Altering gender role expectations: effects on pain tolerance, pain threshold, and pain ratings.
Robinson, Michael E; Gagnon, Christine M; Riley, Joseph L; Price, Donald D
2003-06-01
The literature demonstrating sex differences in pain is sizable. Most explanations for these differences have focused on biologic mechanisms, and only a few studies have examined social learning. The purpose of this study was to examine the contribution of gender-role stereotypes to sex differences in pain. This study used experimental manipulation of gender-role expectations for men and women. One hundred twenty students participated in the cold pressor task. Before the pain task, participants were given 1 of 3 instructional sets: no expectation, 30-second performance expectation, or a 90-second performance expectation. Pain ratings, threshold, and tolerance were recorded. Significant sex differences in the "no expectation" condition for pain tolerance (t = 2.32, df = 38, P <.05) and post-cold pressor pain ratings (t = 2.6, df = 37, P <.05) were found. Women had briefer tolerance times and higher post-cold pressor ratings than men. When given gender-specific tolerance expectations, men and women did not differ in their pain tolerance, pain threshold, or pain ratings. This is the first empirical study to show that manipulation of expectations alters sex differences in laboratory pain.
Seifarth, Joshua E; McGowan, Cheri L; Milne, Kevin J
2012-12-01
A sexual dimorphism in human life expectancy has existed in almost every country for as long as records have been kept. Although human life expectancy has increased each year, females still live longer, on average, than males. Undoubtedly, the reasons for the sex gap in life expectancy are multifaceted, and it has been discussed from both sociological and biological perspectives. However, even if biological factors make up only a small percentage of the determinants of the sex difference in this phenomenon, parity in average life expectancy should not be anticipated. The aim of this review is to highlight biological mechanisms that may underlie the sexual dimorphism in life expectancy. Using PubMed, ISI Web of Knowledge, and Google Scholar, as well as cited and citing reference histories of articles through August 2012, English-language articles were identified, read, and synthesized into categories that could account for biological sex differences in human life expectancy. The examination of biological mechanisms accounting for the female-based advantage in human life expectancy has been an active area of inquiry; however, it is still difficult to prove the relative importance of any 1 factor. Nonetheless, biological differences between the sexes do exist and include differences in genetic and physiological factors such as progressive skewing of X chromosome inactivation, telomere attrition, mitochondrial inheritance, hormonal and cellular responses to stress, immune function, and metabolic substrate handling among others. These factors may account for at least a part of the female advantage in human life expectancy. Despite noted gaps in sex equality, higher body fat percentages and lower physical activity levels globally at all ages, a sex-based gap in life expectancy exists in nearly every country for which data exist. There are several biological mechanisms that may contribute to explaining why females live longer than men on average, but the complexity of the human life experience makes research examining the contribution of any single factor for the female advantage difficult. However, this information may still prove important to the development of strategies for healthy aging in both sexes. Copyright © 2012 Elsevier HS Journals, Inc. All rights reserved.
A varied pattern of change of the sex differential in survival in the G7 countries.
Trovato, Frank; Heyen, Nils B
2006-05-01
Over the course of the 20th century the sex differential in life expectancy at birth in the industrialized countries has widened considerably in favour of women. Starting in the early 1970s, the beginning of a reversal in the long-term pattern of this differential has been noted in some high-income countries. This study documents a sustained pattern of narrowing of this measure into the later part of the 1990s for six of the populations that comprise the G7 countries: Canada, France, Germany, Italy, England and Wales (as representative of the United Kingdom) and USA. For Japan, a persistence of widening sex differences in survival is noted. The sex differences in life expectancy are decomposed over roughly three decades (early 1970s to late 1990s) from the point of view of four major cause-of-death categories: circulatory diseases, cancers, accidents/violence/suicide, and 'other' (residual) causes. In the six countries where the sex gap has narrowed, this has resulted primarily from reduced sex differences in circulatory disease mortality, and secondarily from reduced differences in male and female death rates due to accidents, violence and suicide combined. In some of the countries sex differentials in cancer mortality have been converging lately, and this has also contributed to a narrowing of the difference in life expectancy. In Japan, males have been less successful in reducing their survival disadvantage in relation to Japanese women with regard to circulatory disease and cancer; and in the case of accidents/violence/suicide, male death rates increased during the 1990s. These trends explain the divergent pattern of the sex difference in life expectation in Japan as compared with the other G7 nations.
The Development of Reciprocal Self-Disclosure in Opposite-Sex Interaction
ERIC Educational Resources Information Center
Kohen, Janet A. S.
1975-01-01
Sex differences, personal consistency, and development of reciprocity in the pattern of self-disclosure exchange and the amount of disclosures expressed were expected in opposite-sex interaction dyads. Time analysis of transcripts of conversations between 59 dyadic partners demonstrated no sex differences, a moderate degree of personal consistency…
Rose, Amanda J.; Schwartz-Mette, Rebecca A.; Smith, Rhiannon L.; Asher, Steven R.; Swenson, Lance P.; Carlson, Wendy; Waller, Erika M.
2012-01-01
Although girls disclose to friends about problems more than boys, little is known about processes underlying this sex difference. Four studies (Ns = 526, 567, 769, 154) tested whether middle childhood to mid-adolescent girls and boys differ in how they expect that talking about problems would make them feel. Girls endorsed positive expectations (e.g., expecting to feel cared for, understood) more strongly than boys. Despite common perceptions, boys did not endorse negative expectations such as feeling embarrassed or worried about being made fun of more than girls. Instead, boys were more likely than girls to expect to feel “weird” and like they were wasting time. Sex differences in outcome expectations did help to account for girls’ greater disclosure to friends. PMID:22364264
Guatelli-Steinberg, D; Lukacs, J R
1999-01-01
The purpose of this review is to provide a synoptic, critical evaluation of the evidence of, and potential etiological factors contributing to, sex differences in the expression of enamel hypoplasia (EH). Specifically, this review considers theoretical expectations and empirical evidence bearing on two central issues. The first of these is the impact of a theorized inherent male vulnerability to physiological stress on sex differences in EH. The second issue is the potential contribution to sex differences in EH of intrinsic differences in male and female enamel composition and development. To address this first issue, EH frequencies by sex are examined in samples subject to a high degree of physiological stress. Based on the concept of inherent male vulnerability (or female buffering), males in stressful environments would be expected to exhibit higher EH frequencies than females. This expectation is evaluated in light of cultural practices of sex-biased investment that mediate the relationship between environmental stress and EH expression. Defects forming prenatally afford an opportunity to study this relationship without the confounding effects of sex-biased postnatal investment. Data bearing on this issue derive from previously conducted studies of EH in permanent and deciduous teeth in both modern and archaeological samples as well as from new data on Indian schoolchildren. To address the second issue, fundamental male-female enamel differences are evaluated for their potential impact on EH expression. A large sex difference in the duration of canine crown formation in non-human primates suggests that male canines may have greater opportunity to record stress events than those of females. This expectation is examined in great apes, whose canines often record multiple episodes of stress and are sexually dimorphic in crown formation times. With respect to the first issue, in most studies, sex differences in EH prevalence are statistically nonsignificant. However, when sex differences are significant, there is a slight trend for them to be greater in males than in females, suggesting a weak influence of greater male vulnerability. Cultural practices of sex-biased investment in children appear to have greater impact on EH expression than does male vulnerability/female buffering. With respect to the second issue, sex differences in the composition and development of enamel were reviewed and determined to have limited or unknown impact on EH expression. Of these factors, only the duration of crown formation was expected to affect EH expression by sex within the great apes. The data support an association between higher defect counts in the canines of great ape males relative to those of females that may be the result of longer crown formation times in the canines of great ape males. This review concludes with an assessment of the nature of the evidence currently available to examine these issues and suggests future avenues for research focused on elucidating them.
Paraphilic Interests: An Examination of Sex Differences in a Nonclinical Sample.
Dawson, Samantha J; Bannerman, Brittany A; Lalumière, Martin L
2016-02-01
Little research has been conducted to examine paraphilic sexual interests in nonclinical samples. The little that exists suggests that atypical sexual interests are more common in men than in women, but the reasons for this difference are unknown. In this study, we explored the prevalence of paraphilic interests in a nonclinical sample of men and women. We expected that men would report greater arousal (or less repulsion) toward various paraphilic acts than women. We also examined putative correlates of paraphilias in an attempt to explain the sex difference. In all, 305 men and 710 women completed an online survey assessing sexual experiences, sexual interests, as well as indicators of neurodevelopmental stress, sex drive, mating effort, impulsivity, masculinity/femininity, and socially desirable responding. As expected, significant sex differences were found, with men reporting significantly less repulsion (or more arousal) to the majority of paraphilic acts than women. Using mediation analysis, sex drive was the only correlate to significantly and fully mediate the sex difference in paraphilic interests. In other words, sex drive fully accounted for the sex difference in paraphilic interests. The implications of these findings for understanding the etiology of atypical sexual interests are discussed. © The Author(s) 2014.
Bucholz, Emily M; Normand, Sharon-Lise T; Wang, Yun; Ma, Shuangge; Lin, Haiqun; Krumholz, Harlan M
2015-08-11
Most studies of sex and race differences after acute myocardial infarction (AMI) have not taken into account differences in life expectancy in the general population. Years of potential life lost (YPLL) is a metric that takes into account the burden of disease and can be compared by sex and race. This study sought to determine sex and race differences in long-term survival after AMI using life expectancy and YPLL to account for differences in population-based life expectancy. Using data from the Cooperative Cardiovascular Project, a prospective cohort study of Medicare beneficiaries hospitalized for AMI between 1994 and 1995 (N = 146,743), we calculated life expectancy and YPLL using Cox proportional hazards regression with extrapolation using exponential models. Of the 146,743 patients with AMI, 48.1% were women and 6.4% were black; the average age was 75.9 years. Post-AMI life expectancy estimates were similar for men and women of the same race but lower for black patients than white patients. On average, women lost 10.5% (SE 0.3%) more of their expected life than men, and black patients lost 6.2% (SE 0.6%) more of their expected life than white patients. After adjustment, women still lost an average of 7.8% (0.3%) more of their expected life than men, but black race became associated with a survival advantage, suggesting that racial differences in YPLL were largely explained by differences in clinical presentation and treatment between black and white patients. Women and black patients lost more years of life after AMI, on average, than men and white patients, an effect that was not explained in women by clinical or treatment differences. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
The relationship of sex-related alcohol expectancies to alcohol consumption and sexual behavior.
Leigh, B C
1990-07-01
Recent psychosocial research on alcohol expectancies--beliefs about the effects of alcohol on behavior, moods and emotions--has suggested that these expectancies mediate not only decisions about drinking but the alcohol effects displayed by those who have been drinking. Results of a study of drinking and sexual behavior showed that individuals of different gender and sexual orientation differed in their beliefs about the effects of alcohol on sexual responding. In addition, expectations of sexual enhancement and disinhibition were related to the initiation of sexual activity and to the proportion of sexual encounters that took place while drinking, and interacted with sex guilt to predict the amount drunk in the most recent sexual encounter. These results suggest that beliefs about the effects of alcohol on sex may affect the characteristics of sexual encounters that involve drinking.
Gender role expectations of pain mediate sex differences in cold pain responses in healthy Libyans.
Alabas, O A; Tashani, O A; Johnson, M I
2012-02-01
Previous studies found a relationship between response to experimentally-induced pain and scores for the gender role expectations of pain (GREP) questionnaire. Findings were similar in individuals from America, Portugal and Israel suggesting that gender role expectations may be universal. The aim of this study was to translate and validate Arabic GREP using Factor Analysis and to investigate if sex differences to cold-pressor pain in healthy Libyan men and women are mediated through stereotypical social constructs of gender role expectations and/or pain-related anxiety. One hundred fourteen university students (58 women) underwent two cycles of cold pressor pain test to measure pain threshold, tolerance, intensity, and unpleasantness. Participants also completed the Arabic GREP questionnaire and the Pain Anxiety Symptom Scale-Short form (PASS-20). It was found that Libyan men had higher pain thresholds and tolerances than women (mean difference, 95% CI: threshold = 4.69 (s), -0.72 to 10.1, p = 0.005; tolerance = 13.46 (s), 0.5-26.4, p = 0.018). There were significant differences between sexes in 6 out of 12 GREP items (p < 0.004 after Bonferonni adjustment). The results of mediational analysis showed that GREP factors were the mediators of the effects of sex on pain threshold (z = -2.452, p = 0.014 for Self Sensitivity); (z = -2.563, p = 0.01, for Self Endurance) and on pain tolerance (z = -2.538, p = 0.01 for Self Endurance). In conclusion, sex differences in response to pain were mediated by gender role expectations of pain but not pain-related anxiety. © 2011 European Federation of International Association for the Study of Pain Chapters.
Genetic Diversity on the Sex Chromosomes
Wilson Sayres, Melissa A
2018-01-01
Abstract Levels and patterns of genetic diversity can provide insights into a population’s history. In species with sex chromosomes, differences between genomic regions with unique inheritance patterns can be used to distinguish between different sets of possible demographic and selective events. This review introduces the differences in population history for sex chromosomes and autosomes, provides the expectations for genetic diversity across the genome under different evolutionary scenarios, and gives an introductory description for how deviations in these expectations are calculated and can be interpreted. Predominantly, diversity on the sex chromosomes has been used to explore and address three research areas: 1) Mating patterns and sex-biased variance in reproductive success, 2) signatures of selection, and 3) evidence for modes of speciation and introgression. After introducing the theory, this review catalogs recent studies of genetic diversity on the sex chromosomes across species within the major research areas that sex chromosomes are typically applied to, arguing that there are broad similarities not only between male-heterogametic (XX/XY) and female-heterogametic (ZZ/ZW) sex determination systems but also any mating system with reduced recombination in a sex-determining region. Further, general patterns of reduced diversity in nonrecombining regions are shared across plants and animals. There are unique patterns across populations with vastly different patterns of mating and speciation, but these do not tend to cluster by taxa or sex determination system. PMID:29635328
ERIC Educational Resources Information Center
Kite, Mary E.; Whitley, Bernard E., Jr.
1996-01-01
Used meta-analytic techniques to compare men's and women's attitudes toward homosexual persons, homosexual behaviors, and gay people's civil rights. As expected, size of sex differences varied across these categories. Men were more negative than women toward homosexual persons and homosexual behavior, but the sexes viewed gay civil rights…
Labelle, Réal; Lachance, Lise
2003-01-01
This study evaluated the role of control and efficacy expectations in the thoughts of life and death of 50 male and 50 female university students and investigated sex differences in this regard. It followed a correlational design and employed measures of tridimensional locus of control, expectations of academic efficacy, thoughts of life and death. A comparison of means revealed that male students did not differ from their female counterparts on any of the variables under study. Stepwise regression coefficients indicated that the two cognitive factors accounted more for thoughts of death than for thoughts of life; expectations of academic efficacy were the single variable that most explained variance. Regression equations by sex showed that thoughts of life were associated with internality and expectations of academic efficacy in females, and that thoughts of death were associated with expectations of academic inefficacy in males. The university counseling personnel should be especially sensitive to youths presenting with expectations of externality and of academic inefficacy. The latter variable seems to be particularly important, regardless of sex.
A predictive relationship between population and genetic sex ratios in clonal species
NASA Astrophysics Data System (ADS)
McLetchie, D. Nicholas; García-Ramos, Gisela
2017-04-01
Sexual reproduction depends on mate availability that is reflected by local sex ratios. In species where both sexes can clonally expand, the population sex ratio describes the proportion of males, including clonally derived individuals (ramets) in addition to sexually produced individuals (genets). In contrast to population sex ratio that accounts for the overall abundance of the sexes, the genetic sex ratio reflects the relative abundance of genetically unique mates, which is critical in predicting effective population size but is difficult to estimate in the field. While an intuitive positive relationship between population (ramet) sex ratio and genetic (genet) sex ratio is expected, an explicit relationship is unknown. In this study, we determined a mathematical expression in the form of a hyperbola that encompasses a linear to a nonlinear positive relationship between ramet and genet sex ratios. As expected when both sexes clonally have equal number of ramets per genet both sex ratios are identical, and thus ramet sex ratio becomes a linear function of genet sex ratio. Conversely, if sex differences in ramet number occur, this mathematical relationship becomes nonlinear and a discrepancy between the sex ratios amplifies from extreme sex ratios values towards intermediate values. We evaluated our predictions with empirical data that simultaneously quantified ramet and genet sex ratios in populations of several species. We found that the data support the predicted positive nonlinear relationship, indicating sex differences in ramet number across populations. However, some data may also fit the null model, which suggests that sex differences in ramet number were not extensive, or the number of populations was too small to capture the curvature of the nonlinear relationship. Data with lack of fit suggest the presence of factors capable of weakening the positive relationship between the sex ratios. Advantages of this model include predicting genet sex ratio using population sex ratios given known sex differences in ramet number, and detecting sex differences in ramet number among populations.
Effects of Sex and Birth Order on Sex Role Development and Intelligence in Kindergarten Children.
ERIC Educational Resources Information Center
Laosa, Luis M.; Brophy, Jere E.
The authors investigate MacDonald's (1969) hypothesis that a sex by birth order interaction should be observed in measures related to sex typing. Since first borns are more thoroughly socialized, MacDonald reasons, and since parental expectations differ according to the child's sex, then first born boys and girls on sex typed variables.…
Hurley, Emily A; Brahmbhatt, Heena; Kayembe, Patrick K; Busangu, Michelle-Alphonsine Fatuma; Mabiala, Ma-Umba; Kerrigan, Deanna
2017-01-01
Considering the increased risk of HIV among alcohol users, we explored the role of individual alcohol expectancies in risk behaviors among youth in the Democratic Republic of the Congo. We surveyed 1,396 adolescents (ages 15-19) and young adults (ages 20-24) on alcohol and sexual behaviors in May, 2010. We assessed expectancies of alcohol use (1) leading to sex or positive sexual experiences; (2) diminishing one's ability to resist unwanted sex; and (3) diminishing one's ability to use or negotiate use of condoms. Adjusted logistic regression models assessed the association between alcohol use and alcohol expectancies with unprotected sex and multiple sex partners (MSP). Participants reporting alcohol use (36.8%) were more likely to have engaged in unprotected sex and MSP than nondrinkers (adjusted odds ratio [AOR]: 2.87, 95% confidence interval [CI]: 2.29-3.60; AOR: 3.73 95% CI: 2.94-4.72, respectively). Among alcohol users, after adjusting for drinking quantity, moderate expectancies of alcohol leading to positive sexual experiences were significantly associated with MSP among adolescent boys (AOR: 4.20, 95% CI: 1.49-11.86) and girls (AOR: 3.97, 95% CI: 1.36-11.60), whereas high expectancies were significant among young adult men (AOR: 2.70, 95% CI: 1.19-6.10). Among adolescent girls who used alcohol, adjusted odds of unprotected sex were elevated among those with expectancies of diminished ability to refuse unwanted sex (AOR: 5.13, 95% CI: 1.41-16.64) or to negotiate condom use (AOR: 16.22; 2.08-126.8). HIV prevention efforts for youth should acknowledge the role of alcohol expectancies in sexual risk behaviors and tailor programs to address different roles of expectancies in males and females. Copyright © 2016 Society for Adolescent Health and Medicine. All rights reserved.
Stephens, Alexandre S; Gupta, Leena; Thackway, Sarah; Broome, Richard A
2017-01-10
Despite being one of the healthiest countries in the world, Australia displays substantial mortality differentials by socioeconomic disadvantage, remoteness and sex. In this study, we examined how these mortality differentials translated to differences in life expectancy between 2001 and 2012. Population-based study using mortality and estimated residential population data from Australia's largest state, New South Wales (NSW), between 2001 and 2012. Age-group-specific death rates by socioeconomic disadvantage quintile, remoteness (major cities vs regional and remote areas), sex and year were estimated via Poisson regression, and inputted into life table calculations to estimate life expectancy. Life expectancy decreased with increasing socioeconomic disadvantage in males and females. The disparity between the most and least socioeconomically deprived quintiles was 3.77 years in males and 2.39 years in females in 2012. Differences in life expectancy by socioeconomic disadvantage were mostly stable over time. Gender gaps in life expectancy ranged from 3.50 to 4.93 years (in 2012), increased with increasing socioeconomic disadvantage and decreased by ∼1 year for all quintiles between 2001 and 2012. Overall, life expectancy varied little by remoteness, but was 1.8 years higher in major cities compared to regional/remote areas in the most socioeconomically deprived regions in 2012. Socioeconomic disadvantage and sex were strongly associated with life expectancy. The disparity in life expectancy across the socioeconomic spectrum was larger in males and was stable over time. In contrast, gender gaps reduced for all quintiles between 2001 and 2012, and a remoteness effect was evident in 2012, but only for those living in the most deprived areas. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Black-White Differences in Attitudes Related to Pregnancy among Young Women1
Barber, Jennifer S.; Yarger, Jennifer Eckerman; Gatny, Heather H.
2015-01-01
In this paper we use newly available data from the Relationship Dynamics and Social Life (RDSL) study to compare a wide range of attitudes related to pregnancy for 961 Black and white young women. We also investigate the extent to which race differences are mediated by, or net of, family background, childhood socioeconomic status, adolescent experiences related to pregnancy, and current socioeconomic status. Black women are less positive, in general, than white women, toward young non-marital sex, contraception, and childbearing, and have less desire for sex in the upcoming year. This is largely because Black women are more religious than white women, and in part because they are more socioeconomically disadvantaged in young adulthood. However, in spite of these less positive attitudes, Black women are more likely to expect sex without contraception in the next year, and to expect more positive consequences if they were to become pregnant, relative to white women. This is largely because, relative to white women, Black women have higher rates of sex without contraception in adolescence, and in part because they are more likely to have grown up with a single parent. It is unclear whether attitudes toward contraception and pregnancy preceded or are a consequence of adolescent sex without contraception. Some race differences remain unexplained – net of all potential mediators in our models, Black women have less desire for sex in the upcoming year, but are less willing to refuse to have sex with a partner if they think it would make him angry, and expect more positive personal consequences of a pregnancy, relative to white women. In spite of these differences, Black women's desires to achieve and to prevent pregnancy are very similar to white women's desires. PMID:25962867
Gender role expectations of pain: relationship to experimental pain perception
Wise, Emily A.; Price, Donald D.; Myers, Cynthia D.; Heft, Marc W.; Robinson, Michael E.
2008-01-01
The primary purpose of this study was to investigate the influence of an individual’s Gender Role Expectations of Pain (GREP) on experimental pain report. One hundred and forty-eight subjects (87 females and 61 males) subjects underwent thermal testing and were asked to report pain threshold, pain tolerance, VAS ratings of pain intensity and unpleasantness, and a computerized visual analogue scales (VAS) rating of pain intensity during the procedure. Subjects completed the GREP questionnaire to assess sex-related stereotypic attributions of pain sensitivity, pain endurance, and willingness to report pain. Consistent with previous research, significant sex differences emerged for measures of pain threshold, pain tolerance, and pain unpleasantness. After statistically controlling for age, GREP scores were significant predictors of threshold, tolerance, and pain unpleasantness, accounting for an additional 7, 11, and 21% of the variance, respectively. Sex remained a significant predictor of pain tolerance in hierarchical regression analyses after controlling for GREP scores. Results provide support for two competing but not mutually exclusive hypotheses related to the sex differences in experimental pain. Both psychosocial factors and first-order, biological sex differences remain as viable explanations for differences in experimental pain report between the sexes. It appears that GREP do play a part in determining an individual’s pain report and may be contributing to the sex differences in the laboratory setting. PMID:11973007
Sex differences in Nintendo Wii performance as expected from hunter-gatherer selection.
Cherney, Isabelle D; Poss, Jordan L
2008-06-01
To test the hunter-gatherer theory of cognitive sex differences, men and women each played four video games on a Wii console: two games simulating skills necessary for hunting (navigation and shooting) and two games simulating skills necessary for gathering (fine motor and visual search). Men outperformed women on the two hunting games, whereas there were no sex differences on the gathering skill games. The findings are discussed in terms of evolutionary psychology theory.
Patterns and causes of gender differences in smoking.
Waldron, I
1991-01-01
In the early twentieth century in the United States and other Western countries, women were much less likely than men to smoke cigarettes, due in part to widespread social disapproval of women's smoking. During the mid-twentieth century, growing social acceptance of women's smoking contributed to increased smoking adoption by women. Increased social acceptance of women's smoking was part of a general liberalization of norms concerning women's behavior, reflecting increasing equality between the sexes. These historical trends were due in part to increases in women's employment. However, in the contemporary period employment appears to have little or no effect on women's smoking. Sex role norms and general expectations concerning gender-appropriate behavior have had a variety of effects on gender differences in smoking. First, general characteristics of traditional sex roles, including men's greater social power and generally greater restrictions on women's behavior, contributed to widespread social pressures against women's smoking. Second, traditional sex role norms and expectations have fostered gender differences in personal characteristics and experiences which influence smoking adoption. For example, rebelliousness has been more expected and accepted for males, and greater rebelliousness among adolescent males has contributed to greater smoking adoption by males. Finally, certain aspects of sex roles have contributed to gender differences in appraisal of the costs and benefits of smoking. For example, physical attractiveness is emphasized more for females and the contemporary beauty ideal is very slender, so females are more likely to view weight control as a benefit of smoking. Several other hypotheses concerning the causes of gender differences in smoking are not supported by the available evidence. For example, it appears that women's generally greater concern with health has not contributed significantly to gender differences in the prevalence of smoking. Similarly, it appears that sex differences in physiological responses to smoking have made only minor contributions to gender differences in smoking adoption or cessation.
Astié, Andrea A; Scardamaglia, Romina C; Muzio, Rubén N; Reboreda, Juan C
2015-10-01
Females of avian brood parasites, like the shiny cowbird (Molothrus bonariensis), locate host nests and on subsequent days return to parasitize them. This ecological pressure for remembering the precise location of multiple host nests may have selected for superior spatial memory abilities. We tested the hypothesis that shiny cowbirds show sex differences in spatial memory abilities associated with sex differences in host nest searching behavior and relative hippocampus volume. We evaluated sex differences during acquisition, reversal and retention after extinction in a visual and a spatial discrimination learning task. Contrary to our prediction, females did not outperform males in the spatial task in either the acquisition or the reversal phases. Similarly, there were no sex differences in either phase in the visual task. During extinction, in both tasks the retention of females was significantly higher than expected by chance up to 50 days after the last rewarded session (∼85-90% of the trials with correct responses), but the performance of males at that time did not differ than that expected by chance. This last result shows a long-term memory capacity of female shiny cowbirds, which were able to remember information learned using either spatial or visual cues after a long retention interval. Copyright © 2015 Elsevier B.V. All rights reserved.
Getting back the missing men of Aotearoa: declining gender inequality in NZ life expectancy.
Sandiford, Peter
2009-12-01
Men's health is of increasing concern to policy makers worldwide. Although women generally live significantly longer than men, the difference in life expectancy in many countries is now narrowing. To document the trend in sex differences in New Zealand (NZ) life expectancy at birth (LEB) over the last decades and to determine disease patterns which account for it. Decomposition of sex differences in LEB by age and cause for the periods 1980-82, 1985-87, 1990-92,1995-97, 2000-02, and 2005-06, using registered deaths and model life tables. Sex differences in LEB increased from 1951 to peak in 1976 before narrowing again. In 2006 they reached almost exactly the level they were at 55 years earlier. Changes in relative mortality from ischaemic heart disease (IHD) and to a lesser extent accidents, respiratory disease and other circulatory causes, brought about the recent decline in gender survival disparities. IHD continues to be a significant cause of gender inequality, but cancers have now become a major component of the sex difference in LEB. NZ's experience mirrors closely that of other developed countries in pattern, timingand the age-cause composition of the trend in gender survival disparities. Thus differences in the timing of taking up smoking, found to explain a substantial portion of the trend elsewhere, were probably also important in NZ, but improvements in medical outcomes for smokers also must have played a significant role. Primary care practitioners will continue to reduce gender survival disparities by workingto ensure a high uptake of services such as screening for colorectal cancer, one of many diseases responsible for lower male life expectancy.
Perez-Brena, Norma J; Delgado, Melissa Y; Rodríguez De Jesús, Sue A; Updegraff, Kimberly A; Umaña-Taylor, Adriana J
2017-01-01
Expectancy value theory and a cultural-ecological framework are integrated in this study to examine the trajectories of 246 Mexican-origin adolescents' (M age = 12.52, SD age = 0.58; 51% girls, 62% U.S.-born) educational expectations across eight years. Findings from a multilevel growth model revealed that early adolescents expected to complete a post-bachelor's degree, but expectations declined in middle adolescence and improved in late adolescence. This pattern was more pronounced for immigrant, compared to U.S-born, adolescents. Higher socioeconomic status was associated with higher expectations. Boys and girls differed in their trajectories, such that boys showed a curvilinear trajectory and girls showed a stable trajectory. Nativity moderated these sex differences. Immigrant boys showed curvilinear trajectories that dipped in middle adolescence and immigrant girls showed a declining trajectory. In contrast, U.S.-born boys and girls showed linear and stable trajectories. The discussion addresses suggestions for targeted interventions with at-risk subgroups during a sensitive period in adolescence.
Perez-Brena, Norma J.; Delgado, Melissa Y.; Rodríguez De Jesús, Sue A.; Updegraff, Kimberly A.; Umaña-Taylor, Adriana J.
2017-01-01
Expectancy value theory and a cultural-ecological framework are integrated in this study to examine the trajectories of 246 Mexican-origin adolescents' (Mage = 12.52, SDage = 0.58; 51% girls, 62% U.S.-born) educational expectations across eight years. Findings from a multilevel growth model revealed that early adolescents expected to complete a post-bachelor's degree, but expectations declined in middle adolescence and improved in late adolescence. This pattern was more pronounced for immigrant, compared to U.S-born, adolescents. Higher socioeconomic status was associated with higher expectations. Boys and girls differed in their trajectories, such that boys showed a curvilinear trajectory and girls showed a stable trajectory. Nativity moderated these sex differences. Immigrant boys showed curvilinear trajectories that dipped in middle adolescence and immigrant girls showed a declining trajectory. In contrast, U.S.-born boys and girls showed linear and stable trajectories. The discussion addresses suggestions for targeted interventions with at-risk subgroups during a sensitive period in adolescence. PMID:29242673
Influences of gender role and anxiety on sex differences in temporal summation of pain.
Robinson, Michael E; Wise, Emily A; Gagnon, Christine; Fillingim, Roger B; Price, Donald D
2004-03-01
Previous research has consistently shown moderate to large differences between pain reports of men and women undergoing experimental pain testing. These differences have been shown for a variety of types of stimulation. However, only recently have sex differences been demonstrated for temporal summation of second pain. This study examined sex differences in response to temporal summation of second pain elicited by thermal stimulation of the skin. The relative influences of state anxiety and gender role expectations on temporal summation were investigated. Asymptomatic undergraduates (37 women and 30 men) underwent thermal testing of the thenar surface of the hand in a temporal summation protocol. Our results replicated those of Fillingim et al indicating that women showed increased temporal summation compared to men. We extended those findings to demonstrate that temporal summation is influenced by anxiety and gender role stereotypes about pain responding. When anxiety and gender role stereotypes are taken into account, sex is no longer a significant predictor of temporal summation. These findings highlight the contribution of social learning factors in the differences between sexes' pain perception. Results of this study demonstrate that psychosocial variables influence pain mechanisms. Temporal summation was related to gender role expectations of pain and anxiety. These variables explain a significant portion of the differences between men and women's pain processing, and may be related to differences in clinical presentation.
Intra- Versus Intersex Aggression: Testing Theories of Sex Differences Using Aggression Networks.
Wölfer, Ralf; Hewstone, Miles
2015-08-01
Two theories offer competing explanations of sex differences in aggressive behavior: sexual-selection theory and social-role theory. While each theory has specific strengths and limitations depending on the victim's sex, research hardly differentiates between intrasex and intersex aggression. In the present study, 11,307 students (mean age = 14.96 years; 50% girls, 50% boys) from 597 school classes provided social-network data (aggression and friendship networks) as well as physical (body mass index) and psychosocial (gender and masculinity norms) information. Aggression networks were used to disentangle intra- and intersex aggression, whereas their class-aggregated sex differences were analyzed using contextual predictors derived from sexual-selection and social-role theories. As expected, results revealed that sexual-selection theory predicted male-biased sex differences in intrasex aggression, whereas social-role theory predicted male-biased sex differences in intersex aggression. Findings suggest the value of explaining sex differences separately for intra- and intersex aggression with a dual-theory framework covering both evolutionary and normative components. © The Author(s) 2015.
Weinraub, M; Clemens, L P; Sockloff, A; Ethridge, T; Gracely, E; Myers, B
1984-08-01
The onset and development of preschoolers' awareness of sex role stereotypes, gender labeling, gender identity, and sex-typed toy preference were explored in 26-, 31-, and 36-month-old children. Gender labeling, gender identity, sex-typed toy preferences, and awareness of adult sex role differences were observed in significantly more 26-month-old children than would have been expected by chance. Verbal gender labeling was observed in a majority of 26-month-olds, while verbal and nonverbal gender identity were observed in a majority of 31-month-olds. Nonverbal gender labeling and awareness of adult sex role differences were observed in a majority of children by 36 months. No evidence of awareness of sex differences in children's toys was found in the majority of children at any age. Awareness of sex role differences in children's toys was not related to awareness of adult sex role differences. Brighter children were more aware of adult sex role differences. Sex-typed toy preference was not related to awareness of sex role differences but was related to gender identity. Predictors of sex role development included the mothers' employment, and the father's personality traits, attitudes toward women, and sex-typed activities in the home. Implications for theories of early sex role development are discussed.
Antecedents and sex/gender differences in youth suicidal behavior
Rhodes, Anne E; Boyle, Michael H; Bridge, Jeffrey A; Sinyor, Mark; Links, Paul S; Tonmyr, Lil; Skinner, Robin; Bethell, Jennifer M; Carlisle, Corine; Goodday, Sarah; Hottes, Travis Salway; Newton, Amanda; Bennett, Kathryn; Sundar, Purnima; Cheung, Amy H; Szatmari, Peter
2014-01-01
Suicide is the second leading cause of death in youth globally; however, there is uncertainty about how best to intervene. Suicide rates are typically higher in males than females, while the converse is true for suicide attempts. We review this “gender paradox” in youth, and in particular, the age-dependency of these sex/gender differences and the developmental mechanisms that may explain them. Epidemiologic, genetic, neurodevelopmental and psychopathological research have identified suicidal behaviour risks arising from genetic vulnerabilities and sex/gender differences in early adverse environments, neurodevelopment, mental disorder and their complex interconnections. Further, evolving sex-/gender-defined social expectations and norms have been thought to influence suicide risk. In particular, how youth perceive and cope with threats and losses (including conforming to others’ or one’s own expectations of sex/gender identity) and adapt to pain (through substance use and help-seeking behaviours). Taken together, considering brain plasticity over the lifespan, these proposed antecedents to youth suicide highlight the importance of interventions that alter early environment(s) (e.g., childhood maltreatment) and/or one’s ability to adapt to them. Further, such interventions may have more enduring protective effects, for the individual and for future generations, if implemented in youth. PMID:25540727
Sex differences in common pain events: expectations and anchors.
Robinson, Michael E; Gagnon, Christine M; Dannecker, Erin A; Brown, Jennifer L; Jump, Rebecca L; Price, Donald D
2003-02-01
This study examined (1) the effects of sex-related stereotypes in commonly experienced, potentially painful events and (2) differences in events representing the worst pain sensation imaginable for the typical woman and the typical man. Undergraduates (63 women and 54 men) completed the Situational Pain Questionnaire as the typical woman would and as the typical man would. The participants also answered 2 open-ended questions regarding the worst pain sensation imaginable for the typical woman and for the typical man. Our findings demonstrate that sex-related stereotypes extend to common pain events and that men and women expected that men would report less pain for common pain events than women. This suggests a gender-role related learning history that is relatively consistent for both sexes. The worst pain sensation imaginable was perceived to be different for typical men and women. Both sexes chose injury as the class of events men would find most painful and childbirth and menstrual pain as the class of events women would find most painful. Implications of this finding for common pain scaling approaches are discussed. The results of this study were obtained from a fairly uniform group of undergraduate men and women, which may limit the generalizability of our findings.
Sex chromosomes and speciation in birds and other ZW systems.
Irwin, Darren E
2018-02-14
Theory and empirical patterns suggest a disproportionate role for sex chromosomes in evolution and speciation. Focusing on ZW sex determination (females ZW, males ZZ; the system in birds, many snakes, and lepidopterans), I review how evolutionary dynamics are expected to differ between the Z, W and the autosomes, discuss how these differences may lead to a greater role of the sex chromosomes in speciation and use data from birds to compare relative evolutionary rates of sex chromosomes and autosomes. Neutral mutations, partially or completely recessive beneficial mutations, and deleterious mutations under many conditions are expected to accumulate faster on the Z than on autosomes. Sexually antagonistic polymorphisms are expected to arise on the Z, raising the possibility of the spread of preference alleles. The faster accumulation of many types of mutations and the potential for complex evolutionary dynamics of sexually antagonistic traits and preferences contribute to a role for the Z chromosome in speciation. A quantitative comparison among a wide variety of bird species shows that the Z tends to have less within-population diversity and greater between-species differentiation than the autosomes, likely due to both adaptive evolution and a greater rate of fixation of deleterious alleles. The W chromosome also shows strong potential to be involved in speciation, in part because of its co-inheritance with the mitochondrial genome. While theory and empirical evidence suggest a disproportionate role for sex chromosomes in speciation, the importance of sex chromosomes is moderated by their small size compared to the whole genome. © 2018 John Wiley & Sons Ltd.
The Effect of Offenders' Sex on Reporting Crimes to the Police
ERIC Educational Resources Information Center
Wong, Thessa M. L.; Van de Schoot, Rens
2012-01-01
This article examines the difference in victims' reporting behavior regarding crimes committed by males and by females. The authors expect that victims of female offenders are less likely to report to the police than victims of male offenders because of differences in the victim-offender relationship as well as in the victim's sex. With recent…
Tamate, Tsuyoshi
2015-08-01
Evolutionary ecologists often expect that natural and sexual selection result in systematic co-occurrence patterns of sex-biased mortality and sexual size dimorphism (SSD) within animal species. However, whether such patterns actually occur in wild animals is poorly examined. The following expectation, the larger sex suffers higher mortality, was primarily tested here for apparently native sea-run masu salmon (Oncorhynchus masou) in three populations in Hokkaido, Japan. Field surveys on sex ratios, body sizes, and ages of smolts and returning adults revealed that two of the three populations exhibited an expected pattern, a female-biased marine mortality and SSD, but one population demonstrated an unexpected co-occurrence of male-biased marine mortality and female-biased SSD. These female-biased SSDs were attributed to faster marine growth of females because of no sex difference in smolt body size. It has been previously suggested that breeding selection favoring large size generally act more strongly in females than in males in Japanese anadromous masu, as there is a weak sexual selection on adult males but universally intensive natural selection on adult females. Thus, this hypothesis explains female-biased SSDs well in all study populations. Interpopulation variation in sex-biased mortality found here might result from differences in marine predation and/or fishing pressures, given that selection driving female-biased SSD makes females forage more aggressively than males during the marine phase. Taken together, these results raise the possibility that evolutionary forces have shaped adaptive sex-specific foraging strategies under relationships between growth and mortality, resulting in co-occurrence patterns of sex-biased mortality and SSD within animal species.
Same-Sex and Different-Sex Cohabiting Couple Relationship Stability.
Manning, Wendy D; Brown, Susan L; Stykes, J Bart
2016-08-01
Relationship stability is a key indicator of well-being, but most U.S.-based research has been limited to different-sex couples. The 2008 panel of the Survey of Income and Program Participation (SIPP) provides an untapped data resource to analyze relationship stability of same-sex cohabiting, different-sex cohabiting, and different-sex married couples (n = 5,701). The advantages of the SIPP data include the recent, nationally representative, and longitudinal data collection; a large sample of same-sex cohabitors; respondent and partner socioeconomic characteristics; and identification of a state-level indicator of a policy stating that marriage is between one man and one woman (i.e., DOMA). We tested competing hypotheses about the stability of same-sex versus different-sex cohabiting couples that were guided by incomplete institutionalization, minority stress, relationship investments, and couple homogamy perspectives (predicting that same-sex couples would be less stable) as well as economic resources (predicting that same-sex couples would be more stable). In fact, neither expectation was supported: results indicated that same-sex cohabiting couples typically experience levels of stability that are similar to those of different-sex cohabiting couples. We also found evidence of contextual effects: living in a state with a constitutional ban against same-sex marriage was significantly associated with higher levels of instability for same- and different-sex cohabiting couples. The level of stability in both same-sex and different-sex cohabiting couples is not on par with that of different-sex married couples. The findings contribute to a growing literature on health and well-being of same-sex couples and provide a broader understanding of family life.
A specific sexual orientation-related difference in navigation strategy.
Rahman, Qazi; Andersson, Davinia; Govier, Ernest
2005-02-01
During spatial navigation, women typically navigate an environment using a landmark strategy, whereas men typically use an orientation strategy. To examine the as yet unknown effects of sexual orientation on these normative sex differences, this study required 80 healthy heterosexual and homosexual adult men and women to provide directions from experimental maps for 4 routes. The frequency and type of strategy used by each participant were computed. Expected sex differences were demonstrated, and a robust cross-sex shift was shown by homosexual men in using landmarks. This remained after controlling for differences in mental rotation, directional sense, and general intelligence. The findings may limit the number of putative neurodevelopmental pathways responsible for sex differences in navigation strategy utility. Copyright 2005 APA.
García González, Juan Manuel; Grande, Rafael
To calculate and analyse the contributions of changes in mortality by age groups and selected causes of death to sex differences in life expectancy at birth in Spain from 1980 to 2012. Cross-sectional study with three time points (1980, 1995, and 2012). We used data from Human Cause-of-Death Database and Human Mortality Database. We use a decomposition method of the differences in life expectancy and gender differences in life expectancy from changes in mortality by 5-year age groups and causes of death between women and men. From 1980 to 1995, the lower mortality of women from 25 years old, and the differences in mortality by HIV/AIDS, lung cancer, and chronic obstructive pulmonary diseases contributed to the gap increase. From 1995 to 2012, greatest improvement in mortality of males under 74 years of age, and in improving male mortality from HIV/AIDS, acute myocardial infarction and traffic accidents contributed to the narrowing. The difference in life expectancy at birth between men and women has decreased since 1995 due to a greater improvement in mortality from causes of death associated with risky behaviours and habits of the working age male population. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.
Gender inequality in New Zealand life expectancy: decomposition by age and cause.
Sandiford, Peter
2009-12-11
AIM To quantify gender inequality in life expectancy at birth (LEB) in New Zealand and the contribution to it made by different age groups and causes of death. To examine the response of the health sector.METHOD Determination of the trend in sex differences in LEB. Multiple decrement decomposition of LEB differences into components ages and causes. Review of the gender equity policies and priorities of New Zealand's main health sector stakeholders.RESULTS A difference between the sexes in LEB of 4.7 years for Māori and 4.0 years for non-Māori, reverses the historically lower gender disparity among the Māori. Over half of the sex difference in LEB is accounted for by heart disease and all types of cancer and almost a quarter by accidents and suicide but male survival disadvantage is evident in many other causes of death. The health sector is beginning to acknowledge the survival disadvantage of men as inequitable, and reducing disparity as a legitimate goal for health policy.CONCLUSION Although gender inequality in LEB is declining among the non-Māori it remains high among the Māori. Smoking habits may explain some of the difference in LEB but policies must also address the causes of sex differences in accidental death and suicide.
Nosek, Brian A.; Smyth, Frederick L.; Sriram, N.; Lindner, Nicole M.; Devos, Thierry; Ayala, Alfonso; Bar-Anan, Yoav; Bergh, Robin; Cai, Huajian; Gonsalkorale, Karen; Kesebir, Selin; Maliszewski, Norbert; Neto, Félix; Olli, Eero; Park, Jaihyun; Schnabel, Konrad; Shiomura, Kimihiro; Tulbure, Bogdan Tudor; Wiers, Reinout W.; Somogyi, Mónika; Akrami, Nazar; Ekehammar, Bo; Vianello, Michelangelo; Banaji, Mahzarin R.; Greenwald, Anthony G.
2009-01-01
About 70% of more than half a million Implicit Association Tests completed by citizens of 34 countries revealed expected implicit stereotypes associating science with males more than with females. We discovered that nation-level implicit stereotypes predicted nation-level sex differences in 8th-grade science and mathematics achievement. Self-reported stereotypes did not provide additional predictive validity of the achievement gap. We suggest that implicit stereotypes and sex differences in science participation and performance are mutually reinforcing, contributing to the persistent gender gap in science engagement. PMID:19549876
Does drinking lead to sex? Daily alcohol-sex behaviors and expectancies among college students.
Patrick, Megan E; Maggs, Jennifer L
2009-09-01
A within-person multilevel approach was used to model the links between alcohol use and sexual behavior among first-year college students, using up to 14 days of data for each person with occasions (Level 1, N = 2879 days) nested within people (Level 2, N = 218 people; 51.4% male). Between-persons (Level 2) effects were gender, relationship status, person means of alcohol use, and alcohol-sex expectancies for sexual affect and sexual drive. Within-person (Level 1) effects were weekend days, number of drinks consumed, and the interaction between drinks consumed and alcohol-sex expectancies. Independent of average alcohol use, consuming more drinks on a given day was associated with a greater likelihood of oral sex and with experiencing more positive consequences of sex that day. Significant Alcohol Use x Alcohol-Sex Expectancies interactions were found for oral sex and total sex behaviors, indicating that individuals with more positive expectancies were more likely to have sex after drinking. The negative association between drinks and condom use was at a trend level of significance. Results support the potential for promoting sexual health by focusing on cross-behavior expectancies among late adolescents. 2009 APA, all rights reserved.
Sex Chromosome Translocations in the Evolution of Reproductive Isolation
Tracey, Martin L.
1972-01-01
Haldane's rule states that in organisms with differentiated sex chromosomes, hybrid sterility or inviability is generally expressed more frequently in the heterogametic sex. This observation has been variously explained as due to either genic or chromosomal imbalance. The fixation probabilities and mean times to fixation of sex-chromosome translocations of the type necessary to explain Haldane's rule on the basis of chromosomal imbalance have been estimated in small populations of Drosophila melanogaster. The fixation probability of an X chromosome carrying the long arm of the Y(X·YL) is approximately 30% greater than expected under the assumption of no selection. No fitness differences associated with the attached YL segment were detected. The fixation probability of a deficient Y chromosome is 300% greater than expected when the X chromosome contains the deleted portion of the Y. It is suggested that sex-chromosome translocations may play a role in the establishment of reproductive isolation. PMID:4630586
Wells, Brooke E; Golub, Sarit A; Parsons, Jeffrey T
2011-04-01
Research demonstrates a consistent association between substance use and sexual risk, particularly among men who have sex with men (MSM). The present study builds upon two existing theories (Cognitive Escape Theory and Expectancy Theory) to examine the synergistic role of sexual conflict (surrounding unsafe sex) and expectancies in sexual behavior among 135 MSM. Two conflicts were examined: (1) The conflict between motivation to practice safer sex and temptation for unprotected sex; and (2) The conflict between motivation to practice safer sex and perceived benefits of unprotected sex. Factorial ANOVAs (2 × 2; high versus low expectancies and conflict versus no conflict) revealed a significant interaction between conflict and expectancies-individuals who reported high levels of conflict were more sensitive to the effect of expectancies than were those experiencing low levels of sexual conflict. Results demonstrate the synergistic effects of conflict and expectancies and highlight the importance of integrating existing theories to more fully consider the intrapsychic operation and experience of sexual conflicts.
Gordon, Elizabeth A.; Corbitt, Cynthia
2015-01-01
Sex differences in social behaviors exist in mammals during adulthood, and further evidence suggests that sex differences in behavior are present before sexual maturity. In order to model behavioral disorders in animals, it is important to assess baseline sex-related behavioral differences, especially when studying disorders for which sex-related behavioral effects are expected. We investigated the effect of sex on behavior in 3 strains of pre-pubertal mice (C57BL/6, CFW, and CF1) using a wheel-running assay. We found no significant sex differences in latency to run on the wheel or total duration of wheel running within each strain. During the social interaction test, there were no differences between sexes in latency or total duration of contact or following between a subject and novel mouse. We also evaluated behavioral patterns of wheel running and stereotypical behaviors, such as burrowing and grooming. Both sexes showed characteristic wheel running behavior, spending the majority of each trial interacting with the wheel when it was free and more time performing other activities (e.g., stereotypical behaviors, general locomotion) when it was jammed. These results provide evidence that, among various strains of pre-pubertal mice, baseline sex-related behavioral differences are not strong enough to influence the measured behaviors. PMID:26316671
Gordon, Elizabeth A; Corbitt, Cynthia
2015-08-01
Sex differences in social behaviors exist in mammals during adulthood, and further evidence suggests that sex differences in behavior are present before sexual maturity. In order to model behavioral disorders in animals, it is important to assess baseline sex-related behavioral differences, especially when studying disorders for which sex-related behavioral effects are expected. We investigated the effect of sex on behavior in 3 strains of pre-pubertal mice (C57BL/6, CFW, and CF1) using a wheel-running assay. We found no significant sex differences in latency to run on the wheel or total duration of wheel running within each strain. During the social interaction test, there were no differences between sexes in latency or total duration of contact or following between a subject and novel mouse. We also evaluated behavioral patterns of wheel running and stereotypical behaviors, such as burrowing and grooming. Both sexes showed characteristic wheel running behavior, spending the majority of each trial interacting with the wheel when it was free and more time performing other activities ( e.g. , stereotypical behaviors, general locomotion) when it was jammed. These results provide evidence that, among various strains of pre-pubertal mice, baseline sex-related behavioral differences are not strong enough to influence the measured behaviors.
Rind, Bruce
2017-07-17
This study used an important data set to examine long-term adjustment and functioning in men, who as adolescents had sexual experiences with men. The data came from the National Health and Social Life Survey, which used a national probability sample (Laumann, Gagnon, Michael, & Michaels, 1994). Three perspectives were considered, which offered different predictions. From the "child sexual abuse" (CSA) paradigm, which dominates clinical, legal, and lay views, expected was robust evidence for poorer adjustment, given that intense harm is assumed to be intrinsic. From the "mainstream psychological" perspective, derived from the CSA paradigm but more scientifically based, poorer adjustment was also expected, but with less magnitude, given that minor-adult sex is seen as posing a serious risk of harm, which may not universally apply. From the "relevant-empirical" perspective, which infers response to male adolescent-adult same-sex sex from relevant prior empirical research (as opposed to clinical cases or the female experience), expected was little or no evidence for poorer adjustment. Results supported the relevant-empirical perspective. Compared to several control groups (i.e., men whose first postpubertal same-sex sex was as men with other men; men with no postpubertal same-sex sexual experience or child-adult sex), men whose first postpubertal same-sex sex was as adolescents with men were just as well adjusted in terms of health, happiness, sexual functioning, and educational and career achievement. Results are discussed in relation to cultural influences, other cultures, and comparative data from primates.
Same-Sex and Different-Sex Cohabiting Couple Relationship Stability
Manning, Wendy; Brown, Susan; Stykes, Bart
2016-01-01
Relationship stability is a key indicator of well-being, but most U.S.-based research has been limited to different-sex couples. The 2008 panel of the Survey of Income and Program Participation (SIPP) provides an untapped data resource to analyze relationship stability of same-sex cohabiting, different-sex cohabiting, and different-sex married couples (n = 5,701). The advantages of the SIPP data include the recent, nationally representative, and longitudinal data collection; a large sample of same-sex cohabitors; respondent and partner socioeconomic characteristics; and identification of a state-level indicator of a policy stating that marriage is between one man and one woman (i.e., DOMA). We tested competing hypotheses about the stability of same-sex versus different-sex cohabiting couples that were guided by incomplete institutionalization, minority stress, relationship investments, and couple homogamy perspectives (predicting that same-sex couples would be less stable) as well as economic resources (predicting that same-sex couples would be more stable). In fact, neither expectation was supported: results indicated that same-sex cohabiting couples typically experience levels of stability that are similar to those of different-sex cohabiting couples. We also found evidence of contextual effects: living in a state with a constitutional ban against same-sex marriage was significantly associated with higher levels of instability for same- and different-sex cohabiting couples. The level of stability in both same-sex and different-sex cohabiting couples is not on par with that of different-sex married couples. The findings contribute to a growing literature on health and well-being of same-sex couples and provide a broader understanding of family life. PMID:27383844
Development and validation of the alcohol Expectancy Questionnaire Short Form (EQ-SF).
Mezquita, Laura; Camacho, Laura; Suso-Ribera, Carlos; Ortet, Generós; Ibáñez, Manuel I
2018-01-15
Alcohol expectancies are proximal variables to alcohol use and misuse. In recent decades, different measures have been developed to assess this construct. One of the most frequently used and recommended instruments is the Expectancy Questionnaire (EQ; Leigh y Stacy, 1993). Our aim is to develop a short version of the EQ (EQ-SF) for suitable use in time-limited administrations. Two samples, adolescents (N = 514, 57.20% females) and adults (N = 548, 61.50% females), completed the EQ together with alcohol-use measures. Different item selection strategies were applied to select the 24 items. The EQ-SF structure was explored using confirmatory factor analysis, and measurement invariance was tested running a multi-group analysis comparing groups by sex and age. Reliability was tested using Cronbach's alpha and omega coefficients. Concurrent validity was investigated with regression analyses. The EQ-SF showed acceptable between-groups measurement invariance. Alphas and omegas ranged from .77 to .93. Positive expectancies predicted both alcohol use and alcohol-related problems. Negative expectancies predicted alcohol-related problems. Sex and age moderated these associations. Males with high positive alcohol expectancies showed higher alcohol consumption than females, while adults with high negative alcohol expectancies showed greater alcohol-related problems than adolescents. Different evidence on the validity and reliability of the EQ-SF suggest that it is a suitable instrument to assess alcohol expectancies in the Spanish population.
Mothers adjust offspring sex to match the quality of the rearing environment
Pryke, Sarah R.; Rollins, Lee A.
2012-01-01
Theory predicts that mothers should adjust offspring sex ratios when the expected fitness gains or rearing costs differ between sons and daughters. Recent empirical work has linked biased offspring sex ratios to environmental quality via changes in relative maternal condition. It is unclear, however, whether females can manipulate offspring sex ratios in response to environmental quality alone (i.e. independent of maternal condition). We used a balanced within-female experimental design (i.e. females bred on both low- and high-quality diets) to show that female parrot finches (Erythrura trichroa) manipulate primary offspring sex ratios to the quality of the rearing environment, and not to their own body condition and health. Individual females produced an unbiased sex ratio on high-quality diets, but over-produced sons in poor dietary conditions, even though they maintained similar condition between diet treatments. Despite the lack of sexual size dimorphism, such sex ratio adjustment is in line with predictions from sex allocation theory because nutritionally stressed foster sons were healthier, grew faster and were more likely to survive than daughters. These findings suggest that mothers may adaptively adjust offspring sex ratios to optimally match their offspring to the expected quality of the rearing environment. PMID:22859597
Mothers adjust offspring sex to match the quality of the rearing environment.
Pryke, Sarah R; Rollins, Lee A
2012-10-07
Theory predicts that mothers should adjust offspring sex ratios when the expected fitness gains or rearing costs differ between sons and daughters. Recent empirical work has linked biased offspring sex ratios to environmental quality via changes in relative maternal condition. It is unclear, however, whether females can manipulate offspring sex ratios in response to environmental quality alone (i.e. independent of maternal condition). We used a balanced within-female experimental design (i.e. females bred on both low- and high-quality diets) to show that female parrot finches (Erythrura trichroa) manipulate primary offspring sex ratios to the quality of the rearing environment, and not to their own body condition and health. Individual females produced an unbiased sex ratio on high-quality diets, but over-produced sons in poor dietary conditions, even though they maintained similar condition between diet treatments. Despite the lack of sexual size dimorphism, such sex ratio adjustment is in line with predictions from sex allocation theory because nutritionally stressed foster sons were healthier, grew faster and were more likely to survive than daughters. These findings suggest that mothers may adaptively adjust offspring sex ratios to optimally match their offspring to the expected quality of the rearing environment.
Beltrán-Sánchez, Hiram; Andrade, Flávia Cristina Drumond
2013-08-01
To estimate transition probabilities between disability states, total life expectancy, and the latter's decomposition into years spent disabled and disability-free by age, sex, and education among older adults in São Paulo, Brazil, and urban areas in Mexico. Applied a micro-simulation method (Interpolative Markov Chains) using longitudinal data. We found large between-country educational differences in incidence of and recovery from disability with higher rates in Mexico than in São Paulo, but no differences in mortality. Older adults in Mexico spent longer time being disability-free than in São Paulo for both levels of education. Males and females in São Paulo spent a larger fraction of their remaining life disabled at every age than their counterparts in urban areas in Mexico. There were educational differences in the prevalence of disability in São Paulo and urban areas in Mexico, and significant educational differences in disability incidence and recovery across sites.
A systematic literature review of sex differences in childhood language and brain development.
Etchell, Andrew; Adhikari, Aditi; Weinberg, Lauren S; Choo, Ai Leen; Garnett, Emily O; Chow, Ho Ming; Chang, Soo-Eun
2018-06-01
The extent of sex differences in childhood language development is unclear. We conducted a systematic literature review synthesizing results from studies examining sex differences in brain structure and function relevant to language development during childhood. We searched PubMed and Scopus databases, and this returned a total of 46 published studies meeting criteria for inclusion that directly examined sex differences in brain development relevant to language function in children. The results indicate that: (a) sex differences in brain structure or function do not necessarily lead to differences in language task performance; (b) evidence for sex differences in brain and language development are limited; (c) when present, sex differences often interact with a variety of factors such as age and task. Overall, the magnitude of sexual dimorphism of brain developmental trajectories associated with language is not as significant as previously thought. Sex differences were found, however, in studies employing tighter age ranges. This suggests that sex differences may be more prominent during certain developmental stages but are negligible in other stages, likely due to different rates of maturation between the sexes. More research is needed to improve our understanding of how sex differences may arise due to the influence of sex hormones and developmental stages, and how these differences may lead to differences in various language task performance. These studies are expected to provide normative information that may be used in studies examining neurodevelopmental disorders that frequently affect more males than females, and also often affect language development. Copyright © 2018 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Kutlu, Mustafa
2005-01-01
The objective of this research is to find out the problems and expectations of the students in Inonu University (in Malatya, a city in east Turkey) concerning the orientation services. An additional objective is to ascertain whether students' expectations with regard to orientation services differ according to their sex, their place of origin, and…
A Theory for the Development of Machismo.
ERIC Educational Resources Information Center
Ingoldsby, Bron B.
With changes in sex role expectations in marriage, family researchers have begun to examine the concept of machismo. Two characteristics dominant in the study of machismo are aggressiveness and hypersexuality. A biological model of machismo asserts that males everywhere tend to be more aggressive than females, a sex difference which appears to…
Race, Sex, and Their Influences on Introductory Statistics Education
ERIC Educational Resources Information Center
van Es, Cindy; Weaver, Michelle M.
2018-01-01
The Survey of Attitudes Toward Statistics or SATS was administered for three consecutive years to students in an Introductory Statistics course at Cornell University. Questions requesting demographic information and expected final course grade were added. Responses were analyzed to investigate possible differences between sexes and racial/ethnic…
Wells, Brooke E; Starks, Tyrel J; Parsons, Jeffrey T; Golub, Sarit
2013-01-01
As the mechanisms of the associations between substance use and risky sex remain unclear, this study investigates the interactive roles of conflicts about casual sex and condom use and expectancies of the sexual effects of substances in those associations among gay men. Conflict interacted with expectancies to predict sexual behavior under the influence; low casual sex conflict coupled with high expectancies predicted the highest number of casual partners, and high condom use conflict and high expectancies predicted the highest number of unprotected sex acts. Results have implications for intervention efforts that aim to improve sexual decision-making and reduce sexual expectancies. PMID:23584507
ERIC Educational Resources Information Center
Nuttall, Ronald L.
Variables expected to be associated with academic achievement were examined in a sample (generally exceeding 2500) from eight secondary schools in Baymon Norte, Puerto Rico. Concern was whether variables associated with academic achievement differed by sex or by socioeconomic status (SES). Multivariate analyses of variance with three factors of…
Yao, Humphrey H-C; Capel, Blanche
2014-01-01
Sex determination, the step at which differentiation of males and females is initiated in the embryo, is of central importance to the propagation of species. There is a remarkable diversity of mechanisms by which sex determination is accomplished. In general these mechanisms fall into two categories: Genetic Sex Determination (GSD), which depends on genetic differences between the sexes, and Environmental Sex Determination (ESD), which depends on extrinsic cues. In this review we will consider these two means of determining sex with particular emphasis on two species: a species that depends on GSD, Mus musculus, and a species that depends on ESD, Trachemys scripta. Because the structural organization of the adult testis and ovary is very similar across vertebrates, most biologists had expected that the pathways downstream of the sex-determining switch would be conserved. However, emerging data indicate that not only are the initial sex determining mechanisms different, but the downstream pathways and morphogenetic events leading to the development of a testis or ovary also are different. PMID:16046442
Effects of defendant and victim race on perceptions of juvenile sex offenders.
Stevenson, Margaret C; Sorenson, Katlyn M; Smith, Amy C; Sekely, Ady; Dzwairo, Rukudzo A
2009-01-01
We investigated effects of defendant race, victim race, and juror gender on public perceptions of a juvenile sex offense. We predicted that participants, particularly men, would support registering a juvenile defendant as a sex offender more when he was Black than White and that participants, particularly women, would support registering the defendant more when the female crime victim was portrayed as White than as Black. We also expected that support for registration would be higher when the defendant and victim were different races than when they were the same race. As expected, women (but not men) recommended registration more when the victim was White than Black. Further, participants supported registration more when the defendant and the victim were different races than when they were the same race. These effects were mediated by retributive goals to punish the offender-not by utilitarian goals to protect society. Explanations and implications are discussed.
Lapan; Shaughnessy; Boggs
1996-12-01
A longitudinal study was conducted to test the mediational role of efficacy expectations in relation to sex differences in the choice of a math/science college major. Data on 101 students were gathered prior to their entering college and then again after they had declared a major 3 years later. Path analytic results support the importance of both math self-efficacy beliefs and vocational interest in mathematics in predicting entry into math/science majors and mediating sex differences in these decisions. Also, students who described themselves as more extroverted were less likely to take additional math classes in high school. Students with stronger artistic vocational interests chose majors less related to math and science. School personnel are strongly encouraged to develop programs that challenge the crystallization of efficacy beliefs and vocational interest patterns before students enter college.
Sex and gender differences in therapy of type 2 diabetes.
Kautzky-Willer, Alexandra; Harreiter, Jürgen
2017-09-01
Clinical guidelines for the management of type 2 diabetes recommend individual therapy considering age, duration of disease, presence of complication and risk of hypoglycaemia. However, at present, the patient's sex has no impact on clinical decisions. Yet, there is mounting data pointing at biological and psychosocial differences between men and women with great impact on progression of disease and complications. Moreover, choices and preferences of therapeutic strategies as well as adherence to lifestyle and pharmacological interventions differ in both sexes. In addition, drug therapy may have sex-specific side effects. Therefore, there is need of more research on biological differences and of evidence-based individualised targeted sex-sensitive therapeutic concepts. Clinical guidelines must consider relevant sex-differences. Development and implementation of sex-specific programs may help to improve adherence to therapy and to reduce progression of disease and development of complications. A more gender-sensitive clinical approach may improve quality of life and increase health and life expectancy in men and women with type 2 diabetes. Copyright © 2017 Elsevier B.V. All rights reserved.
Cell-autonomous sex determination outside of the gonad
Arnold, Arthur P.; Chen, Xuqi; Link, Jenny C.; Itoh, Yuichiro; Reue, Karen
2013-01-01
The classic model of sex determination in mammals states that the sex of the individual is determined by the type of gonad that develops, which in turn determines the gonadal hormonal milieu that creates sex differences outside of the gonads. However, XX and XY cells are intrinsically different because of the cell-autonomous sex-biasing action of X and Y genes. Recent studies of mice, in which sex chromosome complement is independent of gonadal sex, reveal that sex chromosome complement has strong effects contributing to sex differences in phenotypes such as metabolism. Adult mice with two X chromosomes (relative to mice with one X chromosome) show dramatically greater increases in body weight and adiposity after gonadectomy, irrespective of their gonadal sex. When fed a high fat diet, XX mice develop striking hyperinsulinemia and fatty liver, relative to XY mice. The sex chromosome effects are modulated by the presence of gonadal hormones, indicating an interaction of the sex-biasing effects of gonadal hormones and sex chromosome genes. Other cell-autonomous sex chromosome effects are detected in mice in many phenotypes. Birds (relative to eutherian mammals) are expected to show more widespread cell-autonomous sex determination in non-gonadal tissues, because of ineffective sex chromosome dosage compensation mechanisms. PMID:23361913
ERIC Educational Resources Information Center
Oswald, Hans; von Salisch, Maria
The study reported in this paper examined: (1) how the expectations of sexual relationships relate to the sexual experiences which male and female adolescents gather in their relationships with the opposite sex; and (2) whether male and female adolescents differ in their sexual behavior, their expectations for sexual relationships, their…
Wells, Brooke E; Starks, Tyrel J; Parsons, Jeffrey T; Golub, Sarit
2014-07-01
As the mechanisms of the associations between substance use and risky sex remain unclear, this study investigates the interactive roles of conflicts about casual sex and condom use and expectancies of the sexual effects of substances in those associations among gay men. Conflict interacted with expectancies to predict sexual behavior under the influence; low casual sex conflict coupled with high expectancies predicted the highest number of casual partners, and high condom use conflict and high expectancies predicted the highest number of unprotected sex acts. Results have implications for intervention efforts that aim to improve sexual decision-making and reduce sexual expectancies. © The Author(s) 2013.
Deaner, Robert O; Lowen, Aaron; Rogers, William; Saksa, Eric
2015-01-01
Sex differences in some preferences and motivations are well established, but it is unclear whether they persist in selective sub-populations, such as expert financial decision makers, top scientists, or elite athletes. We addressed this issue by studying competitiveness in 1,147 varsity intercollegiate distance runners. As expected, across all runners, men reported greater competitiveness with two previously validated instruments, greater competitiveness on a new elite competitiveness scale, and greater training volume, a known correlate of competitiveness. Among faster runners, the sex difference decreased for one measure of competitiveness but did not decrease for the two other competitiveness measures or either measure of training volume. Across NCAA athletic divisions (DI, DII, DIII), the sex difference did not decrease for any competitiveness or training measure. Further analyses showed that these sex differences could not be attributed to women suffering more injuries or facing greater childcare responsibilities. However, women did report greater commitment than men to their academic studies, suggesting a sex difference in priorities. Therefore, policies aiming to provide men and women with equal opportunities to flourish should acknowledge that sex differences in some kinds of preferences and motivation may persist even in selective sub-populations.
Lowen, Aaron; Rogers, William; Saksa, Eric
2015-01-01
Sex differences in some preferences and motivations are well established, but it is unclear whether they persist in selective sub-populations, such as expert financial decision makers, top scientists, or elite athletes. We addressed this issue by studying competitiveness in 1,147 varsity intercollegiate distance runners. As expected, across all runners, men reported greater competitiveness with two previously validated instruments, greater competitiveness on a new elite competitiveness scale, and greater training volume, a known correlate of competitiveness. Among faster runners, the sex difference decreased for one measure of competitiveness but did not decrease for the two other competitiveness measures or either measure of training volume. Across NCAA athletic divisions (DI, DII, DIII), the sex difference did not decrease for any competitiveness or training measure. Further analyses showed that these sex differences could not be attributed to women suffering more injuries or facing greater childcare responsibilities. However, women did report greater commitment than men to their academic studies, suggesting a sex difference in priorities. Therefore, policies aiming to provide men and women with equal opportunities to flourish should acknowledge that sex differences in some kinds of preferences and motivation may persist even in selective sub-populations. PMID:25922790
Luy, Marc; Gast, Katrin
2014-01-01
Although many different factors have been identified to contribute to excess male mortality, it is still unclear which path of the complex cause-effect chain is the decisive driver of the life expectancy gap between women and men. The question behind this study is whether these sex differences are caused primarily by factors leading to low female mortality or rather by factors causing high male mortality. We hypothesise that they are to a large extent caused by specific subpopulations of men with particularly high mortality levels that decrease the average life expectancy of men. To test this hypothesis, we investigate in a meta-analysis the variability in mortality (VM) in women and men - defined as the range of death rates prevailing among subpopulations - in empirical studies analysing specific phenomena of mortality differentials. We used the data of 72 empirical studies, including 146 total effects (TE) and 1,718 single effects (SE) for 21 different risk factors. In 85% of TE and three quarters of SE the VM was higher in men than in women, taking into account men's higher overall mortality. The corresponding figures for the direct differences in the VM between women and men are 92 and 82%, respectively. Cases with higher female VM are rare exceptions and appear in particular in the highest age groups. We find support for our hypothesis that the disproportionate high mortality levels of specific male subpopulations are the central cause of the current extent of sex differences in life expectancy. Thus, public health programmes should be targeted toward these disadvantaged subpopulations among men which seem to be related primarily to socioeconomic characteristics.
ERIC Educational Resources Information Center
Mumbauer, Corinne C.; Gray, Susan W.
1969-01-01
One of the differences in child development caused by the mother-dominant, father-absent structure of disadvantaged Negro families might be the differential development of resistance to temptation in male and female children. It would be expected that girls would be more resistant than boys, that girls would show no difference whether their father…
Patterns of Optimism and Pessimism in Perceptions of Changing Sex Roles.
ERIC Educational Resources Information Center
Marrone, Joseph G.; Rutnik, Carron M.
The utility of a design measuring actual, ideal, and expected sex-role attitudes was demonstrated with a 25-item survey administered to 155 undergraduate men and women under different instructional sets. Although relatively liberal attitudes were expressed overall, men generally expressed less egalitarian attitudes than did women. Moreover,…
Perea-Rodriguez, Juan P.; Saltzman, Wendy
2017-01-01
Parturient females ingest placenta in most mammalian species, whereas fathers may do so in species in which both parents provide care for their offspring. To determine if the propensity to eat placenta varies with reproductive status in the biparental California mouse, we presented placenta to virgin (housed with a same-sex pairmate), expectant (pregnant with their first litter), and multiparous adult males and females. Liver was presented identically, 3–7 days later, as a control. Multiparous females were more likely to eat placenta than expectant and virgin females (p-values <0.016), whereas both multiparous and expectant males had higher incidences of placentophagia than virgins (p-values <0.016). Liver consumption did not differ among groups within either sex. These results suggest that propensity to eat placenta increases with maternal/birthing experience in females, and with paternal experience and/or cohabitation with a pregnant female in males. PMID:24114333
Genetic conflict and sex chromosome evolution
Meiklejohn, Colin D; Tao, Yun
2009-01-01
Chromosomal sex determination systems create the opportunity for the evolution of selfish genetic elements that increase the transmission of one sex chromosome at the expense of its homolog. Because such selfish elements on sex chromosomes can reduce fertility and distort the sex ratio of progeny, unlinked suppressors are expected to evolve, bringing different regions of the genome into conflict over the meiotic transmission of the sex chromosomes. Here we argue that recurrent genetic conflict over sex chromosome transmission is an important evolutionary force that has shaped a wide range of seemingly disparate phenomena including the epigenetic regulation of genes expressed in the germline, the distribution of genes in the genome, and the evolution of hybrid sterility between species. PMID:19931208
Jadwin-Cakmak, Laura A; Pingel, Emily S; Harper, Gary W; Bauermeister, José A
2015-07-01
Few studies have examined the relationship between young gay and bisexual men (YGBM) and their fathers. Based on a phenomenological framework, this study investigated the role of fathers in YGBM's coming-out experience, focusing on how fathers responded to disclosure of same-sex attraction, how fathers' responses compared with sons' expectations, and what sons perceived as having influenced their fathers' responses. Semistructured in-depth interviews with 30 gay and bisexual men aged 18 to 24 years were conducted as part of a larger study; topics explored in the interview included experiences coming out to family and others. Nineteen participants' narratives included discussion about their fathers and were included in the current analyses. The YGBM who were interviewed perceived a complex range of responses upon coming out to their fathers, ranging from enthusiastic acceptance to physical violence. Participants spoke of fathers who were accepting in different manners and who often held contradictory attitudes about same-sex attraction. Fathers' responses commonly differed from sons' expectations, which were informed by homophobic talk and gendered expectations. Sons spoke about what informed their expectations as well as what they perceived as influencing their fathers' responses, including gender norms, beliefs regarding the cause of same-sex attraction, religious and sociopolitical views, and concerns about HIV/AIDS. Particularly striking was the pervasive influence of hegemonic masculinity throughout the YGBM's stories. The implications of these findings for future research and intervention development are discussed, as well as study strengths and limitations. © The Author(s) 2014.
Comparative study of disability-free life expectancy across six low- and middle-income countries.
Chirinda, Witness; Chen, He
2017-04-01
There is a knowledge gap about the disability-free life expectancy (DFLE) in low- and middle-income countries. The present study aimed to compute and compare DFLE in six such countries, and examine sex differences in DFLE in each country. Based on data from the World Health Organization Study on Global Aging and Adult Health wave 1 survey, we used the Sullivan method to estimate DFLE among persons aged years 50 years and older. Disability was divided into moderate disability and severe disability during the calculation. Of the six countries, China had the highest DFLE and lowest expected average lifetime with disability. India had the lowest DFLE and highest life years with moderate and severe disability. In each country, women live longer than men, but with more disabilities in both absolute and proportional terms. The huge sex difference in Russia requires special attention. In addition, most of the life expectancy lived with disability was spent with severe disability, rather than moderate disability. The study has shed some light on the disparities across the six countries with regard to DFLE at old ages. The low percentage of DFLE in life expectancy in some countries, such as India, calls for effective policies on healthy aging. The "sex disability-survival paradox" in DFLE is supported by our results. To differentiate the severity of disability should be routine in calculating DFLE. Geriatr Gerontol Int 2017; 17: 637-644. © 2016 Japan Geriatrics Society.
