a. HIV, HBV, and HCV were found circulating in the male commercial sex workers with injecting drug habits in Surakarta, Indonesia.

Sexual dimorphism of gonadotropin-releasing hormone type-III (GnRH3) neurons and hormonal sex reversal of male reproductive behavior in Mozambique tilapia.

Science.gov (United States)

Kuramochi, Asami; Tsutiya, Atsuhiro; Kaneko, Toyoji; Ohtani-Kaneko, Ritsuko

2011-10-01

In tilapia, hormone treatment during the period of sexual differentiation can alter the phenotype of the gonads, indicating that endocrine factors can cause gonadal sex reversal. However, the endocrine mechanism underlying sex reversal of reproductive behaviors remains unsolved. In the present study, we detected sexual dimorphism of gonadotropin-releasing hormone type III (GnRH3) neurons in Mozambique tilapia Oreochromis mossambicus. Our immunohistochemical observations showed sex differences in the number of GnRH3 immunoreactive neurons in mature tilapia; males had a greater number of GnRH3 neurons in the terminal ganglion than females. Treatment with androgen (11-ketotestosterone (11-KT) or methyltestosterone), but not that with 17β-estradiol, increased the number of GnRH3 neurons in females to a level similar to that in males. Furthermore, male-specific nest-building behavior was induced in 70% of females treated with 11-KT within two weeks after the onset of the treatment. These results indicate androgen-dependent regulation of GnRH3 neurons and nest-building behavior, suggesting that GnRH3 is importantly involved in sex reversal of male-specific reproductive behavior.

Opportunities to improve competitiveness in male sexual strain has genetic sex determination Ceratitis capitata Wiedemann (Diptera: Tephritidae)

International Nuclear Information System (INIS)

Tlemcani, Meriem

2010-01-01

The success of TIS program depends essentially on the capacity of the sterile males to compete with fertile males to couple with wild females. This program becomes more and more efficient if one good mastery its various factors, mainly the performances of males of the origin of ceratite in genetic sexing within the production unit of sterile flies of the National Center of the Sciences and Nuclear Technologies. Researches turned to the improvement of the competitiveness of the sterile males by the addition of bacteria in the nourishing circles of breeding. By basing itself on the symbiotic relations between the present bacteria in the bowel of the ceratite, we adopted, in this present work, a method of breeding which could improve the quality of the males of genetic sexing GSS. This method consists in introducing certain beneficial bacteria in the ceratite (Enterobacteriaceae and Pseudomonas aerogenes) into the middle of breeding according to various combinations. The effect of these bacteria was analyzed by making various tests of quality control (weight, emergence, capacity in the flight, the longevity) and of reproduction (competitiveness, lasted mating, latent period). It turns out that the addition of Enterobacteriaceae in the middle of breeding outstandingly improved the percentage of emergence of the males of the GSS. Besides, these bacteria contributed to the improvement of the competitiveness of these males with regard to those of the other circles. Besides, the addition of Pseudomonas aerogenes in the middle of breeding gave the best latent period to the males GSS. We also noticed that the association of Enterobacteriaceae with Pseudomonas aerogenes has a positive effect on the capacity in the flight of the males of the GSS and their duration of mating.

Risk of epilepsy in opposite-sex and same-sex twins

DEFF Research Database (Denmark)

Mao, Yanyan; Ahrenfeldt, Linda Juel; Christensen, Kaare

2018-01-01

Background: There is a complex interaction between female and male sex hormones and the risk of epilepsy. Whether prenatal exposure to higher levels of sex hormones affects the development of epilepsy in childhood or later in life is not well known. The sex hormone environment of fetuses may...... be affected by the sex of the co-twin. We estimated the risk of epilepsy for twins with an opposite-sex (OS) co-twin compared with twins with a same-sex (SS) co-twin. Methods: From the Danish Twin Registry, we identified OS female twins (n = 11,078), SS female twins (n = 19,186), OS male twins (n = 11...

Unusually dynamic sex roles in a fish.

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Forsgren, Elisabet; Amundsen, Trond; Borg, Asa A; Bjelvenmark, Jens

2004-06-03

Sex roles are typically thought of as being fixed for a given species. In most animals males compete for females, whereas the females are more reluctant to mate. Therefore sexual selection usually acts most strongly on males. This is explained by males having a higher potential reproductive rate than females, leading to more males being sexually active (a male-biased operational sex ratio). However, what determines sex roles and the strength of sexual selection is a controversial and much debated question. In this large-scale field study, we show a striking temporal plasticity in the mating competition of a fish (two-spotted goby, Gobiusculus flavescens). Over the short breeding season fierce male-male competition and intensive courtship behaviour in males were replaced by female-female competition and actively courting females. Hence, sex role reversal occurred rapidly. This is the first time that a shift in sex roles has been shown in a vertebrate. The shift might be explained by a large decline in male abundance, strongly skewing the sex ratio towards females. Notably, the sex role reversal did not occur at an equal operational sex ratio, contrary to established sex role theory.

Maternal Smoking, Obesity and Male Fetal Sex Predispose to a Large Nuchal Translucency Thickness in Healthy Fetuses

DEFF Research Database (Denmark)

Pedersen, Nina Gros; Rode, L; Ekelund, Christer

2010-01-01

to multiples of the median (MoM(NT)) using a previously reported linear regression analysis. Results: The odds ratio (OR) for MoM(NT) >95th centile was 1.5 (95% CI 1.2-1.9) for smokers compared to nonsmokers and 1.4 (95% CI 1.1-1.7) for male fetuses compared to female fetuses. Obese women (BMI >/=30) had...... an increased OR for a large NT of 1.7 (95% CI 1.2-2.6) compared to normal weight women. Obese smokers carrying a male fetus had an OR of 4.2 (95% CI 1.7-10.1) of a MoM(NT) >95th centile compared to normal weight nonsmoking women with a female fetus. The effects of smoking, obesity status and fetal sex were...... independent of each other. Conclusions: Smoking, obesity and male sex are associated to a MoM(NT) >95th centile. This may affect screening performance and entail unnecessary anxiety in these women. Further investigations, including fetuses with adverse outcome, are needed....

Maternal Smoking, Obesity and Male Fetal Sex Predispose to a Large Nuchal Translucency Thickness in Healthy Fetuses

DEFF Research Database (Denmark)

Pedersen, Nina Gros; Rode, Line; Ekelund, Christer

2011-01-01

to multiples of the median (MoM(NT)) using a previously reported linear regression analysis. Results: The odds ratio (OR) for MoM(NT) >95th centile was 1.5 (95% CI 1.2-1.9) for smokers compared to nonsmokers and 1.4 (95% CI 1.1-1.7) for male fetuses compared to female fetuses. Obese women (BMI >/=30) had...... an increased OR for a large NT of 1.7 (95% CI 1.2-2.6) compared to normal weight women. Obese smokers carrying a male fetus had an OR of 4.2 (95% CI 1.7-10.1) of a MoM(NT) >95th centile compared to normal weight nonsmoking women with a female fetus. The effects of smoking, obesity status and fetal sex were...... independent of each other. Conclusions: Smoking, obesity and male sex are associated to a MoM(NT) >95th centile. This may affect screening performance and entail unnecessary anxiety in these women. Further investigations, including fetuses with adverse outcome, are needed....

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

International Nuclear Information System (INIS)

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

2007-01-01

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

[Study on HIV-1 subtype among elderly male clients and female sex workers of low-cost venues in Guangxi Zhuang Autonomous Region, China].

Science.gov (United States)

Deng, Y Q; Li, J J; Fang, N Y; Wang, B; Wang, J W; Liang, S S; Shen, Z Y; Lan, G H; Zhang, H M; Wu, X H; Lu, H X; Ge, X M

2017-03-10

Objective: To understand HIV-1 subtype characteristics and transmission clusters in elderly male clients and female sex workers (FSWs) of low-cost commercial sex venues in Guangxi Zhuang Autonomous Region, China. Methods: A cross sectional survey was conducted in FSWs and elderly male clients (≥50 years) of low-cost commercial sex venues in 4 cities and 9 counties in Guangxi Zhuang Autonomous Region by convenient sampling in 2012. The blood sample was collected from each case for HIV-1 antibody detection. The pol gene fragments were amplified and sequenced from viral RNA template extracted from plasma samples. The phylogenetic tree was constructed and the subtypes were identified. Results: A total of 4 048 elderly male clients and 784 FSWs were surveyed, and 116 HIV-1 infections were detected, the positive rate was 2.5% (103/4 048) in the clients and 1.7% (13/784) in FSWs. The gene amplification and sequencing of HIV-1 detected in 84 blood samples indicated that 53 pol gene sequences were successfully determined (48 blood samples from elderly male clients and 5 blood samples from FSWs). Among 53 pol sequences, 48(90.6% ), 4(7.5% ), and 1(1.9% ) sequences were identified as CRF01_AE, CRF08_BC, and CRF07_BC, respectively. Two transmission clusters were identified among CRF01_AE, including 4 sub-clusters. One transmission cluster was identified among CRF08_BC. The transmission cluster or sub-cluster were from the infected individuals at same low-cost commercial sex venue, or different low-cost commercial sex venues in the same town, or same place, or adjacent villages and towns. Conclusions: CRF01_AE was the predominant HIV-1 subtype among elderly male clients and FSWs of low-cost commercial sex venues in Guangxi Zhuang Autonomous Region, circulating in same venue or adjacent villages and towns. The HIV-1 positive male clients and FSWs might play an important role in the spread of the strains.

A Content Analysis of Testosterone Websites: Sex, Muscle, and Male Age-Related Thematic Differences.

Science.gov (United States)

Ivanov, Nicholas; Vuong, Jimmy; Gray, Peter B

2018-03-01

Male testosterone supplementation is a large and growing industry. How is testosterone marketed to male consumers online? The present exploratory study entailed a content coding analysis of the home pages of 49 websites focused on testosterone supplementation for men in the United States. Four hypotheses concerning anticipated age-related differences in content coding were also tested: more frequent longevity content toward older men, and more frequent social dominance/physical formidability, muscle, and sex content toward younger men. Codes were created based on inductive observations and drawing upon the medical, life history, and human behavioral endocrinology literatures. Approximately half ( n = 24) of websites were oriented toward younger men (estimated audience of men 40 years of age or younger) and half ( n = 25) toward older men (estimated audience over 40 years of age). Results indicated that the most frequent content codes concerned online sales (e.g., product and purchasing information). Apart from sales information, the most frequent codes concerned, in order, muscle, sex/sexual functioning, low T, energy, fat, strength, aging, and well-being, with all four hypotheses also supported. These findings are interpreted in the light of medical, evolutionary life history, and human behavioral endocrinology approaches.

Leadership Behaviour: Does Sex and Level of Education Matter?

Directory of Open Access Journals (Sweden)

Anthony Sumnaya Kumasey

2014-04-01

Full Text Available We examined individual differences in leadership behaviour in the Ghanaian business sector. Specifically, sex differences as well as level of education on leadership behaviour were examined. Cross-sectional survey design was used to study 95 participants conveniently sampled from selected organizations within the Greater Accra Metropolis. Questionnaire was used to collect data from a cross-section of people in the organization. Test of normality and reliability testing were conducted as part of the preliminary analysis. Multivariate test was used to test the hypotheses in the study. The result showed that females showed significantly people-oriented leadership behaviour than their male counterparts. However, level of education did not significantly influence the leadership behaviour of participants. Implications and limitations of the study are provided.

Depression and College Stress among University Undergraduates: Do Mattering and Self-Esteem Make a Difference?

Science.gov (United States)

Dixon, Sarah K.; Kurpius, Sharon E. Robinson

2008-01-01

Depression and college stress, major concerns among undergraduates, are potentially related to self-esteem and mattering. This study investigated the interrelationships among these four variables. Participants included college students (199 males and 256 females) between the ages of 18 and 23. Significant sex differences were found with women…

Brain Mechanisms Underlying Reactive Aggression in Borderline Personality Disorder-Sex Matters.

Science.gov (United States)

Herpertz, Sabine C; Nagy, Krisztina; Ueltzhöffer, Kai; Schmitt, Ruth; Mancke, Falk; Schmahl, Christian; Bertsch, Katja

2017-08-15

Aggression in borderline personality disorder (BPD) is thought to be mediated through emotion dysregulation via high trait anger. Until now, data comparing anger and aggression in female and male patients with BPD have been widely missing on the behavioral and particularly the brain levels. Thirty-three female and 23 male patients with BPD and 30 healthy women and 26 healthy men participated in this functional magnetic resonance imaging study. We used a script-driven imagery task consisting of narratives of both interpersonal rejection and directing physical aggression toward others. While imagining both interpersonal rejection and acting out aggressively, a sex × group interaction was found in which male BPD patients revealed higher activity in the left amygdala than female patients. In the aggression phase, men with BPD exhibited higher activity in the lateral orbitofrontal and dorsolateral prefrontal cortices compared with healthy men and female patients. Positive connectivity between amygdala and posterior middle cingulate cortex was found in female patients but negative connectivity was found in male patients with BPD. Negative modulatory effects of trait anger on amygdala-dorsolateral prefrontal cortex and amygdala-lateral orbitofrontal cortex coupling were shown in male BPD patients, while in female patients trait anger positively modulated dorsolateral prefrontal cortex-amygdala coupling. Trait aggression was found to positively modulate connectivity of the left amygdala to the posterior thalamus in male but not female patients. Data suggest poor top-down adjustment of behavior in male patients with BPD despite their efforts at control. Female patients appear to be less aroused through rejection and to successfully dampen aggressive tension during the imagination of aggressive behavior. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Diclofenac sex-divergent drug-drug interaction with Sunitinib: pharmacokinetics and tissue distribution in male and female mice.

Science.gov (United States)

Chew, Chii Chii; Ng, Salby; Chee, Yun Lee; Koo, Teng Wai; Liew, Ming Hui; Chee, Evelyn Li-Ching; Modamio, Pilar; Fernández, Cecilia; Mariño, Eduardo L; Segarra, Ignacio

2017-08-01

Coadministration of diclofenac and sunitinib, tyrosine kinase inhibitor, led to sex-divergent pharmacokinetic drug-drug interaction outcomes. Male and female mice were administered 60 mg/kg PO sunitinib alone (control groups) or with 30 mg/kg PO diclofenac. Sunitinib concentration in plasma, brain, kidney and liver were determined by HPLC and non-compartmental pharmacokinetic parameters calculated. In male mice, diclofenac decreased AUC 0→∞ 38% in plasma (p diclofenac increased the liver uptake efficiency in male (27%, p diclofenac with probable clinical translatability due to potential different effects in male and female patients requiring careful selection of the NSAID and advanced TDM to implement a personalized treatment.

Do male and female cowbirds see their world differently? Implications for sex differences in the sensory system of an avian brood parasite.

Directory of Open Access Journals (Sweden)

Esteban Fernández-Juricic

Full Text Available BACKGROUND: Male and female avian brood parasites are subject to different selection pressures: males compete for mates but do not provide parental care or territories and only females locate hosts to lay eggs. This sex difference may affect brain architecture in some avian brood parasites, but relatively little is known about their sensory systems and behaviors used to obtain sensory information. Our goal was to study the visual resolution and visual information gathering behavior (i.e., scanning of brown-headed cowbirds. METHODOLOGY/PRINCIPAL FINDINGS: We measured the density of single cone photoreceptors, associated with chromatic vision, and double cone photoreceptors, associated with motion detection and achromatic vision. We also measured head movement rates, as indicators of visual information gathering behavior, when exposed to an object. We found that females had significantly lower density of single and double cones than males around the fovea and in the periphery of the retina. Additionally, females had significantly higher head-movement rates than males. CONCLUSIONS: Overall, we suggest that female cowbirds have lower chromatic and achromatic visual resolution than males (without sex differences in visual contrast perception. Females might compensate for the lower visual resolution by gazing alternatively with both foveae in quicker succession than males, increasing their head movement rates. However, other physiological factors may have influenced the behavioral differences observed. Our results bring up relevant questions about the sensory basis of sex differences in behavior. One possibility is that female and male cowbirds differentially allocate costly sensory resources, as a recent study found that females actually have greater auditory resolution than males.

The evolution of sex roles in birds is related to adult sex ratio

OpenAIRE

Liker, András; Freckleton, Robert P.; Székely, Tamás

2013-01-01

Sex-role reversal represents a formidable challenge for evolutionary biologists, since it is not clear which ecological, life-history or social factors facilitated conventional sex roles (female care and male-male competition for mates) to be reversed (male care and female-female competition). Classic theories suggested ecological or life-history predictors of role reversal, but most studies failed to support these hypotheses. Recent theory however predicts that sex-role reversal should be dr...