Men, Women, and Life Annuities
ERIC Educational Resources Information Center
King, Francis P.
1976-01-01
A senior research officer of Teacher Insurance and Annuity Association (TIAA) and College Retirement Equities Fund (CREF) discusses the issue of different life annuity benefits to men and women concluding that age and sex are two objective and statistically reliable factors used in determining life expectancy and thus the expected duration of…
Janssen, Fanny; van Poppel, Frans
2015-01-01
We examine in depth the effect of differences in the smoking adoption patterns of men and women on the mortality gender gap in Netherlands, employing a historical perspective. Using an indirect estimation technique based on observed lung cancer mortality from 1931 to 2012, we estimated lifetime smoking prevalence and smoking-attributable mortality. We decomposed the sex difference in life expectancy at birth into smoking-related and nonsmoking-related overall and cause-specific mortality. The smoking epidemic in Netherlands, which started among men born around 1850 and among women from birth cohort 1900 onwards, contributed substantially to the increasing sex difference in life expectancy at birth from 1931 (1.3 years) to 1982 (6.7 years), the subsequent decline to 3.7 years in 2012, and the high excess mortality among Dutch men born between 1895 and 1910. Smoking-related cancer mortality contributed most to the increase in the sex difference, whereas smoking-related cardiovascular disease mortality was mainly responsible for the decline from 1983 onwards. Examining nonsmoking-related (cause-specific) mortality shed new light on the mortality gender gap and revealed the important role of smoking-related cancers, the continuation of excess mortality among women aged 40–50, and a smaller role of biological factors in the sex difference than was previously estimated. PMID:26273613
ERIC Educational Resources Information Center
Rose, Amanda J.; Schwartz-Mette, Rebecca A.; Smith, Rhiannon L.; Asher, Steven R.; Swenson, Lance P.; Carlson, Wendy; Waller, Erika M.
2012-01-01
Although girls disclose to friends about problems more than boys, little is known about processes underlying this sex difference. Four studies (Ns = 526, 567, 769, 154) tested whether middle childhood to mid-adolescent girls and boys (ranging from 8 to 17 years old) differ in how they expect that talking about problems would make them feel. Girls…
Effects of Sex and Gender on Adaptation to Space: Neurosensory Systems
Cohen, Helen S.; Cerisano, Jody M.; Clayton, Janine A.; Cromwell, Ronita; Danielson, Richard W.; Hwang, Emma Y.; Tingen, Candace; Allen, John R.; Tomko, David L.
2014-01-01
Abstract Sex and gender differences have long been a research topic of interest, yet few studies have explored the specific differences in neurological responses between men and women during and after spaceflight. Knowledge in this field is limited due to the significant disproportion of sexes enrolled in the astronaut corps. Research indicates that general neurological and sensory differences exist between the sexes, such as those in laterality of amygdala activity, sensitivity and discrimination in vision processing, and neuronal cell death (apoptosis) pathways. In spaceflight, sex differences may include a higher incidence of entry and space motion sickness and of post-flight vestibular instability in female as opposed to male astronauts who flew on both short- and long-duration missions. Hearing and auditory function in crewmembers shows the expected hearing threshold differences between men and women, in which female astronauts exhibit better hearing thresholds. Longitudinal observations of hearing thresholds for crewmembers yield normal age-related decrements; however, no evidence of sex-related differences from spaceflight has been observed. The impact of sex and gender differences should be studied by making spaceflight accessible and flying more women into space. Only in this way will we know if increasingly longer-duration missions cause significantly different neurophysiological responses in men and women. PMID:25401941
Andrade, Flávia Cristina Drumond
2013-01-01
Objectives To estimate transition probabilities between disability states, total life expectancy, and the latter’s decomposition into years spent disabled and disability-free by age, sex and education among older adults in São Paulo, Brazil, and urban areas in Mexico. Methods Applied a micro-simulation method (Interpolative Markov Chains) using longitudinal data. Results We found large between-country educational differences in incidence of and recovery from disability with higher rates in Mexico than in São Paulo, but no differences in mortality. Older adults in Mexico spent longer time being disability-free than in São Paulo for both levels of education. Males and females in São Paulo spent a larger fraction of their remaining life disabled at every age than their counterparts in urban areas in Mexico. Discussion There were educational differences in the prevalence of disability in São Paulo and urban areas in Mexico, and significant educational differences in disability incidence and recovery across sites. PMID:23781016
Gender differences and pain medication.
Richardson, Jen; Holdcroft, Anita
2009-01-01
Subtle genetic and psychological variations are increasingly recognized to contribute to pain and analgesic efficacy and safety. The influence of sex on this relationship remains poorly understood, particularly in humans. The issue is complicated by the overlay of gender onto physical sex, and its associated stereotypes and expectations. Women appear to use more pain-relieving medications than men; however, it remains unclear whether these observations represent true differences in analgesic usage patterns, or reporting bias. Differences in analgesic efficacy relating to body composition, metabolism and hormonal profiles have been demonstrated. Psychological and social elements of gender have also been associated with altered pain experiences and analgesic use profiles, albeit with significant individual variations. Intra-group differences may ultimately prove more important than sex differences. Further research may unravel the various threads linking gender and sex effects on analgesia with the aim of individualizing analgesia to optimize pain relief.
NASA Astrophysics Data System (ADS)
Huang, Victoria; Sakata, Jon T.; Rhen, Turk; Coomber, Patricia; Simmonds, Sarah; Crews, David
2008-12-01
Kratochvil et al. (Naturwissenschaften 95:209 215, 2008) reported recently that in the leopard gecko ( Eublepharis macularius) of the family Eublepharidae with temperature-dependent sex determination (TSD), clutches in which eggs were incubated at the same temperature produce only same-sex siblings. Interpreting this result in light of studies of sex steroid hormone involvement in sex determination, they suggested that maternally derived yolk steroid hormones could constrain sex-determining mechanisms in TSD reptiles. We have worked extensively with this species and have routinely incubated clutches at constant temperatures. To test the consistency of high frequency same-sex clutches across different incubation temperatures, we examined our records of clutches at the University of Texas at Austin from 1992 to 2001. We observed that clutches in which eggs were incubated at the same incubation temperature produced mixed-sex clutches as well as same-sex clutches. Furthermore, cases in which eggs within a clutch were separated and incubated at different temperatures produced the expected number of mixed-sex clutches. These results suggest that maternal influences on sex determination are secondary relative to incubation temperature effects.
The Interface of Family and Society in Sex Role Changes, Emphasizing the Saliency of Occupation.
ERIC Educational Resources Information Center
Settles, Barbara H.
This paper develops a theoretical framework for examining how families interact with the society under conditions in which the expectations for sex roles are changing. The difference between mandated and voluntary change is examined and the cost-benefit ratio to families for participating in the process of change is evaluated in different…
An Analysis of Workers' Attitudes Toward the 4-Day, 40-Hour Workweek.
ERIC Educational Resources Information Center
Dickinson, Terry L.; Wijting, Jan P.
Employees' attitudes toward a proposed 4-day, 40-hour workweek were examined relative to job and worker variables, expectations about the new workweek schedule, and job-aspect satisfactions. Employees classified by their sex, work shifts, wage schedules, and sex and work shifts differed significantly in their attitudes toward the 4-day, 40-hour…
Effects of sex, menstrual cycle phase, and endogenous hormones on cognition in schizophrenia.
Rubin, Leah H; Carter, C Sue; Drogos, Lauren L; Pournajafi-Nazarloo, Hossein; Sweeney, John A; Maki, Pauline M
2015-08-01
In women with schizophrenia, cognition has been shown to be enhanced following administration of hormone therapy or oxytocin. We examined how natural hormonal changes across the menstrual cycle influence cognition in women with schizophrenia. We hypothesized that female patients would perform worse on "female-dominant" tasks (verbal memory/fluency) and better on "male-dominant" tasks (visuospatial) during the early follicular phase (low estradiol and progesterone) compared to midluteal phase (high estradiol and progesterone) in relation to estradiol but not progesterone. Fifty-four women (23 with schizophrenia) completed cognitive assessments and provided blood for sex steroid assays and oxytocin at early follicular (days 2-4) and midluteal (days 20-22) phases. Men were included to verify the expected pattern of sex differences on cognitive tests. Expected sex differences were observed on "female-dominant" and "male-dominant" tasks (p<0.001), but the magnitude of those differences did not differ between patients and controls (p=0.44). Cognitive performance did not change across the menstrual cycle on "female-dominant" or "male-dominant" tasks in either group. Estradiol and progesterone levels were unrelated to cognitive performance. Oxytocin levels did not change across the menstrual cycle but were positively related to performance on "female-dominant" tasks in female patients only (p<0.05). Sex differences in cognitive function are preserved in schizophrenia. Oxytocin levels do not change across the cycle, but relate to enhanced performance on female dominant tests in women. Physiological levels of oxytocin may thus have a more powerful benefit in some cognitive domains than estrogens in schizophrenia. Copyright © 2015 Elsevier B.V. All rights reserved.
Steward, Wayne T; Satyanarayana, Veena A; Heylen, Elsa; Srikrishnan, Aylur K; Vasudevan, Canjeevaram K; Krishnan, Gopal; Solomon, Davidson; Ekstrand, Maria L
2018-05-01
Male migrant workers (MMWs) in India are vulnerable to developing alcohol-related problems and engaging in unprotected sex, putting them at risk of HIV. Research has shown that alcohol-related expectancies mediate vulnerability to alcoholism. We examined which expectancies were associated with sexual risk and drinking. We surveyed 1085 heterosexual MMWs in two South Indian municipalities, assessing expectancies, sex under the influence, and unprotected sex with female sex workers (FSW) and casual female partners in the prior 30 days. Men more strongly endorsed positive than negative expectancies (t = 53.59, p < .01). In multivariate logistic regression, the expectancy of having more fun helped drive the combination of alcohol and unprotected sex with FSW partners (OR = 1.22, p < .05), whereas the expectancy of better sex helped drive a similar combination with casual partners (OR = 1.24, p < .01). Men concerned about alcohol-induced deficits were less likely to drink with FSW partners (OR = 0.81, p < .01), but more likely to have unprotected sex with them (OR = 1.78, p < .01). To reduce risk, MMWs would benefit from combination prevention approaches that use behavioral strategies to address drinking norms and awareness of risk, while using biomedical strategies to reduce viral transmission when risk does occur.
Sex and Gender Differences in Prevention of Type 2 Diabetes.
Harreiter, Jürgen; Kautzky-Willer, Alexandra
2018-01-01
Lifestyle intervention programs are effective in the prevention of type 2 diabetes mellitus (T2DM) in high risk populations. However, most studies only give limited information about the influence of sex and/or gender effectiveness of these interventions. So far, similar outcome was reported for diabetes progression and weight loss. Nevertheless, long-term data on cardiovascular outcome are sparse but favoring women regarding all-cause and cardiovascular mortality. In both men and women, sex hormone imbalances and reproductive disorders are associated with a higher risk of T2DM development. Diabetes prevention approaches are reported for polycystic ovary syndrome, gestational diabetes mellitus, and erectile dysfunction and are presented in this review. In the surgical treatment options for morbid obese patients, sex and gender differences are present. Choices and preferences of adherence to lifestyle and pharmacological interventions, expectations, treatment effects, and complications are influenced by sex or gender. In general, bariatric surgery is performed more often in women seeking medical/surgical help to lose weight. Men are older and have higher comorbidities and mortality rates and worse follow-up outcome after bariatric surgery. A more gender-sensitive clinical approach, as well as consideration of ethnicity may improve quality of life and increase health and life expectancy in men and women with a high risk for subsequent progression to T2DM.
Potential Reporting Bias in Neuroimaging Studies of Sex Differences.
David, Sean P; Naudet, Florian; Laude, Jennifer; Radua, Joaquim; Fusar-Poli, Paolo; Chu, Isabella; Stefanick, Marcia L; Ioannidis, John P A
2018-04-17
Numerous functional magnetic resonance imaging (fMRI) studies have reported sex differences. To empirically evaluate for evidence of excessive significance bias in this literature, we searched for published fMRI studies of human brain to evaluate sex differences, regardless of the topic investigated, in Medline and Scopus over 10 years. We analyzed the prevalence of conclusions in favor of sex differences and the correlation between study sample sizes and number of significant foci identified. In the absence of bias, larger studies (better powered) should identify a larger number of significant foci. Across 179 papers, median sample size was n = 32 (interquartile range 23-47.5). A median of 5 foci related to sex differences were reported (interquartile range, 2-9.5). Few articles (n = 2) had titles focused on no differences or on similarities (n = 3) between sexes. Overall, 158 papers (88%) reached "positive" conclusions in their abstract and presented some foci related to sex differences. There was no statistically significant relationship between sample size and the number of foci (-0.048% increase for every 10 participants, p = 0.63). The extremely high prevalence of "positive" results and the lack of the expected relationship between sample size and the number of discovered foci reflect probable reporting bias and excess significance bias in this literature.
Cameron, Skye F; Wheatley, Rebecca; Wilson, Robbie S
2018-07-01
Studies of sexual selection primarily focus on morphological traits such as body size and secondary trait dimorphism, with less attention been given to the functional differences between the sexes and even more so their thermal performance capacities. Each sex may benefit from possessing different thermal performance capacities that would allow them to maximise their fitness relative to their different reproductive roles; especially when performances are closely related to reproductive success. Here, we examine sexual divergence in thermal sensitivities of performance across three populations of the Asian house gecko (Hemidactylus frenatus) over an extensive latitudinal cline. Using analyses of the thermal sensitivity of routine activity, bite force and sprint speed, we explored whether: (i) males and females differed in their optimal temperatures for performance, (ii) the sexes differed in their thermal sensitivities of performance, and (iii) the degree of sexual divergence in thermal sensitivity varied among the populations. Because male H. frenatus are highly aggressive and frequently engage in combat to gain territories and mating opportunities, we expected males would be active over a wider range of temperatures than females and this would favour broad thermal sensitivity curves for males. In addition, we expected a greater divergence between the sexes in thermal sensitivities for the temperate populations that experience greater daily and seasonal thermal variation. We found that males were more active, and had greater bite forces and faster sprint speeds than females, independent of body size. In addition, we found differences between the sexes in thermal sensitivities for the tropical population; female H. frenatus were less active and possessed lower sprint speeds at higher temperatures than males. Although H. frenatus from the most variable thermal environments also displayed the broadest thermal performance range, it was the more stable tropical population that exhibited the greatest divergence between the sexes in thermal sensitivity of performance. The divergence in thermal physiology that we detected between the sexes of H. frenatus is consistent with the idea that males will derive mating and territorial advantages for maintaining function over a broader range of temperatures.
Sex differences in lizard escape decisions vary with latitude, but not sexual dimorphism.
Samia, Diogo S M; Møller, Anders Pape; Blumstein, Daniel T; Stankowich, Theodore; Cooper, William E
2015-04-22
Sexual selection is a powerful evolutionary mechanism that has shaped the physiology, behaviour and morphology of the sexes to the extent that it can reduce viability while promoting traits that enhance reproductive success. Predation is one of the underlying mechanisms accounting for viability costs of sexual displays. Therefore, we should expect that individuals of the two sexes adjust their anti-predator behaviour in response to changes in predation risk. We conducted a meta-analysis of 28 studies (42 species) of sex differences in risk-taking behaviour in lizards and tested whether these differences could be explained by sexual dichromatism, by sexual size dimorphism or by latitude. Latitude was the best predictor of the interspecific heterogeneity in sex-specific behaviour. Males did not change their escape behaviour with latitude, whereas females had increasingly reduced wariness at higher latitudes. We hypothesize that this sex difference in risk-taking behaviour is linked to sex-specific environmental constraints that more strongly affect the reproductive effort of females than males. This novel latitudinal effect on sex-specific anti-predator behaviour has important implications for responses to climate change and for the relative roles of natural and sexual selection in different species. © 2015 The Author(s) Published by the Royal Society. All rights reserved.
Alabas, O A; Tashani, O A; Johnson, M I
2013-05-01
Gender role expectations of pain (GREP) have been shown to mediate sex differences in experimental pain. Few studies have investigated the role of ethnicity in shaping GREP. The aim of this study was to examine interactions between ethnicity and GREP on experimentally induced pressure and ischaemic pain in Libyan and white British students in their respective countries. Libyan (n = 124) and white British (n = 51) students completed a GREP questionnaire and their response to experimental pain was measured. Blunt pressure pain threshold (PPT) was measured over the 1st interosseous muscle using algometry. Pain intensity and pain unpleasantness (100 mm visual analogue scale) were measured at 1-min intervals during a submaximal effort tourniquet test on the forearm. Multivariate analysis of variance detected significant effects for Sex and Ethnicity on pain measurements. Men had higher PPTs than women (p < 0.001). Libyans had higher PPTs than white British participants (p < 0.001). There were significant effects for Sex and Ethnicity for pain intensity ratings (p < 0.01) but no significant differences between the sexes in pain unpleasantness (p > 0.05). Libyan participants had higher pain intensity (p < 0.01) and pain unpleasantness (p < 0.05) ratings compared with white British participants. There were effects for Sex and Ethnicity for all GREP dimensions. Libyan participants exhibited stronger stereotypical views in GREP than white British participants (p < 0.001). GREP was the mediator of sex but not ethnic differences in pain report, suggesting that gender stereotypical attitudes to pain account for differences in pain expression between men and women. © 2012 European Federation of International Association for the Study of Pain Chapters.
The role of physical content in piagetian spatial tasks: Sex differences in spatial knowledge?
NASA Astrophysics Data System (ADS)
Golbeck, Susan L.
Sex-related differences on Piagetian horizontality (water level) and verticality (plumb line) tasks were examined in 64 college students. It was hypothesized that females' difficulties on these Euclidean spatial problems are due not to differences in underlying spatial competence, but rather to differences in knowledge of task specific information about the physical properties of water levels and plumb lines. This was tested by presenting subjects with the standard water level and plumb line problems and also modified problems not requiring knowledge of physical principles (i.e., drawing straight up and down or straight across lines inside tipped rectangles). While males were expected to outperform females on the standard tasks, no sex differences were expected on the modified tasks. Results of an ANOVA on scores for horizontality and verticality each showed main effects for sex and task version but failed to reveal the hypothesized interaction. However, performance on the Euclidean spatial tasks was also considered in terms of overall success versus failure. While males were more successful than females in the standard format, males and females were equally successful in the modified, nonphysical, format. Hence, college aged males and females generally do not differ in spatial competence although they may be differentially influenced by task content. Findings are discussed in terms of their implications for theory and practice. It is emphasized that science educators must be especially aware of such task influences for females so that performance deficits are not mistaken for competence deficits.
Hampel, Harald; Vergallo, Andrea; Giorgi, Filippo Sean; Kim, Seung Hyun; Depypere, Herman; Graziani, Manuela; Saidi, Amira; Nisticò, Robert; Lista, Simone
2018-06-12
Neurodegenerative diseases (ND) are among the leading causes of disability and mortality. Considerable sex differences exist in the occurrence of the various manifestations leading to cognitive decline. Alzheimer's disease (AD) exhibits substantial sexual dimorphisms and disproportionately affects women. Women have a higher life expectancy compared to men and, consequently, have more lifespan to develop AD. The emerging precision medicine and pharmacology concepts - taking into account the individual genetic and biological variability relevant for disease risk, prevention, detection, diagnosis, and treatment - are expected to substantially enhance our knowledge and management of AD. Stratifying the affected individuals by sex and gender is an important basic step towards personalization of scientific research, drug development, and care. We hypothesize that sex and gender differences, extending from genetic to psychosocial domains, are highly relevant for the understanding of AD pathophysiology, and for the conceptualization of basic/translational research and for clinical therapy trial design. Copyright © 2018 Elsevier Inc. All rights reserved.
Fatima, Iram; Humayun, Ayesha; Anwar, Muhammad Imran; Iftikhar, Adil; Aslam, Muhammad; Shafiq, Muhammad
2017-07-01
Service quality is one of the important gears to appraise services and determine the gray areas that need improvement. In countries with a resource-poor health system, the first step of measuring quality is yet to be taken. This study seeks to inform policy makers in developing contextual service quality models by identifying service quality gaps in tertiary care teaching hospitals using patients' perspective. A cross-sectional study was performed using multistage cluster sampling, and a modified version of the SERVQUAL (SERV-service, QUAL-quality) instrument was administered to determine patient's expectations and perceptions. A total of 817 completed questionnaires were obtained from patients and/or their attendants using convenience sampling. Data analysis revealed statistically significant negative quality gaps between expectations and perceptions of tangibility, reliability, empathy, assurance, responsiveness, and communication. The difference in mean expectation and perception for responsiveness across the sexes was significant ( p < 0.003; p < 0.037, respectively) as well as in perception of communication ( p < 0.026). Other dimensions and overall hospital expected and perceived quality were independent of sex. Educational status showed significant difference in expectation and perception in responsiveness ( p < 0.005), but the perception of each dimension was significantly different in different educational categories (assurance: p < 0.001; empathy: p < 0.001; reliability: p < 0.001; tangibility: p < 0.001; responsiveness: p < 0.001; communication: p < 0.001; and for overall service quality: p < 0.001). Age and service departments showed no relationship with any of the perceived or expected dimension of service quality of hospitals. Tertiary care hospitals failed to meet patients' expectations in all major areas of service quality, posing a question of how hospitals implement and evaluate their quality assurance policy.
Serving her Country: An Analysis of Women’s Enlistment
1990-01-01
microdatabase containing many-indivldual and local market variables, make it possible to circumvent the distorting effects of the Qverall demand constraint that...For example, they consider whether labor market forces influence young men and women differently; the ways in which marriage expectations affect the...enlistment decision; whether the role of education expectations differs between the two sexes; and what impact local labor market conditions have on
Interactions among sex, ethnicity, religion, and gender role expectations of pain.
Defrin, Ruth; Eli, Ilana; Pud, Dorit
2011-06-01
Sex, gender, ethnicity, and religion are powerful factors that may affect pain experience. Recently, gender role expectations of pain (GREP) were suggested to account for some of the differences in pain perception between men and women. However, the interaction between GREP and ethnicity and religion was not examined. This interaction was studied with regard to pain sensitivity, pain endurance, and willingness to report pain. Our objective was to study the interaction among GREP, sex, and ethno-religious belonging. Participants (548 healthy men and women) of 3 different ethno-religious groups (341 Jews, 105 Muslim-Arabs, 102 Christian-Arabs) completed the GREP questionnaire; pain sensitivity, pain endurance, and willingness to report pain were analyzed. Men of all 3 ethno-religious groups perceived themselves and other men as less sensitive and less willing to report pain than typical women. Women of all 3 ethno-religious groups perceived themselves and other women as more sensitive and more willing to report pain than men. Ethno-religious differences were observed in the attitudes towards typical men and women, with Christian men and women exhibiting stronger stereotypical views regarding pain sensitivity and pain endurance. Individual's perceptions of pain regarding one's self compared with the same or opposite sex were similar regardless of ethno-religious belonging and were related to sex. However, attitudes on pain of typical men and women seemed to be influenced by ethno-religious belonging. This differential effect of ethno-religion on GREP with relation to sex suggests that these factors should be considered when pain perception is evaluated. Copyright © 2011 Elsevier HS Journals, Inc. All rights reserved.
The Social Distribution of Health: Estimating Quality-Adjusted Life Expectancy in England.
Love-Koh, James; Asaria, Miqdad; Cookson, Richard; Griffin, Susan
2015-07-01
To model the social distribution of quality-adjusted life expectancy (QALE) in England by combining survey data on health-related quality of life with administrative data on mortality. Health Survey for England data sets for 2010, 2011, and 2012 were pooled (n = 35,062) and used to model health-related quality of life as a function of sex, age, and socioeconomic status (SES). Office for National Statistics mortality rates were used to construct life tables for age-sex-SES groups. These quality-of-life and length-of-life estimates were then combined to predict QALE as a function of these characteristics. Missing data were imputed, and Monte-Carlo simulation was used to estimate standard errors. Sensitivity analysis was conducted to explore alternative regression models and measures of SES. Socioeconomic inequality in QALE at birth was estimated at 11.87 quality-adjusted life-years (QALYs), with a sex difference of 1 QALY. When the socioeconomic-sex subgroups are ranked by QALE, a differential of 10.97 QALYs is found between the most and least healthy quintile groups. This differential can be broken down into a life expectancy difference of 7.28 years and a quality-of-life adjustment of 3.69 years. The methods proposed in this article refine simple binary quality-adjustment measures such as the widely used disability-free life expectancy, providing a more accurate picture of overall health inequality in society than has hitherto been available. The predictions also lend themselves well to the task of evaluating the health inequality impact of interventions in the context of cost-effectiveness analysis. Copyright © 2015 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.
Sex differences in sub-clinical psychosis--results from a community study over 30 years.
Rössler, Wulf; Hengartner, Michael P; Ajdacic-Gross, Vladeta; Haker, Helene; Angst, Jules
2012-08-01
Sex differences in schizophrenia have long been reported. They are found within almost all aspects of the disease, from incidence and prevalence, age of onset, symptomatology, and course to its psycho-social outcome. Many sex-related hypotheses have been developed about the biology, psychology, or sociology of that disease. A further approach to study sex differences would be to examine such differences in sub-clinical psychotic states as well. If factors related to full-blown psychosis were equally meaningful over the entire psychosis continuum, we should expect that "true" sex differences could also be identified in sub-clinical psychosis. Here, we studied sex differences in sub-clinical psychosis within a community cohort in Zurich, Switzerland. This population was followed for over 30 years and included males and females between the ages of 20/21 and 49/50. We applied two different measures of sub-clinical psychosis representing schizotypal signs and schizophrenia nuclear symptoms. Using cross-sectional and longitudinal analyses, we found no significant sex differences in sub-clinical psychosis over time with respect to age of onset, symptomatology, course, or psycho-social outcome. Thus it appears that sex differences in psychosis manifest themselves at the high end of the continuum (full-blown schizophrenia) rather than within the sub-threshold range. Possibly males and females have separate thresholds for certain symptoms because they are differently vulnerable or exposed to various risk factors. Copyright © 2012. Published by Elsevier B.V.
Anderson, Jennifer L.; Rodríguez Marí, Adriana; Braasch, Ingo; Amores, Angel; Hohenlohe, Paul; Batzel, Peter; Postlethwait, John H.
2012-01-01
Within vertebrates, major sex determining genes can differ among taxa and even within species. In zebrafish (Danio rerio), neither heteromorphic sex chromosomes nor single sex determination genes of large effect, like Sry in mammals, have yet been identified. Furthermore, environmental factors can influence zebrafish sex determination. Although progress has been made in understanding zebrafish gonad differentiation (e.g. the influence of germ cells on gonad fate), the primary genetic basis of zebrafish sex determination remains poorly understood. To identify genetic loci associated with sex, we analyzed F2 offspring of reciprocal crosses between Oregon *AB and Nadia (NA) wild-type zebrafish stocks. Genome-wide linkage analysis, using more than 5,000 sequence-based polymorphic restriction site associated (RAD-tag) markers and population genomic analysis of more than 30,000 single nucleotide polymorphisms in our *ABxNA crosses revealed a sex-associated locus on the end of the long arm of chr-4 for both cross families, and an additional locus in the middle of chr-3 in one cross family. Additional sequencing showed that two SNPs in dmrt1 previously suggested to be functional candidates for sex determination in a cross of ABxIndia wild-type zebrafish, are not associated with sex in our AB fish. Our data show that sex determination in zebrafish is polygenic and that different genes may influence sex determination in different strains or that different genes become more important under different environmental conditions. The association of the end of chr-4 with sex is remarkable because, unique in the karyotype, this chromosome arm shares features with known sex chromosomes: it is highly heterochromatic, repetitive, late replicating, and has reduced recombination. Our results reveal that chr-4 has functional and structural properties expected of a sex chromosome. PMID:22792396
Newby, Katie V; Brown, Katherine E; French, David P; Wallace, Louise M
2013-02-13
The prevalence of unwanted pregnancy and sexually transmitted infection amongst young adults represents an important public health problem in the UK. Individuals' attitude towards the use of condoms has been identified as an important determinant of behavioural intentions and action. The Theory of Planned Behaviour has been widely used to explain and predict health behaviour. This posits that the degree to which an individual positively or negatively values a behaviour (termed 'direct attitude') is based upon consideration of the likelihood of a number of outcomes occurring (outcome expectancy) weighted by the perceived desirability of those outcomes (outcome evaluation). Outcome expectancy and outcome evaluation when multiplied form 'indirect attitude'. The study aimed to assess whether positive outcome expectancies of unprotected sex were more important for young adults with lower safe sex intentions, than those with safer sex intentions, and to isolate optimal outcomes for targeting through health promotion campaigns. A cross-sectional survey design was used. Data was collected from 1051 school and university students aged 16-24 years. Measures of intention, direct attitude and indirect attitude were taken. Participants were asked to select outcome expectancies which were most important in determining whether they would use condoms with casual sexual partners. People with lower safe sex intentions were more likely than those with safer sex intentions to select all positive outcome expectancies for unprotected sex as salient, and less likely to select all negative outcome expectancies as salient. Outcome expectancies for which the greatest proportion of participants in the less safe sex group held an unfavourable position were: showing that I am a caring person, making sexual experiences less enjoyable, and protecting against pregnancy. The findings point to ways in which the attitudes of those with less safe sex intentions could be altered in order to motivate positive behavioural change. They suggest that it would be advantageous to highlight the potential for condom use to demonstrate a caring attitude, to challenge the potential for protected sex to reduce sexual pleasure, and to target young adults' risk appraisals for pregnancy as a consequence of unprotected sex with casual sexual partners.
Hunger-dependent and Sex-specific Antipredator Behaviour of Larvae of a Size-dimorphic Mosquito
Wormington, Jillian; Juliano, Steven
2014-01-01
1. Modification of behaviors in the presence of predators or predation cues is widespread among animals. Costs of a behavioral change in the presence of predators or predation cues depend on fitness effects of lost feeding opportunities and, especially when organisms are sexually dimorphic in size or timing of maturation, these costs are expected to differ between the sexes. 2. Larval Aedes triseriatus (Say) (Diptera: Culicidae) were used to test the hypothesis that behavioral responses of the sexes to predation cues have been selected differently due to different energy demands. 3. Even in the absence of water-borne predation cues, hungry females (the larger sex) spent more time browsing than did males, indicating a difference in energy needs. 4. In the presence of predation cues, well-fed larvae of both sexes reduced their activity more than did hungry larvae, and males shifted away from high-risk behaviors to a greater degree than did females, providing the first evidence of sex-specific antipredator behavior in foraging mosquito larvae. 5. Because sexual size dimorphism is common across taxa, and energetic demands are likely correlated with size dimorphism, this research demonstrates the importance of investigating sex specific behavior and behavioral responses to enemies and cautions against generalizing results between sexes. PMID:25309025
The Learning Disabled Girl: A Profile.
ERIC Educational Resources Information Center
Hassett, Irene D.; Gurian, Anita
The learning disabilities literature of the past 15 years pertaining to sex differences is reviewed, including prevalence in children, socialization effects, physiological vulnerability, family patterns, differing expectations of parents and teachers, and differing patterns of response to failure. Analysis of data obtained over the last 2 years on…
Eddleston, Kimberly A; Veiga, John F; Powell, Gary N
2006-03-01
Using survey data from 400 managers, the authors examined whether gender self-schema would explain sex differences in preferences for status-based and socioemotional career satisfiers. Female gender self-schema, represented by femininity and family role salience, completely mediated the relationship between managers' sex and preferences for socioemotional career satisfiers. However, male gender self-schema, represented by masculinity and career role salience, did not mediate the relationship between managers' sex and preferences for status-based career satisfiers. As expected, male managers regarded status-based career satisfiers as more important and socioemotional career satisfiers as less important than female managers did. The proposed conceptualization of male and female gender self-schemas, which was supported by the data, enhances understanding of adult self-schema and work-related attitudes and behavior.
Sex and Gender Differences in Prevention of Type 2 Diabetes
Harreiter, Jürgen; Kautzky-Willer, Alexandra
2018-01-01
Lifestyle intervention programs are effective in the prevention of type 2 diabetes mellitus (T2DM) in high risk populations. However, most studies only give limited information about the influence of sex and/or gender effectiveness of these interventions. So far, similar outcome was reported for diabetes progression and weight loss. Nevertheless, long-term data on cardiovascular outcome are sparse but favoring women regarding all-cause and cardiovascular mortality. In both men and women, sex hormone imbalances and reproductive disorders are associated with a higher risk of T2DM development. Diabetes prevention approaches are reported for polycystic ovary syndrome, gestational diabetes mellitus, and erectile dysfunction and are presented in this review. In the surgical treatment options for morbid obese patients, sex and gender differences are present. Choices and preferences of adherence to lifestyle and pharmacological interventions, expectations, treatment effects, and complications are influenced by sex or gender. In general, bariatric surgery is performed more often in women seeking medical/surgical help to lose weight. Men are older and have higher comorbidities and mortality rates and worse follow-up outcome after bariatric surgery. A more gender-sensitive clinical approach, as well as consideration of ethnicity may improve quality of life and increase health and life expectancy in men and women with a high risk for subsequent progression to T2DM. PMID:29780358
Bowers, E Keith; Thompson, Charles F; Sakaluk, Scott K
2015-03-01
A major component of sex-allocation theory, the Trivers-Willard model (TWM), posits that sons and daughters are differentially affected by variation in the rearing environment. In many species, the amount of parental care received is expected to have differing effects on the fitness of males and females. When this occurs, the TWM predicts that selection should favour adjustment of the offspring sex ratio in relation to the expected fitness return from offspring. However, evidence for sex-by-environment effects is mixed, and little is known about the adaptive significance of producing either sex. Here, we test whether offspring sex ratios vary according to predictions of the TWM in the house wren (Troglodytes aedon, Vieillot). We also test the assumption of a sex-by-environment effect on offspring using two experiments, one in which we manipulated age differences among nestlings within broods, and another in which we held nestling age constant but manipulated brood size. As predicted, females with high investment ability overproduced sons relative to those with lower ability. Males were also overproduced early within breeding seasons. In our experiments, the body mass of sons was more strongly affected by the sibling-competitive environment and resource availability than that of daughters: males grew heavier than females when reared in good conditions but were lighter than females when in poor conditions. Parents rearing broods with 1:1 sex ratios were more productive than parents rearing broods biased more strongly towards sons or daughters, suggesting that selection favours the production of mixed-sex broods. However, differences in the condition of offspring as neonates persisted to adulthood, and their reproductive success as adults varied with the body mass of sons, but not daughters, prior to independence from parental care. Thus, selection should favour slight but predictable variations in the sex ratio in relation to the quality of offspring that parents are able to produce. Offspring sex interacts with the neonatal environment to influence offspring fitness, thus favouring sex-ratio adjustment by parents. However, increased sensitivity of males to environmental conditions, such as sibling rivalry and resource availability, reduces the fitness returns from highly male-biased broods. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.
Children's gender-based reasoning about toys.
Martin, C L; Eisenbud, L; Rose, H
1995-10-01
The goal of these studies was to investigate how preschool children use gender-based reasoning in making judgments about toy preferences for themselves and for others. In Studies 1 and 2, children (n = 22, n = 71) were shown unfamiliar, non-sex-typed toys and asked to rate how much they, other girls, and other boys would like each toy. As expected, children made gender-based inferences: "What I like, children of my sex will also like, and children of the other sex will not like." Study 3 was designed to assess how children use gender-based reasoning to make decisions about attractive and unattractive toys when they are given gender labels. Children (n = 91) were shown unfamiliar toys varying in attractiveness that were given explicit gender labels (e.g., "this is a toy girls really like") or no label. With a different experimenter (to avoid demand characteristics), children rated their own and others' liking of the toys. Children used gender labels to guide their own preferences and their expectations for others. Even with very attractive toys, children liked toys less if they were labeled as being for the other sex, and expected other girls and boys to do the same. The role of gender-based reasoning in cognitive theories of gender and on children's play preferences is discussed.
Sex Differences in Response to Visual Sexual Stimuli: A Review
Rupp, Heather A.; Wallen, Kim
2009-01-01
This article reviews what is currently known about how men and women respond to the presentation of visual sexual stimuli. While the assumption that men respond more to visual sexual stimuli is generally empirically supported, previous reports of sex differences are confounded by the variable content of the stimuli presented and measurement techniques. We propose that the cognitive processing stage of responding to sexual stimuli is the first stage in which sex differences occur. The divergence between men and women is proposed to occur at this time, reflected in differences in neural activation, and contribute to previously reported sex differences in downstream peripheral physiological responses and subjective reports of sexual arousal. Additionally, this review discusses factors that may contribute to the variability in sex differences observed in response to visual sexual stimuli. Factors include participant variables, such as hormonal state and socialized sexual attitudes, as well as variables specific to the content presented in the stimuli. Based on the literature reviewed, we conclude that content characteristics may differentially produce higher levels of sexual arousal in men and women. Specifically, men appear more influenced by the sex of the actors depicted in the stimuli while women’s response may differ with the context presented. Sexual motivation, perceived gender role expectations, and sexual attitudes are possible influences. These differences are of practical importance to future research on sexual arousal that aims to use experimental stimuli comparably appealing to men and women and also for general understanding of cognitive sex differences. PMID:17668311
Lavernia, Carlos J; Contreras, Juan S; Parvizi, Javad; Sharkey, Peter F; Barrack, Robert; Rossi, Mark D
2012-10-01
Many studies show gender and ethnic differences in healthcare utilization and outcomes. Patients' presurgical cognitions regarding surgical outcomes also may vary by gender and ethnicity and play a role in explaining utilization and outcome differences. However, it is unclear whether and to what extent gender and ethnicity play a role in patients' presurgical cognitions. Do gender and ethnicity influence outcome expectations? Is arthroplasty-related knowledge affected by gender and ethnicity? Do gender and ethnicity influence willingness to pay for surgery? In a prospective, multicenter study we gave 765 patients an anonymous questionnaire on expectations, arthroplasty knowledge, and preferences before their consultation for hip and/or knee pain, from March 2005 to July 2007. Six hundred seventy-two of the 765 patients (88%) completed questionnaires. Non-Hispanics and men were more likely to indicate they would be able to engage in more activities. Non-Hispanics and men had greater arthroplasty knowledge. Hispanics and women were more likely to report they would not pay for a total joint arthroplasty (TJA) relative to non-Hispanics and men. Sex and ethnic differences in patients presenting for their initial visit to the orthopaedists for hip or knee pain influence expectations, knowledge, and preferences concerning TJAs. Longitudinal study of relationships between patients' perceptions and utilization or outcomes regarding TJA is warranted.
Male-biased predation of western green lizards by Eurasian kestrels
NASA Astrophysics Data System (ADS)
Costantini, David; Bruner, Emiliano; Fanfani, Alberto; Dell'Omo, Giacomo
2007-12-01
Selective predation can be an important force driving the evolution of organisms. In particular, sex-biased predation is expected to have implications for sexual selection, sex allocation and population dynamics. In this study, we analysed sex differences in the predation of the western green lizard ( Lacerta bilineata) by the Eurasian kestrel ( Falco tinnunculus) during the reproductive season. In addition, we investigated whether the rate of predation differed during the 8-year study period and among the three habitats studied. We collected lizard remains from nest boxes of kestrels. Freshly killed lizards were sexed by visual inspection, whilst the sex of head remains was assigned by analysing the cephalic scale morphology using geometric morphometrics. Our results show that the risk of being predated by a kestrel in our population was overall about 3.55 times higher for males than for females. To our knowledge this is the first study showing a male-biased predation in a lizard species. The selective predation of males was consistent between years over the 8-year study period (1999-2006) and also consistent between the three types of kestrel hunting habitat. Overall predation rates on lizards differed between habitats, depending on the year. We propose that the observed sex-biased predation is mainly due to sex differences in lizard behaviour.
Walsh, Kate; Messman-Moore, Terri; Zerubavel, Noga; Chandley, Rachel B.; DeNardi, Kathleen A.; Walker, Dave P.
2013-01-01
Objectives Although numerous studies have documented linkages between childhood sexual abuse (CSA) and later sexual revictimization, mechanisms underlying revictimization, particularly assaults occurring in the context of substance use, are not well-understood. Consistent with Traumagenic Dynamics theory, the present study tested a path model positing that lowered perceptions of sexual control resulting from CSA may be associated with increased sex-related alcohol expectancies and heightened likelihood of risky sexual behavior, which in turn, may predict adult substance-related rape. Methods Participants were 546 female college students who completed anonymous surveys regarding CSA and adult rape, perceptions of sexual control, sex-related alcohol expectancies, and likelihood of engaging in risky sexual behavior. Results The data fit the hypothesized model well and all hypothesized path coefficients were significant and in the expected directions. As expected, sex-related alcohol expectancies and likelihood of risky sexual behavior only predicted substance-related rape, not forcible rape. Conclusions Findings suggested that low perceived sexual control stemming from CSA is associated with increased sex-related alcohol expectancies and a higher likelihood of engaging in sexual behavior in the context of alcohol use. In turn these proximal risk factors heighten vulnerability to substance-related rape. Programs which aim to reduce risk for substance-related rape could be improved by addressing expectancies and motivations for risky sexual behavior in the context of substance use. Implications and future directions are discussed. PMID:23312991
A Comparison of Selective Pressures in Plant X-Linked and Autosomal Genes
Krasovec, Marc; Filatov, Dmitry A.
2018-01-01
Selection is expected to work differently in autosomal and X-linked genes because of their ploidy difference and the exposure of recessive X-linked mutations to haploid selection in males. However, it is not clear whether these expectations apply to recently evolved sex chromosomes, where many genes retain functional X- and Y-linked gametologs. We took advantage of the recently evolved sex chromosomes in the plant Silene latifolia and its closely related species to compare the selective pressures between hemizygous and non-hemizygous X-linked genes as well as between X-linked genes and autosomal genes. Our analysis, based on over 1000 genes, demonstrated that, similar to animals, X-linked genes in Silene evolve significantly faster than autosomal genes—the so-called faster-X effect. Contrary to expectations, faster-X divergence was detectable only for non-hemizygous X-linked genes. Our phylogeny-based analyses of selection revealed no evidence for faster adaptation in X-linked genes compared to autosomal genes. On the other hand, partial relaxation of purifying selection was apparent on the X-chromosome compared to the autosomes, consistent with a smaller genetic diversity in S. latifolia X-linked genes (πx = 0.016; πaut = 0.023). Thus, the faster-X divergence in S. latifolia appears to be a consequence of the smaller effective population size rather than of a faster adaptive evolution on the X-chromosome. We argue that this may be a general feature of “young” sex chromosomes, where the majority of X-linked genes are not hemizygous, preventing haploid selection in heterogametic sex. PMID:29751495
A Comparison of Selective Pressures in Plant X-Linked and Autosomal Genes.
Krasovec, Marc; Nevado, Bruno; Filatov, Dmitry A
2018-05-03
Selection is expected to work differently in autosomal and X-linked genes because of their ploidy difference and the exposure of recessive X-linked mutations to haploid selection in males. However, it is not clear whether these expectations apply to recently evolved sex chromosomes, where many genes retain functional X- and Y-linked gametologs. We took advantage of the recently evolved sex chromosomes in the plant Silene latifolia and its closely related species to compare the selective pressures between hemizygous and non-hemizygous X-linked genes as well as between X-linked genes and autosomal genes. Our analysis, based on over 1000 genes, demonstrated that, similar to animals, X-linked genes in Silene evolve significantly faster than autosomal genes—the so-called faster-X effect. Contrary to expectations, faster-X divergence was detectable only for non-hemizygous X-linked genes. Our phylogeny-based analyses of selection revealed no evidence for faster adaptation in X-linked genes compared to autosomal genes. On the other hand, partial relaxation of purifying selection was apparent on the X-chromosome compared to the autosomes, consistent with a smaller genetic diversity in S. latifolia X-linked genes (π x = 0.016; π aut = 0.023). Thus, the faster-X divergence in S. latifolia appears to be a consequence of the smaller effective population size rather than of a faster adaptive evolution on the X-chromosome. We argue that this may be a general feature of “young” sex chromosomes, where the majority of X-linked genes are not hemizygous, preventing haploid selection in heterogametic sex.
Jewkes, Rachel; Morrell, Robert; Sikweyiya, Yandisa; Dunkle, Kristin; Penn-Kekana, Loveday
2012-05-02
Sex motivated by economic exchange is a public health concern as a driver of the Sub-Saharan African HIV epidemic. We describe patterns of engagement in transactional sexual relationships and sex with women in prostitution of South African men, and suggest interpretations that advance our understanding of the phenomenon. Cross-sectional study with a randomly-selected sample of 1645 sexually active men aged 18-49 years who completed interviews in a household study and were asked whether they had had sex with a woman in prostitution, or had had a relationship or sex they took to be motivated by the expectation of material gain (transactional sex). 18% of men had ever had sex with a woman in prostitution, 66% at least one type of transactional sexual relationship, only 30% of men had done neither. Most men had had a transactional relationship/sex with a main partner (58% of all men), 42% with a concurrent partner (or makhwapheni) and 44% with a once off partner, and there was almost no difference in reports of what was provided to women of different partner types. The majority of men distinguished the two types of sexual relationships and even among men who had once-off transactional sex and gave cash (n = 314), few (34%) reported that they had had sex with a 'prostitute'. Transactional sex was more common among men aged 25-34 years, less educated men and low income earners rather than those with none or higher income. Having had sex with a woman in prostitution varied little between social and demographic categories, but was less common among the unwaged or very low earners. The notion of 'transactional sex' developed through research with women does not translate easily to men. Many perceive expectations that they fulfil a provider role, with quid pro quo entitlement to sex. Men distinguished these circumstances of sex from having sex with a woman in prostitution. Whilst there may be similarities, when viewed relationally, these are quite distinct practices. Conflating them is sociologically inappropriate. Efforts to work with men to reduce transactional sex should focus on addressing sexual entitlement and promoting gender inequity.
The neuropsychology of sex offenders: a meta-analysis.
Joyal, Christian C; Beaulieu-Plante, Jolyane; de Chantérac, Antoine
2014-04-01
Typically, neuropsychological studies of sex offenders have grouped together different types of individuals and different types of measures. This is why results have tended to be nonspecific and divergent across studies. Against this background, the authors undertook a review of the literature regarding the neuropsychology of sex offenders, taking into account subgroups based on criminological theories. They also conducted a meta-analysis of the data to demonstrate the cognitive heterogeneity of sex offenders statistically. Their main objective was to test the hypothesis to the effect that the neuropsychological deficits of sex offenders are not broad and generalized compared with specific subgroups of participants based on specific measures. In all, 23 neuropsychological studies reporting data on 1,756 participants were taken into consideration. As expected, a highly significant, broad, and heterogeneous overall effect size was found. Taking subgroups of participants and specific cognitive measures into account significantly improved homogeneity. Sex offenders against children tended to obtain lower scores than did sex offenders against adults on higher order executive functions, whereas sex offenders against adults tended to obtain results similar to those of non-sex offenders, with lower scores in verbal fluency and inhibition. However, it is concluded that neuropsychological data on sex offenders are still too scarce to confirm these trends or to test more precise hypotheses. For greater clinical relevance, future neuropsychological studies should consider specific subgroups of participants and measures to verify the presence of different cognitive profiles.
Twinning in Holstein-Friesian Dairy Cows: Proportion Carried to Term and Calf Sex Ratios
Cockcroft, Peter D.; Sorrell, Emma J.
2015-01-01
The purpose of this study was to investigate the proportion of twins carried to term and the sex ratio of twin calves at birth in Holstein-Friesian dairy cattle kept on commercial farms in Devon and Cornwall, England. Ten farms were used in the study. Fifty four cows with twin pregnancies were identified using trans-rectal ultra-sonographic examination between 30 and 70 days of gestation. The farm records were subsequently used to derive the number of calves born. Farm records of 66 additional sets of twin births with the sex of the calves recorded were also identified. Of the 54 cows diagnosed with twin pregnancies, 16 cows (29.6%) aborted or absorbed both fetuses, 11 cows (20.4%) carried one calf to term and 27 cows (50%) carried both calves to term. In the calf sex analysis of the additional 66 sets of twins: 13♂♂ calves (19.7%), 18 ♀♀ calves (27.3%) and 35 ♂♀ calves (53.0%). There was no statistically significant difference from an expected ratio of 1♂♂:2♂♀:1♀♀ (p = 0.61). This study provides bench marks for the expected abortion/absorption rates following the early ultra-sonographic diagnosis of twin pregnancies in comparable populations and supports earlier observations that the expected sex ratio for twinning approximates to1♂♂:2♂♀:1♀♀. PMID:29061937
Positive Feelings After Casual Sex: The Role of Gender and Traditional Gender-Role Beliefs.
Woerner, Jacqueline; Abbey, Antonia
2017-01-01
The purpose of this study was to identify predictors of positive and negative affect following casual sex. Specifically, the primary goal was to investigate how traditional gender-role beliefs, peer approval of casual sex, perceptions of others, sexual assertiveness, and sexual pleasure influence affective experiences. Second, we aimed to determine the extent to which these associations were comparable for men and women. Although we expected mean differences on many of these constructs (e.g., men perceiving more peer approval), we expected the relationships between these constructs to be comparable for women and men. Participants ages 18 to 35 (N = 585) were recruited from a large university and Amazon Mechanical Turk (MTurk) and described their most recent casual sex experience in a self-report questionnaire. Structural equation modeling (SEM) analyses indicated that gender-role beliefs were significantly associated with less sexual assertiveness and more negative perceptions of others; for women they were also associated with less peer approval of casual sex. For women and men, sexual assertiveness predicted sexual pleasure; and sexual pleasure was associated with affect. To decrease the gender discrepancy in positive affect and sexual pleasure, it is important to develop a comprehensive understanding of the interrelationships among norms, casual sex experiences, and affect.
ERIC Educational Resources Information Center
Ritter, Barbara A.; Yoder, Janice D.
2004-01-01
Role congruity theory predicts that women will be less likely than men to emerge as leaders when expectations for the leader role are incongruent with gender stereotypes. A 2 x 2 x 3 design that crossed the sex of the dominant partner, mixed- and same-sex dyads, and masculine, feminine, and neutral tasks involved 120 dyads of unacquainted college…
Coscia, I; Chopelet, J; Waples, R S; Mann, B Q; Mariani, S
2016-10-01
Large variance in reproductive success is the primary factor that reduces effective population size (Ne) in natural populations. In sequentially hermaphroditic (sex-changing) fish, the sex ratio is typically skewed and biased towards the 'first' sex, while reproductive success increases considerably after sex change. Therefore, sex-changing fish populations are theoretically expected to have lower Ne than gonochorists (separate sexes), assuming all other parameters are essentially equal. In this study, we estimate Ne from genetic data collected from two ecologically similar species living along the eastern coast of South Africa: one gonochoristic, the 'santer' sea bream Cheimerius nufar, and one protogynous (female-first) sex changer, the 'slinger' sea bream Chrysoblephus puniceus. For both species, no evidence of genetic structuring, nor significant variation in genetic diversity, was found in the study area. Estimates of contemporary Ne were significantly lower in the protogynous species, but the same pattern was not apparent over historical timescales. Overall, our results show that sequential hermaphroditism may affect Ne differently over varying time frames, and that demographic signatures inferred from genetic markers with different inheritance modes also need to be interpreted cautiously, in relation to sex-changing life histories.
Outcome Expectancy and Sexual Compulsivity among Men who have Sex with Men Living with HIV
Brown, Monique J.; Serovich, Julianne M.; Kimberly, Judy A.
2016-01-01
Sexual compulsivity is operationalized by engaging in repetitive sexual acts, having multiple sexual partners and/or the excessive use of pornography. Outcome expectancy refers to the beliefs about the consequences of engaging in a given behavior. Research examining the relationship between outcome expectancy and sexual compulsivity is limited. The aim of this study was to assess the association between outcome expectancy and sexual compulsivity among men who have sex with men (MSM) living with HIV. Data were obtained from 338 MSM. Simple and multiple linear regression models were used to assess the association between outcome expectancy and sexual compulsivity. After adjusting for age, race/ethnicity, income, education, and employment status, for every one point increase in outcome expectancies for condom use, HIV disclosure and negotiation of safer sex practices, there was, on average, an approximate one point decrease in sexual compulsivity score. Prevention and intervention programs geared towards reducing sexual compulsivity among MSM should focus on increasing outcome expectancies for condom use, HIV disclosure and negotiation of safer sex practices. PMID:26979416
Alkema, Leontine; Chao, Fengqing; You, Danzhen; Pedersen, Jon; Sawyer, Cheryl C
2014-09-01
Under natural circumstances, the sex ratio of male to female mortality up to the age of 5 years is greater than one but sex discrimination can change sex ratios. The estimation of mortality by sex and identification of countries with outlying levels is challenging because of issues with data availability and quality, and because sex ratios might vary naturally based on differences in mortality levels and associated cause of death distributions. For this systematic analysis, we estimated country-specific mortality sex ratios for infants, children aged 1-4 years, and children under the age of 5 years (under 5s) for all countries from 1990 (or the earliest year of data collection) to 2012 using a Bayesian hierarchical time series model, accounting for various data quality issues and assessing the uncertainty in sex ratios. We simultaneously estimated the global relation between sex ratios and mortality levels and constructed estimates of expected and excess female mortality rates to identify countries with outlying sex ratios. Global sex ratios in 2012 were 1·13 (90% uncertainty interval 1·12-1·15) for infants, 0·95 (0·93-0·97) for children aged 1-5 years, and 1·08 (1·07-1·09) for under 5s, an increase since 1990 of 0·01 (-0·01 to 0·02) for infants, 0·04 (0·02 to 0·06) for children aged 1-4 years, and 0·02 (0·01 to 0·04) for under 5s. Levels and trends varied across regions and countries. Sex ratios were lowest in southern Asia for 1990 and 2012 for all age groups. Highest sex ratios were seen in developed regions and the Caucasus and central Asia region. Decreasing mortality was associated with increasing sex ratios, except at very low infant mortality, where sex ratios decreased with total mortality. For 2012, we identified 15 countries with outlying under-5 sex ratios, of which ten countries had female mortality higher than expected (Afghanistan, Bahrain, Bangladesh, China, Egypt, India, Iran, Jordan, Nepal, and Pakistan). Although excess female mortality has decreased since 1990 for the vast majority of countries with outlying sex ratios, the ratios of estimated to expected female mortality did not change substantially for most countries, and worsened for India. Important differences exist between boys and girls with respect to survival up to the age of 5 years. Survival chances tend to improve more rapidly for girls compared with boys as total mortality decreases, with a reversal of this trend at very low infant mortality. For many countries, sex ratios follow this pattern but important exceptions exist. An explanation needs to be sought for selected countries with outlying sex ratios and action should be undertaken if sex discrimination is present. The National University of Singapore and the United Nations Children's Fund (UNICEF). Copyright © 2014 Alkema et al. Open Access article distributed under the terms of CC BY-NC-SA. Published by .. All rights reserved.
Associations with Unprotected Sexual Behavior Among HIV-Infected Drinkers in Western Kenya.
Papas, Rebecca K; Gakinya, Benson N; Mwaniki, Michael M; Wu, Xiaotian K; Lee, Hana; Martino, Steve; Klein, Debra A; Sidle, John E; Loxley, Michelle P; Keter, Alfred K; Baliddawa, Joyce B; Maisto, Stephen A
2018-05-16
Approximately 71% of HIV-infected individuals live in sub-Saharan Africa. Alcohol use increases unprotected sex, which can lead to HIV transmission. Little research examines risky sex among HIV-infected individuals in East Africa who are not sex workers. The study purpose was to examine associations with unprotected sex in a high-risk sample of 507 HIV-infected sexually active drinkers in western Kenya. They were enrolled in a trial to reduce alcohol use. Past-month baseline alcohol use and sexual behavior were assessed using the Timeline Followback. A zero-inflated negative binomial model examined associations with occurrence and frequency of unprotected sex. Results showed heavy drinking days were significantly associated with unprotected sex occurrence across gender, and with unprotected sex frequency among women. Among women, transactional sex, alcohol-related sexual expectations, condom use self-efficacy, drinking-and-protected-sex days and age were associated with unprotected sex occurrence while alcohol-related sexual expectations, depressive symptoms and condom use self-efficacy were associated with unprotected sex frequency. Among men, alcohol-related sexual expectations, condom use self-efficacy, and age were associated with unprotected sex occurrence, while drinking-and-protected-sex days were associated with unprotected sex occurrence and frequency. Findings suggest robust relationships between heavy drinking and unprotected sex. Further research is needed elucidating the temporal relationships between drinking and unprotected sex in this population.
Mitchell, Timothy S; Maciel, Jessica A; Janzen, Fredric J
2013-12-07
Evolutionary theory predicts that dioecious species should produce a balanced primary sex ratio maintained by frequency-dependent selection. Organisms with environmental sex determination, however, are vulnerable to maladaptive sex ratios, because environmental conditions vary spatio-temporally. For reptiles with temperature-dependent sex determination, nest-site choice is a behavioural maternal effect that could respond to sex-ratio selection, as mothers could adjust offspring sex ratios by choosing nest sites that will have particular thermal properties. This theoretical prediction has generated decades of empirical research, yet convincing evidence that sex-ratio selection is influencing nesting behaviours remains absent. Here, we provide the first experimental evidence from nature that sex-ratio selection, rather than only viability selection, is probably an important component of nest-site choice in a reptile with temperature-dependent sex determination. We compare painted turtle (Chrysemys picta) neonates from maternally selected nest sites with those from randomly selected nest sites, observing no substantive difference in hatching success or survival, but finding a profound difference in offspring sex ratio in the direction expected based on historical records. Additionally, we leverage long-term data to reconstruct our sex ratio results had the experiment been repeated in multiple years. As predicted by theory, our results suggest that sex-ratio selection has shaped nesting behaviour in ways likely to enhance maternal fitness.
Mitchell, Timothy S.; Maciel, Jessica A.; Janzen, Fredric J.
2013-01-01
Evolutionary theory predicts that dioecious species should produce a balanced primary sex ratio maintained by frequency-dependent selection. Organisms with environmental sex determination, however, are vulnerable to maladaptive sex ratios, because environmental conditions vary spatio-temporally. For reptiles with temperature-dependent sex determination, nest-site choice is a behavioural maternal effect that could respond to sex-ratio selection, as mothers could adjust offspring sex ratios by choosing nest sites that will have particular thermal properties. This theoretical prediction has generated decades of empirical research, yet convincing evidence that sex-ratio selection is influencing nesting behaviours remains absent. Here, we provide the first experimental evidence from nature that sex-ratio selection, rather than only viability selection, is probably an important component of nest-site choice in a reptile with temperature-dependent sex determination. We compare painted turtle (Chrysemys picta) neonates from maternally selected nest sites with those from randomly selected nest sites, observing no substantive difference in hatching success or survival, but finding a profound difference in offspring sex ratio in the direction expected based on historical records. Additionally, we leverage long-term data to reconstruct our sex ratio results had the experiment been repeated in multiple years. As predicted by theory, our results suggest that sex-ratio selection has shaped nesting behaviour in ways likely to enhance maternal fitness. PMID:24266033
Trends in life expectancy by education in Norway 1961-2009.
Steingrímsdóttir, Olöf Anna; Næss, Øyvind; Moe, Joakim Oliu; Grøholt, Else-Karin; Thelle, Dag Steinar; Strand, Bjørn Heine; Bævre, Kåre
2012-03-01
Educational attainment and longevity are strongly related. Large population studies covering long periods to provide evidence of trends in educational inequalities regarding life expectancy are scarce though, especially prior to the 1980s. Our objective was to document changes in life expectancy by education in Norway in the period 1961-2009, and to determine whether the patterns differ between sexes. This is a register-based population study of all Norwegian residents over 34 years, with data from the National Central Population Registry and the National Education Database. For each calendar year during 1961-2009, death rates by 1 year age groups were calculated separately for each sex and three educational categories (primary, secondary and tertiary). Annual life tables were used to calculate life expectancy at age 35 (e ( 35 )) and survival probability for the three age-intervals 35-44, 45-64, and 65-90. All education groups increased their e ( 35 ) over time, but inequalities in e ( 35 ) between tertiary and primary educational categories widened 5.3 years for men and 3.2 years for women during the study period. The probability for women with primary education to survive to age 64 did not improve from 1961 to 2009. The gain in life expectancy lagged about 10 years in lower compared to higher education groups which might suggest that improvements in life sustaining factors reach different segments of the population at different times. The widening of the gap seems to have partly tapered off over the last two decades, and the changes in life expectancy should be followed carefully in the future to document the development.
2012-01-01
Background Sex motivated by economic exchange is a public health concern as a driver of the Sub-Saharan African HIV epidemic. We describe patterns of engagement in transactional sexual relationships and sex with women in prostitution of South African men, and suggest interpretations that advance our understanding of the phenomenon. Methods Cross-sectional study with a randomly-selected sample of 1645 sexually active men aged 18–49 years who completed interviews in a household study and were asked whether they had had sex with a woman in prostitution, or had had a relationship or sex they took to be motivated by the expectation of material gain (transactional sex). Results 18% of men had ever had sex with a woman in prostitution, 66% at least one type of transactional sexual relationship, only 30% of men had done neither. Most men had had a transactional relationship/sex with a main partner (58% of all men), 42% with a concurrent partner (or makhwapheni) and 44% with a once off partner, and there was almost no difference in reports of what was provided to women of different partner types. The majority of men distinguished the two types of sexual relationships and even among men who had once-off transactional sex and gave cash (n = 314), few (34%) reported that they had had sex with a ‘prostitute’. Transactional sex was more common among men aged 25–34 years, less educated men and low income earners rather than those with none or higher income. Having had sex with a woman in prostitution varied little between social and demographic categories, but was less common among the unwaged or very low earners. Conclusions The notion of ‘transactional sex’ developed through research with women does not translate easily to men. Many perceive expectations that they fulfil a provider role, with quid pro quo entitlement to sex. Men distinguished these circumstances of sex from having sex with a woman in prostitution. Whilst there may be similarities, when viewed relationally, these are quite distinct practices. Conflating them is sociologically inappropriate. Efforts to work with men to reduce transactional sex should focus on addressing sexual entitlement and promoting gender inequity. PMID:22551102
Fatima, Iram; Humayun, Ayesha; Anwar, Muhammad Imran; Iftikhar, Adil; Aslam, Muhammad; Shafiq, Muhammad
2017-01-01
Objectives Service quality is one of the important gears to appraise services and determine the gray areas that need improvement. In countries with a resource-poor health system, the first step of measuring quality is yet to be taken. This study seeks to inform policy makers in developing contextual service quality models by identifying service quality gaps in tertiary care teaching hospitals using patients’ perspective. Methods A cross-sectional study was performed using multistage cluster sampling, and a modified version of the SERVQUAL (SERV-service, QUAL-quality) instrument was administered to determine patient’s expectations and perceptions. A total of 817 completed questionnaires were obtained from patients and/or their attendants using convenience sampling. Results Data analysis revealed statistically significant negative quality gaps between expectations and perceptions of tangibility, reliability, empathy, assurance, responsiveness, and communication. The difference in mean expectation and perception for responsiveness across the sexes was significant (p < 0.003; p < 0.037, respectively) as well as in perception of communication (p < 0.026). Other dimensions and overall hospital expected and perceived quality were independent of sex. Educational status showed significant difference in expectation and perception in responsiveness (p < 0.005), but the perception of each dimension was significantly different in different educational categories (assurance: p < 0.001; empathy: p < 0.001; reliability: p < 0.001; tangibility: p < 0.001; responsiveness: p < 0.001; communication: p < 0.001; and for overall service quality: p < 0.001). Age and service departments showed no relationship with any of the perceived or expected dimension of service quality of hospitals. Conclusions Tertiary care hospitals failed to meet patients’ expectations in all major areas of service quality, posing a question of how hospitals implement and evaluate their quality assurance policy. PMID:28804582
Ide, Jaime S; Zhornitsky, Simon; Hu, Sien; Zhang, Sheng; Krystal, John H; Li, Chiang-Shan R
2017-01-01
Alcohol expectancy and impulsivity are implicated in alcohol misuse. However, how these two risk factors interact to determine problem drinking and whether men and women differ in these risk processes remain unclear. In 158 social drinkers (86 women) assessed for Alcohol Use Disorder Identification Test (AUDIT), positive alcohol expectancy, and Barratt impulsivity, we examined sex differences in these risk processes. Further, with structural brain imaging, we examined the neural bases underlying the relationship between these risk factors and problem drinking. The results of general linear modeling showed that alcohol expectancy best predicted problem drinking in women, whereas in men as well as in the combined group alcohol expectancy and impulsivity interacted to best predict problem drinking. Alcohol expectancy was associated with decreased gray matter volume (GMV) of the right posterior insula in women and the interaction of alcohol expectancy and impulsivity was associated with decreased GMV of the left thalamus in women and men combined and in men alone, albeit less significantly. These risk factors mediated the correlation between GMV and problem drinking. Conversely, models where GMV resulted from problem drinking were not supported. These new findings reveal distinct psychological factors that dispose men and women to problem drinking. Although mediation analyses did not determine a causal link, GMV reduction in the insula and thalamus may represent neural phenotype of these risk processes rather than the consequence of alcohol consumption in non-dependent social drinkers. The results add to the alcohol imaging literature which has largely focused on dependent individuals and help elucidate alterations in brain structures that may contribute to the transition from social to habitual drinking.
Sex differences in play behavior in juvenile tufted capuchin monkeys (Cebus apella).
Paukner, Annika; Suomi, Stephen J
2008-10-01
According to the motor training hypothesis, play behavior in juvenile primates improves motor skills that are required in later adult life. Sex differences in juvenile play behavior can therefore be expected when adult animals assume distinct sexually dimorphic roles. Tufted capuchin monkeys show sexually dimorphic levels of physical antagonism in both inter- and intra-group encounters. Accordingly, it can be predicted that juvenile capuchins also show sex differences in social play behavior. To test this hypothesis, the play behavior of nine juvenile and two infant capuchins was examined. As predicted, juvenile males showed significantly higher levels of social play (wrestle, chase) than juvenile females, but no differences were found in nonsocial play (arboreal, object). Levels of infant play behavior were comparable to that of juveniles. These results lend support to the motor training hypothesis and highlight the need for more detailed investigations of individual differences in play behavior.
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.
A father effect explains sex-ratio bias.
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).
Jadwin-Cakmak, Laura A.; Pingel, Emily S.; Harper, Gary; Bauermeister, José A.
2014-01-01
Few studies have examined the relationship between young gay and bisexual men and their fathers. Using a phenomenological framework, this study investigated the role of fathers in young gay and bisexual men’s coming out experience, focusing on how fathers responded to disclosure of same-sex attraction, how fathers’ responses compared with sons’ expectations, and what sons perceived as having influenced their fathers’ responses. Semi-structured in-depth interviews with 30 gay and bisexual men ages 18–24 were conducted as part of a larger study; topics explored in the interview included experiences coming out to family and others. Nineteen participants’ narratives included discussion about their fathers and were included in the current analyses. The young gay and bisexual men who were interviewed perceived a complex range of responses upon coming out to their fathers, ranging from enthusiastic acceptance to physical violence. Participants spoke of fathers who were accepting in different manners and who often held contradictory attitudes about same-sex attraction. Fathers’ responses commonly differed from sons’ expectations, which were informed by homophobic talk and gendered expectations. Sons spoke about what informed their expectations as well as what they perceived as influencing their fathers’ response, including gender norms, beliefs regarding the cause of SSA, religious views, sociopolitical views, and concerns about HIV/AIDS. The pervasive influence of hegemonic masculinity throughout the young gay and bisexual men’s stories was particularly striking. The implications of these findings for future research and intervention development are discussed, as well as study strengths and limitations. PMID:24989422
Sex in an Evolutionary Perspective: Just Another Reaction Norm
Nylin, Sören
2010-01-01
It is common to refer to all sorts of clear-cut differences between the sexes as something that is biologically almost inevitable. Although this does not reflect the status of evolutionary theory on sex determination and sexual dimorphism, it is probably a common view among evolutionary biologists as well, because of the impact of sexual selection theory. To get away from thinking about biological sex and traits associated with a particular sex as something static, it should be recognized that in an evolutionary perspective sex can be viewed as a reaction norm, with sex attributes being phenotypically plastic. Sex determination itself is fundamentally plastic, even when it is termed “genetic”. The phenotypic expression of traits that are statistically associated with a particular sex always has a plastic component. This plasticity allows for much more variation in the expression of traits according to sex and more overlap between the sexes than is typically acknowledged. Here we review the variation and frequency of evolutionary changes in sex, sex determination and sex roles and conclude that sex in an evolutionary time-frame is extremely variable. We draw on recent findings in sex determination mechanisms, empirical findings of morphology and behaviour as well as genetic and developmental models to explore the concept of sex as a reaction norm. From this point of view, sexual differences are not expected to generally fall into neat, discrete, pre-determined classes. It is important to acknowledge this variability in order to increase objectivity in evolutionary research. PMID:21170116
The Evolution of Sex Chromosomes and Dosage Compensation in Plants
Shearn, Rylan; Marais, Gabriel AB
2017-01-01
Plant sex chromosomes can be vastly different from those of the few historical animal model organisms from which most of our understanding of sex chromosome evolution is derived. Recently, we have seen several advancements from studies on green algae, brown algae, and land plants that are providing a broader understanding of the variable ways in which sex chromosomes can evolve in distant eukaryotic groups. Plant sex-determining genes are being identified and, as expected, are completely different from those in animals. Species with varying levels of differentiation between the X and Y have been found in plants, and these are hypothesized to be representing different stages of sex chromosome evolution. However, we are also finding that sex chromosomes can remain morphologically unchanged over extended periods of time. Where degeneration of the Y occurs, it appears to proceed similarly in plants and animals. Dosage compensation (a phenomenon that compensates for the consequent loss of expression from the Y) has now been documented in a plant system, its mechanism, however, remains unknown. Research has also begun on the role of sex chromosomes in sexual conflict resolution, and it appears that sex-biased genes evolve similarly in plants and animals, although the functions of these genes remain poorly studied. Because the difficulty in obtaining sex chromosome sequences is increasingly being overcome by methodological developments, there is great potential for further discovery within the field of plant sex chromosome evolution. PMID:28391324
ERIC Educational Resources Information Center
Dijker, Anton J. M.
2008-01-01
In order to examine the relative influence of size-based expectancies and social cues on the perceived weight of objects, two studies were performed, using equally weighing dolls differing in sex-related and age-related vulnerability or physical strength cues. To increase variation in perceived size, stimulus objects were viewed through optical…
A meta-analysis of sex and race differences in perceived workplace mistreatment.
McCord, Mallory A; Joseph, Dana L; Dhanani, Lindsay Y; Beus, Jeremy M
2018-02-01
Despite the growing number of meta-analyses published on the subject of workplace mistreatment and the expectation that women and racial minorities are mistreated more frequently than men and Whites, the degree of subgroup differences in perceived workplace mistreatment is unknown. To address this gap in the literature, we meta-analyzed the magnitude of sex and race differences in perceptions of workplace mistreatment (e.g., harassment, discrimination, bullying, incivility). Results indicate that women perceive more sex-based mistreatment (i.e., mistreatment that explicitly targets a person's sex) in the workplace than men (δ = .46; k = 43), whereas women and men report comparable perceptions of all other forms of mistreatment (δ = .02; k = 300). Similarly, although racial minorities perceive more race-based mistreatment (i.e., mistreatment that explicitly targets a person's race) in the workplace than Whites (δ = .71; k = 18), results indicate smaller race differences in all other forms of workplace mistreatment (δ = .10; k = 61). Results also indicate that sex and race differences have mostly decreased over time, although for some forms of mistreatment, subgroup differences have increased over time. We conclude by offering explanations for the observed subgroup differences in workplace mistreatment and outline directions for future research. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Walsh, Kate; Messman-Moore, Terri; Zerubavel, Noga; Chandley, Rachel B; Denardi, Kathleen A; Walker, Dave P
2013-05-01
Although numerous studies have documented linkages between childhood sexual abuse (CSA) and later sexual revictimization, mechanisms underlying revictimization, particularly assaults occurring in the context of substance use, are not well-understood. Consistent with Traumagenic Dynamics theory, the present study tested a path model positing that lowered perceptions of sexual control resulting from CSA may be associated with increased sex-related alcohol expectancies and heightened likelihood of risky sexual behavior, which in turn, may predict adult substance-related rape. Participants were 546 female college students who completed anonymous surveys regarding CSA and adult rape, perceptions of sexual control, sex-related alcohol expectancies, and likelihood of engaging in risky sexual behavior. The data fit the hypothesized model well and all hypothesized path coefficients were significant and in the expected directions. As expected, sex-related alcohol expectancies and likelihood of risky sexual behavior only predicted substance-related rape, not forcible rape. Findings suggested that low perceived sexual control stemming from CSA is associated with increased sex-related alcohol expectancies and a higher likelihood of engaging in sexual behavior in the context of alcohol use. In turn these proximal risk factors heighten vulnerability to substance-related rape. Programs which aim to reduce risk for substance-related rape could be improved by addressing expectancies and motivations for risky sexual behavior in the context of substance use. Implications and future directions are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.
The effects of temperature on sex determination in the bloater Coregonus hoyi: a hypothesis test
Eck, Gary W.; Allen, Jeffrey D.
1995-01-01
The hypothesis that temperature was an epigamic factor in bloater (Coregonus hoyi) sex determination in Lake Michigan was tested by rearing bloater larvae in the laboratory at 6, 11, and 15 degrees C for the first 80 days after hatching. The percentages of females of fish exposed to the three treatment temperatures did not differ significantly from the expected, 50%. Therefore, the null hypothesis, that temperature did not influence bloater sex determination within the confines of this study, could not be rejected. Our study of bloater sex determination was an attempt to explain the extreme female predominance (> 95%) that occurred in the Lake Michigan bloater population during the 1960s.