Relation of cigarette smoking in males of different ages to sex hormone binding globulin and testosterone

International Nuclear Information System (INIS)

El-Nabarawy, F.S.

2002-01-01

The relationship of cigarette smoking, age, total testosterone free testosterone and sex hormone binding globulin (SHBG) were examined by solid phase radioimmunoassay in 90 randomly chosen healthy males of different ages. The serum levels of these hormones were investigated for smokers compared with non-smokers, of the same ages in 3 groups (adolescent males, middle aged males, and old aged males). Results indicated that cigarette smokers showed increased serum levels of testosterone (60.0% higher, P> 0.05), free testosterone (51.0 higher, P > 0.005) in young adolescent males group, testosterone (27.8% higher, P > 0.001), free testosterone (21.3% higher, P > 0.001) in middle aged males group, and testosterone (21.0% higher, P > 0.001), free testosterone (16.8% higher, P > 0.4) in old ages males group. SHBG was calculated as a mean of free and total testosterone in each group. smokers showed higher mean values of SHBG than non-smokers. Age was positively associated with serum SHBG, it was found that SHBG increased by 17.2% from the youngest (> 18 years) to the oldest age (> 65 years)

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

Science.gov (United States)

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.

Serum-sex steroids, gonadotrophins and sex hormone-binding globulin inprostatic hyperplasia

International Nuclear Information System (INIS)

Ansari, Mohammad A. Jalil; Begum, D.; Islam, F.

2008-01-01

Benign prostatic hyperplasia (BPH) develops in elderly males when serumandrogens are relatively lower than in healthy younger males, but is not wellunderstood whether and how sex steroids are altered in prostatic hyperplasia.It is also uncertain that whether there is any change in sex steroids levelsin males older than 40 years of age. The use of androgens in elderly males isoften discouraged because of the probable worsening effect of androgens onprostatism. This study aimed to determine the relationship between prostatichyperplasia and sex steroid levels and whether there is any significantchange in these hormones after the age of 40 years. We studied healthy malesof >40 years with (n=92) or without (n=93) clinical prostatic hyperplasia.Serum testosterone, estradiol, gonadotrophins and sex hormone-bindingglobulin (SHBG) were compared. The hormones and SHGB were also correlatedwith age. No significant difference was found in any hormone in cases withprostatic hyperplasia as compared with the controls. There was no significantage-related change in any hormone except estradiol where as a negativecorrelation (P<0.003) with age was found. Serum sex steroids and SHGBremained unchanged in symptomatic prostatic hyperplasia and except forestrdoil there was no significant age-related change in serum testosterone,gonadotrophins and SHGB in healthy males after the fourth decade. Morestudies are needed to confirm the age-related decline of estrogens in males.(author)

White matter microstructure in transsexuals and controls investigated by diffusion tensor imaging.

Science.gov (United States)

Kranz, Georg S; Hahn, Andreas; Kaufmann, Ulrike; Küblböck, Martin; Hummer, Allan; Ganger, Sebastian; Seiger, Rene; Winkler, Dietmar; Swaab, Dick F; Windischberger, Christian; Kasper, Siegfried; Lanzenberger, Rupert

2014-11-12

Biological causes underpinning the well known gender dimorphisms in human behavior, cognition, and emotion have received increased attention in recent years. The advent of diffusion-weighted magnetic resonance imaging has permitted the investigation of the white matter microstructure in unprecedented detail. Here, we aimed to study the potential influences of biological sex, gender identity, sex hormones, and sexual orientation on white matter microstructure by investigating transsexuals and healthy controls using diffusion tensor imaging (DTI). Twenty-three female-to-male (FtM) and 21 male-to-female (MtF) transsexuals, as well as 23 female (FC) and 22 male (MC) controls underwent DTI at 3 tesla. Fractional anisotropy, axial, radial, and mean diffusivity were calculated using tract-based spatial statistics (TBSS) and fiber tractography. Results showed widespread significant differences in mean diffusivity between groups in almost all white matter tracts. FCs had highest mean diffusivities, followed by FtM transsexuals with lower values, MtF transsexuals with further reduced values, and MCs with lowest values. Investigating axial and radial diffusivities showed that a transition in axial diffusivity accounted for mean diffusivity results. No significant differences in fractional anisotropy maps were found between groups. Plasma testosterone levels were strongly correlated with mean, axial, and radial diffusivities. However, controlling for individual estradiol, testosterone, or progesterone plasma levels or for subjects' sexual orientation did not change group differences. Our data harmonize with the hypothesis that fiber tract development is influenced by the hormonal environment during late prenatal and early postnatal brain development. Copyright © 2014 the authors 0270-6474/14/3415466-10$15.00/0.

White Matter Microstructure in Transsexuals and Controls Investigated by Diffusion Tensor Imaging

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Kranz, Georg S.; Hahn, Andreas; Kaufmann, Ulrike; Küblböck, Martin; Hummer, Allan; Ganger, Sebastian; Seiger, Rene; Winkler, Dietmar; Swaab, Dick F.; Windischberger, Christian; Kasper, Siegfried; Lanzenberger, Rupert

2015-01-01

Biological causes underpinning the well known gender dimorphisms in human behavior, cognition, and emotion have received increased attention in recent years. The advent of diffusion-weighted magnetic resonance imaging has permitted the investigation of the white matter microstructure in unprecedented detail. Here, we aimed to study the potential influences of biological sex, gender identity, sex hormones, and sexual orientation on white matter microstructure by investigating transsexuals and healthy controls using diffusion tensor imaging (DTI). Twenty-three female-to-male (FtM) and 21 male-to-female (MtF) transsexuals, as well as 23 female (FC) and 22 male (MC) controls underwent DTI at 3 tesla. Fractional anisotropy, axial, radial, and mean diffusivity were calculated using tract-based spatial statistics (TBSS) and fiber tractography. Results showed widespread significant differences in mean diffusivity between groups in almost all white matter tracts. FCs had highest mean diffusivities, followed by FtM transsexuals with lower values, MtF transsexuals with further reduced values, and MCs with lowest values. Investigating axial and radial diffusivities showed that a transition in axial diffusivity accounted for mean diffusivity results. No significant differences in fractional anisotropy maps were found between groups. Plasma testosterone levels were strongly correlated with mean, axial, and radial diffusivities. However, controlling for individual estradiol, testosterone, or progesterone plasma levels or for subjects’ sexual orientation did not change group differences. Our data harmonize with the hypothesis that fiber tract development is influenced by the hormonal environment during late prenatal and early postnatal brain development. PMID:25392513

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

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Wenwen Diao

2016-06-01

Full Text Available 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.

Behavioral tactics of male sockeye salmon (Oncorhynchus nerka) under varying operating sex ratios

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Quinn, Thomas P.; Adkison, Milo D.; Ward, Michael B.

1996-01-01

Previous studies have demonstrated several reproductive-behavior patterns in male salmon, including competitive and sneaking tactics, the formation of hierarchies, and non-hierarchical aggregations around ripe females. Through behavioral observations at varying spatial and temporal scales, we examined the hypothesis that operational sex ratio (OSR) determines male sockeye salmon (Oncorhynchus nerka) distribution and breeding tactics. Patterns of male distribution and behavior varied over both coarse and fine scales, associated with apparent shifts in reproductive opportunities, the physical characteristics of the breeding sites, and the deterioration of the fish as they approached death. Females spawned completely within a few days of arriving on the spawning grounds, whereas males courted the available ripe females from the date of their arrival on the spawning ground until their death. This difference in reproductive lifespans tended to elevate late-season OSRs but was partially counterbalanced by male departures and the arrival of other ripe females. The proportion of males able to dominate access to ripe females decreased and the number of large courting groups increased over the course of the season, apparently related to both increasing OSR and the deteriorating physical condition of males. However, great variation in OSR was observed within the spawning sites on a given day. OSRs were generally higher in shallow than in deep water, perhaps because larger females or more desirable breeding sites were concentrated in shallow water. The aggregations of males courting females were not stable (i.e. many arrivals and departures took place) and male aggression varied with group size. Aggression was most frequent at low OSRs and in groups of intermediate size (2–4 males per female), and much less frequent in larger groups, consistent with the needs of maximizing reproductive opportunities while minimizing unproductive energy expenditure. These results indicate

Why we should consider sex (and study sex differences) in addiction research.

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Sanchis-Segura, Carla; Becker, Jill B

2016-09-01

Among mammals, every cell has a biological sex, and the sex of an individual pervades its body and brain. In this review, we describe the processes through which mammals become phenotypically male or female by organizational and activational influences of genes and hormones throughout development. We emphasized that the molecular and cellular changes triggered by sex chromosomes and steroid hormones may generate sex differences in overt physiological functions and behavior, but they may alternatively promote end-point convergences between males and females. Clinical and pre-clinical evidences suggest that sex and gender differences modulate drug consumption as well as of the transition towards drug-promoted pathological states such as dependence and addiction. Additionally, sex differences in drug pharmacokinetics and pharmacodynamics will also influence dependence and addiction as well as side effects of drugs. These effects will further interact with socially gendered factors to result in sex differences in the access to, engagement in and efficacy of any therapeutic attempt. Finally, we maintain that 'sex sameness' is as important as 'sex differences' when building a complete understanding of biology for both males and females and provide a framework with which to classify and guide investigation into the mechanisms mediating sex differences and sex sameness. © 2016 Society for the Study of Addiction.

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

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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.

Sex and Age Differences in Attitude toward the Opposite Sex.

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Silver, Rawley

1997-01-01

Examines fantasies about the opposite sex expressed by 116 children, adolescents, and adults responding to the Drawing from Imagination task of the Silver Drawing Test of Cognition and Emotion. Results indicate that both males and females expressed more negative than positive feelings toward subjects of the opposite sex. Males were more negative.…

A Knowledge, Attitudes and Practices Survey regarding Sex, Contraception and Sexually Transmitted Diseases among Commerce College Students in Mumbai.

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Mutha, Amit S; Mutha, Sonali A; Baghel, Paritosh J; Patil, Ramanand J; Bhagat, Sagar B; Patel, Sadiq B; Watsa, Mahinder C

2014-08-01

One in four Indians is a juvenile. Sexual crimes, pre marital sex, sexually transmitted diseases and unwanted pregnancies are on the rise. It has been shown that lack of sexuality education can significantly contribute to the above. We conducted this study to determine the knowledge and awareness of college students regarding sex and related matters and the factors affecting the prevalent outlook and practices of youth towards the same. A prospective cross-sectional survey was conducted amongst 500 students of the K.P.B. Hinduja College of Commerce from December 2012 to March 2013 as per the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. 1. Sex knowledge scores of males and females regarding contraception, sexually transmitted diseases and HIV/AIDS. 2. Percentage response of males and females to questions depicting attitudes and perceptions regarding premarital sex and promiscuity, sexual fantasy and masturbation, unwanted pregnancies and contraception. 3. Responses depicting participant's premarital and high risk sexual activities. The mean age was 18.6 ±1.6 years, 46% of participants were female. The total sex related knowledge scores of males and females were 8.2±1.2 and 6.2±2.4 (ppractices.

A study to review sex ratio at birth and analyze preferences for the sex of the unborn.

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Warade, Yugali; Balsarkar, Geetha; Bandekar, Pooja

2014-02-01

(1) To study the status of sex ratio at birth with increasing birth order, (2) To ascertain the relationship of declining sex ratio with respect to socio demographic factors. (3) To study outlook of patient towards sex preference, willingness to determine sex of the fetus, wish to terminate the pregnancy in case of unwanted sex of the baby. This is the retrospective study done in the Department of Obstetrics and Gynaecology, Nowrosjee Wadia Maternity Hospital, Parel, Mumbai. The data was collected from the records maintained in Medical Record Department from January 2007 to December 2012 and were studied to determine the sex ratio as well as its relationship with the increasing parity. 95 % confidence interval for the sex ratios was calculated. Average sex ratio of 6 years was 908 females per 1,000 males. Sex ratio was 972 females per 1,000 males in primi para, which decreased to 879 females per 1,000 males in second para, further reduced to 784 females per 1,000 males in third para and 864 females per 1,000 males in fourth para. The 'sex ratio at birth', defined as the number of girls born for every 1,000 boys born, is a more accurate and refined indicator of the extent of prenatal sex selection.

A Comparative Study of Australian and New Zealand Male and Female Nurses' Health: A Sex Comparison and Gender Analysis.

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Tuckett, Anthony; Henwood, Tim; Oliffe, John L; Kolbe-Alexander, Tracy L; Kim, Jae Rin

2016-11-01

The aim of this research was to compare the health and lifestyle behaviors between male and female nursing professionals. Biological, workplace, and lifestyle factors as well as health behaviors and outcomes are reported as different between male and female nurses. Although male nurses show distinct health-related patterns and experience health disparities at work, few studies have investigated health differences by sex in a large cohort group of nursing professionals. This observation study of Australian and New Zealand nurses and midwives drew data from an eCohort survey. A cohort of 342 females was generated by SPSS randomization (total N=3625), to compare against 342 participating males. Measures for comparison include health markers and behaviors, cognitive well-being, workplace and leisure-time vitality, and functional capacity. Findings suggest that male nurses had a higher BMI, sat for longer, slept for less time, and were more likely to be a smoker than their female nurse counterparts. Men were more likely to report restrictions in bending, bathing, and dressing. In relation to disease, male nurses reported greater rates of respiratory disease and cardiovascular disease, including a three times greater incidence of myocardial infarction, and were more likely to have metabolic problems. In contrast, however, male nurses were more likely to report feeling calm and peaceful with less worries about their health. Important for nurse workforce administrators concerned about the well-being of their staff, the current study reveals significant sex differences and supports the need for gender-sensitive approaches to aid the well-being of male nurses. © The Author(s) 2015.

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

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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.

Effects of sex composition by class and instructor's sex on physical self-efficacy of college men.

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Gibbons, E S; Rust, D M; Blassingame, C L; Reed, J L

2000-02-01

The relationship of sex composition of class and instructor's sex to Physical Self-efficacy has yielded conflicting results in several studies. This study examined the relationship of sex composition of class and instructor's sex to scores on Physical Self-efficacy, Perceived Physical Ability, and Physical Self-presentation Confidence of 80 male students enrolled in one of four sections of a strength training class. Analysis indicated no significant difference on Physical Self-efficacy between male students who were enrolled in all male classes or in coeducational classes; improvements in scores on Physical Self-efficacy were not specific to the sex composition of the class or sex of the instructor and no significant difference on Perceived Physical Ability and Physical Self-presentation Confidence between male students who joined an all male class or a coeducational class. Perceived Physical Ability improved from the pretest to the posttest in all classes; and no improvement in scores for Physical Self-presentation Confidence was found in all classes. In conclusion, the analysis showed sex composition of the class and sex of the instructor were not significantly related to scores for self-efficacy.

Regional volumes and spatial volumetric distribution of gray matter in the gender dysphoric brain.

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Hoekzema, Elseline; Schagen, Sebastian E. E.; Kreukels, Baudewijntje P. C.; Veltman, Dick J.; Cohen-Kettenis, Peggy T.; Delemarre-van de Waal, Henriette; Bakker, Julie

2015-01-01

The sexual differentiation of the brain is primarily driven by gonadal hormones during fetal development. Leading theories on the etiology of gender dysphoria (GD) involve deviations herein. To examine whether there are signs of a sex-atypical brain development in GD, we quantified regional neural gray matter (GM) volumes in 55 female-to-male and 38 male-to-female adolescents, 44 boys and 52 girls without GD and applied both univariate and multivariate analyses. In girls, more GM volume was o...

Association between Sex Hormone and Blood Uric Acid in Male Patients with Type 2 Diabetes

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Wen Cao

2017-01-01

Full Text Available The association between serum uric acid (SUA level and sexual dysfunction in patients with diabetes is not well characterized. Type 2 diabetes mellitus (T2DM causes metabolic disorders, including abnormal serum uric acid (SUA levels. In this study, we enrolled 205 male patients with T2DM and investigated the relationship between sex hormone levels and SUA. Patients were divided into four groups based on SUA quartiles. On the other hand, based on the total testosterone (TT level, patients were divided into three groups; SUA and other laboratory indices were determined. Increase in SUA level was significantly associated with decreased levels of TT, luteinizing hormone, follicle-stimulating hormone, sex hormone-binding globulin, and increased levels of dehydroepiandrosterone, age, body mass index (BMI, waist circumference, glycated hemoglobin, serum creatinine, and HOMA-IR levels. SUA, waist circumference, BMI, and HOMA-IR showed a negative correlation with TT level, while age showed a positive correlation with TT level. SUA and body mass index were found to be risk factors for gonadal dysfunction. Therefore, we conclude that hypogonadism of male patients with T2DM is related to SUA level.