Corl, Ammon; Ellegren, Hans
2012-07-01
Genomic levels of variation can help reveal the selective and demographic forces that have affected a species during its history. The relative amount of genetic diversity observed on the sex chromosomes as compared to the autosomes is predicted to differ among monogamous and polygynous species. Many species show departures from the expectation for monogamy, but it can be difficult to conclude that this pattern results from variation in mating system because forces other than sexual selection can act upon sex chromosome genetic diversity. As a critical test of the role of mating system, we compared levels of genetic diversity on the Z chromosome and autosomes of phylogenetically independent pairs of shorebirds that differed in their mating systems. We found general support for sexual selection shaping sex chromosome diversity because most polygynous species showed relatively reduced genetic variation on their Z chromosomes as compared to monogamous species. Differences in levels of genetic diversity between the sex chromosomes and autosomes may therefore contribute to understanding the long-term history of sexual selection experienced by a species. © 2012 The Author(s).
Is sexual concordance related to awareness of physiological states?
Suschinsky, Kelly D; Lalumière, Martin L
2012-02-01
Sexual concordance refers to the degree to which two aspects of human sexual arousal (genital response and self-reported sexual arousal) correspond with each other. Researchers have consistently reported a sex difference in sexual concordance: The relationship between genital responses and reported feelings of sexual arousal in men is positive and large, whereas the relationship in women is positive but much smaller than that seen in men. The study of interoception--people's awareness of their physiological states--reveals a similar sex difference: Men are more aware of a variety of (non-genital) responses (e.g., heart rate) than women in the laboratory. The purpose of the current study was to investigate whether the sex difference in sexual concordance was related to a broader sex difference in interoception. Twenty men and 20 women were presented with twelve 90 s sexual and non-sexual film clips while their genital responses, heart rate, and respiration rate were measured. Participants also estimated their physiological responses. As expected, men were significantly more sexually concordant than women. Men were also significantly more aware of their heart rate, but there was no significant sex difference in respiration rate awareness. Sexual concordance was not significantly correlated with either heart rate or respiration rate awareness. The results suggest that the sex difference in sexual concordance may be a unique phenomenon, separate from general awareness of physiological states.
Danish A.I. field data with sexed semen.
Borchersen, S; Peacock, M
2009-01-01
The objective of this study was to compare conception rates, non-return rates and sex ratios of sexed and conventional semen from the same sires in commercial dairy herds in Denmark. The semen was produced from three bulls from each of the three major dairy breeds in Denmark: Holstein, Jersey and Danish Red Dairy Breed (nine bulls total), in order to answer questions on breeds differences in field results. AI was performed by trained technicians using a minimum of 150 doses of sorted sperm and 50 control doses from each bull. During the trial, a total of 2087 doses were used in 63 herds. The trial showed that the conception rate using sorted semen was 5% points lower than with conventional doses for Danish Reds, 7% points for Jerseys, and 12% points for Holsteins. Translating this into non-return rate revealed differences of 10-20% points among bulls. These differences are thought to be a good indicator of what to expect from commercial use of sexed semen. The sex ratios varied from 89% to 93% female calves among breeds, which on average is consistent with the theoretical average sex ratio of 93% females considering the low number of inseminations.
Monophasic demyelination reduces brain growth in children
Weier, Katrin; Longoni, Giulia; Fonov, Vladimir S.; Bar-Or, Amit; Marrie, Ruth Ann; Yeh, E. Ann; Narayanan, Sridar; Arnold, Douglas L.; Verhey, Leonard H.; Banwell, Brenda; Collins, D. Louis
2017-01-01
Objective: To investigate how monophasic acquired demyelinating syndromes (ADS) affect age-expected brain growth over time. Methods: We analyzed 83 pediatric patients imaged serially from initial demyelinating attack: 18 with acute disseminated encephalomyelitis (ADEM) and 65 with other monophasic ADS presentations (monoADS). We further subdivided the monoADS group by the presence (n = 33; monoADSlesion) or absence (n = 32; monoADSnolesion) of T2 lesions involving the brain at onset. We used normative data to compare brain volumes and calculate age- and sex-specific z scores, and used mixed-effect models to investigate their relationship with time from demyelinating illness. Results: Children with monophasic demyelination (ADEM, non-ADEM with brain lesions, and those without brain involvement) demonstrated reduced age-expected brain growth on serial images, driven by reduced age-expected white matter growth. Cortical gray matter volumes were not reduced at onset but demonstrated reduced age-expected growth afterwards in all groups. Brain volumes differed from age- and sex-expected values to the greatest extent in children with ADEM. All patient groups failed to recover age-expected brain growth trajectories. Conclusions: Brain volume, and more importantly age-expected brain growth, is negatively affected by acquired demyelination, even in the absence of chronicity, implicating factors other than active inflammation as operative in this process. PMID:28381515
Monophasic demyelination reduces brain growth in children.
Aubert-Broche, Bérengère; Weier, Katrin; Longoni, Giulia; Fonov, Vladimir S; Bar-Or, Amit; Marrie, Ruth Ann; Yeh, E Ann; Narayanan, Sridar; Arnold, Douglas L; Verhey, Leonard H; Banwell, Brenda; Collins, D Louis
2017-05-02
To investigate how monophasic acquired demyelinating syndromes (ADS) affect age-expected brain growth over time. We analyzed 83 pediatric patients imaged serially from initial demyelinating attack: 18 with acute disseminated encephalomyelitis (ADEM) and 65 with other monophasic ADS presentations (monoADS). We further subdivided the monoADS group by the presence (n = 33; monoADSlesion) or absence (n = 32; monoADSnolesion) of T2 lesions involving the brain at onset. We used normative data to compare brain volumes and calculate age- and sex-specific z scores, and used mixed-effect models to investigate their relationship with time from demyelinating illness. Children with monophasic demyelination (ADEM, non-ADEM with brain lesions, and those without brain involvement) demonstrated reduced age-expected brain growth on serial images, driven by reduced age-expected white matter growth. Cortical gray matter volumes were not reduced at onset but demonstrated reduced age-expected growth afterwards in all groups. Brain volumes differed from age- and sex-expected values to the greatest extent in children with ADEM. All patient groups failed to recover age-expected brain growth trajectories. Brain volume, and more importantly age-expected brain growth, is negatively affected by acquired demyelination, even in the absence of chronicity, implicating factors other than active inflammation as operative in this process. © 2017 American Academy of Neurology.
Solianik, Rima; Skurvydas, Albertas; Mickevičienė, Dalia; Brazaitis, Marius
2014-10-01
The main aim of this study was to compare the thermal responses and the responses of cognitive and motor functions to intermittent cold stress between males and females. The intermittent cold stress continued until rectal temperature (TRE) reached 35.5°C or for a maximum of 170 min. Thermal response and motor and cognitive performance were monitored. During intermittent cold stress, body temperature variables decreased in all subjects (P < 0.001) and did not differ between sexes. The presence of fast and slow cooling types for participants with similar effect on physiological variables were observed; thus the different rate coolers were grouped together and were attributed only sex specific responses. Overall, TRE cooling rate and cold strain index did not differ between sexes. Maximal voluntary contraction (MVC) decreased after intermittent cold exposure only in males (P < 0.001), whereas changes in muscle electromyography (EMG) activity did not differ between sexes. The effects of intermittent cold stress on electrically evoked muscle properties, spinal (H-reflex), and supraspinal (V-waves) reflexes did not differ between sexes. Intermittent cold-induced cognitive perturbation of attention and memory task performance was greater in males (P < 0.05). Contrary to our expectations, the results of the present study indicated that males and females experience similar thermal stress induced by intermittent whole-body cold immersion. Although no sex-specific differences were observed in muscle EMG activity, involuntary muscle properties, spinal and supraspinal reflexes, some of the sex differences observed (e.g., lower isometric MVC and greater cognitive perturbation in males) support the view of sex-specific physiological responses to core temperature decrease. Copyright © 2014 Elsevier Inc. All rights reserved.
Self-reported sex differences in high-functioning adults with autism: a meta-analysis.
Moseley, R L; Hitchiner, R; Kirkby, J A
2018-01-01
Sex differences in autistic symptomatology are believed to contribute to the mis- and missed diagnosis of many girls and women with an autism spectrum condition (ASC). Whilst recent years have seen the emergence of clinical and empirical reports delineating the profile of young autistic girls, recognition of sex differences in symptomatology in adulthood is far more limited. We chose here to focus on symptomatology as reported using a screening instrument, the Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R). In a meta-analysis, we pooled and analysed RAADS-R data from a number of experimental groups. Analysis of variance (ANOVA) searched for the presence of main effects of Sex and Diagnosis and for interactions between these factors in our sample of autistic and non-autistic adults. In social relatedness and circumscribed interests, main effects of Diagnosis revealed that as expected, autistic adults reported significantly greater lifetime prevalence of symptoms in these domains; an effect of Sex, in circumscribed interests, also suggested that males generally reported more prevalent symptoms than females. An interaction of Sex and Diagnosis in language symptomatology revealed that a normative sex difference in language difficulties was attenuated in autism. An interaction of Sex and Diagnosis in the sensorimotor domain revealed the opposite picture: a lack of sex differences between typically developing men and women and a greater prevalence of sensorimotor symptoms in autistic women than autistic men. We discuss the literature on childhood sex differences in relation to those which emerged in our adult sample. Where childhood sex differences fail to persist in adulthood, several interpretations exist, and we discuss, for example, an inherent sampling bias that may mean that only autistic women most similar to the male presentation are diagnosed. The finding that sensorimotor symptomatology is more highly reported by autistic women is a finding requiring objective confirmation, given its potential importance in diagnosis.
Converging Evidence of Ubiquitous Male Bias in Human Sex Perception
Gaetano, Justin; van der Zwan, Rick; Oxner, Matthew; Hayward, William G.; Doring, Natalie; Blair, Duncan; Brooks, Anna
2016-01-01
Visually judging the sex of another can be achieved easily in most social encounters. When the signals that inform such judgements are weak (e.g. outdoors at night), observers tend to expect the presence of males–an expectation that may facilitate survival-critical decisions under uncertainty. The present aim was to examine whether this male bias depends on expertise. To that end, Caucasian and Asian observers targeted female and male hand images that were either the same or different to the observers’ race (i.e. long term experience was varied) while concurrently, the proportion of targets changed across presentation blocks (i.e. short term experience change). It was thus found that: (i) observers of own-race stimuli were more likely to report the presence of males and absence of females, however (ii) observers of other-race stimuli–while still tending to accept stimuli as male–were not prone to rejecting female cues. Finally, (iii) male-biased measures did not track the relative frequency of targets or lures, disputing the notion that male bias derives from prior expectation about the number of male exemplars in a set. Findings are discussed in concert with the pan-stimulus model of human sex perception. PMID:26859570
Balodis, Iris M; Potenza, Marc N; Olmstead, Mary C
2009-09-01
Binge drinking on university campuses is associated with social and health-related problems. To determine the factors that may predict this behavior, we collected information on alcohol use, alcohol expectations, and impulsivity from 428 undergraduate students attending a Canadian university. The subjective effects of a binge drinking dose of alcohol were assessed in a subset of participants. In the larger sample, 72% of students reported drinking at or above binge drinking thresholds on a regular basis. Men reported alcohol consumption per drinking occasion, which was consistent with other studies, but the frequency of drinking occasions among women was higher than in earlier studies, suggesting that consumption in women may be increasing. Compared with men, women reported different expectations of alcohol, specifically related to sociability and sexuality. Self-reported impulsivity scores were related, albeit weakly, to drinking behaviors and to expectations in both the sexes. Finally, intoxicated binge drinkers reported feeling less intoxicated, liking the effects more, and wanting more alcohol than did non-binge drinkers receiving an equivalent dose of alcohol. These results have implications for sex-specific prevention strategies for binge drinking on university campuses.
Schmid Mast, Marianne; Hall, Judith A; Roter, Debra L
2007-09-01
The present study aimed to investigate the effect of physician sex and physician communication style on patient satisfaction. In real medical visits, physician sex and physician communication style are confounded variables. By using the virtual medical visit paradigm, we were able to disentangle the two variables and study their separate and/or joint effects on patient satisfaction. In an experimental design, analogue patients (167 students) interacted with a computer-generated virtual physician on a computer screen. The patients' satisfaction during the visit was assessed. Depending on the sex composition of the dyad, physician communication style affected analogue patients' satisfaction differently. For instance, in male-male dyads, physician communication style did not affect the patients' satisfaction, whereas in female-female dyads, analogue patients were more satisfied when the physician adopted a caring as opposed to a non-caring communication style. Sex of the physician and sex of the patient moderate how different physician communication styles affect patient satisfaction. In particular, a female-sex role congruent communication style leads to higher patient satisfaction when women see a female physician. Physician communication training cannot be one size fits all. Rather female and male physicians should obtain different training and they need to be made aware of the fact that female and male patients harbor different expectations toward them.
Baert, Jan M; Stienen, Eric W M; Heylen, Brigitte C; Kavelaars, Marwa M; Buijs, Roland-Jan; Shamoun-Baranes, Judy; Lens, Luc; Müller, Wendt
2018-03-29
Sex-, size- or age-dependent variation in migration strategies in birds is generally expected to reflect differences in competitive abilities. Theoretical and empirical studies thereby focus on differences in wintering areas, by which individuals may benefit from avoiding food competition during winter or ensuring an early return and access to prime nesting sites in spring. Here, we use GPS tracking to assess sex- and size-related variation in the spatial behaviour of adult Lesser Black-backed Gulls (Larus fuscus) throughout their annual cycle. We did not find sex- or size-dependent differences in wintering area or the timing of spring migration. Instead, sexual differences occurred prior to, and during, autumn migration, when females strongly focussed on agricultural areas. Females exhibited a more protracted autumn migration strategy, hence spent more time on stopover sites and arrived 15 days later at their wintering areas, than males. This shift in habitat use and protracted autumn migration coincided with the timing of moult, which overlaps with chick rearing and migration. Our results suggest that this overlap between energy-demanding activities may lead females to perform a more prolonged autumn migration, which results in spatiotemporal differences in foraging habitat use between the sexes.
DNA transposon dynamics in populations of Daphnia pulex with and without sex.
Schaack, Sarah; Pritham, Ellen J; Wolf, Abby; Lynch, Michael
2010-08-07
We investigate the role of recombination in transposable element (TE) proliferation in the cyclical parthenogen, Daphnia pulex. Recombination provides a mechanism by which the rate of both TE gain and loss can be accelerated, a duality that has long intrigued many biologists interested in the influence of sex on mutation accumulation. We compared TE loads among populations of D. pulex where sex occurs regularly (cyclical parthenogens or 'sexuals') with those in which the ability to reproduce sexually has been completely lost (obligate 'asexuals') for six different families of DNA transposons. Transposon display assays showed that sexuals have more TEs than asexuals, contrary to the expectations under Muller's ratchet but consistent with the idea that sex facilitates TE spread. Sexuals also exhibit higher insertion site polymorphism among lineages, as predicted because recombination accelerates rates of loss and gain. Asexuals, however, have proportionally more singletons (loci occupied in a single isolate), which differs from previous studies where selfing and outcrossing were used as a proxy for high and low recombination. Our multi-element survey reveals that the impact of sex on TE proliferation is consistent among different Class II TE families and we discuss the genomic consequences of different reproductive strategies over long time periods.
Autonomy-connectedness mediates sex differences in symptoms of psychopathology
Bekker, Marrie H. J.; van Assen, Marcel A. L. M.
2017-01-01
Objectives This study aimed to examine if autonomy-connectedness, capacity for self-governance under the condition of connectedness, would mediate sex differences in symptoms of various mental disorders (depression, anxiety, eating disorders, antisocial personality disorder). Method Participants (N = 5,525) from a representative community sample in the Netherlands filled out questionnaires regarding the variables under study. Results Autonomy-connectedness (self-awareness, SA; sensitivity to others, SO; capacity for managing new situations, CMNS) fully mediated the sex differences in depression and anxiety, and partly in eating disorder -(drive for thinness, bulimia, and body dissatisfaction) and anti-social personality disorder characteristics. The mediations followed the expected sex-specific patterns. SO related positively to the internalizing disorder indices, and negatively to the anti-social personality disorder. SA related negatively to all disorder indices; and CMNS to all internalizing disorder indices, but positively to the anti-social personality disorder. Conclusion Treatment of depression, anxiety, but also eating disorders and the antisocial personality disorder may benefit from a stronger focus on autonomy strengthening. PMID:28771498
Autonomy-connectedness mediates sex differences in symptoms of psychopathology.
Bekker, Marrie H J; van Assen, Marcel A L M
2017-01-01
This study aimed to examine if autonomy-connectedness, capacity for self-governance under the condition of connectedness, would mediate sex differences in symptoms of various mental disorders (depression, anxiety, eating disorders, antisocial personality disorder). Participants (N = 5,525) from a representative community sample in the Netherlands filled out questionnaires regarding the variables under study. Autonomy-connectedness (self-awareness, SA; sensitivity to others, SO; capacity for managing new situations, CMNS) fully mediated the sex differences in depression and anxiety, and partly in eating disorder -(drive for thinness, bulimia, and body dissatisfaction) and anti-social personality disorder characteristics. The mediations followed the expected sex-specific patterns. SO related positively to the internalizing disorder indices, and negatively to the anti-social personality disorder. SA related negatively to all disorder indices; and CMNS to all internalizing disorder indices, but positively to the anti-social personality disorder. Treatment of depression, anxiety, but also eating disorders and the antisocial personality disorder may benefit from a stronger focus on autonomy strengthening.
Multiple chronic conditions and life expectancy: a life table analysis.
DuGoff, Eva H; Canudas-Romo, Vladimir; Buttorff, Christine; Leff, Bruce; Anderson, Gerard F
2014-08-01
The number of people living with multiple chronic conditions is increasing, but we know little about the impact of multimorbidity on life expectancy. We analyze life expectancy in Medicare beneficiaries by number of chronic conditions. A retrospective cohort study using single-decrement period life tables. Medicare fee-for-service beneficiaries (N=1,372,272) aged 67 and older as of January 1, 2008. Our primary outcome measure is life expectancy. We categorize study subjects by sex, race, selected chronic conditions (heart disease, cancer, chronic obstructive pulmonary disease, stroke, and Alzheimer disease), and number of comorbid conditions. Comorbidity was measured as a count of conditions collected by Chronic Conditions Warehouse and the Charlson Comorbidity Index. Life expectancy decreases with each additional chronic condition. A 67-year-old individual with no chronic conditions will live on average 22.6 additional years. A 67-year-old individual with 5 chronic conditions and ≥10 chronic conditions will live 7.7 fewer years and 17.6 fewer years, respectively. The average marginal decline in life expectancy is 1.8 years with each additional chronic condition-ranging from 0.4 fewer years with the first condition to 2.6 fewer years with the sixth condition. These results are consistent by sex and race. We observe differences in life expectancy by selected conditions at 67, but these differences diminish with age and increasing numbers of comorbid conditions. Social Security and Medicare actuaries should account for the growing number of beneficiaries with multiple chronic conditions when determining population projections and trust fund solvency.
The Relationship between Sexual Selection and Sexual Conflict
Kokko, Hanna; Jennions, Michael D.
2014-01-01
Evolutionary conflicts of interest arise whenever genetically different individuals interact and their routes to fitness maximization differ. Sexual selection favors traits that increase an individual’s competitiveness to acquire mates and fertilizations. Sexual conflict occurs if an individual of sex A’s relative fitness would increase if it had a “tool” that could alter what an individual of sex B does (including the parental genes transferred), at a cost to B’s fitness. This definition clarifies several issues: Conflict is very common and, although it extends outside traits under sexual selection, sexual selection is a ready source of sexual conflict. Sexual conflict and sexual selection should not be presented as alternative explanations for trait evolution. Conflict is closely linked to the concept of a lag load, which is context-dependent and sex-specific. This makes it possible to ask if one sex can “win.” We expect higher population fitness if females win. PMID:25038050
Gender differences in disability: a comparison of married patients with schizophrenia.
Shankar, R; Kamath, S; Joseph, A A
1995-07-01
Gender differences in disability constitute a fertile area of research, as disabilities need to be measured and evaluated in the social context which defines role expectations and consequently the role performance. This paper reports on the differences in disability in married patients with schizophrenia, as marital status is an important determinant of role expectation. The study sample constituted 30 married patients, of both sexes, who satisfied DSM-III criteria for schizophrenia, and were living with their spouse at the time of assessment. Disability was evaluated using the DAS (modified version). The findings indicated that women were more disabled than men on many of the evaluation parameters (p < 0.05); there was also a strong correlation between negative symptoms and disability variables in both the sexes. While a correlation between PSE syndromes and disability variables was seen in the case of males, the relationship was not seen in females. Stepwise regression also revealed that negative symptoms predominated among the factors associated with global disability in both sexes. Most of the reports in the literature reveal that women are less disabled than men. The findings of this study, that women are more disabled than men, is discussed in the context of the social conditions prevailing in India.
Differences in sexual guilt and desire in east Asian and Euro-Canadian men.
Brotto, Lori A; Woo, Jane S T; Gorzalka, Boris B
2012-01-01
Differences in sexual desire between individuals of East Asian and European descent are well-documented, with East Asian individuals reporting lower sexual desire. The mechanisms that underlie this disparity have received little empirical attention. Recent research has found that sex guilt, "a generalized expectancy for self-mediated punishment for violating or for anticipating violating standards of proper sexual conduct" (Mosher & Cross, 1971 , p. 27), mediates the relationship between culture and sexual desire in East Asian and Euro-Canadian women. The goal of this study was to explore this role of sex guilt in men. Male Euro-Canadian (n = 38) and East Asian (n = 45) university students completed online questionnaires. The East Asian men reported significantly lower sexual desire and significantly higher sex guilt. Sex guilt was a significant mediator of the relationship between ethnicity and sexual desire, as well as a significant mediator between mainstream acculturation and sexual desire. Among the East Asian men, mainstream acculturation was significantly and negatively correlated with sex guilt such that increasing mainstream acculturation was associated with less sex guilt. The diagnostic and clinical implications of the findings are discussed.
Fluidity models in ancient Greece and current practices of sex assignment
Chen, Min-Jye; McCann-Crosby, Bonnie; Gunn, Sheila; Georgiadis, Paraskevi; Placencia, Frank; Mann, David; Axelrad, Marni; Karaviti, L.P; McCullough, Laurence B.
2018-01-01
Disorders of sexual differentiation such as androgen insensitivity and gonadal dysgenesis can involve an intrinsic fluidity at different levels, from the anatomical and biological to the social (gender) that must be considered in the context of social constraints. Sex assignment models based on George Engel’s biopsychosocial aspects model of biology accept fluidity of gender as a central concept and therefore help establish expectations within the uncertainty of sex assignment and anticipate potential changes. The biology underlying the fluidity inherent to these disorders should be presented to parents at diagnosis, an approach that the gender medicine field should embrace as good practice. Greek mythology provides many accepted archetypes of change, and the ancient Greek appreciation of metamorphosis can be used as context with these patients. Our goal is to inform expertise and optimal approaches, knowing that this fluidity may eventually necessitate sex reassignment. Physicians should provide sex assignment education based on different components of sexual differentiation, prepare parents for future hormone-triggered changes in their children, and establish a sex-assignment algorithm. PMID:28478088
Fluidity models in ancient Greece and current practices of sex assignment.
Chen, Min-Jye; McCann-Crosby, Bonnie; Gunn, Sheila; Georgiadis, Paraskevi; Placencia, Frank; Mann, David; Axelrad, Marni; Karaviti, L P; McCullough, Laurence B
2017-06-01
Disorders of sexual differentiation such as androgen insensitivity and gonadal dysgenesis can involve an intrinsic fluidity at different levels, from the anatomical and biological to the social (gender) that must be considered in the context of social constraints. Sex assignment models based on George Engel's biopsychosocial aspects model of biology accept fluidity of gender as a central concept and therefore help establish expectations within the uncertainty of sex assignment and anticipate potential changes. The biology underlying the fluidity inherent to these disorders should be presented to parents at diagnosis, an approach that the gender medicine field should embrace as good practice. Greek mythology provides many accepted archetypes of change, and the ancient Greek appreciation of metamorphosis can be used as context with these patients. Our goal is to inform expertise and optimal approaches, knowing that this fluidity may eventually necessitate sex reassignment. Physicians should provide sex assignment education based on different components of sexual differentiation, prepare parents for future hormone-triggered changes in their children, and establish a sex-assignment algorithm. Copyright © 2017 Elsevier Inc. All rights reserved.
An fMRI study of sex differences in regional activation to a verbal and a spatial task.
Gur, R C; Alsop, D; Glahn, D; Petty, R; Swanson, C L; Maldjian, J A; Turetsky, B I; Detre, J A; Gee, J; Gur, R E
2000-09-01
Sex differences in cognitive performance have been documented, women performing better on some phonological tasks and men on spatial tasks. An earlier fMRI study suggested sex differences in distributed brain activation during phonological processing, with bilateral activation seen in women while men showed primarily left-lateralized activation. This blood oxygen level-dependent fMRI study examined sex differences (14 men, 13 women) in activation for a spatial task (judgment of line orientation) compared to a verbal-reasoning task (analogies) that does not typically show sex differences. Task difficulty was manipulated. Hypothesized ROI-based analysis documented the expected left-lateralized changes for the verbal task in the inferior parietal and planum temporal regions in both men and women, but only men showed right-lateralized increase for the spatial task in these regions. Image-based analysis revealed a distributed network of cortical regions activated by the tasks, which consisted of the lateral frontal, medial frontal, mid-temporal, occipitoparietal, and occipital regions. The activation was more left lateralized for the verbal and more right for the spatial tasks, but men also showed some left activation for the spatial task, which was not seen in women. Increased task difficulty produced more distributed activation for the verbal and more circumscribed activation for the spatial task. The results suggest that failure to activate the appropriate hemisphere in regions directly involved in task performance may explain certain sex differences in performance. They also extend, for a spatial task, the principle that bilateral activation in a distributed cognitive system underlies sex differences in performance. Copyright 2000 Academic Press.
Differential competitive ability between sexes in the dioecious Antennaria dioica (Asteraceae)
Varga, Sandra; Kytöviita, Minna-Maarit
2012-01-01
Background and Aims Differences in competitive ability between the sexes of dioecious plants are expected as a result of allocation trade-offs associated with sex-differential reproductive costs. However, the available data on competitive ability in dioecious plants are scarce and contradictory. In this study sexual competition was evaluated using the dioecious plant Antennaria dioica in a common garden transplantation experiment. Methods Male and female plants were grown for 3 years either in isolation, or in competition with a plant of the same sex or the opposite sex. Flowering phenology, sexual and asexual reproduction, plant growth, nutrient content and arbuscular mycorrhizal colonization in the roots were assessed. Key Results Our results showed little evidence of sexual differences in competitive ability. Both sexes suffered similarly from competition, and competitive effects were manifested in some traits related to fitness but not in others. Survival was unaffected by competition, but competing plants reduced their vegetative growth and reproductive investment compared with non-competing plants. In addition, differences in sexual competitive ability were observed in relation to flowering frequency, an important life history trait not reported in previous studies. Conclusions The findings indicate that female and male A. dioica plants possess similar intersexual competitive abilities which may be related to the similar costs of reproduction between sexes in this species. Nevertheless, intrasexual competition is higher in females, giving support for asymmetric niche segregation between the sexes. PMID:22887023
Understanding STI Risk and Condom Use Patterns by Partner Type Among Female Sex Workers in Peru.
Kinsler, Janni J; Blas, Magaly M; Cabral, Alejandra; Carcamo, Cesar; Halsey, Neal; Brown, Brandon
2014-01-01
While brothel-based sex work is regulated by the Peruvian government, there is little data on STI risk factors reported by female sex workers (FSW). This study compared high risk behaviors among 120 Peruvian FSW from government regulated brothels with both clients and non-commercial partners. Our study found that 12% of FSW reported unprotected vaginal sex with clients (compared to 75% with non-commercial partners), and 42% reported unprotected anal sex with clients (compared to 87% with non-commercial partners). Group differences were observed in the expectation to have oral sex (32% for partners vs 60% for clients; p<0.01), and a history of anal sex (65% for partners vs 32% for clients; p<0.01) and both vaginal and anal sex with the same partners (46% for partners vs 25% for clients; p<0.001). These findings suggest that FSW constitute an important bridge population for STI/HIV transmission in Peru.
Live birth sex ratios and father's geographic origins in Jerusalem, 1964-1976.
Groeger, J; Opler, M; Kleinhaus, K; Perrin, M C; Calderon-Margalit, R; Manor, O; Paltiel, O; Conley, D; Harlap, S; Malaspina, D
2017-05-06
To examine whether ancestry influenced sex ratios of offspring in a birth cohort before parental antenatal sex selection influenced offspring sex. We measured the sex ratio as the percent of males according to countries of birth of paternal and maternal grandfathers in 91,459 live births from 1964 to 1976 in the Jerusalem Perinatal Study. Confidence limits (CI) were computed based on an expected sex ratio of 1.05, which is 51.4% male. Of all live births recorded, 51.4% were male. Relative to Jewish ancestry (51.4% males), significantly more males (1,761) were born to Muslim ancestry (54.5, 95% CI = 52.1-56.8, P = 0.01). Among the former, sex ratios were not significantly associated with paternal or maternal age, education, or offspring's birth order. Consistent with a preference for male offspring, the sex ratio decreased despite increasing numbers of births over the 13-year period. Sex ratios were not affected by maternal or paternal origins in North Africa or Europe. However, the offspring whose paternal grandfathers were born in Western Asia included fewer males than expected (50.7, 50.1-51.3, P = 0.02), whether the father was born abroad (50.7) or in Israel (50.8). This was observed for descendents of paternal grandfathers born in Lebanon (47.6), Turkey (49.9), Yemen & Aden (50.2), Iraq (50.5), Afghanistan (50.5), Syria (50.6), and Cyprus (50.7); but not for those from India (51.5) or Iran (51.9). The West Asian group showed the strongest decline in sex ratios with increasing paternal family size. A decreased sex ratio associated with ancestry in Western Asia is consistent with reduced ability to bear sons by a subset of Jewish men in the Jerusalem cohort. Lower sex ratios may be because of pregnancy stress, which may be higher in this subgroup. Alternatively, a degrading Y chromosome haplogroup or other genetic or epigenetic differences on male germ lines could affect birth ratios, such as differential exposure to an environmental agent, dietary differences, or stress. Differential stopping behaviors that favor additional pregnancies following the birth of a daughter might exacerbate these lower sex ratios. © 2016 Wiley Periodicals, Inc.
Live birth sex ratios and father’s geographic origins in Jerusalem, 1964–1976
Groeger, J; Opler, M; Kleinhaus, K; Perrin, MC; Calderon-Margalit, R; Manor, O; Paltiel, O; Conley, D; Harlap, S; Malaspina, D
2016-01-01
Objective To examine whether ancestry influenced sex ratios of offspring in a birth cohort before parental antenatal sex selection influenced offspring sex. Methods We measured the sex ratio as the percent of males according to countries of birth of paternal and maternal grandfathers in 91,459 live births from 1964 to 1976 in the Jerusalem Perinatal Study. Confidence limits (CI) were computed based on an expected sex ratio of 1.05, which is 51.4% male. Results Of all live births recorded, 51.4% were male. Relative to Jewish ancestry (51.4% males), significantly more males (1,761) were born to Muslim ancestry (54.5, 95% CI=52.1–56.8, p=.01). Among the former, sex ratios were not significantly associated with paternal or maternal age, education, or offspring’s birth order. Consistent with a preference for male offspring, the sex ratio decreased despite increasing numbers of births over the 13-year period. Sex ratios were not affected by maternal or paternal origins in North Africa or Europe. However, the offspring whose paternal grandfathers were born in Western Asia included fewer males than expected (50.7, 50.1–51.3, p=.02), whether the father was born abroad (50.7) or in Israel (50.8). This was observed for descendents of paternal grandfathers born in Lebanon (47.6), Turkey (49.9), Yemen & Aden (50.2), Iraq (50.5), Afghanistan (50.5), Syria (50.6), and Cyprus (50.7); but not for those from India (51.5) or Iran (51.9). The West Asian group showed the strongest decline in sex ratios with increasing paternal family size. Conclusions A decreased sex ratio associated with ancestry in Western Asia is consistent with reduced ability to bear sons by a subset of Jewish men in the Jerusalem cohort. Lower sex ratios may be due to pregnancy stress, which may be higher in this subgroup. Alternatively, a degrading Y chromosome haplogroup or other genetic or epigenetic differences on male germ lines could affect birth ratios, such as differential exposure to an environmental agent, dietary differences, or stress. Differential stopping behaviors that favor additional pregnancies following the birth of a daughter might exacerbate these lower sex ratios. PMID:27901293
Birth order and ratio of brothers to sisters in Spanish transsexuals.
Gómez-Gil, Esther; Esteva, Isabel; Carrasco, Rocío; Almaraz, M Cruz; Pasaro, Eduardo; Salamero, Manel; Guillamon, Antonio
2011-06-01
Three Western studies have shown that male-to-female (MF) homosexual transsexuals tend to be born later than their siblings and to come from sibships with more brothers than sisters. The objective of this study was to determine whether these variables would be replicated in 530 MF and female-to-male (FM) Spanish transsexuals according to sexual orientation. The results showed that MF homosexual transsexuals had significantly more older brothers than the non-homosexual MF group. Compared with the expected rates in the general population, birth order was significantly higher in both MF (Slater's Index = 0.59; Fraternal Index = 0.61; Sororal Index = 0.58) and FM homosexual transsexuals (Slater's Index = 0.65; Fraternal Index = 0.68; Sororal Index = 0.67), and sibling sex ratio was significantly higher than expected in homosexual MF (sex ratio = 0.55) but not in homosexual FM transsexuals. No significant differences were found in the non-homosexual subgroups. The replication of the later birth order and sibling sex-ratio effect in MF homosexual transsexuals corroborates previous findings in a variety of groups from different cultures and may suggest a common mechanism underlying the etiology of transsexualism.
Expression of anger as a function of assertiveness and sex.
Doyle, M A; Biaggio, M K
1981-01-01
Examined differences between asserters and nonasserters and between the sexes on anger expression. Thirty-seven male and 53 female college students were administered the College Self-Expression Scale, the Buss Durkee Hostility Inventory, and the Anger Self-Report. As hypothesized, asserters and males expressed more anger and aggression, and nonasserters experienced more covert anger. The clinical/treatment implications of these findings were discussed. A finding discrepant with previous research and the present researchers' expectations, that men scored higher than women on guilt and condemnation of anger, was thought to reflect this study's sample rather than an actual population difference.
Clinical epidemiology of Alzheimer's disease: assessing sex and gender differences.
Mielke, Michelle M; Vemuri, Prashanthi; Rocca, Walter A
2014-01-01
With the aging of the population, the burden of Alzheimer's disease (AD) is rapidly expanding. More than 5 million people in the US alone are affected with AD and this number is expected to triple by 2050. While men may have a higher risk of mild cognitive impairment (MCI), an intermediate stage between normal aging and dementia, women are disproportionally affected with AD. One explanation is that men may die of competing causes of death earlier in life, so that only the most resilient men may survive to older ages. However, many other factors should also be considered to explain the sex differences. In this review, we discuss the differences observed in men versus women in the incidence and prevalence of MCI and AD, in the structure and function of the brain, and in the sex-specific and gender-specific risk and protective factors for AD. In medical research, sex refers to biological differences such as chromosomal differences (eg, XX versus XY chromosomes), gonadal differences, or hormonal differences. In contrast, gender refers to psychosocial and cultural differences between men and women (eg, access to education and occupation). Both factors play an important role in the development and progression of diseases, including AD. Understanding both sex- and gender-specific risk and protective factors for AD is critical for developing individualized interventions for the prevention and treatment of AD.
Clinical epidemiology of Alzheimer’s disease: assessing sex and gender differences
Mielke, Michelle M; Vemuri, Prashanthi; Rocca, Walter A
2014-01-01
With the aging of the population, the burden of Alzheimer’s disease (AD) is rapidly expanding. More than 5 million people in the US alone are affected with AD and this number is expected to triple by 2050. While men may have a higher risk of mild cognitive impairment (MCI), an intermediate stage between normal aging and dementia, women are disproportionally affected with AD. One explanation is that men may die of competing causes of death earlier in life, so that only the most resilient men may survive to older ages. However, many other factors should also be considered to explain the sex differences. In this review, we discuss the differences observed in men versus women in the incidence and prevalence of MCI and AD, in the structure and function of the brain, and in the sex-specific and gender-specific risk and protective factors for AD. In medical research, sex refers to biological differences such as chromosomal differences (eg, XX versus XY chromosomes), gonadal differences, or hormonal differences. In contrast, gender refers to psychosocial and cultural differences between men and women (eg, access to education and occupation). Both factors play an important role in the development and progression of diseases, including AD. Understanding both sex- and gender-specific risk and protective factors for AD is critical for developing individualized interventions for the prevention and treatment of AD. PMID:24470773
The Evolution of Sex Chromosomes and Dosage Compensation in Plants.
Muyle, Aline; Shearn, Rylan; Marais, Gabriel Ab
2017-03-01
Plant sex chromosomes can be vastly different from those of the few historical animal model organisms from which most of our understanding of sex chromosome evolution is derived. Recently, we have seen several advancements from studies on green algae, brown algae, and land plants that are providing a broader understanding of the variable ways in which sex chromosomes can evolve in distant eukaryotic groups. Plant sex-determining genes are being identified and, as expected, are completely different from those in animals. Species with varying levels of differentiation between the X and Y have been found in plants, and these are hypothesized to be representing different stages of sex chromosome evolution. However, we are also finding that sex chromosomes can remain morphologically unchanged over extended periods of time. Where degeneration of the Y occurs, it appears to proceed similarly in plants and animals. Dosage compensation (a phenomenon that compensates for the consequent loss of expression from the Y) has now been documented in a plant system, its mechanism, however, remains unknown. Research has also begun on the role of sex chromosomes in sexual conflict resolution, and it appears that sex-biased genes evolve similarly in plants and animals, although the functions of these genes remain poorly studied. Because the difficulty in obtaining sex chromosome sequences is increasingly being overcome by methodological developments, there is great potential for further discovery within the field of plant sex chromosome evolution. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Johnson, John A
2018-06-04
Psychologists often argue that sex roles direct different types of socializing behaviors toward males and females and that this differential treatment, in turn, leads to sex differences in personality. Widely cited in support of this thesis has been the Fels longitudinal study finding that dependency and passivity are stable from childhood to adulthood for females only and aggressiveness and sexuality for males only. The present article explains why the type of sex differences in personality stability cited by Fels researchers actually contradicts the view that sex role expectations cause these differences. The report suggests ways in which social learning theory, the dominant developmental paradigm of the 1960s, may have contributed to the misinterpretation of the Fels data and how the rise of social constructivism maintained this misinterpretation for decades. The article concludes by correcting misconceptions about biology and personality stability and by explaining why theories that incorporate biology are not only more adequate than social constructivism but also more effective in bringing about the changes in society that constructivists desire.
A Role for the X Chromosome in Sex Differences in Variability in General Intelligence?
Johnson, Wendy; Carothers, Andrew; Deary, Ian J
2009-11-01
There is substantial evidence that males are more variable than females in general intelligence. In recent years, researchers have presented this as a reason that, although there is little, if any, mean sex difference in general intelligence, males tend to be overrepresented at both ends of its overall distribution. Part of the explanation could be the presence of genes on the X chromosome related both to syndromal disorders involving mental retardation and to population variation in general intelligence occurring normally. Genes on the X chromosome appear overrepresented among genes with known involvement in mental retardation, which is consistent with a model we developed of the population distribution of general intelligence as a mixture of two normal distributions. Using this model, we explored the expected ratios of males to females at various points in the distribution and estimated the proportion of variance in general intelligence potentially due to genes on the X chromosome. These estimates provide clues to the extent to which biologically based sex differences could be manifested in the environment as sex differences in displayed intellectual abilities. We discuss these observations in the context of sex differences in specific cognitive abilities and evolutionary theories of sexual selection. © 2009 Association for Psychological Science.
Meeting your match: how attractiveness similarity affects approach behavior in mixed-sex dyads.
van Straaten, Ischa; Engels, Rutger C M E; Finkenauer, Catrin; Holland, Rob W
2009-06-01
This experimental study investigated approach behavior toward opposite-sex others of similar versus dissimilar physical attractiveness. Furthermore, it tested the moderating effects of sex. Single participants interacted with confederates of high and low attractiveness. Observers rated their behavior in terms of relational investment (i.e., behavioral efforts related to the improvement of interaction fluency, communication of positive interpersonal affect, and positive self-presentation). As expected, men displayed more relational investment behavior if their own physical attractiveness was similar to that of the confederate. For women, no effects of attractiveness similarity on relational investment behavior were found. Results are discussed in the light of positive assortative mating, preferences for physically attractive mates, and sex differences in attraction-related interpersonal behaviors.
ERIC Educational Resources Information Center
Eisenberg, Nancy; And Others
1984-01-01
The results of three studies showed that mothers of preschoolers hold different expectations for children of different heights (especially boys) even when the effects of perceived age are controlled, that boys' size is associated with their logical capacities, and that taller boys and girls are preferred as playmates by male classmates. (KH)
Antfolk, Jan; Lieberman, Debra; Santtila, Pekka
2012-01-01
It is expected that in humans, the lowered fitness of inbred offspring has produced a sexual aversion between close relatives. Generally, the strength of this aversion depends on the degree of relatedness between two individuals, with closer relatives inciting greater aversion than more distant relatives. Individuals are also expected to oppose acts of inbreeding that do not include the self, as inbreeding between two individuals posits fitness costs not only to the individuals involved in the sexual act, but also to their biological relatives. Thus, the strength of inbreeding aversion should be predicted by the fitness costs an inbred child posits to a given individual, irrespective of this individual’s actual involvement in the sexual act. To test this prediction, we obtained information about the family structures of 663 participants, who reported the number of same-sex siblings, opposite-sex siblings, opposite-sex half siblings and opposite-sex cousins. Each participant was presented with three different types of inbreeding scenarios: 1) Participant descriptions, in which participants themselves were described as having sex with an actual opposite-sex relative (sibling, half sibling, or cousin); 2) Related third-party descriptions, in which participants’ actual same-sex siblings were described as having sex with their actual opposite-sex relatives; 3) Unrelated third-party descriptions, in which individuals of the same sex as the participants but unrelated to them were described as having sex with opposite-sex relatives. Participants rated each description on the strength of sexual aversion (i.e., disgust-reaction). We found that unrelated third-party descriptions elicited less disgust than related third-party and participant descriptions. Related third-party and participant descriptions elicited similar levels of disgust suggesting that the strength of inbreeding aversion is predicted by inclusive fitness costs. Further, in the related and unrelated conditions alike, the strength of inbreeding aversion was positively associated with the degree of relatedness between those described in the descriptions. PMID:23209792
Anterior Tibial Translation in Collegiate Athletes with Normal Anterior Cruciate Ligament Integrity
Rosene, John M.; Fogarty, Tracey D.
1999-01-01
Objective: To examine differences in anterior tibial translation (ATT) among sports, sex, and leg dominance in collegiate athletes with normal anterior cruciate ligament integrity. Design and Setting: Subjects from various athletic teams were measured for ATT in right and left knees. Subjects: Sixty subjects were measured for ATT with a KT-1000 knee arthrometer. Measurements: Statistical analyses were computed for each sex and included a 2 × 3 × 4 mixed-factorial analysis of variance (ANOVA) for anterior cruciate ligament displacement, right and left sides, and force and sport. A 2 × 2 × 3 mixed-factorial ANOVA was computed to compare means for sex and force. A 2 × 3 mixed-factorial ANOVA was computed to compare sex differences across 3 forces. Results: For males and females, no significant interactions were found among leg, force, and sport for mean ATT, for leg and sport or leg and force, or for translation values between dominant and nondominant legs. Males had a significant interaction for force and sport, and a significant difference was found for side of body, since the right side had less translation than the left side. Females had greater ATT than males at all forces. Conclusions: Sex differences exist for ATT, and differences in ATT exist among sports for both sexes. Differences between the right and left sides of the body should be expected when making comparisons of ligamentous laxity. ImagesFigure 2.Figure 3.Figure 5. PMID:16558565
Tryjanowski, Piotr; Adamski, Zbigniew
2007-10-01
Fluctuating asymmetry (FA) that reflects randomly directed deviations from bilateral symmetry has been shown to increase in organisms exposed to environmental and/or genetic stress. We studied fluctuating asymmetry in head and prothorax of chewing lice Docophorulus coarctatus, a parasite of the great grey shrike Lanius excubitor, to investigate associations between parasite body size and fluctuating asymmetry. Samples of ten individual lice (five females, five males) were randomly collected for measurements from 32 shrikes. Relative FA (scaled to trait size) was estimated for head and prothorax. Sex and trait differences in FA were very distinct (all differences significant at P<0.001). However, relative FA of head was not a predictor to relative FA of prothorax in either sex. Moreover, relative FA measurements of females and males from the same host were not significantly correlated, contrary to expectation if hosts imposed similar selection pressures on parasites of the two sexes. Relative FA of a trait was negatively related to its size, except for the relationship between relative FA of prothorax and prothorax in females. Differences in FA between traits may be explained by time when host condition affects louse developmental biology, with the head developing in a very short time during larval and nymph stages. The sex difference in asymmetry was probably related to different selection pressures by hosts on the sexes of the parasite, with females generally being under more intense selection.
Lippa, Richard A; Collaer, Marcia L; Peters, Michael
2010-08-01
Mental rotation and line angle judgment performance were assessed in more than 90,000 women and 111,000 men from 53 nations. In all nations, men's mean performance exceeded women's on these two visuospatial tasks. Gender equality (as assessed by United Nations indices) and economic development (as assessed by per capita income and life expectancy) were significantly associated, across nations, with larger sex differences, contrary to the predictions of social role theory. For both men and women, across nations, gender equality and economic development were significantly associated with better performance on the two visuospatial tasks. However, these associations were stronger for the mental rotation task than for the line angle judgment task, and they were stronger for men than for women. Results were discussed in terms of evolutionary, social role, and stereotype threat theories of sex differences.
Sex differences and plasticity in dehydration tolerance: insight from a tropical liverwort
Marks, Rose A.; Burton, James F.; McLetchie, D. Nicholas
2016-01-01
Background and Aims Adaptations allowing plants to cope with drying are particularly relevant in the light of predicted climate change. Dehydration tolerance (DhT, also dehydration-tolerant) is one such adaptation enabling tissue to survive substantial drying. A great deal of work has been conducted on highly DhT species. However, bryophytes showing less intense and variable DhT are understudied, despite the potential for these species to provide an informative link between highly tolerant and sensitive species. In this study, we tested the degree to which DhT varies across populations and the sexes of a species expected to exhibit a moderate DhT phenotype. Methods To test predicted patterns of tolerance we assessed DhT in males and females of Marchantia inflexa from two distinct habitat types that differ in water availability. Both common garden and field-collected tissue was subjected to drying assays at multiple intensities and recovery was monitored by chlorophyll florescence. Verification studies were conducted to confirm the level of dehydration, the rate of drying and the associated changes in photosynthetic physiology. Key Results We confirmed our expectation that M. inflexa is able to tolerate moderate dehydration. We also found that females exhibited higher DhT than males, but populations did not differ in DhT when cultured in a common garden. However, field-collected samples exhibited differences in DhT corresponding to environmental dryness, suggesting plasticity in DhT. Conclusions By studying a less extreme DhT phenotype we gained insight into how more sensitive (yet still tolerant) organisms cope with dehydration. Additionally, the identified sex-specific variation in DhT may explain ecological patterns such as female-biased sex ratios. Furthermore, plasticity in DhT has the potential to inform management practices aimed at increasing tolerance to drought conditions. PMID:27325895
Absence of sex differences in mental rotation performance in autism spectrum disorder.
Rohde, Melanie S; Georgescu, Alexandra L; Vogeley, Kai; Fimmers, Rolf; Falter-Wagner, Christine M
2017-08-01
Mental rotation is one of the most investigated cognitive functions showing consistent sex differences. The 'Extreme Male Brain' hypothesis attributes the cognitive profile of individuals with autism spectrum disorder to an extreme version of the male cognitive profile. Previous investigations focused almost exclusively on males with autism spectrum disorder with only limited implications for affected females. This study is the first testing a sample of 12 female adults with high-functioning autism spectrum disorder compared to 14 males with autism spectrum disorder, 12 typically developing females and 14 typically developing males employing a computerised version of the mental rotation test. Reaction time and accuracy served as dependent variables. Their linear relationship with degree of rotation allows separation of rotational aspects of the task, indicated by slopes of the psychometric function, and non-rotational aspects, indicated by intercepts of the psychometric function. While the typical and expected sex difference for rotational task aspects was corroborated in typically developing individuals, no comparable sex difference was found in autism spectrum disorder individuals. Autism spectrum disorder and typically developing individuals did not differ in mental rotation performance. This finding does not support the extreme male brain hypothesis of autism.
Olynk, N J; Wolf, C A
2007-05-01
Sexed semen has been a long-anticipated tool for dairy farmers to obtain more heifer calves, but challenges exist for integrating sexed semen into commercial dairy farm reproduction programs. The decreased conception rates (CR) experienced with sexed semen make virgin heifers better suited for insemination with sexed semen than lactating dairy cows. This research sought to identify when various sexed semen breeding strategies provided higher expected net present value (NPV) than conventional artificial insemination (AI) breeding schemes, indicating which breeding scheme is advisable under various scenarios. Budgets were developed to calculate the expected NPV of various AI breeding strategies incorporating conventional (non-sexed) and sexed semen. In the base budgets, heifer and bull calf values were held constant at $500 and $110, respectively. The percentage of heifers expected to be born after breeding with conventional and sexed semen used was 49.2 and 90%, respectively. Breeding costs per AI were held constant at $15.00 per AI for conventional semen and $45.00 per AI for sexed semen of approximately the same genetic value. Conventional semen CR of 58 and 65% were used, and an AI submission rate was set at 100%. Breeding strategies with sexed semen were assessed for breakeven heifer calf values and sexed semen costs to obtain a NPV equal to that achieved with conventional semen. Breakeven heifer calf values for pure sexed semen strategies with a constant 58 and 65% base CR in which sexed semen achieved 53% of the base CR are $732.11 and $664.26, respectively. Breakeven sexed semen costs per AI of $17.16 and $22.39, compared with $45.00 per AI, were obtained to obtain a NPV equal to that obtained with pure conventional semen for base CR of 58 and 65%, respectively. The strategy employing purely sexed semen, with base CR of both 58 and 65%, yielded a lower NPV than purely conventional semen in all but the best-case scenario in which sexed semen provides 90% of the CR of conventional semen. Other potential advantages of sexed semen that were not quantified in the scenarios include biosecurity-related concerns, decreased dystocia due to increased numbers of heifer calves, and implications for internal herd growth.
... Topic En español Talk to Your Kids about Sex Browse Sections The Basics Overview Bodies and Puberty ... healthy expectations for their relationships. Talk about opposite-sex and same-sex relationships. When you talk about ...
An economic analysis of life expectancy by gender with application to the United States.
Leung, Michael C M; Zhang, Jie; Zhang, Junsen
2004-07-01
This paper presents an economic model to explain the behavior of life expectancy of both sexes. It explicitly examines the relationship between the gender gap in life expectancy and the gender gap in pay. It shows that as the latter narrows over the course of economic development, the former may initially expand but will eventually shrink. Simulation results from our model accord with the behavior of life expectancy for both sexes since the 1940s in the United States.
Gender Stereotyping and the Influence of Race in Sport among Adolescents
ERIC Educational Resources Information Center
Hannon, James; Soohoo, Sonya; Reel, Justine; Ratliffe, Thomas
2009-01-01
One of the most dreaded insults in sports is, "You throw like a girl," because it epitomizes society's gender logic about physiological differences between men and women. Although physiological differences between the sexes exist, people label these abilities and behaviors as masculine or feminine as a result of social and cultural expectations.…
Lonsdorf, Tina B; Haaker, Jan; Schümann, Dirk; Sommer, Tobias; Bayer, Janine; Brassen, Stefanie; Bunzeck, Nico; Gamer, Matthias; Kalisch, Raffael
2015-11-01
Anxiety disorders are more prevalent in women than in men. Despite this sexual dimorphism, most experimental studies are conducted in male participants and studies focusing on sex differences are sparse. In addition, the role of hormonal contraceptives and menstrual cycle phase in fear conditioning and extinction processes remain largely unknown. We investigated sex differences in context-dependent fear acquisition and extinction (day 1) and their retrieval/expression (day 2). Skin conductance responses (SCRs), fear and unconditioned stimulus expectancy ratings were obtained. We included 377 individuals (261 women) in our study. Robust sex differences were observed in all dependent measures. Women generally displayed higher subjective ratings but smaller SCRs than men and showed reduced excitatory/inhibitory conditioned stimulus (CS+/CS-) discrimination in all dependent measures. Furthermore, women using hormonal contraceptives showed reduced SCR CS discrimination on day 2 than men and free-cycling women, while menstrual cycle phase had no effect. Possible limitations include the simultaneous testing of up to 4 participants in cubicles, which might have introduced a social component, and not assessing postexperimental contingency awareness. The response pattern in women shows striking similarity to previously reported sex differences in patients with anxiety. Our results suggest that pronounced deficits in associative discrimination learning and subjective expression of safety information (CS- responses) might underlie higher prevalence and higher symptom rates seen in women with anxiety disorders. The data call for consideration of biological sex and hormonal contraceptive use in future studies and may suggest that targeting inhibitory learning during therapy might aid precision medicine.
The landscape of sex-differential transcriptome and its consequent selection in human adults.
Gershoni, Moran; Pietrokovski, Shmuel
2017-02-07
The prevalence of several human morbid phenotypes is sometimes much higher than intuitively expected. This can directly arise from the presence of two sexes, male and female, in one species. Men and women have almost identical genomes but are distinctly dimorphic, with dissimilar disease susceptibilities. Sexually dimorphic traits mainly result from differential expression of genes present in both sexes. Such genes can be subject to different, and even opposing, selection constraints in the two sexes. This can impact human evolution by differential selection on mutations with dissimilar effects on the two sexes. We comprehensively mapped human sex-differential genetic architecture across 53 tissues. Analyzing available RNA-sequencing data from 544 adults revealed thousands of genes differentially expressed in the reproductive tracts and tissues common to both sexes. Sex-differential genes are related to various biological systems, and suggest new insights into the pathophysiology of diverse human diseases. We also identified a significant association between sex-specific gene transcription and reduced selection efficiency and accumulation of deleterious mutations, which might affect the prevalence of different traits and diseases. Interestingly, many of the sex-specific genes that also undergo reduced selection efficiency are essential for successful reproduction in men or women. This seeming paradox might partially explain the high incidence of human infertility. This work provides a comprehensive overview of the sex-differential transcriptome and its importance to human evolution and human physiology in health and in disease.
Sex differences during humor appreciation in child-sibling pairs.
Vrticka, Pascal; Neely, Michelle; Walter Shelly, Elizabeth; Black, Jessica M; Reiss, Allan L
2013-01-01
The developmental origin of sex differences in adult brain function is poorly understood. Elucidating neural mechanisms underlying comparable cognitive functionality in both children and adults is required to address this gap. Humor appreciation represents a particularly relevant target for such developmental research because explanatory theories apply across the life span, and underlying neurocircuitry shows sex differences in adults. As a positive mood state, humor is also of interest due to sex differences in rates of depression, a disorder afflicting twice as many women as men. In this study, we employed functional magnetic resonance imaging (fMRI) to investigate brain responses to funny versus positive (and neutral) video clips in 22 children, ages 6-13 years, including eight sibling-pairs. Our data revealed increased activity to funny clips in bilateral temporo-occipital cortex, midbrain, and amygdala in girls. Conversely, we found heightened activation to positive clips in bilateral inferior parietal lobule, fusiform gyrus, inferior frontal gyrus, amygdala, and ventromedial prefrontal cortex in boys. Many of these effects persisted when looking at sibling-pairs only. We interpret such findings as reflecting the presence of early sex divergence in reward saliency or expectation and stimulus relevance attribution. These findings are discussed in the context of evolutionary and developmental theories of humor function.
SEX DIFFERENCES DURING HUMOR APPRECIATION IN CHILD SIBLING-PAIRS
Vrticka, Pascal; Neely, Michelle; Walter, Elizabeth; Black, Jessica M.; Reiss, Allan L.
2013-01-01
The developmental origin of sex differences in adult brain function is poorly understood. Elucidating neural mechanisms underlying comparable cognitive functionality in both children and adults is required to address this gap. Humor appreciation represents a particularly relevant target for such developmental research because explanatory theories apply across the life span and underlying neurocircuitry shows sex differences in adults. As a positive mood state, humor is also of interest due to sex differences in rates of depression, a disorder afflicting twice as many women as men. In this study, we employed fMRI to investigate brain responses to funny versus positive (and neutral) video clips in 22 children ages 6 to 13 years, including 8 sibling pairs. Our data revealed increased activity to funny clips in bilateral temporo-occipital cortex, midbrain, and amygdala in girls. Conversely, we found heightened activation to positive clips in bilateral inferior parietal lobule, fusiform gyrus, inferior frontal gyrus, amygdala, and ventromedial prefrontal cortex in boys. Many of these effects persisted when looking at sibling-pairs only. We interpret such findings as reflecting the presence of early sex divergence in reward saliency / expectation and stimulus relevance attribution. These findings are discussed in the context of evolutionary and developmental theories of humor function. PMID:23672302
Horsley, Kimberly; Stark, Lloyd R; McLetchie, D Nicholas
2011-05-01
Expected life history trade-offs associated with sex differences in reproductive investment are often undetected in seed plants, with the difficulty arising from logistical issues of conducting controlled experiments. By controlling genotype, age and resource status of individuals, a bryophyte was assessed for sex-specific and location-specific patterns of vegetative, asexual and sexual growth/reproduction across a regional scale. Twelve genotypes (six male, six female) of the dioecious bryophyte Bryum argenteum were subcultured to remove environmental effects, regenerated asexually to replicate each genotype 16 times, and grown over a period of 92 d. Plants were assessed for growth rates, asexual and sexual reproductive traits, and allocation to above- and below-ground regenerative biomass. The degree of sexual versus asexual reproductive investment appears to be under genetic control, with three distinct ecotypes found in this study. Protonemal growth rate was positively correlated with asexual reproduction and sexual reproduction, whereas asexual reproduction was negatively correlated (appeared to trade-off) with vegetative growth (shoot production). No sex-specific trade-offs were detected. Female sex-expressing shoots were longer than males, but the sexes did not differ in growth traits, asexual traits, sexual induction times, or above- and below-ground biomass. Males, however, had much higher rates of inflorescence production than females, which translated into a significantly higher (24x) prezygotic investment for males relative to females. Evidence for three distinct ecotypes is presented for a bryophyte based on regeneration traits. Prior to zygote production, the sexes of this bryophyte did not differ in vegetative growth traits but significantly differed in reproductive investment, with the latter differences potentially implicated in the strongly biased female sex ratio. The disparity between males and females for prezygotic reproductive investment is the highest known for bryophytes.
Arseneau-Robar, T Jean M; Joyce, Megan M; Stead, Samantha M; Teichroeb, Julie A
2018-05-01
Close proximity and social grooming are important bonding mechanisms in primates. These behaviors show the social structure of a species and many studies have found positive correlations between the degree of kinship and grooming and proximity. We used 1 year of data collected via instantaneous scan sampling on a large "supertroop" of Colobus angolensis ruwenzorii at Lake Nabugabo, Uganda, to examine partner preferences for grooming and nearest neighbors in each age-sex class. Little is known about this species, so we based our hypotheses on congeners. Of the five species of black-and-white colobus, data on sex-biased dispersal patterns are available for three (C. guereza, C. vellerosus, and C. polykomos), all of which show male-biased dispersal with occasional female dispersal. We thus predicted that female C. a. ruwenzorii would be more strongly bonded than males, showing greater proximity and grooming. We did not expect bonding between the sexes since congeners do not show this pattern. We found that among adult dyads, males and females were more likely to be found in loose proximity, and to groom, than would be expected given group composition. Conversely, both males and females had relatively weak same-sex relationships. Between the sexes, adult males had higher proximity and grooming indices with adult females without infants than with females with infants. These observations indicate that this subspecies is cross-bonded and that both sexes may disperse. Furthermore, our findings suggest that the social organization and social structure of C. a. ruwenzorii differ greatly from other black-and-white colobus species.
DIFFERENCES IN IMMUNE RESPONSE MAY EXPLAIN LOWER SURVIVAL AMONG OLDER MEN WITH PNEUMONIA
Reade, Michael C.; Yende, Sachin; D’Angelo, Gina; Kong, Lan; Kellum, John A; Barnato, Amber E.; Milbrandt, Eric B.; Dooley, Christopher; Mayr, Florian B.; Weissfeld, Lisa; Angus, Derek C.
2009-01-01
Objective Lower life expectancy in men is generally attributed to higher likelihood of risky behavior and because men develop chronic conditions earlier. If sex-related differences in survival are independent of pre-infection chronic health and health behavior, it would suggest that survival differences may occur due to sex differences in quality of care and biologic response to infection and these differences may contribute to sex differences in life expectancy. We assessed if sex-related survival difference following community-acquired pneumonia (CAP) is due to differences in clinical characteristics, quality of care, or immune response. Design, setting, and subjects Prospective observational cohort of 2183 subjects with CAP. Measurements and main results Mean age was 64.9 years. Compared to women, men were more likely to smoke and had more comorbidity. At emergency department presentation, men had different biomarker patterns, as evidenced by higher inflammation (tumor necrosis factor (TNF), interleukin (IL)-6, and IL-10) and fibrinolysis (D-dimer), and lower coagulation biomarkers (antithrombin-III and Factor IX) (P<0.05). Small differences in favor of men were seen in care quality, including antibiotic timing and compliance with American Thoracic Society guidelines. Men had lower survival at 30, 90, 365 days. The higher one-year mortality was not attenuated when adjusted for differences in demographics, smoking, resuscitation, insurance, and vaccination status, comorbidity, hospital characteristics, and illness severity (unadjusted hazard ratio (HR)=1.35, p=0.003 and adjusted HR=1.29, p=0.004). HR were no longer statistically significant when additionally adjusted for differences in ED concentrations of TNF, IL-6, IL-10, D-dimer, antithrombin-III, and Factor IX (adjusted HR=1.27, p=0.17). Patterns of biomarkers observed in men were associated with worse survival over one year. Conclusions Lower survival among men following CAP was not explained by differences in chronic diseases, health behaviors, and quality of care. Patterns of inflammatory, coagulation, and fibrinolysis biomarkers among men may explain reduced short and long-term survival. PMID:19325487
Balancing Selection in Species with Separate Sexes: Insights from Fisher’s Geometric Model
Connallon, Tim; Clark, Andrew G.
2014-01-01
How common is balancing selection, and what fraction of phenotypic variance is attributable to balanced polymorphisms? Despite decades of research, answers to these questions remain elusive. Moreover, there is no clear theoretical prediction about the frequency with which balancing selection is expected to arise within a population. Here, we use an extension of Fisher’s geometric model of adaptation to predict the probability of balancing selection in a population with separate sexes, wherein polymorphism is potentially maintained by two forms of balancing selection: (1) heterozygote advantage, where heterozygous individuals at a locus have higher fitness than homozygous individuals, and (2) sexually antagonistic selection (a.k.a. intralocus sexual conflict), where the fitness of each sex is maximized by different genotypes at a locus. We show that balancing selection is common under biologically plausible conditions and that sex differences in selection or sex-by-genotype effects of mutations can each increase opportunities for balancing selection. Although heterozygote advantage and sexual antagonism represent alternative mechanisms for maintaining polymorphism, they mutually exist along a balancing selection continuum that depends on population and sex-specific parameters of selection and mutation. Sexual antagonism is the dominant mode of balancing selection across most of this continuum. PMID:24812306
Students’ Spatial Performance: Cognitive Style and Sex Differences
NASA Astrophysics Data System (ADS)
Hanifah, U.; Juniati, D.; Siswono, T. Y. E.
2018-01-01
This study aims at describing the students’ spatial abilities based on cognitive styles and sex differences. Spatial abilities in this study include 5 components, namely spatial perception, spatial visualization, mental rotation, spatial relations, and spatial orientation. This research is descriptive research with qualitative approach. The subjects in this research were 4 students of junior high school, there were 1 male FI, 1 male FD, 1 female FI, and 1 female FI. The results showed that there are differences in spatial abilities of the four subjects that are on the components of spatial visualization, mental rotation, and spatial relations. The differences in spatial abilities were found in methods / strategies used by each subject to solve each component problem. The differences in cognitive styles and sex suggested different choice of strategies used to solve problems. The male students imagined the figures but female students needed the media to solve the problem. Besides sex, the cognitive style differences also have an effect on solving a problem. In addition, FI students were not affected by distracting information but FD students could be affected by distracting information. This research was expected to contribute knowledge and insight to the readers, especially for math teachers in terms of the spatial ability of the students so that they can optimize their students’ spatial ability.
Gálvez-Buccollini, Juan A; Paz-Soldán, Valerie A; Herrera, Phabiola M; DeLea, Suzanne; Gilman, Robert H
2009-06-01
To estimate the effect of sex-related alcohol expectancies (SRAE) on hazardous drinking prevalence and examine gender differences in reporting SRAE. Trained research assistants administered part of a questionnaire to 393 men and 400 women between 18 and 30 years old from a peri-urban shantytown in Lima, Peru. The remaining questions were self-administered. Two measuring instruments-one testing for hazardous drinking and one for SRAE-were used. Multivariate data analysis was performed using logistic regression. Based on odds ratios adjusted for socio-demographic variables (age, marital status, education, and employment status) (n = 793), men with one or two SRAE and men with three or more SRAE were 2.3 (95% confidence interval (CI) = 1.4-3.8; p = 0.001) and 3.9 (95% CI = 2.1-7.3; p < 0.001) times more likely than men with no SRAE, respectively, to be hazardous drinkers. Reporting of SRAE was significantly higher in men versus women. In a shantytown in Lima, SRAE is associated with hazardous drinking among men, but not among women, and reporting of SRAE differs by gender.
Body Mass Transitions Through Childhood and Early Adolescence: A Multistate Life Table Approach
Tran, Melanie K.; Krueger, Patrick M.; McCormick, Emily; Davidson, Arthur; Main, Deborah S.
2016-01-01
The growing prevalence of overweight and obesity among children is well documented, but prevalence estimates offer little insight into rates of transition to higher or lower body mass index (BMI; weight (kg)/height (m)2) categories. We estimated the expected numbers of years children would live as normal weight, overweight, and obese by race/ethnicity and sex, given rates of transition across BMI status levels. We used multistate life table methods and transition rates estimated from prospective cohort data (2007–2013) for Denver, Colorado, public schoolchildren aged 3–15 years. At age 3 years, normal-weight children could expect to live 11.1 of the following 13 years with normal weight status, and obese children could expect to live 9.8 years with obese status. At age 3 years, overweight children could expect to live 4.5 of the following 13 years with normal weight status, 5.1 years with overweight status, and 3.4 years with obese status. Whites and Asians lived more years at lower BMI status levels than did blacks or Hispanics; sex differences varied by race/ethnicity. Children who were normal weight or obese at age 3 years were relatively unlikely to move into a different BMI category by age 15 years. Overweight children are relatively likely to transition to normal weight or obese status. PMID:26984962
Olfactory Performance Is Predicted by Individual Sex-Atypicality, but Not Sexual Orientation
Nováková, Lenka; Varella Valentová, Jaroslava; Havlíček, Jan
2013-01-01
Many previous studies have reported robust sex differences in olfactory perception. However, both men and women can be expected to vary in the degree to which they exhibit olfactory performance considered typical of their own or the opposite sex. Sex-atypicality is often described in terms of childhood gender nonconformity, which, however, is not a perfect correlate of non-heterosexual orientation. Here we explored intrasexual variability in psychophysical olfactory performance in a sample of 156 individuals (83 non-heterosexual) and found the lowest odor identification scores in heterosexual men. However, when childhood gender nonconformity was entered in the model along with sexual orientation, better odor identification scores were exhibited by gender-nonconforming men, and greater olfactory sensitivity by gender-conforming women, irrespective of their sexual orientation. Thus, sex-atypicality, but not sexual orientation predicts olfactory performance, and we propose that this might not be limited to olfaction, but represent a more general phenomenon. PMID:24244657
Olfactory performance is predicted by individual sex-atypicality, but not sexual orientation.
Nováková, Lenka; Varella Valentová, Jaroslava; Havlíček, Jan
2013-01-01
Many previous studies have reported robust sex differences in olfactory perception. However, both men and women can be expected to vary in the degree to which they exhibit olfactory performance considered typical of their own or the opposite sex. Sex-atypicality is often described in terms of childhood gender nonconformity, which, however, is not a perfect correlate of non-heterosexual orientation. Here we explored intrasexual variability in psychophysical olfactory performance in a sample of 156 individuals (83 non-heterosexual) and found the lowest odor identification scores in heterosexual men. However, when childhood gender nonconformity was entered in the model along with sexual orientation, better odor identification scores were exhibited by gender-nonconforming men, and greater olfactory sensitivity by gender-conforming women, irrespective of their sexual orientation. Thus, sex-atypicality, but not sexual orientation predicts olfactory performance, and we propose that this might not be limited to olfaction, but represent a more general phenomenon.
The relationship between sexual selection and sexual conflict.
Kokko, Hanna; Jennions, Michael D
2014-07-18
Evolutionary conflicts of interest arise whenever genetically different individuals interact and their routes to fitness maximization differ. Sexual selection favors traits that increase an individual's competitiveness to acquire mates and fertilizations. Sexual conflict occurs if an individual of sex A's relative fitness would increase if it had a "tool" that could alter what an individual of sex B does (including the parental genes transferred), at a cost to B's fitness. This definition clarifies several issues: Conflict is very common and, although it extends outside traits under sexual selection, sexual selection is a ready source of sexual conflict. Sexual conflict and sexual selection should not be presented as alternative explanations for trait evolution. Conflict is closely linked to the concept of a lag load, which is context-dependent and sex-specific. This makes it possible to ask if one sex can "win." We expect higher population fitness if females win. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.
Hou, Juan; Chen, Xin; Liu, Jinqun; Yao, Fangshu; Huang, Jiani; Ndasauka, Yamikani; Ma, Ru; Zhang, Yuting; Lan, Jing; Liu, Lu; Fang, Xiaoyi
2016-01-01
In the present study, we investigated the relationship among three emotion-motivation systems (adult attachment, romantic love, and sex). We recorded event-related potentials in 37 healthy volunteers who had experienced romantic love while they viewed SEX, LOVE, FRIEND, SPORT, and NEUTRAL images. We also measured adult attachment styles, level of passionate love and sexual attitudes. As expected, results showed that, firstly, response to love-related image-stimuli and sex-related image-stimuli on the electrophysiological data significantly different on N1, N2, and positive slow wave (PSW) components. Secondly, the different adult attachment styles affected individuals’ recognition processing in response to love-related and sex-related images, especially, to sex-related images. Further analysis showed that voltages elicited by fearful attachment style individuals were significantly lower than voltages elicited by secure and dismissing attachment style individuals on sex-related images at frontal sites, on N1 and N2 components. Thirdly, from behavior data, we found that adult attachment styles were not significantly related to any dimension of sexual attitudes but were significantly related to passionate love scale (PLS) total points. Thus, the behavior results were not in line with the electrophysiological results. The present study proved that adult attachment styles might mediate individuals’ lust and attraction systems. PMID:27199830
Hou, Juan; Chen, Xin; Liu, Jinqun; Yao, Fangshu; Huang, Jiani; Ndasauka, Yamikani; Ma, Ru; Zhang, Yuting; Lan, Jing; Liu, Lu; Fang, Xiaoyi
2016-01-01
In the present study, we investigated the relationship among three emotion-motivation systems (adult attachment, romantic love, and sex). We recorded event-related potentials in 37 healthy volunteers who had experienced romantic love while they viewed SEX, LOVE, FRIEND, SPORT, and NEUTRAL images. We also measured adult attachment styles, level of passionate love and sexual attitudes. As expected, results showed that, firstly, response to love-related image-stimuli and sex-related image-stimuli on the electrophysiological data significantly different on N1, N2, and positive slow wave (PSW) components. Secondly, the different adult attachment styles affected individuals' recognition processing in response to love-related and sex-related images, especially, to sex-related images. Further analysis showed that voltages elicited by fearful attachment style individuals were significantly lower than voltages elicited by secure and dismissing attachment style individuals on sex-related images at frontal sites, on N1 and N2 components. Thirdly, from behavior data, we found that adult attachment styles were not significantly related to any dimension of sexual attitudes but were significantly related to passionate love scale (PLS) total points. Thus, the behavior results were not in line with the electrophysiological results. The present study proved that adult attachment styles might mediate individuals' lust and attraction systems.
The Association Between Income and Life Expectancy in the United States, 2001-2014.
Chetty, Raj; Stepner, Michael; Abraham, Sarah; Lin, Shelby; Scuderi, Benjamin; Turner, Nicholas; Bergeron, Augustin; Cutler, David
2016-04-26
The relationship between income and life expectancy is well established but remains poorly understood. To measure the level, time trend, and geographic variability in the association between income and life expectancy and to identify factors related to small area variation. Income data for the US population were obtained from 1.4 billion deidentified tax records between 1999 and 2014. Mortality data were obtained from Social Security Administration death records. These data were used to estimate race- and ethnicity-adjusted life expectancy at 40 years of age by household income percentile, sex, and geographic area, and to evaluate factors associated with differences in life expectancy. Pretax household earnings as a measure of income. Relationship between income and life expectancy; trends in life expectancy by income group; geographic variation in life expectancy levels and trends by income group; and factors associated with differences in life expectancy across areas. The sample consisted of 1,408,287,218 person-year observations for individuals aged 40 to 76 years (mean age, 53.0 years; median household earnings among working individuals, $61,175 per year). There were 4,114,380 deaths among men (mortality rate, 596.3 per 100,000) and 2,694,808 deaths among women (mortality rate, 375.1 per 100,000). The analysis yielded 4 results. First, higher income was associated with greater longevity throughout the income distribution. The gap in life expectancy between the richest 1% and poorest 1% of individuals was 14.6 years (95% CI, 14.4 to 14.8 years) for men and 10.1 years (95% CI, 9.9 to 10.3 years) for women. Second, inequality in life expectancy increased over time. Between 2001 and 2014, life expectancy increased by 2.34 years for men and 2.91 years for women in the top 5% of the income distribution, but by only 0.32 years for men and 0.04 years for women in the bottom 5% (P < .001 for the differences for both sexes). Third, life expectancy for low-income individuals varied substantially across local areas. In the bottom income quartile, life expectancy differed by approximately 4.5 years between areas with the highest and lowest longevity. Changes in life expectancy between 2001 and 2014 ranged from gains of more than 4 years to losses of more than 2 years across areas. Fourth, geographic differences in life expectancy for individuals in the lowest income quartile were significantly correlated with health behaviors such as smoking (r = -0.69, P < .001), but were not significantly correlated with access to medical care, physical environmental factors, income inequality, or labor market conditions. Life expectancy for low-income individuals was positively correlated with the local area fraction of immigrants (r = 0.72, P < .001), fraction of college graduates (r = 0.42, P < .001), and government expenditures (r = 0.57, P < .001). In the United States between 2001 and 2014, higher income was associated with greater longevity, and differences in life expectancy across income groups increased over time. However, the association between life expectancy and income varied substantially across areas; differences in longevity across income groups decreased in some areas and increased in others. The differences in life expectancy were correlated with health behaviors and local area characteristics.
Sex differences in the pathways to major depression: a study of opposite-sex twin pairs.
Kendler, Kenneth S; Gardner, Charles O
2014-04-01
The authors sought to clarify the nature of sex differences in the etiologic pathways to major depression. Retrospective and prospective assessments of 20 developmentally organized risk factors and the occurrence of past-year major depression were conducted at two waves of personal interviews at least 12 months apart in 1,057 opposite-sex dizygotic twin pairs from a population-based register. Analyses were conducted by structural modeling, examining within-pair differences. Sixty percent of all paths in the best-fit model exhibited sex differences. Eleven of the 20 risk factors differed across sexes in their impact on liability to major depression. Five had a greater impact in women: parental warmth, neuroticism, divorce, social support, and marital satisfaction. Six had a greater impact in men: childhood sexual abuse, conduct disorder, drug abuse, prior history of major depression, and distal and dependent proximal stressful life events. The life event categories responsible for the stronger effect in males were financial, occupational, and legal in nature. In a co-twin control design, which matches sisters and brothers on genetic and familial-environmental background, personality and failures in interpersonal relationships played a stronger etiologic role in major depression for women than for men. Externalizing psychopathology, prior depression, and specific "instrumental" classes of acute stressors were more important in the etiologic pathway to major depression for men. The results are consistent with previously proposed typologies of major depression that suggest two subtypes that differ in prevalence in women (deficiencies in caring relationships and interpersonal loss) and men (failures to achieve expected goals, with lowered self-worth).
On Confirming Others' Sex-Role Stereotypes.
ERIC Educational Resources Information Center
Zanna, Mark P.
Research studies concerned with sex-role stereotypes have noted that behavior is often shaped by expectations others hold about certain individuals. In one experiment, female undergraduates who expected to meet attractive desirable men portrayed themselves as more feminine and performed less intelligently on a bogus IQ test when they thought the…
Mating Changes Sexually Dimorphic Gene Expression in the Seed Beetle Callosobruchus maculatus.
Immonen, Elina; Sayadi, Ahmed; Bayram, Helen; Arnqvist, Göran
2017-03-01
Sexually dimorphic phenotypes arise largely from sex-specific gene expression, which has mainly been characterized in sexually naïve adults. However, we expect sexual dimorphism in transcription to be dynamic and dependent on factors such as reproductive status. Mating induces many behavioral and physiological changes distinct to each sex and is therefore expected to activate regulatory changes in many sex-biased genes. Here, we first characterized sexual dimorphism in gene expression in Callosobruchus maculatus seed beetles. We then examined how females and males respond to mating and how it affects sex-biased expression, both in sex-limited (abdomen) and sex-shared (head and thorax) tissues. Mating responses were largely sex-specific and, as expected, females showed more genes responding compared with males (∼2,000 vs. ∼300 genes in the abdomen, ∼500 vs. ∼400 in the head and thorax, respectively). Of the sex-biased genes present in virgins, 16% (1,041 genes) in the abdomen and 17% (243 genes) in the head and thorax altered their relative expression between the sexes as a result of mating. Sex-bias status changed in 2% of the genes in the abdomen and 4% in the head and thorax following mating. Mating responses involved de-feminization of females and, to a lesser extent, de-masculinization of males relative to their virgin state: mating decreased rather than increased dimorphic expression of sex-biased genes. The fact that regulatory changes of both types of sex-biased genes occurred in both sexes suggests that male- and female-specific selection is not restricted to male- and female-biased genes, respectively, as is sometimes assumed. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Mating Changes Sexually Dimorphic Gene Expression in the Seed Beetle Callosobruchus maculatus
Sayadi, Ahmed; Bayram, Helen; Arnqvist, Göran
2017-01-01
Sexually dimorphic phenotypes arise largely from sex-specific gene expression, which has mainly been characterized in sexually naïve adults. However, we expect sexual dimorphism in transcription to be dynamic and dependent on factors such as reproductive status. Mating induces many behavioral and physiological changes distinct to each sex and is therefore expected to activate regulatory changes in many sex-biased genes. Here, we first characterized sexual dimorphism in gene expression in Callosobruchus maculatus seed beetles. We then examined how females and males respond to mating and how it affects sex-biased expression, both in sex-limited (abdomen) and sex-shared (head and thorax) tissues. Mating responses were largely sex-specific and, as expected, females showed more genes responding compared with males (∼2,000 vs. ∼300 genes in the abdomen, ∼500 vs. ∼400 in the head and thorax, respectively). Of the sex-biased genes present in virgins, 16% (1,041 genes) in the abdomen and 17% (243 genes) in the head and thorax altered their relative expression between the sexes as a result of mating. Sex-bias status changed in 2% of the genes in the abdomen and 4% in the head and thorax following mating. Mating responses involved de-feminization of females and, to a lesser extent, de-masculinization of males relative to their virgin state: mating decreased rather than increased dimorphic expression of sex-biased genes. The fact that regulatory changes of both types of sex-biased genes occurred in both sexes suggests that male- and female-specific selection is not restricted to male- and female-biased genes, respectively, as is sometimes assumed. PMID:28391318
The Association Between Income and Life Expectancy in the United States, 2001–2014
Chetty, Raj; Stepner, Michael; Abraham, Sarah; Lin, Shelby; Scuderi, Benjamin; Turner, Nicholas; Bergeron, Augustin; Cutler, David
2016-01-01
Importance The relationship between income and mortality is well established but remains poorly understood. Objectives To measure the level, temporal trend, and geographic variability in the association between income and life expectancy, and identify factors related to small area variation in this association. Design and Setting Income data for the US population were obtained from 1.4 billion de-identified tax records between 1999 and 2014. Mortality data were obtained from Social Security Administration death records. These data were used to estimate race- and ethnicity-adjusted life expectancy at 40 years of age by household income percentile, sex, and geographic area, and to evaluate factors associated with differences in life expectancy. Main Outcomes and Measures Relationship between income and life expectancy; trends in life expectancy by income group; geographic variation in life expectancy levels and trends by income group; and factors associated with differences in life expectancy across areas. Results The sample consisted of 1 408 287 218 person-year observations (mean age at which individuals were analyzed, 53.0 years; median household earnings among working individuals, $61 175 per year [mean, $97 725 per year]). Among those aged 40 to 76 years, there were 4 114 380 deaths among men (mortality rate, 596.3 per 100 000) and 2 694 808 deaths among women (mortality rate, 375.1 per 100 000). The analysis yielded four results. First, higher income was associated with greater longevity throughout the income distribution. The gap in life expectancy between the richest 1% and poorest 1% of individuals was 14.6 years (95% CI, 14.4 to 14.8 years) for men and 10.1 years (95% CI, 9.9 to 10.3 years) for women. Second, inequality in life expectancy increased over time. Between 2001 and 2014, life expectancy increased by 2.34 years for men and 2.91 years for women in the top 5% of the income distribution, but increased by only 0.32 years for men and 0.04 years for women in the bottom 5% (P < .001 for the difference for both sexes). Third, life expectancy varied substantially across local areas. For individuals in the bottom income quartile, life expectancy differed by approximately 4.5 years between areas with the highest and lowest longevity. Changes in life expectancy between 2001 and 2014 ranged from gains of more than 4 years to losses of more than 2 years across areas. Fourth, geographic differences in life expectancy for individuals in the lowest income quartile were significantly correlated with health behaviors such as smoking (r = −0.69, P < .001), but were not significantly correlated with access to medical care, physical environmental factors, income inequality, or labor market conditions. Life expectancy for low income individuals was positively correlated with the local area fraction of immigrants (r = 0.72, P < .001), fraction of college graduates (r = 0.42, P < .001), and local government expenditures (r = 0.57, P < .001). Conclusions and Relevance In the United States between 2001 and 2014, higher income was associated with greater longevity, and differences in life expectancy across income groups increased. However, the association between life expectancy and income varied substantially across areas; differences in longevity across income groups decreased in some areas and increased in others. The differences in life expectancy were correlated with health behaviors and local area characteristics. PMID:27063997
Expected satiation alone does not predict actual intake of desserts.
Guillocheau, Etienne; Davidenko, Olga; Marsset-Baglieri, Agnès; Darcel, Nicolas; Gaudichon, Claire; Tomé, Daniel; Fromentin, Gilles
2018-04-01
The degree to which consumers expect foods to satisfy hunger, referred to as expected satiation, has been reported to predict food intake. Yet this relationship has not been established precisely, at a quantitative level. We sought to explore this relationship in detail by determining whether expected satiation predicts the actual intake of semi-solid desserts. Two separate experiments were performed: the first used variations of a given food (eight apple purées), while the second involved a panel of different foods within a given category (eight desserts). Both experiments studied the consumption of two products assigned to volunteers based on their individual liking and expected satiation ratings, given ad libitum at the end of a standardised meal. A linear model was used to find predictors of food intake and included expected satiation scores, palatability scores, BMI, age, sex, TFEQ-R, TFEQ-D, water consumption during the meal, reported frequency of eating desserts, and reported frequency of consuming tested products as explanatory variables. Expected satiation was a significant predictor of actual food intake in both experiments (apple purée: F(1,97) = 18.60, P < .001; desserts: F(1,106) = 9.05, P < .01), along with other parameters such as product palatability and the volunteers' age, sex and food restriction (variation explained by the model/expected satiation in the experiments: 57%/23% and 36%/17%, respectively). However, we found a significant gap between expected and actual consumption of desserts, on group and on individual level. Our results confirm the importance of expected satiation as a predictor of subsequent food intake, but highlight the need to study individual consumption behaviour and preferences in order to fully understand the role of expected satiation. Copyright © 2017 Elsevier Ltd. All rights reserved.
Antagonistic effect of helpers on breeding male and female survival in a cooperatively breeding bird
Paquet, Matthieu; Doutrelant, Claire; Hatchwell, Ben J; Spottiswoode, Claire N; Covas, Rita
2015-01-01
1. Cooperatively breeding species are typically long lived and hence, according to theory, are expected to maximize their lifetime reproductive success through maximizing survival. Under these circumstances, the presence of helpers could be used to lighten the effort of current reproduction for parents to achieve higher survival. 2. In addition, individuals of different sexes and ages may follow different strategies, but whether male and female breeders and individuals of different ages benefit differently from the presence of helpers has often been overlooked. Moreover, only one study that investigated the relationship between parental survival and the presence of helpers used capture–mark–recapture analyses (CMR). These methods are important since they allow us to account for the non-detection of individuals that are alive in the population but not detected, and thus, the effects on survival and recapture probability to be disentangled. 3. Here, we used multi-event CMR methods to investigate whether the number of helpers was associated with an increase in survival probability for male and female breeders of different ages in the sociable weaver Philetairus socius. In this species, both sexes reduce their feeding rate in the presence of helpers. We therefore predicted that the presence of helpers should increase the breeders' survival in both sexes, especially early in life when individuals potentially have more future breeding opportunities. In addition, sociable weaver females reduce their investment in eggs in the presence of helpers, so we predicted a stronger effect of helpers on female than male survival. 4. As expected we found that females had a higher survival probability when breeding with more helpers. Unexpectedly, however, male survival probability decreased with increasing number of helpers. This antagonistic effect diminished as the breeders grew older. 5. These results illustrate the complexity of fitness costs and benefits underlying cooperative behaviours and how these may vary with the individuals' sex and age. They also highlight the need for further studies on the sex-specific effects of helpers on survival. PMID:25850564
ERIC Educational Resources Information Center
Hollenbeck, John R.; And Others
1987-01-01
Explored utility of adopting supply-side approach to understanding the nature of wage differentials between men and women using job applicants (N=272) as subjects. Results suggested much of the wage gap can be explained by evaluations of outcomes other than pay, and gender-related differences in expectancies, instrumentalities, and valences with…
Biological age and sex-related declines in physical activity during adolescence.
Cairney, John; Veldhuizen, Scott; Kwan, Matthew; Hay, John; Faught, Brent E
2014-04-01
Sex differences in the rate of decline in physical activity (PA) are most pronounced during adolescence. However, once boys and girls are aligned on biological age, sex differences in the patterns of PA become attenuated. The aim of this study was to test whether biological maturation can account for sex differences in participation in PA over time from late childhood to early adolescence. A prospective cohort of children (N = 2100; 1064 boys) was followed from ages 11 to 14 yr, with repeated assessments of PA and anthropometry. Self-reported participation in organized and free play activities was used to track participation in PA. Biological age was measured using an estimate of years to attainment of peak height velocity. Mixed-effects models were used to test whether controlling for biological age attenuates the effect of chronological age and sex on PA. As expected, the rate of decline in participation in PA was greater for girls than for boys (B = -1.18, P < 0.01). In multivariable analyses, adjusting for biological age completely attenuated the effect of sex and chronological age for participation in free play activities, but not for participation in organized play. Overall, biological age was a stronger predictor of participation than chronological age. The effect of biological age on sex by chronological age differences may be specific to certain types of PA participation. Given the importance of maturation to participation in activity, it is suggested that public health strategies target biological not chronological age to prevent declines in PA during adolescence particularly when promoting habitual or lifestyle activity.
Crude and intrinsic birth rates for Asian countries.
Rele, J R
1978-01-01
An attempt to estimate birth rates for Asian countries. The main sources of information in developing countries has been census age-sex distribution, although inaccuracies in the basic data have made it difficult to reach a high degree of accuracy. Different methods bring widely varying results. The methodology presented here is based on the use of the conventional child-woman ratio from the census age-sex distribution, with a rough estimate of the expectation of life at birth. From the established relationships between child-woman ratio and the intrinsic birth rate of the nature y = a + bx + cx(2) at each level of life expectation, the intrinsic birth rate is first computed using coefficients already computed. The crude birth rate is obtained using the adjustment based on the census age-sex distribution. An advantage to this methodology is that the intrinsic birth rate, normally an involved computation, can be obtained relatively easily as a biproduct of the crude birth rates and the bases for the calculations for each of 33 Asian countries, in some cases over several time periods.
Using lod scores to detect sex differences in male-female recombination fractions.
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 likelihood estimates of theta(female) and theta(male), even though ELOD is reduced (see point 2). This fact is important because often investigators cannot control the proportions of paternally and maternally informative families. In conclusion, it is possible to reliably detect sex differences in recombination fraction. Copyright 2004 S. Karger AG, Basel
Tsiligianni, Ioanna; Mezzi, Karen; Fucile, Sebastian; Kostikas, Konstantinos; Shen, Steven; Banerji, Donald; Fogel, Robert
2017-08-01
In this pooled analysis, we compared the effect of indacaterol/glycopyrronium (IND/GLY) by sex versus other commonly used chronic obstructive pulmonary disease (COPD) treatments and placebo. Male and female patients with moderate-to-very-severe COPD who had participated in six randomized controlled trials were included in the analysis. Baseline demographics and disease characteristics were analyzed by sex, and any differences noted. The effects of IND/GLY versus salmeterol/fluticasone (SFC), glycopyrronium, tiotropium and placebo, on lung function and the patient-reported outcomes (health status, dyspnea, rescue medication use and symptoms) were assessed by sex after 26 weeks treatment. The analysis population comprised 4719 men and 1389 women. Most baseline parameters differed significantly between men and women. Nonetheless, despite these differences in baseline characteristics, IND/GLY significantly improved lung function versus placebo (p < 0.0001) and all active comparators (p < 0.01) in men and women. Overall, IND/GLY showed better improvement in dyspnea and health status compared with all other treatments in both sex. Greater reduction of rescue medication use was observed with IND/GLY versus placebo and other treatments (all p < 0.01 expect IND/GLY versus SFC). Although some variability was observed, improvements in health status, dyspnea, rescue medication use and symptoms were generally larger in women than in men. Irrespective of sex, IND/GLY provided superior efficacy to monotherapy or SFC in both men and women. Small differences in efficacy response by sex were observed, which should be evaluated further in prospective clinical studies. Nevertheless, the benefits observed with IND/GLY confirm dual bronchodilator as the preferred therapy in patients with moderate-to-very-severe COPD regardless of sex.
The effects of energy balance, obesity-proneness and sex on the neuronal response to sweet taste.
Cornier, Marc-Andre; Shott, Megan E; Thomas, Elizabeth A; Bechtell, Jamie L; Bessesen, Daniel H; Tregellas, Jason R; Frank, Guido K
2015-02-01
We have previously shown that propensity for weight gain, energy balance state and sex are important determinants of the neuronal response to visual food cues. It is not clear, though, whether these factors also impact the neuronal response to taste. The objective of this study was to examine the neuronal response to sweet taste during energy imbalance in men and women recruited to be obesity-prone (OP) or obesity-resistant (OR). OP (13 men and 12 women) and OR (12 men and 12 women) subjects were studied after 1 day of eucaloric, overfed and underfed conditions in a randomized crossover design. On each test day, fMRI was performed in the respective acute fed state while subjects received in random order 60 trials each of 1M sucrose solution (SU), or artificial saliva (AS) following a visual cue predicting the taste. The neuronal response to SU versus AS expectation was significantly greater in the amygdala, orbitofrontal cortex, putamen and insula in OR versus OP; SU receipt was not different between groups. There were also sex-based differences with men having greater neuronal response to SU versus AS receipt in the caudate than women. The results, however, were not impacted by the state of energy balance. In summary, response to expectation but not receipt of basic sweet taste was different in OR compared to OP, highlighting the importance of learning and conditioning in the propensity to gain weight. Response to sucrose taste receipt was stronger in men than women, raising questions about the effect of sex hormones on brain response to food. Copyright © 2014 Elsevier B.V. All rights reserved.
Papaioannou, Andriana I; Bania, Eleni; Alexopoulos, Evangelos C; Mitsiki, Eirini; Malli, Foteini; Gourgoulianis, Konstantinos I
2014-01-01
Background The prevalence of chronic obstructive pulmonary disease (COPD) in females appears to be increasing. Recent studies have revealed that the percentage of women with COPD in Greece is approximately 12.5%. Aims To evaluate the burden of COPD among males and females in Greece through a nationwide cross-sectional survey and to explore sex differences regarding functional characteristics and exacerbation frequency. Methods Data collection was completed in a 6-month period. The present study followed a nationwide sampling approach of respiratory medicine physicians. The sampling approach included three steps: 1) estimation of expected incidence and prevalence of COPD cases in each prefecture of Greece and in total; 2) estimation of expected incidence of COPD cases per physician in each prefecture; and 3) creation of a frame of three different sampling zones. Following this sampling, data were provided by 199 respiratory physicians. Results The participating physicians provided data from 6,125 COPD patients. Female patients represented 28.7% of the study participants. Female COPD patients were, on average, 5 years younger than male COPD patients. Never smokers accounted for 9.4% within female patients, compared to 2.7% of males (P<0.001). Female patients were characterized by milder forms of the disease. Comorbidities were more prevalent in men, with the exception of gastroesophageal reflux (14.6% versus 17.1% for men and women, respectively, P=0.013). Female COPD patients had a higher expected number of outpatient visits per year (by 8.9%) than males (P<0.001), although hospital admissions did not differ significantly between sexes (P=0.116). Females had fewer absences from work due to COPD per year, by 19.0% (P<0.001), compared to males. Conclusion The differences observed between male and female COPD patients provide valuable information which could aid the prevention and management of COPD in Greece. PMID:24600217
Sex differences in the effects of juvenile and adult diet on age-dependent reproductive effort.
Houslay, T M; Hunt, J; Tinsley, M C; Bussière, L F
2015-05-01
Sexual selection should cause sex differences in patterns of resource allocation. When current and future reproductive effort trade off, variation in resource acquisition might further cause sex differences in age-dependent investment, or in sensitivity to changes in resource availability over time. However, the nature and prevalence of sex differences in age-dependent investment remain unclear. We manipulated resource acquisition at juvenile and adult stages in decorated crickets, Gryllodes sigillatus, and assessed effects on sex-specific allocation to age-dependent reproductive effort (calling in males, fecundity in females) and longevity. We predicted that the resource and time demands of egg production would result in relatively consistent female strategies across treatments, whereas male investment should depend sharply on diet. Contrary to expectations, female age-dependent reproductive effort diverged substantially across treatments, with resource-limited females showing much lower and later investment in reproduction; the highest fecundity was associated with intermediate lifespans. In contrast, long-lived males always signalled more than short-lived males, and male age-dependent reproductive effort did not depend on diet. We found consistently positive covariance between male reproductive effort and lifespan, whereas diet altered this covariance in females, revealing sex differences in the benefits of allocation to longevity. Our results support sex-specific selection on allocation patterns, but also suggest a simpler alternative: males may use social feedback to make allocation decisions and preferentially store resources as energetic reserves in its absence. Increased calling effort with age therefore could be caused by gradual resource accumulation, heightened mortality risk over time, and a lack of feedback from available mates. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.
Lonsdorf, Tina B.; Haaker, Jan; Schümann, Dirk; Sommer, Tobias; Bayer, Janine; Brassen, Stefanie; Bunzeck, Nico; Gamer, Matthias; Kalisch, Raffael
2015-01-01
Background Anxiety disorders are more prevalent in women than in men. Despite this sexual dimorphism, most experimental studies are conducted in male participants, and studies focusing on sex differences are sparse. In addition, the role of hormonal contraceptives and menstrual cycle phase in fear conditioning and extinction processes remain largely unknown. Methods We investigated sex differences in context-dependent fear acquisition and extinction (day 1) and their retrieval/expression (day 2). Skin conductance responses (SCRs), fear and unconditioned stimulus expectancy ratings were obtained. Results We included 377 individuals (261 women) in our study. Robust sex differences were observed in all dependent measures. Women generally displayed higher subjective ratings but smaller SCRs than men and showed reduced excitatory/inhibitory conditioned stimulus (CS+/CS−) discrimination in all dependent measures. Furthermore, women using hormonal contraceptives showed reduced SCR CS discrimination on day 2 than men and free-cycling women, while menstrual cycle phase had no effect. Limitations Possible limitations include the simultaneous testing of up to 4 participants in cubicles, which might have introduced a social component, and not assessing postexperimental contingency awareness. Conclusion The response pattern in women shows striking similarity to previously reported sex differences in patients with anxiety. Our results suggest that pronounced deficits in associative discrimination learning and subjective expression of safety information (CS− responses) might underlie higher prevalence and higher symptom rates seen in women with anxiety disorders. The data call for consideration of biological sex and hormonal contraceptive use in future studies and may suggest that targeting inhibitory learning during therapy might aid precision medicine. PMID:26107163
Lovich, Jeffrey E.; Gibbons, J. Whitfield; Agha, Mickey
2014-01-01
The attainment of sexual maturity has been shown to affect measures of sexual size dimorphism (SSD) and adult sex ratios in several groups of vertebrates. Using data for turtles, we tested the model that sex ratios are expected to be male-biased when females are larger than males and female-biased when males are larger than females because of the relationship of each with the attainment of maturity. Our model is based on the premise that the earlier-maturing sex remains smaller, on average throughout life, and predominates numerically unless the sexes are strongly affected by differential mortality, differential emigration, and immigration, or biased primary sex ratios. Based on data for 24 species in seven families, SSD and sex ratios were significantly negatively correlated for most analyses, even after the effect of phylogenetic bias was removed. The analyses provide support for the model that SSD and adult sex ratios are correlated in turtles as a result of simultaneous correlation of each with sexual differences in attainment of maturity (bimaturism). Environmental sex determination provides a possible mechanism for the phenomenon in turtles and some other organisms.
The Social Networking Arena: Battle of the Sexes
ERIC Educational Resources Information Center
Clipson, Timothy W.; Wilson, S. Ann; DuFrene, Debbie D.
2012-01-01
Social networking via texting, Facebook, Twitter, and similar media is enormously popular with students, though it often leads to communication challenges along gender lines. Research supports the fact that men and women have divergent expectations for social networking and use it differently. Students can benefit from classroom experiences that…
Success in Architecture: Handedness and/or Visual Thinking.
ERIC Educational Resources Information Center
Peterson, John M.; Lansky, Leonard M.
1980-01-01
Some data on sex and handedness in relation to academic predictors and success in architectural education were reexamined. The new variable was the notion of visual thinking, measured by the manner, "visually" or "cognitively," of executing a simple line drawing. As expected, significant differences appeared between persons using these modes.…
Influence of Children's Physical Attractiveness on Teacher Expectations.
ERIC Educational Resources Information Center
Kenealy, Pamela; And Others
1988-01-01
Ratings of the physical attractiveness of 11-to-12-year-old children were obtained, and the association between physical attractiveness and teachers' judgements of these children were examined. Teachers revealed a systematic tendency to rate girls higher than boys, and significant sex differences were observed in teachers' ratings of…
Auer, Matthias K.; Cecil, Alexander; Roepke, Yasmin; Bultynck, Charlotte; Pas, Charlotte; Fuss, Johannes; Prehn, Cornelia; Wang-Sattler, Rui; Adamski, Jerzy; Stalla, Günter K.; T’Sjoen, Guy
2016-01-01
Metabolomic analyses in epidemiological studies have demonstrated a strong sexual dimorphism for most metabolites. Cross-sex hormone treatment (CSH) in transgender individuals enables the study of metabolites in a cross-gender setting. Targeted metabolomic profiling of serum of fasting transmen and transwomen at baseline and following 12 months of CSH (N = 20/group) was performed. Changes in 186 serum metabolites and metabolite ratios were determined by targeted metabolomics analysis based on ESI-LC-MS/MS. RandomForest (RF) analysis was applied to detect metabolites of highest interest for grouping of transwomen and transmen before and after initiation of CSH. Principal component analysis (PCA) was performed to check whether group differentiation was achievable according to these variables and to see if changes in metabolite levels could be explained by a priori gender differences. PCA predicted grouping of individuals-determined by the citrulline/arginine-ratio and the amino acids lysine, alanine and asymmetric dimethylarginine - in addition to the expected grouping due to changes in sex steroids and body composition. The fact that most of the investigated metabolites did, however, not change, indicates that the majority of sex dependent differences in metabolites reported in the literature before may primarily not be attributable to sex hormones but to other gender-differences. PMID:27833161
El-Bassel, Nabila; Jemmott, John B; Bellamy, Scarlett L; Pequegnat, Willo; Wingood, Gina M; Wyatt, Gail E; Landis, J Richard; Remien, Robert H
2016-06-01
Targeting couples is a promising behavioral HIV risk-reduction strategy, but the mechanisms underlying the effects of such interventions are unknown. We report secondary analyses testing whether Social-Cognitive-Theory variables mediated the Eban HIV-risk-reduction intervention's effects on condom-use outcomes. In a multisite randomized controlled trial conducted in four US cities, 535 African American HIV-serodiscordant couples were randomized to the Eban HIV risk-reduction intervention or attention-matched control intervention. Outcomes were proportion condom-protected sex, consistent condom use, and frequency of unprotected sex measured pre-, immediately post-, and 6 and 12 months post-intervention. Potential mediators included Social-Cognitive-Theory variables: outcome expectancies and self-efficacy. Mediation analyses using the product-of-coefficients approach in a generalized-estimating-equations framework revealed that condom-use outcome expectancy, partner-reaction outcome expectancy, intention, self-efficacy, and safer-sex communication improved post-intervention and mediated intervention-induced improvements in condom-use outcomes. These findings underscore the importance of targeting outcome expectancies, self-efficacy, and safer-sex communication in couples-level HIV risk-reduction interventions.
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).
The evolution of sex chromosomes in organisms with separate haploid sexes.
Immler, Simone; Otto, Sarah Perin
2015-03-01
The evolution of dimorphic sex chromosomes is driven largely by the evolution of reduced recombination and the subsequent accumulation of deleterious mutations. Although these processes are increasingly well understood in diploid organisms, the evolution of dimorphic sex chromosomes in haploid organisms (U/V) has been virtually unstudied theoretically. We analyze a model to investigate the evolution of linkage between fitness loci and the sex-determining region in U/V species. In a second step, we test how prone nonrecombining regions are to degeneration due to accumulation of deleterious mutations. Our modeling predicts that the decay of recombination on the sex chromosomes and the addition of strata via fusions will be just as much a part of the evolution of haploid sex chromosomes as in diploid sex chromosome systems. Reduced recombination is broadly favored, as long as there is some fitness difference between haploid males and females. The degeneration of the sex-determining region due to the accumulation of deleterious mutations is expected to be slower in haploid organisms because of the absence of masking. Nevertheless, balancing selection often drives greater differentiation between the U/V sex chromosomes than in X/Y and Z/W systems. We summarize empirical evidence for haploid sex chromosome evolution and discuss our predictions in light of these findings. © 2015 The Author(s).
Tordjman, S
2006-01-01
A strong prevalence of females or males is often found in mental disorders. Based on examples of anorexia (90% females) and autistic disorder (80 to 90% males), arguments that allow a better understanding of these different sex ratios are presented. The role of certain sociocultural factors in the onset of anorexia is developed. The predominance of males in autistic disorder has led to genetic and hormone-based biological hypotheses. However, it is also possible that the cultural representation of sex roles and its effects (expectation, different attitudes and behaviors depending on the child's gender) influence the development of social interaction and communication domains which are impaired in autistic disorder. Indeed, according to most studies, parents solicit and stimulate more social interaction and communication (eye contact specially during the first months of life, vocalizations then verbal language, emotional expression) in girls than in boys during the first three years of life, which corresponds to the period when autistic disorder appears. It is possible that because girls are more solicited than boys in social interaction and communication domains, during a sensitive (or critical) period of development, we may observe that girls show less autistic impairment in reciprocal social interaction and verbal or non-verbal communication, which are two of the three main domains of autistic disorder. It is also possible that impairments in social interaction and communication may be identified earlier for girls than for boys, which could lead to earlier therapeutic care for girls. Indeed, if parents have greater expectations for girls in social interaction and/or communication domains, they may worry more for their girl than for their boy with regard to developmental delay in these domains, and then may ask for professional advice earlier. This is what we have observed in our clinical practice and research, in which we conducted a follow-up in young girls showing autistic disorder aged two and half years old and who evolved positively; in contrast we have observed that parents bring their son for professional advice later, after kindergarten begins. Finally, a more complex, non-linear model is proposed in which biological genetic factors (such as sex-linked chromosomes) and/or hormonal factors (such as sex hormones) may play a role in differentiation of girls' and boys' behavior from birth. These different behaviors would induce differentiated expectations and attitudes in parents depending on the child's gender, which in turn would reinforce sex-related characteristic behaviors in the child. Thus, there may be a continuum in different behavioral domains (for example, boys would interact and communicate less than girls, and girls would express more their emotions), with mental disorders occurring at the extremes of this continuum (for example, autistic disorder for certain boys and anxiety disorder for certain girls). This hypothesis fits within an integrated psycho-biological approach that takes into account sex differences in mental disorders; it stems from a model in which a dimensional conception of mental disorders replaces a categorical nosographical one. New perspectives could be envisioned concerning the identification, follow-up and treatment of mental disorders (or sub-types of mental disorders), which are currently considered to belong to different nosographical categories, but which could overlap through shared common dimensions.
Mulieri, P R; Olea, M S; Patitucci, L D; Battán-Horenstein, M
2018-06-07
Abundance of sarcosaprophagous Calyptratae species was monitored by using baited traps and active captures with hand net. Analysis of field data collected in three protected areas in the Valdivian temperate forest of South America (Lanín National Park, Lago Puelo National Park, and Los Alerces National Park) indicated that bottle traps baited with putrescine is a reliable method to estimate local abundance of sarcosaprophagous species by comparison to the active capture method. Also, we describe and compare general patterns of sex bias for four dominant species: Sarconesia magellanica (Le Guillou), Calliphora vicina Robineau-Desvoidy, Microcerella spinigena (Rondani), and Oxysarcodexia varia (Walker). From these analyses, it can be concluded that abundance fluctuations of flies showed significant relationship between the sampling methods. This study showed that besides the expected interspecific differences in trapping efficiency, there are acute intraspecific differences of sex ratios between sampling methods.
Adults' attitudes about gender nonconformity in childhood.
Thomas, Rachel N; Blakemore, Judith E Owen
2013-04-01
This study examined attitudes about outcomes associated with childhood gender nonconformity. Participants were 518 undergraduate students (337 female; 181 male) at a midwestern university in the U.S. Participants were presented with 1 of 10 vignettes describing a target child (male or female) who varied in gendered traits, interests, and behaviors (strongly masculine, moderately masculine, neutral, moderately feminine or strongly feminine). They completed a 50-item questionnaire including demographics, predicted outcomes for the target (e.g., masculinity and femininity in adulthood, pressure to change, psychological adjustment in childhood and adulthood, and sexual orientation), and the Attitudes toward Women Scale (Spence et al., 1973). Participants thought masculine and feminine targets would be masculine and feminine in adulthood, respectively: thus, stability was expected for both sexes. Feminine targets, boys or girls, were thought to be more likely to display internalizing (e.g., anxiety, depression) behaviors and masculine targets more likely to display externalizing (e.g., aggression, conduct disorders) behaviors in both childhood and adulthood. Gender-nonconforming children were expected to experience more pressure to change their behavior and less likely to be exclusively heterosexual adults, the latter particularly so for strongly feminine boys. There were few significant effects of participant sex and no effects of attitudes about gender on any of these measures. These findings add to the literature by demonstrating that degrees of masculinity and femininity as well as of gender nonconformity are expected to be associated with predictable outcomes in a linear fashion in both sexes, with only a few differences between expectations for boys and girls.
Gratitude for help among adult friends and siblings.
Rotkirch, Anna; Lyons, Minna; David-Barrett, Tamas; Jokela, Markus
2014-07-06
Although gratitude is a key prosocial emotion reinforcing reciprocal altruism, it has been largely ignored in the empirical literature. We examined feelings of gratitude and the importance of reciprocity in same-sex peer relations. Participants were 772 individuals (189 men; mean age = 28.80) who completed an online survey using a vignette design. We investigated (i) differences in reported gratitude and the importance of reciprocity among same-sex siblings and same-sex friends, and (ii) how relationship closeness moderates these associations. Based on the theory of kin altruism, we expect that people would feel more grateful towards friends than towards their siblings, and that lack of gratitude or failure to pay back a loan would bother more with friends than with siblings, irrespective of emotional closeness. Results showed that levels of gratitude and expectations of reciprocity were higher towards friends compared to siblings. This was the case also after controlling for emotional closeness. Being close generally made participants feel more grateful and expect lower displays of gratitude in the other. Closeness was also strongly associated with emotional gratitude among siblings compared to friends. We conclude that feelings and displays of gratitude have a special role in friendships. Although a close sibling may elicit as much gratitude as a friend does, even a very close friend is not exempt from the logic of reciprocity in the same way that a sibling is.
Balancing selection in species with separate sexes: insights from Fisher's geometric model.
Connallon, Tim; Clark, Andrew G
2014-07-01
How common is balancing selection, and what fraction of phenotypic variance is attributable to balanced polymorphisms? Despite decades of research, answers to these questions remain elusive. Moreover, there is no clear theoretical prediction about the frequency with which balancing selection is expected to arise within a population. Here, we use an extension of Fisher's geometric model of adaptation to predict the probability of balancing selection in a population with separate sexes, wherein polymorphism is potentially maintained by two forms of balancing selection: (1) heterozygote advantage, where heterozygous individuals at a locus have higher fitness than homozygous individuals, and (2) sexually antagonistic selection (a.k.a. intralocus sexual conflict), where the fitness of each sex is maximized by different genotypes at a locus. We show that balancing selection is common under biologically plausible conditions and that sex differences in selection or sex-by-genotype effects of mutations can each increase opportunities for balancing selection. Although heterozygote advantage and sexual antagonism represent alternative mechanisms for maintaining polymorphism, they mutually exist along a balancing selection continuum that depends on population and sex-specific parameters of selection and mutation. Sexual antagonism is the dominant mode of balancing selection across most of this continuum. Copyright © 2014 by the Genetics Society of America.
Adaptive Sex Determination and Population Dynamics in a Brackish-water Amphipod
NASA Astrophysics Data System (ADS)
Watt, Penelope J.; Adams, Jonathan
1993-09-01
Gammarus duebeni is a sexually dimorphic amphipod with an unusual and environmentally mediated sex determining system. In seasonal populations, environmental sex determination (ESD) is selectively advantageous and males and females are produced at different times of the year, but it has been predicted that where generations overlap or the breeding season is long, ESD should no longer have a selective advantage over genetic mechanisms of sex determination and males and females should be produced simultaneously. The dynamics of a supposedly bivoltine population at Totton Marsh on the south coast of England were investigated. The field study showed that the breeding season at Totton was not in fact bivoltine but long, extending through most of the year with a short break in early summer. Population sex ratio fluctuated seasonally: this pattern appears to be the product of differences in production of males and females rather than growth or mortality. Thus, contrary to expectations, ESD does occur in this population. Photoperiod is the cue for sex determination in the laboratory, but in the field this alone could not account for the observed pattern of male and female production at Totton Marsh. Another major variable must be involved and it is proposed that it also has an influence on other G. duebeni populations.
Dudycha, Jeffry L; Snoke-Smith, Margaret; Alía, Ricardo
2013-02-01
Genetic correlations among traits alter evolutionary trajectories due to indirect selection. Pleiotropy, chance linkage, and selection can all lead to genetic correlations, but have different consequences for phenotypic evolution. We sought to assess the mechanisms contributing to correlations with size at maturity in the cyclic parthenogen Daphnia pulicaria. We selected on size in each of four populations that differ in the frequency of sex, and evaluated correlated responses in a life table. Size at advanced adulthood, reproductive output, and adult growth rate clearly showed greater responses in high-sex populations, with a similar pattern in neonate size and r. This pattern is expected only when trait correlations are favored by selection and the frequency of sex favors the creation and demographic expansion of highly fit clones. Juvenile growth and age at maturity did not diverge consistently. The inter-clutch interval appeared to respond more strongly in low-sex populations, but this was not statistically significant. Our data support the hypothesis that correlated selection is the strongest driver of genetic correlations, and suggest that in organisms with both sexual and asexual reproduction, adaptation can be enhanced by recombination.
Farren, G L; Zhang, T; Martin, S B; Thomas, K T
2017-01-01
To examine the relations of sex, exercise self-efficacy, outcome expectations, and social support with meeting physical activity guidelines (PAGs). Three hundred ninety-six college students participated in this study in the summer 2013. Students completed online questionnaires that assessed physical activity behaviors and psychosocial factors (ie, self-efficacy, outcome expectancies, and social support). Students' physical activity profile was categorized as meeting no PAGs, meeting aerobic PAGs only, meeting muscle-strengthening PAGs only, or meeting both PAGs. A multinomial logistic regression revealed that students' sex and psychosocial factors significantly affected the odds of meeting any and all PAGs. Sex significantly moderated the relationship between outcome expectancy and meeting aerobic PAGs and between outcome expectancy meeting muscle-strengthening PAGs. Results indicate that interventions designed to increase psychosocial factors may increase the likelihood of students meeting any and all PAGs. Social support may be especially beneficial for increasing muscle-strengthening activity.
Scherbov, Sergei; Weber, Daniela
2017-01-01
Objective To project the proportion of population 65+ years with severe long-term activity limitations from 2017 to 2047. Design Large population study. Setting Population living in private households of the European Union (EU) and neighbouring countries. Participants Participants from the EU Statistics on Income and Living Conditions aged 55 years and older and living in one of 26 EU and neighbouring countries, who answered the health section of the questionnaire. Outcome measures Prevalence of severe long-term activity limitations of particular subpopulations (ie, 55+, 65+, 75+ and 85+ years) by sex and country. Results We find a huge variation in the prevalence of self-reported severe long-term limitations across Europe for both sexes. However, in 2017, about 20% of the female population aged 65 years and above and about 16% of their male counterparts are expected to report severe long-term activity limitations after accounting for differences in reporting. Accounting for cultural differences in reporting, we expect that European countries will have about 21% (decile 1: 19.5%; decile 9: 22.9%) of female and about 16.8% (decile 1: 15.4%; decile 9: 18.1%) of male 65+ years population with severe long-term activity limitations by 2047. Conclusions Overall, despite the expected increase of life expectancy in European countries, our results suggest almost constant shares of older adults with severe long-term activity limitations within the next 30 years. PMID:29061570
Sexual dimorphism in immune function changes during the annual cycle in house sparrows
NASA Astrophysics Data System (ADS)
Pap, Péter László; Czirják, Gábor Árpád; Vágási, Csongor István; Barta, Zoltán; Hasselquist, Dennis
2010-10-01
Difference between sexes in parasitism is a common phenomenon among birds, which may be related to differences between males and females in their investment into immune functions or as a consequence of differential exposure to parasites. Because life-history strategies change sex specifically during the annual cycle, immunological responses of the host aiming to reduce the impact of parasites may be sexually dimorphic. Despite the great complexity of the immune system, studies on immunoecology generally characterise the immune status through a few variables, often overlooking potentially important seasonal and gender effects. However, because of the differences in physiological and defence mechanisms among different arms of the immune system, we expect divergent responses of immune components to environmental seasonality. In male and female house sparrows ( Passer domesticus), we measured the major components of the immune system (innate, acquired, cellular and humoral) during four important life-history stages across the year: (1) mating, (2) breeding, (3) moulting and (4) during the winter capture and also following introduction to captivity in aviary. Different individuals were sampled from the same population during the four life cycle stages. We found that three out of eight immune variables showed a significant life cycle stage × sex interaction. The difference in immune response between the sexes was significant in five immune variables during the mating stage, when females had consistently stronger immune function than males, while variables varied generally non-significantly with sex during the remaining three life cycle stages. Our results show that the immune system is highly variable between life cycle stages and sexes, highlighting the potential fine tuning of the immune system to specific physiological states and environmental conditions.
Doing gender in sex and sex research.
Vanwesenbeeck, Ine
2009-12-01
Gender is central to sexuality, and vice versa, but there are a number of difficulties with the treatment of gender in sex research. Apparently, it is hard to find a balance between two conflicting needs. First, obviously, it is necessary to make distinctions between women and men, for political as well as research-technical and theoretical reasons. A second requirement, at odds with the first one, is the necessity to understand gender and its relation to sexuality and the body as much more complex than simplistically referring to two sets of individuals. This is all the more necessary when one realizes the possible drawbacks of exaggerating the differences between the sexes (in particular when they are biologically explained), because of stereotyping, stigmatizing, and expectancy confirmatory processes. This essay identifies and discusses 10 difficulties in the treatment of gender in sex research, reflects on their origins, and reviews theory and evidence with the aim to (1) consider the relative strength of gender/sex as an explanatory variable compared to other factors and processes explaining differences between men and women on a number of sexual aspects, (2) inform an understanding of gender and its relation to sexuality as an ongoing, open-ended, multi-determined, situated, interactional process, with the body as a third player, and (3) argue in favor of a nuanced, well-balanced treatment of gender in sex research.
[Sexual differentiation of the human brain].
Kula, K; Słowikowska-Hilczer, J
2000-01-01
Normal human development requires the compatibility between genetic sex (sex chromosomes), sex of gonades (tests or ovaries), genitalia (external and internal sex organs), somatic features (body characteristics) and psychic sex. The psychic sex, called frequently gender, consist of gender identity (self-estimation), gender role (objective estimation) and sexual orientation (hetero- or homosexual). It was believed that the psychic gender depends only on socio-environmental influences such as rearing, learning and individual choice. Although, the process of sexual differentiation of human brain is not completely elucidated, it has became recently evident that endogenous hormones more then socio-environmental factors influence gender differences. Experimental studies on animals revealed that transient action of sex steroids during perinatal period of life is crucial for the dymorphism of sexual behavior (male or female) in adulthood. It seems, that also in the human male neonates testosterone produced by testes perinatally takes the main role in the irreversible masculinization of the brain i.e. creation of the differences vs. female brain. The evaluation of patients with disturbances of sexual differentiation of external genitalia (the lack of the testosterone transformation into 5-alpha dihydrotestosterone in peripheral tissues of men or the inborn excess of androgens in women with the congenital adrenal hyperplasia) has served as a useful clinical model for understanding factors, affecting the formation of gender. In these individuals the formal sex established according to genetic sex and somatic sex may be incompatible with gender identity and role. However, it has been found that the female gender identity is most frequently associated with the presence of ovaries or the lack of gonads (gonadal dysgenesis), while the male gender identity appear most frequently in the presence of testicular tissue irrespective of female or hermaphrodite (intersex) phenotype. In genetic men with the absence of male genitalia formation, caused by the aberrant function of androgen receptor, the gender identity depends on the severity of the disorder: female gender identity in the complete androgen insensitivity syndrome and female or male gender identity in the complete androgen insensitivity syndrome and female or male in the partial androgen insensitivity. These clinical observations confirm the experimental data indicating androgen role in the male gender identity creation. This knowledge is necessary for the decision of the direction of surgical correction of sex organs in children with ambiguous genitalia, which should not depend on the expected efficiency to perform sexual intercourse, but mostly on the expected or already present individual gender identity.
What was the ancestral sex-determining mechanism in amniote vertebrates?
Johnson Pokorná, Martina; Kratochvíl, Lukáš
2016-02-01
Amniote vertebrates, the group consisting of mammals and reptiles including birds, possess various mechanisms of sex determination. Under environmental sex determination (ESD), the sex of individuals depends on the environmental conditions occurring during their development and therefore there are no sexual differences present in their genotypes. Alternatively, through the mode of genotypic sex determination (GSD), sex is determined by a sex-specific genotype, i.e. by the combination of sex chromosomes at various stages of differentiation at conception. As well as influencing sex determination, sex-specific parts of genomes may, and often do, develop specific reproductive or ecological roles in their bearers. Accordingly, an individual with a mismatch between phenotypic (gonadal) and genotypic sex, for example an individual sex-reversed by environmental effects, should have a lower fitness due to the lack of specialized, sex-specific parts of their genome. In this case, evolutionary transitions from GSD to ESD should be less likely than transitions in the opposite direction. This prediction contrasts with the view that GSD was the ancestral sex-determining mechanism for amniote vertebrates. Ancestral GSD would require several transitions from GSD to ESD associated with an independent dedifferentiation of sex chromosomes, at least in the ancestors of crocodiles, turtles, and lepidosaurs (tuataras and squamate reptiles). In this review, we argue that the alternative theory postulating ESD as ancestral in amniotes is more parsimonious and is largely concordant with the theoretical expectations and current knowledge of the phylogenetic distribution and homology of sex-determining mechanisms. © 2014 Cambridge Philosophical Society.
ERIC Educational Resources Information Center
Davis, Patricia C.; And Others
Relationships among high school females' self-perceptions on sex-stereotypic attributes and their occupational aspirations and expectations were investigated. Two measures were administered to, and data were collected from, 200 randomly selected females in grade 12 from a large urban school district. Occupational choice was measured by two…
Leickly, Emily; Nelson, Kimberly; Simoni, Jane
2017-09-01
Limited research has investigated the perceived influence of sexually explicit online media (SEOM) on body satisfaction and partner expectations of men who have sex with men (MSM). Semi-structured qualitative interviews were conducted with 16 MSM, covering the perceived influence of MSM-specific SEOM. All nine men who broached the topics of body satisfaction and partner expectations reported that MSM-specific SEOM set unreasonably high physical appearance expectations for themselves and/or their potential partners. Although MSM-specific SEOM might be negatively affecting body satisfaction and partner expectations among MSM, its ubiquity may make it a useful tool to support body positivity.
Nelson, Kimberly; Simoni, Jane
2016-01-01
Limited research has investigated the perceived influence of sexually explicit online media (SEOM) on body satisfaction and partner expectations of men who have sex with men (MSM). Semi-structured qualitative interviews were conducted with 16 MSM, covering the perceived influence of MSM-specific SEOM. All nine men who broached the topics of body satisfaction and partner expectations reported that MSM-specific SEOM set unreasonably high physical appearance expectations for themselves and/or their potential partners. Although MSM-specific SEOM might be negatively affecting body satisfaction and partner expectations among MSM, its ubiquity may make it a useful tool to support body positivity. PMID:28979572
Soleman, Remi S; Schagen, Sebastian E E; Veltman, Dick J; Kreukels, Baudewijntje P C; Cohen-Kettenis, Peggy T; Lambalk, Cornelis B; Wouters, Femke; Delemarre-van de Waal, Henriette A
2013-08-01
In the literature, verbal fluency (VF) is generally described as a female-favoring task. Although it is conceivable that this sex difference only evolves during adolescence or adulthood under influence of sex steroids, this has never been investigated in young adolescents. First, to assess sex differences in VF performance and regional brain activation in adolescents. Second, to determine if untreated transsexual adolescents differ from their sex of birth with regard to VF performance and regional brain activation. Twenty-five boys, 26 girls, 8 Male-to-Female transsexual adolescents (MtFs), and 14 Female-to-Male transsexual adolescents (FtMs) were tested in a cross-sectional study, while performing a phonetic and semantic VF task within an MRI scanner. Functional MRI response during VF task. Boys and girls produced similar amounts of words, but the group MtFs produced significantly more words in the phonetic condition compared to control boys, girls, and FtMs. During the semantic condition, no differences were found. With regard to brain activity, control boys showed more activation in the right Rolandic operculum, a small area adjacent to Broca's area, compared to girls. No significant differences in brain activity were found comparing transsexual adolescents, although sub-threshold activation was found in the right Rolandic operculum indicating a trendwise increase in activation from control girls to FtMs to MtFs to control boys. The better performance of MtFs is consistent with our expectation that MtFs perform better on female-favoring tasks. Moreover, they produced more words than girls and FtMs. Even though a trendwise linear increase in brain activity between the four groups only approached significance, it may indicate differences in individuals with gender identity disorder compared to their birth sex. Although our findings should thus be interpreted with caution, they suggest a biological basis for both transgender groups performing in-between the two sexes. © 2013 International Society for Sexual Medicine.
A Sex Role Inventory with Scales for "Machismo" and "Self-Sacrificing Woman."
ERIC Educational Resources Information Center
Lara-Cantu, Maria Asuncion
1989-01-01
Describes the development of a new sex role inventory, the Masculine-Feminine Personality Traits Scale, based on Bem's Sex Role Inventory and using Mexican sex role stereotypes. The instrument includes scales measuring assertive masculinity, affective femininity, aggressive masculinity, and submissive femininity. Results show expected response…
Horsley, Kimberly; Stark, Lloyd R.; McLetchie, D. Nicholas
2011-01-01
Background and Aims Expected life history trade-offs associated with sex differences in reproductive investment are often undetected in seed plants, with the difficulty arising from logistical issues of conducting controlled experiments. By controlling genotype, age and resource status of individuals, a bryophyte was assessed for sex-specific and location-specific patterns of vegetative, asexual and sexual growth/reproduction across a regional scale. Methods Twelve genotypes (six male, six female) of the dioecious bryophyte Bryum argenteum were subcultured to remove environmental effects, regenerated asexually to replicate each genotype 16 times, and grown over a period of 92 d. Plants were assessed for growth rates, asexual and sexual reproductive traits, and allocation to above- and below-ground regenerative biomass. Key Results The degree of sexual versus asexual reproductive investment appears to be under genetic control, with three distinct ecotypes found in this study. Protonemal growth rate was positively correlated with asexual reproduction and sexual reproduction, whereas asexual reproduction was negatively correlated (appeared to trade-off) with vegetative growth (shoot production). No sex-specific trade-offs were detected. Female sex-expressing shoots were longer than males, but the sexes did not differ in growth traits, asexual traits, sexual induction times, or above- and below-ground biomass. Males, however, had much higher rates of inflorescence production than females, which translated into a significantly higher (24x) prezygotic investment for males relative to females. Conclusions Evidence for three distinct ecotypes is presented for a bryophyte based on regeneration traits. Prior to zygote production, the sexes of this bryophyte did not differ in vegetative growth traits but significantly differed in reproductive investment, with the latter differences potentially implicated in the strongly biased female sex ratio. The disparity between males and females for prezygotic reproductive investment is the highest known for bryophytes. PMID:21320878
A Tale of Two Types of Perspective Taking: Sex Differences in Spatial Ability.
Tarampi, Margaret R; Heydari, Nahal; Hegarty, Mary
2016-11-01
Sex differences in favor of males have been documented in measures of spatial perspective taking. In this research, we examined whether social factors (i.e., stereotype threat and the inclusion of human figures in tasks) account for these differences. In Experiment 1, we evaluated performance when perspective-taking tests were framed as measuring either spatial or social (empathetic) perspective-taking abilities. In the spatial condition, tasks were framed as measures of spatial ability on which males have an advantage. In the social condition, modified tasks contained human figures and were framed as measures of empathy on which females have an advantage. Results showed a sex difference in favor of males in the spatial condition but not the social condition. Experiments 2 and 3 indicated that both stereotype threat and including human figures contributed to these effects. Results suggest that females may underperform on spatial tests in part because of negative performance expectations and the character of the spatial tests rather than because of actual lack of abilities. © The Author(s) 2016.
Sex differences and plasticity in dehydration tolerance: insight from a tropical liverwort.
Marks, Rose A; Burton, James F; McLetchie, D Nicholas
2016-08-01
Adaptations allowing plants to cope with drying are particularly relevant in the light of predicted climate change. Dehydration tolerance (DhT, also dehydration-tolerant) is one such adaptation enabling tissue to survive substantial drying. A great deal of work has been conducted on highly DhT species. However, bryophytes showing less intense and variable DhT are understudied, despite the potential for these species to provide an informative link between highly tolerant and sensitive species. In this study, we tested the degree to which DhT varies across populations and the sexes of a species expected to exhibit a moderate DhT phenotype. To test predicted patterns of tolerance we assessed DhT in males and females of Marchantia inflexa from two distinct habitat types that differ in water availability. Both common garden and field-collected tissue was subjected to drying assays at multiple intensities and recovery was monitored by chlorophyll florescence. Verification studies were conducted to confirm the level of dehydration, the rate of drying and the associated changes in photosynthetic physiology. We confirmed our expectation that M. inflexa is able to tolerate moderate dehydration. We also found that females exhibited higher DhT than males, but populations did not differ in DhT when cultured in a common garden. However, field-collected samples exhibited differences in DhT corresponding to environmental dryness, suggesting plasticity in DhT. By studying a less extreme DhT phenotype we gained insight into how more sensitive (yet still tolerant) organisms cope with dehydration. Additionally, the identified sex-specific variation in DhT may explain ecological patterns such as female-biased sex ratios. Furthermore, plasticity in DhT has the potential to inform management practices aimed at increasing tolerance to drought conditions. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Different sex ratios of children born to Indian and Pakistani immigrants in Norway
2010-01-01
Background A low female-to-male ratio has been observed in different Asian countries, but this phenomenon has not been well studied among immigrants living in Western societies. In this study, we investigated whether a low female-to-male ratio exists among Indian and Pakistani immigrants living in Norway. In particular, we investigated whether the determination of sex via ultrasound examination, a common obstetric procedure that has been used in Norway since the early 1980 s, has influenced the female-to-male ratio among children born to parents of Indian or Pakistani origin. Methods We performed a retrospective cohort study of live births in mothers of Indian (n = 1597) and Pakistani (n = 5617) origin. Data were obtained from "Statistics Norway" and the female-to-male (F/M) sex ratio was evaluated among 21,325 children born, in increasing birth order, during three stratified periods (i.e., 1969-1986, 1987-1996, and 1997-2005). Results A significant low female-to-male sex ratio was observed among children in the third and fourth birth order (sex ratio 65; 95% CI 51-80) from mothers of Indian origin who gave birth after 1987. Sex ratios did not deviate from the expected natural variation in the Indian cohort from 1969 to 1986, and remained stable in the Pakistani cohort during the entire study period. However, the female-to-male sex ratio seemed less skewed in recent years (i.e., 1997-2005). Conclusion Significant differences were observed in the sex ratio of children born to mothers of Indian origin compared with children born to mothers of Pakistani origin. A skewed number of female births among higher birth orders (i.e., third or later) may partly reflect an increase in sex-selective abortion among mothers of Indian origin, although the numbers are too small to draw firm conclusions. Further research is needed to explain the observed differences in the female-to-male ratio among members of these ethnic groups who reside in Norway. PMID:20682027
Ahrenfeldt, Linda Juel; Larsen, Lisbeth Aagaard; Lindahl-Jacobsen, Rune; Skytthe, Axel; Hjelmborg, Jacob v.B.; Möller, Sören; Christensen, Kaare
2017-01-01
Purpose To investigate the twin testosterone transfer (TTT) hypothesis by comparing early-life mortality risks of opposite-sex (OS) and same-sex (SS) twins during the first 15 years of life. Methods We performed a population-based cohort study to compare mortality in OS and SS twins. We included 68,629 live-born Danish twins from 1973 to 2009 identified through the Danish Twin Registry and performed piecewise stratified Cox regression and log-binomial regression. Results Among 1933 deaths, we found significantly higher mortality for twin boys than for twin girls. For both sexes, OS twins had lower mortality than SS twins; the difference persisted for the first year of life for boys and for the first week of life for girls. Conclusions Although the mortality risk for OS boys was in the expected direction according to the TTT hypothesis, the results for OS girls pointed in the opposite direction, providing no clear evidence for the TTT hypothesis. PMID:28024904
Meantime: A Brief Personal Narrative of a Trans* Teacher
ERIC Educational Resources Information Center
Buterman, Jan
2015-01-01
In the context of Alberta public education, teachers should not expect discrimination on the basis of gender identity. However, in practice, exclusionary behaviours towards people whose gender identity is different than the sex they were assigned at birth are frequent and may encompass any and all connected to the school environment including…
Parents' and Teachers' Differing Views of Short Children's Behavior.
ERIC Educational Resources Information Center
Holmes, Clarissa S.; And Others
Children over two standard deviations below height expectations have been described by researchers as being behaviorally immature and shown to be emotionally inhibited. The present study seeks to extend these findings by systematically evaluating what role age, sex, and etiology factors may have in the behavioral adjustment of groups of children…
United States and Brazilian Children's Concepts of Death.
ERIC Educational Resources Information Center
Wass, Hannelore; And Others
1979-01-01
Significant differences in thoughts about death appear to be cultural and specifically tied to sex role expectations. Patterns of thoughts about death appear to be more consistent among Brazilian than U.S. children. It appears that religion strongly influences the Brazilian girls' conceptualizations of death but not the other children's in the…
Sex differences in brain activation elicited by humor.
Azim, Eiman; Mobbs, Dean; Jo, Booil; Menon, Vinod; Reiss, Allan L
2005-11-08
With recent investigation beginning to reveal the cortical and subcortical neuroanatomical correlates of humor appreciation, the present event-related functional MRI (fMRI) study was designed to elucidate sex-specific recruitment of these humor related networks. Twenty healthy subjects (10 females) underwent fMRI scanning while subjectively rating 70 verbal and nonverbal achromatic cartoons as funny or unfunny. Data were analyzed by comparing blood oxygenation-level-dependent signal activation during funny and unfunny stimuli. Males and females share an extensive humor-response strategy as indicated by recruitment of similar brain regions: both activate the temporal-occipital junction and temporal pole, structures implicated in semantic knowledge and juxtaposition, and the inferior frontal gyrus, likely to be involved in language processing. Females, however, activate the left prefrontal cortex more than males, suggesting a greater degree of executive processing and language-based decoding. Females also exhibit greater activation of mesolimbic regions, including the nucleus accumbens, implying greater reward network response and possibly less reward expectation. These results indicate sex-specific differences in neural response to humor with implications for sex-based disparities in the integration of cognition and emotion.
Settles, Isis H; Buchanan, Nicole T; Yap, Stevie C Y; Harrell, Zaje A T
2014-04-01
This study examined data from U.S. military personnel (1,764 men; 4,540 women) to determine whether appraisals of sexual harassment as frightening mediate the relationship between perpetrator characteristics (perpetrator sex and rank) and three psychological/job outcomes (psychological distress, role limitations, and work satisfaction), and whether these relationships were stronger for women than men. Results indicated that frightening appraisals mediated the relationship between perpetrator rank and all outcomes for both sexes. However, frightening appraisals mediated the relationship between perpetrator sex and outcomes only for women. As predicted, having a male perpetrator or a higher status perpetrator was more strongly related to frightening appraisals for women than men. However, unexpectedly, the relationship between frightening appraisals and more psychological distress, more role limitations, and less work satisfaction was stronger for men than women. We discuss the results in terms of expectancy norm violations and sexual harassment as a form of dominance.
Sex Differences Research, Precision Medicine, and the Future of Women's Health
Rocca, Walter A.; Faubion, Stephanie S.
2015-01-01
Abstract The National Institutes of Health's (NIH) commitment to improving health outcomes for women and men through rigorous science has been compromised by the lack of basic science evidence obtained from female animals. To correct this limitation, in June 2015 the NIH announced expectations that “sex,” as a biological variable, be included into research design and analysis in studies of vertebrate animals and humans (NOT-OD-15-102). Scientists must take the responsibility to implement this directive. However, in doing so, there is a risk that attention could be restricted to only studies of direct comparison between female/women and male/men. By contrast, understanding how sex influences health and disease needs to take a programmatic approach that includes the study of sex-specific conditions. A programmatic approach will assure the advancement of knowledge to improve women's health. PMID:26325362
ERIC Educational Resources Information Center
Lockheed, Marlaine E.; And Others
1983-01-01
The purpose of this study was to determine (1) whether sex operated as a diffuse status characteristic in mixed-sex groups of fourth- and fifth-grade children (n=168), and (2) whether an intervention based on expectation states theory would be successful in changing the status relationships within such groups. (PN)
Kydd, Robyn M.; Connor, Jennie
2015-01-01
Aims: To describe inconsistencies in reporting past-year drinking status and heavy drinking occasions (HDOs) on single questions from two different instruments, and to identify associated characteristics and impacts. Methods: We compared computer-presented Alcohol Use Disorder Identification Test-Consumption (AUDIT-C) with categorical response options, and mental health interview (MHI) with open-ended consumption questions, completed on the same day. Participants were 464 men and 459 women aged 38 (91.7% of surviving birth cohort members). Differences in dichotomous single-item measures of abstention and HDO frequency, associations of inconsistent reporting with sex, socioeconomic status (SES) and survey order, and impacts of instrument choice on associations of alcohol with sex and SES were examined. Results: The AUDIT-C drinking frequency question estimated higher past-year abstention prevalence (AUDIT = 7.6%, MHI = 5.4%), with one-third of AUDIT-C abstainers being MHI drinkers. Only AUDIT-C produced significant sex differences in abstainer prevalence. Inconsistencies in HDO classifications were bidirectional, but with fewer HDOs reported on the MHI than AUDIT-C question. Lower SES was associated with inconsistency in abstention and weekly+ HDOs. Abstention and higher HDO frequency were associated with lower SES overall, but sex-specific associations differed by instrument. Conclusions: In this context, data collection method affected findings, with inconsistencies in abstention reports having most impact. Future studies should: (a) confirm self-reported abstention; (b) consider piloting data collection methods in target populations; (c) expect impacts of sex and SES on measurements and analyses. PMID:25648932
Yan, Yunzhi; Xu, Yinsheng; Chu, Ling; He, Shan; Chen, Yifeng
2012-06-01
Identifying the life-history strategies of fish and their associations with the surrounding environment is the basic foundation in the conservation and sustainable utilization of fish species. We examined the age, growth, and reproduction of Sarcocheilichthys nigripinnis using 352 specimens collected monthly from May 2009 to April 2010 in the Qingyi Stream. We found the sex ratio of this study population was 0.58:1 (female: male), significantly different from expected 1:1. Females and males both comprised four age groups. The annuli on the scales were formed during February and March. No obvious between-sex difference was observed in length-weight and length-scale-radius relationships. The total length in back-calculation significantly increased with age for both sexes, but did not differ significantly at each age between the two sexes. An inflection point was observed in the growth curves given by the von Bertalanffy growth function for total weight. At this inflection point, fish were 3.95 years. Both sexes reach their 50% sex maturity at age 2, when females and males were 94.7 mm and 103.0 mm total length. The temporal pattern of the gonado-somatic index corresponded to a spawning period that occurred from April through July. The non-synchronicity of egg diameter in each mature ovary during the breeding period suggested these fish may be batch spawners. The absolute fecundity increased significantly with total length and weight, whereas no significant correlation was observed between the relative fecundity and body size.
Alcohol use, liberal/conservative orientations, and ethnicity as predictors of sexual behaviors.
Neff, J A; Burge, S K
1995-03-01
The present study examined relationships among ethnicity, gender, alcohol consumption, and sexual behaviors in a community survey sample of 1,392 adults. Predictors included liberal versus conservative orientations (sex role orientation, religiosity); traditional versus liberal attitudes regarding sexuality, typical alcohol consumption patterns, expectancies regarding alcohol's effect upon one's sexuality, and frequency of alcohol use before sex. Findings are consistent with other studies indicating more sex partners among males than females and among Blacks (particularly males) than Anglos. Blacks also reported less involvement in oral sex than Anglos and Mexican-Americans--although observed differences for oral sex were more characteristic of females and less characteristic of unmarried nondrinkers. Unmarried Mexican-American males reported somewhat, though not significantly, more partners than did Anglos. Unmarried Black males (particularly nondrinkers) also reported more frequent risky behaviors than did Anglos. Divorced Black female drinkers reported significantly less frequent risky behavior than their Anglo counterparts. Alcohol use-sexual relationships were independent of psychosocial background characteristics and situated drinking (drinking before sex) was more strongly related to sexual behavior dimensions than were general drinking patterns.
Girls in the boat: Sex differences in rowing performance and participation.
Keenan, Kevin G; Senefeld, Jonathon W; Hunter, Sandra K
2018-01-01
Men outperform women in many athletic endeavors due to physiological and anatomical differences (e.g. larger and faster muscle); however, the observed sex differences in elite athletic performance are typically larger than expected, and may reflect sex-related differences in opportunity or incentives. As collegiate rowing in the United States has been largely incentivized for women over the last 20 years, but not men, the purpose of this study was to examine sex differences in elite rowing performance over that timeframe. Finishing times from grand finale races for collegiate championship on-water performances (n = 480) and junior indoor performances (n = 1,280) were compared between men and women across 20 years (1997-2016), weight classes (heavy vs. lightweight) and finishing place. Participation of the numbers of men and women rowers were also quantified across years. Men were faster than women across all finishing places, weight classes and years of competition and performance declined across finishing place for both men and women (P<0.001). Interestingly, the reduction in performance time across finishing place was greater (P<0.001) for collegiate men compared to women in the heavyweight division. This result is opposite to other sports (e.g. running and swimming), and to lightweight rowing in this study, which provides women fewer incentives than in heavyweight rowing. Correspondingly, participation in collegiate rowing has increased by ~113 women per year (P<0.001), with no change (P = 0.899) for collegiate men. These results indicate that increased participation and incentives within collegiate rowing for women vs. men contribute to sex differences in athletic performance.
Girls in the boat: Sex differences in rowing performance and participation
Senefeld, Jonathon W.; Hunter, Sandra K.
2018-01-01
Men outperform women in many athletic endeavors due to physiological and anatomical differences (e.g. larger and faster muscle); however, the observed sex differences in elite athletic performance are typically larger than expected, and may reflect sex-related differences in opportunity or incentives. As collegiate rowing in the United States has been largely incentivized for women over the last 20 years, but not men, the purpose of this study was to examine sex differences in elite rowing performance over that timeframe. Finishing times from grand finale races for collegiate championship on-water performances (n = 480) and junior indoor performances (n = 1,280) were compared between men and women across 20 years (1997–2016), weight classes (heavy vs. lightweight) and finishing place. Participation of the numbers of men and women rowers were also quantified across years. Men were faster than women across all finishing places, weight classes and years of competition and performance declined across finishing place for both men and women (P<0.001). Interestingly, the reduction in performance time across finishing place was greater (P<0.001) for collegiate men compared to women in the heavyweight division. This result is opposite to other sports (e.g. running and swimming), and to lightweight rowing in this study, which provides women fewer incentives than in heavyweight rowing. Correspondingly, participation in collegiate rowing has increased by ~113 women per year (P<0.001), with no change (P = 0.899) for collegiate men. These results indicate that increased participation and incentives within collegiate rowing for women vs. men contribute to sex differences in athletic performance. PMID:29352279
Ishii, Hironori; Onodera, Mariko; Ohara, Shinya; Tsutsui, Ken-Ichiro; Iijima, Toshio
2018-01-01
Different biological requirements between males and females may cause sex differences in decision preference when choosing between taking a risk to get a higher gain or taking a lower but sure gain. Several studies have tested this assumption in rats, however the conclusion remains controversial because the previous real-world like gambling tasks contained a learning component to track a global payoff of probabilistic outcome in addition to risk preference. Therefore, we modified a simple gambling task allowing us to exclude such learning effect, and investigated the sex difference in risk preference of rats and its neural basis. The task required water deprived rats to choose between a risky option which provided four drops of water or no reward at a 50% random chance vs. a sure option which provided predictable amount x (x = 1, 2, 3, 4). The amount and the risk were explicitly instructed so that different choice conditions could be tested trial by trial without re-learning of reward contingency. Although both sexes correctly chose the sure option with the same level of accuracy when the sure option provided the best offer (x = 4), they exhibited different choice performances when two options had the same expected value (x = 2). Males and females both preferred to take risky choices than sure choices (risk seeking), but males were more risk seeking than females. Outcome-history analysis of their choice pattern revealed that females reduced their risk preference after losing risky choices, whereas males did not. Rather, as losses continued, reaction time for subsequent risky choices got shorter in males. Given that significant sex difference features mainly emerged after negative experiences, male and female rats may evaluate an unsuccessful outcome of their decision in different manners. Furthermore, c-Fos expression in the paraventricular nucleus of the thalamus (PV) was higher in the gambling task than for the control task in males while c-fos levels did not differ in females. The present study provides a clear evidence of sex differences in risk preference in rats and suggests that the PV is a candidate region contributing to sex differences in risky decision making. PMID:29692713
Shelmidine, Nichole; McAloose, Denise; McCann, Colleen
2013-03-01
This study examines mortality in the North American (N.A.) population of silvered leaf monkeys (Trachypithecus cristatus) maintained in Association of Zoos and Aquarium's zoos. Understanding the causes of death associated with mortality rates (MR) can highlight relative susceptibility to intrinsic/extrinsic factors and differences between age and sex classes. Overall, life tables can provide insight into a species' population dynamics. We expect that the MR will fit the general mammalian and primate trends of a U-shaped curve when graphed, that males will have a higher MR and shorter life expectancy than females and that infant survival will be higher in captivity than in wild populations. Our results indicate that the N.A. captive population fits expected MR trends of a U-shaped curve. However, no differences in MR or life expectancy were found between the sexes. Infant survivorship did not differ from the wild or other leaf monkey populations (both captive and wild). The majority of infant deaths occurred on day 1 of life (52.8% of all infant deaths) and infant survivorship to 1 year was 66%. Neonates (n = 6, 31.6%) and infants (n = 4, 44.4%) died from trauma, juveniles (n = 2, 33.3%) from nutritional reasons, adults from non-infectious diseases (n = 7, 29.2%) and from post-surgical complications (n = 7, 29.2%), and older adults from idiopathic diseases (n = 4, 26.7%) and non-infectious diseases (n = 4, 26.7%). Only older adult males died from degenerative diseases (i.e., heart failure, n = 3, 42.9%). In general, this captive population demonstrated some similar trends to those observed in mammalian and Old World monkey populations. © 2013 Wiley Periodicals, Inc.
Terminal Investment Strategies and Male Mate choice: Extreme Tests of Bateman.
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.
Vingilis-Jaremko, Larissa; Maurer, Daphne; Gao, Xiaoqing
2014-04-01
We examined how recent biased face experience affects the influence of averageness on judgments of facial attractiveness among 8- and 9-year-old children attending a girls' school, a boys' school, and a mixed-sex school. We presented pairs of individual faces in which one face was transformed 50% toward its group average, whereas the other face was transformed 50% away from that average. Across blocks, the faces varied in age (adult, 9-year-old, or 5-year-old) and sex (male or female). We expected that averageness might influence attractiveness judgments more strongly for same-age faces and, for children attending single-sex schools, same-sex faces of that age because their prototype(s) should be best tuned to the faces they see most frequently. Averageness influenced children's judgments of attractiveness, but the strength of the influence was not modulated by the age of the face, nor did the effects of sex of face differ across schools. Recent biased experience might not have affected the results because of similarities between the average faces of different ages and sexes and/or because a minimum level of experience with a particular group of faces may be adequate for the formation of a veridical prototype and its influence on judgments of attractiveness. The results suggest that averageness affects children's judgments of the attractiveness of the faces they encounter in everyday life regardless of age or sex of face. Copyright © 2013 Elsevier Inc. All rights reserved.
ERIC Educational Resources Information Center
Jones, Christina L.; Jensen, Robin E.; Selzer King, Abigail
2014-01-01
Instructors of sexual health courses in rural areas face unique challenges as they are often forced to use school-based prevention curricula field-tested in urban areas. Research has yet to consider what future sex educators' regional expectations are for their profession and how those expectations might have an impact on the classroom. Drawing…
ERIC Educational Resources Information Center
Montanelli, Dale Soderman; Hill, Kennedy T.