Incarcerated Dutch Juvenile Sex Offenders Compared with Non-Sex Offenders

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van Wijk, Anton Ph.; Vreugdenhil, Coby; van Horn, Joan; Vermeiren, Robert; Doreleijers, Theo A. H.

2007-01-01

There is some debate about whether or not sex offenders are similar to non-sex offenders with regard to family background (parental characteristics), personality, and psychopathology. The central aim of this study focused on the comparison of juvenile sex offenders and non-sex offenders. The sample consisted of incarcerated juvenile male sex (n =…

Sex- and habitat-specific movement of an omnivorous semi-terrestrial crab controls habitat connectivity and subsidies: a multi-parameter approach.

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Hübner, Lena; Pennings, Steven C; Zimmer, Martin

2015-08-01

Distinct habitats are often linked through fluxes of matter and migration of organisms. In particular, intertidal ecotones are prone to being influenced from both the marine and the terrestrial realms, but whether or not small-scale migration for feeding, sheltering or reproducing is detectable may depend on the parameter studied. Within the ecotone of an upper saltmarsh in the United States, we investigated the sex-specific movement of the semi-terrestrial crab Armases cinereum using an approach of determining multiple measures of across-ecotone migration. To this end, we determined food preference, digestive abilities (enzyme activities), bacterial hindgut communities (genetic fingerprint), and the trophic position of Armases and potential food sources (stable isotopes) of males versus females of different sub-habitats, namely high saltmarsh and coastal forest. Daily observations showed that Armases moved frequently between high-intertidal (saltmarsh) and terrestrial (forest) habitats. Males were encountered more often in the forest habitat, whilst gravid females tended to be more abundant in the marsh habitat but moved more frequently. Food preference was driven by both sex and habitat. The needlerush Juncus was preferred over three other high-marsh detrital food sources, and the periwinkle Littoraria was the preferred prey of male (but not female) crabs from the forest habitats; both male and female crabs from marsh habitat preferred the fiddler crab Uca over three other prey items. In the field, the major food sources were clearly vegetal, but males have a higher trophic position than females. In contrast to food preference, isotope data excluded Uca and Littoraria as major food sources, except for males from the forest, and suggested that Armases consumes a mix of C4 and C3 plants along with animal prey. Digestive enzyme activities differed significantly between sexes and habitats and were higher in females and in marsh crabs. The bacterial hindgut community

Density-dependent sex ratio and sex-specific preference for host traits in parasitic bat flies.

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Szentiványi, Tamara; Vincze, Orsolya; Estók, Péter

2017-08-29

Deviation of sex ratios from unity in wild animal populations has recently been demonstrated to be far more prevalent than previously thought. Ectoparasites are prominent examples of this bias, given that their sex ratios vary from strongly female- to strongly male-biased both among hosts and at the metapopulation level. To date our knowledge is very limited on how and why these biased sex ratios develop. It was suggested that sex ratio and sex-specific aggregation of ectoparasites might be shaped by the ecology, behaviour and physiology of both hosts and their parasites. Here we investigate a highly specialised, hematophagous bat fly species with strong potential to move between hosts, arguably limited inbreeding effects, off-host developmental stages and extended parental care. We collected a total of 796 Nycteribia kolenatii bat flies from 147 individual bats using fumigation and subsequently determined their sex. We report a balanced sex ratio at the metapopulation level and a highly variable sex ratio among infrapopulations ranging from 100% male to 100% female. We show that infrapopulation sex ratio is not random and is highly correlated with infrapopulation size. Sex ratio is highly male biased in small and highly female biased in large infrapopulations. We show that this pattern is most probably the result of sex-specific preference in bat flies for host traits, most likely combined with a higher mobility of males. We demonstrate that female bat flies exert a strong preference for high host body condition and female hosts, while the distribution of males is more even. Our results suggest that locally biased sex ratios can develop due to sex-specific habitat preference of parasites. Moreover, it is apparent that the sex of both hosts and parasites need to be accounted for when a better understanding of host-parasite systems is targeted.

Effects of Solanum torvum fruit water extract on hyperlipidemia and sex hormones in high-fat fed male rats

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Supaporn Wannasiri

2017-05-01

Conclusions: S. torvum extract can reverse the level of sex hormones to their normal level and reduce serum cholesterol in HFD-induced obese male rats. Furthermore, the long term oral administration of S. torvum extract is harmless.

Developmental neurogenetics and multimodal neuroimaging of sex differences in autism.

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Chen, Christina; Van Horn, John Darrell

2017-02-01

Examining sex differences in the brain has been historically contentious but is nonetheless important for advancing mental health for both girls and boys. Unfortunately, females in biomedical research remain underrepresented in most mental health conditions including autism spectrum disorders (ASD), even though equal inclusion of females would improve treatment for girls and yield benefits to boys. This review examines sex differences in the relationship between neuroanatomy and neurogenetics of ASD. Recent findings reveal that girls diagnosed with ASD exhibit more intellectual and behavioral problems compared to their male counterparts, suggesting that girls may be less likely diagnosed in the absence of such problems or that they require a higher mutational load to meet the diagnostic criteria. Thus far, the female biased effect of chromosome 4, 5p15.33, 8p, 9p24.1, 11p12-13, 15q, and Xp22.3 and the male biased effect of 1p31.3, 5q12.3, 7q, 9q33.3, 11q13.4, 13q33.3, 16p11.2, 17q11-21, Xp22.33/Yp11.31, DRD1, NLGN3, MAOA, and SHANK1 deletion have been discovered in ASD. The SNPs of genes such as RYR2, UPP2, and the androgen receptor gene have been shown to have sex-biasing factors in both girls and boys diagnosed with ASD. These sex-related genetic factors may drive sex differences in the neuroanatomy of these girls and boys, including abnormal enlargement in temporal gray and white matter volumes, and atypical reduction in cerebellar gray matter volumes and corpus callosum fibers projecting to the anterior frontal cortex in ASD girls relative to boys. Such factors may also be responsible for the attenuation of brain sexual differentiation in adult men and women with ASD; however, much remains to be uncovered or replicated. Future research should leverage further the association between neuroanatomy and genetics in girls for an integrated and interdisciplinary understanding of ASD.

Comparison of landing biomechanics between male and female dancers and athletes, part 1: Influence of sex on risk of anterior cruciate ligament injury.

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Orishimo, Karl F; Liederbach, Marijeanne; Kremenic, Ian J; Hagins, Marshall; Pappas, Evangelos

2014-05-01

The incidence of anterior cruciate ligament (ACL) injuries among dancers is much lower than among team sport athletes, and no clear disparity between sexes has been reported in the dance population. Although numerous studies have observed differences in landing biomechanics of the lower extremity between male and female team sport athletes, there is currently little research examining the landing biomechanics of male and female dancers and none comparing athletes to dancers. Comparing the landing biomechanics within these populations may help explain the lower overall ACL injury rates and lack of sex disparity. The purpose was to compare the effects of sex and group (dancer vs team sport athlete) on single-legged drop-landing biomechanics. The primary hypothesis was that female dancers would perform a drop-landing task without demonstrating typical sex-related risk factors associated with ACL injuries. A secondary hypothesis was that female team sport athletes would display typical ACL risk factors during the same task. Controlled laboratory study. Kinematics and kinetics were recorded as 40 elite modern and ballet dancers (20 men and 20 women) and 40 team sport athletes (20 men and 20 women) performed single-legged drop landings from a 30-cm platform. Joint kinematics and kinetics were compared between groups and sexes with a group-by-sex multivariate analysis of variance (MANOVA) followed by pairwise t tests. Dancers of both sexes and male team sport athletes landed similarly in terms of frontal-plane knee alignment, whereas female team sport athletes landed with a significantly greater peak knee valgus (P = .007). Female dancers were found to have a lower hip adduction torque than those of the other 3 groups (P = .003). Dancers (male and female) exhibited a lower trunk side flexion (P = .002) and lower trunk forward flexion (P = .032) compared with team sport athletes. In executing a 30-cm drop landing, female team sport athletes displayed a greater knee valgus

Prevalence of Same-Sex Sexual Behavior and Associated Characteristics among Low-Income Urban Males in Peru

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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

Sex chromosome-specific regulation in the Drosophila male germline but little evidence for chromosomal dosage compensation or meiotic inactivation.

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Colin D Meiklejohn

2011-08-01

Full Text Available The evolution of heteromorphic sex chromosomes (e.g., XY in males or ZW in females has repeatedly elicited the evolution of two kinds of chromosome-specific regulation: dosage compensation--the equalization of X chromosome gene expression in males and females--and meiotic sex chromosome inactivation (MSCI--the transcriptional silencing and heterochromatinization of the X during meiosis in the male (or Z in the female germline. How the X chromosome is regulated in the Drosophila melanogaster male germline is unclear. Here we report three new findings concerning gene expression from the X in Drosophila testes. First, X chromosome-wide dosage compensation appears to be absent from most of the Drosophila male germline. Second, microarray analysis provides no evidence for X chromosome-specific inactivation during meiosis. Third, we confirm the previous discovery that the expression of transgene reporters driven by autosomal spermatogenesis-specific promoters is strongly reduced when inserted on the X chromosome versus the autosomes; but we show that this chromosomal difference in expression is established in premeiotic cells and persists in meiotic cells. The magnitude of the X-autosome difference in transgene expression cannot be explained by the absence of dosage compensation, suggesting that a previously unrecognized mechanism limits expression from the X during spermatogenesis in Drosophila. These findings help to resolve several previously conflicting reports and have implications for patterns of genome evolution and speciation in Drosophila.

Genetic method of combating the cabbage root fly. Part II. Localization of factor determining male sex in the cabbage root fly Delia brassicae bouche

International Nuclear Information System (INIS)

Samoilov, Yu.B.

1986-01-01

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

Sex Workers, Fem Queens, and Cross-Dressers: Differential Marginalizations and HIV Vulnerabilities Among Three Ethnocultural Male-to-Female Transgender Communities in New York City.

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Hwahng, Sel Julian; Nuttbrock, Larry

2007-12-01

This article describes 3 distinct ethnocultural male-to-female transgender communities in New York City: the low-income African American/Black 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.

The behavioural consequences of sex reversal in dragons

Science.gov (United States)

Li, Hong; Holleley, Clare E.; Elphick, Melanie; Georges, Arthur

2016-01-01

Sex differences in morphology, physiology, and behaviour are caused by sex-linked genes, as well as by circulating sex-steroid levels. Thus, a shift from genotypic to environmental sex determination may create an organism that exhibits a mixture of male-like and female-like traits. We studied a lizard species (Central Bearded Dragon, Pogona vitticeps), in which the high-temperature incubation of eggs transforms genetically male individuals into functional females. Although they are reproductively female, sex-reversed dragons (individuals with ZZ genotype reversed to female phenotype) resemble genetic males rather than females in morphology (relative tail length), general behaviour (boldness and activity level), and thermoregulatory tactics. Indeed, sex-reversed ‘females’ are more male-like in some behavioural traits than are genetic males. This novel phenotype may impose strong selection on the frequency of sex reversal within natural populations, facilitating rapid shifts in sex-determining systems. A single period of high incubation temperatures (generating thermally induced sex reversal) can produce functionally female individuals with male-like (or novel) traits that enhance individual fitness, allowing the new temperature-dependent sex-determining system to rapidly replace the previous genetically based one.

Towards 'reflexive epidemiology': Conflation of cisgender male and transgender women sex workers and implications for global understandings of HIV prevalence.

Science.gov (United States)

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.

Neither Biased Sex Ratio nor Spatial Segregation of the Sexes in the Subtropical Dioecious Tree Eurycorymbus cavaleriei (Sapindaceae)

Institute of Scientific and Technical Information of China (English)

Pu-xin Gao; Ming Kang; Jing Wang; Qi-gang Ye; Hong-wen Huang

2009-01-01

Knowledge of sex ratio and spatial distribution of males and females of dioecious species is both of evolutionary interest and of crucial importance for biological conservation. Eurycorymbus cavaleriei, the only species in the genus Eurycorymbus (Saplndaceae), is a dioecious tree endemic to subtropical montane forest in South China. Sex ratios were investigated in 15 natural populations for the two defined ages (young and old). Spatial distribution of males and females was further studied in six large populations occurring in different habitats (fragmented and continuous). The study revealed a slight trend of malebiased sex ratio in both ages of E. cavaleriei, but sex ratio of most populations (13 out of 15) did not display statistically significant deviation from equality. All of the four significantly male-biased populations in the young class shifted to equality or even female-biased. The Ripley's K analysis of the distribution of males with respect to females suggested that individuals of the opposite sexes were more randomly distributed rather than spatially structured. These results suggest that the male-biased sex ratio in E. cavaleriei may result from the precocity of males and habitat heterogeneity. The sex ratio and the sex spatial distribution pattern are unlikely to constitute a serious threat to the survival of the species.

Integrating HIV Prevention and Relationship Education for Young Same-Sex Male Couples: A Pilot Trial of the 2GETHER Intervention.

Science.gov (United States)

Newcomb, Michael E; Macapagal, Kathryn R; Feinstein, Brian A; Bettin, Emily; Swann, Gregory; Whitton, Sarah W

2017-08-01

Young men who have sex with men are at high risk for HIV, and most new HIV infections occur in serious relationships. This pilot study assessed the feasibility, acceptability and preliminary efficacy of the 2GETHER couples-based HIV prevention and relationship education intervention for young same-sex male couples. We enrolled 57 young male couples (N = 114) into a four-session hybrid group and individual intervention. We assessed acceptability via post-session surveys and exit interviews, and we examined preliminary efficacy at a two week posttest. The vast majority of participants (93%) reported exclusively positive impressions of 2GETHER, and all components received high mean ratings. We observed decreases in HIV risk behavior, increases in information, motivation and behavioral skills related to HIV prevention, and improvement in relationship investment between pretest and posttest. Integrating relationship education and sexual health programming may be an effective way to reduce HIV transmissions in young male couples.

The Stability of Same-Sex Cohabitation, Different-Sex Cohabitation, and Marriage

Science.gov (United States)

Lau, Charles Q.

2012-01-01

This study contributes to the emerging demographic literature on same-sex couples by comparing the level and correlates of union stability among 4 types of couples: (a) male same-sex cohabitation, (b) female same-sex cohabitation, (c) different-sex cohabitation, and (d) different-sex marriage. The author analyzed data from 2 British birth cohort…

Male pattern baldness

Science.gov (United States)

Alopecia in men; Baldness - male; Hair loss in men; Androgenetic alopecia ... Male pattern baldness is related to your genes and male sex hormones. It usually follows a pattern of receding hairline and ...

Oral sex.

Science.gov (United States)

1996-04-05

The Gay and Lesbian Medical Association urges HIV prevention specialists to regard male-to-male oral-genital sex as a low-risk activity and concentrate instead on the danger of unprotected anal intercourse. According to the association, the confusion and mixed messages surrounding oral sex are harming efforts to encourage gay men to make rational choices about truly risky behavior. The recommendations appear in the association's position paper issued March 19, 1996.

Sex before the State: Civic Sex, Reproductive Innovations, and Gendered Parental Identity.

Science.gov (United States)

Murphy, Timothy F

2017-04-01

Certain changes in the way that states classify people by sex as well as certain reproductive innovations undercut the rationale for state identification of people as male or female in signifying gendered parental relationships to children. At present, people known to the state as men may be genetic mothers to their children; people known to the state as women may be genetic fathers to their children. Synthetic gametes would make it possible for transgender men to be genetically related to children as fathers and transgender women to be genetically related to children as mothers, even if they have otherwise relied on naturally-occurring gametes to be genetic mothers and genetic fathers of children respectively. Synthetic gametes would presumably make it possible for any person to be the genetic father or genetic mother of children, even in a mix-and-match way. Other reproductive innovations will also undercut existing expectations of gendered parental identity. Uterus transplants would uncouple the maternal function of gestation from women, allowing men to share in maternity that way. Extracorporeal gestation ((ExCG)-gestation outside anyone's body-would also undercut the until-now absolute connection between female sex and maternity. In kind, effects such as these-undoing conventionally gendered parenthood-undercut the state's interest in knowing whether parents are male or female in relation to a given child, as against knowing simply whether someone stands in a parental relationship to that child, as a matter of rights and duties.

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

Science.gov (United States)

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.

The roles of Dmrt (Double sex/Male-abnormal-3 Related Transcription factor) genes in sex determination and differentiation mechanisms: Ubiquity and diversity across the animal kingdom.

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Picard, Marion Anne-Lise; Cosseau, Céline; Mouahid, Gabriel; Duval, David; Grunau, Christoph; Toulza, Ève; Allienne, Jean-François; Boissier, Jérôme

2015-07-01

The Dmrt (Double sex/Male-abnormal-3 Related Transcription factor) genes have been intensively studied because they represent major transcription factors in the pathways governing sex determination and differentiation. These genes have been identified in animal groups ranging from cnidarians to mammals, and some of the genes functionally studied. Here, we propose to analyze (i) the presence/absence of various Dmrt gene groups in the different taxa across the animal kingdom; (ii) the relative expression levels of the Dmrt genes in each sex; (iii) the specific spatial (by organ) and temporal (by developmental stage) variations in gene expression. This review considers non-mammalian animals at all levels of study (i.e. no particular importance is given to animal models), and using all types of sexual strategy (hermaphroditic or gonochoric) and means of sex determination (i.e. genetic or environmental). To conclude this global comparison, we offer an analysis of the DM domains conserved among the different DMRT proteins, and propose a general sex-specific pattern for each member of the Dmrt gene family. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Differential interactions of sex pheromone and plant odour in the olfactory pathway of a male moth.

Directory of Open Access Journals (Sweden)

Nina Deisig

Full Text Available Most animals rely on olfaction to find sexual partners, food or a habitat. The olfactory system faces the challenge of extracting meaningful information from a noisy odorous environment. In most moth species, males respond to sex pheromone emitted by females in an environment with abundant plant volatiles. Plant odours could either facilitate the localization of females (females calling on host plants, mask the female pheromone or they could be neutral without any effect on the pheromone. Here we studied how mixtures of a behaviourally-attractive floral odour, heptanal, and the sex pheromone are encoded at different levels of the olfactory pathway in males of the noctuid moth Agrotis ipsilon. In addition, we asked how interactions between the two odorants change as a function of the males' mating status. We investigated mixture detection in both the pheromone-specific and in the general odorant pathway. We used a recordings from individual sensilla to study responses of olfactory receptor neurons, b in vivo calcium imaging with a bath-applied dye to characterize the global input response in the primary olfactory centre, the antennal lobe and c intracellular recordings of antennal lobe output neurons, projection neurons, in virgin and newly-mated males. Our results show that heptanal reduces pheromone sensitivity at the peripheral and central olfactory level independently of the mating status. Contrarily, heptanal-responding olfactory receptor neurons are not influenced by pheromone in a mixture, although some post-mating modulation occurs at the input of the sexually isomorphic ordinary glomeruli, where general odours are processed within the antennal lobe. The results are discussed in the context of mate localization.

Regional volumes and spatial volumetric distribution of gray matter in the gender dysphoric brain.

Science.gov (United States)

Hoekzema, Elseline; Schagen, Sebastian E E; Kreukels, Baudewijntje P C; Veltman, Dick J; Cohen-Kettenis, Peggy T; Delemarre-van de Waal, Henriette; Bakker, Julie

2015-05-01

The sexual differentiation of the brain is primarily driven by gonadal hormones during fetal development. Leading theories on the etiology of gender dysphoria (GD) involve deviations herein. To examine whether there are signs of a sex-atypical brain development in GD, we quantified regional neural gray matter (GM) volumes in 55 female-to-male and 38 male-to-female adolescents, 44 boys and 52 girls without GD and applied both univariate and multivariate analyses. In girls, more GM volume was observed in the left superior medial frontal cortex, while boys had more volume in the bilateral superior posterior hemispheres of the cerebellum and the hypothalamus. Regarding the GD groups, at whole-brain level they differed only from individuals sharing their gender identity but not from their natal sex. Accordingly, using multivariate pattern recognition analyses, the GD groups could more accurately be automatically discriminated from individuals sharing their gender identity than those sharing their natal sex based on spatially distributed GM patterns. However, region of interest analyses indicated less GM volume in the right cerebellum and more volume in the medial frontal cortex in female-to-males in comparison to girls without GD, while male-to-females had less volume in the bilateral cerebellum and hypothalamus than natal boys. Deviations from the natal sex within sexually dimorphic structures were also observed in the untreated subsamples. Our findings thus indicate that GM distribution and regional volumes in GD adolescents are largely in accordance with their respective natal sex. However, there are subtle deviations from the natal sex in sexually dimorphic structures, which can represent signs of a partial sex-atypical differentiation of the brain. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sex identification of Nigerian indigenous chicks using Auto-sexing ...

African Journals Online (AJOL)

Sexing has been a challenging task in Nigerian indigenous chickens due to the monomorphism of chicks which makes it impossible to distinguish the male from the female until eight weeks. . Therefore, this study was carried out to determine the sex of Nigerian indigenous chicks using the common auto-sexing methods.

Correlates of condomless anal sex among men who have sex with men (MSM) in Tijuana, Mexico: The role of public sex venues.

Science.gov (United States)

Semple, Shirley J; Pitpitan, Eileen V; Goodman-Meza, David; Strathdee, Steffanie A; Chavarin, Claudia V; Rangel, Gudelia; Torres, Karla; Patterson, Thomas L

2017-01-01

Condomless anal sex between male partners is the primary risk factor for HIV transmission among men who have sex with men (MSM). Correlates of condomless anal sex have been well-studied in developed countries, but they have received less attention in lower-to-middle income countries (LMIC), where MSM are often subject to stigma, discrimination, intolerance, and even the criminalization of same sex behavior. In Mexico, a LMIC where traditional views on homosexuality are common, HIV prevalence among MSM is high (16.9%), yet little research has been conducted on the correlates of condomless anal sex in this high-risk population. The present study examined correlates of condomless anal sex among 201 MSM recruited in Tijuana, Mexico, with a focus on the role of public sex venues in relation to sexual risk behavior. Eligibility requirements were: biologically male, 18 years of age or older, resident of Tijuana, and self-reported anal or oral sex with a male partner in the past year. Participants completed an interviewer-administered, demographic and psychosocial survey, and were tested for HIV and syphilis. A hierarchical multiple linear regression model was tested to identify correlates of condomless anal sex. Thirty-eight percent of participants (N = 76) reported condomless anal sex with a male partner in the past 2 months. Higher levels of condomless anal sex were associated with higher levels of depressive symptoms, greater sexual compulsivity, and more frequent seeking out of sex partners in a public venue in the past 2 months. In view of these findings, we recommend the development of multi-level, "combination" interventions, which in the Mexican context should include enhanced condom promotion and distribution, improved availability and access to mental health treatment and counseling services, and expanded HIV/STI testing in public venues.

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

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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

Inherited XX sex reversal originating from wild medaka populations.

Science.gov (United States)

Shinomiya, A; Otake, H; Hamaguchi, S; Sakaizumi, M

2010-11-01

The teleost fish, medaka (Oryzias latipes), has an XX/XY sex-determining mechanism. A Y-linked DM domain gene, DMY, has been isolated by positional cloning as the sex-determining gene in this species. Previously, we conducted a field survey of genotypic sex and found that approximately 1% of wild medaka are sex-reversed (XX males and XY females). Here, we performed genetic analyses of nine spontaneous XX sex-reversed males to elucidate its genetic basis. In all cases, the F(1) progeny were all females, whereas XX males reappeared in the backcross (BC) progeny, suggesting that XX sex reversal is a recessive trait. Although the incidences of sex reversal in the BC progeny were mostly low, 40% were males derived from one XX male. We performed linkage analysis using 55 BC males and located a single major factor, sda-1 (sex-determining autosomal factor-1), controlling sex reversal in an autosomal linkage group. Thus, genes involved in the sex-determining pathway can be isolated from spontaneous mutants in wild populations.

Why sex and gender matter in implementation research

Directory of Open Access Journals (Sweden)

Cara Tannenbaum

2016-10-01

Full Text Available Abstract Background There has been a recent swell in activity by health research funding organizations and science journal editors to increase uptake of sex and gender considerations in study design, conduct and reporting in order to ensure that research results apply to everyone. However, examination of the implementation research literature reveals that attention to sex and gender has not yet infiltrated research methods in this field. Discussion The rationale for routinely considering sex and gender in implementation research is multifold. Sex and gender are important in decision-making, communication, stakeholder engagement and preferences for the uptake of interventions. Gender roles, gender identity, gender relations, and institutionalized gender influence the way in which an implementation strategy works, for whom, under what circumstances and why. There is emerging evidence that programme theories may operate differently within and across sexes, genders and other intersectional characteristics under various circumstances. Furthermore, without proper study, implementation strategies may inadvertently exploit or ignore, rather than transform thinking about sex and gender-related factors. Techniques are described for measuring and analyzing sex and gender in implementation research using both quantitative and qualitative methods. Summary The present paper describes the application of methods for integrating sex and gender in implementation research. Consistently asking critical questions about sex and gender will likely lead to the discovery of positive outcomes, as well as unintended consequences. The result has potential to strengthen both the practice and science of implementation, improve health outcomes and reduce gender inequities.

Why sex and gender matter in implementation research.

Science.gov (United States)

Tannenbaum, Cara; Greaves, Lorraine; Graham, Ian D

2016-10-27

There has been a recent swell in activity by health research funding organizations and science journal editors to increase uptake of sex and gender considerations in study design, conduct and reporting in order to ensure that research results apply to everyone. However, examination of the implementation research literature reveals that attention to sex and gender has not yet infiltrated research methods in this field. The rationale for routinely considering sex and gender in implementation research is multifold. Sex and gender are important in decision-making, communication, stakeholder engagement and preferences for the uptake of interventions. Gender roles, gender identity, gender relations, and institutionalized gender influence the way in which an implementation strategy works, for whom, under what circumstances and why. There is emerging evidence that programme theories may operate differently within and across sexes, genders and other intersectional characteristics under various circumstances. Furthermore, without proper study, implementation strategies may inadvertently exploit or ignore, rather than transform thinking about sex and gender-related factors. Techniques are described for measuring and analyzing sex and gender in implementation research using both quantitative and qualitative methods. The present paper describes the application of methods for integrating sex and gender in implementation research. Consistently asking critical questions about sex and gender will likely lead to the discovery of positive outcomes, as well as unintended consequences. The result has potential to strengthen both the practice and science of implementation, improve health outcomes and reduce gender inequities.

Why sex hormones matter for neuroscience: A very short review on sex, sex hormones, and functional brain asymmetries.

Science.gov (United States)

Hausmann, Markus

2017-01-02

Biological sex and sex hormones are known to affect functional cerebral asymmetries (FCAs). Men are generally more lateralized than women. The effect size of this sex difference is small but robust. Some of the inconsistencies in the literature may be explained by sex-related hormonal differences. Most studies focusing on neuromodulatory properties of sex hormones on FCAs have investigated women during the menstrual cycle. Although contradictions exist, these studies have typically shown that levels of estradiol and/or progesterone correlate with the degree of FCAs, suggesting that sex differences in FCAs partially depend on hormonal state and day of testing. The results indicate that FCAs are not fixed but are hormone dependent, and as such they can dynamically change within relatively short periods throughout life. Many issues raised in this Mini-Review refer not only to FCAs but also to other aspects of functional brain organization, such as functional connectivity within and between the cerebral hemispheres. Our understanding of sex differences in brain and behavior as well as their clinical relevance will improve significantly if more studies routinely take sex and sex hormones into account. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Reduced anterior internal capsule white matter integrity in primary insomnia.

Science.gov (United States)

Spiegelhalder, Kai; Regen, Wolfram; Prem, Martin; Baglioni, Chiara; Nissen, Christoph; Feige, Bernd; Schnell, Susanne; Kiselev, Valerij G; Hennig, Jürgen; Riemann, Dieter

2014-07-01

Chronic insomnia is one of the most prevalent central nervous system diseases, however, its neurobiology is poorly understood. Up to now, nothing is known about the integrity of white matter tracts in insomnia patients. In this study, diffusion tensor imaging (DTI) was used in a well-characterized sample of primary insomnia (PI) patients and good sleeper controls to fill this void. Voxelwise between-group comparisons of fractional anisotropy (FA) were performed in 24 PI patients (10 males; 14 females; 42.7 ± 14.5 years) and 35 healthy good sleepers (15 males; 20 females; 40.1 ± 9.1 years) with age and sex as covariates. PI patients showed reduced FA values within the right anterior internal capsule and a trend for reduced FA values in the left anterior internal capsule. The results suggest that insomnia is associated with a reduced integrity of white matter tracts in the anterior internal capsule indicating that disturbed fronto-subcortical connectivity may be a cause or consequence of the disorder.

Evaluation of a School-Based Sex Education Program for Low Income Male High School Students in Chile.

Science.gov (United States)

Silva, Monica; Ross, Ines

2003-01-01

Evaluated a 1-year sex education program for low income male high school students in Chile. Findings for 92 students in the baseline year, 1993, and 196 students in the 1998 cohort show a reduction in the percentage of students reporting having had sexual intercourse, changes attitudes toward abstinence, and differences in communication about…

An exploratory study of HIV risk behaviours and testing among male sex workers in Beirut, Lebanon

Science.gov (United States)

Aunon, Frances M.; Wagner, Glenn J.; Maher, Rabih; Khouri, Danielle; Kaplan, Rachel L.; Mokhbat, Jacques

2015-01-01

Male sex workers (MSW) are a particularly high-risk subset of men who have sex with men in Lebanon and report higher numbers of sex partners and lower rates of condom use. The purpose was to explore the factors influencing sexual risk behaviors and HIV testing among MSW. Qualitative interviews were conducted with 16 MSW living in Beirut and working in bathhouses (hammam) or as escorts; content analysis identified emergent themes. Escorts reported more consistent condom use with clients and HIV testing than hammam MSW, with influential factors including HIV risk knowledge and perceived risk susceptibility, job security, and internalized stigma and related feelings of self-worth and fatalism regarding health and HIV risk. In contrast, both groups of MSW typically opted not to condoms with nonclient sex partners, in an effort to differentiate sex for work versus pleasure. The uptake of HIV testing was limited by concerns about the confidentiality of the test results and fear of repercussions of a positive test result for their health and employment. The respondents described an insular existence within the sex work culture, in part to limit exposure to stigma, which has implications for access to support as well as the influence of peer norms regarding sexual risk behavior and health seeking behaviors such as HIV testing. Further research is needed to tailor prevention and HIV testing efforts to reflect the distinct sexual health “cultures” that distinguish these two populations of MSW in Lebanon. PMID:25950906

Sex preferences among mothers delivering at Patan Hospital.

Science.gov (United States)

Chhetri, U D; Ansari, I; Bandary, S; Adhikari, N

2011-01-01

High sex ratios at birth (SRB) are seen in China, Taiwan, South Korea, parts of India and Vietnam. The imbalance is the result of son preference, accentuated by declining fertility. Prenatal sex determination and female feticides are common in many countries. It is reflected in sex ratio To determine reasons for the preferences for different sex; to find out whether there is altered sex ratio at birth and to find out whether female feticide are common among women who had abortion. It is a prospective study. Women who had previous history of abortion and had delivered at Patan Hospital in the year 2066 were interviewed as per questionnaires. Among 560 women with total live births of 965, (462 male and 503 female) during their life time the overall sex ratio was 92 male per 100 female birth; total abortions were 663. Preferences for male were 10%, female 15.4% and either was for 74%. The reason for male preference was to continue family lineage, to bring honor, old age security, and performing funeral rites while the reasons for daughter preferences were that they understand mothers pain, help in household work. The sex ratio of the babies born during the study period was 113 male per 100 female births. The Sex ratio at birth from 1st to 6th deliveries was 61, 79, 101, 210, 286 and 1100 male per 100 female birth respectively. Prenatal sex selection was 8% (by USG) but none had sex selected abortion. Sex ratio of those delivered during the study period was skewed (136 boys per 100 girls) towards male. There was shift in SRB in 4th and subsequent pregnancies in favor of boys. As the male sex ratio increased the number of induced abortion decreased in subsequent pregnancies.