1969-01-01
Presents research patterned on two earlier studies by the Crandalls 1963, 1964 on the effects of praise, criticism, and nonreaction on 10-year-old children involved in a marble-dropping task. The subjects tended to increase in performance and decrease in achievement expectancy when criticized. Table, graphs, and bibliography. (RW)
ERIC Educational Resources Information Center
Rudasill, Kathleen Moritz; Adelson, Jill L.; Callahan, Carolyn M.; Houlihan, Deanna Vogt; Keizer, Benjamin M.
2013-01-01
Children whose parents are warm and responsive yet also set limits and have reasonable expectations for their children tend to have better outcomes than their peers whose parents show less warmth and responsiveness, have low expectations, or both. Parenting behavior is related to family race and children's sex, age, and cognitive ability. However,…
Kannenberg, K; Weichert, J; Rody, A; Banz-Jansen, C
2016-07-01
Anxiety during pregnancy can influence outcomes negatively. The aim of this study was to assess the fears of expectant parents in the setting of antenatal and obstetric care according to their sex, age, parity and education. 259 pregnant women and 183 partners, who had presented for antenatal investigation, routine antenatal care or for delivery in the UKSH women's hospital, Lübeck campus, completed a self-assessment questionnaire of fears and the German version of the STAI (Laux et al.). ANOVA and t-tests were used for significance testing. Pregnant women had higher levels of trait anxiety and state anxiety than their partners. Level of education had a significant, inverse effect on trait anxiety. Age had no influence. Fears for the child's health ranked highest among pregnancy-specific fears. Expectant fathers had the same level of anxiety for the birth irrespective of parity; for women fear of the birth decreased with increasing parity. Anxiety only increased significantly for expectant fathers from the 20th week of gestation onwards. Pregnant women and their partners have different levels of anxiety dependant on their age, education, parity and the stage of pregnancy. These findings could contribute towards improving support of couples during pregnancy. The fears of expectant fathers require particular attention.
Santollo, Jessica; Volcko, K Linnea; Daniels, Derek
2018-02-01
Previous in vivo and in vitro studies demonstrate that the angiotensin type 1 receptor rapidly desensitizes after exposure to angiotensin II (AngII). Behaviorally, this likely underlies the reduced drinking observed after acute repeated central injections of AngII. To date, this phenomenon has been studied exclusively in male subjects. Because there are sex differences in the dipsogenic potency of AngII, we hypothesized that sex differences also exist in desensitization caused by AngII. As expected, when male rats were pretreated with AngII, they drank less water after a test injection of AngII than did rats pretreated with vehicle. Intact cycling female rats, however, drank similar amounts of water after AngII regardless of the pretreatment. To probe the mechanism underlying this sex difference, we tested the role of gonadal hormones in adult and developing rats. Gonadectomy in adults did not produce a male-like propensity for desensitization of water intake in female rats, nor did it produce a female-like response in male rats. To test if neonatal brain masculinization generated a male-like responsiveness, female pups were treated at birth with vehicle, testosterone propionate (TP), or dihydrotestosterone (DHT). When tested as adults, TP-treated female rats showed a male-like desensitization after repeated AngII that was not found in vehicle- or DHT-treated rats. Together, these data reveal a striking sex difference in the behavioral response to elevated AngII that is mediated by organizational effects of gonadal hormones and provide an example of one of the many ways that sex influences the renin-angiotensin-aldosterone system. Copyright © 2018 Endocrine Society.
Sex differences in giraffe foraging behavior at two spatial scales.
Ginnett, T F; Demment, Montague W
1997-04-01
We test predictions about differences in the foraging behaviors of male and female giraffes (Giraffa camelopardalis tippelskirchi Matchie) that derive from a hypothesis linking sexual size dimorphism to foraging behavior. This body-size hypothesis predicts that males will exhibit specific behaviors that increase their dry-matter intake rate relative to females. Foraging behavior was examined at two hierarchical levels corresponding to two spatial and temporal scales, within patches and within habitats. Patches are defined as individual trees or shrubs and habitats are defined as collections of patches within plant communities. Males were predicted to increase dry-matter intake rate within patches by taking larger bites, cropping bites more quickly, chewing less, and chewing faster. Within habitats, males were expected to increase intake rate by increasing the proportion of foraging time devoted to food ingestion as opposed to inter-patch travel time and vigilance. The predictions were tested in a free-ranging population of giraffes in Mikumi National Park, Tanzania. Males spent less total time foraging than females but allocated a greater proportion of their foraging time to forage ingestion as opposed to travel between patches. There was no sex difference in rumination time but males spent more time in activities other than foraging and rumination, such as walking. Within patches, males took larger bites than females, but females cropped bites more quickly and chewed faster. Males had longer per-bite handling times than females but had shorter handling times per gram of intake. Within habitats, males had longer average patch residence times but there was no significant sex difference in inter-patch travel times. There was no overall difference between sexes in vigilance while foraging, although there were significant sex by habitat and sex by season interactions. Although not all the predictions were confirmed, overall the results agree qualitatively with the body-size hypothesis. Sex-related differences in foraging behavior led to greater estimated intake rates for males at the within-patch and within-habitat scales.
High sex ratios in rural China: declining well-being with age in never-married men.
Zhou, Xudong; Hesketh, Therese
2017-09-19
In parts of rural China male-biased sex ratios at birth, combined with out-migration of women, have led to highly male-biased adult sex ratios, resulting in large numbers of men being unable to marry, in a culture where marriage and reproduction are an expectation. The aim of this study was to test the hypotheses that older unmarried men are more predisposed to depression, low self-esteem and aggression than both those who are married, and those who are younger and unmarried. Self-completion questionnaires were administered among men aged 20-40 in 48 villages in rural Guizhou province, southwestern China. Tools used included the Beck Depression Inventory, the Rosenberg's Self-esteem Scale and the Bryant-Smith Aggression Questionnaire. Regression models assessed psychological wellbeing while adjusting for socio-demographic variables. Completed questionnaires were obtained from 957 never-married men, 535 married men aged 30-40, 394 partnered men and 382 unpartnered men aged 20-29. After adjusting for socio-demographic variables, never-married men were more predisposed to depression ( p < 0.05), aggression ( p < 0.01), low self-esteem ( p < 0.05) and suicidal tendencies ( p < 0.001). All the psychological measures deteriorated with age in never-married men. In contrast, married men remained stable on these dimensions with age. Never-married men are a psychologically highly vulnerable group in a society where marriage is an expectation. Since the highest birth sex-ratio cohorts have not yet reached reproductive age, the social tragedy of these men will last for at least another generation.This article is part of the themed issue 'Adult sex ratios and reproductive decisions: a critical re-examination of sex differences in human and animal societies'. © 2017 The Authors.
Inequalities in US Life Expectancy by Area Unemployment Level, 1990–2010
Singh, Gopal K.; Siahpush, Mohammad
2016-01-01
This study examined the association between unemployment and life expectancy in the United States during 1990–2010. Census-based unemployment rates were linked to US county-level mortality data. Life expectancies were calculated by age, sex, race, and unemployment level during 1990–2010. Differences in life expectancy were decomposed by age and cause of death. Life expectancy was consistently lower in areas with higher unemployment rates. In 2006–2010, those in areas with high unemployment rates (≥9%) had a life expectancy of 76.9 years, compared with 80.7 years for those in areas with low unemployment rates (<3%). The association between unemployment and life expectancy was stronger for men than for women. Life expectancy ranged from 69.9 years among black men in high unemployment areas to 90.0 years among Asian/Pacific Islander women in low unemployment areas. Disparities persisted over time. In 1990–1992, life expectancy was 4.7 years shorter in high unemployment than in low unemployment areas. In 2006–2010, the life expectancy difference between the lowest and highest unemployment areas decreased to 3.8 years. Heart disease, cancer, homicide, unintentional injuries, diabetes, HIV/AIDS, and liver cirrhosis contributed most to the lower life expectancy in high unemployment areas. High unemployment areas recorded larger gains in life expectancy than low unemployment areas, contributing to the narrowing gap during 1990–2010. PMID:27073716
Family Size and Sex Preference of Children: A Bi-racial Comparison.
ERIC Educational Resources Information Center
Rao, V.V. Prakasa; Rao, V. Nandini
1981-01-01
Compares the attitudes of 409 White and Black undergraduate students toward the ideal and expected number of children, intentions of having a large family, sex preference for the first child, and sex preference for three children. (Author/CM)
Davis, Shannon N; Risman, Barbara J
2015-01-01
Sociology of gender has developed beyond a personality-centered idea of "sex-roles" to an approach that stresses interaction and social structure. At the same time, there has been a concurrent development in the psychological sex-differences and medical literatures toward including the biological bases of sex-typed behavior and gender identities. In this paper, while we conceptualize gender as a social structure, we focus only on the individual level of analysis: testing the relative strength of (maternal circulating) prenatal hormones, childhood socialization, and the power of expectations attached to adult social roles (cultural interactionist) as explanations for women's self-reported feminine and masculine selves. Our findings are complex, and support some importance of each theory. Prenatal hormones, childhood socialization, and cultural interactionism were all influential factors for gendered selves. While cultural expectations predicted only feminine selves, prenatal hormones were more robust predictors of masculine sense of self. While personality may be a relatively stable characteristic influenced by the body and childhood socialization, our results reinforce the importance of studying how the social world responds to and reinforces gendered personality. Copyright © 2014 Elsevier Inc. All rights reserved.
Rectangularization of the survival curve in The Netherlands, 1950-1992.
Nusselder, W J; Mackenbach, J P
1996-12-01
In this article we determine whether rectangularization of the survival curve occurred in the Netherlands in the period 1950-1992. Rectangularization is defined as a trend toward a more rectangular shape of the survival curve due to increased survival and concentration of deaths around the mean age at death. We distinguish between absolute and relative rectangularization, depending on whether an increase in life expectancy is accompanied by concentration of deaths into a smaller age interval or into a smaller proportion of total life expectancy. We used measures of variability based on Keyfitz' H and the standard deviation, both life table-based. Our results show that absolute and relative rectangularization of the entire survival curve occurred in both sexes and over the complete period (except for the years 1955-1959 and 1965-1969 in men). At older ages, results differ between sexes, periods, and an absolute versus a relative definition of rectangularization. Above age 60 1/2, relative rectangularization occurred in women over the complete period and in men since 1975-1979 only, whereas absolute rectangularization occurred in both sexes since the period of 1980-1984. The implications of the recent rectangularization at older ages for achieving compression of morbidity are discussed.
Alfentanil and placebo analgesia: no sex differences detected in models of experimental pain.
Olofsen, Erik; Romberg, Raymonda; Bijl, Hans; Mooren, René; Engbers, Frank; Kest, Benjamin; Dahan, Albert
2005-07-01
To assess whether patient sex contributes to the interindividual variability in alfentanil analgesic sensitivity, the authors compared male and female subjects for pain sensitivity after alfentanil using a pharmacokinetic-pharmacodynamic modeling approach. Healthy volunteers received a 30-min alfentanil or placebo infusion on two occasions. Analgesia was measured during the subsequent 6 h by assaying tolerance to transcutaneous electrical stimulation (eight men and eight women) of increasing intensity or using visual analog scale scores during treatment with noxious thermal heat (five men and five women). Sedation was concomitantly measured. Population pharmacokinetic-pharmacodynamic models were applied to the analgesia and sedation data using NONMEM. For electrical pain, the placebo and alfentanil models were combined post hoc. Alfentanil and placebo analgesic responses did not differ between sexes. The placebo effect was successfully incorporated into the alfentanil pharmacokinetic-pharmacodynamic model and was responsible for 20% of the potency of alfentanil. However, the placebo effect did not contribute to the analgesic response variability. The pharmacokinetic-pharmacodynamic analysis of the electrical and heat pain data yielded similar values for the potency parameter, but the blood-effect site equilibration half-life was significantly longer for electrical pain (7-9 min) than for heat pain (0.2 min) or sedation (2 min). In contrast to the ample literature demonstrating sex differences in morphine analgesia, neither sex nor subject expectation (i.e., placebo) contributes to the large between-subject response variability with alfentanil analgesia. The difference in alfentanil analgesia onset and offset between pain tests is discussed.
The relationship between sex change and reproductive success in a protandric marine gastropod.
Brante, Antonio; Quiñones, Adriana; Silva, Francisco
2016-07-07
Protandric species switch sex during their lifetime. According to theory, the time (body size) at which sex change occurs is determined by the reproductive success of individuals affected by social interactions as well as by post-copulatory factors. Experimental evidence is biased to few social systems making the exploration of general patterns difficult. We used the protandric marine gastropod Crepidula coquimbensis that partakes in intrabrood sibling cannibalism to test the following hypotheses: 1. Male-male competition for access to females and sibling cannibalism determine male reproductive success; 2. Males with greater access to females and with higher reproductive success will have reduced growth rates and will delay sex change. Artificial aggregations with different social structures were constructed and male reproductive success was estimated by paternity analysis. The results supported our expectations showing that male competitive ability for access to the female, time spent by males in the copulatory position, and sibling cannibalism affect reproductive success and influence time to sex change, with less successful males hastening sex change. Also, males that spent more time in the copulatory position had reduced growth rates. Comparing these results with those reported for other sequential hermaphrodites provides evidence supporting general patterns of sex change in nature.
Koops, Kathelijne; Furuichi, Takeshi; Hashimoto, Chie; van Schaik, Carel P
2015-01-01
Sex differences in immatures predict behavioural differences in adulthood in many mammal species. Because most studies have focused on sex differences in social interactions, little is known about possible sex differences in 'preparation' for adult life with regards to tool use skills. We investigated sex and age differences in object manipulation in immature apes. Chimpanzees use a variety of tools across numerous contexts, whereas bonobos use few tools and none in foraging. In both species, a female bias in adult tool use has been reported. We studied object manipulation in immature chimpanzees at Kalinzu (Uganda) and bonobos at Wamba (Democratic Republic of Congo). We tested predictions of the 'preparation for tool use' hypothesis. We confirmed that chimpanzees showed higher rates and more diverse types of object manipulation than bonobos. Against expectation, male chimpanzees showed higher object manipulation rates than females, whereas in bonobos no sex difference was found. However, object manipulation by male chimpanzees was play-dominated, whereas manipulation types of female chimpanzees were more diverse (e.g., bite, break, carry). Manipulation by young immatures of both species was similarly dominated by play, but only in chimpanzees did it become more diverse with age. Moreover, in chimpanzees, object types became more tool-like (i.e., sticks) with age, further suggesting preparation for tool use in adulthood. The male bias in object manipulation in immature chimpanzees, along with the late onset of tool-like object manipulation, indicates that not all (early) object manipulation (i.e., object play) in immatures prepares for subsistence tool use. Instead, given the similarity with gender differences in human children, object play may also function in motor skill practice for male-specific behaviours (e.g., dominance displays). In conclusion, even though immature behaviours almost certainly reflect preparation for adult roles, more detailed future work is needed to disentangle possible functions of object manipulation during development.
Koops, Kathelijne; Furuichi, Takeshi; Hashimoto, Chie; van Schaik, Carel P.
2015-01-01
Sex differences in immatures predict behavioural differences in adulthood in many mammal species. Because most studies have focused on sex differences in social interactions, little is known about possible sex differences in ‘preparation’ for adult life with regards to tool use skills. We investigated sex and age differences in object manipulation in immature apes. Chimpanzees use a variety of tools across numerous contexts, whereas bonobos use few tools and none in foraging. In both species, a female bias in adult tool use has been reported. We studied object manipulation in immature chimpanzees at Kalinzu (Uganda) and bonobos at Wamba (Democratic Republic of Congo). We tested predictions of the ‘preparation for tool use’ hypothesis. We confirmed that chimpanzees showed higher rates and more diverse types of object manipulation than bonobos. Against expectation, male chimpanzees showed higher object manipulation rates than females, whereas in bonobos no sex difference was found. However, object manipulation by male chimpanzees was play-dominated, whereas manipulation types of female chimpanzees were more diverse (e.g., bite, break, carry). Manipulation by young immatures of both species was similarly dominated by play, but only in chimpanzees did it become more diverse with age. Moreover, in chimpanzees, object types became more tool-like (i.e., sticks) with age, further suggesting preparation for tool use in adulthood. The male bias in object manipulation in immature chimpanzees, along with the late onset of tool-like object manipulation, indicates that not all (early) object manipulation (i.e., object play) in immatures prepares for subsistence tool use. Instead, given the similarity with gender differences in human children, object play may also function in motor skill practice for male-specific behaviours (e.g., dominance displays). In conclusion, even though immature behaviours almost certainly reflect preparation for adult roles, more detailed future work is needed to disentangle possible functions of object manipulation during development. PMID:26444011
Life expectancy in HIV-positive persons in Switzerland: matched comparison with general population
Gueler, Aysel; Moser, André; Calmy, Alexandra; Günthard, Huldrych F.; Bernasconi, Enos; Furrer, Hansjakob; Fux, Christoph A.; Battegay, Manuel; Cavassini, Matthias; Vernazza, Pietro; Zwahlen, Marcel; Egger, Matthias
2017-01-01
Objectives: To estimate life expectancy over 25 years in HIV-positive people and to compare their life expectancy with recent estimates for the general population, by education. Methods: Patients aged 20 years or older enrolled in the Swiss HIV Cohort Study 1988–2013 were eligible. Patients alive in 2001 were matched to up to 100 Swiss residents, by sex, year of birth, and education. Life expectancy at age 20 was estimated for monotherapy (1988–1991), dual therapy (1992–1995), early combination antiretroviral therapy (cART, 1996–1998), later cART (1999–2005) and recent cART (2006–2013) eras. Parametric survival regression was used to model life expectancy. Results: In all, 16 532 HIV-positive patients and 927 583 residents were included. Life expectancy at age 20 of HIV-positive individuals increased from 11.8 years [95% confidence interval (CI) 11.2–12.5] in the monotherapy era to 54.9 years (95% CI 51.2–59.6) in the most recent cART era. Differences in life expectancy across educational levels emerged with cART. In the most recent cART period, life expectancy at age 20 years was 52.7 years (95% CI 46.4–60.1) with compulsory education, compared to 60.0 years (95% CI 53.4–67.8) with higher education. Estimates for the general population were 61.5 and 65.6 years, respectively. Male sex, smoking, injection drug use, and low CD4+ cell counts at enrolment were also independently associated with mortality. Conclusion: In Switzerland, educational inequalities in life expectancy were larger among HIV-infected persons than in the general population. Highly educated HIV-positive people have an estimated life expectancy similar to Swiss residents with compulsory education. Earlier start of cART and effective smoking-cessation programs could improve HIV-positive life expectancy further and reduce inequalities. PMID:27831953
Circadian Rhythms Differ between Sexes and Closely Related Species of Nasonia Wasps
Bertossa, Rinaldo C.; van Dijk, Jeroen; Diao, Wenwen; Saunders, David; Beukeboom, Leo W.; Beersma, Domien G. M.
2013-01-01
Activity rhythms in 24 h light-dark cycles, constant darkness, and constant light conditions were analyzed in four different Nasonia species for each sex separately. Besides similarities, clear differences are evident among and within Nasonia species as well as between sexes. In all species, activity in a light-dark cycle is concentrated in the photophase, typical for diurnal organisms. Contrary to most diurnal insect species so far studied, Nasonia follows Aschoff's rule by displaying long (>24 h) internal rhythms in constant darkness but short (<24 h) in constant light. In constant light, N. vitripennis males display robust circadian activity rhythms, whereas females are usually arrhythmic. In contrast to other Nasonia species, N. longicornis males display anticipatory activity, i.e. activity shortly before light-on in a light-dark cycle. As expected, N. oneida shows activity patterns similar to those of N. giraulti but with important differences in key circadian parameters. Differences in circadian activity patterns and parameters between species may reflect synchronization of specific life-history traits to environmental conditions. Scheduling mating or dispersion to a specific time of the day could be a strategy to avoid interspecific hybridization in Nasonia species that live in sympatry. PMID:23555911
ERIC Educational Resources Information Center
Kelly, Marguerite; Zimmer-Gembeck, Melanie J.; Boislard-P., Marie-Aude
2012-01-01
The most common dating goals of adolescents are identity, intimacy, status and sex. In this study of Australian youth (16-30 years, N = 208), dating goals were expected to explain goal-consistent behavior in each domain. Also, goals coupled with consistent behavior were expected to be associated with greater satisfaction in each domain. Age,…
Shale gas development and cancer incidence in southwest Pennsylvania.
Finkel, M L
2016-12-01
To what extent does unconventional gas development lead to an increase in cancer incidence in heavily drilled Southwest Pennsylvania? Ecological study. Data for urinary bladder, thyroid and leukaemia were abstracted from the Pennsylvania Cancer Registry (PCR). Cancer incidence among counties with high, moderate and minimal number of producing wells is compared before drilling activity and thereafter. Observed vs expected cases, standardized incidence ratio and 95% confidence intervals are presented. Data are presented by county, diagnosis and sex for the years 2000-2004, 2004-2008 and 2008-2012. The percent difference between the observed cases from 2000 to 2004 and 2008-2012 was calculated. The observed number of urinary bladder cases was higher than expected in both sexes in counties with shale gas activity. In counties with the fewest number of producing wells, the increase was essentially non-existent. The number of observed cases of thyroid cancer increased substantially among both sexes over the time period in all counties regardless of the number of wells drilled. The pattern for leukaemia was mixed among males and females and among the counties regardless of the extent of shale gas development activities. Potential risk factors other than shale gas development must be taken into account to explain the higher than expected cancer cases in counties with and without shale gas wells before and during unconventional shale gas activity. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Reported masculinity ratio in Pakistan: a triumph of anthropology and economics over biology.
Krotki, K J
1985-01-01
Reported sex ratios in Pakistan for the 1960s and 1970s are examined, and attempts at explaining the findings are presented. Available data, including census- and survey-reported sex ratios, are considered. Attention is given to sex ratios at birth, expected age-specific sex ratios, and implied versus reported sex ratios at death. Conclusions concerning sex differentials in mortality at selected ages are summarized. In a final section, the author considers the relationship of sex ratios to sex roles. Comments by Syeda Abida Hussain are included (pp. 298-303).
Rodriguez-Cuenca, S; Monjo, M; Proenza, A M; Roca, P
2005-01-01
Sex hormones play an important role in adipose tissue metabolism by activating specific receptors that alter several steps of the lipolytic and lipogenic signal cascade in depot- and sex-dependent manners. However, studies focusing on steroid receptor status in adipose tissue are scarce. In the present study, we analyzed steroid content [testosterone (T), 17beta-estradiol (17beta-E2), and progesterone (P4)] and steroid receptor mRNA levels in different rat adipose tissue depots. As expected, T levels were higher in males than in females (P = 0.031), whereas the reverse trend was observed for P4 (P < 0.001). It is noteworthy that 17beta-E2 adipose tissue levels were higher in inguinal than in the rest of adipose tissues for both sexes, where no sex differences in 17beta-E2 tissue levels were noted (P = 0.010 for retroperitoneal, P = 0.005 for gonadal, P = 0.018 for mesenteric). Regarding steroid receptor levels, androgen (AR) and estrogen receptor (ER)alpha and ERbeta densities were more clearly dependent on adipose depot location than on sex, with visceral depots showing overall higher mRNA densities than their subcutaneous counterparts. Besides, expression of ERalpha predominated over ERbeta expression, and progesterone receptor (PR-B form and PR-A+B form) mRNAs were identically expressed regardless of anatomic depot and sex. In vitro studies in 3T3-L1 cells showed that 17beta-E2 increased ERalpha (P = 0.001) and AR expression (P = 0.001), indicating that estrogen can alter estrogenic and androgenic signaling in adipose tissue. The results highlighted in this study demonstrate important depot-dependent differences in the sensitivity of adipose tissues to sex hormones between visceral and subcutaneous depots that could be related to metabolic situations observed in response to sex hormones.
Reconceptualizing adolescent sexual behavior: beyond did they or didn't they?
Whitaker, D J; Miller, K S; Clark, L F
2000-01-01
Adolescent sexual behavior is typically studied as a dichotomy: Adolescents have had sex or they have not. Broadening this view would lead to a greater understanding of teenagers' sexual behavior. Interview data from 907 high school students in Alabama, New York and Puerto Rico were used to examine the relationships between sexual experience and a variety of social, psychological and behavioral variables. Four groups of teenagers are compared: those who did not anticipate initiating sex in the next year (delayers), those who anticipated initiating sex in the next year (anticipators), those who had had one sexual partner (singles) and those who had had two or more partners (multiples). Compared with delayers, anticipators reported more alcohol use and marijuana use; poorer psychological health; riskier peer behaviors; and looser ties to family school and church. Similarly, multiples reported more alcohol and marijuana use, riskier peer behaviors and looser ties to family and school than singles. Risk behaviors, peer behaviors, family variables, and school and church involvement showed a linear trend across the four categories of sexual behavior. The traditional sex-no sex dichotomy obscures differences among sexually inexperienced teenagers and among adolescents who have had sex. Prevention efforts must be tailored to the specific needs of teenagers with differing sexual experiences and expectations, and must address the social and psychological context in which sexual experiences occur.
Ittig, S; Studerus, E; Papmeyer, M; Uttinger, M; Koranyi, S; Ramyead, A; Riecher-Rössler, A
2015-02-01
Several sex differences in schizophrenia have been reported including differences in cognitive functioning. Studies with schizophrenia patients and healthy controls (HC) indicate that the sex advantage for women in verbal domains is also present in schizophrenia patients. However, findings have been inconsistent. No study focused on sex-related cognitive performance differences in at-risk mental state for psychosis (ARMS) individuals yet. Thus, the aim of the present study was to investigate sex differences in cognitive functioning in ARMS, first episode psychosis (FEP) and HC subjects. We expected a better verbal learning and memory performance of women in all groups. The neuropsychological data analysed in this study were collected within the prospective Früherkennung von Psychosen (FePsy) study. In total, 118 ARMS, 88 FEP individuals and 86 HC completed a cognitive test battery covering the domains of executive functions, attention, working memory, verbal learning and memory, IQ and speed of processing. Women performed better in verbal learning and memory regardless of diagnostic group. By contrast, men as compared to women showed a shorter reaction time during the working memory task across all groups. The results provide evidence that women generally perform better in verbal learning and memory, independent of diagnostic group (ARMS, FEP, HC). The finding of a shorter reaction time for men in the working memory task could indicate that men have a superior working memory performance since they responded faster during the target trials, while maintaining a comparable overall working memory performance level. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
ERIC Educational Resources Information Center
Pavan, Barbara Nelson
A survey of male and female school administrators in Pennsylvania reveals that sexual division of labor in household activities differs little from stereotypical role expectations. A survey, mailed to 1,324 male and female administrative incumbents and aspirants, yielded 622 responses for a rate of 47 percent. The survey explored personal…
Creative Thinking in Five- and Six-Year-Old Kindergarten Children.
ERIC Educational Resources Information Center
Gonen, Mubeccel
1993-01-01
Sixty kindergarten children were studied to determine the effect of age and sex on creativity. No significant difference was found between the girls' and boys' creativity scores, but, as expected, the 6-year olds scored higher than the 5-year olds. Recommends providing opportunities for creative activity for children at home and school. (TJQ)
ERIC Educational Resources Information Center
Betz, Nancy E.; Hackett, Gail
1981-01-01
Subjects, (N=134) female and (N=101) male undergraduates, were asked to indicate their perceptions of their capabilities to successfully complete the educational requirements and job duties of each of 10 traditionally female and 10 traditionally male occupations. Results indicated sex differences in self-efficacy with regard to traditional versus…
The Natural History of Nonobstructive Hypertrophic Cardiomyopathy.
Hebl, Virginia B; Miranda, William R; Ong, Kevin C; Hodge, David O; Bos, J Martijn; Gentile, Federico; Klarich, Kyle W; Nishimura, Rick A; Ackerman, Michael J; Gersh, Bernard J; Ommen, Steve R; Geske, Jeffrey B
2016-03-01
To describe the survival of a large nonobstructive hypertrophic cardiomyopathy (NO-HCM) cohort and to identify risk factors for increased mortality in this population. Patients were identified from the Mayo Clinic HCM database from January 1, 1975, through November 30, 2006, for this retrospective observational study. Patients with resting or provocable left ventricular outflow tract gradients were excluded. Echocardiographic, clinical, and genetic data were compared between subgroups, and survival data were compared with expected population rates. A total of 706 patients with NO-HCM were identified. During median follow-up of 5 years (mean, 7 years), there were 208 deaths. Overall survival was no different than expected compared with age- and sex-matched white US population mortality rates (P=.77). Independent predictors of death were age at diagnosis, "burned out" HCM, and history of transient ischemic attack or stroke; use of an implantable cardioverter defibrillator (ICD) was inversely related to death. After exclusion of patients with an ICD, there was no difference in survival compared with age- and sex- matched individuals (P=.39); age, previous transient ischemic attack/stroke, and burned out HCM were predictors of death. In this cohort, patients with NO-HCM had similar survival rates as age- and sex-matched white US population mortality rates. Although use of an ICD was inversely related to death, no differences in overall survival were seen after those patients were excluded. Burned out HCM was independently associated with an increased risk of death, identifying a subset of patients who may benefit from more aggressive therapies. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.
Field, David L; Pickup, Melinda; Barrett, Spencer C H
2013-05-01
Populations of dioecious flowering plants commonly exhibit heterogeneity in sex ratios and deviations from the equilibrium expectation of equal numbers of females and males. Yet the role of ecological and demographic factors in contributing towards biased sex ratios is currently not well understood. Species-level studies from the literature were analysed to investigate ecological correlates of among-population sex-ratio variation and metapopulation models and empirical data were used to explore the influence of demography and non-equilibrium conditions on flowering sex ratios. The survey revealed significant among-population heterogeneity in sex ratios and this was related to the degree of sampling effort. For some species, sex-ratio bias was associated with the proportion of non-reproductive individuals, with greater male bias in populations with a lower proportion of individuals that were flowering. Male-biased ratios were also found at higher altitudes and latitudes, and in more xeric sites. Simulations and empirical data indicated that clonal species exhibited greater heterogeneity in sex ratios than non-clonal species as a result of their slower approach to equilibrium. The simulations also indicated the importance of interactions between reproductive mode and founder effects, with greater departures from equilibrium in clonal populations with fewer founding individuals. The results indicate that sex-based differences in costs of reproduction and non-equilibrium conditions can each play important roles in affecting flowering sex ratios in populations of dioecious plants.
Behavior, cortical ectopias, and autoimmunity in BXSB-Yaa and BXSB-Yaa+ mice.
Schrott, L M; Waters, N S; Boehm, G W; Sherman, G F; Morrison, L; Rosen, G D; Behan, P O; Galaburda, A M; Denenberg, V H
1993-09-01
The BXSB-Yaa recombinant inbred strain was created by crossing a male SB/Le with a female C57BL/6J. A Y chromosome factor derived from the SB/Le male, known as the autoimmune accelerator (Yaa), leads to an earlier onset and greater severity of autoimmune disease in males. In contrast, male BXSB mice, which lack the Yaa gene (called BXSB-Yaa+) because their Y chromosome is derived from the C57BL/6J, do not develop an autoimmune condition. To examine the influence of the Y chromosome on behavior, cortical ectopia incidence, and immune functioning, males and females of these two strains were compared. Significant strain differences (for both sexes) were found for behavioral measures including discrimination, spatial and avoidance learning, and activity. For immunological parameters, a sex difference was seen in the BXSB-Yaa (males more autoimmune), but not in the BXSB-Yaa+ strain. As expected, male BXSB-Yaas were more autoimmune than male BXSB-Yaa+s. However, there was also a strain difference for IgG in the females (BXSB-Yaa+ greater). No strain difference was found for the presence of ectopias. However, there was a sex difference across both strains, with males having a higher incidence. BXSB-Yaa and BXSB-Yaa+ mice have behavioral and immunological differences greater than would be predicted by their known genetic differences. The significant differences between the two female groups suggest that the two strains differ with respect to autosomal genes, in addition to the Y chromosome. The incidence of ectopias is independent of this genetic difference and is influenced by the subject's sex.
Poissant, Jocelyn; Wilson, Alastair J; Coltman, David W
2010-01-01
The independent evolution of the sexes may often be constrained if male and female homologous traits share a similar genetic architecture. Thus, cross-sex genetic covariance is assumed to play a key role in the evolution of sexual dimorphism (SD) with consequent impacts on sexual selection, population dynamics, and speciation processes. We compiled cross-sex genetic correlations (r(MF)) estimates from 114 sources to assess the extent to which the evolution of SD is typically constrained and test several specific hypotheses. First, we tested if r(MF) differed among trait types and especially between fitness components and other traits. We also tested the theoretical prediction of a negative relationship between r(MF) and SD based on the expectation that increases in SD should be facilitated by sex-specific genetic variance. We show that r(MF) is usually large and positive but that it is typically smaller for fitness components. This demonstrates that the evolution of SD is typically genetically constrained and that sex-specific selection coefficients may often be opposite in sign due to sub-optimal levels of SD. Most importantly, we confirm that sex-specific genetic variance is an important contributor to the evolution of SD by validating the prediction of a negative correlation between r(MF) and SD.
Inter-Annual Variability of Fledgling Sex Ratio in King Penguins.
Bordier, Célia; Saraux, Claire; Viblanc, Vincent A; Gachot-Neveu, Hélène; Beaugey, Magali; Le Maho, Yvon; Le Bohec, Céline
2014-01-01
As the number of breeding pairs depends on the adult sex ratio in a monogamous species with biparental care, investigating sex-ratio variability in natural populations is essential to understand population dynamics. Using 10 years of data (2000-2009) in a seasonally monogamous seabird, the king penguin (Aptenodytes patagonicus), we investigated the annual sex ratio at fledging, and the potential environmental causes for its variation. Over more than 4000 birds, the annual sex ratio at fledging was highly variable (ranging from 44.4% to 58.3% of males), and on average slightly biased towards males (51.6%). Yearly variation in sex-ratio bias was neither related to density within the colony, nor to global or local oceanographic conditions known to affect both the productivity and accessibility of penguin foraging areas. However, rising sea surface temperature coincided with an increase in fledging sex-ratio variability. Fledging sex ratio was also correlated with difference in body condition between male and female fledglings. When more males were produced in a given year, their body condition was higher (and reciprocally), suggesting that parents might adopt a sex-biased allocation strategy depending on yearly environmental conditions and/or that the effect of environmental parameters on chick condition and survival may be sex-dependent. The initial bias in sex ratio observed at the juvenile stage tended to return to 1∶1 equilibrium upon first breeding attempts, as would be expected from Fisher's classic theory of offspring sex-ratio variation.
Mallet, Martin A; Bouchard, Jessica M; Kimber, Christopher M; Chippindale, Adam K
2011-06-06
Sex differences in the magnitude or direction of mutational effect may be important to a variety of population processes, shaping the mutation load and affecting the cost of sex itself. These differences are expected to be greatest after sexual maturity. Mutation-accumulation (MA) experiments provide the most direct way to examine the consequences of new mutations, but most studies have focused on juvenile viability without regard to sex, and on autosomes rather than sex chromosomes; both adult fitness and X-linkage have been little studied. We therefore investigated the effects of 50 generations of X-chromosome mutation accumulation on the fitness of males and females derived from an outbred population of Drosophila melanogaster. Fitness declined rapidly in both sexes as a result of MA, but adult males showed markedly greater fitness loss relative to their controls compared to females expressing identical genotypes, even when females were made homozygous for the X. We estimate that these mutations are partially additive (h ~ 0.3) in females. In addition, the majority of new mutations appear to harm both males and females. Our data helps fill a gap in our understanding of the consequences of sexual selection for genetic load, and suggests that stronger selection on males may indeed purge deleterious mutations affecting female fitness.
Langen, Esther M A; von Engelhardt, Nikolaus; Goerlich-Jansson, Vivian C
2018-07-01
The social environment of reproducing females can cause physiological changes, with consequences for reproductive investment and offspring development. These prenatal maternal effects are often found to be sex-specific and may have evolved as adaptations, maximizing fitness of male and female offspring for their future environment. Female hormone levels during reproduction are considered a potential mechanism regulating sex allocation in vertebrates: high maternal androgens have repeatedly been linked to increased investment in sons, whereas high glucocorticoid levels are usually related to increased investment in daughters. However, results are not consistent across studies and therefore still inconclusive. In Japanese quail (Coturnix japonica), we previously found that pair-housed females had higher plasma androgen levels and tended to have higher plasma corticosterone levels than group-housed females. In the current study we investigate whether these differences in maternal social environment and physiology affect offspring sex allocation and physiology. Counter to our expectations, we find no effects of the maternal social environment on offspring sex ratio, sex-specific mortality, growth, circulating androgen or corticosterone levels. Also, maternal corticosterone or androgen levels do not correlate with offspring sex ratio or mortality. The social environment during reproduction therefore does not necessarily modify sex allocation and offspring physiology, even if it causes differences in maternal physiology. We propose that maternal effects of the social environment strongly depend upon the type of social stimuli and the timing of changes in the social environment and hormones with respect to the reproductive cycle and meiosis. Copyright © 2018 Elsevier Inc. All rights reserved.
Albers, H. Elliott
2014-01-01
Arginine-vasotocin(AVT)/arginine vasopressin (AVP) are members of the AVP/oxytocin (OT) superfamily of peptides that are involved in the regulation of social behavior, social cognition and emotion. Comparative studies have revealed that AVT/AVP and their receptors are found throughout the “Social Behavior Neural Network” and display the properties expected from a signaling system that controls social behavior (i.e., species, sex and individual differences and modulation by gonadal hormones and social factors). Neurochemical signaling within the SBNN likely involves a complex combination of synaptic mechanisms that co-release multiple chemical signals (e.g., classical neurotransmitters and AVT/AVP as well as other peptides) and non-synaptic mechanisms (i.e., volume transmission). Crosstalk between AVP/OT peptides and receptors within the SBNN is likely. A better understanding of the functional properties of neurochemical signaling in the SBNN will allow for a more refined examination of the relationships between this peptide system and species, sex and individual differences in sociality. PMID:25102443
Interests, Gender, and Science.
Valian, Virginia
2014-03-01
In this commentary on Nye, Su, Rounds, and Drasgow (2012) and Schmidt (2011), I address the value of occupational interest inventories for understanding sex differences in occupational choice and the extent to which occupational interests are malleable. In particular, I argue (a) that some subscales in interest inventories are too heterogeneous to be given a single label and that the labels that are applied to some subscales are inaccurate and misleading; (b) that "things versus people" is an inaccurate and misleading characterization of a dimension that is frequently associated with interest inventories and linked to sex differences; (c) that vocational interests will be valid predictors of job performance primarily in cases in which the job has been held for some time by a diverse group of people and not in cases in which jobholders have been homogeneous; (d) that sex differences in interests are malleable and sensitive to small and subtle environmental cues; and (e) that women's interest in math and science will increase if they have a feeling of belonging and an expectation of success. © The Author(s) 2014.
Messman-Moore, Terri L; Ward, Rose Marie; DeNardi, Kathleen A
2013-04-01
A structural equation model examined sexual enhancement alcohol expectancies, heavy episodic drinking (HED), and risky sexual behavior as correlates of alcohol-involved rape in a sample of 353 college women. Prevalence of alcohol-involved rape was 15.6%. Sexual enhancement alcohol expectancies were indirectly associated with alcohol-involved rape via increased levels of HED, greater likelihood of sex while intoxicated, and number of sex partners. All forms of risky behavior were associated with alcohol-involved rape although HED had the strongest relationship. Findings suggest continued focus on women's positive alcohol expectancies and HED as risk factors for alcohol-involved rape. Implications for intervention will be discussed.
Differential female mortality and health care in South Asia.
Harriss, B
1989-04-01
This report examines differential female mortality in South Asia--India, Sri Lanka, Bangladesh, and Pakistan. Under conditions of mortality decline and an aggregate trend toward convergence of life expectancy, disequilibria which are comparatively unusual, persist. The converging life expectancies are a product of changes unique to each sex. Female mortality gains after the reproductive period conceal excess female mortality from the post-neonatal period to 5 years and in most regions of South Asia during the reproductive years as well. These imbalances appear to be most exaggerated on the upper Gangetic plain and among communities such as the Jats and Rajputs. The most marked imbalances do not bear a consistent relationship to economic conditions. They may, however, be declining over time. In certain regions of India, most notably in the peripheral south, discrimination against women is not seen in demographic data and has not been for several decades. Male life expectancy is being affected by only slow improvement in male mortality from age 35. Major social changes are accompanying these changes in gender differences in vital statistics, including changes in the technology of agricultural production, falling female participation rates, the education of girls, the increasing practice of dowry, and fertility decision making changes. It is not clear whether child mortality or maternal mortality is the key to the political economy of Indian demography, whether maldistribution of food or health care is the prime determinant of excess female child mortality, whether excess female mortality is the result of being neglect or conscious selection, whether regional contrasts result from differences in the religious roles of sons between north and south India, whether the female sex is culturally inferior and the male sex superior, whether food scarcity is more important than food availability in the determination of sex bias, whether poverty results in greater discrimination, whether class position determines reproductive strategy, whether major contrasts in demographic regime exist between north and south India, or whether material conditions or cultural practices determine demographic regimes. The workshop papers contributed data for the decision process, advocacy for the agenda, and details on the results of implementation, and the realities of access.
McLellan-Lemal, Eleanor; Toledo, Lauren; O'Daniels, Christine; Villar-Loubet, Olga; Simpson, Cathy; Adimora, Ada A; Marks, Gary
2013-05-24
HIV prevention efforts have given limited attention to the relational schemas and scripts of adult heterosexual women. These broader schemas and scripts of romantic and other sexual liaisons, partner selection, relationship dynamics, and power negotiations may help to better understand facilitators and barriers to HIV risk-reduction practices. We conducted exploratory qualitative interviews with 60 HIV-uninfected heterosexual African-American women from rural counties in North Carolina and Alabama, and Hispanic women from an urban county in southern Florida. Data were collected for relationship expectations; relationship experiences, and relationship power and decision-making. Interview transcripts underwent computer-assisted thematic analysis. Participants had a median age of 34 years (range 18-59), 34% were married or living as married, 39% earned an annual income of $12,000 or less, 12% held less than a high school education, and 54% were employed. Among the Hispanic women, 95% were foreign born. We identified two overarching relationship themes: contradictions between relationship expectations and desires and life circumstances that negated such ideals, and relationship challenges. Within the contradictions theme, we discovered six subthemes: a good man is hard to find; sex can be currency used to secure desired outcomes; compromises and allowances for cheating, irresponsible, and disrespectful behavior; redefining dating; sex just happens; needing relationship validation. The challenges theme centered on two subthemes: uncertainties and miscommunication, and relationship power negotiation. Gender differences in relationship intentions and desires as well as communication styles, the importance of emotional and financial support, and the potential for relationships to provide disappointment were present in all subthemes. In examining HIV risk perceptions, participants largely held that risk for HIV-infection and the need to take precautions were problems of women who differed from them (i.e., abuse drugs, are promiscuous, exchange sex). Underlying women's relational schemas was a belief that relationship priorities differed for men and women. Consequently, expectations and allowances for partner infidelity and negligent behaviors were incorporated into their scripts. Moreover, scripts endorsed women's use of sex as currency in relationship formation and endurance, and did not emphasize HIV risk. Both couple- and gender-specific group-level interventions are needed to deconstruct (breakdown) and reconstruct (rewrite) relationship scripts.
Changing trend? Sex ratios of children born to Indian immigrants in Norway revisited.
Tønnessen, Marianne; Aalandslid, Vebjørn; Skjerpen, Terje
2013-09-05
In some Western countries, a disturbingly low share of girls has been observed among new-borns from Indian immigrants. Also in Norway, a previous study based on figures from 1969-2005 showed a high percentage of boys among children of Indian origin living in Norway, when the birth was of higher order (third birth or later). This was suggested to reflect a practice of sex-selective abortions in the Indian immigrant population. In this article we have seen whether extended time series for the period 2006-2012 give further support to this claim. Based on data from the Norwegian Central Population Register we used observations for the sex of all live births in Norway for the period 1969-2012 where the mother was born in India. The percentage of boys was calculated for each birth order, during four sub periods. Utilising a binomial probability model we tested whether the observed sex differences among Indian-born women were significantly different from sex differences among all births. Contrary to findings from earlier periods and other Western countries, we found that Indian-born women in Norway gave birth to more girls than boys of higher order in the period 2006-2012. This is somewhat surprising, since sex selection is usually expected to be stronger if the mother already has two or more children. The extended time series do not suggest a prevalence of sex selective abortions among Indian-born women in Norway. We discuss whether the change from a majority of boys to a majority of girls in higher order could be explained by new waves of immigrant women, by new preferences among long-residing immigrant women in Norway - or by mere coincidence.
Sanders, G; Wright, M
1997-10-01
With each of the tasks in the present studies we expected to find the reported sex difference between heterosexual women and heterosexual men and we predicted a sexual orientation effect with the performance of homosexual men being similar to that of heterosexual women and different from that of heterosexual men. Study 1 aimed to replicate earlier findings by recording the performance of a group of homosexual men on a visuospatial task, the Vincent Mechanical Diagrams Test (VMDT), a dot detection divided visual field measure of functional cerebral asymmetry, and on five subtests of the Wechsler Adult Intelligence Scale (WAIS). For each task the profile of scores obtained for the homosexual men was similar to that of heterosexual women in that they scored lower than heterosexual men on the VMDT, they showed less asymmetry, and they recorded a higher Verbal than Performance IQ on the WAIS. In Study 2, a male-biased targeted throwing task favored heterosexual men while, in contrast, on the female-biased Purdue Pegboard single peg condition heterosexual men were outperformed by heterosexual women and homosexual men. On neither of these two tasks did the performances of homosexual men and heterosexual women differ. One task, manual speed, yielded neither sex nor sexual orientation differences. Another, the Purdue Pegboard assemblies condition, revealed a sex difference but no sexual orientation difference. Failure to obtain a sexual orientation difference in the presence of a sex difference suggests that the sexual orientation effect may be restricted to a subset of sexually dimorphic tasks.
Complex demographic heterogeneity from anthropogenic impacts in a coastal marine predator.
Oro, Daniel; Álvarez, David; Velando, Alberto
2018-04-01
Environmental drivers, including anthropogenic impacts, affect vital rates of organisms. Nevertheless, the influence of these drivers may depend on the physical features of the habitat and how they affect life history strategies depending on individual covariates such as age and sex. Here, the long-term monitoring (1994-2014) of marked European Shags in eight colonies in two regions with different ecological features, such as foraging habitat, allowed us to test several biological hypotheses about how survival changes by age and sex in each region by means of multi-event capture-recapture modeling. Impacts included fishing practices and bycatch, invasive introduced carnivores and the severe Prestige oil spill. Adult survival was constant but, unexpectedly, it was different between sexes. This difference was opposite in each region. The impact of the oil spill on survival was important only for adults (especially for females) in one region and lasted a single year. Juvenile survival was time dependent but this variability was not synchronized between regions, suggesting a strong signal of regional environmental variability. Mortality due to bycatch was also different between sex, age and region. Interestingly the results showed that the size of the fishing fleet is not necessarily a good proxy for assessing the impact of bycatch mortality, which may be more dependent on the fishing grounds and the fishing gears employed in each season of the year. Anthropogenic impacts affected survival differently by age and sex, which was expected for a long-lived organism with sexual size dimorphism. Strikingly, these differences varied depending on the region, indicating that habitat heterogeneity is demographically important to how environmental variability (including anthropogenic impacts) and resilience influence population dynamics. © 2018 by the Ecological Society of America.
Few Sex Differences in Hospitalized Suicide Attempters Aged 70 and Above.
Wiktorsson, Stefan; Rydberg Sterner, Therese; Mellqvist Fässberg, Madeleine; Skoog, Ingmar; Ingeborg Berg, Anne; Duberstein, Paul; Van Orden, Kimberly; Waern, Margda
2018-01-16
Relatively little research attention has been paid to sex issues in late life suicidal behaviour. The aim was to compare clinical characteristics of women and men aged 70+ who were hospitalized after a suicide attempt. We hypothesized higher depression and anxiety scores in women, and we expected to find that men would more often attribute the attempt to health problems and compromised autonomy. Participants (56 women and 47 men, mean age 80) were interviewed by a psychologist. In addition to psychiatric and somatic health assessments, participants responded to an open-ended question concerning attributions of the attempt. There were no sex differences in depression and anxiety. Forty-five percent of the men and 14% of the women had a history of substance use disorder ( p = 0.02). At least one serious physical disability was noted in 60.7% of the women and 53.2% of the men ( p = 0.55). Proportions attributing their attempt to somatic illness did not differ (women, 14.5% vs. men 17.4%, p = 0.79), and similar proportions attributed the attempt to reduced autonomy (women, 21.8% vs. men, 26.1%, p = 0.64). We found strikingly similar figures for depression scores, functional disability and attributions for attempting suicide in older men and women. Larger studies are needed in diverse settings as sex differences might be influenced by cultural context.
Differences in sociocultural environment perceptions associated with gender in science classrooms
NASA Astrophysics Data System (ADS)
Jegede, Olugbemiro J.; Akinsola Okebukola, Peter
An amount-of-learning outcome variable has been attributed to the environment in which teaching and learning are conducted. Studies carried out so far have, however, not focused on the sociocultural aspect of the classroom environment, which has been theorized to have potential influence on students' learning. The intent of this study was to examine the influence of five aspects of the sociocultural environment in science classes with particular reference to how these are perceived by boys and girls. The 30-item Socio-Cultural Environment Scale (SCES) developed by Jegede and Okebukola (1988) was used to collect data from 707 Nigerian secondary school students in Classes Four and Five (Grades 10 and 11, respectively). Authoritarianism, goal structure, African worldview, societal expectation, and sacredness of science were the five subscales studied. Sex differences were recorded in the societal expectation subscale. Most of the female subjects are of the opinion that society has a negative or low regard for their ability to do science and this has an effect on their motivation to undertake science-based careers. The reverse is true for boys. This perception is in agreement with the literature on sex differences in science education and highlights the social pressure that brings about subject preferences. The implications of these findings for science teaching and further research are highlighted.
Tobler, Michael; Schlupp, Ingo
2005-01-01
The maintenance of sexual reproduction in the face of its supposed costs is a major paradox in evolutionary biology. The Red Queen hypothesis, which states that sex is an adaptation to fast-evolving parasites, is currently one of the most recognized explanations for the ubiquity of sex and predicts that asexual lineages should suffer from a higher parasite load if they coexist with closely related sexuals. We tested this prediction using four populations of the sexual fish species Poecilia latipinna and its asexual relative Poecilia formosa. Contrary to expectation, no differences in parasite load could be detected between the two species. PMID:17148156
Mäki, Netta; Martikainen, Pekka; Eikemo, Terje; Menvielle, Gwenn; Lundberg, Olle; Ostergren, Olof; Jasilionis, Domantas; Mackenbach, Johan P
2013-10-01
Healthy life expectancy is a composite measure of length and quality of life and an important indicator of health in aging populations. There are few cross-country comparisons of socioeconomic differences in healthy life expectancy. Most of the existing comparisons focus on Western Europe and the United States, often relying on older data. To address these deficiencies, we estimated educational differences in disability-free life expectancy for eight countries from all parts of Europe in the early 2000s. Long-standing severe disability was measured as a Global Activity Limitation Indicator (GALI) derived from the European Union Statistics on Income and Living Conditions (EU-SILC) survey. Census-linked mortality data were collected by a recent project comparing health inequalities between European countries (the EURO-GBD-SE project). We calculated sex-specific educational differences in disability-free life expectancy between the ages of 30 and 79 years using the Sullivan method. The lowest disability-free life expectancy was found among Lithuanian men and women (33.1 and 39.1 years, respectively) and the highest among Italian men and women (42.8 and 44.4 years, respectively). Life expectancy and disability-free life expectancy were directly related to the level of education, but the educational differences were much greater in the latter in all countries. The difference in the disability-free life expectancy between those with a primary or lower secondary education and those with a tertiary education was over 10 years for males in Lithuania and approximately 7 years for males in Austria, Finland and France, as well as for females in Lithuania. The difference was smallest in Italy (4 and 2 years among men and women, respectively). Highly educated Europeans can expect to live longer and spend more years in better health than those with lower education. The size of the educational difference in disability-free life expectancy varies significantly between countries. The smallest and largest differences appear to be in Southern Europe and in Eastern and Northern Europe, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.
Ahrenfeldt, Linda Juel; Larsen, Lisbeth Aagaard; Lindahl-Jacobsen, Rune; Skytthe, Axel; Hjelmborg, Jacob V B; Möller, Sören; Christensen, Kaare
2017-02-01
To investigate the twin testosterone transfer (TTT) hypothesis by comparing early-life mortality risks of opposite-sex (OS) and same-sex (SS) twins during the first 15 years of life. We performed a population-based cohort study to compare mortality in OS and SS twins. We included 68,629 live-born Danish twins from 1973 to 2009 identified through the Danish Twin Registry and performed piecewise stratified Cox regression and log-binomial regression. Among 1933 deaths, we found significantly higher mortality for twin boys than for twin girls. For both sexes, OS twins had lower mortality than SS twins; the difference persisted for the first year of life for boys and for the first week of life for girls. Although the mortality risk for OS boys was in the expected direction according to the TTT hypothesis, the results for OS girls pointed in the opposite direction, providing no clear evidence for the TTT hypothesis. Copyright © 2016 Elsevier Inc. All rights reserved.
[Early death of the stronger sex. Could behavior change influence men's fate].
Klotz, T
2003-11-06
Life expectancy in men is approximately 6.5 years shorter than in women. As an explanation for this difference, isolated consideration of the higher prevalence of coronary heart disease and cancer in men is inadequate. But it would also appear erroneous to postulate that differences in male and female thinking and behavior patterns in regard to health-risk behavior are subject to controllable socialization processes and "rational" realizations. The interaction of genetic and environmental risk factors and socialization is largely unknown. A sex-specific consideration of risk behavior and quality of life suggest that a healthy lifestyle, relevant information and preventive measures - in particular in males - must be initiated before puberty if they are to have a positive effect on mortality and morbidity during the course of a person's life.
Child Mortality Estimation: Estimating Sex Differences in Childhood Mortality since the 1970s
Sawyer, Cheryl Chriss
2012-01-01
Introduction Producing estimates of infant (under age 1 y), child (age 1–4 y), and under-five (under age 5 y) mortality rates disaggregated by sex is complicated by problems with data quality and availability. Interpretation of sex differences requires nuanced analysis: girls have a biological advantage against many causes of death that may be eroded if they are disadvantaged in access to resources. Earlier studies found that girls in some regions were not experiencing the survival advantage expected at given levels of mortality. In this paper I generate new estimates of sex differences for the 1970s to the 2000s. Methods and Findings Simple fitting methods were applied to male-to-female ratios of infant and under-five mortality rates from vital registration, surveys, and censuses. The sex ratio estimates were used to disaggregate published series of both-sexes mortality rates that were based on a larger number of sources. In many developing countries, I found that sex ratios of mortality have changed in the same direction as historically occurred in developed countries, but typically had a lower degree of female advantage for a given level of mortality. Regional average sex ratios weighted by numbers of births were found to be highly influenced by China and India, the only countries where both infant mortality and overall under-five mortality were estimated to be higher for girls than for boys in the 2000s. For the less developed regions (comprising Africa, Asia excluding Japan, Latin America/Caribbean, and Oceania excluding Australia and New Zealand), on average, boys' under-five mortality in the 2000s was about 2% higher than girls'. A number of countries were found to still experience higher mortality for girls than boys in the 1–4-y age group, with concentrations in southern Asia, northern Africa/western Asia, and western Africa. In the more developed regions (comprising Europe, northern America, Japan, Australia, and New Zealand), I found that the sex ratio of infant mortality peaked in the 1970s or 1980s and declined thereafter. Conclusions The methods developed here pinpoint regions and countries where sex differences in mortality merit closer examination to ensure that both sexes are sharing equally in access to health resources. Further study of the distribution of causes of death in different settings will aid the interpretation of differences in survival for boys and girls. Please see later in the article for the Editors' Summary. PMID:22952433
Forecasting differences in life expectancy by education.
van Baal, Pieter; Peters, Frederik; Mackenbach, Johan; Nusselder, Wilma
2016-07-01
Forecasts of life expectancy (LE) have fuelled debates about the sustainability and dependability of pension and healthcare systems. Of relevance to these debates are inequalities in LE by education. In this paper, we present a method of forecasting LE for different educational groups within a population. As a basic framework we use the Li-Lee model that was developed to forecast mortality coherently for different groups. We adapted this model to distinguish between overall, sex-specific, and education-specific trends in mortality, and extrapolated these time trends in a flexible manner. We illustrate our method for the population aged 65 and over in the Netherlands, using several data sources and spanning different periods. The results suggest that LE is likely to increase for all educational groups, but that differences in LE between educational groups will widen. Sensitivity analyses illustrate the advantages of our proposed method.
Weingartner, Laura A; Moore, Richard C
2012-12-01
The sex chromosomes of the tropical crop papaya (Carica papaya) are evolutionarily young and consequently allow for the examination of evolutionary mechanisms that drive early sex chromosome divergence. We conducted a molecular population genetic analysis of four X/Y gene pairs from a collection of 45 wild papaya accessions. These population genetic analyses reveal striking differences in the patterns of polymorphism between the X and Y chromosomes that distinguish them from other sex chromosome systems. In most sex chromosome systems, the Y chromosome displays significantly reduced polymorphism levels, whereas the X chromosome maintains a level of polymorphism that is comparable to autosomal loci. However, the four papaya sex-linked loci that we examined display diversity patterns that are opposite this trend: the papaya X alleles exhibit significantly reduced polymorphism levels, whereas the papaya Y alleles maintain greater than expected levels of diversity. Our analyses suggest that selective sweeps in the regions of the X have contributed to this pattern while also revealing geographically restricted haplogroups on the Y. We discuss the possible role sexual selection and/or genomic conflict have played in shaping the contrasting patterns of polymorphism found for the papaya X and Y chromosomes.
Male infidelity high in Argentina.
1995-11-13
170 Argentine men and women of varied age, sexual orientation, occupation, and socioeconomic status were surveyed about their age of sexual initiation, frequency of intercourse, and recurrent fantasies, in addition to other sex-related questions. 37% of men and 12% of women who reported being in a stable couple relationship engaged in extra-couple sex in the six months before the survey. This 3.1 ratio of unfaithful men to unfaithful women is higher than the 1.9, 2.3, and 1.6 ratios found in Great Britain, France, and the US, respectively. The variation in ratios reflects the difference between prevailing norms of sexual identity and cultural expectations in each of the countries. The most recent statistics indicate that there are 6500 known cases of AIDS in Argentina, expected to increase to 12,000 in 1996. Market research, however, suggests that Argentine men generally do not use condoms. The study identified a possible trend toward greater fidelity among younger men, most likely due to the broadening role of Argentine women in society.
ERIC Educational Resources Information Center
Simon, Pamela Reed
2013-01-01
Studies have documented challenges in meeting No Child Left Behind (NCLB) expectations as well as gender differences that contribute to the achievement gaps between boys and girls. In response to increased NCLB accountability and achievement gaps between boys and girls, several experts have promoted single-sex education as a possible strategy to…
Smith, Amanda L; Alexander, Michelle; Rosenkrantz, Ted S; Sadek, Mona Lisa; Fitch, R Holly
2014-04-01
Hypoxia ischemia (HI; reduced oxygen and/or blood flow to the brain) is one of the most common injuries among preterm infants and term infants with birth complications. Both populations show cognitive/behavioral deficits, including impairments in sensory, learning/memory, and attention domains. Clinical data suggests a sex difference in HI outcomes, with males exhibiting more severe cognitive/behavioral deficits relative to matched females. Our laboratory has also reported more severe behavioral deficits among male rats with induced HI relative to females with comparable injury (Hill et al., 2011a,b). The current study initially examined published clinical studies from the past 20years where long-term IQ outcome scores for matched groups of male and female premature infants were reported separately (IQ being the most common outcome measure). A meta-analysis revealed a female "advantage," as indicated by significantly better scores on performance and full scale IQ (but not verbal IQ) for premature females. We then utilized a rodent model of neonatal HI injury to assess sham and postnatal day 7 (P7) HI male and female rats on a battery of behavioral tasks. Results showed expected deficits in HI male rats, but also showed task-dependent sex differences, with HI males having significantly larger deficits than HI females on some tasks but equivalent deficits on other tasks. In contrast to behavioral results, post mortem neuropathology associated with HI was comparable across sex. These findings suggest: 1) neonatal female "protection" in some behavioral domains, as indexed by superior outcome following early injury relative to males; and 2) female protection may entail sex-specific plasticity or compensation, rather than a reduction in gross neuropathology. Further exploration of the mechanisms underlying this sex effect could aid in neuroprotection efforts for at-risk neonates in general, and males in particular. Moreover, our current report of comparable anatomical damage coupled with differences in cognitive outcomes (by sex) provides a framework for future studies to examine neural mechanisms underlying sex differences in cognition and behavior in general. Copyright © 2014. Published by Elsevier Inc.
Effects of Gender Color-Coding on Toddlers' Gender-Typical Toy Play.
Wong, Wang I; Hines, Melissa
2015-07-01
Gender color-coding of children's toys may make certain toys more appealing or less appealing to a given gender. We observed toddlers playing with two gender-typical toys (a train, a doll), once in gender-typical colors and once in gender-atypical colors. Assessments occurred twice, at 20-40 months of age and at 26-47 months of age. A Sex × Time × Toy × Color ANOVA showed expected interactions between Sex and Toy and Sex and Color. Boys played more with the train than girls did and girls played more with the doll and with pink toys than boys did. The Sex × Toy × Color interaction was not significant, but, at both time points, boys and girls combined played more with the gender-atypical toy when its color was typical for their sex than when it was not. This effect appeared to be caused largely by boys' preference for, or avoidance of, the doll and by the use of pink. Also, at both time points, gender differences in toy preferences were larger in the gender-typical than in the gender-atypical color condition. At Time 2, these gender differences were present only in the gender-typical color condition. Overall, the results suggest that, once acquired, gender-typical color preferences begin to influence toy preferences, especially those for gender-atypical toys and particularly in boys. They thus could enlarge differences between boys' and girls' toy preferences. Because boys' and girls' toys elicit different activities, removing the gender color-coding of toys could encourage more equal learning opportunities.
A Game Theoretical Approach to Hacktivism: Is Attack Likelihood a Product of Risks and Payoffs?
Bodford, Jessica E; Kwan, Virginia S Y
2018-02-01
The current study examines hacktivism (i.e., hacking to convey a moral, ethical, or social justice message) through a general game theoretic framework-that is, as a product of costs and benefits. Given the inherent risk of carrying out a hacktivist attack (e.g., legal action, imprisonment), it would be rational for the user to weigh these risks against perceived benefits of carrying out the attack. As such, we examined computer science students' estimations of risks, payoffs, and attack likelihood through a game theoretic design. Furthermore, this study aims at constructing a descriptive profile of potential hacktivists, exploring two predicted covariates of attack decision making, namely, peer prevalence of hacking and sex differences. Contrary to expectations, results suggest that participants' estimations of attack likelihood stemmed solely from expected payoffs, rather than subjective risks. Peer prevalence significantly predicted increased payoffs and attack likelihood, suggesting an underlying descriptive norm in social networks. Notably, we observed no sex differences in the decision to attack, nor in the factors predicting attack likelihood. Implications for policymakers and the understanding and prevention of hacktivism are discussed, as are the possible ramifications of widely communicated payoffs over potential risks in hacking communities.
Aprison, Erin Z.; Ruvinsky, Ilya
2015-01-01
Pheromones are secreted molecules that mediate animal communications. These olfactory signals can have substantial effects on physiology and likely play important roles in organismal survival in natural habitats. Here we show that a blend of two ascaroside pheromones produced by C. elegans males primes the female reproductive system in part by improving sperm guidance toward oocytes. Worms have different physiological responses to different ratios of the same two molecules, revealing an efficient mechanism for increasing coding potential of a limited repertoire of molecular signals. The endogenous function of the male sex pheromones has an important side benefit. It substantially ameliorates the detrimental effects of prolonged heat stress on hermaphrodite reproduction because it increases the effectiveness with which surviving gametes are used following stress. Hermaphroditic species are expected to lose female-specific traits in the course of evolution. Our results suggest that some of these traits could have serendipitous utility due to their ability to counter the effects of stress. We propose that this is a general mechanism by which some mating-related functions could be retained in hermaphroditic species, despite their expected decay. PMID:26645097
NASA Astrophysics Data System (ADS)
Siddik, Muhammad Abu Bakar; Chaklader, Md Reaz; Hanif, Md Abu; Nahar, Ashfaqun; Ilham, Ilham; Cole, Anthony; Fotedar, Ravi
2017-09-01
For the first time, the present study reports the life-history traits, comprising length-frequency distribution (LFD), sex ratio (SR), length-weight relationships (LWRs), condition factors (CFs), and relative growth ( W R), of Clupisoma garua in the coastal waters of Bangladesh. A total of 150 specimens ranging from 8.60 to 25.20 cm total length (TL) and 4.26 to 128.80 g body weight (BW) were collected using traditional fishing gear from August 2013 to July 2014. The overall sex ratio of males to females in the study did not differ significantly from the expected value of 1:1 (χ2 =0.96, P <0.05) but there were significant sex differences ( P <0.05) in the intercepts and slopes of graphs characterizing traits in C. garua. The calculated b values for the LWRs were 2.955, 2.893 and 2.927 for males, females and combined sexes, respectively, and there was negative allometric growth in all cases ( b <3). The condition factors ( K A , K F , K R ) and relative growth ( W R ) also did not differ significantly ( P <0.05) between the sexes. This study provides a useful tool for fishery specialists to evaluate the relative condition of fish and to initiate early management strategies and regulations for the sustainable management of the remaining stocks of this species in the entire coastal region of southern Bangladesh.
NASA Astrophysics Data System (ADS)
Gilbert, Lucy; Rutstein, Alison N.; Hazon, Neil; Graves, Jefferson A.
2005-04-01
The Trivers-Willard hypothesis predicts sex biases in parental investment according to parental condition. In addition, parents may need to sex bias their investment if there is an asymmetry between the sexes in offspring fitness under different conditions. For studying maternal differential investment, egg resources are ideal subjects because they are self contained and allocated unequivocally by the female. Recent studies show that yolk androgens can be beneficial to offspring, so here we test for sex-biased investment with maternal investment of yolk testosterone (T) in zebra finch (Taeniopygia guttata) eggs. From the Trivers-Willard hypothesis, we predicted females to invest more in male eggs in optimum circumstances (e.g. good-condition mother, early-laid egg), and more in female eggs under suboptimal conditions (e.g. poor-condition mother, late-laid egg). This latter prediction is also because in this species there is a female nestling disadvantage in poor conditions and we expected mothers to help compensate for this in female eggs. Indeed, we found more yolk T in female than male eggs. Moreover, in accordance with our predictions, yolk T in male eggs increased with maternal quality relative to female eggs, and decreased with laying order relative to female eggs. This supports our predictions for the different needs and value of male and female offspring in zebra finches. Our results support the idea that females may use yolk androgens as a tool to adaptively manipulate the inequalities between different nestlings.
Modeling and forecasting U.S. sex differentials in mortality.
Carter, L R; Lee, R D
1992-11-01
"This paper examines differentials in observed and forecasted sex-specific life expectancies and longevity in the United States from 1900 to 2065. Mortality models are developed and used to generate long-run forecasts, with confidence intervals that extend recent work by Lee and Carter (1992). These results are compared for forecast accuracy with univariate naive forecasts of life expectancies and those prepared by the Actuary of the Social Security Administration." excerpt
The Impact of PTSD Symptoms on Women's Safer-Sex Negotiation: Influence of Ethnicity
Horsey, Katie J.; Palmieri, Patrick A.; Hobfoll, Stevan E.
2010-01-01
PTSD has been shown to predict later self reported sexual risk behavior, yet behavioral research is lacking in this area. The present study investigated the impact of PTSD severity on negotiation and interpersonal skills effectiveness in simulated high-risk sexual situations among 368 inner-city women. Participants engaged in role-play scenarios involving 1) refusing sex without a condom, 2) abstaining from drinking prior to sex, and 3) refusing sex until both partners were tested for HIV. Interviews were audio taped and rated along dimensions of negotiation effectiveness by blind raters. Hierarchical linear regression analyses were conducted to investigate the impact of PTSD and ethnicity on 4 theoretically derived skill sets 1) assertiveness, 2) using health and preparedness skills 3) social joining skills and 4) higher order negotiation skills. Generally, results indicated that PTSD severity predicted poorer rated negotiation effectiveness among European Americans, but not African Americans. African Americans' expectations that may prepare them for facing more hardship may help explain ethnic differences. PMID:22267974
The relationship between sex change and reproductive success in a protandric marine gastropod
Brante, Antonio; Quiñones, Adriana; Silva, Francisco
2016-01-01
Protandric species switch sex during their lifetime. According to theory, the time (body size) at which sex change occurs is determined by the reproductive success of individuals affected by social interactions as well as by post-copulatory factors. Experimental evidence is biased to few social systems making the exploration of general patterns difficult. We used the protandric marine gastropod Crepidula coquimbensis that partakes in intrabrood sibling cannibalism to test the following hypotheses: 1. Male-male competition for access to females and sibling cannibalism determine male reproductive success; 2. Males with greater access to females and with higher reproductive success will have reduced growth rates and will delay sex change. Artificial aggregations with different social structures were constructed and male reproductive success was estimated by paternity analysis. The results supported our expectations showing that male competitive ability for access to the female, time spent by males in the copulatory position, and sibling cannibalism affect reproductive success and influence time to sex change, with less successful males hastening sex change. Also, males that spent more time in the copulatory position had reduced growth rates. Comparing these results with those reported for other sequential hermaphrodites provides evidence supporting general patterns of sex change in nature. PMID:27385040
Bravo, Adrian J; Pearson, Matthew R; Pilatti, Angelina; Read, Jennifer P; Mezquita, Laura; Ibáñez, Manuel I; Ortet, Generós
2017-11-01
Perceptions about what is "normal" drinking in college, measured by the College Life Alcohol Salience Scale (CLASS; 15 items), have been robustly associated with elevated levels of problematic alcohol use, yet the role of these beliefs has not been studied outside the U.S. The present work examined measurement invariance of the CLASS across sex, drinker status, and in individuals from three different countries (i.e., U.S., Argentina, Spain). Additional goals were to evaluate differences on the CLASS (i.e., latent mean differences) as a function of sex, drinker status and country and to compare construct validity (i.e., correlations with alcohol variables) across sex and different countries. A large sample of 1841 college students enrolled in universities from the U.S., Spain and Argentina completed, via an online survey, a battery of instruments that assess college alcohol beliefs, drinking motives, alcohol consumption and alcohol-related negative consequences. We found that a shortened 12-item version of the CLASS to be invariant across sex and drinker status, but only metric invariance was found across countries. As expected, men and drinkers showed significantly higher scores on the CLASS than women and non-drinkers, respectively. Bivariate correlations between CLASS scores and drinking outcomes strongly supported criterion-related validity of this measure across multiple countries and sex with differing strengths in relationships with alcohol-related constructs. Taken together, perceptions of the centrality of alcohol to the college experience appear to be an important target for college student alcohol interventions across various cultures and countries, especially for male college student drinkers. Copyright © 2017 Elsevier B.V. All rights reserved.
Gender and sex differences in job status and hypertension
Clougherty, Jane E.; Eisen, Ellen A.; Slade, Martin D.; Kawachi, Ichiro; Cullen, Mark R.
2013-01-01
Objectives Studies have shown greater health risks associated with blue-collar manufacturing employment for women than men. It remains challenging, however, to distinguish cultural gendered factors influencing employment decisions (e.g., expected work roles, family responsibilities) from sex-linked biological differences shaping physiological response to workplace physical hazards. Methods We examined effects of hourly (blue-collar) status on incident hypertension among men and women, using health claims data for 14,618 white- and blue-collar aluminum manufacturing employees in eight U.S. states. To explore gender differences in job status, we developed sex-stratified propensity score models identifying key socioeconomic predictors of hourly status for men and women. To examine effects of hourly employment on hypertension risk, after adjusting for gender differences in job placement, we applied time-weighted logistic regression models, stratified by propensity score, with additional adjustment for socioeconomic confounders. Results Family structure (partnership, parity) influenced job status for both sexes; single mothers were more likely to hold hourly jobs (OR = 2.02 (95% CI = 1.37–2.97)), partnered men with children less likely (OR = 0.68 (0.56–0.83)). Education, age at hire, and race influenced job placement for both sexes. The effect of hourly status on hypertension was significant only among women predicted to be hourly (OR = 1.78 (1.34 – 2.35)). Conclusions Our results indicate significant risks of hypertension associated with hourly status for women, possibly exacerbated by sociodemographic factors predicting hourly status (e.g., single parenthood, low education). Greater attention to gender differences in job status, workplace stressors, and health risks associated with hourly work, is warranted. PMID:20864467
Dijkstra, Jan Kornelis; Berger, Christian
2018-01-01
The present study examined to what extent selection and influence processes for physical aggression and prosociality in friendship networks differed between sex-specific contexts (i.e., all-male, all-female, and mixed-sex classrooms), while controlling for perceived popularity. Whereas selection processes reflect how behaviors shape friendships, influence processes reveal the reversed pattern by indicating how friends affect individual behaviors. Data were derived from a longitudinal sample of early adolescents from Chile. Four all-male classrooms ( n = 150 male adolescents), four all-female classrooms ( n = 190 female adolescents), and eight mixed-sex classrooms ( n = 272 students) were followed one year from grades 5 to 6 ( M age = 13). Analyses were conducted by means of stochastic-actor-based modeling as implemented in RSIENA. Although it was expected that selection and influence effects for physical aggression and prosociality would vary by context, these effects showed remarkably similar trends across all-male, all-female, and mixed-sex classrooms, with physical aggression reducing and with prosociality increasing the number of nominations received as best friend in all-male and particularly all-female classrooms. Further, perceived popularity increased the number of friendship nominations received in all contexts. Influence processes were only found for perceived popularity, but not for physical aggression and prosociality in any of the three contexts. Together, these findings highlight the importance of both behaviors for friendship selection independent of sex-specific contexts, attenuating the implications of these gendered behaviors for peer relations.