Sex-dependent effects of larval food stress on adult performance under semi-natural conditions: only a matter of size?

Science.gov (United States)

Rosa, Elena; Saastamoinen, Marjo

2017-07-01

Organisms with complex life-cycles acquire essential nutrients as juveniles, and hence even a short-term food stress during development can impose serious fitness costs apparent in adults. We used the Glanville fritillary butterfly to investigate the effects of larval food stress on adult performance under semi-natural conditions in a population enclosure. We were specifically interested in whether the negative effects observed were due to body mass reduction only or whether additional effects unrelated to pupal mass were evident. The two sexes responded differently to the larval food stress. In females, larval food stress reduced pupal mass and reproductive performance. The reduced reproductive performance was partially mediated by pupal mass reduction. Food stressed females also had reduced within-patch mobility, and this effect was not dependent on pupal mass. Conversely, food stress had no effect on male pupal mass, suggesting a full compensation via prolonged development time. Nonetheless, food stressed males were less likely to sire any eggs, potentially due to changes in their territorial behavior, as indicated by food stress also increasing male within-patch mobility (i.e., patrolling behavior). When males did sire eggs, the offspring number and viability were unaffected by male food stress treatment. Viability was in general higher for offspring sired by lighter males. Our study highlights how compensatory mechanisms after larval food stress can act in a sex-specific manner and that the alteration in body mass is only partially responsible for the reduced adult performance observed.

Correlates of Forced Sex Among Populations of Men Who Have Sex with Men in Thailand

OpenAIRE

Guadamuz, Thomas E.; Wimonsate, Wipas; Varangrat, Anchalee; Phanuphak, Praphan; Jommaroeng, Rapeepun; Mock, Philip A.; Tappero, Jordan W.; van Griensven, Frits

2009-01-01

Although forced sex is a correlate of HIV infection, its prevalence and associated risks are not well described among men who have sex with men (MSM) in developing-country settings. Between March and October 2005, we assessed the prevalence of forced sex and correlates among populations of MSM (this includes general MSM, male sex workers, and male-to-female transgender persons) in Thailand using a community-based sample. Participants were enrolled from venues around Bangkok, Chiangmai, and Ph...

Interactive effects of sex hormones and gender stereotypes on cognitive sex differences--a psychobiosocial approach.

Science.gov (United States)

Hausmann, Markus; Schoofs, Daniela; Rosenthal, Harriet E S; Jordan, Kirsten

2009-04-01

Biological and social factors have been shown to affect cognitive sex differences. For example, several studies have found that sex hormones have activating effects on sex-sensitive tasks. On the other hand, it has been shown that gender stereotypes can influence the cognitive performance of (gender-) stereotyped individuals. However, few studies have investigated the combined effects of both factors. The present study investigated the interaction between sex hormones and gender stereotypes within a psychobiosocial approach. One hundred and fourteen participants (59 women) performed a battery of sex-sensitive cognitive tasks, including mental rotation, verbal fluency, and perceptual speed. Saliva samples were taken immediately after cognitive testing. Levels of testosterone (T) were analysed using chemiluminescence immunoassay (LIA). To activate gender stereotypes, a questionnaire was applied to the experimental group that referred to the cognitive tasks used. The control group received an identical questionnaire but with a gender-neutral content. As expected, significant sex differences favouring males and females appeared for mental rotation and verbal fluency tasks, respectively. The results revealed no sex difference in perceptual speed. The male superiority in the Revised Vandenberg and Kuse Mental Rotations Tests (MRT-3D) was mainly driven by the stereotype-active group. No significant sex difference in MRT-3D appeared in the control group. The MRT-3D was also the task in which a strong gender-stereotype favouring males was present for both males and females. Interestingly, T levels of the stereotype-activated group were 60% higher than that of male controls. The results suggest that sex hormones mediate the effects of gender stereotypes on specific cognitive abilities.

Homage to Bateman: sex roles predict sex differences in sexual selection.

Science.gov (United States)

Fritzsche, Karoline; Arnqvis, Göran

2013-07-01

Classic sex role theory predicts that sexual selection should be stronger in males in taxa showing conventional sex roles and stronger in females in role reversed mating systems. To test this very central prediction and to assess the utility of different measures of sexual selection, we estimated sexual selection in both sexes in four seed beetle species with divergent sex roles using a novel experimental design. We found that sexual selection was sizeable in females and the strength of sexual selection was similar in females and males in role-reversed species. Sexual selection was overall significantly stronger in males than in females and residual selection formed a substantial component of net selection in both sexes. Furthermore, sexual selection in females was stronger in role-reversed species compared to species with conventional sex roles. Variance-based measures of sexual selection (the Bateman gradient and selection opportunities) were better predictors of sexual dimorphism in reproductive behavior and morphology across species compared to trait-based measures (selection differentials). Our results highlight the importance of using assays that incorporate components of fitness manifested after mating. We suggest that the Bateman gradient is generally the most informative measure of the strength of sexual selection in comparisons across sexes and/or species. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Neurogenin 3 Mediates Sex Chromosome Effects on the Generation of Sex Differences in Hypothalamic Neuronal Development

Directory of Open Access Journals (Sweden)

Maria Julia Scerbo

2014-07-01

Full Text Available The organizational action of testosterone during critical periods of development is the cause of numerous sex differences in the brain. However, sex differences in neuritogenesis have been detected in primary neuronal hypothalamic cultures prepared before the peak of testosterone production by fetal testis. In the present study we assessed the hypothesis of that cell-autonomous action of sex chromosomes can differentially regulate the expression of the neuritogenic gene neurogenin 3 (Ngn3 in male and female hypothalamic neurons, generating sex differences in neuronal development. Neuronal cultures were prepared from male and female E14 mouse hypothalami, before the fetal peak of testosterone. Female neurons showed enhanced neuritogenesis and higher expression of Ngn3 than male neurons. The silencing of Ngn3 abolished sex differences in neuritogenesis, decreasing the differentiation of female neurons. The sex difference in Ngn3 expression was determined by sex chromosomes, as demonstrated using the four core genotypes mouse model, in which a spontaneous deletion of the testis-determining gene Sry from the Y chromosome was combined with the insertion of the Sry gene onto an autosome. In addition, the expression of Ngn3, which is also known to mediate the neuritogenic actions of estradiol, was increased in the cultures treated with the hormone, but only in those from male embryos. Furthermore, the hormone reversed the sex differences in neuritogenesis promoting the differentiation of male neurons. These findings indicate that Ngn3 mediates both cell-autonomous actions of sex chromosomes and hormonal effects on neuritogenesis.

BIOLOGICAL SEX, SEX-ROLE ORIENTATION, MASCULINE SEX-ROLE STRESS, DISSIMULATION AND SELF-REPORTED FEARS

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ARRINDELL, WA; KOLK, AM; PICKERSGILL, MJ; HAGEMAN, WJJM

1993-01-01

Given meta-analytic findings showing females to be generally more fearful than males on multi-dimensional self-report measures of fear, an empirical attempt was made to examine whether this outcome could be explained by psychological factors such as sex role orientation and masculine sex role

Sex on the brain: Are gender-dependent structural and functional differences associated with behavior?

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Grabowska, Anna

2017-01-02

A substantial number of studies provide evidence documenting a variety of sex differences in the brain. It remains unclear whether sexual differentiation at the neural level is related to that observed in daily behavior, cognitive function, and the risk of developing certain psychiatric and neurological disorders. Some investigators have questioned whether the brain is truly sexually differentiated and support this view with several arguments including the following: (1) brain structural or functional differences are not necessarily reflected in appropriate differences at the behavioral level, which might suggest that these two phenomena are not linked to each other; and (2) sex-related differences in the brain are rather small and concern features that significantly overlap between males and females. This review polemicizes with those opinions and presents examples of sex-related local neural differences underpinning a variety of sex differences in behaviors, skills, and cognitive/emotional abilities. Although male/female brain differentiation may vary in pattern and scale, nonetheless, in some respects (e.g., relative local gray matter volumes) it can be substantial, taking the form of sexual dimorphism and involving large areas of the brain (the cortex in particular). A significant part of this review is devoted to arguing that some sex differences in the brain may serve to prevent (in the case where they are maladaptive), rather than to produce, differences at the behavioral/skill level. Specifically, some differences might result from compensatory mechanisms aimed at maintaining similar intellectual capacities across the sexes, despite the smaller average volume of the brain in females compared with males. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

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

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

2015-08-01

We examined correlates of love and trust among female sex workers and their noncommercial male partners along the Mexico-US border. 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. 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. 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.

Sexual restrictions beyond anti-gay prejudice: Anal sex, oral sex, masculinity and sexual prejudice in Jamaica

OpenAIRE

West, Keon

2016-01-01

This is the first quantitative research to investigate attitudes toward heterosexual anal and oral sex in Jamaica, compare them to anti-gay and anti-lesbian attitudes, and frame them within a broader understanding of sexual prejudice based on gender norms. Fifty Jamaican participants’ attitudes toward heterosexual anal sex were as negative as attitudes toward gay male sex, and more negative than attitudes toward lesbian sex. Negative attitudes toward male sexual behaviours were predicted by m...

Complete depletion of primordial germ cells in an All-female fish leads to Sex-biased gene expression alteration and sterile All-male occurrence.

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Liu, Wei; Li, Shi-Zhu; Li, Zhi; Wang, Yang; Li, Xi-Yin; Zhong, Jian-Xiang; Zhang, Xiao-Juan; Zhang, Jun; Zhou, Li; Gui, Jian-Fang

2015-11-18

Gynogenesis is one of unisexual reproduction modes in vertebrates, and produces all-female individuals with identical genetic background. In sexual reproduction vertebrates, the roles of primordial germ cells on sexual dimorphism and gonadal differentiation have been largely studied, and two distinct functional models have been proposed. However, the role of primordial germ cells remains unknown in unisexual animals, and it is also unclear whether the functional models in sexual reproduction animals are common in unisexual animals. To solve these puzzles, we attempt to utilize the gynogenetic superiority of polyploid Carassius gibelio to create a complete germ cell-depleted gonad model by a similar morpholino-mediated knockdown approach used in other examined sexual reproduction fishes. Through the germ cell-depleted gonad model, we have performed comprehensive and comparative transcriptome analysis, and revealed a complete alteration of sex-biased gene expression. Moreover, the expression alteration leads to up-regulation of testis-biased genes and down-regulation of ovary-biased genes, and results in the occurrence of sterile all-males with testis-like gonads and secondary sex characteristics in the germ cell-depleted gynogenetic Carassius gibelio. Our current results have demonstrated that unisexual gynogenetic embryos remain keeping male sex determination information in the genome, and the complete depletion of primordial germ cells in the all-female fish leads to sex-biased gene expression alteration and sterile all-male occurrence.

'Just getting by': a cross-sectional study of male sex workers as a key population for HIV/STIs among men who have sex with men in Peru.

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

2014-05-01

To describe the sociodemographic and sex work characteristics, recent sexual practices, HIV risk perception and testing history, and HIV and syphilis prevalence of Cercado (downtown) and non-Cercado (close urban) male sex workers (MSWs) in Lima, Peru. Eighty-nine MSWs completed a self-administered survey and participated in HIV and syphilis testing. Cercado MSWs had significantly lower median weekly earnings than non-Cercado MSWs (US$43 vs US$72, p=0.04). Most non-Cercado MSWs (81%) reported only insertive anal intercourse with male/transgender partners, while Cercado MSWs primarily reported only insertive (52%) or insertive and receptive (45%) anal intercourse (p=0.03). Consistent condom use was low with insertive and receptive anal intercourse in both subgroups. Among MSWs with recent female partners, condom use with the last partner was lower among Cercado versus non-Cercado MSWs for vaginal sex (37% vs 65%, p=0.04) and anal sex (27% vs 80%, p=0.01). More Cercado than non-Cercado MSWs (57% vs 42%) perceived high HIV risk (p=0.05) and Cercado MSWs had a much higher prevalence than non-Cercado MSWs of HIV (23% vs 4%, p=0.04) and syphilis (22% vs 0%, p=0.02) infections. MSWs in Lima are diverse and Cercado MSWs are 'just getting by,' engaging in more risk behaviours, and more likely to have HIV/STIs. Future research should identify, describe and carry out HIV/STI testing with broader groups of MSWs and their client and non-client partners. Prevention efforts should provide HIV/STI risk reduction education for MSWs and related subgroups who are currently not targeted such as female partners.

Sex-Fair Education and the Male Experience.

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Scott, Kathryn P.

1982-01-01

Describes how the traditional, agressive male role has been reinforced by social studies textbooks. The author recommends that teachers teach about new roles for males by presenting images of males in caring, nurturing, and expressive roles. (AM)

A randomized waitlist-controlled trial of culturally sensitive relationship education for male same-sex couples.

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Whitton, Sarah W; Weitbrecht, Eliza M; Kuryluk, Amanda D; Hutsell, David W

2016-09-01

Relationship education, effective in improving relationship quality among different-sex couples, represents a promising and nonstigmatizing approach to promoting the health and stability of same-sex couples. A new culturally sensitive relationship education program was developed specifically for male same-sex couples, which includes adaptations of evidence-based strategies to build core relationship skills (e.g., communication skills training) and newly developed content to address unique challenges faced by this group (e.g., discrimination; low social support). A small randomized waitlist-control trial (N = 20 couples) was conducted to evaluate the program. To assess program efficacy, dyadic longitudinal data (collected at pre- and postprogram and 3-month follow-up) were analyzed using multilevel models that accounted for nonindependence in data from indistinguishable dyads. Results indicated significant program effects in comparison to waitlist controls on couple constructive and destructive communication, perceived stress, and relationship satisfaction. Gains in each of these areas were maintained at 3-month follow-up. Although there was no evidence of within-person program effects on social support, satisfaction, or relationship instability immediately postprogram, all 3 showed within-person improvements by follow-up. Ratings of program satisfaction were high. In summary, study findings support the feasibility, acceptability, and initial efficacy of the program and highlight the potential value of culturally sensitive adaptations of relationship education for same-sex couples. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Is audio computer-assisted self-interview (ACASI useful in risk behaviour assessment of female and male sex workers, Mombasa, Kenya?

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Elisabeth M van der Elst

Full Text Available Audio computer-assisted self-interview (ACASI may elicit more frequent reporting of socially sensitive behaviours than face-to-face (FtF-interview. However, no study compared responses to both methods in female and male sex workers (FSW; MSW in Africa.We sequentially enrolled adults recruited for an HIV-1 intervention trial into a comparative study of ACASI and FtF-interview, in a clinic near Mombasa, Kenya. Feasibility and acceptability of ACASI, and a comparative analysis of enrolment responses between ACASI and FtF on an identical risk assessment questionnaire were evaluated. In total, 139 women and 259 men, 81% of eligible cohort participants, completed both interviews. ACASI captured a higher median number of regular (2 vs. 1, p<0.001, both genders and casual partners in the last week (3 vs. 2, p = 0.04 in women; 2 vs. 1, p<0.001 in men. Group sex (21.6 vs. 13.5%, p<0.001, in men, intravenous drug use (IDU; 10.8 vs. 2.3%, p<0.001 in men; 4.4 vs. 0%, p = 0.03 in women, and rape (8.9 vs. 3.9%, p = 0.002, in men were reported more frequently in ACASI. A surprisingly high number of women reported in ACASI that they had paid for sex (49.3 vs. 5.8%, p<0.001. Behaviours for recruitment (i.e. anal sex, sex work, sex between males were reported less frequently in ACASI. The majority of women (79.2% and men (69.7% felt that answers given in ACASI were more honest. Volunteers who were not able to take ACASI (84 men, and 37 women mostly lacked reading skills.About 1 in 5 cohort participants was not able to complete ACASI, mostly for lack of reading skills. Participants who completed ACASI were more likely to report IDU, rape, group sex, and payment for sex by women than when asked in FtF interview. ACASI appears to be a useful tool for high risk behaviour assessments in the African context.

Sex differences, effects of male presence and coordination of nest visits in prairie voles (Microtus ochrogaster) during the immediate postnatal period

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Mcguire, B.; Parker, E.; Bemis, W.E.

2007-01-01

Little is known about sex differences in parental behavior of biparental mammals and if mates in such species coordinate care of young. We studied parental care displayed by prairie voles (Microtus ochrogaster) under seminatural laboratory conditions during the first 3 d of life of their offspring. Through direct observations and videotaping, we monitored members of male-female pairs to determine if sex differences in early parental behavior exist and if mothers and fathers coordinate visits to the nest. To assess the impact of fathers on survival of pups and behavior of mothers, we also examined parental care displayed by single females toward their young. Male and female members of breeding pairs differed dramatically in degree of parental care. Females spent more time in the nest with young and licked them more frequently than did males. Additionally, females maintained the nest more frequently than did males, whereas they maintained runways less frequently. Although coordination of visits to the nest was not perfect between members of pairs, pups of pairs were left alone for less time than were pups of single females. Parental behavior displayed by paired and single females did not differ, nor did survival of their young to day 3 or 15. We suggest that provision of ample space and cover to vole parents rearing young in captivity promotes expression of sex differences in parental behavior, but that even seminatural conditions are not sufficient to yield benefits of father presence to survival of young. Under more challenging conditions, such as cold temperatures or presence of predators, benefits of father presence might emerge.

Does sex matter? Temporal and spatial patterns of cougar-human conflict in British Columbia.

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Teichman, Kristine J; Cristescu, Bogdan; Nielsen, Scott E

2013-01-01

Wildlife-human conflicts occur wherever large carnivores overlap human inhabited areas. Conflict mitigation can be facilitated by understanding long-term dynamics and examining sex-structured conflict patterns. Predicting areas with high probability of conflict helps focus management strategies in order to proactively decrease carnivore mortality. We investigated the importance of cougar (Puma concolor) habitat, human landscape characteristics and the combination of habitat and human features on the temporal and spatial patterns of cougar-human conflicts in British Columbia. Conflicts (n = 1,727; 1978-2007) involved similar numbers of male and female cougars with conflict rate decreasing over the past decade. Conflicts were concentrated within the southern part of the province with the most conflicts per unit area occurring on Vancouver Island. For both sexes, the most supported spatial models for the most recent (1998-2007) conflicts contained both human and habitat variables. Conflicts were more likely to occur close to roads, at intermediate elevations and far from the northern edge of the cougar distribution range in British Columbia. Male cougar conflicts were more likely to occur in areas of intermediate human density. Unlike cougar conflicts in other regions, cattle density was not a significant predictor of conflict location. With human populations expanding, conflicts are expected to increase. Conservation tools, such as the maps predicting conflict hotspots from this study, can help focus management efforts to decrease carnivore-human conflict.

[Practices and perception of risk in human immunodeficiency virus infected males who have sex with other males].

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Fernández de Mosteyrín, Sol; del Val Acebrón, María; Fernández de Mosteyrín, Teresa; Fernández Guerrero, Manuel L

2014-04-01

The incidence of human immunodeficiency virus (HIV) and other sexually transmitted diseases increases in males who have sex with males (MSM), despite the knowledge on how to prevent them. To determine the mechanisms that are driving this lack of prevention is important to reverse the trend. An anonymous, voluntary and self-reporting questionnaire was completed by HIV+ MSM patients who were seen in a hospital clinic, with the aim of finding out the sexual risk practices and behaviour, as well as their perceptions and assessment as regards this risk. The questionnaire included 58questions, divided into 10sections, to explore the knowledge, attitudes, and behaviour as regards HIV. The questionnaires were also given to the physicians, with the aim of exploring their perceptions, attitudes and opinions as regards the situation of the epidemic, prevention, perception of the diseases and the patient, and values in clinical practice. A total of 495 questionnaires from the patients were analysed. Most of them (87%) said they knew how HIV was acquired, and 97% knew how to prevent it, but 69% knew they were in a risk situation, and 43% had little concern of contracting HIV. Almost two-thirds (65%) had sex with ≥2persons on the same day, 47% met on the Internet and 26% had group sex. The same percentage of those surveyed considered that they acted impulsively. They highlighted a lack of information (33%), bad luck (32%), assumed excessive risk (36%), and lake of concern (25%), as the main reasons for acquiring the infection. When confronted with diagnosis 41% of patients answered «I never thought that it would happen to me», and 32% said «I had bad luck». Of the 121 physicians who completed the questionnaire, 24% considered that infection due to HIV/AIDS was out of control in Spain, and 65% responded that there was an image that HIV/AIDS was a controlled disease and of little concern. A large majority (71%) of those surveyed, considered that the increase in new

Antidepressant-like effects of guanfacine and sex-specific differences in effects on c-fos immunoreactivity and paired-pulse ratio in male and female mice.

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Mineur, Yann S; Bentham, Matthew P; Zhou, Wen-Liang; Plantenga, Margreet E; McKee, Sherry A; Picciotto, Marina R

2015-10-01

The a2A-noradrenergic agonist guanfacine can decreases stress-induced smoking in female, but not male, human smokers. It is not known whether these effects are due to effects on mood regulation and/or result from nicotinic-cholinergic interactions. The objective of the study was to determine whether there are sex differences in the effect of guanfacine in tests of anxiolytic and antidepressant efficacy in mice at baseline and in a hypercholinergic model of depression induced by the acetylcholinesterase inhibitor physostigmine. The effects of guanfacine were measured in the light/dark box, tail suspension, and the forced swim test in female and male C57BL/6J mice. In parallel, electrophysiological properties were evaluated in the prefrontal cortex, a critical brain region involved in stress responses. c-fos immunoreactivity was measured in other brain regions known to regulate mood. Despite a baseline sex difference in behavior in the forced swim test (female mice were more immobile), guanfacine had similar, dose-dependent, antidepressant-like effects in mice of both sexes (optimal dose, 0.15 mg/kg). An antidepressant-like effect of guanfacine was also observed following pre-treatment with physostigmine. A sex difference in the paired-pulse ratio in the prefrontal cortex (PFC) (male, 1.4; female, 2.1) was observed at baseline that was normalized by guanfacine. Other brain areas involved in cholinergic control of depression-like behaviors, including the basolateral amygdala and lateral septum, showed sex-specific changes in c-fos expression. Guanfacine has a robust antidepressant-like effect and can reverse a depression-like state induced by increased acetylcholine (ACh) signaling. These data suggest that different brain areas are recruited in female and male mice, despite similar behavioral responses to guanfacine.

Australian men's sexual practices in saunas, sex clubs and other male sex on premises venues.

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Lyons, Anthony; Smith, Anthony M A; Grierson, Jeffrey W; von Doussa, Henry

2010-06-01

Sex on premises venues (SOPVs) where men have sex with men have been implicated in the spread of sexually transmissible infections, but few studies have described men's sexual encounters in SOPVs, particularly the degree to which men from different backgrounds engage in risky sexual practices. Interviewer administered surveys were conducted with 186 Australian men who have sex with men (MSM) within 48 h of visiting an SOPV. They reported their sexual practices, the characteristics of their partners and other circumstances surrounding their sexual encounters. All analyses were based on the number of sexual encounters (n = 430). Oral sex was the most common practice, occurring in 74.9% of encounters, followed by massage, frottage or kissing (53.7%), solo or mutual masturbation (36.3%), and anal sex (32.1%). Multivariate analyses revealed age as a significant factor for having protected anal sex (P = 0.001), insertive anal sex (P = 0.004) and receptive anal sex (P practices were more frequent in encounters among younger men, while masturbation (P = 0.03) was more frequent among older men. When men's sexual partners were affected by alcohol, encounters were less likely to involve unprotected anal intercourse (P = 0.006) and more likely to involve massage, frottage or kissing (P = 0.009). Men disclosed their HIV status in only 7.7% of encounters. With the likelihood of risky sexual practices varying according to background, results from this study should be used to guide interventions aiming to promote safer sex in SOPVs.

Creativity and Psychopathology: Sex Matters

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Martín-Brufau, Ramón; Corbalán, Javier

2016-01-01

The association between creativity and psychopathology has, for decades, been a focus of heated debate fuelled by contradictory findings. Nevertheless, the findings suggest complex associations between creativity and psychopathology. Other studies have investigated the association between creativity and sex, with inconsistent results. The aim of…

Quality of Life and Patient Satisfaction Following Male-to-Female Sex Reassignment Surgery.

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Papadopulos, Nikolaos A; Lellé, Jean-Daniel; Zavlin, Dmitry; Herschbach, Peter; Henrich, Gerhard; Kovacs, Laszlo; Ehrenberger, Benjamin; Kluger, Anna-Katharina; Machens, Hans-Guenther; Schaff, Juergen

2017-05-01

Surveys on quality of life (QOL) of male-to-female (MTF) transsexuals have found low QOL scores before and increased satisfaction scores after sex-reassignment surgery (SRS). To our knowledge, many of them lack standardized questionnaires and comparisons with normative data to evaluate different vaginoplasty techniques. To analyze patient satisfaction and QOL after SRS. Forty-seven patients participated in this study. All patients had surgery with our self-developed combined technique on average 19 months before the survey. They completed a self-developed indication-specific questionnaire concerning demographic and socioeconomic issues and postoperative satisfaction. Furthermore, a standardized self-assessment questionnaire on satisfaction and QOL (Fragen zur Lebenszufriedenheit Module [FLZ M ]; Questions on Life Satisfaction Modules ) was used. The FLZ M consists of three modules (general life satisfaction, satisfaction with health, and satisfaction with body image) with scores of weighted satisfaction for each item. Results of the general and health modules were compared with normative data. Demographics, QOL, general life satisfaction, satisfaction with health, and satisfaction with body image. The self-developed indication-specific questionnaire showed that 91% experienced an improvement of QOL. All patients stated they would undergo SRS again and did not regret it at all. Patients stated their femininity significantly increased. For the FLZ M , the sum score for general life satisfaction (P patient satisfaction of this complex and non-standardized surgery. This is the first description of a new surgical technique (combined technique) for MTF SRS. QOL was assessed by a large number of patients by standardized questionnaires and could be compared with normative data. Because this is a retrospective study, we can draw only careful conclusions for pre- and postoperative changes. Our self-developed combined surgical technique seemed to have a positive influence on

Impact of Gamma Radiation on Sex Pheromone Gland of Female and Male Response of Ephestia calidella (Guen.)

International Nuclear Information System (INIS)

Hazaa, M.A.M.; Alm El-Din, M. M. S.; Mikhaiel, A.A.

2012-01-01

The sex pheromone gland of female oases date moth, Ephestia calidella is located inter segmentally between eight and nine abdominal segment. Effect of three sub sterilizing doses 75, 100 and 125 Gy of gamma radiation on pheromone production and on male response were studied. The results obtained revealed that gamma irradiation reduce the pheromone production by female and the responsiveness of male. The effect was increased by increasing the radiation dose. Histological studies of pheromone gland also, indicated that gamma irradiation disturb epithelial cells of the gland and becoming thin at certain parts. Also, gland hairs ruptured or completely disappeared at the highest dose of 125 Gy.

Sex differences in circadian food anticipatory activity are not altered by individual manipulations of sex hormones or sex chromosome copy number in mice.

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Aguayo, Antonio; Martin, Camille S; Huddy, Timothy F; Ogawa-Okada, Maya; Adkins, Jamie L; Steele, Andrew D

2018-01-01

Recent studies in mice have demonstrated a sexual dimorphism in circadian entrainment to scheduled feeding. On a time restricted diet, males tend to develop food anticipatory activity (FAA) sooner than females and with a higher amplitude of activity. The underlying cause of this sex difference remains unknown. One study suggests that sex hormones, both androgens and estrogens, modulate food anticipatory activity in mice. Here we present results suggesting that the sex difference in FAA is unrelated to gonadal sex hormones. While a sex difference between males and females in FAA on a timed, calorie restricted diet was observed there were no differences between intact and gonadectomized mice in the onset or magnitude of FAA. To test other sources of the sex difference in circadian entrainment to scheduled feeding, we used sex chromosome copy number mutants, but there was no difference in FAA when comparing XX, XY-, XY-;Sry Tg, and XX;Sry Tg mice, demonstrating that gene dosage of sex chromosomes does not mediate the sex difference in FAA. Next, we masculinized female mice by treating them with 17-beta estradiol during the neonatal period; yet again, we saw no difference in FAA between control and masculinized females. Finally, we observed that there was no longer a sex difference in FAA for older mice, suggesting that the sex difference in FAA is age-dependent. Thus, our study demonstrates that singular manipulations of gonadal hormones, sex chromosomes, or developmental patterning are not able to explain the difference in FAA between young male and female mice.

Disparities in HIV and syphilis prevalence and risk factors between older male clients with and without steady sex partners in southwestern rural China.

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Chen, Li; His, Jenny H; Wu, Xinghua; Shen, Zhiyong; Lu, Huaxiang; Chen, Huanhuan; Huang, Hui; Zhang, Heng; Ruan, Yuhua; Shao, Yiming; Tang, Zhenzhu

2017-04-12

Heterosexual intercourse accounted for 93% of reported HIV cases in Guangxi, and Guangxi had 10% of China's total number of reported HIV cases. Older men are particularly vulnerable to STIs, for example, 46% of Guangxi's HIV cases were men over 50 years of age. As this is an under-studied population in China, effective prevention and control policies have yet to be developed. Thus, the aim of this study was to use a large-scale cross-sectional survey to understand the demographic and behavior factors associated with HIV and syphilis infections among older male clients of female sex workers (FSWs) in a high epidemic area of rural Guangxi, China. A large-scale cross-sectional survey was conducted in 2012 among older male clients of FSWs in low-cost commercial sex venues. Questionnaire interviews were administered to collect sociodemographic and sexual behavior information. Blood samples were collected for HIV and syphilis infection tests. Of the 3485 participants, 2509 (72.0%) clients had a steady sex partner and 976 (28.0%) clients had no steady sex partner. The overall prevalence of HIV and syphilis infection were 3.0% and 3.2%, respectively. Compared to those with a steady sex partner, clients with no steady partner had higher odds of HIV infection (AOR: 1.90, 95% CI: 1.27-2.86), syphilis infection (AOR: 1.53, 95% CI: 1.02-2.30), and having factors associated with HIV or syphilis infection, including non-commercial casual sex encounters in last month (AOR: 3.29, 95% CI: 2.42-4.46), >10 years of commercial sex history (AOR: 1.31, 95% CI: 1.12-1.53), >2 incidents of commercial sex in last month (AOR: 1.53, 95% CI: 1.19-1.96), and aphrodisiac use in last month (AOR: 1.40, 95% CI: 1.16-1.70). Clients with no steady partner had lower odds of having heterosexual intercourse (AOR: 0.66, 95% CI: 0.56-0.79), awareness and knowledge of HIV/AIDS (AOR: 0.75, 95% CI: 0.64-0.88), and having had HIV tests (AOR: 0.65, 95% CI: 0.44-0.98). Older male clients of low

Minority race and male sex as risk factors for non-beneficial gastrostomy tube placements after stroke.

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Faigle, Roland; Carrese, Joseph A; Cooper, Lisa A; Urrutia, Victor C; Gottesman, Rebecca F

2018-01-01

Percutaneous endoscopic gastrostomy (PEG) tubes are widely used for enteral feeding after stroke; however, PEG tubes placed in patients in whom death is imminent are considered non-beneficial. We sought to determine whether placement of non-beneficial PEG tubes differs by race and sex. In this retrospective cohort study, inpatient admissions for stroke patients who underwent palliative/withdrawal of care, were discharged to hospice, or died during the hospitalization, were identified from the Nationwide Inpatient Sample between 2007 and 2011. Logistic regression was used to evaluate the association between race and sex with PEG placement. Of 36,109 stroke admissions who underwent palliative/withdrawal of care, were discharge to hospice, or experienced in-hospital death, a PEG was placed in 2,258 (6.3%). Among PEG recipients 41.1% were of a race other than white, while only 22.0% of patients without PEG were of a minority race (prace was associated with PEG placement compared to whites (OR 1.75, 95% CI 1.57-1.96), and men had 1.27 times higher odds of PEG compared to women (95% CI 1.16-1.40). Racial differences were most pronounced among women: ethnic/racial minority women had over 2-fold higher odds of a PEG compared to their white counterparts (OR 2.09, 95% CI 1.81-2.41), while male ethnic/racial minority patients had 1.44 increased odds of a PEG when compared to white men (95% CI 1.24-1.67, p-value for interaction race and male sex are risk factors for non-beneficial PEG tube placements after stroke.

High HIV Prevalence and Risk Among Male Clients of Female Sex Workers in Hanoi and Ho Chi Minh City, Vietnam.