High sex ratios in rural China: declining well-being with age in never-married men
Zhou, Xudong
2017-01-01
In parts of rural China male-biased sex ratios at birth, combined with out-migration of women, have led to highly male-biased adult sex ratios, resulting in large numbers of men being unable to marry, in a culture where marriage and reproduction are an expectation. The aim of this study was to test the hypotheses that older unmarried men are more predisposed to depression, low self-esteem and aggression than both those who are married, and those who are younger and unmarried. Self-completion questionnaires were administered among men aged 20–40 in 48 villages in rural Guizhou province, southwestern China. Tools used included the Beck Depression Inventory, the Rosenberg's Self-esteem Scale and the Bryant-Smith Aggression Questionnaire. Regression models assessed psychological wellbeing while adjusting for socio-demographic variables. Completed questionnaires were obtained from 957 never-married men, 535 married men aged 30–40, 394 partnered men and 382 unpartnered men aged 20–29. After adjusting for socio-demographic variables, never-married men were more predisposed to depression (p < 0.05), aggression (p < 0.01), low self-esteem (p < 0.05) and suicidal tendencies (p < 0.001). All the psychological measures deteriorated with age in never-married men. In contrast, married men remained stable on these dimensions with age. Never-married men are a psychologically highly vulnerable group in a society where marriage is an expectation. Since the highest birth sex–ratio cohorts have not yet reached reproductive age, the social tragedy of these men will last for at least another generation. This article is part of the themed issue ‘Adult sex ratios and reproductive decisions: a critical re-examination of sex differences in human and animal societies’. PMID:28760765
Radhakrishnan, Srihari; Valenzuela, Nicole
2017-10-30
Sex chromosomes evolve differently from autosomes because natural selection acts distinctly on them given their reduced recombination and smaller population size. Various studies of sex-linked genes compared with different autosomal genes within species support these predictions. Here, we take a novel alternative approach by comparing the rate of evolution between subsets of genes that are sex-linked in selected reptiles/vertebrates and the same genes located in autosomes in other amniotes. We report for the first time the faster evolution of Z-linked genes in a turtle (the Chinese softshell turtle Pelodiscus sinensis) relative to autosomal orthologs in other taxa, including turtles with temperature-dependent sex determination (TSD). This faster rate was absent in its close relative, the spiny softshell turtle (Apalone spinifera), thus revealing important lineage effects, and was only surpassed by mammalian-X linked genes. In contrast, we found slower evolution of X-linked genes in the musk turtle Staurotypus triporcatus (XX/XY) and homologous Z-linked chicken genes. TSD lineages displayed overall faster sequence evolution than taxa with genotypic sex determination (GSD), ruling out global effects of GSD on molecular evolution beyond those by sex-linkage. Notably, results revealed a putative selective sweep around two turtle genes involved in vertebrate gonadogenesis (Pelodiscus-Z-linked Nf2 and Chrysemys-autosomal Tspan7). Our observations reveal important evolutionary changes at the gene level mediated by chromosomal context in turtles despite their low overall evolutionary rate and illuminate sex chromosome evolution by empirically testing expectations from theoretical models. Genome-wide analyses are warranted to test the generality and prevalence of the observed patterns. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Robinson, Michael E; George, Steven Z; Dannecker, Erin A; Jump, Rebecca L; Hirsh, Adam T; Gagnon, Christine M; Brown, Jennifer L
2004-08-01
Recent research suggests that the interpretation of maximal endpoints of pain scales vary between sexes. The purposes of this study were to investigate sex differences in (a) maximal endpoints of pain scales and (b) bias, discrimination, and the "better than average effect" for ratings of common pain events. Study participants described and rated the intensity of events that were the "most intense pain imaginable" for the typical woman, typical man, and one's self. Study participants also described and rated the intensity of the "most painful" events they had experienced. Study participants completed the situational pain questionnaire (SPQ), which measured the amount of pain that the typical woman, typical man, or one's self would be expected to experience during thirty common painful events. One hundred and fifteen undergraduate psychology students completed this study. Men and women differed in the categories of events selected for most intense pain imaginable for one's self. There were no significant sex differences for the intensity of most intense self-imagined pain or most painful event experienced. However, women were more likely to report the intensity of their worst self-imagined pain event as 100/100. In addition, only women demonstrated a significant correlation between the intensity of most painful self-experienced event and intensity of most intense self-imagined event. Analyses of the SPQ discrimination scores revealed no sex or version differences. Analyses of the SPQ bias scores showed that both sexes indicated that the typical woman would rate the intensity of common pain events higher than would the typical man. Women rated the intensity of common pain events for themselves lower than for the typical woman, but higher than the typical man, and men rated also rated themselves as lower than the typical women, but the same as the typical man. Thus, there was inconsistent support for the "better than average effect". Future research is needed to determine the clinical relevance of sex differences in pain anchors and gender-related stereotypes for evaluating other people's pain.
Murphy, Dean A; de Wit, John B F; Donohoe, Simon; Adam, Philippe C G
2015-01-01
Although there is evidence of increasing overall rates of HIV status disclosure among gay and bisexual men, little is known about men's disclosure expectations and practices. In this study, we investigate the importance non-HIV-positive men in Australia vest in knowing the HIV status of their sexual partners, and the extent to which they restrict sex to partners of the same HIV status, and their HIV disclosure expectations. Data were collected through a national, online self-report survey. Of the 1044 men included in the study, 914 were HIV negative and 130 were untested. Participants completed the assessment of socio-demographic characteristics, HIV status preferences, and disclosure expectations and practices. Participants also completed reliable multi-item measures of perceived risk of HIV transmission, expressed HIV-related stigma, and engagement with the gay community and the community of people living with HIV. A quarter (25.9%) of participants wanted to know the HIV status of all sexual partners, and one-third (37.2%) restricted sex to partners of similar HIV status. Three quarters (76.3%) expected HIV-positive partners to disclosure their HIV status before sex, compared to 41.6% who expected HIV-negative men to disclose their HIV status. Less than half (41.7%) of participants reported that they consistently disclosed their HIV status to sexual partners. Multivariate linear regression analysis identified various covariates of disclosure expectations and practices, in particular of disclosure expectations regarding HIV-positive men. Men who expected HIV-positive partners to disclose their HIV status before sex more often lived outside capital cities, were less educated, were less likely to identify as gay, perceived more risk of HIV transmission from a range of sexual practices, were less engaged with the community of people living with HIV, and expressed more stigma towards HIV-positive people. These findings suggest that an HIV-status divide is emerging or already exists among gay men in Australia. HIV-negative and untested men who are most likely to sexually exclude HIV-positive men are less connected to the HIV epidemic and less educated about HIV risk and prevention.
Streicher, S; Lutermann, H; Bennett, N C; Bertelsen, M F; Mohammed, O B; Manger, P R; Scantlebury, M; Ismael, K; Alagaili, A N
2017-01-01
Heterothermy, the ability to allow body temperature (Tb) to fluctuate, has been proposed as an adaptive mechanism that enables large ungulates to cope with the high environmental temperatures and lack of free water experienced in arid environments. By storing heat during the daytime and dissipating it during the night, arid-adapted ungulates may reduce evaporative water loss and conserve water. Adaptive heterothermy in large ungulates should be particularly pronounced in hot environments with severely limited access to free water. In the current study we investigated the effects of environmental temperature (ambient, Ta and soil, Ts) and water stress on the Tb of wild, free-ranging Arabian oryx (Oryx leucoryx) in two different sites in Saudi Arabia, Mahazat as-Sayd (MS) and Uruq Bani Ma'arid (UBM). Using implanted data loggers wet took continuous Tb readings every 10 minutes for an entire calendar year and determined the Tb amplitude as well as the heterothermy index (HI). Both differed significantly between sites but contrary to our expectations they were greater in MS despite its lower environmental temperatures and higher rainfall. This may be partially attributable to a higher activity in an unfamiliar environment for translocated animals in UBM. As expected Tb amplitude and HI were greatest during summer. Only minor sex differences were apparent that may be attributable to sex-specific investment into reproduction (e.g. male-male competition) during rut. Our results suggest that the degree of heterothermy is not only driven by extrinsic factors (e.g. environmental temperatures and water availability), but may also be affected by intrinsic factors (e.g. sex and/or behaviour).
Lutermann, H.; Bennett, N. C.; Bertelsen, M. F.; Mohammed, O. B.; Manger, P. R.; Scantlebury, M.; Ismael, K.; Alagaili, A. N.
2017-01-01
Heterothermy, the ability to allow body temperature (Tb) to fluctuate, has been proposed as an adaptive mechanism that enables large ungulates to cope with the high environmental temperatures and lack of free water experienced in arid environments. By storing heat during the daytime and dissipating it during the night, arid-adapted ungulates may reduce evaporative water loss and conserve water. Adaptive heterothermy in large ungulates should be particularly pronounced in hot environments with severely limited access to free water. In the current study we investigated the effects of environmental temperature (ambient, Ta and soil, Ts) and water stress on the Tb of wild, free-ranging Arabian oryx (Oryx leucoryx) in two different sites in Saudi Arabia, Mahazat as-Sayd (MS) and Uruq Bani Ma’arid (UBM). Using implanted data loggers wet took continuous Tb readings every 10 minutes for an entire calendar year and determined the Tb amplitude as well as the heterothermy index (HI). Both differed significantly between sites but contrary to our expectations they were greater in MS despite its lower environmental temperatures and higher rainfall. This may be partially attributable to a higher activity in an unfamiliar environment for translocated animals in UBM. As expected Tb amplitude and HI were greatest during summer. Only minor sex differences were apparent that may be attributable to sex-specific investment into reproduction (e.g. male-male competition) during rut. Our results suggest that the degree of heterothermy is not only driven by extrinsic factors (e.g. environmental temperatures and water availability), but may also be affected by intrinsic factors (e.g. sex and/or behaviour). PMID:28854247
Non-Sexist Learning and Teaching with Young Children.
ERIC Educational Resources Information Center
Morfield, Sheila
This brief teaching guide provides sex-fair activities for use in grades PS-3. Activities suggested cover five areas: (1) feelings (the need to be able to express feelings regardless of sex), (2) non-sexist behavior (encouraging children to behave according to their needs and desires rather than according to sex role expectations), (3) body…
Correlates of Oral Sex and Vaginal Intercourse in Early and Middle Adolescence
ERIC Educational Resources Information Center
Bersamin, Melina M.; Walker, Samantha; Fisher, Deborah A.; Grube, Joel W.
2006-01-01
This study examined whether a comprehensive set of psychosocial factors was equally predictive of both adolescent vaginal intercourse and oral sex among 1,105 adolescents aged 12-16. Logistic regressions were used to examine the relationships between parental communication, religiosity, bonding to school, heavy drinking, sex expectancies,…
Detailed educational pathways among females after very early sexual intercourse.
Steward, Nicole R; Farkas, George; Bingenheimer, Jeffrey B
2009-12-01
Although studies have shown that early sex is negatively associated with high school graduation and college enrollment, no recent study has examined the extent to which early sex affects educational attainment, and the mediating mechanisms have not been established. Data from 4,613 female participants in the National Educational Longitudinal Study were used to examine the relationship between early sexual intercourse (i.e., first sex prior to age 15) and educational attainment. Logistic regression analyses that controlled for background characteristics, school performance, behavioral factors and academic aspirations were conducted to assess this association, as well as to explore the potential mediating role of early marriage and childbearing. Young women who had had early sex had reduced odds of having graduated from high school (odds ratio, 0.4) and from college (0.5). Postsecondary enrollment was positively associated with expectations of postsecondary education (1.5) and levels of academic achievement (1.4-1.5), but not with early sex. Respondents who had married before their expected high school graduation date had reduced odds of having graduated from high school (0.1), enrolled in postsecondary school (0.4) or completed college (0.1); those who had a child before their expected high school graduation date had reduced odds of having graduated from high school (0.3) or college (0.1). Programs that target early parenthood and marriage, and that provide hope for future educational opportunities, could lessen the impact of early sex for young women.
Exploring sex differences in autistic traits: A factor analytic study of adults with autism.
Grove, Rachel; Hoekstra, Rosa A; Wierda, Marlies; Begeer, Sander
2017-08-01
Research has highlighted potential differences in the phenotypic and clinical presentation of autism spectrum conditions across sex. Furthermore, the measures utilised to evaluate autism spectrum conditions may be biased towards the male autism phenotype. It is important to determine whether these instruments measure the autism phenotype consistently in autistic men and women. This study evaluated the factor structure of the Autism Spectrum Quotient Short Form in a large sample of autistic adults. It also systematically explored specific sex differences at the item level, to determine whether the scale assesses the autism phenotype equivalently across males and females. Factor analyses were conducted among 265 males and 285 females. A two-factor structure consisting of a social behaviour and numbers and patterns factor was consistent across groups, indicating that the latent autism phenotype is similar among both autistic men and women. Subtle differences were observed on two social behaviour item thresholds of the Autism Spectrum Quotient Short Form, with women reporting scores more in line with the scores expected in autism on these items than men. However, these differences were not substantial. This study showed that the Autism Spectrum Quotient Short Form detects autistic traits equivalently in males and females and is not biased towards the male autism phenotype.
Patterns of molecular evolution of an avian neo-sex chromosome.
Pala, Irene; Hasselquist, Dennis; Bensch, Staffan; Hansson, Bengt
2012-12-01
Newer parts of sex chromosomes, neo-sex chromosomes, offer unique possibilities for studying gene degeneration and sequence evolution in response to loss of recombination and population size decrease. We have recently described a neo-sex chromosome system in Sylvioidea passerines that has resulted from a fusion between the first half (10 Mb) of chromosome 4a and the ancestral sex chromosomes. In this study, we report the results of molecular analyses of neo-Z and neo-W gametologs and intronic parts of neo-Z and autosomal genes on the second half of chromosome 4a in three species within different Sylvioidea lineages (Acrocephalidea, Timaliidae, and Alaudidae). In line with hypotheses of neo-sex chromosome evolution, we observe 1) lower genetic diversity of neo-Z genes compared with autosomal genes, 2) moderate synonymous and weak nonsynonymous sequence divergence between neo-Z and neo-W gametologs, and 3) lower GC content on neo-W than neo-Z gametologs. Phylogenetic reconstruction of eight neo-Z and neo-W gametologs suggests that recombination continued after the split of Alaudidae from the rest of the Sylvioidea lineages (i.e., after ~42.2 Ma) and with some exceptions also after the split of Acrocephalidea and Timaliidae (i.e., after ~39.4 Ma). The Sylvioidea neo-sex chromosome shares classical evolutionary features with the ancestral sex chromosomes but, as expected from its more recent origin, shows weaker divergence between gametologs.
Schärer, Lukas; Pen, Ido
2013-03-05
Sex allocation theory predicts the optimal allocation to male and female reproduction in sexual organisms. In animals, most work on sex allocation has focused on species with separate sexes and our understanding of simultaneous hermaphrodites is patchier. Recent theory predicts that sex allocation in simultaneous hermaphrodites should strongly be affected by post-copulatory sexual selection, while the role of pre-copulatory sexual selection is much less clear. Here, we review sex allocation and sexual selection theory for simultaneous hermaphrodites, and identify several strong and potentially unwarranted assumptions. We then present a model that treats allocation to sexually selected traits as components of sex allocation and explore patterns of allocation when some of these assumptions are relaxed. For example, when investment into a male sexually selected trait leads to skews in sperm competition, causing local sperm competition, this is expected to lead to a reduced allocation to sperm production. We conclude that understanding the evolution of sex allocation in simultaneous hermaphrodites requires detailed knowledge of the different sexual selection processes and their relative importance. However, little is currently known quantitatively about sexual selection in simultaneous hermaphrodites, about what the underlying traits are, and about what drives and constrains their evolution. Future work should therefore aim at quantifying sexual selection and identifying the underlying traits along the pre- to post-copulatory axis.
Schärer, Lukas; Pen, Ido
2013-01-01
Sex allocation theory predicts the optimal allocation to male and female reproduction in sexual organisms. In animals, most work on sex allocation has focused on species with separate sexes and our understanding of simultaneous hermaphrodites is patchier. Recent theory predicts that sex allocation in simultaneous hermaphrodites should strongly be affected by post-copulatory sexual selection, while the role of pre-copulatory sexual selection is much less clear. Here, we review sex allocation and sexual selection theory for simultaneous hermaphrodites, and identify several strong and potentially unwarranted assumptions. We then present a model that treats allocation to sexually selected traits as components of sex allocation and explore patterns of allocation when some of these assumptions are relaxed. For example, when investment into a male sexually selected trait leads to skews in sperm competition, causing local sperm competition, this is expected to lead to a reduced allocation to sperm production. We conclude that understanding the evolution of sex allocation in simultaneous hermaphrodites requires detailed knowledge of the different sexual selection processes and their relative importance. However, little is currently known quantitatively about sexual selection in simultaneous hermaphrodites, about what the underlying traits are, and about what drives and constrains their evolution. Future work should therefore aim at quantifying sexual selection and identifying the underlying traits along the pre- to post-copulatory axis. PMID:23339243
Mullens, A B; Young, R McD; Dunne, M; Norton, G
2010-06-01
Substance-related expectancies are associated with substance use and post-substance use thoughts, feelings and behaviours. The expectancies held by specific cultural or sub-cultural groups have rarely been investigated. This research maps expectancies specific to gay and other men who have sex with men (MSM) and their relationship with substance patterns and behaviours following use, including sexual practices (e.g., unprotected anal intercourse). This study describes the development of a measure of such beliefs for cannabis, the Cannabis Expectancy Questionnaire for Men who have Sex with Men (CEQ-MSM). Items selected through a focus group and interviews were piloted on 180 self-identified gay or other MSM via an online questionnaire. Factor analysis revealed six distinct substance reinforcement domains ("Enhanced sexual experience", "Sexual negotiation", "Cognitive impairment", "Social and emotional facilitation", "Enhanced sexual desire", and "Sexual inhibition"). The scale was associated with consumption patterns of cannabis, and in a crucial test of discriminant validity not with the consumption of alcohol or stimulants. The CEQ-MSM represents a reliable and valid measure of outcome expectancies, related to cannabis among MSM. Future applications of the CEQ-MSM in health promotion, clinical settings and research may contribute to reducing harm associated with substance use among MSM, including HIV transmission. Copyright 2010 Elsevier Ltd. All rights reserved.
Jain, S K
1992-05-01
"The paper examines the post-1971 reduction in Australian mortality in light of data on causes of death. Multiple-decrement life tables for eleven leading causes of death by sex are calculated and the incidence of each cause of death is presented in terms of the values of the life table functions. The study found that in the overall decline in mortality over the last 20 years significant changes occurred in the contribution of the various causes to total mortality.... The sex-age-cause-specific incidence of mortality changed and the median age at death increased for all causes except for deaths due to motor-vehicle accidents for both sexes and suicide for males. The paper also deciphers the gains in the expectation of life at birth over various time periods and the sex-differentials in the expectation of life at birth at a point in time in terms of the contributions made by the various sex-age-cause-specific mortality rates." excerpt
Giroud, Marie; Delpont, Benoit; Daubail, Benoit; Blanc, Christelle; Durier, Jérôme; Giroud, Maurice; Béjot, Yannick
2017-04-01
We evaluated temporal trends in stroke incidence between men and women to determine whether changes in the distribution of vascular risk factors have influenced sex differences in stroke epidemiology. Patients with first-ever stroke including ischemic stroke, spontaneous intracerebral hemorrhage, subarachnoid hemorrhage, and undetermined stroke between 1987 and 2012 were identified through the population-based registry of Dijon, France. Incidence rates were calculated for age groups, sex, and stroke subtypes. Sex differences and temporal trends (according to 5-year time periods) were evaluated by calculating incidence rate ratios (IRRs) with Poisson regression. Four thousand six hundred and fourteen patients with a first-ever stroke (53.1% women) were recorded. Incidence was lower in women than in men (112 versus 166 per 100 000/y; IRR, 0.68; P <0.001), especially in age group 45 to 84 years, and for both ischemic stroke and intracerebral hemorrhage. From 1987 to 2012, the lower incidence of overall stroke in women was stable (IRR ranging between 0.63 and 0.72 according to study periods). When considering stroke subtype, a slight increase in the incidence of ischemic stroke was observed in both men (IRR, 1.011; 95% confidence interval, 1.005-1.016; P =0.001) and women (IRR, 1.013; 95% confidence interval, 1.007-1.018; P =0.001). The sex gap in incidence remained unchanged in ischemic stroke and intracerebral hemorrhage. Conversely, the lower subarachnoid hemorrhage incidence in women vanished with time because of an increasing incidence. The sex gap in stroke incidence did not change with time except for subarachnoid hemorrhage. Despite lower rates, more women than men experience an incident stroke each year because of a longer life expectancy. © 2017 American Heart Association, Inc.
An Investigation of Teacher Perceptions of Sex Typed Behaviors
ERIC Educational Resources Information Center
Motta, Robert W.; Vane, Julia R.
1976-01-01
Current emphasis on the changing sex role expectations of women in the direction of increased assertiveness and independence has prompted investigation of the impact this emphasis has on teacher perceptions of student behavior. (DMT)
ERIC Educational Resources Information Center
Kageyama, Junji
2013-01-01
National average happiness and the difference in happiness between women and men are positively correlated in European countries. This study focuses on this cross-country relationship and tests (1) whether, after controlling for socio-economic factors, the correlation is attributed to their direct relationship, or, alternatively, explained by the…
Besaggio, Davide; Fuselli, Silvia; Srikummool, Metawee; Kampuansai, Jatupol; Castrì, Loredana; Tyler-Smith, Chris; Seielstad, Mark; Kangwanpong, Daoroong; Bertorelle, Giorgio
2007-01-01
Background Ethnic minorities in Northern Thailand, often referred to as Hill Tribes, are considered an ideal model to study the different genetic impact of sex-specific migration rates expected in matrilocal (women remain in their natal villages after the marriage and men move to their wife's village) and patrilocal societies (the opposite is true). Previous studies identified such differences, but little is known about the possible interaction with another cultural factor that may potentially affect genetic diversity, i.e. linguistic differences. In addition, Hill Tribes started to migrate to Thailand in the last centuries from different Northern areas, but the history of these migrations, the level of genetic legacy with their places of origin, and the possible confounding effects related to this migration history in the patterns of genetic diversity, have not been analysed yet. Using both original and published data on the Hill Tribes and several other Asian populations, we focused on all these aspects. Results Genetic variation within population at mtDNA is lower in matrilocal, compared to patrilocal, tribes. The opposite is true for Y-chromosome microsatellites within the Sino-Tibetan linguistic family, but Hmong-Mien speaking patrilocal groups have a genetic diversity very similar to the matrilocal samples. Population divergence ranges between 5% and 14% at mtDNA sequences, and between 5% and 36% at Y- chromosomes STRs, and follows the sex-specific differences expected in patrilocal and matrilocal tribes. On the average, about 2 men and 14 women, and 4 men and 4 women, are exchanged in patrilocal and matrilocal tribes every generation, respectively. Most of the Hill Tribes in Thailand seem to preserve a genetic legacy with their likely geographic origin, with children adoption probably affecting this pattern in one tribe. Conclusion Overall, the sex specific genetic signature of different postmarital habits of residence in the Hill Tribes is robust. However, specific perturbations related to linguistic differences, population specific traits, and the complex migratory history of these groups, can be identified. Additional studies in different populations are needed, especially to obtain more precise estimates of the migration parameters. PMID:17767728
Besaggio, Davide; Fuselli, Silvia; Srikummool, Metawee; Kampuansai, Jatupol; Castrì, Loredana; Tyler-Smith, Chris; Seielstad, Mark; Kangwanpong, Daoroong; Bertorelle, Giorgio
2007-08-16
Ethnic minorities in Northern Thailand, often referred to as Hill Tribes, are considered an ideal model to study the different genetic impact of sex-specific migration rates expected in matrilocal (women remain in their natal villages after the marriage and men move to their wife's village) and patrilocal societies (the opposite is true). Previous studies identified such differences, but little is known about the possible interaction with another cultural factor that may potentially affect genetic diversity, i.e. linguistic differences. In addition, Hill Tribes started to migrate to Thailand in the last centuries from different Northern areas, but the history of these migrations, the level of genetic legacy with their places of origin, and the possible confounding effects related to this migration history in the patterns of genetic diversity, have not been analysed yet. Using both original and published data on the Hill Tribes and several other Asian populations, we focused on all these aspects. Genetic variation within population at mtDNA is lower in matrilocal, compared to patrilocal, tribes. The opposite is true for Y-chromosome microsatellites within the Sino-Tibetan linguistic family, but Hmong-Mien speaking patrilocal groups have a genetic diversity very similar to the matrilocal samples. Population divergence ranges between 5% and 14% at mtDNA sequences, and between 5% and 36% at Y-chromosomes STRs, and follows the sex-specific differences expected in patrilocal and matrilocal tribes. On the average, about 2 men and 14 women, and 4 men and 4 women, are exchanged in patrilocal and matrilocal tribes every generation, respectively. Most of the Hill Tribes in Thailand seem to preserve a genetic legacy with their likely geographic origin, with children adoption probably affecting this pattern in one tribe. Overall, the sex specific genetic signature of different postmarital habits of residence in the Hill Tribes is robust. However, specific perturbations related to linguistic differences, population specific traits, and the complex migratory history of these groups, can be identified. Additional studies in different populations are needed, especially to obtain more precise estimates of the migration parameters.
Slabbekoorn, D; van Goozen, S H; Sanders, G; Gooren, L J; Cohen-Kettenis, P T
2000-05-01
It has been proposed that gender identity and sexual orientation are influenced by the prenatal sex steroid milieu. Human dermatoglyphics and brain asymmetry have also been ascribed to prenatal hormone levels. This study investigated dermatoglyphics (total ridge count and finger ridge asymmetry) in 184 male-to-female transsexuals and 110 female-to-male transsexuals. In a subgroup, the relationship between dermatoglyphic asymmetry and spatial ability was tested. All investigations included controls. For all subjects hand preference and sexual orientation were noted. We hypothesized that the dermatoglyphics of male-to-female transsexuals would show similarities with control women and those of female-to-male transsexuals with control men. Our results showed a trend for a sex difference in total ridge count (P<.1) between genetic males and females, but no difference in directional asymmetry was found. Contrary to our expectations, the total ridge count and finger ridge asymmetry of transsexuals were similar to their genetic sex controls. Additionally, directional asymmetry was neither related to sexual orientation, nor to different aspects of spatial ability. In conclusion, we were unable to demonstrate that our chosen dermatoglyphic variables, total ridge count and finger ridge asymmetry are related to gender identity and sexual orientation in adult transsexuals. Hence, we found no support for a prenatal hormonal influence on these characteristics, at least insofar as dermatoglyphics may be regarded as a biological marker of organizing hormonal effects.
Castro, Felipe N; Hattori, Wallisen T; Yamamoto, Maria Emília; Lopes, Fívia A
2013-10-01
This study used the biological market perspective and influential statistical models from the marketing field to investigate males' and females' expectations regarding which combination of characteristics are most relevant in ensuring desirable partnerships for same-sex individuals. Thus, 358 Brazilian undergraduates assessed eight descriptions of same-gender stimulus targets (formulated with different levels of physical attractiveness, social skills, and current or prospective social status) and evaluated the overall desirability of the targets' expected or probable partners. From the possible combinations, three groups emerged: for one group, mainly composed of men, status characteristics were the most important attributes; for the others, mostly composed of women, social skills or physical characteristics were identified as most important in appealing to a desirable partner. This work expands the understanding of variability in male and female romantic expectations, and its implications are discussed from an evolutionary perspective.
Age, gender, and race/ethnic differences in total body and subregional bone density.
Looker, A C; Melton, L J; Harris, T; Borrud, L; Shepherd, J; McGowan, J
2009-07-01
Total body bone density of adults from National Health and Nutrition Examination Survey (NHANES) 1999-2004 differed as expected for some groups (men>women and blacks>whites) but not others (whites>Mexican Americans). Cross-sectional age patterns in bone mineral density (BMD) of older adults differed at skeletal sites that varied by degree of weight-bearing. Total body dual-energy X-ray absorptiometry (DXA) data offer the opportunity to compare bone density of demographic groups across the entire skeleton. The present study uses total body DXA data (Hologic QDR 4500A, Hologic, Bedford MA, USA) from the NHANES 1999-2004 to examine BMD of the total body and selected skeletal subregions in a wide age range of adult men and women from three race/ethnic groups. Total body, lumbar spine, pelvis, right leg, and left arm BMD and lean mass from 13,091 adults aged 20 years and older were used. The subregions were chosen to represent sites with different degrees of weight-bearing. Mean BMD varied in expected ways for some demographic characteristics (men>women and non-Hispanic blacks>non-Hispanic whites) but not others (non-Hispanic whites>Mexican Americans). Differences in age patterns in BMD also emerged for some characteristics (sex) but not others (race/ethnicity). Differences in cross-sectional age patterns in BMD and lean mass by degree of weight-bearing in older adults were observed for the pelvis, leg, and arm. This information may be useful for generating hypotheses about age, race, and sex differences in fracture risk in the population.
Isogenic mice exhibit sexually-dimorphic DNA methylation patterns across multiple tissues.
McCormick, Helen; Young, Paul E; Hur, Suzy S J; Booher, Keith; Chung, Hunter; Cropley, Jennifer E; Giannoulatou, Eleni; Suter, Catherine M
2017-12-13
Cytosine methylation is a stable epigenetic modification of DNA that plays an important role in both normal physiology and disease. Most diseases exhibit some degree of sexual dimorphism, but the extent to which epigenetic states are influenced by sex is understudied and poorly understood. To address this deficit we studied DNA methylation patterns across multiple reduced representation bisulphite sequencing datasets (from liver, heart, brain, muscle and spleen) derived from isogenic male and female mice. DNA methylation patterns varied significantly from tissue to tissue, as expected, but they also varied between the sexes, with thousands of sexually dimorphic loci identified. The loci affected were largely autonomous to each tissue, even within tissues derived from the same germ layer. At most loci, differences between genders were driven by females exhibiting hypermethylation relative to males; a proportion of these differences were independent of the presence of testosterone in males. Loci harbouring gender differences were clustered in ontologies related to tissue function. Our findings suggest that gender is underwritten in the epigenome in a tissue-specific and potentially sex hormone-independent manner. Gender-specific epigenetic states are likely to have important implications for understanding sexually dimorphic phenotypes in health and disease.
Age and Sex Differences in the Vocational Aspirations of Elementary School Children.
Hewitt, Lynn Stewart
1975-08-01
Four hypotheses were proposed: (a) boys would aspire to a greater variety of vocations than girls; (b) boys would change their vocational preferences more frequently than girls; (c) older boys would aspire to a broader range of vocations than younger boys; and (d) older girls would aspire to a similar or smaller range of vocations than younger girls. A total of 128 6- and 8-year-old Dutch boys and girls responded to questions concerning their vocational aspirations. All the hypotheses except (b) received support. The results suggested that sex-role expectations for adult occupations are acquired very early and, moreover, strongly circumscribe the range of vocations perceived as appropriate for females.
Cornish, Flora; Ghosh, Riddhi
2007-01-01
Health promotion interventions with marginalised groups are increasingly expected to demonstrate genuine community participation in their design and delivery. However, ideals of egalitarian democratic participation are far removed from the starting point of the hierarchical and exploitative social relations that typically characterise marginalised communities. What scope is there for health promotion projects to implement ideals of community leadership within the realities of marginalisation and inequality? We examine how the Sonagachi Project, a successful sex-worker-led HIV prevention project in India, has engaged with the unequal social relations in which it is embedded. Our ethnographic study is based on observation of the Project's participatory activities and 39 interviews with a range of its stakeholders (including sex worker employees of the Project, non-sex-worker development professionals, brothel managers, sex workers' clients). The analysis shows that the project is deeply shaped by its relationships with non-sex-worker interest groups. In order to be permitted access to the red light district, it has had to accommodate the interests of local men's clubs and brothel managers. The economic and organisational capacity to run such a project has depended upon the direct input of development professionals and funding agencies. Thus, the 'community' that leads this project is much wider than a local grouping of marginalised sex workers. We argue that, given existing power relations, the engagement with other interest groups was necessary to the project's success. Moreover, as the project has developed, sex workers' interests and leadership have gained increasing prominence. We suggest that existing optimistic expectations of participation inhibit acknowledgement of the troubling work of balancing power relations. Rather than denying such power relations, projects should be expected to plan for them.
NASA Astrophysics Data System (ADS)
Robinson, W. P.; Gillibrand, E.
2004-06-01
The primary purpose was to investigate the efficacy of a full year of single-sex (SS) teaching of science. The secondary aims were to locate any differentiation by set and gender, and to relate these to more proximal variables. Participants were 13 year olds. Higher set girls gave evidence of clear benefits overall, and higher set boys also, except in biology. Lower set pupils performed at or below expectations. Analyses of additional questionnaire and interview data pointed to further reasons for avoiding the making of unqualified generalizations about SS teaching. Pupil preferences for SS teaching were relevant, as were gender differences in attitudes to biology and physics. Qualitative data suggested higher set girls benefited from more learningrelated classroom interaction and less interference and exploitation of girls by boys in SS classes. Lower set pupils complained that SS teaching deprived them of social interaction with the other sex. The concluding suggestion was that SS teaching offers affordances of benefits when mixed-sex teaching has specifiable disadvantages.
Looking beyond HIV: eliciting individual and community needs of male internet escorts.
Parsons, Jeffrey T; Koken, Juline A; Bimbi, David S
2007-01-01
In evaluating the needs of male sex workers (MSWs), past research and community-based outreach efforts have assumed they should receive counseling and be educated regarding drug abuse and HIV/STI prevention. These assumptions have been based upon studies that predominantly sampled heterosexually identified men who work on the street as 'hustlers.' The purpose of this study was to set aside previous assumptions, and elicit directly from MSWs their perceived needs. Semi-structured interviews were conducted with 46 gay and bisexual male escorts who advertise on the Internet, an understudied group that is expected to differ greatly from street-based MSWs. The men identified several areas where attention should be directed beyond safer sex, such as business advice (e.g., taxes, income investment) and assistance with navigating legal issues. These findings have direct implications for community-based organizations, advocates for MSWs, and men in the commercial sex industry.
Notions of Sex, Sexuality and Relationships among Adolescent Boys in Rural Southeastern Nigeria
ERIC Educational Resources Information Center
Izugbara, C. Otutubikey
2004-01-01
Although young people in Nigeria become sexually active at a very early age, little is known about how they view sex, sexuality, and relationships with the opposite sex. Yet knowledge of their notions and expectations regarding these issues has the potential to improve care and inform the development of sexuality education programmes. This paper…
Kanazawa, Satoshi; Apari, Péter
2009-01-01
The generalized Trivers-Willard hypothesis (gTWH) proposes that parents who possess any heritable trait which increases male reproductive success at a greater rate than female reproductive success in a given environment will have a higher-than-expected offspring sex ratio, and parents who possess any heritable trait which increases the female reproductive success at a greater rate than male reproductive success in a given environment will have a lower-than-expected offspring sex ratio. One heritable trait which increases the reproductive success of sons much more than that of daughters is unrestricted sociosexual orientation. We therefore predict that parents with unrestricted sociosexual orientation (measured by the number of sexual partners, frequency of sex, and attitudes toward relationship commitment and sexual exclusivity) have a higher-than-expected offspring sex ratio (more sons). We analyse the US General Social Surveys and the National Longitudinal Study of Adolescent Health (Add Health), both with large nationally representative samples. Our analyses support the prediction from the gTWH. One standard deviation increase in unrestrictedness of sociosexual orientation increases the odds of having a son by 12-19% in the representative American samples.
Laugesen, Murray; Grace, Randolph C
2017-06-02
We compared changes in tobacco consumption and diet in relation to changes in life expectancy in 1988-1998 in 22 OECD (Organisation for Economic Cooperation and Development) countries. Between 1985 and 1995 using regression analysis we estimated differences in tobacco consumption per adult and the differences in the sum of atherogenic and thrombogenic indices against life expectancy. Each index was derived from the various fats per gram of food from standard texts, and from the annual measurements of fat in the food balance sheets of each country. In 1985-1995, New Zealand showed the largest decrease in tobacco consumption per adult (41%) and the greatest decrease (except for Switzerland) in the sum of atherogenic and thrombogenic indices (17%) as a measure of diet. New Zealand ranked first for life expectancy increases from 1988-1998 for men (3.2 years), women (2.8 years) and both sexes combined. Regression analyses revealed that increases in life expectancy across the OECD for males, but not females, were strongly associated with decreases in tobacco consumption, with a weaker effect of diet improvement. These results suggest that reduced tobacco consumption in 1985-1995 likely contributed to New Zealand's gains in life expectancy from 1988-1998.
Chen, Po-Chuan; Lee, Jenq-Chang; Wang, Jung-Der
2015-01-01
Backgrounds and aims Life-expectancy of colon cancer patients cannot be accurately answered due to the lack of both large datasets and long-term follow-ups, which impedes accurate estimation of lifetime cost to treat colon cancer patients. In this study, we applied a method to estimate life-expectancy of colon cancer patients in Taiwan and calculate the lifetime costs by different stages and age groups. Methods A total of 17,526 cases with pathologically verified colon adenocarcinoma between 2002 and 2009 were extracted from Taiwan Cancer Registry database for analysis. All patients were followed-up until the end of 2011. Life-expectancy, expected-years-of-life-lost and lifetime costs were estimated, using a semi-parametric survival extrapolation method and borrowing information from life tables of vital statistics. Results Patients with more advanced stages of colon cancer were generally younger and less co-morbid with major chronic diseases than those with stages I and II. The LE of stage I was not significantly different from that of the age- and sex-matched general population, whereas those of stages II, III, and IV colon cancer patients after diagnosis were 16.57±0.07, 13.35±0.07, and 4.05±0.05 years, respectively; the corresponding expected-years-of-life-lost were 1.28±0.07, 5.93±0.07 and 16.42±0.06 years, significantly shorter than the general population after accounting for lead time bias. Besides, the lifetime cost of managing stage II colon cancer patients would be US $8,416±1939, 14,334±1,755, and 21,837±1,698, respectively, indicating a big saving for early diagnosis and treatment after stratification for age and sex. Conclusions Treating colon cancer at younger age and earlier stage saves more life-years and healthcare costs. Future studies are indicated to apply these quantitative results into the cost-effectiveness evaluation of screening program for colon cancers. PMID:26207912
Ji, Huan; Li, Jin-Hua; Sun, Bing-Hua; Zhu, Yong
2010-08-01
To investigate the relationship between monkey-human aggressive behaviors and age/sex classes of monkey (initiator) and human (recipient), by using all-occurrence sampling and continuous recording, we evaluated the monkey-human aggressive behaviors between macaques (Macaca thibetana) and tourists at Mt. Huangshan in two periods (Nov.-Dec.2008 and Apr.-May 2009). After we divide the aggression into three types according to the dangerous level to tourists, some significant patterns were observed.Our observations indicate that Tibetan macaques respond differently to human according to the age/sex classes involved. On one hand, We found that the adult male monkeys tend to be more aggressive than expected (P<0.01), while the adult female monkeys and immature monkeys participated in AGIII behaviors (threat) less than expected (P<0.01); On the other hand, The adult male human received more aggressive behaviors than expected (P<0.01), while the adult female human and child received less aggressive in AGIII behaviors (threat) (P<0.01). Our results provide not only a scientific basis for the management advice that adult male monkeys and adult male human should be given special attention, but also a good management model of Huangshan for other primate tourist exploring places.
How much of the difference in life expectancy between Scottish cities does deprivation explain?
Seaman, R; Mitchell, R; Dundas, R; Leyland, A H; Popham, F
2015-10-16
Glasgow's low life expectancy and high levels of deprivation are well documented. Studies comparing Glasgow to similarly deprived cities in England suggest an excess of deaths in Glasgow that cannot be accounted for by deprivation. Within Scotland comparisons are more equivocal suggesting deprivation could explain Glasgow's excess mortality. Few studies have used life expectancy, an intuitive measure that quantifies the between-city difference in years. This study aimed to use the most up-to-date data to compare Glasgow to other Scottish cities and to (i) evaluate whether deprivation could account for lower life expectancy in Glasgow and (ii) explore whether the age distribution of mortality in Glasgow could explain its lower life expectancy. Sex specific life expectancy was calculated for 2007-2011 for the population in Glasgow and the combined population of Aberdeen, Dundee and Edinburgh. Life expectancy was calculated for deciles of income deprivation, based on the national ranking of datazones, using the Scottish Index of Multiple Deprivation. Life expectancy in Glasgow overall, and by deprivation decile, was compared to that in Aberdeen, Dundee and Edinburgh combined, and the life expectancy difference decomposed by age using Arriaga's discrete method. Life expectancy for the whole Glasgow population was lower than the population of Aberdeen, Dundee and Edinburgh combined. When life expectancy was compared by national income deprivation decile, Glasgow's life expectancy was not systematically lower, and deprivation accounted for over 90 % of the difference. This was reduced to 70 % of the difference when carrying out sensitivity analysis using city-specific income deprivation deciles. In both analyses life expectancy was not systematically lower in Glasgow when stratified by deprivation. Decomposing the differences in life expectancy also showed that the age distribution of mortality was not systematically different in Glasgow after accounting for deprivation. Life expectancy is not systematically lower across the Glasgow population compared to Aberdeen, Dundee and Edinburgh combined, once deprivation is accounted for. This provides further evidence that tackling deprivation in Glasgow would probably reduce the health inequalities that exist between Scottish cities. The change in the amount of unexplained difference when carrying out sensitivity analysis demonstrates the difficulties in comparing socioeconomic deprivation between populations, even within the same country and when applying an established ecological measure. Although the majority of health inequality between Glasgow and other Scottish cities is explained by deprivation, the difference in the amount of unexplained inequality depending on the relative context of deprivation used demonstrates the challenges associated with attributing mortality inequalities to an independent 'place effect'.
Coordinated Analysis of Age, Sex, and Education Effects on Change in MMSE Scores
2013-01-01
Objectives. We describe and compare the expected performance trajectories of older adults on the Mini-Mental Status Examination (MMSE) across six independent studies from four countries in the context of a collaborative network of longitudinal studies of aging. A coordinated analysis approach is used to compare patterns of change conditional on sample composition differences related to age, sex, and education. Such coordination accelerates evaluation of particular hypotheses. In particular, we focus on the effect of educational attainment on cognitive decline. Method. Regular and Tobit mixed models were fit to MMSE scores from each study separately. The effects of age, sex, and education were examined based on more than one centering point. Results. Findings were relatively consistent across studies. On average, MMSE scores were lower for older individuals and declined over time. Education predicted MMSE score, but, with two exceptions, was not associated with decline in MMSE over time. Conclusion. A straightforward association between educational attainment and rate of cognitive decline was not supported. Thoughtful consideration is needed when synthesizing evidence across studies, as methodologies adopted and sample characteristics, such as educational attainment, invariably differ. PMID:23033357
Coordinated analysis of age, sex, and education effects on change in MMSE scores.
Piccinin, Andrea M; Muniz-Terrera, Graciela; Clouston, Sean; Reynolds, Chandra A; Thorvaldsson, Valgeir; Deary, Ian J; Deeg, Dorly J H; Johansson, Boo; Mackinnon, Andrew; Spiro, Avron; Starr, John M; Skoog, Ingmar; Hofer, Scott M
2013-05-01
We describe and compare the expected performance trajectories of older adults on the Mini-Mental Status Examination (MMSE) across six independent studies from four countries in the context of a collaborative network of longitudinal studies of aging. A coordinated analysis approach is used to compare patterns of change conditional on sample composition differences related to age, sex, and education. Such coordination accelerates evaluation of particular hypotheses. In particular, we focus on the effect of educational attainment on cognitive decline. Regular and Tobit mixed models were fit to MMSE scores from each study separately. The effects of age, sex, and education were examined based on more than one centering point. Findings were relatively consistent across studies. On average, MMSE scores were lower for older individuals and declined over time. Education predicted MMSE score, but, with two exceptions, was not associated with decline in MMSE over time. A straightforward association between educational attainment and rate of cognitive decline was not supported. Thoughtful consideration is needed when synthesizing evidence across studies, as methodologies adopted and sample characteristics, such as educational attainment, invariably differ.
Planning steps forward in development: in girls earlier than in boys.
Unterrainer, Josef M; Ruh, Nina; Loosli, Sandra V; Heinze, Katharina; Rahm, Benjamin; Kaller, Christoph P
2013-01-01
The development of planning ability in children initially aged four and five was examined longitudinally with a retest-interval of 12 months using the Tower of London task. As expected, problems to solve straightforward without mental look-ahead were mastered by most, even the youngest children. Problems demanding look-ahead were more difficult and accuracy improved significantly with age and over time. This development was strongly moderated by sex: In contrast to coeval boys, four year old girls showed an impressive performance enhancement at age five, reaching the performance of six year olds, whereas four year old boys lagged behind and caught up with girls at the age of six, the typical age of school enrollment. This sex-specific development of planning was clearly separated from overall intelligence: young boys showed a steeper increase in raw intelligence scores than girls, whereas in the older groups scores developed similarly. The observed sex differences in planning development are evident even within a narrow time window of twelve months and may relate to differences in maturational trajectories for girls and boys in dorsolateral prefrontal cortex.
Latent class analysis on internet and smartphone addiction in college students.
Mok, Jung-Yeon; Choi, Sam-Wook; Kim, Dai-Jin; Choi, Jung-Seok; Lee, Jaewon; Ahn, Heejune; Choi, Eun-Jeung; Song, Won-Young
2014-01-01
This study aimed to classify distinct subgroups of people who use both smartphone and the internet based on addiction severity levels. Additionally, how the classified groups differed in terms of sex and psychosocial traits was examined. A total of 448 university students (178 males and 270 females) in Korea participated. The participants were given a set of questionnaires examining the severity of their internet and smartphone addictions, their mood, their anxiety, and their personality. Latent class analysis and ANOVA (analysis of variance) were the statistical methods used. Significant differences between males and females were found for most of the variables (all <0.05). Specifically, in terms of internet usage, males were more addicted than females (P<0.05); however, regarding smartphone, this pattern was reversed (P<0.001). Due to these observed differences, classifications of the subjects into subgroups based on internet and smartphone addiction were performed separately for each sex. Each sex showed clear patterns with the three-class model based on likelihood level of internet and smartphone addiction (P<0.001). A common trend for psychosocial trait factors was found for both sexes: anxiety levels and neurotic personality traits increased with addiction severity levels (all P<0.001). However, Lie dimension was inversely related to the addiction severity levels (all P<0.01). Through the latent classification process, this study identified three distinct internet and smartphone user groups in each sex. Moreover, psychosocial traits that differed in terms of addiction severity levels were also examined. It is expected that these results should aid the understanding of traits of internet and smartphone addiction and facilitate further study in this field.
Latent class analysis on internet and smartphone addiction in college students
Mok, Jung-Yeon; Choi, Sam-Wook; Kim, Dai-Jin; Choi, Jung-Seok; Lee, Jaewon; Ahn, Heejune; Choi, Eun-Jeung; Song, Won-Young
2014-01-01
Purpose This study aimed to classify distinct subgroups of people who use both smartphone and the internet based on addiction severity levels. Additionally, how the classified groups differed in terms of sex and psychosocial traits was examined. Methods A total of 448 university students (178 males and 270 females) in Korea participated. The participants were given a set of questionnaires examining the severity of their internet and smartphone addictions, their mood, their anxiety, and their personality. Latent class analysis and ANOVA (analysis of variance) were the statistical methods used. Results Significant differences between males and females were found for most of the variables (all <0.05). Specifically, in terms of internet usage, males were more addicted than females (P<0.05); however, regarding smartphone, this pattern was reversed (P<0.001). Due to these observed differences, classifications of the subjects into subgroups based on internet and smartphone addiction were performed separately for each sex. Each sex showed clear patterns with the three-class model based on likelihood level of internet and smartphone addiction (P<0.001). A common trend for psychosocial trait factors was found for both sexes: anxiety levels and neurotic personality traits increased with addiction severity levels (all P<0.001). However, Lie dimension was inversely related to the addiction severity levels (all P<0.01). Conclusion Through the latent classification process, this study identified three distinct internet and smartphone user groups in each sex. Moreover, psychosocial traits that differed in terms of addiction severity levels were also examined. It is expected that these results should aid the understanding of traits of internet and smartphone addiction and facilitate further study in this field. PMID:24899806
Attia, Tamer; Koch, Colleen G; Houghtaling, Penny L; Blackstone, Eugene H; Sabik, Ellen Mayer; Sabik, Joseph F
2017-03-01
To (1) identify sex-related differences in risk factors and revascularization strategies for patients undergoing coronary artery bypass grafting (CABG), (2) assess whether these differences influenced early and late survival, and (3) determine whether clinical effectiveness of the same revascularization strategy was influenced by sex. From January 1972 to January 2011, 57,943 adults-11,009 (19%) women-underwent primary isolated CABG. Separate models for long-term mortality were developed for men and women, followed by assessing sex-related differences in strength of risk factors (interaction terms). Incomplete revascularization was more common in men than women (26% vs 22%, P < .0001), but women received fewer bilateral internal thoracic artery (ITA) grafts (4.8% vs 12%; P < .0001) and fewer arterial grafts (68% vs 70%; P < .0001). Overall, women had lower survival than men after CABG (65% and 31% at 10 and 20 years, respectively, vs 74% and 41%; P ≤ .0001), even after risk adjustment. Incomplete revascularization was associated equally (P > .9) with lower survival in both sexes. Single ITA grafting was associated with equally (P = .3) better survival in women and men. Although bilateral ITA grafting was associated with better survival than single ITA grafting, it was less effective in women-11% lower late mortality (hazard ratio, 0.89 [0.77-1.022]) versus 27% lower in men (hazard ratio, 0.73 [0.69-0.77]; P = .01). Women on average have longer life expectancies than men but not after CABG. Every attempt should be made to use arterial grafting and complete revascularization, but for unexplained reasons, sex-related differences in effectiveness of bilateral arterial grafting were identified. Copyright © 2016. Published by Elsevier Inc.
Fine scale relationships between sex, life history, and dispersal of masu salmon
Kitanishi, Shigeru; Yamamoto, Toshiaki; Koizumi, Itsuro; Dunham, Jason B.; Higashi, Seigo
2012-01-01
Identifying the patterns and processes driving dispersal is critical for understanding population structure and dynamics. In many organisms, sex-biased dispersal is related to the type of mating system. Considerably less is known about the influence of life history variability on dispersal. Here we investigated patterns of dispersal in masu salmon (Oncorhynchus masou) to evaluate influences of sex and life history on dispersal. As expected, assignment tests and isolation by distance analysis revealed that dispersal of marine-migratory masu salmon was male-biased. However, dispersal of resident and migratory males did not follow our expectation and marine-migratory individuals dispersed more than residents. This may be because direct competition between marine-migratory and resident males is weak or that the cost of dispersal is smaller for marine-migratory individuals. This study revealed that both sex and migratory life history influence patterns of dispersal at a local scale in masu salmon.
Work Activities and Compensation of Male and Female Cardiologists
Jagsi, Reshma; Biga, Cathie; Poppas, Athena; Rodgers, George P.; Walsh, Mary N.; White, Patrick J.; McKendry, Colleen; Sasson, Joseph; Schulte, Phillip J.; Douglas, Pamela S.
2016-01-01
BACKGROUND Much remains unknown about experiences, including working activities and pay, of women in cardiology, which is a predominantly male specialty. OBJECTIVES The goal of this study was to describe the working activities and pay of female cardiologists compared with their male colleagues and to determine whether sex differences in compensation exist after accounting for differences in work activities and other characteristics. METHODS The personal, job, and practice characteristics of a national sample of practicing cardiologists were described according to sex. We applied the Peters-Belson technique and multivariate regression analysis to evaluate whether gender differences in compensation existed after accounting for differences in other measured characteristics. The study used 2013 data reported by practice administrators to MedAxiom, a subscription-based service provider to cardiology practices. Data regarding cardiologists from 161 U.S. practices were included, and the study sample included 2,679 subjects (229 women and 2,450 men). RESULTS Women were more likely to be specialized in general/noninvasive cardiology (53.1% vs. 28.2%), and a lower proportion (11.4% vs. 39.3%) reported an interventional subspecialty compared with men. Job characteristics that differed according to sex included the proportion working full-time (79.9% vs. 90.9%; p < 0.001), the mean number of half-days worked (387 vs. 406 days; p = 0.001), and mean work relative value units generated (7,404 vs. 9,497; p <0.001) for women and men, respectively. Peters-Belson analysis revealed that based on measured job and productivity characteristics, the women in this sample would have been expected to have a mean salary that was $31,749 (95% confidence interval: $16,303 to $48,028) higher than that actually observed. Multivariate analysis confirmed the direction and magnitude of the independent association between sex and salary. CONCLUSIONS Men and women practicing cardiology in this national sample had different job activities and salaries. Substantial sex-based salary differences existed even after adjusting for measures of personal, job, and practice characteristics. PMID:26560679
Therapist Effects on and Predictors of Non-Consensual Dropout in Psychotherapy.
Zimmermann, Dirk; Rubel, Julian; Page, Andrew C; Lutz, Wolfgang
2017-03-01
Whereas therapist effects on outcome have been a research topic for several years, the influence of therapists on premature treatment termination (dropout) has hardly been investigated. Since dropout is common during psychological treatment, and its occurrence has important implications for both the individual patient and the healthcare system, it is important to identify the factors associated with it. Participants included 707 patients in outpatient psychotherapy treated by 66 therapists. Multilevel logistic regression models for dichotomous data were used to estimate the impact of therapists on patient dropout. Additionally, sociodemographic variables, symptoms, personality style and treatment expectations were investigated as potential predictors. It was found that 5.7% of variance in dropout could be attributed to therapists. The therapist's effect remained significant after controlling for patient's initial impairment. Furthermore, initial impairment was a predictor of premature termination. Other significant predictors of dropout on a patient level were male sex, lower education status, more histrionic and less compulsive personality style and negative treatment expectations. The findings indicate that differences between therapists influence the likelihood of dropout in outpatient psychotherapy. Further research should focus on variables, which have the potential to explain these inter-individual differences between therapists (e.g., therapist's experience or self-efficacy). Copyright © 2016 John Wiley & Sons, Ltd. There are substantial differences between therapists concerning their average dropout rates. At the patient level, higher initial impairment, male sex, lower education, less compulsive personality style, more histrionic personality style and low treatment expectations seem to be risk factors of non-consensual treatment termination. Psychometric feedback during the course of treatment should be used to identify patients who are at risk for dropout. Copyright © 2016 John Wiley & Sons, Ltd.
Fassiotto, Magali; Li, Jie; Maldonado, Yvonne; Kothary, Nishita
2018-02-02
Similar to women in Science, Technology, Engineering and Mathematics disciplines, women in medicine are subject to negative stereotyping when they do not adhere to their sex-role expectations. These biases may vary by specialty, largely dependent on the gender's representation in that specialty. Thus, females in male-dominated surgical specialties are especially at risk of stereotype threat. Herein, we present the role of gender expectations using trainee evaluations of physician faculty at a single academic center, over a 5-year period (2010-2014). Using Graduate Medical Education evaluation data of physician faculty from MedHub, we examined the differences in evaluation scores for male and female physicians within specialties that have traditionally had low female representation (e.g., surgical fields) compared to those with average or high female representation (e.g., pediatrics). Stanford Medicine residents and fellows' MedHub ratings of their physician faculty from 2010 to 2014. A total of 3648 evaluations across 1066 physician faculty. Overall, female physicians received lower median scores than their male counterparts across all specialties. When using regression analyses controlling for race, age, rank, and specialty-specific characteristics, the negative effect persists only for female physicians in specialties with low female representation. This finding suggests that female physicians in traditionally male-dominated specialties may face different criteria based on sex-role expectations when being evaluated by trainees. As trainee evaluations play an important role in career advancement decisions, dictate perceptions of quality within academic medical centers and affect overall job satisfaction, we propose that these differences in evaluations based merely on gender stereotypes could account, in part, for the narrowing pipeline of women promoted to higher ranks in academic medicine. Copyright © 2018 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
Sex Differences in the Effects of Marijuana on Simulated Driving Performance†
Anderson, Beth M.; Rizzo, Matthew; Block, Robert I.; Pearlson, Godfrey D.; O'Leary, Daniel S.
2011-01-01
In the United States, one in six teenagers has driven under the influence of marijuana. Driving under the influence of marijuana and alcohol is equally prevalent, despite the fact that marijuana use is less common than alcohol use. Much of the research examining the effects of marijuana on driving performance was conducted in the 1970s and led to equivocal findings. During that time, few studies included women and driving simulators were rudimentary. Further, the potency of marijuana commonly used recreationally has increased. This study examined sex differences in the acute effects of marijuana on driving performance using a realistic, validated driving simulator. Eighty-five subjects (n = 50 males, 35 females) participated in this between-subjects, double-blind, placebo controlled study. In addition to an uneventful, baseline segment of driving, participants were challenged with collision avoidance and distracted driving scenarios. Under the influence of marijuana, participants decreased their speed and failed to show expected practice effects during a distracted drive. No differences were found during the baseline driving segment or collision avoidance scenarios. No differences attributable to sex were observed. This study enhances the current literature by identifying distracted driving and the integration of prior experience as particularly problematic under the influence of marijuana. PMID:20464803
The role of sex, attachment and autonomy-connectedness in personality functioning.
Bachrach, Nathan; Croon, Marcel A; Bekker, Marrie H J
2015-11-01
Previous studies have found significant relationships among sex, attachment and autonomy-connectedness and DSM-IV personality characteristics. In the present study, we aimed to add to the current knowledge about attachment-related aspects of personality pathology, by examining the relationships of these same variables with dimensions of pathological personality structure as conceptualized by Kernberg. The study was performed among 106 ambulatory patients from a Dutch mental healthcare institute. A path model based upon neo-analytical object relation theory and attachment theory was tested. We expected significant associations among sex, attachment, autonomy and aspects of personality functioning. Both insecure attachment styles as well as the autonomy-connectedness components of sensitivity to others (SO) and capacity of managing new situations predicted general personality dysfunctioning significantly. More specifically, reality testing was negatively predicted by the autonomy component of capacity of managing new situations, and aggression was significantly predicted by sex as well as both insecure attachment styles. We advise scientists as well as clinicians to be alert on sex differences in autonomy-connectedness and aspects of personality dysfunctioning. Taking sex-specific variations in attachment and autonomy into account next to a more explicit focus on insecure attachment styles and autonomy problems may enhance, the current relatively low, treatment effectiveness for personality pathology. Copyright © 2015 John Wiley & Sons, Ltd.
Szwarcwald, Célia Landmann; Souza Júnior, Paulo Roberto Borges de; Marques, Aline Pinto; Almeida, Wanessa da Silva de; Montilla, Dalia Elena Romero
2016-11-17
The demographic shift and epidemiologic transition in Brazil have drawn attention to ways of measuring population health that complement studies of mortality. In this paper, we investigate regional differences in healthy life expectancy based on information from the National Health Survey (PNS), 2013. In the survey, a three-stage cluster sampling (census tracts, households and individuals) with stratification of the primary sampling units and random selection in all stages was used to select 60,202 Brazilian adults (18 years and over). Healthy life expectancies (HLE) were estimated by Sullivan's method according to sex, age and geographic region, using poor self-rated health for defining unhealthy status. Logistic regression models were used to investigate socioeconomic and regional inequalities in poor self-rated health, after controlling by sex and age. Wide disparities by geographic region were found with the worst indicators in the North and Northeast regions, whether considering educational attainment, material deprivation, or health care utilization. Life expectancy at birth for women and men living in the richest regions was 5 years longer than for those living in the less wealthy regions. Modeling the variation across regions for poor self-rated health, statistically significant effects (p < 0.001) were found for the North and Northeast when compared to the Southeast, even after controlling for age, sex, diagnosis of at least one non-communicable chronic disease, and schooling or socioeconomic class. Marked regional inequalities in HLE were found, with the loss of healthy life much higher among residents of the poorest regions, especially among the elderly. By combining data on self-rated health status and mortality in a single indicator, Healthy Life Expectancy, this study demonstrated the excess burden of poor health experienced by populations in the less wealthy regions of Brazil. To mitigate the effects of social exclusion, the development of strategies at the regional level is essential to provide health care to all persons in need, reduce risk exposures, support prevention policies for adoption of healthy behaviors. Such strategies should prioritize population groups that will experience the greatest impact from such interventions.
Christiansen, Blaine A; Kopperdahl, David L; Kiel, Douglas P; Keaveny, Tony M; Bouxsein, Mary L
2011-01-01
The biomechanical mechanisms underlying sex-specific differences in age-related vertebral fracture rates are ill defined. To gain insight into this issue, we used finite element analysis of clinical computed tomography (CT) scans of the vertebral bodies of L3 and T10 of young and old men and women to assess age- and sex-related differences in the strength of the whole vertebra, the trabecular compartment, and the peripheral compartment (the outer 2 mm of vertebral bone, including the thin cortical shell). We sought to determine whether structural and geometric changes with age differ in men and women, making women more susceptible to vertebral fractures. As expected, we found that vertebral strength decreased with age 2-fold more in women than in men. The strength of the trabecular compartment declined significantly with age for both sexes, whereas the strength of the peripheral compartment decreased with age in women but was largely maintained in men. The proportion of mechanical strength attributable to the peripheral compartment increased with age in both sexes and at both vertebral levels. Taken together, these results indicate that men and women lose vertebral bone differently with age, particularly in the peripheral (cortical) compartment. This differential bone loss explains, in part, a greater decline in bone strength in women and may contribute to the higher incidence of vertebral fractures among women than men. © 2011 American Society for Bone and Mineral Research. PMID:21542000
Kidawa, Dorota; Kowalczyk, Rafał
2011-07-01
The diet of the red fox Vulpes vulpes was investigated in five regions of northeastern Poland by stomach content analysis of 224 foxes collected from hunters. The red fox is expected to show the opportunistic feeding habits. Our study showed that foxes preyed mainly on wild prey, with strong domination of Microtus rodents, regardless of sex, age, month and habitat. Voles Microtus spp. were found in 73% of stomachs and constituted 47% of food volume consumed. Other food items were ungulate carrion (27% of volume), other mammals (11%), birds (9%), and plant material (4%). Sex- and age-specific differences in dietary diversity were found. Adult males and juvenile foxes had larger food niche breadths than adult females and their diets highly overlapped. Proportion of Microtus voles increased from autumn to late winter. Significant habitat differences between studied regions were found. There was a tendency among foxes to decrease consumption of voles with increasing percentage of forest cover. Based on our findings, red foxes in northeastern Poland can be recognized as a generalist predators, consuming easily accessible and abundant prey. However, high percentage of voles consumed regardless of age, sex, month, or habitats may indicate red fox specialization in preying on Microtus rodents.
Joezy-Shekalgorabi, Sahereh
2017-11-03
In a nucleus breeding scheme, the sire of dams pathway plays an important role in producing genetic improvement. Selection proportion is the key parameter for predicting selection intensity, through truncating the normal distribution. Semen sexing using flowcytometrie reduces the number of vials of sperm that can be obtained from a proved bull. In addition, a lower fertility of this kind of sperm is expected because of the lower sperm dosage in sex sorted semen. Both of these factors could affect the selection proportion in the sire of dams pathway (pSD). In the current study, through a deterministic simulation, effect of utilizing sex sorted semen on selection (pSD) was investigated in three different strategies including 1: continuous use of sex sorted semen in heifers (CS), 2: the use of sex sorted semen for the first two (S2) and 3: the first (S1) inseminations followed by conventional semen. Results indicated that the use of sex sorted semen has a negative impact on the sire of dams (SD) pathway due to increase in selection proportion. Consequently selection intensity was decreased by 10.24 to 20.57, 6.38 to 8.87 and 3.76 to 6.25 percent in the CS, S2 and S1 strategies, respectively. Considering the low effect of sexed semen on genetic improvement in dam pathways, it is necessary to consider the joint effect of using sex sorted semen on the sire and dams pathway to estimate about the real effect of sexed semen on genetic improvement in a nucleus breeding scheme.
How sex and age affect immune responses, susceptibility to infections, and response to vaccination
Giefing-Kröll, Carmen; Berger, Peter; Lepperdinger, Günter; Grubeck-Loebenstein, Beatrix
2015-01-01
Do men die young and sick, or do women live long and healthy? By trying to explain the sexual dimorphism in life expectancy, both biological and environmental aspects are presently being addressed. Besides age-related changes, both the immune and the endocrine system exhibit significant sex-specific differences. This review deals with the aging immune system and its interplay with sex steroid hormones. Together, they impact on the etiopathology of many infectious diseases, which are still the major causes of morbidity and mortality in people at old age. Among men, susceptibilities toward many infectious diseases and the corresponding mortality rates are higher. Responses to various types of vaccination are often higher among women thereby also mounting stronger humoral responses. Women appear immune-privileged. The major sex steroid hormones exhibit opposing effects on cells of both the adaptive and the innate immune system: estradiol being mainly enhancing, testosterone by and large suppressive. However, levels of sex hormones change with age. At menopause transition, dropping estradiol potentially enhances immunosenescence effects posing postmenopausal women at additional, yet specific risks. Conclusively during aging, interventions, which distinctively consider the changing level of individual hormones, shall provide potent options in maintaining optimal immune functions. PMID:25720438
Ives, Rachel; Humphrey, Louise
2017-05-01
Studies of male and female long bone growth in past populations are limited and usually constrained by the lack of personal identification. This article aimed to evaluate long bone growth in a series of mid-19 th century documented burials associated with the urban poor from Bethnal Green, London, UK. Maximum diaphyseal lengths from 74 males and 70 females (2 months to 12 years) were compared to modern reference data from North America. Diaphyseal lengths were expressed as a percentage of expected length and an average percentage value was calculated across all available long bones. An index of growth progression was introduced to explore differences in the progress of males and females towards their projected adult size. Deviation from the expected growth attainment was evident in both sexes in the archaeological series by 2-4 months of age. Only 19.4% (28/144) of the children had attained an average long bone length >90% of the predicted mean in the reference series. The percentage of expected growth attainment decreased steadily in both sexes during infancy and early childhood. Overall, females deviated further from their expected growth progression than males. Growth faltering in both males and females was established during infancy (<1 year) with no evidence for recovery in older age groups. Early weaning and inadequate artificial feeding, together with impoverished living conditions and limited sanitary provision, most likely impacted on childhood growth. © 2017 Wiley Periodicals, Inc.
Causes of death among persons with multiple sclerosis.
Cutter, Gary R; Zimmerman, Jeffrey; Salter, Amber R; Knappertz, Volker; Suarez, Gustavo; Waterbor, John; Howard, Virginia J; Ann Marrie, Ruth
2015-09-01
Multiple Sclerosis (MS) is a leading cause of disability among young Americans. Reports suggest that life expectancy (i.e., average age at death) remains reduced as compared to the general population, but underlying causes of death (UCOD) are less well-characterized. To describe the cause-specific mortality among participants enrolled in the North American Research Committee on Multiple Sclerosis (NARCOMS) registry and to compare the profile of these causes by age, sex, race and disability status at entry into NARCOMS, with U.S. mortality data. The underlying cause of death (UCOD), any mention cause of death and proportionate mortality were compared among U.S. NARCOMS participants by age, sex, race and disability status. Of the 32,445 participants to be considered for this study, 2,927 had died. Compared to survivors, decedents were older at enrollment and MS diagnosis, more likely to be male, and had less education. UCOD differed markedly by age group. In both sexes, MS as the UCOD was proportionately lower by 20% or more in those aged 25-39 compared to those aged 75 or older. Cancer and cardiovascular causes were more frequent as causes of death with increasing age, but were less than expected at older ages. The effect of disability on mortality was roughly equivalent to the effect of aging on mortality. Among NARCOMS participants older age at enrollment, male sex and greater disability were associated with increased mortality risk. This cohort of MS subjects had a lower proportionate mortality from cardiovascular disease and cancer compared to the U.S. population. Copyright © 2015 Elsevier B.V. All rights reserved.
Violent men have more sons: further evidence for the generalized Trivers-Willard hypothesis (gTWH).
Kanazawa, Satoshi
2006-04-21
The generalized Trivers-Willard hypothesis (gTWH) [Kanazawa, S., 2005a. Big and tall parents have more sons; further generalizations of the Trivers-Willard hypothesis. J. Theor. Biol. 235, 583-590] proposes that parents who possess any heritable trait which increases the male reproductive success at a greater rate than female reproductive success in a given environment have a higher-than-expected offspring sex ratio, and parents who possess any heritable trait which increases the female reproductive success at a greater rate than male reproductive success in a given environment have a lower-than-expected offspring sex ratio. One heritable trait which increases the reproductive success of sons significantly more than that of daughters in the ancestral environment is the tendency toward violence and aggression. I therefore predict that violent parents have a higher-than-expected offspring sex ratio (more sons). The analysis of both American samples and a British sample demonstrates that battered women, who are mated to violent men, have significantly more sons than daughters.
Aggen, S. H.; Neale, M. C.; Røysamb, E.; Reichborn-Kjennerud, T.; Kendler, K. S.
2009-01-01
Background Despite its importance as a paradigmatic personality disorder, little is known about the measurement invariance of the DSM-IV borderline personality disorder (BPD) criteria ; that is, whether the criteria assess the disorder equivalently across different groups. Method BPD criteria were evaluated at interview in 2794 young adult Norwegian twins. Analyses, based on item-response modeling, were conducted to test for differential age and sex moderation of the individual BPD criteria characteristics given factor-level covariate effects. Results Confirmatory factor analytic results supported a unidimensional structure for the nine BPD criteria. Compared to males, females had a higher BPD factor mean, larger factor variance and there was a significant age by sex interaction on the factor mean. Strong differential sex and age by sex interaction effects were found for the ‘ impulsivity ’ criterion factor loading and threshold. Impulsivity related to the BPD factor poorly in young females but improved significantly in older females. Males reported more impulsivity compared to females and this difference increased with age. The ‘ affective instability ’ threshold was also moderated, with males reporting less than expected. Conclusions The results suggest the DSM-IV BPD ‘ impulsivity ’ and ‘ affective instability ’ criteria function differentially with respect to age and sex, with impulsivity being especially problematic. If verified, these findings have important implications for the interpretation of prior research with these criteria. These non-invariant age and sex effects may be identifying criteria-level expression features relevant to BPD nosology and etiology. Criterion functioning assessed using modern psychometric methods should be considered in the development of DSM-V. PMID:19400977
Bhopal, S S; Mann, K D; Pearce, M S
2012-06-26
A decade ago it was reported that childhood cancer incidence was higher in boys than girls in many countries, particularly those with low gross domestic product (GDP) and high infant mortality rate. Research suggests that socio-economic and cultural factors are likely to be responsible. This study aimed to investigate the association between cancer registration rate sex ratios and economic, social and healthcare-related factors using recent data (1998-2002). For 62 countries, childhood (0-15 years) cancer registration rate sex ratios were calculated from Cancer Incidence in Five Continents Vol IX, and economic, social and healthcare indicator data were collated. Increased age standardised cancer registration rate sex ratio (M:F) was significantly associated with decreasing life expectancy (P=0.05), physician density (P=0.05), per capita health expenditure (P=0.05), GDP (P=0.01), education sex ratios (primary school enrolment sex ratio (P<0.01); secondary school enrolment sex ratio (P<0.01); adult literacy sex ratio (P<0.01)) and increasing proportion living on less than Int$1 per day (P=0.03). The previously described cancer registration sex disparity remains, particularly, in countries with poor health system indicators and low female education rates. We suggest that girls with cancer continue to go undiagnosed and that incidence data, particularly in low- and middle-income countries, should continue to be interpreted with caution.
Ziv, Ido; Lubin, Or Ben-Haim; Asher, Sapir
2018-02-01
Studies suggest that married people frequently engage in intimate relationships with people other than their spouses, and the literature has extensively examined motives for doing so. However, less is known about what factors prevent spouses from engaging in extramarital sex. While investment theory, interdependence theory, and moral theories offer insights into this question, they have not been subject to much empirical research. We examine these theories in relation to several characteristics of individuals and couples: gender, length of the marriage, and religiosity. In two studies, 423 participants completed a questionnaire on the perceived importance of 29 reasons to resist the temptation for extramarital sex. Participants also reported the likelihood that they would engage in extramarital sex if the opportunity presented itself. Results show that being female, more religious, and married for less time were associated with greater expectations of refraining from extramarital sex when presented with a hypothetical scenario. Multiple hierarchical regression showed that among factors relevant to conscious decision making, moral standards and fundamental anxieties (fear of remaining alone) predict expectations of refraining from extramarital sex better than concerns about effects on the children or the other participant.
Satisfying Friendship Maintenance Expectations: The Role of Friendship Standards and Biological Sex
ERIC Educational Resources Information Center
Hall, Jeffrey A.; Larson, Kiley A.; Watts, Amber
2011-01-01
The ideal standards model predicts linear relationship among friendship standards, expectation fulfillment, and relationship satisfaction. Using a diary method, 197 participants reported on expectation fulfillment in interactions with one best, one close, and one casual friend (N = 591) over five days (2,388 interactions). Using multilevel…
Determinants of Parental Expectations for Children's Education and Occupation.
ERIC Educational Resources Information Center
Usui, Wayne M.; And Others
1981-01-01
Data analyses suggest that family social status, race, sex, and their child's ability influence parents' expectations of educational and occupational attainment for the child. Findings give some support to the notion of crystallization of parental expectations (involving formulation overtime of parental perceptions of the child's ability) for…
Women at the Naval Academy: The First Year of Integration
1978-02-01
Women Intergroup contact hypothesis Integration W Attitudes toward military roles for women II Coeducation 4 20. A STRACT (Continue on tavorao aide It...favorable toward , coeducation , vs. 26% of plebe men). Females and males had very different perceptions of treatment of the sexes in the 1976-77 year...the initial attitudes of male midshipmen-toward coeducation - werelsknoi -to be-generally unfavorable. Problems of Assimilat~ion were expected
Postcraniometric sex and ancestry estimation in South Africa: a validation study.