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Nadol, Patrick; Hoang, Tran Vu; Le, Linh-Vi; Nguyen, Tuan Anh; Kaldor, John; Law, Matthew

2017-08-01

In Vietnam's concentrated HIV epidemic, female sex workers (FSWs) are at increased risk for acquiring and transmitting HIV, largely through their male clients. A high proportion of males in Vietnam report being clients of FSWs. Studying HIV-related risk factors and prevalence among male clients is important, particularly given the potential for male clients to be a 'bridge' of HIV transmission to the more general population or to sex workers. Time-location sampling was used to identify FSW in Hanoi and Ho Chi Minh City, Vietnam's largest cities, in 2013-2014. Recruited FSWs were asked to refer one male client to the study. Demographic and risk behavior data were collected from FSWs and male clients by administered questionnaires. Biologic specimens collected from male clients were tested for HIV and opiates. Sampling weights, calculated based on the FSWs probability of being selected for enrolment, were applied to prevalence estimates for both FSWs and male clients. Logistic regression models were developed to obtain odds ratios for HIV infection among male clients. A total of 804 male clients were enrolled. Overall, HIV prevalence among male clients was 10.2%; HIV prevalence was 20.7% (95% confidence interval (CI) 15.0-27.9%) among those reporting a history of illegal drug use and 32.4% (95% CI 20.2-47.7%) among those with opioids detected in urine. HIV prevalence among male clients did not differ across 'bridging' categories defined by condom use with FSWs and regular partners over the previous 6 months. HIV among male clients was associated with a reported history of illegal drug use (OR 3.76; 95% CI 1.87-7.56), current opioid use (OR 2.55; 95% CI 1.02-6.36), and being referred by an FSW who self-reported as HIV-positive (OR 5.37; 95% CI 1.46-19.75). Self-reported HIV prevalence among enrolled FSWs was 2.8%. Based on HIV test results of male clients and self-reported status from FSWs, an estimated 12.1% of male client-FSW pairs were sero-discordant. These

'He's not my pimp': toward an understanding of intimate male partner involvement in female sex work at the Mexico-US border.

Science.gov (United States)

Mittal, María Luisa; Bazzi, Angela Robertson; Rangel, María Gudelia; Staines, Hugo; Yotebieng, Kelly; Strathdee, Steffanie A; Syvertsen, Jennifer L

2017-11-24

Female sex work is often perceived as women being controlled by men. We used surveys and qualitative interviews with female sex workers and their intimate partners in two Northern Mexico cities to examine couples' own perceptions of their relationships and male partners' involvement in sex work. Among 214 couples, the median age was 34 and relationship duration was approximately 3 years. Only 10 women in the survey reported having a pimp, and the majority reported sole control over sex work decisions. Qualitative analyses revealed that while most men avoided direct involvement in sex work, they offered advice that was largely driven by concern for their partner's well-being. Our discussion of these results considers the broader socio-political context surrounding these relationships and how changing gender roles, economic insecurity and stigma shape couples' everyday social interactions. Assumptions that all sex workers' relationships are coercive and commercial marginalises these couples while leaving their health concerns unaddressed.

Reversal Surgery in Regretful Male-to-Female Transsexuals After Sex Reassignment Surgery.

Science.gov (United States)

Djordjevic, Miroslav L; Bizic, Marta R; Duisin, Dragana; Bouman, Mark-Bram; Buncamper, Marlon

2016-06-01

Sex reassignment surgery (SRS) has proved an effective intervention for patients with gender identity disorder. However, misdiagnosed patients sometimes regret their decision and request reversal surgery. This review is based on our experience with seven patients who regretted their decision to undergo male-to-female SRS. To analyze retrospectively seven patients who underwent reversal surgery after regretting their decision to undergo male-to-female SRS elsewhere. From November 2010 through November 2014, seven men 33 to 53 years old with previous male-to-female SRS underwent reversal phalloplasty. Preoperatively, they were examined by three independent psychiatrists. Surgery included three steps: removal of female genitalia with scrotoplasty and urethral lengthening, total phalloplasty with microvascular transfer of a musculocutaneous latissimus dorsi flap, and neophallus urethroplasty with penile prosthesis implantation. Self-reported esthetic and psychosexual status after reversion surgery and International Index of Erectile Function scores for sexual health after phalloplasty and penile prosthesis implantation. Follow-up was 13 to 61 months (mean = 31 months). Good postoperative results were achieved in all patients. In four patients, all surgical steps were completed; two patients are currently waiting for penile implants; and one patient decided against the penile prosthesis. Complications were related to urethral lengthening: two fistulas and one stricture were observed. All complications were repaired by minor revision. According to patients' self-reports, all patients were pleased with the esthetic appearance of their genitalia and with their significantly improved psychological status. Reversal surgery in regretful male-to-female transsexuals after SRS represents a complex, multistage procedure with satisfactory outcomes. Further insight into the characteristics of persons who regret their decision postoperatively would facilitate better future

On sexual behavior and sex-role reversal.

Science.gov (United States)

Schuiling, Gerard A

2005-09-01

Sex is not about reproduction; sex is about (re-)combination of DNA. Sex, not reproduction, always involves physical contact between two individuals; to achieve this, strategies of sexual behavior evolved. Sexual behavior, therefore, did not evolve as part of a reproductive strategy, but evolved to enable exchange of genetic material. In multicellular organisms the situation is more complicated than in unicellular organisms, as it is impossible for each cell within a multicellular body to have sex with another cell. Hence, evolution selected a system in which the possibility to have sex was limited to only one cell-line: the germ cells. As a result, sex adopted the character of fertilization, and sex and reproduction became inseparably linked. Still, in some species, including humans, sexual behavior still exhibits features of its evolutionary past: in humans (like in bonobo's) most sexual activity and many sexual behavioral patterns have nothing to do with reproduction (masturbation, homosexual behavior, for example); in humans, sexual behavior also became associated with other strategic objectives, such as intensifying the pair bond, expression of love or power. Different genders - male and female - evolved, and each gender evolved typical gender-related sexual and reproductive strategies as well. In most multicellular species, these strategies became inextricably mixed, and sexual behavior increasingly more - and in most species even exclusively - 'served' the interests of reproduction: sexual behavior became more or less synonymous with reproductive behavior. In most species, the 'mix' of sexual and reproductive strategies evolved into typical gender-related patterns of behavior, that is, in typical 'sex-roles'. Often, males are bigger and more 'beautiful' (= more intensely ornamented) than females; males compete with each other for access to females; males court females, while females choose males ('female choice'). However, ecological circumstances may cause

Sex Change Towards Female in Dying Acer rufinerve Trees

Science.gov (United States)

NANAMI, SATOSHI; KAWAGUCHI, HIDEYUKI; YAMAKURA, TAKUO

2004-01-01

• Background and Aims Sex changes within the genus Acer (Aceraceae) may occur because of associations of sex expression and plant health. In this study, a natural population of Acer rufinerve was monitored to clarify the sex change patterns, the relationship between sex expression and plant health, and the causal environmental conditions that precede sex changes. • Methods Sex expression, growth rate and mortality of A. rufinerve trees in a natural population were monitored from 1992 to 1997. • Key Results Three types of sex expression were observed among A. rufinerve: male, female and bisexual. Among the three types of sex expression, sex changes occurred in all directions. In the growing season of 1994, precipitation was reduced. Stem growth rate decreased and mortality was high in 1994. In the spring of 1995, a drastic sex change from male to female or to bisexual occurred. As a result, the sex ratio became female‐biased in 1995, although it had been male‐biased from 1992 to 1994. In 1996 and 1997, the proportion of males in the population increased, partly as a result of female mortality and partly as a result of female‐to‐male sex changes. Sex expression of A. rufinerve was associated with their growth rate and mortality. The growth rate decreased for trees whose sex changed from male to female or to bisexual, and increased for trees whose sex changed from female to male or to bisexual. Dead trees reproduced as females before they died, except for those that died as males in 1994. • Conclusions One explanation for the sex change towards increasing femaleness for this A. rufinerve population in 1995 was the deterioration of plant health in the previous growing season, because of reduced precipitation. Sex changes of unhealthy and dying A. rufinerve towards femaleness may facilitate re‐occupancy by offspring in gaps created by the death of A. rufinerve trees. PMID:15102611

When Empathy Matters: The Role of Sex and Empathy in Close Friendships.

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Ciarrochi, Joseph; Parker, Philip D; Sahdra, Baljinder K; Kashdan, Todd B; Kiuru, Noona; Conigrave, James

2017-08-01

Based on prior theory and research (Ciarrochi & Heaven, 2009; Eagly & Wood, 1999), we hypothesized that the link between empathy and friendship would be moderated by sex: Girls will nominate empathic boys as friends, whereas boys will not tend to nominate empathic girls. We collected measures of empathy, friendship social support, and close friendship nominations in grade 10 across 1,970 students in 16 schools (M age  = 15.70, SD = .44; males = 993, females = 977). Multilevel models revealed that boys high in cognitive empathy attracted an average of 1.8 more girl friendship nominations than did their low empathy counterparts, whereas empathic girls did not attract a greater number of opposite-sex friends. In addition, the more friendship nominations a boy received from either boys or girls, the more they felt supported by their friends; the number of friendship nominations received by girls, in contrast, had no effect on their felt support by friends. Regardless of the quantity of friendship nominations, empathy was linked to more supportive friendships for both males and females. These results inform a contextual understanding of the role of empathy in selecting and maintaining friendships. © 2016 Wiley Periodicals, Inc.

Counselor-Subject Sex Variables in Systematic Desensitization

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Geer, Carol A.; Hurst, James C.

1976-01-01

A Sex of Subject x Sex of Counselor interaction in the desensitization of test anxiety among 44 college students suggested consideration of the sex variable. Results showed significant treatment effects by both male and female counselors and a significant interaction effect by the male counselor with female subjects. (Author)

Sex ratios

OpenAIRE

West, Stuart A; Reece, S E; Sheldon, Ben C

2002-01-01

Sex ratio theory attempts to explain variation at all levels (species, population, individual, brood) in the proportion of offspring that are male (the sex ratio). In many cases this work has been extremely successful, providing qualitative and even quantitative explanations of sex ratio variation. However, this is not always the situation, and one of the greatest remaining problems is explaining broad taxonomic patterns. Specifically, why do different organisms show so ...

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

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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.

Correlates of HIV, STIs and Associated High Risk Behaviors among Male Clients of Female Sex Workers in Tijuana, Mexico

Science.gov (United States)

Patterson, Thomas L.; Goldenberg, Shira; Gallardo, Manuel; Lozada, Remedios; Semple, Shirley J.; Orozovich, Prisci; Abramovitz, Daniela; Strathdee, Steffanie A.

2009-01-01

Objectives To determine sociodemographic and behavioral correlates of HIV infection among male clients of FSWs in Tijuana. Methods 400 men 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 “zone of tolerance,” where prostitution is practiced openly under a municipal permit system. Efforts were made to balance the sample between residents of the U.S. (San Diego County) and of Mexico (Tijuana). Participants underwent interviews and testing for HIV, syphilis, gonorrhea, and Chlamydia. Logistic regression identified correlates of HIV infection. Results Mean age was 36.6. One quarter had injected drugs within the previous 4 months. Lifetime use of heroin, cocaine and methamphetamine was 36%, 50% and 64%, respectively. Men had frequented FSWs for an average of 11 years, visiting FSWs an average of 26 times last year. In the past four months, one half reported having unprotected sex with an FSW; 46% reported frequently being high when having sex with an FSW. Prevalence of HIV, syphilis, gonorrhea, and Chlamydia was 4%, 2%, 2.5% and 7.5%; 14.2% were positive for at least one infection. Factors independently associated with HIV infection were living in Mexico, ever using methamphetamine, living alone, and testing positive for syphilis. Conclusions Male clients of FSWs in Tijuana had a high sex and drug risk profile. While STI prevalence was lower than among FSWs, HIV prevalence was comparable, suggesting the need for interventions among clients to prevent spread of HIV and STIs. PMID:19584699

"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.

Science.gov (United States)

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.

Sexually transmitted infections among heterosexual male clients of female sex workers in China: a systematic review and meta-analysis.

Directory of Open Access Journals (Sweden)

Megan M McLaughlin

Full Text Available Female sex workers have been the target of numerous sexually transmitted infection (STI prevention strategies in China, but their male clients have attracted considerably less public health attention and resources. We sought to systematically assess the prevalence of HIV, syphilis, gonorrhea, and chlamydia among heterosexual male clients of female sex workers in China.Original research manuscripts were identified by searching Chinese and English language databases, and 37 studies analyzing 26,552 male clients were included in the review. Client STI prevalence across studies was heterogeneous. Pooled prevalence estimates and 95% confidence intervals were 0.68% (0.36-1.28% for HIV, 2.91% (2.17-3.89% for syphilis, 2.16% (1.46-3.17% for gonorrhea, and 8.01% (4.94-12.72% for chlamydia.The pooled prevalence estimates of HIV, syphilis, gonorrhea, and chlamydia among clients in this review exceed the prevalences previously reported among population-representative samples and low-risk groups in China. However, heterogeneity across studies and sampling limitations prevent definitive conclusions about how the prevalence of STIs in this population compares to the general population. These findings suggest a need for greater attention to clients' sexual risk and disease prevalence in China's STI research agenda in order to inform effective prevention policies.

Sex Determination, Sex Chromosomes, and Karyotype Evolution in Insects.

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Blackmon, Heath; Ross, Laura; Bachtrog, Doris

2017-01-01

Insects harbor a tremendous diversity of sex determining mechanisms both within and between groups. For example, in some orders such as Hymenoptera, all members are haplodiploid, whereas Diptera contain species with homomorphic as well as male and female heterogametic sex chromosome systems or paternal genome elimination. We have established a large database on karyotypes and sex chromosomes in insects, containing information on over 13000 species covering 29 orders of insects. This database constitutes a unique starting point to report phylogenetic patterns on the distribution of sex determination mechanisms, sex chromosomes, and karyotypes among insects and allows us to test general theories on the evolutionary dynamics of karyotypes, sex chromosomes, and sex determination systems in a comparative framework. Phylogenetic analysis reveals that male heterogamety is the ancestral mode of sex determination in insects, and transitions to female heterogamety are extremely rare. Many insect orders harbor species with complex sex chromosomes, and gains and losses of the sex-limited chromosome are frequent in some groups. Haplodiploidy originated several times within insects, and parthenogenesis is rare but evolves frequently. Providing a single source to electronically access data previously distributed among more than 500 articles and books will not only accelerate analyses of the assembled data, but also provide a unique resource to guide research on which taxa are likely to be informative to address specific questions, for example, for genome sequencing projects or large-scale comparative studies. © The American Genetic Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Male or female? Brains are intersex

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Daphna eJoel

2011-09-01

Full Text Available The underlying assumption in popular and scientific publications on sex differences in the brain is that human brains can take one of two forms male or female, and that the differences between these two forms underlie differences between men and women in personality, cognition, emotion and behavior. Documented sex differences in brain structure are typically taken to support this dimorphic view of the brain. However, neuroanatomical data reveal that sex interacts with other factors in utero and throughout life to determine the structure of the brain, and that because these interactions are complex, the result is a multi-morphic, rather than a dimorphic, brain. More specifically, here I argue that human brains are composed of an ever-changing heterogeneous mosaic of male and female brain characteristics (rather than being all male or all female that cannot be aligned on a continuum between a male brain and a female brain. I further suggest that sex differences in the direction of change in the brain mosaic following specific environmental events lead to sex differences in neuropsychiatric disorders.

The relationship between health worker stigma and uptake of HIV counseling and testing and utilization of non-HIV health services: the experience of male and female sex workers in Kenya.

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Nyblade, Laura; Reddy, Aditi; Mbote, David; Kraemer, John; Stockton, Melissa; Kemunto, Caroline; Krotki, Karol; Morla, Javier; Njuguna, Stella; Dutta, Arin; Barker, Catherine

2017-11-01

The barrier HIV-stigma presents to the HIV treatment cascade is increasingly documented; however less is known about female and male sex worker engagement in and the influence of sex-work stigma on the HIV care continuum. While stigma occurs in all spheres of life, stigma within health services may be particularly detrimental to health seeking behaviors. Therefore, we present levels of sex-work stigma from healthcare workers (HCW) among male and female sex workers in Kenya, and explore the relationship between sex-work stigma and HIV counseling and testing. We also examine the relationship between sex-work stigma and utilization of non-HIV health services. A snowball sample of 497 female sex workers (FSW) and 232 male sex workers (MSW) across four sites was recruited through a modified respondent-driven sampling process. About 50% of both male and female sex workers reported anticipating verbal stigma from HCW while 72% of FSW and 54% of MSW reported experiencing at least one of seven measured forms of stigma from HCW. In general, stigma led to higher odds of reporting delay or avoidance of counseling and testing, as well as non-HIV specific services. Statistical significance of relationships varied across type of health service, type of stigma and gender. For example, anticipated stigma was not a significant predictor of delay or avoidance of health services for MSW; however, FSW who anticipated HCW stigma had significantly higher odds of avoiding (OR = 2.11) non-HIV services, compared to FSW who did not. This paper adds to the growing evidence of stigma as a roadblock in the HIV treatment cascade, as well as its undermining of the human right to health. While more attention is being paid to addressing HIV-stigma, it is equally important to address the key population stigma that often intersects with HIV-stigma.

Sex Roles among Married and Unmarried Couples.

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Kotkin, Mark

1983-01-01

An investigation of sex roles among married and cohabitating couples showed: (1) that male career success, male career precedence, the decision to marry, and conventional allocation of household tasks are all concomitant and (2) that marriage crystallizes sex roles and behaviorally solidifies male career precedence, facilitating the husband's…

Does sex matter? Temporal and spatial patterns of cougar-human conflict in British Columbia.

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Kristine J Teichman

Full Text Available Wildlife-human conflicts occur wherever large carnivores overlap human inhabited areas. Conflict mitigation can be facilitated by understanding long-term dynamics and examining sex-structured conflict patterns. Predicting areas with high probability of conflict helps focus management strategies in order to proactively decrease carnivore mortality. We investigated the importance of cougar (Puma concolor habitat, human landscape characteristics and the combination of habitat and human features on the temporal and spatial patterns of cougar-human conflicts in British Columbia. Conflicts (n = 1,727; 1978-2007 involved similar numbers of male and female cougars with conflict rate decreasing over the past decade. Conflicts were concentrated within the southern part of the province with the most conflicts per unit area occurring on Vancouver Island. For both sexes, the most supported spatial models for the most recent (1998-2007 conflicts contained both human and habitat variables. Conflicts were more likely to occur close to roads, at intermediate elevations and far from the northern edge of the cougar distribution range in British Columbia. Male cougar conflicts were more likely to occur in areas of intermediate human density. Unlike cougar conflicts in other regions, cattle density was not a significant predictor of conflict location. With human populations expanding, conflicts are expected to increase. Conservation tools, such as the maps predicting conflict hotspots from this study, can help focus management efforts to decrease carnivore-human conflict.

Neurosteroids in Adult Hippocampus of Male and Female Rodents: Biosynthesis and Actions of Sex Steroids

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Yasushi Hojo

2018-04-01

Full Text Available The brain is not only the target of steroid hormones but also is able to locally synthesize steroids de novo. Evidence of the local production of steroids in the brain has been accumulating in various vertebrates, including teleost fish, amphibia, birds, rodents, non-human primates, and humans. In this review, we mainly focus on the local production of sex steroids in the hippocampal neurons of adult rodents (rats and mice, a center for learning and memory. From the data of the hippocampus of adult male rats, hippocampal principal neurons [pyramidal cells in CA1–CA3 and granule cells in dentate gyrus (DG] have a complete system for biosynthesis of sex steroids. Liquid chromatography with tandem-mass-spectrometry (LC-MS/MS enabled us to accurately determine the levels of hippocampal sex steroids including 17β-estradiol (17β-E2, testosterone (T, and dihydrotestosterone (DHT, which are much higher than those in blood. Next, we review the steroid synthesis in the hippocampus of female rats, since previous knowledge had been biased toward the data from males. Recently, we clarified that the levels of hippocampal steroids fluctuate in adult female rats across the estrous cycle. Accurate determination of hippocampal steroids at each stage of the estrous cycle is of importance for providing the account for the fluctuation of female hippocampal functions, including spine density, long-term potentiation (LTP and long-term depression (LTD, and learning and memory. These functional fluctuations in female had been attributed to the level of circulation-derived steroids. LC-MS/MS analysis revealed that the dendritic spine density in CA1 of adult female hippocampus correlates with the levels of hippocampal progesterone and 17β-E2. Finally, we introduce the direct evidence of the role of hippocampus-synthesized steroids in hippocampal function including neurogenesis, LTP, and memory consolidation. Mild exercise (2 week of treadmill running elevated

Sex ratio variation and sex determination in Urtica dioica

NARCIS (Netherlands)

Glawe, Grit Anja

2006-01-01

This thesis will first document on variation in progeny sex ratios among individual female plants of Urtica dioica at our field site in Meijendel (Chapter 2). Next, we show that there is also considerable sex ratio variation among male and female flowering shoots in 26 natural populations studied

Cancer risk in opposite-sex and same-sex twins

DEFF Research Database (Denmark)

Juel Ahrenfeldt, Linda

2015-01-01

Twin pregnancies are characterized by simultaneous development of two fetuses that share the womb. An interest in opposite-sex (OS) twins, twin pairs consisting of one male and one female, comes from animal studies that showed that exposure to sex hormones is influenced by the position of the fetus...

A father effect explains sex-ratio bias.

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Malo, Aurelio F; Martinez-Pastor, Felipe; Garcia-Gonzalez, Francisco; Garde, Julián; Ballou, Jonathan D; Lacy, Robert C

2017-08-30

Sex ratio allocation has important fitness consequences, and theory predicts that parents should adjust offspring sex ratio in cases where the fitness returns of producing male and female offspring vary. The ability of fathers to bias offspring sex ratios has traditionally been dismissed given the expectation of an equal proportion of X- and Y-chromosome-bearing sperm (CBS) in ejaculates due to segregation of sex chromosomes at meiosis. This expectation has been recently refuted. Here we used Peromyscus leucopus to demonstrate that sex ratio is explained by an exclusive effect of the father, and suggest a likely mechanism by which male-driven sex-ratio bias is attained. We identified a male sperm morphological marker that is associated with the mechanism leading to sex ratio bias; differences among males in the sperm nucleus area (a proxy for the sex chromosome that the sperm contains) explain 22% variation in litter sex ratio. We further show the role played by the sperm nucleus area as a mediator in the relationship between individual genetic variation and sex-ratio bias. Fathers with high levels of genetic variation had ejaculates with a higher proportion of sperm with small nuclei area. This, in turn, led to siring a higher proportion of sons (25% increase in sons per 0.1 decrease in the inbreeding coefficient). Our results reveal a plausible mechanism underlying unexplored male-driven sex-ratio biases. We also discuss why this pattern of paternal bias can be adaptive. This research puts to rest the idea that father contribution to sex ratio variation should be disregarded in vertebrates, and will stimulate research on evolutionary constraints to sex ratios-for example, whether fathers and mothers have divergent, coinciding, or neutral sex allocation interests. Finally, these results offer a potential explanation for those intriguing cases in which there are sex ratio biases, such as in humans. © 2017 The Author(s).

Male sex, African American race or ethnicity, and triiodothyronine levels at diagnosis predict weight gain after antithyroid medication and radioiodine therapy for hyperthyroidism.

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Ariza, Miguel A; Loken, Won Mee J; Pearce, Elizabeth N; Safer, Joshua D

2010-01-01

To determine whether racial or ethnic differences affect weight gain after treatment of hyperthyroidism and to reassess established risk factors such as sex, age, and cause of hyperthyroidism. We conducted a retrospective review of medical records of 111 patients treated with radioiodine (RAI) for hyperthyroidism, with or without preceding antithyroid medication, during 2002 to 2005. We ascertained age, sex, race or ethnicity, insurance status, compliance with visits, serum triiodothyronine (T3) level at diagnosis, and cause of hyperthyroidism. Weights and serum thyroidstimulating hormone levels were obtained at diagnosis, at time of RAI therapy, and at 0 to 4 months, 4 to 8 months, 8 to 12 months, and 24 months after RAI treatment. There was a significant weight increase after treatment of hyperthyroidism. Levels of T3 at initial diagnosis of hyperthyroidism, male sex, and black or Hispanic ethnicity were found to be independent predictors of weight gain after RAI treatment. We found a significant interaction between race or ethnicity and sex in multivariate models. There was no difference in thyroid function across racial or ethnic groups or the sexes. Age, cause of hyperthyroidism, posttreatment thyroid-stimulating hormone level, compliance, and insurance status were not found to be significant predictors of weight gain. The T3 level at the time of diagnosis of hyperthyroidism is a strong predictor of weight gain after treatment of hyperthyroidism. Black race or ethnicity and male sex are also risk factors for weight gain.

Complementary sex determination in the parasitic wasp Diachasmimorpha longicaudata.

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Leonela Carabajal Paladino

Full Text Available We studied the sex determination in Diachasmimorpha longicaudata, a parasitoid braconid wasp widely used as biological control agent of fruit pest tephritid flies. We tested the complementary sex determination hypothesis (CSD known in at least 60 species of Hymenoptera. According to CSD, male or female development depends on the allelic composition of one sex locus (single-locus CSD or multiple sex loci (multiple-locus CSD. Hemizygote individuals are normal haploid males, and heterozygotes for at least one sex locus are normal diploid females, but homozygotes for all the sex loci are diploid males. In order to force the occurrence of diploid males in D. longicaudata, we established highly inbred lines and examined their offspring using chromosome counting, flow cytometry, and sex ratio analysis. We found that when mother-son crosses were studied, this wasp produced about 20% of diploid males out of the total male progeny. Our results suggest that this parasitoid may represent the second genus with multiple-locus CSD in Hymenoptera. Knowledge about the sex determination system in D. longicaudata is relevant for the improvement of mass rearing protocols of this species. This information also provides the necessary background for further investigations on the underlying molecular mechanisms of sex determination in this species, and a better insight into the evolution of this pathway in Hymenoptera in particular and insects in general.

Correlates of HIV, sexually transmitted infections, and associated high-risk behaviors among male clients of female sex workers in Tijuana, Mexico.

Science.gov (United States)

Patterson, Thomas L; Goldenberg, Shira; Gallardo, Manuel; Lozada, Remedios; Semple, Shirley J; Orozovich, Prisci; Abramovitz, Daniela; Strathdee, Steffanie A

2009-08-24

To determine sociodemographic and behavioral correlates of HIV infection among male clients of female sex workers (FSWs) in Tijuana. Four hundred men aged 18 years or older who had paid or traded for sex with a FSW in Tijuana during the past 4 months were recruited in Tijuana's 'zone of tolerance,' where prostitution is practiced openly under a municipal permit system. Efforts were made to balance the sample between residents of the United States (San Diego County) and of Mexico (Tijuana). Participants underwent interviews and testing for HIV, syphilis, gonorrhea, and Chlamydia. Logistic regression identified correlates of HIV infection. Mean age was 36.6 years. One-quarter had injected drugs within the previous 4 months. Lifetime use of heroin, cocaine, and methamphetamine was 36, 50, and 64%, respectively. Men had frequented FSWs for an average of 11 years, visiting FSWs an average of 26 times last year. In the past 4 months, one-half reported having unprotected sex with a FSW; 46% reported being high fairly or very often when having sex with a FSW. Prevalence of HIV, syphilis, gonorrhea, and Chlamydia was 4, 2, 2.5, and 7.5%; 14.2% were positive for at least one infection. Factors independently associated with HIV infection were living in Mexico, ever using methamphetamine, living alone, and testing positive for syphilis. Male clients of FSWs in Tijuana had a high sex and drug risk profile. Although sexually transmitted infection prevalence was lower than among FSWs, HIV prevalence was comparable suggesting the need for interventions among clients to prevent spread of HIV and sexually transmitted infections.

Sex Reversal in Birds.

Science.gov (United States)

Major, Andrew T; Smith, Craig A

2016-01-01

Sexual differentiation in birds is controlled genetically as in mammals, although the sex chromosomes are different. Males have a ZZ sex chromosome constitution, while females are ZW. Gene(s) on the sex chromosomes must initiate gonadal sex differentiation during embryonic life, inducing paired testes in ZZ individuals and unilateral ovaries in ZW individuals. The traditional view of avian sexual differentiation aligns with that expounded for other vertebrates; upon sexual differentiation, the gonads secrete sex steroid hormones that masculinise or feminise the rest of the body. However, recent studies on naturally occurring or experimentally induced avian sex reversal suggest a significant role for direct genetic factors, in addition to sex hormones, in regulating sexual differentiation of the soma in birds. This review will provide an overview of sex determination in birds and both naturally and experimentally induced sex reversal, with emphasis on the key role of oestrogen. We then consider how recent studies on sex reversal and gynandromorphic birds (half male:half female) are shaping our understanding of sexual differentiation in avians and in vertebrates more broadly. Current evidence shows that sexual differentiation in birds is a mix of direct genetic and hormonal mechanisms. Perturbation of either of these components may lead to sex reversal. © 2016 S. Karger AG, Basel.

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

Science.gov (United States)

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…

Morally sensitive issues and cross-border movement in the EU. The cases of reproductive matters and legal recognition of same-sex relationships

NARCIS (Netherlands)

Koffeman, Nelleke Renate

2015-01-01

Within the European Union there is considerable diversity in morally sensitive issues like legal recognition of same-sex relationships and reproductive matters such as abortion, assisted human reproduction and surrogacy. Cross-border movement within the EU exposes and affects this diversity, as it

Top, Bottom, and Versatile Anal Sex Roles in Same-Sex Male Relationships: Implications for Relationship and Sexual Satisfaction.

Science.gov (United States)

Moskowitz, David A; Garcia, Christopher P

2018-06-01

Across much of the gay and bisexual male research on sexual position self-label (i.e., calling oneself a top, bottom, or versatile), there exist two commonalities: (1) studies tend to focus almost entirely on individual, relationally single androphilic men; (2) studies rarely account for relationships and relationship dynamics. In response, we explored the role of self-label over sexual and relationship satisfaction among gay and bisexual partnered men. Specifically, we looked at whether adopted sexual position identities were consonant or dissonant (i.e., matching or mismatching) with enacted behavior in relationships and how that impacted men's attitudes toward different relational attributes. Through an online survey, we sampled 169 men in same-sex relationships, asking them questions about their ideal penetrative role identities and their reality penetrative roles with their partner. We then asked them to rate their relationship on 10 sexual and interpersonal attributes. Multiple regression modeling suggested ideal-reality penetrative role dissonance was predictive of sexual dissatisfaction among tops who bottomed in their relationships and, to a lesser extent, bottoms who topped. In contrast, penetrative role dissonance was predictive of relationship satisfaction among tops who bottomed in their relationship, but not bottoms who topped. We conclude that a potential reason for this paradox among tops who bottom may be sexual altruism. That is, men may be satisfied with other aspects within their relationships, understand their partner's anal sex preferences, and accommodate that position in response to their initial relationship satisfaction.

Television Sex Roles in the 1980s: Do Viewers' Sex and Sex Role Orientation Change the Picture?

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Dambrot, Faye H.; And Others

1988-01-01

Investigates the viewer perceptions of female and male television characters as a result of viewer sex and sex role orientation, based on the responses of 677 young adults to the Personal Attributes Questionnaire (PAQ). Viewer gender had an impact on the rating of female characters. (FMW)

Terminal Investment Strategies and Male Mate choice: Extreme Tests of Bateman.

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Andrade, Maydianne C B; Kasumovic, Michael M

2005-11-01

Bateman's principle predicts the intensity of sexual selection depends on rates of increase of fecundity with mating success for each sex (Bateman slopes). The sex with the steeper increase (usually males) is under more intense sexual selection and is expected to compete for access to the sex under less intense sexual selection (usually females). Under Bateman and modern refinements of his ideas, differences in parental investment are key to defining Bateman slopes and thus sex roles. Other theories predict sex differences in mating investment, or any expenditures that reduce male potential reproductive rate, can also control sex roles. We focus on sexual behaviour in systems where males have low paternal investment but frequently mate only once in their lifetimes, after which they are often killed by the female. Mating effort (=terminal investment) is high for these males, and many forms of investment theory might predict sex role reversal. We find no qualitative evidence for sex role reversal in a sample of spiders that show this extreme male investment pattern. We also present new data for terminally-investing redback spiders (Latrodectus hasselti). Bateman slopes are relatively steep for male redbacks, and, as predicted by Bateman, there is little evidence for role reversal. Instead, males are competitive and show limited choosiness despite wide variation in female reproductive value. This study supports the proposal that high male mating investment coupled with low parental investment may predispose males to choosiness but will not lead to role reversal. We support the utility of using Bateman slopes to predict sex roles, even in systems with extreme male mating investment.