Liebenberg, Leandi; Krüger, Gabriele C; L'Abbé, Ericka N; Stull, Kyra E
2018-05-24
With the acceptance of the Daubert criteria as the standards for best practice in forensic anthropological research, more emphasis is being placed on the validation of published methods. Methods, both traditional and novel, need to be validated, adjusted, and refined for optimal performance within forensic anthropological analyses. Recently, a custom postcranial database of modern South Africans was created for use in Fordisc 3.1. Classification accuracies of up to 85% for ancestry estimation and 98% for sex estimation were achieved using a multivariate approach. To measure the external validity and report more realistic performance statistics, an independent sample was tested. The postcrania from 180 black, white, and colored South Africans were measured and classified using the custom postcranial database. A decrease in accuracy was observed for both ancestry estimation (79%) and sex estimation (95%) of the validation sample. When incorporating both sex and ancestry simultaneously, the method achieved 70% accuracy, and 79% accuracy when sex-specific ancestry analyses were run. Classification matrices revealed that postcrania were more likely to misclassify as a result of ancestry rather than sex. While both sex and ancestry influence the size of an individual, sex differences are more marked in the postcranial skeleton and are therefore easier to identify. The external validity of the postcranial database was verified and therefore shown to be a useful tool for forensic casework in South Africa. While the classification rates were slightly lower than the original method, this is expected when a method is generalized.
Yoshido, A; Marec, F; Sahara, K
2016-01-01
Moths and butterflies (Lepidoptera) have sex chromosome systems with female heterogamety (WZ/ZZ or derived variants). The maternally inherited W chromosome is known to determine female sex in the silkworm, Bombyx mori. However, little is known about the role of W chromosome in other lepidopteran species. Here we describe two forms of the W chromosome, W and neo-W, that are transmitted to both sexes in offspring of hybrids from reciprocal crosses between subspecies of wild silkmoths, Samia cynthia. We performed crosses between S. c. pryeri (2n=28, WZ/ZZ) and S. c. walkeri (2n=26, neo-Wneo-Z/neo-Zneo-Z) and examined fitness and sex chromosome constitution in their hybrids. The F1 hybrids of both reciprocal crosses had reduced fertility. Fluorescence in situ hybridization revealed not only the expected sex chromosome constitutions in the backcross and F2 hybrids of both sexes but also females without the W (or neo-W) chromosome and males carrying the W (or neo-W) chromosome. Furthermore, crosses between the F2 hybrids revealed no association between the presence or absence of W (or neo-W) chromosome and variations in the hatchability of their eggs. Our results clearly suggest that the W (or neo-W) chromosome of S. cynthia ssp. plays no role in sex determination and reproduction, and thus does not contribute to the formation of reproductive barriers between different subspecies. PMID:26758188
Yoshido, A; Marec, F; Sahara, K
2016-05-01
Moths and butterflies (Lepidoptera) have sex chromosome systems with female heterogamety (WZ/ZZ or derived variants). The maternally inherited W chromosome is known to determine female sex in the silkworm, Bombyx mori. However, little is known about the role of W chromosome in other lepidopteran species. Here we describe two forms of the W chromosome, W and neo-W, that are transmitted to both sexes in offspring of hybrids from reciprocal crosses between subspecies of wild silkmoths, Samia cynthia. We performed crosses between S. c. pryeri (2n=28, WZ/ZZ) and S. c. walkeri (2n=26, neo-Wneo-Z/neo-Zneo-Z) and examined fitness and sex chromosome constitution in their hybrids. The F1 hybrids of both reciprocal crosses had reduced fertility. Fluorescence in situ hybridization revealed not only the expected sex chromosome constitutions in the backcross and F2 hybrids of both sexes but also females without the W (or neo-W) chromosome and males carrying the W (or neo-W) chromosome. Furthermore, crosses between the F2 hybrids revealed no association between the presence or absence of W (or neo-W) chromosome and variations in the hatchability of their eggs. Our results clearly suggest that the W (or neo-W) chromosome of S. cynthia ssp. plays no role in sex determination and reproduction, and thus does not contribute to the formation of reproductive barriers between different subspecies.
Should human beings have sex? Sexual dimorphism and human enhancement.
Sparrow, Robert
2010-07-01
Since the first sex reassignment operations were performed, individual sex has come to be, to some extent at least, a technological artifact. The existence of sperm sorting technology, and of prenatal determination of fetal sex via ultrasound along with the option of termination, means that we now have the power to choose the sex of our children. An influential contemporary line of thought about medical ethics suggests that we should use technology to serve the welfare of individuals and to remove limitations on the opportunities available to them. I argue that, if these are our goals, we may do well to move towards a "post sex" humanity. Until we have the technology to produce genuine hermaphrodites, the most efficient way to do this is to use sex selection technology to ensure that only girl children are born. There are significant restrictions on the opportunities available to men, around gestation, childbirth, and breast-feeding, which will be extremely difficult to overcome via social or technological mechanisms for the foreseeable future. Women also have longer life expectancies than men. Girl babies therefore have a significantly more "open" future than boy babies. Resisting the conclusion that we should ensure that all children are born the same sex will require insisting that sexual difference is natural to human beings and that we should not use technology to reshape humanity beyond certain natural limits. The real concern of my paper, then, is the moral significance of the idea of a normal human body in modern medicine.
Sex differences in razorbill (Family: Alcidae) parent-offspring vocal recognition
NASA Astrophysics Data System (ADS)
Insley, Stephen J.; Paredes Vela, Rosana; Jones, Ian L.
2002-05-01
In this study we examines how a pattern of parental care may result in a sex bias in vocal recognition. In Razorbills (Alca torda), both sexes provide parental care to their chicks while at the nest, after which the male is the sole caregiver for an additional period at sea. Selection pressure acting on recognition behavior is expected to be strongest during the time when males and chicks are together at sea, and as a result, parent-offspring recognition was predicted to be better developed in the male parent, that is, show a paternal bias. In order to test this hypothesis, vocal playback experiments were conducted on breeding Razorbills at the Gannet Islands, Labrador, 2001. The data provide clear evidence of mutual vocal recognition between the male parent and chick but not between the female parent and chick, supporting the hypothesis that parent-offspring recognition is male biased in this species. In addition to acoustic recognition, such a bias could have important social implications for a variety of behavioral and basic life history traits such as cooperation and sex-biased dispersal.
Sex education changes for the worse, say sexual health organisations.
1993-01-01
Amendments to the Education Bill, which was part of the Education act of 1993, included some changes for sex education in Great Britain. These changes included 1) removing from the science curriculum all mention of sexually transmitted diseases (STDs) including HIV infections, 2) giving parents the right to withdraw their children from sex education classes in primary and secondary schools, and 3) placing the responsibility for sex education, including HIV/AIDS and STDs, in "maintained" secondary schools with governors. Family planning and sexual health educators were opposed to the amendment. Over 30 different organizations grouped under the Sex Education Forum also expressed concern about the changes. The UK has not had a compulsory and comprehensive sex education program; compulsory sex education has been a component only within the science curriculum, mostly reproductive biology. The thinking was that this amendment would not strengthen effective sex education. Sex education advocates want a broad-based curriculum, that covers more than reproductive biology and is provided throughout the developmental stages of a young person's schooling. Critics of this amendment have proposed that the parental right to withdraw their children from sex education classes deprives children of potentially life-saving information. There would also appear to be a conflict with the Children Act of 1989 and the UN Convention on the Rights of Children, which assures the rights of children to information. These changes would add to the existing difficulties and create new ones. Implementation is in the hands of the Department of Education. Draft guidelines are expected in the Fall 1993; sex education circulars would be distributed in the Spring 1994, and curriculum changes would be fully implemented in August 1994.
Chang, Man-Huei; Molla, Michael T; Truman, Benedict I; Athar, Heba; Moonesinghe, Ramal; Yoon, Paula W
2015-09-01
Healthy life expectancy (HLE) varies among demographic segments of the US population and by geography. To quantify that variation, we estimated the national and regional HLE for the US population by sex, race/ethnicity and geographic region in 2008. National HLEs were calculated using the published 2008 life table and the self-reported health status data from the National Health Interview Survey (NHIS). Regional HLEs were calculated using the combined 2007-09 mortality, population and NHIS health status data. In 2008, HLE in the USA varied significantly by sex, race/ethnicity and geographical regions. At 25 years of age, HLE for females was 47.3 years and ∼2.9 years greater than that for males at 44.4 years. HLE for non-Hispanic white adults was 2.6 years greater than that for Hispanic adults and 7.8 years greater than that for non-Hispanic black adults. By region, the Northeast had the longest HLE and the South had the shortest. The HLE estimates in this report can be used to monitor trends in the health of populations, compare estimates across populations and identify health inequalities that require attention. Published by Oxford University Press on behalf of Faculty of Public Health 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.
Pfannkuche, Kristina A; Bouma, Anke; Groothuis, Ton G G
2009-04-12
Lateralization of brain and behaviour has been the topic of research for many years in neuropsychology, but the factors guiding its development remain elusive. Based on sex differences in human lateralization, four hypotheses have been postulated that suggest a role for androgens, specifically testosterone. With the discovery that lateralization is a fundamental principle in the organization of brain and behaviour among vertebrates, it has now become possible to experimentally test such hypotheses in animal models. The use of different taxa, humans, other mammalian species and birds (with oestradiol and not testosterone involved in sexual differentiation in birds) facilitates to differentiate between the hypotheses. We used meta-analyses for analysing papers that provided sufficient information, and a semi-quantitative approach based on all relevant studies that we extracted from the literature. We tested the predictions of these hypotheses regarding strength and direction of lateralization for motor output, language and visuospatial cognition in these three taxa. We tested for sex differences and early organizational effects of testosterone (both correlative and experimental studies). We found sex differences in the direction of lateralization for non-human mammals (motor biases similar to humans) and in direction and strength in birds (visual cognitive tasks). However, the prediction that prenatal testosterone exposure affects the direction of lateralization was not supported for humans. In birds and non-human mammals, opposite trends were found, with the effect in non-human mammals being opposite to the expectation based on sex differences. None of the four hypotheses was sufficiently supported and more studies, testing a wider array of functions in different taxa while reporting the data more completely are needed.
Weinrich, Mason T; Rosenbaum, Howard; Scott Baker, C; Blackmer, Alexis L; Whitehead, Hal
2006-01-01
Humpback whales on their feeding grounds in the Gulf of Maine typically form fluid fission/fusion groups of two to three individuals characterized by noncompetitive and, at times, cooperative behavior. Here we test the hypothesis that, despite the apparent absence of close kinship bonds, the fluid associations between feeding whales are influenced by "maternal lineages" as represented by mtDNA haplotypes. Using skin samples collected with a biopsy dart, variation in the hypervariable segment of the mtDNA control region identified 17 unique haplotypes among 159 individually identified whales from the southern Gulf of Maine. The haplotypes of a further 143 individuals were inferred from known direct maternal (cow-calf) relationships. The frequencies of associations among these 302 individuals were calculated from 21,617 sighting records collected from 1980 to 1995, excluding associations between a cow and her dependent calf. For groups of two where the haplotypes of both individuals were known (n = 3,151), individuals with the same haplotype were together significantly more often (26%) than expected by random association (20%). To account for different group sizes and associations with individuals of unknown haplotype and sex, we used Monte Carlo simulations to test for nonrandom associations in the full data set, as well as known female-only (n = 1,512), male-only (n = 730), and mixed-sex (n = 2,745) groups. Within-haplotype associations were significantly more frequent than expected at random for all groups (P = .002) and female-only groups (P = .011) but not male-only groups, while mixed-sex groups approached significance (P = .062). A Mantel test of individual pairwise association indices and haplotype identity confirmed that within-haplotype associations were more frequent than expected for all sex combinations except male-male associations, with females forming within-haplotype associations 1.7 times more often than expected by random assortment. Partial matrix correlations and permutation analyses indicated that the skew toward within-haplotype associations could not be accounted for by short-term temporal co-occurrence or fine-scale spatial distributions of individuals with shared haplotypes. While the mechanism by which individuals with a common mtDNA haplotype assort remains unknown, our results strongly suggest an influence of maternal lineages on the social organization of humpback whales within a regional feeding ground.
Are Women's Orgasms Hindered by Phallocentric Imperatives?
Willis, Malachi; Jozkowski, Kristen N; Lo, Wen-Juo; Sanders, Stephanie A
2018-02-20
Women who have sex with women (WSW) are more likely to report experiencing an orgasm during partnered sex, compared to women who have sex with men (WSM). We investigated whether this difference can be partially accounted for by phallocentric imperatives-gendered sexual scripts that prioritize men's sexual experience. For example, these imperatives emphasize vaginal-penile intercourse (i.e., the coital imperative) and men's physical pleasure (i.e., the male orgasm imperative). We reasoned that a larger variety of sexual behaviors indicates less adherence to the coital imperative and that more self-oriented orgasm goals for women indicate less adherence to the male orgasm imperative. Consistent with previous work, we expected WSW to report higher rates of orgasm than WSM when taking frequency of sex into account. We also hypothesized that this difference in orgasm rates would dissipate when controlling for variety of sexual behavior and women's self-oriented orgasm goals. In a sample of 1988 WSM and 308 WSW, we found that WSW were 1.33 times (p < .001) more likely to report experiencing an orgasm than WSM, controlling for frequency of sex. This incidence rate ratio was reduced to 1.16 (p < .001) after taking into account variety of sexual behavior and self-oriented orgasm goals. Our findings indicate that certain sexual scripts (e.g., phallocentric imperatives) help explain the orgasm discrepancy between WSW and WSM. We discuss masturbation as another male-centered practice that may be relevant to this gap, as well as implications for intervention and future research.
Sex Differences Influencing Micro- and Macrovascular Endothelial Phenotype In Vitro.
Huxley, Virginia H; Kemp, Scott S; Schramm, Christine; Sieveking, Steve; Bingaman, Susan; Yu, Yang; Zaniletti, Isabella; Stockard, Kevin; Wang, Jianjie
2018-06-09
Endothelial dysfunction is an early hallmark of multiple disease states that also display sex differences with respect to age of onset, frequency, and severity. Results of in vivo studies of basal and stimulated microvascular barrier function revealed sex differences difficult to ascribe to specific cells or environmental factors. The present study evaluated endothelial cells (EC) isolated from macro- and/or microvessels of reproductively mature rats under the controlled conditions of low-passage culture to test the assumption that EC phenotype would be sex-independent. The primary finding was that EC, regardless of where they are derived, retain a sex-bias in low-passage culture, independent of varying levels of reproductive hormones. Implications of the work include the fallacy of expecting a universal set of mechanisms derived from study of EC from one sex and/or one vascular origin to apply uniformly to all EC under unstimulated conditions no less in the disease state. Vascular endothelial cells (EC) are heterogeneous with respect to phenotype reflecting at least organ of origin, location within the vascular network, and physical forces. Sex, as an independent influence on EC functions in health or etiology, susceptibility, and progression of dysfunction in numerous disease states, has been largely ignored. The current study focussed on EC isolated from aorta (macrovascular) and skeletal muscle vessels (microvascular) of age-matched male and female rats under identical conditions of short term (passage 4) culture. We tested the hypothesis that genomic sex would not influence endothelial growth, wound healing, morphology, lactate production, or messenger RNA and protein expression of key proteins (sex hormone receptors for androgen (AR) and oestrogen (ERα and ERβ); PECAM-1 and VE-CAD mediating barrier function; α v β 3 and N-Cadherin influencing matrix interactions; ICAM-1 and VCAM-1 mediating EC/white cell adhesion). The hypothesis was rejected as EC origin (macro- versus microvessel) and sex influenced multiple phenotypic characteristics. Statistical model analysis of EC growth demonstrated an hierarchy of variable importance, recapitulated for other phenotypic characteristics, wherein predictions assuming EC homogeneity < Sex < Vessel Origin < Sex and Vessel Origin. Further, patterns of EC mRNA expression by vessel origin and by sex did not predict protein expression. Overall the study demonstrated that accurate assessment of sex-linked EC dysfunction first requires understanding of EC function by position in the vascular tree and by sex. Results from a single EC tissue source/species/sex cannot provide universal insight into the mechanisms regulating in vivo endothelial function in health, no less disease. (250) This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Graham, Cynthia A; Mercer, Catherine H; Tanton, Clare; Jones, Kyle G; Johnson, Anne M; Wellings, Kaye; Mitchell, Kirstin R
2017-09-13
To investigate factors associated with reporting lacking interest in sex and how these vary by gender. British general population. Complex survey analyses of data collected for a cross-sectional probability sample survey, undertaken 2010-2012, specifically logistic regression to calculate age-adjusted OR (AOR) to identify associated factors. 4839 men and 6669 women aged 16-74 years who reported ≥1 sexual partner (opposite-sex or same-sex) in the past year for the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). Lacking interest in sex for ≥3 months in the past year. Overall, 15.0% (13.9-16.2) of men and 34.2% (32.8-35.5) of women reported lacking interest in sex. This was associated with age and physical and mental health for both men and women, including self-reported general health and current depression. Lacking interest in sex was more prevalent among men and women reporting sexually transmitted infection diagnoses (ever), non-volitional sex (ever) and holding sexual attitudes related to normative expectations about sex. Some gender similarities in associated relationship and family-related factors were evident, including partner having had sexual difficulties in the last year (men: AOR 1.41 (1.07-1.86); women: AOR 1.60 (1.32-1.94)), not feeling emotionally close to partner during sex (men: 3.74 (1.76-7.93); women: 4.80 (2.99-7.69) and ease of talking about sex (men: 1.53 (1.23-1.90);women: 2.06 (1.77-2.39)). Among women only, lack of interest in sex was higher among those in a relationship of >1 year in duration and those not sharing the same level of interest (4.57 (3.87-5.38)) or preferences (2.91 (2.22-3.83)) with a partner. Both gender similarities and differences were found in factors associated with lacking interest in sex, with the most marked differences in relation to some relationship variables. Findings highlight the need to assess, and if appropriate, treat lacking interest in sex in a holistic and relationship-specific way. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Graham, Cynthia A; Mercer, Catherine H; Jones, Kyle G; Johnson, Anne M; Wellings, Kaye; Mitchell, Kirstin R
2017-01-01
Objectives To investigate factors associated with reporting lacking interest in sex and how these vary by gender. Setting British general population. Design Complex survey analyses of data collected for a cross-sectional probability sample survey, undertaken 2010–2012, specifically logistic regression to calculate age-adjusted OR (AOR) to identify associated factors. Participants 4839 men and 6669 women aged 16–74 years who reported ≥1 sexual partner (opposite-sex or same-sex) in the past year for the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). Main outcome measure Lacking interest in sex for ≥3 months in the past year. Results Overall, 15.0% (13.9–16.2) of men and 34.2% (32.8–35.5) of women reported lacking interest in sex. This was associated with age and physical and mental health for both men and women, including self-reported general health and current depression. Lacking interest in sex was more prevalent among men and women reporting sexually transmitted infection diagnoses (ever), non-volitional sex (ever) and holding sexual attitudes related to normative expectations about sex. Some gender similarities in associated relationship and family-related factors were evident, including partner having had sexual difficulties in the last year (men: AOR 1.41 (1.07–1.86); women: AOR 1.60 (1.32–1.94)), not feeling emotionally close to partner during sex (men: 3.74 (1.76–7.93); women: 4.80 (2.99–7.69) and ease of talking about sex (men: 1.53 (1.23–1.90);women: 2.06 (1.77–2.39)). Among women only, lack of interest in sex was higher among those in a relationship of >1 year in duration and those not sharing the same level of interest (4.57 (3.87–5.38)) or preferences (2.91 (2.22–3.83)) with a partner. Conclusions Both gender similarities and differences were found in factors associated with lacking interest in sex, with the most marked differences in relation to some relationship variables. Findings highlight the need to assess, and if appropriate, treat lacking interest in sex in a holistic and relationship-specific way. PMID:28903968
Li, Wenhui; Maduro, Gil A; Begier, Elizabeth M
2016-01-01
New York City's (NYC's) life expectancy gains have been greater than those seen nationally. We examined life-expectancy changes over the past decade in selected NYC subpopulations and explored which age groups and causes of death contributed most to the increases. We calculated life expectancy with 95% confidence intervals (CIs) for 2001-2010 by sex and race/ethnicity. Life expectancy was decomposed by age group and cause of death. Logistic regressions were conducted to reinforce the results from decomposition by controlling confounders. Overall, NYC residents' life expectancy at birth increased from 77.9 years (95% CI, 77.8-78.0) in 2001 to 80.9 years (95% CI, 80.8-81.0) in 2010. Decreases in deaths from heart disease, cancer, and HIV disease accounted for 50%, 16%, and 11%, respectively, of the gains. Decreased mortality in older age groups (≥65 years) accounted for 45.6% of the overall change. Life expectancy increased for both sexes, across all racial/ethnic groups, and for both the US-born and the foreign-born. Disparities in life expectancy decreased as overall life expectancy increased. Decreased mortality among older adults and from heart disease, cancer, and HIV infection accounted for most of the increases.
Birth Control: How to Use Your Diaphragm
... Emotional Well-Being Mental Health Sex and Birth Control Sex and Sexuality Birth Control Family Health Infants and Toddlers Kids and Teens ... MoreBMI Calculator Vasectomy: What to ExpectProgestin-Only Birth Control PillsDepo-Provera: An Injectable ContraceptiveTubal Sterilization (Tubal Ligation) ...
ERIC Educational Resources Information Center
Adams, Gerald R.; Hicken, Mandy
1984-01-01
Presents a replication of Looft's 1971 study on vocational preference and expectation in a 1981 study of 108 preschool and primary students. Results showed modest changes in occupational preferences, still mediated by sex role implications. Girls' expectations of obtaining preferred occupations were very low. (JAC)
Visual Cues, Student Sex, Material Taught, and the Magnitude of Teacher Expectancy Effects.
ERIC Educational Resources Information Center
Badini, Aldo A.; Rosenthal, Robert
1989-01-01
Conducts an experiment on teacher expectancy effects to investigate the simultaneous effects of student gender, communication channel, and type of material taught (vocabulary and reasoning). Finds that the magnitude of teacher expectation effects was greater when students had access to visual cues, especially when the students were female. (MS)
Predictors of father-son communication about sexuality.
Lehr, Sally T; Demi, Alice S; Dilorio, Colleen; Facteau, Jeffrey
2005-05-01
Examining the factors that influence adolescents' sexual behaviors is crucial for understanding why they often engage in risky sexual behaviors. Using social cognitive theory, we examined predictors of father-son communication about sexuality. Fathers (N=155) of adolescent sons completed a survey measuring 12 variables, including self-efficacy and outcome expectations. We found that (a) son's pubertal development, father's sex-based values, father's education; father's communication with his father, outcome expectations, and general communication accounted for 36% of the variance in information sharing communication and (b) son's pubertal development, outcome expectations, general communication, and father-son contact accounted for 20% of the variance in values sharing communication. Study findings can aid professionals in designing guidelines for programs to promote father-son general communication and sex-based communication.
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.
Tejeda, M T; Arredondo, J; Pérez-Staples, D; Ramos-Morales, P; Liedo, P; Díaz-Fleischer, F
2014-11-01
Water availability is recognized as one of the most important factors in the distribution and activity of terrestrial organisms. In the case of insects, hydric stress imposes a major challenge for survival because of the small surface-area-to-volume ratio they exhibit. In general, stress resistance is expected to co-vary positively with size; however, this pattern can become obscured in insects that exhibit sexual size dimorphism, as sexes differ in size and/or shape and have dissimilar resource allocations. In the present study, we use an allometric-based approach to (i) assess the desiccation and starvation stress resistance of teneral Anastrepha ludens flies, (ii) disentangle the relationships between resistance, size and sex and (iii) examine the adult fly body differences in water and lipid contents before and after exposure to stress. After controlling for sexual size dimorphism, an allometric increase of resistance with overall size was observed for all stress-based treatments. The scaling exponents that define the proportion of increase resistance varied with size traits and with type and degree of hydric stress. In this allometric relationship, and also in the relationships between mass and wing length and between size and teneral resources, the sexes maintained similar scaling exponents but differed in the intercepts. Males were more resistant to stress than females; this competitive advantage is probably linked to greater amounts of teneral lipids and more water use during stress. Copyright © 2014 Elsevier Ltd. All rights reserved.
Spatial interactions between sympatric carnivores: asymmetric avoidance of an intraguild predator.
Grassel, Shaun M; Rachlow, Janet L; Williams, Christopher J
2015-07-01
Interactions between intraguild species that act as both competitors and predator-prey can be especially complex. We studied patterns of space use by the black-footed ferret (Mustela nigripes), a prairie dog (Cynomys spp.) specialist, and the American badger (Taxidea taxus), a larger generalist carnivore that competes for prairie dogs and is known to kill ferrets. We expected that ferrets would spatially avoid badgers because of the risk of predation, that these patterns of avoidance might differ between sexes and age classes, and that the availability of food and space might influence these relationships. We used location data from 60 ferrets and 15 badgers to model the influence of extrinsic factors (prairie dog density and colony size) and intrinsic factors (sex, age) on patterns of space use by ferrets in relation to space use by different sex and age categories of badgers. We documented asymmetric patterns of avoidance of badgers by ferrets based on the sex of both species. Female ferrets avoided adult female badgers, but not male badgers, and male ferrets exhibited less avoidance than female ferrets. Additionally, avoidance decreased with increasing densities of prairie dogs. We suggest that intersexual differences in space use by badgers create varying distributions of predation risk that are perceived by the smaller carnivore (ferrets) and that females respond more sensitively than males to that risk. This work advances understanding about how competing species coexist and suggests that including information on both intrinsic and extrinsic factors might improve our understanding of behavioral interactions between sympatric species.
Naylor, C D; Levinton, C M
1993-10-01
To assess sex-related differences in coronary revascularization practices in a Canadian setting. Prospective analytic cohort study. Regional referral office in Toronto. A selected but consecutive group of 131 women and 440 men referred by cardiologists for revascularization procedures between Jan. 3, 1989, and June 30, 1991. Coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA). Nurse-coordinators placed the referral with a surgeon or interventional cardiologist at one of three hospitals, who then communicated directly with the referring cardiologist. Symptom status at referral, procedures requested and performed, and time from referral to procedure. Although the women were more likely than the men to have unstable angina at the time of referral (odds ratio [OR] 2.28, 95% confidence interval [CI] 1.38 to 3.79, p = 0.0006), more women than men (16.8% v. 12.1%) were turned down for a procedure. Significant sex-related differences in practice patterns (p < 0.001) persisted after controlling for age or for the referring cardiologists' perception of expected procedural risk. A stepwise multivariate model showed that anatomy was the main determinant of case management; sex was the only other significant variable (p = 0.016). The referring physicians requested CABG more often for men than for women (p = 0.009), and the men accepted for a procedure were much more likely to undergo CABG than the women (OR 2.40, CI 1.47 to 3.93, p = 0.0002). Although the women undergoing CABG waited shorter periods than the men (p = 0.0035), this difference was attributable to their more severe symptoms. In this selected group women had more serious symptoms before referral but were turned down for revascularization more often than men. Reduced use of CABG rather than PTCA largely accounted for the sex-related differences in revascularization. Once accepted for a procedure women had shorter waiting times, which was appropriate given their more severe symptoms.
Dechmann, Dina K. N.; Wikelski, Martin; Varga, Katarina; Yohannes, Elisabeth; Fiedler, Wolfgang; Safi, Kamran; Burkhard, Wolf-Dieter; O'Mara, M. Teague
2014-01-01
Long-distance migration is a rare phenomenon in European bats. Genetic analyses and banding studies show that females can cover distances of up to 1,600 km, whereas males are sedentary or migrate only short distances. The onset of this sex-biased migration is supposed to occur shortly after rousing from hibernation and when the females are already pregnant. We therefore predicted that the sexes are exposed to different energetic pressures in early spring, and this should be reflected in their behavior and physiology. We investigated this in one of the three Central European long-distance migrants, the common noctule (Nyctalus noctula) in Southern Germany recording the first individual partial migration tracks of this species. In contrast to our predictions, we found no difference between male and female home range size, activity, habitat use or diet. Males and females emerged from hibernation in similar body condition and mass increase rate was the same in males and females. We followed the first migration steps, up to 475 km, of radio-tagged individuals from an airplane. All females, as well as some of the males, migrated away from the wintering area in the same northeasterly direction. Sex differences in long-distance migratory behavior were confirmed through stable isotope analysis of hair, which showed greater variation in females than in males. We hypothesize that both sexes faced similarly good conditions after hibernation and fattened at maximum rates, thus showing no differences in their local behavior. Interesting results that warrant further investigation are the better initial condition of the females and the highly consistent direction of the first migratory step in this population as summering habitats of the common noctule occur at a broad range in Northern Europe. Only research focused on individual strategies will allow us to fully understand the migratory behavior of European bats. PMID:25517947
Teitel, Z; Pickup, M; Field, D L; Barrett, S C H
2016-01-01
Sexual dimorphism in resource allocation is expected to change during the life cycle of dioecious plants because of temporal differences between the sexes in reproductive investment. Given the potential for sex-specific differences in reproductive costs, resource availability may contribute to variation in reproductive allocation in females and males. Here, we used Rumex hastatulus, a dioecious, wind-pollinated annual plant, to investigate whether sexual dimorphism varies with life-history stage and nutrient availability, and determine whether allocation patterns differ depending on reproductive commitment. To examine if the costs of reproduction varied between the sexes, reproduction was either allowed or prevented through bud removal, and biomass allocation was measured at maturity. In a second experiment to assess variation in sexual dimorphism across the life cycle, and whether this varied with resource availability, plants were grown in high and low nutrients and allocation to roots, aboveground vegetative growth and reproduction were measured at three developmental stages. Males prevented from reproducing compensated with increased above- and belowground allocation to a much larger degree than females, suggesting that male reproductive costs reduce vegetative growth. The proportional allocation to roots, reproductive structures and aboveground vegetative growth varied between the sexes and among life-cycle stages, but not with nutrient treatment. Females allocated proportionally more resources to roots than males at peak flowering, but this pattern was reversed at reproductive maturity under low-nutrient conditions. Our study illustrates the importance of temporal dynamics in sex-specific resource allocation and provides support for high male reproductive costs in wind-pollinated plants. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.
Mandava, Pitchaiah; Murthy, Santosh B.; Munoz, Melody; McGuire, Dawn; Simon, Roger P.; Alexandrov, Andrei V.; Albright, Karen C.; Boehme, Amelia K.; Martin-Schild, Sheryl; Martini, Sharyl; Kent, Thomas A.
2017-01-01
Background and Purpose Sex and race reportedly influence outcome after recombinant tissue-type plasminogen activator (rtPA). It is, however, unclear whether baseline imbalances (eg, stroke severity) or lack of response to thrombolysis is responsible. We applied balancing methods to test the hypothesis that race and sex influence outcome after rtPA independent of baseline conditions. Methods We mapped group outcomes from the National Institute of Neurological Disorders and Stroke (NINDS) dataset based on race and sex onto a surrogate-control function to assess differences from expected outcomes at their respective National Institutes of Health Stroke Scale and age. Outcomes were also compared for subjects matched individually on key baseline factors using NINDS and 2 recent datasets from southeastern United States. Results At similar National Institutes of Health Stroke Scale and age, 90-day good outcomes (modified Rankin Score, 0–2) in NINDS were similarly improved after rtPA for white men and women. There was a strong trend for improvement in black men. Conversely, black women treated with rtPA showed response rates no different from the controls. After baseline matching, there were nonsignificant trends in outcomes except for significantly fewer good outcomes in black versus matched white women (37% versus 63%; P=0.027). Pooling the 3 datasets showed a similar trend for poorer short-term outcome for black women (P=0.054; modified Rankin Score, 0–1). Conclusions Matching for key baseline factors indicated that race and sex influence outcome most strikingly in black women who demonstrated poorest outcomes after rtPA. This finding supports the hypothesis that poor response to rtPA, rather than differences in baseline conditions, contributes to the worse outcome. This finding requires prospective confirmation. PMID:23674524
Telomere length and early trauma in schizophrenia.
Riley, Gabriella; Perrin, Mary; Vaez-Azizi, Leila M; Ruby, Eugene; Goetz, Raymond R; Dracxler, Roberta; Walsh-Messinger, Julie; Keefe, David L; Buckley, Peter F; Szeszko, Philip R; Malaspina, Dolores
2018-04-02
Childhood trauma is emerging as a risk factor for schizophrenia, but its mechanism with respect to etiology is unknown. One possible pathway is through leucocyte telomere length (LTL) shortening, a measure of cellular aging associated with trauma. This study examined early trauma and LTL shortening in schizophrenia and considered sex effects. The early trauma inventory (ETI) was administered to 48 adults with DSM-5 schizophrenia and 18 comparison participants. LTL was measured using qPCR. Cases had significantly more global trauma (F=4.10, p<0.01) and traumatic events (F=11.23, p<0.001), but case and control groups had similar LTL (1.91±0.74 and 1.83±0.62: p=0.68). The association of early trauma and LTL differed by sex in cases and controls (Fisher's R: Z<0.05). Significant negative associations were shown in male cases and, conversely, in female controls. For example, physical punishment was associated LTL shortening in males' cases (r=-0.429, p<01). Only female controls showed significant telomere shortening in association with early trauma. This data confirms the substantial excess of early trauma among schizophrenia cases. There were significant sex-differences in the relationship of the trauma to LTL, with only male cases showing the expected shortening. There were converse sex effects in the control group. Mean LTL was notably similar in cases and controls, despite the trauma-related shortening in male cases, cigarette smoking, older age and chronic illness of the cases. Factors may lengthen LTL in some schizophrenia cases. The converse sex differences in the cases are consistent with findings defective sexual differentiation in schizophrenia, consistent with other findings in the field. Copyright © 2018 Elsevier B.V. All rights reserved.
Educational differences in life expectancy over five decades among the oldest old in Norway.
Kinge, Jonas Minet; Steingrímsdóttir, Ólöf Anna; Moe, Joakim Oliu; Skirbekk, Vegard; Næss, Øyvind; Strand, Bjørn Heine
2015-11-01
Socioeconomic inequalities in life expectancy have been shown among the middle aged and the youngest of the old individuals, but the situation in the oldest old is less clear. The aim of this study was to investigate trends in life expectancy at ages 85, 90 and 95 years by education in Norway in the period 1961-2009. This was a register-based population study including all residents in Norway aged 85 and over. Individual-level data were provided by the Central Population Register and the National Education Database. For each decade during 1961-2009, death rates by 1-year age groups were calculated separately for each sex and three educational categories. Annual life tables were used to calculate life expectancy at ages 85 (e85), 90 (e90) and 95 (e95). Educational differentials in life expectancy at each age were non-significant in the early decades, but became significant over time. For example, for the decade 2000-9, a man aged 90 years with primary education had a life expectancy of 3.4 years, while a man with tertiary education could expect to live for 3.8 years. Similar numbers in women were 4.1 and 4.5 years, respectively. Even among 95-year-old men, statistically significant differences in life expectancy were found by education in the two last decades. Education matters regarding remaining life expectancy also for the oldest old in Norway. Life expectancy at these ages is low, so a growth of 0.5 years in the life expectancy differential is sizeable. © The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Fellowship and career path preferences in residents of otolaryngology-head and neck surgery.
Golub, Justin S; Ossoff, Robert H; Johns, Michael M
2011-04-01
Assess fellowship and academic/private practice career track preferences in residents of otolaryngology-head and neck surgery. Cross-sectional survey. A total of 1,364 U.S. otolaryngology residents were surveyed. Questions addressed demographics, work hours and sleep, fellowship preference, and career track preference (academic/private practice). Trends in fellowship and career track preference were analyzed by year of clinical otolaryngology training. Data were additionally analyzed after stratification by sex. The response rate was 50%. The desire to complete a fellowship declined from 62% (year 2) to 58% (year 5), whereas the desire to not complete a fellowship increased from 31% (year 2) to 41% (year 5). Fellowship interest increased for rhinology and head and neck surgery by training year, whereas interest declined for neurotology and facial plastics. Expectation of an academic path increased from 29% (year 2) to 38% (year 5), whereas expectation of private practice declined slightly from 59% (year 2) to 57% (year 5). Women were initially more interested in both completing a fellowship (69% women, 60% men) and academics (40% women, 27% men). At the end of training, these sex differences were eliminated or reversed (59% men, 54% women for fellowship; 39% men, 35% women for academics). Residents interested in pursuing fellowship or academics reported working 2 hr/week more than those interested in no fellowship or private practice, respectively (P < 0.01). Fellowship and career track preferences suggest trends that may be useful to residency/fellowship program directors and residents making career choices. Inequalities producing differences according to sex should be addressed. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.
Selvaggi, Gennaro; Ceulemans, Peter; De Cuypere, Griet; VanLanduyt, Koen; Blondeel, Phillip; Hamdi, Moustapha; Bowman, Cameron; Monstrey, Stan
2005-11-01
After studying this article, the participant should be able to discuss: 1. The terminology related to male-to-female gender dysphoria. 2. The different theories regarding cause, epidemiology, and treatment of gender dysphoria. 3. The surgical goals of sex reassignment surgery in male-to-female transsexualism. 4. The surgical techniques available for sex reassignment surgery in male-to-female transsexualism. Gender identity disorder (previously "transsexualism") is the term used for individuals who show a strong and persistent cross-gender identification and a persistent discomfort with their anatomical sex, as manifested by a preoccupation with getting rid of one's sex characteristics, or the belief of being born in the wrong sex. Since 1978, the Harry Benjamin International Gender Dysphoria Association (in honor of Dr. Harry Benjamin, one of the first physicians who made many clinicians aware of the potential benefits of sex reassignment surgery) has played a major role in the research and treatment of gender identity disorder, publishing the Standards of Care for Gender Dysphoric Persons. The authors performed an overview of the terminology related to male-to-female gender identity disorder; the different theories regarding cause, epidemiology, and treatment; the goals expected; and the surgical technique available for sex reassignment surgery in male-to-female transsexualism. Surgical techniques available for sex reassignment surgery in male-to-female transsexualism, with advantages and disadvantages offered by each technique, are reviewed. Other feminizing nongenital operative interventions are also examined. This review describes recent etiopathogenetic theories and actual guidelines on the treatment of the gender identity disorder in male-to-female transsexuals; the penile-scrotal skin flap technique is considered the state of the art for vaginoplasty in male-to-female transsexuals, whereas other techniques (rectosigmoid flap, local flaps, and isolated skin grafts) should be considered only in secondary cases. As techniques in vaginoplasty become more refined, more emphasis is being placed on aesthetic outcomes by both surgeons and patients.
The Weaker Sex? The Propensity for Male-Biased Piglet Mortality
Baxter, Emma M.; Jarvis, Susan; Palarea-Albaladejo, Javier; Edwards, Sandra A.
2012-01-01
For the most part solutions to farm animal welfare issues, such as piglet mortality, are likely to lie within the scientific disciplines of environmental design and genetic selection, however understanding the ecological basis of some of the complex dynamics observed between parent and offspring could make a valuable contribution. One interesting, and often discussed, aspect of mortality is the propensity for it to be sex-biased. This study investigated whether known physiological and behavioural indicators of piglet survival differed between the sexes and whether life history strategies (often reported in wild or feral populations) relating to parental investment were being displayed in a domestic population of pigs. Sex ratio (proportion of males (males/males+females)) at birth was 0.54 and sex allocation (maternal investment measured as piglet birth weight/litter weight) was statistically significantly male-biased at 0.55 (t35 = 2.51 P = 0.017), suggesting that sows invested more in sons than daughters during gestation. Despite this investment in birth weight, a known survival indicator, total pre-weaning male mortality was statistically significantly higher than female mortality (12% vs. 7% respectively z = 2.06 P = 0.040). Males tended to suffer from crushing by the sow more than females and statistically significantly more males died from disease-related causes. Although males were born on average heavier, with higher body mass index and ponderal index, these differences were not sustained. In addition male piglets showed impaired thermoregulation compared to females. These results suggest male-biased mortality exists despite greater initial maternal investment, and therefore reflects the greater susceptibility of this sex to causal mortality factors. Life history strategies are being displayed by a domestic population of pigs with sows in this study displaying a form of parental optimism by allocating greater resources at birth to males and providing an over-supply of this more vulnerable sex in expectation of sex-biased mortality. PMID:22272334
What Happens to Therapists Who Work with Sex Offenders?
ERIC Educational Resources Information Center
Farrenkopf, Toni
1992-01-01
Surveyed 24 experienced therapists working with sex offenders regarding personal impact of work. Most reported shift in perspective, becoming discouraged about client change. Several adjustment phases were reported. One-quarter experienced burnout. Alternative to burnout was adaptation: lowering of expectations, objective detachment, acceptance of…
2015-01-10
Up-to-date evidence on levels and trends for age-sex-specific all-cause and cause-specific mortality is essential for the formation of global, regional, and national health policies. In the Global Burden of Disease Study 2013 (GBD 2013) we estimated yearly deaths for 188 countries between 1990, and 2013. We used the results to assess whether there is epidemiological convergence across countries. We estimated age-sex-specific all-cause mortality using the GBD 2010 methods with some refinements to improve accuracy applied to an updated database of vital registration, survey, and census data. We generally estimated cause of death as in the GBD 2010. Key improvements included the addition of more recent vital registration data for 72 countries, an updated verbal autopsy literature review, two new and detailed data systems for China, and more detail for Mexico, UK, Turkey, and Russia. We improved statistical models for garbage code redistribution. We used six different modelling strategies across the 240 causes; cause of death ensemble modelling (CODEm) was the dominant strategy for causes with sufficient information. Trends for Alzheimer's disease and other dementias were informed by meta-regression of prevalence studies. For pathogen-specific causes of diarrhoea and lower respiratory infections we used a counterfactual approach. We computed two measures of convergence (inequality) across countries: the average relative difference across all pairs of countries (Gini coefficient) and the average absolute difference across countries. To summarise broad findings, we used multiple decrement life-tables to decompose probabilities of death from birth to exact age 15 years, from exact age 15 years to exact age 50 years, and from exact age 50 years to exact age 75 years, and life expectancy at birth into major causes. For all quantities reported, we computed 95% uncertainty intervals (UIs). We constrained cause-specific fractions within each age-sex-country-year group to sum to all-cause mortality based on draws from the uncertainty distributions. Global life expectancy for both sexes increased from 65.3 years (UI 65.0-65.6) in 1990, to 71.5 years (UI 71.0-71.9) in 2013, while the number of deaths increased from 47.5 million (UI 46.8-48.2) to 54.9 million (UI 53.6-56.3) over the same interval. Global progress masked variation by age and sex: for children, average absolute differences between countries decreased but relative differences increased. For women aged 25-39 years and older than 75 years and for men aged 20-49 years and 65 years and older, both absolute and relative differences increased. Decomposition of global and regional life expectancy showed the prominent role of reductions in age-standardised death rates for cardiovascular diseases and cancers in high-income regions, and reductions in child deaths from diarrhoea, lower respiratory infections, and neonatal causes in low-income regions. HIV/AIDS reduced life expectancy in southern sub-Saharan Africa. For most communicable causes of death both numbers of deaths and age-standardised death rates fell whereas for most non-communicable causes, demographic shifts have increased numbers of deaths but decreased age-standardised death rates. Global deaths from injury increased by 10.7%, from 4.3 million deaths in 1990 to 4.8 million in 2013; but age-standardised rates declined over the same period by 21%. For some causes of more than 100,000 deaths per year in 2013, age-standardised death rates increased between 1990 and 2013, including HIV/AIDS, pancreatic cancer, atrial fibrillation and flutter, drug use disorders, diabetes, chronic kidney disease, and sickle-cell anaemias. Diarrhoeal diseases, lower respiratory infections, neonatal causes, and malaria are still in the top five causes of death in children younger than 5 years. The most important pathogens are rotavirus for diarrhoea and pneumococcus for lower respiratory infections. Country-specific probabilities of death over three phases of life were substantially varied between and within regions. For most countries, the general pattern of reductions in age-sex specific mortality has been associated with a progressive shift towards a larger share of the remaining deaths caused by non-communicable disease and injuries. Assessing epidemiological convergence across countries depends on whether an absolute or relative measure of inequality is used. Nevertheless, age-standardised death rates for seven substantial causes are increasing, suggesting the potential for reversals in some countries. Important gaps exist in the empirical data for cause of death estimates for some countries; for example, no national data for India are available for the past decade. Bill & Melinda Gates Foundation. Copyright © 2015 Elsevier Ltd. All rights reserved.
Costa, Ana Rute; Silva, Susana; Moura-Ferreira, Pedro; Villaverde-Cabral, Manuel; Santos, Osvaldo; Carmo, Isabel do; Barros, Henrique; Lunet, Nuno
2017-04-01
Cancer screening has contributed to downward trends in cancer mortality, but is also associated with adverse effects, which highlights the importance of promoting the participation based on informed decisions. We aimed to describe the use of cancer screening (either in organized programmes or as opportunistic screening), awareness of organized programmes and perception of its potential benefits and adverse effects, depicting possible sex differences. We evaluated 1624 Portuguese-speaking dwellers, aged between 16 and 79 years, through face-to-face interviews. To quantify sex differences, adjusted prevalence ratios and respective 95% confidence intervals were computed using Poisson regression. Among eligible age groups, the lifetime prevalence of screening for breast and cervical cancers was 89.8 and 71.9%, respectively. The prevalence was 23.7% for colorectal cancer and no significant sex differences were observed. Prostate cancer screening was reported by 63.8% of men. Over half of the participants referred that cancers such as prostate, skin, lung and stomach should be screened for, in addition to those for which organized programmes are recommended. Reassurance by negative results was identified as the main potential benefit of screening by nearly one-third of men and women. Anxiety while waiting for results was the most mentioned potential adverse effect (60.4%); men refer less often this and financial costs, although statistical significance of these results was borderline. This study provides a benchmark to plan and monitor the effects of awareness-raising interventions, as well as for international comparisons across countries with different cancer prevention and control structures. © 2016 The Authors. Health Expectations Published by John Wiley & Sons Ltd.
Correlation of sex ratio at birth with health and socioeconomic indicators.
Grech, Victor
2018-03-01
The sex ratio at birth (male divided by total live births: M/T) has been mooted as a potential sentinel health indicator. Several metrics indicate individual countries' health and socioeconomic status. In this study, in all available countries (where such data was accessible), M/T and these indicators were compared in order to ascertain whether better (vis-à-vis health and socioeconomic status) levels of these indicators were associated with higher M/T in available countries. The following were obtained (by country) from various sources: M/T, infant mortality rate, under 5 years mortality rate, fertility rate, Human Development Index, gross domestic product per capita, life expectancy for both sexes, females, males, as well as both sexes Health Adjusted Life Expectancy (HALE). Pearson correlation was performed comparing M/T and these indicators. Despite weak correlation values, all except for the Human Development Index (HDI) correlated with M/T at statistically significant levels. A decrease in mortality and an increase in life expectancy and GDP/capita are indicators of socioeconomic wellbeing. In this study, mortality was negatively correlated with M/T. Life expectancy and GDP/capita were both positively correlated with M/T, indicating that M/T may also serve as a surrogate health indicator, and incidentally, also supporting the Trivers-Willard hypothesis. Improving economies lead to increasing education, which in turns tends to lower fertility rate in association with a declining M/T. In conclusion, the global correlation of health and socioeconomic indicators with M/T suggests that M/T may be a useful sentinel health indicator. Copyright © 2018 Elsevier B.V. All rights reserved.
Georges, Arthur
1989-11-01
Mean daily temperature in natural nests of freshwater turtles with temperature-dependent sex determination is known to be a poor predictor of hatchling sex ratios when nest temperatures fluctuate. To account for this, a model was developed on the assumption that females will emerge from eggs when more than half of embryonic development occurs above the threshold temperature for sex determination rather than from eggs that spend more than half their time above the threshold. The model is consistent with previously published data and in particular explains the phenomenon whereby the mean temperature that best distinguishes between male and female nests decreases with increasing variability in nest temperature. The model, if verified by controlled experiments, has important implications for our understanding of temperature-dependent sex determination in natural nests. Both mean nest temperature and "hours spent above the threshold" will be poor predictors of hatchling sex ratios. Studies designed to investigate latitudinal trends and inter-specific differences in the threshold temperature will need to consider latitudinal and inter-specific variation in the magnitude of diel fluctuations in nest temperature, and variation in factors influencing the magnitude of those fluctuations, such as nest depth. Furthermore, any factor that modifies the relationship between developmental rate and temperature can be expected to influence hatchling sex ratios in natural nests, especially when nest temperatures are close to the threshold.
Dufresnes, Christophe; Bertholet, Youna; Wassef, Jérôme; Ghali, Karim; Savary, Romain; Pasteur, Baptiste; Brelsford, Alan; Rozenblut-Kościsty, Beata; Ogielska, Maria; Stöck, Matthias; Perrin, Nicolas
2014-12-01
Occasional XY recombination is a proposed explanation for the sex-chromosome homomorphy in European tree frogs. Numerous laboratory crosses, however, failed to detect any event of male recombination, and a detailed survey of NW-European Hyla arborea populations identified male-specific alleles at sex-linked loci, pointing to the absence of XY recombination in their recent history. Here, we address this paradox in a phylogeographic framework by genotyping sex-linked microsatellite markers in populations and sibships from the entire species range. Contrasting with postglacial populations of NW Europe, which display complete absence of XY recombination and strong sex-chromosome differentiation, refugial populations of the southern Balkans and Adriatic coast show limited XY recombination and large overlaps in allele frequencies. Geographically and historically intermediate populations of the Pannonian Basin show intermediate patterns of XY differentiation. Even in populations where X and Y occasionally recombine, the genetic diversity of Y haplotypes is reduced below the levels expected from the fourfold drop in copy numbers. This study is the first in which X and Y haplotypes could be phased over the distribution range in a species with homomorphic sex chromosomes; it shows that XY-recombination patterns may differ strikingly between conspecific populations, and that recombination arrest may evolve rapidly (<5000 generations). © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.
Velasco, Matthew C
2018-05-16
In the Late Intermediate Period Andes (AD 1100-1450), the proliferation of above-ground sepulchers reconfigured social boundaries within and between communities engaged in protracted conflict. However, the biosocial dimensions of these mortuary practices, and their implications for conflict and alliance formation, remain unexplored. This study examines patterns of phenotypic variation to: (1) evaluate if open sepulchers were organized on the basis of biological relatedness, and (2) explore if sex-specific phenotypic variability conforms to models of postmarital residence. Cranial nonmetric traits were recorded in five skeletal samples from two cemeteries in the Colca Valley, Peru. Biological distances between burial groups were calculated using the Mean Measure of Divergence (MMD) statistic. Postmarital residence was explored by calculating and bootstrapping the ratio of male-to-female mean pairwise differences (MPD) at the within-group level. The MMD analysis yields greater than expected between-group distances for burial groups with a minimum sample size of 20 individuals. In contrast, a prevailing pattern of sex-specific, within-group phenotypic variability is not apparent from the analysis of MPD. The use of 12 or 24 dichotomous traits produces similar results. Greater than expected biological distances suggest that above-ground mortuary practices reinforced biosocial boundaries between corporate household groups. Intracemetery heterogeneity persisted even as cranial vault modification, a correlate of social identity, became more homogenous, revealing how corporate group organization was negotiated at multiple scales. Sex-specific variation does not conform to traditional migration models. If migration occurred, it did not have a homogenizing effect on phenotypic variation. These results should be viewed with caution in light of the smaller sample sizes of sex-specific groupings. © 2018 Wiley Periodicals, Inc.
Davis, Devra Lee; Webster, Pamela; Stainthorpe, Hillary; Chilton, Janice; Jones, Lovell; Doi, Rikuo
2007-06-01
The expected ratio of male to female births is generally believed to be 1.05, also described as the male proportion of 0.515. We describe trends in sex ratio at birth and in fetal deaths in the United States, in African Americans and in whites, and in Japan, two industrial countries with well-characterized health data infrastructures, and we speculate about possible explanations. Public health records from national statistical agencies were assembled to create information on sex ratio at birth and in fetal deaths in the United States (1970-2002) and Japan (1970-1999), using SPSS. Sex ratio at birth has declined significantly in Japan and in U.S. whites, but not for African Americans, for whom sex ratio remains significantly lower than that of whites. The male proportion of fetal death has increased overall in Japan and in the United States. Sex ratio declines are equivalent to a shift from male to female births of 135,000 white males in the United States and 127,000 males in Japan. Known and hypothesized risk factors for reduced sex ratio at birth and in fetal deaths cannot account fully for recent trends or racial or national differences. Whether avoidable environmental or other factors--such as widespread exposure to metalloestrogens or other known or suspected endocrine-disrupting materials, changes in parental age, obesity, assisted reproduction, or nutrition--may account for some of these patterns is a matter that merits serious concern.
Emslie, Carol; Hunt, Kate
2008-09-01
Despite increasing interest in gender and health, 'lay' perceptions of gender differences in mortality have been neglected. Drawing on semi-structured interview data from 45 men and women in two age cohorts (born in the early 1950s and 1970s) in the UK, we investigated lay explanations for women's longer life expectancy. Our data suggest that respondents were aware of women's increased longevity, but found this difficult to explain. While many accounts were multifactorial, socio-cultural explanations were more common, more detailed and less tentative than biological explanations. Different socio-cultural explanations (i.e. gendered social roles, 'macho' constraints on men and gender differences in health-related behaviours) were linked by the perception that life expectancy would converge as men and women's lives became more similar. Health behaviours such as going to the doctor or drinking alcohol were often located within wider structural contexts. Female respondents were more likely to focus on women's reproductive and caring roles, while male respondents were more likely to focus on how men were disadvantaged by their 'provider' role. We locate these narratives within academic debates about conceptualising gender: e.g. 'gender as structure' versus 'gender as performance', 'gender as difference' versus 'gender as diversity'.
Aguiar, G F; Neves, W A
1991-08-01
The analysis of biologic variation in prehistoric human populations separately by sex has been used as a tool to recover post-marital residential rules. These studies, which focus on the sexual distribution of skeletal traits, assume that the degree of intragroup or intergroup biologic diversity is higher in one sex with regard to unilocality (uxori- or virilocality). Despite a recent attempt to interpret this phenomenon in terms of population genetics (Konigsberg 1988), the main assumption has never been tested in situations in which the real residential practice of an indigenous population is known and in which genetic rather than phenotypic data are available. We investigated the within-group and between-group genetic variability among males and females from 4 villages of an uxorilocal Amazonian tribe, the Urubu-Ka'apor, on the basis of 20 polymorphic loci. The results were only partly concordant with the expected. Individual mean per locus heterozygosities were not different between the sexes, and the analysis of genetic heterogeneity showed similar gene frequencies for males and females in all villages. On the other hand, the intergroup approach detected a level of variation significantly greater among females than among males. The ethnographic evidence shows that three of the four subgroups studied belong to the same gamic unity, with the fourth subgroup belonging to another gamic network. Within-sex differences in intergroup analysis turned out to be more evident; yet, when those 3 villages were investigated separately, the female FST (0.0609) proved to be significantly higher than the male FST (0.0218). Such results suggest that the intergroup analysis is more sensitive to the genetic effects of differential migration rates between the sexes. In prehistoric contexts, therefore, an intergroup genetic approach can provide more reliable grounds for sociocultural inferences.
Bradley, Brenda J; Snowdon, Charles T; McGrew, William C; Lawler, Richard R; Guevara, Elaine E; McIntosh, Annick; O'Connor, Timothy
2016-12-01
Producing single versus multiple births has important life history trade-offs, including the potential benefits and risks of sharing a common in utero environment. Sex hormones can diffuse through amniotic fluid and fetal membranes, and females with male littermates risk exposure to high levels of fetal testosterone, which are shown to have masculinizing effects and negative fitness consequences in many mammals. Whereas most primates give birth to single offspring, several New World monkey and strepsirrhine species regularly give birth to small litters. We examined whether neonatal testosterone exposure might be detrimental to females in mixed-sex litters by compiling data from long-term breeding records for seven primate species (Saguinus oedipus; Varecia variegata, Varecia rubra, Microcebus murinis, Mirza coquereli, Cheirogaleus medius, Galago moholi). Litter sex ratios did not differ from the expected 1:2:1 (MM:MF:FF for twins) and 1:2:2:1 (MMM:MMF:MFF:FFF for triplets). Measures of reproductive success, including female survivorship, offspring-survivorship, and inter-birth interval, did not differ between females born in mixed-sex versus all-female litters, indicating that litter-producing non-human primates, unlike humans and rodents, show no signs of detrimental effects from androgen exposure in mixed sex litters. Although we found no evidence for CYP19A1 gene duplications-a hypothesized mechanism for coping with androgen exposure-aromatase protein evolution shows patterns of convergence among litter-producing taxa. That some primates have effectively found a way to circumvent a major cost of multiple births has implications for understanding variation in litter size and life history strategies across mammals. © 2016 Wiley Periodicals, Inc.
Empathy: Gender effects in brain and behavior
Christov-Moore, Leonardo; Simpson, Elizabeth A.; Coudé, Gino; Grigaityte, Kristina; Iacoboni, Marco; Ferrari, Pier Francesco
2016-01-01
Evidence suggests that there are differences in the capacity for empathy between males and females. However, how deep do these differences go? Stereotypically, females are portrayed as more nurturing and empathetic, while males are portrayed as less emotional and more cognitive. Some authors suggest that observed gender differences might be largely due to cultural expectations about gender roles. However, empathy has both evolutionary and developmental precursors, and can be studied using implicit measures, aspects that can help elucidate the respective roles of culture and biology. This article reviews evidence from ethology, social psychology, economics, and neuroscience to show that there are fundamental differences in implicit measures of empathy, with parallels in development and evolution. Studies in nonhuman animals and younger human populations (infants/children) offer converging evidence that sex differences in empathy have phylogenetic and ontogenetic roots in biology and are not merely cultural byproducts driven by socialization. We review how these differences may have arisen in response to males’ and females’ different roles throughout evolution. Examinations of the neurobiological underpinnings of empathy reveal important quantitative gender differences in the basic networks involved in affective and cognitive forms of empathy, as well as a qualitative divergence between the sexes in how emotional information is integrated to support decision making processes. Finally, the study of gender differences in empathy can be improved by designing studies with greater statistical power and considering variables implicit in gender (e.g., sexual preference, prenatal hormone exposure). These improvements may also help uncover the nature of neurodevelopmental and psychiatric disorders in which one sex is more vulnerable to compromised social competence associated with impaired empathy. PMID:25236781
Graça, M B; Pequeno, P A C L; Franklin, E; Morais, J W
2017-10-01
Occurrence patterns are partly shaped by the affinity of species with habitat conditions. For winged organisms, flight-related attributes are vital for ecological performance. However, due to the different reproductive roles of each sex, we expect divergence in flight energy budget, and consequently different selection responses between sexes. We used tropical frugivorous butterflies as models to investigate coevolution between flight morphology, sex dimorphism and vertical stratification. We studied 94 species of Amazonian fruit-feeding butterflies sampled in seven sites across 3341 ha. We used wing-thorax ratio as a proxy for flight capacity and hierarchical Bayesian modelling to estimate stratum preference. We detected a strong phylogenetic signal in wing-thorax ratio in both sexes. Stouter fast-flying species preferred the canopy, whereas more slender slow-flying species preferred the understorey. However, this relationship was stronger in females than in males, suggesting that female phenotype associates more intimately with habitat conditions. Within species, males were stouter than females and sexual dimorphism was sharper in understorey species. Because trait-habitat relationships were independent from phylogeny, the matching between flight morphology and stratum preference is more likely to reflect adaptive radiation than shared ancestry. This study sheds light on the impact of flight and sexual dimorphism on the evolution and ecological adaptation of flying organisms. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.
Not so great expectations: sex and housewives in Hong Kong.
Ying Ho, Petula Sik
2008-01-01
The study explores the life of married women who are being described as having "good," "normal," "blessed" sexuality. The case of si-nais (housewives) in Hong Kong shows that we can never assume that married women (or any social category) are privileged by virtue of their status on the sexual hierarchy. The blessings of social respectability apparently enjoyed by these women may work to enable or hinder women's expression of their erotic desires and sexual fulfillment, depending on their special social circumstances. These women's imagination and experience of good sex is composed of a multitude of components. Women may feel good because they can achieve other psychological and social aims that are important in their lives (which could be related to the maintenance of marriage or the peace of the family). Women may feel good because of the erotic satisfaction that they derive from different pursuits including interests, leisure or other intimate relationships, rather than sexual fulfillment in terms of orgasm or physical pleasure. Women may reformulate their pleasure variously at different stages of their lives. Social respectability, orgasm, emotional intimacy, or any other specific element, may all enter or leave the formula for good sex.
Effects of Age, Sex, and Body Position on Orofacial Muscle Tone in Healthy Adults.
Dietsch, Angela M; Clark, Heather M; Steiner, Jessica N; Solomon, Nancy Pearl
2015-08-01
Quantification of tissue stiffness may facilitate identification of abnormalities in orofacial muscle tone and thus contribute to differential diagnosis of dysarthria. Tissue stiffness is affected by muscle tone as well as age-related changes in muscle and connective tissue. The Myoton-3 measured tissue stiffness in 40 healthy adults, including equal numbers of men and women in each of two age groups: 18-40 years and 60+ years. Data were collected from relaxed muscles at the masseter, cheek, and lateral tongue surfaces in two positions: reclined on the side and seated with head tilted. Tissue stiffness differed across age, sex, and measurement site with multiple interaction effects. Overall, older subjects exhibited higher stiffness coefficients and oscillation frequency measures than younger subjects whereas sex differences varied by tissue site. Effects of body position were inconsistent across tissue site and measurement. Although older subjects were expected to have lower muscle tone, age-related nonmuscular tissue changes may have contributed to yield a net effect of higher stiffness. These data raise several considerations for the development of accurate normative data and for future diagnostic applications of tissue stiffness assessment.
Sex Determination: Sterility Genes out of Sequence.
Pannell, John R; Gerchen, Jörn
2018-01-22
The canonical model for the evolution of separate sexes in plants invokes sterility mutations at two linked loci. A new study claims to have found them in asparagus, but the order of their origin does not conform to expectation. Copyright © 2017 Elsevier Ltd. All rights reserved.
Wright, Jonathan; McDonald, Paul G.; te Marvelde, Luc; Kazem, Anahita J. N.; Bishop, Charles M.
2010-01-01
Indirect fitness benefits from kin selection can explain why non-breeding individuals help raise the young of relatives. However, the evolution of helping by non-relatives requires direct fitness benefits, for example via group augmentation. Here, we examine nest visit rates, load sizes and prey types delivered by breeding pairs and their helpers in the cooperatively breeding bell miner (Manorina melanophrys). In this system, males remain in their natal colony while young females typically disperse, and helpers of both sexes often assist at multiple nests concurrently. We found extremely clear evidence for the expected effect of genetic relatedness on individual helping effort per nest within colonies. This positive incremental effect of kinship was facultative—i.e. largely the result of within-individual variation in helping effort. Surprisingly, no sex differences were detectable in any aspect of helping, and even non-relatives provided substantial aid. Helpers and breeders of both sexes regulated their provisioning effort by responding visit-by-visit to changes in nestling begging. Helping behaviour in bell miners therefore appears consistent with adaptive cooperative investment in the brood, and kin-selected care by relatives. Similar investment by ‘unrelated’ helpers of both sexes argues against direct fitness benefits, but is perhaps explained by kin selection at the colony level. PMID:19846458
Independent Evolution of Transcriptional Inactivation on Sex Chromosomes in Birds and Mammals
Livernois, Alexandra M.; Waters, Shafagh A.; Deakin, Janine E.; Marshall Graves, Jennifer A.; Waters, Paul D.
2013-01-01
X chromosome inactivation in eutherian mammals has been thought to be tightly controlled, as expected from a mechanism that compensates for the different dosage of X-borne genes in XX females and XY males. However, many X genes escape inactivation in humans, inactivation of the X in marsupials is partial, and the unrelated sex chromosomes of monotreme mammals have incomplete and gene-specific inactivation of X-linked genes. The bird ZW sex chromosome system represents a third independently evolved amniote sex chromosome system with dosage compensation, albeit partial and gene-specific, via an unknown mechanism (i.e. upregulation of the single Z in females, down regulation of one or both Zs in males, or a combination). We used RNA-fluorescent in situ hybridization (RNA-FISH) to demonstrate, on individual fibroblast cells, inactivation of 11 genes on the chicken Z and 28 genes on the X chromosomes of platypus. Each gene displayed a reproducible frequency of 1Z/1X-active and 2Z/2X-active cells in the homogametic sex. Our results indicate that the probability of inactivation is controlled on a gene-by-gene basis (or small domains) on the chicken Z and platypus X chromosomes. This regulatory mechanism must have been exapted independently to the non-homologous sex chromosomes in birds and mammals in response to an over-expressed Z or X in the homogametic sex, highlighting the universal importance that (at least partial) silencing plays in the evolution on amniote dosage compensation and, therefore, the differentiation of sex chromosomes. PMID:23874231
Fielding-Miller, Rebecca; Dunkle, Kristin L; Cooper, Hannah L F; Windle, Michael; Hadley, Craig
2016-01-01
Transactional sex is associated with increased risk of HIV and gender based violence in southern Africa and around the world. However the typical quantitative operationalization, "the exchange of gifts or money for sex," can be at odds with a wide array of relationship types and motivations described in qualitative explorations. To build on the strengths of both qualitative and quantitative research streams, we used cultural consensus models to identify distinct models of transactional sex in Swaziland. The process allowed us to build and validate emic scales of transactional sex, while identifying key informants for qualitative interviews within each model to contextualize women's experiences and risk perceptions. We used logistic and multinomial logistic regression models to measure associations with condom use and social status outcomes. Fieldwork was conducted between November 2013 and December 2014 in the Hhohho and Manzini regions. We identified three distinct models of transactional sex in Swaziland based on 124 Swazi women's emic valuation of what they hoped to receive in exchange for sex with their partners. In a clinic-based survey (n = 406), consensus model scales were more sensitive to condom use than the etic definition. Model consonance had distinct effects on social status for the three different models. Transactional sex is better measured as an emic spectrum of expectations within a relationship, rather than an etic binary relationship type. Cultural consensus models allowed us to blend qualitative and quantitative approaches to create an emicly valid quantitative scale grounded in qualitative context. Copyright © 2015 Elsevier Ltd. All rights reserved.
Nuttbrock, Larry A; Hwahng, Sel J
2017-12-01
In conjunction with a 3-year prospective study of 199 transgender women from the New York City Area, we attempted to better understand why non-Whites are much more likely than Whites to become HIV infected. We first assessed associations of ethnicity with sex work, sexual risk behavior for HIV, and biologically-determined HIV/STI, and then assessed the extent to which these ethnic differences are explained by socioeconomic factors, immigration status, and sexual orientation. Statistical techniques included generalized estimating equations and Cox proportional hazards. As expected, compared to Whites, Blacks and Hispanics were more involved in the sex trade, more likely to report unprotected receptive anal intercourse, and as a result, more likely to become HIV/STI infected. All of these associations were mediated by androphilia, and to a lesser extent androphilia/gynephilia. Sexual orientation is a significant but little recognized factors associated with new cases of HIV/STI among transgender women of color.
Contaminated and uncontaminated feeding influence perceived intimacy in mixed-sex dyads.
Alley, Thomas R
2012-06-01
It was expected that viewers watching adult mixed-sex pairs dining together will give higher ratings of the perceived intimacy and involvement of the pair if feeding is displayed while eating, especially if the feeding involves contaminated (i.e., with potential germ transfer) foods. Our hypotheses were tested using a design in which participants viewed five videotapes in varying order. Each video showed different mixed-sex pairs of actors sharing meal and included a distinct form of food sharing or none. These were shown to 50 small groups of young adults in quasi-random sequences to control for order effects. Immediately after each video, viewers were asked about the attractiveness, attraction and intimacy in the dyad they had just observed. As predicted, videos featuring contaminated feeding consistently produced higher ratings on involvement and attraction than those showing uncontaminated feeding which, in turn, mostly produced higher ratings on involvement and attraction than those showing no feeding behaviors. Copyright © 2012 Elsevier Ltd. All rights reserved.
Preferences, constraints, and the process of sex segregation in college majors: A choice analysis.
Ochsenfeld, Fabian
2016-03-01
The persistence of horizontal sex segregation in higher education continues to puzzle social scientists. To help resolve this puzzle, we analyze a sample of college entrants in Germany with a discrete choice design that allows for social learning from the experiences of others. We make at least two contributions to the state of research. First, we test whether essentialist gender stereotypes affect major selection mostly through internalization or rather as external constraints that high school graduates adapt their behavior to. Empirically, we find that internalized vocational interests better explain gendered major choices than conformance with friends' and parents' expectations does. Second, we scrutinize whether segregation results from women's anticipation of gendered family roles or from their anticipation of sex-based discrimination, but we find no evidence for either of these hypotheses. As in most previous studies, differences in mathematics achievement fail to explain gendered patterns of selection into college majors. Copyright © 2016 Elsevier Inc. All rights reserved.
Bigdeli, Shoaleh; Pakpour, Vahid; Aalaa, Maryam; Shekarabi, Robabeh; Sanjari, Mahnaz; Haghani, Hamid; Mehrdad, Neda
2015-01-01
Background: Educational clinical environment has an important role in nursing students' learning. Any difference between actual and expected clinical environment will decrease nursing students’ interest in clinical environments and has a negative correlation with their clinical performance. Methods: This descriptive cross-sectional study is an attempt to compare nursing students' perception of the actual and expected status of clinical environments in medical-surgical wards. Participants of the study were 127 bachelor nursing students of Iran University of Medical Sciences in the internship period. Data gathering instruments were a demographic questionnaire (including sex, age, and grade point average), and the Clinical Learning Environment Inventory (CLEI) originally developed by Professor Chan (2001), in which its modified Farsi version (Actual and Preferred forms) consisting 42 items, 6 scales and 7 items per scale was used. Descriptive and inferential statistics (t-test, paired t-test, ANOVA) were used for data analysis through SPSS version 16. Results: The results indicated that there were significant differences between the preferred and actual form in all six scales. In other word, comparing with the actual form, the mean scores of all items in the preferred form were higher. The maximum mean difference was in innovation and the highest mean difference was in involvement scale. Conclusion: It is concluded that nursing students do not have a positive perception of their actual clinical teaching environment and this perception is significantly different from their perception of their expected environment. PMID:26034726
2017-09-16
Detailed assessments of mortality patterns, particularly age-specific mortality, represent a crucial input that enables health systems to target interventions to specific populations. Understanding how all-cause mortality has changed with respect to development status can identify exemplars for best practice. To accomplish this, the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) estimated age-specific and sex-specific all-cause mortality between 1970 and 2016 for 195 countries and territories and at the subnational level for the five countries with a population greater than 200 million in 2016. We have evaluated how well civil registration systems captured deaths using a set of demographic methods called death distribution methods for adults and from consideration of survey and census data for children younger than 5 years. We generated an overall assessment of completeness of registration of deaths by dividing registered deaths in each location-year by our estimate of all-age deaths generated from our overall estimation process. For 163 locations, including subnational units in countries with a population greater than 200 million with complete vital registration (VR) systems, our estimates were largely driven by the observed data, with corrections for small fluctuations in numbers and estimation for recent years where there were lags in data reporting (lags were variable by location, generally between 1 year and 6 years). For other locations, we took advantage of different data sources available to measure under-5 mortality rates (U5MR) using complete birth histories, summary birth histories, and incomplete VR with adjustments; we measured adult mortality rate (the probability of death in individuals aged 15-60 years) using adjusted incomplete VR, sibling histories, and household death recall. We used the U5MR and adult mortality rate, together with crude death rate due to HIV in the GBD model life table system, to estimate age-specific and sex-specific death rates for each location-year. Using various international databases, we identified fatal discontinuities, which we defined as increases in the death rate of more than one death per million, resulting from conflict and terrorism, natural disasters, major transport or technological accidents, and a subset of epidemic infectious diseases; these were added to estimates in the relevant years. In 47 countries with an identified peak adult prevalence for HIV/AIDS of more than 0·5% and where VR systems were less than 65% complete, we informed our estimates of age-sex-specific mortality using the Estimation and Projection Package (EPP)-Spectrum model fitted to national HIV/AIDS prevalence surveys and antenatal clinic serosurveillance systems. We estimated stillbirths, early neonatal, late neonatal, and childhood mortality using both survey and VR data in spatiotemporal Gaussian process regression models. We estimated abridged life tables for all location-years using age-specific death rates. We grouped locations into development quintiles based on the Socio-demographic Index (SDI) and analysed mortality trends by quintile. Using spline regression, we estimated the expected mortality rate for each age-sex group as a function of SDI. We identified countries with higher life expectancy than expected by comparing observed life expectancy to anticipated life expectancy on the basis of development status alone. Completeness in the registration of deaths increased from 28% in 1970 to a peak of 45% in 2013; completeness was lower after 2013 because of lags in reporting. Total deaths in children younger than 5 years decreased from 1970 to 2016, and slower decreases occurred at ages 5-24 years. By contrast, numbers of adult deaths increased in each 5-year age bracket above the age of 25 years. The distribution of annualised rates of change in age-specific mortality rate differed over the period 2000 to 2016 compared with earlier decades: increasing annualised rates of change were less frequent, although rising annualised rates of change still occurred in some locations, particularly for adolescent and younger adult age groups. Rates of stillbirths and under-5 mortality both decreased globally from 1970. Evidence for global convergence of death rates was mixed; although the absolute difference between age-standardised death rates narrowed between countries at the lowest and highest levels of SDI, the ratio of these death rates-a measure of relative inequality-increased slightly. There was a strong shift between 1970 and 2016 toward higher life expectancy, most noticeably at higher levels of SDI. Among countries with populations greater than 1 million in 2016, life expectancy at birth was highest for women in Japan, at 86·9 years (95% UI 86·7-87·2), and for men in Singapore, at 81·3 years (78·8-83·7) in 2016. Male life expectancy was generally lower than female life expectancy between 1970 and 2016, and the gap between male and female life expectancy increased with progression to higher levels of SDI. Some countries with exceptional health performance in 1990 in terms of the difference in observed to expected life expectancy at birth had slower progress on the same measure in 2016. Globally, mortality rates have decreased across all age groups over the past five decades, with the largest improvements occurring among children younger than 5 years. However, at the national level, considerable heterogeneity remains in terms of both level and rate of changes in age-specific mortality; increases in mortality for certain age groups occurred in some locations. We found evidence that the absolute gap between countries in age-specific death rates has declined, although the relative gap for some age-sex groups increased. Countries that now lead in terms of having higher observed life expectancy than that expected on the basis of development alone, or locations that have either increased this advantage or rapidly decreased the deficit from expected levels, could provide insight into the means to accelerate progress in nations where progress has stalled. Bill & Melinda Gates Foundation, and the National Institute on Aging and the National Institute of Mental Health of the National Institutes of Health. Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.
Bor, Jacob; Rosen, Sydney; Chimbindi, Natsayi; Haber, Noah; Herbst, Kobus; Mutevedzi, Tinofa; Tanser, Frank; Pillay, Deenan; Bärnighausen, Till
2015-01-01
Background Women have better patient outcomes in HIV care and treatment than men in sub-Saharan Africa. We assessed—at the population level—whether and to what extent mass HIV treatment is associated with changes in sex disparities in adult life expectancy, a summary metric of survival capturing mortality across the full cascade of HIV care. We also determined sex-specific trends in HIV mortality and the distribution of HIV-related deaths in men and women prior to and at each stage of the clinical cascade. Methods and Findings Data were collected on all deaths occurring from 2001 to 2011 in a large population-based surveillance cohort (52,964 women and 45,688 men, ages 15 y and older) in rural KwaZulu-Natal, South Africa. Cause of death was ascertained by verbal autopsy (93% response rate). Demographic data were linked at the individual level to clinical records from the public sector HIV treatment and care program that serves the region. Annual rates of HIV-related mortality were assessed for men and women separately, and female-to-male rate ratios were estimated in exponential hazard models. Sex-specific trends in adult life expectancy and HIV-cause-deleted adult life expectancy were calculated. The proportions of HIV deaths that accrued to men and women at different stages in the HIV cascade of care were estimated annually. Following the beginning of HIV treatment scale-up in 2004, HIV mortality declined among both men and women. Female adult life expectancy increased from 51.3 y (95% CI 49.7, 52.8) in 2003 to 64.5 y (95% CI 62.7, 66.4) in 2011, a gain of 13.2 y. Male adult life expectancy increased from 46.9 y (95% CI 45.6, 48.2) in 2003 to 55.9 y (95% CI 54.3, 57.5) in 2011, a gain of 9.0 y. The gap between female and male adult life expectancy doubled, from 4.4 y in 2003 to 8.6 y in 2011, a difference of 4.3 y (95% CI 0.9, 7.6). For women, HIV mortality declined from 1.60 deaths per 100 person-years (95% CI 1.46, 1.75) in 2003 to 0.56 per 100 person-years (95% CI 0.48, 0.65) in 2011. For men, HIV-related mortality declined from 1.71 per 100 person-years (95% CI 1.55, 1.88) to 0.76 per 100 person-years (95% CI 0.67, 0.87) in the same period. The female-to-male rate ratio for HIV mortality declined from 0.93 (95% CI 0.82–1.07) in 2003 to 0.73 (95% CI 0.60–0.89) in 2011, a statistically significant decline (p = 0.046). In 2011, 57% and 41% of HIV-related deaths occurred among men and women, respectively, who had never sought care for HIV in spite of the widespread availability of free HIV treatment. The results presented here come from a poor rural setting in southern Africa with high HIV prevalence and high HIV treatment coverage; broader generalizability is unknown. Additionally, factors other than HIV treatment scale-up may have influenced population mortality trends. Conclusions Mass HIV treatment has been accompanied by faster declines in HIV mortality among women than men and a growing female–male disparity in adult life expectancy at the population level. In 2011, over half of male HIV deaths occurred in men who had never sought clinical HIV care. Interventions to increase HIV testing and linkage to care among men are urgently needed. PMID:26599699
Losing ground--Swedish life expectancy in a comparative perspective.
Drefahl, Sven; Ahlbom, Anders; Modig, Karin
2014-01-01
In the beginning of the 1970s, Sweden was the country where both women and men enjoyed the world's longest life expectancy. While life expectancy continues to be high and increasing, Sweden has been losing ground in relation to other leading countries. We look at life expectancy over the years 1970-2008 for men and women. To assess the relative contributions of age, causes of death, and smoking we decompose differences in life expectancy between Sweden and two leading countries, Japan and France. This study is the first to use this decomposition method to observe how smoking related deaths contribute to life expectancy differences between countries. Sweden has maintained very low mortality at young and working ages for both men and women compared to France and Japan. However, mortality at ages above 65 has become considerably higher in Sweden than in the other leading countries because the decrease has been faster in those countries. Different trends for circulatory diseases were the largest contributor to this development in both sexes but for women also cancer played a role. Mortality from neoplasms has been considerably low for Swedish men. Smoking attributable mortality plays a modest role for women, whereas it is substantially lower in Swedish men than in French and Japanese men. Sweden is losing ground in relation to other leading countries with respect to life expectancy because mortality at high ages improves more slowly than in the leading countries, especially due to trends in cardiovascular disease mortality. Trends in smoking rates may provide a partial explanation for the trends in women; however, it is not possible to isolate one single explanatory factor for why Sweden is losing ground.
Do differences in female sex hormone levels contribute to gastro-oesophageal reflux disease?
Menon, Shyam; Prew, Sandra; Parkes, Gill; Evans, Stephanie; Smith, Lynne; Nightingale, Peter; Trudgill, Nigel
2013-07-01
Hormone replacement therapy is associated with both reflux symptoms and oesophagitis. During pregnancy, elevated sex hormones are thought to contribute to the high prevalence of reflux symptoms. Increased female sex hormone levels may thus contribute to the aetiology of gastro-oesophageal reflux disease (GORD). To determine if female sex hormone levels are associated with symptomatic acid reflux. Women with GORD symptoms undergoing oesophageal pH monitoring were prospectively recruited. 'Cases' and 'controls' were defined by normal and excess total acid exposure on pH monitoring and were age-matched and BMI-matched. Case and control groups were further stratified into premenopausal and postmenopausal groups. Demographic data were collected, body morphological parameters were measured and oestradiol, oestrone, progesterone and sex hormone-binding globulin were measured. One hundred and twenty-one women [mean age 52 (SD 11.6) years] were recruited and 104 [mean age 51 (SD 11.6) years] were matched for age and BMI. Increasing BMI, as expected, correlated with increasing acid exposure [premenopausal (r=0.404, P=0.02), postmenopausal (r=0.401, P=0.01)]. Increasing BMI also correlated with sex hormone levels [premenopausal oestradiol (r=0.52, P=0.004), postmenopausal oestrone (r=0.364, P=0.01)]. In premenopausal women, sex hormone binding globulin (r=-0.27, P=0.05) and testosterone (r=0.29, P=0.05) correlated with increasing acid exposure, but oestradiol fell just short of significance (r=0.26, P=0.06). However, on matching for BMI, no association between sex hormones and increased acid exposure on pH monitoring was found on multivariate logistic regression analysis. Female sex hormone levels do not appear to contribute to GORD, once adjustment is made for the influence of increasing BMI.
ERIC Educational Resources Information Center
Bear, Sheryl; And Others
1979-01-01
While the impact of the women's movement has made therapists more sensitive to societal influences on the behavior of women, comparable attention has not been paid to men who violate stereotypical sex-role expectations. (Author)
Legal Challenges to Single-Sex Colleges Expected to Spread.
ERIC Educational Resources Information Center
Jaschik, Scott
1990-01-01
Court cases arising out of the current legal and political controversy over the Virginia Military Institute's policy of admitting only men are examined as they apply to the nation's three other publicly supported single-sex colleges: the Citadel (South Carolina), Mississippi University for Women, and Texas Woman's University. (DB)
Examinations of Home Economics Textbooks for Sex Bias.
ERIC Educational Resources Information Center
Weis, Susan F.
1979-01-01
Four analyses were conducted on a sample of 100 randomly selected, secondary home economics textbooks published between 1964 and 1974. Results indicated that the contents presented sex bias in language usage, in pictures portraying male and female role environments, and in role behaviors and expectations emphasized. (Author/JH)
Sexism in the Schools: A Handbook for Action.
ERIC Educational Resources Information Center
Rothchild, Nina
This handbook was written for readers aware of and concerned about the sex bias in public schools in the areas of athletic budgets, sex stereotyping in children's books, differential expectations in classroom behavior, counseling attitudes and practices, school personnel assignments, and the impact of defining stereotyped roles to boys and girls…
Attitudes and Expectations about Children with Nontraditional and Traditional Gender Roles.
ERIC Educational Resources Information Center
Martin, Carol Lynn
1990-01-01
Eighty male and female students at the University of British Columbia responded to a questionnaire on the acceptability of cross-sex behavior in children. Effeminate boys were viewed more negatively than masculine girls. Discusses the reasons for this distinction, and the consequences of cross-sex behavior. (DM)
Impressions of Counselors as a Function of Counselor Physical Attractiveness
ERIC Educational Resources Information Center
Carter, Jean A.
1978-01-01
Research assessed the effects of counselor physical attractiveness and inter-actions between attractiveness and counselor subject sex. It is suggested that sex of counselor and client may play a more important role independently and in conjunction with attractiveness than does attractiveness alone in influencing impressions and expectations.…
Work Activities and Compensation of Male and Female Cardiologists.
Jagsi, Reshma; Biga, Cathie; Poppas, Athena; Rodgers, George P; Walsh, Mary N; White, Patrick J; McKendry, Colleen; Sasson, Joseph; Schulte, Phillip J; Douglas, Pamela S
2016-02-09
Much remains unknown about experiences, including working activities and pay, of women in cardiology, which is a predominantly male specialty. The goal of this study was to describe the working activities and pay of female cardiologists compared with their male colleagues and to determine whether sex differences in compensation exist after accounting for differences in work activities and other characteristics. The personal, job, and practice characteristics of a national sample of practicing cardiologists were described according to sex. We applied the Peters-Belson technique and multivariate regression analysis to evaluate whether gender differences in compensation existed after accounting for differences in other measured characteristics. The study used 2013 data reported by practice administrators to MedAxiom, a subscription-based service provider to cardiology practices. Data regarding cardiologists from 161 U.S. practices were included, and the study sample included 2,679 subjects (229 women and 2,450 men). Women were more likely to be specialized in general/noninvasive cardiology (53.1% vs. 28.2%), and a lower proportion (11.4% vs. 39.3%) reported an interventional subspecialty compared with men. Job characteristics that differed according to sex included the proportion working full-time (79.9% vs. 90.9%; p < 0.001), the mean number of half-days worked (387 vs. 406 days; p = 0.001), and mean work relative value units generated (7,404 vs. 9,497; p < 0.001) for women and men, respectively. Peters-Belson analysis revealed that based on measured job and productivity characteristics, the women in this sample would have been expected to have a mean salary that was $31,749 (95% confidence interval: $16,303 to $48,028) higher than that actually observed. Multivariate analysis confirmed the direction and magnitude of the independent association between sex and salary. Men and women practicing cardiology in this national sample had different job activities and salaries. Substantial sex-based salary differences existed even after adjusting for measures of personal, job, and practice characteristics. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Sexual imprinting: what strategies should we expect to see in nature?
Chaffee, Dalton W; Griffin, Hayes; Gilman, R Tucker
2013-12-01
Sexual imprinting occurs when juveniles learn mate preferences by observing the phenotypes of other members of their populations, and it is ubiquitous in nature. Imprinting strategies, that is which individuals and phenotypes are observed and how strong preferences become, vary among species. Imprinting can affect trait evolution and the probability of speciation, and different imprinting strategies are expected to have different effects. However, little is known about how and why different imprinting strategies evolve, or which strategies we should expect to see in nature. We used a mathematical model to study how the evolution of sexual imprinting depends on (1) imprinting costs and (2) the sex-specific fitness effects of the phenotype on which individuals imprint. We found that even small fixed costs prevent the evolution of sexual imprinting, but small relative costs do not. When imprinting does evolve, we identified the conditions under which females should evolve to imprint on their fathers, their mothers, or on other members of their populations. Our results provide testable hypotheses for empirical work and help to explain the conditions under which sexual imprinting might evolve to promote speciation. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.
Birth of kids after artificial insemination with sex-sorted, frozen-thawed goat spermatozoa.
Bathgate, R; Mace, N; Heasman, K; Evans, G; Maxwell, W M C; de Graaf, S P
2013-12-01
Successful sex-sorting of goat spermatozoa and subsequent birth of pre-sexed kids have yet to be reported. As such, a series of experiments were conducted to develop protocols for sperm-sorting (using a modified flow cytometer, MoFlo SX(®) ) and cryopreservation of goat spermatozoa. Saanen goat spermatozoa (n = 2 males) were (i) collected into Salamon's or Tris catch media post-sorting and (ii) frozen in Tris-citrate-glucose media supplemented with 5, 10 or 20% egg yolk in (iii) 0.25 ml pellets on dry ice or 0.25 ml straws in a controlled-rate freezer. Post-sort and post-thaw sperm quality were assessed by motility (CASA), viability and acrosome integrity (PI/FITC-PNA). Sex-sorted goat spermatozoa frozen in pellets displayed significantly higher post-thaw motility and viability than spermatozoa frozen in straws. Catch media and differing egg yolk concentration had no effect on the sperm parameters tested. The in vitro and in vivo fertility of sex-sorted goat spermatozoa produced with this optimum protocol were then tested by means of a heterologous ova binding assay and intrauterine artificial insemination of Saanen goat does, respectively. Sex-sorted goat spermatozoa bound to sheep ova zona pellucidae in similar numbers (p > 0.05) to non-sorted goat spermatozoa, non-sorted ram spermatozoa and sex-sorted ram spermatozoa. Following intrauterine artificial insemination with sex-sorted spermatozoa, 38% (5/13) of does kidded with 83% (3/5) of kids being of the expected sex. Does inseminated with non-sorted spermatozoa achieved a 50% (3/6) kidding rate and a sex ratio of 3 : 1 (F : M). This study demonstrates for the first time that goat spermatozoa can be sex-sorted by flow cytometry, successfully frozen and used to produce pre-sexed kids. © 2013 Blackwell Verlag GmbH.
Thin-plate spline analysis of allometry and sexual dimorphism in the human craniofacial complex.
Rosas, Antonio; Bastir, Markus
2002-03-01
The relationship between allometry and sexual dimorphism in the human craniofacial complex was analyzed using geometric morphometric methods. Thin-plate splines (TPS) analysis has been applied to investigate the lateral profile of complete adult skulls of known sex. Twenty-nine three-dimensional (3D) craniofacial and mandibular landmark coordinates were recorded from a sample of 52 adult females and 52 adult males of known age and sex. No difference in the influence of size on shape was detected between sexes. Both size and sex had significant influences on shape. As expected, the influence of centroid size on shape (allometry) revealed a shift in the proportions of the neurocranium and the viscerocranium, with a marked allometric variation of the lower face. Adjusted for centroid size, males presented a relatively larger size of the nasopharyngeal space than females. A mean-male TPS transformation revealed a larger piriform aperture, achieved by an increase of the angulation of the nasal bones and a downward rotation of the anterior nasal floor. Male pharynx expansion was also reflected by larger choanae and a more posteriorly inclined basilar part of the occipital clivus. Male muscle attachment sites appeared more pronounced. In contrast, the mean-female TPS transformation was characterized by a relatively small nasal aperture. The occipital clivus inclined anteriorly, and muscle insertion areas became smoothed. Besides these variations, both maxillary and mandibular alveolar regions became prognathic. The sex-specific TPS deformation patterns are hypothesized to be associated with sexual differences in body composition and energetic requirements. Copyright 2002 Wiley-Liss, Inc.
Prenatal Testosterone Programming of Insulin Resistance in the Female Sheep.
Puttabyatappa, Muraly; Padmanabhan, Vasantha
2017-01-01
Insulin resistance, a common feature of metabolic disorders such as obesity, nonalcoholic fatty liver disease, metabolic syndrome, and polycystic ovary syndrome, is a risk factor for development of diabetes. Because sex hormones orchestrate the establishment of sex-specific behavioral, reproductive, and metabolic differences, a role for them in the developmental origin of insulin resistance is also to be expected. Female sheep exposed to male levels of testosterone during fetal life serve as an excellent translational model for delineating programming of insulin resistance. This chapter summarizes the ontogeny of insulin resistance, the tissue-specific changes in insulin sensitivity, and the various factors that are involved in the programming and maintenance of the insulin resistance in adult female sheep that were developmentally exposed to fetal male levels of testosterone during the sexual-differentiation window.
Rehearsing decisions may help teenagers: an evaluation of a simulation game.
Alemi, F; Cherry, F; Meffert, G
1989-01-01
This paper presents a new approach to preventing adolescent pregnancy. Information alone is not sufficient to prevent teenage pregnancy. The teenagers ability to choose and remain committed to a decision also needs to be developed. Because decision making skills are best learned through practice in an environment with frequent feedback, we have developed a computer game which simulates the consequences of different sexual roles. In addition, the game is intended to increase communication about sex between teenagers and their role models (peers, teachers and/or parents). Increased communication is expected to reduce the feeling of guilt and lead to either consistent abstention from sex or consistent contraceptive use. The paper reports on the development of the computer game and the preliminary evaluation of its impact.
Survival rates among Seventh Day Adventists compared with the general population in Poland.
Jedrychowski, W; Tobiasz-Adamczyk, B; Olma, A; Gradzikiewicz, P
1985-01-01
The purpose of the work was to test the hypothesis that the survival rate is higher among the Seventh Day Adventists (SDA) than in the general population of Poland, because of the strictly respected customs adhered to by members of this church community, such as abstinence from smoking and from alcohol. The data on life expectancy in the SDA community covered a total of 236 members of this denomination in Kraków (86 males and 150 females). The survival probability rates were estimated by the life table method, for both men and women separately, and were subsequently compared with the corresponding parameters of the Polish Life Tables. Over a period of 10 years, in which these data were studied, there were 11 deaths in males and 24 deaths in females. Mean age at death was 71.9 years among men and 75.1 among women. The survival curves traced over the age groups of both sexes of SDA members were fairly similar, but they were markedly higher than in the general population of Poland. In the general population the survival rates for people over 40 years old were higher in females than in males, whereas no corresponding sex differences in rates concerning SDA members were observed. The greater benefit in life expectancy is gained in the SDA group in comparison with men in the general population. This is attributable to their abstinence from very harmful habits, otherwise more widespread in this sex group.
Sex-specific life history responses to nymphal diet quality and immune status in a field cricket.
Kelly, C D; Neyer, A A; Gress, B E
2014-02-01
Individual fitness is expected to benefit from earlier maturation at a larger body size and higher body condition. However, poor nutritional quality or high prevalence of disease make this difficult because individuals either cannot acquire sufficient resources or must divert resources to other fitness-related traits such as immunity. Under such conditions, individuals are expected to mature later at a smaller body size and in poorer body condition. Moreover, the juvenile environment can also produce longer-term effects on adult fitness by causing shifts in resource allocation strategies that could alter investment in immune function and affect adult lifespan. We manipulated diet quality and immune status of juvenile Texas field crickets, Gryllus texensis, to investigate how poor developmental conditions affect sex-specific investment in fitness-related traits. As predicted, a poor juvenile diet was related to smaller mass and body size at eclosion in both sexes. However, our results also reveal sexually dimorphic responses to different facets of the rearing environment: female life history decisions are affected more by diet quality, whereas males are affected more by immune status. We suggest that females respond to decreased nutritional income because this threatens their ability to achieve a large adult body size, whereas male fitness is more dependent on reaching adulthood and so they invest in immunity and survival to eclosion. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.
Juvenile social relationships reflect adult patterns of behavior in wild geladas.
Barale, Caitlin L; Rubenstein, Daniel I; Beehner, Jacinta C
2015-10-01
Unlike many mammals, primates spend much of their lives as reproductively-immature juveniles. During the juvenile period, they develop social relationships and physical skills that both facilitate survival to adulthood and impact adult fitness. In this study, we use 2 years of observational data to examine the development of these skills across the juvenile period in a wild cercopithecine primate, the gelada (Theropithecus gelada). As adults, male and female geladas require different skills to be successful; we therefore expected sex differences in social behavior and partner choice during the juvenile period to already reflect these sex-specific trajectories. For example, males, who disperse at puberty and ultimately must challenge other adult males for access to mates, should invest in high-energy play-fighting with other males to develop fighting and rival assessment skills. In contrast, philopatric females, who remain with their close kin throughout their lives, should invest more in forming less-physical and more-social bonds with other females within their group. As predicted, sex differences that foreshadowed sex-specific adult roles were apparent in play rates, the average number of play partners per individual, grooming partner types and social partner preferences. Males played more and had more play partners than same-age females. Males also groomed more often with individuals from outside their natal group than females, although no sex difference was observed in either grooming rates or number of grooming partners per individual. Females stopped playing earlier than males, and instead invested in grooming relationships with close relatives. Additionally, we found that individual play and grooming rates were temporally consistent for both males and females (i.e., from one year to the next year), suggesting that individuals exhibit stable behavioral phenotypes. We conclude by discussing how early life in geladas may shape adult behavior and reproductive strategies. © 2015 Wiley Periodicals, Inc.
Contrasting responses of male and female foraging effort to year-round wind conditions.
Lewis, Sue; Phillips, Richard A; Burthe, Sarah J; Wanless, Sarah; Daunt, Francis
2015-11-01
There is growing interest in the effects of wind on wild animals, given evidence that wind speeds are increasing and becoming more variable in some regions, particularly at temperate latitudes. Wind may alter movement patterns or foraging ability, with consequences for energy budgets and, ultimately, demographic rates. These effects are expected to vary among individuals due to intrinsic factors such as sex, age or feeding proficiency. Furthermore, this variation is predicted to become more marked as wind conditions deteriorate, which may have profound consequences for population dynamics as the climate changes. However, the interaction between wind and intrinsic effects has not been comprehensively tested. In many species, in particular those showing sexual size dimorphism, males and females vary in foraging performance. Here, we undertook year-round deployments of data loggers to test for interactions between sex and wind speed and direction on foraging effort in adult European shags Phalacrocorax aristotelis, a pursuit-diving seabird in which males are c. 18% heavier. We found that foraging time was lower at high wind speeds but higher during easterly (onshore) winds. Furthermore, there was an interaction between sex and wind conditions on foraging effort, such that females foraged for longer than males when winds were of greater strength (9% difference at high wind speeds vs. 1% at low wind speeds) and when winds were easterly compared with westerly (7% and 4% difference, respectively). The results supported our prediction that sex-specific differences in foraging effort would become more marked as wind conditions worsen. Since foraging time is linked to demographic rates in this species, our findings are likely to have important consequences for population dynamics by amplifying sex-specific differences in survival rates. © 2015 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of the British Ecological Society.
26 CFR 1.72-5 - Expected return.
Code of Federal Regulations, 2010 CFR
2010-04-01
...) of § 1.72-9 under the age (as of the annuity starting date) and, if applicable, sex of the measuring... case the date of purchase), the annuitant's age at his nearest birthday is 66, the expected return is... Table I, male, age 66 14.4 Expected return (1,200×14.4) 17,280 If, however, the taxpayer had purchased...
Weekes, Carmon V N; Haas, Barbara K; Gosselin, Kevin P
2014-01-01
Despite research that suggests parental communication may help deter high-risk sexual behavior among adolescents, parents report a lack of confidence in their ability to answer sexually related questions. The purpose of this study was to test the effect of a multimedia intervention on outcome expectations and perceived self-efficacy for the sex educator role for parents of African American adolescent males. A pilot study using mixed methods was conducted. A nonprobability sample (N = 61) was obtained from a large urban community using a combination of convenience and snowball recruitment methods. Self-efficacy and outcome expectations were measured using self-reported questionnaires. A multimedia intervention for use at home and incorporating an audio CD and associated activities was implemented over a 3-week time period. Outcome expectations and self-efficacy both significantly improved after the intervention (p < .001). Findings indicate that using a multimedia approach may be effective in improving parents' outcome expectancy and self-efficacy for talking about sex with adolescent sons. © 2013 Wiley Periodicals, Inc.
Sex-Related Neuroanatomical Basis of Emotion Regulation Ability
Li, Jingguang; Huang, Lijie; Wang, Xu; Song, Yiying; Liu, Jia
2014-01-01
Behavioral research has demonstrated that males have a higher capability of regulating their own and others' emotions than females; however, little is known about the sex-specific brain mechanisms involved in emotion regulation ability. In the present study, we used voxel-based morphometry to investigate the neural basis underlying emotion regulation ability in a large sample of young adults. Assessment of emotion regulation ability was performed using the Wong and Law Emotional Intelligence Scale. As expected, males significantly scored higher in emotion regulation ability than females did. More importantly, we found the sex differences in the neuroanatomical basis of emotion regulation ability. Males showed a stronger positive relation between emotion regulation ability and regional gray matter volume (rGMV) in the right dorsolateral prefrontal cortex. In contrast, females demonstrated a stronger positive relation between emotion regulation ability and rGMV in an anatomical cluster that extends from the left brainstem to the left hippocampus, the left amygdala and the insular cortex. The present study provides the first empirical evidence regarding the sex-linked neuroanatomical correlates of emotion regulation ability. These findings may help understand why there is a higher prevalence of affective disorders in females and maladaptive behaviors in males. PMID:24835267
Sex-related neuroanatomical basis of emotion regulation ability.
Kong, Feng; Zhen, Zonglei; Li, Jingguang; Huang, Lijie; Wang, Xu; Song, Yiying; Liu, Jia
2014-01-01
Behavioral research has demonstrated that males have a higher capability of regulating their own and others' emotions than females; however, little is known about the sex-specific brain mechanisms involved in emotion regulation ability. In the present study, we used voxel-based morphometry to investigate the neural basis underlying emotion regulation ability in a large sample of young adults. Assessment of emotion regulation ability was performed using the Wong and Law Emotional Intelligence Scale. As expected, males significantly scored higher in emotion regulation ability than females did. More importantly, we found the sex differences in the neuroanatomical basis of emotion regulation ability. Males showed a stronger positive relation between emotion regulation ability and regional gray matter volume (rGMV) in the right dorsolateral prefrontal cortex. In contrast, females demonstrated a stronger positive relation between emotion regulation ability and rGMV in an anatomical cluster that extends from the left brainstem to the left hippocampus, the left amygdala and the insular cortex. The present study provides the first empirical evidence regarding the sex-linked neuroanatomical correlates of emotion regulation ability. These findings may help understand why there is a higher prevalence of affective disorders in females and maladaptive behaviors in males.
Shuper, Paul A; Joharchi, Narges; Rehm, Jürgen
2016-01-01
Although alcohol consumption is frequently perceived as a driver of condomless sex and subsequent HIV acquisition, the causal nature of this relationship remains unclear, and little is known about alcohol's direct versus indirect impact on the sexual risk dynamics of those who are HIV-positive. To address this gap, we present the protocol for an in-progress NIAAA-funded controlled experiment, wherein a sample of HIV-positive men-who-have-sex-with-men (MSM) undergoes an alcohol consumption manipulation (alcohol/placebo/control) and sexual arousal induction (sexually aroused/non-aroused), and then reports intentions to engage in condom-protected and condomless sexual acts with hypothetical sexual partners differing in HIV serostatus (HIV+/HIV-/HIV status unknown), condom use preference (use/don't use/not stated), and physical attractiveness (attractive/unattractive). Study outcomes will identify alcohol's impact on HIV-positive MSM's condomless sex intentions in the context of experimentally-manipulated factors as well as risk-relevant personality traits and alcohol-related expectancies. Detailed experimental procedures, ethical considerations, and potential implications for HIV prevention are discussed.
Hoffman, Jessica M; Soltow, Quinlyn A; Li, Shuzhao; Sidik, Alfire; Jones, Dean P; Promislow, Daniel E L
2014-01-01
Researchers have used whole-genome sequencing and gene expression profiling to identify genes associated with age, in the hope of understanding the underlying mechanisms of senescence. But there is a substantial gap from variation in gene sequences and expression levels to variation in age or life expectancy. In an attempt to bridge this gap, here we describe the effects of age, sex, genotype, and their interactions on high-sensitivity metabolomic profiles in the fruit fly, Drosophila melanogaster. Among the 6800 features analyzed, we found that over one-quarter of all metabolites were significantly associated with age, sex, genotype, or their interactions, and multivariate analysis shows that individual metabolomic profiles are highly predictive of these traits. Using a metabolomic equivalent of gene set enrichment analysis, we identified numerous metabolic pathways that were enriched among metabolites associated with age, sex, and genotype, including pathways involving sugar and glycerophospholipid metabolism, neurotransmitters, amino acids, and the carnitine shuttle. Our results suggest that high-sensitivity metabolomic studies have excellent potential not only to reveal mechanisms that lead to senescence, but also to help us understand differences in patterns of aging among genotypes and between males and females. PMID:24636523
Garcia Diaz, Virginia; Aisenberg, Anita; Peretti, Alfredo V
2015-07-01
Traditional studies on sexual communication have focused on the exchange of signals during courtship. However, communication between the sexes can also occur during or after copulation. Allocosa brasiliensis is a wolf spider that shows a reversal in typical sex roles and of the usual sexual size dimorphism expected for spiders. Females are smaller than males and they are the roving sex that initiates courtship. Occasional previous observations suggested that females performed body shaking behaviors during copulation. Our objective was to analyze if female body shaking is associated with male copulatory behavior in A. brasiliensis, and determine if this female behavior has a communicatory function in this species. For that purpose, we performed fine-scaled analysis of fifteen copulations under laboratory conditions. We video-recorded all the trials and looked for associations between female and male copulatory behaviors. The significant difference between the time before and after female shaking, in favor of the subsequent ejaculation is analyzed. We discuss if shaking could be acting as a signal to accelerate and motivate palpal insertion and ejaculation, and/or inhibiting male cannibalistic tendencies in this species. Copyright © 2015 Elsevier B.V. All rights reserved.
Surie, Diya; Yuhas, Krista; Wilson, Kate; Masese, Linnet N; Shafi, Juma; Kinuthia, John; Jaoko, Walter; McClelland, R Scott
2017-01-01
As access to antiretroviral therapy in sub-Saharan Africa continues to expand, more women with HIV can expect to survive through their reproductive years. Modern contraceptives can help women choose the timing and spacing of childbearing. However, concerns remain that women with HIV who use non-barrier forms of modern contraception may engage in more condomless sex because of their decreased risk of unintended pregnancy. We examined whether non-barrier modern contraceptive use by HIV-positive female sex workers was associated with increased frequency of recent condomless sex, measured by detection of prostate-specific antigen (PSA) in vaginal secretions. Women who were HIV-positive and reported transactional sex were included in this analysis. Pregnant and post-menopausal follow-up time was excluded, as were visits at which women reported trying to get pregnant. At enrollment and quarterly follow-up visits, a pelvic speculum examination with collection of vaginal secretions was conducted for detection of PSA. In addition, women completed a structured face-to-face interview about their current contraceptive methods and sexual risk behavior at enrollment and monthly follow-up visits. Log-binomial generalized estimating equations regression was used to test for associations between non-barrier modern contraceptive use and detection of PSA in vaginal secretions and self-reported condomless sex. Data from October 2012 through September 2014 were included in this analysis. Overall, 314 women contributed 1,583 quarterly examination visits. There was minimal difference in PSA detection at contraceptive-exposed versus contraceptive-unexposed visits (adjusted relative risk [aRR] 1.28, 95% confidence interval [95% CI] 0.93-1.76). There was a higher rate of self-reported condomless sex at visits where women reported using modern contraceptives, but this difference was not statistically significant after adjustment for potential confounding factors (aRR 1.59, 95% CI 0.98-2.58). Non-barrier methods of modern contraception were not associated with increased risk of objective evidence of condomless sex.
Volkmann, Tyson; Wagner, Karla D.; Strathdee, Steffanie A.; Semple, Shirley J.; Ompad, Danielle C.; Chavarin, Claudia V.; Patterson, Thomas L.
2013-01-01
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 four 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. PMID:23842786
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.
Mills, S C; O'Donnell, J L; Bernardi, G; Beldade, R
2018-03-01
Group-living animals commonly display differences in behaviour, physiology and endocrine profiles between conspecifics within the group, which are tightly linked to reproduction. Teleosts exhibit a variety of social systems, where social status, as well as sex, has been linked to different androgen and oestrogen profiles. Levels of gonadal androgen and oestrogen were investigated as a function of sex and position in a social hierarchy in free-living individuals of the skunk anemonefish Amphiprion akallopisos, a protandrous pomacentrid fish with a size-based dominance hierarchical social system. Plasma levels of 11-ketotestosterone (11-KT), testosterone (T) and 17β-oestradiol (E 2 ), as well as conversion ratios from T, were measured by ELISA from 111 individuals along a linear hierarchy from 38 social groups in the wild. Blood plasma levels of 11-KT and E 2 showed sex differences, being higher in males and females respectively as expected based on their role as the major androgen and oestrogen in fish reproduction. However, no sex differences were found for T, which may represent its role in territorial defence or simply as a precursor for the synthesis of 11-KT and E 2 . In terms of the hierarchical social system within males, 11-KT levels decline as the hierarchy is descended, which may represent their decreasing reproductive opportunity, as well as the decreasing levels of aggression towards males lower in the hierarchy. In summary, the size-based dominance hierarchy is associated with distinct steroid levels of 11-KT and E 2 between individual free-living A. akallopisos that closely resemble those of species in which breeding individuals suppress reproduction of conspecifics lower in the hierarchy. © 2018 The Fisheries Society of the British Isles.
Treit, Sarah; Chen, Zhang; Zhou, Dongming; Baugh, Lauren; Rasmussen, Carmen; Andrew, Gail; Pei, Jacqueline; Beaulieu, Christian
2017-01-01
Quantitative magnetic resonance imaging (MRI) has revealed abnormalities in brain volumes, cortical thickness and white matter microstructure in fetal alcohol spectrum disorders (FASD); however, no study has reported all three measures within the same cohort to assess the relative magnitude of deficits, and few studies have examined sex differences. Participants with FASD (n = 70; 30 females; 5-32 years) and healthy controls (n = 74; 35 females; 5-32 years) underwent cognitive testing and MRI to assess cortical thickness, regional brain volumes and fractional anisotropy (FA)/mean diffusivity (MD) of white matter tracts. A significant effect of group, age-by-group, or sex-by-group was found for 9/9 volumes, 7/39 cortical thickness regions, 3/9 white matter tracts, and 9/10 cognitive tests, indicating group differences that in some cases differ by age or sex. Volume reductions for several structures were larger in males than females, despite similar deficits of cognition in both sexes. Correlations between brain structure and cognitive scores were found in females of both groups, but were notably absent in males. Correlations within a given MRI modality (e.g. total brain volume and caudate volume) were prevalent in both the control and FASD groups, and were more numerous than correlations between measurement types (e.g. volumes and diffusion tensor imaging) in either cohort. This multi-modal MRI study finds widespread differences of brain structure in participants with prenatal alcohol exposure, and to a greater extent in males than females which may suggest attenuation of the expected process of sexual dimorphism of brain structure during typical development.
Dickson, Laura B.; Campbell, Corey L.; Juneja, Punita; Jiggins, Francis M.; Sylla, Massamba; Black, William C.
2016-01-01
Aedes aegypti is one of the most studied mosquito species, and the principal vector of several arboviruses pathogenic to humans. Recently failure to oviposit, low fecundity, and poor egg-to-adult survival were observed when Ae. aegypti from Senegal (SenAae) West Africa were crossed with Ae. aegypti (Aaa) from outside of Africa, and in SenAae intercrosses. Fluorescent in situ hybridization analyses indicated rearrangements on chromosome 1, and pericentric inversions on chromosomes 2 and 3. Herein, high throughput sequencing (HTS) of exon-enriched libraries was used to compare chromosome-wide genetic diversity among Aaa collections from rural Thailand and Mexico, a sylvatic collection from southeastern Senegal (PK10), and an urban collection from western Senegal (Kaolack). Sex-specific polymorphisms were analyzed in Thailand and PK10 to assess genetic differences between sexes. Expected heterozygosity was greatest in SenAae. FST distributions of 15,735 genes among all six pairwise comparisons of the four collections indicated that Mexican and Thailand collections are genetically similar, while FST distributions between PK10 and Kaolack were distinct. All four comparisons of SenAae with Aaa indicated extreme differentiation. FST was uniform between sexes across all chromosomes in Thailand, but were different, especially on the sex autosome 1, in PK10. These patterns correlate with the reproductive isolation noted earlier. We hypothesize that cryptic Ae. aegypti taxa may exist in West Africa, and the large genic differences between Aaa and SenAae detected in the present study have accumulated over a long period following the evolution of chromosome rearrangements in allopatric populations that subsequently cause reproductive isolation when these populations became sympatric. PMID:28007834
Spatial interactions between sympatric carnivores: asymmetric avoidance of an intraguild predator
Grassel, Shaun M; Rachlow, Janet L; Williams, Christopher J
2015-01-01
Interactions between intraguild species that act as both competitors and predator–prey can be especially complex. We studied patterns of space use by the black-footed ferret (Mustela nigripes), a prairie dog (Cynomys spp.) specialist, and the American badger (Taxidea taxus), a larger generalist carnivore that competes for prairie dogs and is known to kill ferrets. We expected that ferrets would spatially avoid badgers because of the risk of predation, that these patterns of avoidance might differ between sexes and age classes, and that the availability of food and space might influence these relationships. We used location data from 60 ferrets and 15 badgers to model the influence of extrinsic factors (prairie dog density and colony size) and intrinsic factors (sex, age) on patterns of space use by ferrets in relation to space use by different sex and age categories of badgers. We documented asymmetric patterns of avoidance of badgers by ferrets based on the sex of both species. Female ferrets avoided adult female badgers, but not male badgers, and male ferrets exhibited less avoidance than female ferrets. Additionally, avoidance decreased with increasing densities of prairie dogs. We suggest that intersexual differences in space use by badgers create varying distributions of predation risk that are perceived by the smaller carnivore (ferrets) and that females respond more sensitively than males to that risk. This work advances understanding about how competing species coexist and suggests that including information on both intrinsic and extrinsic factors might improve our understanding of behavioral interactions between sympatric species. PMID:26306165
Ou, Huang-Tz; Yang, Chen-Yi; Wang, Jung-Der; Hwang, Jing-Shiang; Wu, Jin-Shang
2016-12-01
To assess additional life expectancy (LE), expected years of life lost , and lifetime health care expenditures after type 1 diabetes diagnosis, stratified by sex and age of first diagnosis (early: 0-12 years; late: 13-40 years). A longitudinal cohort of patients with diabetes was constructed from Taiwan's National Health Insurance Research Database of 1999 to 2012. The survival functions for diabetic patients and age- and sex-matched general population were estimated by using a semiparametric extrapolation method with annual life tables. The average monthly health care expenditures were multiplied by the corresponding monthly survival rates and summed to calculate the lifetime health care expenditures. Cox proportional hazard models were constructed to corroborate the effects of sex and age, after being adjusted for comorbidities, complications, and calendar years. A total of 2386 cases (45% early diagnosis, 49% males) were identified. An additional LE after diabetes diagnosis was 45.12 years, with an estimated 17.63 years of life lost. The predicted total and diabetes-related lifetime costs were $56,939 and $102,140, respectively. Early diagnosed patients had a longer LE and lower health care spending compared with those of late-diagnosed patients. Male patients had a shorter LE and a higher expected years of life lost than the female patients, which corresponded to lower lifetime costs for the former. The Cox model results for overall mortality corroborated these trends. Early detection of type 1 diabetes and sex-specific strategies would probably improve long-term health outcomes and save on the cost of diabetes care. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.
Wiseman, Mel; Davidson, Sarah
2012-10-01
Western society recognises male and female sex from physiological attributes, such as genitals and chromosomes. 'Gender' is the social and cultural expectation of how males and females should think, behave and how they should be treated by others (Diamond, 2002). Some children and adolescents experience distress, marginalization, and abuse associated with their gender identifications, preferences and behaviours, which are inconsistent with those expected of their biological sex. Often their families and society find gender non-conformity at best difficult, at worst offensive, distressing and intolerable. There is increasing focus on how mental health professionals work with difference in gender and sexual identity and recent publications highlight the shift from pathologizing transgender to a more 'identity-based' perspective, focussing more on the stigmatizing affects of the environment and the impact on the individual (Bockting, 2009). This article describes the challenges of binary gender discourse for young people and their wider contexts and considers how clinicians may more helpfully respond to avoid unhelpful binaries and so keep the young person in mind. The therapeutic aims of the UK Gender Identity Development Service (GIDS) for children and young people are considered and examples of our work provided.
Saiz, Enric; Calbet, Albert; Griffell, Kaiene
2017-10-04
Planktonic copepods are a very successful group in marine pelagic environments, with a key role in biogeochemical cycles. Among them, the genus Oithona is one of the more abundant and ubiquitous. We report here on the effects of caloric (food) restriction on the ageing patterns of the copepod Oithona davisae. The response of O. davisae to caloric restriction was sex dependent: under food limitation, females have lower age-specific mortality rates and longer lifespans and reproductive periods; male mortality rates and life expectancy were not affected. Males are more active swimmers than females, and given their higher energetic demands presumably generate reactive oxygen species at higher rates. That was confirmed by starvation experiments, which showed that O. davisae males burn through body reserves much faster, resulting in shorter life expectancy. Compared with common, coastal calanoid copepods, the effects of caloric restriction on O. davisae appeared less prominent. We think this difference in the magnitude of the responses is a consequence of the distinct life-history traits associated with the genus Oithona (ambush feeder, egg-carrier), with much lower overall levels of metabolism and reproductive effort.
Factors affecting unintentional harvesting selectivity in a monomorphic species.
Bunnefeld, Nils; Baines, David; Newborn, David; Milner-Gulland, E J
2009-03-01
1. Changes in the abundance of populations have always perplexed ecologists but long-term studies are revealing new insights into population dynamic processes. Long-term data are often derived from harvest records although many wild populations face high harvesting pressures leading to overharvesting and extinction. Additionally, harvest records used to describe population processes such as fluctuations in abundance and reproductive success often assume a random off-take. 2. Selective harvesting based on phenotypic characteristics occurs in many species (e.g. trophy hunting, fisheries) and has important implications for population dynamics, conservation and management. 3. In species with no marked morphological differences between the age and sex classes, such as the red grouse Lagopus lagopus scoticus during the shooting season, hunters cannot consciously select for a specific sex or age class during the shooting process but harvest records could still give a biased reflection of the population structure because of differences in behaviour between age and sex classes. 4. This study compared age and sex ratios in the bag with those in the population before shooting for red grouse at different points in the shooting season and different densities, which has rarely been tested before. 5. More young than old grouse were shot at large bag sizes and vice versa for small bag sizes than would be expected from the population composition before shooting. The susceptibility of old males to shooting compared to females increased with bag size and was high at the first time the area was shot but decreased with the number of times an area was harvested. 6. These findings stress that the assumption made in many studies that harvest records reflect the age and sex ratio of the population and therefore reflect productivity can be misleading. 7. In this paper, as in the literature, it is also shown that number of grouse shot reflects grouse density and therefore that hunting selectivity might influence population dynamics in a cyclic species. 8. The study is not only relevant for red grouse but applies to systems showing interactions between selective harvesting and wider ecological processes, such as age- and sex-related parasitism and territoriality, which may drive population fluctuations.
Emslie, Carol; Hunt, Kate
2008-01-01
Despite increasing interest in gender and health, ‘lay’ perceptions of gender differences in mortality have been neglected. Drawing on semi-structured interview data from 45 men and women in two age cohorts (born in the early 1950s and 1970s) in the UK, we investigated lay explanations for women's longer life expectancy. Our data suggest that respondents were aware of women's increased longevity, but found this difficult to explain. While many accounts were multifactorial, socio-cultural explanations were more common, more detailed and less tentative than biological explanations. Different socio-cultural explanations (i.e. gendered social roles, ‘macho’ constraints on men and gender differences in health-related behaviours) were linked by the perception that life expectancy would converge as men and women's lives became more similar. Health behaviours such as going to the doctor or drinking alcohol were often located within wider structural contexts. Female respondents were more likely to focus on women's reproductive and caring roles, while male respondents were more likely to focus on how men were disadvantaged by their ‘provider’ role. We locate these narratives within academic debates about conceptualising gender: e.g. ‘gender as structure’ versus ‘gender as performance’, ‘gender as difference’ versus ‘gender as diversity’. PMID:18558455
Sex differences in psychological effects of exercise.
Hülya Aşçı, F
2009-08-01
The purpose of this study was to investigate sex differences in psychological effects of exercise on university students. University students (73 female and 65 male) were randomly assigned to experimental and control groups by equating sex in each group. The experimental group participated in step dance sessions of 50 min per day, 3 days per week for 10 weeks with 60-80% of their heart rate reserves. Throughout the 10-week period, the lecture control group was told not to participate in any organized or structured exercise and participated in a lecture that was about the physiological and psychological benefits of exercise. Self-concept, belief in external control, and trait anxiety of the groups were measured before and after the exercise program. A significant improvement in the psychological variables after the exercise program and more improvement for female exercise participants were expected. Analysis revealed no significant initial differences in self-concept, belief in external control, and trait anxiety between the two groups or between males and females, other than family and moral/ethical self. Repeated measures analysis of variance revealed that exercise led to less belief in external control and significant improvement in physical self and identity dimensions of self-concept for the experimental group compared to the control group. However, there was no significant difference in trait anxiety between the two groups after exercise (p>.05). Analysis also revealed that changes in belief in external control, trait anxiety, and self-concept did not differ with regard to sex. Males and females showed no difference in their improvement on trait anxiety, belief in external control, and most dimensions of self-concept during the 10 weeks. Only changes in personal and physical self throughout 10-week period were different for males and females. Exerciser males improved their personal self and physical self scores more than female exercisers and male and female nonexercisers throughout the 10-week period (p<.05).
Massar, Karlijn; Buunk, Abraham Bram P
2016-02-01
This study investigated sex differences in jealousy after subliminal exposure to rivals wearing high-status or low-status clothes. It was expected that individual differences in preventive jealousy would moderate the relationship between a rival's characteristics and jealousy. Participants (Men: n = 54, M age = 21.6 yr., SD = 3.5; women: n = 71, M age = 20.7 yr., SD = 1.9) completed a parafoveal subliminal priming paradigm as well as questionnaires about jealousy and preventive jealousy. As predicted, women were not affected by their rival's status, but women high in preventive jealousy reported more jealousy than women low in preventive jealousy. However, whereas men low in preventive jealousy reported equal amounts of jealousy after exposure to a high-status and a low-status rival, surprisingly, and contrary to the expectations, men high in preventive jealousy reported most jealousy after exposure to a low-status rival. To explain these unexpected results, threats to self-esteem were discussed.
Wolbring, Tobias; Riordan, Patrick
2016-05-01
Plenty of studies show that the physical appearance of a person affects a variety of outcomes in everyday life. However, due to an incomplete theoretical explication and empirical problems in disentangling different beauty effects, it is unclear which mechanisms are at work. To clarify how beauty works we present explanations from evolutionary theory and expectation states theory and show where both perspectives differ and where interlinkage appears promising. Using students' evaluations of teaching we find observational and experimental evidence for the different causal pathways of physical attractiveness. First, independent raters strongly agree over the physical attractiveness of a person. Second, attractive instructors receive better student ratings. Third, students attend classes of attractive instructors more frequently - even after controlling for teaching quality. Fourth, we find no evidence that attractiveness effects become stronger if rater and ratee are of the opposite sex. Finally, the beauty premium turns into a penalty if an attractive instructor falls short of students' expectations. Copyright © 2016 Elsevier Inc. All rights reserved.
Bower, Hannah; Andersson, Therese M-L; Crowther, Michael J; Dickman, Paul W; Lambe, Mats; Lambert, Paul C
2018-04-01
Expected or reference mortality rates are commonly used in the calculation of measures such as relative survival in population-based cancer survival studies and standardized mortality ratios. These expected rates are usually presented according to age, sex, and calendar year. In certain situations, stratification of expected rates by other factors is required to avoid potential bias if interest lies in quantifying measures according to such factors as, for example, socioeconomic status. If data are not available on a population level, information from a control population could be used to adjust expected rates. We have presented two approaches for adjusting expected mortality rates using information from a control population: a Poisson generalized linear model and a flexible parametric survival model. We used a control group from BCBaSe-a register-based, matched breast cancer cohort in Sweden with diagnoses between 1992 and 2012-to illustrate the two methods using socioeconomic status as a risk factor of interest. Results showed that Poisson and flexible parametric survival approaches estimate similar adjusted mortality rates according to socioeconomic status. Additional uncertainty involved in the methods to estimate stratified, expected mortality rates described in this study can be accounted for using a parametric bootstrap, but this might make little difference if using a large control population.
Pinkleton, Bruce E; Austin, Erica Weintraub; Cohen, Marilyn; Chen, Yi-Chun Yvonnes; Fitzgerald, Erin
2008-09-01
The United States has the highest rates of teenage pregnancy and birth in the Western industrialized world, and research indicates that television and other mass media are important sources of sexual information for young people. The purpose of this study was to determine if a teen-led, media literacy curriculum focused on sexual portrayals in the media would increase adolescents' awareness of media myths concerning sex, decrease the allure of sexualized portrayals, and decrease positive expectancies for sexual activity. A posttest-only quasi-experiment with control groups was conducted at 22 school and community sites in Washington state (N = 532). The intervention, a 5-lesson media literacy curriculum targeted primarily to middle school students, encouraged sexual abstinence because of federal government funding requirements. Adolescents evaluated the program positively, with 85% rating it as better than other sex education programs. Compared to control-group participants, students were less likely to overestimate sexual activity among teens, more likely to think they could delay sexual activity, less likely to expect social benefits from sexual activity, more aware of myths about sex, and less likely to consider sexual media imagery desirable. The results showed that media literacy has promise as part of a sex education program by providing adolescents with a cognitive framework necessary to understand and resist the influence of media on their decision making concerning sex.
Vaccarella, Salvatore; Söderlund-Strand, Anna; Franceschi, Silvia; Plummer, Martyn; Dillner, Joakim
2013-01-01
To evaluate the pattern of co-infection of human papillomavirus (HPV) types in both sexes in Sweden. Cell samples from genital swabs, first-void urine, and genital swabs immersed in first-void urine were collected in the present cross-sectional High Throughput HPV Monitoring study. Overall, 31,717 samples from women and 9,949 from men (mean age 25) were tested for 16 HPV types using mass spectrometry. Multilevel logistic regression was used to estimate the expected number of multiple infections with specific HPV types, adjusted for age, type of sample, and accounting for correlations between HPV types due to unobserved risk factors using sample-level random effects. Bonferroni correction was used to allow for multiple comparisons (120). Observed-to-expected ratio for any multiple infections was slightly above unity in both sexes, but, for most 2-type combinations, there was no evidence of significant departure from expected numbers. HPV6/18 was found more often and HPV51/68 and 6/68 less often than expected. However, HPV68 tended to be generally underrepresented in co-infections, suggesting a sub-optimal performance of our testing method for this HPV type. We found no evidence for positive or negative clustering between HPV types included in the current prophylactic vaccines and other untargeted oncogenic types, in either sex.
2012-01-01
Backgrounds This study examines social inequalities in life expectancy and mortality during the transition period of the Korean economic crisis (1993–2010) among Korean adults aged 40 and over. Methods Data from the census and the national death file from the Statistics Korea are employed to calculate life expectancy and age-specific-death-rates (ASDR) by age, gender, and educational attainment for five years: 1993, 1995, 2000, 2005, and 2010. Absolute and relative differences in life expectancy and Age-Specific Death Rates by educational attainment were utilized as proxy measures of social inequality. Results Clear educational gradient of life expectancy was observed at age 40 by both sexes and across five time periods (1993, 1995, 2000, 2005, and 2010). The gradient became notably worse in females between 1993 and 2010 compared to the trend in males. The educational gradient was also found for ASDR in all five years, but it was more pronounced in working age groups (40s and 50s) than in elderly groups. The relative disadvantage of ASDR among working age Korean adults, both males and females, became substantially worse over time. Conclusions Social inequalities in life expectancy and ASDR of the working age group across socioeconomic status over time were closely related to the widening of the social difference created by the macroeconomic crisis and the expansion of neo-liberalism in Korea. PMID:23171369
Decisions Under Uncertainty III: Rationality Issues, Sex Stereotypes, and Sex Role Appropriateness.
ERIC Educational Resources Information Center
Bonoma, Thomas V.
The explanatory cornerstone of most currently viable social theories is a strict cost-gain assumption. The clearest formal explication of this view is contained in subjective expected utility models (SEU), in which individuals are assumed to scale their subjective likelihood estimates of decisional consequences and the personalistic worth or…
Elimination of Sex Bias and Sex Stereotyping. Women in Management. Annual Report.
ERIC Educational Resources Information Center
Ashland Community Coll., KY.
Programs, services, and activities initiated by a project designed to meet special community needs arising out of the changing roles and expectations of men and women are described in this report. During 1986-87, 245 individuals participated in the project's program activities. Program objectives included the following: assess and define barriers…
Doyle, Carol M; Rees, Amy M; Titus, Tana L
2015-01-01
The current study sought to add to the literature that has demonstrated a link between sexism and sexual prejudice. The study evaluated whether a community sample with an age range of 19-64 (n = 122), including 32% sexual minority participants, believe that dating, sex, and marriage with same-sex partners are perceived to be gender role violations. Results varied by participant sexual/gender identity (LGBTQ or heterosexual) and political ideology. Liberal LGBTQ persons do not see same-sex relationships as gender role violations; LGBTQ non-liberals and heterosexual liberals rated same-sex relationships as mild violations; and non-liberal heterosexuals perceive same-sex relationships as "moderate" violations. Our results suggest both positive movement in attitudes toward same-sex relationships, including same-sex marriage, and broader recognition that gender identity, gender role expression, and sexual orientation are separate and distinct components of one's overall sexual identity.
Kinnison, Michael T.
2017-01-01
Abstract Phenotypic plasticity is often an adaptation of organisms to cope with temporally or spatially heterogenous landscapes. Like other adaptations, one would predict that different species, populations, or sexes might thus show some degree of parallel evolution of plasticity, in the form of parallel reaction norms, when exposed to analogous environmental gradients. Indeed, one might even expect parallelism of plasticity to repeatedly evolve in multiple traits responding to the same gradient, resulting in integrated parallelism of plasticity. In this study, we experimentally tested for parallel patterns of predator-mediated plasticity of size, shape, and behavior of 2 species and sexes of mosquitofish. Examination of behavioral trials indicated that the 2 species showed unique patterns of behavioral plasticity, whereas the 2 sexes in each species showed parallel responses. Fish shape showed parallel patterns of plasticity for both sexes and species, albeit males showed evidence of unique plasticity related to reproductive anatomy. Moreover, patterns of shape plasticity due to predator exposure were broadly parallel to what has been depicted for predator-mediated population divergence in other studies (slender bodies, expanded caudal regions, ventrally located eyes, and reduced male gonopodia). We did not find evidence of phenotypic plasticity in fish size for either species or sex. Hence, our findings support broadly integrated parallelism of plasticity for sexes within species and less integrated parallelism for species. We interpret these findings with respect to their potential broader implications for the interacting roles of adaptation and constraint in the evolutionary origins of parallelism of plasticity in general. PMID:29491997
Harper, K E; Bagley, R K; Thompson, K L; Linnen, C R
2016-11-01
Although most Hymenoptera reproduce via arrhenotokous haplodiploidy, the underlying genetic mechanisms vary. Of these, the most widespread mechanism appears to be single-locus complementary sex determination (sl-CSD), in which individuals that are diploid and heterozygous at a sex-determining locus are female, and individuals that are homozygous or hemizygous are male. Because inbreeding increases the probability of producing diploid males, which are often sterile or inviable, sl-CSD can generate substantial inbreeding depression. To counteract this, Hymenoptera with traits that promote inbreeding, such as gregariousness, may evolve one or more of the following: inbreeding avoidance, functional diploid males or alternative sex determination mechanisms. Here, we investigate sex determination, inbreeding depression and inbreeding avoidance in Neodiprion lecontei, a gregarious, pine-feeding sawfly in the family Diprionidae. First, via inbreeding experiments and flow cytometry, we demonstrate that this species has CSD. By modeling expected sex ratios under different conditions, we also show that our data are consistent with sl-CSD. Second, via tracking survival in inbred and outbred families, we demonstrate that inbred families have reduced larval survival and that this mortality is partly attributable to the death of diploid males. Third, using a no-choice mating assay, we demonstrate that females are less willing to mate with siblings than nonsiblings. Together, these results suggest that inbreeding depression stemming from CSD has shaped mating behavior in N. lecontei. These results also set the stage for future comparative work that will investigate the interplay between sex determination, ecology and behavior in additional diprionid species that vary in larval gregariousness.
Harper, K E; Bagley, R K; Thompson, K L; Linnen, C R
2016-01-01
Although most Hymenoptera reproduce via arrhenotokous haplodiploidy, the underlying genetic mechanisms vary. Of these, the most widespread mechanism appears to be single-locus complementary sex determination (sl-CSD), in which individuals that are diploid and heterozygous at a sex-determining locus are female, and individuals that are homozygous or hemizygous are male. Because inbreeding increases the probability of producing diploid males, which are often sterile or inviable, sl-CSD can generate substantial inbreeding depression. To counteract this, Hymenoptera with traits that promote inbreeding, such as gregariousness, may evolve one or more of the following: inbreeding avoidance, functional diploid males or alternative sex determination mechanisms. Here, we investigate sex determination, inbreeding depression and inbreeding avoidance in Neodiprion lecontei, a gregarious, pine-feeding sawfly in the family Diprionidae. First, via inbreeding experiments and flow cytometry, we demonstrate that this species has CSD. By modeling expected sex ratios under different conditions, we also show that our data are consistent with sl-CSD. Second, via tracking survival in inbred and outbred families, we demonstrate that inbred families have reduced larval survival and that this mortality is partly attributable to the death of diploid males. Third, using a no-choice mating assay, we demonstrate that females are less willing to mate with siblings than nonsiblings. Together, these results suggest that inbreeding depression stemming from CSD has shaped mating behavior in N. lecontei. These results also set the stage for future comparative work that will investigate the interplay between sex determination, ecology and behavior in additional diprionid species that vary in larval gregariousness. PMID:27381325
On the variability of alligator sex ratios
Nichols, J.D.; Chabreck, R.H.
1980-01-01
Samples of alligators from wild and 'farm' populations exhibited disproportionate sex ratios. Males predominated among young alligators from wild populations, whereas females were much more abundant than males in the farm population, where resources were superabundant. These results and other considerations lead us to hypothesize that environmental factors influence sex determination in alligators. During favorable environmental conditions natural selection is expected to favor a preponderance of the sex whose individuals exhibit the greater environmentally associated variation in relative fitness. We hypothesize that environmentally associated variation in age at sexual maturity of females produces sufficient variation in relative fitness of females to result in selection for low sex ratios during periods of resource abundance.
The evolution and consequences of sex-specific reproductive variance.
Mullon, Charles; Reuter, Max; Lehmann, Laurent
2014-01-01
Natural selection favors alleles that increase the number of offspring produced by their carriers. But in a world that is inherently uncertain within generations, selection also favors alleles that reduce the variance in the number of offspring produced. If previous studies have established this principle, they have largely ignored fundamental aspects of sexual reproduction and therefore how selection on sex-specific reproductive variance operates. To study the evolution and consequences of sex-specific reproductive variance, we present a population-genetic model of phenotypic evolution in a dioecious population that incorporates previously neglected components of reproductive variance. First, we derive the probability of fixation for mutations that affect male and/or female reproductive phenotypes under sex-specific selection. We find that even in the simplest scenarios, the direction of selection is altered when reproductive variance is taken into account. In particular, previously unaccounted for covariances between the reproductive outputs of different individuals are expected to play a significant role in determining the direction of selection. Then, the probability of fixation is used to develop a stochastic model of joint male and female phenotypic evolution. We find that sex-specific reproductive variance can be responsible for changes in the course of long-term evolution. Finally, the model is applied to an example of parental-care evolution. Overall, our model allows for the evolutionary analysis of social traits in finite and dioecious populations, where interactions can occur within and between sexes under a realistic scenario of reproduction.
The Evolution and Consequences of Sex-Specific Reproductive Variance
Mullon, Charles; Reuter, Max; Lehmann, Laurent
2014-01-01
Natural selection favors alleles that increase the number of offspring produced by their carriers. But in a world that is inherently uncertain within generations, selection also favors alleles that reduce the variance in the number of offspring produced. If previous studies have established this principle, they have largely ignored fundamental aspects of sexual reproduction and therefore how selection on sex-specific reproductive variance operates. To study the evolution and consequences of sex-specific reproductive variance, we present a population-genetic model of phenotypic evolution in a dioecious population that incorporates previously neglected components of reproductive variance. First, we derive the probability of fixation for mutations that affect male and/or female reproductive phenotypes under sex-specific selection. We find that even in the simplest scenarios, the direction of selection is altered when reproductive variance is taken into account. In particular, previously unaccounted for covariances between the reproductive outputs of different individuals are expected to play a significant role in determining the direction of selection. Then, the probability of fixation is used to develop a stochastic model of joint male and female phenotypic evolution. We find that sex-specific reproductive variance can be responsible for changes in the course of long-term evolution. Finally, the model is applied to an example of parental-care evolution. Overall, our model allows for the evolutionary analysis of social traits in finite and dioecious populations, where interactions can occur within and between sexes under a realistic scenario of reproduction. PMID:24172130
Air pollution shortens life expectancy and health expectancy for older adults: the case of China.
Wen, Ming; Gu, Danan
2012-11-01
Outdoor air pollution is one of the most worrying environmental threats China faces today. Comprehensive and quantitative analyses of the health consequences of air pollution in China are lacking. This study reports age- and sex-specific life expectancy and health expectancies (HEs) corresponding to different levels of air pollution based on associations between air pollution and individual risks for a host of health conditions and mortality net of individual- and community-level confounders. This is a multilevel prospective cohort study based a nationally representative sample of Chinese elders. The main outcome measures in this study include life expectancy estimated from mortality and HEs based on five health conditions including activity of daily living, instrumental activity of daily living, cognitive status, self-rated health, and chronic conditions. Net of the controls, exposure to outdoor air pollution corresponded to subsequent reductions of life expectancy and HEs for all five health conditions. These detrimental pollution effects were stronger for women. The gap in life expectancy between areas with good air quality and moderately heavily polluted areas was 3.78 years for women of age 65 and 0.93 years for men. The differences in HEs at age 65 were also large, ranging from 1.47 years for HE for good self-rated health in men to 5.20 years for activity of daily living disability-free HE in women. Air pollution has devastating health impacts on Chinese elders reducing longevity and shortening HEs. Women are more vulnerable than men. More strict air policy should be implemented to pursue sustainable development in China.
Examining relationships between anxiety and dangerous driving.
Dula, Chris S; Adams, Cristi L; Miesner, Michael T; Leonard, Robin L
2010-11-01
Driving anxiety that has developed following crashes has been studied relatively frequently, but anxiety per se and its effects on driving has not as yet garnered much attention in the literature. The current study included 1121 participants and found higher levels of general anxiety were related to a wide variety of dangerous driving behaviors. While there were clear and expected sex differences on many dangerous driving variables, there were still more such differences with regard to anxiety levels and independent of sex, higher levels of anxiety were associated with greater levels of dangerous driving. Of particular import, it was found that the high anxiety group had caused significantly more crashes and engaged in more DUI episodes than the low and/or medium anxiety groups. Taken as a whole, the results suggest there is a tremendous need for more research in the area of anxiety and dangerous driving and that interventions for highly anxious drivers may well be warranted. 2010 Elsevier Ltd. All rights reserved.
Madenjian, Charles P.
2017-01-01
For the past 20 years or so, a commonly used explanation in the scientific literature for higher polychlorinated biphenyl (PCB) concentrations in male fish than in female fish has been that females lose a high proportion of their PCB body burden by releasing eggs at spawning time, and therefore the females undergo a substantial decrease in their PCB concentration immediately after spawning due to shedding of their eggs [1]. Indeed, this explanation can be viewed as the conventional wisdom used by toxicologists to account for differences in PCB concentrations between the sexes of fish. On the surface, this explanation seems plausible. PCBs are lipid soluble, and eggs are thought to be relatively high in lipid concentration. If a sufficiently high proportion of the PCB body burden within a female fish is transferred to the eggs, then the release of eggs at spawning would be expected to result in a dramatic decrease in the PCB concentration of the female.
Bem Sex Role Inventory Validation in the International Mobility in Aging Study.
Ahmed, Tamer; Vafaei, Afshin; Belanger, Emmanuelle; Phillips, Susan P; Zunzunegui, Maria-Victoria
2016-09-01
This study investigated the measurement structure of the Bem Sex Role Inventory (BSRI) with different factor analysis methods. Most previous studies on validity applied exploratory factor analysis (EFA) to examine the BSRI. We aimed to assess the psychometric properties and construct validity of the 12-item short-form BSRI in a sample administered to 1,995 older adults from wave 1 of the International Mobility in Aging Study (IMIAS). We used Cronbach's alpha to assess internal consistency reliability and confirmatory factor analysis (CFA) to assess psychometric properties. EFA revealed a three-factor model, further confirmed by CFA and compared with the original two-factor structure model. Results revealed that a two-factor solution (instrumentality-expressiveness) has satisfactory construct validity and superior fit to data compared to the three-factor solution. The two-factor solution confirms expected gender differences in older adults. The 12-item BSRI provides a brief, psychometrically sound, and reliable instrument in international samples of older adults.
Packiriswamy, Vasanthakumar; Kumar, Pramod; Bashour, Mounir
2018-05-03
In oculoplastic operations, knowledge of the dimensions of periorbital features based on age, gender, and race is essential for achieving better aesthetic result. This article seeks to determine the racial and gender differences of periorbital features among Malaysian Malay (MM), Malaysian Indian (MI), and Malaysian Chinese (MI) subjects. Evaluation of periorbital features was done on photographs of 200 MM, 200 MI, and 200 MC subjects, aged 18 to 26 years. The measured values were evaluated by an independent t -test. A significant difference was found between MM and MI in all measurements except interbrow distance in males, eyebrow thickness in females, and apex to lateral limbus distance in both sexes. Between MI and MC the difference was insignificant for interbrow distance in male groups, apex to lateral limbus distance in females, and palpebral fissure inclination and eyebrow apex angle in both sexes. Between MM and MC, significant differences were found for eyebrow thickness and medial canthus tilt in female group. Male groups showed significant difference for apex to lateral limbus and lateral canthus distance and eyebrow apex angle. Eyebrow height, palpebral fissure width, and intercanthal distance were significantly different in both sexes. Sexual dimorphism was found for all measurements in MI, but MM and MC showed insignificant difference for eyebrow apex angle. Four types of epicanthus were observed in MM and MC and three types in MI. Eyebrow apex between lateral limbus and lateral canthus was the most common position in all racial groups. Significant racial and gender differences exist for certain periorbital measurements. The knowledge of these differences is expected to influence the surgical outcome. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Grech, Victor
2017-12-01
Males are born in excess of females and the ratio is expressed as M/F (male/female births=secondary sex ratio, also known as secondary sex ratio). This is expected to approximate 1.048. Racial M/F disparities are known. A recent study in China showed that pregravid systolic hypertension is higher in women who delivered a boy than in those who had a girl. This study was carried out in order to identify the effect of pregravid hypertension in the United States on M/F by race. Monthly male and female live births by race for the entire US along with the presence/absence of hypertension were obtained from the website of the Centers for Disease Control and Prevention for 2007-2015 for the four racial groups: American Indian or Alaska Native, Asian or Pacific Islander, Black or African American and White. This study analysed 36,364,253 live births. For White births, mothers who had chronic hypertension were likelier to have male than female offspring when compared to non-hypertensives (p=0.003). Conversely, Black or African American mothers who had hypertension were less likely to have male than female offspring when compared to non-hypertensives (p=0.022). There were F differences for/F differences for the presence or absence of hypertension for the other two races or for the total. It is possible that hypothesised innate interracial periconceptual hormonal differences may modulate M/F responses to hypertension in different races. Copyright © 2017 Elsevier B.V. All rights reserved.
Marston, C; Lewis, R
2014-01-01
Objective To explore expectations, experiences and circumstances of anal sex among young people. Design Qualitative, longitudinal study using individual and group interviews. Participants 130 men and women aged 16–18 from diverse social backgrounds. Setting 3 contrasting sites in England (London, a northern industrial city, rural southwest). Results Anal heterosex often appeared to be painful, risky and coercive, particularly for women. Interviewees frequently cited pornography as the ‘explanation’ for anal sex, yet their accounts revealed a complex context with availability of pornography being only one element. Other key elements included competition between men; the claim that ‘people must like it if they do it’ (made alongside the seemingly contradictory expectation that it will be painful for women); and, crucially, normalisation of coercion and ‘accidental’ penetration. It seemed that men were expected to persuade or coerce reluctant partners. Conclusions Young people's narratives normalised coercive, painful and unsafe anal heterosex. This study suggests an urgent need for harm reduction efforts targeting anal sex to help encourage discussion about mutuality and consent, reduce risky and painful techniques and challenge views that normalise coercion. PMID:25122073
Chamizo, V D; Rodríguez, C A; Sánchez, J; Mármol, F
2016-09-01
The effects of early environmental enrichment (EE) and voluntary wheel running on the preference for using a landmark or pool geometry when solving a simple spatial task in adult male and female rats were assessed. After weaning, rats were housed in same-sex pairs in enriched or standard cages (EE and control groups) for two and a half months. Then the rats were trained in a triangular-shaped pool to find a hidden platform whose location was defined in terms of these two sources of information, a landmark outside the pool and a particular corner of the pool. As expected, enriched rats reached the platform faster than control animals, and males and females did not differ. Enriched rats also performed better on subsequent test trials without the platform with the cues individually presented (either pool geometry or landmark). However, on a preference test without the platform, a clear sex difference was found: Females spent more time in an area of the pool that corresponded to the landmark, whereas males spent more time in the distinctive corner of the pool. The present EE protocol did not alter females' preference for the landmark cue. The results agree with the claim that environmental enrichment is a consequence of a reduced anxiety response (measured by thigmotaxis) during cognitive testing. A possible implication of ancestral selection pressures is discussed.
Hong, Jui-Yang; Kilpatrick, Lisa A.; Labus, Jennifer; Gupta, Arpana; Jiang, Zhiguo; Ashe-McNalley, Cody; Stains, Jean; Heendeniya, Nuwanthi; Ebrat, Bahar; Smith, Suzanne; Tillisch, Kirsten; Naliboff, Bruce
2013-01-01
Abnormal responses of the brain to delivered and expected aversive gut stimuli have been implicated in the pathophysiology of irritable bowel syndrome (IBS), a visceral pain syndrome occurring more commonly in women. Task-free resting-state functional magnetic resonance imaging (fMRI) can provide information about the dynamics of brain activity that may be involved in altered processing and/or modulation of visceral afferent signals. Fractional amplitude of low-frequency fluctuation is a measure of the power spectrum intensity of spontaneous brain oscillations. This approach was used here to identify differences in the resting-state activity of the human brain in IBS subjects compared with healthy controls (HCs) and to identify the role of sex-related differences. We found that both the female HCs and female IBS subjects had a frequency power distribution skewed toward high frequency to a greater extent in the amygdala and hippocampus compared with male subjects. In addition, female IBS subjects had a frequency power distribution skewed toward high frequency in the insula and toward low frequency in the sensorimotor cortex to a greater extent than male IBS subjects. Correlations were observed between resting-state blood oxygen level-dependent signal dynamics and some clinical symptom measures (e.g., abdominal discomfort). These findings provide the first insight into sex-related differences in IBS subjects compared with HCs using resting-state fMRI. PMID:23864686
Sex-specific consequences of an induced immune response on reproduction in a moth.
Barthel, Andrea; Staudacher, Heike; Schmaltz, Antje; Heckel, David G; Groot, Astrid T
2015-12-16
Immune response induction benefits insects in combatting infection by pathogens. However, organisms have a limited amount of resources available and face the dilemma of partitioning resources between immunity and other life-history traits. Since males and females differ in their life histories, sex-specific resource investment strategies to achieve an optimal immune response following an infection can be expected. We investigated immune response induction of females and males of Heliothis virescens in response to the entomopathogenic bacterium Serratia entomophila, and its effects on mating success and the female sexual signal. We found that females had higher expression levels of immune-related genes after bacterial challenge than males. However, males maintained a higher baseline expression of immune-related genes than females. The increased investment in immunity of female moths was negatively correlated with mating success and the female sexual signal. Male mating success was unaffected by bacterial challenge. Our results show that the sexes differed in their investment strategies: females invested in immune defense after a bacterial challenge, indicating facultative immune deployment, whereas males had higher baseline immunity than females, indicating immune maintenance. Interestingly, these differences in investment were reflected in the mate choice assays. As female moths are the sexual signallers, females need to invest resources in their attractiveness. However, female moths appeared to invest in immunity at the cost of reproductive effort.
Family matters: Directionality of turning bias while kissing is modulated by context.
Sedgewick, Jennifer R; Elias, Lorin J
2016-01-28
When leaning forward to kiss to a romantic partner, individuals tend to direct their kiss to the right more often than the left. Studies have consistently demonstrated this kissing asymmetry, although other factors known to influence lateral biases, such as sex or situational context, had yet to be explored. The primary purpose of our study was to investigate if turning direction was consistent between a romantic (parent-parent) and parental (parent-child) kissing context, and secondly, to examine if sex differences influenced turning bias between parent-child kissing partners. An archival analysis coded the direction of turning bias for 161 images of romantic kissing (mothers kissing fathers) and 529 images of parental kissing (mothers or fathers kissing sons or daughters). The results indicated that the direction of turning bias differed between kissing contexts. As expected, a right-turn bias was observed for romantic kissing; however, a left-turn bias was exhibited for parental kissing. There was no significant difference of turning bias between any parent-child kissing partners. Interpretations for the left-turn bias discuss parental kissing as a learned lateral behaviour.